sai-primitives

This is a control library that provides an implementation of basic tasks and controllers for a torque controlled robot. It uses the Operatinal Space framework. It offers the possibility to be used with the Ruckig for trajectory generation (community version).

Robot controllers can be defined using different tasks:

• The MotionForce task is a cartesian control task, defined on a robot and a compliant frame:
  • It can be full 6dof (translation and rotation) or a subset of the cartesian motions (for example a planar transation and 1 rotation in that plane)
  • It can be set to use operational space control or impedance control
  • Any direction (defined in robot base frame or compliant frame) can be parametrized to perform force control instead of motion control
  • Force control can be open loop or closed loop with passivity based stabilization (https://ieeexplore.ieee.org/abstract/document/7989050, https://ieeexplore.ieee.org/abstract/document/8206036)
• The joint task implements PD control to control the joint positions of a torque controlled robot:
  • It can be full or defined on a subset of the joints
  • It can be parametrixed to use dynamic decoupling or not

The robot controller then takes a list of tasks and implements a hierarchical controller using all the tasks to compute the robot control torques

Dependencies

sai-primitives depends on sai-model, Eigen3 and Ruckig.

The examples depend on additional libraries : sai-simulation, sai-graphics, sai-common.

Build instructions

First build ruckig:

cd ruckig
mkdir build && cd build
cmake .. && make -j4
cd ../..

Next, build sai-primitives

mkdir build
cd build
cmake .. && make -j4

Run the examples

Remember that you need sai-simulation, sai-graphics and sai-common in order to compile and run the examples. Go to build/examples/desired_example and run the example. For example 1 :

cd build/examples/01-joint_control
./01-joint_control

Documentation

The documentation can also be accessed online at the following link

It can also be generated locally with doxygen:

cd docs
doxygen

License

This software is distributed under the terms of the Stanford Academic Software License Agreement For SAI