Techniques are described for managing redundant steering system for a vehicle. A method includes sending a first control command that instructs a first motor coupled to a steering wheel in a steering system to steer a vehicle, receiving, after sending the first control command, a speed of the vehicle, a yaw rate of the vehicle, and a steering position of the steering wheel, determining, based at least on the speed and the yaw rate, an expected range of steering angles that describes values within which the first motor is expected to steer the vehicle based on the first control command, and upon determining that the steering position of a steering wheel is outside the expected range of steering angles, sending a second control command that instructs a second motor coupled to the steering wheel in the steering system to steer the vehicle.

A method for power saving in a steering system of a motor vehicle including a road wheel actuator acting on a rack to turn steerable road wheels and a controller configured or programmed to generate an operation signal for the road wheel actuator, wherein the controller includes a position controller to generate a motor torque request based on an actual and/or a measured position of the rack and a requested rack position, includes detecting a passive mode of the steering system by a passive mode detector of the controller if the motor vehicle is stopped and no steering input is provided, and if a passive mode is detected by the passive mode detector, setting the motor torque request to zero in order to save power.

A method to control a steer-by-wire steering system for a road vehicle including a steering device, a road wheel actuator to actuate road wheels, and a controller configured or programmed to generate a motor torque request for the road wheel actuator based on an actual or an estimated position and a position request, which is based on the position of the steering device, includes detecting a road wheel actuator power limit situation, modifying the position request so that it can be followed by the road wheel actuator within power limits, and using the modified position request to generate the motor torque request for the road wheel actuator.

A method to control a steer-by-wire steering system of a road vehicle including a steering wheel coupled to a steering shaft, a road wheel actuator to turn steerable road wheels, a shaft sensor to detect a rotation of the steering shaft and a controller configured or programmed to generate an operation signal for the road wheel actuator from a signal detected by the shaft sensor, includes determining a real steering wheel angle by the shaft sensor, modifying the real steering wheel angle by applying an artificial hysteresis to create an offset between the real steering wheel angle and a modified steering wheel angle to mimic a behavior of an electromechanical power steering mechanism, and generating the motor torque request for the road wheel actuator based on the modified steering wheel angle.

A steer-by-wire steering system for a motor vehicle or a steering system for an autonomous driving motor vehicle includes a controller configured or programmed to control steering of steerable road wheels depending on a driver's input or an input of an autonomous driving unit and to include a normal mode of operation with full steering functionality and no quality problems, and at least two degraded modes with degraded operation of the steering system. The steering system includes an evaluator to evaluate a state of performance degradation of the steering system and to set the operation mode of the controller based on an evaluation result from the evaluator.

An electromechanical dual steering system for a utility vehicle includes two steering systems, each having a drive unit for actuating one steering linkage each for wheels of the utility vehicle. Each drive unit has an electric motor. The dual steering system has a main power supply for supplying the electric motors with energy. The electromechanical dual steering system is characterized in that the dual steering system has at least one emergency power supply for supplying at least one electric motor with energy in the event that the main power supply fails.

A steering control method for a redundant steering system. The method includes: receiving, by a first steering controller and a second steering controller, a first command signal and a second command signal, respectively; and synchronizing control outputs of the first steering controller and the second steering controller in a way that at least one of the first steering controller and the second steering controller compensates a control timing according to the first command signal and the second command signal so that the control outputs are synchronized.

A method and device for controlling a rear-axle steering system, in particular a rear-axle steering system of a motor vehicle, determines a current physical condition of the rear-axle steering system on the basis of a detected current operating state and a pre-determined reference operating state of the rear-axle steering system. The method defines a maximum permissible steering angle of the rear-axle steering system depending on the estimated physical condition of the rear-axle steering system and depending on at least one of the operating parameters of driving speed, steering angle and steering angle speed of the vehicle, and actuates the rear-axle steering system such that the steering angle of the rear-axle steering system does not exceed the assigned defined maximum permissible steering angle for the current operating parameter(s) of the vehicle.

A method for determining a friction torque exerted within a steering column of an electric power steering system, the power steering system comprising a steering column provided with a torsion bar undergoing an instantaneous torsion torque, the steering column being linked to a pinion capable of driving a rack, a torsion bar sensor intended to measure the instantaneous torsion torque, the method comprising an acquisition step, during which at least one value of the friction torque is measured by the torsion bar sensor, the acquisition step being carried out following the reception of a trigger signal, the value of the trigger signal depending on values of conditional variables (VL, A, V, C, ΔC, ΔA).

In a control device for an AC rotary machine, having an angle detector for detecting an electrical angle of the AC rotary machine, a detection error produced by the angle detector due to a noise magnetic field generated by a multi-phase alternating current flowing through an inverter connection unit is corrected using a correction signal having a phase and an amplitude that are determined in accordance with a relative positional relationship between the inverter connection unit and the angle detector and a current vector of the multi-phase alternating current, whereupon an inverter is controlled on the basis of the corrected electrical angle. As a result, a simple, low-cost control device for an AC rotary machine with which an angular position of a rotor can be detected with a high degree of precision is obtained.