Abstract: A servomotor control device for a robot which can adjust the characteristics of maximum torque and/or continuous rated output of the servomotor and a robot with easy maintenance. The robot is commanded to execute one cycle of taught motion. During the cycle, a maximum torque required for the servomotor is calculated by a torque command or the like. When the maximum torque lacks, a field weakening current correction value is increased for increasing d-phase current and the maximum torque. Further, lack of continuous rated output may be judged by detected temperature of the servomotor. When a lack of continuous rated output occurs, the correction value is decreased to decrease the d-phase current so as to adjust the characteristic of continuous rated output. Although the servomotors have the same specification, the characteristic of each of the servomotors may be optimized corresponding to the axis by adjusting the field weakening current (or the d-phase current).

Abstract: A magnetic flux produced by the current of a motor is detected by means of a Hall element, and an infinitesimal current proportional to the actual current of the motor is outputted. The outputted infinitesimal current is run through a resistor, and a potential difference across the resistor is detected by a ?? modulator circuit. The motor is subjected to feedback control based on the potential difference detected by the ?? modulator circuit.

Abstract: A motor driving controller that drivingly controls motors for individual axes of an object of control comprises an AC/DC converter circuit for converting AC power into DC power and motor driving DC/AC converter circuits for converting DC power into AC power of optional frequency, for each motor. The controller further comprises an interface through which DC power from the AC/DC converter circuit is delivered to the outside. If motors for peripheral axes are added, motor driving DC/AC conversion devices are added and connected to the interface, whereby DC power is supplied.

Abstract: An inverter apparatus is provided with first and second current detectors for detecting the current of two arbitrary phases and further with first and second A/D converters, and they are integrated into one unit. It furthermore stores, in a storage device, a compensation value for compensating for an unbalance between gains of the first current detector and the first A/D converter, and gains of the second current detector and the second A/D converter. By multiplying the detected current value of either one of the detected phases by this compensation value, it equalizes the current feedback gains for both phases.

Abstract: A motor driving apparatus capable of drivingly controlling a plurality of inverter units with a single motor driving command from a motor control unit, and thereby control a large-capacity motor or the like. The motor control unit sends out a single motor driving command (torque command) S. An intermediary unit obtains motor driving commands S×A1 to S×A4 for the inverter units by multiplying the motor driving command S by each of coefficients A1 to A4 set in advance. The inverter units are fed with the motor driving commands S×A1 to S×A4 individually and drive a single motor. Since the motor is driven by the total current supplied by the inverter units, the motor can generate a large torque. The motor control unit only needs to generate a single motor driving command S, and hence only needs to operate a single processing part. Hence, the motor control unit can generate and send out motor driving commands for other motors to drive them.

Abstract: Semiconductor surge absorbing devices are connected individually between power lines for the U, V and W phases, which connect an inverter and a motor, and between the ground and the power lines. The absorbing devices are adapted to be energized to clamp voltages between opposite terminals thereof when the voltages are higher than a given value.

Abstract: A first and a second motor drive amplifiers connected to a motor drive power supply include a first and a second memories which store specifications of the amplifiers, respectively. A memory provided in a power supply unit stores an overcurrent detection value for detecting an overcurrent according to the specifications of the respective motor drive amplifiers. A microcontroller reads the specifications from the first and second memories, and integrates overcurrent detection values corresponding to the respective specifications. If a current sensor detects that a current exceeding a reference value calculated based on a set integrated value, the current sensor outputs an overcurrent detection signal.

Abstract: A magnetic flux produced by the current of a motor is detected by means of a Hall element, and an infinitesimal current proportional to the actual current of the motor is outputted. The outputted infinitesimal current is run through a resistor, and a potential difference across the resistor is detected by a &Dgr;&Sgr; modulator circuit. The motor is subjected to feedback control based on the potential difference detected by the &Dgr;&Sgr; modulator circuit.

Abstract: A circuit system that includes a sensor circuit for a sensor that detects the state of a motor is provided in an inverter unit for driving the motor. A 0V of the circuit system is connected with a shield braid of a shielded cable that connects the sensor circuit and the sensor. Further, the shield braid of the shielded cable is connected to an earth plate.

Abstract: A motor driving controller that drivingly controls motors for individual axes of an object of control comprises an AC/DC converter circuit for converting AC power into DC power and motor driving DC/AC converter circuits for converting DC power into AC power of optional frequency, for each motor. The controller further comprises an interface through which DC power from the AC/DC converter circuit is delivered to the outside. If motors for peripheral axes are added, motor driving DC/AC conversion devices are added and connected to the interface, whereby DC power is supplied.

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: Amplifiers connected to a CNC are provided individually with memories that are stored with ID data for discriminating the kinds and properties thereof and ID data as maintenance management data. Likewise, motors are provided with memories stored with ID data. The management of the amplifiers and the motors is facilitated by reading these ID data from the CNC and displaying them on a display unit. Based on the ID data, moreover, adaptation or nonadaptation between the motors and the amplifiers is automatically determined by means of the CNC.

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: Amplifiers (41 to 44) connected to a CNC (10) are provided individually with memories (41b to 44b) that are stored with ID data for discriminating the kinds and properties thereof and ID data as maintenance management data. Likewise, motors (41c to 44c) are provided with memories (41c to 44c) stored with ID data. The management of the amplifiers and the motors is facilitated by reading these ID data from the CNC (10) and displaying them on a display unit (20). Based on the ID data, moreover, adaptation or nonadaptation between the motors and the amplifiers is automatically determined by means of the CNC (10).

Abstract: Leg portions are provided at the four corners of a resistor that generates a large amount of heat and a partition panel is secured to the top of the leg portions through a heat-insulating spacer. A adiabatic layer is formed by an empty space between the resistor and the partition panel. Further, the transmission of heat from the resistor through the leg portions to the partition panel is suppressed by the heat-insulating spacer. A servo amplifier is connected to the mounting portions provided on the partition panel, at the side opposite the resistor main body. As the transmission of heat generated by the resistor to the servo amplifier main body is cut off by the partition panel and suppressed, components inside the servo amplifier are protected from heat.

Abstract: Provided to the motor controller is means which can alter a conversion ratio with which a current value detected by a current detector is converted into a unit (such as voltage) easily usable in motor current control. According to the maximum current value of the motor and the demagnetization limit current of the motor, an optimum conversion ratio is selected and switched over. By making it possible to select and preset a conversion ratio, a plurality of motors can be controlled by one motor controller. Therefore, restrictions imposed on the combination of the motor controller and the motor are lightened.

Abstract: A torque command Tc is restricted to a torque limit value Tm′ by torque limiting means and delivered to current restricting means for a motor. The torque limit value Tm′ is derived by adding a torque limit correction value &Dgr;Tm as calculated by torque limit correction value calculating means to a torque limit value Tm corresponding to the target pressing force F. The torque limit correction value &Dgr;Tm is supplied in accordance with the acceleration value when the motor is accelerated or decelerated. This acceleration is calculated from the feedback velocity Vf from the velocity detector, or the command velocity Vc. Alternatively, it may be derived from the output of an observer which inputs the torque command Tc′ supplied to the current control means of the motor, and the feedback velocity Vf.

Abstract: In an injection molding machine whose movable part is driven by an AC servo motor, d-phase current in a direction of magnetic flux produced by a field system and q-phase current orthogonal to the d-phase current are obtained through d-q conversion on the basis of drive current of the AC servo motor and a phase of a rotor. Control of current is made in DC mode on condition that the d-phase current is set to zero, and the q-phase current is adapted for a current command. Control of current in the DC mode as described above is designed to advance the phase of the q-phase current command, which is an effective component of a current command at the time of the occurrence of magnetic saturation, thereby preventing, the influence of magnetic saturation to lessen the fall of torque.

Abstract: Selected switching devices (e.g., Tra and Trd) of an inverter are turned on to supply a current between selected phases. If the respective inclinations of current waveforms then detected by current detection circuits IR and IS are equal to a reference inclination, it can be concluded that the current detection circuit in a circuit through which the current then flows, switching devices, and motor windings are normal. If the inclinations of the detected current waveforms are "0" or smaller than the reference, it can be concluded that the current detection circuits, switching devices, or motor windings are abnormal. In such a case, an abnormal spot is identified by checking the inclinations of the waveforms of the current detection circuits in like manner after changing the switching device to be turned on. If the inclinations of the detected current waveforms are very much greater than the reference, cables or motor windings can be concluded to be shorted.

Abstract: A communication apparatus and method provides communication in a controller of an industrial machine which is not affected by disconnection of cables, external electrical noise, nor complicated lead-around cable work. Communication between a numerical control device, as a main control unit, and servo amplifiers, as drive control units servo motors of a machine tool, is performed by way of infrared communication. The communication may take the form of input/output voltage commands, i.e. PWM commands, and feedback signals. By way of the infrared communication, lead-around cable operation, disconnection, and external electrical noises are eliminated, while simplifying machine tool layout design.