Patents Assigned to Kabushiki Kaisha Yaskawa Denki Seisakusho
  • Patent number: 5359490
    Abstract: A magnetic levitation and transport system has a plate-like moving element (SFT) which is moved by a linear motor disposed in a stator (STT). The moving element is moved vertically by first through fourth electromagnetic devices (MGV.sub.10 -MGV.sub.41), and fifth and sixth electromagnetic devices (MGH.sub.10 -MGH.sub.21) exert forces on the moving element in a horizontal direction perpendicular to the direction in which the moving element is moved. Gaps between the moving element and the electromagnetic devices are detected by gap sensors which produce gap data. In the vertical direction, for example, attractive force commands (f.sub.V1 -f.sub.V2) are produced from the outputs from a circuit for calculating the amount of feedback (10) which is supplied with the gap data (XV.sub.1 -XV.sub.4) and also with the output from a variable gain g.sub.V (l) generator (60) to which the position (l) of the center of gravity of the moving element is supplied.
    Type: Grant
    Filed: October 22, 1993
    Date of Patent: October 25, 1994
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventor: Ryuichi Oguro
  • Patent number: 5263413
    Abstract: The present invention belongs to the technical field of synchronously controlling the phase relationship between a plurality of printing rolls in a corrugated board printing press. The object of this invention is to realize synchronous phase control at low cost and with high precision by software. In this invention, a speed command inputted is converted to a digital value at regular intervals to integrate the digital value, the revolution speed of each of the printing rolls is also integrated, and any deviation between these integrated values is subjected to PI operation, thereby separately correcting the revolution speed commands given to drive motors on the basis of their corresponding results of the PI operation. At this time, when the results of the operation in the course of the integrating the speed command and the individual printing rolls exceed the highest value, their values separately return to 0 to continue the operation.
    Type: Grant
    Filed: March 19, 1992
    Date of Patent: November 23, 1993
    Assignees: Kabushiki Kaisha Yaskawa Denki Seisakusho, Hamada Printing Press Co., Ltd.
    Inventor: Masao Ikeguchi
  • Patent number: 5248923
    Abstract: In order to obtain a manipulator using a plane pulse motor showing advantageous features such that even in a case where a moment of force is applied to the manipulator in a falling direction, the moment can be sustained by magnetic attraction caused by the pulse motor, the weight of the manipulator is reduced, the degree of freedom of the movement can be increased, and a rotating mechanism for a tool itself is eliminated; a plurality of movable members are provided on a stator of the plane pulse motor, a rotatable shaft is provided on each movable member so as to extend vertically, the rotatable shafts are connected with each other through a connecting member, a required tool is secured to the connecting member, and the movements of the movable members are made controllable in a manner correlated with each other. The manipulator using the plane pulse motor of the aforementioned construction is most adapted to be used in combination with an industrial robot and the like.
    Type: Grant
    Filed: May 15, 1991
    Date of Patent: September 28, 1993
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Kaoru Kimura, Syuichi Tounai, Toshio Omata
  • Patent number: 5222199
    Abstract: In a method for changing the relative orientation between a workpiece held or clamped by a robot and an arbitrary working point, without changing a determined position, the working point is defined in a reference coordinate system of the robot. In a teaching operation, the workpiece is held or clamped by the robot with respect to the working point. The workpiece is then rotated about the working point so that the workpiece can assume a desired relative orientation with respect to the working point.
    Type: Grant
    Filed: April 15, 1991
    Date of Patent: June 22, 1993
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Yoshikatsu Minami, Masato Tanaka
  • Patent number: 5222198
    Abstract: The operating range of the conventional multi-axis joint type robot has been restricted, from its structural reason, with .+-.180.degree. for all axes provided. However, recently, expansion of the operating range of robots has been required and improvement in structure and control method of robots has realized expansion of the operating range to under .+-.360.degree.. But, in the case of the robot providing the axis rotating .+-.360.degree. or more, it is sometimes difficult to apply such control methods, resulting in disabling operations. In the present invention, therefore, the signal obtained by adding or subtracting the signal corresponding to the integer number of rotations of the axis to or from the rotating position signal after rotation of the axis depending on the positive or negative sign of the rotating position signal is applied as the rotating position at the time of starting the posture control operation. Since the corrected link angle has a value under .+-.360.degree.
    Type: Grant
    Filed: April 20, 1992
    Date of Patent: June 22, 1993
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Minoru Yamamoto, Satoshi Gosho
  • Patent number: 5187418
    Abstract: A method of controlling an articulated robot having in excess of six axes and up to twelve axes, comprises the steps of dividing the axes into two groups each composed of six axes or less, those axes which are positioned on one side of a dividing point (P) closely to a reference point serving as redundancy axes (11), those axes which are positioned on the other side of the dividing point closely to a robot wrist (Q) serving as basic axes (12), and controlling the dividing point (P), as a first control point, by way of interpolation and controlling the robot (Q), as a second control point, by way of interpolation with the controlled first control point regarded as a new reference point, so that all the axes of the articulated robot can be controlled by way of interpolation.
    Type: Grant
    Filed: September 23, 1991
    Date of Patent: February 16, 1993
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Yoshikatsu Minami, Masato Tanaka
  • Patent number: 5173592
    Abstract: Approximate straight lines or approximate curves at the instructed points are obtained on the basis of coordinates actually passed by a welding torch at the instructed points in the welding of the first layer, points on the approximate straight lines or approximate curves are calculated on the basis of distance at the instructed points, and actual welding path is defined at the points. In the locus of the second and succeeding layers, a shift direction and a shift amount are obtained by calculation on the basis of two points instructed as a welding start point and a termination point in the teaching of the first layer and two reference points designated to define the shift direction, and the locus of operation after the second layer is calculated to effect multi-layer welding.
    Type: Grant
    Filed: October 17, 1990
    Date of Patent: December 22, 1992
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Shinji Okumura, Keiichi Takaoka, Tatsumi Nakazato
  • Patent number: 5162716
    Abstract: First, second, and third compensation signals are generated from the information on the position and speed of the first servo system having a speed control loop as a minor loop. The speed error of the speed control loop of the second servo system which has the speed control loop as a minor loop and uses a signal obtained by sampling the position detection signal, executing a digital calculation process on the sampled signal to obtain a speed signal and integrating the speed signal as a position command signal or a signal obtained by sampling the position detection signal of the first servo system and executing a digital calculation process on the sampled signal as a position command signal is compensated by the first, second and third compensation signals. Thus, even in cases where the acceleration and deceleration of the first servo system are executed even at constant power, positional synchronizing error is not generated.
    Type: Grant
    Filed: March 25, 1991
    Date of Patent: November 10, 1992
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Nobuhiro Kyura, Yoshiji Hiraga
  • Patent number: 5150029
    Abstract: This invention relates to an induction motor magnetic flux operation method in a vector control device in which a primary current is supplied to the induction motor in response to an excitation current command value and a torque current command value and the frequency is controlled on the basis of the magnetic flux operated from the voltage and current applied on the motor, characterized in that, when the magnetic flux is operated on the basis of the voltage, current on the motor and a magnetic flux command signal by using a primary delay circuit, the time constant of the primary delay circuit is set equal to that of the secondary circuit of the motor. According to this invention, it is possible to minimize the phase error with respect to the true secondary magnetic flux included in the secondary magnetic flux value, which leads to an accurate torque control.
    Type: Grant
    Filed: November 17, 1989
    Date of Patent: September 22, 1992
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Eiji Watanabe, Tsugutoshi Ohtani
  • Patent number: 5134354
    Abstract: When a workpiece is cut or otherwise machined by a machine using a servo motor control apparatus having a position feedback loop, a velocity feedback loop, and a current feedback loop, it is the common practice to preset the instructed current value to a voltage corresponding to friction torque when rotation of the motor is started or reversed. This is to compensate for the response delay of the motor introduced by the friction torque. The present invention relates to improvements in this technique. After the instructed motor velocity changes from a positive value, to a negative value or vice versa, or after the detected motor velocity changes from a positive value to a nonpositive value or from a negative value to a nonnegative value, the value of the integration element of a velocity control portion is reversed according to a function. The obtained output value is added to the instructed current value or to the integration term to compensate for the response delay, thus reducing machining error.
    Type: Grant
    Filed: December 3, 1990
    Date of Patent: July 28, 1992
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Yoichi Yamamoto, Takayuki Tohya, Yoshiji Hiraga
  • Patent number: 5128536
    Abstract: An encoder of the invention comprises: an abnormality detecting circuit for detecting an abnormal state of an encoder main body; and a circuit which inverts a part of output signals of the encoder main body and outputs or does not output a part of the output signals of the encoder main body in response to an abnormality detection signal which is output from the abnormality detecting circuit when the encoder main body is abnormal. Thus, the occurrence of the abnormality of the encoder main body can be detected from the outside.
    Type: Grant
    Filed: February 26, 1991
    Date of Patent: July 7, 1992
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventor: Kouichi Higashi
  • Patent number: 5124620
    Abstract: When a welding teaching program employing a plurality of robots is completed, if a robot does not operate properly it may be preferably to make the robot retreat and operate in accordance with a different teaching program, urgently and at an optional timing. In the invention, when the operation of a program being executed is suspended, the program addresses are memorized and a different prestored teaching program is executed. Upon the termination of the different teaching program, the execution of the suspended program is resumed, referring to the memorized addresses.
    Type: Grant
    Filed: August 21, 1990
    Date of Patent: June 23, 1992
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Toshiyuki Kurebayashi, Satoshi Kuranaga, Tatsuya Fukunaga, Osamu Hidaka
  • Patent number: 5119287
    Abstract: A conventional design method intended for repetitive target values utilizes a tracking error of one period before or such a error at the time t' at the preceding trial corresponding to the present time t. The error from the time of one period before up to the present or what is the time t' after has not been utilized, though it is very useful when the present invention uses an algorithm for making the output of a controlled system follow up a periodic target value in an optimum determined manner with only four fundamental arithmetic operations, using an incremental amount of modification at individual sampling time, tracking errors of one period before and thereafter, the present tracking error, the past incremental amounts of modification, the control input of one period before and preset constants.
    Type: Grant
    Filed: April 28, 1989
    Date of Patent: June 2, 1992
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Hiroshi Nakamura, Shigeru Futami
  • Patent number: 5117105
    Abstract: A sequence of random numbers of a desired length is produced using an algorithm for shifting a binary code M bits and adding 0 or 1 so that all produced codes are different from each other. An absolute encoder of a desired resolution is provided using such a sequence of random numbers. Where a slit pattern of M-series random number codes is employed, a circuit for generating a pattern comprising a combination of the M-series random number codes and 0s is employed to provide an absolute encoder having a resolution of 2.sup.k.
    Type: Grant
    Filed: March 7, 1991
    Date of Patent: May 26, 1992
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Takashi Nagase, Kouichi Higashi
  • Patent number: 5083352
    Abstract: According to the present invention, there is provided a tool changing device for a robot comprising a piston reciprocating in a cylinder, a supporting block provided at the distal end of a piston rod, a pair of links interconnecting the supporting block to a pair of cramp members cramping a tool mounting plate.Even in a case where the supply of a pressurized fluid is interrupted during the cramped state, and outside uncramping force is applied to the cramp members, a side surface of each cramp member abuts against a side surface of the supporting block, and the cramping members are thereby held in the cramping state.
    Type: Grant
    Filed: July 1, 1991
    Date of Patent: January 28, 1992
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventor: Toru Nakako
  • Patent number: 5040125
    Abstract: A method of detecting information on an arc welding position by monitoring the shape and/or position of an welding arc. When in the arc welding along a welding groove position while locating the same, the shape of the arc is picked up from above the joint portion of a member to be welded by means of an image pickup device, and the arc shape picked up is binary-coded. This binary arc shape and/or position are monitored to detect the welding groove position, the height of the welding torch, the welding start point, the welding end point, the external corner point, the internal corner point, the contact point of the welding wire with the work, and the welding groove gap.
    Type: Grant
    Filed: June 27, 1990
    Date of Patent: August 13, 1991
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Shinji Okumura, Hiroaki Ito, Seigo Nishikawa, Tatsumi Nakazato
  • Patent number: 5038292
    Abstract: A method of detecting information on an arc welding position by monitoring the shape and/or position of an welding arc. When in the arc welding along a welding groove position while locating the same, the shape of the arc is picked up from above the joint portion of a member to be welded by means of an image pickup device, and the arc shape picked up is binary-coded. This binary arc shape and/or position are monitored to detect the welding groove position, the height of the welding torch, the welding start point, the welding end point, the external corner point, the internal corner point, the contact point of the welding wire with the work, and the welding groove gap.
    Type: Grant
    Filed: June 27, 1990
    Date of Patent: August 6, 1991
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Shinji Okumura, Hiroaki Ito, Seigo Nishikawa, Tatsumi Nakazato
  • Patent number: 4998830
    Abstract: In a device for supporting arm driving shafts, articulating portions of adjacently provided first and second arms constituting a parallel link type robot are rotatably supported, via separately provided bearings, from supporting posts projecting from the robot structure, and the first arm and second arm are also coupled through another bearing. All of these bearings are of a type in which an axial force applied to either one of inner and outer races of the bearing beforehand presses rolling members of the bearing toward the other of the races, while a pressing plate is provided for applying the axial force to one of the bearings. The application of the axial force shifts the supporting frame of the first arm relative to the driving shaft of the second arm, so that all of the bearings are prepressurized for eliminating unnecessary play.
    Type: Grant
    Filed: October 3, 1989
    Date of Patent: March 12, 1991
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Syuichi Tounai, Toshiaki Iwanaga
  • Patent number: 4988945
    Abstract: The rotation type absolute encoder of the present invention is constituted by a magnetic type one-pulse encoder for detecting one or more rotations, and an optical type absolute encoder comprising a plural number of aspheric LED lens as a light source, a group of detecting elements corresponding to the area of the light source, a slit disc beginning from the track of two slits, and a differential input type current-to-voltage convertor. This absolute encoder is also so constructed as to back up the circuit voltage by an external battery and an internal large capacitance capacitor when a current is cut, and has a circuit for serially transmitting a signal indicating the number of rotations and the absolute angle to an external controller, and a circuit for synthesizing and outputting one reference pulse per rotation from the signals of the magnetic type one-pulse encoder and the optical type absolute encoder.
    Type: Grant
    Filed: March 9, 1988
    Date of Patent: January 29, 1991
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventor: Takashi Nagase
  • Patent number: 4951218
    Abstract: Herein disclosed is a method of detecting information on an arc welding position by monitoring the shape and/or position of an welding arc. When in the arc welding along a welding groove position while locating the same, the shape of the arc is picked up from above the joint portion of a member to be welded by means of an image pickup device, and the arc shape picked up is binary-coded. This binary arc shape and/or position are monitored to detect the welding groove position, the height of the welding torch, the welding start point, the welding end point, the external corner point, the internal corner point, the contact point of the welding wire with the work, and the welding groove gap.
    Type: Grant
    Filed: March 7, 1988
    Date of Patent: August 21, 1990
    Assignee: Kabushiki Kaisha Yaskawa Denki Seisakusho
    Inventors: Shinji Okumura, Hiroaki Ito, Seigo Nishikawa, Tatsumi Nakazato