Abstract: The present invention provides for electronic braking of DC brushless motors by developing a feedback signal based on the back EMF of the motor. This feedback signal is used to provide a signal to the motor permitting current flow from the motor into the controller of a controlled level to slow the motor down. Reliance on the back EMF of the motor eliminates the need for a commutation signal when an emergency stop is required.

Abstract: An autotuning procedure for a PID-type controller employs a low frequency sine wave as an exciting input and models the controlled system as a second order linear system. The system is tuned to a desired damping ratio by following an overdamped trajectory, in closed loop gain and phase lag space, to the target closed loop gain and phase lag values on a locus of a desired damping ratio as based on that modeling system.

Abstract: A method for control of servomotors includes limiting velocity feedforward as a second input to a velocity control loop in response to a velocity command, which is a first input, reaching a predetermined limit. Gain parameters for proportional and integral portions of a velocity-torque control loop and for the proportional and integral portions of the velocity feedforward loop may be adjusted independently to obtain varying control responses from the control system. The method is carried out in a microcomputer-based control module for an industrial controller.