Abstract: The present invention provides an excellent electric power steering apparatus in which torque ripple caused by a quantization error of a current control system generated in case of slow steering state and steering holding state, namely, vibration and noise on a steering wheel can be suppressed. A current controller in which a steady state gain of feedback control is a finite value is used so as to be capable of suppressing the vibration and noise. Further, according to the present invention, a smoothing filter is included in a current control system so that the quantization error is smoothed so that the torque ripple is suppressed.

Abstract: An electric power steering device changes the non-continuous, non-linear component in the duty ratio of the PWM signal versus motor current generated during steering wheel handle return into linear characteristics to suppress noise and allow a smooth and natural feeling during steering wheel handling. The electric control circuit (13) provided a current reference value calculator (22A) to calculate Iref a current controller (22B) to obtain Vref2, a compensation adder (25) to obtain a duty D1, and a current discontinuity compensator (24) in order to obtain a duty D2. A motor drive circuit (35) including an H bridge circuit whose upper stage FET (1) is driven by the duty D1, and whose lower stage FED (3) paired with the upper stage FET (1), is driven by the duty D2 to allow forming a continuous linear duty ratio characteristic in the duty ratio of the PWM signal versus the motor current.

Abstract: A motor drive control apparatus for controlling a motor has a main control part that performs a flux weakening control by a vector control of d-q axes and a rate-limit control part that controls a rate of change in a d axis current command value in the vector control. Further, there is provided a motor control apparatus for controlling a motor has a motor angular speed detection part that detects a motor angular speed of the motor and a motor control part having a current control system that controls the electric motor based on a motor current and a current command value. The motor control part calculate the current command value in which torque becomes constant by considering characteristics of the current control system based on a motor angular speed detected by the motor angular speed detection part.

Abstract: In a control device for an electric power steering system for controlling a motor on the basis of an auxiliary steering command value calculated from a steering torque generated in a steering shaft and a vehicle speed, and a current detection value of the motor that applies an auxiliary steering force to a steering mechanism, the device comprises a damping compensation unit that calculates a basic damping compensation value on the basis of a steering speed and adjusts the basic damping compensation value on the basis of an SAT estimated value and the steering speed, wherein an adjusted damping compensated value that is adjusted in the damping compensation unit is added to the auxiliary steering command value.

Abstract: In a motor driving device where a motor having a winding wire with small inductance value is driven by a digital control means comprised of control means including a current command value calculating means, a current control means and a PWM control means whose sampling periods are different from each other, when discrete signals sampled by the respective control means are zero-order-held, a motor current includes a lot of higher harmonic waves due to a quantization error, thereby increasing a motor noise. When an n-th-order hold means is provided between the respective control means with different sampling periods, the quantization error can be reduced remarkably, and thus the higher harmonic wave components included in the motor current are reduced, thereby greatly reducing the motor noise.

Abstract: An object of the present invention is to provide an electric power steering apparatus that can detect failure of a current detector quickly and with less misdetection using torque oscillation from a torque sensor. When the number of times N an absolute value of a differential value of a torque command value Tref exceeds a predetermined threshold value dTq in a predetermined time Tmr has reached a predetermined number Nref it is judged that the current detector has failed.

Abstract: An object of the present invention is to provide an electric power steering apparatus that can detect failure of a current detector quickly and with less misdetection using torque oscillation from a torque sensor. When the number of times N an absolute value of a differential value of a torque command value Tref exceeds a predetermined threshold value dTq in a predetermined time Tmr has reached a predetermined number Nref it is judged that the current detector has failed.

Abstract: The present invention provides an excellent electric power steering apparatus in which torque ripple caused by a quantization error of a current control system generated in case of slow steering state and steering holding state, namely, vibration and noise on a steering wheel can be suppressed. A current controller in which a steady state gain of feedback control is a finite value is used so as to be capable of suppressing the vibration and noise. Further, according to the present invention, a smoothing filter is included in a current control system so that the quantization error is smoothed so that the torque ripple is suppressed.

Abstract: There is provided a control unit for an electric power steering apparatus that controls a motor for giving steering assist force to a steering mechanism, based on a current control value calculated from a steering assist command value calculated based on the steering torque generated in the steering shaft, and a current value of the motor. The control unit has a first controller and a second controller for controlling the motor. Based on a current command value calculated by the second controller, the second controller monitors the first controller that controls the driving of the motor based on the steering assist command value calculated by the first controller. When the first controller is in a status not controlling the steering assist command value, the function of the second controller for monitoring the first controller is limited.

Abstract: There have been cases wherein the program itself does not operate normally and only continues to output the monitoring pulse so that racing cannot be detected, or due to electromagnetic waves or noise a pulse signal being outputted normally is measured erroneously and a mis-detection is made. In a control apparatus of an electric power steering system for, on the basis of a current command value computed from a current detected value of a motor and a steering assist command value computed on the basis of a steering torque arising in a steering shaft, controlling the motor, which applies a steering assist force to a steering mechanism, a control apparatus of an electric power steering system characterized in that it comprises a first control part and a second control part each inputting at least a torque signal, a vehicle speed signal, the motor current detected value and a motor terminal voltage, and the motor is controlled with the first control part and the second control part.

Abstract: There is provided a control unit for an electric power steering apparatus that controls a motor for giving steering assist force to a steering mechanism, based on a current control value calculated from a steering assist command value calculated based on the steering torque generated in the steering shaft, and a current value of the motor. The control unit has a first controller and a second controller for controlling the motor. Based on a current command value calculated by the second controller, the second controller monitors the first controller that controls the driving of the motor based on the steering assist command value calculated by the first controller. When the first controller is in a status not controlling the steering assist command value, the function of the second controller for monitoring the first controller is limited.

Abstract: A third-order nonlinear optical material having a metal oxide contained in a transparent polymer.

Abstract: A third-order nonlinear optical material comprising a complex compound represented by the general formula:A.sub.k B.sub.l (LIG.sub.a).sub.i (LIG.sub.b).sub.j (1)wherein A represents one metallic element selected from the group consisting of Cr, Mo and W; B represents one metal selected from the group consisting of Ni, Pd and Pt; each of LIG.sub.a and LIG.sub.b represents one ligand selected from the group consisting of monodentate and higher ligands; k is an integer of 0 or 1 to 4; l is an integer of 0 or 1 to 4; k+l is 2 or 4; i is an integer of 0 to 18; j is an integer of 0 to 18; and i+j is an integer of 1 to 18; provided that i and i+j are determined depending on the type and number of metals and the types of LIG.sub.a and LIG.sub.b.

Abstract: There are provided a third-order nonlinear optical material comprising a film formed on the surface of a transparent substrate and consisting essentially of an oxide of a metal selected from the group consisting of V, Cr, Mn, Fe, Co, Ni and Cu; and a third-order nonlinear optical material of the type as described above wherein the film additionally contains a metal selected from the group consisting of Au, Ag and Cu in the form of particles dispersed therein and having a particle size of at most 500 nm.

Abstract: There are provided a third-order nonlinear optical material comprising a film formed on the surface of a transparent substrate and consisting essentially of an oxide of a metal selected from the group consisting of V, Cr, Mn, Fe, Co, Ni and Cu; and a third-order nonlinear optical material of the type as described above wherein the film additionally contains a metal selected from the group consisting of Au, Ag and Cu in the form of particles dispersed therein and having a particle size of at most 500 nm.

Abstract: An apparatus for conducting flash photographing by a camera capable of incorporating or setting therein a flashlight device and generating a trigger signal at full opening of a shutter, and a capacitor adapted to release electric charge stored therein in response to said trigger signal for a flash discharge tube to emit flash.