Robotic fixture calibration system and method

Abstract

The present application belongs to the technical field of automatic equipment manufacturing, and particularly relates to a robot fixed tooling calibration system and method, which comprises a fixed tooling side sensor box, a robot gripper side sensor box, a PC notebook computer, a computer end wireless transceiver and a robot system; the fixed tooling side sensor box is installed on the fixed tooling and used for measuring the angle value of the fixed tooling; the robot gripper side sensor box is installed on the robot gripper tooling, connected with the robot and moved with the robot, and used for measuring the angle value of the robot gripper tooling and recording the position and posture information of the robot tool coordinate point TCP. The present application can quickly establish the accurate position relationship between the robot and the fixed equipment, effectively correct the offline trajectory, greatly reduce the time of manual adjustment and calibration, improve the overall debugging efficiency and speed up the production progress.

Description

Technical Field

[0001] This invention belongs to the field of automated equipment manufacturing technology, specifically relating to a robot fixture calibration system and method. Background Technology

[0002] In the automotive welding industry, welding fixtures and various fixing equipment are crucial for the precise welding and assembly of automotive parts. As the automotive manufacturing industry develops towards higher efficiency, higher precision, and higher automation, the requirements for the accuracy and stability of the welding process are becoming increasingly stringent. However, many current fixing devices, such as those for fixing studs, welding nuts, and applying adhesives, lack a strict coordinate system, making it difficult to establish accurate positional relationships when working collaboratively with robots.

[0003] Existing calibration methods utilize the calibration software built into robots of different brands to construct external TCPs (positional coordinate systems) to simulate positional relationships. This method has several drawbacks: first, it is time-consuming, impacting production efficiency; second, the accuracy of the calibrated external TCPs is poor, failing to meet the demands of high-precision production; and third, it is limited by robot brands, as some brands lack built-in calibration software, making calibration impossible. During on-site debugging, due to the unknown or inaccurate relative positions of the robot and fixed fixtures, the offline program output from the simulation requires manual adjustment and calibration of each weld point and trajectory in actual applications, consuming significant manpower and time, and increasing production costs. Summary of the Invention

[0004] To effectively address the problems mentioned in the background art, this invention proposes a robot fixed fixture calibration system and method. The aim is to accurately calculate the position of various fixed fixtures in the robot coordinate system, establish stable and precise positional relationships, significantly reduce the debugging time of offline simulation programs, improve production efficiency, and reduce production costs.

[0005] The specific technical solution is as follows:

[0006] A robot fixture calibration system includes a fixture-side sensor box, a robot gripper-side sensor box, a PC laptop, a computer-side wireless transceiver, and a robot system. The fixture-side sensor box is mounted on the fixture and is used to measure the angle values ​​of the fixture. The robot gripper-side sensor box is mounted on the robot gripper fixture, connected to the robot, and moves with the robot. It is used to measure the angle values ​​of the robot gripper fixture and to record the position and attitude information of the robot tool's coordinate points (TCP). The PC laptop runs a program system to read and analyze sensor data, interact with the robot system, and perform core algorithm calculations. The computer-side wireless transceiver reads sensor data and transmits it to the PC laptop. The robot system works in conjunction with a robot tool alignment system, receiving correction values ​​output from the PC laptop and correcting the offline trajectory.

[0007] Preferably, the fixed tooling side sensor box includes a first extension rod, a second extension rod, a notch for aligning with the glue gun rod, and a sensor; the first extension rod and the second extension rod are used to adjust the relative position of the fixed tooling side sensor box so that it is in the desired measurement position; the notch for aligning with the glue gun rod facilitates the installation of the fixed tooling side sensor box onto the glue gun rod of the fixed tooling; the sensor is used to record angle values.

[0008] Preferably, the robot gripper tooling has a sensor box mounting surface, and the robot gripper side sensor box has a mounting surface that matches the sensor box mounting surface, so as to facilitate the installation and connection of the two.

[0009] Preferably, when the fixed fixture is a fixed glue application fixture, the glue gun rod and glue gun head of the fixed glue application fixture are parallel and their axes are on the same straight line, and the projection of the glue gun rod on the ground is perpendicular to the glue application bracket mounting base biased towards the glue gun side plane.

[0010] A calibration method based on the robot fixture calibration system includes the following steps:

[0011] Install the sensor box on the fixed fixture side onto the fixed fixture, adjust its position, and record the sensor information;

[0012] Install the robot gripper side sensor box onto the robot gripper fixture to record the position and attitude information of the sensor and the robot head TCP;

[0013] The attitude relationship between the robot tool coordinate point TCP and the robot gripper side sensor box is obtained through mathematical calculations, and then the angular attitude relationship between the robot TCP and the fixed tooling side sensor box is calculated.

[0014] Move the robot to the first offline trajectory key point and record the positional deviation.

[0015] Based on the known angle and attitude relationships and positional deviations, establish the accurate positional relationship between the robot and the fixed fixture, and create an external TCP to correct the offline trajectory.

[0016] Preferably, in the step of installing the sensor box on the fixed fixture side onto the fixed fixture, for the fixed glue application fixture, the first extension rod and the second extension rod need to be adjusted so that they are parallel to the glue gun side plane of the glue application bracket mounting base, respectively; in the step of installing the sensor box on the robot gripper side onto the robot gripper fixture, ensure that the mounting surface of the robot gripper side sensor box is in close contact with the sensor box mounting surface of the robot gripper fixture.

[0017] Preferably, the step of obtaining the attitude relationship between the robot tool coordinate point TCP and the robot gripper side sensor box through mathematical calculations, and calculating the angular attitude relationship between the robot TCP and the fixed tooling side sensor box, is specifically implemented through an algorithm preset in the PC laptop program system. This algorithm is based on mathematical principles such as trigonometric functions and vector operations, and performs calculations by combining the angle values ​​recorded by the sensors and the position information of the robot TCP.

[0018] Preferably, after the step of moving the robot to the first offline trajectory key point and recording the position deviation, the process further includes clicking "calculate" on the PC laptop, where the program system performs internal calculations based on the recorded data and outputs a correction value to the robot system. After receiving the correction value, the robot system corrects the offline trajectory on the teach pendant.

[0019] The beneficial effects of this invention are: This invention uses sensors to accurately record the posture of important parts on the fixed fixture (such as the glue gun head of the glue application equipment, the projection welding gun head of the projection welding nut equipment, etc.), as well as the posture of the robot's side gripper and the position posture of the robot tool coordinate point TCP. Accurate positional relationships are established through mathematical calculations, and the calibration accuracy is significantly improved compared with traditional methods.

[0020] This invention can quickly establish an accurate positional relationship between a robot and a fixed device, effectively correct offline trajectories, significantly reduce the time required for manual adjustment and calibration, improve overall debugging efficiency, and accelerate production progress.

[0021] This invention reduces the manpower and time costs required for manual debugging, avoids production delays caused by excessive debugging time, lowers production costs, and enhances the company's market competitiveness.

[0022] This calibration system is applicable to a variety of fixed tooling equipment, is not limited by robot brand, overcomes the limitations of traditional calibration methods, and has broad application prospects. Attached Figure Description

[0023] Figure 1This is an overall schematic diagram of the fixed adhesive application fixture of the present invention;

[0024] Figure 2 This is an overall schematic diagram of the robot gripper side of the present invention;

[0025] Figure 3 This is a schematic diagram of the fixed adhesive application fixture of the present invention;

[0026] Figure 4 This is a schematic diagram of the sensor box on the fixed tooling side of the present invention;

[0027] Figure 5 This is a schematic diagram of the robot gripper tooling of the present invention;

[0028] Figure 6 This is a schematic diagram of the sensor box on the side of the robot gripper of the present invention;

[0029] Figure 7 This is a schematic diagram of signal interaction in this invention. Detailed Implementation

[0030] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, rotated 90 degrees, or in other orientations, and the spatial relative descriptions used herein will be interpreted accordingly.

[0031] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings and preferred embodiments.

[0032] See Figure 1 A robot fixture calibration system includes a base 1, a limit bar 2, a fixed adhesive applicator 3, and a fixed fixture side sensor box 4. When calibrating using this system, the fixed fixture side sensor box 4 is installed on the fixed adhesive applicator 3 for measuring angle values.

[0033] See Figure 2 A schematic diagram of the robot gripper side, including robot gripper fixture 5 and robot gripper side sensor box 6; when calibrating using this system, the robot gripper side sensor box 6 is installed on the robot gripper fixture 5 for measuring angle values.

[0034] For a detailed schematic diagram of the fixed adhesive application fixture, please refer to [link / reference needed]. Figure 3 The glue gun rod 3.1 and glue gun head 3.2 are parallel and their axes are on the same straight line. The projection of the glue gun rod 3.1 on the ground is perpendicular to the glue application bracket mounting base biased towards the glue gun side plane 3.3.

[0035] For a detailed schematic diagram of the sensor box on the fixed tooling side, please refer to [link / reference]. Figure 4 The notch 4.2, which is designed to avoid the glue gun rod 4.1, facilitates the installation of the tooling-side sensor box 4 onto the glue gun. The sensor 4.4 is used to record angle values. The first extension rod 4.1 and the second extension rod 4.3 are used to adjust and fix the relative position of the tooling-side sensor box. When the first extension rod 4.1 and the second extension rod 4.3 are adjusted to be parallel to the glue gun side plane 3.3 of the glue gun mounting base, the current direction of the sensor is the desired position.

[0036] For a detailed schematic diagram of the robot gripper tooling, please refer to [link / reference]. Figure 5 The sensor box mounting surface 5.1 is used to mount the robot gripper side sensor box 6. During the calibration process, the robot gripper fixture is connected to the robot, and the robot can move and rotate with the gripper.

[0037] A detailed schematic diagram of the robot gripper side sensor box can be found here. Figure 6 The mounting surface 6.1 is used to match the mounting surface 5.1 of the sensor box, and the sensor 6.2 is used to record the angle value.

[0038] The signal interaction diagram is shown below. Figure 7 The computer-side wireless transceiver 7.1 is used to read sensor data, the robot system 7.3 represents the robot used with the robot tool alignment system, and the PC laptop 7.2 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 laptop.

[0039] The working principle of this invention is as follows: First, the fixed tooling side sensor box 4 is installed onto the glue gun rod 3.1 of the fixed glue application fixture, and its position is adjusted to record sensor information. Then, the robot gripper side sensor box 6 is installed onto the robot gripper fixture 5, and the position and attitude information of the sensor and the robot head TCP are recorded (the gripper is installed on the robot and moves with the robot). Through mathematical calculations, we can obtain the attitude relationship between the robot tool coordinate point (TCP) and the robot gripper side sensor box 6, and further calculate the angular attitude relationship between the robot TCP and the fixed tooling side sensor box 4, that is, the positional relationship between the robot TCP and the glue gun head 3.2. Then, the robot is moved to the first offline trajectory key point, and the position deviation is recorded at this time. Based on the previously known angular attitude relationship and position deviation, the accurate positional relationship between the robot and the fixed glue application fixture 3 can be established. Thus, by creating an external TCP to correct the offline trajectory, the manual adjustment and calibration time is significantly reduced, the overall debugging efficiency is improved, and the production cost is reduced.

[0040] The working process of this invention is as follows: First, connect the PC laptop (7.2) and the control cabinet of the robot system (7.3) via a network cable. Then, insert the wireless transceiver (7.1) on the PC into its USB port. Install the sensor box (4) on the fixed tooling side onto the glue gun rod (3.1) of the fixed glue application tooling, and adjust the first extension rod (4.1) and the second extension rod (4.3) to be parallel to the glue gun side plane (3.3) of the glue application bracket mounting base. Install the robot gripper side sensor box (6) onto the robot gripper tooling (5), ensuring that the mounting surface (6.2) mates with the sensor box mounting surface (5.1) during installation. Run a program on the PC to record the current angles of sensors (4.4 and 6.4) and the current position angle information of the robot tool coordinate point TCP. Then, move the robot to the first offline trajectory key point, click "calculate" on the PD computer, perform internal calculations, and output correction values ​​to the robot system. The robot teach pendant corrects the offline trajectory, and this calibration process is complete.

[0041] It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention.

Claims

1. A robot fixture calibration system, characterized in that, The system includes a fixed-fixture side sensor box, a robot gripper side sensor box, a PC laptop, a computer-side wireless transceiver, and a robot system. The fixed-fixture side sensor box is mounted on the fixed fixture and is used to measure the angle values ​​of the fixed fixture. The robot gripper side sensor box is mounted on the robot gripper fixture, connected to the robot, and moves with the robot. It is used to measure the angle values ​​of the robot gripper fixture and to record the position and attitude information of the robot tool's coordinate points (TCP). The PC laptop runs a program system to read and analyze sensor data, interact with the robot system, and perform core algorithm calculations. The computer-side wireless transceiver reads sensor data and transmits it to the PC laptop. The robot system works in conjunction with the robot tool alignment system, receiving correction values ​​output from the PC laptop and correcting the offline trajectory. The fixed-tool side sensor box includes a first extension rod, a second extension rod, a notch for aligning with the glue gun rod, and a sensor; the first extension rod and the second extension rod are used to adjust the relative position of the fixed-tool side sensor box so that it is in the desired measurement position; the notch for aligning with the glue gun rod facilitates the installation of the fixed-tool side sensor box onto the glue gun rod of the fixed fixture; the sensor is used to record angle values. The robot gripper fixture is provided with a sensor box mounting surface, and the robot gripper side sensor box is provided with a mounting surface that matches the sensor box mounting surface, so as to facilitate the installation and connection of the two. When the fixed fixture is a fixed glue application fixture, the glue gun rod and glue gun head of the fixed glue application fixture are parallel and their axes are on the same straight line. The projection of the glue gun rod on the ground is perpendicular to the glue application bracket mounting base biased towards the glue gun side plane.

2. A calibration method based on the robot fixed tooling calibration system of claim 1, characterized in that, Includes the following steps: Install the sensor box on the fixed fixture side onto the fixed fixture, adjust its position, and record the sensor information; Install the robot gripper side sensor box onto the robot gripper fixture to record the position and attitude information of the sensor and the robot head TCP; The attitude relationship between the robot tool coordinate point TCP and the robot gripper side sensor box is obtained through mathematical calculations, and then the angular attitude relationship between the robot TCP and the fixed tooling side sensor box is calculated. Move the robot to the first offline trajectory key point and record the positional deviation. Based on the known angular and orientation relationships and positional deviations, an accurate positional relationship is established between the robot and the fixed fixture, and an external TCP is created to correct the offline trajectory.

3. The calibration method according to claim 2, characterized in that, In the step of installing the sensor box on the fixed fixture, for the fixed glue application fixture, the first extension rod and the second extension rod need to be adjusted so that they are parallel to the glue gun side plane of the glue application bracket mounting base, respectively; in the step of installing the sensor box on the robot gripper fixture, ensure that the mounting surface of the robot gripper sensor box is in close contact with the sensor box mounting surface of the robot gripper fixture.

4. The calibration method according to claim 2, characterized in that, The process of obtaining the attitude relationship between the robot tool coordinate point TCP and the robot gripper side sensor box through mathematical calculations, and calculating the angular attitude relationship between the robot TCP and the fixed tooling side sensor box, is specifically implemented through an algorithm preset in the PC laptop program system. The mathematical principles based on this algorithm include trigonometric functions and vector operations, combined with the angle values ​​recorded by the sensors and the position information of the robot TCP for calculation.

5. The calibration method according to claim 2, characterized in that, After moving the robot to the first offline trajectory key point and recording the position deviation, the process also includes clicking "calculate" on the PC laptop, where the program system performs internal calculations based on the recorded data and outputs a correction value to the robot system. After receiving the correction value, the robot system corrects the offline trajectory on the teach pendant.

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