Visteon Global Technolgoies, Inc.

Ashraf A Zeid

Darrel Alan Recker

Robert A Stopper

Dale Killins

Qiusheng Zhang

A power steering system includes at least one motor to assist the operator of a vehicle in turning the wheels and steering the vehicle and at least one computer or microprocessor controller. One of the processors adjusts the motor assist torque to reduce the driver effort based on specified requirements defined by boost curves. A second microprocessor controller uses an algorithm to calculate the output of the power steering motor, and compare the relationship between the driver torque and the power assist torque. If the relationship between the two is out of specified bounds, then the power steering assist is deemed inappropriate and the power system may go to a power-off state to assure that the motor does not generate an undesirable torque that has not been requested by the driver.

Electric power assist torque check

A motor controller for regulating the speed and limiting the input current to a dc motor is disclosed. The motor controller includes an electronic control unit, a current sensor and a speed sensor. The motor controller provides control of the dc motor by applying a varying voltage to maintain a motor speed in the presence of a varying load. The motor controller also monitors the input current to the dc motor to predict an input current to the dc motor. The ECU compares the predicted input current to a input current limit range and switches to a current-limiting mode when it determines that an overcurrent condition is reached based on the comparison. The motor controller modifies the control signal by a first control decay factor when the predicted input current exceeds the input current limit range. The motor controller modifies the control signal by a second control decay factor when the predicted input current is within the input current limit range level. When the input current has stabilized less than the input current limit range, the motor controller modifies a target motor speed to returns to a speed-regulating mode.

Growing community of inventors

Troy, MI, United States of America

Ashraf A Zeid