To say I'm somewhat disappointed in the AlphaBot would be putting it mildly. I'm having lots of repeatability issues. I thought I'd try some obstacle avoidance using the ultrasonic sensor. I'm still having significant speed repeatability issues for the wheels and even the IR sensors and servo aren't really consistent. The first thing that I noted when I looked at the AlphaBot library code is that the optical sensors on the wheels are not used. I guess this is an exercise left to the user. So, that's one thing to fix. The lack of speed repeatability looks like it could also be attributable to using the delay() function for timing of the motor control.
I've noticed that the sensors and servos perform much better when tested separately than when the functions are integrated. Certainly lack of using interrupts and any real time elements is going to add to a lot of response variability. It's probably time to pick an appropriate processor and RTOS to use for control rather than continuing with the Arduino Uno Plus.
I thought I should make a before video just to document where I started from. It's pretty comical. It just won't run straight. I tried tweaking the left and right speeds, but it varies run to run. I'm trying to use the ultrasonic sensor to do some obstacle avoidance. If it detects an obstacle, it supposed to back up, look left and right, and determine which direction to turn. Of course, the backing up and turning are inconsistent, so it doesn't do very well. And the ultrasonic sensor doesn't do very well with non-orthogonal surfaces.
Top Comments