JPH0431122B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a control device for a robot that accurately and repeatedly executes a programmed task. The present invention relates to a robot control device that facilitates recovery when a robot is stopped.

<Prior Art> Robots have been developed and used in many fields such as factories and logistics. The ability to do this was limited to movement on one axis, but now multi-axis, multi-joint types are being developed and put into practical use, and are capable of handling even more complex tasks.

As the processing power of robots increases,
As the degree of freedom of the robot's mechanism increases, its movement trajectory becomes impossible for the controller to predict. In other words, when the robot mechanism is stopped at an arbitrary position,
When moving the mechanism to any other arbitrary position, it is impossible to predict what kind of locus of movement the mechanism will take to reach the other arbitrary position.

Therefore, before the robot starts work, it is confirmed that the robot mechanism has returned to a predetermined origin, the so-called work original position, and the robot follows a predetermined program from the work original position. If you do not start the work, that is, if you have the robot start work from an arbitrary position, if there is an obstacle on the movement path of the robot's mechanism while moving to the work start position, the obstacle will be damaged and the robot itself will be damaged. There is a risk of causing destruction.

For this reason, a robot control device has been proposed that is provided with an interlock so that the robot cannot be started unless the robot mechanism is stopped at a single point in space called the work original position.

<Problems to be Solved by the Invention> However, the above-mentioned robot control device also has the following problems and is still not satisfactory.

That is, when a robot mechanism is stopped at a desired position, the robot control device must be switched to manual operation mode in order to move the stopped mechanism to a desired position, for example, a working position. Manual operation using a so-called teaching box is required.

Therefore, when performing manual operation, a worker who is familiar with the robot's functions is required to freely operate the robot's mechanism and move it to the work location, etc., and moreover, if this movement is caused by a work error, There was a possibility of accidents such as collisions with obstacles.

Furthermore, when a robot's mechanism stops for some reason while it is executing a certain program, the robot's control device may still be executing that program. In such a case, before manually operating the robot's mechanism, perform operations such as causing the robot's control device to stop executing the program and moving the robot accurately to the work location. Even after moving, operations must be performed to execute the next program to be executed, which not only reduces work efficiency, but also increases the possibility of erroneous operations due to the rush to recover if such a mechanism stops. It was big.

Furthermore, it is impossible to return to the working position by manual operation with high precision because it is done manually, and after recognizing that the robot has come close to the working position, the robot control device moves from the stopping point to the working position. However, since the robot could not accurately predict its path of motion in advance, there was a possibility that the robot would perform unexpected motions and collide with obstacles.

The present invention has been made in order to solve the above problems, and even if the mechanism of the robot stops at an arbitrary position in accordance with its program, the robot can be moved to the desired evacuation position without manual operation. The object of the present invention is to provide an excellent control device for a robot that can be easily moved to a certain position without causing a collision with an obstacle.

<Means for Solving the Problems> The means constructed by the present invention to solve the above problems is, as shown in the basic configuration diagram of FIG. 1, a work procedure memory that stores a series of work contents of the robot. means M1; and mechanism operation means M for operating the mechanism R of the robot according to the stored contents of the work procedure storage means M1.
2, a mechanism stop detection means M3 for detecting the stoppage of the operation of the mechanism R operated by the mechanism operation means M2 and its stop position; and the mechanism operated by the mechanism operation means M2. an evacuation route storage means M4 that stores in advance a dedicated evacuation route for operating R to a predetermined evacuation position corresponding to a predetermined operating position; The gist of the present invention is a robot control device characterized by comprising a retracting execution means M5 for retracting the mechanism R according to stored contents.

<Operation> The work procedure storage means M1 in the present invention stores the work performed by the robot, and is constituted by, for example, a computer. In recent years, advanced robot mechanisms have been developed and put into practical use in which various sensors are attached to the robot mechanism R and jobs are selected according to the detection results from the sensors. It may also be something that remembers.

The mechanism operating means M2 is a device that actually operates the robot mechanism according to the contents stored in the work procedure storage means M1, and is composed of a drive circuit such as a servo motor system or a hydraulic system, an actuator, etc. It is.

The mechanism operation means M2 is the work procedure storage means M1
By driving the mechanism R of the robot according to the stored contents of the robot, it becomes possible to have the robot perform a desired task.

In addition to the above configuration means, the present invention further includes the following means of operation.

First, the mechanism stop detection means M3 detects the stop and stop position when the mechanism R of the robot driven as described above stops in the middle of a series of operations due to some reason. This is a method that detects the position where the robot mechanism R has actually stopped as a position in a predetermined coordinate system, or a work procedure that cannot be executed midway because the robot mechanism R has stopped. Any method may be used, such as a method that estimates the stop position from the vehicle.

Next, the evacuation route storage means M4 is a point of view that determines what route the robot mechanism R should take in order to evacuate to a safe position without colliding with any obstacle, that is, to the evacuation position. A dedicated evacuation route determined from the above is stored in advance. Therefore, depending on the environment in which the robot is used, the stored contents correspond to the position at which evacuation is started. Furthermore, if the work original position of the robot is selected as the evacuation position at this time, it is convenient for the robot to perform the next work.

The evacuation execution means M5 actually operates the robot mechanism R.
, and drives the mechanism R by selecting the evacuation route stored in the evacuation route storage means M4 according to the detection result of the mechanism stop detection means M3, that is, the stoppage of the mechanism R and its stop position. do. When retracting the mechanism R, the structure can be simplified by using the mechanism operating means M2 already provided in the robot without providing a separate retracting actuator.

EXAMPLES Hereinafter, in order to explain the present invention more specifically, the present invention will be described in detail by giving examples.

<Example> FIG. 2 is a block diagram of a robot control system equipped with a robot control device of the present invention.
represents the robot. robot 10
The mechanism section 12 that actually executes the work, the power source unit 14 as the mechanism operation means M2 that drives the mechanism section 12, and the work procedure storage means M1 that stores a series of tasks to be performed by the robot 10. It is composed of a robot controller 16 with functions. As shown in the figure, the robot controller 16 is composed of a computer, and has an input/output port 16 that serves as a port for transmitting information to the power source unit 14 and the system sequence controller 30.
A. CPU 16B that actually executes calculations, ROM 16 that stores information such as control programs to be described later.
Stores temporary information such as C and calculation results.
Consists of 16D RAM. Further, 16E represents a bus line which serves as a path for transmitting information between the above-mentioned components.

Reference numeral 20 indicates other external equipment that assists the work performed by the robot 10. That is, a transport vehicle that transports the workpiece to be worked on by the robot 12 to a predetermined work position stored in the robot 10, and a clamper that fixes the workpiece so that the robot 10 can easily perform the work. Consists of various equipment such as.

30 is a system sequence controller that controls the entire robot control system. When the operator of this system starts the system from the operation panel 40, the workpiece is moved to a predetermined work position of the robot 10 by, for example, driving a transport vehicle according to a predetermined sequence, and then the clamper After fixing the workpiece, the robot controller 16 is in charge of a series of work flows such as instructing the robot controller 16 to start the robot 10.

The operation panel 40 includes a switch for instructing the start of the system as described above, as well as various control switches and display devices, such as a display section for displaying the current operating status of the system and a stop switch for stopping the operation of the system. Consisting of

The robot control device of this embodiment is composed of the robot controller 16 and power source unit 14 described above.

That is, as mentioned above, the robot controller 16 constitutes a work procedure storage means M1 that stores the execution of the robot 10 and all the work procedures, but at the same time, an evacuation route storage means M4 is stored in the storage section that stores the robot controller 16. It even remembers the evacuation route. This is the robot controller 16
This can be easily achieved by increasing the storage capacity of the computer storage device normally used as a computer.
The robot controller 16 also constitutes a mechanism stop detection means M3. That is, the robot controller 16 controls the power source unit 1 to operate the mechanical section 12 according to the stored work procedure.
A drive signal is output to 4. The robot is stopped due to an emergency stop, an abnormality in an external device, an interlock provided for safety, or the like. Then, the stop position can be determined by knowing what kind of drive signal was output to the mechanism section 12 when the stop occurred.
That is, it can be detected by searching which drive signal in the work procedure was output when the machine stopped. Furthermore, the robot controller 16
When the mechanism serving as the evacuation executing means M5 detects the stoppage of the mechanism section 12 and its stop position as described above, it selects the above-mentioned stored evacuation route corresponding to the stopped position, and It is constituted by a control program that outputs a drive signal to the power source unit to operate the mechanism section 12 along the set evacuation path. That is, it is composed of a robot controller 16 that stores and processes the control program, and a power source unit 14 that executes operations according to the processing results.

A control program for the robot control device of this embodiment configured as described above is shown in FIGS. 3 and 4.

FIG. 3 shows a work program for performing a series of works to be executed by the robot control system, and is executed when the system is started up and a command to start work is input from the operation panel 40.

When this program is executed, the first step is
100 is processed and the robot controller is started up and initialized to prepare for the following processing. Next, it is determined whether the mechanical part 12 of the robot is in the original working position and ready to start working (step 1).
110), if it is not in the original position, outputs a message to that effect to the system sequence controller 30, which causes the system sequence controller 30 to
The abnormality of the system is displayed on the display section 0 (step 120). If the mechanism section 12 is on standby at the work original position, the variable n is cleared in step 130.
This variable n is used to display the work number assigned corresponding to the work performed by the robot 10, and by knowing the work number n, the current robot 10
It is possible to search for the location of the mechanical section 12 and the type of work it is performing. When the clearing of variable n is completed, the variable n
is incremented (step 140), and the process moves on to the execution of the work corresponding to the incremented value of the variable n.

In step 150, input is made from the system sequence controller 30 as to whether or not the necessary preparations for the robot 10 to execute the work with work number n have been completed.If the preparations have not been completed, the process proceeds to step 120 as described above. If the preparation is completed, the next processing step 160 is executed. That is, the robot 10 waits until the control of other external devices controlled by the system sequence controller 30 is executed normally and a signal to start operation is input to the robot 10. The following step 160 is a step in which the work stored in the work procedure storage means M1 as the work with work number n is actually executed, and a drive signal is given to the power source unit according to the stored contents to perform the work. Next, it is determined whether the work n has been completed (step 170), and if the processing according to the memory contents has been successfully completed, it is determined whether the work for the last work number N has been performed. (step)
180), if n<N, return to step 140 again,
If n≧N, the mechanical section 12 is returned to its original working position (step 190), and then all processing of this program is terminated. However, if it is determined in step 170 that the mechanical section 12 stops for some reason during the execution of work n and that work n is not completed, the automatic evacuation routine (step 200) is executed.

FIG. 4 shows a control flowchart for automatic evacuation performed in step 200.

When the process moves to step 200, it first moves to step 201.
is executed, and an input is asked on the operation panel 40 to determine whether or not to execute automatic evacuation. If automatic evacuation is not desired, the routine ends without executing this routine, and if automatic evacuation is desired, the next step is performed. Proceed to step 202.

In step 202, a search is first made to find out at what position the mechanism section 12 is stopped. As mentioned above, in this embodiment, the work number n is robot 10.
The number n is assigned to each work performed by the operator, and the stopping position of the mechanism section 12 can be determined from this number n. Figure 5 shows this work number n and mechanism part 1.
FIG. 2 is an explanatory diagram schematically representing a movement locus of No. 2;
In the figure, O indicates the original working position of the mechanism section 12, and the solid line indicates the movement locus of the mechanism section 12, Pn (n=
1, 2...7) represent the coordinates of the position. The mechanism section 12 has a work number n from position P1 to P2.
Work number n = 1 is executed, work number n = 2 is executed from P2 to P3, and the same relationship is shown below. Then, the mechanism section 12 moves from position P1 to P
After completing all the tasks n=1 to 6 through step 7, the machine returns to the original work position O and prepares for the next task.

However, if the mechanism section 12 stops for some reason during execution of the above-mentioned work (point indicated by an x mark in the figure), the automatic evacuation routine shown in FIG. 4 is processed. Then, in step 202, a search is made to find out during which work number n the mechanical section 12 stopped, and an evacuation route corresponding to the work number n is selected from the storage device (step 203). Selection of the evacuation route is to determine which evacuation route is used to evacuate the mechanism part 12 among the movement loci of the mechanism part 12 shown by the dotted line in FIG. When = 1 and 2, the mechanism section 12 is moved once to the evacuation position A and then draws a large arc to the work original position O, and when the work number n = 3 and 4, the work original is moved after moving to the evacuation position B. An evacuation route is selected that moves the workpiece to position O, from evacuation position C to work original position O when work number n=5, and directly to work original position O when work number n=6. . The evacuation route indicated by the dotted line is determined in advance from the surrounding situation in which the robot 10 is used, and which evacuation route should be taken to return the mechanism part 12 to the work original position O without colliding with any obstacles. The robot controller 16 stores the results of the investigation to see if it is possible.

Once the optimum evacuation route is determined in this way, in the next step 204, the robot controller 16 outputs a drive signal to the power source unit 14 in order to drive the mechanism section 12 along the evacuation route.

In the next step 205, it is determined whether or not the mechanism part 12 has actually moved according to the drive signal output in the step 204, and if the mechanism part 12 has returned to the original working position O, it is determined whether or not the mechanism part 12 has actually moved. Returning to the work program in FIG. 3, if not, the process proceeds to step 206 to output the malfunction of the mechanism section 12 to the system sequence controller 30, display the system abnormality on the display section of the operation panel 40, and then similarly proceed to step 206. Return to the program shown in the figure.

The robot control device of this embodiment configured as described above has the following excellent effects.

That is, even if the mechanical part 12 of the robot 10 stops its operation for some reason, the operator can perform automatic evacuation from the operation panel with a single switch operation, and the mechanical part 12 will be able to safely evacuate while avoiding obstacles. This allows for a significant improvement in work efficiency.

Moreover, since the point at which the evacuation is completed is the work original position O of the robot, the robot can simultaneously complete preparations for moving to the next process.

Further, since the evacuation position (points A, B, and C) corresponding to the stopped position of the mechanism section 12 is prepared, and the evacuation route from that position to the work original position O is stored in the storage means, the mechanism It is not necessary to separately set evacuation routes for all the positions of the moving points of the section 12, and it is possible to create an evacuation program with a small storage capacity. Then, as shown in work number n=6, if the position is a place where no obstacles can exist, the work may be directly returned to the original work position O.

In this embodiment, a device that stores all evacuation routes has been described, but in a place where no evacuation route is required, for example, where all obstacles are 50 cm above the floor.
If the system is located at
B and C may all be defined as points 50 cm or more upward from the stopping position, and then there may be a degree of freedom such as returning to the original work position in a straight line or in an arc.

[Effects of the Invention] As described above in detail with reference to the embodiments, the robot control device of the present invention includes a work procedure storage means for storing a series of work contents of the robot, and a memory content of the work procedure storage means. a mechanism operating means for operating a mechanism of the robot according to the following: a mechanism stop detection means for detecting the stoppage of the operation of the mechanism operated by the mechanism operating means and the stop position thereof; an evacuation route storage means for storing in advance a dedicated evacuation route for operating the mechanism operated by the operating means to a predetermined evacuation position corresponding to a predetermined operation position; The present invention is characterized by comprising a retraction execution means for retracting the mechanism according to the contents stored in the route storage means.

Therefore, the mechanism of the robot normally executes a series of tasks according to the contents stored in the work procedure storage means, and even if a trouble that causes the robot to stop for some reason occurs, the robot mechanism stores an evacuation route according to the stop position. The evacuation can be completed automatically by following the evacuation route stored in the .

This prevents a decrease in work efficiency that would otherwise occur due to manual operation of the robot mechanism, and also prevents damage to the robot that would otherwise occur due to manual operation errors.

In addition, since the configuration is such that a dedicated evacuation route is stored in advance, the evacuation position for each predetermined operation position, such as the ``shortest and safest route'' to the work location, is considered in advance during teaching. It is also possible to safely and quickly return to the original working position.

On the other hand, if the purpose is to safely return to the original work position, it is conceivable to retreat by retracing the movement path based on the previous work procedure. That is, instead of storing a dedicated evacuation route in advance in relation to the operating position, it is conceivable to have a configuration in which the work procedure is reversed each time. In this case, if the mechanism were to stop at the final stage of the work procedure, there is a problem in that it would take an extremely long time to return to the original work position. In addition, since a collision between the workpiece and the mechanism can be considered as a condition for the mechanism to stop, there is a risk that the position of the workpiece will move due to the collision, and in this case, there is a problem that it will not be a safe evacuation route. There is also.

That is, only by adopting a configuration in which a dedicated evacuation route is stored in advance according to the operating position as in the present invention, it is possible to always evacuate the safest evacuation route for each operating position. However, it is also possible to evacuate the shortest evacuation route, and in this sense, it is extremely significant to store a path exclusively for evacuation in advance. The present invention can achieve the above-mentioned remarkable functions and effects precisely because the present invention is completely different from other inventions that are limited to the technical idea of simply executing the evacuation operation according to a predetermined program.

[Brief explanation of drawings]

Figure 1 is a basic configuration diagram of the present invention, Figure 2 is a configuration block diagram of an embodiment thereof, Figure 3 is a flowchart of its work program, Figure 4 is a flowchart of its automatic evacuation routine, and Figure 5. shows an explanatory diagram of the evacuation operation. M1...Work procedure storage means, M2...Mechanism operation means, M3...Mechanism stop detection means, M4...Evacuation route storage means, M5...Evacuation execution means, 10...Robot,
20...Other external devices, 30...System sequence controller, 40...Operation panel.

Claims (1)

[Scope of Claims] 1. A robot control device comprising: a work procedure storage means for storing a series of work contents of the robot; and a mechanism operation means for operating the mechanism of the robot according to the contents stored in the work procedure storage means. Mechanism stop detection means for detecting the stoppage of the operation of the mechanism operated by the mechanism operation means and the stop position of the mechanism; and a mechanism stop detection means for detecting the stop position of the mechanism operated by the mechanism operation means; and evacuation execution means for evacuating the mechanism according to the storage contents of the evacuation route storage means in accordance with the detection result of the mechanism stop detection means. Characteristic control device for robots.