Topic 2: Servo Testing

The second Advanced R&D topic researched was with the servo. When comparing the AEV’s movement with the servo to without (coasting), there were many clear differences. The servo allowed for an easier reverse and stop, shown in the graphs and described below. A code was written for both tests, one to react the servo and one without. Both configurations were run 3 times each for consistency. The configuration of the AEV stayed the same, the only difference being the servo added for servo testing. After analyzing the data and observations, the group decided to continue with the servo and possibly consider other uses of it.

 

ENERGY ANALYSIS PLOTS

Servo: Power vs. Distance 

This graph represents the power used when the servo was utilized. It is clear that the AEV did not move much further after power was cut to the motors due to the servo being coded to press on the wheel to stop further movement.

 

Coasting: Power vs. Distance 

This graph represents the power used when the AEV was coasting. There is a clear drop in power between the forward and reverse movements of the AEV. It is also apparent that the AEV travelled about 4 meters after the power was cut to the motors, proving that the servo is much more effective when preparing for the system to reverse or stop.

 

Here you can see that the servo is held snugly between two brackets at an angle. When coded, the servo is programmed to have the handle press up against the left wheel, stopping the movement of the entire AEV. Other designs for the servo set up were considered but this was the best to keep the servo both stable and productive.

 

Servo code:

// Push_Pull Code below
reverse(1);
celerate(4, 0, 25, 3);
motorSpeed(4,25);
goToAbsolutePosition(300);
brake(4);
rotateServo (37);
goFor(2.5);
rotateServo (0);
reverse(4);
celerate(4, 0, 25, 3);
motorSpeed(4, 25);
goToAbsolutePosition(0);
brake(4);
rotateServo (37);
goFor (2.5);
rotateServo (0);

 

Coasting code:

// Push_Pull Code below
reverse(1);
celerate(4, 0, 25, 3);
motorSpeed(4,25);
goToAbsolutePosition(300);
brake(4);
goFor(2.5);
reverse(4);
celerate(4, 0, 25, 3);
motorSpeed(4, 25);
goToAbsolutePosition(0);
brake(4);
goFor (2.5);