R&D 2: SERVO MOTORS

Purpose:
Be able to determine the how servo motor works, benefits of using it, and compare with
motors.
Equipment:
AEV
Servo motor
Battery
Track
Procedure:
1. Test and calibrate the servo with the following code
Code for test with servo:
// Rotate servo
RotateServo(90);
// Accelerate all motors from 0% to 40% power in 2 seconds
celerate(4, 0, 40, 2);
// Run both motors at 40% power for 4ft (99 marks)
motorSpeed(4, 40);
goToRelativePosition(99);
// Rotate servo
RotateServo(0);
// Brake both motors
brake(4);
2. Do a control run without the servo with the following code
Code for test without servo:
// Accelerate all motors from 0% to 40% power in 2 seconds
celerate(4, 0, 40, 2);
// Run both motors at 40% power for 4ft (99
marks)
motorSpeed(4, 40);
goToRelativePosition(99);
// Brake both motors
brake(4);
3.With results, decide whether to implement the angle-rotation stop method, and how.
Note* angle must be between 0-180 degrees.
Data Analysis:
We expect the servo to help the AEV brake more quickly and efficiently. We will create Distance v. Time charts to compare how long it takes the AEV to brake with the servo and without the servo. We will also create Power v. Time charts to compare the amount of energy used with and without the servo.
Runs (with servo)  Distance (meters)  Max Power (watts)  Time (seconds) 
1  2.90  14.80  8.043 
2  2.74  15.22  8.102 

 

Runs (without servo)  Distance (meters)  Max Power (watts)  Time (seconds) 
1  3.05  10.91  8.102 
2  2.87  10.85  8.101 

 

Progress Report:

1. Does using the servo improve how quickly the AEV brakes?

Using the servo increased how quickly the AEV brakes, but not by much.

2. Does the ability to brake more quickly outweigh the cost of the servo and its components? 

The ability to brake does not outweigh the cost of the servo and its components because it substantially increases the max power and does not improve the braking by that much. 

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Information on Servo Motors was found in [6].