chenlin/Mujoco_WASM
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Changes to dcmotor:

Browse Source 
- Remove `lugre:viscous`, should now be added directly to actuator `damping`. Trying to do this for the user was incompatible with default inheritance (compounding instead of overriding).
- Move voltage limiting from the `saturation` to the `controller` attribute.
- Fix indexing issues in default inheritance.

PiperOrigin-RevId: 897087642
Change-Id: I5388c2633e15c7e223992e7eb5d6a28db75a6438
This commit is contained in:
Yuval Tassa
2026-04-09 06:51:57 -07:00
committed by Copybara-Service
parent 26fb65c7a7
commit 81720071b8
14 changed files with 335 additions and 85 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/user/user_api.cc
+16 -16
View File
@@ -1122,9 +1122,9 @@ const char* mjs_setToAdhesion(mjsActuator* actuator, double gain) {
const char* mjs_setToDCMotor(mjsActuator* actuator, double motorconst[2], double resistance,
double nominal[3], double saturation[4], double inductance[2],
double cogging[3], double controller[5], double thermal[6],
double lugre[6], int input_mode) {
double nominal[3], double saturation[3], double inductance[2],
double cogging[3], double controller[6], double thermal[6],
double lugre[5], int input_mode) {
double R = resistance; // electrical resistance
double Kt = motorconst ? motorconst[0] : 0; // torque constant
double Ke = motorconst ? motorconst[1] : 0; // back-EMF constant
@@ -1134,9 +1134,8 @@ const char* mjs_setToDCMotor(mjsActuator* actuator, double motorconst[2], double
// derive Ke from nominal: omega0 = vn*Ke / (Ke^2 + R*B)
if (vn > 0 && Ke <= 0 && omega0 > 0) {
// viscous damping (linear), add lugre sigma2 contribution if any
// viscous damping (linear)
double B = actuator->damping[0];
if (lugre && lugre[0] > 0) B += lugre[2];
if (B > 0 && R > 0) {
// R known: solve quadratic Ke^2*omega0 - Ke*vn + R*B*omega0 = 0
@@ -1184,12 +1183,9 @@ const char* mjs_setToDCMotor(mjsActuator* actuator, double motorconst[2], double
actuator->dynprm[7] = controller ? controller[3] : 0; // slewmax
actuator->dynprm[8] = controller ? controller[4] : 0; // Imax
// saturation: [tau_max, i_max, (di/dt)_max, v_max]
if (saturation && saturation[2] > 0) {
actuator->dynprm[1] = saturation[2]; // (di/dt)_max
}
if (saturation && saturation[3] > 0) {
actuator->gainprm[7] = saturation[3]; // v_max
// controller parameters: gainprm[7] for v_max
if (controller && controller[5] > 0) {
actuator->gainprm[7] = controller[5]; // v_max
}
// saturation -> forcerange
@@ -1203,6 +1199,11 @@ const char* mjs_setToDCMotor(mjsActuator* actuator, double motorconst[2], double
actuator->forcelimited = 1;
}
// saturation: [tau_max, i_max, (di/dt)_max]
if (saturation && saturation[2] > 0) {
actuator->dynprm[1] = saturation[2]; // (di/dt)_max
}
// cogging: [amplitude, periodicity, phase] -> biasprm[0:3]
actuator->biasprm[0] = cogging ? cogging[0] : 0; // amplitude
actuator->biasprm[1] = cogging ? cogging[1] : 0; // periodicity
@@ -1258,14 +1259,13 @@ const char* mjs_setToDCMotor(mjsActuator* actuator, double motorconst[2], double
actdim++;
}
// lugre: {stiffness, damping, viscous, coulomb, static, stribeck}
// lugre: {stiffness, damping, coulomb, static, stribeck}
if (lugre && lugre[0] > 0) {
actuator->dynprm[5] = lugre[0]; // stiffness -> sigma0
actuator->dynprm[6] = lugre[1]; // damping -> sigma1
actuator->damping[0] += lugre[2]; // viscous -> sigma2
actuator->biasprm[3] = lugre[3]; // coulomb -> tau_c
actuator->biasprm[4] = lugre[4]; // static -> tau_s
actuator->biasprm[5] = lugre[5]; // stribeck -> omega_s
actuator->biasprm[3] = lugre[2]; // coulomb -> tau_c
actuator->biasprm[4] = lugre[3]; // static -> tau_s
actuator->biasprm[5] = lugre[4]; // stribeck -> omega_s
actdim++;
}