Louisiana Tech - College of Engineering & Science

Louisiana Tech - College of Engineering & Science

Louisiana Tech UniversityCollege of Engineering and Science

Microprocessor-Based Control System Project for Integrated Freshman Curriculum

Michael SwanbomDavis HarbourHisham Hegab

Danny Eddy

www.livingwiththelab.com

LOUISIANA TECH UNIVERSITYMECHANICAL ENGINEERING PROGRAM

Fall Winter Spring

Course Credits Course Credits Course Credits

ENGR 120 2 ENGR 121 2 ENGR 122 2

MATH 240 3 MATH 241 3 MATH 242 3

CHEM 100 2 CHEM 101 / 103 2 / 1 PHYSICS 201* 3

College of Engineering and Science

Open-Ended “Smart” Product Design Project



Salinity Feedback

% Weight NaCl versus COUNT Output

y = 0.00003976x - 0.00048891

R2 = 0.980246580.00

0.05

0.10

0.15

0.20

0 500 1000 1500 2000 2500 3000 3500 4000 4500

COUNT output

% W

eigh

t NaC

l

• Conductivity is measured to determine salinity

• Two electrodes are embedded into a student-manufactured inline sensor

• A 555 circuit is used to produce AC across the electrodes

• Resulting frequency is proportional to conductivity

• Boe-Bot counts the number of cycles in a given period

• System is calibrated with known salt concentrations



RTD Design (Resistance Temperature Detector)

Required Specifications

• Nominal Resistance: 100• Thickness of film: ~200nm• 5mm x 5mm solder pads• Minimum width of trace: 200μm• One RTD must fit in 2.5cm x

2.5cm square

• Length versus width tradeoff must be

calculated to achieve required nominal resistance

• Students encouraged to be creative within the guidelines

• 2D Drafting skills in SolidWorks are reinforced


RTD Fabrication Steps

1. Nickel Deposition2. Spinning3. Soft Bake4. Exposure5. Development6. Hard Bake7. Etching8. Dicing9. Inspection10.Soldering11.Sealing

Red – Freshmen do not perform these stepsItalics – no picture shown

2 3

4 5

7

9

10

8



Actuators

• Controller must actuate solenoid valves and a heating element to achieve control of the system

• Electrical limitations of controller are discovered

• Cascaded switching circuits are introduced

• These circuits are then implemented



Typical Program Flowchart

N N


Total cost per student: $3.78



Assessment


Assessment


Assessment

Freshman ProjectsLaboratory

Two classrooms designed to support the curriculum (40 students, 24 students)

Classrooms allow us to easily switch between lecture, laboratory and shop activities within a single 110 minute class period.



Questions?

For More Information:Michael K. Swanbom, Ph.D.P.O. Box 10348Ruston, LA [email protected] (318) 257-3908FAX (318) 257-4630

This project was funded in part by NSF CCLI Grant No. 0618288

Documents

Louisiana Tech - College of Engineering & Science