An ECU includes plural sensor units and plural control units. The sensor units include magnetic field detection elements for detecting a rotation of a motor, and output mechanical angles related to the rotation angle in one rotation and count values related to the number of rotations of the motor, respectively. One rotation of the motor is divided into indefinite regions, in which detection deviation of the count values may occur, and definite regions, in which no detection deviation occurs. The definite region of the count value is set to deviate from the definite region of the other count value. Absolute angle calculation units calculate the absolute angles using the count values of the definite regions.

A vehicle (10) includes a VP (120) that carries out vehicle control in accordance with a command from an autonomous driving system (202) and a vehicle control interface (110) that interfaces between the autonomous driving system (202) and the VP (120). A tire turning angle command that requests for a wheel steer angle is transmitted from the autonomous driving system (202) to the VP (120). A signal indicating an estimated wheel angle which is an estimated value of the wheel steer angle is transmitted from the VP (120) to the autonomous driving system (202). The VP (120) steers the vehicle in accordance with the tire turning angle command set based on a wheel estimation angle while the vehicle (10) is in a straight-ahead travel state.

An absolute steering sensor assembly (10) is provided, comprising a printed circuit board (18), at least one hall sensor (20, 22) being attached to the printed circuit board (18), at least one magnet (34, 36) being rotatably mounted such that the magnet (34, 36) is rotated upon a rotation of a steering column (26), the at least one magnet (34, 36) being placed in proximity of the at least one hall sensor (20, 22) such that the hall sensor (20, 22) can detect the magnetic field emitted by the magnet (34,36), and a protective cover (38, 40) being attached to the printed circuit board (18) such that the protective cover (38, 40) is placed between the magnet (34, 36) and the printed circuit board (18).

A fly-by-wire steering system uses one or more magnets and one or more magnetic sensors to determine the position the rack of the steering system. The magnetic sensors provide a high-level signal when proximate to magnet. The signals from magnetic sensors provide an indication of the position of the rack. The sequence of changing values of the signals magnetic sensors provides an indication of the direction of travel of the rack. The signals may be used to calibrate a steering sensor and/or an actuator.

A rotation angle detection device including: an angular position calculation unit configured to calculate angular position information representing an angular position of the motor rotation shaft based on a first sensor signal of the first sensor; an rotation number detection unit configured to detect a rotation number of the motor rotation shaft based on a second sensor signal of a second sensor and outputs rotation number information representing the rotation number; a rotation angle calculation unit configured to calculate rotation angle information indicating a rotation angle of the motor rotation shaft based on the angular position information and the rotation number information; and a power supply unit configured to stop supplying power to the first sensor, the angular position calculation unit and the rotation angle calculation unit and to supply power to the second sensor and the rotation number detection unit when the power switch is off.

An absolute steering angle sensor includes a single main gear having first gear teeth with a first pitch, second gear teeth with a second pitch, wherein the first and second gear pitches are different. A first magnet gear is driven by the first gear teeth, wherein the first magnet gear has a first gear profile and a first diameter. A second magnet gear is driven by the second gear teeth, wherein the second magnet gear has a second gear profile and a second diameter. The first and second gear profiles are different, and the first and second diameters are different. A first magnet rotates with the first magnet gear and emits a first magnetic field, and a second magnet rotates with the second magnet gear and emits a second magnetic field. A sensor assembly measures strengths of the first and second magnetic fields and calculates an absolute steering angle.

The power control unit sets a drive interval for driving the sensor by providing power intermittently to the sensor to a first time interval when no change is detected in the sine-wave signal and the cosine-wave signal, sets to the second time interval that is shorter than the first time interval when a change in only one of the sine-wave signal and the cosine-wave signal is detected, and sets to the third time interval that is shorter than the second time interval when a change in one of the sine-wave signal and the cosine-wave signal is detected and then a change in the other is detected.

A control unit and a method for determining a steering reference state for a vehicle. A first wheel speed value that is a wheel speed value for a wheel on the vehicle is obtained. At least one second wheel speed value that is a wheel speed value for another wheel on the vehicle is obtained. Using the first and second wheel speed value, a steering reference state is determined, corresponding to travel in a straight line by the vehicle.

An apparatus for diagnosing malfunction of a steering angle sensor. A steering angle sensor includes a main gear mounted on a steering shaft, first and second sub-gears meshed with the main gear at a specific gear ratio different from that of the main gear, and position sensors attached to the first and second sub-gears, respectively. A processor receives a signal output with rotation of the corresponding sub-gear from each of the position sensors of the steering angle sensor, detects at least one of the two position sensors which outputs different output signal values that are not designated in correspondence with a value of the same system angle, and determines the detected at least one position sensor as a cause of a malfunction.

The power management unit supplies first power that is continuous power to the second sensor when the power switch is on, supplies second power that is intermittent power having a voltage lower than the first power to the second sensor when the power switch is off, and outputs rotation number information representing a rotation number of the motor rotation shaft based on the second sensor signal. The power management unit includes a comparator that operates using the second power as the power source when the power switch is off and compare the second sensor signal and the reference voltage, and a counter that detects the rotation number of the motor rotation shaft by counting the output of the comparators.