CA1323699C - Method of detecting a position of a robot - Google Patents
Method of detecting a position of a robotInfo
- Publication number
- CA1323699C CA1323699C CA000566558A CA566558A CA1323699C CA 1323699 C CA1323699 C CA 1323699C CA 000566558 A CA000566558 A CA 000566558A CA 566558 A CA566558 A CA 566558A CA 1323699 C CA1323699 C CA 1323699C
- Authority
- CA
- Canada
- Prior art keywords
- robot
- pulses
- counts
- incremental
- counter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J9/00—Programme-controlled manipulators
- B25J9/16—Programme controls
Landscapes
- Engineering & Computer Science (AREA)
- Robotics (AREA)
- Mechanical Engineering (AREA)
- Numerical Control (AREA)
- Manipulator (AREA)
- Control Of Position Or Direction (AREA)
- Length Measuring Devices With Unspecified Measuring Means (AREA)
- Control And Safety Of Cranes (AREA)
Abstract
ABSTRACT
The present invention relates to a method of detecting the original point of an axis-control machine such as a robot.
Namely, according to the method of the invention, there are provided an incremental encoder disposed for detecting a position of a driven member and another incremental encoder adapted to work in cooperation with (or interlock) the former incremental encoder, and a ratio of cooperative movements of both incremental encoders is established in such a manner that zero signals from both incremental encoders can be transmitted only once at a same time within the range of actuation of said driven member, thereby detecting the position of transmission of zero signals as the original point of the machine.
The present invention relates to a method of detecting the original point of an axis-control machine such as a robot.
Namely, according to the method of the invention, there are provided an incremental encoder disposed for detecting a position of a driven member and another incremental encoder adapted to work in cooperation with (or interlock) the former incremental encoder, and a ratio of cooperative movements of both incremental encoders is established in such a manner that zero signals from both incremental encoders can be transmitted only once at a same time within the range of actuation of said driven member, thereby detecting the position of transmission of zero signals as the original point of the machine.
Description
1~23~99 SPECIFICATION
1. TITLE OF THE INVENTION
METHOD OF DETECTING A POSITION OF A ROBOT
1. TITLE OF THE INVENTION
METHOD OF DETECTING A POSITION OF A ROBOT
2. FIELD OF THE INVENTION AND RELATED ART STATEMENT
The present invention relates to a method of detecting a position of a robot and which is applied to a robot, a manipulator, a machine tool, a transportation machine and the like.
Fig. 4 shows an example of a conventional position detection mechanism of a robot, in which numeral 1 denotes a robot axis which is driven by an actuator not shown in accordance with a command from a controller 5 including a central processor unit (CPU), numeral 2 denotes an incremental position transducer which is mounted to the robot axis to produce pulse signals in response to movement of the robot axis, numeral 3 denotes a reference point detector which is disposed at a reference position to produce a detection signal indicative of a reference point for measurement of a position of the robot when the robot axis 1 is detected at the reference position, numeral 4 denotes a position counter which counts pulse signals produced from the position transducer 2, and numeral 5 denotes a controller which initializes the position counter `
13~99 4 when the reference point detection signal produced from the reference point detector 3 is supplied to the controller 5 and wh;ch controls the robot axis 1.
In the above conventional position detection mechanism of the robot, when the robot is used, the position of the robot axis 1 is not known only by turning on a power source. Accordingly, after turning on the power source, the robot axis 1 is first moved to the reference point detector 3 and when the detector 3 detects the robot axis I the detector 3 produces the detection signal which is supplied to the controller 5. The controller 5 initializes the position counter 4 in response to the detection signal. When the position counter 4 is initialized, the pulse signals produced from the position transducer 2 are counted by the position counter 4 of which a count is increased or decreased with regard to the initialized value so that the position of the robot axis 1 can be detected.
The above description has been made to one robot axis 1 of the conventional robot, while the similar operation is made to all of the robot axes 1.
However, in the case where the conventional position detection mechanism of the robot uses an incremental pulse generator as the position transducer, the position information of the robot axis 1 disappears upon turning off of a control power source of the robot and it is 13'~3~99 21326-111 difficult to control the robot. Consequently, each time the control power source of the robot ls turned on, it is necessary to move the robot axis 1 to the reference point detector 3 and initialize the position counter 4. Accordingly, there is a practical problem that it takes several minutes for each operation to detect the reference polnt. Further, slnce the robot axis 1 is once returned to the reference point detector 3 automatlcally by the detection operation of the reference polnt regardless of the stop posltlon of the robot axls 1, lf there ls any obstacle between the robot axls 1 and the reference point detector 3 the robot axls 1 may colllde against the ob~tacle.
In order to ~olve the above problem, Japanese Patent Provlslonal Publication No. 59-110594 (No. 110594/1984) discloses two lncremental encoders whlch are interlocked wlth each other by a mechanlsm employing gears each having the number of teeth slightly dlfferent from each other and each of which is adapted to produce a zero slgnal slmultaneously only one tlme wlthin an operatlon range of a follower of the robot axis. A posltlon in whlch the zero signals are produced from the encoders simultaneously 18 deflned as a polnt of orlgin for the machlne.
Thus, the polnt of orlgln for the machlne ls detected by detectlng the position, while even such method is not suffisient as detection means of the polnt of origin.
3. OBJECT AND SUMMARY OF THE INVENTION
It i8 an ob~ect of the present invention to solve the above problem and provide a position detection method of a robot which can greatly reduce a detection time of a reference position and a preparatory tlme of operatinq a robot even lf an incremental pulse generator is used as a position transducer.
It is another object of the present inventlon to provide a po~ition detection method of a robot which can greatly reduce a moving dlstance of a robot axis nece~sary for detection of a positlon of the robot even if the incremental pulse generator is u~ed as a position transducer to improve the safety in detectlon of a reference polnt.
In order to achieve the above objects, there is provided a method of detecting a positlon of a robot, characterized ln.
moving the robot to move and rotate flr~t and second lncremental posltion tran~ducers respectively and to cause one of said two incremental transducers to particularly produce finely divlded pulses accordlng to the movement of the robot and indicatlng the dlstance of ~ald move~ent with a counter; causlng said fir~t incremental positlon transducer upon lts movément to produce flrst successive pulses or a first pulse train having an interval corresponding to Pl counts of sald flnely dlvlded pul~es and sald second incremental position transducer upon it~ movement to produce second successive pulses or a second pulse train having an interval corre~pondlng to P2 counts less than sald Pl counts;
reference pulses of sald flrst and second pulses being prevlously made coincldent with a reference position of the robot, and when the current position of the robot ls to be detected, moving the robot for some dlstance to an arbitrary positlon; wlth a controller, detecting the lnitlal pulse of said flrst pulses and then reading in a difference of P21 counts of said flnely dlvided 13~3~99 21326-111 pulses between ~aid initial pul~e of said first pulses and that of said second pulse~ with said counter, and subsequently calculatlng the pulse number i from said reference pul~e of ~ald first pulses as (Pl P2i) / (Pl P2) t so that said po~ition of the robot is obtalned as P1 x i counts;
and said P1 x i counts i8 inltialized on said counter by means of said controller and then current position of the robot i8 indlcated on said counter.
Accordingly, in the position detection method of the robot as described above, the two lncremental position transducer~
disposed rotatably in interlocked relationshlp with the moving robot axis are cau~ed to produce pulses of dlfferent number in accordance with the moving distance of the robot axis. Reference pulses can be detected at any positlon of the robot axls moved over æhort dlstance to calculate the posltlon of the robot axi~ on the basis of the number of pulses between the reference pulses immediately. Accordingly, the moving distance necessary for detection of the reference point can be shortened to less than two rotation~ of the position transducers greatly and the time necessary for the detection of the reference point can be also reduced greatly.
As descrlbed above, according to the present lnvention, the preparatory time of operating the robot can be reduced and the moving distance of the robot axis nece~sary for the positlon detectlon can be shortened to improve the safety in detection of the reference polnt.
13~3~99 4. BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a block diagram showing an embodiment for explaining the position detection method of the robot according to the present invention;
Fig. 2 is a timing chart for explaining operation of the embodiment of Fig. 1;
Fig. 3 is a flowchart for explaining operation of the embodiment of ~ig. 1; and Fig. 4 is a block diagram showing a conventional position detection mechanism of the robot.
The present invention relates to a method of detecting a position of a robot and which is applied to a robot, a manipulator, a machine tool, a transportation machine and the like.
Fig. 4 shows an example of a conventional position detection mechanism of a robot, in which numeral 1 denotes a robot axis which is driven by an actuator not shown in accordance with a command from a controller 5 including a central processor unit (CPU), numeral 2 denotes an incremental position transducer which is mounted to the robot axis to produce pulse signals in response to movement of the robot axis, numeral 3 denotes a reference point detector which is disposed at a reference position to produce a detection signal indicative of a reference point for measurement of a position of the robot when the robot axis 1 is detected at the reference position, numeral 4 denotes a position counter which counts pulse signals produced from the position transducer 2, and numeral 5 denotes a controller which initializes the position counter `
13~99 4 when the reference point detection signal produced from the reference point detector 3 is supplied to the controller 5 and wh;ch controls the robot axis 1.
In the above conventional position detection mechanism of the robot, when the robot is used, the position of the robot axis 1 is not known only by turning on a power source. Accordingly, after turning on the power source, the robot axis 1 is first moved to the reference point detector 3 and when the detector 3 detects the robot axis I the detector 3 produces the detection signal which is supplied to the controller 5. The controller 5 initializes the position counter 4 in response to the detection signal. When the position counter 4 is initialized, the pulse signals produced from the position transducer 2 are counted by the position counter 4 of which a count is increased or decreased with regard to the initialized value so that the position of the robot axis 1 can be detected.
The above description has been made to one robot axis 1 of the conventional robot, while the similar operation is made to all of the robot axes 1.
However, in the case where the conventional position detection mechanism of the robot uses an incremental pulse generator as the position transducer, the position information of the robot axis 1 disappears upon turning off of a control power source of the robot and it is 13'~3~99 21326-111 difficult to control the robot. Consequently, each time the control power source of the robot ls turned on, it is necessary to move the robot axis 1 to the reference point detector 3 and initialize the position counter 4. Accordingly, there is a practical problem that it takes several minutes for each operation to detect the reference polnt. Further, slnce the robot axis 1 is once returned to the reference point detector 3 automatlcally by the detection operation of the reference polnt regardless of the stop posltlon of the robot axls 1, lf there ls any obstacle between the robot axls 1 and the reference point detector 3 the robot axls 1 may colllde against the ob~tacle.
In order to ~olve the above problem, Japanese Patent Provlslonal Publication No. 59-110594 (No. 110594/1984) discloses two lncremental encoders whlch are interlocked wlth each other by a mechanlsm employing gears each having the number of teeth slightly dlfferent from each other and each of which is adapted to produce a zero slgnal slmultaneously only one tlme wlthin an operatlon range of a follower of the robot axis. A posltlon in whlch the zero signals are produced from the encoders simultaneously 18 deflned as a polnt of orlgin for the machlne.
Thus, the polnt of orlgln for the machlne ls detected by detectlng the position, while even such method is not suffisient as detection means of the polnt of origin.
3. OBJECT AND SUMMARY OF THE INVENTION
It i8 an ob~ect of the present invention to solve the above problem and provide a position detection method of a robot which can greatly reduce a detection time of a reference position and a preparatory tlme of operatinq a robot even lf an incremental pulse generator is used as a position transducer.
It is another object of the present inventlon to provide a po~ition detection method of a robot which can greatly reduce a moving dlstance of a robot axis nece~sary for detection of a positlon of the robot even if the incremental pulse generator is u~ed as a position transducer to improve the safety in detectlon of a reference polnt.
In order to achieve the above objects, there is provided a method of detecting a positlon of a robot, characterized ln.
moving the robot to move and rotate flr~t and second lncremental posltion tran~ducers respectively and to cause one of said two incremental transducers to particularly produce finely divlded pulses accordlng to the movement of the robot and indicatlng the dlstance of ~ald move~ent with a counter; causlng said fir~t incremental positlon transducer upon lts movément to produce flrst successive pulses or a first pulse train having an interval corresponding to Pl counts of sald flnely dlvlded pul~es and sald second incremental position transducer upon it~ movement to produce second successive pulses or a second pulse train having an interval corre~pondlng to P2 counts less than sald Pl counts;
reference pulses of sald flrst and second pulses being prevlously made coincldent with a reference position of the robot, and when the current position of the robot ls to be detected, moving the robot for some dlstance to an arbitrary positlon; wlth a controller, detecting the lnitlal pulse of said flrst pulses and then reading in a difference of P21 counts of said flnely dlvided 13~3~99 21326-111 pulses between ~aid initial pul~e of said first pulses and that of said second pulse~ with said counter, and subsequently calculatlng the pulse number i from said reference pul~e of ~ald first pulses as (Pl P2i) / (Pl P2) t so that said po~ition of the robot is obtalned as P1 x i counts;
and said P1 x i counts i8 inltialized on said counter by means of said controller and then current position of the robot i8 indlcated on said counter.
Accordingly, in the position detection method of the robot as described above, the two lncremental position transducer~
disposed rotatably in interlocked relationshlp with the moving robot axis are cau~ed to produce pulses of dlfferent number in accordance with the moving distance of the robot axis. Reference pulses can be detected at any positlon of the robot axls moved over æhort dlstance to calculate the posltlon of the robot axi~ on the basis of the number of pulses between the reference pulses immediately. Accordingly, the moving distance necessary for detection of the reference point can be shortened to less than two rotation~ of the position transducers greatly and the time necessary for the detection of the reference point can be also reduced greatly.
As descrlbed above, according to the present lnvention, the preparatory time of operating the robot can be reduced and the moving distance of the robot axis nece~sary for the positlon detectlon can be shortened to improve the safety in detection of the reference polnt.
13~3~99 4. BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a block diagram showing an embodiment for explaining the position detection method of the robot according to the present invention;
Fig. 2 is a timing chart for explaining operation of the embodiment of Fig. 1;
Fig. 3 is a flowchart for explaining operation of the embodiment of ~ig. 1; and Fig. 4 is a block diagram showing a conventional position detection mechanism of the robot.
5. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT
An embodiment of the present invention is now described with reference to the drawings.
Fig. 1 shows a configuration of the position detection mechanism of the robot. In Fig. 1, numeral 13 denotes a drive shaft of a position transducer which rotates in response to movement of a robot axis not shown. A gear mounted to the drive shaft 13 is meshed with a first reduction gear 16 and is then meshed with a second reduction gear 17 through the first reduction gear 16 having the number of teeth different from that of the second reduction gear 17. A first incremental position transducer (PLG1) 11 is mounted to a rotating shaft of the first reduction gear 16 and a second incremental position transducer (PLG2) 12 is 132~99 also mounted to a rotating shaft of the second reduction gear 17. The first and second position transducers 11 and 12 are adapted to produce pulse signals having a different number in accordance with a moving distance of the robot axis on the basis of a difference between the numbers of teeth of the first and second reduction gears 16 and 17.
Further, numeral 14 denotes a position counter which counts pulses A produced from the first position transducer 11 each time the transducer 11 rotates by a predetermined angle tif the transducer 11 produces one pulse for each 10 degrees, for example, the transducer 11 produces 36 pulses per one rotation). Numeral 15 denotes a controller including a CPU
which is supplied with reference pulses Z1 and Z2 produced from the first and second position transducers 11 and 12, respectively, and a count of the pulses A counted by the position counter 14. When the controller 15 detects the supply of the reference pulses Zl and Z2 from the first and second position transducer 11 and 12 and the pulses A from the first position transducers 11, the controller 15 initializes the position counter 14 and at the same time the controller 15 performs a predetermined calculation on the basis of the the reference pulses Zl and Z2 and the pulses A
to detect a moving position of the robot axis. In this case, the reference pulses Zl and Zl of the first and second position transducers 11 and 12 are caused to previously 1 3 ~
coincide with a reference position of the robot axis.
Operation of the position detection mechanism of the robo t configured as above is described with reference to a timing chart shown in Fig. 2 and a flowchart shown in Fig.
3. When the robot axis is moved to any position after turning on a power source, the drive shaft 13 rotates in response to the movement. When the drive shaft 13 is rotated, the first position transducer 11 is rotated through the first reduction gear 16 and the second position transducer 12 is also rotated through the second reduction gear 17 so that the first and second position transducers 11 and 12 produce the reference pulses Z1 and Z2 at the timing shown in Fig. 2. When the reference pulses Zl and Zz are supplied to the controller 15 and at the same time a count of the pulses A produced from the first position transducer 11 and counted by the position counter 14 is read in the controller 15, the controller 15 performs the following operation to detect the position of the robot axis.
At the same time when the robot axis begins to move, the controller begins to detect the reference pulses Z1 of the first position transducer 11 as shown in flow of o~ ~ ~ of Fig. 3. It is assumed that the rotational number from the reference position of the first position transducer 11 at the time when the reference pulse Zl has been first detected is i-1 and that the count of the 13~3~9 position counter 14 until the first reference pulse Zz read in flow of ~ ~ ~ of Fig. 3 is detected after detection of the pulses Z1 for the (i-l)th rotation as shown in Fig. 2 is Pzi. Thus, the rotational number ~ of the reference pulses Zl from the reference position is calculated by i=~ Pi/~ Po=(PI-Pzi) ~ Po as shown in floW of of Fig. 3. Accordingly, the position of the robot axis upon detection of the second reference pulse Zl can be calculated by Position of Ro'bot Axis = Pl x i In this case, when the controller 15 has detected the second reference pulse Zl, the count (P1 x i) of the position counter 14 is initialized to the robot position calculated above.
Thereafter, the position counter 14 counts the pulses A produced from the first position transducer 11 in response to the movement of the robot axis to add or subtract the count to the initial value of the counter 14 so that the result of the addition or subtraction expresses the position of the robot.
As described above, in the embodiment, the first and second incremental position transducers 11 and 12 are mounted to each of the shafts of the first and second reduction gears l6 and 17 which are sequentially coupled ', ~ ' ' ' ' ' , , , 132~9 with the drive shaft 13, which is driven in response to the movement of the robot axis, through the respective gears having the number of teeth different from each other. The reference pulses produced from each of the first and second position transducers 11 and 12 each time the first and second position transducers 11 and 12 make one revolution are supplied to the controller 15 and the pulses A produced from the first position transducer 11 each time the first position transducer 11 is rotated at a predetermined angle are counted by the position counter 14 to supply the count to the controller 15. Consequently, the controller 15 calculates the difference (P2i) of the pulse number between the reference pulses of the first and second position transducers 11 and 12 at any position of the robot axis and then calculates the pulse number ti) of a next reference pulse from the reference position on the basis of i=tP1-Pz~)/(P1-Pz) so that the position of the robot axis is obtained from Pl x i.
Accordingly, the method of detecting the position of the robot axis by using the incremental position transducer can greatly reduce the moving distance necessary for detection of the reference point to less than two rotations of the position transducer. Thus, the time required to detect the reference point can be also greatly reduced and the preparatory time for operating the robot can 13~3~99 be reduced. Further, since the moving distance necessary for detection of the position of the robot axis can be shortened greatly, the safety in the detection of the reference point can be improved.
; In the embodiment, description has been made to one robot axis of the robot, while it is a matter of course that the similar configuration is applied to all of the robot axes of the robot.
As describe above, according to the present invention, there can be provided the position detection method of the robot which can reduce the preparatory time for operating the robot and greatly shorten the moving distance of the robot axis necessary for the position detection to improve the safety in the detection of the reference point since the detection time of the reference position can be greatly reduced even if the incremental pulse generator is employed as the position transducer.
An embodiment of the present invention is now described with reference to the drawings.
Fig. 1 shows a configuration of the position detection mechanism of the robot. In Fig. 1, numeral 13 denotes a drive shaft of a position transducer which rotates in response to movement of a robot axis not shown. A gear mounted to the drive shaft 13 is meshed with a first reduction gear 16 and is then meshed with a second reduction gear 17 through the first reduction gear 16 having the number of teeth different from that of the second reduction gear 17. A first incremental position transducer (PLG1) 11 is mounted to a rotating shaft of the first reduction gear 16 and a second incremental position transducer (PLG2) 12 is 132~99 also mounted to a rotating shaft of the second reduction gear 17. The first and second position transducers 11 and 12 are adapted to produce pulse signals having a different number in accordance with a moving distance of the robot axis on the basis of a difference between the numbers of teeth of the first and second reduction gears 16 and 17.
Further, numeral 14 denotes a position counter which counts pulses A produced from the first position transducer 11 each time the transducer 11 rotates by a predetermined angle tif the transducer 11 produces one pulse for each 10 degrees, for example, the transducer 11 produces 36 pulses per one rotation). Numeral 15 denotes a controller including a CPU
which is supplied with reference pulses Z1 and Z2 produced from the first and second position transducers 11 and 12, respectively, and a count of the pulses A counted by the position counter 14. When the controller 15 detects the supply of the reference pulses Zl and Z2 from the first and second position transducer 11 and 12 and the pulses A from the first position transducers 11, the controller 15 initializes the position counter 14 and at the same time the controller 15 performs a predetermined calculation on the basis of the the reference pulses Zl and Z2 and the pulses A
to detect a moving position of the robot axis. In this case, the reference pulses Zl and Zl of the first and second position transducers 11 and 12 are caused to previously 1 3 ~
coincide with a reference position of the robot axis.
Operation of the position detection mechanism of the robo t configured as above is described with reference to a timing chart shown in Fig. 2 and a flowchart shown in Fig.
3. When the robot axis is moved to any position after turning on a power source, the drive shaft 13 rotates in response to the movement. When the drive shaft 13 is rotated, the first position transducer 11 is rotated through the first reduction gear 16 and the second position transducer 12 is also rotated through the second reduction gear 17 so that the first and second position transducers 11 and 12 produce the reference pulses Z1 and Z2 at the timing shown in Fig. 2. When the reference pulses Zl and Zz are supplied to the controller 15 and at the same time a count of the pulses A produced from the first position transducer 11 and counted by the position counter 14 is read in the controller 15, the controller 15 performs the following operation to detect the position of the robot axis.
At the same time when the robot axis begins to move, the controller begins to detect the reference pulses Z1 of the first position transducer 11 as shown in flow of o~ ~ ~ of Fig. 3. It is assumed that the rotational number from the reference position of the first position transducer 11 at the time when the reference pulse Zl has been first detected is i-1 and that the count of the 13~3~9 position counter 14 until the first reference pulse Zz read in flow of ~ ~ ~ of Fig. 3 is detected after detection of the pulses Z1 for the (i-l)th rotation as shown in Fig. 2 is Pzi. Thus, the rotational number ~ of the reference pulses Zl from the reference position is calculated by i=~ Pi/~ Po=(PI-Pzi) ~ Po as shown in floW of of Fig. 3. Accordingly, the position of the robot axis upon detection of the second reference pulse Zl can be calculated by Position of Ro'bot Axis = Pl x i In this case, when the controller 15 has detected the second reference pulse Zl, the count (P1 x i) of the position counter 14 is initialized to the robot position calculated above.
Thereafter, the position counter 14 counts the pulses A produced from the first position transducer 11 in response to the movement of the robot axis to add or subtract the count to the initial value of the counter 14 so that the result of the addition or subtraction expresses the position of the robot.
As described above, in the embodiment, the first and second incremental position transducers 11 and 12 are mounted to each of the shafts of the first and second reduction gears l6 and 17 which are sequentially coupled ', ~ ' ' ' ' ' , , , 132~9 with the drive shaft 13, which is driven in response to the movement of the robot axis, through the respective gears having the number of teeth different from each other. The reference pulses produced from each of the first and second position transducers 11 and 12 each time the first and second position transducers 11 and 12 make one revolution are supplied to the controller 15 and the pulses A produced from the first position transducer 11 each time the first position transducer 11 is rotated at a predetermined angle are counted by the position counter 14 to supply the count to the controller 15. Consequently, the controller 15 calculates the difference (P2i) of the pulse number between the reference pulses of the first and second position transducers 11 and 12 at any position of the robot axis and then calculates the pulse number ti) of a next reference pulse from the reference position on the basis of i=tP1-Pz~)/(P1-Pz) so that the position of the robot axis is obtained from Pl x i.
Accordingly, the method of detecting the position of the robot axis by using the incremental position transducer can greatly reduce the moving distance necessary for detection of the reference point to less than two rotations of the position transducer. Thus, the time required to detect the reference point can be also greatly reduced and the preparatory time for operating the robot can 13~3~99 be reduced. Further, since the moving distance necessary for detection of the position of the robot axis can be shortened greatly, the safety in the detection of the reference point can be improved.
; In the embodiment, description has been made to one robot axis of the robot, while it is a matter of course that the similar configuration is applied to all of the robot axes of the robot.
As describe above, according to the present invention, there can be provided the position detection method of the robot which can reduce the preparatory time for operating the robot and greatly shorten the moving distance of the robot axis necessary for the position detection to improve the safety in the detection of the reference point since the detection time of the reference position can be greatly reduced even if the incremental pulse generator is employed as the position transducer.
Claims
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of detecting a position of a robot, characterized in:
moving the robot to move and rotate first and second incremental position transducers respectively and to cause one of said two incremental transducers to particularly produce finely divided pulses according to the movement of the robot and indicating the distance of said movement with a counter;
causing said first incremental position transducer upon its movement to produce first successive pulses or a first pulse train having an interval corresponding to P1 counts of said finely divided pulses and said second incremental position transducer upon its movement to produce second successive pulses or a second pulse train having an interval corresponding to P2 counts less than said P1 counts;
reference pulses of said first and second pulses being previously made coincident with a reference position of the robot, and when the current position of the robot is to be detected, moving the robot for some distance to an arbitrary position;
with a controller, detecting the initial pulse of said first pulses and then reading in a difference of P2i counts of said finely divided pulses between said initial pulse of said first pulses and that of said second pulses with said counter, and subsequently calculating the pulse number i from said reference pulse of said first pulses as i = (P1 - P2i) / (P1 - P2), so that said position of the robot is obtained as P1 x i counts;
and said P1 x i counts is initialized on said counter by means of said controller and then current position of the robot is indicated on said counter.
moving the robot to move and rotate first and second incremental position transducers respectively and to cause one of said two incremental transducers to particularly produce finely divided pulses according to the movement of the robot and indicating the distance of said movement with a counter;
causing said first incremental position transducer upon its movement to produce first successive pulses or a first pulse train having an interval corresponding to P1 counts of said finely divided pulses and said second incremental position transducer upon its movement to produce second successive pulses or a second pulse train having an interval corresponding to P2 counts less than said P1 counts;
reference pulses of said first and second pulses being previously made coincident with a reference position of the robot, and when the current position of the robot is to be detected, moving the robot for some distance to an arbitrary position;
with a controller, detecting the initial pulse of said first pulses and then reading in a difference of P2i counts of said finely divided pulses between said initial pulse of said first pulses and that of said second pulses with said counter, and subsequently calculating the pulse number i from said reference pulse of said first pulses as i = (P1 - P2i) / (P1 - P2), so that said position of the robot is obtained as P1 x i counts;
and said P1 x i counts is initialized on said counter by means of said controller and then current position of the robot is indicated on said counter.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP121079/1987 | 1987-05-20 | ||
| JP62121079A JPS63286705A (en) | 1987-05-20 | 1987-05-20 | Position detecting method for robot |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1323699C true CA1323699C (en) | 1993-10-26 |
Family
ID=14802334
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000566558A Expired - Fee Related CA1323699C (en) | 1987-05-20 | 1988-05-12 | Method of detecting a position of a robot |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS63286705A (en) |
| KR (1) | KR940000366B1 (en) |
| CN (1) | CN1010887B (en) |
| AU (1) | AU611149B2 (en) |
| CA (1) | CA1323699C (en) |
| MY (1) | MY102208A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112374371A (en) * | 2020-11-20 | 2021-02-19 | 中船华南船舶机械有限公司 | Control method of crane rotation zero-position switch |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100351720C (en) * | 2002-05-05 | 2007-11-28 | 旋永南 | Operation and control system and mehod |
| JP5915417B2 (en) * | 2012-07-03 | 2016-05-11 | トヨタ車体株式会社 | Rotation position detector |
| CN108120370A (en) * | 2016-11-26 | 2018-06-05 | 沈阳新松机器人自动化股份有限公司 | Position of mobile robot acquisition methods and device |
| CN113364385B (en) * | 2021-06-09 | 2023-12-29 | 湖南东嘉智能科技有限公司 | Brushless motor initial position detection method without position sensor |
Family Cites Families (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5911054A (en) * | 1982-07-12 | 1984-01-20 | Omron Tateisi Electronics Co | Data transmitter |
| JPS5988612A (en) * | 1982-11-15 | 1984-05-22 | Toshiba Mach Co Ltd | Method and apparatus for detecting absolute position |
| JPH0629723B2 (en) * | 1984-02-06 | 1994-04-20 | シンシナテイ・ミラクロン・インコーポレーテツド | Absolute position measuring method and device |
| JPS6191510A (en) * | 1984-10-12 | 1986-05-09 | Yaskawa Electric Mfg Co Ltd | Method and apparatus for detecting present position |
-
1987
- 1987-05-20 JP JP62121079A patent/JPS63286705A/en active Pending
-
1988
- 1988-05-11 MY MYPI88000497A patent/MY102208A/en unknown
- 1988-05-12 CA CA000566558A patent/CA1323699C/en not_active Expired - Fee Related
- 1988-05-12 AU AU16083/88A patent/AU611149B2/en not_active Ceased
- 1988-05-18 KR KR1019880005823A patent/KR940000366B1/en not_active IP Right Cessation
- 1988-05-19 CN CN88102951A patent/CN1010887B/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112374371A (en) * | 2020-11-20 | 2021-02-19 | 中船华南船舶机械有限公司 | Control method of crane rotation zero-position switch |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63286705A (en) | 1988-11-24 |
| AU1608388A (en) | 1988-11-24 |
| KR880013662A (en) | 1988-12-21 |
| CN1010887B (en) | 1990-12-19 |
| MY102208A (en) | 1992-04-30 |
| AU611149B2 (en) | 1991-06-06 |
| KR940000366B1 (en) | 1994-01-19 |
| CN88102951A (en) | 1988-11-30 |
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