摘要:
A controller (32) for a vehicular system (10) that includes a hand-wheel (16) and an electric motor (34) includes a torque-assist function (56) responsive to a signal representing the torque applied to the hand-wheel (16) for providing a torque-assist command to the motor (34), and a steering-pull compensator (52) responsive to a signal representing a valid ignition cycle for modifying the torque-assist command to the motor (34) by an offset corresponding to a detected steering-pull condition; where the method of control includes receiving the signal indicative of the torque applied to the hand-wheel (16), providing a torque-assist command to the motor (34) in response to the received torque signal, detecting an enabling signal related to the signal representing a valid ignition cycle, quantifying a steering-pull condition in response to the received and detected signals, and modifying the torque-assist command to the motor (34) by an offset corresponding to the quantified steering-pull condition.
摘要:
A method, system, and apparatus for providing enhanced steering pull compensation are provided. The method compensates for steering pull in a vehicle steering system that includes a handwheel. The method includes monitoring the vehicle to determine whether the vehicle is heading forward along a substantially linear straight-ahead path and, if so, measuring handwheel torque, as a sensed torque signal, to determine an amount of steering pull existing at the handwheel. The method also includes generating a torque assist signal in response to the sensed torque signal and calculating an offset signal for reducing the amount of steering pull to substantially zero. The method further includes producing a modified torque assist signal by adding the offset signal to the torque assist signal, and applying the modified torque assist signal to the vehicle steering system.
摘要:
A method, system, and apparatus for providing enhanced steering pull compensation are provided. The method compensates for steering pull in a vehicle steering system that includes a handwheel. The method includes monitoring the vehicle to determine whether the vehicle is heading forward along a substantially linear straight-ahead path and, if so, measuring handwheel torque, as a sensed torque signal, to determine an amount of steering pull existing at the handwheel. The method also includes generating a torque assist signal in response to the sensed torque signal and calculating an offset signal for reducing the amount of steering pull to substantially zero. The method further includes producing a modified torque assist signal by adding the offset signal to the torque assist signal, and applying the modified torque assist signal to the vehicle steering system.
摘要:
A method for conforming an input signal to fault requirements comprising: receiving an input signal; dividing the input signal into a low frequency component and a high frequency component; limiting the low frequency component to a maximum value, to create a limited signal; and combining the limited signal and the high frequency component, to create a limited command signal. A system for conforming an input signal to fault requirements comprising: an input signal in operable communication with a low pass filter. The input signal is also in operable communication with one of: a high pass filter and a first summing device in operable communication with said low pass filter. The system also includes a maximum value limiting device in operable communication with the low pass filter. A second summing device is in operable communication with the maximum value limiting device and one of, the high pass filter and the first summing device.
摘要:
A control system for controlling an electric power steering system is provided. The control system includes a first module configured to compute an on-center torque adjustment compensation based on a sensed handwheel torque. The on-center torque adjustment compensation is configured to compensate for inertia of a steering actuator motor using a frequency-based methodology. The control system also includes a second module configured to generate a command signal to control the steering actuator motor of the electric power steering system based on the on-center torque adjustment compensation.
摘要:
A control system for providing an assist torque is provided. The control system includes a control algorithm module and a comfort limit module. The control algorithm module calculates a corrective steering torque based on a target vehicle state and an estimated vehicle state. The comfort limit module receives a handwheel torque. The comfort limit module calculates a limited corrective steering torque based on the corrective steering torque and the handwheel torque. The limited steering torque represents an allowable amount of the assist torque provided by the control system.
摘要:
A watercraft steer-by-wire control system for watercraft comprising: a direction control system including a rudder position sensor; a helm control system including at least one of; a helm position sensor to produce and transmit a helm position signal and an optional torque sensor to produce and transmit a helm torque sensor signal. The system optionally including a watercraft speed sensor and a master control unit in operable communication with the watercraft speed sensor, the helm control system, and the direction control system. The master control unit includes a position control process for generating the directional command signal in response to the watercraft speed signal, the helm torque sensor signal and the helm position signal. The master control unit includes a torque control process for generating the helm command signal, based on the helm torque sensor signal, the helm position signal and the watercraft speed signal.
摘要:
An electric motor actuator used in an environment of varying loads for varying time periods is efficiently designed to a predetermined specification in terms of both motor load and time and operated up to but not exceeding this specification over the full expected operating range. A motor load signal is low pass filtered with a plurality of time constants spanning a range of expected motor operation to generate a plurality of filtered motor load signals each associated with one of the time constants. Each of these filtered motor load signals is compared with a predetermined reference value corresponding to the associated time constant. If one or more of the filtered motor load signals exceeds the predetermined reference value with which it is compared, the one that so exceeds by the greatest margin is selected. A command current limit factor is derived from the selected filtered motor load signal and used to limit the commanded motor current. The motor load signal preferably indicates motor operating current and may be derived from a motor current sensor or from the limited command current signal, motor speed and operating voltage to compensate for a decrease of current with motor speed due to inductance/slope compensation and voltage limit effects.
摘要:
An electric power steering control for a motor vehicle reduces motor torque ripple and road generated disturbances communicated to the vehicle handwheel while promoting system stability. In deriving an output command torque signal to the EPS motor, the control (1) derives an electric motor speed signal, (2) differentiates the electric motor speed signal, (3) stores a schedule of gain as an increasing function of electric motor torque, (4) modifies the differentiated estimated electric motor speed signal in response to the gain to provide a damping correction value and (5) derives the output command signal responsive to the damping correction. In a preferred embodiment, the control (1) stores power assist torque data as a function of handwheel torque and vehicle velocity, (2) provides a vehicle velocity signal, (3) provides a handwheel torque signal, (4) modifies the handwheel torque signal in response to the damping correction value, (5) derives a power assist torque value from the stored power assist torque data in response to the vehicle velocity signal and the modified handwheel torque signal and (6) derives the output command signal from the power assist torque value. The control may use an electric motor voltage signal as an estimate of electric motor speed and, for high torque loads, may use the pulse on-time parameter in a pulse width modulated, current switching control to represent the voltage of the controlled electric motor, and therefore the estimate of electric motor speed, so that no additional sensor is needed. The control may use separate stored relationships between the pulse width on-time and electric motor voltage for different commutation modes of the pulse width modulated, current switching control.
摘要:
In an electric power steering system in which a torque assist command is generated for controlling a motor that provides electric power assist torque at a desired torque, a method of motor control according to the steps of: determining a voltage mode motor command responsive to the torque assist command, wherein the voltage mode motor command commands a first motor torque that is (a) greater than the desired torque when the desired torque is low and (b) substantially equal to the desired torque when the desired torque is high; determining a current mode motor command responsive to the torque assist command, wherein the current mode motor command commands a second motor torque that is (a) substantially equal to the desired torque when the desired torque is low and (b) greater than the desired torque when the desired torque is high; and controlling the motor responsive to the voltage and current mode motor commands, wherein the motor assist torque is equal to a lesser of the first and second motor torques.