Patent ID: 7855525
Filing Date: 2010-12-21
Classification: G05B

Abstract:
1. A method of operating an actuator having a motor wherein the actuator is coupled to a manipulated device that is configured to travel through a range of motion limited by first and second mechanical stops located at opposing low and high ends of such range, said method comprising the steps of: determining an error signal between a commanded actuator position and a present actuator position; determining a candidate level for a drive signal for use in driving the motor as a function of the determined error signal and a predetermined control strategy; limiting the candidate level of the drive signal level so as to not exceed a predetermined maximum level when a holding force limit flag is set, the predetermined maximum level corresponding to a predetermined holding effort of the manipulated device against one of the mechanical stops; and controlling the drive signal driving the motor at the predetermined maximum level such that the actuator pushes the manipulated device against one of the mechanical stops with the predetermined holding force after reaching the mechanical stop.