Lead Or Lag Networks Patents (Class 318/621)
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Patent number: 11515822Abstract: An adaptive torque disturbance cancellation method and motor control system for rotating a load are described. The system has: (i) a speed controller for receiving a first input signal indicating a desired motor speed and, in response, for outputting a motor control signal; (ii) current sensing circuitry for sensing current through a motor that rotates in response to the speed controller; (iii) circuitry for storing, into a storage device, history data representative of the current through a motor when the motor operates to rotate the load; and (iv) circuitry for modifying the motor control signal in response to the history data.Type: GrantFiled: May 4, 2020Date of Patent: November 29, 2022Assignee: Texas Instruments IncorporatedInventors: David L. Wilson, Jorge Zambada Tinoco, David Patrick Magee
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Patent number: 10661657Abstract: A PI/PID controller that generates a torque compensation value KPID through PI control or PID control, from a deviation between an allowable rotation speed and a rotation speed of a wheel; an adder that adds the torque compensation value to a torque command input value received from a higher-order controller, thereby obtaining a torque command output value; and a dead time compensator that has a control target model including a dead time and that applies a dead time compensation in generation of the torque compensation value by the Smith method. An input to the dead time compensator is an output of a P compensation or a PD compensation excluding an I compensation from a PI compensation or a PID compensation.Type: GrantFiled: April 24, 2018Date of Patent: May 26, 2020Assignee: NTN CORPORATIONInventor: Tomohiro Sugai
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Patent number: 10379510Abstract: The present disclosure discloses a command control in a multi-servo feedback control system. The command control includes: a servo acquiring preset delay time when a first action command is received from a main controller via serial data bus; the servo sending feedback information to the main controller after the preset delay time; wherein the preset delay time of the plurality of servos are different from each other, and the feedback information is configured to identify work status of the servo; receiving a second action command from the main controller; performing actions corresponding to the second action command and sending the feedback information to the main controller after the preset delay time if the second action command is valid. A servo and a multi-servo feedback control system for performing the command control are also provided.Type: GrantFiled: December 30, 2016Date of Patent: August 13, 2019Assignee: UBTECH Robotics Corp.Inventors: Tingshuang Huang, Lifu Zhang, Youjun Xiong
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Patent number: 9662727Abstract: A machine tool includes a first-pass rotation speed computing section. The first-pass rotation speed computing section automatically decides whether the main spindle rotation speed in the first pass should be a high rotation speed or a low rotation speed so that cutting in the last tool pass is performed at the high rotation speed. Thus, cutting of the last tool pass at the low rotation speed can be reliably prevented.Type: GrantFiled: October 11, 2013Date of Patent: May 30, 2017Assignee: Okuma CorporationInventor: Kohei Nishimura
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Patent number: 9075400Abstract: A motor control device that controls motion of a control target including a motor and a vibratable element includes a generating unit configured to generate, according to state information representing a state of the control target related to a vibration characteristic of the control target, a first parameter representing the vibration characteristic of the control target, a first calculating unit configured to calculate a second parameter corresponding to a temporal change amount of the first parameter generated by the generating unit, a second calculating unit configured to calculate, using a motion target value, the first parameter, and the second parameter, model torque such that the control target does not excite vibration, and a developing unit configured to develop, according to the model torque calculated by the second calculating unit, a torque command such that the motion of the control target follows the motion target value.Type: GrantFiled: December 16, 2011Date of Patent: July 7, 2015Assignee: Mitsubishi Electric CorporationInventors: Yuji Igarashi, Hidetoshi Ikeda, Hiroto Takei
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Patent number: 9035594Abstract: 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: GrantFiled: April 19, 2011Date of Patent: May 19, 2015Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Naoyoshi Takamatsu, Masaki Okamura
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Patent number: 8866430Abstract: An apparatus for controlling a boost 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; a controlling device for controlling the output voltage of the boost converter on the basis of the calculated PID controlled variable; a judging device for judging whether or not loss suppression on the direct current power supply is to be prioritized; and a switching device for switching an operation mode of the operating device from a variation suppression mode to a loss suppression mode if it is judged that the loss suppression is to be prioritized. In the loss suppression mode, a cutoff frequency of the bandpass filter is corrected to a lower frequency side at a lower rotational speed of the three-phase alternating current motor.Type: GrantFiled: April 19, 2011Date of Patent: October 21, 2014Assignee: Toyota Jidosha Kabushiki KaishaInventors: Naoyoshi Takamatsu, Masaki Okamura
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Patent number: 8823314Abstract: A system and method are provided for reducing the energy consumed by a pump jack electric motor by reducing the supply voltage to the motor when the motor would be generating energy in open loop mode. By substantially eliminating the energy generation mode, the braking action of the utility grid in limiting the acceleration of the motor and system that would otherwise occur is substantially removed. The motor and system will speed up, allowing the natural kinetic energy of the cyclic motion to perform part of the pumping action. A closed loop controller in electrical connection with the motor computes the necessary information from the observed phase angle between the voltage and current supplied to the motor. By reducing the supply voltage to the motor, the observed phase angle may be reduced to a target phase angle value.Type: GrantFiled: September 1, 2010Date of Patent: September 2, 2014Assignee: The Powerwise Group, Inc.Inventors: John L. Lumsden, Paul H. Kelley, Vasan Venkataraman
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Patent number: 8704478Abstract: A motor-drive circuit includes: a filter circuit to attenuate a frequency band including a resonance frequency of an actuator in a target-current signal, which is a digital signal indicating a target value of a driving current to be supplied to a voice-coil motor that drives the actuator; a digital-analog converter to convert an output signal of the filter circuit into an analog signal, to be outputted as a current-control signal; and a driving circuit to supply the driving current to the motor in accordance with the current-control signal, the filter circuit including: a digital-notch filter to attenuate a frequency band around the resonance frequency in the target-current signal; and a digital-low-pass filter to attenuate a frequency band greater than or equal to a predetermined frequency in the output signal of the digital-notch filter, the digital-low-pass filter having a sampling frequency higher than a sampling frequency of the digital-notch filter.Type: GrantFiled: September 23, 2011Date of Patent: April 22, 2014Assignee: Semiconductor Components Industries, LLCInventor: Takeshi Arai
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Patent number: 8698446Abstract: A system and method are disclosed for turning off the voltage to a pump jack electric motor during predetermined periods of time to save energy. In the method, the motor's response to closed-loop control may be evaluated over several pump strokes. The periods of the pump stroke when it is feasible to turn off the motor may be identified. The consistency of the measurements over several strokes may be evaluated. The motor may be turned off during predetermined periods on subsequent pump strokes when each pump stroke shows sufficiently similar behavior to that predicted during the closed-loop control process. The system may return to the closed-loop control process after a predetermined period of time to adjust to any changes in the system.Type: GrantFiled: December 14, 2010Date of Patent: April 15, 2014Assignee: The PowerWise Group, Inc.Inventor: Vasan Venkataraman
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Patent number: 8698447Abstract: A system and method are provided for reducing the energy consumed by a pump jack electric motor by reducing the supply voltage to the motor when the motor would be generating energy in open loop mode. By substantially eliminating the energy generation mode, the braking action of the utility grid in limiting the acceleration of the motor and system that would otherwise occur is substantially removed. The motor and system will speed up, allowing the natural kinetic energy of the cyclic motion to perform part of the pumping action.Type: GrantFiled: April 19, 2012Date of Patent: April 15, 2014Assignee: The Powerwise Group, Inc.Inventors: John L. Lumsden, Paul H. Kelley, Vasan Venkataraman
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Patent number: 8653780Abstract: Presented is a system and method for controlling an actuator in a multirate control system using an integrated upsampler and filter, comprising an incremental command limiter for changing a command from a first control system into a limited incremental command in a second control system, a lead-lag filter for filtering the limited incremental command to attenuate high frequencies, and a feed forward path for reducing phase loss in rate output signal at low frequencies. In embodiments, a command position signal received at the sampling rate of the first control system is interpolated into incremental command position signals at the sampling rate of the second control system. Position error signals and rate error signals from the devices being controlled are used as feedback to further stability the control loops.Type: GrantFiled: September 28, 2010Date of Patent: February 18, 2014Assignee: The Boeing CompanyInventor: Douglas C. Cameron
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Patent number: 8629642Abstract: A control loop circuit for use in a closed-loop control system that controls a system such as a linear motor is presented. The control loop circuit includes a lead-lag compensator that features a lead compensation network configured to reduce output noise without substantially changing the effect of the lead compensation in the control system's frequency response.Type: GrantFiled: February 15, 2012Date of Patent: January 14, 2014Assignee: Allegro Microsystems, LLCInventors: Michael G. Ward, David J. Haas
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Patent number: 8427117Abstract: Electromechanical arrangements are utilized widely whereby a prime mover in the form of a mechanical assembly such as a gas turbine engine is utilized to drive an electrical machine as an electrical generator. Unfortunately the loads applied to the electrical generator may vary creating oscillation across phases of the electrical generator. Such oscillations generally will be translated to the mechanical assembly in the form of torque oscillations which may cause stressing. Stressing of the mechanical assembly will reduce its life and may alter its performance as well as fuel consumption. By provision of appropriate mechanisms for balancing electrical loads across an electrical machine as well reducing the time decay period for stored charge within an electrical assembly associated with an electrical machine it is possible to reduce torque oscillations as presented to the mechanical assembly and therefore improve its operational performance.Type: GrantFiled: July 21, 2009Date of Patent: April 23, 2013Assignee: Rolls-Royce PLCInventors: David R Trainer, Thomas C J Feehally, Gareth E Moore
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Patent number: 8274252Abstract: A motor control apparatus includes a sub-controller including a two-degree-of-freedom repetitive compensator and a shaping filter. The two-degree-of-freedom repetitive compensator includes a forward delay placed in a forward route of a loop and a feedback delay placed in a feedback route thereof and is configured so that a total delay time provided by the forward delay and the feedback delay is equal to the cycle of a target command or a disturbance. The shaping filter is configured so that the product of the pulse transfer function of the two-degree-of-freedom repetitive compensator and the complementary sensitivity function of a general-purpose control system has a low-pass characteristic.Type: GrantFiled: September 23, 2011Date of Patent: September 25, 2012Assignee: Kabushiki Kaisha Yaskawa DenkiInventors: Wennong Zhang, Hiroshi Nakamura
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Publication number: 20120146570Abstract: A control loop circuit for use in a closed-loop control system that controls a system such as a linear motor is presented. The control loop circuit includes a lead-lag compensator that features a lead compensation network configured to reduce output noise without substantially changing the effect of the lead compensation in the control system's frequency response.Type: ApplicationFiled: February 15, 2012Publication date: June 14, 2012Applicant: ALLEGRO MICROSYSTEMS, INC.Inventors: Michael G. Ward, David J. Haas
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Patent number: 8138708Abstract: A control loop circuit for use in a closed-loop control system that controls a system such as a linear motor is presented. The control loop circuit includes a lead-lag compensator that features a lead compensation network configured to reduce output noise without substantially changing the effect of the lead compensation in the control system's frequency response.Type: GrantFiled: November 26, 2008Date of Patent: March 20, 2012Assignee: Allegro Microsystems, Inc.Inventors: Michael G. Ward, David J. Haas
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Patent number: 8120302Abstract: A servo control apparatus capable of suppressing adverse effects of disturbance, load variation and the like, and realizing robust and high-performance speed control. The apparatus includes both of the following observers: a disturbance observer for adding a disturbance compensation torque Tf, calculated from a torque command T* and an electric motor rotational speed ?m, to a torque command basic signal T0*, calculated on the basis of a deviation between a speed command ?* and a feedback speed ?f by a PI control section, thus outputting the torque command T*; and a phase advance compensation observer for generating, from the torque command basic signal T0* and the electric motor rotational speed ?m, an output of a nominal plant serving as an element in which no delay occurs, thus outputting the output as the feedback speed ?f.Type: GrantFiled: January 23, 2007Date of Patent: February 21, 2012Assignee: Kabushiki Kaisha Yaskawa DenkiInventors: Wennong Zhang, Mitsujiro Sawamura, Yasuyuki Takei
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Publication number: 20120007541Abstract: A motor control apparatus includes a sub-controller including a two-degree-of-freedom repetitive compensator and a shaping filter. The two-degree-of-freedom repetitive compensator includes a forward delay placed in a forward route of a loop and a feedback delay placed in a feedback route thereof and is configured so that a total delay time provided by the forward delay and the feedback delay is equal to the cycle of a target command or a disturbance. The shaping filter is configured so that the product of the pulse transfer function of the two-degree-of-freedom repetitive compensator and the complementary sensitivity function of a general-purpose control system has a low-pass characteristic.Type: ApplicationFiled: September 23, 2011Publication date: January 12, 2012Applicant: KABUSHIKI KAISHA YASKAWA DENKIInventors: Wennong ZHANG, Hiroshi Nakamura
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Patent number: 7956567Abstract: A motor drive control device for controlling a rotational speed of a motor includes: a motor driver for rotationally driving a motor; a correction amount calculating section for detecting a rotational speed of an output of the motor in accordance with an alternate current signal outputted from an FG sensor and detecting a rotational position of a photoconductive drum, which is rotated by a rotational drive force of the motor, in accordance with a pulse outputted from an encoder; a speed controller for generating a speed control signal corresponding to a total correction amount, which is a sum of a correction amount calculated in the correction amount calculating section based on a rotational speed of the motor and a correction amount calculated based on a rotational position of the photoconductive drum, and outputting the generated speed control signal to the motor driver.Type: GrantFiled: August 25, 2008Date of Patent: June 7, 2011Assignee: Kyocera Mita CorporationInventor: Gunmun Ryu
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Patent number: 7957844Abstract: A method for stabilization of the power balance in an electric power system including a number of nodes. An instantaneous value of the mains frequency of the electric power system is sensed. In dependence on the frequency deviation of the instantaneous value from a reference frequency value, a selected part of the electric power system, connected in a node, is disconnected in the node. A voltage amplitude value is sensed in the node. A measure of the magnitude of the deviation of the voltage amplitude value from a reference amplitude value is formed. A time lag is formed in dependence on the measure of the magnitude. The part of the electric power system is disconnected in dependence on the time lag.Type: GrantFiled: January 26, 2004Date of Patent: June 7, 2011Assignee: ABB ABInventors: Lars Messing, Daniel Karlsson
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Patent number: 7911172Abstract: 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: GrantFiled: March 31, 2006Date of Patent: March 22, 2011Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Hidetoshi Ikeda, Yoshihiro Marushita, Kei Terada, Takashi Isoda, Hiroto Takei
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Patent number: 7911173Abstract: A method of power control for an electrical motor using open-loop principles is disclosed. 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 include reduced power consumption of a motor controlled by an embodiment of the method or controller, and faster response time between the detection of load changes on the motor and the issuance of power control signals.Type: GrantFiled: March 10, 2008Date of Patent: March 22, 2011Assignee: Power Efficiency CorporationInventor: George I. Boyadjieff
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Patent number: 7902786Abstract: A motor controller includes a command part that generates a command signal, a control part that drives a control object through an output filter when the command signal is input, an operating amount detector that detects an operating amount of the control object, a frequency response characteristic measurement part that generates an open loop frequency response characteristic on the basis of the command signal and the operating amount, a model calculation part that simulates a frequency characteristic of the output filter, and a display that displays the add result of an amplitude characteristic of the frequency characteristic of the frequency response characteristic measurement part and an amplitude characteristic of the frequency characteristic of the model calculation part.Type: GrantFiled: May 26, 2009Date of Patent: March 8, 2011Assignee: Kabushiki Kaisha Yaskawa DenkiInventors: Nobuhiro Umeda, Tetsuro Izumi
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Patent number: 7847509Abstract: System and methods of controlling a plurality of motors based on a motor motion attribute, such as rotor position, velocity, or acceleration, which simulate the properties of a mechanical differential, including a pure differential, a limited slip differential, and/or a locking differential. The method may be employed in a number of applications, including, without limitation, a paper handling system, such as an inserter, to control the nips of a pinless cutter of an inserter, and in a vehicle.Type: GrantFiled: December 26, 2007Date of Patent: December 7, 2010Assignee: Pitney Bowes Inc.Inventors: John W. Sussmeier, Boris Rozenfeld, Arthur H. DePoi, Anthony E. Yap
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Patent number: 7808199Abstract: A control apparatus of the present invention comprising a control unit outputting a control signal controlling a servo motor and suppressing natural vibration of a controlled object including a motor and a machine driven by the motor while controlling the controlled object, comprising a frequency analysis unit analyzing a frequency component included in a torque command, an analysis control unit controlling the start or stopping of the frequency analysis unit, a detection unit detecting a natural frequency of the controlled object from an analysis result of the frequency analysis unit, a-band rejection filter receiving as input the torque command, stripping the command of the natural frequency component, and outputting the resultant command to the motor through a current control unit and servo amplifier, and a filter characteristic setting unit setting the frequency to be stripped at the filter based on the natural frequency detected by the detection unit.Type: GrantFiled: June 25, 2008Date of Patent: October 5, 2010Assignee: Fanuc LtdInventors: Tadashi Okita, Yukio Toyozawa, Naoto Sonoda
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Patent number: 7733041Abstract: A plurality of detection target portions are arranged around a rotating shaft of a rotating-body, one of which causes a detector to generate a first detection signal different from a second detection signal generated from the others. A first generating unit generates a reference signal indicating a reference rotational-position of the rotation-driving source or the rotating-body before one rotation from a timing of the first detection signal. A second generating unit reads periodic variation information from a storage unit based on the reference signal, and generates a rotation-velocity correction signal for the rotation-driving source.Type: GrantFiled: March 13, 2007Date of Patent: June 8, 2010Assignee: Ricoh Company, LimitedInventor: Yuusuke Ishizaki
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Publication number: 20100127655Abstract: A control loop circuit for use in a closed-loop control system that controls a system such as a linear motor is presented. The control loop circuit includes a lead-lag compensator that features a lead compensation network configured to reduce output noise without substantially changing the effect of the lead compensation in the control system's frequency response.Type: ApplicationFiled: November 26, 2008Publication date: May 27, 2010Inventors: Michael G. Ward, David J. Haas
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Patent number: 7725201Abstract: In a feedback control apparatus comprising a controller, a control object to be controlled by the controller, and an observer for inputting a control output from the control object and an output of the controller and setting an output of a control object model to be a feedback signal, the observer includes an observer compensator for inputting a difference between the control output and an output of an element model and inputs, to the control object model, a sum of an output of the observer compensator and the output of the controller. Consequently, a control system having an excellent response performance can be constituted and a stable observer can easily be constituted.Type: GrantFiled: December 13, 2001Date of Patent: May 25, 2010Assignee: Kabushiki Kaisha Yaskawa DenkiInventors: Wennong Zhang, Yasuhiko Kaku
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Patent number: 7715964Abstract: A method of operating a vehicle at a substantially low speed based on change in the vehicle position. The method comprises the following steps: (A) transforming a steering control algorithm into a substantially low speed (SLS) steering control algorithm, wherein the (SLS) steering control algorithm is configured to operate the vehicle in an asynchronous low speed mode; and (B) implementing the SLS steering control algorithm as a controller configured to operate the vehicle in the asynchronous low speed mode.Type: GrantFiled: May 10, 2005Date of Patent: May 11, 2010Assignee: Trimble Navigation, Ltd.Inventor: John Arnold Connally
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Publication number: 20090284208Abstract: Even when rigidity of a load drive system using a motor is relatively low, by performing a load position control in which a load position signal is fed back as stable as a semi-closed control system in which only a motor position signal is fed back, an accurate load position control can be made possible. Therefore, regarding a load position signal xl as a present-position measurement value of a load 20, after compensation in response to a phase delay thereof has been performed by a stability compensation circuit 80, the high-frequency portion thereof is taken as a control-target position signal xfb by replacing, in a position-signal combination circuit 90, by a motor position signal xm as a present-position measurement value of a motor 30, and then the control-target position signal xfb is fed back to a position control circuit 110; thereby, a torque command signal indicating a torque target value that the motor 30 drives the load 20 is configured to be outputted.Type: ApplicationFiled: March 31, 2006Publication date: November 19, 2009Applicant: MITSUBISHI ELECTRIC CORPORATIONInventors: Hidetoshi Ikeda, Yoshihiro Marushita, Kei Terada, Takashi Isoda, Hiroto Takei
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Publication number: 20090230912Abstract: A motor controller includes a command part that generates a command signal, a control part that drives a control object through an output filter when the command signal is input, an operating amount detector that detects an operating amount of the control object, a frequency response characteristic measurement part that generates an open loop frequency response characteristic on the basis of the command signal and the operating amount, a model calculation part that simulates a frequency characteristic of the output filter, and a display that displays the add result of an amplitude characteristic of the frequency characteristic of the frequency response characteristic measurement part and an amplitude characteristic of the frequency characteristic of the model calculation part.Type: ApplicationFiled: May 26, 2009Publication date: September 17, 2009Applicant: KABUSHIKI KAISHA YASKAWA DENKIInventors: Nobuhiro UMEDA, Tetsuro IZUMI
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Patent number: 7589484Abstract: Method and apparatus for accelerating a multi-phase motor having a rotatable rotor are disclosed. A first commutation state in which the rotor resides is identified, after which a Proportional, Integral and Derivative (PID) control routine is executed for closed loop control of an acceleration of the rotor from a stopped position to an intermediate velocity, after which back electromotive force (Bemf) commutation is used to control the motor. The PID control routine utilizes a loop gain value optimized through voltage feedback indicative of a response of windings of the rotor to an application of a drive current across the windings. Based on the voltage feedback a controller programmed with the PID control routine provides an updated commanded current for each successive commutation state of the motor for use by a motor driver circuitry, which drives the motor through each commutation state until attainment of the intermediate velocity.Type: GrantFiled: June 5, 2003Date of Patent: September 15, 2009Assignee: Seagate Technology LLCInventors: Raye Abdoulie Sosseh, James Wilford DuLaney, Ryan Todd Lyle
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Patent number: 7528566Abstract: Disclosed is a method for controlling a voltage of a DC link for an electric vehicle, which can reduce a capacitance of the DC link interposed between an inverter and a DC/DC converter. The method for controlling the voltage of the DC link in a power system of a vehicle including a battery, a DC/DC converter, the DC link, an inverter, a motor, and a control part controlling the DC/DC converter and the inverter includes the steps of installing a compensator in a control loop of the control part such that a DC link current of the DC/DC converter follows a DC link current of the inverter, calculating a predetermined compensation term based on information of the motor inputted into the compensator, and applying the compensation term to a voltage node in the control loop of the control part in the compensator.Type: GrantFiled: December 13, 2005Date of Patent: May 5, 2009Assignees: Hyundai Motor Company, Pohang University of Science & TechnologyInventors: Hong Seok Song, Doo Yong Oh, Kwang Hee Nam, Sung Young Kim
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Patent number: 7498760Abstract: A drive control apparatus including a feed-forward operation amount generation device, a feed-back operation amount generation device, a feed-forward correction amount generation device and a feed-forward operation amount correction device is provided. The drive control apparatus is configured to input an input operation amount, which is obtained by adding a feed-back operation amount to a feed-forward operation amount corrected by the feed-forward operation amount correction device, into a control target thereby to drive the control target.Type: GrantFiled: September 27, 2006Date of Patent: March 3, 2009Assignee: Brother Kogyo Kabushiki KaishaInventor: Shigeki Akiyama
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Patent number: 7495409Abstract: The lead or lag relationship between the stator and rotor of a stepper motor is monitored on a continuing basis by an incremental encoder, in feed-back relation, and adjusts the lead or lag to within optimum range values to thereby prevent motor stalls and motor cogging.Type: GrantFiled: October 30, 2006Date of Patent: February 24, 2009Inventor: David Coutu
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Patent number: 7432681Abstract: A scanner system includes a servo control unit. A rotation angle of a rotating shaft supporting a mirror is detected, and an error of the detected value with respect to a commanded value is integrated by an integral compensator so that the detected value is able to track the commanded value. A tracking error proportional compensator is disposed in parallel with the integral compensator so as to add a correction value proportional to the error to the integrated value of the error. A plurality of gains are prepared for each of the integral compensator, the tracking error proportional compensator, a detected value proportional compensator and a detected value differential compensator of the servo control unit. Each gain is changed in accordance with a travel angle of the commanded value. Thus, the mirror can be positioned quickly so that the machining speed can be improved.Type: GrantFiled: August 27, 2004Date of Patent: October 7, 2008Assignee: Hitachi Via Mechanics, Ltd.Inventors: Souichi Toyama, Haruaki Otsuki, Atsushi Sakamoto, Kenta Seki, Yaichi Okubo
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Publication number: 20080201041Abstract: A control device for an electric power steering apparatus includes a control unit which controls a motor giving steering assist force to a steering system according to a current command value computed based on steering toque and vehicle speed in a vector control manner and an advance angle map for compensating for a phase lag occurring in a motor current relative to the current command value. Advance angle compensation is made for the current command value based on the advance angle map.Type: ApplicationFiled: February 6, 2008Publication date: August 21, 2008Applicant: NSK LTD.Inventor: ChunHao JIANG
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Patent number: 7376063Abstract: A control circuit of an optical storage device includes a loop phase calculation unit for calculating a closed loop phase of a servo system according to at least one error signal of the servo system and a system control unit coupled to the loop phase calculation unit for generating an optimized control parameter according to the closed loop phase to perform compensation control, wherein the servo system comprises a tracking servo control system or a focusing servo control system, the compensation control is radial tilt control or focus balance adjustment, and the optimized control parameter is at least one optimized control parameter determined according to a plurality of closed loop phases calculated by the loop phase calculation unit.Type: GrantFiled: June 20, 2006Date of Patent: May 20, 2008Assignee: Media Tek Inc.Inventors: Yuh Cheng, Gwo-Huei Wu
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Publication number: 20080100249Abstract: The lead or lag relationship between the stator and rotor of a stepper motor is monitored on a continuing basis by an incremental encoder, in feed-back relation, and adjusts the lead or lag to within optimum range values to thereby prevent motor stalls and motor cogging.Type: ApplicationFiled: October 30, 2006Publication date: May 1, 2008Inventor: David Coutu
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Patent number: 7345448Abstract: Preferred embodiments of the invention implement techniques for modifying the command trajectory, the architecture of a servomechanism control system, or both, to reduce the servo error during and/or after the command trajectory. An iterative refinement procedure generates for use by the servomechanism control system a corrective input, du, which significantly reduces the error between the desired and actual servomechanism control system outputs. In one embodiment, a uniquely identified plant model is employed in the iterative refinement procedure to compute an approximate gradient that improves the performance and reliability of the refinement procedure. In another embodiment, the actual plant response is used in place of the identified model in the iterative refinement procedure. This is accomplished by time-reversing the stored error signal from a training run, before applying it to the plant to generate an update to the corrective input signal du.Type: GrantFiled: May 12, 2005Date of Patent: March 18, 2008Assignee: Electro Scientific Industries, Inc.Inventors: David Watt, Mehmet Alpay, Mark Unrath, John Wen, Ben Potsaid
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Patent number: 7345442Abstract: Distortions of motor voltage and current and a torque ripple of the motor are generated by dead band compensation for preventing an arm short circuit of an inverter, and a feeling of physical disorder is given in a handle operation. Therefore, the distortions of the motor voltage and current and the torque ripple of the motor are improved by using the dead band compensation for estimating the voltage distortion on the basis of a model current generated from a current command value such that no feeling of physical disorder is given in the handle operation of an electric power steering apparatus.Type: GrantFiled: September 1, 2004Date of Patent: March 18, 2008Assignees: NSK Ltd., NSK Steering Systems Co., Ltd.Inventors: CaoMinh Ta, Hiroaki Takase, Hideyuki Kobayashi
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Patent number: 7265507Abstract: A method of correcting the determination of extended rotor flux using a lag function and a correction algorithm that closely approximates a pure integrator function to correct for lag function errors that can extend the EFS control down to dynamoelectric machine speeds corresponding to as low as 10 Hz electrical frequency.Type: GrantFiled: February 20, 2006Date of Patent: September 4, 2007Assignee: Hamilton Sundstrand CorporationInventor: Albert L. Markunas
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Patent number: 7245975Abstract: A system and method for generating master and slave reference signals is disclosed, wherein at least one axis of the plurality of axes is a master section and at least one axis of the plurality of axes is a slave section, said slave section being a slave of said master section. The system and method generates a first reference signal and a second reference signal, wherein the second reference signal lags the first reference signal by a first delay period, and the processor provides the first reference signal to the slave section and the second reference signal to the master section. As a result, the slave section can lead the master section.Type: GrantFiled: April 20, 2005Date of Patent: July 17, 2007Assignee: Parker-Hannifin CorporationInventor: Marghub Mirza
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Patent number: 7208901Abstract: A control method for controlling a speed of a movable machine element of a numerically controlled industrial processing machine with jerk limitation is described. The processing machine can be, for example, a machine tool, a production machine and/or a robot. A travel path of the movable machine element is first decomposed into a plurality of sequentially arranged, interpolatable travel sections. Jerk profiles are then determined for the interpolatable travel sections, which are modified with a parameter-dependent shape function. The modified jerk profiles provide a filter action that can be represented by bandpass filters having blocking frequencies. The blocking frequencies of the bandpass filters are selected so as to substantially correspond to characteristic frequencies of the machine element. The control method significantly improves the machine dynamics without sacrificing accuracy.Type: GrantFiled: April 2, 2004Date of Patent: April 24, 2007Assignee: Siemens AktiengesellschaftInventors: Uwe Ladra, Elmar Schäfers
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Patent number: 7184847Abstract: A method and system are disclosed for controlling a process by establishing a control factor for a proportional-integral-derivative (PID) controller used to control a parameter of a process relative to a setpoint. A feedback signal regarding the parameter of the process is received via a sensor of the process and a first feedback loop. Automatic adjusting of the control factor of the PID controller is based on the feedback signal.Type: GrantFiled: December 17, 2004Date of Patent: February 27, 2007Assignee: Texaco Inc.Inventors: Hongqiao Sun, W. Spencer Wheat, Vesna R. Mirkovic
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Patent number: 7102315Abstract: When either a command value or an actually measured value is appropriately selected as an angular velocity used for the frictional torque calculation, the frictional compensation can be made valid at all times in both the case in which a robot is actively operated according to an angular velocity command and the case in which the robot is passively operated being pushed by an external force. In the case where a motor rotating direction and a collision direction are reverse to each other after a collision has been detected, the control mode is switched from the positional control to the electric current control and a torque, the direction of which is reverse to the direction of the motor rotation is generated by the motor, so that the motor rotating speed can be reduced and the collision energy can be alleviated.Type: GrantFiled: July 2, 2004Date of Patent: September 5, 2006Assignee: Matsushita Electric Industrial Co., Ltd.Inventors: Hiroyuki Nakata, Naoto Masunaga, Atsumi Hashimoto, Yasushi Mukai
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Patent number: 7042186Abstract: A method for decoupling a harmonic signal from an input signal wherein the harmonic signal is harmonic relative to a signal other than the input signal. An angular position of the other signal is multiplied by a value representing the harmonic to obtain an angular position multiple. A harmonic decoupling block uses the angular position multiple to obtain correction signals representing the harmonic signal, and subtracts the correction signals from the input current to decouple the harmonic signal from the input signal. This method is useful for decoupling unwanted harmonics from currents into which high-frequency signals have been injected for control of electric motors.Type: GrantFiled: November 24, 2003Date of Patent: May 9, 2006Assignee: General Motors CorporationInventors: Constantin C. Stancu, Silva Hiti, Steven E. Schulz, Nitinkumar R. Patel
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Patent number: 6914404Abstract: A motor controller, comprising a first simulation control unit (8) and a second simulation control unit (9) as a feed forward control means for inputting a command to an actual control unit (10) performing a feedback control, wherein the control parameter of the first simulation control unit (8) is set so that the high-speed property of a control response is increased, and the control parameter of the second simulation control unit (9) is set so that the stability of the control response is increased, whereby an entire feed forward control means can be designed so as to meet the requirements for the high-speed property and high stability of the control response.Type: GrantFiled: September 25, 2001Date of Patent: July 5, 2005Assignee: Kabushiki Kaisha Yaskawa DenkiInventors: Souki Kaku, Ryuichi Oguro, Hideki Honda
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Patent number: 6861816Abstract: In a positional control device for controlling a position of a controlled object using a motor, when generating a torque command value ?c which serves as the command value for the servo motor of the controlled object system (112), a friction compensation value for use when the controlled object initiates a movement is calculated based on a velocity command value V and a torque command value ?c determined according to a positional command value Xo supplied from a superordinate device. More specifically, an initial friction compensation calculating section calculates a torque compensation amount Vsfc1 corresponding to a difference between torque being generated during the standstill state and torque required by the controlled object to initiate the movement, and a torque compensation amount Vsfc2 to an amount of change in friction that occurs during a transition from static friction to kinetic friction in a period immediately before and after initiation of the movement.Type: GrantFiled: April 28, 2003Date of Patent: March 1, 2005Assignee: Okuma CorporationInventor: Satoshi Eguchi