Abstract: A bottom casting apparatus comprises a pouring pipe, a stool, molds, and runners, wherein the runner satisfies the following equations (1) and (2) and a gap formed between a side wall of a groove for a runner provided in the stool and a runner brick is filled with heat resisting granules, A−D≦D(Z/100)+2.5 (mm)  (1) A−D>B−E>0  (2) where, A and B are widths (mm) at an upper portion and a bottom portion of the groove, respectively, D and E are widths (mm) at an upper portion and a bottom portion of the runner brick disposed within the groove, respectively, and Z is a mean coefficient of linear expansion (%) of the runner brick in the temperature range of a room temperature to 1000° C.

Abstract: A DC motor driven power steering system for a motor vehicle includes a motor current detection circuit for detecting a motor current flowing through the DC motor, a power supply voltage detection circuit for detecting a power supply voltage applied to the bridge commutation circuit, a motor voltage estimating unit for estimating a voltage applied across the DC motor on the basis of the power supply voltage applied to the bridge commutation circuit and the pulse-width modulated control signals used for controlling the bridge commutation circuit, and a motor rotation detecting means for detecting the rotation state of the DC motor on the basis of the motor current and the estimated motor voltage applied to the DC motor. High reliability can be ensured for detection of the rotation state of the DC motor.

Abstract: An electric power steering control system in which the steering "feel" is improved, having a steering force detector an electric motor for producing an auxiliary steering force, a motor current detector and a control unit for deciding the motor current value and rotational direction at least in accordance with the detected steering force. The motor current is limited in accordance with the detected steering force and motor current values.

Abstract: A vehicle control apparatus includes a steering torque sensor (1) for sensing a steering torque, a motor (3) for generating a steering assisting force, a CPU (22) for determining a motor drive direction based on at least the steering force and a motor drive direction restricting circuit (25) for restricting the drive direction of the motor (3) determined by the CPU (22) based on a steering force determination level as a motor drive direction determination criterion and the steering force, and the steering force determination level is changeable.

Abstract: A vehicle control apparatus includes a steering torque sensor (1) for sensing a steering torque, a motor (3) for generating a steering assisting force, a CPU (22) for determining a motor drive direction based on at least the steering force and a motor drive direction restricting circuit (25) for restricting the drive direction of the motor (3) determined by the CPU (22) based on a steering force determination level as a motor drive direction determination criterion and the steering force, and the steering force determination level is changeable.

Abstract: An electric power steering control system in which the steering "feel" is improved, having a steering force detector an electric motor for producing an auxiliary steering force, a motor current detector and a control unit for deciding the motor current value and rotational direction at least in accordance with the detected steering force. The motor current is limited in accordance with the detected steering force and motor current values.

Abstract: An electric power steering control apparatus is intended to improve the convergence and control stability of a returning motion of a steering wheel when a driver of a vehicle on which the apparatus is installed lets his or her hands free from the steering wheel, and to reduce a burden to the driver when an excessive steering torque occurs during the returning motion. The apparatus includes a steering torque sensor 8 for detecting a steering torque of a steering system of the vehicle, a motor rotational-speed detector 7 for detecting a rotational speed of the electric motor, and a rotational-speed controller for controlling the electric motor based on output signals from the steering torque sensor and the motor rotational-speed sensor so that when the steering torque as detected is less than a predetermined torque value, the rotational speed of the electric motor does not exceed a predetermined speed value corresponding to the predetermined torque value.

Abstract: A vehicle control apparatus includes a steering torque sensor (1) for sensing a steering torque, a motor (3) for generating a steering assisting force, a CPU (22) for determining a motor drive direction based on at least the steering force and a motor drive direction restricting circuit (25) for restricting the drive direction of the motor (3) determined by the CPU (22) based on a steering force determination level as a motor drive direction determination criterion and the steering force, and the steering force determination level is changeable.

Abstract: An electric power steering control system in which the steering "feel" is improved, having a steering force detector an electric motor for producing an auxiliary steering force, a motor current detector and a control unit for deciding the motor current value and rotational direction at least in accordance with the detected steering force. The motor current is limited in accordance with the detected steering force and motor current values.

Abstract: A DC motor driven power steering system for a motor vehicle includes a motor current detection circuit for detecting a motor current flowing through the DC motor, a power supply voltage detection circuit for detecting a power supply voltage applied to the bridge commutation circuit, a motor voltage estimating unit for estimating a voltage applied across the DC motor on the basis of the power supply voltage applied to the bridge commutation circuit and the pulse-width modulated control signals used for controlling the bridge commutation circuit, and a motor rotation detecting means for detecting the rotation state of the DC motor on the basis of the motor current and the estimated motor voltage applied to the DC motor. High reliability can be ensured for detection of the rotation state of the DC motor.

Abstract: A power steering motor control unit for driving a motor in a PWM mode with feedback motor current control reduces fluctuations in the output torque of the motor caused by switching among a plurality of motor driving modes or a change in the duty value of the PWM signal. The control unit as a switching device driving circuit for driving the motor in the PWM mode and a plurality of motor driving modes for the driving control system of a motor, Q/D switching circuitry 14 for switching the motor driving mode, and detected current correcting circuitry 16 for correcting at least one input signal of an input signal comparing circuit provided in a feedback control loop in accordance with the motor driving mode. When the motor driving mode is switched, the correction value given by the detected current correcting circuitry is changed.

Abstract: A control system for an electrically operated power steering apparatus which is capable of eliminating an incongruous steering sensation and improving the converging performance of a steering wheel. The control system comprises a steering torque detecting unit 20 for detecting a steering torque applied to a steering system, a motor 10 coupled to the steering system, and a control unit for controlling the motor 10 using an output of the steering torque detecting unit 20 phase-compensated on the basis of a speed of the motor 10. The control unit includes a target current determining section 25 for determining a target current to the motor 10 on the basis of the output of the steering torque detecting unit 20 and a phase compensating section 21 for obtaining a phase compensation value on the basis of the output of the steering torque detecting unit 20 and the speed of the motor 10. The target current is corrected by the phase compensation value.

Abstract: A controller apparatus for a vehicle includes a computer for controlling devices mounted in the vehicle, and a detector means for detecting the state of the computer immediately before the computer enters a reset state. The computer determines its processing contents on the basis of the detection result of the detection means immediately after the computer is started. Thus, the controller apparatus detects the abnormal reset of the computer in control, thereby assuring the safe control of the devices.

Abstract: [Object] To improve system reliability and safety. [Constitution] The rotation speed of the motor 6 is detected by the motor rotation speed detection circuit 17 and the amount of rotation of the motor 6 is calculated from the detected rotation speed by the motor rotation amount calculating means 10a. Then, a fault is determined when the amount of rotation exceeds a predetermined value and the drive of the motor 6 is stopped by the motor stopping means 123.

Abstract: In a electric power steering controller, an output signal of motor driving direction discrimination means is compared with a driving direction discrimination processing result to detect a failure of the motor driving direction discriminator in accordance with the comparison result, so as to prevent the runaway of a motor supplying steering force to a steering wheel.

Abstract: A motor for a motor-assisted power steering device is controlled with a control value which is obtained by detecting an error between an actual steering torque which has undergone phase lead compensation and a target steering torque, and by summing a proportional value, an integration value and a differentiation value of the error, or with a control value which is obtained by detecting an error between actual steering torque and a target torque; obtaining a proportional value, an integration value and a differentiation value of the error; clipping the lower limit value of the integration value with a first clipping circuit, and clipping the upper and lower limit values of motor-controlling quantity obtained by summing the proportional value, the integration value and the differentiation value by using a second clipping circuit.

Abstract: A control apparatus for an electric motor-driven power steering system includes a main CPU for arithmetically determining the steering assist torque to be generated by the electric motor and a driving direction thereof on the basis of outputs of a torque sensor and the vehicle speed sensor, a subsidiary CPU for arithmetically determining the driving direction of the motor on the basis of outputs of the torque sensor and the vehicle speed sensor and compare the driving direction signal supplied from the main CPU with a signal of the driving direction determined by the subsidiary CPU to generate a second driving direction signal. A coincidence/discrepancy signal representing coincidence or discrepancy between the motor driving direction signal and the steering torque signal is also supplied to the subsidiary CPU from the main CPU.

Abstract: A motor for a motor-assisted power steering device is controlled with a control value which is obtained by detecting an error between an actual steering torque which has undergone phase lead compensation and a target steering torque, and by summing a proportional value, an integration value and a differentiation value of the error, or with a control value which is obtained by detecting an error between actual steering torque and a target torque; obtaining a proportional value, an integration value and a differentiation value of the error; clipping the lower limit value of the integration value with a first clipping circuit, and clipping the upper and lower limit values of motor-controlling quantity obtained by summing the proportional value, the integration value and the differentiation value by using a second clipping circuit.

Abstract: A motor-driven type power steering apparatus for assisting a driver in manipulating a steering wheel of a motor vehicle includes a steering-wheel return state decision circuit for deciding whether the steering wheel is in the state to be returned to a center position, a control quantity generating and selecting circuit for generating control quantities corresponding to respective driving modes on the basis of a control quantity of the electric motor and selecting one of the control quantities in dependence on the result of the decision made as to the return state of the steering wheel, and a conversion circuit for converting the control quantities into PWM duty ratios, respectively. In the normal steering operation, switching elements for energizing the motor are driven with the PWM duty ratio corresponding to a first driving mode, while upon return of the steering wheel to the center position, the switching elements are driven with the PWM duty ratio corresponding to a second driving mode.

Abstract: A motor-driven power steering apparatus and method for a vehicle are able to avoid frequent on-off operations of an electromagnetic clutch 14 as much as possible, which connects or disconnects a motor 13 with or from a steering system, thus improving the durability of the clutch 14 and suppressing the generation of undesirable noise and shocks upon connection and disconnection of the clutch 14. A clutch controller 191 controls a clutch current Ic supplied to the clutch 14 based on the vehicle speed V in such a manner that it sets the clutch current Ic to a first predetermined clutch current level I(V) so as to place the clutch into a substantially engaged state when the vehicle speed V is less than a first predetermined vehicle speed Vo, and to a second predetermined clutch current level Icr which is less than the first predetermined clutch current level I(V) so as to place the clutch into a partially engaged state when the vehicle speed V is equal to or greater than the first predetermined vehicle speed Vo.