- Adhesion actuators using contact normals as force transmission mechanism.
- Related video: https://youtu.be/HdBue4MUZysCloses#229
PiperOrigin-RevId: 464389367
Change-Id: I9f69b3cd152d957e8f65870d208788463c036a6d
- Never modify `d->ctrl`:
- `ctrl` values which are outside their respective `ctrlrange` are clamped internally, but `d->ctrl` itself is unmodified.
- Similarly, if `mjWARN_BADCTRL` is raised (NaNs or huge values), `ctrl` is cleared internally, but `d->ctrl` itself is unmodified.
- `mjWARN_BADCTRL` is no longer raised for `d->ctrl` values that are larger in absolute value than `mjMAXVAL`, if clamping makes them smaller than that.
- Added `mju_clip()` utility function.
- Added missing warning string for `case mjWARN_BADCTRL`.
PiperOrigin-RevId: 459025950
Change-Id: Ifbf974f9c02c3d70afdaa3114018fc81dfd746d3
- 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
- Introduced private function `mj_advance()` as single point of state & time advancement.
PiperOrigin-RevId: 456525969
Change-Id: Iae17217e305c7baf07cb5ecd1e1b84b936421097
The introduction of additional mjData arrays for the implicit integrator caused in a shift in data alignment in memory. In certain combinations of machines and models, this change resulted in ~5% performance regression that appears to be attributable to L2 cache misses.
This change aligns all arrays in mjData to the boundary of a typical L2 cache line size. Benchmarking shows that this resolves the performance regression on a Broadwell machine.
PiperOrigin-RevId: 451652783
Change-Id: I4ed2c2d03453a83a0b4a9b8e224e2fd7c0dadea9
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
Yuval Tassa