Abstract: A method of controlling synchronous running of a plurality of electronically commutated motors (22, 24, 26), each of which includes a stator having a stator winding (40, 42, 44), a permanent-magnet rotor (28, 30, 32), and at least one arrangement (34, 36, 38), associated with the respective motor, for sensing its rotor position and for generating a rotor position signal (H1, H2, H3). Also provided is an energization arrangement (46), to which the stator windings (40, 42, 44) of the motors are connected. The method includes the steps of detecting occurrence of a predetermined state of the rotor position signals (H1, H2, H3) and, in response thereto, triggering simultaneously commutation of the currents in all the motors.

Abstract: A method and apparatus is disclosed for detecting whether belt slip is occurring between an electric machine and a machine drivingly connected together by a drive belt using only measurements of rotor speed, voltage and current derived from the electric machine, thereby improving the sensitivity of slip detection and eliminating the need for a comparison of rotor speed with a measurement of the rotational speed of the machine.

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

Abstract: An electric motor drive system having a first electric motor, a first drive shaft to which the first electric motor is coupled, a second electric motor having a higher power rating than the first, a second drive shaft to which the second electric motor is coupled, an epicyclic gear system comprising a sun gear to which the first drive shaft is coupled, a ring gear to which the second drive shaft is coupled, and planetary gears meshing with both the sun gear and the ring gear, an output drive coupled to the planetary gears, and, a one-way rotation restraining means coupled to the second shaft to permit rotation of the second shaft in one direction and to prevent rotation of the second shaft in the other direction for restraining motion of the second shaft during start up of the first motor, and a one-way rotation restraining means coupled to the first drive shaft for restraining rotation of the first shaft during start up of the second motor, and clutch means operable to interconnect said first and second moto

Abstract: In a method for numerical position control of motordriven shafts whose rotations are to be synchronous with one another under a certain transmission ratio a control loop is provided for each shaft. A speed setpoint, weighted with the corresponding transmission ratio, is applied as a position setpoint per unit of time simultaneously to the control loops of the respective shafts. If the actual speeds of the shafts differ from one another due to a disturbance within the controlled system, the difference between these actual speeds is used to readjust the speed and the position within the speed controlled section of one of the control loops.

Abstract: A control system for synchronizing a combination press line comprised of a transfer press and a double-action press.The transfer press is set as a master press and the double-action press as a slave press following the transfer press in operation.The transfer and double-action press each has a synchro coupled to respective drive shafts for detecting an angular position of each press. A comparator is provided for comparing signals from both synchros and generating a signal corresponding to a difference between signals from both synchros. The output signal from the comparator is fed only to a motor for the double-action press for controlling the speed of the motor, thus enabling the double-action press to follow the transfer press in operation.

Abstract: In a speed control method for digitally controlling the speeds of motors in a sectional drive system including the steps of setting a speed difference of each section with respect to a line speed reference, the speed difference set value is varied by pressing a push button switch and varying the speed difference set value by a unit value every unit operation time when the button switch is pressed.

Abstract: A belt movement sensor detects the movement of a belt having signal generating means embedded in or emplaced on the surface of a drive belt, and actuates a warning signal and/or controls the drive motor when the signal from the sensor varies by more than a pre-determined amount from a set point.

Abstract: A speed control system is provided for apparatus and process for shaping and treating web material of indefinite length wherein the apparatus includes a master processing unit, one or more slave processing units communicating with the master unit through web storage or buffer means and a computer. Information as to the desired speed and mode of operation of the master unit and the mode of operation of the slave units is inputted to the computer which communicates with the drive motors of the master and slave units through special buffered isolated amplifiers and automatically controls the speed of the slave units so as to maintain the desired quantity of partially processed web material in the web storage means and to maintain the selected operating speed of the master unit.

Abstract: A control system is described for use in a web transport in which a web is advanced from a supply spool to a take-up spool by a pair of drive motors, the latter of which are actuated by a servo control. The system includes a variable gain network which enhances the gain of the servo system at very low speeds without sacrificing system stability at higher speeds, and a circuit for adding a hold-back torque to the motor driving the take-up spool to smooth its rotation under low torque conditions. In addition, the system includes a device for inhibiting the rotation of the spools when an operator has removed the web from the spools, thereby preventing the servo control from rotating the spools in an uncontrolled manner in response to inadvertent operator movement of one of the spools.

Abstract: A system is described for controlling the speed and direction of rotation of first and second spools in a web transport system in which a web is advanced between the spools by first and second drive motors. The system incorporates a servo control which continuously reacts to variations in the speed of the spools so as to drive the spools at respective speeds whose sum is constant and proportional to a selectable control voltage. To achieve this result, the first and second spools, driven, respectively by the first and second drive motors, are coupled to means, such as a corresponding pair of servo generators, for generating electrical outputs representative of the direction and speed of rotation of the spools. A control voltage, proportional to the sum of the desired speeds of the two spools, is continuously and algebraically summed with the outputs of the two servo generators, the summed signal constituting a motor drive signal.

Abstract: Long and short term variations in the speed at which a magnetic tape is moved with respect to a read and/or write head are minimized by maintaining the product of the speed of the tape payout and take-up reels constant. In accordance with a preferred embodiment the rotational speed of the payout reel and the rotational speed of the take-up reel are sensed and effectively multiplied to derive a signal which is compared with a predetermined constant magnitude reference signal. The result of the comparison is an error voltage which is employed to energize and thus control the speed of the drive motor for the take-up reel.

Abstract: A facsimile transceiver comprises a rotatably mounted drum and an information transducer juxtaposed to the drum for marking on a copy medium carried by the drum or detecting dark-light variations in a document carried by the drum. The drum is driven by a DC motor with the speed of the motor controlled by a phase locked loop in which the phase and frequency of reference pulses are compared with the phase and frequency of pulses having a frequency proportional to the speed of rotation of the drum.

Abstract: A method and apparatus for rapidly detecting acceleration variations in a moving object by monitoring the instantaneous velocity of the object. A signal representative of instantaneous velocity is operated on to derive signals representative of average acceleration, instantaneous acceleration and predicted velocity. The average acceleration and instantaneous acceleration signals are compared to determine acceleration changes. In a preferred embodiment the invention is applied as a wheel slip/slide detector in a traction vehicle and a signal generated when the instantaneous acceleration deviates from the average acceleration by a predetermined magnitude is utilized as a wheel slip/slide signal to implement corrective action to the power control system of the vehicle. Upon generation of the wheel slip/slide signal, calculation of average acceleration is inhibited to prevent its influence by the sudden acceleration change.

Abstract: A motor control system for use in maintaining substantially constant linear speed of a web moving between a supply and a takeup reel such as in a reel driven magnetic tape transport. The rotational periods of the reels are measured to provide representative signals which are summed and compared with a reference to yield an error signal for control of takeup reel motor driving voltage such that the error voltage tends to become zero, resulting in substantially constant linear web speed. In alternative embodiment, the period representative signals are each non-linearly processed prior to summing to enhance the accuracy of web speed control. In further embodiment, the rotational frequencies of the web reels are measured to provide representative signals which are each non-linearly processed and then summed and from which summed signal is derived a resulting error voltage for web speed control.

Abstract: Two movable members driven by individual motors are positioned accurately at any given time and are tracking each other for all displacements. Individual positioning is used with differential positioning to force a follow-up of one member relative to the other. One feedback position loop provides a master reference for a second position loop of the slave motor drive, and the differential position signal makes the second loop operate as a vernier of the master loop. A limiter prevents the master drive from running ahead of the slave drive.

Abstract: A control system is provided for stopping the operation of a bulk material conveyor system in response to an indication that the speed of either drive or driven elements thereof are above or below acceptable amounts, that the output speed of a particular material handling component falls below an acceptable difference from the input speed to said component, or that the speed of an upstream material handling component falls outside an acceptable difference with respect to the speed of a downstream material handling component feeding material to said upstream component. Speed indication is provided by the electrical signal output from dc tachometer-generators associated with the drive or driven shafts of the component whose speed is being sensed.