Abstract: A reactor having a predetermined small capacity is connected to a rectifier, and a capacitor having a predetermined small capacity is connected between DC bus lines of the inverter, so that a small, light and low-cost inverter controller for driving a motor can be implemented, and even when an inverter DC voltage largely fluctuates and it is difficult to drive the motor, the motor can be kept driving by operating the inverter such that a voltage applied to the motor may stay constant by a motor voltage command corrector which generates a motor voltage command correction value of the motor.

Abstract: An electric power assist steering control system having an electric motor actuator and a motor driver circuit for generating and applying a motor current to the electric motor actuator. A current sensor is included for measuring the motor current from the motor driver circuit and generating a feedback signal. A torque sensor is included for sensing an applied steering torque and providing a torque command signal having a value indicative of the applied steering torque. A controller calculates a temperature of the electric temperature of the electric motor actuator by evaluating the motor current applied to the electric motor actuator. In the case that the calculated temperature of the electric motor actuator surpasses a predetermined temperature, the electric power assist steering control system reduces the amount of motor current applied to the electric motor actuator thereby reducing the temperature of the electric motor actuator.

Abstract: Method and apparatus for accelerating a motor from an intermediate velocity to a final operational velocity. The motor is accelerated from rest to the intermediate velocity through application of fixed duration drive pulses to the spindle motor. Once the motor reaches the intermediate velocity, commutation circuitry and back electromotive force (bemf) detection circuitry use detected bemf from the motor to electronically commutate the motor to accelerate to the final operational speed. A phase lock oscillator (PLO) attempts to acquire frequency lock for the motor. A control circuit measures the current in the motor to evaluate the effectiveness of the phase lock. If the measured current is found to be above a threshold value, the motor is restarted.

Abstract: The gaming machine according to the present invention has the reels 3L, 3C, 3R on each of which a plurality of symbols are formed, the stepping motors 59L, 59C, 59R for rotating and stopping the reels, the stop buttons 11L, 11C, 11r for stopping rotation of the reels 3L, 3C, 3R and the microcomputer 40 and the motor drive circuit 49 for controlling rotation and stop of the stepping motors. And both the microcomputer 40 and the motor drive circuit 49 divides the step angle per one step in the stepping motors into a plurality of small step angles, thereby both the microcomputer 40 and the motor drive circuit 49 conducts the step control for the stepping motors based on the divided step angles.

Abstract: In a vehicle air conditioner with an electrical actuator system, a transmission mechanism transmits a rotation force of an electrical motor to an air mixing door when first and second pulse signals are generated from first and second brushes in a door operation region of a pattern plate. In contrast, the transmission mechanism stops the transmission of the rotation force to the air mixing door, when the first and second pulse signals are generated in the first and second brushes in an initialization region. Therefore, in the initialization region, the detection position of the air mixing door is the same regardless of a rotation direction of the electrical motor. As a result, even when the initialization region is arranged at a middle position in the door operation region, the rotation position of the air mixing door can be accurately detected.

Abstract: In the motor stop control device utilizable for the reel-type gaming machine 1, there are provided the stepping motor 70 having two pairs of excitation phases for rotating the reel 3 on the outer periphery of which a plurality of symbols are formed, the speed reduction mechanism 700 for transmitting rotation of the stepping motor 70 to the rotation shaft of the reel 3 with a predetermined speed reduction ratio and the main CPU 40 for conducting speed reduction treatment to reduce rotation speed of the stepping motor 70 and excitation treatment by 2-phase excitation against the stepping motor 70 when the motor stop command occurs.

Abstract: A method for differentiating if a feedback signal is a result of an unintentional collisions in a servo system includes injecting a feed forward term in the servo system.

Abstract: A control system and method for an electric machine includes a first calculation module that receives a modified torque command and a calculated stator flux command and that generates first and second current commands and first and second voltage commands. A voltage magnitude calculation module generates a voltage magnitude based the first and second voltage commands. A reference voltage calculator module generates a reference voltage based on a DC link voltage, an angular stator velocity and the first and second current commands. A flux weakening module generates the calculated flux command based on the angular stator velocity, the reference voltage and the voltage magnitude.

Abstract: Temperature of the disk drive is measured using components of the disk drive without the need of including a separate temperature sensor to optimize performance of the spindle motor during startup. To measure temperature, the resistance of the VCM winding is measured and used to estimate the spindle bearing temperature. Back emf is measured from VCM windings and used during startup to accurately determine actuator position. Because the VCM coil resistance varies significantly with temperature, coil resistance variations with temperature are determined to enable compensation for inaccuracies in determination of actuator velocity. This inferred temperature is then used to optimize the start up procedure for the spindle motor to accommodate the increased frictional loading of the spindle bearing. In this way an improved performance in the reliability and spin up operation time can be realized without the addition of a separate temperature measurement hardware element.

Abstract: The present invention provides an electric power steering device enabled to compensate for the influence of the inertia of a steering-assisting-force generating motor on steering with accurate timing even when a steering direction is reversed at high speed. Based on steering torque and a rotation angular speed of a steering-assisting-force generating motor, a steering angular acceleration correspondence value is obtained. The device has means for regulating a gain, which is multiplied to a change acceleration of the steering torque. The motor is controlled so that the steering assisting force is corrected according to a motor output correction value obtained on the basis of the relation between the motor output correction value and the steering angular acceleration correspondence value, which is preliminarily determined and stored in such a way as to compensate for the influence of the inertia on steering, and the obtained steering angular acceleration correspondence value.

Abstract: A foam core chuck for use in a scanning stage of a lithography system is disclosed. In accordance with an embodiment of the present invention, the lithography stage includes a frame and a chuck supported by the frame. The chuck has a foam core structure that is covered by a shell layer. An electromagnetic device for supporting and positioning the chuck is coupled to the stage. The electromagnetic device, for example an electromagnetic motor, is coupled to the stage such that at least one coil is coupled to the frame and at least one magnet is coupled to the foam core structure of the chuck. The foam core structure acts as a distributed flexure for the magnet.

Abstract: A single phase motor driving unit includes: a first driving transistor supplying a single phase coil with a driving electric current in a certain direction; a second driving transistor supplying the single phase coil with a driving electric current in the opposite direction; a comparison section comparing an intensity of a sine wave signal obtained from a Hall device detecting a rotational position of a single phase motor and a reference value, and generating a timing signal in a predetermined period starting immediately before and ending immediately after a point at which the direction of the driving electric current for the single phase coil changes; and a recirculating section recirculating the driving electric current by controlling ON-OFF timings of the first and the second driving transistors in the predetermined period in which the timing signal is generated such that, within a given period in which the first and the second driving transistors on the side to which the driving electric current flows out

Abstract: Temperature of the disk drive is measured using components of the disk drive without the need of including a separate temperature sensor to optimize performance of the spindle motor during startup. To measure temperature, the resistance of the VCM winding is measured and used to estimate the spindle bearing temperature. Back emf is measured from VCM windings and used during startup to accurately determine actuator position. Because the VCM coil resistance varies significantly with temperature, coil resistance variations with temperature are determined to enable compensation for inaccuracies in determination of actuator velocity. This inferred temperature is then used to optimize the start up procedure for the spindle motor to accommodate the increased frictional loading of the spindle bearing. In this way an improved performance in the reliability and spin up operation time can be realized without the addition of a separate temperature measurement hardware element.

Abstract: Corresponding to a target torque, the control device calculates a target value of a feature based on at least one of the length of a long axis of a current vector locus and the length of the short axis and further superimposes a superimposed current on a drive current for the motor, the superimposed current having a frequency different from the frequency of the drive current. Further, the control device detects an actual value of the feature based on at least one of the length of a long axis of a current vector locus of the superimposed current and the length of the short axis of the same and finally detects a phase angle of the motor based on the target value and the actual value for the feature. The manipulation of a detecting phase is performed by feedback of a feature obtained by the magnitude of the superimposed current. That is, when the actual feature is more than the target value, the detecting phase is advanced.

Abstract: A single phase motor driving unit comprises a first driving transistor supplying a single phase coil with a driving electric current in a certain direction, a second driving transistor supplying the single phase coil with a driving electric current in the opposite direction, and a recirculating section which recirculates the driving electric current for the single phase coil by controlling on-off timings of the first driving transistor and the second driving transistor in a predetermined period immediately before the direction of the driving electric current for the single phase coil changes.

Abstract: A method of compensation for current-sensor gain errors in an electric machine drive 14 includes a high frequency carrier signal electrically injected into the electric machine 14. A current-sensor signal of the electric machine 14 is determined. The current-sensor signal is separated into current-sensor carrier signal negative and current-sensor carrier signal positive sequence reference frames. A proportional compensator signal for one of the current-sensor carrier signal reference frames is generated in a feedback loop 24. A magnitude signal of another one of the current-sensor carrier signal reference frames is generated in a different feedback loop 26.

Abstract: The invention is a motor stop control device for a rotating reel type gaming machine 1 which includes a stepping motor 70 having two pairs of excitation phases as a driving source of reels 3 having a plurality of symbols drawn thereon and in which the stepping motor is stopped in accordance with an operational instruction from outside. The device includes a deceleration transmission mechanism 700 for transmitting the rotation of the stepping motor 70 to rotating shafts for rotating the reels 3 at a predetermined reduction ratio and a main CPU 40 for performing control for reducing the rotating speed of the stepping motor 70 when a stop command for the stepping motor 70 is generated according to an operational instruction from the outside and for performing stop control of the stepping motor 70 through two-phase excitation.

Abstract: A method for determining the mass moment of inertia of an electric motor drive system of a machine, having a drive motor and further drive elements arranged downstream of the drive motor. The method includes a) determining a compensation current, which compensates losses occurring at a constant speed of the motor, so that a motor speed of the drive motor remains constant and b) determining an acceleration current, which generates a defined acceleration of the drive motor when the losses occurring at the constant speed of the drive motor are compensated. The method further entails c) calculating a mass moment of inertia of the electric motor drive system based on the determined acceleration current.

Abstract: A positioning apparatus having a brushless motor, a positioning mechanism, and a motor control circuit to rotate a rotor of the brushless motor by sequentially supplying a driving pulse to a plurality of fixed coils of the brushless motor. The motor control circuit includes a driving pulse generator, a present stage number detector to detect a present stage number of the rotor in accordance with an output signal from at least one magneto-sensitive device of the brushless motor, an initializer to move the movable member to at least a forward or a backward traveling limit within the movable range so as to set the rotor present stage number, and a speed reducer to reduce a rotating speed of the brushless motor by reducing power of the driving pulse when the rotor present stage number is equal to at least a forward traveling or a backward traveling stage number.

Abstract: The present invention provides a biped (two-footed) walking mobile system, its walk controller, and walk control method therefore, which are to realize enhancing an walk stability, as well as a consumed energy saving. A walk controller (30) of a biped walking mobile system forms a gait data by a gait forming part (33) based on parameters from a gait stabilizing part (32), and drive-controls drive means of respective joint portions (15L, 15R–20L, 20R) of each leg portion based on said gait data. In this case, the walk controller (30) is so constituted as to selectively witch a powered mode to conduct ordinary drive-control and a passive mode to drive-control the drive means similarly with passive joints, whereby drive-controlling respective joint portions.