gravity compensation
Gravity compensation is the calculation and application of motor torques needed to counteract gravity, allowing a robot to hold its configuration without drooping or sagging. By computing the gravitational force acting on each link and converting it to required joint torques, the robot maintains stable positions even without active motion—as if each joint were mechanically locked against gravity.
Simple idea: Calculate how much each motor must "push" to keep the robot suspended in its current pose, then apply those torques continuously.
Key Takeaway
Gravity compensation is the "anti-sag controller"—a model-based or sensor-based technique that calculates and applies motor torques to counteract gravitational forces on the robot structure. By computing the exact torque needed to balance gravity at each joint configuration and adding it to normal control commands, gravity compensation allows robots to maintain stable poses with minimal power while giving PID controllers "clean" error signals to work with. It's a fundamental technique in industrial robotics, enabling energy-efficient operation, smooth motion, and precise position control.
Share: