Abstract: A gear machining controller capable of performing a gear machining of high precision. A gear machining tool and a workpiece are driven by a first motor and a second motor, respectively, to be synchronized with each other, to perform gear machining on the workpiece such as gear cutting and gear finishing. A position amending section is provided at least one of position control loops of servo systems for controlling position/velocity of the first and second motors. The position amendment section obtains amendment amounts based on position deviations and amends a position command of a present processing period by the amendment amount obtained at the processing period preceding by one cycle period of variation of a load torque. An error of synchronization of the first and second motors is reduced so that the gear machining of high precision is performed.

Abstract: A servo controller capable of driving a single movable member by two motors with high loop-gain setting to obtain a quick response. A servo controller includes two position controllers associated with respective motors and a damping controller. Each of the position controllers has a position control section to output a velocity command based on an identical position command from a host controller and a position feedback value from an associated position detector, a velocity control section to output a current command based on the velocity command and a velocity feedback value from an associated velocity detector, and a current control section to output a voltage command based on the current command and a current feedback value from an associated current detector. The damping controller outputs a current command correction value for compensating an interference between the two motors based on the velocity feedback values from the velocity detectors for the two motors.

Abstract: First, a direct current is supplied to an excitation phase at 180 degrees, and stopped when the rotor rotates. If it is forward rotation, the rotor magnetic pole position is in the range from 180 to 360 degrees, and the starting point thereof, 180 degrees, is treated as the estimated magnetic pole position &thgr;. If rotation is in reverse, on the other hand, the magnetic pole position lies in the range from 0 to 180 degrees, and the starting point thereof, 0 degrees, is treated as the estimated magnetic pole position &thgr;. A reverse current is supplied, and the rotor is returned to its original position. A phase quantity &bgr; of ½ of the width of a detected range (this time it will constitute 90 degrees) is added to an estimated magnetic pole position, and the result is treated as an excitation phase. The same processing is carried out thereafter, and the range in which the magnetic pole position is estimated to exist is steadily narrowed.

Abstract: A servo controller capable of driving a single movable member by two motors with high loop-gain setting to obtain a quick response. A servo controller includes two position controllers associated with respective motors and a damping controller. Each of the position controllers has a position control section to output a velocity command based on an identical position command from a host controller and a position feedback value from an associated position detector, a velocity control section to output a current command based on the velocity command and a velocity feedback value from an associated velocity detector, and a current control section to output a voltage command based on the current command and a current feedback value from an associated current detector. The damping controller outputs a current command correction value for compensating an interference between the two motors based on the velocity feedback values from the velocity detectors for the two motors.

Abstract: A d-phase current in the direction of a magnetic flux generated by a field system and a q-phase current in a direction perpendicular thereto are obtained from a driving current and a rotor phase of an AC servomotor by d-q conversion. DC-mode current control is carried out with this d-phase current adjusted to zero and using the q-phase current as a current command. In this DC-mode current control, the influence of magnetic saturation is restrained to lessen torque reduction by advancing the phase of the q-phase current command, which is effective component of the current command, in case of magnetic saturation.

Abstract: In the tandem control method designed for driving one axis using a main motor and a sub motor, a speed difference between the main motor and the sub motor is calculated, and a value for correction of torque is obtained based on this speed difference. Then, the value for correction of torque is added to respective torque commands of both the main motor and the sub motor, thereby making it possible to suppress vibrations occurring in the transmission mechanism. Furthermore, the sign of the torque command generated from a speed control section is detected, whereby a positive or negative torque command is suppressed in accordance with its sign, and the current control section of each motor is always supplied with a one-directional torque command whose direction differs from that of the other motor. Thus, it becomes possible to suppress the occurrence of backlash even when a large torque is applied. Furthermore, the position control is performed by the motor corresponding to the position command.

Abstract: Rotation of a code plate fixed to a shaft of a detecting object is detected for producing a one-rotation signal and an incremental signal corresponding to a division of one revolution into a plurality of equal sections. The incremental signal is counted by a counter, thereby detecting an absolute position using an encoder. The counter is cleared in response to a one-rotation signal arriving first after the encoder starts its detecting operation. The counter continues to count the incremental signal in proportion to rotation of the shaft of the detecting object after its count value is once cleared, without clearing the count value in response to subsequent one-rotation signals. Thus, the counter obtains an absolute distance from a position where the counter received the first one-rotation signal to a present position.

Abstract: A counter circuit for counting pulses inputted thereto asynchronously during a fixed period includes a counter 12' for counting the input pulses, a register 13 for storing pulses outputted by the counter 12' at fixed periods, and a control circuit 11' for generating a signal that controls the operating state of the counter 12' and register 13. When a signal that decides the operating period of the counter 12' is not being generated, namely between pulses indicative of the operating period, the counter 12' performs an ordinary counting operation. If an input pulse for counting is applied to the counter 12' during a period of time in which the abovementioned pulse is being generated, the control circuit 11' causes the counting operation to continue without clearing the counted value in the counter 12', after which the counted value in counter 12' is outputted to the register 13 to be latched therein, thereby preventing miscounting in the register 13.

Abstract: A pulse encoder (2) is provided for generating a position code IP corresponding to the rotational position of a rotor of a motor (1), as well as rotation pulses AP, BP each of which is produced whenever the rotor rotates by a predetermined amount. The rotation pulses AP, BP are applied to a counter (32) via quadrupling pulse generating circuit (30). A leading edge/trailing edge sensing circuit (31) is provided for sensing a transition point of the position code, with the counter (32) being preset by an output from the circuit (32). Thus, the position of the rotor is capable of being indicated precisely based on the position code and the value counted by the counter.

Abstract: An apparatus for processing the energy regenerated by an AC motor, which comprises a regeneration detection logic circuit (7) that produces a regeneration detection signal when the AC motor driving semiconductor switches are nonconductive and when the direction of the current flowing through the AC motor is opposite to that of the current when the AC motor is driven and a regeneration drive circuit 8 which drives the regenerated energy processing semiconductor switches responsive to the regeneration detection signal. The apparatus renders the regenerated energy processing semiconductor switches conductive so that the regenerated energy is returned to the AC power source only when the AC motor is in a regenerative condition. Therefore, electric power need be consumed in only small amounts by the resistors that protect the semiconductor switches for processing the regenerated energy, and the apparatus can be constructed so that it is small in size.