PBP projects for R/C models

[Kenjones1935]

There is a big write-up in the latest SERVO magazine on the advantages of Arduino. Maybe.....

I've been thinking..... In my robocar I am controlling rates by measuring scalors. My PIC signals PWM to control rate of speed and rate of turn. Its sonar sensors are giving it distance. My code does not divide by time elapsed. ie differentiate. Is this a basically flawed concept?

I have not been using the BASIC math operators. If I were to work in closing rates rather than pure distance would my error feedback be more appropriate?

Ken

[Kenjones1935]

I need help figuring how to control a robocar at speed. Simply said:

The MODEL level car has proportional control. I preset the max velocity with a POT. I need a robo system that can figure out when to turn given the speed and the distance of oncoming obstacles.

The TOY level cars have only bang-bang controls. Their tires are plastic. They slide and skid. The 1/12 scale car is slow enough for simple sonar distance threshold control. Boring!! The 1/10 scale car is a big fast colorful device: spectacular and fun! With size and speed comes momentum. I need to get better control of the steering (current drivers instead of DPDT relays?) and an algorithm to implement that control.

Any ideas?

Ken

[Kenjones1935]

Some robots first map their environment. If my car were to have a map of the room and could find its location, speed and direction in that room then given constant update of the robot's location and two dimensional velocity it ought to be able to maneuver the wall race. Any ideas how to implement such a scheme? I think the little car will need a compass or something similar. It sure would help if it knew the angle of its motion relative the four walls.

Ken

[Kenjones1935]

The solution is obvious for the MODEL level robocar.

I made the wheel velocity proportional to the POT position. Stopping and turning distance requirements are proportional to speed. Make these distances proportional to the POT also. Easily done.

I have no answer for the 1/10 TOY car aside from making it expensive by implementing a proportional control system.

Ken