A method for synchronizing an MDPS motor and a motor position sensor may include: sequentially aligning, by a controller, a rotor of the MDPS motor by sequentially applying preset three-phase current pulses to the MDPS motor, the three-phase current pulses corresponding to one electrical-angle cycle of the rotor of the MDPS motor, and detecting an actual rotational position of the aligned rotor through the motor position sensor; determining a zero point rotational position of the rotor based on the actual rotational position; determining a reference rotational position of the rotor based on the actual rotational position and the number of pole pairs in the MDPS motor, and determining an offset rotational position of the rotor based on the actual rotational position and the reference rotational position; and correcting the zero point rotational position by adding the offset rotational position to the zero point rotational position.

A method for synchronizing an MDPS motor and a motor position sensor may include: sequentially aligning, by a controller, a rotor of the MDPS motor by sequentially applying preset three-phase current pulses to the MDPS motor, the three-phase current pulses corresponding to one electrical-angle cycle of the rotor of the MDPS motor, and detecting an actual rotational position of the aligned rotor through the motor position sensor; determining a zero point rotational position of the rotor based on the actual rotational position; determining a reference rotational position of the rotor based on the actual rotational position and the number of pole pairs in the MDPS motor, and determining an offset rotational position of the rotor based on the actual rotational position and the reference rotational position; and correcting the zero point rotational position by adding the offset rotational position to the zero point rotational position.

A steering control device controls an assist torque to be outputted by a motor connected to a steering system mechanism generating a steering torque. A response compensation filter performs a filter process compensating for a response in a specific frequency band with respect to a target steering torque generated by a target generation unit, and outputs a response-compensated target steering torque (Ts**). A servo controller calculates an assist torque command value (Ta*) in order for a torque deviation (ΔTs), which is a difference between the steering torque (Ts) and the response-compensated target steering torque (Ts**), to become zero. A transfer characteristic of the response compensation filter is set to suppress a mechanical resonance frequency band where a gain due to resonance of the steering system mechanism becomes large.

In a drive assist system, a map data acquiring section acquires at least one of a driver's operation ability and a load of a vehicle. An adjustment section determines an assist control amount as a control parameter of drive assist for the vehicle so that a degree of the driver's operation is increased according to reduction of the driver's operation ability or increasing of the load of the vehicle. An assist control amount calculation section transmits the assist control amount to a steering motor and a notification section so as to execute the drive assist for the vehicle.

A steering return control apparatus of MDPS may include: a column torque sensor configured to sense a column torque of a steering wheel; a steering angle sensor configured to measure a steering angle of the steering wheel; a column velocity calculator configured to calculate a column velocity at which a steering column is rotated; a vehicle velocity sensor configured to sense a vehicle velocity; a lateral acceleration sensor configured to sense a lateral acceleration of the vehicle; and a damping controller configured to detect a damping compensation gain in an on-center region according to at least one of the column torque, the column velocity and the lateral acceleration, and applies the damping compensation gain to a default damping amount, when the steering angle falls within the on-center region while at least one of the column torque, the column velocity and the vehicle velocity satisfies a preset damping compensation condition.

In a system that shares a battery with an external device, the system includes a power storage device connected to the battery via a power supply line. The system includes a switch provided on the power supply line, and a control unit. The control unit controls on-off switching operations of the switch to selectively establish an electrical conduction between the battery and the power storage device or interrupt the electrical conduction therebetween. The battery has a battery voltage thereacross, and the power storage device has a power-storage voltage thereacross. The battery charges the power storage device while the electrical conduction is established so that the power-storage voltage follows the battery voltage. The control unit turns off the switch when the battery voltage is in a predetermined insufficient voltage state to prevent electrical power charged in the power storage device from being discharged to the battery.

In a drive assist system, a map data acquiring section acquires a forward road shape and a rearward road shape. The forward road shape represents a road shape at a forward position in front of a current position of an own vehicle on a road on which the own vehicle drives. The rearward road shape represents a road shape at a rearward position on the road. The rearward position is behind the forward position and in front of the current position of the own vehicle on the road. An assist control calculation section determines steering characteristics of the own vehicle at the target position located between the forward position and the rearward position based on the forward road shape and the rearward road shape, and adjusts a steering angle of the own vehicle on the basis of the determined steering characteristics of the own vehicle.

A snowmobile having enhanced steering control has driving control system including an electrically actuated device coupled to a steering system having a user operated steering element with the device applying torque to the steering system, a throttle, a plurality of sensors including a torque sensor and at least one additional sensor to generate terrain condition data and operational data, and at least one controller coupled to the device and the sensors. The at least one controller selects a terrain condition mode using the generated terrain condition and generated operational data, determines the torque to apply responsive to the angle and speed of rotation of user operated steering element, and operates the electrically actuated device to apply the torque to the steering system, with the torque being applied only by the electrically actuated device.

A snowmobile having enhanced steering control has driving control system including an electrically actuated device coupled to a steering system having a user operated steering element with the device applying torque to the steering system, a throttle, a plurality of sensors including a torque sensor and at least one additional sensor to generate terrain condition data and operational data, and at least one controller coupled to the device and the sensors. The at least one controller selects a terrain condition mode using the generated terrain condition and generated operational data, determines the torque to apply responsive to the angle and speed of rotation of user operated steering element, and operates the electrically actuated device to apply the torque to the steering system, with the torque being applied only by the electrically actuated device.

A steering system is provided with a control unit (15) configured to determine a target steered angle (αt) according to a steering angle (β) of a steering shaft (18) which is fitted with a steering wheel (19) and drive a steering actuator so as to cause the steered angle (α) to coincide with the target steered angle, and to determine a target reaction force (Tt) according to a steered state of the wheels and drive a reaction force actuator (13) so as to cause the reaction force to coincide with the target reaction force. The control unit is configured to correct an output of the steering angle sensor in such a manner that a geometric steering center of the steering wheel coincides with a mechanical steering center of the steering shaft upon receiving a prescribed input (S) from a manual input switch (37).