Abstract: Rotating machine with a rotor (44) with an inductor of an electrical radial field machine (48) arranged on the rotor (44), which radial field machine is designed for absorption of the radial bearing forces acting on the rotor, and with an inductor of an axial field machine (46) arranged on the rotor (44), which axial field machine is designed for absorption of the axial bearing forces acting on the rotor. For normal force control, means for field control with the aid of current influencing are provided in the stators of the two electrical machines, which for their part are each subdivided into four quadrants with their own regulating units. The two electrical machines (46, 48) are of multipole design, there being at least two poles per winding quadrant. The axial field machine (46) is provided with three controllers for the stabilization of three degrees of freedom and the radial field machine (48) is provided with two controllers for the stabilization of two degrees of freedom.
Abstract: An abnormal state detecting apparatus of a machine tool having a servomotor. The apparatus is provided with a device for detecting an abnormal acceleration and an abnormal torque of the servomotor and a device for detecting an abnormal operation state of the servomotor from the directions of the detected acceleration and torque. When the torque, acceleration and operation state are all abnormal, the machine tool is judged to be in an abnormal state and the servomotor is controlled, thereby protecting the machine tool from an impact in an abnormal operation state.
Abstract: When a workpiece is cut or otherwise machined by a machine using a servo motor control apparatus having a position feedback loop, a velocity feedback loop, and a current feedback loop, it is the common practice to preset the instructed current value to a voltage corresponding to friction torque when rotation of the motor is started or reversed. This is to compensate for the response delay of the motor introduced by the friction torque. The present invention relates to improvements in this technique. After the instructed motor velocity changes from a positive value, to a negative value or vice versa, or after the detected motor velocity changes from a positive value to a nonpositive value or from a negative value to a nonnegative value, the value of the integration element of a velocity control portion is reversed according to a function. The obtained output value is added to the instructed current value or to the integration term to compensate for the response delay, thus reducing machining error.
Abstract: A stepping motor comprises a rotor, a stator, coils for magnetizing the stator, and a controller for controlling the excitation of the coils to control the rotation of the rotor. The rotor is cylindrical and has a multiplicity of alternately arranged north and south poles. The stator has a plurality of stator teeth arranged about the rotor. The controller is arranged to rotate the rotor a predetermined amount to a selected stop position and then determine whether to maintain the excitation of the coils or to inhibit the excitation of the coils based upon the relative position between the stator teeth and the rotor poles in the stop position.
Abstract: A method and apparatus for accurately and reliably positioning an actuator arm (12) is disclosed. The actuator arm (12) is driven by a conventional DC motor (38). The conductors which supply current to the motor (38) serve as primary windings (60) of a current transformer (58). The signal induced on secondary windings (62) of the transformer (58) responds to fluctuations in average current flowing in the motor (38). These fluctuations are amplified (64) and filtered (66) so that an AC burst (68) is produced in response to each commutation of the motor (38). The AC burst (68) triggers a one-shot timing circuit (72), which generates a pulse that remains active until the AC burst (68) has decayed. The pulse disappears prior to a subsequent commutation of the motor (38). Thus, one pulse is generated for each commutation of motor (38). A counter (76) is clocked by these pulses. The counter (76) increments when the motor (38) moves in one direction and decrements when the motor (38) moves in the opposing direction.
Abstract: A control circuit (10) for an extrusion die (13) is operatively arranged to supply a command signal (e.sub.c) to an actuator (24,25) for controlling the movement of a mandrel (11) relative to a die head (12) as plasticized material is extruded through an orifice (14) to form a parison (15). The controller includes a memory (28) for receiving and storing a plurality of initial set points supplied from a keypad (29). A recalculation circuit (42) is operatively arranged to recalculate the magnitude of each set point according to the equation S.sub.n(r) =(S.sub.n(i) -G.sub.1)B+G.sub.2, where S.sub.n(r) is the recalculated value a particular set point, G.sub.1 is a first reference die gap, G.sub.2 is a second reference die gap, B is a scaling factor, and S.sub.n(i) is the corresponding initial set point stored in memory. The recalculation circuit is operatively arranged to supply each recalculated set point to the memory to replace the initial set point stored therein.
Abstract: An NC program drawing method for an interactive numerical control device is provided, in which an NC program is represented by a composite drawing composed of a solid drawing (1a, 1b, 1c) and a wire frame drawing (1d, 1e), whereby the drawing of machining profiles and tool paths, etc., can be processed in a short time and the machining profiles can be easily recognized, thus facilitating the creation of machining programs. According to a preferred mode of carrying out the invention, simple surfaces and the like are drawn by the solid drawing method (1a, 1b, 1c), and complicated profiles (1d, 1e) and tool paths, etc., are drawn by the wire frame drawing method.
Abstract: A system is provided for carrying out a reference point return in a numerical control device. A deceleration dog (31) is arranged at a machine table (1) and includes a reference point (4). A deceleration limit switch (2) is operated when in contact with the deceleration dog (31), to generate a first deceleration signal (DEC1). A portion of the deceleration dog (31) from an end thereof with which the deceleration limit switch (2) first comes into contact to a predetermined distance therefrom is used as a hypothetical dog. A deceleration signal generating means generates a second deceleration signal (DEC1) when the deceleration limit switch (2) is in contact with the hypothetical dog. A reference point return processing means carries out a reference point return based on the first and second deceleration signals (DEC1, DEC2). Accordingly, an adjustment of the deceleration dog becomes unnecessary, and the assembling and maintenance are made easy.
Abstract: A system for a remote diagnosis of a numerical control apparatus (CNC), for remotely diagnosing a failure of the CNC. A personal computer is operated by a service engineer and a remote operation command is output to the CNC through a communication line. Diagnosis data of the CNC is selected based on the remote operation command, transferred to the personal computer, and displayed on a display unit, whereby the service engineer can make diagnosis of the cause of the failure at the CNC, based on the diagnosis data displayed.
Abstract: A moving fader system, primarily for the processing and combining of audio signals, includes a dedicated preprocessor to implement the execution of repetious input instructions. Other features contributing to the operation of the system include (1) "Look-up Tables" included in the preprocessor for conversion purposes, (2) a fiberoptic link for transmission of digital signals between the preprocessor and the servo circuits associated with each fader assembly, and (3) circuitry for combining the outputs of a position digital-to-analog (D/A) converter, an offset correction D/A converter and a gain correction D/A converter, to provide accurate analog servo signals to each fader assembly.
Abstract: A gain and phase compensation circuit for use in the servo control system for an optical disk device comprises a digital signal input terminal for receiving an input digital signal to be treated, a first digital filter circuit having an input connected to the digital signal input terminal for compensating a gain of a low frequency band for the input digital signal, a second digital filter circuit having an input connected to the digital signal input terminal for compensating a phase of a high frequency band for the input digital signal, and an output circuit having a first input connected to an output of the first digital filter circuit and a second input connected to an output of the second digital filter circuit for combining the output of the first digital filter circuit with the output of the second digital filter circuit so as to generate a digital servo control signal.
Abstract: A positioning control apparatus comprises a plurality of servo mechanisms corresponding to respective axes, a sequence operation part for successively outputting start commands for the respective servo mechanisms, a positioning operation part for storing a plurality of programs specified in accordance with the start commands and for processing the program in accordance with specified one of the programs to thereby output a positioning control command, and a servo interface for supplying the positioning control command to one of the servo mechanisms to be actuated to start.
Abstract: A non-linear dynamic compensation subsystem is added in the feedback loop of a high precision optical mirror positioning control system to smoothly alter the control system response bandwidth from a relatively wide response bandwidth optimized for speed of control system response to a bandwidth sufficiently narrow to reduce position errors resulting from the quantization noise inherent in the inductosyn used to measure mirror position. The non-linear dynamic compensation system includes a limiter for limiting the error signal within preselected limits, a compensator for modifying the limiter output to achieve the reduced bandwidth response, and an adder for combining the modified error signal with the difference between the limited and unlimited error signals.
Abstract: The invention relates to a reference-point return method for returning a movable element of a machine to a reference point using solely a linear scale, without relying upon a limit switch. The method includes providing the linear scale (1) with a second scale portion (2) for stipulating a deceleration starting position and a reference-point position, in addition to first scale portion (3, 4) for generating two-phase signals for position detection, generating signals (S.sub.1, S.sub.2) indicative of the deceleration starting position (D) and reference-point position (O) from the second scale portion (2) of the linear scale, slowing a reference point return rapid-traverse velocity (Va) to a reference-point return rapid-traverse velocity (Vb) using the deceleration starting signal (S.sub.1), and effecting return to the reference point by stopping movement in response to the reference-point signal (S.sub.2).
Abstract: A stepping motor having independently energizable windings for respectively producing magnetic fields at right angles to each other and directed at the axis of a rotor having a fixed polarity perpendicular to its axis, is operated so that the advance from one step to the next is produced by energizing one winding with a voltage producing a current continuously in one direction, while the voltage applied to the other winding is a rectangularly alternating voltage of a constant period and a gradually changing keying ratio. The roles of the two windings are interchanged between successive steps. A microcomputer for control of the motor has a pulse timing table and a program memory. Two control code memories are provided, one for specifying the direction of current in each of the windings during pulses of a sequence and one for specifying the direction of current in each of the windings during pauses between pulses of a sequence, as well as during an energized interval preceding the beginning of a pulsed step.
Abstract: A mechanical drive system with different load requirements is enabled by a motor whose input is varied in response to known changes in output torque requirements during various time segments of the duty cycle. In one example a fuser roll in a copier is driven by a DC stepper motor during a period in which a copy sheet is in the fusing area at a first speed V.sub.1. Upon completion of the fusing portion of the cycle, the fuser load requirements increase requiring a higher torque to be delivered by the motor. The change in fuser operation is determined by timing and an appropriate signal is sent to the control circuit reducing the motor speed, and allowing the motor to produce the additional torque required.
Abstract: In a stepping motor having a plurality of phase windings, a phase-angle range of an electrifying signal for each of the phase windings is made smaller than 180.degree., and a counterelectromotive voltage generated in each of the phase windings is detected during an off time of the electrifying signal, to realize a closed-loop driving.
April 13, 1990
Date of Patent:
April 7, 1992
Matsushita Electric Industrial Co., Ltd.
Abstract: An involute interpolation speed control method controls a machining speed during a numerical control machining process with involute curve interpolation. A radius of curvature is determined from equations of the involute curve (S3), and whether said radius of curvature is smaller than a predetermined value is then determined (S4). The machining speed is reduced with an override value if the radius of curvature is smaller than the predetermined value (S5, S6, S7). In the vicinity of a base circle for the involute curve, since the radius of curvature is small, any well machined surface would not be produced at a given tangential speed. Therefore, the machining speed is reduced with the override value in the vicinity of the base circle.
Abstract: A recording apparatus in which a stepping motor is used as a driving source to reciprocate a carriage on which a recording head is mounted and recording is executed by the recording head in accordance with the timing when the stepping motor rotates. The apparatus includes a rotational position detector to detect a rotational position of the stepping motor; a current switching circuit to switch energization currents to the stepping motor on the basis of a detection signal from the rotational position detector; a motor speed control circuit to closed loop control a rotational speed of the stepping motor through the current switching circuit; and a controller for detecting a load corresponding to the stepping motor by a speed control output from the motor speed control circuit and for controlling the motor so as to change output torque of the stepping motor in accordance with the load.
Abstract: A table for use with CNC machines has section one table feature being mounted for movement on the base and the other table section being mounted on the one table section. The table means are movable along mutually perpendicular axes, and are controlled in the axes. Motion error is compensated by providing feedback signals that sense and feed back position signals in one controlled axis as the table sections are moved in the other perpendicular axis. Compensation for deviations in motion in the mutually perpendicular axis is provided so that position in each direction of motion is controlled by two feedback signals for error compensation.