Abstract: A method controls an electric vehicle which is so constituted as to drive a synchronous motor by way of a switch and an inverter circuit. A battery acts as a source of driving a controlling power. The synchronous motor has a permanent magnet acting as an outer rotor. The method includes the following operations of: 1) detecting that the electric vehicle has an acceleration signal of zero; 2) detecting that an actual speed of the electric vehicle is less than a predetermined percent of a rated speed; 3) supplying a current to a winding of a fixed phase of the synchronous motor, by way of the inverter circuit; and 4) generating a braking force.

Abstract: Disclosed is an electronic pulse width modulation (PWM) regulator of a low frequency rectangular wave signal serving to control the speed of a direct current motor. The invention aims at simplifying the design of said regulator by eliminating the classical inductive element so that the motor continuously operates as a filter of the output signal provided by the switching component. The invention also aims at preventing noises caused by switching. To this end, subsonic switching frequencies of less than 50 Hz are used.

Abstract: A load in an electrical apparatus is driven by two motors M1, M2. Switching means (R1, R2) switches the motors M1, M2 between: a series configuration, in which the motors M1, M2 are connected in series across a power supply and driven with a dc supply; and a parallel configuration in which the motors M1, M2 are connected in parallel across the power supply and driven with an ac supply. In the series configuration, a bridge rectifier BR is switched across the ac supply to provide the dc supply for the motors M1, M2 and in the parallel configuration, the rectifier BR is removed from the circuit. The arrangement can be used to drive a drum of a washing machine or a load in some other kind of appliance.

Abstract: A method for controlling starting of a synchronous motor having an excellent starting ability and capable of coming into a commutation mode in a short time is provided. An AC current having a predetermined frequency is supplied to a field coil 81 of a synchronous motor 8 by an inverter 91, thereby starting the synchronous motor 8. By detecting a terminal voltage of the field coil 81 of the synchronous motor 8 at the starting time, and decreasing a voltage waveform component based on the AC current supplied by the inverter 91 from the detected voltage, the waveform is corrected so that the voltage waveform component based on the counter electromotive force can be confirmed (110). And after integrating the corrected waveform (111) and converting the same into a square wave (112), a phase difference between the same (104) and an output of a 120° energization waveform generating circuit 102 is detected to be fed back.

Abstract: A control system for an electric vehicle, such as a golf car, that includes a plurality of power MOSFETs. The vehicle includes a shunt wound motor including an armature coil and a field coil. One of the MOSFETs is connected in parallel across the armature coil and another MOSFET is connected in series with the armature coil. The MOSFET across the armature coil includes a freewheel diode. When the motor is operating below its base speed, i.e., when the back EMF is below the power supply voltage, a current flow can be induced by momentarily turning on the series MOSFET, shorting the armature coil. Because of the residual inductance in the motor, a current flow in the counter clockwise direction is initiated at which point the series MOSFET is turned off. Consequently, a large voltage spike across the motor occurs which results in current flow back into the battery pack. By quickly turning the series MOSFET on and off the current flow can be maintained, and the regenerative braking can occur even at slow speeds.

Abstract: A vehicle seat includes a seat movable along a path a motor for driving the seat on the path, a sensor generating a signal indicating movement of the seat on the path, and a controller operating the motor to move said seat along the path. The sensor is preferably a Hall-effect device or a potentiometer. The controller is in communication with the sensor to receive the signal and form a feed-back control loop. The controller accelerates the seat at a controlled rate of acceleration to a controlled constant speed and decelerates the seat from the constant speed at a controlled rate of deceleration. The controller controls the rate of acceleration of the seat at a stored predetermined rate of acceleration by adjusting operation of the motor to maintain the predetermined rate of acceleration.

Abstract: An improved window covering and lighting system for a window in a room includes a plurality of cornices, each cornice including a window covering supported by the cornice and movable between an open position and a closed position, an actuator supported by the cornice for moving the window covering between the open position and the closed position, a lighting system mounted to the cornice, and a programmable logic unit for operating at least one of the actuator and the lighting system independently from one another upon demand. The system also includes a remote control unit providing a signal selectively to the programmable logic unit to operate at least one of the plurality of cornices. Each of the plurality of cornices further includes a light sensor for sensing ambient light conditions in the room, and a motion detector for detecting occupance of the room. The programmable logic control unit is responsive to the sensed ambient light conditions and the detected occupance.

Abstract: An integrated control and diagnostics system for a controlled system (e.g., a motor) includes a diagnostics module and a controller coupled to the motor. To optimize operation, the diagnostics information signal is used to modify the control provided by the controller as required. Moreover, the output of the control module is coupled to the diagnostics module so that the health assessment made by the diagnostics module can be based at least in part on the output of the controller. The invention uses a model-based diagnostics approach that allows integration of control algorithms with diagnostics algorithms to intelligently trade off optimizing performance to avert or accommodate failures, and to meet performance requirements in a wide range of applications.

Abstract: An electric power steering control system is arranged so as to control a drive current of a brushless motor that generates a steering assist force on the basis of a steering torque acting on a steering shaft and a vehicle speed.

Abstract: Axial error calculation unit is provided for estimating an axial error &Dgr;&thgr; between a d-q axis and a dc-qc axis by using Ld, Lq, Ke, Id*, Iq*, Idc and Iqc in a range of all rotational speeds except zero of a rotational speed command of a synchronous motor, Ld denoting an inductance on a magnetic pole axis d of the synchronous motor, Lq an inductance on a q axis orthogonal to the magnetic pole axis d, Ke a generated power constant of the motor, Id* a current command of the d axis, Iq* a current command on a q axis, Idc a detected current value on an assumed dc axis on control, and Iqc a detected current value on an assumed qc axis orthogonal to the assumed dc axis. Irrespective of presence of saliency, position sensorless control can be achieved in a wide range a low to high speed zone.

Abstract: The present invention relates to a current limit circuit of an inverter refrigerator. The present invention comprises a current limit unit for outputting a current limit signal by comparing an excess current generation due to load change with a limit current level set in advance. Accordingly, the present invention can extend life span of a compressor by protecting a BLDC motor from the excess current and reducing permanent magnet demagnetization due to the excess current. In addition, the present invention can improve a mobility of a motor by maintaining uniform torque with stable current in the operation, and can operate a compressor stably without turning off by a momentary excess current in the compressor operation.

Abstract: A mechanism controller for controlling power to motors of a mechanism having several motors, such as a robot. Each motor has a resolver for indicating the motor position. A driver unit is associated with each motor to supply power to the motor. Each driver unit includes a monitoring unit to monitor indications from the resolver of the associated motor. In one embodiment a control unit is connected to the driver units in a series circuit to control power to the motors and to receive the monitored indications from the monitoring units. In a second embodiment, the control unit is connected to the driver units in a ring circuit, rather than in a series circuit. Preferably, each driver unit also includes a memory device, and the control unit can send commands to the driver units and receive data from the driver units in sets equal in number to the number of driver units so that the commands and data do not need to include the addresses of the specific driver units.

Abstract: An oscillation isolator for supporting an oscillation isolation platform on a pedestal includes an active oscillation isolator having a displacement generating type actuator to reduce oscillation of the platform and a displacement adjuster provided between the active oscillation isolator and the platform or the pedestal for adjusting relative displacement between the active oscillation isolator and the platform or the pedestal. The displacement adjuster has a rigidity higher than that of the active oscillation isolator and is dynamically located in series between the active oscillation isolator and the platform or the pedestal.

Abstract: A numerical control apparatus for the numerical control of a roll grinding machine comprises a flaw detecting means for scanning the entire surface of a roll (11), provided with an ultrasonic detecting head (23) for detecting flaws formed in the surface of the roll (11), a command generating means for generating cross-feed commands to repair detected flaws on the basis of flaw information about the positions and levels of the detected flaws, a control means for executing a first shaft position control operation on the basis of the cross-feed command to position the grinding wheel at a position with respect to a Z-axis corresponding to the position of the flaw by moving the wheel spindle stock in parallel to the axis of the roll and a second shaft positioning control operation to cross-feed the grinding wheel in parallel to an X-axis, and a decision means for deciding whether or not the flaw has been completely repaired and invoking the next cross-feed command if the flaw has been completely repaired.

Abstract: A guideless stage for aligning a wafer in a microlithography system is disclosed, and a reaction frame is disclosed which isolates both external vibrations as well as vibrations caused by reaction forces from an object stage. In the guideless stage an object stage is disclosed for movement in at least two directions and two separate and independently movable followers move and follow the object stage and cooperating linear force actuators are mounted on the object stage and the followers for positioning the object stage in the first and second directions. The reaction frame is mounted on a base structure independent of the base for the object stage so that the object stage is supported in space independent of the reaction frame. At least one follower is disclosed having a pair of arms which are respectively movable in a pair of parallel planes with the center of gravity of the object stage therebetween.