Commit Graph

14 Commits

Author SHA1 Message Date
Alessio Quaglino d26501c0f3 Add two new attributes to weld constraints:
- `anchor` determines the point of wrench application, in the frame of body2.
- `tfratio` scales applied torques relative to applied forces.
- Add visualisation of both anchor points to both weld and connect constraints.
- Add a test model showing how the new weld parameters behave.

PiperOrigin-RevId: 470021901
Change-Id: I3faba0e5dcab2e29ee81096f5ff71ff66d99758c
2022-08-25 10:22:15 -07:00
Alessio Quaglino abc0a39b7a Add two new attributes to weld constraints:
- `anchor` determines the point of wrench application, in the frame of body2.
- `tfratio` scales applied torques relative to applied forces.
- Add visualisation of both anchor points to both weld and connect constraints.
- Add a test model showing how the new weld parameters behave.

PiperOrigin-RevId: 469228149
Change-Id: I836b0791f10fb624607a12ef3c687da991c21789
2022-08-22 10:46:46 -07:00
Alessio Quaglino 8ca5887c20 Add two new attributes to weld constraints:
- `anchor` determines the point of wrench application, in the frame of body2.
- `tfratio` scales applied torques relative to applied forces.
- Add visualisation of both anchor points to both weld and connect constraints.
- Add a test model showing how the new weld parameters behave.

PiperOrigin-RevId: 469190483
Change-Id: I20f6da85b09cd2c4c0b5d29eb8003eabb524e55e
2022-08-22 08:19:22 -07:00
Yuval Tassa ae0ac86ec3 Add catenary visualisation to string-like tendons.
https://youtu.be/I2q7D0Vda-A

PiperOrigin-RevId: 468687422
Change-Id: I84f34e149cf098346a77a51f265113d8fa4f2525
2022-08-19 06:25:07 -07:00
Yuval Tassa ea956dfe34 Derivatives of ellipsoid fluid model.
PiperOrigin-RevId: 459751881
Change-Id: I52db87d82e20e10698b13065df2e983b9841bd7a
2022-07-08 07:19:48 -07:00
Alessio Quaglino 2d0995b47c Add visualisation groups to skins.
PiperOrigin-RevId: 458441645
Change-Id: I14324e8efda5142b2718a5cc9215228c7556dbf7
2022-07-01 04:57:34 -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
Alessio Quaglino 307cf692e5 Add <damper> actuator shortcut and related mjGAIN_AFFINE.
**Rationale**

A general `mjGAIN_AFFINE` actuator adds the term `force = (c + kp * length + kv * velocity) * ctrl`. The damper shortcut restricts it to `kv * velocity * ctrl` and sets the `ctrllimited` attribute to true.

**API**

```xml
<actuator>
  <damper ctrlrange="0 1" kv="1"/>
</actuator>
```

* Required attributes: `ctrlrange` (>=0)
* Optional attributes: `kv` (>=0)

PiperOrigin-RevId: 455366866
Change-Id: I88773abbeccabb6442f215c9fc05e205df63f692
2022-06-16 06:21:17 -07:00
Alessio Quaglino 6ead14614f Adds rendering of ball and free joints actuators using an inflated joint geometry.
PiperOrigin-RevId: 453939612
Change-Id: I621f91d242b2974e6ae6acf239cdcb10efcb2629
2022-06-09 09:10:03 -07:00
Alessio Quaglino 066367fcc8 Add visualisation flag for activations.
- Added illustrative model: `test/engine/testdata/activation.xml`

PiperOrigin-RevId: 453628961
Change-Id: I061ec3d17e57c6baffa0fe446a0be3564c44519d
2022-06-08 02:19:03 -07:00
Alessio Quaglino 736e0b391b Added visualization of site actuators.
PiperOrigin-RevId: 453609866
Change-Id: Icde220687f0c0e9e7fbbe0e3e56d995f823ffe07
2022-06-07 23:59:06 -07:00
Alessio Quaglino f3453cf87f Stricter parsing of XML array attributes.
PiperOrigin-RevId: 451456510
Change-Id: I2556d4365762378261c04d3c9f1942166fbd156e
2022-05-27 12:51:02 -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
Saran Tunyasuvunakool 1913a02b40 Initial open sourcing of MuJoCo.
PiperOrigin-RevId: 450374687
Change-Id: Ie3225a46ce095fc28ae8e63c326a640261f562bb
2022-05-23 01:08:49 -07:00