Abstract: Dual light beams directed onto adjacent surface elements defining a seam therebetween produce reflected light images which contact an electro-optic linear array sensor which in turn generates light spot position information for determining seam location via triangulation calculations.

Abstract: An industrial robot in which both a column which is pivotally mounted on a rotatable base member and a boom which is pivotally mounted on the upper end of the column are of hollow construction to provide a rigid lightweight structure capable of carrying substantial loads. The column is counterbalanced by a spring and the boom is counterbalanced by pneumatic cylinders on a movable carriage so that the major axes of the robot can be driven by relatively low energy driving sources. A simplified hand gear train is provided which is capable of carrying substantial loads and is easily serviced.

Abstract: The invention is a wire harness fabrication apparatus for use in the manual fabrication of wire harnesses and as a wire receiving member for use in combination with an automated factory cell. The apparatus is a rotatable cylindrical member with a continuous surface upon which the wire is disposed. The wire is secured to the continuous surface by clamps and the various branches of the harness are defined by further clamps and routing pins. The various lengths of wire are secured to the surface as the cylindrical member rotates about a generally horizontal axis. Upon completion of the fabrication of the wire harness, the cylindrical member is rotated in the opposite direction to remove the wire harness.

Abstract: A control system for manipulator apparatus having a manipulator arm movable in a plurality of axes utilizes resolved compliant motion control to improve servo response characteristics. The position and velocity of the manipulator arm are controlled using load modeling to account for compliance in the arm and to synthesize feedback signals representing movement of a remote point of the arm to provide a loop bandwidth greater than is possible using feedback signals from inner less remote points of the manipulator that are closer to the drive points. The feedback signals are derived using predetermined combinations of force related feedback signals from the axis drive arrangements and position and velocity feedback signals of the manipulator apparatus at points closer to the main drive and support structure of the manipulator and before certain compliant portions of the manipulator arm.

Abstract: The present invention is directed to an improvement for an apparatus which utilizes a preheating step in which the wire heat content of a consumable electrode is increased by means other than the welding current. Thus, the invention provides in combination with at least a first source of electrical power for heating a consumable electrode, a first electrode contact tip having a bore therethrough, a second electrode contact tip having a bore therethrough and a dielectric element having a bore therethrough disposed between the first and second electrode contact tips. The bores are adapted to receive therethrough the consumable electrode for the application of electrical power thereto. The bore of at least one of the electrode contact tips is axially displaced relative to the electrode contact bore of the other electrode contact tip. The invention provides several embodiments whereby either one of the electrode tip bores or the bores of both electrode contact tips are axially displaced.

Abstract: Manipulator apparatus is provided with an energy efficient control arrangement. The control arrangement in a point-to-point mode of operation utilizes a servo valve to selectively admit fluid from a pressurized source to one end of a cylinder. A piston is slidably mounted within the cylinder and connected to move a manipulator arm that is movable in a plurality of axes. The servo valve is closed when a predetermined arm velocity is reached and a bypass valving arrangement is opened to interconnect the ends of the cylinder. At a predetermined position of the manipulator arm, the control arrangement closes the bypass valving arrangement and the manipulator arm is decelerated as the arm approaches the desired final position.

Abstract: Control apparatus for manipulator welding apparatus is provided that includes a vision correction system for workpiece sensing. During an initial teach mode, the manipulator is taught the desired welding path on a workpiece and data is recorded representing the welding path relative to a frame of reference defined by the workpiece. In addition to the data representing the taught welding path and the frame of reference, data representing one or more reference images or templates are also recorded in the teach mode. As successive workpieces are presented to the manipulator for performing the desired welding path, the control apparatus in a repeat work cycle mode is first controlled to measure and define the new location and orientation of the frame of reference in accordance with the workpiece. The new frame of reference data is utilized to modify the path data.

Abstract: A combined image sensing and welding torch hand is provided for programmable manipulator welding apparatus. During a sensing operation the sensing components emerge from a protective enclosure which surrounds the welding torch and move linearly downwardly to a sensing position outside the protective enclosure. During the welding operation, the sensing components are retracted back into the protective enclosure and staging doors, which are pivotally mounted on the bottom edge of the protective enclosure are closed so as to completely shield the sensing components from welding fumes and splatter. In addition, when the sensing assembly is in the retracted position within the protective housing, air under pressure is supplied to the interior of the enclosure to provide a purge during the welding cycle and prevent fumes from entering the enclosure and damaging the optical components of the sensing assembly.

Abstract: There is provided a method of detecting any positional deviation of a workpiece from a reference position with the aid of an image sensor. First, a sample workpiece is put at the predetermined position, and is detected by the image sensor to provide reference image information. Likewise, a workpiece under inspection is detected by the image sensor to provide workpiece image information. The reference information is subjected to a parallel transformation and/or rotation and is compared with the workpiece image which remains in the original state, to detect the correlation degree between the two sets of information. The detection of the correlation degree is repeated for each incremental parallel transformation and/or rotation of the reference information.

Abstract: A control system is provided for servo controlled apparatus such as a programmable manipulator having a manipulator arm movable in a plurality of axes. The control system provides improved dynamic performance and control of the manipulator arm over a wide range of arm loads, dynamic operating parameters of the arm and over the full range of operating positions. The control system for one or more of the controlled axes includes servo control loops utilizing various feedback signals. In one arrangement, an inertia correlated signal provided as a pressure signal from a hydraulic actuator of an appropriate axis is utilized in combination with a function generator circuit to provide variable inertial scaling of selected loop command signals. The axis utilized for the pressure signal is determined by the mounting of the manipulator apparatus so as to provide a signal correlated to the inertial mass system of the manipulator arm.

Abstract: Manipulator apparatus with weld seam tracking capabilities is provided with a sensing hand attached to the manipulator arm. The manipulator apparatus traverses a taught welding path on a workpiece to determine any deviation between the workpiece path and the taught path. The sensing hand includes a projection unit for projecting an optical slit pattern onto the workpiece. The sensing hand also includes a path sensing unit including an objective lens and a fiber optic cable for receiving by reflection from the workpiece the projected optical slit pattern. The fiber optic cable is connected to a camera located remotely from the sensing hand. The image received by the camera is utilized by the manipulator apparatus to determine the deviation between the path traversed by the manipulator during sensing and the sensed workpiece path. The deviation is then utilized to calculate the workpiece path data.

Abstract: A weld gun mounted on the end of the manipulator arm of a programmable manipulator is repositioned with respect to the initially taught path in accordance with variations in the dimensions of successive workpieces on which a series of spot welds are to be made.A sensing means carried by the weld gun is employed to measure the position of the welding tips relative to the edge of the flanges which are to be welded. The output of this sensing means is employed to reposition the weld gun prior to the next weld. Repositioning may be accomplished by moving the weld gun bodily with respect to the end of the manipulator arm while the manipulator arm remains stationary at the taught position, or by modifying the command signal for the appropriate axis so that the manipulator arm is itself moved to a different position than the initially taught position.

Abstract: A programmable manipulator is provided in which the manipulator arm is counter-balanced in all of its major axes and these axes are provided with low friction joints so that a relatively small force is needed to move the arm in each of its principal axes. A separate low power driving source is then used to move the arm during the teaching operation, this low power driving source being capable of developing the relatively small force needed to move the arm at low speed during the teaching operation, but being incapable of moving the arm at high speed or exerting a torque on said arm which will be potentially harmful to programming personnel. After the desired path has been taught, the manipulator apparatus is switched over to a playback mode wherein a second relatively high power source is employed to move the arm at relatively high speed during successive playback cycles.

Abstract: A sequence of or controls pulse-transfer stages supplies or controls pulses between a start limit and a stop limit in the sequence. The device whose position is to be encoded selects and controls a responsive means in a limiting stage. Each stage has a pulse-control device responsive to the selector or in itself incorporates the selector-responsive pulse-control function, being arranged to serve in different embodiments as a start limit or as a stop limit. In one example, the start limit is the initial stage of the sequence and the selected stage is the stop limit. In an alternative, the selected stage is the start limit and a pulse-transfer stage at or near the end of the sequence is the stop limit. An encoding counter counts pulses between the start and stop limits. The pulse-control devices have a prescribed physical arrangement, which is a circle in the case of a shaft position encoder, so that the counter provides a code that represents the position of a shaft.

Abstract: Control apparatus for manipulator welding apparatus is provided that includes a vision correction system for workpiece sensing. During an initial teach mode, the manipulator is taught the desired welding path on a workpiece by the appropriate recording of data representing the welding path as an operator controls movement of the manipulator. In addition to the data representing the taught welding path, data representing a reference image or template is also recorded in the teach mode. The reference image or template data is provided by a vision system including a camera carried by the manipulator arm. As successive workpieces are presented to the manipulator for performing the desired welding path, in a repeat work cycle mode the manipulator is controlled to move in accordance with the recorded taught data in a first repeat pass wherein images of the welding seam region are detected at successive points.

Abstract: A control system is provided for a programmable manipulator having an arm movable in a plurality of axes that results in improved dynamic performance and control of a manipulator arm over a wide range of arm loads, dynamic operating parameters of the arm, and over the full range of arm operating positions. The control system for one or more of the controlled axes includes several servo control loops utilizing force or pressure feedback from the axis actuators and variable inertia scaling of selected loop command signals and loop parameters. The variable inertia scaling in accordance with the inertia of the arm provides improved dynamic performance of the manipulator arm while maintaining stable servo-loop operation over a wide range of operating parameters. In a preferred arrangement, the variable inertia scaling is accomplished by the use of a look up table with appropriate interpolation of the table entries.

Abstract: An automatic arc welding machine having a welding torch adapted to be placed against a workpiece and a monitoring sensor such as an image taking tube for sensing the workpiece. The operation of the sensor is so controlled that it is operated when the welding current to the torch is interrupted or decreased so that any effect of welding arc on the image taking tube can be avoided.

Abstract: Teach assist apparatus is provided for a programmable manipulator arm to precompute a projected fixed path solution during an initial teaching operation. The projected fixed path solution represents a desired series of manipulator arm work operations to be performed with respect to a workpiece in the minimum execution time while the workpiece is moving at a projected velocity. During the teaching operation, the manipulator arm is moved to various teach positions corresponding to the desired series of work operations relative to the workpiece. The teach assist apparatus computes the minimum execution time on the basis of the maximum dynamic capabilities of the manipulator arm being taught. The precomputed path data is stored and control apparatus is provided to reconstruct the precomputed fixed path solution in a playback work cycle in accordance with dynamic movement of the workpiece.

Abstract: An automatic arc welding machine includes a work monitoring device comprising a light source for projecting a light to the workpiece and an image taking device which receives the light as reflected by the workpiece. The light source is so controlled in accordance with the operation of the image taking device that the average intensity of the projected light is increased when the image taking device is in operation. The arrangement is effective to increase the signal-to-noise ratio.

Abstract: The invention discloses a digital position instruction signal modification device for use with a memory controlled manipulator apparatus of the type in which, during a teaching operation, a desired position of manipulator arm means is stored in memory means, and the stored position is read out during repetitive work cycles to cause the manipulator apparatus to reproduce a series of motions taught during the teaching operation. The digital position instruction or command read out from the memory means may be modified by a modifying value entered by a modifying value setting device so that all or desired digital position command or instruction signals stored in the memory means may be modified without repeating the teaching operation.