rover position control: fix stuttering (speed fluctuation) motion patern #517
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jlaitine
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Oct 6, 2023
| @@ -330,6 +330,17 @@ RoverPositionControl::control_position(const matrix::Vector2d ¤t_position, | |||
| return setpoint; | |||
| } | |||
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| float RoverPositionControl::lowpass_filter(const float sample_rate, const float cutoff_req, float input) | |||
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There are ready made lowpass filters in px4, e.g. a second order one in mathlib: src/lib/mathlib/math/filter/LowPassFilter2p.hpp
Why not use one of those?
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sure, I am gonna switch to one of the ready made one when this is confirmed a solution. I was just experimenting with this LPF idea if it would help with the stuttering motion.
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LPF is actually not a solution
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LPF is actually not a solution
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…trol rover linear speed
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Sorry, we just tested further today and this PR is no longer relevant. I will not merged it and will create another PR for a much simplier solution |
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The reason for the stuttering was that in the speed control function, the output of the throttle PID controller is forwarded to set rover linear speed. This gives raise to the fluctuation effect of the throttle value getting smaller as the target speed is being reached, hence reduce the speed which prompts the PID controller to increase the throttle again. This results in the stuttering motion pattern.
The solution is to subtract the throttle norm from the desired speed and output the result as the linear speed that will be forwarded to the chassis.
The D component is also disabled.
Tested on UGV2 with 1 and 2m/s in PMK
Bug ticket:
https://ssrc.atlassian.net/browse/DP-6914