A.c. Networks Patents (Class 318/622)
  • Patent number: 9035594
    Abstract: A boost converter control apparatus for controlling a motor drive system which is provided with a boost converter disposed between an electric power converter and a direct current power supply, the boost converter boosting a direct current voltage of the direct current power supply and supplying it to the electric power converter, is provided with: an operating device provided with a proportional element, an integral element and a derivative element, the derivative element being configured as a bandpass filter, the operating device calculating a PID controlled variable corresponding to an electric current command value of the boost converter for maintaining an output voltage of the boost converter at a command value of an inter-terminal voltage VH of a smoothing condenser; and a controlling device which is configured to control the output voltage of the boost converter on the basis of the calculated PID controlled variable.
    Type: Grant
    Filed: April 19, 2011
    Date of Patent: May 19, 2015
    Inventors: Naoyoshi Takamatsu, Masaki Okamura
  • Patent number: 7911172
    Abstract: An accurate load position control is made possible even when rigidity of a load drive system using a motor is relatively low. Load position signal xl is a present-position measurement value of a load, and after compensation in response to a phase delay thereof has been performed by a stability compensation circuit, the high-frequency portion thereof is taken as a control-target position signal xfb by replacing, in a position-signal combination circuit, a motor position signal xm as a present-position measurement value of a motor, and then the control-target position signal xfb is fed back to a position control circuit. Thereby, a torque command signal indicating a torque target value for driving the load is outputted.
    Type: Grant
    Filed: March 31, 2006
    Date of Patent: March 22, 2011
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Hidetoshi Ikeda, Yoshihiro Marushita, Kei Terada, Takashi Isoda, Hiroto Takei
  • Publication number: 20080224646
    Abstract: Aspects of the present invention pertain to a method of power control for an electrical motor using open-loop principles. The method employs a desired control line function that determines hold-off time based on a detected phase lag of a motor drive signal. The motor to be controlled is driven with a motor drive signal at a given load for a first number of cycles to detect the phase lag of the motor drive signal. Controlling for phase lag for a second number of cycles is then accomplished by firing a thyristor according to the phase lag of the motor drive signal. Advantages of the present invention include reduced power consumption of a motor controlled by an embodiment of the inventive method or inventive controller, and faster response time between the detection of load changes on the motor and the issuance of power control signals.
    Type: Application
    Filed: March 10, 2008
    Publication date: September 18, 2008
    Inventor: George I. Boyadjieff
  • Patent number: 5500580
    Abstract: An integrated compliance electrohydraulic servovalve system connected to a load such as a simulated living being to provide more realistic movement thereto. The system includes a pressure transducer for sensing the pressure appearing at the output of the electrohydraulic servovalve and which is applied to an actuator connected to the load. The pressure as sensed is developed into a corresponding electrical signal which is used as a feed back signal to the drive motor of the electrohydraulic servovalve. The actuator position signal is also provided and is summed with the position command input signal to provide the command signal which is also summed with the pressure signal prior to application to the drive motor. The utilization of the pressure feed back signal provides compliance to the over all system resulting in a realistic movement of the simulated living being.
    Type: Grant
    Filed: September 19, 1994
    Date of Patent: March 19, 1996
    Assignee: HR Textron Inc.
    Inventor: Stephen J. Tranovich
  • Patent number: 4387624
    Abstract: The invention relates to a device for increasing the tracking accuracy of an aiming system for a gun or the like which includes a gun servo. The gun servo comprises a special stabilizing and accuracy-increasing network (20) which comprises one or a plurality of integrating second-degree filters (25) the transmission functions (G.sub.R) of which have such a form that the amplitude as a function of the frequency has a maximum near the expected frequency of the base movements of the gun and/or the movement of the target, which makes it possible to have a high system gain around and below said frequency.
    Type: Grant
    Filed: October 1, 1980
    Date of Patent: June 14, 1983
    Assignee: Aktiebolaget Bofors
    Inventor: Lennart Bjurstrom
  • Patent number: 4325013
    Abstract: A control for a profiling machining tool, and a method for controlling such a tool. The machine tool includes a sensing head which moves along a template or pattern to produce a signal that causes motors relatively to shift a cutting tool and a workpiece so as to duplicate in the workpiece the profile of the template or pattern. Two sinusoidal signals are generated as a consequence of stylus deflection along orthogonal axes. They are combined to form a single sinusoidal signal which is then variously processed to produce an error signal which causes the motors to operate in directions which tend to reduce the error signal, and to cause the stylus automatically to move along the profile while doing so.
    Type: Grant
    Filed: March 28, 1980
    Date of Patent: April 13, 1982
    Inventor: Robert H. Wenzel
  • Patent number: 4298833
    Abstract: Apparatus for damping operator induced oscillations of a controlled system responding to an operator controlled signal (DEP) utilizing a lag-lead filter (14) for frequency and amplitude estimation of the control input, and a rectification and smoothing filter (16) for producing a signal proportional to the absolute value of the frequency and amplitude estimate for use in suppression of the control system output signal (DEC). In one embodiment, this is accomplished by computing a correction signal in a correction generating section (18). In a second embodiment, a second rectification and smoothing filter (21) produces a signal proportional to the absolute value of the controlled input signal. A ratio of the outputs of the first and second rectification and smoothing filters is then used in a generator (24) to generate a gain factor k.sub.
    Type: Grant
    Filed: February 29, 1980
    Date of Patent: November 3, 1981
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: John W. Edwards, John W. Smith
  • Patent number: 4283665
    Abstract: In a motor control circuit, a rotational speed detection signal containing a ripple component superimposed on a d.c. component is applied to both a low pass filter/phase lagging circuit and to a phase leading circuit, the output signals of which have a phase difference of approximately 180 degrees, to effectively cancel the ripple component and thereby extract only the d.c. component. The latter is balanced against an r.p.m. reference voltage in a comparison circuit whose output is fed back to a drive winding control circuit of the motor.
    Type: Grant
    Filed: August 27, 1976
    Date of Patent: August 11, 1981
    Assignee: Pioneer Electronic Corporation
    Inventor: Katsuzi Mizumoto
  • Patent number: 4221995
    Abstract: A precision numerical controlled servo-positioning system is provided for continuous closed-loop position control of a machine slide or platform driven by a linear-induction motor. The system utilizes filtered velocity feedback to provide system stability required to operate with a system gain of 100 inches/minute/0.001 inch of following error. The filtered velocity feedback signal is derived from the position output signals of a laser interferometer utilized to monitor the movement of the slide. Air-bearing slides mounted to a stable support are utilized to minimize friction and small irregularities in the slideway which would tend to introduce positioning errors. A microprocessor is programmed to read command and feedback information and converts this information into the system following error signal. This error signal is summed with the negative filtered velocity feedback signal at the input of a servo amplifier whose output serves as the drive power signal to the linear motor position control coil.
    Type: Grant
    Filed: July 24, 1978
    Date of Patent: September 9, 1980
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: William E. Barkman
  • Patent number: 4184109
    Abstract: A nonlinear servo compensator for insertion in the position servo loop of a robot or automatic machine comprising a direct path with an operational amplifier and a second amplifier for summing the direct signal and its derivative; and a shunt path with an inversion circuit, an analog multiplier, a resistive divider, a follower amplifier and a differentiating circuit.
    Type: Grant
    Filed: April 27, 1977
    Date of Patent: January 15, 1980
    Assignee: Regie Nationale des Usines Renault
    Inventor: Christian Mauller
  • Patent number: 4128795
    Abstract: A device is disclosed for damping the critical frequencies of a rotor suspended by a radial electromagnetic bearing which has means associated therewith for detecting the radial position of the rotor, comprising a servo-circuit for connection between the detecting means and windings of the electromagnetic bearing and including a circuit for controlling the current supply to the windings in response to signals from the detecting means to keep the rotor in a predetermined radial position. The servo-circuit is provided with means for the selective amplification of the phase advance gain of said circuit in a frequency equal to the speed of rotation of the rotor for damping said critical frequencies.
    Type: Grant
    Filed: December 17, 1976
    Date of Patent: December 5, 1978
    Assignee: Societe Europeene de Propulsion
    Inventors: Helmut Habermann, Maurice Brunet, Pierre Joly