Nimrod Gileadi
c062a8db19
Maintain separate state for each actuator in the Plugin object. PiperOrigin-RevId: 587760569 Change-Id: I633a1b94f0dde9377120145066a26aef6a4033b8
Actuator plugins
PID
The mujoco.pid actuator plugin implements a configurable PID controller:
f(t) = K_\text{p} e(t) + K_\text{i} \int_0^t e(\tau) \,\mathrm{d}\tau + K_\text{d} \frac{\mathrm{d}e(t)}{\mathrm{d}t},
where e(t) = u(t) - \ell(t) is the difference between the control u and the actuator length \ell.
You can use it like:
<mujoco>
<extension>
<plugin plugin="mujoco.pid">
<instance name="pid">
<config key="kp" value="40.0"/>
<config key="ki" value="40"/>
<config key="kd" value="4"/>
<config key="slewmax" value="3" />
<config key="imax" value="1"/>
</instance>
</plugin>
</extension>
<worldbody>
<body>
<joint name="j" type="slide" axis="0 0 1" />
<geom size="0.01" mass="1"/>
</body>
</worldbody>
<actuator>
<plugin joint="j" plugin="mujoco.pid" instance="pid" />
</actuator>
</mujoco>
The available options are:
| Attribute | Default | Meaning |
|---|---|---|
kp |
0 | P gain for the controller. |
ki |
0 | I gain for the controller. |
- : : : :
: :If nonzero, one activation variable will be added to `mjData.act`, containing the current I term (in units of force). :- |
kd|0 |D gain for the controller. | - |
imax|Optional|If specified, the force produced by the I term will be clipped to the range[-imax, -imax]. | - |
slewmax|Optional|The maximum rate at which the setpoint for the PID controller can change. | : : :: :If a bigger change is requested between two timesteps, it will be clipped to the range `[ctrl - slewmax * dt, ctrl + slewmax * dt]` :: : :: :If specified, one activation variable will be added to `mjData.act` containing the previous value of `ctrl`. :