Method for controlling robot system and robot system

Abstract

To provide a control method for a robot system that can exhibit excellent operating accuracy, and a robot system.SOLUTION: According to a control method for a robot system that comprises a movable stage, a tool attached to the movable stage, and a robot arm for holding one of the movable stage and an object, and performs a prescribed operation for the object by use of the tool, the operation performs while moving the tool with respect to the object by the movable stage in the state that the robot arm is stopped, and a range of the operation is smaller for a part with a large curvature than a part with a small curvature of the object.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to a control method for a robot system and a robot system. [Background technology]

[0002] Patent Document 1 discloses a robot system that has a robot with a spray nozzle supported via a head slide unit at the tip of a robot arm, and that paints the surface of an object by spraying paint from the spray nozzle. In this type of robot system, the entire object is painted by repeating a moving step in which the robot arm is moved to bring the spray nozzle into opposition to an unpainted area of ​​the object, and a painting step in which the robot arm is stopped and the head slide unit is used to move the spray nozzle relative to the object while painting the unpainted area. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2-31850 Summary of the Invention [Problem to be solved by the invention]

[0004] However, for example, when printing on a curved surface using an inkjet head, if the inkjet head is moved relative to the surface to be printed using a slide unit, the distance between the surface to be printed and the inkjet head changes during the movement, causing printing unevenness within the printing area and deteriorating the quality of the printing work. This problem becomes more pronounced the greater the curvature of the printing area. [Means for solving the problem]

[0005] A method for controlling a robot system according to the present invention includes a moving stage, a tool attached to the moving stage, and a robot arm that holds either the moving stage or an object, and performs a predetermined task on the object using the tool, the method comprising the steps of: performing the work while moving the tool relative to the object by the moving stage while the robot arm is stopped; The range of operation is smaller in areas of the object with greater curvature than in areas with less curvature.

[0006] A robot system according to the present invention includes a moving stage, a tool attached to the moving stage, and a robot arm that holds either the moving stage or an object, and performs a predetermined operation on the object using the tool, performing the work while moving the tool relative to the object by the moving stage while the robot arm is stopped; The range of operation is smaller in areas of the object with greater curvature than in areas with less curvature. [Brief description of the drawings]

[0007] [Figure 1] 1 is a perspective view showing an overall configuration of a robot system according to a first embodiment. [Diagram 2] FIG. 2 is a plan view showing a moving stage. [Diagram 3] 4 is a flowchart showing a printing process. [Figure 4] FIG. 2 is a diagram showing a state in which a printing surface is divided into a plurality of regions. [Diagram 5] 4A to 4C are diagrams illustrating the movement of an inkjet head in a printing step. [Figure 6] 4A to 4C are diagrams illustrating the movement of an inkjet head in a printing step. [Figure 7] 4A to 4C are diagrams illustrating the movement of an inkjet head in a printing step. [Figure 8] FIG. 11 is a diagram illustrating the effect of a printing method. [Figure 9] FIG. 11 is a diagram illustrating the effect of a printing method. [Figure 10] FIG. 13 illustrates a modified example of a printing method. [Figure 11] FIG. 13 illustrates a modified example of a printing method. [Figure 12] 13A to 13C are diagrams illustrating the movement of an inkjet head in a printing step according to a second embodiment. [Figure 13] 13A to 13C are diagrams illustrating the movement of an inkjet head in a printing step according to a second embodiment. [Figure 14] FIG. 11 is a diagram illustrating the effect of a printing method. [Figure 15] FIG. 11 is a diagram illustrating the effect of a printing method. [Figure 16] FIG. 11 is a perspective view showing an overall configuration of a robot system according to a third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Hereinafter, preferred embodiments of a control method for a robot system and a robot system will be described with reference to the accompanying drawings.

[0009] First Embodiment FIG. 1 is a perspective view showing the overall configuration of a robot system according to a first embodiment. FIG. 2 is a plan view showing a moving stage. FIG. 3 is a flowchart showing a printing process. FIG. 4 is a diagram showing a state in which a printing surface is divided into a plurality of regions. FIGS. 5 to 7 are diagrams explaining the movement of an inkjet head in a printing step. FIGS. 8 and 9 are diagrams explaining the effect of a printing method. FIGS. 10 and 11 are diagrams showing modified examples of the printing method.

[0010] The robot system 100 shown in FIG. 1 includes a robot 200, a robot control device 900 that controls the driving of the robot 200, and a fixing member 700 that supports and fixes an object Q.

[0011] The robot 200 is a six-axis robot having six drive axes. The robot 200 has a base 210 fixed to the floor, a robot arm 220 connected to the base 210, and a tool 400 connected to the robot arm 220 via a moving stage 300.

[0012] The robot arm 220 is a robotic arm in which multiple arms 221, 222, 223, 224, 225, and 226 are rotatably connected, and includes six joints J1 to J6. Among these, the joints J2, J3, and J5 are bending joints, and the joints J1, J4, and J6 are torsion joints. The joints J1, J2, J3, J4, J5, and J6 are each provided with a motor M as a drive source and an encoder E that detects the amount of rotation of the motor M (the rotation angle of the arm).

[0013] A tool 400 is connected to the tip of the arm 226 via a moving stage 300. That is, the moving stage 300 is held by the arm 226, and the tool 400 is attached to the moving stage 300. The tool 400 is not particularly limited and can be set appropriately depending on the target work, but in this embodiment, a printer head, especially an inkjet head 410, is used. The inkjet head 410 has an ink chamber (not shown), a vibration plate arranged on the wall of the ink chamber, and ink ejection holes 411 connected to the ink chamber, and is configured so that ink in the ink chamber is ejected from the ink ejection holes 411 by vibration of the vibration plate. However, the configuration of the inkjet head 410 is not particularly limited. The printer head is not limited to the inkjet head 410.

[0014] 2, the moving stage 300 connecting the inkjet head 410 and the robot arm 220 includes a base 310 connected to the arm 226, a stage 320 that moves relative to the base 310, and a moving mechanism 330 that moves the stage 320 relative to the base 310. When the three mutually orthogonal axes are the X-axis, the Y-axis, and the Z-axis, the stage 320 includes an X-stage 320X that can move in a direction along the X-axis relative to the base 310, a Y-stage 320Y that can move in a direction along the Y-axis relative to the X-stage 320X, and a θ-stage 320θ that can rotate around the Z-axis relative to the Y-stage 320Y, and the inkjet head 410 is attached to the θ-stage 320θ. The X-stage 320X and the Y-stage 320Y are linearly guided in the X-axis and Y-axis directions, respectively, by linear guides, and can move smoothly and without backlash in the rail direction of the linear guide.

[0015] The movement mechanism 330 also has an X movement mechanism 330X that moves the X stage 320X in a direction along the X axis relative to the base 310, a Y movement mechanism 330Y that moves the Y stage 320Y in a direction along the Y axis relative to the X stage 320X, and a θ movement mechanism 330θ that rotates the θ stage 320θ around the Z axis relative to the Y stage 320Y.

[0016] Moreover, the X-moving mechanism 330X, the Y-moving mechanism 330Y, and the θ-moving mechanism 330θ each have a piezoelectric actuator 340 as a driving source. This allows the moving stage 300 to be made smaller and lighter. The driving accuracy of the moving stage 300 is improved, and the tool 400 can be easily moved at a constant speed. In addition, since direct driving can be performed without using a reducer, further weight and size can be reduced. The piezoelectric actuator 340 is configured to vibrate using the expansion and contraction of a piezoelectric element, and the vibration is transmitted to each stage 320X, 320Y, and 320θ to move each stage 320X, 320Y, and 320θ. However, the driving source is not particularly limited, and for example, an electromagnetic motor may be used.

[0017] The robot control device 900 controls the driving of the joints J1 to J6, the moving stage 300, and the inkjet head 410 to cause the robot 200 to perform a predetermined task. The robot control device 900 is, for example, configured from a computer, and has a processor (CPU) for processing information, a memory communicatively connected to the processor, and an external interface. In addition, various programs executable by the processor are stored in the memory, and the processor can read and execute the various programs stored in the memory.

[0018] The configuration of the robot system 100 has been described above. With the robot control device 900 controlling each part of the system, the robot system 100 can perform an operation of printing a desired pattern using the inkjet head 410 on a printing surface Q1 provided on the surface of an object Q having a three-dimensional shape (hereinafter, also simply referred to as a "printing operation"), for example, as shown in FIG. 1. Note that this printing operation is performed by moving the inkjet head 410 in the direction indicated by the arrow N for each of the four regions R1, R2, R3, and R4, as described below (see FIG. 4). A control method for performing this operation will be described below.

[0019] 3, the printing operation includes a shape calculation step S1 for calculating the shape of the object Q, specifically the shape of the printing surface Q1, an area setting step S2 for dividing the printing surface Q1 into a plurality of areas R based on the shape of the printing surface Q1, a printing order determination step S3 for determining the printing order of each area R, and a printing step S4 for performing printing on each area R using the inkjet head 410 according to the determined printing order. The printing step S4 also includes a unit printing step S40 including a moving step S41 for driving the robot arm 220 to make the inkjet head 410 face the area R, and an operation step S42 for performing printing on the area R using the inkjet head 410 while moving the inkjet head 410 relative to the printing surface Q1 by the moving stage 300 with the robot arm 220 stopped, and this unit printing step S40 is repeatedly performed for each area R according to the order determined in the printing order determination step S3. Each step will be described below in order.

[0020] [Shape calculation step S1] In the shape calculation step S1, the shape of the object Q, specifically the shape of the printing surface Q1, is calculated. In this embodiment, CAD data, which is 3D data of the object Q, is acquired in advance, and the shape of the printing surface Q1 is calculated based on this CAD data. According to this method, the shape of the printing surface Q1 can be calculated more simply and accurately.

[0021] However, the method for calculating the shape of the printing surface Q1 is not particularly limited, and for example, a 3D camera or multiple 2D cameras may be added to the robot system 100, and the shape of the printing surface Q1 may be calculated based on the image data of the object Q acquired by the added cameras. This method also makes it possible to calculate the shape of the printing surface Q1 more easily and accurately. Other examples include a method of calculating the shape of the printing surface Q1 using a depth sensor, and a method of calculating the shape of the printing surface Q1 by a phase shift method using a projector that projects a striped light pattern onto the printing surface Q1 and a camera that images the printing surface Q1 in a state where the light pattern is irradiated thereon.

[0022] [Area setting step S2] In the area setting step S2, the printing surface Q1 is divided into a plurality of areas R based on the shape of the printing surface Q1 calculated in the shape calculation step S1. At this time, the larger the curvature of the printing surface Q1, the smaller the area is divided into the plurality of areas R. For example, in the example shown in FIG. 4, the printing surface Q1 is divided into four areas R1, R2, R3, and R4. And the magnitude relationship of the curvatures of these four areas R1, R2, R3, and R4 is area R1 < area R2 < area R3 < area R4, and the magnitude relationship of the areas is area R1 > area R2 > area R3 > area R4. In this way, by dividing the printing surface Q1 into a plurality of areas R so that the larger the curvature, the smaller the area (range), as will be described later, high-quality printing can be performed on the printing surface Q1 with high accuracy. Note that the above "curvature" means, for example, the average curvature or the maximum curvature of the area R. Also, the above "area" means, for example, the length in the direction along the arrow N of each area R.

[0023] In this embodiment, the area of the area R is continuously reduced as the curvature increases, but the method for determining the area of the area R is not particularly limited. For example, if A1 < curvature ≤ A2, the area of the area R is set to C1, if A2 < curvature ≤ A3, the area of the area R is set to C2 (<C1), if A3 < curvature ≤ A4, the area of the area R is set to C3 (<C2), and so on. The area of the area R may be gradually reduced as the curvature increases.

[0024] [Printing order determination step S3] In the printing order determination step S3, the printing order of the four areas R1, R2, R3, and R4 in the printing step S4 is determined. In this embodiment, the areas R1, R2, R3, and R4 are printed in this order. Thereby, the unnecessary movement of the robot 200 during the printing operation is reduced, and the printing step S4 can be performed efficiently. Therefore, the tact time is shortened and the productivity is improved. However, the printing order is not particularly limited, and in addition to the sequential order, for example, it can be in the order of increasing curvature, decreasing curvature, etc.

[0025] Furthermore, in the printing order determination step S3, the operating conditions of the robot 200 in each of the regions R1, R2, R3, and R4 are determined. The operating conditions are not particularly limited, but may include, for example, the posture of the robot arm 220 in each of the regions R1, R2, R3, and R4, the acceleration, deceleration, and maximum speed of the inkjet head 410, and output conditions of the inkjet head 410 such as the ink ejection amount and the ink ejection interval.

[0026] [Printing step S4] In printing step S4, printing is performed for each of regions R1, R2, R3, and R4 in the order determined in printing order determination step S3 using the inkjet head 410. Specifically, printing step S4 has unit printing step S401 for printing on region R1, unit printing step S402 for printing on region R2, unit printing step S403 for printing on region R3, and unit printing step S404 for printing on region R4.

[0027] As described above, each unit printing step S401 includes a movement step S41 in which the robot arm 220 is driven to bring the inkjet head 410 into contact with the regions R1, R2, R3, and R4, and an operation step S42 in which, with the robot arm 220 stopped, the inkjet head 410 is moved relative to the printing surface Q1 by the moving stage 300 and printing is performed on the regions R1, R2, R3, and R4 using the inkjet head 410.

[0028] Since unit printing steps S402, S403, and S404 are repetitions of unit printing step S401, only unit printing step S401 will be described below with reference to Figures 5 to 7, and descriptions of unit printing steps S402, S403, and S404 will be omitted. Also, for convenience of explanation, in Figures 5 to 7, the curved printing surface Q1 is illustrated as a flat surface.

[0029] <<Unit printing step S401>> 5, in a movement step S41, the robot arm 220 is driven to move the inkjet head 410 to face the region R1. At this time, the distance between the inkjet head 410 and the region R1 is set within an appropriate gap that is preset for the inkjet head 410. In this state, the range of movement of the inkjet head 410 caused by driving the moving stage 300 overlaps with the entire region R1.

[0030] Next, operation step S42 is performed with the robot arm 220 stopped. In operation step S42, first, the moving stage 300 is driven to move the inkjet head 410 to a movement start position P1, as shown in Fig. 6. The movement start position P1 is outside the region R1 and is located on the base end side of the arrow N from the region R1.

[0031] 7, the moving stage 300 is driven to move the inkjet head 410 from the movement start position P1 along the arrow N to the movement end position P2, while ejecting ink from the inkjet head 410 at a predetermined timing to perform printing in the region R1. Here, the movement end position P2 is outside the region R1 and is located on the tip side of the arrow N from the region R1. In this way, by stopping the robot arm 220, it is not affected by vibrations or trajectory deviations caused by the motors and reducers driven by the joints of the robot arm 220, and further, if the moving stage 300 is driven, it slides along the linear guide of the moving stage 300, so that printing can be performed with high accuracy along the moving direction.

[0032] 7, the inkjet head 410 moves at a constant speed within region R1, and printing in region R1 is performed while moving at the constant speed. In other words, printing is not performed while the inkjet head 410 is accelerating or decelerating. In this way, by printing while the inkjet head 410 is moving at a constant speed, it becomes easier to control the ink ejection timing of the inkjet head 410, and printing in region R1 can be performed with greater accuracy.

[0033] As described above, the reason why the movement start position P1 is set outside the region R1 is to end the accelerated movement of the inkjet head 410 before it enters the region R1 and transition to uniform speed movement. Similarly, the reason why the movement end position P2 is set outside the region R1 is to start the decelerated movement and stop the inkjet head 410 after it leaves the region R1. This allows the inkjet head 410 to move at a uniform speed throughout the entire region R1, and the above-mentioned effects can be more reliably achieved. In other words, the movement start position P1 is set at a position sufficient to move the inkjet head 410 at a uniform speed before it enters the region R1, and the movement end position P2 is set at a position sufficient to decelerate and stop the inkjet head 410 after it leaves the region R1.

[0034] Following this unit printing step S401, unit printing steps S402, S403, and S404 are similarly performed to complete printing on the entire printing surface Q1. As shown in Fig. 3, when printing on the printing surface Q1 is completed, it is determined whether printing work has been performed on a predetermined number of objects Q, and if so, the work by the robot system 100 is terminated. On the other hand, if not, a new object Q is fixed to the fixing member 700, and the printing work is performed from printing step S4.

[0035] Next, the effect of such a printing method will be described with reference to Figs. 8 and 9. Fig. 8 shows regions R1 and R4 with different curvatures. When the inkjet head 410 moves along the arrow N, the distance between the inkjet head 410 and the printing surface Q1 when it is closest to the printing surface Q1 is the minimum distance Dmin, the distance between the inkjet head 410 and the printing surface Q1 when it is farthest from the printing surface Q1 is the maximum distance Dmax, and the difference between Dmin and Dmax is the distance difference ΔD. As shown in Fig. 8, if the areas of the regions R1 and R4 are the same, the maximum distance Dmax of the region R4 with a larger curvature is larger than that of the region R1 with a smaller curvature, and the distance difference ΔD is also larger. If the maximum distance Dmax becomes large enough that the distance between the inkjet head 410 and the printing surface Q1 exceeds the appropriate gap, the range of adhesion of one ink droplet may become wider or the adhesion location may shift, which may result in a decrease in print quality. Furthermore, when the distance difference ΔD increases, unevenness in print quality becomes more likely to occur within region R4.

[0036] Therefore, in this embodiment, as shown in Fig. 9, the area of ​​the region R4 with the large curvature is made smaller than the area of ​​the region R1 with the smaller curvature, so that the maximum separation distance Dmax and the difference ΔD do not become excessively large. Also, the separation distance between the inkjet head 410 and the printing surface Q1 is preferably made substantially constant so as to fall within the appropriate gap. This makes it difficult for the above-mentioned problems to occur, and allows printing on the region R4 to be performed with high accuracy.

[0037] In particular, by setting each of the regions R1, R2, R3, and R4 so that the minimum separation distance Dmin, the maximum separation distance Dmax, and the difference ΔD are approximately equal to each other, printing on the printing surface Q1 can be performed uniformly and accurately. Note that the minimum separation distance Dmin, the maximum separation distance Dmax, and the difference ΔD are not particularly limited, and can be appropriately set depending on the characteristics of the inkjet head 410, the movement speed of the inkjet head 410, etc.

[0038] The robot system 100 of this embodiment has been described above. As described above, the control method for such a robot system 100 is a control method for the robot system 100 that includes a moving stage 300, a tool 400 attached to the moving stage 300, and a robot arm 220 that holds either the moving stage 300 or the object Q, and performs a predetermined operation on the object Q using the tool 400. The operation is performed while the tool 400 is moved relative to the object Q by the moving stage 300 with the robot arm 220 stopped, and the range of operation, i.e., the region R, is smaller in the portion of the object Q where the curvature is large than in the portion where the curvature is small. This allows the relative movement of the tool 400 and the object Q to be performed with high accuracy, and the variation in the distance between the tool 400 and the object Q is also less likely to occur, allowing the operation on the object Q to be performed uniformly and with high accuracy.

[0039] As described above, the robot arm 220 holds the moving stage 300. This makes it easier to perform work on the object Q. The moving stage 300 also holds the tool 400. This makes it easier to perform work on the object Q.

[0040] As described above, in the control method of the robot system 100, the moving stage 300 has the piezoelectric actuator 340 as a driving source. This makes it possible to reduce the size and weight of the moving stage 300. In addition, the driving accuracy of the moving stage 300 is improved, and furthermore, it becomes easier to move the tool 400 at a constant speed.

[0041] As described above, in the control method of the robot system 100, the tool 400 is the inkjet head 410 as a printer head. This makes it possible to perform a printing operation on the object Q. This makes the robot system 100 highly convenient.

[0042] As described above, in the control method of the robot system 100, the shape of the object Q is calculated based on the CAD data of the object Q.

[0043] As described above, in the control method of the robot system 100, the shape of the object Q may be calculated based on imaging data obtained by imaging the object Q. This makes it possible to calculate the shape of the object Q more simply and accurately.

[0044] As described above, in the control method of the robot system 100, no work is performed while the tool 400 is accelerating or decelerating due to the driving of the moving stage 300. This makes it easier to control the driving of the tool, and improves the accuracy of the work.

[0045] As described above, in the control method of the robot system 100, the movement start position P1 of the tool 400 during work is located outside the region R1, which is outside the range of work. This allows the inkjet head 410 to end its accelerated movement and transition to uniform speed movement before it enters region R1. This improves the accuracy of work in region R1.

[0046] As described above, the robot system 100 includes the moving stage 300, the tool 400 attached to the moving stage 300, and the robot arm 220 that holds either the moving stage 300 or the object Q, and performs a predetermined operation on the object Q using the tool 400. The operation is performed while the tool 400 is moved relative to the object Q by the moving stage 300 with the robot arm 220 stopped, and the range of operation, i.e., the region R, is smaller in the portions of the object Q where the curvature is large than in the portions where the curvature is small. This makes it difficult for the distance between the tool 400 and the object Q to vary, and the operation on the object Q can be performed uniformly and accurately.

[0047] Although the robot system 100 has been described above, the robot system 100 is not particularly limited. For example, in this embodiment, the arrow N, which is the movement direction of the inkjet head 410 in the printing step S4, is aligned with the arrangement direction of the regions R1, R2, R3, and R4, but, for example, as shown in Fig. 10, the movement direction of the inkjet head 410 in each of the regions R1, R2, R3, and R4 may be perpendicular (intersect) with the arrangement direction of the regions R1, R2, R3, and R4. Also, as shown in Fig. 11, the movement direction of the inkjet head 410 in each of the regions R1, R2, R3, and R4 may meander two-dimensionally.

[0048] <Second embodiment> Figures 12 and 13 are diagrams illustrating the movement of the inkjet head in the printing step according to the second embodiment. Figures 14 and 15 are diagrams illustrating the effect of the printing method. For ease of explanation, in Figures 12 to 15, the curved printing surface Q1 is shown as a flat surface.

[0049] The robot system 100 of this embodiment is similar to the robot system 100 of the first embodiment described above, except for the printing step S4. Therefore, in the following description, the differences between this embodiment and the first embodiment will be mainly described, and descriptions of similar matters will be omitted. In addition, in each drawing of this embodiment, the same reference numerals are used for configurations similar to those of the above-mentioned embodiment.

[0050] <<Unit printing step S401>> First, as in the first embodiment described above, in a movement step S41, the robot arm 220 is driven to move the inkjet head 410 to face the region R1. Next, with the robot arm 220 stopped, a work step S42 is performed. In the work step S42, first, as shown in Fig. 12, the movement stage 300 is driven to move the inkjet head 410 to a movement start position P1. Here, the movement start position P1 is set at the end of the region R1, unlike the first embodiment described above.

[0051] 13, the moving stage 300 is driven to move the inkjet head 410 from the movement start position P1 along the arrow N to the movement end position P2, while ejecting ink from the inkjet head 410 at a predetermined timing to perform printing on the region R1. Here, the movement end position P2 is set at the end of the region R1, unlike the first embodiment described above.

[0052] According to this method, for example, compared to the first embodiment described above, it is possible to shorten the movement distance of the inkjet head 410 when printing on the region R1, i.e., the distance between the movement start position P1 and the movement end position P2, and therefore the time required for the printing step S4 can be further shortened.

[0053] As shown in FIG. 13, in this embodiment, unlike the first embodiment, the acceleration region G1 and deceleration region G2 of the inkjet head 410 are located within region R1. Therefore, it is necessary to eject ink from the inkjet head 410 to perform printing even when the inkjet head 410 is accelerating and decelerating. In this case, it is preferable to control the timing of ejecting ink from the inkjet head 410 according to the moving speed of the inkjet head 410 so that the pitch of the ink dots is equal. Specifically, it is preferable to shorten the time interval for ejecting ink from the inkjet head 410 as the moving speed of the inkjet head 410 increases. This allows printing in region R1 to be performed uniformly and accurately.

[0054] The above has been a description of unit printing step S401, but the same is true for unit printing steps S402, S403, and S404. However, when the moving speeds of the inkjet head 410 during uniform movement in unit printing steps S401, S402, S403, and S404 are V1, V2, V3, and V4, respectively, V1>V2>V3>V4. In other words, the greater the curvature of region R, the lower the moving speed of the inkjet head 410 during uniform movement.

[0055] 14, the area of ​​region R1 with small curvature is large, so the constant velocity movement region G0 can be sufficiently secured even if the movement speed during constant velocity movement of inkjet head 410 is increased. On the other hand, the area of ​​region R4 with large curvature is small, so if the movement speed during constant velocity movement of inkjet head 410 is increased to the same level as region R1, the acceleration region G1 and deceleration region G2 become large, and the constant velocity movement region G0 cannot be sufficiently secured.

[0056] Therefore, in this embodiment, as shown in Fig. 15, the movement speed of the inkjet head 410 during constant movement in region R4 is set low, thereby making the acceleration region G1 and deceleration region G2 small and ensuring a sufficient constant-velocity movement region G0 within region R4. It is easier to control the ink ejection timing of the inkjet head 410 during constant-velocity movement than during acceleration and deceleration, and printing quality is also higher. Therefore, as described above, the movement speed of the inkjet head 410 during constant-velocity movement is set lower for regions R with larger curvature so that a sufficient constant-velocity movement region can be ensured in each of regions R1, R2, R3, and R4.

[0057] Note that if the moving speed of the inkjet head 410 during constant speed movement were uniformly lowered in all regions R1, R2, R3, and R4, the constant speed movement region G0 could be made larger in all regions R1, R2, R3, and R4, but this would increase the time required for printing step S4 and reduce productivity. Therefore, in this embodiment, as described above, the moving speed of the inkjet head 410 during constant speed movement is lowered in regions R with larger curvature, thereby achieving both work efficiency and work accuracy.

[0058] As described above, in the control method of the robot system 100 of this embodiment, the moving speed of the tool 400 is slower in a portion where the curvature of the target object Q is large than in a portion where the curvature is small. This makes it possible to achieve both efficiency and accuracy in the work.

[0059] The second embodiment as described above can also achieve the same effects as the first embodiment described above.

[0060] <Third embodiment> FIG. 16 is a perspective view showing the overall configuration of a robot system according to the third embodiment.

[0061] The robot system 100 of this embodiment is similar to the robot system 100 of the first embodiment described above, except that the arrangement of the moving stage 300 and the tool 400 is different. Therefore, in the following description, the present embodiment will be described mainly with respect to the differences from the first embodiment described above, and the description of the similar points will be omitted. In addition, in each drawing of this embodiment, the same reference numerals are used for the same configurations as those of the above-mentioned embodiment.

[0062] 16, a hand 600 is disposed at the tip of the robot arm 220, i.e., at the arm 226, and during operation, the hand 600 grasps an object Q. That is, the robot arm 220 holds the object Q via the hand 600. On the other hand, the movable stage 300 is fixed to a fixed member 700 at a distance from the robot arm 220, and an inkjet head 410 is disposed on the movable stage 300.

[0063] The third embodiment can also achieve the same effects as the first embodiment. Alternatively, for example, the hand 600 may be connected to the arm 226 via the moving stage 300, and the inkjet head 410 may be fixed to the fixed member 700 at a distance from the robot arm 220. Alternatively, the inkjet head 410 may be connected to the arm 226 and at a distance from the robot arm 220, and the hand 600 may be connected to the fixed member 700 via the moving stage 300.

[0064] Although the robot system control method and the robot system of the present invention have been described above based on the illustrated embodiment, the present invention is not limited thereto, and the configuration of each part can be replaced with any configuration having a similar function. Any other configuration may be added to the present invention. Furthermore, each embodiment may be appropriately combined.

[0065] Furthermore, the tool 400 is not limited to the inkjet head 410, but may be, for example, a tool for laser processing, a tool for soldering work, a tool for welding, or a tool for work performed in synchronization with the movement trajectory of the tool. [Explanation of symbols]

[0066] 100... robot system, 200... robot, 210... base, 220... robot arm, 221... arm, 222... arm, 223... arm, 224... arm, 225... arm, 226... arm, 300... moving stage, 310... base, 320... stage, 320X... X stage, 320Y... Y stage, 320θ... θ stage, 330... moving mechanism, 330X... X moving mechanism, 330Y... Y moving mechanism, 330θ... θ moving mechanism, 340... piezoelectric actuator, 400... tool, 410... inkjet head, 411... ink ejection hole, 600... hand, 700... fixing member, 900... robot control device, Dmax... maximum separation distance, Dmin... minimum separation distance separation, E...encoder, G0...constant speed movement area, G1...acceleration area, G2...deceleration area, J1...joint, J2...joint, J3...joint, J4...joint, J5...joint, J6...joint, M...motor, N...arrow, P1...start position of movement, P2...end position of movement, Q...object, Q1...printing surface, R...area, R1...area, R2...area, R3...area, R4...area, S1...shape calculation step, S2...area setting step, S3...printing order determination step, S4...printing step, S40...unit printing step, S401...unit printing step, S402...unit printing step, S403...unit printing step, S404...unit printing step, S41...movement step, S42...working step, ΔD...distance difference

Claims

1. A moving stage, a tool attached to the moving stage, and the moving stage or a robot arm that holds one of the objects, and A method for controlling a robot system that performs a predetermined task using a With the robot arm stopped, the tool is moved to the target by the moving stage. The operation is performed while moving the object, The range of the work is smaller in a portion of the object having a large curvature than in a portion of the object having a small curvature; The distance between the tool and the object when the tool is closest to the object is minimized. The tool and the object are spaced at a small distance when the tool is at its farthest from the object. The distance between the objects is defined as the maximum distance, and the difference between the minimum distance and the maximum distance is defined as the distance difference. Then, the operation is performed based on the minimum separation distance, the maximum separation distance, and the distance difference. A method for controlling a robot system, comprising the steps of:

2. The robot system according to claim 1 , wherein the robot arm holds the moving stage. How to control the system.

3. The method for controlling a robot system according to claim 2, wherein the moving stage holds the tool. Law.

4. 10. The moving stage according to claim 1, further comprising a piezoelectric actuator as a driving source.

4. A method for controlling a robot system according to any one of claims 3 to 3.

5. The robot according to any one of claims 1 to 4, wherein the tool is a printer head. A method for controlling a network system.

6. 6. The method according to claim 1, wherein the shape of the object is calculated based on CAD data of the object.

2. A method for controlling a robot system according to claim 1 .

7. The shape of the object is calculated based on imaging data obtained by imaging the object. A method for controlling a robot system according to any one of claims 1 to 5.

8. While the tool is accelerating or decelerating due to the driving of the moving stage, the work is performed. The method for controlling a robot system according to any one of claims 1 to 7, wherein the method does not include a step of rotating the robot.

9. 2. The tool according to claim 1, wherein the movement start position of the tool during the work is located outside the range of the work.

9. A method for controlling a robot system according to any one of claims 8 to 8.

10. The moving speed of the tool is slower in a portion where the curvature of the object is large than in a portion where the curvature is small. A method for controlling a robot system according to any one of claims 1 to 9.

11. A moving stage, a tool attached to the moving stage, and the moving stage or a robot arm that holds one of the objects, and A robot system for performing a predetermined task, With the robot arm stopped, the tool is moved to the target by the moving stage. The operation is performed while moving the object, The range of the work is smaller in a portion of the object having a large curvature than in a portion of the object having a small curvature; The distance between the tool and the object when the tool is closest to the object is minimized. The tool and the object are spaced at a small distance when the tool is at its farthest from the object. The distance between the objects is defined as the maximum distance, and the difference between the minimum distance and the maximum distance is defined as the distance difference. Then, the operation is performed based on the minimum separation distance, the maximum separation distance, and the distance difference. A robot system characterized by setting a range.

12. A moving stage, a tool attached to the moving stage, and a moving stage or a robot arm that holds one of the objects, and A method for controlling a robot system that performs a predetermined task using a With the robot arm stopped, the tool is moved to the target by the moving stage. The operation is performed while moving the object, The range of the work is smaller in a portion of the object having a large curvature than in a portion of the object having a small curvature; The portion of the object with small curvature and the portion of the object with large curvature are located in the same front A control method for a robot system, comprising the steps of: performing the predetermined task using the tool;

13. A moving stage, a tool attached to the moving stage, and a moving stage or a robot arm that holds one of the objects, and A robot system for performing a predetermined task, With the robot arm stopped, the tool is moved to the target by the moving stage. The operation is performed while moving the object, The range of the work is smaller in a portion of the object having a large curvature than in a portion of the object having a small curvature; The portion of the object with small curvature and the portion of the object with large curvature are A robot system comprising: a tool for performing the predetermined task.

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