Abstract: A control device for a die cushion mechanism, for carrying out force control with high accuracy and at a high speed. The control device for controlling the force generated by the die cushion mechanism utilizes a press working cycle which is repeatedly carried out. A correcting part of the control device corrects each deviation in one working cycle based on a time-series of deviation data in the just before press working cycle. By repeating this operation, the deviation between the detected value and the commanded value may be converged toward zero. Therefore, the deviation may become smaller than that of the conventional feedback control, whereby it is possible to respond to a change in the commanded value in a short time.

Abstract: A servo motor for driving a die is provided with position and speed detectors. Further, a pressure sensor for detecting the pressure applied to a workpiece is provided. In the servo motor control unit, the smaller one of the speed command obtained by feedback control of the position and the speed command obtained by the pressure feedback control is selected as an output of a comparator. Based on the speed command output from the comparator, feedback control of the speed is performed and the servo motor is driven. In the state where the die does not press against the workpiece, a pressure error is large, the speed command by pressure control becomes large, and the speed command by position control becomes small. Therefore, position control is performed. When the workpiece is pressed, the position error increases, and the pressure error decreases, a speed command by pressure control is employed and pressure control is performed.

Abstract: A control apparatus for controlling a die cushion mechanism including a servo-motor as a drive source and producing a force adapted to be applied to a slide in a press machine. The control apparatus includes a force commanding section for commanding a force to be produced by the die cushion mechanism; a force detecting section for detecting the force produced by the die cushion mechanism; a motor-speed detecting section for detecting an operating speed of the servo-motor; a slide-speed detecting section for detecting a moving speed of the slide; and a force controlling section for executing a force control on the servo-motor, based on a force command value commanded by the force commanding section, a force detected value detected by the force detecting section, a motor-speed detected value detected by the motor-speed detecting section and a slide-speed detected value detected by the slide-speed detecting section.

Abstract: A control apparatus for controlling a die cushion mechanism including a servo-motor as a drive source and producing a force adapted to be applied outside. The control apparatus includes a force commanding section for commanding a force to be produced by the die cushion mechanism; a force detecting section for detecting a force produced by the die cushion mechanism; a force controlling section for executing a force control on the servo-motor, based on a force command value commanded by the force commanding section and a force detected value detected by the force detecting section; and an abnormality preventing section for preventing, in association with a control state of the servo-motor, the die cushion mechanism from producing an abnormal force.

Abstract: In the control of a synchronous motor having a permanent magnet, an alternating current power supply voltage that is input to a power amplifier or a direct current link voltage of which input voltage is rectified is measured. A reactive current (a d-axis current) or a current control phase advance is changed, according to this power supply voltage. With this arrangement, reactive current control or current phase control can be carried out directly according to a change in the input power supply voltage. A motor control device includes a voltage measuring unit that measures a voltage supplied to a driving amplifier, and a current control unit that controls a current passed to a synchronous motor based on the measured voltage. The voltage measuring unit measures a voltage supplied to the amplifier. The current control unit controls a current that is passed to the synchronous motor, according to the measured voltage.

Abstract: A servo motor for driving a die is provided with position and speed detectors. Further, a pressure sensor for detecting the pressure applied to a workpiece is provided. In the servo motor control unit, the smaller one of the speed command obtained by feedback control of the position and the speed command obtained by the pressure feedback control is selected as an output of a comparator. Based on the speed command output from the comparator, feedback control of the speed is performed and the servo motor is driven. In the state where the die does not press against the workpiece, a pressure error is large, the speed command by pressure control becomes large, and the speed command by position control becomes small. Therefore, position control is performed. When the workpiece is pressed, the position error increases, and the pressure error decreases, a speed command by pressure control is employed and pressure control is performed.

Abstract: A waveform display apparatus which acquires data from a plurality of channels, and displays information relating to the acquired data in the form of a waveform based on the result of a mathematical operation performed in accordance with a user-entered mathematical expression, wherein at least one mathematical expression is entered and the data output from the plurality of channels are sampled (S01), the entered mathematical expression is analyzed (S02), the at least one mathematical expression is applied to the digital data of the plurality of channels based on the analysis (S03), and the information relating to the data is displayed in the form of a waveform on a display unit based on the result of the mathematical operation (S04). In this way, the user can have the result of the mathematical operation displayed in the desired manner, without having to add a new data processing method each time a necessary operation is added.

Abstract: A controller monitoring an operating state and performing a suitable process when detecting a magnetic pole position by means of a sensor for detecting a position and velocity of a movable part (rotor or movable member) of a synchronous motor. If tandem control is not employed, PWM of the motor is made enable to commence the operation of detecting the magnetic pole position, thus detecting an operation abnormality based on feedback of the position. In the case of tandem control including two position detectors, either a master or slave motor is brought into a free state, and the other is caused to perform the operation of detecting the magnetic pole position, thus detecting an operation abnormality based on the feedback of the position.

Abstract: Parameter set 1: T1a, T2a, Fa, Aa, parameter set 2: T1b, T2b, Fb, Ab, and parameter set 3: T1c, T2c, Fc, Ac, which consist of parameters having discrete values in three stages (large, medium and small) are prepared in the memory for example of the CNC 1 or the personal computer 3. For a given parameter set, the set giving priority to accuracy (S=0) is indicated by P (T1p, T2p, Fp, Ap), while the set giving priority to speed (S=1) is indicated by Q (T1q, T2q, Fq, Ag), and interpolation is performed and the parameter set Y=(1−S)×P+S×Q is obtained. The CNC 2 creates operating commands based on set Y and outputs these to the servo control section 2.

Abstract: A controller monitoring an operating state and performing a suitable process when detecting a magnetic pole position by means of a sensor for detecting a position and velocity of a movable part (rotor or movable member) of a synchronous motor. If tandem control is not employed, PWM of the motor is made enable to commence the operation of detecting the magnetic pole position, thus detecting an operation abnormality based on feedback of the position. In the case of tandem control including two position detectors, either a master or slave motor is brought into a free state, and the other is caused to perform the operation of detecting the magnetic pole position, thus detecting an operation abnormality based on the feedback of the position.

Abstract: A servo controller capable of preventing downward displacement of a gravitating axis of a machine when an excitation of a servomotor for driving the gravitating axis is discontinued. When a shutdown command is issued, a command for shifting a position of the gravitating axis by an offset amount in a direction opposing the gravitation is issued to a servo system. Also, a command for operating a mechanical brake to apply a braking force on the gravitating axis is issued. After a predetermined time period, the excitation of the servomotor is discontinued. The position of the gravitating axis is shifted upward by the offset amount within a time-lag between an issuance of the mechanical brake operating command and actual application of the braking force by the mechanical brake, and the braking force is applied to the gravitating axis at the shifted position.

Abstract: In a controller where a contour machining is performed through a synchronous control between a mechanically movable portion (servo axis) driven by a servo motor and a main shaft (spindle axis) driven by a spindle motor, the position of the servo axis and the position of the spindle axis are collected at the same timing for each predetermined cycle and are stored. The position data of the servo axis and the spindle axis stored are converted to obtain a machining contour shape data, and the shape obtained is displayed on a display device of a personal computer or the like.

Abstract: A servo controller capable of preventing downward displacement of a gravitating axis of a machine when an excitation of a servomotor for driving the gravitating axis is discontinued. When a shutdown command is issued, a command for shifting a position of the gravitating axis by an offset amount in a direction opposing the gravitation is issued to a servo system. Also, a command for operating a mechanical brake to apply a braking force on the gravitating axis is issued. After a predetermined time period, the excitation of the servomotor is discontinued. The position of the gravitating axis is shifted upward by the offset amount within a time-lag between an issuance of the mechanical brake operating command and actual application of the braking force by the mechanical brake, and the braking force is applied to the gravitating axis at the shifted position.

Abstract: Parameter set 1: T1a, T2a, Fa, Aa, parameter set 2: T1b, T2b, Fb, Ab, and parameter set 3: T1c, T2c, Fc, Ac, which consist of parameters having discrete values in three stages (large, medium and small) are prepared in the memory for example of the CNC 1 or the personal computer 3. For a given parameter set, the set giving priority to accuracy (S=0) is indicated by P (T1p, T2p, Fp, Ap), while the set giving priority to speed (S=1) is indicated by Q (T1q, T2q, Fq, Ag), and interpolation is performed and the parameter set Y=(1−S)×P+S×Q is obtained. The CNC 2 creates operating commands based on set Y and outputs these to the servo control section 2.

Abstract: In a controller where a contour machining is performed through a synchronous control between a mechanically movable portion (servo axis) driven by a servo motor and a main shaft (spindle axis) driven by a spindle motor, the position of the servo axis and the position of the spindle axis are collected at the same timing for each predetermined cycle and are stored. The position data of the servo axis and the spindle axis stored are converted to obtain a machining contour shape data, and the shape obtained is displayed on a display device of a personal computer or the like.

Abstract: When contents of a program for machining to be executed by a servomotor indicate a cutting mode, a current command is generated by performing speed loop processing by using a speed loop gain for cutting mode, and moreover, a voltage command to a servo amplifier is generated by performing proportional-plus-integral (PI) current loop processing in accordance with the generated current command. On the other hand, when the contents of the machining program indicate a positioning mode, a current command is generated by performing speed loop processing by using a speed loop gain for positioning mode, and moreover, a voltage command to the servo amplifier is generated by performing integral-plus-proportional (I-P) current loop processing in accordance with the generated current command.

Abstract: A control mode changing over method for a servo control system, which is capable of reducing a shock occurring in changing over a control mode from a torque control mode to a position/velocity control mode. In the torque control mode, a value of an integrator in a velocity loop for the position/velocity control mode is rewritten into a torque command value for torque control so that the value of the integrator is always set to the same value as the torque command. When a control mode is changed over from the torque control mode to the position/velocity control mode, a torque command value for a servo motor is obtained based on the value of the integrator rewritten in the torque control mode. Thus, a continuous torque command value is given to the servo motor in changing over the control mode.

Abstract: A servo parameter adjusting program is sent out from a servo parameter automatic adjusting apparatus to a servo controller of a servo control system, to cause the servo control system to perform an operation in accordance with this adjusting program and servo parameters presently stored in the servo controller. Then, the servo parameter automatic adjusting apparatus receives servo information obtained when the servo control system performs the adjusting program. A judgement is made as to whether or not the servo parameters set for the execution of the adjusting program is adequate. When the servo parameters set for the execution of the adjusting program are inappropriate, the servo parameter automatic adjusting apparatus performs a renewal adjustment of the servo parameter, thereby renewing the servo parameters stored in the servo controller.

Abstract: A method for estimating a load acting on a machine tool and controlling a life of the machine tool based on the estimated load. When predetermined machining is effected on a predetermined workpiece, a disturbance load torque acting on a motor for a spindle or a motor for a feed shaft is estimated by a disturbance estimating observer. When the estimated disturbance load becomes not lower than a set reference value, a timer is reset and started. If the estimated disturbance load torque is kept not smaller than the set reference value until the timer reaches a predetermined set time, a tool change command is issued to stop the machining. Since the tool life is determined in accordance with the magnitude of the load acting on the tool, the tool life is controlled objectively and accurately.

Abstract: The present invention relates to motor control at the time of reversal of direction of feed axes of a machine tool using a servomotor. The present invention includes a disturbance torque estimating unit for estimating a disturbance torque and estimating a frictional torque. The value in a speed loop integrator is divided into a frictional torque component and an acceleration torque component. An integrator target value for the time of reversal of motor rotation is obtained in accordance with the acceleration torque component and a value obtained by inverting the sign of the frictional torque component. Backlash acceleration correction is effected using a value obtained by applying a certain offset to a speed command so that the integrator target value is reached, as a backlash acceleration value. In estimating the frictional torque, a ratio of torque constant to inertia is estimated automatically, and the frictional torque is estimated by using this ratio.