1. Lab 04: AEV External Sensors Advanced Energy Vehicle (AEV)

2. AEV Project Objective (Problem Definition) INITIAL CONCEPTS (Brainstorming) EXPERIMENTAL RESEARCH ANALYZE DESIGN DECISION RESEARCH COMPARE FINAL DESIGN Present AEV Design PT 1 PT 2 PT 3 PT 4 (System Analysis)(Programming)

3. Learning Objectives  Become familiar with the external sensor hardware components Become familiar with troubleshooting techniques  Program the function calls in controlling the AEV using the external sensors

4. External Sensors  The importance of external sensors on the AEV is to provide real-time information being provided to the Arduino for autonomous vehicle operation This is known as a feedback control  The sensor that will be focus of today’s lab is the Reflective Sensor Image: from Arduino Website

5. Reflective Sensors  The sensor will produce a low voltage due to the reflectance of the aluminum tape and produce a high voltage due to the dark color of the wheel 1 Mark  This voltage change is called a “mark.” For one full wheel revolution, a sensor will have 4 voltage changes or 4 marks. Since we have two sensors, one full wheel revolution will have how many marks?? EIGHT Marks!!

6. Mounting the Sensor  The closer the sensor is to the wheel, the better voltage reading the sensor will usually have Optimum Too Far Away

7. Troubleshooting the Sensors  To make sure the sensors are on correctly  Run the “reflectanceSensorTest();”  Make sure to set to set the serial monitor to 115200 Baud

8. Making the Connections  Take careful consideration where the reflective sensor is attached to on the Arduino.  Read the AEV Lab Manual for proper orientation and pin locations  When in doubt ASK IF UNCERTAIN! Important Note: Make sure the connections are installed with the white wire facing the Arduino mini-USB connection.

9. Arduino Programming Sensor Function Calls  goToRelativePosition(M); One Argument; works specifically with the reflectance sensor  M: wheel marks Example: motorSpeed(4,27); goToRelativePosition(44);  Each wheel has 8 marks and the wheel has a circumference of 3.902 inches  Therefore: (44 marks)*(3.902/8) inches = 21.46 inches traveled Sets all motors to 27% full power Continues the last command for 44 wheel marks.

10. Arduino Programming Sensor Function Calls  goToAbsolutePosition(M); One Argument; works specifically with the reflectance sensor  M: wheel marks Example: motorSpeed(2,30); goToAbsolutePosition(500);  Each wheel has 8 marks and the wheel has a circumference of 3.902 inches  Therefore: (500marks)/(3.902/8) inches = 243.76 inches traveled Sets motor 2 to 30% full power Continues the last command for until the AEV accumulates 500 total wheel marks.

11.  We want to go ANOTHER 40 inches (aka 82 marks) what code do we want? motorSpeed(4,20); goToAbsolutePosition(164); OR goToRelative(82); Difference Between goToAbsolutePosition and goToRelativePosition 40 Inches 80 Inches  We want to go 40 inches (aka 82 marks) what code do we want? motorSpeed(4,20); goToAbsolutePosition(82); OR goToRelativePosition(82); 0 Inches  Note: This is assuming the AEV stops at exactly said distance and does not coast!

12. Questions?