jaco-mpc

This repository basically reimplements the parallel motion planning architecture [1] on a Kinova-jaco arm to guarantee both safety and efficiency. The implementation is done in a simulation platform——vrep, but it can also be easily transferred to a real Kinova arm.

In the motion planning problem, the end effecter is required to fetch a dynamic target, while collision is required to be avoided between the arm and a dynamic obstacle. Considering no static obstacle, global planning can be simply handled in real time with a trajectory generator; local planner leverages Safety Set Algorithm(SSA)[2] to modify the trajectory dynamically to ensure safety.

The motion planning problem is formulated in a kinematic form. On a real robot, the embedded controller has taken care of the low-level control, and thus the end effector can track the planner trajectory by giving velocity commands. In vrep, even though we don't have a great low-level controller, we still ignore the effect of dynamics by throwing away the robot hand.

[1] https://arxiv.org/pdf/1808.03983.pdf

[2] http://www.cs.cmu.edu/~cliu6/files/dscc14.pdf

Dependencies

• ros kinetic
• vrep 3.2.1

Contents

The repository consists of two folders, kinova-ros-modified and kinova_planning, and one "ttt" file.

kinova-ros-modified

kinova-ros-modified is modified from official ros packages of Kinova-jaco. The ros package of greatest interest is kinova_driver. The source code files modified are:

• src
  • kinova_fake_joint_trajectory_controller.cpp
  • joint_trajectory_action
    • fake_joint_trajectory_action_server.cpp
  • nodes
    • kinova_arm_driver.cpp

kinova_planning

kinova_planning includes the main program which solves the motion planning problem as well as the launch files to start the whole process. The files mainly come into effect are:

• src
  • base_planning.cpp
• scripts
  • qp_solver.py
• launch
  • kinova_planning.launch
  • trajectory_follower.launch

kinova.ttt

kinova.ttt can be opened in vrep. It builds the scene and serves as the plant in the planning simulation.

How to use

1. Open kinova.ttt with vrep and start the simulation.
2. Launch trajectory_follower.launch
3. Launch kinova_planning.launch