JPS61502809A - Improved product processing equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Product processing equipment prisoner deputy FIELD OF THE INVENTION This invention relates to product processing, and more particularly to robotic structural positioning equipment.

Automated product handling during manufacturing and transportation operations requires monitoring the exact location of the product being processed. There is a must-have. In robotic loading, the controller controls the desired product position. It is equipped with a position sensor that maintains the trajectory of its current position and a circuit for that purpose.

The arms of the robot are interconnected by means of joints, as is known, and the products to be manipulated are Consists of one or more links to supporting manipulators. This arm movement is directed by a control device, typically a computer operated control device. The controller provides signals to the fittings and manipulators. Positive indicating arm position Accurate signals are generated at the fittings and manipulators, allowing the control to Automatically adjust robot arm motion signals according to programmed design .

Methods of measuring the position and angle of a robot arm are known.

Position monitoring5Normally, each component of the robot is rigid and does not deform. The stiffness assumption is made based on the assumption that each element of the robot is It is only effective if it is large enough for the product. Therefore, each element of the robot is , generally constructed of sturdy and bulky materials. However, using such materials This makes the design of the joints and the equipment necessary to move them difficult and expensive.

If the robot element deforms due to the weight or inertia of the product being processed, the end of the element Changes in position are not incorporated into motor control, and the requested movement is not performed successfully. Not possible. Therefore, the robot structure, which has limited mass, size, and rigidity, has become smaller and lighter. It would be desirable to devise a device that allows processing of items other than products.

A system that monitors the position of a robot hand considering the deformation of robot arm elements. A system is disclosed in US Pat. No. 4,119,212. The method described in this According to A lock member is used. This link member pivots to different elements of the robot arm. A detecting device is connected to the free-floating pivot joint and the pivot joint point position on the arm element. be taken in. This detection device detects when the position of the product holding end of the robot arm changes. The angle between the two link elements and the pose of this link element so that it can be calculated independently of the shape. Measure. However, with this conventional method, especially in areas with small angular movements, In this case, the mechanical precision of the sensing device is poor, resulting in errors in position determination. Furthermore, the above U.S. Patent No. 4. The free floating pivot coupling link member described in No. 119,212 is It is suitable for one-plane operation. However, deformation may be due to product mass or inertia effects. or in any direction as a result of other effects, and due to external torsional forces. , or because the link member lacks rigidity.

Therefore, the present invention provides solutions regardless of the magnitude or type of deformation caused to the product processing structure. The objective is to provide improved product processing equipment that can accurately monitor .

A brief summary of Ming According to the invention, a link arm is provided having first and second ends; A product processing structure is provided that monitors part position. A light beam is placed at the end of the first link above. a light beam source is mounted and the light beam source includes at least one light beam along the link arm. the second end of the second end. attached to the second end above. A light beam detector indicates a direction of the second end relative to the first end in response to the light beam. It is made to generate a warning signal.

According to one aspect of the invention, the controller controls the link arm in response to a direction indicating signal. Reposition and compensate for the load on the link arm.

According to another aspect of the invention, said light beam source alternates light beams along said link. The optical beam detector also detects the direction-indicating signal from twisting and bending of the link arm. A pair of signals corresponding to the alternating light beams is provided to indicate the deformation.

M” conquest (7) g4W key exchange Figure 1 shows the robot arm structure according to the present invention, and Figure 2 shows the robot arm structure shown in Figure 1. This is a detailed diagram of one link of the bot arm structure in its undeformed state. the law of nature.

FIG. 3 shows details of the link shown in FIG. 2 in a deformed state, Figure 4 outlines the light beam source and detection circuit used in the configurations of Figures 1, 2 and 3. FIG. 5 is a schematic representation of another type of photodetector that may be used in the configuration of FIG. Show the structure.

Figure 6 shows other optical beams used to determine torsional and bending deformations of link arm structures. schematically illustrates the beam source and detection circuit; FIG. 7 is a graph showing waveforms showing the operation of the circuit shown in FIG. Figure 8 shows the phase sensing detection circuit of Figures 4 and 6. FIG. 1 shows a robot arm device 10 processing a product 70, which is vertically Offset to an angle consisting of a direction. This arm 1o has a fixing member 15 at an end 22. The robot has an indirect joint 20 that connects to a hollow robot link member 30. hollow link The end 42 of the member 50 is connected to the end 32 of the link 30 via an indirect joint 40; Further, the manipulator member 65 passes through the link 50 through the manipulator joint 60. is attached to the end 58 of. The product 70 is held at a fixed position by the manipulator member 65. is maintained.

Each joint of the robot arm device 1o is individually controlled by a control device 90, and this control The controller 90 can be operated from one of many robot control computers known in the art. Become.

The control device 9o controls the movement of the arm to perform a desired operation on the product 70. joint 20.40, and 6° cooperates with the movement of the manipulator member 65.

The link members 30 and 50 may be nested as shown in FIG. It forms a well-known straight link member.

A signal indicating the current position of the link member of the robot arm device 10 and the manipulator. is requested by the controller 90 to convey the product 7o through a fixed trajectory. Ru.

If link members 30 and 50 are not sturdy enough to bear the load of product 70, Either or both of the members may be deformed to such an extent. Fittings and manipulators The position signal generated by the rotor is not responsive to such deformations. Therefore, robot The cut arm movement deviates from the above trajectory. This deformation causes link members 30 and 50 to become This can be avoided by making the container large enough, but this method reduces the scope of application. This makes robotic equipment expensive and difficult to control.

Figure 2 shows the detection of deviation from the predicted position due to deformation due to load using the present invention. This figure shows in detail the link member 50 configured to do so. Shown in Figure 2 As shown, the ring member 50 has a directed energy light beam source 45 provided at the end portion 42. It has a position detector 55 provided at an end portion 58. This directed energy light beam source 4 5 is an electromagnetic energy source such as a light beam source, and a detector 55 is a position detection optical detector. It is a source. The light beam source 45 includes a laser device or a light emitting diode, and and an appropriate lens system to collect the light. This light beam source consists of multiple spaced Consisting of individually controlled light emitting diodes and lens system, n1calNotesTN-1 02, January 1.982) Consists of a position detector. Where light emitting diode sources are used, the light from the light source is detected. A lens system that focuses light on one point on the output device 55 is mounted between the light source and the detector. light beam The source is held rigidly in the center of end 42 by rod member 227, and the position detector is located at the end. 58 and is rigidly maintained by a rod member 237. Figure 2 shows link members. is shown in its undeformed state, and the light beam from light g45 is directed towards the center of detector 55. It will be done.

FIG. 3 is similar to FIG. 2 except that the link elements are shown in a deformed state. this Such deformations may be due to the configuration of the member 50, the weight of the product 70, inertial effects during movement, Alternatively, it may be caused by a force externally applied to product 70 by another object. this Deformation occurs as a result of forces applied from any direction. It is immediately clear from Figure 1 that As if

The deformation effect of the weight of the product 70 is also given from outside the plane formed by the links 30 and 50, and Deformations may occur within members 30 or 50, or both. Shown in Figure 3 The bending of the link member 50 allows the center point of the detector 55 to be aligned with the light beam from the light source 45. Move by amount ΔY and amount ΔX.

The above-mentioned displacement of the end portion 58 is normally controlled by a position sensing device built into the indirect joint. It is not reflected in the signal sent to the control device 90.

The circuit of FIG. It generates signals ΔX and ΔY representing . According to FIG. 4, the light source 45 is a light emitting diode. 425, the light output of which is directed to the lens along an internal line of the link member 50. 470 and enters the photodetector 55 through the lens 475.

The light beam position sensor 55 shown in FIG. and a pair of orthogonal low resistance contact strips. This location information is transmitted to the light It is obtained by measuring how the charge released by the resistor is divided within the resistive layer. It will be done. Position X is where the signal current (iXi and iX2) as follows.

The total photocurrent (iX2+iXI) and (iYZ+iy□) are equal in magnitude and This value represents the light spot intensity.

Some kind of method that stabilizes the light source with a servo mechanism to give a constant photocurrent (const) Countermeasures may be taken. This eliminates the need for division by variables. position The following relationship is used to determine .

Light emitting diodes (LEDs) determine the light beam spot position using alternating current measurement method. A lamp current steering circuit consisting of transistors 410 and 415 as shown in FIG. It is driven by a 50% duty cycle.

Oscillator 401 drives flip-flop 405.

This flip-flop 405 has a predetermined impact coefficient of 50%, for example, 100K. Outputs an output frequency of Hz. The output of the flip-flop 405 is the current steering input. circuit and phase sensitive detector (ρhase5 sensitive detector) used to drive. The fo output from flip-flop 405 is npn Applied to the base 412 of transistor 410. f of flip-flop 405 0 is supplied to the base 417 of the low output npn transistor 415.

Therefore, the current available at emitters 418 and 413 is such that the signal fO flows through LED 425 for a half cycle that is positive for . Lead 485 AC power Current signal ix1 is amplified in circuit 435 to provide voltage signal x1. Similarly, Lee Current iX2 in node 487 is amplified in circuit 445 to provide signal X2, and l The signal Y is amplified by a circuit 440 to provide a signal Y1.

The sum of signals X1 and x2 at the outputs of amplifiers 435 and 445 is Respond to the flow. These signals are connected to amplifier 420 via resistors 421 and 423. Combined on output. The output of amplifier 420 is connected to phase sensitive detector 425 and resistor 42. 7 to the negative input of amplifier 430. The output of amplifier 430 is connected to the resistor 433 to drive the emitters 413 and 418 of the lamp steering transistor. move. In this way, a negative feedback loop ensures that the light beam intensity is It is maintained at a level determined by control voltage VL.

FIG. 8 shows a circuit known in the art for use as a phase sensitive detector. amplifier For example, Natj, onal LF347 types are used for 825 and 880. Swish As the switching circuit 849, for example, a Tlarris H1-307 type is used.

As shown in FIG. 8, input B is a clock signal of a predetermined frequency from flip-flop 405. Input B receives switch 855 and 870 and opens switches 86o and 8. 65 is closed as shown in FIG. During the second half, switch 855 and 870 is closed, and switches 860 and 865 are also closed. Explanation 5 Photodetector in Figure 4 A signal 1 obtained from 55, for example, a sine wave of a predetermined frequency, is applied to input A, and its positive Assuming that the half-cycle of 9 occurs when the signal fo is "high", the positive input signal is It is inverted by a unity gain amplifier 825, passes through a resistor 830 and a switch 865, and is amplified. is applied to the negative input of device 880. Amplifier 880 regenerates the signal applied to it. is inverted, so the output signal at C is positive. Second half of a given clock frequency During the cycle, amplifier 825 inverts the negative half cycle of the sine wave and opens its output. Grounded via switch 855. However, the negative half cycle of the sine wave is It is applied to the negative input of amplifier 880 via open switch 870. obtained with C The output is the positive half cycle of a sine wave. Therefore, the circuit of Figure 8 is a phase sensitive aftereffect filter. The output is filtered to provide a direct current corresponding to the rms value of the signal at A. give a signal. Phase-sensitive detectors have a relatively narrow bandwidth, so they can easily detect both low-frequency interference and high-frequency interference. Noise is removed. In the circuit of FIG. These are DC signals corresponding to the positions of the center and the corner of the light beam incident on the light beam.

Signal X1 from amplifier 435 is converted to a DC signal by phase sensitive detector 450, which The DC signal represents the position of the light beam on the rotational axis of the detector 55. From voltage source 407 The voltage v1 is adjusted as known in the art to provide a centering bias to amplifier 455. As a result, the output signal ΔX of the amplifier is shifted from the center point of the detector 55 to its fundamental axis. is given to correspond to the deviation of the light beam along. Similarly, amplifier 440 The signal Y1 is converted into a DC signal by the phase detector 460. 55 represents the position of the light beam on one axis. Voltage v2 from voltage source 407 is technically is adjusted in a known manner to provide a centering bias to amplifier 465. Therefore, the increase The output signal of the width transducer 465, that is, the signal ΔY is generated along one axis from the center point of the photodetector. This corresponds to the deviation of the light beam. Provide accurate information regarding the deformation of the link member 50 The signals ΔX and ΔY are applied to the control device 90. In this way, the link member 3 0 and 50 are made of relatively light materials, and the load on the joints depends on the product processing capacity or is significantly reduced without affecting accuracy.

Detector 55 in FIG. 4 is composed of an anode resistance layer 480 and a cathode resistance layer 486. increase generated in response to the beam from light source 425 occurring at the outputs of width transducers 455 and 465. The photocurrent depends on the uniformity of the resistive layer. If the resistive layer is uneven, the beam position Limits the accuracy of force signals ΔX and ΔY.

Higher accuracy is obtained from the detector configuration shown in FIG. A set of high conductivity parallel strips 505-1 to 505-7 are arranged on the anode surface of the photodetector 535. and orthogonal sets of high conductivity parallel strips 507-1 to 507-1. is placed on the cathode side of the detector. External resistors 510-1 to 510-6 are anode strips. resistors 520-1 through 520-6 are used to interconnect the Interconnect the pole strips. A Gaussian beam with width σ has a pitch of 1.4σ. is sufficient to guarantee the linearity of the position output signal.

FIG. 6 shows another link arm light beam configuration, where a pair of light beams are used to determine the orientation of one link end relative to the other end . These light beams are turned on alternately with a 25% impact factor for each; The point where the beam is incident on the photodetector is detected individually, so that the signal from the detector device indicates the direction of the detector end spatially with respect to the source end. one or more light beam sources It is placed at an intermediate position along the ring to detect higher-order modes of link motion.

As shown in FIG. 6, timing signal generator 640 is connected to semiconductor switch 610. The driver 612 is given the signal f1, and the driver 617 of the semiconductor switch 615 is A signal f2 is given to. Signals f1 and f2 are shown by waveforms 703 and 705 in FIG. It will be done. In response to signal f1, switch element 613 is closed and switch element 6 14 is opened. A current with a controlled magnitude flows from the intensity control amplifier 622 to L. A light beam of a predetermined intensity is supplied to the ED 601 and passes through lenses 642 and 644. The light is applied from the LED 601 to the photodetector 650. while signal f2 is on.

LED 605 is enabled and current is switched by intensity control amplifier 620. 618, thereby controlling the controlled intensity from the LED 605. is provided to a photodetector 650 through lenses 642 and 644. this The light beam intensity is determined by voltage VD from voltage source 646. amplifier 620 A feedback device includes a feedback device that maintains the light beam intensity from the LED 605 at a constant level. hold Similarly, the feedback device with amplifier 622 is maintain the light beam intensity at a predetermined level.

Bias voltage +VB is applied to the edge of photodetector 650, while bias voltage +VB is applied to the edge of photodetector 650; A voltage -VB is applied to the left edge of photodetector 650 through resistor 658.

Since the light level of each light source is stabilized by a servomechanism, the photodetector 650 A signal proportional to the position of the incident light beam along the horizontal or cardinal axis of the left edge of given and also proportional to the position of the incident light beam along its vertical or -Y-axis. Additionally, a signal at its upper edge is provided.

Between tl and 1 and 2 in FIG. 7, the signal fl (waveform 703) is at a high level. LED 601 is on and the light beam from this LED is incident on the detector 650. . Appears on the beam of light.

The pivot position signal from lead 654 is passed through amplifier 660 to phase sensitive detector 662. 4 times t1 and t3 applied to and passing through it according to the clock pulse fO The timing signal f3 (waveform 707) is at a high level between Switch element 669 of conductor switch 665 is closed and switch element 668 is opened. Become free.

A signal in which the phase of the beam from the LED 601 due to the person's position is detected is A filter formed by amplifier 670 with backing elements 671 and 673 is provided. be provided. Therefore, the signal X1 corresponding to the axial position of the light beam from the LED 601 is Appears at the output of amplifier 670.

Connected to the right edge of detector 650 or generated at node 652 between times t1 and t3. The similar signal represents the portion of the light beam from LED 601 that is not sent to the left edge. vinegar.

This signal is amplified by circuit 688, and the output of amplifier 660 is added to provide a single phase sensitivity. The signal is applied to an amplifier 694 through a detection detector 690 and a semiconductor switch 692. increase Signal R1 from width scaler 694 corresponds to the intensity of the light beam from LED 601. increase The output of the width amplifier 694 is fed back to the intensity control amplifier 622 and is adjusted by the voltage VD. maintain the light beam intensity as set. This light beam intensity remains constant Therefore, the X1 signal gives the X-axis position of the incident light beam, and the Y1 signal gives the 601 gives the X-axis position of the incident light beam.

Between times t1 and t3 in FIG. 7, signal f3 is high.

Therefore, the output of phase sensitive detector 676 is filtered via closure switch 682. Connected to the input of circuit 684.

Its output Y1 gives the position of the light beam spot due to LED 601.

Between times t3 and t4, the LED activation signal f2 (waveform 705) is on; Signal fl (waveform 703) is turned off. LED 605 connects semiconductor switch 615 and the light beam therefrom is directed to a photodetector 650. signal f3 (waveform 7o7) is low, so the left edge signal of part 654 is a phase sensitive detector. 662 , a semiconductor switch element 668 , and an amplifier 672 . amplifier 6 The output of 72, signal X2, represents the X-axis position of the light beam from LED 605.

The right edge signal from photodetector 690 between times t3 and t5 is detected by phase sensitive detector 6. 90, a switch element 691, and an amplifier 696. Signal from amplifier 696 R2 is used to maintain the light beam intensity from LED 605.

Between times t3 and t5, signal f3 is off, causing lead 656 to The resulting top edge signal from photodetector 650 is sent to phase sensitive detector 676, switch element 681, and amplifier 686. Therefore, the Y2 output of amplifier 686 represents the X-axis position of the light beam from LED 60'5. The circuit operation in Figure 6 is as follows. Iterated according to the timing control signals in the figure, thus from LEDs 601 and 605. The signals X1°Yl, , X2 and Y2 corresponding to the positions of the alternating light beams are is supplied to the control device of the gate structure. These beam position signals are at the end of the link arm. 1 indicates the relative direction and reflects the deformation of the link arm due to bending and torsional deformation.

The invention has been illustrated and described in terms of specific embodiments thereof. Examples disclosed herein is merely an illustration of the present invention, and those skilled in the art can make various modifications without departing from the spirit and scope of the present invention. It is understood that modifications and changes may be made. For example, a light beam source or a light beam position. The position of the detector is such that the light source is at the second end of the link, while the detector is at the first link. It can be reversed as shown at the end. The light source does not need to be located at the edge. The detector is placed at a midpoint between the layers of the link, and the detector is placed at a more convenient point along the link other than at the end. It may be placed in a suitable position. Alternatively, the source and detector can be placed at the same point along the link. or a reflector may be placed at one end of the link to reflect the light beam. good.

Procedural City Official Letter (Method) October 2, 1986

Claims (20)

[Claims] 1. a product handling structure comprising a link arm having a first and a second end; , means for determining the orientation of the second end relative to the first end; The direction determining means is attached to a first end of a link arm and directs at least one light beam to said second end; a light beam source mounted on the second end and configured to direct the light beam at the second end; an optical beam generating at least one signal representative of the direction of the second end with respect to the beam source; A product processing structure comprising a system detector and a system detector. 2. further comprising a control means for changing the direction of the second end in response to a direction indicating signal. A product processing structure according to claim 1, characterized in that: 3. The light beam source directs a plurality of light beams along the link arm toward the second end. and the light beam detection means detects the light beam in response to each light beam. characterized by comprising means for generating a signal representing the position where the beam is incident on the second end. A product processing structure according to claim 1. 4. The light beam source further includes one of a plurality of light beams along the link arm at a time. and means for directing the The light beam detection means further includes, in response to each directed light beam, whether the directed light beam is a second A claim comprising means for generating a signal representing the position of incidence on the end. The product processing structure described in Scope No. 3. 5. The means for directing a plurality of light beams includes a pair of light beams along a link arm. 4. The method according to claim 4, characterized in that Product processing structure. 6. the light beam detector at the end of the second link comprises a sheet of photosensitive material; an incident position of the light beam along the first predetermined axis according to the light beam incident on the photosensitive sheet; means for generating a first signal indicative of the position; incidence along a second predetermined axis according to a light beam from a light source incident on the photosensitive sheet; and means for generating a second signal representative of the position. Product processing structure. 7. The first and second signal generating means are configured to generate a center locus (center) of the incident light beam. oid) means for generating a signal representative of the position. Product processing structure as described in Section 6. 8. The photosensitive sheet includes a set of spaced apart photosensitive strips substantially parallel to a first axis. a lip and a set of spaced apart photosensitive strips substantially parallel to a second axis. The product processing structure according to claim 7, characterized in that: 9. characterized in that the link arm consists of a hollow link element; the light beam source directing a light beam along the interior of the hollow link element; further characterized in that the light beam detector detects a light beam within the hollow link element. The product according to claim 7, characterized in that the product is adapted to detect the position of Processing structure. 10. Predecessor characterized in that the link arm consists of a plurality of elements in a telescoping manner A product processing structure according to any one of claims 1 to 9. 11. A robotic structure, a link arm having first and second ends and relative positions of the first and second ends; and a means for determining the The relative position determining means is attached to the first end of the link arm so that the second end is in its unloaded state; an electromagnetic beam source directing at least one light beam to a predetermined location at the second end; attached to the second end and responsive to the electromagnetic beam from its unloaded state of the second end; an electromagnetic beam detector adapted to generate a signal indicative of the deviation; The link arm is repositioned to compensate for the link arm load in response to a signal representing the A robotic structure consisting of control means. 12. The electromagnetic beam is a light beam, and the electromagnetic beam source is a light beam source. 12. Robotic structure according to claim 11, characterized in that: 13. the light beam detector at the second link end comprises a sheet of photosensitive material; an incident position of the light beam along the first predetermined axis according to the light beam incident on the photosensitive sheet; means for generating a first signal indicative of the position; incident along a second predetermined axis in response to a light beam from a light source incident on the photosensitive sheet; and means for generating a second signal representing the firing position. Robotic structure according to paragraph 12. 14. The first and second signal generating means represent the center trajectory position of the incident light beam. 14. The device according to claim 13, comprising means for generating a signal. Bot type structure. 15. The photosensitive sheet includes a set of spaced apart photosensitive sheets substantially parallel to the first axis. a set of spaced apart photosensitive strips substantially parallel to the second axis; 15. The robotic structure according to claim 14, comprising: 16. The link arm consists of a hollow link element, and the light beam source is connected to the hollow link element. adapted to direct a light beam along an interior of the link element; a detector is adapted to detect a light beam position within said hollow link element; 13. Robotic structure according to claim 12, characterized in that: 17. Claim characterized in that the link arm consists of a plurality of elements in a telescoping manner. The robotic structure according to any one of items 11 to 16. 18. A robotic structure, a link element having first and second ends; and an orientation of the second end relative to the first end. means for determining the directed energy beam mounted along the link element; a signal representative of the direction of the second end with respect to the directed energy beam source in response to A robotic structure consisting of a position-sensing energy beam detector and a position-sensing energy beam detector. 19. The directed energy beam is an electromagnetic energy beam, and the directed energy beam is an electromagnetic energy beam. Claims characterized in that the energy beam source is an electromagnetic energy beam source. Robotic structure according to paragraph 1. 20. The electromagnetic beam is a light beam, and the electromagnetic beam source is a light beam source. 20. Robotic structure according to claim 19, characterized in that: