Impedance control method, and controller and robot using the same

A controller for a robotic arm, comprising:

• a processor;
• a memory coupled to the processor, and
• one or more computer programs stored in the memory and executable on the processor;
• wherein, the one or more computer programs comprise:
• instructions for obtaining current joint motion information and current joint force information in a joint space of the robotic arm and an actual interaction force acting on an end-effector of the robotic arm, and calculating actual motion information of the end-effector in a task space of the robotic arm based on the joint motion information through forward kinematics;
• instructions for calculating a corrected desired trajectory of the end-effector using current environment information and a pre-planned desired end-effector interaction force in the task space, and calculating the impedance control torque of the robotic arm in the joint space based on the joint force information, the actual interaction force, the actual motion information of the end-effector, and desired end-effector information including the corrected desired trajectory;
• instructions for constructing a dynamics equation of the robotic arm, and determining a compensation torque based on a nonlinear term in the dynamics equation;
• and
• instructions for performing a joint torque control on the robotic arm based on the impedance control torque and the compensation torque.

A robot comprising a controller, wherein the controller comprises:

• a processor;
• a memory coupled to the processor;
• and
• one or more computer programs stored in the memory and executable on the processor;
• wherein, the one or more computer programs comprise:
• instructions for obtaining current joint motion information and current joint force information in a joint space of the robotic arm and an actual interaction force acting on an end-effector of the robotic arm, and calculating actual motion information of the end-effector in a task space of the robotic arm based on the joint motion information through forward kinematics;
• instructions for calculating a corrected desired trajectory of the end-effector using current environment information and a pre-planned desired end-effector interaction force in the task space, and calculating the impedance control torque of the robotic arm in the joint space based on the joint force information, the actual interaction force, the actual motion information of the end-effector, and desired end-effector information including the corrected desired trajectory;
• instructions for constructing a dynamics equation of the robotic arm, and determining a compensation torque based on a nonlinear term in the dynamics equation;
• and
• instructions for performing a joint torque control on the robotic arm based on the impedance control torque and the compensation torque.