Abstract: An electronic drive for vector control of an induction motor controls slip and operating frequency in response to changes in stator voltage. The drive includes a torque control loop, a flux control loop and a frequency control loop. The control is based on a commanded stator current that is resolved into a torque-producing, or q-axis, current component and a flux-producing, or d-axis, current component that are in quadrature. The frequency control loop includes slip control in which a slip frequency command is produces based on a value for the leakage inductance of the motor. The leakage inductance value dynamically varies as a function of the q-axis current reference command.

Abstract: A method for controlling a motorized barrier operator after detecting an obstruction includes the steps of providing a motorized barrier operator that moves a barrier between limit positions and providing at least one control switch that upon actuation moves the barrier in a direction toward one of the limit positions. Actuation of the at least one control switch during movement of the barriers at least causes the barrier to stop. If an obstruction is detected by the motorized barrier operator during movement of the barrier, the operator allows only uni-directional movement of the barrier, regardless of actuation of the at least one control switch, after the detecting step.

Abstract: The sensorless motor driving apparatus according to the invention may include: a timing generation circuit generating a timing signal at intervals T; a driving signal generation circuit receiving the timing signal and generating, at the intervals T, pulse signals, the number of which M (=m×L+k) is defined by a sum of a predetermined number k and a product of the number of statuses L of the rotor and an integer (m) equal to or greater than 1; and an amplitude control circuit switching between commutation patterns of the driving signal in synchronization with the pulse signals.

Abstract: A three-phase spindle motor has three terminals each driven with pulse width modulated signals. Rotation of the motor is controlled by iteratively measuring an electrical period of the motor, determining a rotational position of the motor, and synchronizing the sinusoidal pulse width modulation of the spindle motor with the measured electrical period. The electrical period of the motor is measured by detecting zero crossings in the a back electromotive force induced at a first terminal of the motor and determining the time between successive zero crossings. The rotation position of the motor is determined based upon the last measured electrical period and a location of last detected zero crossing. The zero crossings are detected by selecting a time window during which the back electromotive force signal is sensed for zero crossings. The time window is selected as a function of the last measured electrical period and the rotational position of the motor.

Abstract: A controller capable of preventing response delay and generation of vibrations attributable thereto during position control of a movable part of a machine having low rigidity. A motor for driving a machine having low rigidity is subjected to position and velocity loop control. Compensation amount Q1 proportional to command velocity obtained by differentiating a position command and compensation amount Q2 proportional to second-order differentiated command acceleration are obtained. Compensation amounts Q1 and Q2 are added together, thus obtaining a velocity offset amount Vof corresponding to a estimated torsion amount. A differentiated value of the velocity offset amount is multiplied by coefficient ? to obtain a torque offset amount Tof. The velocity offset amount Vof is added to a velocity command Vcs obtained by position loop control 1. The torque offset amount Tof is added to a torque command Tc outputted in velocity loop control 2, and the result is used as a drive command to the motor.

Abstract: A transient response system includes a power source operable to generate a power output and a transmission operatively coupled to the power source. The transient response system also includes a generator operatively coupled to the power source and a controller in communication with the generator and at least one of the power source and the transmission. The controller is operable to receive at least one input having a value indicative of a change in load on the power source and operable to cause the generator to remove power from the power output at a rate corresponding to the value of the at least one input.

Abstract: The invention concerns a method for stabilizing the motion of an articulated chain of a chain block, especially to prevent the formation of resonance oscillation of the chain, in which an articulated chain is led across a polygonal chain wheel with non-uniform pitch, which is driven by an electric motor. In order to create a method to prevent the formation of a resonance oscillation of the articulated chain, it is proposed that a periodic and/or stochastic and dampening actuating variable is superimposed on the velocity of the chain wheel (4) and the dampening actuating variable produces a change in the chain velocity so as to prevent a formation of a resonance oscillation. The chain drive with reduced polygon effect is characterized in that an electronic damper (8) is hooked up in front of the electric motor (2), which produces a control of the electric motor (2) such that a formation of a resonance oscillation of the articulated chain (5) is prevented.

Abstract: A method for operating a doubly-fed machine by determining its rotational speed (nact), forming a rotational speed reference (nref), measuring network voltage and current, and calculating network active power (Pact) and reactive power (Qact). Thereafter, calculating shaft torque (T) based on active power (Pact) and rotating speed (nact), forming a frequency reference (Fref) for the inverter based on machine rotating speed (nact), rotating speed reference (nref), shaft torque (T), and the known pole pair number and network frequency, forming a reactive power reference (Qref) for the machine.

Abstract: An electric motor control apparatus of this invention estimates changes in temperature of a semiconductor device to compute temperature change amplitude 108 based on an output current signal 105 computed from a current flowing through the semiconductor device of a switching circuit 5, an operating frequency signal and a carrier frequency signal by a temperature change estimation part 11, and makes conversion into the number of power cycles 110 corresponding to the temperature change amplitude 108 from power cycle curve data stored in a power cycle curve data storage part 14 and computes a thermal stress signal 111 by a thermal stress computation part 13, and does life estimation of the semiconductor device based on the thermal stress signal 111 and produces an output to a display part 16 as a life estimation result signal 112 by a life estimation part 15a.

Abstract: A driving control device for an actuator comprises a driving device to drive an actuator having an electric motor (30) and a driving control device (50) to control the rotation of the electric motor (30) by controlling the driving device. The driving control device includes an H bridge circuit constructed by four switching semiconductor elements (Tr1 to Tr4), and rotates the electric motor in normal and reverse directions by turning on and turning off the switching semiconductor elements (Tr1 to Tr4). The driving control device (50) conducts to activate and to stop the electric motor (30) by applying a PWM signal to the switching semiconductor elements (Tr3 and Tr4) constructing the lower arm of the H bridge circuit (51).

Abstract: The wiper control apparatus comprises a precipitation detector, a surrounding state detector and a wiper controller. The precipitation detector detects a precipitation condition at a position where the vehicle is. The surrounding state detector detects an exit of the vehicle out of a roofed space. The wiper controller controls the wiper to be in an automatic operation mode according to the precipitation condition detected by the precipitation detector, and controlling the precipitation detector to detect the precipitation condition following the exit detected by the surrounding state detector in a response time shorter than the normal response time for the precipitation detector to detect the precipitation not following the exit.

Abstract: A wiper control system is provided which comprises a rain droplet detector, a multiplexer, a count register, and a wiper control unit. The rain droplet detector has a plurality of switches that are configured to be electrically connected by rain droplets, and each switch outputs one of two different signals according to an electrical connection thereof. The multiplexer receives signals from each of the plurality of the switches, and it is configured to repeatedly perform a process of selecting one of the received signals and outputting the selected signal. The count register is connected to the multiplexer to receive the signal output from the multiplexer, and it counts a number of the signals corresponding to the electrical connection of the switches of the rain droplet detector and outputs a counted value. The wiper control unit controls a speed of a wiper based on the counted value.

Abstract: The motor driver having a plurality of output circuits each having two switching elements connected in series includes: a phase switch circuit for putting a switching element on one side of one output circuit among the plurality of output circuits in the ON state during a time period corresponding to a predetermined electrical angle, and performing switching operation for switching elements on the other side of plural output circuits among the remaining output circuits; and a conduction period control section. The conduction period control section generates a signal for controlling the switching operation. Specifically, when the number of times of switching operation performed during the time period corresponding to the predetermined electrical angle is equal to or less than a predetermined value, a switching element corresponding to a phase, for which the magnitude of the current should be decreased, is turned OFF in the time period corresponding to the next predetermined electrical angle.

Abstract: A windshield wiper system activated by sensing rainwater via a rain sensor placed inside the wiping pattern when a multifunction switch lever is in automatic mode. A rain sensor module activates a relay for low speeds and/or a relay for high speeds depending on the detected amount of rainwater. A first voltage detecting means detects battery voltage, a second voltage detecting means detects voltage of an automatic signal, and a microcomputer adjusts the sensitivity of the rain sensor based on a voltage ratio of the automatic signal voltage and the battery voltage. A reformed wiring structure connects the multifunction switch and the rain sensor module, which contributes to a reduction of the weight and cost of the wiring harness. The sensitivity of the rain sensor is not affected by a voltage change.