Abstract: A lift assembly including an article to be lifted between a lowered position and a raised position, a flexible drive element coupled to the article and defining a longitudinal axis, a power mechanism coupled to the flexible drive element, a drum powered by the power mechanism and dimensioned to facilitate winding of the flexible drive element onto the drum, and a cable keeper providing a force on the flexible drive element to bias the flexible drive element toward the drum.

Abstract: A method is provided. A command to correspond to a target speed of a motor is received. A rotational speed of the motor is measured, and a brake-to-off ratio for a braking interval is calculated based at least in part on the rotation speed, the target speed, a braking parameter. An off state for an inverter that is coupled to motor is induced during an off portion of the braking interval, and a brake signal is applied to the inverter during a braking portion of the braking interval.

Abstract: An electric braking device for printing material processing machines includes at least one electric drive to be braked that is supplied by a power converter in motor operation and is braked by the power converter in generator operation. A control unit switches on a redundant electric braking device in the case of a failure of the power converter by using a switch. The braking device has at least two braking stages, an additional switch for actuation in at least two stages, and at least one brake resistor. In the circuit of the redundant electric braking device, a braking current is measured and the measured value is fed to a comparator for comparing the actual braking current to a desired braking current. A printing press having the braking device is also provided.

Abstract: An electric brake device is provided for electronically controlled synchronous motors which are supplied with voltage by way of a converter. The synchronous motor contains a winding center point and that the winding center point is connected by way of an electric resistor and a switch to a ground point of the converter and that the phases of the converter that are connected to the ground point contain in each case a free-wheeling diode.

Abstract: Systems and methods for controlling servomotors are described herein. Servomotor controllers and related control circuitry are configured to generate control signals for controlling the servomotor. The control signals include directional control signals to control the rotational direction and position of the servomotor, and power control signals control the rotational speed and/or torque of the servomotor.

Abstract: An electrodynamic braking device for a universal motor is proposed, wherein during a braking operation a field winding is supplied from a network, and an armature is directly short-circuited, and a braking operation is carried out using a program of a controller of a control electronics system, whereby good braking is achieved with relatively low brush wear. Such an electrodynamic braking device is advantageously applied in a power tool equipped with a dangerous tool.

Abstract: Disclosed is a method for controlling an electro-mechanical brake system including a cascade controller, in which a position controller, a speed controller and a current controller are integrated to control a motor. The method includes determining whether an actual speed of a motor exceeds a command speed of the motor in an early stage of a motor operation; and restricting speed reduction of the motor until a braking force is generated if the actual speed of the motor exceeds the command speed of the motor in the early stage of the motor operation. Speed reduction of the motor is restricted until braking force is generated even if a speed error (actual speed of the motor>command speed of the motor) occurs in the early stage of the motor operation in the EMB system, thereby improving the braking responsiveness.

Abstract: In a method for monitoring a stationary condition of a drive device, a monitoring device provides the drive device with a temporally varying monitoring signal which, when a sensor device connected to the drive device functions properly, modulates a sensor output signal of the sensor device in accordance with the monitoring input signal. The monitoring device receives the sensor signal and monitors it for the presence of a corresponding signal component. In the absence of such a signal component, the monitoring device controls a safety device which converts the drive device into a safe state. When the drive device is controlled by means of at least two phase-shifted current regulators, it is possible for the monitoring device to monitor an output signal of at least one of the current regulators for constancy and to control the safety device when the output signal of the at least one current regulator changes.

Abstract: A motor has built therein a brake for stopping the rotation of the motor and a brake controlling circuit for controlling the brake. The motor is further provided with a bypass circuit for supplying an electric power directly to the brake and a terminal for connecting a power source to the bypass circuit. When the brake controlling circuit develops a fault, the brake is directly released by an external power source.

Abstract: A method for controlling the release of a brush motor which has applied a load includes several steps. One step includes applying a release current to the brush motor to rotate the brush motor in a direction toward releasing the applied load of the brush motor. Another step includes sensing the commutator bar ripple current of the brush motor. Another step includes determining when to remove the release current using at least the sensed commutator bar ripple current.

Abstract: An electromagnetic suspension system for a vehicle, comprises an electromagnetic actuator interposed between a sprung mass and an unsprung mass and disposed substantially in parallel with an spring element. An electric motor is provided for driving the electromagnetic actuator. A motor controller is configured to calculate a displacement input applied to the electromagnetic actuator and to control the electric motor in a manner that the electromagnetic actuator generates an optimum damping force corresponding to the displacement input. A motor control circuit is provided for the electric motor, through which the electric motor is connected to the motor controller. Additionally, an electrical damping element is electrically connected to the motor control circuit and in parallel with the electric motor to generate a damping force in a passive manner under a dynamic braking of the electric motor in response to the displacement input to the electromagnetic actuator from the unsprung mass.

Abstract: According to the invention, the controller cascades are suitably divided up and the oscillation damped only in the load rotational-speed controller. Here, a motor rotational-speed setpoint value (z) of a quickly regulated motor rotational-speed controller (9) and not the motor torque, is selected as the connection point for a load acceleration (i). In order to achieve a shorter transient response time, according the invention the difference between a setpoint rotational speed (x) and load rotational speed (y) is connected to the motor rotational-speed setpoint value (z). The solution in principle according to the invention which is presented has, in contrast to other known methods, the advantage that the actuation of the corresponding controllers is comparatively simple with very good control results.

Abstract: To provide a vibration-damping positioning controller capable of effecting stable positioning operation within a short period of time.

Abstract: A blended electrical/friction braking system includes an electric brake feedback monitor which monitors a first signal corresponding to an electric brake effort request of an electric motor of an electrically powered vehicle. The electric brake feedback monitor detects one or more electrical conditions of the electric motor during electric braking and selectively supplies/terminates the first signal to/from a brake controller as a function of the first signal and the one or more electrical conditions. In response to termination of the first signal thereat, the brake controller causes a friction brake of the vehicle to assume the entire braking effort of the vehicle.

Abstract: The controller comprises (a) an interpolation calculator for dividing move data of a robot arm tip position into each sample period, the data fed from a position teaching section, (b) a load inertia calculator, (c) a gravity torque calculator, (d) acceleration and deceleration (A & D) time calculator for calculating an optimum A & D time by using the load inertia calculated by the load inertia calculator and the gravity torque calculated by the gravity torque calculator, (e) an A & D processor for providing an A & D process to move data of each sample time calculated by the interpolation calculator based on the A & D time calculated by the A & D time calculator, and (f) position controllers for controlling each motor based on the move data processed by the A & D processor. The A & D time is calculated with the following equation:T=.alpha..multidot.(J.sub.m +J.sub.L)/(T.sub.m -T.sub.L).multidot.Vwhere: V=desirable speed, J.sub.m =motor inertia, J.sub.L =load inertia, T.sub.m =motor torque, T.sub.

Abstract: An apparatus for preventing a picture fluctuation and correcting a reverse pulse in a servo system for a video cassette recorder having a still or slow motion playback function. The apparatus comprises speed and phase error detectors for detecting speed and phase errors, speed and phase controllers for controlling a speed and a phase in response to output signals from the speed and phase error detectors, mixers for mixing output signals from the speed and phase controllers, a system control circuit for controlling an operation of the servo system, the system control circuit including a correction circuit for varying widths or edges of correction signals in response to speed and phase information, and drivers for driving motors of the servo system in response to the correction signals.

Abstract: A plurality of speed-sliding compensation amount functions are stored in a sliding compensation amount data memory and one of these functions is selected in response to input of a selection signal. In the selected function, sliding compensation amount data corresponding to the speed of the object of positioning is read out. At least one of current position data and positioning target position data of the object is corrected by the read out sliding compensation amount data. A brake signal is generated on the basis of comparison of the current position data and target position data which have been subjected to this correction and a positioning control of the object is performed by this brake signal. On the other hand, a sliding amount detection circuit is provided for detecting sliding amount of the object from generation of the brake signal until actual stop of the object.

Abstract: A method and apparatus for controlling the position of a rotary member, particularly a rotary knife, utilizes a motor that is continuously coupled to the rotary member. A shaft position sensor and velocity sensor cooperate with motor control and drive circuitry to energize and brake the motor in accordance with the position and velocity of the motor drive shaft to provide a single cutting cycle each time a cut is required.

Abstract: An electronic controller is provided to control the energization of an electrical actuator to readjust a valve which controls the flow of a fluid in a controllable process. The controller is responsive to two signals, one of which is produced by a process sensor to represent the instantaneous magnitude of a predetermined process parameter and the second of which constitutes a set signal representative of a desired magnitude of the parameter. The signals are compared, and the sense of any resulting error signal is used to control the direction of movement of the actuator while the instantaneous magnitude of the error signal, during a succession of equal time intervals, is used to control the rate of movement of the actuator by controlling the extent of movement of the actuator during each of the time intervals.

Abstract: A driver for positioning the postage amount handles of a postage meter, the driver including motors which, in response to control signals from a postage computer, axially displace shafts along paths generally parallel to the paths of the postage meter handles. The shafts support actuator fingers which couple the shaft movement to the respective handles. An optical interruptor for each shaft senses various shaft positions and provides signals to the postage computer which are used in part to develop the control signals.

Abstract: Apparatus is disclosed for controlling the movement of a movable element to bring the movable element to rest at a desired stopping position.

Abstract: Apparatus is disclosed for controlling the movement of a movable element between an initial starting position and a final stopping position. The apparatus comprises drive means coupled to the movable element and responsive to motor drive signals for moving the movable element along a predefined path between said starting and stopping positions; and first generating means for generating a first command velocity signal having a first state when the actual velocity of the movable element exceeds a predetermined value and a second state when the actual velocity of the movable element is less than the predetermined value.

Abstract: In a control apparatus of a flying shear wherein a clutch is actuated to transmit the rotation of a drive motor to a cutting blade to rotate the same for achieving cutting and then the clutch is disengaged and the cutting blade is stopped by means of a brake, there are provided a speed signal generator for generating a signal corresponding to the speed of the cutting blade, a rest point establishing device for establishing a rest point for the cutting blade, an operation circuit receiving the output of the speed signal generator and performing an operation, and an instruction circuit responsive to the output of the operation circuit and the output of the rest point establishing device to produce at least one of an instruction for declutching and an instruction for braking.

Abstract: A system for accurately stopping a motor operated positioning device permits satisfactory motor tolerance limits for economical production by incorporation of a processor controlled motor plugging routine. The plugging routine includes an initial reverse polarity pulse to the motor of a duration sufficient to brake an ideal motor operating in the device. To accommodate motor characteristics within tolerance limits, a plurality of alternating bursts of positive and reverse polarity are applied to the motor following the initial pulse. Each of the alternating bursts is for a duration less than the system response time.

Abstract: A solid state motor control circuit for controlling the operation of a servo motor comprises a comparator circuit including a differential amplifier having its inputs connected across terminals of the motor and having its output connected to a drive circuit the output of which is connected to a supply terminal of the motor. A reference circuit maintains a reference terminal of the motor at a reference level, and in the absence of a command signal, the differential amplifier and drive circuit maintain the voltage at the motor supply terminal at the reference level. A control switch enabled by the command signal applies a control signal to an input of the differential amplifier, and the differential amplifier responsively enables the drive circuit to raise or lower the potential at the motor supply terminal relative to the reference level, thereby energizing the motor.

Abstract: An improved feed for a D.C. motor driven feed including a feed screw and nut which moves the table of a machine tool through predetermined positions in accordance with orders to change the rate of feed. The improved feed includes a power damping circuit, a switching circuit for electrically coupling the power damping circuit for a predetermined length of time to the D.C. motor whenever there is an order to change the rate of feed, thrust bearings provided in the D.C. motor whereby loads applied to the table are borne by the thrust bears and a cylindrical protective cover coupled to the nut and covering the feed screw such that the bottom inside surface of the cover is in relative near proximity to the feed screw and the top inside surface of the cover is in relative far proximity to the feed screw.

Abstract: An analog/digital numerical control system that utilizes analog techniques to process large scale (macro) differences and digital techniques to process small scale (micro) differences. In this manner, advantage is taken of the respective virtues of both analog and digital processing techniques while avoiding the disadvantages associated with the exclusive use of either approach. In addition, a novel tach responsive braking generator is disclosed for particular use in controlling the positioning of high mass heads that is adapted to provide dynamic braking of the controlled machine assembly to accomplish proper positioning without "hunting".

Abstract: A system for monitoring a machine tool under automatic control is provided which uses the actual path of the tool in all directions of motion for comparison with a mathematically ideal path to detect tool error. Machine tool position is obtained from independent feedback devices on each axis of tool movement. The system monitors the machine control commands independently of a machine control command generating means, the machine control command generating means commonly bring a computer of a conventional type. Thus, a monitoring loop is placed about the entire machine tool, that loop being capable of detecting malfunction or mispositioning of the tool, as that tool operates under automatic control. An independent dynamic braking means enables the system of this invention to bring the machine to a stop without part scrappage in the event of a machine shut down, occurring for example, because of a power system failue, or mispositioning error detection.

Abstract: A solid-state valve actuator control system using three-phase AC motors as prime movers having a summing point with a set point input, a position feedback input and a velocity feedback input. Velocity feedback being produced by differentiating position feedback. Summing point output error signal provides input to each of three integrators. Integrator outputs, synchronized with the three-phase AC power input, supply control signals to an AC solid-state power bridge having as its power input three-phase AC and as its power output controlled three-phase AC to drive three-phase AC motors in the proper direction. For small errors, the AC drive supplied to the prime mover is proportional to the magnitude of the error. For large errors, full voltage is applied to the prime mover. Motor transients are minimized by the proportional band on start-up and on motor reversal.

Abstract: A circuit for synchronizing a motor at the receiving end of a communication link with one at the transmitting end thereof, the circuit preventing an indication of synchronization until the receiving end motor reaches its rated speed.

Abstract: A control system for a d.c. motor, in which a cyclical d.c. drive signal is applied to the motor power input terminals as the system approaches balance. In each cycle, during at least part of the time interval between drive signal application to the motor terminals, a very low impedance (virtually a short circuit) is applied to the motor terminals. These braking pulses provide progressive braking as the motor approaches its balance point, limiting overshoot and ensuring a return without hunting from an overshoot condition to the balance point. As the system nears its deadband range, each braking pulse exceeds in duration the electrical time constant of the motor and constitutes a substantial portion of its associated cycle.

Abstract: A positioning apparatus includes a platen and a head independently movable relative to the platen. First and second coils having a particular phase relationship are disposed relative to each other on the head are independently energized to produce first and second electromagnetic forces. These electromagnetic forces have varying characteristics for moving the head relative to the platen and constant characteristics for maintaining the head in a substantially fixed relationship to the platen. Abrupt changes from the variable to the constant characteristics of the applied electromotive forces allow inertial forces to impart a decaying oscillation of the head about the positional origin determined by the constant characteristics of the applied electromotive force.Oscillation of the head relative to the platen produces first and second back-electromotive force sinusoids in the first and second coils, respectively.