Programming and execution of force-based tasks with torque-controlled robot arms

A non-transitory computer readable memory having stored thereon instructions that, when executed by a computing device, cause the computing device to perform functions comprising:

• receiving task information defining (i) a nominal trajectory for an end-effector coupled to a manipulator of a robotic device, and (ii) forces to be exerted by the end-effector at points along the nominal trajectory, wherein the robotic device includes a joint coupled to the manipulator;
• determining, based on the task information, a modified trajectory that is offset from the nominal trajectory so as to cause the forces to be exerted by the end-effector;
• determining, based on the modified trajectory and the forces, torques to be applied to the manipulator via the joint of the robotic device over time;
• causing the torques to be applied to the manipulator via the joint so as to cause the end-effector to follow the modified trajectory and substantially exert the forces along the modified trajectory;
• as the end-effector follows the modified trajectory, receiving force feedback information from a sensor coupled to the robotic device indicating respective forces being experienced by the end-effector at respective points along the modified trajectory;
• and
• adjusting the torques to be applied to the manipulator based on the force feedback information as the end-effector follows the modified trajectory.

A robotic device, comprising:

• a manipulator;
• an end-effector coupled to the manipulator;
• a sensor;
• a joint coupled to the manipulator;
• one or more processors;
• and
• memory configured to store instructions, that when executed by the one or more processors, cause the robotic device to perform functions comprising:
• receiving task information defining (i) a nominal trajectory for the end-effector, and (ii) forces to be exerted by the end-effector at points along the nominal trajectory;
• determining, based on the task information, a modified trajectory that is offset from the nominal trajectory so as to cause the forces to be exerted by the end-effector;
• determining, based on the modified trajectory and the forces, torques to be applied to the manipulator via the joint over time;
• causing the torques to be applied to the manipulator via the joint so as to cause the end-effector to follow the modified trajectory and substantially exert the forces along the modified trajectory;
• as the end-effector follows the modified trajectory, receiving force feedback information from the sensor indicating respective forces being experienced by the end-effector at respective points along the modified trajectory;
• and
• adjusting the torques to be applied to the manipulator based on the force feedback information as the end-effector follows the modified trajectory.