Including Velocity Control Patents (Class 318/568.18)
  • Patent number: 6801830
    Abstract: An operation confirming method capable of making, in order to enhance an operation program correction efficiency, an operation path at an operation confirming time (teaching mode) identical with that at an actual job time (play mode) as much as possible; and a control device therefor. The method comprises the steps of inputting respective shaft operation instruction values (&ohgr;j) based on an actual operation speed to a mechanical simulator-carrying low-speed instruction converter (7), and instructing to a servo controller unit (4) a quantity (&ohgr;ij) (=&ohgr;sj/P), obtained by dividing an output (&ohgr;sj) from the mechanical simulator by a specified positive real number P at the low-speed instruction converter, as respective shaft operation values N times (N; maximum natural number not exceeding the real number P).
    Type: Grant
    Filed: April 19, 2002
    Date of Patent: October 5, 2004
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Koji Tomita, Tatsumi Nakazato
  • Patent number: 6798611
    Abstract: A discrete-time sliding mode controller (SMC) controls the motion of a read head actuated over a disk storage medium during tracking operations. The discret-time SMC comprises a linear signal generator for generating a linear control signal, and a sliding mode generator for generating a sliding mode signal. These signals are combined and applied to a voice coil motor (VCM) for positioning the read head over a particular data track recorded on the disk. The linear signal generator and the gain (c&Ggr;)−1&Dgr; are designed such that once the sliding mode variable &sgr;k crosses the sliding line the first time, it will cross the sliding line in every successive sample period resulting in a zigzag motion about the sliding line wherein &sgr;k changes sign at every sample period. The switching action and resulting chatter of the sliding mode controller are minimized by adjusting the width of the boundary layer through appropriate selection of predetermined constants &Dgr; and &lgr;.
    Type: Grant
    Filed: September 2, 1998
    Date of Patent: September 28, 2004
    Assignee: Cirrus Logic, Inc.
    Inventors: Paul M. Romano, Louis Supino, Christopher T. Settje
  • Patent number: 6781337
    Abstract: In an industrial robot having a plurality of arms, each arm is coupled with other elements, such as a mounting base, another arm, a robotic hand, and revolved by a motion of the revolvable joint. The revolvable joint has a rotary electric connecting structure such as a slip ring or a rotary transformer which can be rotated endlessly. Electric powers for driving motors by which the arms are revolved and control signals for controlling the driving of the motors are supplied or transmitted through the rotary electric connecting structure, so that the arms can be rotated endlessly without twisting or breaking of electric cables.
    Type: Grant
    Filed: October 9, 2002
    Date of Patent: August 24, 2004
    Assignees: Japan Servo Co., Ltd., Tazmo Co. Ltd.
    Inventors: Masafumi Sakamoto, Kaoru Endo, Katsuhiro Yamazoe, Takahiro Kobiki
  • Publication number: 20040124802
    Abstract: Method for optimising the movement performance of an industrial robot for a current movement path with respect to thermal load on the driving system of the robot, wherein the method comprises the following steps: for at least one component in the driving system, the thermal load is calculated for the whole or parts of the movement path if the calculated thermal load is compared with a maximally allowed load for the component; and dependent on said comparison, a course of accelerations and velocities for the current movement path are adjusted.
    Type: Application
    Filed: January 29, 2004
    Publication date: July 1, 2004
    Inventors: Torgny Brogardh, Magnus Ahlback, Jesper Bergsjo, Staffan Elfving, Anders Lager, Stig Moberg, Mats Myhr, Dan Rylander
  • Patent number: 6728580
    Abstract: An apparatus for estimating the time to failure acceleration factor of a large industrial motor includes a sensor, a clock for controlling sensor sampling times, and a memory address calculator for mapping output signals of the sensor to a memory address. A unit is provided for incrementing the content of a specified memory address by unity.
    Type: Grant
    Filed: February 20, 2001
    Date of Patent: April 27, 2004
    Assignee: General Electric Company
    Inventors: John Erik Hershey, Brock Estel Osborn, Kati Illouz, Gerald Burt Kliman
  • Patent number: 6643577
    Abstract: When operating a work machine having more than one function, there are situations in which an operator may need to simultaneously control both functions. For instance, when a backhoe loader operator would like to perform a maneuver referred to as the “duck walk”, the operator must simultaneously control at least one aspect of a backhoe and one aspect of a loader. A work machine that has an operator control station with at least two controllers, which may be assigned a first mode pattern, a second mode pattern, and a hybrid mode pattern. When the at least two controllers are in the first mode pattern, the at least two controllers are operably coupled to a first set of equipment, such as a loader. When the at least two controllers are in the second mode pattern, the at least two controllers are operably coupled to a second set of equipment, such as a backhoe.
    Type: Grant
    Filed: August 22, 2002
    Date of Patent: November 4, 2003
    Assignee: Caterpillar Inc
    Inventors: Clayton L. Padgett, Darren M. Knutson, Jeffrey S. Alig, W. Christopher Swick
  • Patent number: 6615110
    Abstract: A controlling method and apparatus for positioning a robot that can output an optimal speed instruction for controlling residual vibration after completion of a moving operation, achieve reduction in tact time for the moving operation, and shorten the length of setting time. The method is a controlling method for positioning a robot (1) for performing a point-to-point moving operation comprising: performing a test operation to measure a frequency of a residual vibration that is stopped at a target position; measuring a magnitude of the residual vibration based on the frequency during each of different lengths of moving time for a predetermined moving distance to find a relationship between the length of moving time and the magnitude of the vibration; calculating a shortest moving time at which vibration magnitude is minimized; and performing the point-to-point operation for the calculated shortest moving time, thereby to position the robot (1) at the target position.
    Type: Grant
    Filed: June 11, 2002
    Date of Patent: September 2, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventors: Seiichi Matsuo, Youichi Tanaka, Takahiro Kurokawa, Seishiro Yanachi
  • Patent number: 6608460
    Abstract: A method for driving a head includes the steps of: determining a head-present-position by a head-position-data supplied from a head-position-detector; calculating in advance a target-sector accessible-time by the head for a first time based on a data of a head-present-position, a location data of a target sector at a destination and a driving capability of a head assembly; and controlling a head-assembly-driver by determining a moving speed and an acceleration/deceleration pattern of the head for completing a seek to a track including the target sector within the accessible-time. The method is useful for controlling the head of a disc driving apparatus, especially a magnetic head of a magnetic disc driving apparatus, and the method reduces power consumption at a seek-operation without extending an access time.
    Type: Grant
    Filed: July 9, 2001
    Date of Patent: August 19, 2003
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Shuhei Okada
  • Patent number: 6597971
    Abstract: An interference avoiding device for determining occurrence of an interference in a robot operation in advance and automatically avoiding the interference, to be suitably applied to an automatic picking-up operation of randomly stored workpieces. A position/orientation of a workpiece and a position/orientation of a tool for getting hold of the workpiece in a teaching operation, and shapes/dimensions of the tool and the storage box are determined and stored in a storage device. A command position/orientation Ta of the tool for getting hold of an objective workpiece is determined based on a detected position/orientation Wa of the workpiece and it is determined whether or not an interference between the tool an the storage box will occur based on the position/orientation Ta and the stored information.
    Type: Grant
    Filed: May 9, 2002
    Date of Patent: July 22, 2003
    Assignee: Fanuc Ltd.
    Inventor: Ichiro Kanno
  • Patent number: 6580245
    Abstract: A critical resonant frequency (fres) of the axes of a moving machine element is damped as effectively as possible with the aid of a jerk limitation. Good damping in the case of a desired frequency is achieved when the longest possible time (TrLim) which can be traveled with a maximum permissible jerk (rLim) is selected such that 1/TrLim coincides with the lowest natural frequency (fres) of the participating axes. This finding is implemented by adapting the path dynamics such that the TrLim=aMax/rLim yielded by the prescribed dynamics limiting values is varied by reducing the maximum jerk (rLim) to achieve good damping results for the lowest natural frequency (fres) of the participating axes.
    Type: Grant
    Filed: August 14, 2001
    Date of Patent: June 17, 2003
    Assignee: Siemens Aktiengesellschaft
    Inventors: Bernd Quaschner, Theo Reichel, Elmar Schaefers, Wilhelm Westermeyer, Georg Wiegaertner
  • Patent number: 6546295
    Abstract: An industrial process material flow within an industrial process is controlled by a process control loop that includes a process controller, a field device controller and a field device in the process as well as process variable feedback from the process to the process controller. Both the process controller and the field device controller, such as a valve controller, are fine-tuned so that their interaction is taken into account and controller parameters, which provide an optimal control loop performance are found. This results in a significant improvement in the control loop performance, i.e., in a lower process variability, as compared with the traditional tuning method, which does not take into account the interaction between the two controllers.
    Type: Grant
    Filed: February 16, 2000
    Date of Patent: April 8, 2003
    Assignee: Metso Automation Oy
    Inventors: Jouni Pyötsiä, Mika Kreivi, Pasi Heikkinen
  • Patent number: 6528963
    Abstract: Disclosed is a method of controlling a robot including a motor having a rotation shaft, an arm part having one end connected to the rotation shaft and interlocking with a rotation of the motor, a position controller controlling the motor, and a main controller generating a speed command profile for controlling the motor, based on the inputted motion command of the arm part and transmitting the profile to the position controller, comprising a step of generating the speed command profile controlling a speed of the motor so as to allow the arm part to have an acceleration profile in uniform speed. With this configuration, the slipping of a workpiece can be prevented and further increasing the motion speed while the arm part is traveling, by making the motion speed of the arm part constant.
    Type: Grant
    Filed: May 30, 2001
    Date of Patent: March 4, 2003
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Yong-joon Hong
  • Patent number: 6522096
    Abstract: A mechanism controller for controlling power to motors of a mechanism having several motors, such as a robot. Each motor has a resolver for indicating the motor position. A driver unit is associated with each motor to supply power to the motor. Each driver unit includes a monitoring unit to monitor indications from the resolver of the associated motor. In one embodiment a control unit is connected to the driver units in a series circuit to control power to the motors and to receive the monitored indications from the monitoring units. In a second embodiment, the control unit is connected to the driver units in a ring circuit, rather than in a series circuit. Preferably, each driver unit also includes a memory device, and the control unit can send commands to the driver units and receive data from the driver units in sets equal in number to the number of driver units so that the commands and data do not need to include the addresses of the specific driver units.
    Type: Grant
    Filed: February 28, 2000
    Date of Patent: February 18, 2003
    Assignee: Kuka Roboter GmbH
    Inventor: Stefan Roth
  • Publication number: 20030025473
    Abstract: A robot controller for keeping the posture of a tool in a task coordinate system by a simple processing and allowing a robot to perform flexible translational motion. A robot controller for controlling a motor for driving a joint by means of a control circuit having a position/speed state feedback loop, comprising means for measuring the angle of a joint of a robot, means (11) for storing the initial posture of a tool attached to the end of a hand of the robot, means (10) for setting the position or speed gain of a specific joint axis smaller than the position or speed gains of the other joint axes, and means (12) for calculating the correction of a position or speed command to keep the tool posture with respect to the robot base on the basis of the angle of the joint and the initial posture of the tool.
    Type: Application
    Filed: May 29, 2002
    Publication date: February 6, 2003
    Inventors: Hideo Nagata, Yasuyuki Inoue, Ken?apos;Ichi Yasuda, Toshiyuki Kurebayashi
  • Patent number: 6515442
    Abstract: To overcome the problem of a low frequency disturbance causing minute vibrations affecting response attributable to the difficulty of adaption to the phase of the vibrations, the present invention provides a position controller, which includes a subtracter for subtracting a motor position signal from a movement position signal to produce an angle-of-twist signal; a high-pass filter for advancing the phase of the angle-of-twist signal; a low pass filter for eliminating only high-frequency components of the signal received from the high-pass filter; a circuit for multiplying the signal from a low-pass filter by a torque-corrective gain to produce a torque-corrected signal; a torque correction evaluation section for varying the torque-corrective gain according to the position deviation signal that is the difference between a position command and the movement position signal; and a subtracter for combining the torque-corrective signal and the torque command to produce a new torque command.
    Type: Grant
    Filed: May 24, 2001
    Date of Patent: February 4, 2003
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Tadashi Okubo, Wennong Zhang, Yasuhiko Kaku, Kenichi Murata
  • Patent number: 6487458
    Abstract: A closed-loop control of a servo motor in which multiple closed-loop terms of a motor command are adaptively tuned and selectively activated to achieve both stable operation and improved performance. The motor command includes a first term proportional to an error signal, a second term based on the integral of the error signal, and a third term based on the rate of change of the measured feedback signal, and representing the kinetic energy of the system. The first term is continuously active, whereas the second term is only activated when the rate of change of the measured feedback signal is below a threshold, and the third term is only activated when the error signal is within a reference window, thereby allowing relatively high gains while ensuring stable operation.
    Type: Grant
    Filed: August 31, 1999
    Date of Patent: November 26, 2002
    Assignee: Delphi Technologies, Inc.
    Inventor: David James Trapasso
  • Patent number: 6477433
    Abstract: In a position in control, a velocity error is compared to a limit that is a non-linear, continuous and differentiable function of the position error. If the position error is greater than a limit or magnitude, the velocity limit is used for the velocity command; otherwise the position error is used.
    Type: Grant
    Filed: May 20, 1999
    Date of Patent: November 5, 2002
    Assignee: Honeywell International Inc.
    Inventor: David A. Bailey
  • Patent number: 6477445
    Abstract: An equipment for controlling an industrial robot, which robot has a plurality of rotation and/or translation axles (ax 1-6), comprising a motor (15) at each of said axles for generating desired movements of the arms and/or the wrist, of which the robot is constituted, a sensor at each of the axles for measuring axle angle and/or axle position, a servo (9) for each of the axles for controlling the motors based on measurement values from the sensors, and a path generator (8) for generating at least one reference (&phgr;ref, &phgr;ref, &tgr;ffw) for each of the servos (9).
    Type: Grant
    Filed: September 26, 2001
    Date of Patent: November 5, 2002
    Assignee: ABB AB
    Inventors: Karl-Gustav Ramström, Torgny Brogårdh
  • Patent number: 6469467
    Abstract: In a servo control apparatus including a speed controller (35) for controlling a servo motor so a difference between a speed command value and a speed feedback value becomes a zero, a filter (41) having characteristics that are reverses of, or approximate the reverses of, at least one set of anti-resonance and resonance characteristics of a control object is built in the speed controller (35).
    Type: Grant
    Filed: May 5, 2000
    Date of Patent: October 22, 2002
    Assignee: Toshiba Kikai Kabushiki Kaisha
    Inventor: Jun Fujita
  • Patent number: 6462501
    Abstract: When a movement destination P is designated, a switching time t1 when the movement is switched from acceleration to constant-speed-movement and a switching time t2 when the movement is switched from the constant-speed-movement to deceleration are determined with respect to a designated time T0. Then, a constant-speed-movement start position A and a deceleration start position B are set. Next, the constant speed (inclination of a straight line AB) during the constant-speed-movement period is found. An operation equation of the acceleration period is determined with an exponential function so that the panhead is smoothly shifted from the acceleration to the constant-speed-movement. In like manner, an operation equation of the deceleration period is determined with an exponential function so that the panhead is smoothly shifted from the constant-speed-movement to the deceleration.
    Type: Grant
    Filed: September 15, 2000
    Date of Patent: October 8, 2002
    Assignee: Fuji Photo Optical Co., Ltd.
    Inventor: Akira Higo
  • Patent number: 6462499
    Abstract: The number of operation keys is decreased, realizing cost reduction and miniaturization of a teaching device. Further, the working efficiency and operational safety are considerably improved. Also, the operations of the robot ranging from delicate positioning and high-speed continuous operation can be readily controlled by serial manipulations. The present invention includes (a) a plurality of operation keys to designate one out of a plurality of operation coordinates of the robot arm, and (b) a controller which controls the operation of the robot arm. The controller has a function to control the robot arm so that the robot arm is positioned on the designated operation coordinates and also a function to control the operation speed of the robot arm. The controller includes a jog dial disposed in a manner such that the jog dial can be rotated and pushed.
    Type: Grant
    Filed: March 28, 2001
    Date of Patent: October 8, 2002
    Assignee: Matsushita Electric Industrial Co., Ltd.
    Inventor: Yasushi Mukai
  • Patent number: 6453213
    Abstract: A robot control system and method for controlling a robot that performs working on a working path between a specified working start point and a working end point. The robot control system includes an interrupt request signal generating section for generating a signal for requesting change of the working path of the robot, an upper controller for generating an interrupt signal including a specified changed value for changing in real time the working path of the robot in accordance with the interrupt request signal generating section, and a robot controller for controlling in real time the operation of the robot in accordance with the interrupt signal from the upper controller. Thus, the motion of the robot that is working can be changed in real time.
    Type: Grant
    Filed: May 9, 2001
    Date of Patent: September 17, 2002
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Sung-jin Hong
  • Patent number: 6448723
    Abstract: A stage system includes a movable stage, a position measuring device for measuring the position of the stage, a velocity sensor for detecting the velocity of the stage, and a control unit having a position feedback loop based on an output of the position measuring device and a feedback loop for applying a damping to the stage on the basis of an output of the velocity sensor. With the addition of the feedback loop for applying the damping to the stage by using an output of the velocity sensor, a strong braking function is provided, such that the positioning settlement time can be shortened.
    Type: Grant
    Filed: August 25, 2000
    Date of Patent: September 10, 2002
    Assignee: Canon Kabushiki Kaisha
    Inventor: Shinji Wakui
  • Patent number: 6430472
    Abstract: Motorized slides are inserted between the end of a robot arm and a robot tool/sensor arrangement to provide additional positioning ability. A control unit of the slides cooperates with the control unit of the sensor to maintain the tool correctly positioned over a feature while the robot arm moves following a programmed path. The control unit of the sensor has look-ahead and additional buffers from which corrected information is determined to compensate for robot teaching inaccuracies, calibration and robot arm response errors. A sensor with two distinct probing zones is used to get information about the position of the tool tip and of the feature to assist in calibrating the sensor/tool relation.
    Type: Grant
    Filed: December 20, 1999
    Date of Patent: August 6, 2002
    Assignee: Servo-Robot Inc.
    Inventors: Jean-Paul Boillot, Denis Villemure
  • Patent number: 6427098
    Abstract: A method and apparatus for control of pivoting machine members propelled by linear actuators so as to permit coordinated motion of the pivoting members with translating machine members. Position commands for the pivoting machine members are given in angular units. The propelling linear actuators are controlled by servomechanism control providing position and velocity control. Position measurements for the pivoting members measure linear displacement of the propelling actuator. Position commands for the pivoting members are compensated according to the non-linear relationship between displacement of the propelling actuator and the angular displacement of the pivoting member.
    Type: Grant
    Filed: March 22, 2000
    Date of Patent: July 30, 2002
    Assignee: UNOVA IP CORP
    Inventors: Steven E. Alverson, Kirby L. Stone
  • Patent number: 6400117
    Abstract: A slider mechanism includes two parallel guide rails, a first slider and a second slider constituted as separate members that are frictionally retained by and slidable along the guide rails, a first actuator for driving the first slider to change frictional force between it and the guide rails, a second actuator connecting the first and second sliders and adapted to move the second slider in the longitudinal direction of the guide rails, and a driving device for applying to the first actuator and second actuator a drive command that periodically produces a drive operation composed of four sequentially executed drive operation stages each consisting of a linear drive operation.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: June 4, 2002
    Assignee: Agency of Industrial Science & Technology, Ministry of International Trade & Industry
    Inventor: Yuichi Okazaki
  • Patent number: 6340875
    Abstract: A robot controller which controls a process controlled variable of an operational tool mounted on a robot in synchronism with the robot motion. The position of each axis of the robot is detected by a sensor such as a position detector. In a calculating section, motion variables such as position Pn, velocity vn and acceleration &agr;n of a tool center point (TCP) are detected from the respective positions of the robot axes. An ideal output (target value) of a sensor for detecting a controlled variable to be controlled in accordance with the motion state is determined in a calculating section. A sensor output is subtracted from the target value to determine a deviation. The deviation is multiplied by a proportional gain K to determine a manipulated variable. By using this manipulated variable, the process of an arc welding machine, sealing machine, or laser beam machine in which a tool is mounted on a distal end of a robot wrist is controlled.
    Type: Grant
    Filed: December 22, 1999
    Date of Patent: January 22, 2002
    Assignee: Fanuc Ltd.
    Inventors: Atsushi Watanabe, Tetsuaki Kato
  • Patent number: 6327518
    Abstract: An off-line teaching apparatus includes an operation command-receiving device for receiving an operation command inputted via an input/output port from a key input device or a coordinate input device and successively storing the operation command in a buffer; an operation command-reading device for successively reading the operation command stored in the buffer; an operation command-counting device for counting a number of operation commands stored in the buffer; and a confirmation sound-generating device for generating confirmation sound upon receipt of the operation command by the operation command-receiving device when a counted value obtained by the operation command-counting device is not less than a predetermined number. Accordingly, the operator is informed, in real time, of the fact that the system responds to the input of the operation command from the operator. Thus, it is possible to improve the operability of the off-line teaching.
    Type: Grant
    Filed: September 11, 2000
    Date of Patent: December 4, 2001
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Masakatsu Kaneko, Shinji Aoki
  • Patent number: 6316900
    Abstract: A single shaft type table feed device comprises a movable body and an auxiliary movable body 34. The movable body is supported by a guide rail 31 and can be freely moved by a feed screw shaft 35 in the axial direction thereof. The auxiliary movable body 34 includes an inside diameter portion through which the feed screw shaft 35 can be inserted. The auxiliary movable body 34 is supported by the guide rail 31 and freely movable in the axial direction thereof. The inside diameter portion 38a of the auxiliary movable body 34 is slidingly contacted with the feed screw shaft 35.
    Type: Grant
    Filed: December 19, 2000
    Date of Patent: November 13, 2001
    Assignee: NSK, Ltd.
    Inventors: Toshiharu Kajita, Hiroshi Fujita
  • Patent number: 6294891
    Abstract: Systems and methods for reducing unwanted vibration in motion system are provided using a Robust Vibration Suppression (RVS) methodology, in which acceleration frequency spectra are obtained for each of a number of command input functions developed for moving a load a specified distance within a specified move time interval using an actuator. The frequency spectra comprise peaks, with notches defined between adjacent peaks. A desirable command input function is one with a frequency spectra having either a notch with a maximum width or a peak with a minimum magnitude relative to frequency spectra associated with other command input functions, or, alternatively, a peak with a magnitude of less than or equal to a pre-established magnitude or a frequency notch having a width greater than or equal to a pre-established width. A suitable command input function may be characterized by a ramp function, a cosine function, a sine function, or a combination thereof.
    Type: Grant
    Filed: November 12, 1998
    Date of Patent: September 25, 2001
    Assignee: Iowa State University Research Foundation, Inc.
    Inventors: Kenneth G. McConnell, Chad E. Bouton
  • Patent number: 6295484
    Abstract: When a multiaxial robot with a mechanism having spring elements between electric motors of respective axes and robot arms is controlled, the path precision of a tool tip is increased without causing vibrations produced by mechanical interference between axes and high-frequency vibrations of electric motors. A model controller (1) is supplied with position commands Xref—L, Xref—U with respect to the electric motors and outputs model motor position commands &thgr;Mm—L, &thgr;Mm—U, model motor speed commands {dot over (&thgr;)}Mm—L, {dot over (&thgr;)}Mm—U, and model feed-forward commands UFF—L, UFF—U to feedback controllers (10L, 10U) which actuate and control the electric motors and the robot arms. The model controller (1) includes therein corrective quantity calculators (3L, 3U) for calculating corrective quantities (corrective torques) in view of interfering forces acting between the axes from the other axes to cancel the interfering forces.
    Type: Grant
    Filed: November 24, 1999
    Date of Patent: September 25, 2001
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Masao Ojima, Hirokazu Kariyazaki, Hidenori Tomisaki
  • Patent number: 6289265
    Abstract: The posture inclination of the robot is detected, a moment of compensating total floor reaction force about a desired total floor reaction force central point is determined therefrom to be distributed to each foot such that the position/posture of the feet are rotated by predetermined amounts about the desired total floor reaction force central point and a desired foot floor reaction force central points respectively. And by parallel-translating the feet in phase, the force component of the actual total floor reaction force is also controlled. In addition, the internal force components (which do not influence on the actual total floor reaction force) generated by the actual foot floor reaction force are controlled independently.
    Type: Grant
    Filed: October 19, 2000
    Date of Patent: September 11, 2001
    Assignee: Honda Giken Kogyo Kabushiki Kaisha
    Inventors: Toru Takenaka, Tadaaki Hasegawa, Takashi Matsumoto
  • Patent number: 6243624
    Abstract: A compliant controller implements a biological model of a primate muscle so as to provide simultaneous position and force control with nonlinear damping for an actuator. The compliant controller uses one or more position sensors but does not require the use of a force sensor to provide force control. The compliant controller implements a force determining algorithm that is a function of an initial actuator position, a subsequently sensed actuator position, a desired actuator position and a position calculated from a nonlinear damping function. The algorithm updates or resets the initial actuator position or the calculated position depending upon the amount of actuator movement sensed. The compliant controller in accordance with the force determining algorithm and resetting of the various position values allows a desired position to be quickly attained while allowing the controller to compliantly respond to the presence or removal of an unknown or unexpected disturbing force.
    Type: Grant
    Filed: March 19, 1999
    Date of Patent: June 5, 2001
    Assignee: Northwestern University
    Inventors: Chi-haur Wu, Der-Tsai Lee
  • Patent number: 6236895
    Abstract: A discrete-time sliding mode controller (SMC) controls the motion of mechanical apparatus such as a read head in a disk storage system. The overall control effort is generated by combining a linear control effort with a discrete-time sliding mode control effort generated by switching between gains in order to drive the system's phase states toward a sliding line trajectory. An estimate of a reference is generated and added to the control effort, thereby providing an approximation of the derivative of the reference signal. Estimating the reference signal may be performed by various methods, depending on whether the reference is known, unknown but repeatable, or completely unknown and non-repeatable. A least-mean-square (LMS) algorithm is employed to estimate the reference signal by computing coefficients of a function which minimizes a particular system parameter.
    Type: Grant
    Filed: September 2, 1998
    Date of Patent: May 22, 2001
    Assignee: Cirrus Logic, Inc.
    Inventors: Paul M. Romano, Louis Supino, Christopher T. Settje
  • Patent number: 6191548
    Abstract: A single shaft type table feed device comprises a movable body and an auxiliary movable body 34. The movable body is supported by a guide rail 31 and can be freely moved by a feed screw shaft 35 in the axial direction thereof. The auxiliary movable body 34 includes an inside diameter portion through which the feed screw shaft 35 can be inserted. The auxiliary movable body 34 is supported by the guide rail 31 and freely movable in the axial direction thereof. The inside diameter portion 38a of the auxiliary movable body 34 is slidingly contacted with the feed screw shaft 35.
    Type: Grant
    Filed: January 28, 1999
    Date of Patent: February 20, 2001
    Assignee: NSK Ltd.
    Inventors: Toshiharu Kajita, Hiroshi Fujita
  • Patent number: 6185480
    Abstract: An interference preventing method for industrial robots comprising a step (II) of reading a present position of the hand, a step (III) of computing the difference between the taught target position and the present position of the hand, a step (IV) of judging whether this difference is within a predetermined range or not, a step (V) of setting a moving speed of the hand to a predetermined normal speed when the difference is within the predetermined range, a step (VI) of setting the moving speed of the hand to a predetermined low speed when the difference is out of the predetermined range, and a step (VII) of moving the hand automatically to the target position at the set speed. When the hand is moved over a long distance in the case of which interference is liable to occur, the moving speed thereof is low; when the hand is moved over a short distance, the moving speed thereof is normal.
    Type: Grant
    Filed: December 12, 1997
    Date of Patent: February 6, 2001
    Assignee: Toyo Kohan Co., Ltd
    Inventors: Toshiyuki Takahashi, Atsushi Nakajima, Yukimasa Shiomichi