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Publication numberUS3835750 A
Publication typeGrant
Publication dateSep 17, 1974
Filing dateMay 14, 1973
Priority dateMay 14, 1973
Publication numberUS 3835750 A, US 3835750A, US-A-3835750, US3835750 A, US3835750A
InventorsM Dunne
Original AssigneeUnimation Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Record-playback manipulator system utilizing hydraulic microbit actuators
US 3835750 A
Abstract
A pulse generator common to all of the controlled axes of the manipulator arm is employed to develop a stream of pulses which may be selectively applied to the count up or count down lead of a bidirectional counter. Individual stages of the counter control individual pressure sensitive hydraulic actuators which are arranged in a series and have binary related strokes. Accordingly, the arm is moved in each axis in response to the pulse stream and at a rate corresponding to the rate of occurrence of pulses in said stream during the initial teaching operation. A series of limit switches are employed to detect the physical position of the series of actuators during the repeat mode of operation of the manipulator. These limit switches are also employed to set each bi-directional counter to an initial setting corresponding to the physical position of the arm on start up so that undesired movement of the arm at start up time is avoided.
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United States Patent [1 1 Dunne [451 Sept. 17, 1974 RECORD-PLAYBACK MANIPULATOR SYSTEM UTILIZING HYDRAULIC Primary ExaminerEdgar W. Geoghegan I Assistant ExaminerA. M. Zupcic MICROBIT ACTUATORS Attorney, Agent, or FirmMason, Kolehmainen, [75] Inventor: Maurice J. Dunne, Fairfield, Conn. Rathbum & wyss [73] Assignee: Unimation, lnc., Bethel, Conn. 57 ABSTR CT A [22] Filed: May 14, 1973 1 A pulse generator common to all of the controlled [21] Appl 359697 axes of the manipulator arm is employed to develop a stream of pulses which may be selectively applied to [52] US. Cl. 91/35, 91 /167 the count up or count down lead of a bidirectional [51] Int. Cl. Fl5b 11/18 counter. Individual stages of the counter control indi- [58] Field of Search 91/35, 36, 37, I67, 361, vidual pressure sensitive hydraulic actuators which are 91/363 arranged in a series and have binary related strokes.

1 Accordingly, the arm is moved in each axis in response to the pulse stream and at a rate corresponding [56] Referen Cited to the rate of occurrence of pulses in said stream dur- UNITED PATENTS ing the initial teaching operation. A series Of limit switches are employed to detect the physical position w g of the series of actuators during the repeat mode of 3:125856 341964 /363 R operation of the manipulator. These limit switches are 1141:3138 7/1964 Brandstadter 91/167 also employed to set each bi-directional counter to an 3,162,365 12/1964 Gizeski 91 I167 initial Setting corresponding to the P y Position of 3,550,630 12/1970 Panissidi 91/35 the arm on start up so that undesired movement of the 3,661,051 /1972 Dunne 91/35 arm at start up time is avoided.

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I4 l Is 2s 34 36 l I 20 74 l I TEACH CONTROLS IZ I 5 66 g? l I w gyr COUNT UP l I PM 2 2 2 2 I r m COUNT] DOWN I Lf ii li il i fi J so 52 F h 4 g ROEPEAT -l SWIVEL AXIS 82 PULSE g SHAPER TEACH 8 J2 {IVHIIYIELSWITCHES H DOWN-UP AXIS I L-- DOWN-UP LIMIT SWITCHES I k h a 92 BEND AXIS I BEND LIMIT SWITCHES I 94 -I ROTARY AXIS I I ROTARY LIMIT SWITCHES RECORD BUTTON RECORD-PLAYBACK MANIPULATOR SYSTEM UTILIZING HYDRAULIC MICROBIT ACTUATORS The present invention relates to manipulator apparatus and, more particularly, to an improved arrangement for providing both record and playback facilities in a manipulator apparatus of the type which employs hydraulic microbit actuators.

In certain types of manipulator apparatus heretofore proposed, it is contemplated that the actuator for controlling each controlled axis of the manipulator arm will each comprise a series of fluid pressure actuators which are mechanically connected to one another and arranged with binary related strokes so that a binary code command signal can be applied bit by bit to different hydraulic actuators in the series, thereby eliminating conventional digital to analog converters, etc. One such arrangement is shown in Devol US. Pat. No. 3,476,266 wherein a series of fluid-pressure actuators, each having an extended state and a contracted state, are operable in various combinations to provide arelatively high power driving output by collectively changing in overall size. While the arrangement shown in Devol US. Pat. No. 3,476,266 is suitable for its intended purpose, it proposes to employ a manually operable drum for each of the controlled axes of the manipulator arm and presumably each of these drums is motor driven during the teaching operation to move the manipulator arm to different desired points to accomplish a certain programmed series of steps. Furthermore, in the arrangement shown in the DeVol patent, no facilities are provided for insuring that the manipulator arm does not move wildly about when power is first applied to the manipulator apparatus on startup. Such an arrangement can be extremely dangerous to personnel using the apparatus in the event that the pre viously programmed step calls for movement of' the arm in a path which would strike the operator as he starts to perform a new teaching operation, or in the event that he is in the area covered by the movement of the arm on startup on that particular morning.

It is, therefore, an object of the present invention to provide a new and improved recording or teaching arrangement for use in a manipulator apparatus of the type which utilizes hydraulic microbit actuators as power sources for moving the manipulator arm in its various controlled axes.

It is a further object of the present invention to provide a new and improved teaching arrangement for a manipulator apparatus of the type utilizing hydraulic microbit actuators wherein facilities are provided for controlling the series of hydraulic actuators in each axis to prevent unexpected or undesired movement of the arm on startup.

It is another object of the present invention to provide a new and improved record-playback arrangement for manipulator apparatus of the type utilizing hydraulic microbit actuators wherein a pulse source common to all axes is employed to control a series of electronic counters which in turn control selective actuation of each series of hydraulic microbit actuators to effect desired movements of the arm in each of its controlled axes during the initial teaching operation. I I

It is another object of the present invention to provide a new and improved record-playback arrangement for manipulator apparatus of the type employing hy draulic microbit actuators wherein the position of the manipulator arm in each controlled axis is detected by employing limit switch means associated with each actuator in each series, the output from said limit switch means being employed to immediately set an electronic counter which isemployed to control actuation of the microbit actuators during both the teaching operation and subsequent playback operations.

Briefly, in accordance with one aspect of the invention, a common pulse source is employed to control counting in either direction of a series of electronic bidirectional counters which are provided for each controlled axis of the manipulator arm. A stream of pulses from this common pulse generator may thus be selectively applied to either the up-lead or down-lead of each counter so as to move the manipulator arm to a desired position during the initial recording or teaching operation. When the desired position is reached, the output of each counter is recorded on a suitable memory drum and this recorded signal may then be employed during successive playback operations as a command signal to control movement of the manipulator arm to the desired position in each of the controlled axes thereof. On playback, the recorded signal is applied in parallel to the same electronic counter which is employed to control movement of the arm during the record or teaching operation and the binary related outputs of each counter areemployed to control solenoid operated valves which in turn control actuation of the series of fluid pressure sensitive actuators which form each hydraulic microbit actuator of the manipulator apparatus. On playback, the recorded memory drum signal is also applied to one input of a comparator to the other input of which is supplied the binary code combination of limit switch means associated with each actuator in the series. Furthermore, all of the controlled axes of the manipulator may be sequentially scanned during a multiplex cycleso that only a single comparator is required to provide the desired total coincidence signal which signifies that the next programmed step in the memory drum should be selected.

The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawings in which:

FIG. 1 is a schematic diagram, partly in block diagram form, of the control system arrangement of the present invention for one of the controlled axes of a programmable manipulator arm, shown during the initial teaching or recording operation;

FIG. 2 is a similar circuit diagram of the apparatus of FIG. 1 but shown in the playback or repeat mode; and

FIG. 3 is a schematic diagram of one of the stages of No, 3,661,051, wherein the manipulator arm is movable in a 'number'of controlled axes by means of hydraulic actuators under the control of command signals which are sequentially read from a memory drum, or the like. In said Dunne et al patent the hydraulic actuators are of the simple piston and cylinder type and are controlled by suitable solenoid operated valves, these valves in turn being controlled by means of a comparator system which compares the binary coded output from an encoder geared to the movable member of the hydraulic actuator with a related binary code command signal from the memory drum.

In the arrangement of the present invention, a different type of hydraulic actuator is employed, which may be termed an hydraulic microbit actuator, and is of the type shown in Devol U.S. Pat. No. 3,476,266. One of these microbit actuators is shown generally in FIG. 1 at as comprising a series of fluid pressure actuators which have different binary related strokes so that binary coded signals may be applied directly thereto to establish a predetermined distance. More particularly, the microbit actuator 10 comprises a first cylinder portion 12 which is secured to an end flange 14 of the actuator. A movable piston 16 is slidably mounted in the clyinder 12 and is controlled by means of a two-way solenoid operated valve 18, the valve 18 being supplied from a suitable source of fluid pressure 20 and exhausting to a suitable sump 22. The stroke of the piston 16 is chosen to be equal to the smallest unit of movement of the manipulator arm and the piston 16 is integrally attached to the cylinder 24 of the next unit in the series of fluid pressure actuators. A piston 26 is slidably mounted within the cylinder 24 and is controlled by means of the two-way solenoid operated valve 28, the valve 28 being supplied with pressure from the same pressure source 20 and exhausting to the same sump 22. The stroke of the piston 26 is exactly twice that of the piston 16, so that binary related motions of the overall actuator may be achieved by controlling thesolenoid operated valves 18 and 28 in accordance with the binary input.

The piston 26 is integrally connected to the cylinder portion 30 of the next series related fluid pressure actuator, a piston 32 being slidably mounted within the cylinder 30 and having a stroke equal to twice that of the piston 26. A similar two-way solenoid operated valve 34 is employed to control movement of the piston 32 from one end of the cylinder 30 to the other.

In a similar manner an additional number of fluid pressure actuators may be connected in series to the illustrated units, the piston of the end one of these actuators being connected to the end flange 36 of the overall hydraulic microbit actuator. The flanges 14 and 36 are attached to fixed and movable portions of the mechanism employed to move the manipulator arm in a particular axis, as described in detail in said Dunne et a] patent and in Devol U.S. Pat. No. 3,476,266.

In accordance with an important feature of the present invention, a series of limit switches are associated with individual ones of the series of fluid pressure actuators in the microbit actuator 10 and are employed to provide feedback information indicative of the actual position of the actuator 10 at any particular moment. More particularly, a microswitch 38 is secured to the cyclinder l2 and the contacts thereof are arranged to be closed by engagement with the left-hand edge of the cylinder 24 when the piston 16 is in its left-hand-most position as shown in FIG. 1. However, when'the piston 16 is actuated to the other end of the cylinder 12, the contacts of the microswitch 38 are opened. In a similar manner, microswitches 40 and 42 are associated with the cylinders 24 and 30 respectively and additional microswitches are associated with each of the other binary related fluid pressure actuators in the series making up the acutator 10. Accordingly, on the output conductors 44, 46 and 48, of the microswitches 38, 40 and 42, respectively, output signals appear in accordance with the on or off condition of these microswitches which represent the physical position of the pistons within the individual cylinders of the microbit actuator. In this connection it will be understood that a common connection (not shown) may be employed for one side of all of these microswitches or in the alternative one side of each microswitch may be connected to ground through the illustrated cylinder and piston arrangement.

In accordance with a further important feature of the present invention, an oscillator 50 is provided which is common to all of the five illustrated axes of the manipulator apparatus, the output of the oscillator 50 being supplied to a suitable pulse shaper 52 so that pulses suitable for actuation of the electronic bi-directional counter are provided. These pulses are supplied through a teach-repeat switch 54 to a pair of teach control switches 56 and 58 when the switch 54 is in the teach position. When the switch 54 is in the repeat position no pulses are supplied to the teach controls 56 and 58. However, when the apparatus is in the teach position one of the push buttons 56 may be closed, for example, the button 56, in which case a stream of pulses is supplied to the count up lead 60 of an electronic bi-directional counter made up of a series of binary related stages 62, 64, 66, etc. On the other hand when the push button 58 is depressed this same stream of pulses is supplied over a count-down input lead 68 to a different input of the stages of the bi-directional electronic counter. The electrical output of each stage of this counter is employed to control a suitable solenoid which actuates an associated two-way valve to control the position of the piston in the associated section of the microbit actuator 10. Thus, the output of the first stage 62 is supplied to a solenoid 70 which controls movement of the two-way valve 18. The output of the stage 64 is supplied to a solenoid 72 which controls the valve 28 and the output of the stage 66 is supplied to a solenoid 74 which controls the valve 34.

The teach control arrangement described thus far is provided for the out-in axis of the manipulator apparatus. In accordance with a further feature of the invention, the common pulse source 52 is employed to supply a stream of pulses to similar control apparatus for each of the other controlled axes of the manipulator. Thus, these pulses are supplied during the teaching mode through the switch 54 to similar apparatus, indicated generally at for the swivel axis of the manipulator arm, the positions of the various sections of the microbit actuator associated with this axis, which is similar to the microbit actuator 10, being provided on the limit switch output conductors 82. In a similar manner, the pulses from the shaper 52 are supplied to the control apparatus 84 for the down-up axis, to the apparatus 86 for the wrist bend axis and to the apparatus 88 for the rotary axis of the manipulator apparatus. Each of the microbit actuators associated with these different axes produce output signals which are supplied to the conductors 90, 92 and 94, respectively. A pair of directional control push buttons, similar to the push button 56 and 58, is provided for each of the other four illustrated axes of the manipulator apparatus so that a stream of pulses from the common pulse shaper 52 may be supplied to either desired input of the electronic counter provided for each of these axes, as described in detail heretofore in connection with the out-in axis. Accordingly, during the teaching mode when it is necessary to move the manipulator arm to a desired position and record this position as a command signal on the associatedmemory drum of the manipulator apparatus, the push buttons 56, 58 in each of the controlled axes are selectively actuated by depressing the same a length of time necessary to cause the manipulator arm to move in that controlled axis by the required distance, as visually determined by the teaching operator by visual inspection of the position of the manipulator arm.

Thus, if it is desired to move the arm a certain distance in the out direction, the button 56 is depressed and a stream of pulses is supplied over the lead 62 to step the electronic'counter comprising the stages 62, 64, etc. As this counter is stepped to successively higher counts in response to each of the input pulses, the associated solenoids 70, 72, 74, etc. control their associated two-way valves 18, 28 and 34 so that the various sections of the microbit actuator are moved so that an overall movement in the out direction is produced at a rate determined by the rate of occurrence of the pulses developed by the pulse shaper 52. In this connection it will be understood that this pulse rate is chosen so that the manipulator arm will be moved smoothly to the desired position at a rate sufficiently slow that the operator is permitted by visual inspection to determine when the end of the manipulator arm has arrived at the desired position. It is also contemplated that the frequency of the oscillator 50 may be varied by any suitable means well known in the art so that various slewing rates in the controlled axes of the manipulator apparatus may be provided. For example, in an actuator 10 having ten binary related sections the smallest of which has a stroke of 0.1 inches, a pulse rate of 100 pulses per second may be employed to provide a fast slewing rate during the initial phase of movement of the arm during the teaching operation and a slow-down operation may be effected by simply changing the frequency of the oscillatorl50 to 10 pulses per second as the end of the arm approaches the desired end position. When the end of the manipulator arm has been programmed in all of the five controlled axes of the apparatus, the main record button 96 of the manipulator apparatus is closed so that the outputs from all of the limit switches in each controlled axis are supplied through the transfer control panel 98 to a shift register and may be supplied to the recording heads of the associated memory drum of the manipulator apparatus, as described in detail in said Dunne et al patent. Reference may be had to said Dunne et al patent for a complete and detailed description of the manner in which the recording of these signals during the teaching operation is effected. Accordingly, the desired positions of the manipulator are, as represented by the limit switches associated by each of the microbit actuators 10, are simultaneously recorded as command signals in the memory drum of the manipulator control apparatus for each desired position of the manipulator arm, it being noted that the microswitch signals take the place of the digital encoder signals provided in the arrangement described in detail in said Dunne et al patent. These limit switches thus provide in a simple and economical manner a feedback or encoder signal representative of the actual physical position of the microbit actuator 10 which in turn represents the position of the manipulator arm in that controlled axis.

Considering now the operation of the arrangement of the present invention during the playback or repeat mode of operation of the manipulator apparatus, and referring to FIG. 2, during playback no pulses are supplied to the input leads 60, 68 of the electronic counter. However, this counter is arranged so that any desired binary number may be set into the counter by means of binary related signals applied in parallel to separate 1 and 0 inputs of each stage of the counter, this type of electronic counter being conventionally referred to as a presettable down-up counter. More particularly, the binary coded command signal, which is derived from the memory drum and is stored in a temporary buffer storage register indicated generally at 100, is supplied to the individual stages of the electronic counter over the indicated conductors 102, 104, 106, etc. In this connection it will be understood that the manner in which the command signal is read from the memory drum and stored in the buffer register is described in detail in said Dunne et al patent, and reference, may be had to the specification of said patent for a more complete understanding of this readout arrangement. A second section of the repeat cycle switch 54 is arranged to supply an enabling signal over the conductor 108 to all of the stages of the electronic counter, as will be described in more detail hereinafter in connection with FIG. 3. Accordingly, the command signal corresponding to the first programmed step in the recorded program is supplied on an individual bit basis to the individual stages of the electronic counter and the solenoids 70, 72, 74, etc. associated with these stages are immediately energized in accordance with the individual bits of the first command signal binary number so that the microbit actuator 10 in energized to move the manipulator arm to the desired position. The command signal corresponding to the first out-in command of the recorded program is also supplied by way of the conductors 102, 104, 106, etc. to one section of a multiplex scanning switch indicated generally at 110, the common output of this switch being supplied at one input to the comparator 112. Also, the output signals derived from the limit switches 38, 40 and 42, etc. are supplied by way of the conductors 44, 46 and 48, to one input 114 of a second multiplex scanning switch indicated generally at 116, the common output of this switch being supplied as the other input of the comparator 112. A distributor scanning switch 118 is provided at the output of the comparator 112 and successively provides comparator output signals to a series of flip-flops 120, 122, 124, 126, and 128 corresponding to the five controlled axes of the manipulator apparatus, the uppermost flip-flop 120 corresponding to the illustrated out-in controlled axis of the manipulator. Accordingly, when the manipulator arm has been moved to the desired position as indicated by coincidence of the command signal developed on the conductors 44, 46 and 48, a comparator output signal is employed to set the flip-flop 120 thereby indicating that movement in the out-in axis has been completed. In a similar manner the scanning switches 1 10, l 16 and 118 are successively connected to different command and limit switch signals on the input side of the comparator and control the corresponding flip-flop ,on the output side of the comparator 112 so that movement in all five controlled axes is monitored as these scanning switches are rotated. When all five of the flip-flops 120 to 128, inclusive, are set, a five input ANDgate 130 is arranged to develop an output signal which is supplied to a total coincidence AND-gate 132 to which other output signals such as wait external, etc. may be supplied. A total coincidence signal is thus developed on the output conductor 134 when movement in all of the controlled axes and any other options have been completed, as described in detail in said Dunne et a1 patent. In this connection it will be understood that the output of the AND-gate 130 may be employed as an accuracy No. 1 signal and suitable accuracy 2 and accuracy 3 coincidence circuits employed, if desired, as described in said Dunne et al patent, it being noted that the comparator 112 corresponds to the comparator 422 shown in said Dunne et al patent and may be associated with a suitable digital analog converter (not shown), corresponding to the converter 456 of said Dunne et al patent, to provide suitable output signals for the flip-flops 120 to 128, inclusive. In this connection it is also noted that gray to binary code converters may be employed between the multiplex switches 110 and 116 to the inputs of the comparator 112, as described in detail in said Dunne et al patent.

When a total coincidence signal is developed on the conductor 134, the manipulator control apparatus is arranged to sense another command signal recorded in the associated memory drum and the next command signal is supplied to the buffer register 100, as described in detail in said Dunne et al patent. Accordingly, this next command signal is set into the individual stages of the electronic counter associated with the outin axis, as described in detail heretofore, and the microbit actuator is moved to the desired position corresponding to this command signal. Coincidence is again indicated by a comparison of the limit switch signals with this command signal, as described in detail heretofore. In a similar manner command signals are supplied to all of the other four controlled axes of the apparatus, one such controlled axis being shown in FIG. 2 as the wrist swivel command signal 136 and its associated apparatus 138, the limit switch output and command signal output of the apparatus 138 being supplied to the second level of the multiplex scanning switches 110 and 116.

From the above description it will be understood that the manipulator arm is moved to successive positions as determined by the binary coded command signals set into the electronic counters associated with each of the controlled axes of the manipulator. It will also be noted that the manipulator arm is left in a position corresponding to the last command signal when the apparatus is turned off and power is removed from the microbit actuators 10. If a teaching operation is to be performed as soon as the apparatus is turned on the next morning, the manipulator arm will immediately be moved to the position corresponding to the command signal previously set into the electronic counter when power is supplied to the hydraulic microbit actuators 10 on start-up. Accordingly, it is possible that the teaching operator may be injured if the manipulator arm is not otherwise controlled on start-up. To prevent such a condition, each stage of each one of the electronic counters provided for each of the five controlled axes is arranged also to be controlled from a start-up pulse which is generated at the time power is initially supplied to the microbit actuators 10 and the presettable electronic counter is immediately set to the actual physical position of each of these actuators on start-up by employing the limit switch signals directly as input signals in place of the conventional command signals derived from the memory drum.

More particularly, each of the stages of the presettable electronic counter, such as the first stage shown in FIG. 3 of the drawings, is provided with a pair of AND- gates and 142 to one input of which an enabling pulse is supplied over the conductor 144 whenever the manipulator apparatus is initially energized and power is supplied to the microbit actuators 10. The signal from the limit switch 38 is applied directly as the other input of the AND-gate 140 and through an inverter 146 as the other input of the AND-gate 142. Accordingly, as soon as an enabling pulse is developed on the conductor 144 an output is derived from either the AND- gate 140 or the AND-gate 142 and is supplied through the corresponding one of the OR-gates 148 or 150 to either the set 1 or the set 0 terminal of the initial stage of the presettable electronic counter. In a similar manner, each of the other stages of this counter is immediately set to a position corresponding to one of the other limit switches 40, 42 when an enabling pulse is developed on the conductor 144. Accordingly, as soon as the manipulator apparatus is energized and power is supplied to the microbit actuators 10, the limit switch signals are employed to set the presettable electronic counter to the actual physical position of the arm on start-up so that no movement of the manipulator arm can'occur. Either a teaching operation or a playback operation may now proceed without fear of being injured by initial movement of the manipulator arm on start-up.

Assuming that a teaching operation is performed after start-up, as soon as the teaching operation is completed and the teach-repeat switch is thrown to the repeat position, an enabling pulse is developed on the repeat conductor 108. This pulse is supplied as one input to a second pair of AND-gates 152 and 154. The memory drum command signal on the conductor 102 is applied directly to the AND-gate 152 and through an inverter 156 to the AND-gate 154 so that an output is supplied to the set 1 or set 0 terminal of this stage of the presettable counter. In a similar manner, the other stages of each counter are set by the signals on the conductors 104, 106, etc. The manipulator arm is then moved to the programmed position, as described in detail heretofore. In this connection, it is noted that an enabling pulse is supplied to the conductor 144 only on start-up and hence the application of the limit switch signals to the AND-gates 140 and 142 is ineffective to modify the operation of the apparatus during the repeat mode of operation.

While there has been illustrated and described a single embodiment of the present invention, it will be apparent that various changes and modifications thereof will occur to those skilled in the art. It is intended in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the present invention.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. In a programmed manipulator, the combination of, a manipulator arm, power actuator means for moving said arm simultaneously along a plurality of axes, each of said power actuator means comprising a plurality of actuators, driving energy supply means, and selectively operable elements for controlling the supply of driving energy to said actuators, said actuators each having an extended state and a retracted state and adapted to be driven by the driving energy of said supply means for assuming or maintaining either of said states in accordance with the selective operation of said elements, said actuators being fastened to one another to effect driving operation in either direction, means for detecting the expanded or retracted position of each of said actuators and developing an electrical position signal corresponding thereto, presettable electronic counter means for controlling said elements, and means for supplying said electrical position signals to said counter means to provide an initial setting of said counter means corresponding to the expanded or retracted states of each of said actuators.

2. The combination of claim 1, which includes switch means for selectively supplying said electrical signals to said counter means, and means responsive to the application of driving energy to said actuators for actuating said switch means, thereby to set said counter means to an initial setting corresponding to the expanded or retracted states of said actuators at the time said driving energy is applied thereto.

3. The combination of claim 1, wherein said detecting means comprises a series of limit switches individually positioned to be operated by the movable member of one of said actuators, and means controlled by said limit switches for presetting the individual stages of said counter means.

4. The combination of claim 1, wherein said counter means has count up and count down inputs, means for developing a stream of pulses occurring at a predetermined rate, and teach control means for selectively supplying said pulses to either said count up input or said count down input of said counter means to increase or decrease the count therein, thereby to cause said manipulator arm to be moved smoothly by said actuators to a desired position along one of said axes.

5. The combination of claim 4, wherein said detecting means comprises a series of limit switches individually positioned to be operable by the movable member of one of said actuators, a memory storage arrangement, and means for recording the condition of said limit switches when said manipulator arm has been moved to said desired position.

6. The combination of claim 5, which includes playback means utilizing said recorded limit switch conditions as a command signal and also as a presetting signal for said counter means, and comparator means jointly responsive to said command signal and the respective conditions of said limit switches for developing a total coincidence signal when said limit switch conditions all correspond to said command signal.

7. In a programmed manipulator, the combination of, manipulator arm, power actuator means for moving said arm simultaneously along a plurality of axes, each of said power actuator means comprising a plurality of actuators, driving energy supply means, and selectively operable elements for controlling the supply of driving energy to said actuators, said actuators each having an extended state and a retracted state and adapted to be driven by the driving energy of said supply means for ments are controlled in accordance with the respective digits of said first command signal, comparing means jointly responsive to said first command signal and said detecting means for developing an output signal when the electrical signals developed by said detecting means correspond to the respective digits of said first command signal, and means responsive to said output signal for selecting the next command signal in said series and supplying the same to said counter means and said comparing means.

8. The combination of claim 7, which includes means for sequentially connecting said comparing means to different command and position signal combinations corresponding to movement in different ones of said axes during different periods in a repetitive multiplex scanning cycle.

9. The combination of claim 8, which includes a series of flip-flop circuits one for each of said axes, means for distributing the output of said comparing means to different ones of said flip-flop circuits during different periods of said scanning cycle, and means controlled by said flip-flop circuits for developing a total coincidence signal when all of said flip-flop circuits have been set in response to the output of said comparing means.

10. In a programmed manipulator, the combination of, a manipulator arm, power actuator means for moving said arm simultaneously along a plurality of axes, each of said power actuator means comprising a plurality of actuators, driving energy supply means, and selectively operable elements for controlling the supply of driving energy to said actuators, said actuators each having an extended state and a retracted state and adapted to be driven by the driving energy of said supply means for assuming or maintaining either of said states in accordance with the selective operation of said elements, said actuators being fastened to one another to effect driving operation in either direction, an electronic counter corresponding to each of said controlled axes and each having a count up and a count down input, means common to said axes for developing a continuous stream of pulses, and teach control means for selectively applying said stream of pulses to either the count up input or count down input of said counters, thereby to cause said manipulator arm to be moved smoothly to a desired position, and means for recording said desired position of said arm once it is achieved.

11. The combination of claim 10, wherein said last named means includes a series of limit switches individually associated with the actuators of each of said power actuator means and arranged to develop an electrical signal corresponding to its physical position thereof.

Patent Citations
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4460324 *Apr 23, 1981Jul 17, 1984Prince CorporationShot cylinder controller for die casting machines and the like
US4607998 *Feb 15, 1983Aug 26, 1986Deep Ocean Engineering IncorporatedElectromechanical manipulator assembly
US4904933 *Sep 8, 1986Feb 27, 1990Tektronix, Inc.Integrated circuit probe station
US5000649 *Aug 22, 1986Mar 19, 1991Deep Ocean Engineering IncorporatedElectromechanical manipulator assembly
EP0062070A1 *Oct 7, 1981Oct 13, 1982Fanuc Ltd.Device for operating hand of industrial robot
EP0068768A2 *Jun 21, 1982Jan 5, 1983Fanuc Ltd.System for controlling an industrial robot
Classifications
U.S. Classification91/35, 901/49, 901/22, 91/167.00R, 901/13, 901/5
International ClassificationG05B19/425, F15B11/18, B25J9/14, B25J9/20
Cooperative ClassificationB25J9/20, G05B19/425, B25J9/14, G05B2219/41309, F15B11/18
European ClassificationF15B11/18, B25J9/20, G05B19/425, B25J9/14