Calibration method for marking devices

Abstract

Perform accurate calibration of the marking device. [Solution] The calibration method for the marking device 10 includes a target position measurement step of measuring the position of the target part 20, a marking position measurement step of measuring the marking position marked from the marking part 18 when the marking device 10 is in a state where the position of the target part 20 is measured, a position relationship calculation step of determining the positional relationship between the marking part 18 and the target part 20 before calibration based on the position of the target part 20 measured in the target position measurement step and the marking position measured in the marking position measurement step, and a calibration step of calibrating the positional relationship between the marking part 18 and the target part 20 based on the positional relationship before calibration, wherein the target position measurement step is performed at least in the state after rotating the marking device 10 by a predetermined angle around an arbitrarily set central axis and in the state before rotation.

Description

Technical Field

[0001] The present invention relates to a calibration method for an inkjet device.

Background Art

[0002] Patent Document 1 discloses an automatic inkjet system including an inkjet robot that performs inkjet at a preset target point.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In order to accurately perform inkjet at a specified target point by moving an inkjet robot as in the automatic inkjet system described in Patent Document 1, the positional relationship between the part for specifying the position of the inkjet robot and the part for performing inkjet needs to be in a preset state. To calibrate these positional relationships, for example, it is conceivable to measure the position of the inkjet robot and measure the inkjet position where inkjet is performed when the position of the inkjet robot is measured, and perform calibration based on these differences.

[0005] However, for example, when the inkjet surface is inclined, the required magnitude of the difference changes according to the inclination degree and inclination direction of the inkjet surface on which the inkjet robot is installed. Therefore, even if the difference is obtained multiple times, it is difficult to perform accurate calibration.

[0006] ]>An object of the present invention is to accurately calibrate an inkjet device at a work site.

Means for Solving the Problems

[0007] The present invention relates to a calibration method for a marking device comprising a marking unit that marks a marking surface, a running unit having a plurality of wheels, and a target unit whose position is measured by a three-dimensional measuring device, the calibration method comprising: a target position measurement step for measuring the position of the target unit; a marking position measurement step for measuring the marking position marked from the marking unit when the marking device is in a state where the position of the target unit is measured; a position relationship calculation step for determining the positional relationship between the marking unit and the target unit before calibration based on the position of the target unit measured in the target position measurement step and the marking position measured in the marking position measurement step; and a calibration step for calibrating the positional relationship between the marking unit and the target unit based on the positional relationship before calibration, wherein the target position measurement step is performed at least in the state after rotating the marking device by a predetermined angle around an arbitrarily set central axis and in the state before rotation. [Effects of the Invention]

[0008] According to the present invention, the calibration of a marking device can be performed accurately at the work site. [Brief explanation of the drawing]

[0009] [Figure 1] This is an illustrative diagram showing an image of the marking work performed by a marking device calibrated by a calibration method according to an embodiment of the present invention. [Figure 2] This is a plan view showing the schematic configuration of a marking device. [Figure 3] This is a block diagram showing the overall configuration of an automated marking system, including a marking device. [Figure 4] This is a diagram illustrating general calibration methods. [Figure 5] This flowchart shows the calibration procedure for a marking device performed by the calibration method according to an embodiment of the present invention. [Figure 6] This diagram illustrates the positional relationship between the target area and the marking location. [Figure 7]This is an enlarged view of a portion of Figure 6, illustrating the calculation of the amount of deviation of the marking position relative to the position of the target. [Figure 8] This diagram shows an example of the positional relationship between the actual target area and the marking location. [Modes for carrying out the invention]

[0010] The calibration method for a marking device according to an embodiment of the present invention will be described below with reference to the drawings.

[0011] An embodiment of the present invention is a method for calibrating the marking position of a marking device 10 before performing marking in an automatic marking system 100 as shown in Figure 1.

[0012] The automatic marking system 100 is a system that automatically marks marking lines and other reference lines for construction on the floor surface of a building. As shown in Figure 1, it comprises a marking device 10 that marks lines on the floor surface 1, which is the marking surface, while moving; a three-dimensional measuring device 50 that tracks the marking device 10 and can measure the three-dimensional spatial position of the marking device 10; and a control device 30 that controls the movement and marking of the marking device 10 based on the three-dimensional spatial position of the marking device 10 measured by the three-dimensional measuring device 50. In the following description, the case in which the control device 30 is built into the marking device 10 will be explained, but the control device 30 may be built into the three-dimensional measuring device 50, or it may be provided separately from the marking device 10 and the three-dimensional measuring device 50.

[0013] The marking device 10 is an autonomous mobile robot that does not require external operation. As shown in Figure 2, it has a mobile unit 12 for traveling on the floor surface 1 which is the marking surface, a marking unit 18 for marking on the floor surface 1, a target unit 20 that is tracked by a three-dimensional measuring device 50, and a base unit 24 to which the mobile unit 12, marking unit 18, and target unit 20 are attached. Figure 2 is a plan view of the marking device 10 seen from above, showing the state in which the cover member 25 attached to the base unit 24 so as to cover the mobile unit 12 and the marking unit 18 has been removed.

[0014] The running section 12 has three omni-wheels 13 (all-directional wheels) whose rotation direction and rotation speed are independently controlled. Each omni-wheel 13 is rotationally driven by an electric motor 15 via an axle 14. The axle 14 and the electric motor 15 may be connected via a reduction gear (not shown).

[0015] The three omniwheels 13 are arranged at equal intervals (120° intervals) on the circumference of a common circle (on the same circumference), and the axial direction of their axles 14 points toward the rotation center CR, which is the center of the common circle. In other words, the three omniwheels 13 are arranged so that the axial direction of each axle 14 points toward the common center point, and this configuration allows the running unit 12 to rotate the marking device 10 in place around the rotation center CR, a so-called super-tight turn.

[0016] Each electric motor 15 is controlled separately by the control device 30 in terms of its rotation direction and rotation speed. In other words, the rotation direction and rotation speed of each of the three omni wheels 13 are controlled independently.

[0017] Note that the traveling unit 12 may have four or more omnidirectional wheels 13. For example, when four omnidirectional wheels 13 are provided, the omnidirectional wheels 13 are arranged at equal intervals (90° intervals) on the circumference of a common circle, and the axial directions of each axle 14 are arranged to face a common center point. Also, for example, when six omnidirectional wheels 13 are provided, the omnidirectional wheels 13 are arranged at equal intervals (60° intervals) on the circumference of a common circle, and the axial directions of each axle 14 are arranged to face a common center point.

[0018] However, when the number of omnidirectional wheels 13 is four or more, if the floor surface 1 is not flat but has irregularities, there is a possibility that some of the omnidirectional wheels 13 may not contact the ground, resulting in a decrease in traveling stability. Therefore, it is preferable that the number of omnidirectional wheels 13 be three.

[0019] Also, the traveling unit 12 may have two wheels whose rotational directions and rotational speeds are independently controlled. In this case, the wheels are arranged at equal intervals (180° intervals) on the circumference of a common circle, and the axial directions of each axle 14 are arranged to face a common center point. Also, in this case, one or more auxiliary wheels are provided to stabilize the posture of the marking device 10 with respect to the floor surface 1.

[0020] Also, the omnidirectional movement wheels of the traveling unit 12 are not limited to the omnidirectional wheels 13, and any configuration of wheels that can move the marking device 10 in the axial direction of the axle 14 may be used. For example, mecanum wheels or Mbius wheels may be used. Also, the arrangement of the wheels of the traveling unit 12 is not limited to being arranged at equal intervals on the circumference of a common circle, and it may be an arrangement that enables the marking device 10 to turn on the spot around the rotation center CR, so-called ultra-precise turning.

[0021] By configuring the traveling unit 12 to have a plurality of omnidirectional movement wheels in this way, the marking device 10 can smoothly move in all directions without turning.

[0022] The marking unit 18 is an inkjet printing device having a predetermined marking width W1, and includes a nozzle head (not shown) with multiple nozzles capable of ejecting ink onto the floor surface 1 at predetermined minute intervals, and an ink supply unit (not shown) that supplies ink to the nozzle head. The nozzle head is mounted on a base unit 24 such that multiple nozzles are arranged along the direction of the marking width W1.

[0023] Here, as described above, the marking device 10 can move freely in all directions, and there is no particular concept of "forward." However, for the sake of explanation below, the basic travel direction of the marking device 10 will be defined as the travel direction that is approximately perpendicular to the direction of the marking width W1, which allows for the free drawing of characters and lines on the floor surface 1 via the marking unit 18 as described above. Furthermore, the side of the first omniwheel 13A (right side in Figure 2) where the axle 14 does not rotate when the marking device 10 is traveled in the basic travel direction will be defined as the "forward" of the marking device 10, and the first omniwheel 13A positioned in front will be defined as the "steering wheel" that steers the direction of movement of the marking device 10. Note that the definition of "forward" of the marking device 10 is not limited to this.

[0024] The target unit 20 is a directional prism capable of reflecting laser light emitted from the three-dimensional measuring device 50, and is rotated by the target rotation unit 21 so as to always point towards the three-dimensional measuring device 50. The target rotation unit 21 is a servo motor, and its rotation angle is controlled by the control device 30 based on angle data from the optical measurement unit 55 transmitted from the three-dimensional measuring device 50, so that the target unit 20 always faces the optical measurement unit 55, which will be described later. Note that the target unit 20 may also be a 360-degree prism, in which case the target rotation unit 21 may not be provided.

[0025] In addition to the aforementioned traveling unit 12, marking unit 18, and target unit 20, the base unit 24 of the marking device 10 is equipped with a posture detection unit 26 capable of detecting the posture of the marking device 10 while it is traveling, a communication unit 27 for sending and receiving data with the three-dimensional measuring device 50 and an external server 120, and a battery 28 for supplying power to the traveling unit 12 and other electrical components. A control device 30 is also installed on the base unit 24.

[0026] The attitude detection unit 26 is a so-called inertial measurement unit (IMU) that integrates an acceleration sensor, a gyro sensor, and a geomagnetic sensor capable of detecting the attitude of the marking device 10. For example, it can detect which direction the "forward" of the marking device 10 is facing relative to the direction in which the marking device 10 is traveling, that is, how much the direction of the marking width W1 is tilted relative to the direction in which the marking device 10 is traveling, and it can also detect the inclination state of the floor surface 1, which is the surface on which the marking device 10 travels, based on the attitude of the marking device 10.

[0027] The communication unit 27 is a short-range wireless communication device such as BLE (Bluetooth® Low Energy) or Wi-Fi®, and is mainly used to send and receive data with the three-dimensional measuring device 50. The communication unit 27 may also be equipped with a general wireless communication device capable of sending and receiving data via an internet connection.

[0028] As shown in Figure 1, the three-dimensional measuring device 50 includes a trolley unit 60 that can move on the floor surface 1 which is the marking surface, and an optical measuring unit 55 that can measure the three-dimensional spatial position of the target unit 20 based on the reflected light of the laser beam irradiated onto the target unit 20.

[0029] The trolley section 60, like the running section 12 of the marking device 10, has three omniwheels 61, a motor (not shown) provided for each omniwheel 61, and a battery (not shown) that supplies power to the motors. As a result, the three-dimensional measuring device 50, like the marking device 10, can move smoothly in all directions without rotating.

[0030] The bogie section 60 may have four omniwheels 61. Furthermore, the wheels of the bogie section 60 are not limited to omniwheels 61, but may also be Mecanum wheels or Mobius wheels. Also, since the movement of the bogie section 60 is not as frequent as that of the marking device 10, the bogie section 60 may be a general-purpose running device capable of self-propulsion in all directions (forward, backward, left, and right) and moving to a predetermined position.

[0031] Furthermore, the trolley section 60 is provided with a mounting base 62 for installing the optical measuring unit 55 on the trolley section 60. Although the mounting base 62 shown in Figure 1 is a simple columnar structure, it may also be configured to be extendable and retractable in the vertical direction.

[0032] The optical measurement unit 55 has a light-emitting unit 56 that emits laser light and a light-receiving unit 57 located at the same position as the light-emitting unit 56 that receives the reflected laser light. Based on the time from when the laser light is emitted toward the object to be measured, such as the target unit 20, until the reflected laser light is received, it is possible to measure the distance to the object and measure its three-dimensional spatial coordinates. This is a three-dimensional coordinate surveying instrument, such as a laser tracker or tracking total station.

[0033] The light-emitting unit 56 and the light-receiving unit 57 are configured to be rotatable horizontally around the vertical axis C1 and vertically around the horizontal axis C2. This configuration allows the optical measurement unit 55 to always receive the laser light reflected by the target unit 20 at the light-receiving unit 57, even when the target unit 20 is moving, thus enabling it to track the target unit 20. A camera may be provided to improve tracking of the target unit 20.

[0034] Furthermore, as shown in Figure 3, the three-dimensional measuring device 50 includes a CPU (Central Processing Unit) as a control unit 51, a microcomputer equipped with ROM (Read Only Memory) and RAM (Random Access Memory) as storage units 52, and an input / output interface (I / O interface), as well as a communication unit 53 for sending and receiving data with the marking device 10 and an external server 120.

[0035] The control unit 51 controls the operation of the trolley unit 60 and the optical measurement unit 55 based on commands from the control device 30, and transmits the measured values ​​measured by the optical measurement unit 55 to the marking device 10 and the external server 120 via the communication unit 53.

[0036] The memory unit 52 stores control programs and the like that executed by the control unit 51, as well as measured values ​​measured by the optical measurement unit 55 and data acquired from an external server 120 or the like via the communication unit 53.

[0037] The communication unit 53 is a short-range wireless communication device similar to the communication unit 27 of the marking device 10, and is mainly used to send and receive data with the marking device 10. The communication unit 53 may also be equipped with a general wireless communication device capable of sending and receiving data via an internet connection.

[0038] The three-dimensional measuring device 50 configured in this way tracks the target unit 20, which moves along with the movement of the marking device 10, using the optical measuring unit 55, and measures the three-dimensional spatial position (position coordinates) of the target unit 20 within the space where marking is performed.

[0039] The optical measurement unit 55 automatically determines its own position in the space by measuring the distance and angle to multiple reference prisms pre-installed in the space where marking is performed. Furthermore, the optical measurement unit 55 automatically updates its own position each time the three-dimensional measuring device 50 moves and stops. In this way, the optical measurement unit 55 always knows its own position coordinates in the space where marking is performed, and can therefore constantly measure the three-dimensional spatial position coordinates of the target unit 20 in the space where marking is performed.

[0040] Furthermore, the three-dimensional measuring device 50 may transmit the position coordinates of the target unit 20 in a pre-set coordinate system to the control device 30, or it may transmit data such as distance and angle necessary to calculate the position coordinates of the target unit 20 to the control device 30. In addition, the depression angle and rotation angle of the optical measuring unit 55, which are necessary to control the rotation angle of the target rotation unit 21, are transmitted from the three-dimensional measuring device 50 to the control device 30.

[0041] The control device 30 controls the operation of the travel section 12 and the marking section 18 of the marking device 10 based on the three-dimensional spatial position of the marking device 10 measured by the three-dimensional measuring device 50 and the pre-loaded design data. The control device 30 also performs the calibration method described later.

[0042] As shown in Figure 3, the control device 30 is a microcomputer equipped with a CPU (Central Processing Unit) as a control unit 31, ROM (Read Only Memory) and RAM (Random Access Memory) as storage units 32, and an input / output interface (I / O interface).

[0043] The control unit 31 has, for example, a function to recognize the orientation of the marking device 10 (orientation recognition unit 33) and a function to recognize the three-dimensional spatial position of the marking device 10 (position recognition unit 34), as well as a function to generate drawing data from design data and a function to set the target marking position based on the drawing data.

[0044] In the automatic marking system 100 with the above configuration, before the marking device 10 marks the floor surface 1, the marking position is calibrated, that is, it is checked whether the positional relationship between the position of the target unit 20 and the position of the ink ejected from the marking unit 18 is in a predetermined relationship.

[0045] Generally, the position of the target unit 20 and the position of a measuring prism (not shown) placed at the position of the ink ejected from the marking unit 18 are measured by a three-dimensional measuring device 50. The position of the target unit 20 or the marking unit 18 is adjusted, or the offset value between the position of the target unit 20 and the marking unit 18 is updated, so that the difference between these positions falls within a predetermined reference value.

[0046] However, the magnitude of the difference measured in this way is relatively stable when the floor surface 1 is flat and horizontal, as shown in Figure 4(a). However, the surface of the concrete on which marking is actually performed is often slightly sloped or uneven. For example, the difference G2 measured when the marking device 10 is slightly tilted along the floor surface 1, as shown in Figure 4(b), and the difference G3 measured when the wheels of the marking device 10 are on a protrusion, as shown in Figure 4(c), will be different in magnitude from the difference G1 measured in the condition shown in Figure 4(a), which is the actual difference.

[0047] Therefore, it is difficult to perform accurate calibration at the work site where marking out is carried out.

[0048] Therefore, the calibration method according to this embodiment makes it possible to accurately calibrate the marking device 10 even at work sites where the floor surface 1 is not flat.

[0049] Next, with reference to Figures 5 to 7, a calibration method for the marking device 10 performed in the control device 30 of the automatic marking system 100 with the above configuration will be described. Figure 5 is a flowchart showing the calibration procedure for the marking device 10 performed by the calibration method according to this embodiment, and Figures 6 and 7 are diagrams for explaining the calculation of the positional relationship between the position of the target unit 20 and the position of the ink ejected from the marking unit 18.

[0050] When the control device 30 receives a command to start calibration from an operating terminal (not shown) or server 120, etc., in step S11, the control device 30 first measures the position of the target part 20 of the marking device 10 using the three-dimensional measuring device 50 (target position measurement step).

[0051] Then, in the following step S12, the control device 30, when the marking device 10 is in the same state as when the position of the target unit 20 was measured, ejects ink from the marking unit 18 in a predetermined shape, for example, a dot or a circle, at a single point (point marking process). Note that step S12 may be performed simultaneously with step S11.

[0052] Once the position measurement of the target unit 20 and the ejection of ink from the marking unit 18 are completed, the process proceeds to step S13, where the control device 30 determines whether the ejection of ink from the marking unit 18 has been performed the number of times predetermined.

[0053] The number of times ink is ejected from the marking unit 18 is set to any number of times, two or more. In the following description, we will explain the case where the number of times ink is ejected from the marking unit 18 is set to three, which corresponds to the number of omniwheels 13, which are the wheels of the marking device 10.

[0054] If the ink ejection from the marking unit 18 has not reached a preset number of times, the process proceeds to step S13, where the control device 30 rotates the marking device 10 in place by a predetermined angle α around the rotation center CR to set the marking device 10 to the next measurement position.

[0055] Specifically, in step S14, the angle at which the marking device 10 is rotated is set to the angle obtained by dividing 360 degrees by a divisor of the number of omniwheels 13 (wheels of the marking device 10), excluding 1. In other words, the measurement posture of the marking device 10 means the posture when the marking device 10 is rotated at intervals of 360 degrees, excluding a divisor of the number of omniwheels 13 (wheels).

[0056] For example, as shown in Figure 2, if there are three omniwheels 13, the angle at which the marking device 10 rotates will be 120 degrees; if there are four omniwheels 13, it will be 90 degrees or 180 degrees; and if there are six omniwheels 13, it will be 60 degrees, 120 degrees, or 180 degrees. If there are two wheels, the rotation angle will be 180 degrees.

[0057] In this way, the angle at which the marking device 10 is rotated is set according to the number of omniwheels 13 (wheels), so that the next measurement position of the marking device 10 is the position in which the positions of omniwheels 13 are swapped with the positions of other omniwheels 13.

[0058] In other words, in step S14, the marking device 10 is rotated (performed a pivot turn) by the travel unit 12 around the rotation center CR (central axis) such that the positions of the omniwheels 13 are sequentially swapped with the positions of other omniwheels 13.

[0059] Therefore, if there are irregularities (unevenness) on the floor surface 1 and one of the omniwheels 13 rides onto a protrusion, another omniwheel 13 will take its place and ride onto the protrusion. As a result, the orientation (measurement orientation) of the marking device 10 when measuring the position of the target section 20 and dispensing ink from the marking section 18 will be maintained in the same inclined state each time.

[0060] In other words, even if the floor surface 1 has irregularities, it is possible to measure the position of the target unit 20 and the marking position of the marking unit 18 in multiple measurement positions without changing the inclination of the marking device 10. Furthermore, whether the orientation of the marking device 10 during measurement is the same inclination each time may be determined by the orientation recognition unit 33, which recognizes the orientation of the marking device 10.

[0061] Furthermore, a certain tolerance range may be set for the angle at which the marking device 10 is rotated. For example, if the angle at which the marking device 10 is rotated is 120 degrees, the actual rotation angle does not have to be exactly 120 degrees, and there may be an error or deviation of a few percent depending on the control accuracy of the traveling unit 12.

[0062] In step S14, once the rotation of the marking device 10 is complete, the process returns to step S11, where the position of the target section 20 of the marking device 10, now in a new measurement position, is measured by the three-dimensional measuring device 50. In step S12, ink is ejected from the marking section 18 of the marking device 10, now in a new measurement position.

[0063] The rotation of the marking device 10 in step S14, that is, the change in the measurement posture of the marking device 10, is repeated until the ink is ejected from the marking unit 18 a preset number of times (for example, 3 times).

[0064] In step S13, if it is determined that the number of times ink has been ejected from the marking unit 18 has reached a preset number, the process proceeds to step S15, where the control device 30 measures the position of the ink ejected from the marking unit 18 using the three-dimensional measuring device 50 (marking position measurement step).

[0065] Specifically, the position of the ink ejected from the marking unit 18 the first time is determined by placing a measuring prism at the position of the ink ejected from the marking unit 18 the first time and measuring the position of the placed measuring prism with the three-dimensional measuring device 50. Subsequently, the position of the ink ejected from the marking unit 18 the second time is determined by placing a measuring prism at the position of the ink ejected from the marking unit 18 the second time and measuring the position of the placed measuring prism with the three-dimensional measuring device 50. Finally, the position of the ink ejected from the marking unit 18 the third time is determined by placing a measuring prism at the position of the ink ejected from the marking unit 18 the third time and measuring the position of the placed measuring prism with the three-dimensional measuring device 50.

[0066] Once the positions of the ink ejected from the marking unit 18 and the positions of the target unit 20 in each measurement position have been measured in a predetermined number of measurement positions (for example, three), the process proceeds to step S16, where the control device 30 determines the pre-calibration positional relationship between the marking unit 18 and the target unit 20 (positional relationship calculation step).

[0067] The control device 30 determines the positional relationship between the marking unit 18 and the target unit 20 before calibration, which is the displacement amount rd, which represents the positional relationship between the marking unit 18 and the target unit 20 in the radial direction of a virtual circle centered on the rotation center CR (central axis), and the displacement amount td, which represents the positional relationship between the marking unit 18 and the target unit 20 in the direction perpendicular to the radial direction, i.e., the tangential direction.

[0068] In the following, we will explain the case where, if there is no radial or tangential misalignment between the marking unit 18 and the target unit 20, the marking position by the marking unit 18 and the position of the target unit 20 coincide. That is, the marking by the marking unit 18 is performed directly below the directional prism, which is the target unit 20, and the marking position by the marking unit 18 is not offset from the position of the target unit 20 in the design.

[0069] First, the method for calculating the radial displacement rd will be explained with reference to Figures 6 and 7. Figure 6 shows an example of the position of the target section 20 and the marking position measured when the floor surface 1 is a smooth horizontal surface and there is a radial displacement (displacement rd) and a tangential displacement (displacement td) between the marking section 18 and the target section 20. Figure 7 shows a magnified portion of Figure 6.

[0070] Of the measurement points A11-A13 and B11-B13 shown in Figure 6, measurement points A11-A13 indicate the position of the target unit 20, and measurement points B11-B13 indicate the marking positions. These are projected onto the same horizontal plane (XY plane).

[0071] Specifically, measurement points A11 and B11 are points measured or marked before the marking device 10 is rotated around the rotation center CR (central axis), measurement points A12 and B12 are points measured or marked after the marking device 10 is rotated by a predetermined angle α (120 degrees) around the rotation center CR, and measurement points A13 and B13 are points measured or marked after the marking device 10 is further rotated by a predetermined angle α around the rotation center CR.

[0072] As shown in Figure 6, there are radial displacement amounts rd1 to rd3 between measurement points A11 to A13 indicating the position of the target section 20 and measurement points B11 to B13 indicating the marking positions. In this embodiment, instead of simply determining these displacement amounts rd1 to rd3 from the coordinate positions of measurement points A11 to A13 and measurement points B11 to B13, they are determined based on the lengths of the line segments LA11 to LA13 and LB11 to LB13 connecting the measurement points, the angles θ11 to θ13 formed by the intersecting line segments LA11 to LA13 and LB11 to LB13, and the angle α (120 degrees) when the marking device 10 is rotated when measuring each measurement point A11 to A13 and B11 to B13.

[0073] The radial displacement amounts rd1 to rd3 are the difference between the position of the target section 20 (A11 to A13) and the marking position by the marking section 18 (B11 to B13) on the axis (L1x, L2x, L3x: radial axis) connecting the position of the target section 20 (A11 to A13) and the rotation center CR, as shown in Figure 6.

[0074] For example, as shown in Figure 7, the displacement rd1 is the distance from measurement point A11 to intersection point P11, where a perpendicular line drawn from measurement point B11 intersects the line passing through measurement point A11 and the rotation center CR. The line segment from intersection point P11 to the rotation center CR and the line segment connecting measurement point B11 and the rotation center CR are in a relationship of the base and hypotenuse of a right triangle with an angle θ11 in between.

[0075] Therefore, each of the deviation amounts rd1 to rd3 can be calculated using the following equations (1) to (3), with respect to the length of the line segment connecting the measurement points A11, A12, A13 and the rotation center CR, the length of the line segment connecting the measurement points B11, B12, B13 and the rotation center CR, the angles θ11 to θ13 formed by the intersecting line segments LA11 to LA13 and LB11 to LB13, and the angle α obtained by rotating the marking device 10 when measuring each of the measurement points A11 to A13 and B11 to B13.

[0076] rd1=(LA11 / 2) / cos(90°-α / 2)-((LB11 / 2) / cos(90°-α / 2))*cos(θ11) ···(1) rd2=(LA12 / 2) / cos(90°-α / 2)-((LB12 / 2) / cos(90°-α / 2))*cos(θ12) ···(2) rd3=(LA13 / 2) / cos(90°-α / 2)-((LB13 / 2) / cos(90°-α / 2))*cos(θ13) ···(3)

[0077] In the above equation, LA11 is the length of the line segment LA11 connecting measurement point A11 and measurement point A12, LA12 is the length of the line segment LA12 connecting measurement point A12 and measurement point A13, and LA13 is the length of the line segment LA13 connecting measurement point A13 and measurement point A11. Also, in the above equation, LB11 is the length of the line segment LB11 connecting measurement point B11 and measurement point B12, LB12 is the length of the line segment LB12 connecting measurement point B12 and measurement point B13, and LB13 is the length of the line segment LB13 connecting measurement point B13 and measurement point B11. Furthermore, in each of the above equations, θ11 is the acute angle between line segment LA11 and line segment LB11, θ12 is the acute angle between line segment LA12 and line segment LB12, and θ13 is the acute angle between line segment LA13 and line segment LB13.

[0078] In addition, the calculated values ​​in each of the above formulas will be positive if the positions of the measurement points B11 to B13, which indicate the marking positions, are closer to the rotation center CR than the measurement points A11 to A13, which indicate the position of the target unit 20, and will be negative if the positions of the measurement points B11 to B13, which indicate the marking positions, are further from the rotation center CR than the measurement points A11 to A13, which indicate the position of the target unit 20.

[0079] The radial displacement rd between the marking section 18 and the target section 20 is determined by averaging these displacement amounts rd1 to rd3.

[0080] Thus, the radial displacement rd is determined based on the lengths of the line segments LA11~LA13 and LB11~LB13 connecting the measurement points, the angles θ11~θ13 formed by the intersecting line segments LA11~LA13 and LB11~LB13, and the angle α (120 degrees) obtained by rotating the marking device 10 when measuring each measurement point A11~A13 and B11~B13.

[0081] Furthermore, the formulas for determining the radial displacement amounts rd1 to rd3 are not limited to the above formulas. Any formula is acceptable as long as it allows for an approximate determination of the displacement amounts rd1 to rd3 by using the lengths of the line segments LA11 to LA13 and LB11 to LB13 connecting the measurement points, the angles θ11 to θ13 formed by the intersecting line segments LA11 to LA13 and LB11 to LB13, and the angle α obtained by rotating the marking device 10 when measuring each measurement point A11 to A13 and B11 to B13.

[0082] Next, the method for calculating the tangential displacement td will be explained with reference to Figures 6 and 7.

[0083] As shown in Figure 6, there are tangential displacement amounts td1 to td3 between measurement points A11 to A13 indicating the position of the target section 20 and measurement points B11 to B13 indicating the marking positions. In this embodiment, instead of simply determining these displacement amounts td1 to td3 from the coordinate positions of measurement points A11 to A13 and measurement points B11 to B13, they are determined based on the lengths of the line segments LA11 to LA13 and LB11 to LB13 connecting the measurement points, the angles θ11 to θ13 formed by the intersecting line segments LA11 to LA13 and LB11 to LB13, and the angle α (120 degrees) when the marking device 10 is rotated when measuring each measurement point A11 to A13 and B11 to B13.

[0084] The tangential displacement amounts td1 to td3 are the difference between the position of the target section 20 (A11 to A13) and the marking position by the marking section 18 (B11 to B13) on the axis (L1y, L2y, L3y: tangential axis) that is perpendicular to the axis (L1x, L2x, L3x: radial axis) connecting the position of the target section 20 (A11 to A13) and the rotation center CR, as shown in Figure 6.

[0085] For example, as shown in Figure 7, the displacement td1 is the length of the perpendicular line drawn from measurement point B11 to the line passing through measurement point A11 and the rotation center CR. This line segment (perpendicular line) corresponding to the displacement td1 and the line segment connecting measurement point B11 and the rotation center CR have a relationship with respect to angle θ11 that is the same as the relationship between the height and hypotenuse of a right triangle.

[0086] Therefore, each displacement amount td1 to td3 can be calculated using the following equations (4) to (6), with respect to the length of the line segment connecting the measurement points B11, B12, B13 and the rotation center CR, the angles θ11 to θ13 formed by the intersecting line segments LA11 to LA13 and LB11 to LB13, and the angle α obtained by rotating the marking device 10 when measuring each measurement point A11 to A13 and B11 to B13.

[0087] td1=((LB11 / 2) / cos(90°-α / 2))*sin(θ11) ···(4) td2=((LB12 / 2) / cos(90°-α / 2))*sin(θ12) ···(5) td3=((LB13 / 2) / cos(90°-α / 2))*sin(θ13) ···(6)

[0088] In the above equation, LB11 is the length of the line segment LB11 connecting measurement point B11 and measurement point B12, LB12 is the length of the line segment LB12 connecting measurement point B12 and measurement point B13, and LB13 is the length of the line segment LB13 connecting measurement point B13 and measurement point B11. Also, in the above equation, θ11 is the acute angle between the line segment LA11 and the line segment LB11, θ12 is the acute angle between the line segment LA12 and the line segment LB12, and θ13 is the acute angle between the line segment LA13 and the line segment LB13.

[0089] Furthermore, when the positions of measurement points B11 to B13, which indicate the marking positions, are to the right of measurement points A11 to A13, which indicate the position of the target section 20, as viewed from the rotation center CR, the angles θ11 to θ13 when line segments LA11 to LA13 and LB11 to LB13 intersect are considered positive values. When the positions of measurement points B11 to B13, which indicate the marking positions, are to the left of measurement points A11 to A13, which indicate the position of the target section 20, as viewed from the rotation center CR, the angles θ11 to θ13 when line segments LA11 to LA13 and LB11 to LB13 intersect are considered negative values.

[0090] Therefore, the calculated values ​​in each of the above formulas will be positive when the positions of measurement points B11 to B13, which indicate the marking positions, are to the right of measurement points A11 to A13, which indicate the position of the target unit 20, as viewed from the rotation center CR, and will be negative when the positions of measurement points B11 to B13, which indicate the marking positions, are to the left of measurement points A11 to A13, which indicate the position of the target unit 20, as viewed from the rotation center CR.

[0091] The tangential displacement td between the marking section 18 and the target section 20 is obtained by averaging these displacement amounts td1 to td3.

[0092] Thus, the tangential displacement td is determined based on the length of the line segment LB11~LB13 connecting the measurement points, the angle θ11~θ13 formed by the intersecting line segments LA11~LA13 and LB11~LB13, and the angle α (120 degrees) obtained by rotating the marking device 10 when measuring each measurement point A11~A13 and B11~B13.

[0093] Furthermore, the formulas for determining the tangential displacement amounts td1 to td3 are not limited to the formulas above. Any formula is acceptable as long as it allows for an approximate determination of the tangential displacement amounts td1 to td3 by using the lengths of the line segments LA11 to LA13 and LB11 to LB13 connecting the measurement points, the angles θ11 to θ13 formed by the intersecting line segments LA11 to LA13 and LB11 to LB13, and the angle α obtained by rotating the marking device 10 when measuring each measurement point A11 to A13 and B11 to B13.

[0094] For example, in the above formula, measurement point A11, which indicates the position of the target part 20, is used as the reference point, and the amount of displacement td1 is calculated by assuming that the height from the straight line passing through measurement point A11 and the rotation center CR to measurement point B11, which indicates the marking position, corresponds to the amount of displacement td1. However, it is also possible to use measurement point B11, which indicates the marking position, as the reference point, and calculate the amount of displacement td1 by assuming that the height from the straight line passing through measurement point B11 and the rotation center CR to measurement point A11, which indicates the position of the target part 20, corresponds to the amount of displacement td1. Alternatively, the average value of these values ​​may be used to calculate the amount of displacement td1.

[0095] Here, if the floor surface 1 is sloped or if there are irregularities on the floor surface 1 that the omniwheel 13 (wheel) of the marking device 10 rides onto, when the marking device 10 is rotated as described above to measure the marking position by the marking unit 18 and the position of the target unit 20, for example, as shown in Figure 8, the measurement points B31 to B33 indicating the marking position will be offset overall from the measurement points A31 to A33 indicating the position of the target unit 20, regardless of the magnitude of the radial displacement rd and the tangential displacement td, due to the influence of the degree of slope and irregularities.

[0096] Therefore, even if the distance between points is determined simply based on the coordinate positions of measurement points A31 to A33 and measurement points B31 to B33, it is difficult to determine the amount of displacement in the radial and tangential directions between the marking section 18 and the target section 20.

[0097] In contrast, in this embodiment, as described above, the radial displacement rd between the marking section 18 and the target section 20 is determined based on the lengths of the line segments LA11~LA13 and LB11~LB13 connecting the measurement points, the angles θ11~θ13 formed by the intersecting line segments LA11~LA13 and LB11~LB13, and the angle α obtained by rotating the marking device 10 when measuring each measurement point A11~A13 and B11~B13. The tangential displacement td is determined based on the lengths of the line segments LB11~LB13 connecting the measurement points, the angles θ11~θ13 formed by the intersecting line segments LA11~LA13 and LB11~LB13, and the angle α obtained by rotating the marking device 10 when measuring each measurement point A11~A13 and B11~B13.

[0098] In other words, in this embodiment, even if the measurement points indicating the marking positions are generally offset from the measurement points indicating the position of the target section 20 due to the influence of the degree of inclination and unevenness of the floor surface 1, it is possible to accurately determine the radial displacement rd and the tangential displacement td between the marking section 18 and the target section 20.

[0099] In step S16, once the positional relationship between the marking unit 18 and the target unit 20 before calibration is determined, the process proceeds to step S17, where the control device 30 compares the determined radial displacement rd and tangential displacement td with a pre-stored tolerance range (reference value).

[0100] In step S17, if it is determined that both deviation amounts rd and td are within the acceptable range (reference value), the control device 30 sends a message to an operation terminal (not shown) or server 120 indicating that the calibration work has been successfully completed, and terminates the process. The marking device 10 then enters a standby state until it receives instructions for the next operation from the operation terminal or server 120.

[0101] On the other hand, if it is determined in step S17 that either of the deviation amounts rd,td exceeds the allowable range (reference value), the process proceeds to step S18, where the control device 30 adjusts (calibrates) the positional relationship between the marking unit 18 and the target unit 20 (calibration process).

[0102] The positional relationship between the marking unit 18 and the target unit 20 may be adjusted by updating the radial and tangential offset values ​​stored in the memory unit 32 within the control device 30, or by the operator making fine adjustments to the mounting position of the marking unit 18 or the target unit 20 relative to the base unit 24. When the mounting position of the marking unit 18 or the target unit 20 is adjusted, the adjustment direction and amount are displayed on an operation terminal (monitor) (not shown).

[0103] Once the adjustment in step S18 is complete, the process returns to step S11, and the positional relationship between the marking unit 18 and the target unit 20 is acquired again.

[0104] Furthermore, even if the marking position by the marking unit 18 relative to the position of the target unit 20 is offset by a predetermined design offset amount in the radial or tangential direction during the design phase, the radial displacement amount rd and the tangential displacement amount td can be determined by the same procedure, and the positional relationship between the marking unit 18 and the target unit 20 can be adjusted (calibrated) based on the determined displacement amounts rd and td and the design offset amount, with the design offset state as the reference.

[0105] Through the above process, the marking device 10 is calibrated accurately, enabling it to perform markings with high precision.

[0106] According to the above embodiments, the following effects are achieved.

[0107] According to the calibration method described above, in order to determine the positional relationship between the target unit 20 and the marking unit 18, the position measurement of the target unit 20 and the marking from the marking unit 18 are performed at least in the state after rotating the marking device 10 by a predetermined angle α around the rotation center CR (central axis) and in the state before rotation.

[0108] Therefore, for example, if the floor surface 1, which is the marking surface, is inclined, the positional relationship between the target section 20 and the marking section 18 will be determined based on points measured or marked when the marking device 10 was in at least two measurement positions that were similarly inclined with respect to the floor surface 1.

[0109] Therefore, regardless of the inclination of the floor surface 1, it becomes possible to accurately determine the positional relationship between the marking unit 18 and the target unit 20 before calibration, and as a result, the marking device 10 can be calibrated accurately even at the work site.

[0110] Furthermore, according to the calibration method described above, in order to determine the positional relationship between the target unit 20 and the marking unit 18, the position measurement of the target unit 20 and the marking from the marking unit 18 are performed at least in the state in which the marking device 10 is rotated by a predetermined angle α around the rotation center CR (central axis) so that the position of one omniwheel 13 (wheel) is swapped with the position of another omniwheel 13 (wheel), and in the state before the swap.

[0111] Therefore, for example, even if the floor surface 1, which is the marking surface, is uneven and one of the omniwheels 13 (wheels) rides up on a convex part or falls into a concave part, the positional relationship between the target part 20 and the marking part 18 will be determined based on the points measured or marked when the marking device 10 was in at least two measurement positions that were tilted in the same way with respect to the floor surface 1.

[0112] Therefore, regardless of the unevenness of the floor surface 1, it becomes possible to accurately determine the positional relationship between the marking unit 18 and the target unit 20 before calibration, and as a result, the marking device 10 can be calibrated accurately even at the work site.

[0113] Furthermore, the following modifications are also within the scope of the present invention, and it is possible to combine the configurations shown in the modifications with the configurations described in the embodiments described above, or to combine the configurations described in the following different modifications.

[0114] In the above embodiment, the displacement rd,td between the marking unit 18 and the target unit 20 is determined by averaging three displacement amounts obtained based on points measured or marked when the marking device 10 was in three different measurement positions. Alternatively, the displacement rd,td may be determined based on points measured or marked when the marking device 10 was in two different measurement positions, without being determined by averaging. In other words, if the position of the target unit 20 and the marking position of the marking unit 18 are measured in two different measurement positions, it is possible to determine the displacement rd,td between the marking unit 18 and the target unit 20.

[0115] Furthermore, in the above embodiment, the position of the rotation center CR (central axis) is the center position of the pivot turning of the traveling unit 12. The position of the rotation center CR is not limited to this, and may be set to a position slightly offset from the center position of the pivot turning. Also, the position of the rotation center CR can be set to any position, and may be set inside the marking device 10 in a plan view, or outside the marking device 10.

[0116] Furthermore, in the above embodiment, the position measurement of the target unit 20 and the marking from the marking unit 18 are performed each time the marking device 10 is rotated by a predetermined angle α. The position measurement of the target unit 20 and the marking from the marking unit 18 only need to be performed when the marking device 10 is in any two measurement positions. For example, if the marking device 10 has six omniwheels 13 (wheels), it is not necessary to perform measurements each time the marking device 10 is rotated by 60 degrees. It may be performed every other position (after 120 degrees of rotation) or every two positions (after 180 degrees of rotation), and it is possible to arbitrarily set which measurement position the measurement is performed in.

[0117] Furthermore, in the above embodiment, the rotation angle α of the marking device 10, which rotates around the rotation center CR, is set according to the number of omniwheels 13 (wheels) so that the positions of the omniwheels 13 (wheels) are swapped. Alternatively, the rotation angle α may be set to any angle regardless of the number of omniwheels 13 (wheels). In this case as well, it is possible to accurately determine the positional relationship between the marking unit 18 and the target unit 20 before calibration, regardless of the inclination of the floor surface 1. However, if the floor surface 1 is uneven, the state in which the omniwheels 13 (wheels) ride over the uneven parts will change with each measurement posture. Therefore, if the floor surface 1 is uneven, it is preferable to set the rotation angle α according to the number of omniwheels 13 (wheels).

[0118] Furthermore, in the above embodiment, when the marking device 10 is calibrated, the three-dimensional spatial position of one marking device 10 is measured by one three-dimensional measuring device 50. Alternatively, the three-dimensional measuring device 50 may measure the three-dimensional spatial positions of multiple marking devices 10 when the marking device 10 is calibrated.

[0119] Although embodiments of the present invention have been described above, these embodiments only represent a part of the application examples of the present invention, and are not intended to limit the technical scope of the present invention to the specific configurations of the above embodiments. [Explanation of symbols]

[0120] 100...Automatic Layout Marking System 1. Floor surface (marking surface) 10. Marking device 12. Running section 13. Omni-wheel (wheel, wheel that moves in all directions) 18. Marking section 20..Target section 30.. Control device 50. Three-dimensional measuring device

Claims

1. A calibration method for a marking device comprising a marking unit that marks a marking surface, a running unit having multiple wheels, and a target unit whose position is measured by a three-dimensional measuring device, A target position measurement step for measuring the position of the target portion, A marking position measurement step is performed when the marking device is in a state where the position of the target portion is measured, and the marking position marked from the marking portion is measured. A positional relationship calculation step that determines the positional relationship between the marking section and the target section before calibration based on the position of the target section measured in the target position measurement step and the marking position measured in the marking position measurement step, The calibration step includes calibrating the positional relationship between the marking section and the target section based on the positional relationship before calibration, The aforementioned target position measurement process is performed at least in the state after the marking device has been rotated by a predetermined angle around an arbitrarily set central axis, and in the state before the rotation. Calibration method for a marking device.

2. The aforementioned running unit has a configuration that allows for super-tight turning, The target position measurement process is performed in at least two states: one in which the position of the wheel is swapped with the position of another wheel by pivoting the marking device, and the other in which the marking device is in a state before pivoting. A method for calibrating a marking device according to claim 1.

3. The aforementioned wheels are omnidirectional wheels arranged at equal intervals on the same circumference, The aforementioned travel unit is capable of rotating the marking device around the central axis to a predetermined measurement position. The measurement posture is set at angles obtained by dividing 360 degrees by a divisor of the number of wheels, excluding 1. The target position measurement step is performed while the marking device is in at least two different measurement positions. A method for calibrating a marking device according to claim 1.

4. In the positional relationship calculation step, The radial positional relationship between the marking section and the target section with respect to the central axis is determined based on at least the length of the line segment connecting the measured positions of the target section and the length of the line segment connecting the measured marking positions. The positional relationship between the marking section and the target section in a direction perpendicular to the radial direction is determined at least based on the angle formed by the line segment connecting the measured positions of the target section and the line segment connecting the measured marking positions. A method for calibrating a marking device according to any one of claims 1 to 3.

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