Abstract: Pulsed control of electric motors, and more particularly, to selectively adjusting one or more of a pulsing frequency, an amplitude of the pulses and/or a duty cycle of the pulses for reducing Noise, Vibration and Harshness (NVH) while maintaining high levels of operating efficiency.

Abstract: A construction machine capable of achieving favorable operability in a combined operation is provided. A hybrid excavator includes: a boom cylinder 10 driven by hydraulic fluid from a hydraulic pump 16b; a swing hydraulic motor 5 driven by hydraulic fluid from the hydraulic pump 16b; a swing electric motor 6 connected mechanically with the swing hydraulic motor 5; an inverter 19 that controls operation of the swing electric motor 6; and a controller 21 that outputs to the inverter 19 a torque command value for controlling electric driving torque or electricity generating torque of the swing electric motor 6.

Abstract: Embodiments of the present invention are directed to a controller that is configured to limit the rate of change of speed of a motor (e.g., the acceleration or deceleration) regardless of the operating mode of the motor (e.g., speed, torque, or power control mode). The controller can include an acceleration estimator which monitors the output speed of a motor and provides an acceleration-limited speed set point. The output of the acceleration estimator may be limited to a range of acceptable acceleration values that correspond to the required limits of acceleration and deceleration. The acceleration estimator can be configured such that it causes the speed regulator to override the torque and/or power regulators when the acceleration range is exceeded.

Abstract: A system and method are provided for controlling a movable element in accordance with a speed command. The movable element, which may be an excavator swing platform, is moved via an actuator that is driven in accordance with a torque command. The speed of the movable element is sensed, and a torque command is generated via PID control based on the speed command and the sensed speed. The PID control uses a set of gains including a P-gain, an I-gain, and a D-gain. At least one of these gains is set based on a counter, and the counter is set, cleared, incremented, or decremented based on one or more of the speed command, the torque command and the sensed speed. In this way, the movable element responds aggressively to operator input, but stability is maintained.

Abstract: Provided is an apparatus for controlling speed in induction motor in which tension command and friction loss compensation are used to calculate a torque limit relative to an output of a speed controller, which is then used to limit the speed of the induction motor, whereby a tension sensor and a position sensor are not used in the continuous processing line to improve performance of the vector control type induction motor.

Abstract: A multi-pressure-quantity fan control system for a computer system is provided. The multi-pressure-quantity fan control system includes a controller. The controller provides a pressure-quantity control signal to a fan of the computer system, in order to set the fan to operate in one of a first pressure-quantity setting and a second pressure-quantity setting, wherein under a predetermined rotating speed, the fan has a first pressure-quantity curve for the first pressure-quantity setting and a second pressure-quantity curve for the second pressure-quantity setting.

Abstract: A fan speed control circuit is provided. The circuit includes a sensor, a control chip, a first integrated circuit, an integrated operational amplifier, a second integrated circuit, and a feedback comparator. The sensor senses a temperature of an electronic component. The control chip outputs a PWM signal corresponding to the temperature to a fan. The first integrated circuit and the second integrated circuit respectively generate a first equivalent voltage and a second equivalent voltage. The integrated operational amplifier amplifies the first equivalent voltage to generate an upper limit voltage and reduces the first equivalent voltage to generate a lower limit voltage. The feedback comparator compares the second equivalent voltage with the upper limit voltage and the lower limit voltage to generate a comparison value. The control chip adjusts the duty cycle of the PWM signal according to the comparison value, and outputs the adjusted PWM signal to the fan.

Abstract: Embodiments of the invention provide a fire-extinguishing system and method for injecting foamant into a stream of water. The system can include a flow meter determining a flow rate of the stream of water and a foam pump having an inlet coupled to a supply of foamant and an outlet coupled to the stream of water. The system includes a servo motor driving the foam pump. The servo motor includes a sensor used to determine a rotor shaft speed and/or a rotor shaft torque.

Abstract: A method for sensing and compensating for variances in load and voltage in a closed loop voice coil system is described. A load in a system which included a supply voltage and the load, which includes an inductive element, is excited with a known duty cycle for a time interval. At an end time, at the end of the time interval, the current which flows through the load is sensed. A lumped term based at least in part on the time interval and a change in the load current during the time interval is calculated. The lumped term is representative of the supply voltage and one or more electrical characteristic of the load. A control signal to control a voltage applied to the load may be generated based at least in part on the lumped term. Apparatus and computer-readable media are also described.

Abstract: An ECU that controls a motor includes: a target current value setting unit setting a target current; a voltage detecting unit detecting a detected voltage on the basis of a detection signal from a voltage sensor; a voltage calculation unit calculating an estimated voltage on the basis of a power supply voltage of a battery; and an induced voltage observer calculating an induced voltage generated at the motor using an inter-terminal voltage based on the estimated voltage when the target current is set to a value other than zero; whereas the induced voltage observer calculates the induced voltage using an inter-terminal voltage based on the detected voltage when the target current is set to zero.

Abstract: Systems and methods for estimating an inertia and a friction coefficient for a controlled mechanical system are provided. In one or more embodiments, an inertia estimator can generate a torque command signal that varies continuously over time during a testing sequence. The velocity of a motion system in response to the time-varying torque command signal is measured and recorded during the testing sequence. The inertia estimator then estimates the inertia and/or the friction coefficient of the motion system based on the torque command data sent to the motion system and the measured velocity data. In some embodiments, the inertia estimator estimates the inertia and the friction coefficient based on integrals of the torque command data and the velocity data.

Abstract: In a wiper control apparatus, a water drop detector outputs an output signal in accordance with water drops adhering to a windshield of a vehicle. When a traveling determination portion determines that the vehicle is traveling, a first level setting portion sets a sensitivity for detecting the output signal to a first sensitivity. When the traveling determination portion determines the vehicle is not traveling, a second level setting portion sets the sensitivity for detecting the output signal to a second sensitivity that is larger than the first sensitivity. A water drop adhesion determination portion determines that water drops adhere to the windshield when a determination waiting time elapses in a state where detection of the output signal continues. A driving control portion controls a wiper driving portion to drive the wiper when the water drop adhesion determination portion determines that water drops adhere to the windshield.

Abstract: During rain, including a light source (5) for radiating light such that the light is transmitted through a vehicle window (2), a light receiving element (6) for sensing an optical signal when the light radiated from the light source (5) is reflected from the raindrop fallen on the vehicle window (2) and performing a photoelectric transduction, and a receiver (9) for receiving the photoelectrically transduced signal from the light receiving element (6) and judging the level of rainfall. The light source (5) and the light receiving element (6) are inclined with respect to the surface of the vehicle window (2) such that the light of the light source (5) directly reflected from the vehicle window (2) exits to the outside of the light receiving element (6) and the light reflected from a raindrop (8) on the vehicle window (2) is received by the light receiving element (6) to operate a vehicle wiper.

Abstract: A pulse width modulation (PWM) fan controller includes a sensor, a generator, a selector, and a multiplexer. The sensor is configured for sensing a current temperature of an electronic device. The generator is configured for generating different PWM signals, each of which is suitable for regulating the rotational speed of a fan for dissipating heat for the electronic device of a corresponding temperature. The selector is configured for generating a selection control signal based upon the current temperature of the electronic device. The selection control signal is used for selecting a PWM signal corresponding to the current temperature of the electronic device from the PWM signals from the generator. The multiplexer is configured for performing the selection of the PWM signal.

Abstract: A windshield wiper control unit that controls a windshield wiper based on the position of an operation member, includes: an electric value detection unit that detects an electric value that continuously changes based on the position of the operation member; a setting unit that sets a reference electric value range that is a portion of a variation range of the electric value; a determination unit that determines whether the electric value detected by the electric value detection unit falls within the reference electric value range; and a position determination unit that determines the position of the operation member based on the reference electric value range. When the detected electric value falls outside the reference electric value range, the reference electric value range is updated in such a manner that the electric value, which falls outside the pre-update reference electric value range, falls within the post-update reference electric value range.

Abstract: An electric power tool includes a direct current motor, at least one switching device, a trigger switch, a control unit, and a drive unit. The control unit sets a driving duty ratio for PWM controlling the direct current motor so as to increase the driving duty ratio in a stepwise manner in accordance with an operation continuation time of the trigger switch during a period from when an operation of the trigger switch is started until when a predetermined start-up time has elapsed.

Abstract: Systems and methods for using variable speed drives to restart downhole submersible pump motors. In one embodiment, a downhole pump is controlled using a variable speed drive that includes a control system configured to detect interruptions in the operation of the pump system. After an interruption that requires the restart of the pump motor, the control system determines the reverse rotational speed of the pump motor and restarts the motor when this speed is sufficiently low. The control system may be configured to reduce the output voltage of the variable speed drive and sweep through a range of output frequencies to determine the frequency at which the current drawn by the motor is lowest. This is the frequency at which the drive's output matches the speed of the motor and the apparent impedance of the motor is highest. When the speed is low enough, the motor is restarted.

Abstract: A system compatible for different types of signals relates to a motor includes a differential amplifier, a comparator, and a transmitting device. The differential amplifier is configured to receive one of a differential digital pulse signals pair and a differential analog signals pair. The differential digital pulse signals pair is converted to a first digital signal, and the differential analog signals pair is converted to an analog signal by the differential amplifier. The comparator is configured to convert the analog signal into a second digital signal. The first digital signal is received and outputted by the comparator. The transmitting device is configured to convert a data signals pair to a binary code, and convert differential reference digital signals pairs to reference digital signals. The reference digital signals, the first and second digital signals are received by an external computing device.

Abstract: Embodiments of the invention provide a fire-extinguishing system and method for injecting foamant into a stream of water. The system can include a flow meter determining a flow rate of the stream of water and a foam pump having an inlet coupled to a supply of foamant and an outlet coupled to the stream of water. The system includes a servo motor driving the foam pump. The servo motor includes a sensor used to determine a rotor shaft speed and/or a rotor shaft torque.

Abstract: A control device for an opening/closing member includes a speed detecting unit, a variation calculating unit, a judgment unit, a control unit, and a state detecting unit. The speed detecting unit detects a rotation speed of a motor for opening/closing the opening/closing member. The variation calculating unit calculates the variation in the rotation speed based on a present value and a past value of the rotation speed. The judgment unit compares the variation to a predetermined threshold value and judges whether or not a foreign object is trapped in the opening/closing member based on the comparison. The control unit controls the motor to open or stop the opening/closing member when the judgment unit judges that there is a foreign object trapped. The state detecting unit detects a state of the opening/closing member or a state of the surroundings of the opening/closing member.

Abstract: In a method for determining a gradient-limited setpoint torque from a requested setpoint drive torque and a controller setpoint torque of a closed-loop speed control, the gradient of an unlimited cumulative setpoint torque, which is a function of the requested setpoint drive torque and the controller setpoint torque of the closed-loop speed control, is limited in a region of the zero crossing of the gradient-limited setpoint torque by a rate-of-change limitation to a maximally permitted or a minimally permitted value. The maximally permitted or the minimally permitted value of the rate-of-change limitation is a function of the controller setpoint torque of the closed-loop speed control.

Abstract: A method for sensing and compensating for variances in load and voltage in a closed loop voice coil system (95) is described. A load (55) in a system (95) which included a supply voltage (45) and the load (55), which includes an inductive element, is excited with a known duty cycle for a time interval. At an end time, at the end of the time interval, the current which flows through the load (55) is sensed. A lumped term based at least in part on the time interval and a change in the load current during the time interval is calculated. The lumped term is representative of the supply voltage (45) and one or more electrical characteristic of the load (55). A control signal (25) to control a voltage applied to the load (55) may be generated based at least in part on the lumped term. Apparatus and computer-readable media are also described.

Abstract: A DC motor mechanical shock protection system monitors the motor current to determine the torque the motor is applying to the gearbox, and takes mitigating action if the torque approaches a level that can damage the driven device and/or the drive system. This protects the system from mechanical shock without limiting the available torque during normal operation. The change in motor current is monitored to detect the inertial torque before the elasticity between the motor and the driven device is fully compressed and the motor mounting or gearbox begin to be damaged.

Abstract: The rotational speed of a motor is detected, and stored in a rotational speed memory. The difference between the present rotational speed output and each of plural past rotational speeds stored in the rotational speed memory is calculated in a plural difference calculator. Whether the difference between the present rotational speed and the most past rotational speed out of the plural differences is larger than a first threshold value is judged. Whether at least one of the differences is larger than a second threshold value is judged. The first and second threshold values are set to values for detecting that the rotational speed of the motor has a decelerating trend through the comparison with the differences concerned, and the first threshold value is set to be smaller than the second threshold value. When both judgments have positive judgment results, it is judged that rotation abnormality of the motor occurs.

Abstract: A disk drive system is set forth that comprises a rotatable storage medium adapted to store data, a spindle motor disposed to rotate the rotatable storage medium, and a spindle motor control system. The spindle motor control system brakes rotation of the spindle motor in response to inductive sensing of the rotation of the spindle motor.

Abstract: A motor drive system control provides global closed loop feedback to cooperatively operate system components to adaptively reduce noise and provide noise cancellation feedback. An active EMI filter reduces differential and common mode noise on an input and provides a noise level indication to a system controller. Power switches in both a power converter and power inverter are cooperatively controlled with dynamic dv/dt control to reduce switching noise according to a profile specified by the controller. The dv/dt control is provided as an analog signal to a high voltage IC and codified as a pulse width for a level shifting circuit supplying control signals to the high voltage gate drive. A noise extraction circuit and technique obtain fast noise sampling to permit noise cancellation and adaptive noise reduction.

Abstract: To rotate a rotary body at a constant velocity, a swing control device 50 of an electric rotary excavator controls the rotation of the rotary body with a small first torque command value T1. Thus, when inertia moment of the rotary body is changed due to extension or retraction of a boom and an arm, the change of the inertia moment affects the rotation velocity of the rotary body, and an operator can perform a rotation operation with the same feeling as in a hydraulically-driven excavator. In contrast, when operating a swing lever 10 for acceleration, the rotation is controlled with a large second torque command value T2. Accordingly, a good and quick operational feeling is obtained without a delay in acceleration or deceleration, and the degradation of workability can be avoided.

Abstract: A thermal control variable-speed circuit without switching noise is connected with a driving circuit, which controls the rotation speed of a fan motor using a driving voltage. The thermal control variable-speed circuit includes a reference voltage output circuit and a driving voltage control circuit. The reference voltage output circuit outputs a corresponding reference voltage signal according to ambient temperature changes. The reference voltage output circuit has one end connected to a first resistor in series and to a second resistor in parallel. The driving voltage control circuit outputs a corresponding driving voltage according to the magnitude of the reference voltage signal.

Abstract: An object detecting apparatus includes a piezoelectric sensor provided at an edge portion of an opening/closing body for emitting an output voltage which changes corresponding to an external force applied to the edge portion and a detection circuit for receiving the output voltage of the piezoelectric sensor and for judging an entrapment. The detection circuit includes a voltage-measuring circuit for measuring the output voltage of the piezoelectric sensor, a time-measuring circuit for measuring time, and a judging circuit configured to judge the entrapment. The judging circuit judges the entrapment corresponding to the output voltage of the piezoelectric sensor. The judging circuit calculates a changing value of the output voltage after the output voltage of the piezoelectric sensor reaches a predetermined first level. The judging circuit judges that the entrapment has not occurred in a situation where the changing value of the output voltage is larger than a predetermined value.

Abstract: A motor drives a window glass of a door of a vehicle in an opening direction and a closing direction. A rotation sensing device outputs a pulse signal in response to rotation of the motor. A controller senses pinching of an object by the window glass based on the rotational speed signal. Specifically, the controller computes a rate of change in the rotational speed, i.e., a rotational speed difference based on the rotational speed signal. The controller senses start of the pinching based on the rotational speed difference. When an amount of change in the rotational speed since the time of sensing the start of the pinching exceeds a pinching determining threshold value, the controller confirm the pinching of the object.

Abstract: A motor drive system control provides global closed loop feedback to cooperatively operate system components to adaptively reduce noise and provide noise cancellation feedback. An active EMI filter reduces differential and common mode noise on an input and provides a noise level indication to a system controller. Power switches in both a power converter and power inverter are cooperatively controlled with dynamic dv/dt control to reduce switching noise according to a profile specified by the controller. The dv/dt control is provided as an analog signal to a high voltage IC and codified as a pulse width for a level shifting circuit supplying control signals to the high voltage gate drive. A noise extraction circuit and technique obtain fast noise sampling to permit noise cancellation and adaptive noise reduction.

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: In the method of controlling a process for moving a part (20) by an electric motor (12) against an end stop, pinching events are detected by monitoring a motor operating variable, such as a motor rpm, and if pinching is detected the motor (12) is stopped and/or reversed. The electric power triggering the motor (12) at the start of and during a startup phase while system slack is taken up is controlled so that it is constant and lower than the power triggering the motor in an ensuing operating phase (54) in which the part (20) moves. Preferably power during the startup phase is reduced to power values that are just barely enough to move the motor while system slack is taken up. In a preferred embodiment the applied motor voltage is reduced and controlled by a power end stage that includes a bipolar transistor or a field effect transistor.

Abstract: An opening and closing device for an opening and closing member of a vehicle includes a driving motor, a feedback control unit for controlling an output duty to the driving motor so that a preset target speed of the driving motor can be achieved, a high-pass filter for filtering a frequency of an actual speed of the driving motor, and a pinching determination unit for determining a pinching of an object based on an output from the high-pass filter.

Abstract: The invention relates to a simple, economical and reliable method for providing anti-jamming protection. According to said method, the excess force—the difference between the driving force and the friction force—is compared with a trigger threshold. To this end, the curve of the friction force of the current actuation process, which is dependent on the actuation path of the electrical drive unit, is compared to the curve of the friction force of at least one previous actuation process and the trigger threshold value is modified according to how the friction force curves correspond. The invention also relates to a method for providing anti-jamming protection for an electrical drive unit for window lifting drives.

Abstract: A rain sensor includes an amplifier circuit that amplifies an output voltage from a photodiode and then provides this voltage signal to a CPU. The amplifier circuit conducts an offset amplification. The output voltage from the amplifier circuit is controlled to be at a predetermined level, for example, 3.0V, and the CPU detects rainfall based on the drop in the output voltage from the predetermined level, 3.0V. Then it becomes possible to improve sensor sensitivity, maintain a small sensor size, and a low manufacturing cost.

Abstract: A method and apparatus for moving a gate a distance in a predetermined period of time. In one embodiment the current load for an electric motor to move a gate is first measured to determine whether the gate's motion is being hindered or helped. A microprocessor then controls voltage supplied to the motor to enhance or retard the evolved power of the motor according to the load and the predetermined time.

Abstract: An electric motor is rotated at a velocity &ohgr;1. After that, during &Dgr;t12 seconds, the 1st acceleration is executed at a rate (&ohgr;2−&ohgr;1)/&Dgr;t12. During this acceleration, the torque &tgr;m is calculated so as to execute the time integration. After the lapse of &Dgr;t12, the integrated result is stored. Next, the velocity is set to be &ohgr;3. After that, during &Dgr;t34 seconds, the 2nd acceleration is executed at a rate (&ohgr;4−&ohgr;3)/&Dgr;t34. At the 2nd acceleration, although the integration-starting and the integration-terminating velocities are each equal to those at the 1st acceleration, the acceleration rate is modified (&ohgr;3=&ohgr;1, &ohgr;4=&ohgr;2, &Dgr;t12≠&Dgr;t34). During this acceleration, the torque &tgr;m is calculated so as to execute the time integration, after the lapse of &Dgr;t34, storing the integrated result. The inertia J is calculated using the 1st and 2nd integrated results.

Abstract: Apparatus and method for providing digital signal processing method for controlling the speed and phase of a motor involves inputting a reference signal having a frequency and relative phase indicative of a time based signal; modifying the reference signal to introduce a slew-rate limited portion of each cycle of the reference signal; inputting a feedback signal having a frequency and relative phase indicative of the operation of said motor; modifying the feedback signal to introduce a slew-rate limited portion of each cycle of the feedback signal; analyzing the modified reference signal and the modified feedback signal to determine the frequency of the modified reference signal and of the modified feedback signal and said relative phase between said modified reference signal and said modified feedback signal; and outputting control signals to the motor for adjusting said speed and phase of the motor based on the frequency determination and determination of the relative phase.

Abstract: In a power window device an MCU detects motor torque values one by one when a window is opened and closed, compares the detected motor torque values with base values set to the travel regions and stops or reverses a motor determining that an object is pinched in the window when the former values exceed the latter values.

Abstract: The invention relates to a method for standardizing the pane position of an external force actuated vehicle window lifter wherein the window pane is moved by means of the drive of the window lifter into a closed position provided with a seal and this closed position is used to standardize the pane position. According to the invention, in order to check whether the window pane has reached its closed position, the change is evaluated in a value (T) correlated with the dynamics of the window pane as the window pane enters into the seal area associated with the closed position.

Abstract: An apparatus invention relates to an apparatus and method for monitoring an interior space which is closed off by a locked and/or manually non-unlockable door, flap, sliding sunroof or the like, for example a passenger compartment or luggage compartment of a motor vehicle, with respect to living entities enclosed therein and the quality of their living environment, having a control circuit and sensor evaluation arrangements connected thereto, which arrangements each interact with at least one sensor, a first sensor evaluation arrangement outputting a first signal to the control circuit if there are living entities in the interior space, and a second sensor evaluation arrangement outputting a second signal to the control circuit if the living environment changes in the direction of life- and/or health-threatening states, at least one actuator connected to the control circuit acting on a motor-actuatable closure of the door, flap, sliding sunroof or the like, which is activated by the control circuit for the pu

Abstract: An apparatus for reducing motor noise in a motor driven system (12) has a sensor (22) coupled to the system that generates an electrical signal indicative of a system operating parameter. A controller (24) is coupled to the motor (14) and the sensor (22). The controller (24) drives the motor (14) with a pulse width modulated signal having a variable duty cycle. The controller (24) monitors the electrical signal and varies the pulse width modulated signal from a low duty cycle corresponding to a low noise operation of the motor (14) to a higher duty cycle in response to an increased demand as indicated by the sensor.

Abstract: A method and apparatus for reducing winding failures in electric machines resulting from the application of high frequency or high dV/dt voltage pulses or voltage signals to the phase windings of the machine in which an inductive element is provided between the source of the high-frequency or high dV/dt pulses and the phase winding to absorb a portion of the voltage stresses on the phase windings that result from the application of the high-frequency or high dV/dt pulses to the machine.

Abstract: A power window apparatus for a vehicle, which has an emergency switch being capable of cutting off a power-window-closing control switch element conjointly with the operation of a switch for opening the power window and has a contactor sliding between normally closed contacts and normally open contacts provided in the form of electrode patterns on a printed circuit board, whereon electrodes extend over the contactor sliding area and a entire surface of the board except the contactor sliding area is covered with a coating of waterproof resin. The emergency switch can eliminate an abnormal simultaneous energization of both the window-opening and closing relays in an accident (such as the vehicle sinking into water) by maintaining the conducting state of the normally open contact even if the exposed portions of the electrode patterns are partly damaged by electrolysis of material.

Abstract: Disclosed are apparatus and method for determining whether a foreign object or the like is caught in an open-and-closure mechanism such as a power window of an automotive vehicle. An external disturbance torque T imposed on a the open-and-closure mechanism motor as its load is calculated on the basis of at least two of three parameters of a terminal voltage Em across the motor, a current flowing through the motor Im, and a motor angular velocity .omega.. Furthermore, the calculated external disturbance torque is differentiated to derive a change rate at which the external disturbance torque T is changed with time as dT/dt (T'). Since dT/dt (T')=dTs'/dt (Ts')+dTd'/dt (Td') and dTd/dt (Td')=0 (Td: a dynamic friction resistance force and dTd/dt: the change rate of the dynamic friction resistance force per time), dT/dt=dTs'/dt (Ts: an external disturbance force imposed on the motor by the caught foreign object and dTs/dt (Ts'): the differentiation value of the external disturbance force).

Abstract: An opening/closing device for an automobile door comprising a speed sensor for detecting a moving speed of a door, a motor for applying an opening/closing assisting force to the door, and a control unit for controlling the driving of the motor, is provided. The control unit includes an acceleration computing unit for differentiating speed signals supplied from the speed sensor to compute accelerations and output acceleration signals and a control variable setting unit for setting control variables of the motor based on acceleration signals from the acceleration computing unit. Thereby, even if a torque sensor for detecting the operating force of a person operating the door is omitted, it is possible to generate control variables corresponding to acceleration signals which are equivalent to control variables corresponding to torque to drive the motor.

Abstract: A first method for detecting movement of an actuator includes supplying a demand current to a voice coil motor of the actuator (A.sub.1), sampling a voice coil motor voltage (B.sub.1), performing a slope detection of a voice coil motor voltage function (C.sub.1) and extrapolating the voice coil motor function (D.sub.1) to identify a change in slope of the voice coil motor function.A second method for detecting movement of an actuator includes supplying a continuously increasing current ramp to the voice coil motor of an actuator (A.sub.2), measuring a back e.m.f. voltage of the voice coil motor (B.sub.2), performing a change in slope detection of a back e.m.f. voltage function (C.sub.2) and integrating the back e.m.f. voltage function (D.sub.2) to determine movement of the actuator.

Abstract: Method and apparatus for detecting breakage in a yarn strand being wound onto a yarn support member rotatably driven by a DC motor and having a closed-loop motor control system for maintaining a desired velocity of the motor and for signaling commutation of the phases of the motor during the yarn winding operation. The closed-loop motor control system monitors the signal conduction angles delivered to commutate the phase windings of the motor, detects a sudden minimum preestablished decrease in the monitored conduction angles, and generates a control signal in response to a sudden decrease in the conduction angle resulting from a yarn strand breakage. The control signal may be employed to stop current supply to the motor.

Abstract: An obstruction sensing and control arrangement for door or gate opening-closing mechanisms. The arrangement compares the operating rate of change of a predetermined characteristic with a preset rate of change and stops or reverses the motor in the opening/closing mechanism. The characteristic preferred is motor body temperature which is monitored indirectly. The control arrangement also includes a back up static control threshold to sense a second static operating characteristic of the motor and a second comparator means set at a preset threshold level to stop or reverse the motor. A common motor sensor is used for both the dynamic and static control thresholds. The invention also includes means to sense operating temperature and to alter the preset static threshold level automatically in response to temperature changes.