Honda Motor Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Shigeru Yamawaki

Yasuo Shimizu

Atsuhiko Yoneda

Katsuji Watanabe

Kazushige Sugamata

Yoshihiro Oniwa

Yasuhiro Terada

Yasuharu Ohyama

Yoshinobu Mukai

Yoshimichi Kawamoto

Satoshi Matsushita

Takashi Horiguchi

Shigenori Takimoto

Shinzi Hironaka

Takehito Shiraishi

Yukihiro Wakakuwa

A traveling control apparatus includes: an information obtainer configured to obtain braking state information of a braking device in the host vehicle; and an ACC-ECU configured to execute traveling control including constant speed traveling control to cause the host vehicle to travel at a constant speed based on a preset vehicle speed, and follow-up traveling control to cause the host vehicle to travel so as to follow another vehicle traveling ahead of the host vehicle at a predetermined inter-vehicle distance. The ACC-ECU deactivates the ACC at a time when a braking performance index EV, derived from braking state information obtained by the information obtainer while the ACC being in operation, is deemed to be decreased by more than a predetermined first variation width IN_dif, as compared with a braking performance index EVat a time of the ACC having been activated.

Traveling control apparatus

An electric power steering apparatus includes a motor control unit for controlling an electric motor operatively connected to a steering shaft. The motor control unit includes a first control unit for controlling a steering torque detected by a torque detecting unit so as to bring the steering torque to zero or to a first predetermined value, and a second control unit for controlling the steering torque detected by the torque detecting unit so as to bring the steering torque to a second predetermined value which is greater than zero or than the first predetermined value, based on an operational quantity detected by an operational-quantity detecting unit or a quantity representative of a vehicle behavior detected by a vehicle-behavior detecting unit. The motor control unit controls the electric motor based on an output signal from the first control unit and an output signal from the second control unit.

Electric power steering apparatus

An electric power steering device wherein mechanical friction is electrically provided. A steering torque value is detected by a steering torque sensor according to the operation of a steering wheel. An assist current value is calculated by an assist control section on the basis of the steering torque value. A target current value based on the assist current value is determined. For providing friction to the operation of the steering wheel, a friction control section and a friction torque value/current value conversion section generate a corrected steering torque value. A second corrected target current value is created by correcting a first corrected target current value by a friction current value. The corrected steering torque value is obtained by correcting the steering torque value by a friction torque value. The target current value is generated, resulting in a motor being subjected to driving control.

Electric power steering device

In an electric power steering apparatus, an elastic member, disposed between the steering shaft and the housing, configured to be elastically deformed in accordance with rotation or displacement in a vehicle width direction, of the steering shaft. At least two bearings, disposed with a gap in an axial direction of the steering shaft, are configured to support the steering shaft. The elastic member is disposed between the bearings. A supporting member may be disposed between the steering shaft and the elastic member and configured to be displaced by a rotation of a predetermined angle or predetermined distance in accordance with the rotation or a displacement, in the width direction of the vehicle, of the steering shaft with slidable support for the steering shaft. The elastic member is fixed to the supporting member and abuts the housing.

The present invention discloses a controller of an electric power-assist steering system including a torque detector for detecting a torque applied with a steering wheel that steers a steering system; a steering status determining section for determining a steering status of either 'turn' or 'return' of a steering wheel; and a motor controlling unit for driving a motor in accordance with a target current value calculated based on at least a torque value from the torque detector and the steering status of either &#x201c;turn&#x201d; or &#x201c;return&#x201d; of the steering wheel from the steering status determining section, wherein the motor controlling unit sets a target current value right after a time when the steering status is switched between &#x201c;turn&#x201d; and &#x201c;return&#x201d; to be substantially equal to an actual current value right before a time when the steering status is switched between &#x201c;turn&#x201d; and &#x201c;return&#x201d;.

Controller of electric power-assist steering system

An electric power steering device is configured to transmit an auxiliary torque to a steering unit of front wheels, and includes: an operator; an electric motor configured to generate the auxiliary torque in accordance with at least a steering torque generated by input from the operator; the steering unit of front wheels which includes a pinion shaft; and a rotation terminating mechanism which provides a motion terminating end of the operator, the rotation terminating mechanism being disposed between the operator and the pinion shaft.

An electric damper which does not transmit unbalance wheel vibration to a vehicle body is provided. A low-pass cutoff frequency setting unit and a high-pass cutoff frequency setting unit respectively set the cutoff frequencies for band-stop filters to a frequency band corresponding to unbalance wheel vibration based on a signal indicating a vehicle speed from a vehicle speed sensor, and a function as a band-stop filter comprising a low-pass filter computation unit, a high-pass filter computation unit and an adder is computed for a displacement rate of the vertical motion of a wheel calculated by a differentiating unit in a damper control unit. A damper control amount computation unit calculates a control amount of controlling an electric motor for a motor-driven damper based on the calculated filtered displacement rate, and outputs a control signal to a motor driving unit through a driving circuit output unit.

Electric damper

An electric steering system includes a steering torque measuring device for measuring a steering torque input into a steering system, a steering speed measuring device for measuring a steering speed of the steering system; a target current computing section for computing a target current based on the steering torque measured by the steering torque measuring device, and a control section for applying a steering power to the steering system by driving a motor according to the target current. When the measured steering speed is less than a predetermined speed value, the control section applies damping to the steering system based on the measured steering speed and when it is not the control section performs a control operation of adding a specified steering torque defined when the steering speed is equal to the predetermined speed value and an increment for the steering torque determined in accordance with the steering speed to each other, defining the sum of the addition as a target steering torque, and controlling the target current so that the measured steering torque coincides with the target steering torque.

Electric steering system for rapidly increasing damper gain after steering speed exceeds a specific value

An electric steering system includes a device for measuring a steering input into a steering system; a device for measuring a steering speed; a section for computing a target current based on the steering input; and a control section for applying a steering power to the steering system by driving a motor according to the target current, and applying damping to the steering system based on the steering speed. A rate of increase in a damper gain defined when the steering speed is equal to or greater than a predetermined value is higher than that defined when the steering speed is less than the predetermined value, or the damper gain defined when the steering speed is equal to or greater than a predetermined value has a constant value increased in a step form from values of the damper gain defined when the steering speed is less than the predetermined value.

An electric power steering apparatus comprising a rack shaft having two racks, a first rack-and-pinion mechanism for transferring a steering torque to the rack shaft, and a second rack-and-pinion mechanism for transferring an assist torque to the rack shaft. The second rack-and-pinion mechanism includes a pinion and a rack both being helical gears so that a large torque can be transmitted to the rack shaft. Teeth of the pinion and rack are arc profiled. The arc profiled teeth mesh with each other through a large contact area of concave and convex surfaces thereof and hence with a reduced contact pressure compared to involute profiled teeth. The arc profiled teeth thus have increased surface fatigue strength, bending strength and bending fatigue strength and can transmit an assist torque sufficiently to the rack shaft. Moreover, they have durability sufficient to withstand a torque load of a motor inertia.

A magnetostrictive torque sensor includes a magnetostrictive film of width W provided along a circumference of a rotational shaft. The film causes magnetostriction in correspondence to a torque applied to the rotational shaft. The torque sensor also includes excitation and detection cores each having substantially U-shaped configuration. These cores are disposed in opposed relation to the film. The excitation core extends through an excitation coil while the detection core extends through a detection coil. The excitation core is disposed on the detection core at right angles. The film has a magnetic path passing therethrough. The magnetic path, the excitation coil, and the detection coil cooperate with each other to provide a magnetic circuit. The excitation coil and the detection coil provides a bridge circuit in cooperation with each other. When a torque is applied to the rotational shaft, the film causes magnetostriction in correspondence to the torque. The magnetostriction is electrically detected by the bridge circuit.

Magnetostrictive torque sensor and electric power steering apparatus including the same

A vehicle behavior control apparatus is disclosed. The vehicle behavior control apparatus comprises: a slip angle difference predicting section for predicting a difference between a slip angle of front wheels and a slip angle of rear wheels; a steer angle detecting section for detecting a steer angle of the vehicle; and a control section for controlling turning behaviors of the vehicle, based on an angle difference signal from said slip angle difference predicting section and a steer angle signal from said steer angle detecting section.

Vehicle behavior control apparatus

An electric power steering apparatus having a motor for producing assist torque according to the steering torque, and a rack and pinion mechanism for transferring torque assistance to the rack shaft. The pinion and rack of the rack and pinion mechanism are both helical gears, and transfer high torque to the rack shaft. The helical gears have a curved arc tooth profile. The teeth of a curved arc tooth profile gear set mesh with contact between convex and concave surfaces. The contact area is therefore increased and contact pressure is decreased compared with involute teeth. Surface fatigue strength, bending strength, and bending fatigue strength are thus greater compared with involute teeth. The combined steering torque and assist torque is efficiently transferred to the rack shaft, and durability is sufficient to withstand torque loads from motor inertia.

Electric power steering apparatus includes a control nit for controlling an electric motor to impart electric steering assist torque to the steering system of an automotive vehicle. The control unit is provided with a non-steady state detector section that generates a modification signal when it detects a non-steady state of the vehicle in which the steering wheel is turned to an excessive extent. Target motor current signal, which acts to impart the electric steering assist torque corresponding to manual steering torque, is modified by the control unit in accordance with the modification signal generated by the non-steady state detector section. Thus, the tire-to-steering-wheel torque is assisted in a returning direction of the steering wheel, so that the steering wheel is allowed to return to its center position at an increased speed.

An electric power steering apparatus comprises a control unit for drive-controlling a motor to apply an assist torque to a steering system based on signals from various sensors. The control unit comprises a slip angle difference predicting section for predicting a difference between a slip angle of front wheels and a slip angle of rear wheels, and a correcting section for correcting, based on an angle difference signal outputted from the slip angle difference predicting section, a target torque signal supplied to the motor. Behavior of a vehicle is predicted from the angle difference signal and the target torque signal is corrected by a correction amount corresponding to the angle difference signal so that the motor can be drives controlled with the influence of a change in a road surface reaction force taken into consideration.

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Wako, Japan

Shigeru Yamawaki