A method for damping an oscillation of a superimposed steering system of a motor vehicle in which a sensor of the superimposed steering system detects an actual steering angle of a motor of the superimposed steering system and a control device of the superimposed steering system determines an oscillation of the superimposed steering system as a periodic change of the detected actual steering angle and, in the case of a determined oscillation, carries out a measure for damping the oscillation.

A steer-by-wire system includes a transmission torque sensor, a handwheel position sensor, and a controller. The transmission torque sensor is configured to measure and output a transmission torque signal. The handwheel position sensor is configured to measure and output a handwheel position signal. The controller includes an angle-based load calculation submodule, a torque steer ratio calculation submodule, and a torque control module. The angle-based load calculation submodule is configured to transform the transmission torque signal and the handwheel position signal into an estimated second load value. The torque steer ratio calculation submodule is configured to transform the estimated second load value, a first load value indicative of roadwheel load including torque steer influence, and the transmission torque signal into a torque steer ratio. The torque control module is configured to transform the first load value, the handwheel position signal, and the torque steer ratio into a handwheel torque command signal.

A method estimates a track rod force which is exerted, in a power steering system with which a vehicle is equipped, on a track rod belonging to a steering mechanism which connects an actuator to a steered wheel which is orientable in the yaw direction and which bears a tyre of which the tread is in contact with the ground, the value of the estimated track rod force being corrected as a function of the longitudinal speed of the vehicle by a force component that models the release of the elastic torsion of the tyre so as to reduce, the estimated track rod force according to the longitudinal speed of the vehicle, when the vehicle transitions from a park situation in which the longitudinal speed of the vehicle is zero to a drive situation in which the longitudinal speed of the vehicle is non-zero.

The steer-by-wire system includes a steering device, a reaction force device, and a controller. The steering device turns wheels of a vehicle. The reaction force device applies a steering reaction force to a steering wheel. The controller is configured to control the steering reaction force by drive control of the reaction force device in response to an operation of the steering wheel. The controller is further configured to: obtain a signal including a component due to a reaction force which acts on the wheels from a road surface; extract a signal being greater than or equal to a predetermined frequency from the signal including the component due to the reaction force; and calculate a control amount of the reaction force device based on the extracted signal equal to or greater than the predetermined frequency.

A technique for reducing an operation noise even when a high-pass filter is used for controlling a motor is provided. A controller is used in a motor control system for driving a motor used for position control by using a drive circuit and an inverter. The controller includes a current control block for receiving a motor current and outputting a reference voltage, a motor control circuit for outputting a signal indicating a duty ratio from the reference voltage output from the current control block, a dead band compensation block for calculating a compensation value of a non-linear element of a drive system, and an adder. The dead band compensation block outputs a duty value corresponding to the dead band at a timing at which the motor current crosses zero. The adder adds the duty value to a signal indicating the duty ratio and outputs the signal.

A power steering system reduces or prevents an unintended jerking of a steering input device due to an unintended torque being input into the power steering system from an output of the power steering system. The unintended torque may be determined based on an acceleration of a motor of the power steering system.

Systems and methods are provided for limit cycle detection and cessation. A control system generates a drive signal with at least one drive component. An actuator effects a response to the drive signal and a sensor measures the response. Characteristics of the drive signal and of the drive components are accessed by a controller. The characteristics are compared to a predetermined set of characteristics. When the characteristics fall within the predetermined set of characteristics, a magnitude of at least one of the characteristics is evaluated. When the magnitude exceeds a predetermined value indicative of the limit cycle, an action is undertaken to stop the limit cycle.

A method for operating an electrical power steering system of a transportation vehicle wherein a steering wheel angle is pre-defined by a steering wheel as a measure for a desired wheel steering angle for at least one steerable wheel of the transportation vehicle, where an electrical power drive with an electric motor provides a steering support, and where a support torque of the steering support is reduced based on a damping function in response to the combustion engine of the transportation vehicle being started. Also disclosed is an associated electrical power steering system, to a computer program, and to a control appliance.

A steering system includes an electric motor drivably coupled to a steering column, and a computer communicatively coupled to the electric motor. The computer is programmed to isolate a nibble signal in data representing a torque of the steering column, and instruct the electric motor to output a motor torque based on the nibble signal shifted by a phase shift, the phase shift based on a vehicle-wheel frequency.

Methods and apparatus to reduce noise and vibration in a hybrid hydraulic power steering system are disclosed. A method includes receiving sensor data from sensors of a vehicle and mapping the sensor data to filter coefficients. The method further includes generating a torque demand based on an input of the filter coefficients into a polynomial filter and tuning at least one of a torque assistance or a steering damping of an assisted steering system of the vehicle based on the torque demand.