A method, device, and computer program product for compensating robot movement deviations caused by a gear box as well as to a robot arrangement including such a device. The device has a drift estimating block configured to obtain motor data ({dot over (q)}.sub.r) and motor torque data () related to the motor, determine a measure of the temperature of the gear box based on the motor data ({dot over (q)}.sub.r) and motor torque data () and estimate the drift (q) based on a drift value of the robot section, the drift value in turn being obtained based on the gearbox temperature measure and a gravitational torque (.sub.grav) of the motor, and a drift adjusting block (44) configured to adjust a control value (q.sub.r) used to control the positioning of the robot based on the estimated drift (q).

A method, device, and computer program product for compensating robot movement deviations caused by a gear box as well as to a robot arrangement including such a device. The device has a drift estimating block configured to obtain motor data ({dot over (q)}.sub.r) and motor torque data () related to the motor, determine a measure of the temperature of the gear box based on the motor data ({dot over (q)}.sub.r) and motor torque data () and estimate the drift (q) based on a drift value of the robot section, the drift value in turn being obtained based on the gearbox temperature measure and a gravitational torque (.sub.grav) of the motor, and a drift adjusting block (44) configured to adjust a control value (q.sub.r) used to control the positioning of the robot based on the estimated drift (q).

Methods and apparatus for adjusting and controlling a robotic manipulator based on a dynamic manipulator model. A model for gear mechanism friction torque is determined for at least one axis, based on driven axis speeds and accelerations, and on a motor temperature on the drive side of one of the motors that is associated with the axis. The model is used to determine target values, such as motor position or current. The gear mechanism friction torque that complies with the model is determined in accordance with a gear mechanism temperature.