Jtekt Corporation

Koyo Seiko Company, Ltd.

Masayasu Higashi

Shuuji Kimura

Shingo Maeda

Ryouhei Hayama

Masaya Segawa

Toyoki Sugiyama

Tomoyasu Kada

Takeshi Watanabe

Katsutoshi Nishizaki

Robert Fuchs

Naotake Kanda

Kenji Higashi

Shirou Nakano

Takeo Iino

Hiroshi Yoshimoto

Masayuki Ueno

Daisuke Miki

Provided is a steering system including a controller that controls an electric motor. The controller has a combined friction torque estimation unit that estimates a combined friction torque combining friction torques occurring in respective transmission devices including a first transmission device. The combined friction torque estimation unit has a slipping speed calculation part that calculates a slipping speed of the first transmission device based on an angular speed of the electric motor, a friction coefficient calculation part that calculates a friction coefficient of the first transmission device based on the slipping speed, a tooth flank normal force calculation part that calculates a normal force acting on a tooth flank of the first transmission device, and a friction torque calculation part that calculates the combined friction torque using the friction coefficient, the tooth flank normal force, and one or more preset correction factors.

Steering system

An electric power steering system includes: an electric motor that generates assist torque; an auxiliary power supply device including a capacitor connected to a main power supply and discharging electric power to the electric motor; and a control device that controls the auxiliary power supply device. There is a plurality of modes of connection between the main power supply and the auxiliary power supply device. The control device switches the mode of connection between the main power supply and the auxiliary power supply device, depending on the situation.

Electric power steering system

An electric power steering system includes: an assist motor that generate assist force for assisting steering of a steering member; a motor drive circuit that controls driving of the assist motor; a capacitor that is electrically connected to a main power supply that supplies electric power to the assist motor, the motor drive circuit, and electrical components; and a controller that controls charging and discharging of the capacitor. The controller discharges electricity to the electrical components when an amount of electric charge remaining in the auxiliary power supply is equal to or greater than a first threshold value in an engine start-up period in a vehicle.

A vehicle attitude control system includes a control unit that calculates a front wheel control amount and a rear wheel control amount on the basis of a front-side slip angle at a front axle of front wheels and a rear-side slip angle at a rear axle of rear wheels, and that controls the front wheels on the basis of the front wheel control amount and controls the rear wheels on the basis of the rear wheel control amount at the same time.

Vehicle attitude control system

A target sideslip angle computing unit calculates a target sideslip angle used when a vehicle makes a turn, based on a steering angle and a vehicle speed. A target sideslip angle correcting unit corrects the target sideslip angle calculated by the target sideslip angle computing unit using a sideslip angle correction amount calculated based on at least one of a steering angular velocity, a depression amount of an accelerator pedal, a depression velocity of the accelerator pedal and a depression amount of a brake pedal. Vehicle attitude control is executed using the target sideslip angle corrected by the target sideslip angle correcting unit.

An auxiliary power supply device includes a capacitor that is connected to a main power source, and that is able to discharge an electric current to an electric motor, the main power source supplying electric power to the electric motor; and a booster circuit that boosts a voltage of the main power source and applies the boosted voltage to the auxiliary power source. An operation of the auxiliary power supply device is controlled by a control device. When supply of the electric power from the main power source to the capacitor is started in a state where a voltage across terminals of the capacitor is equal to or higher than a voltage of the main power source, the control device increases the voltage applied to the capacitor by the booster circuit as the capacitor voltage increases.

Auxiliary power supply device and electric power steering system including auxiliary power supply device

A steering system includes: an operation mechanism that includes an operation member used to perform a steering operation; and a steered mechanism that is not mechanically coupled to the operation mechanism, and that steers a wheel based on the steering operation of the operation member. The operation mechanism includes a steering angle sensor that detects a steering angle of the operation member, and steering direction detection unit that detects only a steering direction of the operation member.

The steering device is constructed by supporting a center portion of a rectangle-plate-shaped operation plate at one end of a supporting shaft projected from the front face of a dashboard so as to freely swing in right and left directions. A steering apparatus for a vehicle having the steering device detects the swing direction and the swing angle of the operation plate with a steering angle sensor provided at a support portion and moves a steering mechanism in the detected direction in accordance with the detected angle so as to steer the vehicle. With this structure, a load in steering can be decreased and tiredness in driving can be reduced. Furthermore, such a steering apparatus can realize a steering device which physically handicapped drivers can operate easily.

Steering apparatus for vehicle

Steering angle is determined by the combined use of a potentiometer and a rotary encoder, and the correction of the error in the determination of the steering angle based on the time-dependent change of the potentiometer.

Steering angle correction device

A Steering system for a motor vehicle is provided. The system is provided with a principal steering actuator for applying a driving force to a steering mechanism; an auxiliary steering actuator capable of applying a driving force to the steering mechanism; a counter force actuator for applying a counter force to an operation member; a principal steering control section; an auxiliary steering control section; a counter force control section; first and second vehicle condition sensors; and a main controller for comprehensively controlling the control sections. An output signal of the first vehicle condition sensor is inputted to the main controller through a first vehicle condition signal line; and an output signal of the second vehicle condition sensor is inputted, through a second vehicle condition signal line, to at least one of the control sections.

Steering system for motor vehicle

In a vehicle steering apparatus, a steering actuator is controlled so that the steering angle varies in accordance with the operation of an operating member. A transmission mechanism connects an operating side rotating member that is mechanically connected to the operating member and a vehicle wheel side rotating member that is mechanically connected to the vehicle wheels so that the mutual transmission of rotation is possible. Furthermore, the rotational transmission ratio between the operating side rotating member and the vehicle wheel side rotating member can be varied.

Growing community of inventors

Kashihara, Japan

Masayasu Higashi