Nissan Motor Company Limited

Yuya Takeda

Takeshi Kimura

Satoshi Tange

Yukinori Nishida

Tomoyuki Kashiwaya

Genpei Naito

Yosuke Kobayashi

Tomohiro Yamamura

Taku Takahama

Taku Suzuki

Toshiyuki Murata

A steering control device is provided that calculates a white line approach suppression steering reaction force that is based on a distance in which a host vehicle is separated from either a left or a right white line when the host vehicle approaches the left or a right white line. The steering control device applies a steering reaction force to a steering unit that receives steering input from a driver, based on the white line approach suppression steering reaction force, and upon determining that the other among the left and right white lines cannot be detected and a distance between the host vehicle and the left or right white line is decreasing, the white line approach suppression steering reaction force is limited.

Steering control device

A steering control device includes a steering reaction force control unit that applies a steering reaction force to a steering unit in accordance with a steering reaction force characteristic that is based on steering torque and steering angle of the steering unit in which the steering torque increases as the steering angle increases. A curvature detection unit detects a curvature of a white line. An offset unit calculates an offset amount that increases as the detected curvature increases and that offsets the steering reaction force characteristic such that a neutral point of the steering is moved in a curve direction according to a magnitude of the detected curvature. A lateral acceleration detection unit detects a lateral acceleration of a host vehicle. An offset suppression unit suppresses an increase in the offset amount more as an absolute value of the detected lateral acceleration increases.

A steering control device is provided that calculates a white line approach suppression turning amount that is based on a distance between a host vehicle is separated from either a left or a right white line when a host vehicle approaches either a left or a right white line. The steering control device controls a turning unit for turning a turnable wheel based on the white line approach suppression turning amount, and upon determining that the other among the left and right white lines cannot be detected and a distance between the host vehicle and the left or right white line is decreasing, an increase in the white line approach suppression turning amount is inhibited while permitting a decrease in the white line approach suppression turning amount.

A steering control device includes a steering reaction force control unit that applies a steering reaction force to a steering unit in accordance with a steering reaction force characteristic that is based on steering torque and steering angle of the steering unit in which the steering torque increases as the steering angle increases. A curvature detection unit detects a curvature of a white line. An offset unit calculates an offset amount that increases as the detected curvature increases and that offsets the steering reaction force characteristic such that a neutral point of the steering is moved in a curve direction according to a magnitude of the detected curvature. A curve direction steering torque detection unit programmed to detect a steering torque in a curve direction. An offset suppression unit suppresses a change in the offset amount more as a detected steering torque in the curve direction increases.

The turning amount of a turning unit is controlled according to the steering amount of a steering unit mechanically uncoupled from the turning unit. A steering reaction force characteristic such that the larger the self-aligning torque, the larger the steering reaction force is set on coordinates with the self-aligning torque and the steering reaction force as coordinate axes. When a steering reaction force corresponding to the self-aligning torque is applied to the steering unit based on the steering reaction force characteristic, the steering reaction force characteristic is offset on the coordinates in such a direction that the larger the integral value of a yaw angle, the larger the absolute value of the steering reaction force, the yaw angle being an angle formed by a white line and a traveling direction of an own vehicle.

A stability control device is provided that controls a turning amount of the turning unit based on a steer-by-wire turning amount corresponding to a steering amount of a steering unit that is mechanically detached from the turning unit and based on a suppression turning amount for suppressing a yaw angle that is generated to a vehicle by a disturbance. The stability control device corrects the suppression turning amount to increase as the lateral position of a host vehicle becomes closer to the white line, when controlling the steering reaction force that is applied to the steering unit based on the steering amount, without reflecting the suppression turning amount on the steering reaction force that is applied to the steering unit.

Stability control device

The turning amount of a turning unit is controlled according to the steering amount of a steering unit mechanically uncoupled from the turning unit. A steering reaction force characteristic in which the larger the self-aligning torque, the larger the steering reaction force is set on coordinates with the self-aligning torque and the steering reaction force as coordinate axes. When the steering reaction force corresponding to the self-aligning torque is applied to the steering unit based on the steering reaction force characteristic, the steering reaction force characteristic is offset on the coordinates in such a direction that the closer the lateral position of an own vehicle to a white line, the larger the absolute value of the steering reaction force.

A steering control device set a steering reaction force characteristic to coordinates so that the self-aligning torque increases as the steering reaction force increases. Upon applying a steering reaction force corresponding to the self-aligning torque to a steering unit based on the steering reaction force characteristic to offset the steering reaction force characteristic at coordinates more in a direction in which an absolute value of the steering reaction force increases as a lateral position of a host vehicle approaches to a white line, the offset of the steering reaction force characteristic is suppressed when a turn signal operation is started while suppression of the offset of the steering reaction force characteristic is released when the turn signal operation is ended so that an absolute value of an increase gradient when releasing suppression of the offset becomes smaller than an absolute value of a decrease gradient when suppressing the offset.

A stability control device is provided that is capable of reducing an unpleasant sensation imparted to a driver in a steer-by-wire vehicle. The stability control device includes a steer-by-wire controller that controls a turning amount of the turning part based on a steer-by-wire turning amount that corresponds to a steering amount of the steering unit, a turning amount for suppressing the yaw angle, which is an angle formed by a white line and a traveling direction of a host vehicle, and a turning amount for returning the host vehicle to the center of a lane when the host vehicle has departed from the center of the lane. The controller controls a steering reaction force based on the steering amount without the yaw angle-suppressing turning amount and the lane-center-returning turning amount being reflected in the steering reaction force imparted to the steering unit.

A steering control device includes a steering reaction force control unit that applies a steering reaction force to a steering unit in accordance with a steering reaction force characteristic that is based on steering torque and steering angle of the steering unit in which the steering torque increases as the steering angle increases. Upon applying the steering reaction force to the steering unit, an offset amount is calculated that is greater as a curvature of the white line increases, and a suppression offset amount is calculated that applies a predetermined limit to a change rate of the offset amount. When the steering torque that is opposite of the curvature is detected upon offsetting the steering reaction force characteristic, the predetermined limit is changed to a greater limit than the predetermined limit to suppress an increase in the offset amount.

The turning amount of a turning unit is controlled based on the steering amount of a steering unit mechanically uncoupled from the turning unit, and the change amount of the steering reaction force relative to the change amount of the self-aligning torque in a steering reaction force characteristic is increased as a curvature of a white line is increased when the steering reaction force corresponding to the self-aligning torque is applied to the steering unit based on the steering reaction force characteristic corresponding to the self-aligning torque such that the larger the self-aligning torque, the larger the steering reaction force.

The turning angle of the left and right front wheels is controlled based on an SBW command turning angle corresponding to the steering angle of a steering wheel mechanically uncoupled from the left and right front wheels and a disturbance suppression command turning angle to suppress the yaw angle generated in the vehicle by disturbance. The steering reaction force to be applied to a column shaft is controlled based on the steering angle of the steering wheel.

Lateral displacement reference positions LXL, LXR are set on left and right from a center in a width direction of a traffic lane L where a vehicle travels. Then, at least in a case where the vehicle is positioned on an inner side of the left and right lateral displacement reference position LXL, LXR, the vehicle is feedback-controlled so as to decrease a yaw angle deviation. Further, in a case where the vehicle is positioned at an outer side of the left and right lateral displacement reference position LXL, LXR with respect to the traffic lane center, the feedback control is performed so as to decrease the angle deviation and a lateral displacement deviation.

Lane keeping assist device and lane keeping assist method

The in-lane running support system includes a steering input device and a steering input detector. The in-lane running support system further comprises a reaction force device that changes a condition of the steering input device between a normal operation mode that provides a normal reaction force to the driver, and a hapthic operation mode that performs a notification operation to the driver, a turning output device that is in a state mechanically disconnected from the steering input device and that turns steerable wheels, and a turning output controller. A running state detecting device acquires information of a running state of the vehicle with respect to a lane. An in-lane running support device controls the turning output device and the haptic device based on the information of the running state such that the vehicle runs in the lane, and has a first control mode that controls the turning output control device and causes the reaction force device to operate in the normal operation mode, and a second control mode that controls the turning output control device and causes the reaction force device to operate in the haptic operation mode.

In-lane running support system, automobile and in-lane running support method

A motor vehicle includes a vehicle driving operation support system. The vehicle driving operation support system senses an environment surrounding the motor vehicle; senses a traveling condition of the motor vehicle; calculates a risk potential of the motor vehicle on a basis of the sensed environment and the sensed traveling condition; controls the motor vehicle on a basis of a control setpoint. The vehicle driving operation support system sets on a basis of the calculated risk potential the control setpoint to a provisional setpoint effective for reducing the risk potential; senses driver's operation in reaction to the controlling operation with the control setpoint set to the provisional setpoint; and sets the control setpoint to a normal setpoint on a basis of the sensed driver's operation.

Growing community of inventors

Yokohama, Japan

Yuya Takeda