Robot clamp calibration system and method
By using a calibration system of level and induction balls between the robot and the welding fixture, the problems of complex calibration process, low accuracy and high labor costs in the prior art are solved, and more efficient welding trajectory debugging and production efficiency are achieved.
Patent Information
- Application Number
- CN202510217911.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-26
- Publication Date
- 2025-05-13
AI Technical Summary
In the prior art, in the calibration process between the robot and the welding fixture, there are problems such as high labor costs, complex operation, large accuracy deviations and a large amount of time and manpower to debug.
A robot fixture calibration system is adopted to accurately calculate and calibrate the relative position between the robot and the fixture by installing a level and an induction ball on the fixture and the welding gun, combining the sensor box and signal interaction components.
It significantly reduces the time required for manual commissioning, improves overall work efficiency, reduces production costs, and improves the accuracy of welding trajectory.
Smart Images
Figure CN119973507A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of automated equipment manufacturing, and in particular relates to a robot fixture calibration system and method. Background Art
[0002] In modern industrial production, welding fixtures and various types of fixtures are the key to ensuring accurate welding and assembly of automotive parts. Robot offline programming technology is widely used in welding trajectory debugging. Its operation process is to plan the robot's movement trajectory in a simulation environment, and then output the corresponding offline program according to the robot's brand and model. In order to apply these offline programs to actual operations, the relative position of the robot and the fixture must be calibrated to ensure that the real baseline data (BASE data) between the robot and the on-site fixture matches.
[0003] The commonly used technology at present is to calibrate using the measurement method of three-coordinate articulated arm + robot + external program. However, this method has many disadvantages. The three-coordinate articulated arm equipment requires specialized personnel to operate, which increases labor costs; different robot brands have different corresponding measurement methods, which makes the operation complicated; and whether the welding gun is installed on the robot has a great influence on the measurement accuracy. Even after detailed calibration, the final relative position value still has a large deviation. During the on-site debugging process, each welding point and trajectory needs to be manually adjusted and calibrated, which makes the calibration and debugging process require more personnel and consumes a lot of time, seriously affecting production efficiency and increasing production costs. Summary of the invention
[0004] In order to effectively solve the problems in the above-mentioned background technology, the present invention proposes a robot fixture calibration system and method, which accurately calculates the relative positions of various fixtures in the robot coordinate system, establishes a precise positional relationship between the robot and the fixture, and effectively reduces the debugging time of the simulation offline program.
[0005] The specific technical solutions are as follows:
[0006] A robot fixture calibration system comprises a fixture side component and a robot welding gun side component, wherein the fixture side component comprises a fixture and a level, wherein the level is used to measure position information and is installed on the fixture and is level with the BASE surface of the fixture; the robot welding gun side component comprises an induction ball, a sensor box and a welding gun, wherein the induction ball is installed on the electrode cap on the static electrode arm side of the welding gun, and the sensor box is adsorbed and installed on the static electrode arm of the welding gun.
[0007] Preferably, the level comprises a level base, a horizontal laser emitter Z, a vertical laser emitter X and a vertical laser emitter Y, and the laser rings emitted by the horizontal laser emitter Z, the vertical laser emitter X and the vertical laser emitter Y are perpendicular to each other.
[0008] Preferably, the fixture comprises a fixture BASE surface, a first measurement Z surface, a second measurement Y surface and a third measurement X surface, wherein the first measurement Z surface, the second measurement Y surface and the third measurement X surface are unit surfaces parallel to the planes where the three directions X\Y\Z are located in the fixture coordinate system.
[0009] Preferably, the sensing ball comprises a mounting hole on the sensing ball, a mating surface on the sensing ball and a spherical surface of the sensing ball body, the mounting hole on the sensing ball is used to be mounted on the electrode cap of the welding gun, the mating surface on the sensing ball is used to match the shape of the static electrode arm of the welding gun, and the spherical surface of the sensing ball body is used to fit and measure with the fixture unit during the calibration process.
[0010] Preferably, the sensor box comprises a sensor and a quick-plug magnetic surface, and the quick-plug magnetic surface is used to adsorb and install the sensor box on the static electrode arm of the welding gun.
[0011] Preferably, it also includes a signal interaction component, which includes a computer-side wireless transceiver, a PC laptop and a robot system. The computer-side wireless transceiver is used to read sensor data, and the PC laptop is used to run the program system to extract and write data to the robot system, read and analyze sensor data, and the robot system is used in conjunction with a robot tool alignment system.
[0012] A calibration method for a robot fixture calibration system comprises the following steps:
[0013] Place the sensor box on the welding gun, record the sensor angle value, and simultaneously record the position and posture of the robot tool coordinate point TCP;
[0014] Place the sensor on the fixture and record the angle value of the sensor;
[0015] The posture relationship between the robot tool coordinate point TCP and the sensor is obtained through mathematical operations, and the angle posture relationship between the robot tool coordinate point TCP and the fixture is further calculated;
[0016] According to the tightness of the unit on the fixture, choose to use a level or a sensor ball to measure the distance, measure the three positions of the robot, and calculate the relative position relationship between the robot and the fixture;
[0017] The program calculates the relative position of the fixture in the robot coordinate system and passes the workpiece coordinate value corresponding to the fixture to the robot system to complete the fixture target.
[0018] The beneficial effect of the present invention is that the present invention places sensors on the welding gun and the fixture to record the angle value, obtains the posture relationship through mathematical calculation, and then calculates the relative position relationship through a level or a sensing ball, and finally obtains the relative position of the fixture in the robot coordinate system and transmits the coordinate value. Using the newly calibrated workpiece coordinate value for offline trajectory calibration can significantly reduce the time required for manual debugging and improve overall work efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is an overall schematic diagram of the clamp side in the present invention;
[0020] Figure 2 It is an overall schematic diagram of the welding gun side of the robot in the present invention;
[0021] Figure 3 is a schematic diagram of a level meter in the present invention;
[0022] Figure 4 It is a schematic diagram of the clamp in the present invention;
[0023] Figure 5 It is a schematic diagram of the induction ball in the present invention;
[0024] Figure 6 is a schematic diagram of the sensor box in the present invention;
[0025] Figure 7 It is a schematic diagram of a welding gun in the present invention;
[0026] Figure 8 It is a schematic diagram of signal interaction in the present invention. DETAILED DESCRIPTION
[0027] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used herein to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways, rotated 90 degrees or in other orientations, and the spatially relative descriptions used herein are interpreted accordingly.
[0028] The specific implementation of the present invention is described in detail below with reference to the accompanying drawings and preferred embodiments.
[0029] The robot fixture calibration system is applicable to various types of fixtures. This patent only uses the calibration of the side inner panel welding fixture of a certain A model as an example. The fixtures and welding guns involved are schematic diagrams. The fixture and welding gun models will change depending on the project area, but the working principle and working process are the same.
[0030] See also Figure 1 , the overall schematic diagram of the fixture side, including the fixture 4 and the level 3. When using this system for calibration, the level 3 is placed on the fixture 4 and adjusted to be level with the fixture BASE surface 4.4 for measuring position information.
[0031] See also Figure 2 , the overall schematic diagram of the robot welding gun side, including the induction ball 5, the sensor box 6 and the welding gun 7. When using this system, the induction ball 5 is installed on the electrode cap on the static electrode arm side of the welding gun 7, and the sensor box 6 is adsorbed and installed on the static electrode arm of the welding gun 7.
[0032] The schematic diagram of the level is shown in Figure 3 , which includes a level base 3.1, a horizontal laser transmitter Z 3.3, a vertical laser transmitter X 3.2 and a vertical laser transmitter Y 3.4, wherein the laser rings emitted by the three transmitters are perpendicular to each other.
[0033] The schematic diagram of the fixture is shown in Figure 4 , which include the fixture BASE surface 4.4, the first measurement Z surface 4.1, the second measurement Y surface 4.2 and the third measurement X surface 4.3. These three measurement surfaces are not fixed and immutable, but are selected by the operator before the fixture is calibrated. The selection standard is to use the unit surface parallel to the plane of the three directions X\Y\Z in the fixture coordinate system as the measurement surface.
[0034] The schematic diagram of the induction ball is shown in Figure 5 The mounting hole 5.1 on the induction ball is used to be installed on the electrode cap 7.2 of the welding gun, the matching surface 5.2 on the induction ball is used to match the shape on the static electrode arm 7.3 of the welding gun during the installation process, and the spherical surface 5.3 of the induction ball body is used to fit the fixture unit for measurement during the calibration process.
[0035] The sensor box schematic diagram is shown in Figure 6 , which includes a sensor 6.1 and a quick-plug magnetic surface 6.2.
[0036] The welding gun schematic diagram is shown in Figure 7 , including a welding gun moving electrode arm 7.1, an electrode cap 7.2, and a welding gun static electrode arm 7.3.
[0037] The signal interaction diagram is shown in Figure 8, where the computer-side wireless transceiver 8.1 is used to read sensor data, the robot system 8.3 represents a robot used together with the robot tool alignment system, and the PC notebook computer 8.2 is used to run the program system, including extracting and writing data to the robot system, reading and analyzing sensor data, etc. The core algorithms are all implemented through the PC notebook computer.
[0038] The working principle of the present invention is as follows: first, the sensor box 6 is placed on the welding gun 7, the sensor angle value is recorded, and the position and posture of the robot tool coordinate point TCP are recorded synchronously, and then the sensor is placed on the fixture to record the angle value of the sensor. Through mathematical operations, we can obtain the posture relationship between the robot tool coordinate point TCP and the sensor, and further calculate the angle and posture relationship between the robot tool coordinate point TCP and the fixture. Then, according to the tightness of the unit on the fixture, the distance measurement is selected through the level 3 or the induction ball 5, and the three positions of the robot are measured through the level 3 (or the induction ball 5), and the relative position relationship between the robot and the fixture is calculated. Finally, the program calculates the relative position of the fixture in the robot coordinate system, and passes the workpiece coordinate value corresponding to the fixture to the robot system to complete the calibration of this fixture.
[0039] The working process of the present invention is as follows: first, we need to connect the PC laptop 8.2 and the control cabinet of the robot system 8.3 through a network cable, then insert the computer-side wireless transceiver 8.1 into the USB interface of the PC, and adsorb the sensor box 6 to the welding gun static electrode arm 7.3 through the quick-plug magnetic surface 6.2, and run the program on the PC side to record the angle information between the sensor 6.1 and the robot tool coordinate point TCP. Then, according to the tightness of the unit on the fixture, choose to use the level 3 or the induction ball 5 to measure the distance. (1) If you choose to measure with the induction ball 5, insert the mounting hole 5.1 on the induction ball into the electrode cap 7.2 of the welding gun, then select the induction ball on the program page, move the robot until the spherical surface 5.3 of the induction ball body contacts the first measurement Z surface 4.1 on the fixture, click Record Z, then move the robot until the spherical surface 5.3 of the induction ball body contacts the second measurement Y surface 4.2 on the fixture, click Record Y, then move the robot until the spherical surface 5.3 of the induction ball body contacts the third measurement X surface 4.3 on the fixture, click Record X, then click the Calculate and Apply button on the program, the program will pass the calculated coordinate value of the fixture corresponding to the workpiece to the robot system, and this calibration is completed. (2) If you choose to measure using the level 3, place the level base 3.1 on the corresponding position on the BASE surface 4.4 of the fixture, then select the level on the program page, move the robot to the position where the level X laser beam frame just irradiates the robot electrode cap 7.3, click Record X, and record the positions of Y and Z in the same way, then click Calculate and Apply on the program. The program will pass the calculated workpiece coordinate values corresponding to the fixture to the robot system, and this calibration is completed.
[0040] It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as within the scope of protection of the present invention.
Claims
1. A robot fixture calibration system, characterized in that: It includes a fixture side component and a robot welding gun side component. The fixture side component includes a fixture and a level. The level is used to measure position information and is installed on the fixture and is level with the BASE surface of the fixture; the robot welding gun side component includes an induction ball, a sensor box and a welding gun. The induction ball is installed on the electrode cap on the static electrode arm side of the welding gun, and the sensor box is adsorbed and installed on the static electrode arm of the welding gun.
2. The robot fixture calibration system according to claim 1, characterized in that: The level comprises a level base, a horizontal laser emitter Z, a vertical laser emitter X and a vertical laser emitter Y. The laser rings emitted by the horizontal laser emitter Z, the vertical laser emitter X and the vertical laser emitter Y are perpendicular to each other.
3. The robot fixture calibration system according to claim 1, characterized in that: The fixture comprises a fixture BASE surface, a first measurement Z surface, a second measurement Y surface and a third measurement X surface, wherein the first measurement Z surface, the second measurement Y surface and the third measurement X surface are unit surfaces parallel to the planes where the three directions X\Y\Z are located in the fixture coordinate system.
4. The robot fixture calibration system according to claim 1, characterized in that: The sensing ball includes a mounting hole on the sensing ball, a mating surface on the sensing ball and a spherical surface of the sensing ball body. The mounting hole on the sensing ball is used to be mounted on the electrode cap of the welding gun, the mating surface on the sensing ball is used to match the shape of the static electrode arm of the welding gun, and the spherical surface of the sensing ball body is used to fit and measure with the fixture unit during the calibration process.
5. The robot fixture calibration system according to claim 1, characterized in that: The sensor box comprises a sensor and a quick-plug magnetic surface, and the quick-plug magnetic surface is used to adsorb and install the sensor box on the static electrode arm of the welding gun.
6. The robot fixture calibration system according to claim 1, characterized in that: It also includes a signal interaction component, which includes a computer-side wireless transceiver, a PC laptop and a robot system. The computer-side wireless transceiver is used to read sensor data, and the PC laptop is used to run the program system to extract and write data to the robot system, read and analyze sensor data, and the robot system is used in conjunction with a robot tool alignment system.
7. The calibration method of the robot fixture calibration system according to any one of claims 1 to 6, characterized in that: The following steps are involved: Place the sensor box on the welding gun, record the sensor angle value, and simultaneously record the position and posture of the robot tool coordinate point TCP; Place the sensor on the fixture and record the angle value of the sensor; The posture relationship between the robot tool coordinate point TCP and the sensor is obtained through mathematical operations, and the angle posture relationship between the robot tool coordinate point TCP and the fixture is further calculated; According to the tightness of the unit on the fixture, choose to use a level or a sensor ball to measure the distance, measure the three positions of the robot, and calculate the relative position relationship between the robot and the fixture; The program calculates the relative position of the fixture in the robot coordinate system and transmits the workpiece coordinate value corresponding to the fixture to the robot system to complete the fixture calibration.