Abstract: An actual position value transmitter for an elevator position control circuit includes a pulse transmitter in the form of a digital tachometer which is driven by way of a cable and a car distance counter responsive to the pulses for generating an actual position signal. Stopping errors of the elevator car caused by slip of the cable are avoided by utilizing a correction table in the form of a write-read memory, in which correction values assigned to the floors and corresponding to the stopping errors are stored. The correction table is connected to the car distance counter and on departure of the elevator car from a floor or on passing a floor, a correction value assigned to the next floor is fetched from the correction table and fed to the car distance counter for the purpose of correction of the actual position signal.

Abstract: A motor drive control that permits a DC electric motor to be rapidly driven and accurately stopped at predetermined stop positions is disclosed. An indexer (V) generates a deceleration point signal at a deceleration point that occurs before a predetermined stop point of load (VI) and a stop point signal at the stop point corresponding to a predetermined destination of the load (VI). A rotational direction detector (III) detects the rotational direction of the motor (IV) as the motor (IV) passes the stop point and produces a rotational direction signal representing the rotational direction of the motor (IV). A rotation control circuit (I) generates a drive signal in response to movement and movement direction signals; a deceleration direction signal in response to the deceleration point signal; an inhibit signal in response to the stop point signal; and a decelerated drive signal representing a reverse rotational direction of the motor (IV).

Abstract: An electro-hydraulic servo-valve having a valve spool and comprising: an adjustment motor, and a control apparatus for adjusting said adjustment motor to depending on the input nominal value, wherein said adjustment motor transmits its movement directly to the valve spool of the hydraulic valve, and wherein a preferably electrically operating additional drive is provided which will be switched on in case the valve spool gets stuck so as to release the valve spool from its stuck condition.

Abstract: A negative-phase braking control device for accurately stopping a plural-phase stepping motor in a very short time. The negative-phase braking control is performed by comparing the present position signal value representing the position of a rotor of the motor with the signal values which the present position signal value should take at a target position and at a predetermined position before the target position and controlling the rotation of the motor in the forward and reverse directions in accordance with the result of the comparison.

Abstract: A permanent magnet two degree of freedom gyroscope (10) utilizing a single rotor (12) having a trapezoidal shaped pattern formed thereon. The trapezoidal pattern consists of a reflective segment (11) and a non reflective segment (13). Two optical sensors (14, 18) fixed with respect to the stator, obtain angular displacement information about the two axes perpendicular to the spin axis, rotor pole location information, which is used for commutation, and, rotor speed information. The present invention deals with an apparatus and method for starting, running and torquing the two degree of freedom permanent magnet gyro motor (10) based on position and displacement information obtained from the two optical detectors (14, 18). The angular displacement information is obtained by sensing differences in the optical pattern as the rotor (12) spins and is displaced about cross-axes, perpendicular to the spin axis.

Abstract: A controller for stepper motors used in servo systems is implemented for being controlled by a microprocessor via appropriate input/output circuitry. Upon application of discrete commands, the controller produces stepper motor drive signals at a predetermined rate in predetermined drive sequences for driving one motor and for concurrently driving one of a plurality of motors. Closed loop positioning of the stepper motors using digital position feedback is achieved, as is simultaneous manual control of the stepper motors utilizing a slew stick.

Abstract: In this invention, an excitation current is switched in accordance with a change in number of phases so as to reduce an excitation current per phase in a 2-phase mode to be smaller than that in a 1-phase mode. The excitation current in the 2-phase mode is set to be about 0.6 to 0.8 times larger than that in the 1-phase mode, so that a constant torque is always generated.

Abstract: An electropneumatic position regulator having a current/pressure transducer has, as electric input, at least one coil (11) fed with a current (setting signal), as well as a permanent magnet (16) whose relative position is variable as a function of the current for the adjustment of a nozzle/impact-plate arrangement (17, 18) of a pneumatic system. The position regulator serves for a pneumatic setting device (23) which has a stroke output and is connected with the nozzle/impact-plate arrangement. The position regulator furthermore comprises a position report device with an electric path transmitter (31) which is connected to the stroke output (32) of the setting device (23). The report signal from the electric path transmitter (31) is fed back to the electric input (coil 12) of the current/pressure transducer.

Abstract: High resolution microstepping of an unipolar stepping motor is accomplished by applying from a look-up table the values of the SINE and COSINE of a given angle to the control circuit of a unipolar stepping motor. The difference between the present position and the desired position is calculated and depending upon the magnitude of the difference, the degree of microstepping is determined from four steps per ninety electrical degrees of motor rotation to thirty-two steps. By such selection, the positioning of the output shaft of the motor is smoothly and accurately accomplished.

Abstract: A positioning system rotates a servomotor (4) in response to a command value to move a movable unit and compares a feedback signal from a position detector, such as a servomotor or the like, with the command value to output a servo command signal. Pulses from an encoder (5) are counted to generate a positional information signal (6) directly indicative of an angular position of the servomotor (4), and the positional information signal is fed back to a command processor (2) to effect a positioning operation.

Abstract: A motor driven mechanical positioner is provided which will position a movable arm to any one of 840 discrete angular positions. A total angular range of +/-42.degree. can be covered in 0.1.degree. increments. Electronic circuitry controls the nonlinear drive mechanism. A drive shaft wheel has six evenly spaced holes through which light from an IR LED is allowed to shine on a phototransistor placed on the other side of the wheel. As a result of the intermittent light striking the phototransistor, six clock pulses are generated for every revolution of the drive shaft. A desired angular position is entered into the electronics via thumb wheel BCD switches. The BCD information from the switches is transformed into binary information to address EPROMs. For each possible binary address representative of a desired angular position, the selected EPROMs output binary data that is representative of the clock pulse count for that particular angular position.

Abstract: A system and method for driving a stepper motor utilizing a near minimum amount of driving power is described. A stepping detector is utilized to determine whether the motor has actually stepped in response to a driving power applied thereto. When it is determined that the motor has stepped, the magnitude of the driving power is decreased. When the stepping detector indicates a stall condition, the driving power is increased. As a result, the motor operates near stall condition and power consumption is minimized. In the preferred embodiment during each consecutive step a different phase of the motor is deenergized to conserve power. By stepping the motor a voltage pulse is induced into the deenergized phase. The polarity and magnitude of that voltage pulse are examined after each step to determine whether the motor has actually stepped. The use of the deenergized phase to ascertain motor status eliminates the need for an external stepping detector.

Abstract: A proportional control circuit for the direction and precise speed control of D.C. electric motors such as those used to drive camera tilt/pan mountings. The circuit applies current to D.C. motors in a push/pull proportional scheme whereby slewing speed is smoothly and precisely controlled and electromotive force provides motor braking. A single current source powers the motors through an "H" bridge switching amplifier arrangement responsive to the balance between two voltage dividers, one of which includes a controlling potentiometer that regulates both direction and speed.

Abstract: A stepper motor control circuit having a reduced number of discrete components is provided by using an on-chip analog to digital converter of a single chip microcomputer to control the waveforms of chopped winding currents. Four power MOSFET's, four diodes and two sense resistors can be added to the circuitry of a board populated by the single chip microcomputer to implement a full step motor controller. The addition of a holding current circuit frees the computer for servicing other tasks when the motor is idle.

Abstract: A driver circuit for a stepping motor includes first and second windings for two-phase magnetization to give a magnetomotive force to the stepping motor. A first control signal and a second control signal are generated by a control circuit when the stepping motor seeks and is held respectively. The first and second windings are connected in series or in parallel with a power supply in response to the first control signal or the second control signal, respectively. The directions of the currents flowing through the first and second windings are controlled in response to the control signals. The connections of the windings and the current flow directions through the windings are controlled by MOS transistors.

Abstract: A digital-to-synchro converter is provided where a binary input code specifies a desired shaft angle and where an resolver type position transducer is employed with additional circuitry to generate a shaft position error signal indicative of the angular difference between the desired shaft angle and the actual shaft angle. The additional circuitry corrects for known and calculated errors in the shaft position detection process and equipment.

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: A first servo system (31) which feeds back at least position and speed and a second servo system (32) which effects integral control by feeding back position are connected in series. A first signal obtained by multiplying the output of the integral controller of the second servo system by a first gain is added to the position feedback signal of the first servo system, while a second signal obtained by multiplying the input of the integral controller of the second servo system by a second gain is added to the speed feedback signal of the first servo system. In this way, feedback control is effected using one mutual position detector, thereby eliminating the dynamic interference between the first and second servo systems, and thus enabling the two servo systems to be activated simultaneously.

Abstract: A control device is provided for a stepping motor which connects with a drive system comprising a somewhat resilient member exerting a rebound force, such as a gear for the platen or a wire for the carriage in an electronic typewriter. When the stepping motor stops rotating in a determined direction, the control device rotates the stepping motor in the opposite direction for a minimum step to compensate for the unnecessary reverse rotation of the stepping motor caused by the resiliency in the drive system. Therefore, a transmission shaft of the stepping motor is freed from such an undesired external force as the resiliency of other parts and the stepping motor is always stopped in a position appropriate for a subsequent rotation.

Abstract: A stream of binary bits is converted into blocks of eight parallel bits. A first group of five of the eight bits addresses a memory device which has thirty-two code words each having four numbers representing the coordinates of signal points in four-dimensional space. The remaining three of the eight bits are expanded to four bits by a convolutional encoder having three bits of memory. These four bits are then used to multiply the four numbers of a code word read out from the memory device. This method permits a block of eight binary bits to be coded into any one of five hundred and twelve four-dimensional code words.