In one of the PR&D exercises, the performance of the AEV was recorded using the MATLAB-based AEV Analysis Software. This was done so that the team could learn how to use this tool to analyze future runs.
To begin this exercise, the team created a simple program and uploaded it to the AEV’s controller board such that the motors would perform the following tasks:
- Accelerate all motors from start to 25% in 3 seconds.
- Run all motors at a constant speed (25% power) for 1 second.
- Run all motors at 20% power for 2 seconds.
- Reverse all motors.
- Run all motors at a constant speed (25% power) for 2 second.
- Brake all motors
The code was written as follows:
- celerate(4,0,25,3);
- motorspeed(4,25);
- goFor(1);
- motorspeed(4,20);
- goFor(2);
- reverse(4);
- motorspeed(4,25);
- goFor(2);
- brake(4);
The AEV analysis software has the ability to crate plots of Power vs. Time and Power vs. Distance. Since the AEV was not hooked up to a track while this test was run, no distance was traversed, and thus the only graph created was one of Power vs. Time.
Figure 1: Power Consumed by AEV Motors over Time in Lab Exercise 4
As can be seen in this graph, the AEV’s power consumption steadily grows to 6.22 W over the 3 seconds during which it accelerates to 25% power. It maintains the 6.22 W power consumption for 1 second, and then drops down to 20% power (4.67 W) for 2 seconds. The motors are then reversed, which requires a large amount of power, as seen by the sudden spike up to 10.89 W. The motors then run at 6.22 W again, since they run at 25% for 2 seconds after being reversed. The motors then stop, and so the power consumption on the graph drops to 0 at 8 seconds.