Commit Graph

7 Commits

Author SHA1 Message Date
Yuval Tassa c004d144d1 Correct DC motor derivative calculation and enforce actearly.
PiperOrigin-RevId: 898983657
Change-Id: I008529eacf3e400696d26bd3a52a4cf4c1c12225
2026-04-13 10:56:58 -07:00
Yuval Tassa 81720071b8 Changes to dcmotor:
- 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
2026-04-09 06:52:45 -07:00
Yuval Tassa 70a7647ad9 Add <dcmotor> actuator and related docs and tests.
PiperOrigin-RevId: 892927987
Change-Id: I38ed6412801341ba03ddf5fe7b93a6081df24d37
2026-04-01 07:50:23 -07:00
Yuval Tassa c50177d301 Add mjd_inverseFD for finite-difference approximations of inverse dynamics Jacobians.
Fixes #703.

PiperOrigin-RevId: 527899700
Change-Id: I10e41a381dcecf62c53b3b9aa72a4ce666161366
2023-04-28 09:04:41 -07:00
Yuval Tassa ea956dfe34 Derivatives of ellipsoid fluid model.
PiperOrigin-RevId: 459751881
Change-Id: I52db87d82e20e10698b13065df2e983b9841bd7a
2022-07-08 07:19:48 -07:00
Yuval Tassa 228264c92b Add efficient finite-difference Jacobians of mj_step.
- Add `qH` and `qHDiagInv` to `mjData` to save factorized modified inertia.
- Add `mj_EulerSkip`, `mj_implicitSkip`, to `engine_forward.c`.
- Using the above functions, implement `mj_stepSkip` in `engine_derivative.c`.
- Add `mjd_stepFD` and `mjd_transitionFD` to `engine_derivative.c` to compute `mj_step` Jacobians.
  - Exploit "Skip" functionality for speed.
  - Correctly handle quaternion derivatives.
  - Handle warmstarts and control limits.

PiperOrigin-RevId: 456584811
Change-Id: Iee8541f11e7b66feb8f431cb102d9bbe65461f79
2022-06-22 12:48:48 -07:00
DeepMind 64bc6d27b2 Add implicit integrator.
Added analytic derivatives of smooth (unconstrained) dynamics forces, with respect to velocities:
  - Centripetal and Coriolis forces computed by the Recursive Newton-Euler algorithm.
  - Damping and fluid-drag passive forces.
  - Actuation forces.

A new implicit-in-velocity integrator is implemented using the analytic derivatives. This integrator lies between the Euler and Runge Kutta integrators in terms of both stability and computational cost.

PiperOrigin-RevId: 450377010
Change-Id: Ie192b441876c22e732fb749333926f296e0a09cc
2022-05-23 01:22:15 -07:00