/Kinematics-UR5e-arm

Primary LanguageC++

Kinematics for a UR5e arm

Run simulation

  • run

     mkdir build
 cd build
 cmake ..

  • execute

     ./examples/inverse_kinematics_mujoco [ur5e_model_file_path] [target coordinates in R^3]

Overview

This project contains a forward kinematics and an inverse kinematics solution for a UR5e.

The library analytical_ik.h contains these main functions:

  • int inverse_kinematics_2PI(double *q_sols, double x, double y, double z);

  • int inverse_kinematics(double *q_sols, double x, double y, double z);

  • std::tuple<double, double, double> forward_kinematics(double *q);

  • void joint_jacobian(double *jacobian, double *q);

Furthermore he last two functions have their version for each joint.

The joint_jacobian() function returns the jacobian for the end-effector.

The forward_kinematics() function returns the coordinates of a point in the R^3 space of the position of the end-effector or the UR5e arm, for a given configuration of it's joint positions.

The inverse_kinematics() functions count the inverse kinematics for the UR5e arm - given a point in the R^3 space, the functions will return (in the parameter q_sols) the joint positions which will position the arm, so that it's end-effector is located in that point.

Both functions return an integer indicating the number of inverse kinematics solutions.

The inverse_kinematics() function counts the joint positions in the interval [-PI ; PI] and the inverse_kinematics_2PI() function counts the joint positions in the interval [0 ; 2 * PI]

We base our analytical solution of forward and inverse functions on Kelsey P. Hawkins' paper "Analytic Inverse Kinematics for the Universal Robots UR-5/UR-10 Arms" and his implementation of it https://github.com/ros-industrial/universal_robot/blob/kinetic-devel/ur_kinematics/src/ur_kin.cpp.