Jiminy-py

Another small release consisting mainly in bug fixes. In addition, a new type of pre-defined visco-elastic coupling force has been added, acting independently in each direction instead of only along coupling direction.

New features

* [core] Add non-directional visco-elastic coupling force (acting independently in each direction).

Improvements
* [core] Fix adaptive RK dopri stepper MAX_FACTOR wrongly scaled by SAFETY factor.
* [gym/common/envs] Do not log internal steps in debug mode to keep log consistent with experience replay.

Bug fixes

* [core] Fix visco-elastic directional coupling force.
* [core] Fix pinocchio_data updated with joint forces not taking into account the external forces.
* [core] Fix telemetry logging failed internal stepper steps.
* [core] Fix wrong computation of multi-systems coupling forces.
* [python/viewer] Fix replay using rigid instead of flexible model.
* [python/viewer] Fix mesh path on windows.

Miscellaneous

* [gym/common] Rename 'size' argument of 'sample' method in 'shape' for consistency with standard API.

Tiny release to fix a critical bug causing corruption of sensors data (IMU, Force Sensors, and Contact Sensors).

Bug fixes

* [core] Fix joints accel/force restored right after computations instead of before sensor update.

Miscellaneous

* [misc] Check no memory allocation by Eigen during simulation.
* [misc] Update Eigen to latest release (3.3.9) on CI.

Simulation speed has been increased by at least 15%, mainly avoiding memory allocation during simulation, postponing accelerations and forces updates until successful stepper step, and not computing all terms for internal stepper steps.

* [core] Avoid algebraic loop in internal stepper steps by postponing accel/force updates after successful outer step.
* [core] Move centroidal kinematics computations in stepper outer loop for efficiency.
* [core] Assume slow variation of subtree inertia during one integration step for efficiency.
* [core] Avoid memory allocation for 'computeAcceleration', 'updateTelemetry' and 'computeAllEffort'.
* [misc] Fix double_pendulum c++ example using Eigen::Ref for controller handles instead of vectorN_t.

Simulation speed has been increased by at least 15% by avoiding the stepper to allocate memory dynamically once a simulation has started.

Improvements

* [gym] Use float32 action space instead of float64 because it is the usual dtype for neural networks.
* [core] Avoid memory allocation during Lie algebra computations without relying on compiler optimizations.

Miscellaneous

* [misc] Update Cmake to support RelWithDebInfo. Enable more Cmake warnings.

This release makes it possible to add visco-elastic (spring-damper mechanism) coupling force between two frame on the same or different robots, without having to implement them manually. It brings a huge speedup wrt doing it in Python (even using Numba). In addition, a few redundant computations have been removed, resulting in a minor overall speedup.

New features
* [core] Add viscoelastic coupling force between frames.

Improvements
* [core] Disable stepper 'iterMax' by default.
* [core] Abort simulation if 'nan' detected in 'q', 'v', 'a' instead of 'a' only.
* [core] Increase maximum simulation timestep.
* [core] Do not call rnea directly in 'computeAcceleration' to avoid redundant computations.
* [python/controller] Improve efficiency by making controller/observer handles optional.
* [gym/common/env] Return is_done=True if simulation is not running anymore.
* [gym/common/env] Use OrderedDict instead of dict to avoid conflicts with ray[rllib].

Bug fixes
* [core] Fix segfault when initializing sensor using unvalid robot.
* [core] Fix Euler Explicit stepper not working as expected.
* [python] Fix potential infinite recursion loop during custom attribute lookup.
* [python/log] Fix 'Global.Time' not in seconds when reading hdf5 logfiles.
* [python/viewer] Fix legend warning wrongly displayed.
* [gym/common/wrapper] Rework 'PartialFrameStack' to be consistent with official 'FilterStack'.

Miscellaneous
* [misc] Update gitignore to ignore log folders.
* [misc] Increase stepper tolerance in unit test to be consistent with check accuracy.
* [misc] Fix new Cmake policy CMP0111.
* [misc] Fix type checking to support latest mypy/pylint releases.
* [misc] Assume pip 21.0 for Cmake and install it on Windows CI. Minor improvements of Cmake files.
* [misc] Remove useless boost submodules dependencies.
* [misc] Do NOT support Numpy >= 1.20 explicitly, since not compatible with Python3.6.
* [misc] Fix toy model learning unit tests.

Co-authored-by: Alexis Duburcq <alexis.duburcqwandercraft.eu>

This release fixes the long lasting issue of robot getting deleted without letting know the others relying on it, causing erratic segfaults hard to diagnose. It also adds several mechanisms to ensure the consistency of the data, and proper update of low-level `pinocchio::Data`, to avoid having to manually update anything that the user may expect already having been computing. It comes at an addition computational burden, but it is the price to pay to avoid nasty mistakes.

New features

* [core/python] Enable to define custom constraints directly in Python.

Improvements

* [core] Use std::weak_ptr instead of raw pointer to avoid segfault if object gets destroyed in the meantime.
* [core] Make sure controller's robot and system's robot are consistent when add system to engine.
* [core] Refactor constraints to improve efficiency and make it more intuitive to define and use.
* [core] Fix joint acceleration not properly updated after calling 'computeAcceleration' method of Engine.
* [core/python] Add 'BaseControllerFunctor', allowing overloading of 'reset' method in Python.
* [python/simulator] Avoid attribute lookup infinite loop.
* [python/simulator] Ensure consistent model between robot model and log data before plotting them.
* [gym/common/env] Set the controller before resetting it and getting sensors data since the robot may no longer exists.

Miscellaneous

* [core/python] Rename 'AbstractControllerWrapper' in 'BaseController' to clarify it is not abstract but the base controller class.
* [python/controller] Inherit from 'BaseController' instead of 'BaseControllerFunctor' since callbacks are handled manually.