Booklet.… · Web view‘AutoMaxi’ stands for the autonomous vehicular robots. In this we receive proximity data trough some proximity sensors and then process the data via some

‘AutoMaxi’‘AutoMaxi’ stands for the autonomous vehicular robots. In this we receive proximity data trough some proximity sensors and then process the data via some electronic circuitry or via Microcontrollers on which artificial decisions are taken with the help of sophisticated algorithm and computing to control the deriving motors to guide vehicle in proper direction the follow the instructions therein. This is application and example of real world in electronic world interfacing. In this tutorial the fundamental building blocks are discussed to boost up the strong foundation in autonomous-field which helps you to design any autonomous systems.

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The entire document is the property of EKLAVYA INNOVISION. Any commercial use without prior permission prohibited.http://www.eklavyainnovision.com [1/10] [email protected]

Image Processing/ Computer interface Based

ROBOTS or ROBOTIC SYSTEM

MANUAL AUTONOMOUS SEMIMANUAL or MIXED

Control by Human Itself

Control by circuits or microcontroller

Both type of control

Wired

Wireless (Remote controlled)

(Remote controlled)

Circuit Based

Microcontroller/Processor Based

Image Processing/ Computer interface Based

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http://www.eklavyainnovision.com/

This Study material is made for review of various components which meant for robot design. This list is not exhausted, the components varies as per the design, working and control mechanism of subjected robot.

1. MOTORMotor which are used in robotics are commonly specified by three measures, (a) Supply voltage, normally 6V, 12V, 24V DC (b) speed, normally 10-100 rpm & (c) power rating, average 3-6 Watt used in robot fabrication practices. By motor we are generally concern with three things (a) required speed (b) torque needed, in other word the load carrying capability & (c) available supply voltage. Problem of torque and speed can be resolved by application of gear assembly as by transferring to low radius gear we get more speed and less torque & vice-versa.

>>>>In general, for a motor: Torque(load)*speed= Power and for fixed power like 4 W we can find high toque on low speed and vice versa.>>>> Another general property of DC motors: speed ∝ supply voltage current drawn by motor ∝ load carried Note: as a controller we can only control the voltage that being supplied to the motor, current is not in our hand it varies as the load varied on the motor. Normally current drawn in the range of 10 mA-1A by the said motors.

Note: Motor as an inductive entity produce very high reverse instantaneous EMF on supply off which may circulate current of the order of 100 A which is cause of electronic circuit burn if the interfacing not done properly. (to overcome this problem normally H-bridge or Diode protection or Power transistor is used).

2. SENSORSensor is used to measure some environmental parameters like temperature, light, distance from a source or obstacles etc. which further provides to logic circuit or controller for controlling purpose of robots. Mainly used sensors are LDR (Light Dependent Resistor, for detection of light presence in its vicinity), RTD (Resistive Temperature Detector, for measurement of temperature), IR sensor like PT (photo-transistor), tough sensor, accelerometers, tilt sensor and many more. In addition Sonar sensor and micro-mikes are used for sound based sensing applications

3. Electronics componentsIn electronics components normally three basic components i.e resistor, capacitor and inductor in of main concern in which inductor are used rarely. In addition following are components may use Transistors:: QN2222 (normal transistor, low rating), MJC3055T (power transistor, high

rating) Motor derive:: L293D (H-bridge motor derive), MJC3055T can also use as motor derive due

to its high ratings IC (Integrated circuits):: IC7404 (NOT GATE), IC7408, IC7416, IC7432, IC7486, IC741

(OP-AMP), NE555D (Timer circuit), IC7474 (D flip-flop, can be used as 1 bit of memory) Diode:: LED (IR, white, red, yellow, blue etc) in which IR & white may use in couple with

PT (photo-transistor) & LDR (light dependent resistor) as sensor couple, Zener Diode for The entire document is the property of EKLAVYA INNOVISION. Any commercial use without prior permission prohibited.http://www.eklavyainnovision.com [1/10] [email protected]



constant voltage drop across variable current carrying component like motor and for voltage regulation, Normal diodes used for protection applications and many more

Voltage regulators:: This is important to supply fixed voltage to certain component like TTL logic family IC supply . 7805, 7809, 7812 & 7815 are +ve voltage regulator of 5, 9, 12 & 15 Volts respectively. Similarly 7905, 7909, 7912 &7915 are –ve voltage regulators of 5, 9, 12 & 15 Volts respectively. In addition LM317 are used for variable power regulation.

Advanced Components:: In this Microcontrollers, Microprocessors and other MSI (Medium Scale Integrated), LSI (Large Scale Integrated) circuits are employed for more complex applications.

Relay:: This is used for current/ Voltage driven ON/OFF switch, Normally Relay with 6V and 12V are available in market for use.

4. Power supply Power management is very important area in robotics design after all it is the power who derive your robot. For this Some adopter are use for motor supply (12V, DC) and most of the electronic circuit are derive by 5V for which you can use your cell phone charger which is normally of 6V rating (Never use cell phone charger for motor, since motor draws current of the order of Amperes which may damage your charger, so limit its use only up to electronics circuit). DC battery also available in market, in which 9V High Watt battery is most famous due to its small size, low cost, low weight & easy application. We can also use pencil battery of 1.5 V each along with battery holder and connector to make ~5V onboard power supply.

5. Circuit simulation tools Before implementing any circuit on the desk we should simulate it so that any malfunction may be resolved before its operation which will save lots of component from its burning & damage which occurs frequently by new practitioner. Fro this purpose two circuit simulation tools are very famous. Microsim, P_Spice & Tina-Pro . On these tools we can analyze any circuit on various ways, like time domain analysis, frequency domain analysis and also able to decide the values of basic components like resistances, capacitances etc for specific performance.

6. Mechanical ComponentsThese are various components which may helps you during your Robot design Adhesive: Fevicol(SH), M-SEAL, Cello-Tape etcc Switches: Toggle switch is best for use A very control efficient wheel called Caster wheel always better to use on the place of

supporting wheel for optimal control of our mobile robot. Pulley, Gears, Springs , Gripper etc these are commonly used components for various

application.

# ROBOT PARTS




Manipulator: Body structure of Robotic systemPower Supply Unit: Different type of power sources and power management Sensor: Devices to sense Robot environmentController: Circuit or Processing unit to take decisionActuator: Powerful Device to execute powerful work as per controller decision

MANIPULATOR (BODY) CONSTRUCTION:

Generally body of any robotic system designed as per the task requirement to be performed by the Robots. Body design is very important which affects the dynamics and controlling efficiency of the Robot. Usually following are the main techniques & tools which used frequently.

A. Body material: Thermocol, Plywood, ceramic sheets or any other material having good strength, low weight, easy for cutting, electrically isolator (to avoid any short circuit in case of autonomous and where lots of circuit present ) etc

B. Joints:(i) Temporary joint: It is done by Nut-Bolt, Screw system, Cello taping or simply threading mechanism.(ii) Permanent joint: permanent joint usually done by Welding, Brazing etc(iii)Semi-permanent Joint: It is usually done with the help of adhesive like Fevicol SH, M-Seal, Feviquick and other glue capable to hold the joint load at the time of operation

C. Body construction tools: This includes Hammer, Driller, Saw, File (to rub the corners to shape up) etcD. Steering Mechanism for Robotic Car:

(i) Differential speed Based: Direction of movement control by creating speed of left and right side motor (which is connected to deriving wheel).(ii) Formal steering Based: In this the direction of wheel itself changes but the speed of both wheels always equal.

POWER SUPPLY

In this various type of power supply system are kept to derive the Robot. Generally two type of power source used, Electrical and Hydraulic#ELECTRICAL POWER SOURCE: Either AC or DC, but DC supply used frequently. DC supply can onboard (like small battery mounted on Robot structure itself) or off-board (DC supply given through wires by the help of DC adopters or external heavy battery)




NOTE: for logic as well as electronic circuits where 5Volt required it is good practice to use your phone charges to supply the DC power to circuit. #HYDRAULIC POWER SOURCE: This supply is given by pressurized cylinder trough pipes and tubes and used for very high load applications, like ROBOT FIGHT application.

COMPONENT DETAILS:1. DC Geared Motor:

Characteristics:(i) On changing the DC supply polarity direction of rotation will reverse(ii) n ∝ V (up to certain limit)(iii) I ∝ τ (up to a certain limit)

(iv) (keeping I & V constant)2. Q2N2222 (General purpose transistor)


n= Speed of motor

τ= Torque on motor

V= Supply voltage

I= current drawing

∅= Magnetic Flux



Maximum Ratings:

(i) VCE = 40 V(dc)(ii) VCB=75 V(dc)(iii) VBE= 6 V(dc)(iv) IC = 600 mA(dc)

3. MJE3055T (Power transistor)

Maximum ratings:(i)VCE= 60 V(dc)(ii)VCB= 70 V(dc)(iii)VBE= 5 V(dc)(iv)IC= 10 Amp(dc)(v)IB= 6 Amp(dc)

4. LDR (Light dependent resistor)




Maximum ratings:(i)Maximum current = 20 mA (for typical LDR)Resistance rating: >In light = 2-4 KΩ >In dark = 40-50 KΩ

5. LED (light emitting diode)

Operating voltage normal LED is about 2-3 Volts Operating voltage IR LED is about 4 Volts IR LED emits light in the IR region (about 1x1013 Hz) Never operate > 4 Volts, it will burn the LED

6. NE555D (A timer device)




Useful ratings:(i)Supply voltage (VCC) ϵ [4.5 V, 18 V], i.e 4.5 Volts < VCC< 18 Volts(ii)Maximum output Current, i.e current from terminal 3 as,

IOUT = 200mA @ VCC=+15VIOUT = 100mA @ VCC=+5V

7. KA7805 (+ve Voltage regulator)

8. DM7404 (NOT GATE, an inverter element)


Ratings:

(i) VINPUT = 40 V(dc)

(ii) IO = 1.5 Amp



Maximum Ratings(i)Supply voltage 4.75 Volts < VCC < 5.25 Volts(ii)Maximum output Current = 16 mA

9. IR Receiver/ Phototransistor

Maximum current trough the Phototransistor in the order of 20 mA

ASSEMBLING:

1. Transistor as a Switch




On Condition

Off Condition

2. Use of IC-7404 as a Switch




CICIRCUIT DESIGN1. (LED+LDR)+Xsistor-Xsistor Circuit.

>>As LDR detects the light Xsistor-1 (Nearest to LDR) off, so Xsistor-2 on which causes for Xsistor-3 off and so Motor is off.

>> You can reduced no. of Xsistor by taking LDR on the upper side of voltage divider arm, but in this case loading effect plays very significant role.

2. (LED+LDR)+Xsistor-Relay circuit.




>> Here ground of Motor segment and electronic circuit is different

>> Generally Relays comes in two operating range 6 V and 12 V.

>> General purpose transistor sufficient to drive the Relay.

3. (LED+LDR)+7404-Xsistor circuit.

>> Here r is the safety resistance for the Xsistor because output of NOT GATE corresponding to bit ‘1’ is 5 volts and we cant give this much amount to the base-emitter terminal.

>> Here supply for electronic circuit is taken 5 volts because we are employing logic gate.

>> Transistor is power transistor to carry sufficient allowed Ic for Motor.




4. (LED+LDR)+7404-Relay circuit.

>>Relay working around 6V, If with 5v to electronic circuit (left part) relay not work you can change it to 6v.




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Booklet.… · Web view‘AutoMaxi’ stands for the autonomous vehicular robots. In this we receive proximity data trough some proximity sensors and then process the data via some