Abstract: There is provided an reliable electric power steering system. The electric power steering system includes a torque sensor that outputs a detection signal corresponding to a steering torque, and a controller. The controller computes a detected steering torque value based on the detection signal, and a torque differential value, which is a first-order time differential value of the detected steering torque value. The controller computes a current command value by providing compensation to a basic current command value based on the detected steering torque value with the use of a compensation value based on the torque differential value. When the detected steering torque value is held for a predetermined period, the controller holds the torque differential value at a value computed before the detected steering torque value is held, during the period in which the detected steering torque value is held.

Abstract: Disclosed herein is a system and method for improving a steering feeling of a driver while preventing a heavy feeling of a steering wheel or a kickback phenomenon during an eco-roll operation for improving a fuel ratio of the vehicle. The method includes determining, by a controller, an eco-roll operation condition in which a brake is disengaged, an accelerator pedal is disengaged, and a speed of the vehicle is a reference speed or higher. Furthermore, when the eco-roll operation condition is determined, the controller coverts a gear state of a transmission into a neutral gear state. The controller also controls an engine RPM to an idle RPM to start the eco-roll mode and an operation of an emergency steering system to assist steering power according to a steering input due to a driver manipulation of a steering wheel while the traveling in a neutral gear state of an eco-roll mode.

Abstract: A steering assembly for steering a vehicle. The steering assembly comprises a first steering knuckle having a first wheel rotatably mounted thereto, a first swing mechanism for enabling displacement of the first steering knuckle along a first arced path and a first guiding mechanism for pivoting the first steering knuckle when the first steering knuckle is displaced along the first arced path in order to maintain the first wheel oriented tangentially relative to the first arced path. The first arced path is concave relative to a central longitudinal axis of the vehicle and spaced from the first frame member, away from a central longitudinal axis of the vehicle, by a distance sufficient to prevent the first wheel from contacting the first frame member when the first steering knuckle is pivoted. There is further provided a method of operating the steering assembly.

Abstract: A vehicle steering apparatus that can prevent a large returning torque from acting when a steering wheel is turned. Through processing of an assist control program, rotational torque (assist torque) of an electric motor is calculated by adding returning torque g·Trto to turning torque Tc (in actuality, subtracting the returning torque g·Trto from the turning torque Tc). The electric motor is driven and controlled in accordance with the calculated assist torque. When the steering torque is large, the calculated returning torque gain g decreases, and therefore, the returning torque g·Trto decreases or becomes zero. With this control, the greater the force (torque) required to operate the steering wheel, the smaller the influence of the returning torque, and steering feel at the time of turning the steering wheel is improved.

Abstract: In a power steering device employing a hydraulic power cylinder, a motor-driven pump, and a driving power source for the motor, a power steering control system is configured to electrically connected to at least the motor and the power source for controlling a driving state of the motor and a power source voltage of the power source. The power steering control system includes a motor control circuit that generates a motor driving signal, whose command signal value is determined based on a steering assist force applied through the power cylinder to steered road wheels, a booster circuit that boosts the power source voltage, a motor angular acceleration detection circuit that detects or estimates a motor angular acceleration, and a booster-circuit control circuit that controls, responsively to the motor angular acceleration, switching between operating and non-operating states of the booster circuit.

Abstract: In a steering mechanism for a motor vehicle having a steering wheel with a steering shaft connected to a steering gear arrangement, the steering shaft comprises a first vibration damping element for accommodating and attenuating vibrations with relatively low amplitudes as they are generated by uneven road surfaces and a second element having lower damping characteristics than the first element for the transmission of steering movements from the steering wheel to the steering gear arrangement.

Abstract: To keep low the cross frequency of current feedback control and provide a good steering feeling, a first operation expression is selected when a difference &xgr; between a current instruction value computed based on a steering state of a steering wheel and a traveling state of a vehicle and a motor drive current value supplied from a battery to a motor for providing assist force to a system for transmitting power from the steering wheel to the wheels is larger than a predetermined value Th1, a second operation expression is selected when the difference &xgr; is smaller than the predetermined value Th1, and the difference &xgr; is corrected using the selected operation expression.

Abstract: A power steering apparatus for generating a steering assist force by a hydraulic pressure generated by a pump driven by an electric motor. The apparatus includes: a steering torque detecting mechanism (13) for detecting a steering torque; a steering urgency level calculating section (S5) for calculating a steering urgency level by using a time-based second-order differential value of the steering torque detected by the steering torque detecting mechanism; a target speed determining section (31, S6, S7) for determining, on the basis of the steering urgency level calculated by the steering urgency level calculating section, an assist starting speed as an initial target speed at which the electric motor (M) is actuated; and a control section (31) for controlling driving of the electric motor to equate the speed of the electric motor to the target speed determined by the target speed determining section.