Mechanical Design of a Multi Mode Linear Actuatordivf.eng.cam.ac.uk/birl/pub/Main/Publications/GuetherF2010.pdf · Mechanical Design of a Multi Mode Linear Actuator Semester Thesis

Prof Dr Fumiya Iida

Mechanical Design of aMulti Mode Linear Actuator

Semester Thesis

07 July 2010

Supervised by

Nandan Maheshwari

Prof Dr Fumiya Iida

Author

Fabian Gunther

Abstract

In this report the development manufacturing and testing of a MMLA (Multi Mode Linear Actu-

ator) is described

The MMLA is a linear actuator which is able to switch between different motion states during the

run The four mastered motion states are active mode passive mode spring mode and rigid mode

It can be mounted in a legged robot which is able to walk run stand and conquer barricades

An MMLA can achieve a very high energy efficiency because of its inherent ability to select the

optimal motion state for each part of the challenge

The MMLA was designed on a Unigraphics NX6 CAD system basic calculations were done to

optimize the mechanics and the motors A first prototype was build to test the clutch mechanics

which allow the mode switching during the run A second prototype was build to test the complete

system during a hopping task The clutches as well as the actuator fulfill their function detailed

hopping measurements are shown in the report

In the last chapter the actual setup of the MMLA is discussed and improvements and key tasks

for future designs are shown

In the appendix and on the data CD a detailed documentation of the second prototype of the

MMLA can be found

Acknowledgements

First I want to thank Prof Dr Fumiya Iida He gave me the chanche to do this semester thesis

made essential suggestions during the work and developed the very first control concept for the

second prototype of the MMLA Further I want to thank Nandan Maheshwari for supervising my

work and supporting me during the purchasing and manufacturing process

Finally I want to thank the team from the ASL workshop for their support Special thanks go

to Pascal Wespe who analyzed the actual design and gave essential inputs for further prototypes

Alessandro Rotta who manufactured the CNC parts and Dario Fenner who supported me with the

mounting of the spring

CONTENTS

Contents

1 Introduction 1

11 Goal and Timeline 1

12 The Robots of the BIRL 1

13 Terms and Definitions 1

131 Coordinate Frame 1

132 Words 2

2 Development of the MMLA 3

21 Former Conditions 3

22 Conceptual Design 3

221 Mechanical Concept 3

222 Actuator Type 3

223 Clutch Type 4

224 Motor 4

225 Division of Work 4

23 The First Prototype 5

24 Requirements for the Second Prototype 5

3 Description of the Second Prototype 7

31 Assembly 7

32 Motion States 7

33 Operating Mode of the Clutches 8

34 Sensors 9

4 Technical Data and Experimental Results 11

41 Technical Data of the Second Prototype 11

42 The Clutch Mechanism 11

43 Hopping Tests 12

5 Assembling and Attendance 15

51 Assembling 15

511 Assembling the Rotational Clutch 15

512 Assembling the Ball Screw Nut 15

513 Adjusting the Clutch 16

514 Replacing the Brake Shoes 16

CONTENTS

515 Lubricate the Ball Screw 16

516 Cleaning and Attending the Guide 16

52 Safety System 16

521 Obligatory Safety System 16

522 Optional Safety System 17

53 Advices for Installation 17

6 Future Topics and Discussion 19

61 Potential of Future Setups 19

62 Potential of the Actual Setup 19

63 Tasks for the Third Prototype 20

631 Data Collection with the Second Prototype 20

632 Data Collection using Simulations 20

633 Control 20

634 Third Clutch 20

635 Clutch Motors 21

636 Usability 21

637 Brake Shoe Material 21

638 Guide Performance 21

64 Future Tasks for the MMLA 22

641 Higher Forces 22

642 Closed Design 22

643 Smaller Size and Mass 23

644 Beyond the Clutch 23

A Basic Schedule 25

B Calculations 31

B1 Spring Data 31

B2 Ballscrew 31

B3 Clutch Force 32

B31 Compression Moment 33

B32 Friction Moment 33

B33 Matlab Calculation 34

B4 Basic Assumptions for the Actuator 34

B5 Static Force in the Robots Knee 35

C Matlab Code for the Clutch Force 37

D Budget 39

E Timeline 41

F Plug Connection 43

G Blueprints 45

CONTENTS

H Data Sheets 53

I Data CD 67

Bibliography 69

CONTENTS

Chapter 1

Introduction

11 Goal and Timeline

The goal of this semester thesis has been to develop and build an MMLA (Multi Mode Linear

Actuator) which is able to switch between active passive spring and rigid mode during the run

With a certain actuator it is possible to combine the efficiency of a passive dynamic walker with

the power and the flexibility of a fully actuated walker

The duration of this semester thesis was fixed to 4 months1 with an initial budget of CHF 500002

12 The Robots of the BIRL

At the BIRL3 most of the actual robots weight between 200 and 1000 g To prevent the various

parts of the MMLA from getting to small its minimum weight was committed to 500 g Such an

actuator would be too heavy for mounting in one of the robots of the BIRL but as a self hopping

system it would lie in the weight range of the BIRL robots

Additional specifications (especially the decision between linear or rotational actuator) were not

given at the projects starting point The guideline for the dimensioning of the actuator was the

idea to achieve a hopping height of 100 mm with a robot of 1 kg total mass

13 Terms and Definitions

In the following section the terms and definitions used in this semester thesis will be introduced

131 Coordinate Frame

The coordinate frame of the second prototype is shown in Figure 11 The x-axis of the coordinate

frame goes through the symmetry line of the MMLA The y-axis lies in the connection plane of

the two guides the z-axis shows in the direction of the clutch ellipses The yz-plane lies on the

leading plane of the guide connector

1A detailed timeline can be found in Appendix E2A detailed budget can be found in Appendix D3Bio Inspired Robotics Lab httpwwwbirlethzch

CHAPTER 1 INTRODUCTION

Figure 11 Coordinate frame of the MMLA

132 Words

MMLA shortens the term ldquoMulti Mode Linear Actuatorrdquo It describes the whole actuator

including the guide the motor assembly the clutches and the mounting parts

Motor main motor describes the electric motor (rotational) including the ballscrew Talking

about the motion of the motor means the linear motion of the ballscrew

Motor assembly involves the complete motor assembly including the electric motor the rota-

tional clutch and the ballscrew

Clutch force clutch longitudinal force describes the external longitudinal force which the

closed clutch can resist without sliding on the guide

Brake shoe force clutch transverse force describes the compressive force between the clutch

brake shoe and the brake area on the guide

Chapter 2

Development of the MMLA

21 Former Conditions

During the first meetings the amount of the thesis and the very first specifications were fixed

The initial plan was to develop and build only one clutch After the first designs it appeared that

it would be not possible to realize the clutch and the actuator as independent assemblies Hence

it was decided to build a whole actuator instead of a single clutch

22 Conceptual Design

The conceptual design took four weeks and included sketches first CAD designs and investigations

on material and sources Based on these informations the decisions described below were made

221 Mechanical Concept

With regard to the experiences of the author and the BIRL it was decided to realize the actuator

with a conventional mechanical concept With the exception of the springs and the cables every

part of the actuator should be able to fulfill its function as a rigid body too (ie no constant

bending or lengthening of the parts during the operation necessary) The smallest screw was set

to have thread diameter M2 Special micro mechanical techniques or smart materials were not

included

The actuator was set to be an electric motor because the BIRL is not using any pneumatic or

hydraulic systems currently

222 Actuator Type

It was decided to use a linear actuator instead of a rotational one The reasons for this choice are

the following

CHAPTER 2 DEVELOPMENT OF THE MMLA

Geometry A Geometry B Geometry C Geometry D

Figure 21 Different friction clutch mechanisms (A) Outer clutch with arms (B)(C) Inner clutchwith arms (D) Inner clutch without arms the brake shoes are linear guided

In the joints of walking robots appear very high torque occurs at low rotational speed and

low angles of rotation (normally below 180deg) Rotational actuators (eg electric motor

and gearbox) in contrast achieve their maximum performance at low torque and high

rotational speed A rotational actuator for a walking robot would need big and heavy

gearboxes and shafts large shear forces resulting from the high torque would demand a

very large and heavy clutch mechanism With linear actuators it is possible to use higher

strokes and reduce the forces Thereby the mass of the actuator and the clutches can be

reduced

The connection between shaft and gear under high torque combined with lightweight

design is very problematic These problems nearly do not exist with a linear actuator

The mechanical design of the serial and parallel connection of motors springs and damping

elements is simpler with linear actuators

Mechanical push-pull-springs are lighter less expensive and easier to find than torsion

springs with the same stiffness

223 Clutch Type

Prof Iida suggested to use a friction clutch instead of a form fitting clutch The friction clutch

is able to couple at any position under full longitudinal force This concept was refined for inner

and for outer clutches The clutch should be activated by a rotating ellipse since every sort of arm

mechanism would result in too many small parts for the desired clutch size (max 50times50times50 mm)

Some clutch variants the ellipse enables are shown in Figure 21

224 Motor

Inspired by [1] the linear motion should be realized economically with a rotational electric motor

and a M6 screw Due to the higher efficiency and the lower heat generation a ballscrew from the

manufacturer KSS-Ballscrew was established finally

225 Division of Work

The CNC parts were manufactured in the ASL workshop of the ETH the other parts were manu-

factured by the author in the students workshop of the ETH

24 REQUIREMENTS FOR THE SECOND PROTOTYPE

(a) (b)

Figure 22 (a) CAD model of the first prototype (b) Clutch one of the firtst prototype

23 The First Prototype

Based on a linear guide of the manufacturer Igus1 and on the clutch geometry A (see Figure

21) the first prototype of the complete actuator was designed on the CAD (see Figure 22 (a))

The first handmade clutch showed that the mechanism works very well even with parts with high

tolerances The achieved clutch force during a pulling test by hand has been clearly higher than

calculated before (see Section B3)

24 Requirements for the Second Prototype

Based on the experience with the first prototype the following requirements were made for the

second prototype

1 Four motion states active passive spring rigid

2 Two clutches switch between the motion states The clutches are friction clutches without

any form fitting elements Thus an unmeant clamping of the closed clutch can be prevented

and the clutch is able to couple under full forcemotion

3 A rotational motor with a ballscrew generates the linear motion

4 Force symmetric actuator design The forces of the ballscrew the brake shoes and the

linear guides lie on the x-axis without any annoying moments along the y- and z-axis

The only residual moment is the ballscrew moment along the x-axis

5 The actuator should afford a fast disassembling and access to all components including

the cables

6 High performance at low weight taking advantage of the geometric conditions

The resulting second prototype will be described in the following sections

1DryLin TK-04-12-3 350 httpwwwigusdewpckdefaultaspxPageNr=2201ampCL=DE-de

Chapter 3

Description of the Second

Prototype

The second prototype of the MMLA (Multi Mode Linear Actuator Figure 31) is a linear actuator

which is able to switch between different motion states using two clutches It is designed for

mounting eg in a robot leg between the points A and B (see Figure 31) A possible application

is shown in Section 53 The whole actuator is shown in Figure 34 and 35

31 Assembly

The second prototype contains a guide two clutches a spring and a motor assembly with a

ballscrew The clutches and the motor assembly are able to slide along the guide the spring

connects the clutches elastically The nut of the ballscrew is connected to the second clutch

32 Motion States

The two clutches have two swich states On status ldquoOnrdquo the clutch realizes a rigid connection

between the guide and the clutch On status ldquooffrdquo the clutch slides freely on the guide without any

longitudinal connection The motor assembly has two switching states too On status ldquoMotor Offrdquo

the motor avoids the ballscrew to turn the distance between motor motor assembly and clutch 2

Clutch 1

Clutch 2Spring

Motor assembly

Figure 31 Overview of the second prototype of the MMLA The motion is described with resprectto the connection points A and B

CHAPTER 3 DESCRIPTION OF THE SECOND PROTOTYPE

Clutch 1 Clutch 2 Motor Stateoff off off 1 Passiveoff off on 2 Passive IIoff on off 3 Rigidoff on on 4 Activeon off off 5 Spring passiveon off on 6 Spring activeon on off 7 Energy store passiveon on on 8 Energy store active

Table 32 Motion states of the second prototype

is fixed On status ldquoMotor Onrdquo the motor turns and changes actively the distance between the

motor assembly and the clutch 2 With these two switching states for three elements it is possible

to create at large eight different motion states They are shown in Table 32

Passive Free outer movement of the actuator only the friction of the linear

bearings is sensible

Passive 2 Free outer movement of the actuator the motor is able to correct

the distance between the motor assembly and the clutch 2

Rigid Rigid connection between A and B

Aktive Normal stiff linear actuator

Spring passive Spring without actuation

Spring active Serial connection of an actuator and a spring

Energy store passive If both clutches are closed the energy of the spring can be stored

Energy store active Serial connection of an energy store with a linear actuator

Excessing the max clutch force the actuator operates like a safety clutch and draws back in every

motion state

33 Operating Mode of the Clutches

The two clutches have an identical geometry and operate as friction clutches During the coupling

the clutch motor turns an ellipse for about 90deg Thus the ellipse presses two brake-blocks on the

(a) (b)

Figure 32 Operating Mode of the Clutches (a) Clutch opened (b) Clutch closed

34 SENSORS

Figure 33 The clutch mechanism of the second prototype

brake surfaces where a frictional connection is established between clutch and guide The brake

shoes are fixed on one arm each the geometry is shown in Figure 21 (B)

34 Sensors

The Sensors used in the second prototype are shown in Table 33 Additional values (the position

of the clutch 2 the spring length position of the motor assembly) are easy to calculate using

the sensor data shown in the table Because of the serial connection of the sensors the sensor

displacements sum up and the motor can be used for a large range of motion

Sensor Indicated Value RealizationLinear Sensor 1 Distance between clutch 1 and guide

connectorLinear potentiometer100 mm displacement

Linear Sensor 2 Distance between clutch 1 and 2 Linear potentiometer100 mm displacement

Encoder Distance between clutch 2 and motorassembly

Encoder on the motor

Switches 1 Final positions of ellipse 1 Press switchSwitches 2 Final positions of ellipse 2 Press switch

Table 33 Sensor configuration of the second prototype

Figure 34 The complete second prototype of the MMLA The aluminium plate above the mainmotor and the foam on the guide are part of the hopping guide described in Section 43

Figure 35 The complete second prototype of the MMLA

42 THE CLUTCH MECHANISM

Chapter 4

Technical Data and Experimental

Results

41 Technical Data of the Second Prototype

Data Value

Dimensions (length times widht times height) 450times75times60 mm

Distance between the mounting points A and B 180 minus 380 mm

Clutch force 100 N

Nominal speed (1) 160 mm sminus1

Stall force motor (1) 955 N

Nominal force motor (1) 90 N

Total weight 780 g

Clutch 1 99 g

Clutch 2 101 g

Motor assembly 276 g

Guide 201 g

Main cable 38 g

Static friction clutch 1 + clutch 2 + motor assembly on the guide 05 minus 3 N1

Table 41 Technical Data of the second prototype of the MMLA

(1) Main motor voltage 24 V see Section B2

42 The Clutch Mechanism

The clutch mechanism of the first prototype was tested by pulling the closed clutch by hand along

the guide It appeared that the clutch mechanism is able to produce much more than the required

1The friction strongly depends on the guide surface properties and on the precision of the parts (clamping)

CHAPTER 4 TECHNICAL DATA AND EXPERIMENTAL RESULTS

Position on the guide Clutch force 1 Clutch force 230 mm away from point A 64 N 113 N80 mm away from point A 57 N 108 N

Table 42 Clutch force 1 was measured without washers between the ellipse blocks and the clutcharms (see Section 513) Clutch force 2 was measured using 05mm washers between the left ellipseblock and clutch arm With this setup the opened clutch 1 is still able to slide freely on the guide

50 N clutch force

The clutch mechanism of the second prototype was tested in the same way A spring balance was

used to measure the longitudinal force The results are shown in Table 42

The clutch force strongly depends on the geometry of the clutch mechanism A difference of 05 mm

in the thickness of one ellipse block can duplicate the clutch force For a proper setup of the clutch

mechanism a continuously adjustable thickness of the ellipse block will be essential (see Section

The changeover from the static friction to the dynamic friction proceeded very smooth during the

measurements From 23 of the max clutch force a very small movement of the clutch appeared

The max clutch force was defined on the point where the clutch moves around 1 mm sminus1 A further

increase of the longitudinal force increases the clutch movement continuously These observarions

fit in the typical behavior of rubber on raw surfaces with a velocity dependent friction coefficient

and a limited validity of the static friction model

43 Hopping Tests

The second prototype was designed to hop around 100 mm high mounted in a robot leg with

1 kg total mass For the first experiments the second prototype was fixed without a leg on a linear

guide which allows the whole actuator to hop in the x-direction Some steel parts were added on

the motor assembly to simulate different robot masses The setup is shown in Figure 42

The second prototype was actuated in the active spring mode (see Table 32) The Motor was

controlled with a PID controller which realizes an oscillation with adjustable amplitude and fre-

quency A position control of the whole motor assembly which reads out the sensor data was

not implemented The setup was stable at every tested frequencyamplitude ie after several

Figure 41 Simplified model of the hopping setup The hopping guide is not shown

43 HOPPING TESTS

(a) (b)

Figure 42 (a) The hopping setup (b) The hopping height of the actuator was measured using alinear potentiometer

jumps the movement became periodic Until now a hopping height of 45 mm using an additional

load of 880 g has been reached For a further enhancement of the hopping height a more detailed

adjustment of the motor control the spring constant and the experimental setup is necessary

A simplified model of the hopping setup is shown in Figure 41 The model contains three masses

which represent the clutch 1 and the guide (m1) the clutch 2 and the spring (m2) and the motor

assembly with the additional weight (m3) The spring and the friction on the guide are represented

by a spring damping system (KD) The main Motor with the ballscrew is represented by a pris-

matic actuator (l(t) double arrow) Experimentally the following data for the simplified model

was calculated m1 = 350 g m2 = 160 g 1160 g le m3 le 1820 g depending on the payload The

spring constant is K = 227 N mm

Figure 43 and 44 show the hopping movements of the motor assembly and the guide with different

payloads It can be seen that the whole setup is not jet capable to let the whole actuator hop The

ratio between the guide movement and the motor assembly movement is quite small

Figure 43 Actuator movement while hopping Additional weight on the motor 880 g sinusodialballscrew movement with an amplitude of plusmn12 mm and variable frequency Measureable hoppingheights of the guide appeared between 43 and 45 Hz The maximum hopping height (45 mm)appeared around 435 Hz

Figure 44 Actuator movement while hopping Additional weight on the motor 1540 g sinusodialballscrew movement with an amplitude of plusmn10 mm and variable frequency Measureable hoppingheights of the guide appeared between 39 and 4 Hz The maximum hopping height (2 mm) appearedaround 395 Hz

51 ASSEMBLING

Chapter 5

Assembling and Attendance

51 Assembling

In the following sections some special assembling steps are described The numbers in brackets

refer to the basic schedule in Appendix A

511 Assembling the Rotational Clutch

The space to assemble the rotational clutch (see Page 27 MBS03) is very small The following

order is advisable

1 Slide the distance sleeve (MBS08) on the shaft of the ballscrew (MBS02)

2 Insert the diameter sleeve (MBS07) into the clutch (MBS03)

3 Plug the motor screws (MBS06) into their holes in the motor block (MB02)

4 Hold the motor screws with your fingers perpendicular arrange the motor block and lay

the second distance sleeve (MBS09) on the ball bearing (MBS01)

5 Insert the clutch with the diameter sleeve upstairs in the chamber of the motor block and

push it against the motor screws

6 Insert the ballscrew shaft through the ball bearing and the distance sleeve 2 into the

clutch

7 Insert the motor shaft into the diameter sleeve on the other side of the clutch

8 Fix the motor screws Use an Allen key with a ball if possible If no Allen key with a ball

is aviable use the short side of a normal Allen key It fits in the screw head touching the

clutch

9 Fix both clutch screws Be careful to not excess the max torque for the clutch screws

(the clutch is made of aluminium)

512 Assembling the Ball Screw Nut

The design of the fixation of the ballscrew is not optimal and the ballscrew is very sensitive

Hence it is very important to do the following steps properly to prevent the ballscrew from getting

damaged

The ballscrew nut is fixed on the four screws sticking out of the clutch 2 using four locking nuts

CHAPTER 5 ASSEMBLING AND ATTENDANCE

After fixing the locking nuts it is essential to reopen the nuts a quarter of a turn If the stop

nuts stay fixed completely the system composed on clutch 2 and motor assembly will clamp on

the guide and the ballscrew will get damaged after a few cycles

513 Adjusting the Clutch

The height of the brake shoes (C1A03 C2A03) is reduced continuously through the abrasion on

the guide To level this abrasion it is necessary to put thin washers (lt 05 mm thickness) between

the clutch arms (C1A01 C2A01) and the ellipse blocks (C1A04 C2A04) from time to time If

the washers sum up more than 15 mm it is time to replace the brake shoes

514 Replacing the Brake Shoes

The brake shoes are made of a stiff shoe sole Cut the brake shoes out of the shoe sole with some

oversize and drill the holes for the brake srcews (C1A06 C2A06) with 15 or 16 mm diameter

Screw the blocks with the brake screws to the clutch arm (C1A01 C2A01) It is necessary to

push the brake screws into the brake shoes for the first turns just until the screws ldquobiterdquo After

that normal turning is adequate the screws will cut their thread on their own After that cut the

brake shoes with a cardboard cutter to the correct size and do precise trimming with a file The

thickness of the brake shoes is correct if they narrowly do not touch the brake areas on the guide

while the clutch is open (no washers between clutch arm and ellipse block)

515 Lubricate the Ball Screw

The ballscrew should be oiled periodical with thin machine oil It is important to use the oil

economically and take care that no oil reaches the brake surfaces or the brake shoes

516 Cleaning and Attending the Guide

The guide especially the brake surfaces and the friction bearings of the clutches and the motor

assembly should be cleaned periodical with a fabric If the clutch force becomes abnormally low

it is recommended to scour the brake surfaces and the brake shoes The friction bearings are

self-lubricating and need no additional oil (which would eliminate the clutch effect)

52 Safety System

The procedures described in the following section guarantee a secure use of the actuator and

reduce damages during accidents The emergency stop procedure mentioned in the following

section contains motor off clutch 1 off clutch 2 on1

521 Obligatory Safety System

Mechanical minimum and maximum end stop for the ballscrew2

1See Table 322The maximum end stop is not implemented yet

53 ADVICES FOR INSTALLATION

Figure 51 An application of the MMLA

Electrical end stop if the maxmin buffer of the ballscrew is below 10 mm3

Electronic emergency stop if the encoder or one linear sensor drops out

Electronic emergency stop if the current of the motorclutch motor is above the maximum

current

522 Optional Safety System

Spring mounted mechanical end stops for the motor aseembly and the clutch 1

Rated break points for the swtich arms (C1E08 C2E09)

Minmax buffer for linear sensor 1 below 10 mm motor off clutch 1 on

Max buffer for linear sensor 2 below 10 mm emergency stop

Min buffer for spring lt 5 mm audio warning

Distance between motor assembly and guide connector below 20 mm emergency stop

The closed clutch moves more than 2 mm along the guide audio warning

The closed clutch moves more than 20 mm along the guide emergency stop

Average motor current to high warning light

53 Advices for Installation

The second prototype of the MMLA is designed to work in the knee joint of a walking robot

Figure 51 shows such an application

The four mounting screws lie in the axes A and B shown in the Figure 31 Mounted like this the

second prototype is able to manage high longitudinal forces As soon as the external forces do not

apply on the x-axis the manageable forces decrease dramatically because the second prototype is

3The electric minimum end stop is not implemented yet

not designed to manage appreciable moments around the y- and z-axis Using only one of the two

screws along axis B would be such a case

Chapter 6

Future Topics and Discussion

With this semester thesis a first step of the development of an MMLA has been completed In the

following section the actual concept is evaluated and the potential of future designs is estimated

Furthermore some topics for the future work are described

61 Potential of Future Setups

Compared to a specialized actuator an MMLA of the same power is of larger size heavier more

complex more error prone and more expensive Such a specialized actuator would contain only one

or two functions of the MMLA for example a stiff linear actuator a serial connection of a spring

and a linear actuator a spring or a locked joint Therewith it is subjected to the MMLA at every

application which needs only one of these specialized abilities Examples for such applications are

a fixed grappler a hopping robot a passive dynamic walker or a self assembling framework

As soon as a flexible robot concept is needed the situation changes Such a concept could be for

example a walking robot which is able to walk run and conquer barricades In such a case the

MMLA is able to achieve a higher performance combining its different functions in an adequate

manner With the swichable spring the ability to disconnect the actuator from the joint and the

possibility to lock the joint without spending energy permanently the MMLA can is able to achieve

higher efficiency during running walking or standing This allows a mass reduction of the energy

storage which compensates for the additional weight of the MMLA Finally with the ability to

pretense the spring using a third clutch on the motor assembly the main motor can be lighter

slower and cheaper without the actuator will lose its springiness

62 Potential of the Actual Setup

The actual setup is suitable to prove the mechanical concepts and to develop and optimize the

control concept With the retrofitting third clutch the second prototype is able to reach all nec-

essary motion states On the other hand the actual setup is unsuitable for the application in a

robot leg because of the small power density

CHAPTER 6 FUTURE TOPICS AND DISCUSSION

63 Tasks for the Third Prototype

The BIRL plans to build a more reliable prototype 3 which is able to produce continuous measuring

results These results will be used to further optimize the control and the mechanics The key

tasks for this third prototype are shown in this section

631 Data Collection with the Second Prototype

The second prototype has been measured The following points needs clarification before designing

the third prototype

Mechanical and thermal behavior of the clutch motors (reachable speed brake shoe forces

and coupling time heat generation durability)

Mechanical and thermal behavior of the main motor (reachable speed force and oscillation

frequency heat generation behavior of the ballscrew durability)

Mechanical behavior of the clutch mechanics (abrasion static and dynamic friction coef-

ficients clutch force)

Mechanical behavior of the guide (friction coefficients durability clamping behavior with

moments around the y- and z-axis)

632 Data Collection using Simulations

Forces moments and desired spring constants must be evaluated using a simulation of a simple

walkingjumping robot including the actuator Based on this data the design and dimensioning

of the third prototype can be done

633 Control

Fabian Muller1 is developing a control concept based on a mechanical model of the second prototype

of the MMLA [2] This control concept will be able to work on the second prototype as well as

on future prototypes One of the possible goals of this project is the estimation of the brake shoe

abrasion With a cloupling time of 100 ms and a motor speed of 200 mm sminus1 a ldquoclosing distancerdquo

of 20 mm is resulting The point in between this 20 mm where the clutch stops during the coupling

depends on the needed clutch force and mainly on the thickness of the brake shoes This thickness

is reduced continuously caused by abrasion

To be able to close the clutch at a certain position the controller needs an estimation of the

thickness of the brake shoes Possible data for this estimation could be eg the previous closing

distances and the electric current distribution of the clutch motor

In addition reliable procedures for an emergency stop are necessary The main motor as well as the

clutch motors have enough power to damage already the second prototype in case of a malfunction

634 Third Clutch

A third clutch integrated in the motor assembly allows to pretense the spring without changing

the length of the MMLA and enables its full functional range The clutch can be implemented

1famuellestudentethzch

63 TASKS FOR THE THIRD PROTOTYPE

Figure 61 Design for the Motor Clutch

already in the second prototype by replacing the motor block Completed CAD data for the third

clutch is available on the data CD (see Appendix I) A visualization is shown in Figure 61

635 Clutch Motors

Due to rotational inertia a control mechanism is required in the clutch motors The switches would

have to be mounted on springs to be able to give way if the switch arm touches and the dynamics of

the clutch motors will be limited The swiches and their mechanics need space and cause additional

effort in wiring If possible in future setups the motor position should be determined using the

current distribution of the motor andor using an encoder signal Thus no switches and in case

of the motor current control no additional wiring will be needed

636 Usability

To perform extensive series of measurements the third prototype needs to be easy to use For

example the adjustment of the clutch force using a screw instead of the washers must be imple-

mented Furthermore it should be possible to change the spring very fast ideally without using

any screws

637 Brake Shoe Material

The behavior of rubber does not fit the static friction theory (see Section 42) Based on the

simulations it has to be decided whether its special behavior is preferable If not other brake shoe

materials need to be used (eg aluminium)

638 Guide Performance

The actual guide works quite good but the friction is high and the risk of the blocks clamping on

the guide exists furthermore Pascal Wespe2 suggested to use four rails on the third prototype

two for the linear guide and two for the brake surface Thereby standard linear bearings can be

2pascalwespemavtethzch

Figure 62 Higher force design of the MMLA using two guides

used which would eliminate the problems with the friction and the clamping The shape surface

and material of the brake rails could be optimized independently from the guide rails

64 Future Tasks for the MMLA

In the following section some tasks for future prototypes (generation four or five) are shown

641 Higher Forces

In the future the MMLA should be able to work in the knee joint of a walking robot With respect

to the geometry of the mounting situation a lognitudal force up to 710 N is resulting out of 10 kg

robot mass3 The main changes in the geometry are the following

The surface of the brake shoes needs do be increased because of the high shear forces on

the rubber

The clutch motors need to be replaced by stronger and tougher ones to achieve the high

clutch forces This entails a redesign of the ellipse because the new motors are too big to

fit into the ellipses

The main motor needs to be replaced by a stronger one and the connection between the

motor and the ballscrew needs a redesign A good solution would be the mounting of

a brushless outrunner motor directly on the ballscrew (viz the shaft of the ballscrew

replaces the motor shaft) With this concept no motor axis and no rotational clutch is

needed

The clutch mechanics need to be optimized finding a good balance between low clutch

motor power (little compression of the brake shoes) and high robustnessreliability (higher

compression of the brake shoes)

A design study for a high forces MMLA using two guides is shown in Figure 62

642 Closed Design

For the use in the field the MMLA needs a closed design to prevent dirt and water from reaching

the mechanics A simple solution would be a glass fiber box around the finished MMLA but it is

3A detailed calculation is shown in Appendix B5

64 FUTURE TASKS FOR THE MMLA

Figure 63 Design study for a closed MMLA

also possible to combine the box and the guide A design study of such an MMLA is shown in

Figure 63

643 Smaller Size and Mass

With the actual size the MMLA demands walking robots of at least one meter total height To

realize smaller MMLA significant changes and simplifications in the mechanics are necessary A

conventional MMLA below 200 mm total length would require micro mechanics

644 Beyond the Clutch

Based on one of the very first decisions (see Section 221) the MMLA was build with a conventional

mechanical concept Especially if the MMLA should become much smaller or angular flexible

around the y- and z-axis (according to muscles) it is necessary to take an eye on other realizations

for example electroactive polymers or memory alloys

Appendix A

Basic Schedule

(1) ITET workshop httpwerkstatteeethzch

(2) ASL workshop httpwwwaslethzch

(3) Igus httpwwwigusch

(4) Farnell httpchfarnellcom

(5) Conrad httpwwwconradch

(6) Physics workshop httpwwwphysethzchphysdepdienstetechbetrlager

(7) Pololu httpwwwpololucom

(8) Maedler httpwwwmaedlerch

(9) Maxon httpwwwmaxonmotorch

(10) KSS Ballscrew httpwwwkss-ballscrewcom

The part number appearing after a screw describes the part the screw head touches when

mounted

The part number appearing after a nut describes the screw the nut is screwed on when

mounted

The part number appearing after a sleevewasher describes the axescrew the washer

touches when mounted

The cables 2p and 3p were made out of a cable 14p

Basic Schedule

Clutch 1

No Qnt Part (Details) - Material Dealer

C1A01 2 Arm - Flat stock Al 25 times 4 mm ITET (1)

C1A02 2 Axe - Round stock St-37 2 mm ITET (1)

C1A03 2 Brake shoe - Shoe rubber Shoemaker

C1A04 2 Ellipse block - Sheet plastic 5 mm ITET (1)

C1A05 2 Nut M3 (C1A07) ASL-W (2)

C1A06 4 Screw M2x8 hexagon barrel head (C1A01) ASL-W (2)

C1A07 2 Screw M3x10 hexagon raised head (C1A09) ASL-W (2)

APPENDIX A BASIC SCHEDULE

C1A09 1 Spring 3 times 02 times 10 mm ASL-W (2)

C1A10 2 Washer 6 times 2 times 05 mm (C1A02) - Plastic ASL-W (2)

C1B01 1 Clutch block - Aluminium ASL-W (2)

C1B02 4 Friction bearing - Igus JSM-1012-05 Igus (3)

C1E01 1 Ellipse - Steel ASL-W (2)

C1E02 1 Ellipse plate two holes - Flat stock St-52 25 times 8 mm ITET (1)

C1E03 1 Motor and gearbox - Pololu 995 Pololu (7)

C1E04 2 Nut M3 (C1E06) ASL-W (2)

C1E05 2 Screw M16x2 hexagon counter sunk (C1E08) ASL-W (2)

C1E06 2 Screw M3x12 hexagon raised head (C1B01) ASL-W (2)

C1E07 1 Screw M3x4 hexagon headless (C1E02) ASL-W (2)

C1E08 1 Switch arm - Sheet St 1203 1 mm ITET (1)

C1E09 2 Switches - Farnell 1217764 Schurter 13019315 Farnell (4)

C1W01 1 Connector 14p female (main cable) - Farnell 1096986 Farnell (4)

C1W02 1 Connector 3p female (linear sensor connector) Farnell

1668104

Farnell (4)

C1W03 2 Connector plate - Plastic Farnell (4)

C1W04 1 Cable 2p 100 mm (motor) - Farnell 1207437 Farnell (4)

C1W05 1 Cable 2p 100 mm (switches) - Farnell 1207437 Farnell (4)

C1W07 2 Screw M2x5 hexagon barrel head (C1W03) ASL-W(2)

Clutch 2

C2A04 2 Ellipse block - Sheet plastic 5mm ITET (1)

C2A05 2 Nut M3 (C2A07) ASL-W (2)

C2E02 1 Ellipse plate four holes - Flat stock St-52 25 times 8 mm ITET (1)

C2E04 4 Nut M3 05 (C2E07) ASL-W (2)

C2E05 2 Nut M3 lock (C2E07) ASL-W (2)

C2W02 2 Connector plate plastic - Farnell 1302358 Farnell (4)

GG01 1 Guide connector block 1 - Aluminium 10mm ASL-W (2)

GG03 2 Guides - Igus AWMP-10 Igus (3)

GG04 4 Screw M4x12 hexagon barrel head(GG03) ASL-W (2)

GM01 1 Actuator connector - Flat stock St-52 30 times 15 mm ITET (1)

GM02 4 Screw M3x12 hexagon raised head(GM01) ASL-W (2)

GM03 2 Screw M4x10 hexagon barrel head(GM01) ASL-W (2)

GS01 1 Connector plate (linear sensor) sheet St 1203 15 mm ITET (1)

GS02 1 Linear sensor - Farnell 8795959 Panasonic EVA-

JQLR15B14

Farnell (4)

GS03 2 Nut M3 lock (GS04) ASL-W (2)

GS04 1 Screw M3x10 hexagon headless (GS02) ASL-W (2)

GW01 1 Cable 3p 150 mm (linear sensor) - Farnell 1207437 Farnell (4)

GW02 1 Connector 14p female - Farnell 1096986 Farnell (4)

GW03 1 Connector plate plastic - Farnell 1302358 Farnell (4)

GW04 2 Nut M2 (GW05) ASL-W (2)

GW05 2 Screw M2x6 hexagon barrel head (GW03) ASL-W (2)

MBS01 1 Ball bearing (16x5) - Physics Workshop 202681 PW (6)

MBS02 1 Ballscrew (page 54) KSS (10)

MBS03 1 Clutch - Aluminium Maedler 60271400 Maedler (8)

MBS04 1 Motor + encoder - Maxon 339152 Maxon 110511 Maxon (9)

MBS05 2 Screw M25x8 hexagon barrel head (MBS03) - Included at

the clutch

Maedler (8)

MBS06 4 Screw M2x5 hexagon barrel head (MB02) ASL-W (2)

MBS07 1 Sleeve 5x3x14 (MBS04) - Round stock Al 6 mm ITET (1)

MBS08 1 Sleeve 8x5x10 (MBS02) - Round stock St-37 8 mm ITET (1)

MB01 4 Friction bearing - Igus JSM-1012-05 Igus (3)

MB02 1 Motor block - Aluminium ASL-W (2)

MM01 1 Actuator connector - Flat stock St-52 30 times 15 mm ITET (1)

MM02 4 Screw M3x12 hexagon raised head (MM01) ASL-W (2)

MM03 2 Screw M4x10 hexagon barrel head (MM01) ASL-W (2)

MW01 1 Connector 2p male (motor power) - Farnell Farnell (4)

MW02 1 Cable 2p 500mm (motor power) - Farnell Farnell (4)

Spring

SSE01 1 Linear sensor - Farnell 8795959 Panasonic EVA-

JQLR15B14

Farnell (4)

SSE02 2 Nut M3 lock (SSE03 SSE04) ASL-W (2)

SSE03 1 Screw M3x10 hexagon headless (SSE01) ASL-W (2)

SSE04 1 Screw M3x8 hexagon raised head (SSE01) ASL-W (2)

SSE05 1 Sensor plate 1 - Aluminium 2mm ITET (1)

SS01 6 Screw M3x12 hexagon raised head (SS03 SSE05 SSE06) ASL-W (2)

SS02 1 Spring (steel 85x16x2mm) - Conrad 229058-62 Conrad (5)

SS03 2 Spring plate - Flat stock St 4 times 40 mm ITET (1)

SW01 1 Connector 3p male (linear sensor) - Farnell 1668104 Farnell (4)

SW02 1 Cable 3p 150mm (linear sensor) - Farnell 1207437 Farnell (4)

Main Cable

W01 3 Binder Farnell (4)

W02 4 Connector 14p male - Farnell 1188911 Farnell (4)

W03 1 Cable 14p (1000 mm) - Farnell 1207437 Farnell (4)

Divers

D01 Solder

D02 Oil (ballscrew)

D03 Shrink hose (wiring)

D04 WD 40 (rust protection)

D05 Loctite (headless screws in the linear sensors)

D06 Hot glue (mounting the switches)

Table A2 Basic schedule for the second prototype of the MMLA

General Survey (Next Page)

Figure A1 General drawing of the second prototype of the MMLA

Appendix B

Calculations

B1 Spring Data

Spring Constant

K =G middot d4D

8 middot d3F middot n= 227 N mm (B1)

G = 79 500 N mmminus2 Spring steel shear modulus

dD = 2 mm Wire diameter see Page 65

dF = 18 mm Average spring diameter see Page 65

n = 12 Elastic turns see Page 65

MaxSpring Force

F = K middot ∆ls = 1362 N (B2)

∆ls = 60 mm Compression range of the spring

B2 Ballscrew

Longitudinal Force

Fx = ηBS middot MMot

rBSmiddot pBS

lBS= ηBS middot MMot middot 2 middot π

lBS(B3)

Fxnominal = 90 N (B4)

Fxstall = 955 N (B5)

ηBS = 05 Efficiency of the ballscrew

lBS = 1 mm Lead of the ballscrew see Page 54

rBS = 3 mm Radius of the ballscrew see Page 54

pBS = 1885 mm Perimeter of the ballscrew see Page 54

MMotnominal = 288 N mm Continuus moment of the motor see Page 55

MMotstall = 304 N mm Stall moment of the motor see Page 55

APPENDIX B CALCULATIONS

Figure B1 Clutch mechanism used for the second prototype and for the calculation The leverratio described below is i gt 1 eg the ellipse forces are smaller than the brake shoe forces

Vmax =1

60middot nNoLoad middot lBS = 182 mm sminus1 (B6)

Vnom =1

60middot nnom middot lBS = 160 mm sminus1 (B7)

nNoLoad = 10900lsquorpm No load motor speed see Page 55

nnom = 9620lsquorpm Nominal motor speed see Page 55

B3 Clutch Force

The forces applying on the ellipse were calculated using Matlab In the following section the

calculation is done with Fby on one single brake shoe

The brake shoe force is calculated based on the desired longitudinal force

Fbymax =Fx

microb(B8)

Fx Desired longitudinal force

microb Dynamic friction coefficient between brake surface and brake shoe

Depending on the clutch geometry (lever proportions) the ellipse forces and strokes vary This fact

is considered introducing the lever ratio

i =z1 + z2z2

The ellipse force is calculated als follows

Feymax =1

imiddot Fbymax (B10)

B3 CLUTCH FORCE

Grosse WertFx 50 Nt 01 s∆ϕ π4∆s 15 mma 8 mmmicrob 10microe 01i 16

Table B1 Numerical values for the Matlab calculation

B31 Compression Moment

The resistance of the brake shoes is approximated by a replacement spring opposite to the ellipse1

The necessary spring stiffness is calculated as follows

Kr =Feymax

∆s(B11)

∆s Compression of the replacement spring

The compression distribution is approximated by a sinusoidal distribution

s(ϕ) = ∆s middot sin(ϕ) (B12)

0 lt ϕ lt π2 Rotation angle of the ellipse

The compression force of the ellipse is calculated using the spring stiffness

Fey(ϕ) = s(ϕ) middotKr (B13)

The compression moment is calculated balancing the energies

Mec(ϕ) =d

dts(ϕ) middot Fey(ϕ) middot 1

ω(B14)

ω = ∆ϕt Rotational speed of the ellipse (constant)

∆ϕ Total rotation angle of the ellipse

t Rotation time of the ellipse

B32 Friction Moment

The friction force is calculated as follows

Fez(ϕ) = Fey(ϕ) middot microe (B15)

microe Friction coefficient between ellipse and brake shoe

The friction moment results using the bigger semiaxis of the ellipse

Mef (ϕ) = Fez(ϕ) middot a (B16)

1The compression of the brake shoes is ∆sbrake = ∆s middot 1i

0 01 02 03 04 05 06 07 080

phi[rad]

Figure B2 Friction and compression force of the ellipse

a Bigger semiaxis of the ellipse

B33 Matlab Calculation

The calculation was done using the Matlab file shown in Appendix C The resulting moment

distributions are shown in Figure B2 the used numerical values are shown in Table B1 The

clutch motor (see Page 26 C1E03 C2E03) produces a stall torque of Mstall = 530 mN m The

ratio MstallMtot = 815 should guarantee a sufficient durability in alternating operation

B4 Basic Assumptions for the Actuator

As mentioned in 12 the second prototype of the MMLA should be able to hop around 100 mm high

with a robot of 1 kg total mass

h = 100 mm Hopping height of the robot

m = 1 kg Mass of the robot

∆l = 50 mm Max compression of the spring

The calculation was done using a simple mechanical model of the MMLA It is shown in Figure

Figure B3 Simplified model for the basic assumptions of the MMLA

B5 STATIC FORCE IN THE ROBOTS KNEE

(a) (b)lt

mg middot g

Figure B4 (a) Robot position (b) Used variables on the robots knee

Potential energy of the robot

Epr = m middot g middot (h+ ∆l) = 147 J (B17)

Potential energy of the compressed spring

Eps =1

2middotKb middot ∆l2 (B18)

Energy balance

Kbmin =2 middotm middot g middot (h+ ∆l)

∆l2= 118 N mm (B19)

The max spring force is equal to the max clutch force

Fmax = Kbmin lowast ∆l = 59 N (B20)

B5 Static Force in the Robots Knee

For the calculation the robot shown in Figure B4 was created The following data was used

sk = 60 mm Lengths of the knee lever

α = 30deg Angle between knee lever and lower leg

mb = 10 kg Mass of the robots body

lt = ll = 500 mm Length of the thigh and lower leg

ϕ = 60deg Knee angle

Effective body lever

lbeff = lt middot cos(05 middot ϕ) = 433 mm (B21)

Effective knee lever

skeff = sk middot sin(ϕminus α) = 30 mm (B22)

Knee moment of one of both legs

2middot lbeff middotmb middot g = 21 23927 N mm (B23)

Force on the MMLA

FA =Mk

skeff= 70798 N (B24)

Appendix C

Matlab Code for the Clutch Force

close a l l

clear a l l

Given Constants

F x=50 [N] Desired c l u t c h f o r ce

t =01 [ s ] Time fo r c lu tchminuscompression

Del ta ph i=pi 4 [ rad ] E l l i p s eminusr o t a t i on fo r c l u t c h compression

De l ta s =15 [mm] Compression disp lacement o f the replacement spr ing

a=8 [mm] Bigger semiax is o f the e l l i p s e

mu b=1 [minus] Fr i c t i on c o e f f i c i e n t o f the c l u t c h pads

mu e =01 [minus] Fr i c t i on c o e f f i c i e n t o f the e l l i p s e

i =16 [minus] r a t i o in the c l u t c h mechanics

Constants From Ca lcu la t i on

omega=De l ta ph i t Rota t iona l speed o f the e l l i p s e

F bymax=F xmu b Max brake shoe fo r ce

F eymax=F bymax i Max e l l i p s e f o r ce

K r=F eymax De l ta s Replacement spr ing s t i f f n e s s

Var iab l e s From Ca lcu la t i on

for j =11000

phi ( j )=(jminus1)pi (4(1000minus1) ) Angle s t e p s from phi=0 to phi=pi 4

s ( j )=De l ta s sin ( ( phi ( j ) De l ta ph i ) (pi 2) ) Compression o f the replacement

spr ing

F ey ( j )=s ( j ) K r Compression fo r ce o f the e l l i p s e

dot s ( j )=De l ta s cos ( ( phi ( j ) De l ta ph i ) (pi 2) ) ( omega De l ta ph i ) (pi 2)

Compression v e l o c i t y o f the e l l i p s e

M ec ( j )=dot s ( j ) F ey ( j ) omega Compression moment o f the e l l i p s e

F ez ( j )=F ey ( j ) mu e Fr ic t i on fo r ce o f the e l l i p s e

M ef ( j )=F ez ( j ) a Fr ic t i on moment o f the e l l i p s e

M tot ( j )=M ef ( j )+M ec ( j ) Total Moment

Plo t t i n g the r e s u l t s

APPENDIX C MATLAB CODE FOR THE CLUTCH FORCE

figure (1 )

plot ( phi M tot phi M ef phi M ec )

GRID ON

xlabel ( rsquo phi [ rad ] rsquo )

ylabel ( rsquo E l l i p s e Moment [mNm] rsquo )

legend ( rsquoM to t rsquo rsquoM e f rsquo rsquoM ec rsquo )

Appendix D

Budget

At the beginning of the project the budget was set to CHF 50000 (see Section 11) During the

project it emerged that the clutch mechanisms and the whole actuator will work satisfactorily so

the budget was increased to CHF 100000 After the first successful test of the first prototype (see

Section 23) the budget limit was canceled completely

No Product Costs

C1B02 C2B02

MB01 GG03

25 Rotational bearings Igus JSM-1012-05 2 guides 10mm

Igus AWMP-10

8150 (1)

C1E03 C2E03 4 Clutch motors Pololu 995 3400 (2)

C1E09 C2E10 8 Switches Farnell 1217764 Schurter 13019315 380 (2)

C1W01 C2W01 6 Connectors 14p female Farnell 1096986 1560 (2)

C1W02 6 Connectors 3p malefemale Farnell 1668104 380 (2)

div 2m Ribbon cable 14p Farnell 1207437 310 (2)

GS02 SSE01 3 Linear sensors Farnell 8795959 Panasonic EVA-

JQLR15B14

3860 (2)

MBS01 Ball Bearing Physics Workshop 202681 000 (3)

MBS02 2 Ballscrews (54) 61860 (1)

MBS03 1 Rotatonal clutch Maedler 60271400 2350 (2)

MBS04 Motor and encoder Maxon 339152 Maxon 110511 29490 (1)

SS02 1 Spring Conrad 229058-62 400 (2)

W02 6 Connectors 14p male Farnell 1188911 2250 (2)

div 1 Metal Order 000 (3)

div CNC Manufacturing Clutch blocks motor block guide con-

nectors ellipses (ASL-Workshop)

000 (3)

div Screws (ASL-Workshop) 000 (3)

- Hopping guide mounting material (Coop) 1500 (1)

- Linear guide DryLin Igus TK-04-12-3350 8090 (1)

Total 123980

Table D1 Budget for the first and second prototype of the MMLA

APPENDIX D BUDGET

(1) Packaging and shipping included

(2) Packaging and shipping excluded

(3) Price unknown

Appendix E

Timeline

At the beginning of March it was planned to design build test and document a complete MMLA

until the end of May At the end of March it was decided to build two prototypes a reduced first

prototype to test the clutch mechanics and an advanced second prototype The goal to finish the

whole project until the end of May was retained Figure E1 shows the scheduled timeline from

the end of April

Due to some problems during the manufacturing of the prototype two the manufacturing time

decreased for two weeks The manufacturing of an additional hopping guide to mount the whole

actuator during the hopping tests demanded an additional week Due to the additional work of

the semester courses of the author it was not possible to write the report in parallel to the tests

of the second prototype For this reason the semester thesis took four months of time instead of

Figure E1 The scheduled timeline from the end of April It was planed to write the report inparallel to the tests of the second prototype

Figure E2 Definite timeline from the end of June In comparsion to the scheduled timeline themanufacturing of the second prototype demanded more time an additional hopping guide for thesecond prototype had to be manufactured and the report was written after the tests

APPENDIX E TIMELINE

Appendix F

Plug Connection

Figure F1 and Table F1 show the plug connection of the main cable (W03) of the second proto-

2 4 6 8 10 12 14

1 3 5 7 9 11 13

Figure F1 Numbering of the pins of the male 14p connector (a) and the linear sensor (b)

Pin Connected part Part Pin

1 Linear sensor 1 (GS02) 1

3 Clutch motor 1 (C1E03) +

5 Switch 1 (C1E09)

6 Clutch motor 1 (C1E03) -

7 Linear sensor 2 (SSE01) 1

8 Switch 1 (C1E09)

13 Switch 2 (C2E10)

14 Switch 2 (C2E10)

Table F1 Plug connection of the 14p male connector and the linear sensor

APPENDIX F PLUG CONNECTION

Appendix G

Blueprints

Clutch block (C1B01 C2B01)

Motor block (MB02)

Guide connector 1 (GG01)

Arm (C1A01 C2A01)

Ellipse (C1E01 C2E01)

Spring plate (SS03)

APPENDIX G BLUEPRINTS Clutch block (C1B01 C2B01)

APPENDIX G DATA SHEETS Motor block (MB02)

APPENDIX G BLUEPRINTS Guide Connector 1 (GG01)

APPENDIX G DATA SHEETS Guide Connector 2 (GG02)

APPENDIX G BLUEPRINTS Arm (C1A01 C2A01)

APPENDIX G DATA SHEETS Ellipse (C1E01 C2E01)

APPENDIX G BLUEPRINTS Spring plate (SS03)

Appendix H

Data Sheets

Ballscrew KSS-Ballscrew (MBS02)

Main Motor RE 25 Maxon 339152 (MBS04)

Encoder HEDS 5540 Maxon 110511 (MBS04)

Linear potentiometer Farnell 8795959 Panasonic EVAJQLR15B14 (GS02 SSE01)

Clutch switch Farnell 1217764 Schurter 13019315 (C1E09 C2E10)

Friction bearing Igus JSM-1012-05 (C1B02 C2B02 MB01)

Clutch motor Pololu 995 (C1E03 C2E03)

Guide Igus AWMP-10 (GG03)

Rotational clutch Maedler 60271400 (MBS03)

Spring Conrad 229058-62 (SS02)

APPENDIX H DATA SHEETS Ballscrew

Operating Range Comments

Continuous operationIn observation of above listed thermal resistance(lines 17 and 18) the maximum permissible windingtemperature will be reached during continuousoperation at 25degC ambient= Thermal limit

Short term operationThe motor may be briefly overloaded (recurring)

Assigned power rating

n [rpm]

maxon Modular System Overview on page 16 - 21

Specifications

78 maxon DC motor May 2010 edition subject to change

Stock programStandard programSpecial program (on request)

Order Number

RE 25 25 mm Graphite Brushes 20 Watt

2015000

025 05 10

10 20 30

339155

302534 339149 339150 339151 339152 339153 339154 339155 339156 339157 339158

Motor DataValues at nominal voltage

1 Nominal voltage V 72 9 12 18 24 30 36 48 48 48 482 No load speed rpm 10500 9700 9620 10400 10900 9200 10100 9540 8450 6720 46503 No load current mA 133 932 68 506 402 25 237 164 137 989 64 Nominal speed rpm 8830 8160 8240 9140 9620 7990 8840 8350 7260 5520 34205 Nominal torque (max continuous torque) mNm 202 228 262 281 288 308 303 313 32 326 3256 Nominal current (max continuous current) A 34 279 233 179 142 103 0917 0673 0608 0491 03397 Stall torque mNm 259 238 268 297 304 265 279 270 243 192 1278 Starting current A 421 281 232 184 146 861 824 567 451 284 139 Max efficiency 786 812 841 864 875 879 882 887 885 878 863

Characteristics10 Terminal resistance 0171 032 0517 098 164 349 437 847 106 169 36811 Terminal inductance mH 00163 00308 00573 0112 0186 0407 0493 0979 125 197 41112 Torque constant mNm A 615 846 115 161 208 308 338 477 538 677 97613 Speed constant rpm V 1550 1130 828 591 460 311 282 200 177 141 97814 Speed torque gradient rpm mNm 432 428 371 359 363 352 365 356 351 352 36915 Mechanical time constant ms 652 606 562 536 526 517 516 513 512 512 51416 Rotor inertia gcm2 144 135 145 143 138 14 135 138 139 139 133

Planetary Gearhead26 mm05 - 20 NmPage 228

Recommended ElectronicsLSC 302 Page 282ADS 505 282ADS_E 505 283EPOS2 Module 362 304EPOS2 245 305EPOS2 505 305EPOS2P 245 308Notes 18

Thermal data17 Thermal resistance housing-ambient 144 K W18 Thermal resistance winding-housing 51 K W19 Thermal time constant winding 292 s20 Thermal time constant motor 543 s21 Ambient temperature -30 +100degC22 Max permissible winding temperature +155degC

Mechanical data (ball bearings)23 Max permissible speed 14000 rpm24 Axial play 005 - 015 mm25 Radial play 0025 mm26 Max axial load (dynamic) 20 N27 Max force for press fits (static) 60 N

(static shaft supported) 1000 N28 Max radial loading 5 mm from flange 35 N

Other specifications29 Number of pole pairs 130 Number of commutator segments 1131 Weight of motor 115 g

Values listed in the table are nominalExplanation of the figures on page 49

OptionEncoder MR on requestEncoder HED_ 5540 on request

Planetary Gearhead32 mm075 - 60 NmPage 230 231 233Koaxdrive32 mm10 - 45 NmPage 236Spindle Drive32 mmPage 249 250 251

Encoder MR128 - 1000 Imp3 channelsPage 262Encoder HED_ 5540500 Imp3 channelsPage 267 270DC-Tacho DCT22 mm052 VPage 276Brake AB 2824 VDC04 NmPage 318

APPENDIX H DATA SHEETS Main Motor RE 25 Maxon 339152

overall length overall length

266 maxon sensor May 2010 edition subject to change

maxon Modular System+ Motor Page + Gearhead Page + Brake Page Overall length [mm] see GearheadRE 25 7779 753RE 25 7779 GP 26 05 - 20 Nm 228

RE 25 7779 GP 32 075 - 45 Nm 230

RE 25 7779 GP 32 075 - 60 Nm 231233

RE 25 7779 KD 32 236

RE 25 7779 GP 32 S 249-251

RE 25 20 W 79 AB 28 318 1057RE 25 20 W 79 GP 26 05 - 20 Nm 230 AB 28 318

RE 25 20 W 79 GP 32 075 - 45 Nm 232 AB 28 318

RE 25 20 W 79 GP 32 075 - 60 Nm 231233 AB 28 318

RE 25 20 W 79 KD 32 236 AB 28 318

RE 25 20 W 79 GP 32 S 249-251 AB 28 318

RE 35 90 W 81 917RE 35 90 W 81 GP 32 075 - 45 Nm 230

RE 35 90 W 81 GP 32 075 - 60 Nm 232233

RE 35 90 W 81 GP 32 40 - 80 Nm 235

RE 35 90 W 81 GP 42 30 - 15 Nm 238

RE 35 90 W 81 GP 32 S 249-251

RE 35 90 W 81 AB 28 318 1241RE 35 90 W 81 GP 32 075 - 45 Nm 230 AB 28 318

RE 35 90 W 81 GP 32 075 - 60 Nm 232233 AB 28 318

RE 35 90 W 81 GP 32 40 - 80 Nm 235 AB 28 318

RE 35 90 W 81 GP 42 30 - 15 Nm 238 AB 28 318

RE 35 90 W 81 GP 32 S 249-251 AB 28 318

RE 40 150 W 82 917RE 40 150 W 82 GP 42 30 - 15 Nm 238

RE 40 150 W 82 GP 52 40 - 30 Nm 241

RE 40 150 W 82 AB 28 318 1242RE 40 150 W 82 GP 42 30 - 15 Nm 238 AB 28 318

RE 40 150 W 82 GP 52 40 - 30 Nm 241 AB 28 318

VCC 5 VDC

Rpull-up 33 k

Ambient temperature range u = 25degC

Encoder 500 Counts per turn 3 Channels

Order Number

110511 110513 110515Type

Counts per turn 500 500 500Number of channels 3 3 3Max operating frequency (kHz) 100 100 100Max speed (rpm) 12000 12000 12000Shaft diameter (mm) 3 4 6

Technical Data Pin Allocation Connection exampleSupply voltage 5 V 10

Encoder Description Pin no from3409506

Pin 5 Channel B 1Pin 4 VCC 2Pin 3 Channel A 3Pin 2 Channel I 4Pin 1 GND 5

Cable with plugmaxon Art No 3409506The plug (Harting 9185066803)can be fixed in the required position

Cable with plug (compatiblewith encoder HEDS5010)maxon Art No 3409504The plug (3M 89110-0101) canbe fixed in the required position

Output signal TTL compatiblePhase shift 90dege plusmn 45degeSignal rise time(typically at CL = 25 pF RL = 27 k 25degC) 180 nsSignal fall time(typically at CL = 25 pF RL = 27 k 25degC) 40 nsIndex pulse width (nominal) 90degeOperating temperature rang -40 +100degCMoment of inertia of code wheel 06 gcm2

Max angular acceleration 250 000 rad s-2

Output current per channel min -1 mA max 5 mA

The index signal I is synchronised with channel A or B

Direction of rotation cw (definition cw p 48)

Channel A

Channel B

Channel I

s∆ 45deges2 s = 90dege14s1s4s3

90dege

Channel A

Channel B

Channel I

Cycle C = 360dege

Pulse P = 180dege

Phase shift

APPENDIX H DATA SHEETS Encoder HEDS 5540 Maxon 110511

Slide PotentiometersEVA(B)JQEVA(B)NAEVA(B)NB

13 13 13 13 13 13 13 13 13 13 13 13 13 13

Thin type Faders for Audio MixersSlide Potentiometers

Features

Major Specifications

1000 mm Type

600 mm Type

450 mm Type

Custom specifications negotiableNotes1 Custom design for Lever Style also negotiable2 450 mm travel type also available (External dimensions same as 600 mm type)

Explanation of Part Numbers

Recommended Applications

APPENDIX H DATA SHEETS Linear Potentiometer Farnell 8795959 Panasonic

EVAJQLR15B14

13 13 13 13 13 13 13 13 13 13 13 13 13 13

Dimensions in mm (not to scale)

EVANAEVBNA

13 13 13

amp () amp

ampampamp

No 1No 1

$$ amp ( (

- $ $)

$$ amp ( (

- $ $)

EVANBEVBNB

EVAJQEVBJQ

APPENDIX H DATA SHEETS Linear Potentiometer Farnell 8795959 Panasonic EVA-

JQLR15B14

131313 $ amp$$$($()amp +$--(amp +$amp$$amp( amp$$amp0 amp$amp $$ amp amp $($ 123--13-13 --13 --($amp($ $($$amp 4567 896lt+$(0 $=gt ABCDE FGCHECICJBCDE FGCHECICJBCDE KLMNCBJCDE KLMNCJOCDE+$((ampamp$=gt PG PG PG KLMNCPG KLMNCABP$amp)(($ GNABC GNAB GNJOC BNJG$Q$amp$amp)(($R SAGP SAGT SAGT SAGT SAGTC$( $($amp$(+ U KLMNCAGG VPGCC VPGCC VPGCC VPGCC$( $($amp$($amp$ U KLMNCAGG VAPGCC VAPGCC VPGCC VPGCC$ amp$( U SAGOC SAGO SAGO SAGO $($ ($ WXYNCGNA WXYNCGNAPC WXYNCGNAP WXYNCGNA WXYNCGNAC(($($$ amp( Z[CJGC ANTCCGNPC ANTCCGNJC ANTCCGNJC BNPCCGNPC BNPCCGNPZ[CT]C ANOC_abC ANOCCGNJ $($$amp0 GNBPCCcCGNBIdGNA GNFPCGNA GNFPCGNA GNJPCGNA GNJPCGNA$ $amp$ PGeIF8 SAGG SAGG SPG SPG$ amp$ SAGP SAGT SAGT SAGT SAGT$amp$amp amp $($ Z[CJG Z[CJGIZ[CT] Z[CJGIZ[CT] Z[CJG Z[CJG amp$ fCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCZgdgh65iCCCCCCCCCCCCCZgdgh65iCCCCCCCCCCCCCCCCCCCCCCCCCCCjLCCCCCCCCCCCCCCCCCCCCCCCCCCCjLCCCCCCCCCCCCCCCCCCCCCCCCCCCCjL amp$amp$( fklmIklnoCZgCgh65iCp- BJGIBGfk[qIk[lIk[moCp-CCBTGIFCr7sCrdltDdGBGECCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCBJPIP CCCCCCCCCCCCCBJOuPIACCCCCCCCCCCCCCCCCCCCCCCCBJOuPIAC BJOuPIAC$$amp$amp p dBGCvCc]G dJGCvCcOP dJGCvCcOP dBPCvCcOP dBPCvCcOP$ amp$amp$amp p dFGCvCcOP dJGCvCcOP dJGCvCcOP dBPCvCcOP dBPCvCcOP$amp w8Wlt5x w8Wlt5x=yamp Z[T]CCZ[T]$ampamp23 qz qz $($$amp E|wxF]CCCe9CcCH|CCCCCCCCCCCCCCCC E|wxCdFKCe9CcBKCH| $($$amp0amp ~C E|wxCdBNPKCH4CYL889LW7amp ~CCCCCCCCCCE|wxF]CdClx ()$ ~ tltK5Y6L8WC[HCJNT tltK5Y6L8WC[l($$ amp ~ tltK5Y6L8WC[[l tltK5Y6L8WC[E 0amp$ ~ CABElte9A]] 3 13APPENDIX H DATA SHEETS Switch Farnell 1217764 Schurter 13019315

13 $amp()++-( (amp()++-( (amp01 +( (amp+$(23456789lt88=9lt88 gtltgtltA9Alt88=9Alt88 gtltgtlt7BCDEFGGHlt88AH88 gtltgtHltgtlt88lt88 gtltgtgt gtltgtltgtlt88Hltlt88 gtltgtgtH gtltgtlt9lt88IgtH88 gtltgtHlt9lt88Jltlt88 gtltgtgtI gtltgtltlt88Jlt88 gtltgtgtJ gtltgtltgtlt88Altlt88 gtltgtgtA gtltgtltH9lt88Hlt88 gtltgtgt gtltgtltIltlt88gtgtH88 gtltgtHlt9ltlt88gt9Hlt88 gtltgt9lt gtltgtltJ3KL= 9==============M 3M 3 3NENNOPMQ3MQ3Q3NPORMSE4TROE4UVWXYWZ[W]_ZWabWcdeZWfW_ghijWfkWZ[WjeX_jWl_eXaYmn($0$0opq )2++nor2(s+20om$2++no tuv w xyvuxyxxz xy wy|x zvyz xyv~ uxyxxtyux wy|xuywx wy|xzy|x twuv (0 wy|xzy|x twuv (0twuv (0wy|xyxx ty|xwvut (0AAPPENDIX H DATA SHEETS Switch Farnell 1217764 Schurter 13019315

1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 1313 $ $ $ amp (amp)++--amp)-)01 )23- (145(+)67 8+ 39+(0 8 5(+)67 8+ 39+(0 8197+lt=9gt(+01= 0-30-(3+01)3AB(0-(9 0-30-CC 197+lt $D E2( amp+0+9()30)3)2 )+7)7+$(+)03 FGGHIJKLMNOPIHQJIKLQRSQJQLTUUA0)+0)VVV17- W (90amp3X17-5230Y Z([Y17-lt 8] E39310 amp) (979()30E_amp9-(0 72 3+-73+) ` abcdeafghgihjAPPENDIX H DATA SHEETS Friction bearing Igus JSM-1012-05

APPENDIX H DATA SHEETS Clutch motor Pololu 995

13 13 $ amp () $+ - amp 0123 $ 4 4 13 5 3 $ 13 6 7 2amp 13 11389 89 8913lt0123 =gtAB=CDEF G HIII IJIKI012lt3 =gtAB=CDEF K HIII IJLMM0123 =gtAB=CDEF LI HIII IJNLK0123 =gtAB=CDEF LN HIII IJHNH0123 =gtAB=CDEF LG HIII IJOPH0123 =gtAB=CDEF NI HIII IJKQG012$3 =gtAB=CDEF NO HIII LJMLL 894 0 134 RCSBTgt=FBUSVgtTTSWASAB=CDEFBTDFSUDBEgtUBDBWSDUBXSDUWY=BTDASEUgtTBYAZU[BDWABYAZU[NII]DDXSBEUgtTB=FgtV_DFSUDaB ]ZTWZTRgtSUDWVSaBCKbDUAWS==aBPOBbcdZUEDVSaB bDUABDWgtAeSAfSD=SBUSTSTXSUBFCDFBFC=B=BDBFSVCWVDB=ZUEDVSgBdTDBVgtgtZUBDUDFgtW=BDUSBhgt==XSBAZSBFgtBDUDXSBVgtDFWYBAShFC=g 113 44 i1 4 jDUXgtWBEXUSBFZXS]ZTWZTBkCVl ]ZTWZT jEOH dFDWS==B=FSSCDUABDWgtAeSA ZWVgtDFSA CDUASWSAjDUXgtWBEXUSBFZXS]ZTWZTBkCVl ]ZTWZT jEOH dFDWS==B=FSSCDUABDWgtAeSA ZWVgtDFSA CDUASWSAjDUXgtWBEXUSBFZXS]ZTWZTBkCVl ]ZTWZT jEOH dFDWS==B=FSSCDUABDWgtAeSA ZWVgtDFSA CDUASWSAm 4 0 13 01253 443 0 413 nnnopqrsotuvuwvsxyzsAPPENDIX H DATA SHEETS Guide Igus AWMP-10

- - 602 996 00 - - 045 2 300 127 32 635 3 007 - - 2- 602 702 00 602 996 02 - 04 05 3 318 142 45 952 3 01 - 2 6

602 608 00 602 708 00 602 996 08 024 09 10 4 600 1905 6 1270 5 0127 2 6 10602 610 00 602 710 00 602 996 10 024 09 10 6 600 1905 6 1270 5 0127 2 6 10602 612 00 602 712 00 602 996 12 035 15 18 4 635 203 6 1587 5 0127 3 8 22602 614 00 602 714 00 602 996 14 035 15 18 5 635 203 6 1587 5 0127 3 8 22602 616 00 602 716 00 602 996 16 035 15 18 6 635 203 6 1587 5 0127 3 8 22602 620 00 602 720 00 602 996 20 064 25 27 6 800 2285 65 1905 5 0127 8 12 34602 622 00 602 722 00 602 996 22 064 25 27 8 800 2285 65 1905 5 0127 8 12 34602 624 00 602 724 00 602 996 24 14 40 60 6 1100 3175 9 2540 5 0127 13 32 90602 626 00 602 726 00 602 996 26 14 40 60 8 1100 3175 9 2540 5 0127 13 32 90602 628 00 602 728 00 602 996 28 14 40 60 10 1100 3175 9 2540 5 0127 13 32 90602 630 00 602 730 00 602 996 30 25 60 100 10 1600 4445 12 3175 5 0127 35 76 220602 632 00 602 732 00 602 996 32 25 60 100 12 1600 4445 12 3175 5 0127 35 76 220602 634 00 602 734 00 602 996 34 25 60 100 16 1600 4445 12 3175 5 0127 35 76 220

- 602 900 00 602 998 00 - 1 15 3 476 1955 53 952 3 012 - 4 8- 602 902 00 602 998 02 - 1 15 4 476 1955 53 952 3 012 - 4 8

602 806 00 602 906 00 - 051 2 - 4 635 2285 65 127 5 017 4 8 -602 808 00 602 908 00 - 051 2 - 6 635 2285 65 127 5 017 4 8 -

- - 602 998 12 - - 3 4 635 2540 65 127 5 017 - - 18- - 602 998 14 - - 3 6 635 2540 65 127 5 017 - - 18

602 818 00 602 918 00 602 998 18 091 34 5 5 800 2540 65 1587 5 02 6 10 30602 820 00 602 920 00 602 998 20 091 34 5 6 800 2540 65 1587 5 02 6 10 30602 824 00 602 924 00 - 13 53 - 6 1000 2650 65 1905 7 025 12 16 -602 826 00 602 926 00 - 13 53 - 8 1000 2650 65 1905 7 025 12 16 -

- - 602 998 30 - - 8 6 1000 2800 65 1905 7 025 - - 46- - 602 998 32 - - 8 8 1000 2800 65 1905 7 025 - - 46

602 834 00 602 934 00 602 998 34 25 10 16 6 1270 3810 11 254 7 038 20 44 115602 836 00 602 936 00 602 998 36 25 10 16 8 1270 3810 11 254 7 038 20 44 115602 838 00 602 938 00 602 998 38 25 10 16 10 1270 3810 11 254 7 038 20 44 115602 840 00 602 940 00 602 998 40 4 15 25 10 1600 5715 16 3175 7 05 58 100 290602 842 00 602 942 00 602 998 42 4 15 25 12 1600 5715 16 3175 7 05 58 100 290602 844 00 602 944 00 602 998 44 4 15 25 16 1600 5715 16 3175 7 05 58 100 290602 846 00 602 946 00 602 998 46 6 22 36 12 1900 6667 18 381 7 06 86 160 440602 848 00 602 948 00 602 998 48 6 22 36 16 1900 6667 18 381 7 06 86 160 440602 850 00 602 950 00 602 998 50 6 22 36 19 1900 6667 18 381 7 06 86 160 440

- 602 958 00 602 998 58 - 40 73 16 2600 9530 2506 508 7 09 - 405 1045- 602 960 00 602 998 60 - 40 73 19 2600 9530 2506 508 7 09 - 405 1045- 602 962 00 602 998 62 - 40 73 24 2600 9530 2506 508 7 093 - 405 1045- 602 966 00 602 998 66 - 55 102 24 3000 1300 32 5715 7 095 - 800 2155- 602 968 00 602 998 68 - 55 102 30 3000 1300 32 5715 7 095 - 800 2155

Betriebsfaktoren Seite 325 beachten Welle kann tiefer eingesteckt werden Kupplung ist mittig freigedreht Stellschraubenausfuumlhrung 1) gegen Mehrpreis

Betriebsfaktoren Seite 325 beachten Welle darf nicht tiefer eingesteckt werden 1) gegen Mehrpreis

Ausgleichskupplungen LA lange Ausfuumlhrung

Bestellangaben zB Art-Nr 602 806 00 Ausgleichskupplung LA lange AusfuumlhrungKunststoff 4 mm Bohrung

Werkstoff Kunststoff AcetalAluminium 2014AEdelstahl 14305

bull hohe Torsionssteifigkeitbull absolute Spielfreiheitbull hohe Drehmomentuumlbertragungbull sehr geringe Ruumlckstellkraumlftebull Drehzahl max 5000 min-1

Ausgleichskupplungen KA kurze Ausfuumlhrung

Bestellangaben zB Art-Nr 602 608 00 Ausgleichskupplung KA kurze AusfuumlhrungKunststoff 4 mm Bohrung

bull hohe Torsionssteifigkeitbull absolute Spielfreiheitbull hohe Drehmomentuumlbertragungbull sehr geringe Ruumlckstellkraumlftebull Drehzahl max 5000 min -1

Artikel-Nr Artikel-Nr Artikel-Nr Max Betriebsdrehmoment Bohrung Bohr L1 L2 D1 Winkel- Parallel- GewichtKunststoff Alu Edelstahl Kunststoff Alu Edelstahl B +003 max1) versatz versatz Kunststoff Alu Edelst

Nm Nm Nm mm mm mm mm mm Grad mm g g g

APPENDIX H DATA SHEETS Rotational clutch Maedler 60271400

APPENDIX H DATA SHEETS Spring Conrad 229058-62

APPENDIX H DATA SHEETS

Appendix I

Data CD

Contents

Basic Schedule

The basic schedule of the second prototype in EXCEL format

Blueprints

The blueprints of the second prototype in PDF format

CAD STP

This folder contains ldquostprdquo-files of all CAD parts of the second prototype

CAD UGX

The CAD data was created using Unigraphics 6043 Older versions can cause problems show-

ing the data correctly ldquo03 Linearmotor 02 asmprtrdquo contains the main assembly of the second

prototype of the MMLA ldquoRoboter asmrdquo contains the main assembly of the walking robot used to

illustrate possible applications of the second prototype

Data Sheets

Data sheets of the parts used in the second prototype

Matlab Clutch

The file ldquoCaltulation Clutchmrdquo performs the calculation of the clutch force described in Section

Matlab Measurements

Run the files ldquoCalibrationmrdquo ldquoMeasurements01mrdquo to ldquoMeasurements05mrdquo to see the results of

the measurements discussed in Section 43

APPENDIX I DATA CD

Pictures

The pictures of the report in higher resolution

Report

The report in PDF format

BIBLIOGRAPHY

Bibliography

[1] David J Barnes Quotient Robotics Blog httpwwwquotientroboticscomsearchlabelBiPed20Robot

[2] Fabian Muller Modeling and Control of the MMLA 2010

Introduction

Goal and Timeline

The Robots of the BIRL

Terms and Definitions

Coordinate Frame

Words


Former Conditions

Conceptual Design

Mechanical Concept

Actuator Type

Clutch Type

Motor

Division of Work

The First Prototype

Requirements for the Second Prototype

Description of the Second Prototype

Assembly

Motion States

Operating Mode of the Clutches

Sensors

Technical Data and Experimental Results

Technical Data of the Second Prototype

The Clutch Mechanism

Hopping Tests


Assembling

Assembling the Rotational Clutch

Assembling the Ball Screw Nut

Adjusting the Clutch

Replacing the Brake Shoes

Lubricate the Ball Screw

Cleaning and Attending the Guide

Safety System

Obligatory Safety System

Optional Safety System

Advices for Installation


Potential of Future Setups

Potential of the Actual Setup

Tasks for the Third Prototype

Data Collection with the Second Prototype

Data Collection using Simulations

Control

Third Clutch

Clutch Motors

Usability

Brake Shoe Material

Guide Performance

Future Tasks for the MMLA

Higher Forces

Closed Design

Smaller Size and Mass

Beyond the Clutch

Basic Schedule

Calculations

Spring Data

Ballscrew

Clutch Force

Compression Moment

Friction Moment

Matlab Calculation

Basic Assumptions for the Actuator

Static Force in the Robots Knee


Budget

Timeline

Plug Connection

Blueprints

Data Sheets

Data CD

Bibliography