An electric power-steering device has a speed-reducing mechanism (17) for reducing the speed of an output shaft (16) of an electric motor (15). The speed-reducing mechanism (17) has an internal gear (39) engaged and rotated with the output shaft (16) and an external gear (40) with which the internal gear (39) internally meshes. A drive pulley (41) rotatable together with the external gear (40) and a driven pulley (42) provided so as to surround a steering shaft are connected by an endless belt (43). Speed reduction is obtained by the internal gear (39) and the external gear (40), and the speed-reducing mechanism (17) as a whole achieves a high reduction ratio without greatly reducing the diameter of the drive pulley (41).

Electric power-steering device

An electric power steering apparatus has a steering mechanism SM having universal joints 4, 6 in a torque transmitting system, a steering toque detecting unit 14, a steering angle detecting, unit 18, a torque fluctuation detecting unit 43 for detecting a torque fluctuation due to the crossing angle α in the universal joints 4, 6 on the basis of the steering angle θ detected by the steering angle detecting unit 18 and any one of the steering torque T detected by the steering torque detecting unit, a current command value It and self-aligning torque SAT; and a current command value correcting unit 44 for correcting the current command value on the basis of the torque fluctuation detected by the torque fluctuation detecting unit 43 and the steering angle θ detected by the steering angle detecting unit 18.

Electric Power Steering Apparatus

A control computing unit blends a feedforward axial force and a feedback axial force at an allocation ratio, based on an axial force difference, a lateral acceleration, a vehicle velocity, a steering angle, and a steering angular velocity so as to set a final axial force. Then, the control computing unit applies a steering reaction force based on the final axial force that has been set.

Steering control device

A control device of an electric power steering device capable of accurately detecting the abnormality of a steering angle sensor without modifying the steering angle sensor in a double- system or without using an expensive position detection sensor. A relative steering angle is calculated by using an inexpensive position detection sensor outputting binaries disposed in the motor of the electric power steering device, and the varied amounts of the absolute steering angle detected by the steering angle sensor and the calculated relative steering angle are compared with each other to detect the abnormality of the steering angle sensor.

Control device of electric power steering device

There is provided a vehicle control system capable of ensuring stability even if an ego vehicle runs off a travel path. According to the invention, when yaw moment control is carried out to reduce a formed angle between a travel-path defining line of the travel path, which is recognized from information about an area located in a traveling direction of the ego vehicle, and a traveling-direction virtual line extending from the ego vehicle in the traveling direction, if it is judged that the ego vehicle has departed from the travel-path defining line, the yaw moment control is suspended.

Vehicle control system

A steering angle estimation section 40 calculates a front wheel-side estimative steering angle θFr and a rear-wheel-side estimative steering angle θRr through use of wheel speeds ωfL, ωfR, ωrL, ωrR of respective wheels, and averages these steering angles θFr and θRr to thereby obtain an accurate estimative steering angle θc. It also calculates an estimative steering angle difference Δθ between the steering angles θFr and θRr. An axial force estimation section 50 calculates a base axial force Fb through use of the estimative steering angle θc and a vehicle speed V, and calculates a correction axial force Fa which applies an axial force difference (hysteresis) to the base axial force Fb in accordance with a turning or returning operation by a driver. The axial force estimation section 50 adds the base axial force Fb and the correction axial force Fa together to thereby calculate an accurate estimative axial force Fc. An assist computation section 60 compares a target steering torque Th, which changes with the vehicle speed V, and the accurate estimative axial force Fc, and subtracts the target steering torque Th from the estimative axial force Fc, to thereby calculate an assist torque Ta.

Electric power steering device for vehicle

A vehicle information processing device mounted on a vehicle includes a future position calculating unit configured to calculate a future position of the vehicle based on steering input information corresponding to a steering input, a vehicle state amount that prescribes a turning state, and a vehicle speed, and an estimating unit configured to estimate a turning curvature of the vehicle at a provisional travel position ahead of a present position based on at least three vehicle positions according to the vehicle including at least the one calculated future position as well as including a vehicle position corresponding to the present position of the vehicle. As a result, a turning curvature of the vehicle at a vehicle position ahead of a present position can be estimated by a simple configuration and further the estimated turning curvature can be preferably used to stabilize vehicle behavior.

Vehicle information processing device

A power steering system, which is disposed in the forward part of a vehicle, allows an electric motor to boost the steering torque applied by a driver, and transmits the steering torque to wheels via a steering transmission mechanism. The power steering system includes an impact detection device that detects the impact of an object on a rack housing that houses a rack bar constituting the steering transmission mechanism to detect the impact on the power steering system more accurately.

Power steering system

A steering angle estimation section calculates a front-wheel-side estimative steering angle and a rear-wheel-side estimative steering angle through use of wheel speeds of respective wheels, and averages these steering angles to thereby obtain an accurate estimative steering angle It also calculates an estimative steering angle difference between the steering angles An axial force estimation section calculates a base axial force through use of the estimative steering angle and a vehicle speed, and calculates a correction axial force which applies an axial force difference (hysteresis) to the base axial force in accordance with a turning or returning operation by a driver The axial force estimation section adds the base axial force and the correction axial force together to thereby calculate an accurate estimative axial force An assist computation section compares a target steering torque, which changes with the vehicle speed, and the accurate estimative axial force, and subtracts the target steering torque from the estimative axial force, to thereby calculate an assist torque

Electric power steering apparatus for vehicle

A speed reducer 40 of an electric power steering apparatus is configured as a 2-stage speed reducer equipped with a worm speed reducer 41 adapted to receive rotational torque from an electric motor 30 and output the rotational torque from an output element (worm wheel 412) while reducing rotational speed, and with a planetary-gear-type speed reducer 42 adapted to receive the rotational torque from the output element and output the rotational torque while reducing rotational speed. The rotational speed of the electric motor 30 is reduced at two stages by the two speed reducers, thereby achieving high output (high speed reduction). Speed-reducing elements (a sun gear, planetary gears, a carrier, etc.) of the planetary-gear-type speed reducer 42 are disposed in the interior of the worm wheel 412 of the worm speed reducer 41, thereby implementing compactness.

Masaki Fujimoto

Papers

Electric power steering device for vehicle

Vehicle information processing device

Power steering system

Electric power steering apparatus for vehicle

Steering apparatus for vehicle