Jtekt Corporation

Toyota Jidosha Kabushiki Kaisha

Maxime Moreillon

Robert Fuchs

Tsutomu Tamura

Naoki Shoji

Tomohiro Nakade

Frederic Wilhelm

Naoki Nishimura

Takahiro Kojo

Yoji Kunihiro

Hisaya Akatsuka

Takahiko Kuwabara

A vehicle steering device includes a first setting portionthat sets a target assist torque in accordance with a steering torque, a second setting portionthat sets an angle controlling target torque for bringing an angular deviation between a target steering angle and an actual steering angle close to zero, an estimator that estimates a compensation objectload with respect to the angle controlling target torque, a first calculating portionthat calculates a target automatic steering torque based on the angle controlling target torque set by the second setting portion and the compensation object load estimated by the estimator, and a second calculating portionthat performs weighted addition of the target automatic steering torque and the target assist torque in accordance with a value that changes in accordance with a driver input to calculate a target motor torque that is a target value of a motor torque of the electric motor.

Vehicle steering device

A vehicle steering device includes an electric motor applying a steering force to a vehicle turning mechanism, a first setting portion setting a target assist torque in accordance with a steering torque, a second setting portion setting an angle controlling target torque for bringing an angular deviation between a target steering angle and an actual steering angle close to zero, a restriction processing portion restricting the angle controlling target torque set by the second setting portion, a first calculating portion calculating a target automatic steering torque using the angle controlling target torque after the restriction process by the restriction processing portion, and second calculating portions performing weighted addition of the target automatic steering torque and the target assist torque in accordance with a value that changes in accordance with a driver input to calculate a target motor torque that is a electric motor target motor torque value.

A steering determination device determines a steering state in which a driver of a vehicle is steering a steering wheel of the vehicle. The device includes a torque recognition unit configured to recognize a steering torque based on a measurement result of a torque sensor provided on a steering shaft, an acceleration recognition unit configured to recognize longitudinal acceleration or lateral acceleration, a threshold value setting unit configured to set a threshold value for the determination of the steering state, based on the longitudinal acceleration or the lateral acceleration, and a steering determination unit configured to determine that the driver is in the steering state if the steering torque is equal to or greater than the threshold value. The threshold value setting unit is configured to set the threshold value such that the threshold value decreases as an absolute value of the longitudinal acceleration or the lateral acceleration decreases.

Steering determination device and autonomous driving system

An electric power steering system includes a second shaft coupled to a first shaft via a torsion bar, a basic driver torque estimation unit (extended state observer) configured to estimate a basic driver torque by using a disturbance observer based on a torsion bar torque and a rotation angle of the second shaft, a gravity torque calculation unit configured to calculate, by using a rotation angle of a steering wheel, a gravity torque applied to the first shaft by gravity acting on the center of gravity of the steering wheel, and a driver torque estimation unit configured to estimate a driver torque by using the basic driver torque estimated by the basic driver torque estimation unit and the gravity torque calculated by the gravity torque calculation unit.

Driver torque estimation apparatus and steering system including the same

A steering device includes a steering wheel, a torsion bar, a spiral cable, a torque sensor, and an electronic control unit. The electronic control unit is configured to compute a rotational angle of the steering wheel. The electronic control unit is configured to compute, as driver torque, a value that includes a sum obtained by adding torsion bar torque, a steering wheel inertial torque compensation value and a spiral cable torque compensation value. The steering wheel inertial torque compensation value is the product of a steering wheel inertial moment and a second-order differential value of the rotational angle of the steering wheel. The spiral cable torque is torque that acts on the steering wheel because of the spiral cable.

Steering device

A steering apparatus includes: a first shaft which is coupled to a steering wheel; a torsion bar; a second shaft which is coupled to the first shaft through the torsion bar; a torsion bar torque detection unit detecting a torsion bar torque which is applied to the torsion bar; and an electronic control unit configured to estimate a driver torque which is applied to the steering wheel by a driver. The electronic control unit is configured to: i) compute a steering wheel rotation angle which is a rotation angle of the steering wheel; and ii) compute a value including an added value, as the driver torque, the added value being a value resulting from adding the torsion bar torque, a steering wheel inertia torque compensation value, and a gravity torque compensation value.

Steering apparatus

A vehicle steering device includes a steering wheel, an input shaft, an output shaft coupled to the input shaft via a torsion bar, an electric motor, a torque detector that detects a torsion bar torque applied to the torsion bar, a rotational angle detector that detects a rotational angle of the electric motor, and a microcomputer. The microcomputer is configured to estimate a driver torque applied to the steering wheel using at least (i) the torsion bar torque detected by the torque detector, (ii) the rotational angle of the electric motor detected by the rotational angle detector, and (iii) a physical model that is constructed with a torsion bar viscosity and a torsion bar rigidity, and determine whether the steering wheel is operated in a hands-on state or a hands-off state based on the estimated driver torque.

A vehicle steering device includes a driver torque estimation unit that includes a driver torque estimation observer, a low-pass filter, and a hands-on/off determination unit. The driver torque estimation observer estimates driver torque applied to a steering wheel by a driver on the basis of a detected value that includes at least torsion bar torque detected by a torque sensor and the rotational angle of an electric motor detected by a rotational angle sensor. The low-pass filter performs a low-pass filtering process on the estimated driver torque. The hands-on/off determination unit determines whether in a hands-on state or a hands-off state on the basis of the driver torque after being subjected to the low-pass filtering process.

Growing community of inventors

Nara, Japan

Maxime Moreillon