A steering control device includes a target torque generator configured to generate a target torque which is a target value of the motor torque and a control signal generator configured to generate a control signal for controlling the motor such that the motor torque corresponding to the target torque is generated. The target torque generator includes a pre-adjustment axial force calculator, a first axial force calculator, a second axial force calculator, a post-adjustment axial force calculator, and a target torque calculator. The post-adjustment axial force calculator is configured to set a proportion of a first axial force contributing to a post-adjustment axial force to be smaller when a state of a vehicle speed is abnormal than when the state of the vehicle speed is normal.

A computer includes a processor and a memory, the memory storing instructions executable by the processor to detect an actual steering column torque and an actual steering wheel angle, predict a steering wheel torque with a state-estimation algorithm that outputs a plurality of vehicle states including the predicted steering wheel torque, adjust the plurality of vehicle states based on an algorithm noise that is based on a steering wheel angular speed to generate estimated vehicle states, output the estimated vehicle states including an estimated user-applied steering wheel torque, and transition from an autonomous mode to a manual mode when the estimated steering wheel torque exceeds a threshold. The state-estimation algorithm accepts input including the actual steering column torque and the actual steering wheel angle and outputs the plurality of vehicle states.

A computer includes a processor and a memory, the memory storing instructions executable by the processor to detect an actual steering column torque and an actual steering wheel angle, predict a steering wheel torque with a state-estimation algorithm that outputs a plurality of vehicle states including the predicted steering wheel torque, adjust the plurality of vehicle states based on an algorithm noise that is based on a steering wheel angular speed to generate estimated vehicle states, output the estimated vehicle states including an estimated user-applied steering wheel torque, and transition from an autonomous mode to a manual mode when the estimated steering wheel torque exceeds a threshold. The state-estimation algorithm accepts input including the actual steering column torque and the actual steering wheel angle and outputs the plurality of vehicle states.

A method for providing steering assist for a vehicle includes determining whether a primary communication system of the vehicle communicated a first vehicle speed signal, the first vehicle speed signal indicating a first vehicle speed of the vehicle. The method also includes, in response to a determination that the primary communication system did not communicate the first vehicle speed signal, detecting a fault in the primary communication system. The method also includes, in response to detecting the fault in the primary communication system, determining whether a secondary communication system communicated a second vehicle speed signal, the second vehicle speed signal indicating a second vehicle speed of the vehicle. The method also includes, in response to a determination that the secondary communication system communicated the second vehicle speed signal, selectively providing steering assist to a steering mechanism of the vehicle based on the second vehicle speed of the vehicle.

A method for providing steering assist for a vehicle includes determining whether a primary communication system of the vehicle communicated a first vehicle speed signal, the first vehicle speed signal indicating a first vehicle speed of the vehicle. The method also includes, in response to a determination that the primary communication system did not communicate the first vehicle speed signal, detecting a fault in the primary communication system. The method also includes, in response to detecting the fault in the primary communication system, determining whether a secondary communication system communicated a second vehicle speed signal, the second vehicle speed signal indicating a second vehicle speed of the vehicle. The method also includes, in response to a determination that the secondary communication system communicated the second vehicle speed signal, selectively providing steering assist to a steering mechanism of the vehicle based on the second vehicle speed of the vehicle.

A power steering device includes a steering mechanism structured to steer a steerable wheel in accordance with steering of a steering wheel. A first sensor is structured to sense a specific state quantity of steering. A second sensor is structured to sense the specific state quantity. A first actuation part is structured to apply a steering force to the steering mechanism. A second actuation part is structured to apply a steering force to the steering mechanism. A first microprocessor is configured to receive an output signal from the first sensor, and control driving of the first actuation part based on the output signal received from the first sensor. A second microprocessor is configured to receive an output signal from the first sensor and an output signal from the second sensor, and control driving of the second actuation part based on the output signal received from the first sensor.

A power steering device includes a steering mechanism structured to steer a steerable wheel in accordance with steering of a steering wheel. A first sensor is structured to sense a specific state quantity of steering. A second sensor is structured to sense the specific state quantity. A first actuation part is structured to apply a steering force to the steering mechanism. A second actuation part is structured to apply a steering force to the steering mechanism. A first microprocessor is configured to receive an output signal from the first sensor, and control driving of the first actuation part based on the output signal received from the first sensor. A second microprocessor is configured to receive an output signal from the first sensor and an output signal from the second sensor, and control driving of the second actuation part based on the output signal received from the first sensor.

A method for controlling a power steering system utilizes a vehicle having a motor, a controller coupled to the motor, and a steering assembly. The method includes detecting a steering rate using the controller and determining a vehicle speed. A base level steering damping is computed using the steering rate and the vehicle speed. At least one approximate vehicle acceleration is determined. A steering torque of the steering assembly is sensed through a torque sensor configured to sense the steering torque of the steering assembly. Moreover, a user torque is determined using the torque sensor. A damping boost is computed using the user torque and the at least one approximate vehicle acceleration. A final steering damping gain is determined using the base level steering damping and the damping boost. The final steering damping gain is applied to the steering assembly to minimize unwanted feedback to the steering assembly.

A motor vehicle has an electrically assisted steering system. A steering angle velocity of the motor vehicle, and a driver manual torque change applied by a driver of the motor vehicle are determined. At least the steering angle velocity and the driver manual torque change are analyzed to determine whether the driver manual torque change and the steering angle velocity are not correlated. An error signal is output if the driver manual torque change and the steering angle velocity are not correlated.

A motor vehicle has an electrically assisted steering system. A steering angle velocity of the motor vehicle, and a driver manual torque change applied by a driver of the motor vehicle are determined. At least the steering angle velocity and the driver manual torque change are analyzed to determine whether the driver manual torque change and the steering angle velocity are not correlated. An error signal is output if the driver manual torque change and the steering angle velocity are not correlated.