Jtekt Corporation

Koyo Seiko Company, Ltd.

Toshiaki Oya

Masahiko Sakamaki

Shigeki Nagase

Takeshi Ueda

Katsutoshi Nishizaki

Yoshinobu Shimizu

Ken Matsubara

Yasuhiro Kamatani

Kazuhiro Watanabe

Masaharu Yamashita

Yuji Fujita

Yuji Kariatsumari

Yosuke Yamashita

Akihiko Shiina

Osamu Sano

Kosuke Yamanaka

Shintaro Takayama

Toshihiro Takahashi

Yuuta Kajisawa

Shirou Nakano

Kenichi Abe

Yasuyuki Yoshii

Yoshikazu Kuroumaru

Yasuhiro Saitou

Takayasu Yamazaki

Kotaro Okada

Yoshimi Kotake

Ryouichi Tokioka

Takashi Ohata

Hiroji Ueda

Katsuyuki Oguchi

Masayoshi Ashitaka

Masakazu Furuyoshi

Takeshi c/o Jtekt Corporation Ueda

Yasuhiro c/o Jtekt Corporation Saitou

A steering control device includes an emergency determination unit configured to determine whether or not an emergency exists in which an emergency avoidance operation is to be performed, and a work adjustment unit configured to adjust work of a driver required to steer steered wheels. The work adjustment unit is configured to execute emergency adjustment processing for adjusting the work in accordance with a determination result of whether or not an emergency exists. The emergency adjustment processing includes reduction processing for reducing the work in an initial stage after the emergency determination unit determines that an emergency exists, as compared in a case in which determination is not made that an emergency exists.

Steering control device and steering control method

A steering system is configured such that electric power is supplied to a steering actuator and a turning actuator from a first power supply when a power state of a vehicle is an on state and supply of the electric power from the first power supply is cut off when the power state is an off state. The steering system includes a rotation curbing unit configured to operate such that rotation of the steering wheel is curbed in at least a part of a first power-off period from when the power state becomes an off state until when the power state becomes the on state next, as an operating period, and a second power supply configured to supply, to the rotation curbing unit, the electric power required for operation of the rotation curbing unit in the operating period, the second power supply being different from the first power supply.

Steering system

A second target steered angle setter includes: a first multiplier configured to, when the vehicle is making a right turn, reduce a base target steered angle correction amount so as to set the reduced base target steered angle correction amount to be a left target steered angle correction amount, and configured to, in other states, set the base target steered angle correction amount to be the left target steered angle correction amount on an as-is basis; and a second multiplier configured to, when the vehicle is making a left turn, reduce the base target steered angle correction amount so as to set the reduced base target steered angle correction amount to be a right target steered angle correction amount, and configured to, in other states, set the base target steered angle correction amount to be the right target steered angle correction amount on an as-is basis.

Steering assist apparatus

A left steering ECU includes switching control unit that switches control mode between a first control mode and a second control mode. The first control mode is mode in which the left steering ECU controls left steering motor so that the steered angle of a left steered wheel becomes equal to a left target steered angle received from a higher-level control device. The second control mode is a mode in which the left steering ECU controls the left steering motor by torque feedback control so that the steered angle of the left steered wheel becomes equal to an angle corresponding to a neutral position of the left steered wheel. The switching control unit normally sets the control mode to the first control mode. The switching control unit switches the control mode to the second control mode if abnormal communication occurs between the higher-level control device and the left steering ECU.

Vehicle steering device

In a vehicular steering system, a steering wheel (steering member) operated for steering and a steering operation mechanism are not mechanically coupled together, and the steering operation mechanism is driven by a steering operation motor. The vehicular steering system includes a reaction force motor that applies a reaction force to the steering member, and a reaction force motor control unit that controls the reaction force motor. The reaction force motor control unit includes a torque limiter that limits a current flowing through the reaction force motor to a predetermined value or smaller during automatic operation.

Vehicular steering system

In a steering assist device, a lane keep assist current value calculation unit calculates, based on a lateral deviation and a lateral deviation change rate, a lane keep assist current value that makes the lateral deviation and the lateral deviation change rate closer to zero. When the steering direction represented by the sign of control steering torque is the same as the steered direction represented by the sign of the fourth lane keep assist current value, a switch unit selects zero received at its second input terminal and outputs zero as a final lane keep assist current value.

Steering assist device

A vehicle steering device includes: a target-steered-angle setting unit configured to set a left target steered angle that is a target value of the steered angle of a left steered wheel and a right target steered angle that is a target value of the steered angle of a right steered wheel; left motor controllers configured to control a left steering motor based on a left-steered-angle deviation that is a difference between the left steered angle and the left target steered angle; right motor controllers configured to control a right steering motor based on a right-steered-angle deviation that is a difference between the right steered angle and the right target steered angle; and an abnormality determination unit configured to determine that an abnormality has occurred when an absolute value of difference between the left-steered-angle deviation and the right-steered-angle deviation is equal to or larger than a first threshold.

In a steering assist device, a main lane keep assist current value setting unit sets a main lane keep assist current value that generates main lane keep assist torque according to a lateral deviation and a lateral deviation change rate. A sub lane keep assist current value setting unit sets a sub lane keep assist current value that generates sub lane keep assist torque according to curvature ct of a target travel line.

A vehicle steering system includes a higher-level ECU and a lower-level ECU. The lower-level ECU includes a steered angle limit setter, and steered angle limiters. The steered angle limit setter sets an allowable upper limit to a target inner and outer wheel steered angle difference responsive to the absolute value of a target outer steered angle. The steered angle limit setter calculates a limit to the absolute value of a target inner steered angle. The steered angle limit setter subsequently sets this limit for one of the steered angle limiters that is fed the target inner steered angle in the present calculation cycle. The limiter, which is fed the target inner steered angle, limits the absolute value of the target inner steered angle so that the absolute value of the target inner steered angle is equal to or below the limit, and outputs the resulting value.

Vehicle steering system

In a steering assist device, a correction gain setting unit sets correction gain to one if it determines that that the sign of a lateral deviation change rate is different from that of a second derivative value of a lateral deviation. The correction gain setting unit sets the correction gain to a predetermined value that is larger than one, if it determines that that the sign of the lateral deviation change rate is the same as that of the second derivative value of the lateral deviation. A gain multiplication unit corrects a lane keep assist current value calculated by a lane keep assist current value calculation unit by multiplying the lane keep assist current value by the correction gain set by the correction gain setting unit.

There is provided a steering assist device that allows a vehicle to avoid departing from a lane. A basic target current value setting unit sets a basic target current value on the basis of steering torque and a vehicle speed. A current compensation value computation unit computes a current compensation value for compensating the basic target current value on the basis of a lateral deviation and a lateral deviation variation rate such that the lateral deviation and the lateral deviation variation rate get close to zero. A target current value computation unit computes a target current value by subtracting the current compensation value computed by the current compensation value computation unit from the basic target current value set by the basic target current value setting unit.

An auxiliary power supply device that can always supply stable auxiliary power at the time of using an auxiliary power source and an electric power steering device employing the auxiliary power supply device are provided. In the auxiliary power supply device including a discharge circuit selectively constituting a state where a motor is supplied with power from only a battery and a state where the motor is supplied with power from a power source in which an auxiliary power source is connected in series to the battery by PWM control, when the power consumption of the battery is greater than an upper limit, a control circuit is provided which controls the power consumption to return to the upper limit by performing an electric power feedback control using a duty as an amount of operation at the time of turning on and off switching elements by a PWM control on the basis of the difference.

Auxiliary power supply device and electric power steering device

In an electric power steering apparatus of the invention, a control circuit determines a command value of drive voltage supplied to a motor drive circuit based on an actual current through a motor and a target current. When the command value exceeds the previous value having a lower limit equivalent to a limit value representing the limit of the power supply from a battery, the control circuit controls the amount of discharge from the auxiliary power supply according to a difference between the command value and the previous value by increasing or decreasing a duty of switching devices. Thus, the power steering apparatus can save the energy of the auxiliary power supply for efficiently using the auxiliary power supply.

Electric power steering apparatus

A current sensor of a motor controller detects the current applied to a motor drive circuit and thus a phase where a failure cannot be detected would occur without taking any measures. However, an abnormal current monitor section contained in a microcomputer receives a voltage signal of an average value of the currents detected in the current sensor by allowing a signal to pass through a first LPF having a cutoff frequency sufficiently lower than the frequency of a PWM signal. Therefore, whether or not the value is within a predetermined normal range is checked, whereby whether or not some failure containing a failure of the current sensor occurs can be easily determined about every phase.

Motor controller and electric power steering system

An electric power steering system includes: a band-stop filterhaving a transfer function G(s) for suppressing resonance, and a phase compensatorhaving a transfer function G(s). The above function G(s) is represented by an expression G(s)=(s+2&#x3b6;&#x3c9;+&#x3c9;)/(s+2&#x3b6;&#x3c9;+&#x3c9;), where s is a Laplace operator, &#x3b6;is a damping coefficient, &#x3b6;is a damping coefficient, and &#x3c9;is an angular frequency. On the other hand, the above function G(s) is represented by an expression G(s)=(s+2&#x3b6;&#x3c9;+&#x3c9;)/(s+2&#x3b6;&#x3c9;+&#x3c9;),where s is a Laplace operator, &#x3b6;is a damping coefficient, &#x3b6;is a damping coefficient, and &#x3c9;is an angular frequency. Furthermore, the above damping coefficients &#x3b6;, &#x3b6;satisfy an expression &#x3b6;24 &#x3b6;Thus, a filter such as a phase compensator may attain a design freedom while preventing the increase of arithmetic load, whereby both the suppression of resonance and a good assist response in a normal steering speed region, for example, may be achieved.

Growing community of inventors

Sakai, Japan

Toshiaki Oya