6
If you're going to use the millwright's method, tune \$k_d\$ first, then \$k_p\$, then \$k_i\$.
And if you're going to use an integrator, put in anti-windup.
6
You have some heuristic approach, as copy from textbook or lessons to algorithm. You don't have any wind-up control, hence your integration and differentiation is not affected by changing Kp.
The Ziegler-Nichols type PID is little bit different
$$u=K_p (\varepsilon + \dfrac{1}{T_i}\int\varepsilon\cdot dt \ + T_d\dfrac{d\varepsilon}{dt}) $$
You can see, ...
3
Double-check your directions and signs. Which direction of roll/pitch/yaw is considered "positive" on your sensors? Which direction does the drone move for a "positive" command of roll/pitch/yaw? And when you calculate error, are you inadvertently doing "measured minus target" instead of "target minus measured"?
If your system is going unstable for even ...
3
Well...the first approach seems rather messy doesn't it? Not only are you sampling at unpredictable positions in the cycle, but you are increasing the processing load by having more samples to deal with.
Plus you are probably only going to be updating once per PWM cycle at most anyways...so is your latency really any better? What good is all that extra ...
2
Figure 1. From the datasheet we can see that the leakage current is 7 mA.
A 12 W lamp will draw \$ I = \frac P V = \frac {12}{240} = 50 \ \text {mA} \$ (using 240 V to make the maths easy). 7 mA is a significant current for this lamp.
When control inputs are not connected there is a drop of around 180 V across the relay. Why is this?
That's the voltage ...
1
I don't have Matlab, but looking at their online help for c2d and c2dOptions:
'FractDelayApproxOrder'
Maximum order of the Thiran filter used to approximate fractional delays in the 'tustin' and 'matched' methods. Takes integer values. A value of 0 means that c2d rounds fractional delays to the nearest integer multiple of the sample time.
So, ...
1
Using proportional only, the longer you drive, the more angular momentum you will build up. The system apparently lacks sufficient inherent damping, so proportional-only control will oscillate as it starts applying more and more accumulated torque in each iteration. Derivative (effectively controlled damping) helps control for this, but another likely ...
1
I'm surprised this doesn't have an adequate answer after all this time. Yes, physical components do have pole and zero behavior. We exploit this behavior build analog PID systems.nRLC circuits are used to implement simple lead and lag compensators, here is a photo of one taken from Stevens and Lewis Aircraft Control and Simulation
Here we can see that the ...
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