JP3783545B2 - Robot control apparatus and robot control method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a robot control device and a robot control method using the control device.
[0002]
[Prior art]
FIG. 7 is a diagram illustrating a gate-type operation by a conventional robot control device disclosed in, for example, Japanese Patent Laid-Open No. 1-108604. The robot follows a speed and acceleration / deceleration pattern specified on the condition that the robot linearly rises vertically from the position A to the position B by the distance L1 and descends vertically to the position H by a certain distance L2 from the position G. , From position A to position H.
Next, the operation will be described. First, the rising time tAB (not shown) from the position A to the distance L1, the falling time tFG (not shown) from the position F to the position G above the distance L2 from the position H, and the horizontal movement time tCF (not shown). ) An upward servo command from position A is issued to the robot, then a servo command for starting horizontal movement is issued after time tAB, and a downward servo command is issued after time tCF-tFG.
FIG. 8 is a diagram showing a velocity waveform of a conventional portal type operation. The ascending operation is started at time tA, and the horizontal operation is started at time tB. The ascending operation continues at a constant speed until time tI, and then completes the ascending operation at time tC with a deceleration specified in advance. At time tF, a descent operation is started by a predetermined acceleration. At time tJ, the highest speed is reached. At time tG, the horizontal movement is completed at the same time as passing through the position G while maintaining the highest speed. The descent operation is completed.
[0003]
[Problems to be solved by the invention]
In the conventional robot control apparatus and robot control method, according to the specified fixed acceleration / deceleration time, the robot suddenly decelerates from time tI during the ascending operation, and accelerates rapidly from time tF to time tJ during the descending operation. There was a problem that it was likely to occur. Further, when the ascending and horizontal operations and the horizontal and descending operations are performed in duplicate, the time tB to time tI and the time tJ to tG perform the ascending and descending operations at the highest speed. There is a problem that vibration occurs in the robot, and a large centrifugal force is applied to the object held by the robot, causing it to come off the robot.
The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a robot control device and a robot control method for realizing a smooth robot operation without vibration at high speed. is there.
[0004]
[Means for Solving the Problems]
According to a first aspect of the present invention, there is provided a robot control device for a horizontal operation time calculating means for obtaining an operation time of a horizontal operation in a robot control device for performing a gate-type composite operation that partially performs ascending, horizontal and descending operations. An overlapping operation time calculating means for calculating the sum of the operation time of the ascending operation and the descending operation operating overlapping with the horizontal operation, a means for determining whether or not the horizontal operation time is longer than the overlapping operation time, As a result, when the horizontal operation time is longer than the overlapping operation time, a vertical operation acceleration / deceleration time adjusting means for changing the ascending operation deceleration time and the descending operation acceleration time is provided.
[0005]
According to a second aspect of the present invention, there is provided a robot control apparatus for controlling a horizontal operation time in a robot control apparatus that performs a gate-type complex operation in which a part of the ascending, horizontal, and descending actions is overlapped. calculation means, passed through the vertical elevating distance specified in advance, and upward movement pattern generating means starts deceleration immediately after passing through the vertical rise amount, generates an operation pattern that reaches the upward movement target position, after completing the accelerated to the vertical descent amount from the upper end downward movement start position to a pre-specified vertical descending distance can reach the target position through while Hayashi reduction in downward movement, object constant speed operation, and deceleration A descending motion pattern generating means that reaches a position, an overlapping motion time of the ascending motion and the horizontal motion generated by the ascending motion pattern generating means, and the descending motion Ascending operation target position and descending operation start position calculating means for obtaining the ascending operation target position and the descending operation start position so that the sum of overlapping times of the descending action and the horizontal action generated in the turn generating means is equal to the horizontal operation time. It is to be prepared.
[0006]
Further, the robot control apparatus according to the third configuration of the present invention is configured such that the ascending motion target position and the descending motion start position calculating means determine that the height of the ascending motion target position and the descending motion start position are equal. is there.
[0007]
The robot control method according to the fourth configuration of this invention, elevated, horizontal, method of controlling a robot to perform a portal combined operation performed by partially overlapping the downward movement, the horizontal operation time corresponding to the horizontal operation Obtain the overlap operation time that is the sum of the operation time of the ascending operation and the descending operation that overlaps with the horizontal operation, determine whether the horizontal operation time is longer than the overlap operation time, and as a result of the determination, When the horizontal operation time is longer than the overlapping operation time, the deceleration time for the ascending operation and the acceleration time for the descending operation are changed .
[0008]
According to a fifth aspect of the present invention, there is provided a robot control method for obtaining a horizontal operation time corresponding to a horizontal operation in the control method for a robot performing a gate-type composite operation in which the ascending, horizontal and descending operations are partially overlapped. , filtered through a vertical elevating distance specified in advance, generates upward movement pattern to reach a raised operation target position to start deceleration immediately after passing through the vertical rise amount, pre specified in downward movement perpendicular after the downward movement start position to reach the target position through while Hayashi reduced the descending stroke has completed accelerated by vertical descent amount upper, constant speed operation, the lowering operation pattern by deceleration reaches to the target position The sum of the overlapping operation time of the rising operation and horizontal operation generated by the rising operation pattern and the overlapping time of the descending operation and horizontal operation generated by the descending operation pattern is Is obtained by configured to determine the operating time becomes equal to such increase operation target position and lowering operation start position.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is a diagram for explaining a robot control apparatus according to Embodiment 1 of an embodiment for carrying out the present invention.
In FIG. 1, 1 is a robot control device, 101 is an arithmetic device for executing a robot program and calculating a robot command value, 102 is a storage device for storing the robot program and calculation results, and 103 is for communication with an external device. An input / output device 104 is a servo control unit for driving the robot based on the command value calculated by the arithmetic unit 101. Reference numeral 2 denotes a robot controlled by the robot control device 1.
[0010]
FIG. 2 is an explanatory diagram showing the operation of the robot 2 according to the present invention. The movement start position P1, the target position P8, the vertical lift amount L1 that must rise vertically from the start position P1, the vertical drop distance L2 that must fall vertically to the target position P8, and the height at the time of lift Ascending height h1 that is the upper limit and descending height h2 that is the upper limit of the height when descending are given in advance. The robot 2 starts the ascending operation from the start position P1 toward the position P3 that is higher by the ascent height h1. The vertical movement from the position P3 to the position P6 is started when reaching the position P2 where the vertical ascent distance L1 has risen. Then, the ascending operation is terminated at the position P4 (P4 ′). Next, in the descending operation from the position P6 to the position P8, a time T57 from the start of the operation from the position P6 to the position P7 which is higher by the vertical descending distance L2 from the position P8 is obtained, and the remaining time until the horizontal operation reaches the position P6. When the horizontal movement reaches the position P5 (P5 ′) at which T becomes T57, the lowering movement is started. The horizontal movement ends at position P7, and the robot descends vertically from position P7 to position P8.
[0011]
FIG. 3 shows a velocity waveform during the operation of the robot 2 according to the first embodiment of the present invention, and FIG. 4 shows a flowchart for obtaining the deceleration time of the ascending operation and the acceleration time of the descending operation.
In FIG. 3, t1 to t8 represent times when the robot passes positions P1 to P8, respectively. At time t1, the robot starts an ascending operation and also starts a horizontal operation from time t2. The rising operation ends at time t3 = t4 or t3 ′ = t4 ′. The descending operation is started from time t5 or t5 ′, and the horizontal operation is ended at time t6 = t7. Then, the descent operation is also completed at time t8, and all the operations are completed.
In step ST1 of FIG. 4, first, the horizontal operation time Th = t6-t2 is obtained. In step ST2, the overlapping operation time T23 = t3-t2 of the ascending operation and the horizontal operation and the overlapping operation time T57 = t7-t5 of the horizontal operation and the descending operation are obtained. At this time, the acceleration / deceleration time given in advance is used as the deceleration time for the ascending operation and the acceleration time for the descending operation. In step ST3, a time T45 = t5−t4 = Th−T23−T57 in which the horizontal independent operation that does not overlap with the vertical operation is obtained. In step ST4, it is determined whether the horizontal single operation time T45 is positive or negative. If it is positive, there is a horizontal single operation, so the process proceeds to step ST5. If negative, there is no horizontal single operation, and the process ends without changing the acceleration / deceleration time.
[0012]
In step ST5, the overlapping operation time T23 of the ascending operation is compared with the deceleration time of the ascending operation. If the deceleration time is shorter, the process proceeds to step ST6. If the deceleration time is longer, the total operation time becomes longer if the deceleration time is lengthened, and therefore cannot be corrected. In step ST7, the deceleration extension possible time Tu1 = 0 in the ascending operation.
In step ST6, a decelerable extension time Tu1 = t3′−t3 that satisfies the condition that the decelerating operation in the ascending operation is not started before reaching the position P2 is obtained. If the deceleration time given in advance is Tu0, Tu0 + Tu1 is the corrected maximum deceleration time.
[0013]
In step ST8, the overlapping operation time T57 of the descending operation is compared with the acceleration time of the descending operation. If the acceleration time is shorter, the process proceeds to step ST9. If the acceleration time is longer, the total operation time becomes longer if the acceleration time is lengthened, so that the correction cannot be made. In step ST10, the acceleration extension possible time Td1 = 0 is set in the descending operation.
In step ST9, an acceleration extension possible time Td1 = t5′−t5 that satisfies the condition that the acceleration operation in the descending operation ends before reaching the position P7 is obtained. Assuming that the preset acceleration time is Td0, Td0 + Td1 is the maximum acceleration time.
[0014]
In step ST11, the optimum ascending operation deceleration time Tu2 and descending operation acceleration time Td2 are obtained from the horizontal single operation time T45, the ascending operation deceleration extendable time Tu1, and the descending operation acceleration extendable time Td1. In the case of Tu1 + Td1 ≦ T45, even if the deceleration time and acceleration time are extended by Tu1 and Td1, respectively, the up and down movements do not overlap, so that Tu2 = Tu0 + Tu1 and Td2 = Td0 + Td1. In the case of Tu1 + Td1> T45, if the acceleration / deceleration time is extended to the maximum, the vertical motion overlaps. Therefore, Tu1 ′ and Td1 ′ satisfying Tu1 ′ + Td1 ′ = T45 are obtained, and Tu2 = Tu0 + Tu1 ′, Td2 = Td0 + Td1 ′. To do. Td1 ′ and Td2 ′ can be obtained by the following equations.
Tu1 ′ = Tu1 × T45 / (Td1 + Tu1)
Td1 ′ = Td1 × T45 / (Td1 + Tu1)
By changing the acceleration / deceleration time to the ascending operation deceleration time Tu2 and the descending operation acceleration time Td2 obtained as described above, the positions P4 and P5 in FIG. 2 are changed to positions P4 ′ and P5 ′, and the total operation time is reached. It is possible to realize a smooth operation of P1->P2-> P4 '->P5'->P7-> P8 without increasing the length. In addition, as shown in FIG. 3, the acceleration / deceleration of the up / down motion is moderated by changing the time at which the ascent operation reaches the position P3 from t3 to t3 ′ and the start time of the descending operation from t5 to t5 ′. This makes it difficult for vibration to occur.
[0015]
Embodiment 2. FIG.
FIG. 5 is a waveform diagram showing a velocity waveform in the portal operation. In FIG. 5, t1 to t8 represent times when the robot passes positions P1 to P8, respectively. At time t1, the robot starts an ascending operation and also starts a horizontal operation from time t2. The ascending operation ends at time t3 = t4 or t3 ′ = t4 ′. The descending operation is started from time t5 or t5 ′, and the horizontal operation is ended at time t6 = t7. Then, the descent operation is also completed at time t8, and all the operations are completed.
[0016]
In FIG. 6, the start position, the target position, the vertical ascent distance, and the vertical descend distance are specified in advance in the portal operation, and the ascending height and descending descending height are not specified or are simply specified to represent the upper limit. It is a flowchart explaining the method of calculating | requiring the optimal height in the case where it may pass what kind of track | orbit if it is lower than the made height. In FIG. 6, positions P1 to P8 are the positions shown in FIG.
In step ST20, first, a horizontal operation time Th = t6-t2 is obtained. When operating the specified vertical elevating distance L 1 between the vertical downward distance L 2 from the position P1 to the position P8, position P3, P6 which the shortest time and most Operation height becomes low, passes through the position P2 The position after decelerating immediately after reaching the position P3 and the operation start position for completing the acceleration before passing the position P7 during the descending operation are obtained as the position P6. When the ascending operation is performed with the position P3 thus obtained as the target position, the ascending operation is terminated at time t3 in FIG. Further, when the descent operation is started from the position P6, the operation is started from the time t5 in FIG. 5, and the operation is ended at the time t8. In step ST21, the overlapping operation time T23 of the ascending operation and the horizontal operation and the overlapping operation time T57 of the horizontal operation and the descending operation when the operation is performed using the positions P3 and P6 thus determined are obtained.
[0017]
In step ST22, the overlapping operation times T23 and T57 are compared with the horizontal operation time Th. If T23 + T57 <Th, the process proceeds to step ST23. If T23 + T57 ≧ Th, the process proceeds to step ST25. In step ST25, when Tu0 + Td0 ≧ Th, if the operation is performed so as to decelerate after passing P2 during the ascending operation and the acceleration is completed by P7 during the descending operation, the ascending operation and the descending operation overlap. The position P3 and the position P6 are determined so as not to end, and the process ends.
In step ST23, optimum deceleration time Tu3 for the ascending operation and acceleration time Td3 for the descending operation are obtained by the following equations so as to satisfy Tu3 + Td3 = Th.
Tu3 = T23 × Th / (T23 + T57)
Td3 = T57 × Th / (T23 + T57)
Instead of using the above formula, Tu3 and Td3 may be obtained so that Tu3 + Td3 = Th is satisfied and the height difference between P3 and P6 is minimized.
[0018]
In step ST24, the positions P3 and P6 when the acceleration / deceleration of the up and down motion is performed in Tu3 and Td3 obtained in step ST23 are obtained, and these are ended with the optimum position for the ascending motion and the starting position for the descending motion. When the positions P3 and P6 are obtained in this way, the end time of the ascending operation is t3 ′, and the start time of the descending operation is t5 ′. As described above, by obtaining the position P3 and the position P6, the operation is performed from the position P1 to the position P8 in the shortest time, and the acceleration / deceleration time of the ascending / descending operations is increased without changing the total operation time, thereby vibrating. Smooth operation with a small amount of movement becomes possible. Further, by reducing the height of the operation, it is possible to operate in a narrow space.
Further, by obtaining the position P3 and the position P6 so as to be the same height, the robot capable of independently controlling the horizontal movement and the vertical movement can operate at a high speed because the horizontal movement and the rising / lowering movement are independent. Become.
[0019]
In the first and second embodiments, the case of the trapezoidal shape has been described as the speed waveform of the operation. However, when passing through a speed filter in order to make this smooth, it can be obtained in the same manner in consideration of the delay of the filter. Good.
[0020]
In Embodiments 1 and 2, the rising height and the falling height are specified separately. However, if only one height is specified and both are set to the same height, the same effect can be obtained. Needless to say.
[0021]
In the first and second embodiments, the case has been described in which the predetermined vertical ascent distance is passed in the shortest time and the predetermined vertical descent distance is decelerated in the shortest time while passing in the shortest time. Cases other than the case are included in the scope of the present invention.
[0022]
【The invention's effect】
According to the robot control device of the first configuration of the present invention, in the portal operation, the ascending / descending operation is performed by setting the deceleration time of the ascending operation and the acceleration time of the descending operation long in a range where the total operation time does not become long. The acceleration / deceleration operation in the operation is gradual, and the smooth operation is realized. Therefore, there is an effect that high-speed operation can be performed without causing vibration.
[0023]
Further, according to the robot control device of the second configuration of the present invention, in the portal operation, the acceleration / deceleration operation in the ascending / descending operations is gently performed by setting the height of the ascending / descending operations as low as possible. Therefore, since smooth operation is realized, there is an effect that high-speed operation is possible without causing vibration.
[0024]
Further, according to the robot control apparatus of the third configuration of the present invention, the height of the ascending motion and the height of the descending motion are determined to be the same height, so that the effect of enabling high speed operation is achieved. is there.
[0025]
Further, according to the robot control method of the fourth configuration of the present invention, in the gate type operation, by setting the deceleration time of the ascending operation and the acceleration time of the descending operation long in a range where the total operation time does not become long, Since the acceleration / deceleration operation in the descending operation is gradual and smooth operation is realized, there is an effect that high-speed operation is possible without causing vibration.
[0026]
Further, according to the robot control method of the fifth configuration of the present invention, the acceleration / deceleration operation in the ascending / descending operations is moderated by setting the height of the ascending / descending operations as low as possible in the portal operation. Since smooth operation is realized, there is an effect that high-speed operation is possible without causing vibration.
[Brief description of the drawings]
FIG. 1 is a configuration diagram for explaining a robot control device and a robot control method according to first and second embodiments;
FIG. 2 is an explanatory diagram for explaining a gate-type operation of the first and second embodiments.
FIG. 3 is a waveform diagram for explaining a velocity waveform of a gate-type operation in the first embodiment.
FIG. 4 is a flowchart for explaining a process flow in the first embodiment;
FIG. 5 is a waveform diagram for explaining a velocity waveform of a portal operation in the second embodiment.
FIG. 6 is a flowchart for explaining a process flow in the second embodiment;
FIG. 7 is an explanatory diagram for explaining a conventional gate-type operation.
FIG. 8 is a waveform diagram for explaining a velocity waveform of a conventional portal type operation.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Robot controller, 2 Robot, ST1 Horizontal motion calculation means, ST2 Overlapping motion time calculation means, ST4-11 Vertical motion acceleration / deceleration time adjustment means, ST20 Horizontal motion time calculation means, ST21 Ascending motion pattern generation means, descending motion pattern generation Means, ST22-25 Ascending operation target position and descending operation start position calculating means.

Claims (5)

  In a robot control device that performs a gate-type compound operation that partially performs ascending, horizontal, and descending operations, a horizontal operation time calculating means for obtaining an operation time of the horizontal operation, and an ascending operation that overlaps the horizontal operation When the overlap operation time calculation means for calculating the sum of the operation time of the operation and the descent action, the means for determining whether or not the horizontal operation time is longer than the overlap operation time, and as a result of the determination, the horizontal operation time is longer than the overlap operation time Includes a vertical operation acceleration / deceleration time adjusting means for changing the ascending operation deceleration time and the descending operation acceleration time. Rise, horizontal, in the control apparatus for a robot which performs gantry combined operation performed partially overlapping the lowering operation, passed through the horizontal operating time calculation means for calculating the operating time of the horizontal motion, a vertical elevating distance previously designated , starts to decelerate immediately after passing through the vertical rise amount, and the lifting movement pattern generating means for generating an operation pattern that reaches the upward movement target position, while Hayashi reduced vertical downward distance specified in advance in the lowering operation A descent operation pattern generating means for completing the acceleration from the descent operation start position to the upper end of the vertical descent amount so that it can pass and reach the target position, and then reaches the target position by performing a constant speed operation and a decelerating operation; and the ascending operation pattern An overlapping operation time of the ascending motion and the horizontal motion generated by the generating means, a descending motion and a horizontal motion generated by the descending motion pattern generating means, Robot controller sum of overlapping time is characterized in that it comprises a lifting operation target position and lowering operation start position calculating means obtains the lifting operation target position and lowering operation start position so as to be equal to the horizontal operating time.   3. The robot control apparatus according to claim 2, wherein the ascending motion target position and the descending motion start position calculating means determine that the heights of the ascending motion target position and the descending motion start position are equal. Rise, horizontal, method of controlling a robot to perform a portal combined operation performed by partially overlapping the lowering operation, obtains the horizontal operation time corresponding to the horizontal operation, the upward movement operating overlaps the horizontal operation, The overlap operation time that is the sum of the operation time of the descent operation is obtained, and it is determined whether or not the horizontal operation time is longer than the overlap operation time. The robot control method is characterized in that it is configured to change the deceleration time and the acceleration time of the descending motion. Rise, horizontal, method of controlling a robot for performing duplicate portal combined operation performed by partially lowering operation, obtains the horizontal operation time corresponding to the horizontal motion, passed through the vertical elevating distance specified in advance, the vertical rise the amount to generate the upward movement pattern to reach a raised operation target position to start deceleration immediately after passing through the pass through while Hayashi reduced vertical downward distance specified in advance in the downward movement so that it can reach the target position After completing the acceleration from the descent start position to the upper end of the vertical descent amount, generate a descent action pattern that reaches the target position by constant speed operation and deceleration operation, and the ascending action and horizontal action generated by the ascending action pattern Ascending operation target position and descending so that the sum of overlapping operation time of descent operation generated by descent operation pattern and descent operation generated by descent operation pattern and horizontal operation is equal to horizontal operation time Robot control method characterized by being configured to determine the work starting position.

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