KR102033241B1 - Device and method controlling a movement speed of robot - Google Patents

Abstract

When there exists a part (for example, a joint part) which moves faster than the tip of a robot, the safety at the time of teaching of a robot is raised more.
When teaching by controlling the robot, which is a horizontal articulated robot, in the Cartesian coordinate system, when the input instruction value for the moving speed exceeds the limit value using different limits determined based on the coordinates of the tip of the robot in the Cartesian coordinate system. The robot is moved by the movement speed that limits the input instruction value to the limit value.

Description

DEVICE AND METHOD CONTROLLING A MOVEMENT SPEED OF ROBOT}

The present invention relates to a moving speed control device and method for limiting the moving speed of a robot when teaching (teaching) an industrial robot.

In the teaching playback type robot, it is necessary to teach the robot an operation to be executed in advance. In the case of teaching the working position with respect to the horizontal articulated robot, the robot is operated in a rectangular coordinate system (XYZ coordinate system), and the moving speed of the robot is a linear velocity of the working point (point to be taught and generally the tip of the arm). Specify with. Under normal operation, no person enters or leaves the robot's operating space and does not cause any harm to the worker.However, when teaching to the robot, a teaching worker (also called a teacher) approaches the robot. The movement of the robot may cause harm to the instructor. In particular, in the teaching of a so-called transfer robot that carries an article in a narrow space called a chamber or the like, since the instructor enters into the chamber and teaches, there is a high possibility that the robot will collide with the instructor. In order to eliminate such a concern, it is required to make the movement speed of the tip of the robot during teaching be less than or equal to a predetermined upper limit speed (for example, 250 mm / sec).

Patent document 1 is providing the detection apparatus which detects the position of a teacher, and discloses that the operation speed of a robot is automatically reduced when a teacher approaches a robot. Patent document 2 detects the acceleration and the speed of the front-end | tip part of a robot arm, and discloses emergency stopping of a robot when any one becomes larger than predetermined value. Patent document 3 describes a command speed for driving each axis so as to move at a speed as close as possible to the speed commanded by the operation command from the teaching apparatus, while limiting the movement speed of the tip of the robot to a predetermined upper limit speed or lower during teaching. Disclosed is a method of calculating. Although Patent Document 4 does not relate to ensuring safety during teaching, when the rated speed is determined for each axis of the robot, the speed of each axis is calculated based on the speed data of the tip of the robot given by the teaching, and the rating of any axis Correction of speed data is started when the speed is exceeded.

International Publication No. 2004/009303 Japanese Patent Laid-Open No. 6-91587 Japanese Patent Laid-Open No. 9-193060 Japanese Patent Laid-Open No. 5-233052

As described in Patent Literature 1, the method for detecting the position of the teacher is likely to be large-scale and cost is easy to increase since it requires a detection device. The method of ensuring the safety of a teacher without providing the detection apparatus which detects the position of a teacher is basically making the speed of the tip of a robot below a predetermined upper limit speed. However, for example, consider a horizontal articulated robot in which two arms are connected so that they can all move in a horizontal plane (XY plane), so that the connection position (ie joint) between the arms is faster than the tip of the robot. It may move. It is also possible to limit the moving speed of the robot by calculating the velocity of the joints one by one, but the computational burden is large. Therefore, it is desired that there is a possibility of moving at high speed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a moving speed control device and method which can further increase the safety during teaching of the robot with a simple mechanism when there is a part moving faster than the tip of the robot.

The movement speed control apparatus of this invention is a main body part, the 1st arm which one end side connects to a main body part, the 1st motor which rotates a 1st arm with respect to a main body part, and the one end side is the other end part of a 1st arm. A movement speed control device for controlling a robot, which is a horizontal articulated robot having at least a second arm connected to the side and a second motor for rotating the second arm with respect to the first arm, the robot being controlled in a Cartesian coordinate system, When teaching the horizontal articulated robot, when the input instruction value for the moving speed exceeds the limit value, using a different limit value determined based on the coordinates of the tip of the robot's second arm side in the Cartesian coordinate system, the limit value. And a control unit for moving the robot by the movement speed at which the input instruction value is limited.

The method of the present invention includes a main body portion, a first arm having one end connected to the main body, a first motor for rotating the first arm with respect to the main body, and one end connected to the other end of the first arm. A method of controlling a robot, which is a horizontal articulated robot having at least a second arm and a second motor for rotating the second arm with respect to the first arm, wherein the robot is a horizontal articulated robot by controlling the horizontal articulated robot in a Cartesian coordinate system. When the teaching is performed, using different limit values determined based on the coordinates of the tip of the robot's second arm side in the Cartesian coordinate system, when the input instruction value for the moving speed exceeds the limit value, the input instruction is the limit value. The robot is moved by the limited movement speed.

When the front end of the horizontal articulated robot is moved by the control of the Cartesian coordinate system, the movement trajectory of the connecting portions of the two arms increases, and this connecting portion (joint portion or elbow of the robot) may move at high speed. This movement is unexpected for the instructor and may not be avoided by the instructor. However, the movement is limited to the instructor approaching the robot by limiting the movement speed by a limit value determined based on the coordinates of the tip of the Cartesian coordinate system. It can increase safety. The limit value can be determined to be smaller as the distance between the tip and the origin of the rectangular coordinate system is shorter, for example. Or, for example, letting the coordinates of the tip be (x, y), | x | and | y | The larger the smaller, the smaller the limit value can be determined.

In the present invention, one end side of the first arm is used as the origin, and a plane parallel to the movable range of the tip including the origin can be divided into a plurality of regions, and a single limit value can be determined for each region. By setting the limit values in this way, the computational load can be reduced as compared with the case where the angular velocity for each joint is calculated to limit the movement speed. As a division | segmentation method of an area | region, it can be set as the area | region defined by the square centering on the origin in the plane parallel to the movable range of a front-end including an origin. In the case where the area is set in this way, the XY coordinate of the position of the tip is (x, y), and the limit value is simply applied by applying a comparison formula for x and y or an expression for sum of absolute values of x and y. It can be determined, and a light calculation load is sufficient. As another division method of an area | region, it can also be set as the area | region delimited by the concentric circle centering on an origin. In this case, a square operation is required, but the movement speed is not excessively limited.

In the present invention, when the current movement speed exceeds the limit value based on the current position of the tip during the movement of the robot, the movement speed of the robot may be updated by the limit value based on the current position of the tip. With this configuration, for example, when the tip of the robot moves to approach the origin, safety can be further improved. In the present invention, the robot is moved by the movement speed limited at the start of this period during the period in which the operation instructing the movement of the robot is continued, and when the operation is resumed after the operation is resumed. The movement speed may be limited based on the coordinates of the tip. In this structure, since the moving speed is limited depending on the position of the tip at the time of resuming the operation instructing the movement, it is possible to substantially improve safety while reducing the computational load as compared with the case of acquiring the tip position sequentially. Herein, the operation of instructing the movement of the robot is, for example, an operation of pressing a push button provided on the teaching pendant. The robot continues to move while the push button is pressed, and stops the movement of the robot when the finger is released from the push button. .

In the present invention, the teaching pendant is configured as a teaching pendant connected to a robot controller of a robot, and an auxiliary storage unit for storing a parameter table describing a limit value according to the coordinates of the tip is provided in the teaching pendant, and the parameter table is referred to. It is also possible to limit the input instruction value by using a limit value obtained by the method. By configuring in this way, processing load can be distributed without giving a processing load to a robot controller. When the teaching pendant is connected to the robot controller, the parameter table may be read from the robot controller to the auxiliary storage unit. Since the teaching pendant is a small device and can be shared with other robots, it is recommended to use a single teaching pendant to increase the safety of teaching of various robots by using a single teaching pendant to read the parameter table from the robot controller. It becomes possible.

According to the present invention, when there is a portion that moves faster than the tip of the robot, the safety when teaching the robot by a simple mechanism becomes higher.

1 is a diagram showing an example of the configuration of a robot to which the movement speed limiting method of the present invention is applied.
2 is a block diagram showing the configuration of a robot controller and a teaching pendant.
3 is a flowchart for explaining a process for limiting the moving speed of the robot.
4 is a diagram illustrating an example of the contents of a parameter table.
5 is a diagram illustrating a relationship between the position of the tip and the moving speed after restriction.
6 is a flowchart for explaining another example of the process of limiting the moving speed of the robot.
7 is a view for explaining an example of the movement operation of the robot.
8 is a diagram for explaining another example of the movement operation of the robot.

Next, embodiment of this invention is described with reference to drawings. In the present invention, when teaching a horizontal articulated robot by operating in a Cartesian coordinate system (XYZ coordinate system), the robot is close to the origin O when the tip of the robot is close to the origin O based on the positional relationship between the tip of the robot and the origin O preset in the robot. The robot is operated at low speed and the speed of the robot at the time of teaching is limited by the position (XY coordinate) of the tip of the robot so that the robot can operate at high speed when the tip is away from the origin O.

1 shows an example of a robot to which a moving speed control method based on the present invention is applied in one embodiment of the present invention, (a) is a perspective view showing a movable portion of the robot 10, (b) is a mechanism diagram of the robot 10. It is assumed here that a rectangular coordinate system (XYZ coordinate system) is determined as indicated by an arrow in the figure. This robot 10 is a horizontal articulated robot, and is provided with the arm part containing the 1st arm 13 and the 2nd arm 15 connected to each other via the connection part 14. As shown in FIG. The base end side of the 1st arm 13 is provided in the main-body part 11 via the connection part 12, and the 1st arm 13 can be rotated in XY plane centering on the connection part 12. As shown in FIG. Moreover, the base end side of the 2nd arm 15 is connected to the front end side of the 1st arm via the connection part 14, and can be rotated in an XY plane centering on the connection part 14 center. Moreover, the hand 17 is provided in the front end side of the 2nd arm 15 via the connection part 16. As shown in FIG. The connection parts 12, 14, and 16 all contain a cylindrical joint, a motor, a reducer, etc., for example. The robot 10 is used for conveying an article or the like, and the hand 17 is always directed in the same direction in the XY plane by a link or the like or by motor control. In other words, the hand 17 performs only parallel movement in the XY plane. The movable range of the hand 17 is an XY plane or a plane parallel to the XY plane. In the following description, it is assumed that the movable range of the hand 17 is XY plane, ignoring the thickness in the Z direction of the first arm 13 and the second arm 15.

The robot 10 is further provided with a robot controller 30 which causes the robot to perform a predetermined movement by driving the motors 22, 24, 26,..., Which are installed in the robot 10. Here, the motors 22, 24, and 26 are, for example, motors that are built into the connecting portions 12, 14, and 16 and used for the rotation of the arms 13, 15 and the hand 17, respectively.

A teaching pendant 40, which is operated by a teacher when teaching the robot 10, is connected to the robot controller 30 via a cable 50. The robot controller 30 includes a robot driver 31 including a driver for driving the motors 22, 24, 26,..., And an arithmetic unit that performs calculations necessary for the robot 10 to execute predetermined movements ( 32, an auxiliary storage unit 33 including a flash memory, and the like, and a communication unit 34 that communicates with the teaching pendant 40 via the cable 50. The auxiliary storage unit 33 stores operation parameters and the like of the robot 10 as a parameter file, and also stores teaching results and the like.

The teaching pendant 40 includes an input unit 41 including a touch panel, a button, a switch, and the like, and an input of a command from a teacher, and a display unit including a liquid crystal display and the like for displaying information to the teacher ( 42, communication with the robot controller 30 via the cable 50, a control unit 43 for controlling the robot during teaching and teaching necessary for teaching, an auxiliary storage unit 44 including a flash memory, and the like. It has a communication unit 34 for performing the operation. The auxiliary storage unit 44 stores parameter files relating to the specifications and operating conditions of the robot 10. The teaching pendant 40 itself can be used in common with different kinds of robots, and when the teaching pendant 40 is connected to the teaching target robot, the above-described parameter file relating to the robot is read from the robot and stored in the auxiliary storage unit 44. Save it. In this embodiment, although the movement speed of the robot at the time of teaching execution is restrict | limited based on the position of the front end of the robot 10, how to limit a movement speed differs according to the specifications of a robot. Therefore, the parameter file for limiting the movement speed is also stored in the auxiliary storage unit 33 of the robot controller 30 of the robot in advance for each robot, and when the teaching pendant 40 is connected, It can be stored in the auxiliary storage unit 44 of the teaching pendant 40 from the auxiliary storage unit 33. In this embodiment, the process of limiting the movement speed itself is executed by the teaching pendant 40, and since the movement speed command after the restriction is sent from the teaching pendant 40 to the robot controller 30, the teaching pendant 40 sees this. It corresponds to a moving speed limiting device based on the invention.

In the teaching of the robot 10, the hand 17 is moved to the target position with the hand 17 as the object of teaching. As described above, since the hand 17 only moves in parallel in the XY plane, the movement speed in the Cartesian coordinate system is the same throughout the hand 17. So, in the following description, the position of the connection part 16 between the hand 17 and the 2nd arm 15 is handled as the tip of the 2nd arm 15 of the robot 10, ie, the tip of an arm part, This tip is used as a work point, and the movement speed of the robot 10 at the time of teaching is limited based on the position of the tip in the Cartesian coordinate system, that is, the coordinate value of the tip. In the robot 10 shown in FIG. 1, the position of the work point of the robot 10 is determined by the rotation of two axes of the first arm 13 and the second arm 15. Here, if the work point is moved by a certain distance in the XY plane based on the Cartesian coordinate system, the rotation angle of each arm 13, 15 is determined whether the work point is near the outer periphery or near the center of the work area of the robot 10. It depends greatly. When the connecting portion 14 between the first arm 13 and the second arm 15 is considered to be an elbow or a joint portion in the arm portion, the movement of the elbow portion is a movement of the tip portion near the center of the work area. Even if the distance is short and its moving speed is slow, there may be a case where the teacher rotates larger and faster than expected by the teacher. Since the rotation of the elbow portion is centered on the connecting portion 12 of the main body 11 and the first arm 13, the position of the connecting portion 12 in the XY plane is referred to as the origin O in the following description.

The control part 43 of the teaching pendant 40 controls the position of the front-end | tip of the 2nd arm 15 which is a working point based on the input to the input part 41 by the rectangular coordinate system. At this time, the control unit 43 uses the robot 10 at different upper limit values determined based on the coordinates of the tip of the second arm 15 in the XY coordinate system in order to prevent the elbow from rotating large and fast in this way. ). This upper limit is called a limit value. 3 shows the procedure of the specific example of such a process. First, in step 101, in order to set the moving speed of a robot with the instructor with respect to the input part 41, input of a moving speed is made. For example, when 250 mm / sec is made into 100% and a teacher inputs a numerical value in 1 to 100% of range, input of a moving speed is performed. The movement speed input by the instructor is referred to as the input instruction value Vin. The control part 43 acquires the coordinate value of the position of the front-end | tip of the 2nd arm 15 by step 102, and acquires the limit value Vlim of the moving speed corresponding to the acquired position in step 103. The limit value Vlim may be determined based on, for example, the parameter table read in advance from the robot controller 30 to the auxiliary storage unit 44 of the teaching pendant 40, or may be determined by calculation. Although the specific example of the limit value Vlim corresponding to the position of the tip of the 2nd arm 15 is mentioned later, the point is that when the tip of a 2nd arm is close to origin 0, the limit value Vlim will become small.

In the next step 104, the control unit 43 determines whether the input instruction value Vin is greater than the limit value Vlim. In the case where the input instruction value Vin exceeds (Vin> Vlim) above the limit value Vlim, the limit value Vlim is set to the speed command value Vcmd in step 105, and in other cases, the input instruction value Vin is set in step 106. The speed command value is Vcmd. When the speed command value Vcmd is determined in step 105 or 106, the control unit 43 sends a speed command to the robot controller 30 to drive the robot by the speed command value Vcmd in step 110. In this way, when the robot 10 has a larger input instruction value Vin for the moving speed than the limit value Vlim determined by the position of the tip of the second arm 15 at the time when the input instruction value Vin is inputted, The movement speed is limited to the limit value Vlim to operate.

In the case of using the teaching pendant 40 in which the robot 10 moves only during a period during which operation with a specific switch such as an operation button is performed at the time of teaching, the operation button is operated when the above-described processing is executed. The movement is started based on the limit value at that time, and the speed is maintained while the operation button is operated. If the finger is released from the operation button, it will become inoperative state.If the operation button is operated again after the non-operation state has been operated, the robot moves at a limited speed according to the limit value according to the position of the tip at the time of reoperation. Can be initiated. By setting it as such an operation form, since it can be set as the moving speed according to the position of the front end of the robot 10, teaching efficiency can be improved. In addition, when the tip of the robot 10 moves in the direction close to the origin O, by performing the intermittent operation in this manner, the moving speed is more limited as the origin approaches, and therefore the safety is higher. Here, although it becomes a limit value according to the position of the tip at the time of reoperation, as mentioned later, while operating an operation button, you may acquire the present position of a tip in real time, and may limit a movement speed according to the acquired position.

Next, a method of determining the limit value Vlim corresponding to the position of the tip of the second arm 15 will be described. 4 shows an example of the contents of the parameter table used to determine the limit value Vlim. Here, the index L which shows how far from the origin O the tip of the 2nd arm 15 is introduce | transduced is introduced. The index L is introduced to prevent unexpectedly rapid movement because the tip of the second arm 15 is near the origin O, and is determined to be a small value when the tip is near the origin O as a whole. However, the magnitude at the actual distance (Euclidean distance) does not necessarily have to be the magnitude of the index L as it is. The parameter table as shown in FIG. 4 is used for dividing the XY plane into a plurality of regions and defining a single limit value Vlim depending on how far the region is from the origin for each region. In the example shown here, the indicator L is divided into five steps of 0 or more and less than D1, D1 or more and less than D2, D2 or more and less than D3, D3 or more and less than D4, and D4 or more, respectively, and limit values V1, V2, and V3 for these steps, respectively. , V4 and V5 are allocated. Here, as V1 <V2 <V3 <V4 <V5, the smaller the index L is, the smaller the limit value Vlim is. Then, by searching this parameter table based on the index L, the limit value Vlim can be obtained.

5 is a diagram showing a relationship between the position of the tip at the time of inputting the input instruction value Vin and the upper limit (that is, the limit value Vlim) of the movement speed limited by the limit value Vlim. The coordinate of the position of the front-end | tip of the 2nd arm 15 in an XY plane is set to (x, y). In FIG. 5A, the absolute value | x | of the X coordinate of the position of the tip of the second arm 15 in the XY plane. And absolute values of the Y coordinate | y | The case where the larger one is set as the index L is shown. The region per limit value Vlim is defined by a square having sides parallel to each of the X axis and the Y axis with respect to the origin. In the illustration, the limit value is V3 if the position of the tip is P1, and the limit value is V4 if the position of the tip is P2. As shown in Fig. 5A, the index L is derived by obtaining the XY coordinates of the tip position and performing only a few comparison operations, and thus there is an advantage that the calculation amount for calculating the index L is small and the calculation can be performed at high speed. . On the other hand, as shown in FIG. 5B, the normal position (Euclidean distance) between the tip position of the second arm 15 and the origin O in the XY plane is indicated by the index L (ie, L ² = x ² + y ² ), the zones are divided by this index L. In other words, the region defined by the concentric circles in the XY plane is the region of the limit value Vlim region. P1 and P2 in FIG. 5B are located at the same position in the XY plane with P1 and P2 in FIG. 5A, respectively, but in the case shown in FIG. If the position is P1, the limit value is V3 as in the case of FIG. In the case where the distance is the index L, a square operation for each of the X and Y coordinates of the tip position and an operation for calculating their sum are required in addition to the comparison operation, and the amount of calculation increases, but is based on the actual distance. As shown here with respect to the position P2, there is an advantage that the movement speed is not excessively limited. As a modification of what is shown to Fig.5 (a), there exist some which L = | x | + | y |. In this case, the area | region by index L becomes an area | region delimited by the square which makes the X-axis and Y-axis diagonal.

In FIG. 5, the XY plane is divided into several regions, and the limit value Vlim is determined based on which region the position of the tip of the second arm 15 exists. The method of determining is not limited to this. For example, the limit value Vlim may be determined by a function monotonically increasing in accordance with the index L (for example, a linear function proportional to the index L). A normal distance may be sufficient as the index L here, and it may be a larger one among the absolute value of the X coordinate of the tip position, or the absolute value of the Y coordinate.

In the process shown in the flowchart of FIG. 3, the moving speed of the robot 10 is determined based on an indicator L indicating how far from the origin O the tip of the second arm 15 at the time when the input instruction value Vin is input. It is limited. Here, a case in which the tip of the arm portion moves the robot 10 in a direction away from the origin O as in the movement from the position P3 to the position P4 in FIG. 5A is considered. At this time, the movement speed is limited by the limit value V3 at the position P3, and the robot 10 moves at a speed equal to or less than the limit value V3. However, since the limit value Vlim becomes larger as it moves away from the origin O, a safety problem is unlikely to occur by increasing the moving speed of the robot 10 within the range of the input instruction value Vin. In addition, in the case of a movement approaching to the origin O, such as the movement from the position P5 to the position P6 in FIG. 5 (b), when the movement is made to the limit value V4 corresponding to the position P5, the elbow is moved in the vicinity of the position P6. The movement speed may be excessive. Therefore, it is considered to change the control for limiting the moving speed of the robot 10 at any time according to the current position of the tip of the second arm 15. Fig. 6 shows a process in the case where the control of the limit of the movement speed is changed at any time in accordance with the current position of the tip.

In the processing shown in FIG. 6, the processes of steps 101 to 106 and 110 are performed similarly to that shown in FIG. 3. After execution of step 110, the control part 43 acquires the present position of the front-end | tip in step 111, and acquires the limit value Vlim corresponding to the present position acquired in step 112. FIG. The present position means the position of the tip at the present point in time during the movement of the robot 10, not the input point of time of the input instruction value Vin. The acquisition method of the limit value Vlim is the same as that described using FIG. Next, in step 113, the control unit 43 determines whether the input instruction value Vin is greater than the speed command value Vcmd at that time and is equal to or less than the limit value Vlim corresponding to the current position (that is, whether Vlim? Vin> Vcmd). Determine. In the case where Vlim≥Vin> Vcmd, since it is possible to increase the moving speed to the input instruction value Vin, in step 114, the control unit 43 increases the speed through the display unit 42 with respect to the instructor. Inquiry is made as to whether or not the instruction is made in step 115 to determine whether or not an instruction for speed increase has been made. The instruction of the speed increase is input by the teacher operating, for example, a button provided in the teaching pendant 40. When it is determined in step 115 that the speed increase instruction has been made, the control unit 43 sets the input command value Vin already input in step 101 as the speed command value Vcmd in step 116, and then the process proceeds to the step. Proceed to 119 In contrast, when there is no instruction to increase the speed in step 115, the process proceeds to step 119 without changing the speed command value Vcmd.

When Vlim≥Vin> Vcmd is not established in step 113, the control part 43 determines whether the speed command value Vcmd exceeds the limit value Vlim in step 117, and when it exceeds, in step 118, The moving speed is limited by setting the limit value Vlim as the speed command value Vcmd, and after the limitation of the moving speed, the process proceeds to step 119. If Vcmd> Vlim is not found in step 117, the process proceeds to step 119 without changing the speed command value Vcmd. In step 119, the control unit 43 determines whether a predetermined end condition, for example, a condition such as the movement of the robot 10 to the specified position is satisfied or not, and if the end condition is not satisfied, proceeds to step 110. When the robot 10 is returned and the end condition is satisfied, the robot 10 is driven by the speed command value Vcmd at that time. In step 120, the robot is terminated. When returning to step 110, the speed command value Vcmd up to that time may differ from the speed command value Vcmd determined in step 116 or step 118. In that case, you may control so that a movement speed may change slowly. Also in the process shown in FIG. 6, the moving speed of the robot 10 is limited by the limit value Vlim determined based on the indicator L determined by the position of the tip of the robot 10, but especially at the current position of the tip. It is therefore limited by the limit value Vlim which changes from time to time.

7 and 8 simulate the movements of the arms 13 and 15 and the hand 17 when the tip of the robot 10 is moved by 400 mm in the -Y direction assuming the robot shown in FIG. The results are shown. In these figures, the azimuth angle of the tip of the arm portion viewed from the origin is θ1 with the angle toward the counterclockwise direction as the basis of the Y-axis direction being positive, and the angle formed by the first arm 13 and the second arm 15 is made. Half of is called θ2. 7 is a state in which the elbow of the robot 10 is closed to some extent (in other words, the state where the tip is close to the origin O), and the XY coordinates of the tip of the arm portion 10 are (470, 200) at the initial position. The movement in the case of is shown. (A) of FIG. 7 shows the state in the initial position, (b) of FIG. 7 shows the state in which it moved by -200 mm in the Y-axis direction, and (c) of FIG. The state in which the XY coordinates of the front end became (470, -200) is shown. On the other hand, FIG. 8 shows the motion when the elbow of the robot 10 is open to some extent (the tip is far from the origin O), and the XY coordinates of the initial position of the tip are (1800, 200). have. (A) of FIG. 8 shows the state in the initial position, (b) of FIG. 8 shows the state in which it moved by -200 mm in the Y-axis direction, and FIG. 8 (c) shows the end state, namely The state in which the XY coordinates of the front end became (1800, -200) is shown. In FIG. 7, the movement of an elbow (coupling part 13 of the 1st arm 13 and the 2nd arm 15) is larger than the movement of the front end of the robot 10, and this is the speed of the front end. It is not possible to sufficiently control the speed of the elbow movement just by regulating the pressure. In contrast, in FIG. 8, the elbow movement is smaller than the tip movement. 7 and 8, when teaching, the robot is operated at a low speed when the tip of the robot is close to the origin O, and the movement speed is limited so that the robot can operate at a high speed when the tip is away from the origin O, It can be seen by the instructor that the elbow part of the robot can be prevented from moving at an unexpected speed.

In the above-described embodiment, since the teaching pendant 40 functions as a movement speed limiter, the robot controller does not need to execute a process for limiting the movement speed based on the limit value, so that a computational load may be applied to the robot controller. There is no. In addition, since this movement speed limit is necessary only for teaching, there is no need to incorporate a function for the movement speed limit into the robot controller. The parameter table itself necessary for the movement speed limit is stored in advance in the robot controller, and the parameter table is read into the teaching pendant when the teaching pendant 40 is connected, thereby limiting the movement speed based on the present invention. It is possible to execute using the same teaching pendant 40 for the robot. Alternatively, the parameter table for each model of the robot may be stored in the teaching pendant 40 in advance, and the parameter table may be selected according to the model when teaching.

The robot to which the present invention can be applied is not limited to the horizontal articulated robot having the first arm 13 and the second arm 15 shown in FIG. 1. For example, an elastic joint is provided between the main body portion 11 and the connecting portion 12 so that the portion from the first arm 13 to the hand 17 can move up and down in the Z-axis direction as it is. The present invention also applies to a robot, a robot provided with a third arm that rotates in the XY plane at the distal end of the second arm 15, a robot having a tool for moving in the Z-axis direction in the hand 17, and the like. Can be applied. When the present invention is applied to a robot having a movement in the Z direction, for example, the XYZ space may be divided into several small spaces, and the movement speed may be limited depending on which small space the tip of the robot is in. .

10: robot
11: body
12, 14, 16: connections
13, 15: arm
17: Hand
22, 24, 26: motor
30: robot controller
31: robot drive unit
32: calculation unit
33, 44: auxiliary memory
40: teaching pendant
43: control unit
50: cable

Claims (14)

delete delete A main body, a first arm having one end connected to the main body, a first motor for rotating the first arm with respect to the main body, and an end having one end connected to the other end of the first arm. It is a movement speed control apparatus which controls a horizontal articulated robot provided with the 2nd arm and the 2nd motor which rotates the said 2nd arm with respect to the said 1st arm,
Control the robot in a Cartesian coordinate system, and when teaching the robot, input to the movement speed using different limit values determined based on the coordinates of the tip of the second arm side of the robot in the Cartesian coordinate system. When the instruction value exceeds the limit value, the controller is provided with a control unit for moving the robot by the movement speed in which the input instruction value is limited to the limit value.
The one end side of the first arm is the origin, and a plane including the origin and parallel to the movable range of the tip is divided into a plurality of regions, and the single limit value is defined for each region.
And the area is an area defined by a square around the origin. A main body, a first arm having one end connected to the main body, a first motor for rotating the first arm with respect to the main body, and an end having one end connected to the other end of the first arm. It is a movement speed control apparatus which controls a horizontal articulated robot provided with the 2nd arm and the 2nd motor which rotates the said 2nd arm with respect to the said 1st arm,
Control the robot in a Cartesian coordinate system, and when teaching the robot, input to the movement speed using different limit values determined based on the coordinates of the tip of the second arm side of the robot in the Cartesian coordinate system. When the instruction value exceeds the limit value, the controller is provided with a control unit for moving the robot by the movement speed in which the input instruction value is limited to the limit value.
The one end side of the first arm is the origin, and a plane including the origin and parallel to the movable range of the tip is divided into a plurality of regions, and the single limit value is defined for each region.
And the area is an area defined by a concentric circle centered on the origin. The said control part is a limit value based on the current position of a said tip, when the present movement speed exceeds the limit value based on the present position of the said tip in the movement of the said robot. The movement speed control device which updates the movement speed of the said robot. The said control part moves a said robot by the said moving speed which was limited at the start of the said period, during the period in which the operation | movement which instruct | indicates the movement of the said robot is continued, The completion | finish of the said operation | movement of Claim 3 or 4 And in the case where the operation is resumed later, the movement speed control device is limited based on the coordinates of the tip at the time of resumption. The said movement speed control apparatus is comprised as a teaching pendant of Claim 3 or 4 connected with respect to the robot controller of the said robot,
The teaching pendant has an auxiliary storage unit for storing a parameter table describing the limit value according to the coordinates,
And the control unit limits the input instruction value by using the limit value obtained by referring to the parameter table. The movement speed control device according to claim 7, wherein the parameter table is read from the robot controller to the auxiliary storage unit when the teaching pendant is connected to the robot controller. delete delete A main body, a first arm having one end connected to the main body, a first motor for rotating the first arm with respect to the main body, and an end having one end connected to the other end of the first arm. A method for controlling a horizontal articulated robot, comprising at least a second arm and a second motor that rotates the second arm with respect to the first arm,
When teaching the robot by controlling the robot in a Cartesian coordinate system, an input instruction to a moving speed is made using different limit values determined based on the coordinates of the tip of the second arm side of the robot in the Cartesian coordinate system. When the value exceeds the limit value, the robot is moved by the moving speed that limits the input indication value to the limit value,
The one end side of the first arm is the origin, a plane including the origin and parallel to the movable range of the tip is divided into a plurality of regions, and the single limit value is determined for each region.
And the area is an area defined by a square around the origin. A main body, a first arm having one end connected to the main body, a first motor for rotating the first arm with respect to the main body, and an end having one end connected to the other end of the first arm. A method for controlling a horizontal articulated robot, comprising at least a second arm and a second motor that rotates the second arm with respect to the first arm,
When teaching the robot by controlling the robot in a Cartesian coordinate system, an input instruction to a moving speed is made using different limit values determined based on the coordinates of the tip of the second arm side of the robot in the Cartesian coordinate system. When the value exceeds the limit value, the robot is moved by the moving speed that limits the input indication value to the limit value,
The one end side of the first arm is the origin, a plane including the origin and parallel to the movable range of the tip is divided into a plurality of regions, and the single limit value is determined for each region.
And said area is an area defined by concentric circles about said origin. The robot according to claim 11 or 12, wherein when the current moving speed exceeds the limit value based on the current position of the tip, the robot is limited by the limit value based on the current position of the tip during the movement of the robot. How to update the speed of movement. The robot according to claim 11 or 12, wherein the robot is moved by the movement speed limited at the start of the period during the period in which the operation instructing the movement of the robot continues, and the operation is completed after the end of the operation. If resumed, limiting the speed of movement based on the coordinates of the tip at the resume.

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