CN110355788B - Large-scale spatial high-precision online calibration system for mobile manipulation robots - Google Patents

Abstract

The present invention relates to a large-scale spatial high-precision online calibration system for a mobile operating robot, which comprises a measuring subsystem and a calibration compensation subsystem. The measuring subsystem comprises a multi-view measuring device whose field of view covers the working space of the mobile operating robot, at least one group of local measuring devices and a vehicle-mounted laser micrometering device arranged on the mobile platform, and the calibration compensation subsystem comprises a mobile operating robot controller, a communication module connected to the measuring subsystem and a calibration workstation. The multi-view measuring device comprises an infrared camera, an image acquisition workstation connected to the infrared camera and a reflective target ball associated with the mobile platform. Each local measuring device comprises a CCD camera and a plurality of laser ranging sensors. Compared with the calibration of a traditional mobile robot, the scheme of the present invention has the advantages of fully automatic, large space and online calibration; at the same time, it also improves the operational flexibility, reduces the cost, and effectively improves the practical value of the mobile operating robot system.

Description

Large-scale spatial high-precision online calibration system for mobile manipulation robots

Technical Field

The present invention relates to the field of robot technology, and in particular to a large-scale spatial high-precision online calibration system for a mobile operating robot.

Background technique

The processing and measurement of large and complex structural parts, such as aerospace structural parts and high-speed rail body structural parts, usually require high precision and high surface quality. They have always relied on large processing equipment such as gantry machine tools and large milling machines. The size of the parts to be processed determines the size of the processing equipment. Therefore, this will not only cause the investment cost of the processing equipment to be very high, but also, if the characteristics of the processed parts change or the size increases, the original equipment may not be able to meet the new requirements, resulting in high equipment investment risks and failure to meet the flexible needs of actual applications.

Therefore, when faced with the processing of large and complex structural parts, a mobile operating robot system composed of an industrial robot and a mobile robot is a feasible solution. It has high dexterity and a large working space. At the same time, it can effectively improve work efficiency through the collaborative operation of multiple mobile operating robot systems.

However, the key problem encountered by mobile operating robot systems is large-scale high-precision positioning. The current solutions are to measure the end of the robot directly or indirectly, and to ensure the absolute accuracy of the robot end in a large range of workspaces through robot motion control, all of which require the use of high-cost iGPS, laser trackers and other equipment to complete. In addition, this requires real-time tracking and measurement of the end of the operating arm of the mobile operating robot. Therefore, when the number of mobile operating robots increases, or when there is occlusion caused by complex processing environments, the number of iGPS or laser trackers must be increased, which not only leads to a significant increase in costs, but also greatly reduces the flexibility of their application. At present, although such applications appear in a small number in the fields of aerospace processing, manufacturing and measurement, their high prices and low flexibility have greatly limited their promotion and application.

In summary, the calibration of traditional fixed industrial robots is often carried out in small indoor spaces. The measurement range of the precision measuring instruments used is generally less than a few meters. The combination of precise mechanical structure and optical principles can achieve high-precision measurement; traditional mobile operating robots have a large range of free working space, but are limited by centimeter-level positioning accuracy. Based on this, it is necessary to provide a system that can realize high-precision online calibration of mobile operating robots in large spaces, so that there is no need to track and measure the end position of the robot in real time to ensure accuracy. A calibration system that meets this demand can not only greatly improve flexibility, but also reduce costs, effectively improving the practical value of the mobile operating robot system.

Summary of the invention

The present invention provides a high-precision online calibration solution for a mobile robot suitable for large-scale spaces to solve the above technical problems.

The technical solution of the present invention is an online calibration system for a mobile operating robot, which includes a measurement subsystem and a calibration compensation subsystem. The measurement subsystem includes a multi-view measurement device whose field of view covers the working space of the mobile operating robot, at least one group of local measurement devices and a vehicle-mounted laser micrometer device arranged on the mobile platform, and the calibration compensation subsystem includes a mobile operating robot controller, a communication module connected to the measurement subsystem and a calibration workstation. The multi-view measurement device includes an infrared camera, an image acquisition workstation connected to the infrared camera and a reflective target ball associated with the mobile platform. Each of the local measurement devices includes a CCD camera and multiple laser ranging sensors.

According to some aspects of the present invention, an array consisting of multiple infrared cameras with different viewing angles is arranged above the working space of the mobile operating robot; the image acquisition workstation establishes a communication connection with each infrared camera; and multiple reflective target balls are installed at the corners of the mobile platform.

According to some aspects of the present invention, a plurality of laser ranging sensors are distributed in a spatial triangular pattern around the CCD camera under the support of a fixture; the shooting direction of the CCD camera faces the movement area of the mobile operating robot.

According to some aspects of the present invention, the external auxiliary equipment of the local measuring device also includes an equilateral triangle target, a supporting fixture and a linear motion device, wherein the equilateral triangle target is installed at the end of the robotic arm of the mobile operating robot, and the local measuring device is fixed to the moving table of the linear motion device through the supporting fixture, so that the linear motion device can drive the local measuring device to perform distance-controlled linear motion.

According to some aspects of the present invention, the linear motion device includes a linear motor, a guide rail for guiding the linear motion of the motion platform, a grating sensor, and a motion driver connected to the linear motor and the grating sensor.

According to some aspects of the present invention, the vehicle-mounted laser micrometer device includes a dual-axis outer diameter micrometer fixedly mounted on the mobile platform through a mounting support; the working part of the dual-axis outer diameter micrometer is in the shape of a plate, with a laser measurement area left in the middle, which is used to detect the outer diameter of a rod-shaped object inserted into the laser measurement area, providing a measurement basis for the posture calibration of the end effector of the operating arm with rod-shaped features.

According to some aspects of the present invention, an equilateral triangle block serving as a target is disposed at the end of the robotic arm, target balls are disposed at the vertices of the equilateral triangle block, and a visual detection mark is disposed at the center of the equilateral triangle block.

According to some aspects of the present invention, the mobile operating robot controller includes an industrial motion controller, a memory, and a motion control program of the mobile operating robot.

According to some aspects of the present invention, the calibration workstation is connected to the mobile operation robot controller by using a communication module, controls the movement of the robotic arm to the measurement position, receives the robotic arm in place information and collects the angle data of each joint of the robotic arm, and is also connected to the various electrical equipment of the measurement subsystem through the communication module to receive the measurement subsystem data and control the measurement subsystem; the calibration workstation stores the robotic arm kinematic error model, and obtains the nominal geometric parameters from the robotic arm controller; based on the true values obtained by the above-mentioned measurement subsystem, the robotic arm body base coordinate parameters, geometric parameters and end effector bias parameters at the working location are calibrated respectively, and a new motion trajectory is generated and the motion controller is compensated.

According to some aspects of the present invention, the laser ranging sensor is pre-calibrated by an offline calibration device, which includes a laser tracker, one or more target balls associated with the laser tracker and arranged at the end of a robotic arm, a rod connecting the target balls, and a laser tracker auxiliary measurement device Tmac.

The technical solution of the present invention also relates to a large-scale spatial high-precision calibration method for a mobile operating robot, comprising the following steps:

S1. Arrange a global reference network of a large-scale space in the world coordinate system of the on-site space, and deploy multi-view measurement equipment for coarse measurement and multiple local measurement equipment for fine measurement based on the global reference network;

S2. When the mobile platform of the mobile operating robot stops at the preset working position, the mobile platform is roughly positioned using the multi-view measuring device, and the mechanical arm base coordinate system under the rough positioning is used as a reference to control the end of the mechanical arm of the mobile operating robot with the self-made target to enter the measuring range of the local measuring device;

S3. Within the precise measurement range, through local visual recognition, guide the target at the end of the robot arm to move to a position so that the target is successfully hit by the measuring laser, calculate the end position of the robot arm according to the multi-laser ranging principle and the target geometric information, and then change the end position of the robot arm multiple times and measure and record the changed end position value, calibrate the robot arm base coordinate system deviation and kinematic geometric parameter error;

S4, based on the calculated posture error between the robot body and the base, recalculate the planned posture of the robot end effector, and compensate for the error of the robot end effector through a compensation algorithm;

S5. Build a vehicle-mounted laser micrometer system on the mobile platform, use the vehicle-mounted laser micrometer system to measure the posture of the cylindrical reference object, and calibrate the bias parameters of the end effector of the robot arm online.

The beneficial effects of the present invention are:

The present invention proposes a global coarse precision plus local high precision online calibration scheme, which has the advantages of fully automatic, large space and online calibration compared with the calibration of traditional fixed and mobile robots; in addition, the calibration scheme according to the present invention also improves operational flexibility while reducing costs, effectively improving the practical value of the mobile operating robot system.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic diagram of the global vision measurement subsystem and online calibration system.

FIG. 2 is a schematic diagram of a rail-based mobile local vision guidance device.

FIG3 is a schematic diagram of a dual-axis laser micrometer measurement mounted on a mobile operating robot.

FIG. 4 is a schematic diagram of an example of global reference network points.

FIG. 5 is an enlarged view of the details of the terminal target of FIG. 4 .

FIG6 is a flowchart of the online calibration system implementation.

FIG. 7 is a calibration compensation flow chart of the calibration workstation.

FIG8 is a diagram showing the relationship between the components of the online calibration system and the calibration implementation process.

Detailed ways

The following will be combined with the embodiments and drawings to clearly and completely describe the concept, specific structure and technical effects of the present invention, so as to fully understand the purpose, scheme and effect of the present invention. It should be noted that the embodiments and features in the embodiments of this application can be combined with each other without conflict.

It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature, or it may be indirectly fixed or connected to the other feature. In addition, the descriptions of up, down, left, right, etc. used in the present invention are only relative to the relative positional relationship of the components of the present invention in the accompanying drawings. The singular forms "a", "said", and "the" used in the present invention and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

It should be understood that although the terms first, second, third, etc. may be used to describe various elements in the present disclosure, these elements should not be limited to these terms. These terms are only used to distinguish elements of the same type from each other. For example, without departing from the scope of the present disclosure, the first element may also be referred to as the second element, and similarly, the second element may also be referred to as the first element.

In addition, the "large-scale space" referred to in the present invention refers to a space that is several times larger than the size of a traditional fixed or mobile robot. Generally speaking, it can be understood as a space of at least 10 meters × 10 meters × 10 meters, but in various practical applications, the "large-scale space" can be considered and limited based on factors such as the processed parts and the robot's motion range. The "high precision" referred to in the present invention refers to the processing accuracy and motion accuracy that are higher than the existing technology in various applications, so as to obtain better technical effects and improvements.

1 to 3 , the calibration system according to the present invention includes a measurement subsystem and a calibration compensation subsystem.

The measurement subsystem is used to perform visual measurement on the coordinate system of the mobile platform 110 , the position and posture of the end arm 113 , and the position and posture offset of the end effector of the robot arm.

The measurement subsystem includes: a spatially distributed multi-view measurement device, a local measurement device 120, and a vehicle-mounted laser micrometer device.

The multi-view measurement device includes: an infrared camera 116 , an image acquisition workstation 130 connected to the infrared camera 116 , and a reflective target ball associated with the mobile operation robot 109 .

The infrared camera 116 is set in the space above the mobile operation robot 109. A plurality of infrared cameras 116 can be fixedly installed in a distributed manner using supports and beams such as steel and aluminum. The measurement field of view of the plurality of infrared cameras 116 can cover a large-scale space, such as a space of at least 10 meters × 10 meters × 10 meters.

The image acquisition workstation 130 establishes a communication connection with each camera, controls the camera to synchronously acquire image information of the mobile platform 110 , extracts feature points of the image and fuses multi-camera data, obtains positioning information of the mobile platform 110 and sends it to the calibration workstation 127 .

Reflective target balls are installed at the four corners of the robot mobile platform 110 to facilitate the camera to spatially locate the mobile platform 110.

The local measuring device 120 and its external auxiliary devices may be arranged in the working area of the mechanical arm 111 of the mobile operating robot 109 .

The external accessory device includes a linear motion device with high-precision linear motion characteristics, which includes a linear motor, a guide rail, a grating sensor, a driver, and the like.

The local measuring device 120 is fixed to the motion table of the linear motion device through the supporting fixture 102, so that the linear motion device can drive the local measuring device 120 to perform distance-controlled fine linear motion.

The local measurement device 120 includes a plurality of (preferably 9) laser distance sensors 121 and a CCD camera 122. The CCD camera 122 is used to guide the target at the end of the robotic arm 113 into the measurable area of the laser distance sensor 121, and is therefore installed at the center of the fixture. The plurality of laser distance sensors 121 can be divided into three groups and are distributed around the CCD camera 122 in a spatial triangle (for example, at intervals of 120°) on the fixture. Each group of lasers can determine the spatial position of the center of a target ball in the target at the end of the robotic arm 113, which is used to further calculate the position and posture information of the center point of the equilateral target;

The equilateral triangle target 123 is mounted on the end 113 of the robot arm of the mobile operation robot 109. A high-precision reflective target ball is mounted on each vertex of the triangle target 123, and a visual detection mark 128 is pasted on the center of the triangle block. The reflective target ball is, for example, a target ball made of a smooth ceramic material, or a target ball made of a polished metal material.

The vehicle-mounted laser micrometering device includes a mounting support and a dual-axis outer diameter micrometer 125, which is mounted and fixed on the robot's mobile platform 110. The working part of the dual-axis outer diameter micrometer is in the shape of a plate, and a laser measurement area is left in the middle, which is used to detect the outer diameter of a rod-shaped object inserted into the laser measurement area, providing a measurement basis for the position and posture calibration of the end effector of the manipulator with rod-shaped features.

The calibration and compensation subsystem includes: a mobile operation robot controller 129 , a communication module and a calibration workstation 127 .

The mobile robot controller 129 is used to control the motion of the robot arm 111 and the mobile platform 110, and the controller stores the motion geometric nominal parameters of the robot arm 111. The mobile robot controller 129 includes an industrial motion controller (such as a PLC, a motion control card), a driver of the mobile robot 109, and the like.

The communication module is used for communication between controllers, field buses, switches and various devices, and may include gateways, switches, data forwarders of various protocols, wireless network cards, etc.

Calibration workstation 127: connects to the mobile operation robot controller 129 by using the communication module, controls the robot arm 111 and the mobile platform 110 to move to the measurement position, receives the position information of the robot arm 111 and collects the angle data of each joint of the robot arm 111; connects to various electrical equipment of the measurement subsystem (including the image acquisition workstation 130) by using the communication module, receives the measurement subsystem data and can control the measurement subsystem; establishes the kinematic error model of the robot arm 111, and infers the nominal geometric parameters of the robot arm 111 motion from the mechanical structure of the robot arm 111, based on the true values obtained by the above-mentioned measurement subsystem, calibrates the base coordinate parameters, geometric parameters and end effector bias parameters of the robot arm 111 body at the working place, generates a new motion trajectory and compensates the controller.

In conjunction with Figures 6 to 8, some embodiments of the calibration operation process of the calibration system according to the present invention are described below through 5 main steps. As shown in Figure 8, step S1 involves the construction of each hardware platform of the above-mentioned calibration system and the offline calibration of the corresponding ranging sensor. Steps S2 to S5 involve the online calibration system gradually advancing from the low-precision calibration of the mobile platform 110 cm level to the high-precision calibration of the robotic arm 111 micron level, and also realizing the micron-level high-precision calibration of the tool at the end of the robotic arm 113. In some application scenarios, each sensor device of the online calibration system according to the present invention only needs to be calibrated offline once, and then the process of steps S2 to S5 can be repeated in real time during the working process of the mobile operation robot 109 to update the robot's posture and calibration tools online. Among them, step S2 is mainly implemented through the infrared camera 116 of the multi-view measuring device and the vehicle-mounted reflective target ball on the mobile operating robot 109; the guiding step S3.1 in step S3 is implemented through the CCD camera 122 of the local measuring device 120 and the visual detection mark 128 set at the end of the robotic arm 113, and the subsequent measurement step S3.2 is implemented through the laser ranging sensor 121 of the local measuring device 120 and the target and target installed at the end of the robotic arm 113; step S4 can be executed by an external computing device, or directly or indirectly by the motion controller of the mobile operating robot 109; step S5 is mainly implemented by the dual-axis micrometer sensor on the vehicle-mounted platform of the mobile operating robot 109.

Each step is described below through detailed examples.

Step S1

A large-scale spatial global reference network is built to solve the error accumulation problem caused by multiple conversions of the reference coordinate systems of measurement equipment in large-scale industrial robot manufacturing sites. The distribution of points in the global reference network is related to the measurement distance and accuracy of the sensors in the space, spatial occlusion and other factors.

Use non-contact, large-range, and highly convenient standard measuring equipment such as laser tracker 101 to directly or indirectly measure the position information of sensors in space at the reference points. For sensor devices outside the measurable space, move the laser tracker 101 to the next reference point, where part of the position information of the sensor at the previous point can also be measured, and the transformation information of this point relative to the previous point can be calculated. In order to reduce the cumulative error between points, the construction is carried out by spreading from the central point to the surrounding areas, and finally the position information of the sensor in space relative to the unified world coordinate system is established by splicing.

In one example, as shown in FIG4 and FIG5, a laser tracker 101 (e.g., a product of Leica) is used as a reference point to construct an instrument and calibrate the position of a laser distance sensor 121 and an infrared camera 116 at the reference point. A support fixture 102 is installed at the end of the robotic arm 113, and the fixture is equipped with: (1) a high-precision ceramic target ball 124 with a small diameter (e.g., 1 mm) for reflecting the laser of the laser distance sensor 121; (2) a laser tracker auxiliary measurement device Tmac 104, which can directly feedback 6-DOF position and posture information; (3) a reflective target ball group 105 for infrared camera 116 recognition. The reflective target balls are connected by high-precision rods 106.

The robot arm 111 is controlled to move to the first position 107, so that the ceramic target ball 124 is aligned with the laser line of the laser ranging sensor 121, and the laser tracker 101 is used to capture and convert it into the position and posture of the ceramic target ball 124 at this position; the robot arm 111 is controlled to move to the second position 108, and similarly, the ceramic target ball 124 is aligned with the laser line of the laser ranging sensor 121, and the position and posture of the ceramic target ball 124 at this position can also be obtained. The direction of the incident laser from the laser ranging sensor 121 can be obtained through the position and posture of the two points of the ceramic target ball 124, and the distance information can be measured by the laser ranging sensor 121 itself, and finally the position and posture information of the laser ranging sensor 121 at the reference point is obtained. Similarly, the infrared camera 116 can also obtain its own position and posture relative to the reference point by measuring the reflective target ball group 105 twice.

Step S2

In order to reduce the probability of being blocked by space obstacles, as shown in FIG1 , a bracket 115 composed of steel, aluminum and other supports and beams is used to install the infrared camera 116 visual measurement subsystem. The reflective target balls 117 are installed at the four corners of the mobile platform 110. When the mobile operation robot 109 and the mobile platform 110 move to the measurable range of the infrared camera 116, the infrared camera 116 identifies the reflective target balls 117 and further calculates and determines the spatial position of the mobile platform 110 based on the geometric distribution of the reflective target balls.

Since multiple infrared cameras 116 are deployed in space, the mobile platform 110 may be captured by multiple infrared cameras 116 at the same time, and the redundant positioning data generated by the multiple cameras are utilized and optimized by a data fusion algorithm.

Afterwards, since the robot base 112 and the mobile platform 110 are rigidly connected to the vehicle body, the conversion relationship between them can be determined by offline calibration at the factory; thus, under the condition that the posture information of the mobile platform 110 is obtained through the above measurement, the posture information of the robot base 112 relative to the world coordinate system can be obtained. However, the accuracy of visual measurement in a large space is limited, and the positioning of the robot base 112 is only a preliminary positioning, which provides a reference for the next step of controlling the movement of the robot end 113 to the local high-precision measurement area in the world coordinate system.

Step S3

As shown in FIG2 , an equilateral triangle block 123 is precisely machined, and three high-precision ceramic target balls 124 are respectively installed at the vertices of the triangle block 123, and a visual detection mark 128 (for example, a mark point mark) is pasted at the center of the triangle block 123. The equilateral triangle block 123 is installed as a target on the flange of the end 113 of the robot arm (or installed on the end flange through an extension rod). Nine laser ranging sensors 121 and a CCD camera 122 (for example, a CCD guide camera) form a local measurement device 120, which is installed on a support fixture 102 that can move with a precision linear guide 118. In order to correspond to the target 123 of the equilateral triangle block, the nine laser ranging sensors 121 are divided into three groups, each group occupies a corner in the space triangle, and the CCD camera 122 is installed at the center of the space triangle.

At the local high-precision local measurement area where the target 123 moves to at the end of the robot arm 113, the visual detection mark 128 attached to the target 123 enters the field of view of the guiding CCD camera 122. By guiding the visual detection mark 128 to a certain posture, the three laser beams of each group of laser ranging sensors 121 can hit the corresponding target ball 124 in the equilateral triangle block target 123. At this time, the robot arm 111 pauses, and the calibration workstation 127 records the ranging data of each laser ranging sensor 121 through the communication module on the one hand, and captures the joint values of the robot arm 111 through the mobile operation robot controller 129 on the other hand. According to the triangulation method, each group of lasers can determine the spatial position of the center of a target ball 124, and through geometric calculation, the position and posture information of the center point of the equilateral triangle block 123 can be calculated. The CCD camera 122 is used to track the marker position to ensure that the three groups of lasers can hit their respective target balls. The position of the robot end 113 is changed multiple times and the above measurement results are recorded. The calibration algorithm of the calibration workstation 127 is used to obtain the deviation of the coordinate system of the robot base 112 relative to the world coordinate system and the kinematic geometric parameter error.

Considering that the mobile operating arm moves freely in a large working area, in order to ensure that there is at least one local measuring device 120 next to each working point to perform high-precision measurement on the end of the robot arm 113 and save the number of deployed local measuring devices 120, a segmented high-precision mobile guide rail 118 is used to carry the local measuring device 120 to move within the operable range of the robot arm 111. In order to improve the quality of parameter calibration of the robot arm 111, at least two local measuring devices 120 are guaranteed and there is a certain spatial distance between the two local measuring devices 120, and the posture of the robot arm 111 has sufficient changes to "stimulate" as many kinematic parameters to be calibrated as possible during the mathematical operation process.

Step S4

Generally speaking, in order to ensure the efficiency and accuracy of robot programming, the robot's work tasks and positioning programs must be planned and generated through an offline programming system, and the robot is programmed by specifying the absolute position of the end effector center point (TCP) in the world coordinate system. Based on steps S2-S3, the base coordinate system parameters and geometric parameters of the robot arm 111 at the work site are calibrated respectively, and the calibration of the end effector offset parameters is after the geometric parameters of the robot arm 111 are calibrated and compensated, that is, to implement the calibration of the end effector offset parameters, the robot arm 111 body needs to be accurate.

As shown in Figure 7, since not every robot arm 111 allows direct modification of the kinematic parameter file, the robot arm 111 is more often compensated by modifying the end effector posture. First, the robot arm 111 base coordinate system is compensated into the posture of the robot arm end effector after offline programming, and the compensated posture is subjected to inverse kinematics solution using real geometric parameters to obtain each joint value, and then each joint value is subjected to forward kinematics solution using nominal geometric parameters (or geometric parameters of the last calibration) to obtain a new end effector posture value. Compensation for the end effector offset is also to compensate for the posture value of the end effector.

Compensation is accomplished by modifying controller instructions according to the new end effector pose value through communication between the calibration workstation 127 and the mobile manipulation robot controller 129 .

Step S5

As shown in Figure 3, a vehicle-mounted dual-axis laser micrometer 125 is built on the mobile platform 110. After the geometric parameters of the robot 111 are calibrated, if the end effector has a conical or rod-shaped geometric feature. Control the end effector of the robot to vertically insert into the center plane of the dual-axis laser micrometer 125, record the position point where the light-receiving elements in the two directions of the dual-axis laser micrometer 125 are blocked, and use this position as the reference position of the end effector offset. The offset of the end effector posture at the reference position is zero. After the end effector of the robot has been operating for a period of time, check whether the relationship between the end effector and the end of the robot 113 has changed, and move the end effector to insert into the center plane again according to the original set motion command. At this time, the offset of the end effector will be manifested as a change in the position point where the light-receiving element in the laser micrometer 125 is blocked. At this time, the end effector needs to be calibrated.

The end effector with an offset is inserted into the center detection surface of the dual-axis laser micrometer 125 in different postures for multiple times, and the calibration workstation 127 stops and waits to record the position points where the light-receiving elements in two directions are blocked each time the center surface is inserted, and the joint angles of the robotic arm 111 at this time are captured, and the offset value of the relationship between the end effector and the end 113 of the robotic arm is calculated.

The above is only a preferred embodiment of the present invention. The present invention is not limited to the above implementation. As long as the technical effect of the present invention is achieved by the same means, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present disclosure shall be included in the scope of protection of the present disclosure. All should belong to the protection scope of the present invention. Within the protection scope of the present invention, its technical scheme and/or implementation method can have various modifications and changes.

List of Reference Numerals

101 Laser Tracker

102 Support fixture

103 small diameter high precision ceramic target ball

104 Laser Tracker Auxiliary Measurement Device Tmac105 Reflective Target Ball Set

106 rods

107 First Position

108 Second Position

109 Mobile Operation Robot

110 mobile platforms

111 Robotic Arm

112 Robotic Arm Base

113 Robotic Arm End

115 bracket

116 Infrared Camera

117 infrared reflective target ball

118 linear motion guide

119 Support fixture

120 local measuring equipment

121 Laser Distance Sensor

122 CCD Camera

123 equilateral triangle target

124 Ceramic Target Ball

125 dual axis laser micrometer

126 Robotic Arm Control Cabinet

127 calibration workstations

128 visual inspection marks

129 Mobile Operation Robot Controller

130 image acquisition workstations.

Claims (8)

1. A large-scale spatial high-precision online calibration system for a mobile operating robot (109), comprising a measurement subsystem and a calibration compensation subsystem, wherein the mobile operating robot (109) comprises a mobile platform (110) and a mechanical arm (111), The method is characterized in that the measurement subsystem comprises a multi-view measurement device whose field of view covers the working space of the mobile operation robot (109), at least one group of local measurement devices (120) and a vehicle-mounted laser micrometer device arranged on the mobile platform (110); the calibration compensation subsystem comprises a mobile operation robot controller (129), a communication module connected to the measurement subsystem and a calibration workstation (127), wherein: The multi-view measurement device comprises an infrared camera (116), an image acquisition workstation (130) connected to the infrared camera (116), and a reflective target ball associated with the mobile platform (110); Each of the local measurement devices (120) comprises a CCD camera (122) and a plurality of laser distance measuring sensors (121); The mobile operation robot controller (129) comprises an industrial motion controller, a memory and a motion control program of the mobile operation robot (109); The calibration workstation (127) is connected to the mobile operation robot controller (129) by using a communication module, controls the mechanical arm (111) to move to a measurement posture, receives information about the mechanical arm (111) being in position and collects angle data of each joint of the mechanical arm (111), and is also connected to each electrical device of the measurement subsystem via the communication module to receive measurement subsystem data and control the measurement subsystem; The calibration workstation (127) stores a kinematic error model of the robot arm (111) and obtains nominal geometric parameters from the robot arm (111) controller. Based on the true values obtained by the measurement subsystem, the robot arm (111) body base coordinate parameters, geometric parameters and end effector bias parameters at the working position are calibrated respectively, and a new motion trajectory is generated and the motion controller is compensated. 2. The online calibration system according to claim 1, characterized in that: Arranging an array consisting of a plurality of infrared cameras (116) with different viewing angles above the working space of the mobile operating robot (109); The image acquisition workstation (130) establishes a communication connection with each infrared camera (116); A plurality of the reflective target balls are installed at the corners of the mobile platform (110). 3. The online calibration system according to claim 1, characterized in that: A plurality of laser distance measuring sensors (121) are distributed in a spatial triangular pattern around the CCD camera (122) under the support of a fixture; The shooting direction of the CCD camera (122) faces the movement area of the mobile operation robot (109). 4. The online calibration system according to claim 1 or 3 is characterized in that the external auxiliary equipment of the local measuring device (120) also includes an equilateral triangle target (123), a supporting fixture (102) and a linear motion device, wherein the equilateral triangle target (123) is installed at the end (113) of the mechanical arm of the mobile operating robot (109), and the local measuring device (120) is fixed to the moving table of the linear motion device through the supporting fixture (102), so that the linear motion device can drive the local measuring device (120) to perform distance-controlled linear motion. 5. The online calibration system according to claim 4 is characterized in that the linear motion device includes a linear motor, a guide rail for guiding the linear motion of the motion table, a grating sensor, and a motion driver connected to the linear motor and the grating sensor. 6. The online calibration system according to claim 1, characterized in that: The vehicle-mounted laser micrometer device comprises a dual-axis outer diameter micrometer (125) fixedly mounted on the mobile platform (110) via a mounting support; The working part of the dual-axis outer diameter micrometer (125) is in the shape of a plate, with a laser measurement area in the middle, which is used to detect the outer diameter of a rod-shaped object inserted into the laser measurement area, thereby providing a measurement basis for the position and posture calibration of an end effector of a manipulator arm with rod-shaped features. 7. The online calibration system according to claim 1 or 6, characterized in that: An equilateral triangle block as a target is provided at the end (113) of the robot arm, target balls are respectively arranged at the vertices of the equilateral triangle block, and a visual detection mark (128) is arranged at the center position of the equilateral triangle block. 8. The online calibration system according to claim 1 is characterized in that the laser ranging sensor (121) is pre-calibrated by an offline calibration device, which includes a laser tracker (101), one or more target balls associated with the laser tracker (101) and arranged at the end of a robotic arm (113), a rod (106) connecting the target balls, and a laser tracker auxiliary measurement device Tmac (104).