JP2006334731A - Product transport carriage, robot position measuring system and its measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve workability and safety while measuring a working point of a robot on a production line with high precision. <P>SOLUTION: A product transport means 10 to transport a working object product placed thereon on a transport rail is stopped at a specified position. A working part 15 of the robot 12 for product manufacturing is moved to a design designating position 9 of the working object product as a target and a position of the working part 15 of the robot 12 is measured by a measuring means 11 fixed and set on the product transport means 10. Thereafter, an error between the position of the working part 15 of the robot 12 and the design designating position (designated point 9) is computed and correction instruction is made to the robot 12 so that the position of the working part 15 of the robot 12 matches with the design designating position in accordance with the error. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a product transport cart, a robot position measurement system, and a measurement method thereof, for example, a product transport cart in a production line such as an automobile production factory, and a robot working unit that operates on a product transported by the product transport cart. BACKGROUND OF THE INVENTION 1. Field of the Invention

  Currently, industrial robots that are used in large numbers in production lines such as automobile production plants pick up or hold work target products or parts necessary for work, etc., by a work unit called a hand provided at the tip of the robot. And hold various operations such as cutting, screw tightening and welding. The hand can be moved three-dimensionally by the arm. Further, each time the work target product is transferred to a predetermined area called a robot installation area or a robot work area, the arm moves to a plurality of predetermined design designated positions (also referred to as “teaching positions”) in the work space. The hand is driven to move sequentially. Thus, various predetermined operations are performed on the work target products that are sequentially transported on the transport carriage.

  The design designated position to be the movement target of the robot hand is accurately analyzed and simulated using a computer. Then, after being converted into data through these processes, the work is executed according to a predetermined program using the data. However, depending on the environment in which the robot is installed, there may be a deviation between a position where the robot actually works (hereinafter also referred to as a work position) and the design designated position.

  For example, when the rigidity of the robot arm or the like is reduced due to weight reduction accompanying the increase in the speed of the robot, or when a heavy object such as a welding gun with an eccentric center of gravity is attached to a part of the robot The preconditions may not match the actual situation. Furthermore, in general, design specified positions are calculated from the drive data of servo motors etc. that are inherent to control the drive of the robot. However, the robot is accurately installed at a predetermined position, and the transport carriage is accurately It is premised that the vehicle stops accurately at a specified position on the conveyance rail laid on the rail. However, the transport carriage does not always stop at the specified stop position, and there may be a difference between the design designated position and the position where the robot actually works. In addition to this, another factor that causes the deviation may be a reason such as an error due to the inclination or twist of the transport rail.

  Therefore, in order to move the robot to the design designated position of the work target product and perform the work accurately, the deviation amount between the design designated position and the robot work position is calculated, and the robot hand is correctly placed at the design designated position. In order to move, it is necessary to perform correction according to the amount of deviation.

  As one of the methods to measure whether the robot hand accurately moves to the design designated position, prepare a product of the same shape as the product to be worked on, put a marking on the design designated position, etc. There is a method of manually measuring an error between the marking position and the robot work position.

  An example of the manual measurement will be described with reference to FIGS. 10A and 10B. First, as shown in FIG. 10A, the vehicle 102 to be worked is placed on the transport carriage 101, transported on a transport rail (not shown), and stopped at a predetermined stop position. The robot 103 freely drives the arm 104 and moves the hand 105 at the tip of the arm 104 to the design designated position 106 that has been inscribed on the vehicle 102 in advance. The robot 103 determines the position of the hand 105 using the vehicle origin 107 set on the coordinate system of the transport carriage 101 as a reference when moving.

  FIG. 10B is an enlarged view of a main part surrounded by a broken line in FIG. 10A. The distance L and the positional relationship between the design designation position 106 that has been marked and the work point 105a of the robot are measured. Then, based on the measurement result, an error between the design designation position 106 and the position of the robot is calculated, and the error is corrected. Whether or not the hand 105 has accurately stopped at the design designated position 106 can be determined from the error amount.

  Next, a method using a measuring device that performs three-dimensional coordinate measurement will be described as another method of the manual measurement method described above. An example of a robot position measurement system using a measuring device is shown in FIG. In this system, a measuring instrument 110 including, for example, a laser measuring instrument is installed outside the production line. Then, the base 113 of the robot 112 is fixed at a predetermined position on the floor, and the robot 112 is installed. The robot 112 includes an arm 114, and a marker 120a for three-dimensional measurement is installed on the hand 115 at the tip of the arm. The measuring device 110 emits a laser beam from the laser input / output point 111 and analyzes the laser beam reflected by the marker provided on the robot 112. The marker 120a is three-dimensionally measured, and the work point coordinates of the robot 112 with the vehicle origin 116 as the coordinate origin are acquired.

  FIG. 12 is a diagram showing a coordinate system in the system shown in FIG. As shown in FIG. 12, the work space of the robot 112 includes a measurement device coordinate system to which the measurement device 110 belongs, a vehicle coordinate system having the vehicle origin 116 as a coordinate origin, and a robot work start that is a reference when the robot starts work. The robot coordinate system is divided into the origin 119 as the coordinate origin. The work point 120 representing the position of the hand 115 at the tip of the robot belongs to the measuring device coordinate system, and is controlled by the robot coordinate system when moving and correcting. A designated point 121 representing a design designated position where the robot 112 should work belongs to the vehicle coordinate system.

  In the case of a system in which the measuring device 110 is installed outside the production line, three-dimensional measurement is performed on the vehicle coordinate system (product design coordinate system) including the robot coordinate system, the robot work point 120, and the stop reference point of the transport carriage 101. The difference between the robot work point 120 and the designated point 121 can be calculated, and the necessary correction amount of the hand 115 can be calculated in the robot coordinate system.

For example, if the coordinates of the work point 120 are (Rx, Ry, Rz), the coordinates of the designated point 121 are (Px, Py, Pz), and the offset amount between the work point 120 and the designated point 121 is Δ,
The coordinates (Px, Py, Pz) of the designated point 121 are expressed by the following equations.

ただし、θ：作業点１２０を基準とした指定点１２１の仰角
φ：作業点１２０を基準とした指定点１２１の方向角

Where θ is the elevation angle of the designated point 121 with respect to the work point 120
φ: Direction angle of the designated point 121 with respect to the work point 120

On the other hand, Patent Document 1 describes an online three-dimensional measurement system in which a three-dimensional measurement device capable of measuring the shape of a three-dimensional object to be measured is incorporated in an automobile body assembly process.
JP 2003-315023 A

  By the way, in the above-described manual measurement method, it is necessary to actually measure the design designation position 106 and the position of the work point 105a of the hand 105 that are injured by the vehicle to determine whether or not the robot has stopped at the teaching position. However, due to manual work, there is a problem in the reliability of the three-dimensional measurement for measuring the positions of the design designated position 106 and the work point 105a. In addition, preparation work such as preparing products with markings is cumbersome, and many work points are measured manually, and corrections are made based on the results. There was a problem of becoming longer. Furthermore, the correction by the control operation on the robot side based on the measurement result often depends on the operator's intuition, and there is a problem that the robot coordinate system and the vehicle coordinate system do not exactly match. Furthermore, there is a problem that it is complicated because it is necessary to perform measurement for each product and each robot, for example, measurement is performed again when the vehicle type is changed.

  In addition, since the measurement method by manual work is performed while the worker approaches the work target product or the robot, it is necessary to sufficiently consider the arm 104 or the hand 105 of the robot not to hit the worker.

  On the other hand, in the measurement method using the measurement device, it is necessary to measure many measurement points. That is, three or more measurement points are required to determine one coordinate system, but there are three coordinate systems, a vehicle coordinate system, a robot coordinate system, and a measurement device coordinate system, and there are as many measurement points as the number of coordinate systems. Increases and the amount of calculation processing also increases. In addition, there is a problem that preparation for accurately installing the measuring device at a predetermined position outside the production line takes time, and the operation stop time of the production line becomes long.

  Further, when the measuring device is provided outside the production line, there is a problem that the correction calculation after measuring each measurement point is complicated. For example, there are error factors in each of the vehicle coordinate system, the robot coordinate system, and the like, and after the work point is measured, correction calculation must be performed in consideration of each error factor. Further, although the work point 120 is in the measuring device coordinate system, the control is performed in the robot coordinate system, while the designated point 121 belongs to the vehicle body coordinates, so that the conversion process between these coordinate systems is complicated.

  Further, in a narrow and congested space where many robots are operated, it is difficult to secure a line of sight from the measuring device to the work point due to the overlapping of the robots or the movement of the robots themselves. Furthermore, in recent years, the life cycle of products has been shortened, and it is necessary to change the installation position of measuring instruments in accordance with new products each time. For this reason, there is a problem that it is difficult to quickly respond to multi-variety production and change of production line in the same production line.

  The present invention has been made in view of the above points, and has as its object to solve the above-mentioned problems, measure the work point of a robot in a production line with high accuracy, and improve workability and safety. And

  The present invention is characterized in that a measuring means for measuring the position of the working part of the robot is fixedly installed at a predetermined portion of the product transporting carriage that transports the work target product of the product manufacturing robot.

  According to the configuration described above, since the measuring unit moves integrally with the work target product, the measuring unit coordinate system to which the measuring unit belongs and the product design coordinate system to which the product and the product transport carriage belong are unified into one coordinate system. Can do.

  Further, the present invention moves the working part of the robot for product manufacture with the target of the design designation position of the work target product transported by the product transport cart described above, and the measuring means fixedly installed on the product transport cart. Measure the position of the working part of the robot, calculate the error between the measured position of the working part of the robot and the design designated position, and work the robot so that it matches the design designated position based on the error The position of the part is corrected.

  According to the configuration described above, the measuring means and the product transport carriage are moved together, and the measuring means coordinate system to which the measuring means belongs and the product design coordinate system to which the product and the product transport carriage belong are processed as one coordinate system. I have to. As a result, it is possible to perform measurement in an environment close to actual work and in a state where the deflection and error of each part are absorbed. Further, since the measurement unit coordinate system and the product design coordinate system can be processed as one coordinate system, the correction calculation after measuring the position of the working unit of the robot is simplified.

  According to the present invention, the measuring means and the product transport carriage are moved together, and the measuring means coordinate system to which the measuring means belongs and the product design coordinate system to which the product and the product transport carriage belong are processed as one coordinate system. As a result, since the position of the working part of the robot is measured in an environment close to the actual work and in a state where the deflection and error of each part are absorbed, a highly accurate measurement result can be obtained. In addition, since the measurement unit coordinate system and the product design coordinate system can be processed as one coordinate system, correction calculation after measuring the position of the robot working unit is simplified, so that the calculation time can be shortened. .

  In addition, there are few preparations for measurement, such as preparing products with markings, and there is no need to change the installation location of the measurement means due to changes in the production line or work target product. Can be minimized. Thus, there is an effect that the efficiency of the measurement work can be improved.

  In addition, since the worker does not enter the movable range of the robot arm during measurement, the safety is improved.

Hereinafter, an example of an embodiment of the present invention will be described with reference to FIGS.
First, the configuration of the robot position measurement system will be described. In this example, a robot position measurement system that accurately measures and corrects the position of the working part of a product manufacturing robot (hereinafter simply referred to as “robot”) is applied to an automobile production line. In addition, the present invention is not limited to this example, as long as it is a production line using a robot that performs a predetermined work based on product design for a product to be worked that is transported by a transport cart. can do.

  FIG. 1 is a diagram showing the concept of the robot position measurement system of this example. As shown in FIG. 1, the work space of the robot is set with respect to a measuring instrument coordinate system to which a measuring instrument (measuring means) that three-dimensionally measures the position of the robot and a vehicle that moves together with the transport carriage. There are a vehicle coordinate system including 2 as a coordinate origin and a robot coordinate system including a robot work start origin 5 which is a reference when the robot moves. The vehicle coordinate system is a coordinate system serving as a reference when designing a product, and is also referred to as a product design coordinate system. The work point 8 represents a position where the robot moves to the design designated position as a target and actually performs the work, and belongs to the measurement equipment coordinate system. The designated point 9 represents the design designated position where the robot should work, and belongs to the vehicle coordinate system.

  The x-axis default point 3 and the y-axis default point 4 are located at a distance from the vehicle origin 2 by a distance in the x direction or the y direction, and are arbitrarily set in advance to determine the xy plane of the vehicle coordinate system. Coordinates. For example, the coordinate of the x-axis default point 3 is (1, 0, 0), the coordinate of the y-axis default point 4 is (0, 1, 0), etc., and is matched with the coordinate (0, 0, 0) of the vehicle origin 2 The xy plane is determined by the three points. Similarly, the xy plane of the robot coordinate system is determined by the three points of the x-axis predetermined point 6, the y-axis predetermined point 7, and the robot work start origin point 5.

  In the present invention, the measuring device coordinate system and the vehicle coordinate system (product design coordinate system) are configured by mounting the measuring device on the transport carriage and allowing the measuring device to move integrally with the vehicle to be operated. Can be processed as one coordinate system, the coordinates of the work point and the designated point can be measured as coordinates in the vehicle coordinate system. When correcting the work point of the robot, the correction value is converted from the vehicle coordinate system to the robot coordinate system and controlled by the robot coordinate system.

  FIG. 2 is a schematic diagram showing an example in which the concept of the robot position measurement system shown in FIG. 1 is embodied. As shown in FIG. 2, in this example, one measuring device 11 is fixedly installed on a carriage 10 that maintains rigidity so as to convey a vehicle (not shown) in each process, and the measuring device 11 is connected to a vehicle coordinate system (product). Install in the design coordinate system. That is, the measurement instrument coordinate system and the vehicle coordinate system (product design coordinate system) are matched. At this time, regarding the installation of the measuring device 11, it is essential to install the measuring device 11 at a predetermined position on the transport carriage and to ensure consistency with the vehicle coordinate system. In other words, the x, y, and z axes of the measurement device coordinate system by the measurement device 11 are installed so as to be parallel to the respective axes of the vehicle coordinate system.

  Further, the base 13 is fixed at a predetermined position on the floor surface on which a transport rail (not shown) is laid, and the robot 12 is installed thereon. Of course, each vehicle is mounted and transported at a position determined in the product design of each transport carriage.

  The robot 12 includes an arm 14 having one end fixed to the base 13, and a measurement marker 8 a is provided on the hand 15 at the tip of the arm. The marker is like a mark for measuring the working point of the robot, and a spherical object made of a material that reflects laser light is employed. Furthermore, the present system includes an information processing apparatus (control means) that is connected to the measuring device 11 and the robot 12 by wireless or the like and is configured by a computer (not shown) that controls the entire system. The information processing apparatus includes a nonvolatile memory in which a program for realizing the system and a database in which designated points in each process are registered are stored.

  First, the robot 12 is moved to the robot work start origin 5, the x-axis default point 6, and the y-axis default point 7. At this time, the measuring device 11 three-dimensionally measures the marker 8a of the hand 15 when moving to the three points from the transport carriage 10 to obtain the robot coordinate system. Further, the work point 8 at which the hand 15 of the robot 12 performs work is measured.

  In order to three-dimensionally measure the position of the hand 15 of the robot 12, a laser is emitted from the laser input / output point 1 of the measuring device 11 and the laser beam reflected by the mirror of the marker 8 a provided on the hand 15 is received. Then, the reflected light received by the measuring device 11 is analyzed, and the analysis result is transmitted to the information processing apparatus.

  Further, the information processing apparatus acquires the position of the marker 8a, that is, the coordinates of the work point 8 in the vehicle coordinate system, from the analysis result of the received reflected light. Then, an error between the acquired coordinates of the work point 8 and the coordinates of the designated point registered in the database is calculated. Based on the result, the correction amount and correction direction of the robot 12 are calculated. The information processing apparatus converts the correction information including the correction amount and the correction direction from the vehicle coordinate system (product design coordinate system) to the information of the robot coordinate system, and issues a correction instruction to the robot 12. The robot 12 corrects the position of the hand 15 in accordance with a movement instruction from the information processing apparatus, and performs predetermined operations such as welding, screw tightening, and cutting. Note that the robot 12 may perform the conversion process of the correction information from the vehicle coordinate system to the robot coordinate system.

  In general, in one block of the work process, work by a plurality of robots is performed on both sides of a carriage from one vehicle. As shown in the example of FIG. 2, when the measuring device 11 is provided on the center line along the transport direction of the transport carriage 10 and at the front thereof, the overlapping of the arms of the robots is reduced. Prospects up to the markers provided in Therefore, the position of the marker of each robot can be satisfactorily measured from the measuring device 11. In addition, the position where the measurement device 11 is installed on the transport carriage 10 is a position where the marker of each robot can be satisfactorily seen from the measurement equipment 11 and does not interfere with the measurement. It can be installed at any position such as the rear part on the center line.

Here, a laser measuring instrument used as a measuring instrument of this system will be described.
FIG. 3 is an external view showing an example of a laser measuring device. As shown in FIG. 3, the laser measuring instrument 11 includes a fixed portion 17 that is fixed to the transport carriage 10 and a rotating portion 18 in which the sensor portion 16 is disposed at the center. The rotating unit 18 (and the sensor unit 16 provided on the rotating unit 18) has a structure that can rotate in the z-axis direction perpendicular to the xy plane while rotating on the xy plane using the fixed unit 17 as a bearing. The laser beam emitted from the laser input / output point 1 of the sensor unit 16 is reflected by a marker 8a provided for measuring the robot working point. The measuring instrument 11 receives the reflected light from the laser input / output point 1 and performs an analysis process.

  Since the laser measuring instrument 11 is configured to be able to track and measure the marker 8a by analyzing the reflected light, the working point of the robot can be easily measured. Therefore, it is easy to control the robot 12 and guide the hand 15 to the designated point.

  In this example, the laser measuring device is used as the measuring device. However, the measuring device is not limited to this example, and any device capable of measuring the three-dimensional coordinates of the measurement target may be used.

  Next, robot position measurement processing by the robot position measurement system will be described with reference to FIGS. FIG. 4 is a flowchart showing the measurement process, FIG. 5A shows an example of a production line in which the present system is adopted, and FIG. 5B is an enlarged view of the main part of FIG. 5A. FIG. 6 shows a state after completion of one step of the production line shown in FIG. 5A.

  In the flowchart of FIG. 4, first, the information processing apparatus determines whether or not all designated operations have been completed on the production line in which the robot position measurement system of this example is employed (step S1). When all the processes are finished, the measurement process is finished. On the other hand, when all the processes are not completed, the transport carriage is stopped at a predetermined stop position of the next process (step S2). The stop error of the transport carriage and the inclination of the transport carriage (vehicle) are structurally absorbed by the fixed installation of the measuring device on the transport carriage.

  The stop position of the transport cart is determined for each product manufacturing process. In the example of FIG. 5A, the conveyance carriage 23 is stopped at a predetermined position in the A block process, the conveyance carriage 22 is stopped in the B block process, and the conveyance carriage 21 is stopped in the C block process. Hereinafter, the description will be made while paying attention to the transport carriage 23, but the same applies to other transport carriages.

  Next, the vehicle origin, the x-axis default point, and the y-axis default point are measured by the measuring device 27 fixedly installed on the transport carriage 23, and the vehicle coordinate system (product design coordinate system) is set (step S3). Thus, by setting the vehicle coordinate system in each step, it is possible to cope with a case where a plurality of types of vehicles are flowing on the same production line. Of course, when only vehicles of the same vehicle type are flowing, it is not necessary to measure and set the vehicle coordinates at each step. Subsequently, on the vehicle coordinate system, designated points (design designated positions) in one step of the robot 31 are sequentially read from the database and set (step S4).

  FIG. 7 shows an example of the designated point list registered in the database. As shown in FIG. 7, a designated point is registered for each process of each manufacturing line, and each designated point is registered for each robot included in the block of that process in one process. The robot performs work based on the specified point list. For example, since the robot 31 is designated at three locations of the first designated point, the second designated point, and the third designated point of the transported vehicle, the robot 31 performs work at these three locations as shown in FIGS. Note that the format of the designated point list is not limited to this example.

  Then, it is determined whether or not the work has been completed for all designated points of each robot in one process registered in the designated point list (step S5). If all the operations in one process have been completed, the process proceeds to step S1, and it is determined again whether all the manufacturing processes have been completed. If not, the transport carriage 23 is moved to the stop position of the next B block process. (See FIG. 6) and the measurement process is continued. On the other hand, if all the processes have not been completed, the coordinates of the robot work start origin, the x-axis default point, and the y-axis default point are measured, and the robot coordinate system of the robot 31 is set (step S6). Subsequently, as an initial robot operation, the robot 31 is moved to the robot work start origin (see FIG. 2) (step S7).

  Here, it is determined whether or not the operation of the robot has ended (step S8). That is, it is confirmed whether or not the work to be performed by one robot is completed in one process. For example, it is determined whether the robot 31 in the A block process has completed all the operations up to the first to third designated points. When the operation of the robot 31 is completed, the process proceeds to step S5, and it is confirmed again whether all the operations in one step of the designated point list have been completed. In the determination step of step S5, when the work of one process is not completed, the measurement target of the measuring device 27 is changed to the robot 32, and the work of the robot 32 is continued. Thus, predetermined work is performed in order with the robots 33, 34, 35, and 36, and the work of one process is completed.

  On the other hand, when the robot operation has not been completed, for example, when the robot 31 has not finished the operation of the second designated point in FIG. 5A, the robot 31 is operated (step S9). And the measuring device 27 irradiates the marker of the robot 31 with a laser beam, and measures a work point three-dimensionally (step S10).

  The information processing apparatus receives the measurement result of the marker position of the hand from the measurement device, calculates the error between the robot work point and the designated point from the measurement result, and determines how much correction is necessary (step S11). For example, an allowable error amount may be set in advance, and a determination may be made based on whether an error obtained by actual measurement exceeds an allowable error amount. If the actual error is smaller than the allowable value, it is determined that the robot correction is unnecessary, and the process proceeds to the determination step of step S8, and it is confirmed again whether or not the robot operation is completed.

  On the other hand, when it is determined that correction processing is necessary, a correction command is issued from the information processing apparatus to the robot. In response to the correction command from the information processing apparatus, the robot controls the robot by the difference between the work point and the design designated position (designated point) so that the position of the hand marker matches the design designated position ( Step S12). On the robot side, correction processing is performed using the information obtained by converting the vehicle coordinate system correction information calculated by the information processing apparatus into the robot coordinate system correction information.

  After the correction process in step S12 is completed, the process proceeds to step S11, and it is determined again whether the robot position needs to be corrected. For example, when the correction cannot be completely completed by one correction process, the necessity of the correction process is monitored until the work point of the robot matches the designated point.

  According to the above-described configuration, since the measurement device is fixedly installed at a predetermined position on the transport carriage, the vehicle coordinate system (product design coordinate system) and the measurement device coordinate system can be matched. As a result, the robot position can be measured with high accuracy in an environment close to actual work, and correction calculation after measurement is simplified. For example, measurements reflecting actual conditions such as eccentricity of the center of gravity due to the tilt of the hand at the tip of the robot and deflection of the robot arm can be performed. In addition, it is possible to absorb the robot installation error and the stop position error of the transport carriage. Furthermore, the distortion of the transport rail can be absorbed. In this way, errors and distortions of each part can be absorbed, and since there are few coordinate systems to be calculated, correction calculation is simplified and the time required for correction calculation can be shortened.

  Moreover, according to the above-described configuration, there is an effect that the efficiency of the measurement work can be achieved. For example, it is not necessary to prepare a product with an inscription for measurement, and only a minor pre-operation such as creating a designated point list can be performed. Moreover, it is not necessary to perform manual measurement. Therefore, the operation stop time of the production line can be minimized.

  In addition, even if the production line or the product to be worked on is changed, there is no need to change the installation position of the measurement device each time as in the past, so the product type can be selected simply by creating a list of designated points. It can respond regardless. In addition, the measuring device itself is a general one, and can be used for most robots and the like simply by being fixed to the transport carriage. In addition, since the preparation for measurement is simple, periodic inspection and measurement can be performed.

  Further, since the worker does not enter the movable range of the robot arm during the measurement, safety is improved.

Next, an example of another embodiment of the present invention will be described with reference to FIGS.
FIG. 8 is a diagram showing the concept of the robot position measurement system of this example. In FIG. 8, parts corresponding to those in FIG. In the example of FIG. 8, in addition to the first measuring device 11, a second measuring device to be described later is additionally provided on the transport carriage with respect to the robot position measuring system shown in FIGS. 1 and 2. A laser is emitted from the laser input / output point 41 of the measuring device, and three-dimensional measurement is performed at each measurement point. Thus, the first measurement device coordinate system by the first measurement device 11 and the second measurement device coordinate system by the second measurement device are made to coincide with the vehicle coordinate system.

  FIG. 9 is a schematic diagram illustrating an example in which the concept of the robot position measurement system illustrated in FIG. 8 is embodied. In this example, a second measuring device 42 is provided at the rear part of the transport carriage 10 with respect to the robot position measuring system shown in FIG. Two measuring devices 11 and 42 are fixedly installed on the transport cart 10, and the measuring devices 11 and 42 are installed in a vehicle coordinate system (product design coordinate system), respectively. That is, the measurement device coordinate system of each measurement device is matched with the vehicle coordinate system (product design coordinate system). At this time, like the measuring device 11, the measuring device 42 is installed at a predetermined position on the transport carriage so as to ensure the consistency with the vehicle coordinate system.

  According to the configuration described above, the measurement obtained from the two measurement devices by performing the three-dimensional measurement of each measurement point such as a work point using the two measurement devices 11 and 42 fixedly installed on the transport cart 10. The error between the work point and the specified point can be calculated using the result, and the error in the robot hand position can be calculated with high accuracy. Therefore, the robot correction process can be performed with high accuracy.

  In addition, the instrument attached to the robot becomes an obstacle, and depending on the installation location of the measurement device, there are cases where the measurement point cannot be measured. Can be solved. In addition, the example of FIG.8 and FIG.9 has the same effect as the case where the measuring device of FIGS. 1-7 is one.

  In the above-described embodiment, a laser measuring device is used as a measuring device, but an image processing device such as a CCD (Charge Coupled Devices) camera can also be used. For example, in FIG. 8, a CCD camera may be installed as the second measuring device. If the laser measuring device and the CCD camera are integrated, only one measuring device needs to be installed, and space can be saved. Further, two measuring devices may be installed and selectively used according to the situation.

  The present invention is not limited to the above-described embodiments, and various other configurations can be taken without departing from the gist of the present invention.

It is a system conceptual diagram by one embodiment of the present invention. It is a system schematic diagram by one embodiment of the present invention. It is the figure which showed an example of the measuring device by one embodiment of this invention. It is a flowchart of the measurement process by one embodiment of this invention. It is a figure (1) with which it uses for description of the measurement process by one embodiment of this invention. It is a figure (2) with which it uses for description of the measurement process by one embodiment of this invention. It is an example of the designated point list by one embodiment of this invention. It is a system conceptual diagram by other embodiment of this invention. It is a system schematic diagram by other embodiment of this invention. It is a figure where it uses for description of a prior art example. It is a system schematic diagram of another conventional example. It is a figure where it uses for description of another prior art example.

Explanation of symbols

  1, 41 ... laser input / output point, 2 ... vehicle origin, 3 ... x-axis default point, 4 ... y-axis default point, 5 ... robot work start origin, 6 ... x-axis default point, 7 ... y-axis default point, 8 ... work point, 8a ... marker, 9 ... designated point, 10,21,22,23,24 ... conveyance carriage, 11,25,26,27,28,42 ... measuring instrument, 12,31,32,33,34 , 35, 36 ... Robot, 13 ... Base, 14 ... Arm, 15 ... Hand, 16 ... Sensor part

Claims (10)

A product transport cart that transports a product to be worked by a product manufacturing robot,
A measuring means for measuring the position of the working part of the robot is fixedly installed at a predetermined portion of the product conveying carriage. The product transport carriage according to claim 1, wherein the measuring means is fixedly installed near a center line along the transport direction of the product transport carriage. The product transport carriage according to claim 1 or 2, wherein the measuring means is fixedly installed at a front portion, a rear portion, or both of the product transport cart. The position information of the working part of the robot measured by the measuring means is transmitted to a control means for calculating an error between the position information and the design designated position of the work target product. The product transport cart according to any one of the above. A robot position measurement system for measuring the position of a working part of a product manufacturing robot,
Product conveying means for conveying the work target product of the robot;
Measuring means fixed to a predetermined part of the product conveying means and measuring the position of the working part of the robot;
And a control unit that calculates an error between the position of the working unit of the robot measured by the measuring unit and a design designated position, and instructs the robot to correct the position of the working unit based on the error. Robot position measurement system characterized by The control means calculates the error in a product design coordinate system to which the measuring means and the work target product belong, calculates correction information for the robot based on the error, and calculates the correction information from the product design coordinate system. The robot position measurement system according to claim 5, wherein the robot position measurement system converts the information into a robot coordinate system to which the robot belongs and issues a correction instruction to the robot. The robot position measurement system according to claim 5 or 6, wherein the measurement unit is fixedly installed near a center line along a conveyance direction of the product conveyance carriage. The robot position measurement system according to any one of claims 5 to 7, wherein the measurement unit is fixedly installed at a front part, a rear part, or both of the product transport carriage. Move the working part of the product manufacturing robot to the designated design position of the work target product that has been transported,
The position of the working part of the robot is measured by the measuring means fixedly installed on the product conveying means for conveying the work target product,
Calculate the error between the measured position of the working part of the robot and the designated design position,
Based on the error, the position of the working unit of the robot is corrected so as to coincide with the design designated position. The error is calculated in the product design coordinate system to which the measuring means and the work target product belong, the correction information for the robot is calculated based on the error, and the correction information is transferred from the product design coordinate system to the robot to which the robot belongs. The robot position measuring method according to claim 9, wherein the robot position is converted into coordinate system information and a correction instruction is issued to the robot.

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