The present invention is a method and system for detecting position errors in robotic motion According to the method, a Doppler motion detector unit is placed proximate a critical position of a robot. Signals from the Doppler motion detector unit are monitored. Robot position errors are detected in the robot at least partially based on the signals from the Doppler motion detector unit. The industrial robot can be halted upon detection of an error and/or an alarm signal can be activated. The system includes the robot, the detector with a low-pass filter and a control system operatively connected to the detector and low-pass filter.