Robotic work system and robotic work method

Abstract

This invention provides a robotic work system and robotic work method that allow for easy setting of the robot's position relative to the work object. [Solution] The robot comprises a sensing means 30 for measuring the relative position between the robot 12 and the workpiece S, and a position setting means 32 for setting the position of the robot 12 relative to the workpiece S. The sensing means 30 includes a distance sensor 16 provided on the robot arm 14, a height measuring unit 36 ​​for measuring the height from the robot 12 to the workpiece S using the distance sensor 16, a Y-distance / angle measuring unit 38 for measuring the Y-distance, which is the distance from the robot 12 to the workpiece S in the Y direction, and the inclination angle of the robot 12 with respect to the Y direction, using the distance sensor 16, and an X-distance measuring unit 40 for measuring the X-distance, which is the distance from a predetermined reference position set based on the workpiece to the robot 12 in the X direction, using the distance sensor 16.

Description

Technical Field

[0001] The present invention relates to a robot working system and a robot working method used for spraying refractory coating materials at construction sites and the like.

Background Art

[0002] When a general industrial robot arm is used in a factory or the like, the robot arm is fixed at a certain position, and the work object is conveyed to a fixed position by a belt conveyor or the like. Since the relative position of the work object with respect to the position of the robot arm is the same every time, once the operation of the robot is determined, the work can be completed by simply repeating the same operation.

[0003] On the other hand, in the case of a robot such as a spraying device used at a construction site, since the work object (beam, column, floor, etc.) is a part of the building and its position is fixed, it is necessary to move the robot to the position of the work object (for example, refer to Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When it is necessary for the robot itself to move as described above, it is often necessary to attach some kind of traveling mechanism (wheels) to move it, but the movement accuracy becomes an issue. Specifically, if the accuracy is rough, the relative position with the work object will not be the same every time, so it is necessary to adjust the position of the robot every time after the robot moves. If you want to save the trouble of adjustment, it is conceivable to provide a corresponding mechanism to improve the movement accuracy of the robot, but if the mechanism becomes complicated, the cost may increase. For this reason, a technology that can easily set the position of the robot with respect to the work object has been demanded.

[0006] The present invention has been made in view of the above, and aims to provide a robot work system and a robot work method that can easily set the position of the robot relative to the work object. [Means for solving the problem]

[0007] To solve the above-mentioned problems and achieve the objective, the robot work system according to the present invention is a system that performs work on a fixed work object by moving a robot arm provided on a robot positioned in a workable position, and comprises sensing means for measuring the relative position between the robot and the work object, and position setting means for setting the position of the robot relative to the work object based on the measured relative position, wherein the sensing means comprises a distance sensor provided on the robot arm, a height measuring unit for measuring the height from the robot to the work object with the distance sensor, a Y distance / angle measuring unit for measuring the Y distance, which is the distance from the robot to the work object in the Y direction, and the inclination angle of the robot with respect to the Y direction, when the horizontal direction which is the longitudinal direction of the work object is defined as the X direction and the horizontal direction perpendicular to the X direction is defined as the Y direction, and an X distance measuring unit for measuring the X distance, which is the distance from a predetermined reference position set based on the work object to the robot in the X direction, with the distance sensor, and the relative position is measured from the measured height, Y distance, inclination angle, and X distance.

[0008] Furthermore, another robotic work system according to the present invention is characterized in that, in the above-described invention, the work object is a steel beam made of H-shaped steel, and the work of spraying a spray material onto the work object from a nozzle provided on the robotic arm based on the position set by the position setting means.

[0009] Furthermore, the robot work method according to the present invention is a robot work method that performs work on a fixed work object by moving a robot arm provided on a robot positioned in a workable position, and comprises a sensing step of measuring the relative position between the robot and the work object, and a position setting step of setting the position of the robot relative to the work object based on the measured relative position, wherein the sensing step comprises a height measurement step of measuring the height from the robot to the work object using a distance sensor provided on the robot arm, a Y distance / angle measurement step of measuring the Y distance, which is the distance from the robot to the work object in the Y direction, and the inclination angle of the robot with respect to the Y direction, when the horizontal direction which is the longitudinal direction of the work object is defined as the X direction and the horizontal direction perpendicular to the X direction is defined as the Y direction, and an X distance measurement step of measuring the X distance, which is the distance from a predetermined reference position set based on the work object to the robot in the X direction, using the distance sensor, and the relative position is measured from the measured height, Y distance, inclination angle, and X distance.

[0010] Furthermore, another robotic work method according to the present invention is characterized in that, in the above-described invention, the work object is a steel beam made of H-shaped steel, and the method includes a step of spraying a spray material onto the work object from a nozzle provided on the robot arm based on the position set in the position setting step. [Effects of the Invention]

[0011] The robotic work system according to the present invention is a system that performs work on a fixed work object by moving a robot arm provided on a robot positioned in a workable location, and comprises sensing means for measuring the relative position between the robot and the work object, and position setting means for setting the position of the robot relative to the work object based on the measured relative position, wherein the sensing means includes a distance sensor provided on the robot arm, a height measuring unit for measuring the height from the robot to the work object with the distance sensor, a Y distance / angle measuring unit for measuring the Y distance, which is the distance from the robot to the work object in the Y direction, and the inclination angle of the robot with respect to the Y direction, when the horizontal direction which is the longitudinal direction of the work object is defined as the X direction and the horizontal direction perpendicular to the X direction is defined as the Y direction, and an X distance measuring unit for measuring the X distance, which is the distance from a predetermined reference position set based on the work object to the robot in the X direction, with the distance sensor, and the relative position is measured from the measured height, Y distance, inclination angle, and X distance, so that the position of the work object can be grasped by the sensing means. This has the effect of making it easy to set the robot's position relative to the workpiece.

[0012] Furthermore, according to another robotic work system of the present invention, the work object is a steel beam made of H-shaped steel, and the work of spraying a spraying material onto the work object is performed from a nozzle provided on the robot arm based on the position set by the position setting means, thereby providing the effect of being able to perform spraying work on steel beams appropriately.

[0013] Furthermore, the robot work method according to the present invention is a robot work method that performs work on a fixed work object by moving a robot arm provided on a robot positioned in a workable position, and comprises a sensing step of measuring the relative position between the robot and the work object, and a position setting step of setting the position of the robot relative to the work object based on the measured relative position, wherein the sensing step comprises a height measurement step of measuring the height from the robot to the work object using a distance sensor provided on the robot arm, a Y distance / angle measurement step of measuring the Y distance, which is the distance from the robot to the work object in the Y direction, and the inclination angle of the robot with respect to the Y direction, when the horizontal direction which is the longitudinal direction of the work object is defined as the X direction and the horizontal direction perpendicular to the X direction is defined as the Y direction, and an X distance measurement step of measuring the X distance, which is the distance from a predetermined reference position set based on the work object to the robot in the X direction, using the distance sensor, and the relative position is measured from the measured height, Y distance, inclination angle, and X distance, so that the position of the work object can be grasped by the sensing means. This has the effect of making it easy to set the robot's position relative to the workpiece.

[0014] Furthermore, according to another robotic work method of the present invention, the work object is a steel beam made of H-shaped steel, and the method includes a step of spraying a spraying material onto the work object from a nozzle provided on the robot arm based on the position set in the position setting step, thus providing the effect of being able to appropriately perform spraying work on steel beams. [Brief explanation of the drawing]

[0015] [Figure 1] Figure 1 is a schematic diagram showing an embodiment of the robotic work system according to the present invention, where (1) is a side view and (2) is a top view. [Figure 2] Figure 2 is an explanatory diagram of Y distance, slope angle, and X distance. [Figure 3]FIG. 3 is an explanatory diagram of the height measurement step. [Figure 4] FIG. 4 is an explanatory diagram of the Y-distance / angle measurement step. [Figure 5] FIG. 5 is an explanatory diagram of the X-distance measurement step.

Embodiments for Carrying Out the Invention

[0016] Hereinafter, embodiments of the robot work system and the robot work method according to the present invention will be described in detail based on the drawings. Note that the present invention is not limited by this embodiment.

[0017] As shown in FIG. 1, a robot work system 10 according to an embodiment of the present invention is a system that moves a robot arm 14 provided on a robot 12 arranged at a workable position with respect to a fixed work object S to perform work, and includes a distance sensor 16 provided at the tip of the robot arm 14 and an operation terminal 18. The target work assumes a spraying operation of a fireproof coating material on a large number of steel beams (work objects) constructed at a construction site, and a nozzle (not shown) for spraying the fireproof coating material is attached to the tip of the robot arm 14.

[0018] The work object S is a steel beam made of an H-shaped steel having a web S1 and upper and lower flanges S2, S3. When the horizontal direction in the longitudinal direction of the steel beam is defined as the X direction and the horizontal direction orthogonal to the X direction is defined as the Y direction, the normal direction of the surface of the web S1 faces the Y direction, and the normal directions of the surfaces of the upper and lower flanges S2, S3 face the vertical direction (Z direction: height direction).

[0019] The robot 12 is composed of a carriage 22 having wheels capable of traveling on the floor surface 20, a lifter 24 installed on the carriage 22, and a robot arm 14 installed on the lifter 24. The robot 12 is arranged at an appropriate position diagonally below the work object S where spraying work is possible. The lifter 24 is a pantograph mechanism capable of raising and lowering the robot arm 14 in the vertical direction.

[0020] The robot arm 14 includes a base 26 installed on the lifter 24 and an arm portion 25 installed on the base 26 so as to be rotatable around a vertical axis. The arm portion 25 is of a multi-joint type including a plurality of joint portions. The arm portion 25 is configured to be movable by an actuator (not shown) and can move its tip position and orientation in each of the X direction, Y direction, and Z direction.

[0021] The distance sensor 16 measures the distance between the measurement target point and itself and is attached to the tip of the robot arm 14. The distance sensor 16 measures the distance between itself and the measurement point set on the work object S. Information on the tip position and orientation of the robot arm 14 is always grasped in a robot coordinate system, which is a three-dimensional coordinate system with the center position C of the robot 12 as the origin. The measurement value by the distance sensor 16 can be acquired in the robot coordinate system. By the distance sensor 16, the relative position between the center position of the robot 12 and the measurement point can be measured in the robot coordinate system. The distance sensor 16 can be configured as, for example, a laser distance meter that measures distance using laser light. The distance sensor 16 can transmit and receive information to and from the operation terminal 18, and the operation of the distance sensor 16 can be controlled by the operation terminal 18.

[0022] The operation terminal 18 includes robot operation means 28, sensing means 30, and position setting means 32.

[0023] The robot operating means 28 is connected to the robot 12 via a wired or wireless communication line, and can transmit control information to the robot 12 and receive information transmitted by the robot 12. The robot operating means 28 can also transmit control information to the sensing means 30 and the position setting means 32, and can receive information transmitted by the sensing means 30 and the position setting means 32. The robot operating means 28 can receive information such as the cross-sectional shape and position of the steel beam, which is the work object S, including its beam depth; the beam ceiling height of the building (height from the floor 20 to the ceiling 34 to which the steel beam is fixed); the appropriate positional relationship between the robot 12 and the steel beam; and the spraying range and spraying order on the steel beam. The cross-sectional shape, position, and beam ceiling height of the steel beam can use values ​​predetermined in design drawings, etc. The robot operating means 28 obtains the position and orientation of the robot 12 from the robot coordinate system. The center position C of the robot 12 is located at the center of the base 26.

[0024] The robot operating means 28 generates control information for controlling the robot 12 based on this information. The robot operating means 28 also transmits the generated control information to the robot 12 to control the position and orientation of the robot 12, the spraying operation by the robot 12, and the sensing operation by the sensing means 30. The orientation of the robot 12 relative to the work object S is such that the work object S is located on the front side of the robot 12, with the positive Y direction being the front side.

[0025] The sensing means 30 includes a height measuring unit 36, a Y-distance / angle measuring unit 38, and an X-distance measuring unit 40. The sensing means 30 measures the height, Y-distance, tilt angle, and X-distance in that order by sensing using the distance sensor 16, and measures the relative position of the robot 12 with respect to the work object S from these measured values. Figure 2 shows the positional relationship of the Y-distance, tilt angle, and X-distance of the robot 12 and the work object S as viewed from above.

[0026] The height measurement unit 36 ​​measures the height in the Z direction from the robot 12 to the workpiece S. Specifically, the height measurement unit 36 ​​operates the robot arm 14 by executing a pre-created sensing operation program, while simultaneously performing a sensing operation to measure the distance to the workpiece S using the distance sensor 16. Based on the measurement value obtained from the distance sensor 16 at that time, the height is measured (height measurement step).

[0027] Here, the beam ceiling height may have errors (construction errors) compared to the values ​​on the drawings in actual buildings. On the other hand, the dimensions of the steel beams, such as the beam depth, have almost no errors compared to the values ​​on the drawings. For this reason, if the error in the beam ceiling height is not corrected by the measurement of the distance sensor 16, the target position may be off when spraying the lower flange end in a later process. Therefore, this height measurement unit 36 ​​measures the distance from the distance sensor 16 placed below the steel beam to the bottom surface of the lower flange S3.

[0028] Measurements are taken at multiple points (for example, three points) set on the underside of the lower flange S3, and it is desirable to adopt the largest value among these measurements, excluding outliers. The adopted height is used in the robot operating means 28 to correct the beam ceiling height. The reason for measuring at multiple points is to reduce the possibility that the distance sensor 16 may not be positioned precisely in the center of the underside of the steel beam, causing the light from the distance sensor 16 to miss the steel beam and making measurement impossible. It is also to reduce the possibility that a portion of the underside of the lower flange S3 may have already been sprayed from the back side, which could prevent proper measurement.

[0029] Figure 3 shows an example of measurement by the height measurement unit 36. As shown in Figure 3(1), first, the robot 12 is positioned diagonally below the work object S so that the work object S is within the operating range of the robot arm 14. Next, the tip of the robot arm 14 is pointed upward and positioned so that its height is lower than the lower flange S3. In this case, the approximate height of the lower flange S3 may be calculated from the beam ceiling height and beam depth information input to the robot operating means 28, and the tip of the robot arm 14 may be positioned a certain distance lower than that. After that, the tip of the robot arm 14 is moved horizontally. At this time, the measurement value of the distance sensor 16 is used to detect that the lower surface of the lower flange S3 is located above the tip of the robot arm 14, and the distances are obtained for three different measurement points on the lower surface of the lower flange S3. It is desirable that the measurement points be set at intervals from the center of the lower surface of the lower flange S3 toward the front in the flange width direction.

[0030] As shown in Figure 3(2), the interval D between measurement points may be set to equal intervals of approximately 100 mm, for example. The largest value among these measured values, excluding outliers, is adopted. In this case, the largest value among the measured values ​​that satisfies the relationship measurement distance - threshold ≤ measured value ≤ measurement distance + threshold can be adopted. Here, the measurement distance is the appropriate distance between the tip of the robot arm 14 and the lower surface of the lower flange S3 during the spraying operation (e.g., 400 mm), and the threshold is a value to exclude outliers (e.g., 150 mm). The measurement distance and threshold can be set, for example, via input to the robot operating means 28.

[0031] The Y-distance / angle measurement unit 38 measures the Y-distance, which is the distance in the Y-direction from the center position C of the robot 12 to the workpiece S, and the tilt angle of the robot 12 with respect to the Y-direction. Specifically, the Y-distance / angle measurement unit 38 operates the robot arm 14 by executing a pre-created sensing operation program, while simultaneously performing a sensing operation to measure the distance to the workpiece S using the distance sensor 16. Based on the measured values ​​obtained from the distance sensor 16 at that time, it calculates the Y-distance and tilt angle (Y-distance / angle measurement step).

[0032] Figure 4 shows an example of measurement by the Y-distance / angle measuring unit 38. As shown in Figure 4(1), the tip of the robot arm 14 is positioned horizontally toward the surface of the web S1. In this case, the approximate height range of the web surface can be calculated from the beam ceiling height and beam depth information input to the robot operating means 28, and the tip of the robot arm 14 can be positioned within that range. In this state, the robot arm 14 is moved to measure the distance to three different measurement points on the web surface. For example, the robot arm 14 may be moved horizontally left and right and up and down to measure the distance to the three measurement points. It is desirable that the measurement points be set from the vertices of a rectangle whose four sides are virtual horizontal and vertical lines set within the operating range of the robot arm 14 on the web surface. For example, they may be set to measurement points P1 to P3 in Figure 4(2). The lengths of the measurement upper end offset, measurement lower end offset, measurement left end, and measurement right end shown in Figure 4(2) can be set as appropriate.

[0033] In this way, the distances to three different points on the web surface are measured, and the Y distance and the inclination angle are calculated based on these measurements. If the measured distances to each measurement point P1, P2, and P3 in Figure 4(2) are L1, L2, and L3, the inclination angle θ can be calculated, for example, by tanθ = |L2 - L3| / X1, where X1 is the length the robot arm 14 moves horizontally left and right. The Y distance can be calculated, for example, by Y distance = (L2 - L3) / 2 × cosθ. L1 may be used instead of L2.

[0034] The calculated Y-distance and inclination angle are sent to the robot operating means 28 and used to correct control information for aligning the robot 12's position and orientation directly with the workpiece S, and to correct control information for adjusting the Y-distance to an appropriate range. This makes it possible to align the robot 12 directly with the workpiece S during the subsequent spraying operation. It also makes it possible to perform the spraying operation while maintaining a constant distance between the tip of the robot arm 14 and the workpiece S.

[0035] The X-distance measurement unit 40 measures the X-distance, which is the distance in the X-direction from a predetermined reference position set based on the work object S to the center position C of the robot 12. Specifically, the X-distance measurement unit 40 operates the robot arm 14 by executing a pre-created sensing operation program, while simultaneously performing a sensing operation to measure the distance to the reference position with the distance sensor 16, and calculates the X-distance based on the measured value obtained from the distance sensor 16 at that time (X-distance measurement step).

[0036] Figure 5 shows an example of measurement by the X-distance measuring unit 40. As shown in Figures 5(1) and (2), the tip of the robot arm 14 is positioned in front of the web S1, facing the X direction. In this case, for example, the approximate height range of the web surface is calculated from the beam ceiling height and beam depth information input to the robot operating means 28, and the tip of the robot arm 14 is positioned to fall within that range.

[0037] The tip of the robot arm 14 is positioned to face either a beam (another workpiece) or a joining member (stiffener) attached to either the left or right side of the workpiece S. In the examples in Figures 5(1) and 5(2), the tip is positioned to face a beam 42 attached to the left side of the workpiece S. The longitudinal direction of this beam 42 is the Y direction. In this state, the robot arm 14 is moved in the X direction to measure the distance to a single measurement point (reference position) set on the surface of the beam 42. This allows the X distance from the side of the workpiece S to the center position C of the robot 12 to be calculated, as shown in Figure 5(3). The calculated X distance is sent to the position setting means 32. Since the position and orientation of the robot 12 are corrected by the Y distance / angle measurement unit 38, the robot arm 14 can translate in the X direction while maintaining a constant Y distance from the workpiece S. The robot arm 14 may be controlled to translate until the measured distance enters the measurement range of the distance sensor 16, and then stop when the measured value is acquired. The height offset value and measurement distance shown in Figure 5 can be set as appropriate.

[0038] The position setting means 32 sets the position of the robot 12 relative to the work object S during the spraying operation, based on the relative position of the robot 12 with respect to the work object S measured by the sensing means 30. Specifically, the position of the robot 12 relative to the work object S is set based on the X distance. The set position is sent to the robot operating means 28 and used to generate control information for the robot 12. This allows the spray position of the nozzle attached to the robot arm 14 to be set appropriately during the subsequent spraying operation.

[0039] According to this embodiment, by performing three sensing operations using a distance sensor 16 provided at the tip of the robot arm 14, the relative positional relationship between the robot 12 and the workpiece S can be easily determined without requiring high movement precision. This makes it easy to set the position of the robot 12 relative to the workpiece S. Based on the set position, the spraying work can be performed appropriately.

[0040] As described above, the robot work system according to the present invention is a system that performs work on a fixed work object by moving a robot arm provided on a robot positioned in a workable position, comprising sensing means for measuring the relative position between the robot and the work object, and position setting means for setting the position of the robot relative to the work object based on the measured relative position, wherein the sensing means includes a distance sensor provided on the robot arm, a height measuring unit for measuring the height from the robot to the work object using the distance sensor, and the work object The robot has a Y-distance / angle measuring unit that measures the Y-distance (the distance from the robot to the workpiece in the Y-direction) and the inclination angle of the robot with respect to the Y-direction, when the horizontal direction, which is the longitudinal direction, is defined as the X-direction, and the horizontal direction perpendicular to the X-direction is defined as the Y-direction, using the distance sensor. It also has an X-distance measuring unit that measures the X-distance (the distance from the robot to the workpiece in the X-direction) using the distance sensor, using the distance sensor. The relative position is measured from the measured height, Y-distance, inclination angle, and X-distance, so the position of the workpiece can be determined by the sensing means. This makes it easy to set the position of the robot relative to the workpiece.

[0041] Furthermore, according to another robotic work system of the present invention, the work object is a steel beam made of H-shaped steel, and the work of spraying a spray material onto the work object is performed from a nozzle provided on the robot arm based on the position set by the position setting means, so that spraying work on the steel beam can be performed appropriately.

[0042] Furthermore, the robot work method according to the present invention is a robot work method that performs work on a fixed work object by moving a robot arm provided on a robot positioned in a workable position, and comprises a sensing step of measuring the relative position between the robot and the work object, and a position setting step of setting the position of the robot relative to the work object based on the measured relative position, wherein the sensing step comprises a height measurement step of measuring the height from the robot to the work object using a distance sensor provided on the robot arm, a Y distance / angle measurement step of measuring the Y distance, which is the distance from the robot to the work object in the Y direction, and the inclination angle of the robot with respect to the Y direction, when the horizontal direction which is the longitudinal direction of the work object is defined as the X direction and the horizontal direction perpendicular to the X direction is defined as the Y direction, and an X distance measurement step of measuring the X distance, which is the distance from a predetermined reference position set based on the work object to the robot in the X direction, using the distance sensor, and the relative position is measured from the measured height, Y distance, inclination angle, and X distance, so that the position of the work object can be grasped by the sensing means. This makes it easy to set the robot's position relative to the workpiece.

[0043] Furthermore, according to another robotic work method of the present invention, the work object is a steel beam made of H-shaped steel, and the method includes a step of spraying a spraying material onto the work object from a nozzle provided on the robot arm based on the position set in the position setting step, so that spraying work on the steel beam can be performed appropriately.

[0044] Furthermore, the Sustainable Development Goals (SDGs) are 17 international goals adopted at the UN Summit in September 2015. The robotic work system and robotic work method according to this embodiment can contribute to achieving some of the 17 SDGs, such as Goal 8, "Decent Work and Economic Growth." [Industrial applicability]

[0045] As described above, the robotic work system and robotic work method according to the present invention are useful for robots used in construction sites and other places for tasks such as spraying fire-resistant coatings, and are particularly suitable for easily setting the position of the robot relative to the work object. [Explanation of Symbols]

[0046] 10 Robotic work systems 12 Robots 14 Robot Arm 16 Distance Sensor 18 Operating terminal 20 Floor surface 28 Robot operating means 30 Sensing means 32 Position setting means 34 Ceiling 36 Height measurement section 38 Y Distance / Angle Measurement Unit 40 X distance measurement unit C center position S Work Object S1 Web S2 Upper Flange S3 Lower flange

Claims

1. A system that performs work on a fixed workpiece by moving a robotic arm equipped on a robot positioned in a workable location, The system comprises sensing means for measuring the relative position between the robot and the workpiece, and position setting means for setting the position of the robot relative to the workpiece based on the measured relative position, The sensing means comprises a distance sensor provided on the robot arm; a height measuring unit that measures the height from the robot to the work object using the distance sensor; a Y-distance / angle measuring unit that measures the Y-distance, which is the distance from the robot to the work object in the Y-direction, and the inclination angle of the robot with respect to the Y-direction, when the horizontal direction which is the longitudinal direction of the work object is defined as the X-direction and the horizontal direction perpendicular to the X-direction is defined as the Y-direction; and an X-distance measuring unit that measures the X-distance, which is the distance from a predetermined reference position set based on the work object to the robot in the X-direction, using the distance sensor, and the robot work system is characterized by measuring the relative position from the measured height, Y-distance, inclination angle, and X-distance.

2. The robotic work system according to claim 1, characterized in that the work object is a steel beam made of H-shaped steel, and the work is performed by spraying a spray material onto the work object from a nozzle provided on the robot arm based on a position set by the position setting means.

3. A robotic work method that performs work on a fixed work object by moving a robotic arm equipped on a robot positioned in a workable location, The system includes a sensing step of measuring the relative position between the robot and the workpiece, and a position setting step of setting the position of the robot relative to the workpiece based on the measured relative position. The sensing step comprises a height measurement step of measuring the height from the robot to the work object using a distance sensor provided on the robot arm; a Y distance / angle measurement step of measuring the Y distance, which is the distance from the robot to the work object in the Y direction, and the inclination angle of the robot with respect to the Y direction, when the horizontal direction which is the longitudinal direction of the work object is defined as the X direction and the horizontal direction perpendicular to the X direction is defined as the Y direction; and an X distance measurement step of measuring the X distance, which is the distance from a predetermined reference position set based on the work object to the robot in the X direction, using the distance sensor, and the relative position is measured from the measured height, Y distance, inclination angle, and X distance.

4. The robotic work method according to claim 3, characterized in that the work object is a steel beam made of H-shaped steel, and the robotic work method includes a step of spraying a spray material onto the work object from a nozzle provided on the robotic arm based on the position set in the position setting step.

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