CA1246636A - Control apparatus for multi-jointed arm mechanism - Google Patents
Control apparatus for multi-jointed arm mechanismInfo
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- CA1246636A CA1246636A CA000465452A CA465452A CA1246636A CA 1246636 A CA1246636 A CA 1246636A CA 000465452 A CA000465452 A CA 000465452A CA 465452 A CA465452 A CA 465452A CA 1246636 A CA1246636 A CA 1246636A
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Abstract
Abstract A control apparatus for a multi-jointed arm mechanism having a plurality of arm elements is designed to improve the operating speed of each arm element. A true control error between a remote end of an arm element and a target position thereof, resulting from a movement of the arm element, and a predicted control error thereof have their difference evaluated. The arm element is then controlled to make this difference zero.
Description
6~
Control ap~aratus for multi-jointed arm mechanism The present invention relates to apparatus for controlling a multi-jointed arm mechanism that is composed of a plurality of arm elements associated with one another and joints for interconnec-ting them.
Such a multi-jointed arm mechanism for use in a robot is disclosed in U.S. Patent No. 4/221r997 issued September 9, 1980 to John P.W. Flemming. In such a mechanism, it is necessary to detect the movement magnitudes of its respective arm elements by means of a sensor and to adjust the cutputs of the respective arm elements on the basis of the outputs of the sensor. Since the arm elements are associated with one another, the outputs of the respective arm elements need to be~adjusted while maintaining co-operative relations with the other arm elements. To realize such cooperative control, there has heretofore been adopted a concentrated tvpe of control apparatus that comprises a single calculator for integrating and controlling the plurality of arm elements. This control apparatus applies signals from the sensor to the single calculator which ~20 computes on the basis of the signals emitted ~y all the arm ; ~ elements and supplies the xespective arm elements with control signals~ Since the respecti~e arm elements are thus operated by signals from~a single calculator, the problems s~tated below can be encountered. For thus computing the 25 ~control signals for a large number of arm elements , ~
~,' .
;i3~
collectively in a single calculator, a matrix operation on a large scale is required~ A considerable period of time is needed for executing the matrix operation, so that the control apparatus and also the whole multi-jointed arm mechanism have unfavorable response rates~ Slow response rates form a hindrance to the achievement of a high opexating speed for the mechanism.
The present invention has been made in view of the aforementioned drawbacks and has for its object to provide a control apparatus that can enhance the operating speed of such a multi-jointed arm mechanism.
To this end, the invention provides a control apparatus for a multi-jointed arm mechanism having a plurality of arm elements which are respectively driven by actuator means, the control apparatus comprising input means for detecting information indicative of a displace-ment of the multi-jointed arm mechanism relative to a target position therefor and for providing a common output indicative of the displacement as a common control error signal, arithmetic means coupled to the actuator means of at least one of the arm elements for calculating a taryet movement magnitude of the arm element in response to the common control error signal from the input means and predictive information of the displacement calculated on the basis of movement information of the arm element and for providing an output target movement magnitude signal, means for detecting an actual movement magnitude o the arm element and providing an output signal indicative thereof, and comparison means for comparing the actual movement magnitude signal from the detecting means and the target movement magnitude signal from the arithmetic means and for providing an output signal indicative of the deviation therebetween to the associated actuator means for the arm element.
~2~63 2a Other features of the present invention will become apparent from embodiments thereof described below.
In the drawings:
Fig. 1 is a diagram showing a multi-jointed arm mechanism equipped with control apparatus according to an embodiment of the present invention;
Fig. 2 is a diagram showing a calculator for use in the apparatus of Fig~ l;
:: :
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,.
Fig. 3 is an operating flow chart of the calculator shown in Fig. 2;
Fig~ 4 is a diagram of a second embodiment; and Fig. 5 is a diagram of a still further embodiment.
Fig. 1 shows amulti-jointed arm mechanism A installed on, for example, a movable base B. This mechanism A is constructed of a first arm element 2 which is rotatably mounted on the base B by a first joint 1, a second arm element 4 similarly mounted on the remote end of the first arm element 2 by a second joint 3, a third arm element 6 similarly mounted on the remote end of the second arm element 4 by a third joint 5, a fourth arm element 8 similarly mounted on the remote end of the third arm element 6 by a fourth joint 7, and a grip 9 located at the remote end of the fourth arm element 8. An object to be grasped by the grip 9 is indicated by numeral 10. The arm elements 2, 4, 6 and 8 constituting the mechanism A are respectively driven by actuakoxs 11 - 14, e.g. stepping motors,on the shafts o~
the respective joints 1, 3, 5 and 7. These shafts are respectively furnished with detectors 15 - 18 for detecting the magnitudes ~ 4 f the movements of the arm elements
Control ap~aratus for multi-jointed arm mechanism The present invention relates to apparatus for controlling a multi-jointed arm mechanism that is composed of a plurality of arm elements associated with one another and joints for interconnec-ting them.
Such a multi-jointed arm mechanism for use in a robot is disclosed in U.S. Patent No. 4/221r997 issued September 9, 1980 to John P.W. Flemming. In such a mechanism, it is necessary to detect the movement magnitudes of its respective arm elements by means of a sensor and to adjust the cutputs of the respective arm elements on the basis of the outputs of the sensor. Since the arm elements are associated with one another, the outputs of the respective arm elements need to be~adjusted while maintaining co-operative relations with the other arm elements. To realize such cooperative control, there has heretofore been adopted a concentrated tvpe of control apparatus that comprises a single calculator for integrating and controlling the plurality of arm elements. This control apparatus applies signals from the sensor to the single calculator which ~20 computes on the basis of the signals emitted ~y all the arm ; ~ elements and supplies the xespective arm elements with control signals~ Since the respecti~e arm elements are thus operated by signals from~a single calculator, the problems s~tated below can be encountered. For thus computing the 25 ~control signals for a large number of arm elements , ~
~,' .
;i3~
collectively in a single calculator, a matrix operation on a large scale is required~ A considerable period of time is needed for executing the matrix operation, so that the control apparatus and also the whole multi-jointed arm mechanism have unfavorable response rates~ Slow response rates form a hindrance to the achievement of a high opexating speed for the mechanism.
The present invention has been made in view of the aforementioned drawbacks and has for its object to provide a control apparatus that can enhance the operating speed of such a multi-jointed arm mechanism.
To this end, the invention provides a control apparatus for a multi-jointed arm mechanism having a plurality of arm elements which are respectively driven by actuator means, the control apparatus comprising input means for detecting information indicative of a displace-ment of the multi-jointed arm mechanism relative to a target position therefor and for providing a common output indicative of the displacement as a common control error signal, arithmetic means coupled to the actuator means of at least one of the arm elements for calculating a taryet movement magnitude of the arm element in response to the common control error signal from the input means and predictive information of the displacement calculated on the basis of movement information of the arm element and for providing an output target movement magnitude signal, means for detecting an actual movement magnitude o the arm element and providing an output signal indicative thereof, and comparison means for comparing the actual movement magnitude signal from the detecting means and the target movement magnitude signal from the arithmetic means and for providing an output signal indicative of the deviation therebetween to the associated actuator means for the arm element.
~2~63 2a Other features of the present invention will become apparent from embodiments thereof described below.
In the drawings:
Fig. 1 is a diagram showing a multi-jointed arm mechanism equipped with control apparatus according to an embodiment of the present invention;
Fig. 2 is a diagram showing a calculator for use in the apparatus of Fig~ l;
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,.
Fig. 3 is an operating flow chart of the calculator shown in Fig. 2;
Fig~ 4 is a diagram of a second embodiment; and Fig. 5 is a diagram of a still further embodiment.
Fig. 1 shows amulti-jointed arm mechanism A installed on, for example, a movable base B. This mechanism A is constructed of a first arm element 2 which is rotatably mounted on the base B by a first joint 1, a second arm element 4 similarly mounted on the remote end of the first arm element 2 by a second joint 3, a third arm element 6 similarly mounted on the remote end of the second arm element 4 by a third joint 5, a fourth arm element 8 similarly mounted on the remote end of the third arm element 6 by a fourth joint 7, and a grip 9 located at the remote end of the fourth arm element 8. An object to be grasped by the grip 9 is indicated by numeral 10. The arm elements 2, 4, 6 and 8 constituting the mechanism A are respectively driven by actuakoxs 11 - 14, e.g. stepping motors,on the shafts o~
the respective joints 1, 3, 5 and 7. These shafts are respectively furnished with detectors 15 - 18 for detecting the magnitudes ~ 4 f the movements of the arm elements
2, 4, 6 and 8 controlled by the respective joints 1, 3, 5 and 7. The detection signals ~1 ~ 9~ are negatively fed back to comparators 19 - 22 which constitute the drive control systems of the corresponding arm elements 2, 4, 6 and 8. These comparators 19 - 22 compare target movement magnitudes ~ 4' from calculators 23 - 26 with the actual movement magnitudes ~1 ~ 04 from the detectors 15 - 18 and deliver difference errors el ~ e4 to the respective actuators 11 - 14. The calculators 23 - 26, which are respectively incorporated in the drive control systems of the arm elements 2, 4, 6 and 8, are all supplied with a signal concerning the positional deviation magnitude ~control error magnitude) E
of the grip 9 relative to the object 10, this signal being delivered from an input device 27, e.g. television camera or the like. These calculators predictively compute the move-ment magnitudes of the respective axm elements 2, 4, 6 and 8 ,~
."
of the grip 9 relative to the object 10, this signal being delivered from an input device 27, e.g. television camera or the like. These calculators predictively compute the move-ment magnitudes of the respective axm elements 2, 4, 6 and 8 ,~
."
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to successively deliver the target movement magnitudes ~l' ~
' to compensate for the control error E.
An example of such a calculator 23 - 26 is shown in Fig. 2 where numeral 28 designates an arithmetic unit for computing a compensation value ~ of the corresponding one of the movement magnitudes ~ 4 f the respective arm elements 2, 4, 6 and 8 on the hasis of t:he control error magnitude E as delivered from the input device 27. The compensation value ~8 can be computed from the following equation (l):
~x = ~ (E - ~) ....(l) cL
where ~, ~: are coefficients, ~: is a proportion coefficient for compensation, which is a positive constant smaller than l.
Numeral 29 designates a delay circuit. Numeral 30 designates an adder which adds the last control error E and a control error El obtained with the arm compensation value ~x and thus evaluates the true variation ~e between them. Numeral 31 indicates an arithmetic unit for a predictive variation, which computes the predictive variation ~ex of the control error E on the basis of the aforementioned compensation value ~x This predictive variatlon ~ex can be computed from the following equation (2):
~ex = ~ x + ~ .......................... (2) where ~ are coefficients.
Shown at numeral 32 is an adder which evaluates an error variation ~E (= ~e -~ex) using the true variation ~e and the predictive variation ~ex. Numeral 33 denotes an arithmetic unit for updating the coefficients/ which unit computes the coef~icients ~ and ~ in the operating equation of the predicti~e~variation arithmetic unit 31, i.e.~ the foregoing equ2tion (2) and the operating equation of the arm-compensation value arithmetic unit 28, i.e., the foregoing equatlon (l), into updated coefficients ~' and ~' indicated in the following equations (3) and (4), respectively, on the basis of the error variation ~E, , 6~3~
respectively, and which delivers the updated coefficients ~' and ~' as updated values to the predictive-variation arithmetic unit 31 and the arm-compensation-value arithmetic unit 28:
~x ~ ....(3) ~ E ....(4) where a: is a positive constant.
Operations for controllinq the arm mechanism by means of this control apparatus will now be described with reference to the flow chart in Fig. 3.
As illustrated in Eig. 1, it is now assumed that when the actuator 11, for example, has been operated to change the first arm element 2 by an angle ~, the grip 9 of the multi-jointed arm mechanism A involves a control error E
relative to the object 10 to be grasped. The control error of the grip 9 relative to the object 10 before changing the Eirst arm element 2 by the angle ~ as stated above, is denoted by Eo~ The error E of the grip 9 relative to the object 10, ascribable to the change of the first arm element 2 by the angle ~, i5 applied to the respective calculators 23 - 26 by the vision device 27. Since, in this case, only the first arm element 2 has been operated as described above, the error E is used in only the calculator 23. The error E
applied to the calculator 23 is compared with the last error Eo in the adder 30, to find the difference ~e = E - Eo~
Meanwhile, the unit 31 receives the arm compensation angle ~x of the first arm element 2 from the unit 28 to be described below and computes a predictive variation ~ex on the basis of Equation (2~. Upon receiving the error E, the unit~28 computes an actual arm compensation angle ~x on the basis of Equation (1). The actual arm compensation angle x is delivered to the actuator 11. The first arm element 2 is thus moved. As a result, the grip 9 adopts an error El relative to the obiect 10. This error El is detected by the vision device 27 and applied to the adder 30 of the calcuIator 23. Thus the adder 30 evaluates the true variation ~e between .
3~
this error El and the last error E. This true variation ~e is compared in the adder 32 with the predictive variation x delivered from the unit 31, whereby an error variation ~E = ~e ~ ~ex is computed. This error variation ~E is applied to the unit 33 which computes the updated coefficients ~' and ~' on the basis of Equations (3) and (4) and delivers them to the unit 31 and the unit 28 to substitute them for the respective coefficients ~ and ~ in these units. In this way, the unit 31 and the unit 28 are prepared for the next control operations for positioning the grip 9 at the object 10.
While the above operations have been explained in relation to a single arm element, the respective arm elements
to successively deliver the target movement magnitudes ~l' ~
' to compensate for the control error E.
An example of such a calculator 23 - 26 is shown in Fig. 2 where numeral 28 designates an arithmetic unit for computing a compensation value ~ of the corresponding one of the movement magnitudes ~ 4 f the respective arm elements 2, 4, 6 and 8 on the hasis of t:he control error magnitude E as delivered from the input device 27. The compensation value ~8 can be computed from the following equation (l):
~x = ~ (E - ~) ....(l) cL
where ~, ~: are coefficients, ~: is a proportion coefficient for compensation, which is a positive constant smaller than l.
Numeral 29 designates a delay circuit. Numeral 30 designates an adder which adds the last control error E and a control error El obtained with the arm compensation value ~x and thus evaluates the true variation ~e between them. Numeral 31 indicates an arithmetic unit for a predictive variation, which computes the predictive variation ~ex of the control error E on the basis of the aforementioned compensation value ~x This predictive variatlon ~ex can be computed from the following equation (2):
~ex = ~ x + ~ .......................... (2) where ~ are coefficients.
Shown at numeral 32 is an adder which evaluates an error variation ~E (= ~e -~ex) using the true variation ~e and the predictive variation ~ex. Numeral 33 denotes an arithmetic unit for updating the coefficients/ which unit computes the coef~icients ~ and ~ in the operating equation of the predicti~e~variation arithmetic unit 31, i.e.~ the foregoing equ2tion (2) and the operating equation of the arm-compensation value arithmetic unit 28, i.e., the foregoing equatlon (l), into updated coefficients ~' and ~' indicated in the following equations (3) and (4), respectively, on the basis of the error variation ~E, , 6~3~
respectively, and which delivers the updated coefficients ~' and ~' as updated values to the predictive-variation arithmetic unit 31 and the arm-compensation-value arithmetic unit 28:
~x ~ ....(3) ~ E ....(4) where a: is a positive constant.
Operations for controllinq the arm mechanism by means of this control apparatus will now be described with reference to the flow chart in Fig. 3.
As illustrated in Eig. 1, it is now assumed that when the actuator 11, for example, has been operated to change the first arm element 2 by an angle ~, the grip 9 of the multi-jointed arm mechanism A involves a control error E
relative to the object 10 to be grasped. The control error of the grip 9 relative to the object 10 before changing the Eirst arm element 2 by the angle ~ as stated above, is denoted by Eo~ The error E of the grip 9 relative to the object 10, ascribable to the change of the first arm element 2 by the angle ~, i5 applied to the respective calculators 23 - 26 by the vision device 27. Since, in this case, only the first arm element 2 has been operated as described above, the error E is used in only the calculator 23. The error E
applied to the calculator 23 is compared with the last error Eo in the adder 30, to find the difference ~e = E - Eo~
Meanwhile, the unit 31 receives the arm compensation angle ~x of the first arm element 2 from the unit 28 to be described below and computes a predictive variation ~ex on the basis of Equation (2~. Upon receiving the error E, the unit~28 computes an actual arm compensation angle ~x on the basis of Equation (1). The actual arm compensation angle x is delivered to the actuator 11. The first arm element 2 is thus moved. As a result, the grip 9 adopts an error El relative to the obiect 10. This error El is detected by the vision device 27 and applied to the adder 30 of the calcuIator 23. Thus the adder 30 evaluates the true variation ~e between .
3~
this error El and the last error E. This true variation ~e is compared in the adder 32 with the predictive variation x delivered from the unit 31, whereby an error variation ~E = ~e ~ ~ex is computed. This error variation ~E is applied to the unit 33 which computes the updated coefficients ~' and ~' on the basis of Equations (3) and (4) and delivers them to the unit 31 and the unit 28 to substitute them for the respective coefficients ~ and ~ in these units. In this way, the unit 31 and the unit 28 are prepared for the next control operations for positioning the grip 9 at the object 10.
While the above operations have been explained in relation to a single arm element, the respective arm elements
4, 6 and 8 will be similarly controlled.
As thus far described, the control apparatus evaluates the predictive variation ~ex of the control error of the grip 9 relative to the object 10 on the basis of the angular displacements of the respective arm elements, computing the true variation ~e obtained with the angular displacements, and updating the error variation on the basis of the variations ~ex and ~e. The respective arm elements 2, 4, 6 and 8 are thus cooperatively controlled. In other words, since the control operation is performed separately for each of the arm elements 2, 4, 6 and 8, it is possible to do so at a higher speed than in an apparatus having a higher-ranking computer that provides a single control mechanism for the respective arm elements 2, 4, 6 and 8.
Fig. 4 shows another embodiment wherein,in order to increase or decrease control errors attributed to the operations between the respective arm elements 2, 4, 6 and 8, the calculators 23 - 26 are interconnected by communication units 34. In this case, an error variation ~El caused when another arm element has been changed by ~xl is applied to the arm-compensation-angle arithmetic unit 28 shown in Fig. 2.
For this reason, the foregoing equation (1) in the unit 28 needs to be altered to the following equation (5):
~x ~ (E - ~ - ~El) ~5) ,, . .
While, in -the embodiments described above, the coefficients of Equation (2) for ~he predictive computation are updated on the basis of data or are learn~, they may be computed beforehand and kept stored.
In the foregoing embodiments, the control error of the grip 9 rela-tive to the object 10 is c:ontrolled on the basis of the positioning error of the re~lote end of the grip 9. In ordinary cases, the operating space of the mechanism A will be sufficient so that such control apparatus is applicable. However, in a case where the operating space is insufficiently due to an obstacle, this situation can be coped with by the control apparatus being supplied with information on any approach to the obstacle of the arm element located midway of the mechanism A. As illustrated in Fig. 5, an intermediate arm element is provided with a sensor 35 for sensing the obstacle B'. A signal from the sensor 35 is applied to the calculator 25 to prevent ~le inter-mediate arm element from moving toward the obstacle B'. The calculator can -treat the sensed signal just as the control error of the grip .9 relative to the object 10 is treated in the calculator shown in Fig. 2.
~ hile, in the ~oregoing embodiments, separate calculators 23 - 26 are employed for the respective actuators 11 - 14, they can be constructed as a single calculator. Besides, the calculators need not be connected to all the actuators 11 - 14.
. . .
As thus far described, the control apparatus evaluates the predictive variation ~ex of the control error of the grip 9 relative to the object 10 on the basis of the angular displacements of the respective arm elements, computing the true variation ~e obtained with the angular displacements, and updating the error variation on the basis of the variations ~ex and ~e. The respective arm elements 2, 4, 6 and 8 are thus cooperatively controlled. In other words, since the control operation is performed separately for each of the arm elements 2, 4, 6 and 8, it is possible to do so at a higher speed than in an apparatus having a higher-ranking computer that provides a single control mechanism for the respective arm elements 2, 4, 6 and 8.
Fig. 4 shows another embodiment wherein,in order to increase or decrease control errors attributed to the operations between the respective arm elements 2, 4, 6 and 8, the calculators 23 - 26 are interconnected by communication units 34. In this case, an error variation ~El caused when another arm element has been changed by ~xl is applied to the arm-compensation-angle arithmetic unit 28 shown in Fig. 2.
For this reason, the foregoing equation (1) in the unit 28 needs to be altered to the following equation (5):
~x ~ (E - ~ - ~El) ~5) ,, . .
While, in -the embodiments described above, the coefficients of Equation (2) for ~he predictive computation are updated on the basis of data or are learn~, they may be computed beforehand and kept stored.
In the foregoing embodiments, the control error of the grip 9 rela-tive to the object 10 is c:ontrolled on the basis of the positioning error of the re~lote end of the grip 9. In ordinary cases, the operating space of the mechanism A will be sufficient so that such control apparatus is applicable. However, in a case where the operating space is insufficiently due to an obstacle, this situation can be coped with by the control apparatus being supplied with information on any approach to the obstacle of the arm element located midway of the mechanism A. As illustrated in Fig. 5, an intermediate arm element is provided with a sensor 35 for sensing the obstacle B'. A signal from the sensor 35 is applied to the calculator 25 to prevent ~le inter-mediate arm element from moving toward the obstacle B'. The calculator can -treat the sensed signal just as the control error of the grip .9 relative to the object 10 is treated in the calculator shown in Fig. 2.
~ hile, in the ~oregoing embodiments, separate calculators 23 - 26 are employed for the respective actuators 11 - 14, they can be constructed as a single calculator. Besides, the calculators need not be connected to all the actuators 11 - 14.
. . .
Claims (19)
1. A control apparatus for a multi-jointed arm mechanism having a plurality of arm elements which are respectively driven by actuator means, the control apparatus comprising input means for detecting information indicative of a displacement of the multi-jointed arm mechanism relative to a target position therefor and for providing a common output indicative of the displacement as a common control error signal, arithmetic means coupled to the actuator means of at least one of the arm elements for calculating a target movement magnitude of the arm element in response to the common control error signal from the input means and predictive information of the displacement calculated on the basis of movement inform-ation of the arm element and for providing an output target movement magnitude signal, means for detecting an actual movement magnitude of the arm element and providing an output signal indicative thereof, and comparison means for comparing the actual movement magnitude signal from the detecting means and the target movement magnitude signal from the arithmetic means and for providing an output signal indicative of the deviation therebetween to the associated actuator means for the arm element.
2. A control apparatus according to claim 1, wherein the actuator means is responsive to the deviation signal from the comparison means for controlling the positioning of the arm element to make the deviation between the actual movement magnitude signal and the target movement magnitude signal to be zero.
3. A control apparatus according to claim 2, wherein the input means includes means for detecting a positioning error between a fore end of the multi-jointed arm mechanism and a target position therefor as the common control error signal and for supplying the common control error signal to the arithmetic means.
4. A control apparatus according to claim 30 wherein the input means includes vision means for viewing the fore end of the multi-jointed arm mechanism and the target position therefor to detect the displacement.
5. A control apparatus according to claim 3, wherein the input means further includes sensor means for sensing an obstacle and for supplying a signal indicative of the displacement of the multi-jointed arm mechanism from the obstacle to the arithmetic means.
6. A control apparatus according to claim 5, wherein the sensor means is disposed on an arm element of the multi-jointed arm mechanism positioned between a base end and the fore end of the multi-jointed arm mechanism.
7. A control apparatus according to claim 5, wherein the arithmetic means calculates a target movement magnitude signal on the basis of the present common control error signal and a previous common control error signal and movement thereof.
8. A control apparatus according to claim 7, wherein the arithmetic means includes means for storing the previous common control error signal.
9. A control apparatus according to claim 7, wherein the arithmetic means includes first calculating means for calculating the target movement magnitude signal .delta..theta.x in accordance with the equation .delta..theta.x=(.pi./.alpha.)(E-.beta.), where E is the present common control error signal, .alpha. and .beta. are coefficients, and v is a proportion coefficient for compensation which is a positive constant smaller than 1, first comparing means for comparing the present common control error signal E with the previous common control error signal Eo and providing a true error deviation output signal .delta.e, second calculating means for calculating a predictive error signal .delta.ex in response to the calculated target movement magnitude signal .delta..theta.x in accordance with the equation .delta.ex=.alpha...delta..theta.x+.beta., second comparing means for comparing the predictive error signal .delta.ex with the true error deviation signal .delta.e and providing an error variation signal .delta.E as an output thereof, and third calculating means for calculating updated coefficient values .alpha.' and .beta.' for the coefficient value .alpha. and .beta. utilized by the first and second calculating means in accordance with the equations .alpha.'=.alpha.+.gamma.?.delta..theta.x?.delta.E and .delta.'=.gamma.?.delta.E, where .gamma. is a positive constant, the third calculating means supplying the updated coefficient values to the first and second calculating means.
10. A control apparatus according to claim 9, wherein a plurality of arithmetic means are provided, a respective arithmetic means being associated with a respective actuator means of an arm element, and further comprising communication means interconnecting the respective arithmetic means for supplying the error variation signal .delta.E generated by one of the arithmetic means to another of the arithmetic means.
11. A control apparatus according to claim 3, wherein the arithmetic means calculates a target movement magnitude signal on the basis of the present common control error signal and a previous control error signal and movement magnitudes thereof.
12. A control apparatus according to claim 11, wherein the arithmetic means includes means for storing the previous common control error signal.
13. A control apparatus according to claim 12, wherein a plurality of arithmetic means are provided, a respective arithmetic means being associated with a respective actuator means of an arm element, and further comprising communication means interconnecting the respective arithmetic means for supplying a signal generated by one of the arithmetic means to another of the arithmetic means.
14. A control apparatus according to claim 11, wherein the arithmetic means includes a first calculating means for calculating the target movement magnitude signal .delta..theta.x in accordance with the equation .delta..theta.x=(.lambda./.alpha.)(E-.beta.), where E is the present common control error signal, .alpha. and .beta. are coefficients, and .lambda. is a proportion coefficient for compensation which is a positive constant smaller than 1, first comparing means for comparing the present common control error signal E with the previous common control error signal Eo and providing a true error deviation output signal .delta.e, second calculating means for calculating a predictive error signal .delta.ex in response to the calcul-ated target movement magnitude signal .delta..theta.x in accordance with the equation .delta.ex=.alpha.?.delta..theta.x+.beta., second comparing means for comparing the predictive error signal .delta.ex with the true error deviation signal .delta.e and providing an error variation signal .delta.E as an output thereof, and third calculating means for calculating updated coefficient values .alpha.' and .beta.' for the coefficient value .alpha. and .beta. utilized by the first and second calculating means in accordance with the equations .alpha.'=.alpha.+.gamma.?.delta..theta.x.delta.E and .beta.'=.gamma.'.delta.E, where .gamma. is a positive constant, the third calculating means supplying the updated coefficient values to the first and second calculating means.
15. A control apparatus according to claim 14, wherein a plurality of arithmetic means are provided, a respective arithmetic means being associated with a respective actuator means of an arm element, and further comprising communication means interconnecting the respective arithmetic means for supplying the error variation signal .delta.E generated by one of the arithmetic means to another of the arithmetic means.
16. A control apparatus according to claim 2, wherein a plurality of arithmetic means are provided, a respective arithmetic means being associated with a respective actuator means of an arm element.
17. A control apparatus according to claim 1, wherein the arithmetic means includes a first calculating means for calculating the target movement magnitude signal .delta..theta.x in accordance with the equation .delta..theta.x=(.lambda./.alpha.)(E-.beta.), where E is the present common control error signal, .alpha. and .beta. are coefficients, and .lambda. is a proportion coefficient for compensation which is a positive constant smaller than 1, first comparing means for comparing the present common control error signal E with the previous common control error signal Eo and providing a true error deviation output signal .delta.e, second calculating means for calculating a predictive error signal .delta.ex in response to the calcul-ated target movement magnitude signal .delta..theta.x in accordance with the equation .delta.ex=.alpha...delta..theta.x+.beta., second comparing means for comparing the predictive error signal .delta.ex with the true error deviation signal .delta.e and providing an error variation signal .delta.E as an output thereof, and third calculating means for calculating updated coefficient values .alpha.' and .beta.' for the coefficient value .alpha. and .beta. utilized by the first and second calculating means in accordance with the equations .alpha.'=.alpha.+.gamma.?.delta..theta.x?.delta.E and .beta.'=.gamma.?.delta.E, where .gamma. is a positive constant, the third calculating means supply-ing the updated coefficient values to the first and second calculating means.
18. A control apparatus according to claim 17, wherein a plurality of arithmetic means are provided, a respective arithmetic means being associated with a respective actuator means of an arm element, and further comprising communication means interconnecting the respective arithmetic means for supplying the error variation signal .delta.E generated by one of the arithmetic means to another of the arithmetic means.
19. A control apparatus according to claim 1, wherein a plurality of arithmetic means are provided, a respective arithmetic means being associated with a respective actuator means of an arm element.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP192352/1983 | 1983-10-17 | ||
| JP58235219A JPS59120683A (en) | 1982-12-17 | 1983-12-15 | Manufacture of hydrocarbon |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1246636A true CA1246636A (en) | 1988-12-13 |
Family
ID=16982842
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000465452A Expired CA1246636A (en) | 1983-10-17 | 1984-10-15 | Control apparatus for multi-jointed arm mechanism |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1246636A (en) |
-
1984
- 1984-10-15 CA CA000465452A patent/CA1246636A/en not_active Expired
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