Abstract: In order to reduce the risk of damage on external objects, material articles or persons during the operation of a robot, particularly a miniature robot, the invention provides a method for limiting the force action of a robot part, such as a robot arm, on such an external object during a collision in such a way that as a result of a maximum permitted force, maximum force Fmax, acting on the object in the case of a collision, a corresponding, maximum permitted kinetic energy, maximum energy Ekin,max of the robot part is determined, continuously and at adequately short time intervals the actual kinetic energy, actual energy Ekin, of the robot part is determined and on exceeding the maximum permitted energy Ekin,max, the actual operating speed V of the robot is reduced.

Abstract: A creel (18) for a textile machine (1) producing cheeses (11), with a drive device (27) integrated into the creel (18) having an electromotor (35) which can be loaded with a braking current for braking the cheese (11) by initiating a braking moment directed counter to the rated current of the electromotor. A coolant circuit (36) is arranged inside the creel (18) for removal of the motor heat of the electromotor (35) of the drive device (27).

Abstract: A creel (18) for a textile machine (1) producing cheeses (11), with a drive device (27) integrated into the creel (18) having an electromotor (35) which can be loaded with a braking current for braking the cheese (11) by initiating a braking moment directed counter to the rated current of the electromotor. A coolant circuit (36) is arranged inside the creel (18) for removal of the motor heat of the electromotor (35) of the drive device (27).

Abstract: A method (10, 30) for actively controlling the temperature (tmotor) of an electric machine operating under torque (T*), speed and/or position control. A controlled output (T*), i.e. torque command, voltage, current or power, is adjusted such that the temperature of the electric machine does not exceed a predetermined reference limit (tref). The method (10, 30) of the present invention performs proportional-integral control (14) to reduce the commanded output (T*) to the motor and thereby prevent the steady-state motor temperature (tmotor) from increasing beyond the predetermined limit (tref). In one embodiment of the method (10), an error term (e) is filtered through a negative pass filter (12) before being combined with an optional decay term (&egr;decay) in a proportional-integral controller (14). A positive pass filter (20) and a negative pass filter (22) provide outputs that are summed and provide an adjusted output command (Tlimited) based upon predetermined relationship.

Abstract: A position control apparatus includes a stepping motor, a lead screw arranged to be rotated by the stepping motor being driven, a moving member arranged to move according to rotation of the lead screw, a first detecting device which detects that the moving member passes a particular position, a second detecting device which detects that the lead screw passes a particular rotating position, and a determination device which determines an amount of deviation of the moving member from a reference position on the basis of outputs from the first detecting device and the second detecting device.

Abstract: A semiconductor integrated circuit device 1 for use in a disk drive has a temperature detection section 9 that detects the temperature inside the semiconductor integrated circuit device 1 to switch a signal TSD between high and low levels when a predetermined temperature is reached, and a delay circuit 11 that receives this signal TSD and a clock from a control section 10 to output signals TSD1 and TSD2.

Abstract: Torque is distributed by calculating first and second torque commands using a requested torque and a ratio of speeds of first and second wheels and limiting them in accordance with respective torque command approved ranges and approved change rates; converting the limited torque commands to horsepower commands and limiting them in accordance with respective horsepower command approved ranges and approved change rates; and converting the limited horsepower commands to present torque commands. Maximum horsepower available is determined by using an engine speed to determine a nominal amount of available horsepower; applying a desired load status signal and an actual engine load status signal to a proportional-integral regulator; and using the nominal amount of available horsepower and an output signal of the regulator to determine the maximum amount of available horsepower.

Abstract: The head/disk tester of the invention has a housing 43 that houses spindle 44 that rotatingly supports a magnetic disk 31. The housing supports a moveable carriage 30 that, in turn, supports a magnetic head 32. Positioning means 39 and 41 are used to move the carriage and the magnetic head across the magnetic disk. These positioning means include stepper motors that realize coarse positioning of the magnetic head, and a piezo actuator 37 that is used for fine positioning. Linear encoders 40 and 42 located at both sides of the carriage provide feedback information to a closed-loop positioning system that controls the piezo actuator. A set of special signals ("servo bursts") pre-written at a given track of the magnetic disk is used as an additional source of feedback information for the same closed-loop positioning system. This positioning system includes a servo analyzer 45 that reads and processes servo burst signals from the magnetic disk, and a position controller 49 that controls the piezo actuator.

Abstract: A memory device, e.g. a capacitor, is provided for a collectorless DC motor. This component is charged whenever a particular rotor position is reached. In so doing, a voltage value or quantity on this memory device is changed. This quantity is compared to another quantity, which is dependent on a desired parameter, e.g. ambient temperature or gas or dust concentration. A reference signal is produced when a particular reference criterion is satisfied. The difference between the beginning of this reference signal and a second predetermined rotor position, which follows the initial predetermined rotor position with respect to time, is measured, and on the basis of this measurement, the current flow of the collectorless DC motor is influenced or regulated. In particular, the current can be toggled on and off as the rotor passes certain predetermined positions.

Abstract: There is provided a method for estimating the thermal displacement of a component of a machine tool comprising the steps of detecting the temperature of at lease one rotatable component of a machine tool having a variable rotational speed and a variable temperature; converting the detected temperature into a numerical value; and estimating the thermal displacement of the component based on the numerical value using an operational expression which includes a time-varying coefficient.

Abstract: A start-up controller is programmed to reduce current to a motor during a coast phase of an alignment state of the motor. The alignment state is divided into a plurality of phases based on time elapsed from the start of the alignment phase and the controller reduces the current when the elapsed time is substantially between a start and end time that define the coast phase. Because reduced current is provided to the motor during the coast phase, the total power and thus the thermal load on control components for the motor is decreased while the time the motor requires to "settle" into alignment is only slightly increased.

Abstract: A method and system for limiting current in a read/write head retract circuit is disclosed. The system includes a temperature sensor (75) for sensing a temperature of the disk drive read/write head retract circuit (53). The temperature sensor (75) generates an output signal indicating whether the temperature is above or below a threshold temperature. The system also includes a voltage regulator (100) which applies a voltage to an actuator motor (54). The voltage regulator (100) receives an input signal operatively associated with the output signal of the temperature sensor (75), and adjusts the voltage applied to the actuator motor (54) in response to the input signal. In one embodiment, the system includes a hysteresis circuit (88) which adjusts the threshold temperature of the temperature sensor (75) when the temperature sensor output changes.

Abstract: A spindle motor operates dynamically in one of two modes for a disc drive. During power-up, the disc drive electronics are configured to operate the motor in a line-to-line configuration, thus assuring generation of adequate torque. An operating condition circuit senses when the motor has attained substantially the desired running velocity .omega., after which, the drive electronics are dynamically reconfigured to operate the spindle motor in a line-to-neutral mode. A power interruption circuit senses when the source power supply V.sub.cc voltage level is too low or turned off, thereafter initiating a reconfiguration back to line-to-line mode, wherein the highest voltage pair of motor windings are electrically held across the source power supply V.sub.cc lines. Simultaneously, a switching circuit electrically connects the V.sub.cc lines across the transducer positioning voice coil motor in the disc drive, thereby delivering current from the spindle motor to the voice coil.

Abstract: A method of correcting thermal displacement error in a driving system of a machine tool comprises forming a heat distribution model including the driving system, and finding an amount of drive in the driving system in the heat distribution model, estimating a heating value supplied to the heat distribution model depending upon the amount of drive, estimating a temperature distribution state in the distribution model by finding a time variation of heating value in the heat distribution model receiving supply of the estimated heating value, finding an amount of heat displacement in the driving system depending upon the temperature distribution state and finding a correction value for thermal displacement correction depending upon the amount of thermal displacement. It is thereby possible to correct the thermal displacement error in the driving system of the machine tool without a detector.

Abstract: A revolution detecting apparatus which detects and outputs a compensated revolution position adjusted according to compensation values, stored according to the ranges of a rotation position indicated on the basis of the number of revolutions of a motor for driving a table. Compensation values for a plurality of revolving angle ranges within one revolution of a revolving shaft are stored beforehand, and are read out on the basis of detected rotation position ranges of the revolving shaft determined from the output of a revolution counter and a rotation angle detector. A compensated rotation position is calculated according to the read-out compensation values, the detected rotation angle and the detected revolution count. The apparatus also can store backlash and temperature compensation data and can judge when such data is to be applied so that the speed and accuracy of a servo control apparatus is improved.

Abstract: A register stores the value from the integral controller of the PID controller whenever it receives a feedback signal. A main controller outputs a warm-up drift compensation value whenever the servo motor is at a standstill. An arithmetic unit calculates the sum of the speed command signal from the PID controller, the warm-up drift compensation value from the main controller and a speed feedback signal and applies the result to the servo motor. In order to compensate for the warm-up drift in the servo motor, the main controller controls the position control apparatus by resetting the warm-up drift compensation value as described above.

Abstract: An actuator employing a unidirectional electric motor driving a first rotating member connected to a second rotating member through a pivotable link of which a first end is connected to the first rotating member at a smaller distance from its axis of rotation than the distance between the point at which the second end is connected to the second rotating member and its axis of rotation. An enegerization circuit includes first and second limit switches through which the motor is alternately energized to rotate the second men%her in opposite directions to first and second limiting positions respectively.

Abstract: A device for braking an electric motor as the drive source of an operating mechanism in camera by means of an electrical circuit is disclosed. This circuit includes a detector for levels of the rotation speed of the motor or of factors of influencing the rotation speed sensed when the motor is supplied with current flowing in a direction to activate the operating mechanism, and control means responsive to the output of the detector for altering the time for which a current flow of reversed direction is supplied to brake the motor.

Abstract: A thermoelectrically adjustable magnetic head for reading and writing information comprising a read/write core, and position detection cores on both sides thereof generating compensatory output in proportion to the relative positional drift of the magnetic head with position detection and correction device from the center lines of a magnetic disk data tracks by feeding back signals to the magnetic head to rectify said magnetic head's position to the center of said disk data tracks, and in the course of such compensatory operation also eliminates noise generated at the time of recording from the gaps between said tracks.

Abstract: An industrial robot system comprises a control unit including programs for operating an industrial robot and a peripheral device of the industrial robot according to the programs; a memory for storing the steps of the programs which are effected when the industrial robot and peripheral device are stopped unintentionally; a detector for detecting the conditions of the industrial robot and peripheral device when the industrial robot and peripheral device are stopped unintentionally; and a restarter for starting the industrial robot and peripheral device again when the contents of the memory coincide with the conditions detected by the detectors.

Abstract: A composable protection and control apparatus for motors is provided with a power case including semiconductor switches controlling the switching on and off of the power of the phase currents as well as a detector for detecting all or part of these currents and a control module which can be removably fixed to said case and be connected to the switches and to the detector. This module contains a logic circuit for managing the switches which includes a circuit for identifying the size of the power case and a circuit for selecting the working characteristics of the apparatus as a function of this size.

Abstract: Method of controlling at least one electric motor on an offset printing machine by inputting a set point for the rotational speed, which comprises forming a set point for the rotational speed by means of a device for controlling the electric motor, and reducing the value of the set point as a function of a measured line voltage when the line voltage is inadequate.

Abstract: A motor is disclosed comprising a housing and a plurality of parallel stator laminations mounted on the interior wall of the housing surrounding the rotor. The stator comprises a plurality of coils wound around the stator poles. Each coil or group of coils connected in series with each other are further connected in series with a thermistor network. Preferably, the thermistor is supported on a printed circuit board mounted adjacent to the coils, with the thermistor being inserted in a space directly adjacent to or between adjacent stator coils in order for the thermistor to accurately respond to the actual operating temperature of the coils. With increases in temperature, the resistance of the negative temperature coefficient thermistor will decrease, lowering the resistance of the motor circuit and maintaining the L/R time constant of the system. The opposite effect will occur with decreasing tempreature.

Abstract: A thermal displacement compensating apparatus capable of compensating for the thermal displacement of the main spindle of a machine tool is disclosed. A feed back scale and a measuring head are provided in order to detect the actual position of the front end portion of the spindle head. Furthermore, a distance sensor is provided for detecting the thermal extension of the main spindle with respect to the spindle head. The output signal from the distance sensor is used for modifying the present position detected by the measuring head or modifying a commanded target position. With this arrangement, a tool attached to the front end portion of the main spindle is moved to the commanded position regardless of the thermal displacement of the spindle head and the main spindle.

Abstract: A carriage device of a floppy disk apparatus includes a carriage main body arranged for linear movement and a head arm extending parallel to the main body. The body and arm are formed of synthetic resin. First and second magnetic heads are respectively mounted on the main body and head arm, so as to oppose each other. Regulating members are fixed to the main body and head arm, to prevent expansion and contraction thereof. Each regulating member is made of a material having a thermal expansion coefficient and hygroscopicity lower than those of the synthetic resin.

Abstract: An apparatus and method for positioning a transducer over the center of a track is disclosed. An arm carries the transducer. Embedded in the arm is a heating element. The heating element is positioned so that the linear expansion or contraction of the arm resulting from the temperature rise or drop due to the amount of heat applied to the arm by the heating element will move the transducer across the track. In operation, a constant amount of heat is initially applied to the arm to center the transducer. During tracking, a circuit varies the amount of power applied to the heating element so that the transducer is kept over the center of the track.

Abstract: A control system for positioning a head in a magnetic disk device. The control system including a stepping motor, an index timing sensor for indicating the starting point of a data track, a rectifier for rectifying the servo position information, and a envelope detector for detecting the envelope of the rectified servo information. The servo position information is recorded in at least two data tracks and is formed in a staggered, offset pattern. The outside and inside tracks can serve as reference tracks for use in predicting the expected position of an intermediate track between the reference tracks by the use of linear interpolation.

Abstract: A disk drive apparatus includes apparatus for elimination of off-track errors of a read/write head by deriving and storing correction data for all of the tracks on a disk on the basis of the signal level resulting from read-out of the contents of gap portions of the format data in two specific tracks. If, as indicated by a read error indication signal from a host computer, read errors subsequently occur in spite of position correction based on a stored correction value, then the off-track error for the track concerned is detected and an updated correction value is derived and stored. Accurate position control is thereby attained without a need for servo data tracks or regions to be recorded on each disk.

Abstract: A motor speed control apparatus which is provided with means for performing the control to always apply to a motor a driving force smaller than a frictional load of a driving system which is driven by the motor and to apply to the motor a driving force larger than the frictional force of the driving system when the motor is accelerated.

Abstract: According to the invention, a magnetic head positioning control apparatus using an index servo data has a circuit for determining a final correction value such that a magnetic head position correcting operation is repeatedly performed at a designated track position. The apparatus also has a circuit for obtaining final correction values for two different tracks, to calculate a thermal offset value accordingly. A correction current value and a track position can be expressed by a linear relation, and two coefficients of the relation can be determined using the two final correction current values. When an arbitrary track position is designated, a thermal offset value can be determined with reference to the two coefficients of the relation and the designated track position.

Abstract: In an industrial robot system, the robot is first moved to a starting position, and, when the temperature of the robot exceeds a predetermined value, a position checking operation is effected to move the robot towards the starting position so that, according to the difference between the starting position and the position where the robot has been stopped by the position checking operation, a compensation value is provided for temperature compensation of the robot, whereby, even when the working arms of the robot are extended or contracted by temperature variations, the robot can perform its working operation correctly.

Abstract: Gyroscopes, particularly those with permanent magnet torquers, may be temperature sensitive. A temperature signal may be derived and used to correct the temperature dependent parameters such as gyro scale factor. Herein, instead of or in addition to such correction, it is proposed to regulate the gyro temperature by varying the torquer signals and hence controlling the power dissipated in the torquer coils. The torquer signals may comprise positive- and negative-going pulses of fixed amplitude and having respective durations appropriate to produce the required torquing effect. Then, the dissipated power can be controlled by varying the durations of the inter-pulse dead-zones.

Abstract: An automatic apparatus for an NC machine tool which automatically changes tools, automatically measures the tool size and automatically compensates for the amount of abrasion without stopping for indexing and positioning. The apparatus can automatically and easily measure and compensate for variations in the diameter of cutters in an end mill, a boring machine, etc.

Abstract: An apparatus for compensating for thermal expansion and contraction causing structural part size variations of machine components. The apparatus senses the displacement and temperature of various components of a machine which are designed to move relative to each other along one axis and adjusts this motion in predetermined manner depending upon the sensed displacement and temperature. A programmed control system is responsive to the sensed temperature and converts various sensor outputs to the necessary correction signals for application to the motor causing the relative motion.

Abstract: A method and apparatus by which the output value of a resolver position detection system is compensated for systematic phase shift errors produced by signal conditioning circuitry through which the signal passes.

Abstract: A method and apparatus used to compensate for thermal displacement and to correct a positional error caused by the thermally induced displacement of a spindle positioned in response to a numerical control system. The amount of thermally induced displacement of the spindle, at a predetermined point in time after application of electric power to the machine tool, is stored in a memory. When the spindle is to be positioned in response to numerical control data, the commanded amount of spindle movement is compensated by using the amount of thermally induced displacement stored in the memory, and the spindle is then positioned on the basis of the compensated commanded amount of movement.

Abstract: A track positioning apparatus for a (floppy) disk record medium to compensate for physical changes in the disk resulting from variations in temperature or humidity. A grating, used to position a read-write head, includes reference marks thereon corresponding to reference tracks on the disk. The grating is stretched or compressed proportionally during a calibration operation to compensate for changes in the flexible disk.

Abstract: A separately excited D.C. motor employs an analog servo control responsive to a speed control input signal that controls the derivation of a compensating signal for the motor back emf. The speed control and compensating signals are combined to control the motor speed via an analog regulator. A digital shaft encoder responsive to the motor position supplies a pulsed signal to a comparator that is also responsive to a desired position signal that is derived from the speed control signal. The comparator derives an integrated error signal that is supplied to the analog regulator. Application of the speed control signal to the regulator is delayed if a thermal simulator for the motor characteristics indicates motor overheating. In response to the compensated, desired speed indicating signal indicating that the motor has been ordered to stop, the error signal is decoupled from the analog regulator.

Abstract: An inductive potentiometer for supplying a d.c. output voltage, which is linearly variable as a function of the rotation angle of a spindle. The potentiometer is constituted by a synchro-resolver and two associated circuits, an a.c. voltage supply circuit of one stator winding incorporating an oscillator whose amplitude is controlled by the supply voltage and an output circuit connected to the rotor which incorporates a demodulator stage. The linearization of the voltage as a function of the angular position of the spindle is ensured by a circuit shunt incorporating an amplifier whose gain is close to 0.5 controlling another stator winding. Temperature compensating windings can be included on the stator.

Abstract: A thermally controlled servo system in which a member supporting the drive for a device to be accurately positioned is moved relative to a stationary support member in response to changes in temperature of an elongated, tensioned member. Changes in temperature of the tensioned member are achieved by regulating the current flow through the tensioned member in accordance with a control signal derived from an error signal generated by the device to be positioned.

Abstract: A system for the automatic management (detection and control) of tool life in a numerically controlled machine tool having means for automatically measuring the dimension of workpieces and correcting the tool offset of a cutting tool depending on wear on the cutting tool. In the system, the mechanical deformation error component (radial deviation component of a spindle of the machine tool) due to heat is removed from the amount of tool offset value (tool feed position compensation) so as to accumulate solely the net tool wear component, and the cutting tool is exchanged when the accumulated value attains a predetermined setting.

Abstract: A transient temperature compensation system for use in a magnetic disk drive comprised of both fixed and removable disks. The system includes first and second thermistors respectively mounted immediately adjacent the fixed and removable disks. The second thermistor is preferably mounted for movement between an operative position and an inoperative position. In the operative position, the thermistor is positioned in very close proximity to the disk. In the inoperative position, the thermistor is spaced from the disk to permit sufficient clearance to enable the disk to be removed from the drive. The outputs of the two thermistors are used to develop a signal representing the temperature differential between the two discs which signal is supplied to the disk drive head positioning system. This signal is used to modify the positioning of the heads relative to the fixed disk to compensate for differences in the radial positions of corresponding tracks on the fixed and removable disks.

Abstract: In an automatic measuring apparatus and method for a numerically controlled machine tool, the dimension of a stylus secured to a cross slide and a desired dimension between two opposite points on a workpiece to be measured are inputted into an automatic measuring device in advance, the cross slide is moved under numerical control to bring the stylus into contact with the two points and to remove the stylus therefrom, and measurement of the amount of movement of the cross slide is started when the stylus leaves from one of the two points and the measurement is ended when the stylus leaves from the other point. The measurement value thus obtained, the dimension of the stylus and the desired dimension are subjected to addition and subtraction, thereby to automatically measure the actual dimension between the two points, and the difference between this actual dimension and the desired dimension.

Abstract: A machine with automatic feed speed control comprising, a work-piece advancing device for advancing a work-piece in a feed path at a feed speed, a work-piece tooling device having a tool member movable in the feed path with a portion engageably with the work-piece for tooling the work-piece and for receiving a load from the advancing work-piece through the action of the work-piece advancing device. The load is proportional to the size of the portion of the tool member engaged with the work-piece. A speed controller is connected to the work-piece advancing device for increasing and decreasing the speed thereof and thereby increasing and decreasing the feed speed of the work-piece. Work-piece sensors are provided in the feed path engageably with the work-piece for sensing the size of the portion of the tool member which will become engaged with the work-piece, which size corresponds to a maximum load on the work-piece tooling device.

Abstract: A monolithic photosensor array comprises first, second and third identical photodiodes. A light emitting diode illuminates the third photodiode continuously. An occluder disc is rotatably driven from the shaft of a servo motor between the light emitting diode and the first and second photodiodes. The disc is formed with a plurality of circumferentially spaced apertures which alternately cover and uncover the photodiodes which produce quasisinosoidal position signals in response thereto, the position signals of the first and second photodiodes being relatively 90.degree. out of phase. A computing circuit produces a motor shaft velocity command signal corresponding to the number of steps the shaft must rotate from the initial position to the new desired position and progressively reduces the magnitude of the velocity signal in response to the position signals.

Abstract: A sensor array produces two sinusoidal position signals which vary in phase by 90.degree. in response to rotation of a servo motor shaft. These position signals are inverted and the position signals and their inversions are commutated to produce a velocity signal. A position error signal is generated which indicates the difference between the actual motor shaft position and the command position. A reference signal is voltage divided in accordance with the position error signal to produce a velocity command signal which is compared with the velocity signal to produce a motor drive signal. The position signals and their inversions are half wave rectified, integrated and summed to produce the reference signal as a varying D. C. signal, the magnitude of which corresponds to the amplitude of the position signals and compensates for variations in said amplitude caused by high frequency attenuation in the sensor array and like phenomenon.

Abstract: In a magnetic-disc data storage device using exchangeable discs for the recording of data on circular tracks, a reference track is provided on the disc and during interruptions in the transfer of data, a read-write head is moved to the reference track and the error in its expected position, due to dimensional changes in the disc or the storage device or due to misalignment of the head, is measured. In subsequent data tracks access the position of the head is corrected by error measured so that the head is correctly aligned with the selected data track. Measurement of the error is carried out more frequently when the error is changing rapidly.

Abstract: Disclosed is a positioning system and method particularly useful for so-called floppy disks for positioning a device with respect to a reference on a disk in accordance with a command signal despite temperature and humidity variances.

Abstract: An analogue control device with at least one electric stroke control emitter for the abutment-free stroke limitation of machine tools, especially honing machines, with which either a tool carrier or the workpiece connected to the machine tool carries out a reciprocatory stroke of adjustable length. As stroke control emitter there is provided a simple resistor which is adjustable in conformity with the machining movement and which is passed through by electric current, while pre-set values of the current or of the voltage generated by the current on the resistor are employed for limiting the stroke. The device also includes a warming-up or conditioning control which makes it possible automatically to carry out a predetermined number of working strokes with changed stroke length, the number and/or stroke length being adjustable.

Abstract: The positioning of the head positioning mechanism of a magnetic disc file is controlled by a servo system arrangement which involves separately monitoring the temperature conditions in the vicinity of the center track of a disc file and the head positioning mechanism; producing related electrical signals which are used in conjunction with signals defining the address of a required track of a disc and a reference voltage to obtain a temperture corrected signal which is used to produce a head positioning control signal.