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 variable speed drive is provided having a converter to convert an AC voltage to a DC voltage, a DC link to filter and store energy from the converter, and a plurality of inverters, wherein each inverter is configured to convert a DC voltage to an AC voltage to power a corresponding load connected to the inverter The converter is electrically connected to an AC power source, the DC link is electrically connected to the converter, and the plurality of inverters are electrically connected in parallel to the DC link. Each inverter of the plurality of inverters is configured to operate substantially independently of other inverters of the plurality of inverters.

Abstract: Apparatus for optimizing performance of a stepper motor includes interaction between on-hardware system drivers and a host controlling computer through an intermediate target computer. The command instructions from the host computer are optimized by the interaction using an objective function to define the best performance of the stepper motor and real-time feedback from operation of the motor. A method for optimizing the stepper motor performance is also disclosed.

Abstract: A method for controlling a parallel kinematic mechanism machine and control device therefor, which includes the steps of (1) obtaining each actuator command based on kinematic parameters; (2) calculating loads exerted by the weight of each component of a machine; (3) obtaining loads in the direction of axis of each actuator; (4) decomposing loads in the direction of axis of each strut into directions of axes of the first and second universal joints; (5) obtaining the amounts of elastic deformation of each element; (6) converting approximately the amounts of elastic deformation of each universal joint to displacement in the direction of axis of each actuator; (7) subtracting displacement in the direction of axis of each actuator obtained at steps (5) and (6) from each actuator command to renew each actuator command, and controlling the machine according to each renewed actuator command.

Abstract: Provided herewith is an improved scheme for parking a load such as an indicator pointer and calibrating its position in a system for controlling the position of the load. The system also has a stopper for physically impeding the load when it is to be parked. In one embodiment, a parking method involves driving the motor in a reduced torque mode to move the load toward the stopper, stopping the load at the stopper while the motor is driven in the reduced torque mode, and maintaining the motor in a reduced torque mode until transitioning to an insignificant torque mode.

Abstract: The present invention provides a motor control system and method thereof. The motor control system comprises a motor controller and a compensation device. The motor controller is used for generating a motor control output according to a reference signal and a first signal. The compensation device is used for generating a compensated motor control output according to the motor control output and a second signal. Moreover, the compensation device utilizes the compensated motor control output to reduce the steady-state phase error between the first signal and the reference signal.

Abstract: A motor drive and a choke therefor are disclosed, wherein the choke comprises a magnetic core with an inner leg and two outer legs, and four coils, which may be connected in DC current paths in the motor drive. First and second differential coils are wound around first and second outer legs, respectively; and first and second common-mode coils are wound around the inner leg of the choke. The first and second differential coils smooth the DC current on a DC bus in the motor drive, and the first and second common-mode coils suppress common-mode voltages in the motor drive. Also disclosed is a method for suppressing common-mode voltages in a motor drive.

Abstract: An increase in angular acceleration ? of a rotating shaft of a motor, which outputs a torque to a drive shaft linked to drive wheels, may cause a skid on the drive wheels. In response to detection of a skid, the control procedure of the invention sets a maximum torque Tmax according to a preset map representing a relation between the angular acceleration ? and the maximum torque Tmax, and restricts an output torque level to the drive shaft. The map is set to decrease the maximum torque Tmax with an in crease in angular acceleration ?. The restricted output torque level is restored at a zero cross timing of the angular acceleration ? after a negative peak in the course of convergence of the skid. This arrangement makes the direction of the torque restored from the torque restriction identical with the direction of the angular acceleration, thus effectively reducing torsions of the drive shaft and thereby preventing potential torsional vibrations of the drive shaft.

Abstract: A motor controller comprising, a detector configured to perform a difference processing for information relating to a counter electromotive force and an induced electromotive force generated by a stepping motor, and to generate a driving control signal based on a result of the difference processing, and a driver configured to drive the stepping motor based on the driving control signal.

Abstract: The invention provides an electric power steering apparatus which can detect a ground fault of an angular resolver without fault. Values of a first resistance (R1), a second resistance (R2), a third resistance (R3) and a fourth resistance (R4) are set such that a difference between a minimum output potential (Vout Min) of a first differential amplifier (OP1) at a time when an angular resolver is not in a ground fault which may be generated on the basis of a dispersion of the first resistance (R1), the second resistance (R2), the third resistance (R3) and the fourth resistance (R4), and a direct-current resistance component (Rdc) of the angular resolver, and a maximum potential (Vout Max) at a time when the angular resolver is in the ground fault becomes equal to or more than a predetermined margin for preventing an erroneous ground fault detection in a CPU (62) side.

Abstract: A motor and a rotary potentiometer, or other position sensor, running on the motor shaft are mounted in a first enclosure with an output shaft for driving a power switch open or closed. A part of the system outside the first enclosure makes use of a motor position signal from the rotary potentiometer that is processed by a microcontroller that a worker can interact with at a switch panel to set and adjust motor travel limits without needing access into the motor enclosure. The first enclosure and its components can be used for various applications, including those for either underground or pad-mounted switches, which for the latter case can have the first enclosure inside a second enclosure on a pad, and the second enclosure also contains other power and control elements of the system. A portable unit with the switch panel for travel limits can be provided.

Abstract: A protective circuit, for reducing electrical disturbances or interference during operation of a DC motor, features a series transistor (62) arranged in a supply lead from a DC voltage source (12) to a DC motor; an auxiliary voltage source (52), associated with that series transistor, having a substantially constant auxiliary voltage which is configured to make the series transistor (62) fully conductive when a supply voltage furnished by the DC voltage source is substantially free of electrical interference; and an analyzer circuit (32, 34, 36) for analyzing the supply voltage, which analyzer circuit is configured, upon the occurrence of electrical interference in the supply voltage, to increase the resistance of the series transistor (62) correspondingly, in order to reduce the influence of that electrical interference on the operation of the DC motor.

Abstract: A system and method for sensor less control of a stepper motor is described. The system and method includes estimation of the position of a rotor of the motor by way of sensing circuitry on the windings of the motor, without the use of positional sensors. The system and method of stepper motor control further includes magnetic field optimization for increasing the torque generating component of a magnetic field generated by stators of the motor, and magnetic field weakening for countering some of the effects of back electromotive force generated by the magnetic rotor.

Abstract: Rapid connection of multiple motor drive modules for safety operation may be made using screw terminals for initial connections to a safety controller and pre-wired cables for daisy chaining subsequent motor drives responsive to the same safety signals. Adaptor modules may be used to provide for a variety of different connector configurations depending on the location of the motor drive within the signal chain.

Abstract: The present invention can diagnose a potential discrepancy in electrical operating characteristics of a three phase electric motor by generating two independent torque estimates using a plurality of current sensors and a shaft position sensor. The invention provides a strategy to generate two independent torque estimates of a three phase electric motor comprising first and second systems to determine currents in two motor phases, first and second systems to generate a first and second estimate of motor shaft position, and first and second systems to generate first and second estimates of motor torque using the first and second systems to determine current in each motor phase and the first and second values of motor shaft position. The present invention detects also an electrical operating characteristic discrepancy in an electric motor-propelled vehicle's electrical components and subsystems, including single subsystem discrepancies between the two independent torque estimates.

Abstract: A motor control device for a multiple-phase motor includes a drive circuit (PWM inverter) which drives the multiple-phase motor (three-phase DC brushless motor), and a micro-controller that controls the drive circuit, wherein the micro-controller limits a motor current in accordance with an integrated value of a predetermined function of a phase current.

Abstract: An apparatus provides protection to an electric traction motor of a vehicle. The vehicle has a first powertrain and a second powertrain. The first powertrain includes an engine and it is coupled with a first set of road wheels. The second powertrain includes the electric traction motor and it is coupled with a second set of road wheels. The apparatus comprises a revolution speed sensor operatively associated with the electric traction motor. The apparatus also comprises at least one controller. The controller includes control logic for modifying operation of the vehicle in response to monitoring the revolution speed sensor to restrain the vehicle speed from increasing in such a manner as to limit revolution speed of the electric traction motor to revolution speed values below an allowable upper revolution speed limit.

Abstract: A drive controller (10?) of the present invention comprises control means (28, 29, 32 to 38) configured to perform control to cause a driven element to move by a driver (M) and a collision detecting means (20?) configured to detect a collision of the driven element. The collision detecting means detects the collision of the driven element based on an estimated speed deviation which is an estimated deviation from an actual speed of the driven element or an estimated acceleration deviation which is an estimated deviation from an actual acceleration of the driven element.

Abstract: A servo motor with a built-in drive circuit in which a sensor circuit portion, a drive control circuit portion, and a motor drive circuit are collectively provided on two boards, thereby achieving simplification and a reduction in the size of the circuit configuration. In the servo motor with the built-in drive circuit, the sensor circuit portion and the drive control circuit portion are formed on a sensor circuit board, and the motor drive circuit is formed on a motor drive board, thereby achieving a reduction in size.

Abstract: In a press having a plunger supported so as to be movable linearly back and forth by drive means which include at least one servomotor in combination with a rotatably supported inertia structure connected for rotation with the servomotor, the inertia structure has an inertia moment which is small enough to permit reversal of the servomotor within a stroke length of the plunger so that the stroke of the plunger is adjustable under the control of a control device connected to the servomotor for controlling its operation.