Abstract: In a closed loop control method of a linear vibration actuator which vibrates linearly and energized by a switching element driven in a PWM control method, a crest or peak point (Bc, Bp) of the back electromotive force occurring in the linear vibration actuator is detected (S14). The detected crest or peak point (Bc, Bp) is compared with a reference value (Bcr, Bpr) (S15), and adjusting the PWM duty (?) applied to the switching element and controlling the operating frequency of the linear vibration actuator to resonant frequency (S16 to S19), thereby keeping the crest or peak point (Bc, Bp) of the back electromotive force always constant.

Abstract: A discrete rotor position estimation method for a synchronized reluctance motor is provided. A d.c.-link voltage Vdc and a phase current Iph are sensed. A flux-linkage ?ph of an active phase is calculated from the sensed d.c.-link voltage Vdc and the sensed phase current Iph. The calculated flux-linkage ?ph is compared with a reference flux-linkage ?r. The reference flux-linkage ?r corresponds to a reference angle ?r which lies between angles corresponding to aligned rotor position and non-aligned rotor position in the synchronized reluctance motor. An estimated rotor position ?cal is obtained only once when the calculated flux-linkage ?ph is greater than the reference flux-linkage ?r.

Abstract: A discrete rotor position estimation method for a synchronized reluctance motor is provided. A d.c.-link voltage Vdc and a phase current Iph are sensed. A flux-linkage ?ph of an active phase is calculated from the sensed d.c.-link voltage Vdc and the sensed phase current Iph. The calculated flux-linkage ?ph is compared with a reference flux-linkage ?r. The reference flux-linkage ?r corresponds to a reference angle ?r which lies between angles corresponding to aligned rotor position and non-aligned rotor position in the synchronized reluctance motor. An estimated rotor position ?cal is obtained only once when the calculated flux-linkage ?ph is greater than the reference flux-linkage ?r.

Abstract: An apparatus and method for controlling an electric motor is disclosed. The apparatus includes an instruction inputting section for transmitting an instruction for an electric motor or a control object coupled to said electric motor and a prefilter section for outputting a follow-up instruction value by acting on the instruction. The prefilter section has a prefilter concurrently having characteristics of lowered gain at a prescribed frequency and frequencies in the vicinity thereof, and characteristics of limiting the gain in a high range. An instruction follow-up controlling section provides a controlling instruction follow-up so that a quantity of a state of said electric motor or control object follows the follow-up instruction value.

Abstract: In a brushless motor control method and a brushless motor controller in accordance with the present invention, a rotor rotation position detection means detects the time of the intersection of a detected induced voltage and an induced voltage reference value. In addition, a motor speed calculation means calculates the rotation speed of a brushless motor on the basis of the interval of the intersection times detected by the rotor rotation position detection means. Furthermore, a speed control means outputs a duty factor index on the basis of the deviation between the command speed and the rotation speed of the brushless motor. Still further, a switching signal generation means outputs switching signals to groups of switching devices on the basis of the rotation speed and the duty factor index at the time of the intersection.

Abstract: An electric motor position control apparatus in accordance with the present invention has a plurality of sets of control parameters including at least the proportional gain of a position control section and the proportional gain of a speed control section beforehand, wherein set selection and the measurement of the response state of an electric motor to a position command at the time when the electric motor is controlled by using the control parameters of the selected set are carried out sequentially, one preferable set is selected depending on the measured response state, the control parameters of the selected set are set, and the control parameters are changed as a set.

Abstract: An electric motor position control apparatus in accordance with the present invention has a plurality of sets of control parameters including at least the proportional gain of a position control section and the proportional gain of a speed control section beforehand, wherein set selection and the measurement of the response state of an electric motor to a position command at the time when the electric motor is controlled by using the control parameters of the selected set are carried out sequentially, one preferable set is selected depending on the measured response state, the control parameters of the selected set are set, and the control parameters are changed as a set.

Abstract: The invention provides a method for controlling an electric motor and an apparatus for controlling the same, which lower vibrations generated due to low rigidity of a control object, secure vibration-suppressing performance without depending on instruction patterns and characteristics of a control object, and achieve high positioning accuracy.

Abstract: A method for position-sensorless motor control is provided, wherein a rotor-position estimation current signal is superimposed on the &ggr;-axis direction component of a target current vector representing target currents of stator windings. The period of the current signal is an even multiple of a PWM carrier period and varies at random. The amplitude of the current signal increases with the amplitudes of the target currents. An even number of samples are obtained from the &dgr;-axis direction component of a current vector representing detected currents of the stator windings in each period of the current signal. A discrete Fourier integration of the samples determines the amplitude of a current response to the current signal in the &dgr;-axis direction. The &ggr;-axis direction is corrected so that the current response substantially shrinks to zero in the &dgr;-axis direction.

Abstract: The invention provides an motor drive apparatus comprising a detector for detecting a terminal voltage in a non-energized phase and a detector for detecting a DC voltage applied to the main line of an inverter. The rotation of the brushless motor is controlled by specifying the inverter circulating current period from the terminal voltage and the DC voltage and calculating the magnetic pole position of the rotor from the terminal voltage after the end of the inverter circulating current period and a waveform of the terminal voltage predetermined from the characteristics of the brushless motor. As a result, the brushless motor can be rotated stably throughout a wide revolution range from low to high speeds.

Abstract: A position sensorless motor control apparatus is provided that achieves high resolution and high accuracy angle estimation, achieves angle estimation even in the presence of phase voltage saturation, and achieves high accuracy angle estimation even when a back electromotive force constant changes. An angle estimating unit which generates estimated rotor angle comprises: an estimation phase selecting unit for selecting an estimation phase designating the stator winding phase to be used for the generation of the estimated angle; a deviation generating unit for generating, based on the estimated angle and phase voltage value, a deviation relative to a model expressed by a phase voltage equation of the estimation phase; an angle correcting unit for correcting the estimated angle so that the deviation converges to zero; and an estimated coefficient value correcting unit for correcting an estimated coefficient value which is the estimated value of a coefficient in the phase voltage equation.

Abstract: In a brushless motor control method and a brushless motor controller in accordance with the present invention, a rotor rotation position detection means detects the time of the intersection of a detected induced voltage and an induced voltage reference value. In addition, a motor speed calculation means calculates the rotation speed of a brushless motor on the basis of the interval of the intersection times detected by the rotor rotation position detection means. Furthermore, a speed control means outputs a duty factor index on the basis of the deviation between the command speed and the rotation speed of the brushless motor. Still further, a switching signal generation means outputs switching signals to groups of switching devices on the basis of the rotation speed and the duty factor index at the time of the intersection.

Abstract: The invention provides an motor drive apparatus comprising a detector for detecting a terminal voltage in a non-energized phase and a detector for detecting a DC voltage applied to the main line of an inverter. The rotation of the brushless motor is controlled by specifying the inverter circulating current period from the terminal voltage and the DC voltage and calculating the magnetic pole position of the rotor from the terminal voltage after the end of the inverter circulating current period and a waveform of the terminal voltage predetermined from the characteristics of the brushless motor. As a result, the brushless motor can be rotated stably throughout a wide revolution range from low to high speeds.

Abstract: A motor control apparatus and a motor unit having such a motor control apparatus according to the present invention are constructed to detect a terminal voltage for switching elements of the same phase in a dead time period by a voltage output circuit 10, and to detect the instant when the sign of a phase current changes from the detected terminal voltage by a current sign change detection part 11. Based on the phase of a current sign change timing provided from the current sign change detection part 11 and the phase of a phase applied voltage, the first applied voltage control circuit 14 generates a phase applied voltage command to a switching element modulation circuit 9. Such arrangement makes it possible to provide motor continuous energization or motor energization drive near to 180 degrees at high efficiency, without the provision of any current sensors.

Abstract: A motor controller according to the present invention is so configured that time interval measuring means measures the time interval of a rotational position signal indicating the rotational position of a rotor based on said rotational position signal, correction coefficient storage means stores the correction coefficient indicating the inaccuracy of said rotational position signal, estimated rotational angle production means produces an estimated rotational angle providing an estimated value of the rotational angle by extrapolating the rotational angle based on said time interval and said correction coefficient, and command production means produces a current command or a voltage command based on said estimated rotational angle and outputs it to driving means for driving a motor.

Abstract: A brushless motor having at least one current influence detector (10a, 10b, 10c) for detecting influence of an induced voltage caused by variations of current flowing in an armature winding (3). Furthermore, a positional signal detecting circuit means (11) detects a positional signal corresponding to rotational position of the rotor (2) in accordance with the voltage signal appearing at the armature winding (3) and the output signal issued from the at least one current influence detector (10a, 10b, 10c).

Abstract: A rotor of a motor includes a plurality of sets of permanent magnets 8a, 8b embedded in the rotor. Each includes a permanent magnet at an inner side and another permanent magnet at an outer side with a distance between them. Each permanent magnet 8a, 8b is formed like an arch projecting towards the center of the rotor. Magnetic flux flows easily through an interval between the permanent magnets at inner and outer sides, and the inductance in a q-axis is enlarged. Then, the reluctance torque is generated in addition to the magnet torque, and the motor has a high torque and a high output power.

Abstract: A motor controller comprising drive unit for supplying power to the stator windings of a motor based on a current command, a stator current detection unit for detecting the stator current flowing in the stator windings, a saturation degree production unit for producing the saturation degree data indicating the extent to which the stator current deviates from the current command based on the current command and the stator current, a reference value production unit for producing a reference value of the saturation degree, a gain production unit for producing a gain indicating the rate at which the current command is changed, and a current command production unit for producing the current command data based on the saturation degree, the reference value and the gain, wherein the gain production unit produces the gain data based on at least one of the rotational speed of the motor and the current command.

Abstract: A motor controller comprises a stator current production unit for producing stator current commands that are command values for the stator current flowing through the stator windings, a drive unit for supplying electric power to the stator windings based on the stator current commands, a stator current detection unit ZU, ZV, and ZW, for detecting the stator currents flowing through the stator windings, and a saturation degree production unit for producing a saturation degree indicating by how much the stator current is not following the stator current command. The stator current production unit produces the stator current commands based on the saturation degree. The saturation degree production unit produces the saturation degree based on the current commands, the stator current signals, and the pole-position signals.

Abstract: The brushless motor has: a field unit having a rotor permanent magnet (12); three-phase driving windings (20A, 20B, and 20C) of the stator; driving transistors for supplying a power to the driving windings; a driving command unit (43) for generating sinusoidal driving command signals; and a driving unit which supplies to the driving windings sinusoidal driving currents in accordance with the driving command signals. The driving command unit (43) consists of: a time interval measurement device (42) which measures timing intervals from a pulse signal of a rotation detector (41), the timing intervals being inversely proportional to the rotational speed of the rotor; and a driving command generation unit (43) which changes an estimated electric angle at time intervals responding to the measurement result of the time interval measurement device thereby to generate the sinusoidal driving command signals corresponding to the estimated electric angle.