Robot Arm Force/Torque Compliance Control

A wrist-mounted force/torque sensor is the difference between a robot arm that can pick up an egg and one that crushes it. This simulator drives a 2-link robot arm's end-effector with an impedance controller — a virtual spring-damper law, m ẍ + D(ẋ − ẋ_ref) + K(x − x_ref) = F_env — that presses down onto a compliant surface instead of commanding a raw position. Tune the controller's commanded stiffness and damping, choose how soft or rigid the surface is, and press to watch the sensed contact force settle toward the series-spring prediction F_ss = K·k_env/(K+k_env)·d while the arm's joint torques update live via the manipulator Jacobian, τ = J^TF — exactly the relation real torque-controlled joints use to hold a safe contact force.