JPH11114858A - Locus control method and locus control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reconcile a high speed and high accuracy by synthesizing it by presetting a synthetic rate of decelerating motion in a first section and accelerating motion in a second section. SOLUTION: A control device 70 performs setting processing of an internal dividing point after an imparted command point sequence is divided into blocks to satisfy a prescribed condition. In the setting processing of this internal dividing point, first of all, a maximum speed of a first block and a maximum speed of a second block continuing with this are calculated, and decelerating time in a first section and accelerating time in a second section are calculated on the basis of these. Next, among a decelerating section in the first section, a preset value of a speed synthesizing rate being a rate to synthesize a speed with an accelerating section of the second section is read in. This synthetic rate is a value of from 0 to 1, and in 0, a speed is not synthesized, and in 1, the speed is synthesized by 100%. That is, an inward rotating quantity of a locus changes by changing this rate. Therefore, high speed work and highly accurate work can be reconciled by adjusting the rate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trajectory control method for controlling a trajectory of a moving body such as a tool and a trajectory control device for performing the method.

[0002]

2. Description of the Related Art As this kind of trajectory control technology, PTP is used.
(Point To Point) control and CP (Continuous Path) control
You are known. As shown in FIG.
P₀To P₁Through P_TwoWhen controlling the trajectory leading to
In the PTP control, the speed pattern shown in FIG.
U, P₀To P₁Start acceleration at acceleration a toward
And time t₁When the target (maximum) speed v is reached at
Move, and P₁Deceleration start point at which the speed becomes 0 at
(Time t_Two) Starts deceleration at deceleration a (acceleration-a)
Then P₁Then, the speed once becomes zero. At the same time P₁From
P_TwoAcceleration at the acceleration a toward
Speed and deceleration_TwoTo On the other hand, in CP control,
As in the velocity pattern shown in FIG.₀To P
₁Acceleration at an acceleration a toward₁In goal
When the (maximum) speed v is reached, the robot moves at a constant speed and₁
Deceleration starting point (time t_Two)
Deceleration starts at speed a (acceleration-a), and at the same time,
P₁To P_TwoThe acceleration starts at an acceleration a toward. P
₀To P₁Deceleration in the direction to and P₁To P_TwoHead for
By combining the accelerations in the directions₀To P₁Speed to
When the degree component becomes 0, P₁To P_TwoVelocity component to
Is the target (maximum) speed v, so that the mobile is P ₁
Keep the target (maximum) speed almost without deceleration
Can be.

Further, the present applicant has previously filed Japanese Patent Application No. 9-1066.
No. 84 proposes a trajectory control device that can move a moving body at high speed even when the interval between command points is short in CP control. In this method, a command point sequence satisfying a predetermined condition is defined as one block, and acceleration and acceleration are performed within this block.
This block performs constant speed and deceleration control.
If one section of the P control and the CP control is considered (that is, the start point and the end point of the block are set as command points), control similar to the above-described PTP control and CP control can be performed.

[0004]

However, FIG. 11 (a)
As shown in, by PTP control, the mobile P ₁ from P ₀
Will follow the trajectory up to P ₂ faithfully.
_{At 1} there is a problem that the speed cannot be increased because the speed once becomes 0. Conversely, in the CP control, the speed is increased by synthesizing the speed, but P ₀ −P ₁ −P ₂
A trajectory turns inward with respect to a straight line connecting the lines, and when the speed is increased, the amount of inward rotation becomes large. Therefore, there is a contradictory problem that high-precision movement cannot be performed.

For example, when performing die machining using a machine tool utilizing a parallel link mechanism described in Japanese Patent Application Laid-Open No. 8-150526, the machining time is enormous in PTP control, and desired accuracy is obtained in CP control. There is a problem that you can not.

[0006]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has been made to achieve both high speed and high accuracy. Along with the trajectory of the moving body, and the deceleration movement of the moving body in the first section from the nth command point to the (n + 1) th command point and the (n + 2) th command from the (n + 1) th command point. In a trajectory control method for synthesizing an acceleration motion of a moving body in a second section toward a point and controlling a trajectory of the moving body at the synthesized speed, a deceleration movement in the first section and an acceleration in the second section The rate of combination with exercise is set in advance, and the first rate is set by the set rate.
And the acceleration motion in the second section are synthesized. Further, the ratio of the combination is a ratio between the deceleration time in the first section or the acceleration time in the second section and the combined time.

According to a third aspect of the present invention, in the trajectory control device for controlling the trajectory of a moving body along a plurality of command point sequences, the command points are converted into blocks comprising a command point sequence including a block start point and a block end point. Means for dividing the block, means for calculating an acceleration end point on the trajectory and separated from the block start point by a distance necessary to accelerate from the speed 0 to the target speed, and a speed on the trajectory and from the target speed Means for calculating a deceleration start point separated from the block end point by a distance required to decelerate to zero, and moving the moving body at a constant speed on the trajectory and between the acceleration end point and the deceleration start point. Means for calculating an internal division point for causing the first block to be divided by the block dividing means from the deceleration start point to the block end point and to the first block. Combining ratio setting means for setting a ratio of combining the speed of the moving body from a block start point to an acceleration end point in a second block that follows immediately after the first block, and a deceleration start point to a block end point in the first block. And the speed at which the deceleration in the first block and the acceleration in the second block are combined at the ratio set by the combination ratio setting means between the block start point and the acceleration end point in the second block. And a synthesizing means. In addition, the ratio set by the combination ratio setting means may be a moving time when the moving body is controlled to decelerate from the target speed to the speed 0 from the deceleration start point to the block end point in the first block, or It is a ratio of a moving time when the moving body is accelerated from a speed 0 to a target speed between a block start point and an acceleration end point in the second block and a combined time. Further, when the break angle of the trajectory is more acute than the predetermined angle, the block dividing means makes the distance from the block start point to the command point shorter than the distance from the block start point to the immediately preceding command point. When the next operation satisfies one of the conditions when the user does not move due to only a change in posture, the image is divided into blocks.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. FIG. 1 is an overall configuration diagram showing a machine tool M using a parallel link mechanism 10 according to the present embodiment. The parallel link mechanism 10 is suspended from a ceiling of a portal frame 50 having a table 52 on which a workpiece W is placed via a support column 51, and the control device 70 drives the parallel link mechanism 10 to drive the parallel link mechanism 10. The processing of the workpiece W is performed by moving the tool unit T mounted on the tip thereof to a desired position or directing the tool unit T in a desired direction (posture).

Next, the parallel link mechanism 10 will be described in detail with reference to FIGS. As shown in FIG. 2, the parallel link mechanism 10 is mainly
A base 11 suspended from the ceiling of the base unit 0 via support columns 51;
A traveling plate 12, which is located below the base 11 and on which a tool unit T is mounted on a lower surface, and six arms 13U, 13u, 13V, 13v, 13W, 13w for connecting the traveling plate 12 to the base 11. It is composed of

The base 11 is a hexagonal flat plate member, and arms 13U, 13u,
13V, 13v, 13W and 13w are connected to the arm 13U and 1
3u, two arms 13V and 13v and two arms 13W and 13w are radially attached in three directions as a set. Each arm 13U, 13u, 13V, 13v, 13
Since the configurations of W and 13w are all the same,
If only U is described, the arm 13U is
U and a guide 20U.

The guide 20U includes a base 22U, a slide table 26U, a ball screw 24U, and a servomotor 25U.
And a motor position detecting encoder 31U. The base 22 </ b> U is a member having a U-shaped cross section, and is fixed to the base 11 by a fixing member 32 at a predetermined angle with respect to the base 11. A slide table 26U is slidably supported on the base 22U in the longitudinal direction. The slide table 2 is provided on the base 22U.
A ball screw 24U screwed to a nut (not shown) of 6U is rotatably supported, and is rotated by driving a servo motor 25U fixed to the base 22 and connected to the ball screw 24. As a result, the slide table 26U is moved in the longitudinal direction of the base 22U.

A rod 15U is connected to the slide table 26U by a ball joint 16U, and the rod 15U can swing three-dimensionally with respect to the slide table 26U with the ball joint 16U as a fulcrum. Further, the other end of the rod 15U is connected to the traveling plate 12 by a ball joint 17U, and the rod 15U can swing three-dimensionally with respect to the traveling plate 12 with the ball joint 17U as a fulcrum.

The traveling plate 12 is a hexagonal plate member smaller than the base 11, and has the above-mentioned ball joints 17U, 17u, 17V, 17v, 17W, 17
w is connected on the same plane at every other side corresponding to the side of the base 11. On the lower surface of the traveling plate 12, a tool unit T including a tool such as a drill and an end mill and a spindle for rotating the tool is mounted.

With the above configuration, the servomotors 25 are individually driven to swing the six rods 15 independently by giving an operation command from the control device 70. Then, by the combination of the swinging of the six rods, the traveling plate 12 can be controlled in six degrees of freedom (position and posture). That is, each guide 20
The position of the traveling plate 12 is determined by synchronizing the pair of arms 13 supported by the pair and individually driving the three pairs of arms 13.
The attitude of the traveling plate 12 can be determined by driving one of the arms 13 of this set, that is, three arms 13 in total.
The workpiece W is controlled by controlling the tool attached to the traveling plate 12 to a desired position and posture.
The processing is performed.

Next, the control device 70 will be described with reference to FIG. The control device 70 is a central processing unit (CPU) 7
1, a memory 72, and interfaces 73 and 74. The memory 72 stores a program for executing the actual processing. The interface 73 includes the servo motors 25U, 25u, 25V, 25v,
Digital servo unit 81 to drive 5W, 25W
86 are connected. Each digital servo unit 81
86 drive the servomotors 25 based on the command values from the CPU 71, and perform feedback control by outputs from the motor position detection encoders 31U, 31u, 31V, 31v, 31W, 31w. Then, by moving the slide table 26 driven by each servo motor 25 to a desired position, as a result, the traveling plate 12 connected via the six rods 15 is controlled to a desired position and posture. It has become.

The interface 74 is connected to a keyboard 76 for inputting processing data and the like, a CRT 77 for displaying the processing data and the current state of the machine tool M, and an external storage device 78 for storing the processing data such as a hard disk. ing.

Next, the processing by the control device 70 will be described.
This will be described with reference to FIGS. As shown in FIG.
First, the control device 70 inputs a program for die machining by the machine tool M (S10). Next, the program is decoded (S11), and it is determined whether the decoded instruction is an end instruction (S12). Unless the instruction is an end instruction (NO in S16), it is determined whether the instruction is an operation instruction (S13). If the instruction is not an operation instruction (the determination in S13 is N
In O), the non-operation process is advanced (S14), and for example, processes such as jetting and stopping of coolant are performed.

On the other hand, if the instruction is an operation instruction (the judgment in S13 is Y
In the case of ES), the block generation processing of step 15 is performed. In this block generation processing, a given command point sequence is divided into blocks that can be controlled in one pattern of acceleration, constant velocity, and deceleration. Here, description will be made with reference to FIG.

First, a start point P _i is obtained (S30), and a variable n is initialized to 0 (S31). Then, after acquiring the next command point P _{i + 1 + n} (S32), the command point P _{i + n}
Calculates the P _{i + 1 +} vector directed to _n from (S33), and calculates the distance to the next mark P _{i + 1 + n} from the starting point P _i (S3
4). Then, the next next command point P _{i + 2 + n} is obtained (S3
5) calculates a vector from the runner-up P _{i + 1 + n} toward the next runner-up _{P i + 2 + n (S36} ), the following from the starting point P _i next mark P _{i + 2 + n}
The distance to is calculated (S37).

Next, P _{i + n} obtained in step 33 is obtained.
From the vector heading to _{Pi + 1 + n} and the vector heading from _{Pi + 1 + n} to _{Pi + 2 + n} obtained in step 36, the angle between the two is equal to or greater than a predetermined angle (for example, 150 °). It is determined (S68). Then, if it is not the predetermined angle or less (NO in the determination in S38), the order command point direction P _{i + 1 + n} varies greatly, and the point the command point P _{i + 1 + n} blocks of the intermediate Since it is not preferable to perform this operation, the block end point is set so that one block ends at the command point P _{i + 1 + n} (S43), and when the direction does not change significantly (S38)
Is YES), the process proceeds to step 39.

[0021] In step 39, runner-up P from the starting point P _i
It is determined whether the distance to _{i + 1 + n} is shorter than the distance from the starting point P _i to the next next point P _{i + 2 + n} (S39). If it is shorter (NO in S39), Proceed to step 43,
If not short (YES in S39), step 40
Proceed to. This is when the distance from the start point P _i to the next mark P _{i + 1 + n} is not shorter than the distance from the starting point P _i to the next runner-up P _{i + 2 + n,} command point P _{i + 1 + n means} that the trajectory makes a U-turn, and it is not preferable to set such a command point P _{i + 1 + n} as an intermediate point of the block. Therefore, this command point P _{i + 1 + This} is because the block end point is set so that one block ends with _n (S43).

In step 40, it is determined whether the next point P _{i + 1 + n} is _equal to the next point P _{i + 2 + n} , that is, whether the tip of the tool is moved only by a change in posture. When the tool tip does not move due to only the posture change (NO in S40), it is not preferable to set such a command point P _{i + 1 + n} as an intermediate point of the block. _{1 at Pi + 1 + n}
A block end point is set so as to end the block (S4
3) If the tip of the tool is moved (the determination in S40 is YE
S) proceeds to step 41.

In step 41, it is determined whether the given command point is the end point. If it is the end point (YES in S41), this end point is set as the block end point (S43).
If it is not the end point (NO in S41), the next point P _{i + 1 + n} may be an intermediate point of the block. The process proceeds to step 42, where 1 is added to the variable n, and the process proceeds to step 32. Returning, it repeats the determination whether the next command point may be the middle point of the block or the end point of the block. Referring to FIG. 9A, first, P ₀
Are the starting points (block starting points), P ₁ , P ₂ , P _3.
And these command points satisfy the above conditions (S38, S39, S
40, S41) determines whether meet, since the direction in P ₅ converts large, the determination in step 38 becomes NO, P ₅ is the end of the block at step 43. Similarly, this time, with P ₅ as the block starting point, P ₆ , P _7.
... and continue to determine, since P ₈ is at the end, the determination in step 41 becomes YES, P ₈ is the end of the block at step 43. Thus, the first block having P ₀ as the block start point and P ₅ as the block end point, and P ₅
Is generated as a block start point and P ₈ is a block end point.

According to the above block generation processing (S15)
Block that satisfies given conditions
After the division, the process proceeds to step 16 to set an internal division point.
Perform processing. This internal dividing point setting processing is shown in FIG.
It will be described in the light of the above. First, the block start point P_i(P in FIG. 9
₀) To block end point P_{i + 1 + n}(P in FIG. 9_Five)For up to
The total length of the polygonal line is calculated (S50). That is, each command
Between points (P ₀And P₁, P₁And P_Two, P_TwoAnd P_Three···)of
Find the distance and add it.

Next, the acceleration end point and the deceleration start point are calculated from the preset acceleration and the calculated total length of the polygonal line (S
51). That is, as shown in FIG. 9B, a point (acceleration end point B ₁₁ , at which time is t ₁ ) obtained from the block start point P ₀ by accelerating with the acceleration α and reaching the target speed V is obtained.
Deceleration α (acceleration-α) predetermined from target speed V
In the start of the deceleration, the point such that zero velocity at the end of the block P ₅ (deceleration start point C _11, the time at this time is t ₂₎ obtained.

[0026] Then, a moving distance of each interpolation cycle at the time of constant velocity (velocity = V) (S53), the routine proceeds to step 53, during the constant speed section (the acceleration end point B ₁₁ to the deceleration start point C ₁₁ An internal division point is set for each of the above movement distances on the polygonal line of the parentheses. Next, proceeding to step 54, the speeds are synthesized in the deceleration section (from the deceleration start point to the block end point) and the acceleration section of the subsequent block (from the block start point to the acceleration end point). Speed synthesis processing for setting the internal division point of Here, in the acceleration section of the first block and the deceleration section of the second block shown in FIG. 9, the block start point of the first block is the start point of the trajectory (that is, there is no block before this). Since the block end point of the block No. 2 is the end point of the trajectory (that is, there are no blocks after this point), there is no need to synthesize the speed, and the moving distance for each interpolation cycle is obtained in the same manner as the internal division point in the above constant speed section. (However, since the speed changes, the moving distance for each interpolation cycle is not constant as in the constant velocity section.) Based on this moving distance, an internal division point may be set on a polygonal line. Therefore, the speed combining process of step 54 will be described below with reference to FIGS. 7 and 8 by taking the speed combining of the deceleration section of the first block and the acceleration section of the second block in FIG. 9 as an example.

First, at step 60, the m-th block (first
), And the maximum speed V _m + 1 of the (m + 1) th block (second block) following the maximum speed V _m .
Here, in the example of FIG. 9, V _m = V as shown in FIG.
_{m +} 1 = is a V, as shown in (b) in FIG. 8, V _m <
In some cases, V _{m +1} or, as shown in FIGS. 8C and 8D, V _m > V _{m +1} . This is because the section of the m-th block or the (m + 1) -th block is too short to reach the maximum speed (in this case, there is no constant-speed section in the block) or other conditions (for example, processing conditions). This is the case where the target speed is set low.

Next, in step 61, the deceleration time T _m in the m-th section from the maximum speed V _{m is} calculated by calculating the deceleration time T _m from the maximum speed V _{m + 1} to the m-th
The acceleration time T _{m + 1} in one section is calculated. Then, in step 62, the set value R of the speed synthesis ratio is read. The set value R indicates a ratio of the speed synthesis with the acceleration section in the (m + 1) th section among the deceleration sections in the 1m section, and can be set in advance in a program. May be entered. This combination ratio R is a value of 0 ≦ R ≦ 1, and is set to be small where high precision is required as shown in FIG. 10C, and high speed is required as shown in FIG. 10B. 10 (d), R = 0 means that velocity combining is not performed.
As shown in (a), R = 1 means that 100% speed synthesis is performed. That is, by changing this R, the inward turning amount of the trajectory as shown in FIG. 11A changes. Therefore, for example, R
May be set to a large value to perform high-speed machining, and at the time of finish machining, a small value of R may be set to perform high-precision machining. In addition, when it is desired to precisely process the shape of the corner, for example, in accordance with not only the type of processing but also the processing location, the value of R can be set small at this processing location.

In step 63, the read set value R
Calculating a synthesis time T _R from step 64, from the synthesis time T _R, calculates the time T _S until the combination start time from the deceleration start time of the 1m block. The synthesis time T _R is T _R = T _m × R, and the time T _S until the start of the synthesis is T _S
= A T _m -T _R. Next, the synthesis start time t _G and the synthesis end time t _E are obtained. When V _m = V _{m + 1} as shown in FIG. 8A, and as shown in FIG. V _m <V _{m + 1} in the case of (a determination of S65 YES), the deceleration starting time t of the m blocks obtained in step 64
_{Since the} time when the time T _S from ₂ to the synthesis disclosure time has elapsed is the synthesis start time as it is, the synthesis disclosure time t _G is t
_G = t ₂ + T _S , and the synthesis end time t _E is t _E = t _G + T _R obtained by adding the synthesis time obtained in step 63 (S 65).

On the other hand, in the case of _{V m> V m + 1 (} S65 determination is NO), comparing the synthesis time T _R and the acceleration time of the m + 1 block T _{m + 1} in step 67. When T _R ≦ T _{m + 1} (the determination in S67 is YES), when V _m ≦ V _{m + 1} (S6
Similarly to the case of (YES in step 5), the time when the time T _S from the deceleration start time t ₂ of the m-th block obtained in step 64 to the synthesis start time has passed is not a problem as the synthesis start time. Going forward, t _G = t ₂ +
_Let T _S , t _E = t _G + T _R. However, T _R > T _{m + 1}
In the case (NO in S67), t is set in the same manner as in the above case.
When _G = t ₂ + T _S, since synthesis time T _R is longer than the acceleration time T _{m + 1} of the (m + 1) -th block, synthesis section is the m
It extends to the constant velocity section of +1 block, and the m +
The target speed _{Vm + 1} is exceeded in a constant speed section of one block. Therefore, when T _R > T _{m + 1} (the determination in S67 is N
O) goes to step 68 to set the synthesis start time to the (m + 1) th
Delayed until the start of acceleration time t ₃ of the block, we carry out the synthesis. That is, _{t G = t 2 + (t} m -t m + 1).
Also, since the synthesis time is shortened by delaying the synthesis start time, the synthesis end time is t _E = t _G + T _{m + 1} (= t ₂
+ T _m ).

When the synthesis start time t _G and the synthesis end time t _E are determined in this way, the internal division points are set in this synthesis section as in steps 52 and 53 of the internal division point setting process described above. . Until synthesis start time, or velocity synthesis between the time t ₂ of t _G is not performed, the m
Since only block deceleration is performed, a moving distance for each interpolation cycle is obtained based on the speed pattern in the decelerating section, and an internal dividing point is set on a polygonal line based on the moving distance (S6).
9). Next, in the synthesis section, that is, from time t _G to t _E
In the period up to, the deceleration of the m-th block and the acceleration of the (m + 1) -th block are combined, the moving distance for each interpolation cycle is obtained based on the synthesized speed pattern, and the internal dividing point is drawn on the polygonal line based on this moving distance. Is set (S70). After the end of the synthesis section, that is, after time t _E , speed synthesis is not performed and only the acceleration of the (m + 1) th block is performed. Therefore, a moving distance for each interpolation cycle is obtained based on the speed pattern of the acceleration section. An internal division point is set on the polygonal line based on the distance (S71). Here, in the pattern shown in FIG. 8D, since the end of the velocity synthesis coincides with the acceleration end point of the (m + 1) th block, there is no acceleration section of the (m + 1) th block after the completion of the synthesis. No processing is required.

The processing for setting the internal division point as described above (S
When 16) is completed, it is determined whether the section is an acceleration section (S17), a constant velocity section (S19), or a deceleration section (S21), and respective processes (S18, S20, S22) are performed.
The operation of the moving object is actually controlled. Then, when the operation processing is completed (YES in S23), the process returns to step 11 to perform decoding processing of the next instruction. When processing of all instructions is completed, the determination in step 12 becomes YES and the processing is performed. Complete.

In the above-described embodiment, a description has been given of the synthesis of speeds between blocks that span a plurality of command point sequences. However, as another embodiment, ordinary CP control is performed. It is also possible to apply to velocity synthesis in. In this case, the block generation processing in step 15 is not required in the above-described embodiment, and the block start point and the block end point in the above-described embodiment are merely set as the command points of the CP control. This is the same as the embodiment. In this other embodiment, when R = 1, the conventional CP control is performed, and when R = 0, the conventional PTP control is performed.

In the above embodiment, the acceleration / deceleration has been described as being constant.
Although the acceleration / deceleration pattern described in (1) is trapezoidal, it is not limited to the trapezoidal acceleration / deceleration, and the same applies to a so-called S-shaped acceleration / deceleration pattern.

[0035]

According to the first and third aspects of the present invention, the deceleration movement of the first section or the first block and the acceleration movement of the second section or the second block are set in advance. Since the composition can be synthesized at the same ratio, it is possible to move the moving object at high speed by setting the ratio of this combination to be large, or to move the moving object with high accuracy by setting the combination ratio to be small. It can be set arbitrarily. Therefore, the high-speed control emphasizing the moving speed and the high-accuracy control emphasizing the trajectory accuracy can be achieved by one trajectory control device. Further, it is possible to selectively use high-speed control and high-accuracy control in controlling one trajectory.

Further, according to the third aspect of the present invention,
In addition to the above effects, a plurality of command point sequences are divided into blocks satisfying a predetermined condition, internal division points are set from a block start point to a block end point, and a moving body is moved through each internal division point. As a result, the moving body can be sent at a high speed even when the interval between the command points is short.

According to the second and fourth aspects of the present invention, since the above-mentioned composition ratio is the ratio of the acceleration time or deceleration time to the composition time, the composition ratio can be set very easily. According to the fifth aspect of the present invention, even if the control is performed over a plurality of command points, when the trajectory is at an acute angle, the distance from the block start point to the command point is one before the block start point. When the distance to the command point is shorter than the distance to the command point, and the next operation does not move only due to the change in posture, it is divided into blocks, so that the trajectory accuracy does not greatly deteriorate.

[Brief description of the drawings]

FIG. 1 is a diagram showing a machine tool according to an embodiment of the present invention.

FIG. 2 is a view showing a parallel link mechanism of the machine tool shown in FIG. 1;

FIG. 3 is a control block diagram of the parallel link mechanism of FIG. 2;

FIG. 4 is a flowchart showing a process of a control device of the parallel link mechanism of FIG. 3;

FIG. 5 is a flowchart illustrating a subroutine of a block generation process of FIG. 4;

FIG. 6 is a flowchart showing a subroutine of an internal dividing point setting process of FIG. 4;

FIG. 7 is a flowchart showing a subroutine of the speed synthesis processing of FIG. 5;

FIG. 8 is a diagram showing types of velocity synthesis patterns.

9A is a diagram showing a command point sequence, blocks obtained by dividing the sequence, and internal division points, and FIG. 9B is a diagram showing a velocity pattern of the locus of FIG. 9A.

FIG. 10 is a diagram showing a speed pattern when a set value R of a rate of speed synthesis is changed, wherein (a) shows R = 1,
(B) R = 0.8, (c) R = 0.2, (d) R
= 0.

FIG. 11 is a diagram illustrating a trajectory and a speed pattern of PTP control and CP control according to the related art.

[Explanation of symbols]

 M Machine tool R Set value of rate synthesis 10 Parallel link mechanism 70 Controller

Claims (5)

[Claims] A trajectory of a mobile unit is controlled along a plurality of command point sequences, and a deceleration motion of the mobile unit in a first section from an n-th command point to an (n + 1) -th command point and an (n + 1) -th A trajectory control method for synthesizing the acceleration motion of the moving body in a second section from the second command point to the (n + 2) th command point and controlling the trajectory of the moving body at the synthesized speed; A combination ratio of the deceleration motion and the acceleration motion in the second interval is set in advance, and the first deceleration motion and the acceleration motion in the second interval are synthesized by the set ratio. Trajectory control method. 2. The trajectory control method according to claim 1, wherein the combination ratio is a ratio between a deceleration time in the first section or an acceleration time in the second section and a combined time. A characteristic trajectory control method. 3. A trajectory control device that controls a trajectory of a moving body along a plurality of command point sequences, wherein: a block dividing unit that divides the command point into blocks each including a command point sequence including a block start point and a block end point; Means for calculating an acceleration end point separated from the block start point by a distance necessary for accelerating from the speed 0 to the target speed on the trajectory; necessary for decelerating from the target speed on the trajectory to the speed 0 Means for calculating a deceleration start point separated from the block end point by a short distance, and an internal division point for moving the moving body at a constant speed on the trajectory and between the acceleration end point and the deceleration start point. Means for calculating, between the deceleration start point and the block end point in the first block divided by the block dividing means,
Combining ratio setting means for setting a ratio of combining the speed of the moving body from a block start point to an acceleration end point in a second block immediately following the block, and from a deceleration start point in the first block. Between the block end point and the block start point to the acceleration end point in the second block, the deceleration in the first block and the acceleration in the second block are combined at the ratio set by the combination ratio setting means. A speed synthesizing means, and an internal dividing point for moving the moving body at a speed synthesized by the speed synthesizing means between a deceleration start point of the first block and an acceleration end point of the second block. A trajectory control device, comprising: 4. The trajectory control device according to claim 3, wherein the ratio set by the combination ratio setting unit is the first ratio.
The moving time when the moving body is controlled to decelerate from the target speed to the speed 0 from the deceleration start point to the block end point in the block, or the movement from the block start point to the acceleration end point in the second block. A trajectory control device characterized by a ratio of a moving time when the body is accelerated from a speed of 0 to a target speed and a synthesized time. 5. The trajectory control device according to claim 3, wherein the block dividing means is configured to determine a distance from a block start point to a command point when a trajectory bend angle is greater than a predetermined angle. Trajectory control characterized by dividing into blocks when the distance is shorter than the distance from the start point of the block to the command point immediately before, or when the next operation satisfies any condition of not moving due to only posture change apparatus.