Abstract: Provided is a mechanical-vibration detecting apparatus in which not only adjustment is easy but also mechanical vibration can be taken out with high accuracy, and a vibration-reduction control apparatus by which reduction of mechanical vibration can be achieved. In a motor control apparatus for controlling the torque of a motor, provided are an equivalent rigid body model 103; a proportional operation means 104; a high-pass filter 105; and means for adding a torque signal and an output of the proportional operation means to supply a resulting addition signal to the equivalent rigid body model, and for subtracting an output of the equivalent rigid body model from a velocity signal of the motor control apparatus to supply a resulting difference signal to the proportional operation means and to the high-pass filter so that an output of the high-pass filter is used as a mechanical vibration control signal.

Abstract: A object sensor system for a swing door includes swing-side and approach-side sensors. Each of the sensors includes light-emitters and light-receivers which are mounted on a swing door. The light-emitters emit light toward a floor, and the light-receivers receive the light as reflected from the floor. The light emitted and received provides an object sensing zone which has a rectangular shape on the floor having a width equal to or larger than the width of the door. The sensing zone includes a main sensing area closer to the door and an auxiliary sensing area extending along the main sensing area. The auxiliary sensing area is disabled when the door moves.

Abstract: An apparatus has a mass suspended between two mounting plates by a separate springs to form a resonant structure that absorbs vibration in a structural member to which the mounting plates are attached. Permanent magnets are fixed to opposite sides of the mass. A sensor produces a signal indicating the frequency of the vibration. A feedback circuit receives the signal from the sensor and produces an output signal having first component frequency which corresponds to a harmonic of the frequency of the vibration. The output signal is applied to a separate voice coil adjacent to each permanent magnet. The magnetic fields produced by the output signal flowing through the voice coils interact with the magnetic fields from the permanent magnets to generate forces that act on the mass in a manner that increases the impedance of the absorber to the vibration in the structural member.

Abstract: An apparatus for electromagnetically and rotationally vibrating a rotary body that is supported by bearings. The apparatus comprises a ring-shaped magnet bipolarly magnetized and mounted coaxially on a shaft of the rotary body, a ring-shaped stator having a coil and adapted to generate a rotating magnetic field by controlling an electric current supplied to the coil, and a frequency variable vibration power source adapted to supply alternating electric power to the coil in the stator. The distance between a location of a magnetic pole in the stator and an axis of the shaft is different than the distance between a location of a magnetic pole in the magnet and the axis of the shaft. The magnet and the stator are disposed so as to be adjacent to each other. Thus a rotational exciting force is applied to the rotary body by an interaction of the rotating magnet field generated by the stator with the magnet.

Abstract: The present invention relates to a device (1) for damping the vibrations of a structure (2) subjected to dynamic stresses, of the type including a main mass (3) mounted on an elastic plate (4) which is itself fitted into the structure (2) whose vibrations are to be damped.According to the invention, the damping device (1) additionally comprises at least one auxiliary mass (5) connected to said main mass (3) and capable of being moved at least substantially parallel to said elastic plate (4) as a function of the control pulses which are received from a computer (9) and are computed from signals output by a first (10) and/or a second accelerometer (11) respectively measuring the vibrations of said structure (2) and those of said main mass (3).

Abstract: A deformation detection system including an elongated element having a hollow deformable wall member that defines a radiation transmission path. A sound radiation transmission source positioned at one end of the elongated member transmits acoustical radiation into the radiation transmission path. A sound radiation detector positioned at an opposite end of the radiation transmission path is responsive to and detects the acoustical radiation transmitted from the radiation source. Deformation of the wall member at least partially interrupts the radiation transmission path such that transmitted acoustical radiation from the sound radiation source is attenuated, and the attenuated acoustical radiation is detected and assessed by the radiation detector. The detection system has particular applicability to monitor a body opening of a motor vehicle in which a closure member, such as a window, is movable towards a peripheral edge of the body to close the opening by an electrically operated drive mechanism.

Abstract: An automatic windshield wiper control system detects and monitors impacts on a vehicle's surface due to water drops in order to automatically and appropriately control the speed of the windshield wipers. Preferably, the automatic control system is activated when the manual windshield wiper control is switched to the intermittent setting. An operator can still manually select the slow and fast continuous speed settings of the windshield wipers. An acoustic sensor is mounted behind an exterior surface of the vehicle, preferably the outer casing of a side rear-view mirror. The acoustic sensor detects noises due to impacts on the surface and generates an electrical signal representing the impact noises. The electrical signal from the acoustic sensor is filtered, thereby electronically isolating the frequency components due to the impacts of water drops and creating a filtered signal. A voltage signal is then formed representative of the frequency of the impacts of water drops on the surface.

Abstract: A control equipment for controlling a current to the motor provided in an electric vehicle is disclosed. The control equipment has a motor torque control means for inputting the motor speed No and the motor current, and generating an inverter drive signal to control the torque of the motor, a notch filter for eliminating the mechanical resonance frequency; and a torque command generating means for generating the torque command.The control equipment for an electric vehicle is not influenced by the mechanical vibration of the electric vehicle, can generate the accurate motor torque command, and can execute the stable running control.

Abstract: The composite wall comprises a first sheet and second sheet separated by an intermediate layer as well as an ultrasonic detection device placed on a face of said second sheet and comprising a transducer element able to emit an incidental ultrasonic signal of frequence f, and able to receive an ultrasonic signal reflected on a face of said first sheet. The intermediate layer comprises at least facing the transducer element, an inserted element whose two faces are respectively in close contact with the first and second sheets. Further, the frequence f of the transducer element satisfies the following relationships:f.apprxeq.K.sub.1. V.sub.1 /2e.sub.1 .apprxeq.K.sub.2.V.sub.2 /2e.sub.2 .apprxeq.K.sub.3.V.sub.3 /2e.sub.3where K.sub.1, K.sub.2 and K.sub.3 are defined integers, e.sub.1, e.sub.2 and e.sub.3 are respectively the thickness of the first sheet, the second sheet and the inserted element, and V.sub.1, V.sub.2 and V.sub.

Abstract: A hard disk drive that contains a detection circuit which senses the back emf of a voice coil. The detection circuit generates a shock detection signal when the back emf of the voice coil exceeds a pre-determined value. The write disable gate of the disk drive is disabled when the voltage detection circuit generates the shock detection signal.

Abstract: An electronic damping system is disclosed which dampens mechanical resonant vibrations of a gantry beam end. The system includes a secondary velocity feedback loop in addition to the main servo motor-tach velocity loop. The resonant velocity of the beam is sensed from the movement of the end of the beam. The velocity feedback signal is summed as negative feedback with the velocity command signal from the position controller. The resultant sum of the signals are combined to form the velocity reference input command signal to a servo power amplifier. The servo power amplifier is connected to a main servo motor which controls the movement of the gantry beam in the Y-direction relative to printed circuit board.

Abstract: An automatically controlled cleaning device (14) for removing visibility-impairing foreign matter, e.g. rain, snow or mud, from the surface of a window such as a motor vehicle windscreen (8). The device uses a sensor such as an ultrasonic transducer (12a, 12b) in which the frequency (f) and the spacing (d) between the transmitter (12a) and the receiver (12b) enable the presence of foreign matter to be detected simply by measuring the phase difference between the transmitted signal and the received signal. This device may be used in automatic wiper systems or the like.

Abstract: An improved door edge safety sensor for use with an automatic door operator which uses a motor to move a door between open and closed conditions with a controller for controlling operation of the motor and, an improved sensor comprising a tactile obstruction detector for generating a safety signal, a door vibration detector for detecting movement of the door, a safety signal transmitter operable in response to detected door motion, and control electronics which monitor the obstruction detector and the vibration detector and direct the signal transmitter to reverse the motor upon the door engaging an obstruction which reverses the door to an upward direction.

Abstract: This invention aims to prevent an obstacle from being trapped between a vehicle window and a window frame. A supersonic wave f is emitted into a vehicle window W. A reflection wave i of the supersonic wave is received to decide whether the reflection wave i is one reflected from peripheral faces of a target to be detected or not. If the received reflection wave i is one reflected from the peripheral faces from the target, a driving motor M for the vehicle window W is stopped. Thus, when an obstacle contacts with the peripheral faces of the vehicle window, it is possible to previously prevent the obstacle from being caught by the window since a driving source for the vehicle window is stopped.

Abstract: A device for attenuating the periodic vibrations of a mechanical structure adapted to obtain cancellation of periodic vibrations of rotating machines including at least one transducer, detecting original vibrations, delivering a detected signal, a detector of the periodicity of these vibrations delivering a synchronizing signal, and a control circuit and a transducer generating compensation vibrations which are applied to the mechanical structure. The control circuit includes a circuit for synchronous filtering of the detected signal, controlled by the synchronizing signal and delivering a filtered signal whose frequency spectrum contains only the instaneous fundamental frequency of the detected signal. A circuit for regulating the filtered signal delivers an antivibration-control signal applied to a generating transducer in order to minimize the amplitude of the detected signal.

Abstract: A torque oscillation compensation system and circuit that uses torque transducer feedback derived from an output shaft of an electric vehicle motor to compensate for electrical motor pulsations such as are experienced in an electric vehicle. A torque input source provides a torque input signal, that is coupled to a summing circuit. A controller is coupled to the summing circuit, and power switching circuitry is coupled between the controller and the electric motor. A torque transducer is coupled to the output shaft of the motor to sense torque pulsations. An oscillation compensation circuit is coupled between the torque transducer and the summing circuit that generates a feedback compensation signal that is combined with the torque input signal to compensate for output shaft oscillators.

Abstract: An arrangement involving apparatus and process damps vibrations, for example, rotary or linear vibrations, in a member to be damped, for example, in a supply tension arm forming part of a tape transport of a digital cassette recording system. The arrangement includes a limited angle torquer motor having an output connected to the member such that the presence of the detected vibrations to be damped imparts corresponding vibrations to the shaft (output) of the motor which, in turn, results in a corresponding back EMF voltage within the motor. A servo circuit connected to the input of the motor is designed to be responsive to the back EMF voltage within the motor, actually to an emulated version of the back EMF voltage, for driving the motor in a way to thereby damp the vibrations within the motor shaft which, in turn, damps the rotary or linear vibrations within the member itself. Approximately 20dBs of attenuation in vibration at the resonant frequency has been shown.

Abstract: A control system for mixing materials in a container. A screw-driven pressure plate clamps the container during mixing. Current of the clamping motor driving the screws is monitored and control circuitry allows multiple speed, multiple current draw, automatic switch-over operation of the clamping motor. Circuit components are automatically checked, and control over a mixing or clamping operation is assumed if necessary.

Abstract: An automatically controlled cleaning device is adapted to remove foreign bodies such as water from the surface of a window, such as a car window, which has an inside surface and an outside surface. This device has cleaning element which define at least one predetermined area on the outside surface of this window, driving circuit for the cleaning element which operate in response to a control signal, detection element capable of supplying a detection signal representative of the presence of foreign bodies on the outside surface of the window and control device capable of supplying a control signal in response to the detection signal wherein the detection element comprise a transducer able to emit at least one incident ultrasonic signal propagating within the thickness of the window and able to receive a reflected ultrasonic signal representative of the presence of the foreign bodies to analyse the detection signal and where the transducer is fixed by a first face against the inside surface of the window.

Abstract: A control device for an ultrasonic motor for controlling to drive the ultrasonic motor according to a logical AND operation between a control pulse having a duty ratio changing from 100% to 0% according to a moving position of the ultrasonic motor and a driving signal having a resonance frequency of the ultrasonic motor. Accordingly, after starting the ultrasonic motor at a maximum speed, a moving speed of the ultrasonic motor can be gradually reduced until it reaches a target position, and when reaching the target position, the ultrasonic motor can be stopped precisely at the target position.

Abstract: A rotating machine including a rotating body connected to and driven by a drive unit via a drive shaft is protected by stopping rotation of the rotating body and drive shaft in response to a detected vibration amplitude exceeding a predetermined allowable value at two spaced time instants.

Abstract: A noise prevention apparatus for a blower unit using a brushless motor is disclosed in which, when a setting speed of rotation set by a rotational speed setting unit is judged as being equal to a speed of rotation corresponding to a natural frequency of the blower unit, a drive pulse which is to be provided to a switching unit for controlling the rotation of the blower is corrected by a drive pulse correction unit such that the setting speed of rotation is deviate from the speed of rotation corresponding to the natural frequency of the blower unit. With this arrangement, the brushless motor is driven at speeds other than the speed corresponding to the natural frequency of the blower. Consequently, a higher harmonic of the vibration of the motor is always kept out of coincidence with the natural frequency of the blower unit, so that a operation noise caused by resonance does not take place any more.

Abstract: A vibration reduction apparatus uses a electromagnetic exciter mechanism to reduce vibrations induced in a machine by a rotating component of the machine. The electromagnetic exciter mechanism employs a magnetic inertial mass coupled in a non-contacting manner externally on a housing of the machine remote from the vibration-inducing rotating component. To operate the electromagnet exciter mechansism, the apparatus employs a vibration sensor attached externally on the machine housing. The sensor senses the vibrations and generates an output signal representative thereof. Also, the apparatus employs signal processing units coupled to the machine for sensing the frequency of an electrical input power signal to the machine which drives the rotating component and generating an output signal representative thereof.

Abstract: A structural magnetic vibration controller and a method for actively controlling vibrations through the use of a magnetic coupling between a damper mass and a stationary component of rotary machinery wherein the stiffness and damping characteristics of the magnetic coupling are controlled as a function of the relative movements between a first electromagnet carried by the machinery and a second electromagnet carried by the damping mass.

Abstract: A method for controlling the noise and vibration of machine tools in correspondence with environmental control standards includes determining a first level of noise and vibration generated by the machine tool during its operation, selecting a desired level of noise and vibration generated by said machine tool during its operation, and controlling the operation of said machine tool so that said machine tool operates at a second level of noise and vibration, wherein said second level of noise and vibration is below said desired level of noise and vibration. In a specific embodiment the stroke speed of the stroke section of a plate processing machine is controlled.

Abstract: An oscillating device for oscillating an object includes a single motor mounted on a base, a support base mounted on the base for supporting an object and movable in first and second orthogonal horizontal directions, a first converter mechanism mounted on the base and coupled to the support base for converting rotation from the motor into a first linear motion in the first horizontal direction and applying the first linear motion in the support base, a second converter mechanism mounted on the base and coupled to the support base for converting rotation from the motor into a second linear motion in the second horizontal direction and applying the second linear motion to the support base, and a clutch mechanism mounted on the base and having two clutch plates with respective engaging surfaces thereof angularly displaced from each other for selectively transmitting the rotation from the motor to the second converter mechanism.

Abstract: A motor control circuit for a machine, such as a granulator, having an intake adapted to receive parts to be machined. The motor control circuit detects the introduction of parts into the machine intake and automatically activates the motor for a predetermined period of time. Thereafter, the motor control circuit detects the presence of a machining operation through a vibration or sound transducer. In the absence of an output from the vibration or sound transducer, indicative that the machining operation has been completed, the motor control circuit deactivates the motor.

Abstract: A negative feedback control system includes a step of amplifying digital information by an amplifying operation at a high response speed and not including an integration. The negative feedback control system detects a predetermined amount of increase and decrease in the controlled variable, and outputs an increment signal or a decrement signal according to the predetermined amount of increase and decrease in the controlled variable, respectively, receives increment signals and the decrement signals from a controlled variable detecting unit 4, ignores the first successive n increment signals immediately after an arbitrary decrement signal, then begins to count each increment signal as a +1 unit from the n+1-th increment signal after the arbitrary decrement signal, and ignores the first successive n decrement signals immediately after an arbitrary increment signal, then begins to count each decrement signal as a -1 unit from the n+l-th decrement signal after the arbitrary increment signal (FIG.

Abstract: Mechanical oscillations of a mechanism containing a stepper motor, such as a solar-array powered spacecraft, are reduced and minimized by the execution of step movements in pairs of steps, the period between steps being equal to one-half of the period of torsional oscillation of the mechanism. Each pair of steps is repeated at needed intervals to maintain desired continuous movement of the portion of elements to be moved, such as the solar array of a spacecraft. In order to account for uncertainty as well as slow change in the period of torsional oscillation, a command unit may be provided for varying the interval between steps in a pair.

Abstract: The electromagnetic device comprises at least one compensation ring placed in the vicinity of the fluid bearing and mounted relative to the rotor by means of an active radial magnetic bearing whose electromagnet windings are powered as a function firstly of the signals delivered by a position detector for detecting the position of the compensation ring relative to the rotor, and secondly of the signals delivered by at least two vibration detectors disposed on the casing of the machine and having nonparallel sensitivity axes which are perpendicular to the axis of the rotor. The signals delivered by the vibration detectors are applied to a high-gain narrow-band selective feedback circuit whose central frequency is synchronized with a reference frequency fo. The compensation ring is of relatively small mass and serves to exert a rotary compensation force on the rotor via the radial magnetic bearing, which force is equal to the centrifugal force due to the out-of-balance mass of the rotor but which is 180.degree.

Abstract: An active force actuated vibration isolation system uses a velocity sensor in the form of a velocity-sensitive geophone to sense payload velocity and modifies the geophone signal to control the force applied to oppose the vibration. The modified signal effectively reduces the inherent resonant frequency of the geophone and avoids instability.

Abstract: A pulse-drive circuit for an electric motor in which the steep edges in the drive-signal are made to vary substantially stepwise, i.e. around a first time instant the signal changes from a first level to a second level and around a second instant the signal changes to a third level. This makes it possible to reduce a mechanical resonance vibration having a period of twice the time interval between the two instants.

Abstract: In a rotary compressor provided with a motor to be controlled by an inverter, the power-supply frequency or impressed voltage during one rotation of the induction motor is varied in accordance with the changes in the load torque to make the production torque of the induction motor correspond to the changes in the load torque so as to fundamentally and effectively reduce the oscillations which are caused by the load torque changes.

Abstract: A positive electronic feedback circuit for mechanical vibration damping. The feedback circuit is connected from an output transducer fixed to a vibratable structure to an input transducer fixed to the structure. Preferably the feedback circuit has an output signal with a phase about 90 degrees lagging its input signal. Three conditions set forth herein make this possible.

Abstract: A device for reducing the vibrations of a rotating machine equipped with an active magnetic suspension comprises at least two vibration detectors located on the machine frame for detecting disturbances applied to the frame, and at least an additional selection feedback loop with narrow band and high gain whose central frequency is synchronized with a reference frequency and which receives signals delivered by the vibration detectors. The additional selective feedback loop comprises means for integrating the signals delivered by the vibration detectors and filtering means for eliminating the transient signals whose frequency is not linked to the reference frequency.

Abstract: An object sensing apparatus includes a plurality of light emitting diodes for illuminating a region of space and a plurality of closely arranged light detectors for receiving light reflected from an object. The apparatus is particularly useful in connection with automatically operated doors.

Abstract: A spacing safety mechanism for operation microscopes with electromotive stands is described, in which ultrasonic transmitter and an ultrasonic receiver are arranged in the vicinity of the operation microscope. When the travel time of the ultrasonic signals reflected by the body of the patient is less than a predeterminable value, the voltage supply of the motor for the downward movement of the operation microscope is interrupted.

Abstract: There is provided an electrical inching control for inching a drive system comprising a grinding mill driven by one or more three phase synchronous motors. The electric inching control includes an inching power bus and contactors or the solid state equivalent thereof. The inching bus supplies energy for the stator windings of the synchronous motors. The contactors or switches connect the positive and negative sides of a direct current power supply to the different phases of the stator windings in a sequence which provides a stepped rotating magnetic field, and the rotor field windings are excited with direct current. The interacting stator and rotor fields causes a rotation of the rotor a predetermined amount with each step causing the mill also to rotate a respective predetermined amount.

Abstract: An apparatus for preventing vibration in a centrifugal separator comprising an upright electric motor supported by a resilient member from a machine casing and wherein excessive vibration of the motor is detected for opening an electric power circuit of the motor. A mercury type vibration sensitive element is employed in the detector and comprises a mercury contact in a metallic casing. The vibration sensitive element is attached to a resilient plate and is in pressure contact with a lateral surface of a casing of the motor.

Abstract: A circuit for eliminating a.c. noise current which is produced as a result of the interruption of electrical contact between a brush and a commutator of a d.c. motor and comprises a capacitor which applies the noise current to a transistor, which in turn inverts the waveform of the current and applies it in an inverted phase to a power source for the motor, thereby cancelling the a.c. noise.

Abstract: An active force actuated vibration isolation system uses a velocity sensor in the form of a velocity-sensitive geophone to sense payload velocity and modifies the geophone signal to control the force applied to oppose the vibration. The modified signal effectively reduces the inherent resonant frequency of the geophone and avoids instability.