JPH02144705A - Robot arm control method - Google Patents

Abstract

PURPOSE:To attain the general accelerating/decelerating and positioning operations with high universal applicability and high accuracy by magnifying and reducing an acceleration/deceleration pattern table in accordance with its working distance and ensuring the optimum working of a robot arm. CONSTITUTION:Both the acceleration and deceleration pattern tables show the value obtained by multiplying the table value to be referred to when the shift of a robot arm is controlled between two points by a constant of conversion as the speed and the minute shift distance of the robot arm. These two pattern tables are added into an arithmetic procedure memory part 16 of a controller 1. The distance needed for deceleration set in case the present working speed is reduced based on the deceleration pattern table, i.e., the acceleration/deceleration working distance is referred to as L. While the remaining shift value of the difference between the present position and the target position, i.e., a designated working distance is referred to as L0 respectively. Thus the table value is reduced and at the same time the table reference step is magnified so that L0=L is satisfied. As a result, the working time of the robot arm is shortened while the working characteristics of the arm is kept satisfactory.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method of controlling a robot arm, and in particular, to a robot suitable for high-precision control that performs arbitrary acceleration and deceleration to enable accurate positioning. This invention relates to a method of controlling an arm.

[Conventional technology]

The conventional control method used to accelerate and decelerate a robot arm is 1, for example, as disclosed in Japanese Patent Application Laid-Open No. 1986-1932.
One that uses a trapezoidal speed pattern as described in JP-A-59-83210, and one that prepares a speed table and a distance table and searches them to determine the operating speed including acceleration and deceleration. There are known methods that determine , and methods that utilize functional calculations as described in Japanese Patent Laid-Open No. 61-5311.

[Problem to be solved by the invention]

Most of the above-mentioned conventional techniques lack flexibility in response to changes in system specifications, and insufficient consideration has been given to application to robot arms that perform various functions through teaching.

The present invention has been made to solve the problems in the prior art described above, and is more general and versatile, can be freely adapted to various operating conditions of robot arms, and can perform high-precision acceleration, deceleration, and positioning. The purpose of this invention is to provide a method for controlling a robot arm that enables the following.

[Means to solve the problem]

In order to achieve the above object, the configuration of the robot arm control method according to the present invention is such that, in the robot arm calculation control method using one-point movement control, movement between two points is controlled in the calculation procedure storage unit of the control device. An acceleration pattern table and a deceleration pattern table are provided in which the value obtained by multiplying the table value by a conversion constant is the speed or minute movement distance of the robot arm, and the movement distance Ω0 between two given points and the addition , and the moving distance Ω when the deceleration table is operated according to the predetermined reference steps, and Q o
< Q, the conversion constant is reduced and the table reference step is expanded so that 0 becomes equal to 10, and using the obtained conversion constant and table reference step, when the robot arm starts operating, The acceleration pattern table is searched sequentially from the low-speed side to the high-speed side, and the obtained table value is multiplied by a conversion constant as the speed command value for the robot arm. After the acceleration table search is completed, the self-oscillation position and the current position are Find the remaining travel distance (specified operating distance) Lo, which is the difference between the current operating speed and the required deceleration distance (acceleration/deceleration operating distance)
In comparison, in the case of LoΣL, the current speed command value is held, and in the case of Lo<L, ', the reference address of the deceleration table is decreased by the table reference step, and the table value on the low speed side of the deceleration table is searched. , the required distance for deceleration is corrected by this value set for the time being, and the robot arm is controlled by using the value obtained by multiplying the table value by the conversion constant as the speed command value or minute incremental movement amount, and the robot arm is controlled according to the acceleration and deceleration pattern. It was made to work.

[Effect]

The present invention expands and contracts an acceleration/deceleration pattern table according to the operating distance to optimally operate a robot arm.

When the acceleration/deceleration operating distance is L and the specified operating distance is Lo, the present invention provides a method of reducing the table value and expanding the table reference step to correct Lo = L. Ru.

That is, reducing the table values will reduce the maximum velocity and acceleration. Therefore, by expanding the table reference step by that amount and correcting the acceleration so that it becomes the acceleration shown in the initial table pattern, it is possible to shorten the operation time while maintaining good operation characteristics of the robot arm.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. 1 to 10.

FIG. 1 is a block diagram showing the configuration of a robot system according to an embodiment of the present invention, FIG. 2 is a perspective view of a general robot device, and FIG. 3 shows an example of the teaching means shown in FIG. The configuration diagram shown in FIG. 4 is a block diagram showing the configuration of the calculation means in FIG. 1.

As shown in FIG. 1, the robot system is comprised of a robot body 2 and a control device 1.

The control device 1 manually operates the robot, instructs the position storage means 18 to store the operated position, inputs the robot's operation procedure, instructs the operation procedure storage means 17 to store it, and controls the operation. A teaching means 14 including a plurality of operation switches for instructing the robot to operate according to the operation procedure stored in the procedure storage means 17 and a display device for displaying operation status, etc., and a calculation means 1
a PWM signal generation circuit 11 that generates a PWM signal in response to a pulse width modulation (hereinafter referred to as PWM) command output by the robot body 2; 12, a pulse counter 13 that counts encoder pulses of an encoder attached to the servo motor to measure the rotational position of the servo motor, and a position storage means 18 that stores the positions passed by a plurality of robot arm tips.

an operation procedure storage means 17 for storing operation procedures for a plurality of positions stored in the position storage means 18; an operation procedure storage means 16 for storing the operation procedures of the calculation means 15; Predetermined calculation procedure storage means 1
6, and read out the appropriate operation procedure stored in the operation procedure storage means 17 and position storage means 18 as necessary.
It is composed of a calculation means 15 such as a microcomputer that performs calculations using information stored in the robot and controls the operation of the robot.

Here, PWM signal generation circuit 11. Power circuit 12, servo motor 2. The pulse counters 13 are connected as shown in FIG. 1, and are provided as many times as there are degrees of freedom of movement of the robot.
Only groups are shown.

Although not shown in FIG. 1, an I10 interface for transmitting and receiving data with external devices and a communication interface for communicating with host devices are also provided.

FIG. 2 shows an example of a robot device used to explain this embodiment.

The robot arm shown in FIG. 2 is a well-known horizontal articulated robot, and has three rotations (θ machining, θ2...
θ8) degree of freedom and one linear motion (za force direction degree of freedom. However, the present invention is not limited to robots with a specific mechanism, and its application target is vertical multi-joint robots. It goes without saying that a robot with a shape or a robot with orthogonal motion may be used.

FIG. 3 shows an example of the operating switches and display device of the teaching means 14.Detailed explanation thereof will be omitted and will be referred to as necessary in the description of the embodiment below.

First, the configuration of the calculation means 15 will be explained with reference to FIG.

FIG. 4 shows the minimum functional configuration of the calculation means.

When the initial settings for turning on the power are completed, the calculation means 15 performs the following steps.

In the operation mode button import unit 20, the operation mode button (
It is waiting for input from buttons such as position teach, program teach, origin alignment, test operation, continuous operation, etc. in Figure 3. When any button (key) is pressed, the origin alignment processing section 21.degree. motion teaching processing section 229 position teaching processing section 23. Test operation processing section 24. Playback operation processing section 25
Execute one of the processing units in . Motion teaching processing section 22
Except for the above case, all other cases are related to the operation control of the robot, and below these, as shown by the broken line, a servo control unit 30 is equipped that executes the operation control of the robot arm according to these instructions. has been done.

Among these, the origin alignment processing section 219, position teaching processing section 23. Test operation processing section 24. When the robot arm is to be operated by executing any of the processes of the reproduction motion processing unit 25, the current position and target position of the robot arm are given, and an appropriate acceleration/deceleration mode is given to move the robot arm between them. The points are calculated and given to the servo control unit 30 to operate the robot arm.

An acceleration/deceleration pattern processing method for operating the robot arm according to an appropriate acceleration/deceleration pattern will be described below.

FIG. 5 is a histogram showing an example of an acceleration pattern, and FIG. 6 is a configuration diagram of an acceleration and deceleration table.

In FIG. 5, the horizontal axis represents a table address, and the vertical axis represents a dimensionless velocity. Specifically, FIG. 5 is composed of an acceleration and deceleration table shown in FIG. 6.

In FIG. 6, the pattern of the acceleration and deceleration table may be arbitrary, and the designer can set the pattern that is most suitable for acceleration/deceleration control of the robot arm. Also, acceleration,
The size of the deceleration table may also be different. The maximum dimensionless speed when both are used in combination is the same or approximately the same during use, and a speed gap does not occur when switching between the two. Furthermore, if the same pattern is used during acceleration and deceleration, it is also possible to provide only an acceleration table and use it also during deceleration.

The acceleration and deceleration tables shown in FIG. 6 may be prepared separately for each rotational motion of the robot and for linear motion, but this does not change the gist of the present invention described below. .

In the following, an example will be explained in which two tables, an acceleration table and a deceleration table, are provided and shared under all operating conditions. The above-mentioned modification can also be applied with some modification.

To share acceleration and deceleration tables and to be able to reference any part of the table.

For each axis of motion and for linear motion, the nth
Prepare shaft circumference ROM memory. In the following description, the expression of the n-th axis circumference is the name of one representative example of those prepared individually for all motion axes and linear motion.

Label the table of FIG. 6 to refer to the acceleration and deceleration table as the nth axis circumference.

ASTRN: Acceleration start reference address AMAXN: Acceleration end reference address DMINN: Deceleration end reference address DMAXN: Deceleration start reference address nth @ROM memory area ASTR, AMAX.

The value of the above label is stored in DMIN and DMAX. This can be done automatically, for example, by writing ASTRDC, W ASTRN in assembly language as shown below and running it in the assembler.

The value of ASTRN in the area labeled ASTR,
That is, the labeling procedure is accomplished by storing the table address.

This makes it possible to refer to the range from ASTRN to AMA-XN in the acceleration table during acceleration, and from DMINN to DMAXN in the deceleration table during deceleration. Furthermore, by arbitrarily resetting the position of the label of each table, it becomes possible to refer to the table within an arbitrary range.

The reference reduction rate of the table is defined in the area defined by 5HUKU of the nth @ ROM memory.

For example, when the defined value is 1.0, the table reference interval indicates that the tables are referenced one by one, that is, sequentially, and when it is defined as 0.5, the table reference interval is referenced every other table. represents something.

That is, the reciprocal of the defined value represents the table reference interval. As explained later, this reciprocal value does not have to be an integer.

5PDG1 to 5PDGn of the n-th @ROM memory correspond to the speed specified when operating the robot arm, and when the maximum value of the acceleration or deceleration table is multiplied by that value, the result becomes the specified speed. This is an area to store selected conversion constants. Here, n conversion constants are prepared discretely, but it is also possible to prepare only one and calculate the actual conversion constant by multiplying it by the specified speed.

The 5PDG area of the n-th axis RAM memory is
It is provided to store the value of Gn or a value corrected for actual operation.

KASOKU and GENSOKU (7)! jJ
7 stores the address of each table currently referred to when referencing the table.

DELTBL is the table reference interval, i.e. the 5
The reciprocal of the HUKU value or its corrected value is stored and used for table reference address calculation.

KASOKU, GENSOKU and DELTBL store table reference addresses and reference steps that contain less than a decimal value, but KASOKU or GENSOKU
When referring to a table using the values in SOKU, values below the decimal point are rounded down.With this function, a table created with a fixed pitch can be referred to with a free pitch.

IKPULS and IDP of nth @ RAM memory
In the ULS area, the integrated value of the table values within the table range referenced and defined in the n-th axis ROM memory is stored. Each value umbrella reduction rate-conversion constant gives an acceleration distance and a deceleration distance, respectively.

If the table is fixed, the values of IKPULS and IDPULS can be calculated in advance and
It is also possible to store it in the axis memory.

Here, when the arithmetic system is initialized, the arithmetic means is n M
It is assumed that the integrated value is obtained by referring to the ROM memory and stored in the area.

The above table and memory are prepared, and the specified operating distance Lo and specified speed Vo of the robot arm are set.
(Actually, the nth @ 5PDGI~5P of ROM memory
Next, the procedure for planning a table reference when given from an index that refers to DGn will be explained.

FIG. 7 is a flowchart explaining the table reference plan of this embodiment, FIG. 8 is a flowchart showing a correction method for the table reference plan, and FIG. 9 is a table reference method when accelerating and decelerating the robot arm. FIG. 10 is a diagram showing an example of the acceleration/deceleration pattern according to this embodiment.

Block 4000 shown in FIG.
Using as an index, the conversion constants are read from 5PDGI to SPDGn of the n-th @It ROM memory and set in the 5PDG area of the n-th axis RAM memory.

Block 4001 determines the total number of members in the acceleration and deceleration tables using the table reference address stored in the n-th axis ROM memory. When the pitch of table reference addresses is 1, the formula shown in block 4001 is obtained. If the pitch is other than 1, it may be corrected accordingly. This value indicates the number of times the table is referenced when the robot arm is operated only by acceleration and deceleration and the table is referenced one by one, and it also indicates the movement time of the robot arm.

Brozug 4002 calculates the operating distance when the robot arm is operated only by acceleration and deceleration operations.

In block 4003, the designated operating distance Lo is compared with the acceleration/deceleration operating distance.

If Lo>L, the specified operating distance Lo is
It is greater than the acceleration/deceleration operation distance specified in the acceleration/deceleration table. That is, it indicates that the robot arm needs to be operated in a pattern of acceleration → constant velocity → deceleration, and in this case, the process of block 4004 is performed.

In block 4004, the number of times the table is referred to including the second constant velocity section, which is actually the travel time of the n-th axis of the robot arm I T
Find i ME. This is used when all axes of the robot arm are started and stopped at the same time, as will be described later.

Next, the deceleration integrated value IDPULS is corrected to ti-DPULS, and the table reference step DELTBL is further determined.

DPULS is used as a reference value for deceleration control during deceleration.

DELTBL is used as a step increment/decrement for table lookups.

If L o > L, this indicates that if acceleration/deceleration is performed according to the table pattern, the robot arm will pass the target position. In such a case,
One possible method is to cut off the high-speed side of the table pattern, but with this method, the table pattern that has been optimally prepared will not be used effectively.
This is undesirable as unexpected vibrations and sudden changes in acceleration may occur in the robot arm, and the table values may be reduced.
In other words, it is possible to reduce 5PDG and use it by modifying it so that Lo=L, but in this case, even though the operating distance is short, the operating time is the same as the time set in the table pattern. This results in a long period of time, which is not desirable.

Therefore, the present invention provides a method of reducing the table value and expanding the table reference step to correct Lo='+L.

The principle is as follows. That is, reducing the table values will reduce the maximum velocity and acceleration. Therefore, expand the table reference step by that amount,
If the acceleration is corrected to match the initial table pattern, the operating time can be shortened while maintaining good operating characteristics of the robot arm. The issue here is how to determine the allocation rate for reductions and expansions.

If the table value is prepared using a functional formula, it is possible to use the reduction rate of the table value as a parameter to determine the enlargement rate of the reference step at which the maximum acceleration is the same.

Here, block 4005 is shown as a method that can deal with any table pattern and easily determines the allocation ratio.

The table pattern reduction rate is set to M=~n]=Σ, and the table step enlargement rate is set to 1/M.

As a result, the conversion constant 5PDG becomes Corrected from 5PDG*M to 5PDG.

Number of table references or travel time I T i M E
becomes N・5HUKU skewer M. The integrated deceleration value is IDPU
LS fist 5 HUKU umbrella M.

Therefore, table reference step D[ELTBL is 1/(
SHUKU*M).

After the above preparations, in block 4006, the initial address of the table reference is set to KASOKU and GENSO.
Set to KU.

As described above, a table reference plan is required for each axis of motion of the robot or for linear/curved motion.

Here, the reduction of the table pattern in block 4o05 is made to be the same on both the horizontal and vertical axes.

However, depending on the table pattern to be prepared, when the same ratio of reduction is performed, the motion acceleration may be greater than that of the initial table pattern. Such an example is
For example, it appears when using a cycloid curve. Such a table pattern in which the operating acceleration is higher than the initial table pattern during contraction is undesirable because it may cause an unexpected vibration when the operating distance is short. In such a case, it is desirable that the reduction rate in the horizontal axis direction is smaller than the reduction rate in the vertical axis direction.
An example of such a method is shown below. When the moving distance between two given points is 00, and the moving distance when the acceleration and deceleration table is operated according to the predetermined reference steps is Q, then x=mFQ M=x+(1-x>/yM '=(12o
/I2)/M (y>=1), 1/M is the expansion rate of the table reference step, and M' is the reduction rate of the conversion constant, then M'<M is obtained. If y-2N (an integer with N>=O) is used here, the logical operation can be executed by shifting data, so that the operation efficiency can be improved.

As a supplementary note, when y=1, M=1, indicating that the table is not reduced in the horizontal axis direction.
-40f), M=x, indicating that the same reduction is performed in both the horizontal and vertical directions. Therefore, by appropriately specifying the value of y or the value of N,
It is possible to determine the horizontal and vertical axis distribution ratios that optimally utilize the table pattern.

Regarding 1M', the Σ table value may be determined again using the table reference step determined by M, and then determined by Ω.

Next, a method for correcting the table reference plan when all the motion axes of the robot are simultaneously started and finished in two mechanical coordinate systems will be described with reference to FIG.

First, in 4010 shown in FIG. 8, the maximum travel time ITiM for the motion axes to be operated simultaneously is determined from the travel time ITiME of each motion axis obtained using FIG.
Find EMAX. Next, in block 4o11, blocks 4012 to 4012 are executed for the axes to be operated simultaneously.
Step 4014 is executed.

In block 4012, the nth axis travel time increment ΔI T
Find i ME. In block 4013, the operating distance of the n-th axis is determined when a constant velocity moving part is added by the time increment.

L=Ln+ΔITiME skewer table maximum value 5PDG Here, Ln is the operating distance of the n-th axis, the table maximum value is the maximum table value referenced by the n-th axis, that is, the dimensionless maximum speed, and 5PDG is the This is a conversion constant for the n-axis table value.

Next, in block 4014, the conversion constant for the nth axis is reduced.

5PDG=SPDG*Ln/L As a result, even if the robot arms are servo-controlled to operate each axis independently with reference to the acceleration/deceleration table, the robot arms operate to start and stop at the same time.

A table reference method for accelerating and decelerating the robot arm when the trajectory is planned as described above will be explained with reference to FIG. 9.

In FIG. 9, as initial values, the address indicating the reference start address of the acceleration table is KASOKU, the final address (minimum value) of the deceleration table is GENSOKU, the table reference step is DELTBL, and the sum of deceleration table values is DPULS. , a conversion constant for converting table values into values for controlling the motion of the robot arm is set to 5PDG. This is similar to what was described for table reference plans. Furthermore, an acceleration mode is set in Flag as a flag for controlling table reference. under these conditions.

The table reference of FIG. 9 is executed.

First, since the acceleration mode is initially set in Flag, block 4101 is executed based on the determination in block 4100. In block 4101, it is checked whether the address indicated by KASOKU exceeds the maximum. Initially, since it has not been exceeded, block 4103 is executed.

That is, read the acceleration table value from the acceleration table address indicated by KASOKU and set it in the register. Next, set the table reference step DELTBL to KASOK.
Add to U and GENSOKU. GENSOK here
The reason why it is added to U is to set a deceleration table address when the robot arm is forcibly decelerated during operation, although the explanation will be omitted. This updates the table address to be referenced next.

As mentioned above here, DE! LTBL, ) [ASO
Xυ, GENSOKU includes the value after the decimal point, and when referring to the actual table, it is KASOKU or GENSOKU.
An integer point is used.

The resulting table value is then multiplied by a conversion constant in block 4110 to obtain the speed at which the robot arm is actually driven. The above process is executed repeatedly, and velocity patterns during acceleration are determined one after another using a table. Finally, the maximum limit of the KASOKU table is reached. In this case, blocks 4102 and 411
0 is executed.

In other words, after acceleration is completed, the operation will be in constant speed or deceleration mode, so set the deceleration start address to G.
ENSOKU, set the judgment flag Flag to constant speed mode, read the deceleration table value indicated by GENSOKU to the register, and convert it to obtain the operating speed.Next, when table reference is activated, constant speed mode is set. Therefore, block 4104 and subsequent blocks are executed.

In other words, remaining travel amount = target attachment - current position or target operating distance -
The required low operating distance deceleration amount = the integrated value of the deceleration table (DPULS) and the force transformation constant (SPDG) are compared, and if the former is greater than the latter, there is no need for deceleration, so the processes of blocks 4105 and 4110 are executed. Ru. Although not shown in Fig. 9, the low operating distance = Σ (speed determined from the table), GEN
Since the table address value indicated by SOKU is read, if the value of GENSOKU does not change, the value remains constant, that is, a constant speed specification is obtained, and the robot arm operates at a constant speed. If this state continues, the robot arm will gradually approach the movement target point, so the determination result in block 4104 will be No, and the processing from block 4106 onwards will be executed.

In block 4106, the value of GHNSOKU is decreased by the table lookup step DELTBL.

That is, the value is updated to indicate an address indicating a value on the low speed side of the deceleration table. Blocks 4107 and 41
06 is a safety measure to prevent referencing outside the definition of the deceleration table.

At block 4109 GE! The deceleration table value is read from the address indicated by N5OKU. In addition, the value of DPULS is decreased by the read value, and the value of the required deceleration amount is updated at the next reference.6 block 411
0 is the common processing described above.

In this way, a command value that instructs the robot arm to accelerate → constant velocity → decelerate or accelerate → decelerate is obtained.

Although not shown above, when it becomes necessary to forcibly decelerate and stop the moving robot arm, the deceleration table is used to refer to the deceleration table so that the deceleration can be started from any point as described above. Since the address of GENSOKU is set, this is used to always block
If steps 6 and subsequent steps are executed, the robot arm can be controlled to decelerate.

In this case, there is no need to perform correction regarding DPULS in block 4109.

The first example shows the case where one axis of the robot arm is accelerated/decelerated using the above table reference plan and table reference.
Shown in Figure 0.

The acceleration pattern and deceleration pattern given in FIG. 10 are the same, and a cycloid curve was used here.

In Figure 10, ■ indicates a case where the operating distance is short and the table pattern is reduced and the table pattern is reduced, and the operation is performed in an acceleration → deceleration mode, and ■ indicates a case where the operating distance is sufficiently long and the operation is performed in an acceleration → constant velocity → deceleration mode. Yes, ■ corresponds to the boundary between the two.

In this way, according to the deceleration table processing method of this embodiment,
The robot arm can always be operated in an optimal pattern regardless of the operating distance.

The acceleration/deceleration pattern processing method described above uses an acceleration table and a deceleration table in which dimensionless speed is used as a table value.

Here, if the acceleration pattern and the deceleration pattern are the same, even if only the acceleration pattern table is provided and used in common with the deceleration table, the present embodiment can be applied without any change in content.

In addition, the table may be constructed using a non-dimensional operating distance instead of a non-dimensional velocity. In this case, if a non-dimensional velocity is required, it can be easily achieved by taking the difference between the table values. The speed can be determined, and this can be handled by slightly changing the table processing method described above.

Further, even if the acceleration table is given with a dimensionless velocity and the deceleration table is given with a dimensionless operating distance as a reference, the content of this embodiment can be easily applied and substantially the same result can be obtained. Further, when the acceleration/deceleration pattern can be described by a certain specific function, the present invention can be easily realized by providing a function value calculation processing section in place of the table and using the function value calculation for table reference. In this case, it is also possible to realize an acceleration/deceleration plan using the characteristics specific to the function, as described above.

According to this embodiment, as described above, an arbitrary acceleration and deceleration pattern table that is optimal for driving the robot arm is provided, and when the operating distance is large, a constant speed section is inserted between acceleration and deceleration sections. , when the operating distance is small, create a table reference plan to reduce the table values and enlarge the table reference steps, refer to the table according to this plan, and use the obtained values to drive the robot arm. As a result, the following excellent effects are brought about.

(1) Any optimal table pattern can be freely designed.

(2) The robot arm always operates smoothly according to the table pattern and does not generate vibrations even when stopped.

(3) When the operating distance is short, the table reference step is expanded, so the operating time is shortened.

Note that the technique of the above embodiment is not only applicable to simply controlling a robot arm, but also widely applicable to controlling the movement of an object by point movement control.

〔Effect of the invention〕

As described above, according to the present invention, a robot arm that is more general and versatile, can be freely adapted to various operating conditions of the robot arm, and enables high-precision acceleration, deceleration, and positioning. A control method can be provided.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a robot system according to an embodiment of the present invention, FIG. 2 is a perspective view of a general robot device, and FIG. 3 shows an example of the teaching means shown in FIG. FIG. 4 is a block diagram showing the configuration of the calculating means in FIG. 1, FIG. 5 is a columnar diagram showing an example of an acceleration pattern,
FIG. 6 is a configuration diagram of an acceleration and deceleration table, FIG. 7 is a flowchart explaining the table reference plan of this embodiment, FIG. 8 is a flowchart showing a correction method for the table reference plan, and FIG. 9 is a flowchart showing the table reference method when accelerating and decelerating the robot arm,
FIG. 10 is a diagram showing an example of an acceleration/deceleration pattern according to this embodiment. DESCRIPTION OF SYMBOLS 1... Control device, 14... Teaching means, 15... Calculating means, 16... Calculating procedure storage means, L... Acceleration/deceleration operation distance. Lo...Specified operating distance, Q...Movement distance, Q
o... Movement distance between two given points, M... Table pattern reduction rate, M'... Reduction rate of conversion constant, 1/
M...Magnification rate of table reference step. No.? Houkiyodai No. 80/'I2 Ha. Teigurua FL's 1st Husband Hayame ■ 1st period

Claims (1)

[Claims] 1. In the calculation control method of a robot arm using point movement control, conversion constants are stored in the calculation procedure storage unit of the control device to table values to be referred to when controlling movement between two points. An acceleration pattern table and a deceleration pattern table are provided whose multiplied value is the speed or minute movement distance of the robot arm, and when the movement distance l_0 between two given points and the acceleration and deceleration table are operated according to the predetermined reference steps. , and if l_0<l, then l is equal to l_0,
The conversion constant is reduced and the table reference step is expanded, and the obtained conversion constant and table reference step are used to sequentially search the acceleration pattern table from the low speed side to the high speed side when the robot arm starts moving. The speed command value of the robot arm is set by multiplying the table value obtained by the conversion constant by the conversion constant. After completing the search of the acceleration table, the remaining movement amount L_0, which is the difference between the target position and the current position, is determined, and the current Compare the required deceleration distance L when decelerating from the operating speed according to the deceleration table, and if L_0>L, hold the current speed command value, and if L_0<L, set the reference address of the deceleration table to
Subtract the table reference step, search the table value on the low speed side of the deceleration table, correct the required deceleration distance L by the amount equivalent to this value, and use the value obtained by multiplying the table value by the conversion constant as the speed command value or minute incremental movement amount. A method for controlling a robot arm, the method comprising controlling the motion of the robot arm as follows: and operating the robot arm according to an acceleration and deceleration pattern. 2. In the method according to claim 1, l_0
<l, M=√(l_0/l) is the reduction rate of the conversion constant, 1/M is the expansion rate of the table lookup step,
A method for controlling a robot arm, characterized in that the reduction rate in the horizontal axis direction of the table is smaller than the reduction rate in the vertical axis direction. 3. In the method according to claim 1, l_0
If <l, x=√(l_0/l), M=x+(1-x)/yM'×
M=l_0/l (y>=1), 1/M is the expansion rate of the table reference step, M' is the reduction rate of the conversion constant, and y=2^N (an integer with N>=0). A method for controlling a robot arm, characterized by: 4. In the method according to claim 1, the acceleration pattern table and the deceleration pattern table are shared.
1. A method for controlling a robot arm, the method comprising using a plurality of tables. 5. The method according to claim 1, characterized in that the acceleration and deceleration pattern table is a motion distance pattern table, and the speed command is obtained by multiplying the difference between the table values by a conversion constant. How to control a robot arm. 6. Control of a robot arm in the method according to claim 1, characterized in that the table values of the acceleration and deceleration pattern table are obtained by functional calculation using numerical values corresponding to table reference addresses. Method.