Automatic measurement system for objects to be measured

Abstract

To provide an automatic measurement system capable of automatically and accurately measuring an object to be measured that stops at an arbitrary position.SOLUTION: The automatic measurement system includes: a mobile autonomous robot; a tracker mounted on the autonomous robot; a metrology scanner mounted on the autonomous robot; and a control unit that generates a virtual map. The automatic measurement system is configured so as to automatically and accurately measure an object to be measured by executing the steps of: setting the object to be measured, the tracker and the stop position of the metrology scanner on the virtual map; and aligning the position with the object to be measured stopped in the actual space and the object to be measured on the virtual map; and subsequently by mutually confirming the difference from the stop position set on the virtual map with the tracker and metrology scanner when measuring the object to be measured.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an automatic measurement system for measuring gaps, steps, etc. of an object to be measured. [Background technology]

[0002] Conventionally, gaps and steps between the body frame that constitutes the vehicle being measured and the components attached to the body frame have been measured by moving a measurement scanner along the gaps and steps between adjacent components.

[0003] This measurement work is performed manually, with the worker visually checking the gap between adjacent components, irradiating the gap with laser light from a measurement scanner, and receiving the reflected light.

[0004] Since the measurement work of measuring the gaps of the object to be measured is performed manually, it takes a long time to complete the measurement if all the gaps and steps formed on the vehicle as the object to be measured. Furthermore, since the measurement work is performed manually, the measurement results vary depending on the skill level of the worker, and in order to obtain accurate measurement results, the worker needs to be trained to improve his or her measurement accuracy. Furthermore, manual measurement is prone to variations in measurement results, even when performed by the same worker, making it difficult to identify trends in defective assembly from the accumulated data.

[0005] As a means for solving such problems, an automatic measurement system has been disclosed that automatically measures the body dimensions of a vehicle, which is an object to be measured (see Patent Document 1). Patent Document 1 discloses an automatic measurement system having a freely movable mobile platform, a robotic joint arm mounted and fixed on the mobile platform, a triangulation scanner fixed to the tip of the robotic joint arm, a laser tracker for adjusting the position of the mobile platform, and a target that serves as an index for the movement of the mobile platform.

[0006] The automatic measurement system in Patent Document 1 is configured so that a laser tracker can move around the vehicle using a target installed on the floor as an index, and a triangulation scanner that moves using the laser tracker as a reference can move around the vehicle without coming into contact with the vehicle body, automatically measuring gaps and steps on the vehicle. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Special Publication No. 2018-515774 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0008] In the automatic measurement system described in Patent Document 1, a vehicle is stopped at a predetermined position in a space where a target is installed. In particular, with a configuration in which the vehicle body is automatically measured by moving a laser tracker, which serves as a position reference, the following problems arise when measuring the installation accuracy of the vehicle.

[0009] A laser tracker is a positioning reference for a mobile platform that automatically measures the dimensions of a vehicle body and is configured to move relative to targets installed on the floor. In such cases, the laser tracker emits laser light at multiple installed targets and receives the reflected light, allowing the laser tracker to determine its own position. Therefore, the positional relationship between the vehicle and the targets is important for the laser tracker to move around the vehicle without coming into contact with it.

[0010] Specifically, a laser tracker measures the distance to a target placed on the floor by emitting infrared light and receiving the light reflected from the target. Therefore, if the emitted infrared light of the laser tracker is blocked by a stopped vehicle, there is a risk that the laser tracker will not be able to confirm its own location information, or that the accuracy of the confirmed location information will be reduced.

[0011] One possible solution to the above problem is to fix the target at a height where the laser light emitted from the laser tracker will not be blocked by the vehicle body. However, this solution may cause problems in measurement systems that measure the dimensions of vehicle bodies with complex shapes.

[0012] Specifically, the measurement scanner used in conventional measurement systems is fixed to the tip of a robotic articulated arm, and is configured to automatically measure dimensions by moving the robotic articulated arm along the measurement location. Therefore, when measuring the dimensions of a car body, it is necessary to ensure a movable area in which the robotic articulated arm can move freely.

[0013] If a target were to exist within the movable range of the robot articulated arm, the movement of the robot articulated arm would be hindered, making it impossible to measure the dimensions correctly, or the orientation of the installed target would change if the robot articulated arm came into contact with the target, making it impossible to move the laser tracker correctly and making it impossible to perform accurate measurements.

[0014] Furthermore, when moving using a target, various measurements are made based on the target, so unless the vehicle is stopped precisely relative to the target, the stopping position of the laser tracker relative to the vehicle may shift, which could result in an error in the measurement results of the measurement scanner.

[0015] The present invention has been made in view of the above problems, and has as its object to provide an automatic measurement system that can automatically and accurately measure an object stopped at any position. [Means for solving the problem]

[0016] A first aspect of the present invention is a system comprising a tracker mounted on an autonomous mobile robot that moves around the periphery of an object to be measured, and a measurement scanner mounted on the autonomous mobile robot, and a virtual map is formed in a separately provided control unit, a virtual object stop position is set at a predetermined virtual position on the virtual map, the virtual stop positions of the tracker and measurement scanner are set on the virtual map, the actual positions of the tracker and measurement scanner are set on the virtual map, the reference coordinates of the actual object to be measured that has stopped at the virtual object stop position on the virtual map are measured, a comparison is made with the reference coordinates of the virtual object to move the virtual map by the amount of deviation to match the virtual object to the actual object to be measured, the position of the tracker relative to the actual object to be measured is identified as the virtual map moves, and the actual measurement scanner is moved on the virtual map. and a tracker irradiates the measurement scanner with a laser beam to check the position of the measurement scanner, and if the position of the measurement scanner deviates from the preset virtual stop position, the position of the measurement scanner is corrected via the autonomous traveling robot, and the tracker irradiates a laser beam to check the position of the measurement scanner after correction to check the accuracy of the position correction of the measurement scanner, and if there is an error in the position, the position of the measurement scanner is corrected again via the autonomous traveling robot, thereby enabling the measurement scanner to be correctly positioned at the position of gaps or steps between the components of the measurement object and to automatically recognize situation information of gaps or steps between the components of the measurement object. [Effects of the Invention]

[0017] According to a first aspect of the present invention, a virtual map is formed in a separately provided control unit, a virtual measurement object stop position is set at a predetermined virtual position on the virtual map, the virtual stop positions of the tracker and measurement scanner are set on the virtual map, the actual positions of the tracker and measurement scanner are set on the virtual map, the reference coordinates of the actual measurement object stopped at the virtual measurement object stop position on the virtual map are measured, a comparison is made with the reference coordinates of the virtual measurement object and the virtual map is moved by the amount of deviation to match the virtual measurement object and the actual measurement object, the position of the tracker relative to the actual measurement object is identified as the virtual map is moved, the actual measurement scanner is moved to the virtual stop position set on the virtual map, and the measurement scanner is read from the tracker. The position of the measurement scanner is confirmed by shining a laser beam onto the tracker, and if the position of the measurement scanner deviates from a preset virtual stopping position, the position of the measurement scanner is corrected via the autonomous mobile robot.In addition, a laser beam is irradiated from the tracker to check the position of the measurement scanner after correction to confirm the accuracy of the position correction of the measurement scanner.If there is an error in the position, the position of the measurement scanner is corrected again via the autonomous mobile robot.This allows the measurement scanner to be positioned correctly at the position of gaps and steps between the components of the object to be measured, and the system is configured to automatically recognize situational information about gaps and steps between the components of the object to be measured.By doing so, the measurement scanner can be positioned at a preset position for the gaps and steps between the components that make up the object to be measured, and the gaps and steps between the components of the object to be measured can be measured automatically and accurately. In other words, by measuring the measurement space for measuring the vehicle's position and creating a virtual map, the vehicle's position can be measured accurately regardless of the measurement space, simply by arbitrarily setting the tracker, measurement scanner, and vehicle stopping position on the virtual map. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is a perspective view showing an autonomous mobile robot according to an embodiment of the present invention. [Figure 2]FIG. 1 is a perspective view of a tracker according to an embodiment of the present invention. [Figure 3] 1 is a perspective view showing a robot arm according to an embodiment of the present invention. FIG. [Figure 4] 1 is a perspective view showing a measurement scanner according to an embodiment of the present invention. [Figure 5] FIG. 1 is a block diagram according to an embodiment of the present invention. [Figure 6] FIG. 1 is a diagram showing a measurement flow of an automatic measurement system according to an embodiment of the present invention. [Figure 7] FIG. 10 is a diagram showing the stopping positions of a tracker and a measurement scanner according to an embodiment of the present invention displayed on a virtual map. DETAILED DESCRIPTION OF THE INVENTION

[0019] An embodiment of the present invention will be described with reference to Figures 1 to 7. In the description of this embodiment, the object to be measured will be described as a vehicle. However, the object to be measured in the present invention is not limited to a vehicle, and may be anything that can be measured by a tracker mounted on an autonomous mobile robot and a measurement scanner mounted on an autonomous mobile robot.

[0020] In this embodiment, the automatic measurement system includes a freely movable autonomous mobile robot 10, a laser tracker 20 mounted and fixed on one of the autonomous mobile robots 10, a robot arm 30 mounted and fixed on the other autonomous mobile robot 10, a measurement scanner 40 fixed to the tip of the robot arm 30, a virtual map V that stores the stopping positions of the vehicle and the autonomous mobile robot 10, and a control unit 50 that controls the moving distance and moving angle of the measurement scanner 40, It has.

[0021] As shown in Figure 1, the autonomous mobile robot 10 has a roughly box-shaped robot body 11, running units 12, 12 respectively provided at the left and right lower ends of the robot body 11, a laser scanner 13 provided at approximately the center in the vertical direction of the front end of the robot body 11, a laser sensor 14 installed below the laser scanner 13, an autonomous mobile robot control unit 15 that controls the autonomous mobile robot 10 stored in the robot body 11, and a data memory unit 16 for storing control information and various data for the autonomous mobile robot 10.

[0022] The robot body 11 is formed in a generally box-like shape with an opening at the bottom, and has a front surface 11a, a rear surface 11b, left and right side surfaces 11c and 11d, and a top surface 11e. The front surface 11a of the robot body 11 is formed in a generally arc-like shape that bulges forward in a plan view, and has an opening 11f that is generally rectangular in a front view at the approximately center of the top and bottom. That is, the front surface 11a is divided into two parts, an upper front surface 11a1 and a lower front surface 11a2, by the opening 11f. An insertion hole is drilled in the approximately center of the lower front surface 11a2. Furthermore, a front bumper 17 is disposed in front of the lower front surface 11a2.

[0023] The front bumper 17 has approximately the same shape as the front lower part 11a2 when viewed from the front, and has a constant thickness in the front-to-rear direction. A support rod 17a protrudes rearward from approximately the center of the back of the front bumper 17. The support rod 17a is inserted into an insertion hole drilled in the front lower part 11a2, and its tip is connected to the robot main body 11. In other words, the front bumper 17 is supported by the robot main body 11 at a certain distance forward from the front lower part 11a2, and is configured to be able to move backward by the distance separated from the front lower part 11a2.

[0024] As a result, when the front bumper 17 comes into contact with an obstacle, the support rod 17a supporting the front bumper 17 is pushed into the insertion hole. The robot body 11 detects that the robot body 11 has come into contact with an obstacle and stops when the support rod 17a is pushed into the inside of the robot body 11. In this way, the front bumper 17 functions as an emergency stop device in case of contact with an obstacle. The robot body 11 has running parts 12, 12 on the left and right side surfaces 11c, 11d, respectively.

[0025] The travel unit 12 has left and right wheels 12a, 12b for moving the autonomous mobile robot 10, and left and right encoders for controlling the rotation amount of the left and right wheels 12a, 12b. The left and right wheels 12a, 12b are arranged at approximately the center lower part in the front-to-rear direction of the left and right side surfaces 11c, 11d of the robot body 11. The left and right wheels 12a, 12b are journaled to the robot body 11 so that approximately one-quarter of the wheels protrude downward from the lower edges of the left and right side surfaces 11c, 11d. The left and right wheels 12a, 12b are of a two-wheel independent mechanism type that can be controlled so that they can rotate independently, and each wheel is connected to a left and right encoder, respectively.

[0026] The left and right encoders are connected to an autonomous mobile robot control unit 15 mounted on the robot body 11 and function to ensure that the autonomous mobile robot 10 moves reliably to its destination. Specifically, the autonomous mobile robot 10 is configured so that the rotational amounts of the left and right wheels 12a, 12b can be controlled by the left and right encoders. Therefore, if the rotational amounts of the left and right wheels 12a, 12b are the same, the autonomous mobile robot 10 moves straight. If the rotational amount of one of the left and right wheels 12a, 12b is less than the rotational amount of the other wheel, the autonomous mobile robot 10 can change its direction of travel toward the wheel with the smaller rotational amount. This allows the autonomous mobile robot 10 to change its direction of travel without rotating the left and right wheels 12a, 12b left or right. The left and right encoders can be various types, such as optical or magnetic encoders. Any type of encoder can be used as long as it can independently control the rotational amounts of the left and right wheels 12a, 12b.

[0027] By configuring the left and right wheels 12a, 12b in this manner, when the autonomous mobile robot 10 is traveling autonomously, the left and right wheels 12a, 12b do not protrude from the left and right side surfaces 11c, 11d of the robot main body 11. In other words, the autonomous mobile robot 10 can reliably travel to its destination by reducing as much as possible the risk of the robot main body 11 coming into contact with an obstacle that is in a range that cannot be detected by the laser scanner 13 and laser sensor 14 described below.

[0028] Furthermore, the autonomous mobile robot 10 stores the rotation amount of each of the left and right wheels 12a, 12b in a data storage unit 16 housed in the robot body 11. The rotation amount information of the left and right wheels 12a, 12b stored in the data storage unit 16 is transmitted to a control unit 50 that manages a virtual map V while the autonomous mobile robot 10 is moving. This allows the control unit 50 to estimate the self-position of the autonomous mobile robot 10 on the virtual map V.

[0029] A laser scanner 13 is disposed in the opening 11f of the robot body 11, and a laser sensor 14 is disposed in the lower front surface 11a2.

[0030] The laser scanner 13 is an object detection sensor that has a scanner function for mapping the measurement space and detecting obstacles when the autonomous mobile robot 10 is traveling.

[0031] The laser scanner 13 emits laser light at a certain angle, and measures the distance from the autonomous mobile robot 10 to an object by measuring the time from when the laser light starts to be emitted until it is reflected by the object and returns to the laser scanner 13.

[0032] The laser scanner 13 stores distance measurement information using laser light in the data storage unit 16 and completes the mapping of the measurement space by synchronizing it with information on the amount of rotation of the left and right wheels 12a, 12b stored in the data storage unit 16. The mapped information of the measurement space is converted into a virtual map V by the control unit 50. In other words, the autonomous mobile robot 10 equipped with the laser scanner 13 can read obstacle information in the measurement space and easily map it on the virtual map V simply by traveling through the measurement space.

[0033] Below the laser scanner 13 configured in this manner, that is, at the front lower portion 11 a 2 of the front bumper 17 , a laser sensor 14 is disposed. The laser sensor 14 is an object detection sensor for obstacle avoidance that detects low-lying obstacles. While traveling, the autonomous mobile robot 10 can detect obstacles placed on the floor surface using the laser sensor 14 and automatically stop or avoid the obstacle and move to its destination. In other words, by detecting an obstacle on the floor surface using the laser sensor 14, the autonomous mobile robot 10 reduces the risk of either the left or right wheel 12a, 12b of the traveling unit 12 running over the obstacle, causing the robot to lose balance and fall, and can reliably travel to its destination.

[0034] The information on the measurement space acquired by the laser scanner 13 and laser sensor 14 described above is recorded in the data storage unit 16 of the autonomous mobile robot 10, and then transmitted to the control unit 50 in which the virtual map V is saved. This allows the autonomous mobile robot 10 to estimate where it is located on the virtual map V.

[0035] One of the autonomous mobile robots 10 configured in this manner is equipped with a laser tracker 20, and the other autonomous mobile robot 10 is equipped with a robot arm 30 and a measurement scanner 40 connected to the tip of the robot arm 30.

[0036] (About Laser Tracker 20) As shown in FIG. 2, the laser tracker 20 has a base 21 mounted and fixed to the top surface 11e of the autonomous mobile robot 10 with fasteners such as bolts, and a tracker 22 mounted and fixed to the upper end surface of the base 21.

[0037] The base 21 is a hollow box having a substantially rectangular horizontal cross section, and has front and rear side surfaces 21a and 21b, left and right side surfaces 21c and 21d, and upper and lower side surfaces 21e and 21f. The base 21 has a tracker 22 standing upright in the substantially center of the top surface 21e.

[0038] The tracker 22 has a left-right rotating part 23 that is erected on the upper surface 21e of the base 21 so as to be rotatable horizontally, a tracker housing 24 that is connected to the left-right rotating part 23, and a tracker main body 25 that is journaled on the tracker housing 24 so as to be rotatable vertically.

[0039] The horizontal cross section of the left-right rotating part 23 is circular. The left-right rotating part 23 is configured to be rotatable in the circumferential direction. A tracker housing 24 is disposed above the left-right rotating part 23.

[0040] When viewed from the front, the tracker housing 24 is formed in a roughly U-shape with an open top, and has a lower support portion 24d and left and right support portions 24a, 24b erected on the left and right ends of the lower support portion 24d.

[0041] The left and right support portions 24a, 24b are formed in a substantially semi-elliptical shape in a side view, which is obtained by cutting an elliptical shape with its major axis extending in the vertical direction horizontally at the substantially center between the top and bottom. Also, the left and right support portions 24a, 24b are formed in a substantially rectangular shape in a front view.

[0042] The lower support part 24d has a roughly rectangular parallelepiped shape and is connected at its approximate center to the left-right rotation part 23. The left-right rotation part 23 allows the tracker housing 24 to rotate left and right while maintaining a horizontal state. A rotation space 24e is formed in the approximate center of the tracker housing 24, surrounded on three sides by the upper surface of the left-right rotation part 23 and the left and right support parts 24a, 24b. The tracker main body 25 is disposed in the rotation space 24e.

[0043] The tracker main body 25 is formed in a generally elliptical shape with its major axis extending in the vertical direction when viewed from the side. The tracker main body 25 is supported by left and right support parts 24a, 24b via rotation shafts that protrude from the left and right sides of the tracker main body 25. This allows the tracker main body 25 to rotate freely up and down based on the rotation shafts.

[0044] The tracker main body 25 has a laser light emitting unit 25a at approximately the center in the up-down direction of the front end portion.

[0045] The laser light emitting unit 25a is a cylindrical body that protrudes forward from approximately the center in the vertical direction of the tracker main body 25, and has the functions of emitting laser light and capturing images. The laser light emitting unit 25a has a distance measurement function that can measure the distance to an object by measuring the time it takes for the emitted laser light to reflect off the object and return. Specifically, the tracker main body 25 can measure the distance to the measurement location by emitting laser light from the laser light emitting unit 25a to a reflector installed at the measurement location and receiving the light reflected by the reflector. The reflector installed at the measurement location is a corner cube reflector in which the angle of incidence and angle of reflection of the irradiated light are the same.

[0046] The laser light emitting unit 25a also has an angle measurement function that captures an image of a characteristic point of the measurement object and measures the stop angle of the object. The laser light emitting unit 25a captures an image of the measurement scanner 40 (described later) and can measure the attitude (stop angle) of the measurement scanner 40 from the relative positional relationship of the angle detection LEDs 46, 46... that are protruded from the measurement scanner 40.

[0047] In this way, the tracker main body 25 measures the distance from the tracker 22 to the measurement scanner 40 by having the laser light emitting unit 25a irradiate the reflector 45 of the measurement scanner 40 with laser light and receive the reflected light, and further, the laser light emitting unit 25a detects the light from multiple angle detection LEDs 46, 46... arranged on the surface of the measurement scanner 40, and can detect the attitude (stop angle) of the measurement scanner 40 from the relative positional relationship of each detected LED.

[0048] A pedestal 21 is placed and fixed on the top surface 11e of the other autonomous mobile robot 10. A robot arm 30 is placed and fixed on approximately the center of the top surface 21e of the pedestal 21.

[0049] (Regarding the robot arm 30) As shown in Fig. 3, the robot arm 30 is configured as a flexible robot arm (multi-joint robot) whose posture can be controlled to various positions and angles. By operating the robot arm 30, the measurement scanner 40 connected and fixed to the tip of the robot arm 30 moves three-dimensionally in any direction within its movable range. The robot arm 30 is, for example, a six-axis robot having six joints.

[0050] The robot arm 30 is connected to a robot control unit 31, which serves as a control unit for controlling the operation of the robot arm 30, and operates in response to control signals from the robot control unit 31. The robot control unit 31 is housed in the base 21, and causes the robot arm 30 to perform predetermined operations that have been taught in advance. The operation of the robot arm 30 allows the measurement scanner 40 to move along steps and gaps between components that make up the vehicle while its position and orientation (posture) are controlled.

[0051] (About Measurement Scanner 40) The measurement scanner 40 is configured as a high-precision 3D scanning device having two measurement LED irradiation units. The measurement scanner 40 simultaneously emits a linear LED light and a point-like LED light, focuses on the overlapping portion of the two LED lights, and measures the object within the range illuminated by the linear LED light. In other words, the measurement scanner 40 is configured so that when the linear LED light is irradiated within the irradiation range of the point-like LED light, position information relative to the measurement scanner 40 of the range illuminated by the linear LED light is measured.

[0052] As shown in Figure 4, the measurement scanner 40 has a measurement scanner housing 41, two measurement LED irradiation units 42, 43 provided on the front of the measurement scanner housing 41, a light receiving unit 44 arranged below the measurement LED irradiation units 42, 43, reflectors 45, 45, 45 protruding from the top and both side surfaces of the measurement scanner 40, and multiple angle detection LEDs 46, 46... provided on the left and right side surfaces and top surface of the measurement scanner 40.

[0053] The measurement scanner housing 41 is a box having a substantially rectangular shape in plan and side views. The measurement scanner housing 41 has two measurement LED irradiation units 42 and 43 arranged above and below on the front surface, and a light receiving unit 44 disposed below the measurement LED irradiation units 42 and 43.

[0054] The measurement LED irradiation unit 42 located on the upper side is configured to emit linear LED light extending in the left-right direction. The measurement LED irradiation unit 43 located on the lower side is configured to emit LED light in a substantially circular shape. After irradiating the measurement object, these LED lights are reflected toward the measurement scanner housing 41. This reflected light is received by the light receiving unit 44 provided on the front surface of the measurement scanner housing 41, allowing the position information of the measurement site to be measured.

[0055] Furthermore, measurement scanner housing 41 has approximately cylindrical reflectors 45, 45, 45 arranged on the top and both side surfaces. Reflector 45 is configured as a so-called corner cube reflector that reflects incident light in the direction of incidence. As a result, no matter what angle measurement scanner 40 is transformed, laser light irradiated from laser light irradiator 25a of tracker 22 is reflected toward tracker 22, allowing the distance from tracker 22 to measurement scanner 40 to be measured accurately.

[0056] The measurement scanner housing 41 also has angle detection LEDs 46, 46 protruding from the front and rear ends of the top surface, as well as angle detection LEDs 46, 46, 46 protruding from the upper and lower corners near the rear ends of both left and right sides and near the upper front end.

[0057] The angle detection LED 46 has a substantially hemispherical LED housing 46a with a substantially circular opening 46b at the top of the LED housing 46a. The LED housing 46a houses a weakly luminous LED. The LED housed in the LED housing 46a is radiated from the opening 46b to the outside of the LED housing 46a. This LED light is detected by the imaging unit 25b of the tracker 22 and acts to measure the angle at which the measurement scanner 40 is stopped. Specifically, the tracker 22 can detect the measurement posture of the measurement scanner 40 by using the imaging unit 25b of the tracker 22 to detect a total of five angle detection LEDs 46, 46, 46, 46: two angle detection LEDs 46, 46 at the front and rear of the top surface of the measurement scanner housing 41, and three angle detection LEDs 46, 46, 46, respectively, on the left and right sides of the measurement scanner housing 41.

[0058] In this way, with the use of multiple reflectors 45, 45 and multiple angle detection LEDs 46, 46, the trajectory of the measurement scanner 40 can be reliably tracked by the tracker 22 even when the measurement scanner 40 is moved along the measurement portion of the vehicle body, and gaps and steps between components that make up the vehicle can be accurately measured using the trajectory of the tracked measurement scanner 40 and the measurement data from the two measurement LED irradiation units 42, 43 of the measurement scanner 40. The various measured measurement data is transmitted to the control unit 50 in real time.

[0059] (Regarding the control unit 50) The control unit 50 is configured to be able to communicate with each of the components that make up the automatic measurement system as shown in Fig. 5, and is responsible for generating a virtual map V that maps the measurement space for measuring the vehicle, confirming and correcting the positions of each of the autonomous mobile robots 10, 10, laser tracker 20, robot arm 30, and measurement scanner 40, and performing comparison calculations between pre-stored official CAD information of the vehicle and the 3D information of the measured vehicle. Note that the measurement scanner 40 does not have a direct means of movement, so its position is corrected via the robot arm 30.

[0060] In this way, the automatic measurement system for gaps and steps between components that make up a vehicle corrects the positions of the tracker 22 and measurement scanner 40 relative to the actual vehicle by adjusting the position of the vehicle's normal CAD information set on the virtual map V to correspond to the stopping position of the actual vehicle being measured, and can automatically and accurately measure the position (gaps and steps between components) of a vehicle stopped at any position.

[0061] Furthermore, the tracker 22 and the measurement scanner 40, which have been moved to positions previously specified on the virtual map V, can be stopped accurately with respect to the actual vehicle by checking their relative positions after moving to positions previously set on the virtual map V. This allows for accurate automatic measurement of mounting gaps and steps between components that make up the vehicle.

[0062] <Measurement procedure> The procedure for measuring gaps and steps between members mounted on a vehicle using the automatic measurement system configured in this way will be described in detail with reference to FIGS. 6 and 7. FIG.

[0063] As shown in FIG. 6, the automatic measurement system of the present invention consists of four processes: a virtual map generation process S1 for generating a virtual map V; a position setting process S2 for setting movement positions of laser tracker 20 and measurement scanner 40 on the virtual map V generated in the virtual map generation process S1; a synchronization process S3 for aligning the vehicle stop position on the generated virtual map V with the stop position of the actual vehicle; and a measurement process S4 for measuring steps and gaps between the members attached to the vehicle body and the vehicle frame.

[0064] <Virtual map generation process S1> The virtual map generation process S1 includes a space measurement process S1-1 for sensing a measurement space for measuring the vehicle, and a map generation process S1-2 for inputting the trajectory traveled by the autonomous mobile robot 10 into the control unit 50 and mapping it.

[0065] The space measurement step S1-1 is a step of moving the autonomous mobile robot 10 in a measurement space for measuring steps and gaps between components that make up the vehicle, and acquiring and recording obstacle information in the measurement space.

[0066] While traveling, the autonomous traveling robot 10 acquires information about surrounding obstacles by emitting laser light from the laser scanner 13. The autonomous traveling robot 10 also records in the data storage unit 16 the amount of rotation of each of the left and right wheels 12 a, 12 b and information about surrounding obstacles corresponding to the amount of rotation of the left and right wheels 12 a, 12 b. When mapping the measurement space, the autonomous mobile robot 10 may travel in any manner to perform measurements, such as automatically, manually by connecting a controller, or semi-automatically by combining automatic and manual operations.

[0067] The information stored in the data storage unit 16 of the autonomous mobile robot 10 in the space measurement step S1-1 is transmitted to the control unit 50 of the automatic measurement system. The control unit 50 generates a virtual map V based on the information stored in the data storage unit 16 of the autonomous mobile robot 10 and obstacle information in the measurement space (map generation step S1-2).

[0068] The position setting step S2 is a step of determining the stopping positions of the tracker 22 and the measurement scanner 40 during vehicle measurement on the virtual map V of the measurement space generated in the map generation step S1-2.

[0069] The position setting process S2 includes a no-travel area setting process S2-1 that sets areas in which each autonomous mobile robot 10, 10 cannot travel on the virtual map V of the measurement space generated in the map generation process S1-2; a vehicle stopping position setting process S2-2 that sets the vehicle stopping position where gaps and steps between components are measured; a measurement scanner position setting process S2-3 that sets the stopping location of the autonomous mobile robot 10 equipped with the measurement scanner 40; and a tracker position setting process S2-4 that sets the stopping location of the autonomous mobile robot 10 equipped with the tracker 22.

[0070] In the no-travel area setting step S2-1, a no-travel area F in which the autonomous mobile robot 10 cannot travel is set on the virtual map V generated in the map generation step S1-2. The no-travel area F is set by the control unit 50 by painting the no-travel area on the monitor.

[0071] The no-travel area F is set, for example, as an obstacle when the autonomous mobile robot 10 travels or a wall surface of the measurement space, to minimize the risk of the autonomous mobile robot 10 coming into contact with an obstacle or a wall surface and becoming unable to move while automatically traveling. Furthermore, by setting the no-travel area F, when changing measurement positions, the autonomous mobile robot 10 can move to the next measurement location in the shortest possible time without following an unnecessary travel route.

[0072] The vehicle stop position setting process S2-2 is a process of setting a vehicle stop position R in a no-travel area F set on the virtual map V. The vehicle stop position R is preferably set at a position in the measurement space where the autonomous mobile robot 10 can move freely around the vehicle, and is preferably set, for example, at approximately the center of the measurement space. The vehicle stop position R is set by a stop space R1 set to be approximately rectangular in plan view to accommodate the vehicle, and a wheel stop position R2 indicating the wheel stop position set within the stop space R1. The wheel stop position R2 is displayed as an approximately triangular shape in plan view, and is set so that the wheel stops at approximately the center in the fore-and-aft direction at the vertex of the triangle.

[0073] The measurement scanner position setting process S2-3 is a process of setting a measurement position (scan position) of the autonomous mobile robot 10 equipped with the measurement scanner 40 around the vehicle stopping position R set on the virtual map V. The measurement scanner position setting process S2-3 is a process of setting an optimal position for measuring gaps and steps between components when a vehicle having correct CAD information (vehicle of ideal configuration) is stopped at the vehicle stopping position set in the vehicle stopping position setting process S2-2.

[0074] A total of eight measurement positions are set: three measurement positions P1, P2, and P3 on the front side of the actual vehicle, two measurement positions P4 and P5 on the left side of the actual vehicle, one measurement position P6 on the rear side of the actual vehicle, and two measurement positions P7 and P8 on the right side of the actual vehicle. Note that in this embodiment, the autonomous mobile robot 10 equipped with the measurement scanner 40 has eight stopping positions, but the stopping positions of the autonomous mobile robot 10 are not limited to this, and any number of stopping positions may be set as long as all gaps and steps between members assembled to the vehicle can be accurately measured.

[0075] The tracker position setting process S2-4 is a process of setting the stop position of the autonomous mobile robot 10 equipped with the tracker 22 to match the vehicle stop position R set on the virtual map V. In the tracker position setting process S2-4, the stop position of the tracker 22 is set so that the tracker 22 and the measurement scanner 40 can measure each other's positions when the autonomous mobile robot 10 stops at each measurement position set in the measurement scanner position setting process S2-3. In other words, the stop position of the autonomous mobile robot 10 equipped with the tracker 22 is set at a position where the laser light emitted from the laser light irradiation unit 25a of the tracker 22 is not blocked by the vehicle body stopped at the stop position set in the vehicle stop position setting process S2-2. This allows the measurement scanner 40 and the tracker 22 to confirm each other's positions.

[0076] The tracker positions set in the tracker position setting step S2-4 are a total of three positions: a first position T1 located directly in front of the stopped vehicle in the direction of travel; a second position T2 located to the left and rear of the stopped vehicle; and a third position T3 located to the right and rear of the stopped vehicle. In this embodiment, the autonomously traveling robot 10 equipped with the tracker 22 is set to three stop positions. However, the number of stop positions of the autonomously traveling robot 10 is not limited to three. Any number of tracker positions may be set as long as the measurement scanner 40 and the tracker 22 can confirm each other's positions without being obstructed by the vehicle body. However, because the tracker positions are reference points when the measurement scanner 40 moves, increasing the number of stop positions for the tracker positions increases the likelihood of errors in the measurement results. Therefore, it is desirable to set as few tracker positions as possible.

[0077] The position confirmation step S2-5 is a step of checking the current positions of the autonomous mobile robot 10 equipped with the tracker 22 and the autonomous mobile robot 10 equipped with the measurement scanner 40 against the virtual map V.

[0078] The position confirmation process S2-5 is a process of comparing information about surrounding obstacles measured by the laser scanner 13 of each autonomous mobile robot 10, 10 with information about obstacles illustrated on the virtual map V to determine the current positions (waiting positions Tw, Pw) of the autonomous mobile robots 10, 10. The waiting positions Tw, Pw are recorded in the control unit 50.

[0079] The actual vehicle stopping step S2-6 is a step of stopping the actual vehicle at the vehicle stopping position R set on the virtual map V. In the actual vehicle stopping step S2-6, a stop line that fits the vehicle's longitudinal and lateral dimensions is affixed to the floor of the measurement space. This stop line is a roughly rectangular part in a plan view, and is marked on the floor with tape or the like. Note that it is sufficient that the actual vehicle's overall length and width fit within the stop line in a plan view.

[0080] The synchronization step S3 is a step of aligning the position of the actual vehicle stopped within the stop line in the measurement space with the position of the regular stopped vehicle set on the virtual map V.

[0081] In the synchronization step S3, first, the autonomous mobile robot 10 equipped with the tracker 22 is moved from a waiting position Tw set on the virtual map V to a first position T1.

[0082] Next, the worker opens the hood of the actual vehicle parked at vehicle parking position R in the measurement space and installs corner cube reflectors at each measurement point in the engine compartment.

[0083] The operator measures the three-dimensional coordinates of each reflector and its angle relative to tracker 22 by irradiating the corner cube reflector with laser light from laser light irradiator 25a of tracker 22. The measured three-dimensional coordinates and angle information of each reflector are recorded in control unit 50.

[0084] The control unit 50 compares the measured three-dimensional coordinates of each reflector with the three-dimensional coordinates of each reflector of the genuine vehicle set in advance on the virtual map V, and calculates the amount of deviation. The control unit 50 corrects the virtual map V and the position of the genuine vehicle set on the virtual map V by the calculated amount of deviation. As a result, the stopping position and stopping pattern of the actual vehicle match the stopping position of the genuine vehicle set on the virtual map V.

[0085] In the synchronization step S3, to ensure that the vehicle stopping positions of the actual vehicle and virtual map V are aligned, the holes of the actual vehicle other than the mounting locations of the corner cube reflectors are covered with covers. The control program of the control unit 50 may be configured to issue an error message indicating a measurement error if the measured three-dimensional coordinates of each reflector significantly deviate from the three-dimensional coordinates set on virtual map V.

[0086] In this way, by accurately measuring the three-dimensional coordinates of the corner cube reflector and configuring the system so that the actual vehicle and the vehicle stopping position on virtual map V are reliably aligned, it is possible to accurately measure gaps and steps between the components that make up the vehicle. Furthermore, this configuration can minimize the risk of autonomous mobile robot 10 coming into contact with the vehicle while autonomous mobile robot 10 is traveling, and the risk of measurement scanner 40 coming into contact with the vehicle body when measuring the vehicle.

[0087] The measurement step S4 is a step of moving the measurement scanner 40 and the tracker 22 to the measurement position P and the tracker position T set in the position setting step S2, and measuring gaps and steps between members assembled to the vehicle.

[0088] The measurement process S4 includes a first measurement process 4-1 for measuring the front of the vehicle, a second measurement process 4-3 for measuring the left side of the vehicle, a third measurement process 4-5 for measuring the right side of the vehicle, a first changeover process 4-2 for moving the tracker 22 between the first measurement process 4-1 and the second measurement process 4-3, and a second changeover process 4-4 for moving the tracker 22 between the second measurement process 4-3 and the third measurement process 4-5.

[0089] In the first measurement step 4-1, the autonomous mobile robot 10 equipped with the measurement scanner 40 is first moved from the waiting position Pw to the measurement position P1. At this time, the autonomous mobile robot 10 determines its own travel distance based on the rotation timing and amount of rotation of the left and right wheels 12a, 12b.

[0090] The measurement scanner 40, which has moved to the measurement position P1, stops the reflectors 45, 45 provided on both sides of the measurement scanner 40 at preset regular position information P1A (three-dimensional coordinates) in a vehicle coordinate system based on the regular vehicle set on the virtual map V. At this time, the measurement scanner 40 stops in a preset form so that the tracker 22 stopped at the first position T1 can measure the three-dimensional coordinates of one of the reflectors 45, 45 protruding from the left and right sides.

[0091] The tracker 22 irradiates the reflector 45 of the measurement scanner 40 with laser light from the laser light irradiation unit 25a in a tracker coordinate system based on the tracker 22, and acquires position information P1a of the measurement scanner 40. The position information P1a of the measurement scanner 40 is transmitted from the tracker 22 to the control unit 50.

[0092] The control unit 50 converts the position information P1a measured by the measurement scanner 40 into position information P1c in a vehicle coordinate system based on the vehicle.

[0093] The control unit 50 compares the position information P1c in the vehicle coordinate system with the normal position information P1A of the measurement scanner 40 that is set in advance, and calculates the amount of deviation P1d of the position information.

[0094] The control unit 50 transmits the calculated deviation amount P1d of the position information to the measurement scanner 40 via the tracker 22.

[0095] The measurement scanner 40 moves the autonomous mobile robot 10 in accordance with the amount of deviation P1d.

[0096] The movement of the autonomous mobile robot 10 equipped with the above-described measurement scanner 40 is adjusted by repeatedly moving the autonomous mobile robot 10 until each coordinate (three-dimensional coordinate) of the deviation amount P1d falls within the range of ±15 mm.

[0097] Then, the tracker 22 measures the position information P1e of the measurement scanner 40 in the tracker coordinate system.

[0098] The tracker 22 transmits the position information P1e of the measurement scanner 40 to the control unit 50. The control unit 50 converts the position information P1e measured in the tracker coordinate system into position information P1f in the vehicle coordinate system.

[0099] The control unit 50 compares the position information P1f of the measurement scanner 40 converted into the vehicle coordinate system with the regular position information P1A to calculate the difference P1g. The control unit 50 converts the calculated difference P1g from the vehicle coordinate system to the difference P1h in the robot coordinate system.

[0100] The difference P1h converted into the robot coordinate system is converted into a bit signal and transmitted to the robot control unit 31. The robot control unit 31 converts the received bit signal back into difference information P1j.

[0101] The robot arm 30 moves by the amount of the difference information P1j, thereby allowing the measurement scanner 40 to stop at the measurement start position that is approximately ±0 mm from the normal stop position.

[0102] In other words, the measurement scanner 40 can accurately measure gaps and steps between the components that make up the vehicle by performing position correction by the autonomous mobile robot 10 to keep the deviation from the above-mentioned measurement position P1 to ±15 mm or less, and by performing position correction by the robot arm 30 to keep the deviation from the measurement start position to approximately ±0 mm.

[0103] When the tracker 22 confirms again that the measurement scanner 40 is stopped at the measurement start position, the measurement scanner 40 starts measuring the gaps and steps between the components that make up the vehicle.

[0104] At measurement position P1, measurement scanner 40 moves along a pre-taught trajectory with the measurement start position as the base point. Measurement scanner 40 measures using LED light emitted from measurement LED irradiation units 42 and 43 provided on the front of measurement scanner 40. When measurement scanner 40 moves to the end point of the pre-taught trajectory, it notifies control unit 50 that measurement has ended.

[0105] When the control unit 50 receives a signal at measurement position P1 that the measurement scanner 40 has moved to the end point, it transmits a signal to the measurement scanner 40 to move the measurement scanner 40 to measurement position P2. This movement signal from measurement position P1 to measurement position P2 is also transmitted to the tracker 22, which confirms the position of the measurement scanner 40.

[0106] The measurement scanner 40, which has moved to measurement position P2, is repeatedly corrected by the autonomous mobile robot 10 until the deviation from the normal position at measurement position P2 is within ±15 mm, just as with measurement position P1. The measurement scanner 40 then undergoes position correction by the robot arm 30 so that the deviation from the measurement start position is approximately ±0 mm. Once the tracker 22 confirms that the measurement scanner 40 is positioned at the measurement start position, the measurement scanner 40 begins measuring the gaps and steps between the components that make up the vehicle. Similarly to measurement position P1, the measurement scanner 40 performs measurements along a pre-taught trajectory at measurement position P2. Once the measurement scanner 40 has completed moving along the pre-taught trajectory, it notifies the control unit 50 that the measurement has ended.

[0107] Once measurement of the vehicle's steps and gaps at measurement position P2 is complete, measurement scanner 40 moves to measurement position P3. At measurement position P3, as with measurement position P2, measurement scanner 40 is corrected to its correct measurement start position, and measurement scanner 40 is moved along a pre-taught trajectory to measure the vehicle's steps and gaps. Note that the position correction of measurement scanner 40 is the same as the correction method at measurement position P1, so a description thereof will be omitted.

[0108] When the measurement scanner 40 completes the measurement at the measurement position P3, the reflector 45 of the measurement scanner 40 is moved by the robot arm 30 to a predetermined three-dimensional coordinate position.

[0109] After the measurement scanner 40 has been moved to a predetermined position, the tracker 22 measures the three-dimensional coordinates of the reflector 45. The measured three-dimensional coordinates of the reflector 45 are transmitted to the control unit 50.

[0110] The autonomous mobile robot 10 equipped with the tracker 22 is moved from the first position T1 to the second position T2 (first changeover step 4-2).

[0111] The first changeover step 4-2 is a step of moving the tracker 22 to the second position T2 set in the tracker position setting step 2-4.

[0112] The tracker 22, which has moved to the second position T2, measures the three-dimensional coordinates of the reflector 45 of the measurement scanner 40, which has stopped at a predetermined standby position, at the measurement position P3, and transmits and stores the coordinates to the control unit 50 as position information.

[0113] The control unit 50 compares the three-dimensional coordinates of the reflector 45 before and after the movement of the tracker 22 and measures the difference.

[0114] If there is a difference between the three-dimensional coordinates of reflector 45 before and after movement, tracker 22 corrects the position by moving autonomous mobile robot 10 according to the difference. After correcting the position, tracker 22 measures the three-dimensional coordinates of reflector 45 again.

[0115] The first changeover step S4-2 ends when the three-dimensional coordinates of the reflector 45 match before and after the movement of the tracker 22. After the first changeover step S4-2 ends, the automatic measurement system proceeds to the second measurement step S4-3, which measures the left side of the vehicle.

[0116] The second measurement step S4-3 is a step of measuring steps and gaps on the left side and rear of the vehicle.

[0117] In the second measurement step S4-3, first, the autonomous mobile robot 10 equipped with the measurement scanner 40 is moved from the measurement position P3 to the measurement position P4. The measurement scanner 40, which has moved to the measurement position P4, moves the robot arm 30 to move the reflector 45 of the measurement scanner 40 to a specified three-dimensional coordinate.

[0118] The tracker 22 measures the three-dimensional coordinates of the reflector 45 of the measurement scanner 40 in the same way as for measurement position P1, compares the measured three-dimensional coordinates with the correct three-dimensional coordinates, and corrects the position of the measurement scanner 40 using the autonomous mobile robot 10 until the difference between the coordinates is within ±15 mm. Note that the detailed correction method is the same as the correction method described for measurement position P1, so a detailed explanation will be omitted.

[0119] After moving to measurement position P4, the measurement scanner 40 moves the robot arm 30 so that the reflector 45 is positioned at the initial measurement position at measurement position P4. The position correction of the measurement scanner 40 to the initial measurement position is the same as the correction method for measurement position P1, so a description thereof will be omitted. When measurement at measurement position P4 is completed, the measurement scanner 40 notifies the control unit 50 that the measurement has been completed. The control unit 50 transmits a command to move the measurement scanner 40 to measurement position P5.

[0120] The measurement scanner 40 moves from measurement position P4 to measurement position P5. The position correction of the measurement scanner 40 to the measurement initial position and the measurement procedure are the same as the procedures described for measurement position P1, so detailed description will be omitted.

[0121] Once measurement by the measurement scanner 40 in the second measurement step S4-3 is completed, the tracker 22 is moved from the second position T2 to the third position T3 in the second changeover step S4-4. Note that the second changeover step S4-4 is carried out by having the tracker 22 measure the position information of the reflector 45 of the measurement scanner 40 before and after the movement of the tracker 22, just like the first changeover step S4-2. Details are the same as those of the first changeover step S4-2, so a description thereof will be omitted. Once the movement of the tracker 22 to the third position T3 is completed in the second changeover step S4-4, the process proceeds to the third measurement step S4-5.

[0122] The third measurement step S4-5 is a step of moving the measurement scanner 40 to measurement positions P7 and P8 using the tracker 22 stopped at the third position T3 as a reference, and measuring the steps and gaps on the right side of the vehicle.

[0123] The alignment of the measurement scanner 40 when it moves to measurement position P7 and measurement position P8, and the method of measuring steps and gaps using the measurement scanner 40, are the same as the alignment and measurement method of the measurement scanner 40 at measurement position P1, so detailed explanations will be omitted.

[0124] When the measurement by the measurement scanner 40 in the third measurement step S4-5 is completed, the robot arm 30 is transformed to stop the measurement scanner 40 at a position away from the vehicle.

[0125] Thereafter, the vehicle for which the measurement has been completed is moved, and the measurement of the steps and gaps for that vehicle is completed.

[0126] As described above, measurements are taken of the front of the vehicle in the first measurement process S4-1, the tracker 22 that serves as the position reference is moved from the first position T1 to the second position T2 in the first changeover process S4-2, measurements are taken of the left side and rear of the vehicle using the tracker 22 that has moved to the second position T2 as a reference in the second measurement process S4-3, the tracker 22 that serves as the position reference is moved from the second position T2 to the third position T3 in the second changeover process S4-4, and measurements are taken of the right side of the vehicle using the tracker 22 that has moved to the third position T3 in the third measurement process S4-5, thereby making it possible to accurately measure the steps and gaps between the vehicle and the components that make up the vehicle.

[0127] That is, in the present invention, by understanding the mutual positional relationship between the tracker 22, which serves as the positional reference for the measurement scanner 40, and the measurement scanner 40, the tracker 22 and the measurement scanner 40 can be positioned at a preset three-dimensional coordinate position, and measurements by the measurement scanner 40 can be performed automatically and accurately.

[0128] It should be noted that the present invention is not limited to the above-described embodiments, but also includes configurations in which the components disclosed in the above-described embodiments are mutually substituted or modified, known inventions, and configurations in which the components disclosed in the above-described embodiments are mutually substituted, etc. Furthermore, the technical scope of the present invention is not limited to the above-described embodiments, but extends to the matters set forth in the claims and their equivalents. [Explanation of symbols]

[0129] 10 Autonomous Robot 11 Robot body 12 Running part 13. Laser scanner 14 Laser Sensor 15 Autonomous driving robot control unit 16 Data storage unit 17 Front bumper 20 Laser Tracker 21 Pedestal 22 Tracker 23 Left and right rotating part 24 Tracker housing 25 Tracker body 30 Robot Arm 31 Robot control unit 40 Measurement Scanner 41 Measurement scanner housing 42, 43 Measurement LED irradiation unit 44 Light receiving part 45 Reflector 46 Angle detection LED 50 control section F No driving area M Measurement Space P Measurement position R Parking position T Tracker Position V Virtual Map

Claims

[Claim 1] An automatic measurement system that automatically measures gaps and steps in an object, comprising: an autonomous mobile robot capable of moving around the outer periphery of the object to be measured; a tracker mounted on one of the autonomous mobile robots; A measurement scanner mounted on the other autonomous mobile robot; a control unit for generating a virtual map; Equipped with The control unit setting, on the virtual map, the stop position of the object to be measured, three-dimensional coordinates of measurement points provided in the engine room, and the stop positions of the tracker and the measurement scanner; comparing the stopping positions of the tracker and the measurement scanner in the measurement space with the virtual map; The three-dimensional coordinates of the measurement point of the object to be measured are compared with the three-dimensional coordinates of the measurement point in the measurement space, and the deviation is corrected by moving the virtual map based on the three-dimensional coordinates of the object to be measured in the measurement space; and locating a tracker in the measurement space within the virtual map; After moving the measurement scanner in the measurement space to the stop position, the tracker irradiates the measurement scanner with a laser beam to confirm its position; If the position of the measurement scanner deviates from the virtual stop position, The autonomous traveling robot performs position correction until the amount of deviation from the stop position falls within a predetermined range. An automatic measurement system for measuring objects, characterized in that the measurement scanner is correctly positioned at the position of the gaps and steps between the components of the object to be measured, so that the gaps and steps between the components of the object to be measured can be automatically measured.

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