Is there a good solution to build more aggressively correcting turn and straight movement functions?

[TheWanderingShadow]

Currently, our robot has not been moving with enough precision both when trying to move straight and when turning, even with the gyro movement activated. We want to build methods to make more rapid proportional adjustments of the robot's movement to efficiently achieve the precision we want. One solution we attempted was to use multitask to manually adjust the speeds of the left and right motors:

async def msp(left_motor_speed, right_motor_speed):
    multitask(left_motor.run_until_stalled(left_motor_speed), right_motor.run_until_stalled(right_motor_speed))

however, running this constantly in a while loop quickly overloads the robot's memory, and we are unsure how to just adjust the parameters of the movement to avoid this issue. Could someone please explain how to use this in a manner that doesn't waste memory, or suggest a better solution altogether?

[dlech]

This is missing await in front of multitask. That will probably solve the running out of memory problem.

But I'm not sure how this will help with motor control. Can you give some more details on what kinds of problems you are having with the precision?

[TheWanderingShadow]

When our robot is supposed to move straight it often twitches and moves off course at the start of its movement. It stabilizes after, but by then it is too late. Our attempts at turning often are too far off for our purposes. We would like the robot to align itself to a specific heading, both when going straight and when turning.

[TheWanderingShadow]

The problem with using await is that I am trying to consistently update the speeds that the motors are going, and await will simply run the function once at the same speed forever. How can I update the speed of both motors at once without crashing the hub?

[laurensvalk]

multitask is intended to do two or more things at once. It has little to do with speed.

To make a drivebase more responsive, you'd want to change the speed and acceleration settings:

You can even increase or tweak the PID values for driving if you want to take things a bit further. This can be helpful if your robot is a bit heavier than a typical small robot. I would start looking (printing) at the existing values and then increase them as needed.

[TheWanderingShadow]

We will tweak the PID settings, as the robot is indeed quite heavy now. Which one do you think would solve the issue of the weight of the robot leaning off course? I am assuming acceleration/deceleration. Also, is there a place to check the maximum values available for these settings?

[laurensvalk]

The maximums depend on your design. The motors can go up to about 1000 deg/s, but much less under load. This works out to a drive and turn speed depending on your wheel base and diameter.

[TheWanderingShadow]

After several tweaks our robot is still not moving straight. We will continue to experiment, but as a safeguard if these settings fail, we would like to create a program that forces the robot to stay aligned to a heading relative to the initial zero heading. How would you suggest we go about this?

[k-paulius]

I have also noticed that changing profile parameter value on Motor class can make a difference in how "quickly" robot corrects.