Abstract: A method of transitioning a motor from a torque control mode to a speed control mode includes providing the motor with a torque command to eliminate torque holes at the transition. A speed controller generates a speed error, which is used to generate two torque terms. The first torque term is proportional to the speed error, and the second torque term includes the integral of the speed error. A third torque term comprises a feedforward torque, which is added to the first two torque terms to generate the torque command.

Abstract: A method of transitioning a motor from a torque control mode to a speed control mode includes providing the motor with a torque command to eliminate torque holes at the transition. A speed controller generates a speed error, which is used to generate two torque terms. The first torque term is proportional to the speed error, and the second torque term includes the integral of the speed error. A third torque term comprises a feedforward torque, which is added to the first two torque terms to generate the torque command.

Abstract: A battery current limiter and current-limiting method for a battery system and an electric motor in a hybrid automotive vehicle powertrain. The battery current limiter monitors measured battery current and torque commands. A modified current is developed to take a predetermined current margin into account. The modified current reduces battery current in a closed loop fashion simultaneously with a reduction in commanded torque by a feed-forward torque value.

Abstract: A position sensor and variable reluctance type controller interface circuit (10) is provided. The circuit (10) includes a position sensor (22) having an output terminal (OUT) and generating a position signal. A variable reluctance type controller (20), having an input bus (26), is electrically coupled to the position sensor (22) via a voltage divider circuit (24). The circuit (24) supplies a voltage differential output signal in response to the position signal to the input bus (26). A method of interfacing between the position sensor (22) and the controller (20) is also provided. The method includes generating a position signal. The reference voltage on the controller (20) is divided to an approximately fixed voltage level. The approximately fixed voltage level is supplied to a negative input terminal (INPUT−) on the variable reluctance type controller. The position signal is received on a positive input terminal (INPUT+) of the controller (20).

Abstract: A method is provided for controlling an electro-hydraulic power assist steering system including a variable-speed electric motor for pumping hydraulic fluid in the system. The method includes monitoring vehicle speed and vehicle steering wheel angle. A vehicle yaw rate is estimated using the monitored vehicle speed and monitored vehicle steering wheel angle. A control signal for setting the speed of the variable speed electric motor is compensated based based on the estimated vehicle yaw rate. Accordingly, a wide range of vehicle driving conditions are accommodated and vehicle fuel efficiency is improved.

Abstract: A method and apparatus for determining a center position of the vehicular steering system includes a vehicle speed sensor, a steering sensor and a control unit. The control unit uses a strategy to determine an estimate of the steering assist force. When the steering assist force is below a force threshold and a vehicle speed is above a speed threshold, the controller filters data from the steering sensor so as to rapidly determine a precise center position for the steering system.

Abstract: A method is provided for controlling an electro-hydraulic power assist steering system including a variable-speed electric motor for pumping hydraulic fluid in the system. The method includes monitoring a vehicle steering wheel angle and determining if the vehicle steering wheel angle exceeds a steering travel limit. If the steering travel limit is exceeded, the method reduces a desired motor speed to a predetermined end of travel motor speed until the steering wheel angle drops below the steering travel limit. Accordingly, energy is conserved by reducing the power consumed while the steering system is maintained at its steering travel limit.

Abstract: A method is provided for controlling an electro-hydraulic power assist steering system including a variable-speed electric motor for pumping hydraulic fluid in the system. The method includes monitoring vehicle speed, vehicle steering wheel angle, and vehicle steering wheel turning rate. A parking mode or a driving mode is selected based upon the monitored vehicle speed. The speed of the variable speed electric motor is controlled based upon the monitored vehicle steering wheel turning rate if the parking mode is selected. If the driving mode is selected, the speed of the variable speed electric motor is controlled based upon the monitored vehicle speed, vehicle steering wheel angle and vehicle steering wheel angle turning rate. Accordingly, a wide range of vehicle driving conditions are accommodated and vehicle fuel efficiency is improved.