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mzahana / px4_pid_tuner

Python script for system identification and tuning of PX4 PID loops based on PX4 logs (ulog only).
MIT License
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u and y arrays seem to lose their float type when passing to SIPPY #1

Open StrawsonDesign opened 4 years ago

StrawsonDesign commented 4 years ago

when passing u and y into SIPPY those two arrays seem to not have a type when they should be floats. I poked a little and self._y and self._u in the PX4SYSID class seem to be 1x1250 floats as expected but the type is lost after being run through numpy's atleast_2d() function.

Forcing A stability Forcing A stability Forcing A stability Forcing A stability Processing batch# 5 Best fit = 0.0 Traceback (most recent call last): File "./px4_pid_tuner.py", line 907, in main(args) File "./px4_pid_tuner.py", line 849, in main sysid = PX4SYSID(best_t, best_u, best_y, use_subspace =True, subspace_method='N4SID', Ts=dt, u_name='best_input', y_name='best_ouput', subspace_p=best_p, plot = True) File "./px4_pid_tuner.py", line 310, in init self.do_sys_id() File "./px4_pid_tuner.py", line 364, in do_sys_id sys_id = system_identification(self._y, self._u, self._subspace_method, SS_fixed_order=num_poles, SS_p=self._subspace_p, SS_f=50, tsample=self._Ts, SS_A_stability=True, centering='MeanVal') File "/usr/local/lib/python3.6/dist-packages/sippy-0.1.0-py3.6.egg/sippy/init.py", line 22, in system_identification TypeError: unsupported operand type(s) for *: 'float' and 'NoneType'

StrawsonDesign commented 4 years ago

Looks like when no sysid solution is found, best_u and best_y are never set and remain "none". The check for a valid solution should have come before running sysid on best_u and best_y. This is fixed in the following commit:

https://github.com/StrawsonDesign/px4_pid_tuner/commit/09e6fd4b71a6df33188ed2d1c541f1283f243483

I'll hold off on submitting more pull requests as I see many more fixes and tweaks in the near future.