Abstract: A vehicular steering control apparatus is comprised of a steering system of receiving a steering torque inputted by a driver, a torque control actuator connected to the steering system to produce an actuator torque relative to the steering torque and a steering controlling section connected to the torque actuator. The steering controlling section controls the torque control actuator and increases a phase delay of the actuator torque relative to the steering torque toward a neighborhood of 180° as the frequency of the inputted steering torque increases.

Abstract: In a multiplex power steering device for a wheeled vehicle, there is provided a control unit which includes a feedback computing part. The feedback computing part comprises an operating force estimating section that, by analyzing an output from a controlled system of actuators of a steering mechanism, estimates an output of the actuators, a disturbance estimating section that, by comparing a control signal actually fed to the actuators and the estimated output of the actuators, estimates a disturbance applied to the controlled system from the exterior, and a disturbance compensating section that adjusts the control signal in a manner to remove the estimated disturbance therefrom. The control unit calculates the control signal on the assumption that the actuators constitute a single actuator.

Abstract: A vehicle motion control device is configured to determine whether the lane in which the vehicle is traveling is straight or curved. If the road is curved, a target yaw rate is set such that the yaw rate of the vehicle to the target position is averaged. If the road is straight, the target yaw rate is set such that the response delay does not exceed a target value. Therefore, wavering of the vehicle with respect to the lane is suppressed, and the vehicle is controlled to move smoothly when the road is curved and briskly when the road is straight. When the road switches between a curved road and a straight road, the target yaw rate is gradually changed between a target yaw rate calculated for a curved road and a target yaw rate calculated for a straight road.

Abstract: A lane-keep control system includes a traveling condition detector and a controller. The controller includes a steering intention detecting section that detects whether a driver has an intention to steer a vehicle, a first steering torque control section that controls, when the driver has an intention to steer the vehicle, a steering torque according to the traveling condition so that the vehicle keeps a predetermined position between lane markings of a lane, and a second steering torque control section that controls, when the driver has no intention to steer the vehicle, the steering torque according to the traveling condition so that a steering operation of the driver is readily reflected on steering of the vehicle. A lane-keep control method is also provided.

Abstract: An electric power steering system for an automotive vehicle, including a steering torque detecting device which detects a steering torque of a steering shaft. An electric motor is provided to generate an assist torque for assisting a driver's steering effort required for steering the vehicle and a counter-assist torque for increasing the driver's steering effort. The assist torque and the counter-assist torque are applied to a steering mechanism. Additionally, a controller is provided to output a drive command to the electric motor in accordance with the detected steering torque. The drive command is for causing the electric motor to generate the counter-assist torque when the detected steering torque is a transitional torque.

Abstract: A lane recognition apparatus for a vehicle is comprised of an image picking-up section which picks up a road image in front of the vehicle, a lane-marker candidate-point detecting section which detects coordinate values of a plurality of lane marker candidate points from the road image, and a road model parameter calculating section which estimates a road model parameter representative of a road shape in front of the vehicle and a vehicle state quantity of the vehicle using an extended Kalman filter, on the basis of the coordinate values of the lane marker candidate points.

Abstract: In a multiplex power steering device for a wheeled vehicle, there is provided a control unit which includes a feedback computing part. The feedback computing part comprises an operating force estimating section that, by analyzing an output from a controlled system of actuators of a steering mechanism, estimates an output of the actuators, a disturbance estimating section that, by comparing a control signal actually fed to the actuators and the estimated output of the actuators, estimates a disturbance applied to the controlled system from the exterior, and a disturbance compensating section that adjusts the control signal in a manner to remove the estimated disturbance therefrom. The control unit calculates the control signal on the assumption that the actuators constitute a single actuator.

Abstract: In a steering mechanism of steer-by-wire type which includes a first steering unit that is handled by a driver and a second steering unit that steers steered road wheels with the aid of a steering motor, there is employed a control system which input and output detecting sections that detect input and output of the steering motor, a road surface disturbance estimating section that estimates a disturbance of road surface based on both the detected input and output of the steering motor, and a steering reaction force calculating section that, based on the estimated disturbance of road surface, calculates a steering reaction force that is to be applied to a steering wheel of the first steering unit.

Abstract: A CCD camera or equivalent sensor is mounted on a vehicle and used to detect lane markings (usually the white or yellow painted lines) on a roadway. An electric motor coupled to a steering system is used to provide a torque input to the steering, which may either assist or oppose the steering torque from a driver. A steering controller is designed to assist the driver to maintain the vehicle lane position by holding the vehicle at a target point using a biasing torque. The controller resumes application of the biasing torque upon expiration of a predetermined period of delay time since a change from the absence of detection of lane marking to the presence of detection of lane marking after the presence of detection of lane marking that continues for a period of time less than a predetermined period of time has occurred a predetermined number of times within a predetermined period of monitoring time or the absence of detection of lane marking continues for a predetermined period of time.

Abstract: In a steering mechanism of steer-by-wire type which includes a first steering unit that is handled by a driver and a second steering unit that steers steered road wheels with the aid of a steering motor, there is employed a control system which input and output detecting sections that detect input and output of the steering motor, a road surface disturbance estimating section that estimates a disturbance of road surface based on both the detected input and output of the steering motor, and a steering reaction force calculating section that, based on the estimated disturbance of road surface, calculates a steering reaction force that is to be applied to a steering wheel of the first steering unit.

Abstract: A system for assisting a lane-keep traveling of a vehicle is comprised of a camera for detecting a view ahead of the vehicle, a vehicle behavior detector including a vehicle speed sensor and a yaw rate sensor, and a controller. The controller is arranged to estimate a road shape on the basis of lane markers detected by the camera, to detect a target yaw rate necessary to return the vehicle at a center of the lane markers, and to determine that there is a possibility that the vehicle deviates from the lane when a difference between the target yaw rate and an actual yaw rate detected by the yaw rate sensor becomes greater than a threshold.

Abstract: An apparatus for vehicle lane following in which a look ahead sensor including a CCD camera and an image processor detects a lane marking on the surface of a roadway. The image processor estimates a lateral displacement of a point at a preview distance in front of a vehicle from a target line. The target line is a line between lane markings defining a lane. An electric motor coupled to the steering mechanism is used to provide a bias (a torque input) to the steering, which may either assist or oppose to the steering torque from the driver. A steering controller is designed to assist the driver to maintain the vehicle's lane position by holding the vehicle at the target line using a biasing torque if the lane following is selected by the driver. In order to reflect the driver preference in the lane following, the controller collects a sufficient number of measures of the vehicle lateral displacement when the lane following is not selected.

Abstract: A pneumatic tire comprising a tread portion which comprises a surface rubber layer which is disposed in an outer portion of the tread portion in the radial direction of said tire and has a specific resistance of 108 &OHgr;·cm or more after curing by vulcanization and conductive rubber members which comprise a rubber composition having a specific resistance of 106 &OHgr;·cm or less and replace a portion of the surface rubber layer, wherein the conductive rubber members are disposed in portions of the surface rubber layer extending from the outer surface to the inner surface in the radial direction of said tire discontinuously in the circumferential direction of said tire at the outer surface of the surface rubber layer in the radial direction of said tire, is provided. The pneumatic tire shows not only an excellent effect of static discharge but also excellent durability.

Abstract: A lane recognition apparatus for a vehicle is comprised of an image picking-up section which picks up a road image in front of the vehicle, a lane-marker candidate-point detecting section which detects coordinate values of a plurality of lane marker candidate points from the road image, and a road model parameter calculating section which estimates a road model parameter representative of a road shape in front of the vehicle and a vehicle state quantity of the vehicle using an extended Kalman filter, on the basis of the coordinate values of the lane marker candidate points.

Abstract: A system for assisting a lane-keep traveling of a vehicle is comprised of a camera for detecting a view ahead of the vehicle, a vehicle behavior detector including a vehicle speed sensor and a yaw rate sensor, and a controller. The controller is arranged to estimate a road shape on the basis of lane markers detected by the camera, to detect a target yaw rate necessary to return the vehicle at a center of the lane markers, and to determine that there is a possibility that the vehicle deviates from the lane when a difference between the target yaw rate and an actual yaw rate detected by the yaw rate sensor becomes greater than a threshold.

Abstract: A pneumatic tire comprising a tread portion which comprises a surface rubber layer which is disposed in an outer portion of the tread portion in the radial direction of said tire and has a specific resistance of 108 &OHgr;·cm or more after curing by vulcanization and conductive rubber members which comprise a rubber composition having a specific resistance of 106 &OHgr;·cm or less and replace a portion of the surface rubber layer, wherein the conductive rubber members are disposed in portions of the surface rubber layer extending from the outer surface to the inner surface in the radial direction of said tire discontinuously in the circumferential direction of said tire at the outer surface of the surface rubber layer in the radial direction of said tire, is provided. The pneumatic tire shows not only an excellent effect of static discharge but also excellent durability.

Abstract: The present invention provides a method for estimating a tire wear life which enables estimation of the tire wear life accurately in a short time. In this method, a rubber index Gi of a rubber test piece which is made of the same material as the material used in the tire tread portion of the tire whose tire wear life is to be estimated is measured using an abrasion tester which can be operated under a slip ratio of about 0.5 to 5% (step 100). Then, friction energies of the tire in free rolling, in a state in which the tire is provided with a toe angle, in a state in which a side force is applied to the tire, in a state in which a driving force is applied to the tire and in a state in which a braking force is applied to the tire are measured (step 102), respectively. An expected value of the tire wear life T1 is calculated from the rubber index Gi and the friction energies obtained above (step 104). The tire wear life is estimated from the expected value of the tire wear life T1 thus obtained (step 106).

Abstract: A wear resistance index G1 of a tire whose wear life is to be estimated is measured by the Lambourn abrasion tester. Then, friction energies in free rolling, when the tire is fitted with a toe angle, under application of a side force, under application of a braking force and under application of a driving force of the tire are measured. An expected value of the wear life T1 is calculated using the wear resistance index G1 and the friction energies thus obtained and the wear life of the tire is estimated on the basis of the expected value of the wear life T1. The wear life of a tire can be estimated accurately in a short time in accordance with the method for estimating a tire wear life of the present invention.

Abstract: A road curvature estimating apparatus for a vehicle includes a vehicle attitude detector which detects an attitude of the vehicle with respect to a road, a front-and-rear wheel steer-angle detector, a vehicle speed detector and a road curvature calculator. The road curvature calculator calculates a curvature of a road ahead of the vehicle on the basis of the measured vehicle attitude, the measured vehicle speed and the measured steer angles of the front and rear wheels by means of a state estimation of modern control theory. A controller executes a control of an automatic steering mechanism on the basis of the road curvature calculated.

Abstract: A vehicle steering system includes a first steering mechanism for a manual steering mode and a second steering mechanism for an automatic steering mode. A controller steers the vehicle in accordance with information on driving environment, with the second steering mechanism when the automatic mode is selected with a mode selector. There is further provided a holding device for holding the steering angle of the first steering mechanism when the automatic steering operation of the second steering mechanism is under way. In response to selection of the automatic mode, the controller performs the automatic steering control only when a sensor senses a straightforward neutral position of the first steering mechanism.