Abstract: An electric discharge machining apparatus comprises a power supply (5) for applying a voltage to a work gap formed between a tool electrode (E) and the workpiece (W) and a motor (7) that moves the tool electrode relative to the workpiece. An electric discharges counter (45) counts a number of electric discharge occurrences within a specified period (Td1) and generating a first count. A gap controller (48) multiplies the first count by a gain to generate position command or speed command for motor drive. An inversion counter (42) counts a number of inversions of the gap voltage upwards or downwards within a second specified period (Td2) and generating a second count. An electric discharge discriminator (44) discriminates the occurrence of electric discharge when the second count reaches a set value.

Abstract: A motor control system for controlling a plurality of motors for moving an object in respectively different axial directions that includes a plurality of target devices, each target device including a (pulse width modulation) PWM signal generator that generates a PWM signal for driving a motor using a triangular signal, and a host device for supplying a synchronization signal to each of the target devices, wherein each target device is arranged with a corresponding motor, and each PWM signal generator resets the triangular signal in response to the synchronization signal.

Abstract: A communication control system and method of communicating between a numerical control device and a plurality of servomotors, includes connecting the numerical control device to a plurality of servoamps of the plurality of servomotors in a loop configuration via bi-directional serial communication cables, splitting command data in the numerical control device, outputting a first portion of command data to one of the plurality of servoamps from the numerical control device in a counter-clockwise direction and a second portion of command data to one of the plurality of servoamps from the numerical control device in a clockwise direction, splitting feedback data in one of the plurality of servoamps, transmitting a first portion of feedback data to the numerical control device in a counter-clockwise direction from the one of plurality of servoamps in response to the first portion of command data, and transmitting a second portion of data to the numerical control device from the one of the plurality of servoamps i

Abstract: A position control device for causing a position of a control system, including a servomotor and a moving body driven by the servomotor, to track a command value. The position control device includes a sliding mode controller for receiving command position r and state variable x of the control system and for providing a control input u to the servomotor. State variable x is expressed as follows: x = [ ? ? . ] , where ? is feedback position and {dot over (?)} is feedback velocity. The position control device also includes a disturbance variable compensator for compensating control input u based on feedback velocity {dot over (?)}.

Abstract: A motion controller for maintaining a controlled system on a switching hyperplane regardless of the magnitude of disturbance. The motion controller includes a target position generator, a sliding mode controller, a disturbance observer and a state observer. The target observer generates a target position to the sliding mode controller based on position and velocity data. The state observer estimates the state of the controlled system and provides the state to the sliding mode controller. And, the disturbance observer provides an estimated disturbance to the sliding mode control. The sliding mode controller generates a control input to the controlled system with the nonlinear component set to equal the negative estimated disturbance and the linear component based on the estimated state and target position.

Abstract: A sinker electric discharge machine jump control device for reciprocating a tool electrode along a Z-axis with respect to a workpiece using a servo motor in order to expel contaminated fluid from a work gap. The jump control device includes a commanded current generator, the current generator generating a commanded current for the servo motor, and a commanded velocity generator, the velocity generator dividing a locus of a jump stroke into a plurality of segments and generating a commanded velocity for each of the plurality of segments. Additionally, the jump control device includes a velocity override calculator, the calculator generating a velocity override according to the commanded current, and a commanded velocity modifying device, the modifying device modifying the commanded velocity according to the velocity override during the jump stroke.

Abstract: A numeric control apparatus for machine tools having a moveable member which is operated by a servomotor, including a controlled system, where the controlled system includes a servomotor and a moveable member, and a model of the controlled system, having a system parameter. The numeric control apparatus also includes a command generator for generating a command value, a reference input value generating controller for transmitting a reference input value to the controlled system and to the model, in response to receiving the command value, and an analyzing section for storing a measured output of the controlled system and a measured output of the model.

Abstract: A PWM controller for an inverter includes a feedback circuit and a deadtime circuit for masking out of synchronization conditions which occur when the deadtime duration between switching the polarities of the desired output AC waveform is nearly equal to or longer than the duration of its PWM source waveform. The PWM controller for an inverter also includes a carrier range regulation circuit for reducing loss of the PWM duty cycle to prevent compromising the frequency spectrum of the desired AC waveform without requiring complicated software or additional CPU or DSP processing time.

Abstract: A PWM controller for an inverter includes a feedback circuit and a deadtime circuit for masking out of synchronization conditions which occur when the deadtime duration between switching the polarities of the desired output AC waveform is nearly equal to or longer than the duration of its PWM source waveform. The PWM controller for an inverter also includes a carrier range regulation circuit for reducing loss of the PWM duty cycle to prevent compromising the frequency spectrum of the desired AC waveform without requiring complicated software or additional CPU or DSP processing time.