Abstract: A servo control apparatus controls an object according to a target position signal and a detected position signal and drives the object according to a drive torque signal. The servo control apparatus includes an observer receptive of the drive torque signal and the detected position signal which determines an estimated disturbance torque in response thereto. A function unit produces an error command signal dependent on the estimated disturbance torque. The error command signal is successively subtracted from the target position signal to set a temporary position signal which is effective to impart a mechanical compliance to the control object.

Abstract: A control arrangement for a reluctance motor, comprising stator poles (11a, b; 12a, b) provided with windings (13a, b; 14a, b) which cooperate in pairs, and a rotor (15) made of soft magnetic material and having at least two poles (16a, b; 17a, b) disposed diametrically opposite each other. The motor is controlled by a sensor (X1) which each time a rotor pole is about to move in over a stator pole generates a ramp of a first polarity and when the rotor pole leaves the stator pole generates a ramp of a second polarity, opposite said first polarity. Electronic switching means (33, 34; 35, 36) are provided which in dependence on the first ramp apply voltage to the windings of one (12a, b) of the stator pole pairs and in dependence on the second ramp disconnect the voltage to said stator pole pair (12a, b) and apply voltage to the stator pole pair to follow.

Abstract: A position control system for an information storage system, for example, an optical disc system, includes a stepping motor for moving a read-write head and a DC motor for moving a beam reflecting unit, such as an object lens mounted on the head. The position control system drives the stepping motor to compensate a positional error of the beam reflecting unit in a tracking mode after a seek without disturbing the movement of the beam reflecting unit. The position control system includes a master control unit operatively connected to a host controller, a stepping motor control unit, and a track servo control unit. The master control unit activates the stepping motor control unit for a seek operation upon receipt of a seek command from the host controller. The stepping motor control unit drives the stepping motor with a large drive current until the head moved by the stepping motor reaches a position adjacent to a target track on the recording medium.

Abstract: Disclosed is an NC command system of a CNC lathe having a plurality of tool posts, the position of which can be independently controlled, and a plurality of spindles an rpm of which can be independently controlled, wherein a coupling relationship during machining by the spindles (3, 5) and the tool posts (1, 2) can be established and switched by a machining program, and thus a more effective machining can be realized.

Abstract: In a method for performing a synchronized superposed operation of two servomotors, controllers for the servomotors perform the control for achieving the synchronized superposed operation by: calculating, for each of the servomotors, the difference, or differences, between the ideal speed and/or position deviations obtained from a control command and the actual speed and/or position deviations obtained from the rotation of the servomotor; calculating a speed correction quantity, or a speed correction quantity and a current correction quantity, from the discrepancy, or discrepancies, between the differences calculated for both of the servomotors; and adding the correction quantity, or quantities, to a speed command, or to a speed command and a current command, given to the subsidiary shaft side. Thus, a synchronized superposed operation of servomotors in which speeds and responses of the main shaft and the subsidiary shaft are well balanced therebetween can be achieved.

Abstract: Disclosed is a spindle control system of a numerical control apparatus capable of independently controlling a plurality of spindles by a plurality of paths. Connecting relationships between respective paths (11 to 14) and respective spindles (61 to 65) are defined in a region (3), the content of the region (3) is changed by a machining program to change the spindles (61 to 65) to be controlled by the respective paths (11 to 14), whereby a more effectively machining can be realized.

Abstract: A spindle drive system of a machine tool, wherein a control mode changeover section of a control unit selects one of both a speed control mode for controlling a rotational speed of a spindle through negative feedback of the rotational speed of the spindle and a position control mode for controlling a rotational position of the spindle through negative feedback of the rotational position of the spindle, and a gain changeover section changes speed loop and position loop gains to a greater value during cutting operation than during non-cutting rapid feed operation when the position control mode has been selected.

Abstract: A stability compensating circuit of a servomechanism wherein the output displacement of an actuator is controlled, comprising: a unit generating a reference input signal corresponding to a target value; a first adder which is provided in a first line between the reference input signal generating unit and the actuator and to which a feedback signal from the actuator is inputted through a second line between the first adder and the actuator; a second adder provided in the first line between the first adder and the actuator; a first compensating circuit provided in the first line between the first and second adders; and a second compensating circuit provided in a third line between the second adder and the actuator, the feedback signal from the actuator being inputted to the second adder through the second compensating circuit.

Abstract: A servo control apparatus comprises an abnormality detection circuit which calculates a difference between the quantity of rotation of a servo motor from a reference point calculated on the basis of an accumulated value of the position feedback and the quantity of rotation of the servo motor from the reference point counted by a rotational detector, and puts out an absolute position abnormality signal when the calculated difference value exceeds a predetermined value.

Abstract: An apparatus is described which controls the movement and positioning of a platen on which wafers may be mounted. The apparatus comprises a stepper motor having a motor sprocket member operatively coupled to a platen by a drive mechanism. The drive mechanism comprises a chain which cooperates with the the stepper motor by engaging with the motor sprocket member. The drive mechanism also comprises a platen chain sprocket having a platen shaft member. The platen is movably connected to the platen shaft member. The chain cooperates with the platen by engaging with the platen chain sprocket. Operation of the stepper motor rotates the motor sprocket member and drives the drive mechanism, thereby rotating the platen chain sprocket and determining the movement and positioning of the platen. The apparatus is capable of controlled movement and positioning of the platen inside processing equipment, such as ion implantation equipment.

Abstract: A recording apparatus in which the movement of a recording head for recording scanning is effected includes a carriage carrying the recording head thereon, a step motor for moving the carriage, a linear encoder for detecting the amount of movement of the carriage, the linear encoder being installed over the movement range of the carriage and generating pulse signals in conformity with the amount of movement of the carriage, a controller for counting the pulse signals from the linear encoder and outputting a control signal for the starting and stoppage of the carriage in conformity with the count value, and current switch-over device for switching over and controlling an energization current supplied to the coil of the step motor in conformity with the pulse signals from the linear encoder.

Abstract: A feedback system control device includes an adder producing a control signal from a feed forward signal and a correction signal. A system which processes the control signal drives the feedback system, which produces an output signal. A feed forward circuit, e.g., a four-pole network, receives the input signal and produces the feed forward signal. An error amplifier in the corrector processes the difference between the input signal and the output signal to produce an error signal. A corrector produces the correction signal from an input signal and this error signal. Two processors in the corrector each receive the error signal and produce respective modification signals between which there is a relative phase shift. An adder sums the modification signals to produce the correction signal.

Abstract: A numerically-controlled driving system has a rate-of-change limiter that is applicable to positioning- and continuous-path-control systems as used in robots, machine tools, elevators, etc. When control signals are input, sudden variations in acceleration or velocity are damped, because the discrete control values calculated by a numerical control system are filtered by a pulse filter in accordance with the principle of discrete convolution.

Abstract: Rotor position information for a switched reluctance (SR) motor drive is obtained indirectly in response to the motor phase inductance. An oscillator generates a signal having a time period that is a function of the inductance. The signal is processed by other circuits to obtain proper instants of commutation. In the preferred motor drive, the energized phase windings are isolated from the oscillator, and periodic signals are obtained which have periods indicating the phase inductances of the unenergized phase windings. The periods are compared to threshold values to obtain position indicating signals, and commutating signals are derived from the position indicating signals.

Abstract: A stepping motor driving apparatus includes a stepping motor and a pulse output circuit for outputting drive pulses for driving the stepping motor. A pulse generator generates further pulses which not only have frequency higher than that of the drive pulses but are capable of a variable duty factor at the frequency of the further pulses. A gate circuit receives the drive pulses from the pulse output circuit and the further pulses from the pulse generator so as to output the further pulses of the pulse generator during excitation of the drive pulses such that the stepping motor is driven by the further pulses outputted from the gate circuit.

Abstract: A control system having an open loop transfer function G expressed by a transfer function G.sub.2 of one control component having at least one integration element and a mass transfer function G.sub.1 of other control components and a saturation level of the other components expressed by the transfer function G.sub.2 set lower than that of the component expressed by G.sub.1.

Abstract: In a four-phase stepping motor driving apparatus phase-A and phase-A, or phase-B and phase-B are prevented from simultaneously becoming conductive. A device for this includes a change-over circuit which validates either of the phase-A and the phase-A, a change-over circuit which validates either of the phase-B and the phase-B, a change-over circuit which renders both the phase-A and the phase-A conductive or nonconductive and a change-over circuit which rendered both the phase-B and the phase-B conductive or nonconductive.

Abstract: A power supply module for control electronics of a DC motor, the module comprising a power cell of the stepdown type controlled as a function of peak current, the current flowing in both directions, and the module including a bridge stage likewise capable of passing current in both directions and including a reactive element constituted by one of the windings of the DC motor. The invention is particularly suitable for space applications.

Abstract: The system for stabilizing a support comprises a working rotor mounted on the support by frictionless bearings and fixed to a working member for which at least one parameter associated with the rotation of the working rotor is variable as a function of time. A nested reaction rotor is mounted concentrically relative to the working rotor by frictionless bearings such as magnetic bearings or gas bearings and it supports a reaction inertia member. A single servo-controlled electric motor is interposed between the working rotor and the reaction rotor in order to drive the working rotor and the reaction rotor in opposite directions in such a manner that the torque disturbances generated on the support by the motion of the working rotor are cancelled by the simultaneous reaction motion of the reaction rotor, with the ratio of the speeds of the working rotor and the reaction rotor being such that the total angular momentum of the working rotor and of the reaction rotor is kept equal to zero.

Abstract: Disclosed is a machining data display system for displaying data at a display of a numerical control apparatus (CNC) while a machining operation is being carried out, wherein machining data (11) to (14) specified by a machining program are selected from machining data registered in advance and displayed at the display (10). With this arrangement, machining data actually required is displayed and machining conditions are correctly monitored.