CN205466311U - Calibration system of robot based on terminal incomplete coordinate information - Google Patents

Abstract

The utility model relates to a calibration system of robot based on terminal incomplete coordinate information belongs to the robot and marks the field. The magnetism gauge stand passes through magnetic force to be installed on fixed platform, and the magnetism gauge stand links together through the connecting rod with cable sensor, and the end that cable sensor acted as go -between is installed on the universal joint, posts angular transducer on the universal joint, and angular transducer moves along with the universal joint, and the universal joint is installed in the robot, cable sensor, angular transducer pass through cable sensor cable, angular transducer cable and computer connecting communication respectively, and the robot passes through robot cable and computer connecting communication, through computer acquisition cable sensor's the length of acting as go -between, angular transducer's angle, the joint corner of robot. The utility model provides reliability and precision that high structural parameters resolved, the operating is simplified step has improved calibration efficiency.

Description

A Robot Calibration System Based on Incomplete Coordinate Information of Terminal

technical field

The utility model relates to a robot calibration system based on terminal incomplete coordinate information, which belongs to the field of robot calibration.

Background technique

With the widespread use of robots in various industries, the industry has strict requirements on the repetitive positioning accuracy and absolute positioning accuracy of industrial robots during motion. Since the robot is a multi-degree-of-freedom device, there is error accumulation in this structural form. The disadvantage of magnification is that the structural parameter errors of joints at all levels will be magnified step by step, resulting in a decrease in the accuracy of the robot.

Calibration is an effective method to eliminate the error of robot structure parameters. Currently, commonly used robot calibration methods generally rely on precision measuring instruments such as laser trackers, laser interferometers, and three-coordinate measuring machines.

The common feature of the above methods is to measure the coordinate value of the end of the robot. The cost of the required calibration equipment is high, the operation steps are cumbersome, the technical level of the operator is high, the data collection is time-consuming and laborious, and it is difficult to realize automation.

Contents of the invention

The utility model provides a robot calibration system based on the incomplete coordinate information of the terminal to solve the problems of high cost, cumbersome operation steps and low positioning accuracy of the existing equipment.

The technical solution of the utility model is: a robot calibration system based on incomplete coordinate information at the end, including a fixed platform 1, a magnetic table base 2, a connecting rod 3, a cable sensor 4, an inclination sensor 5, a universal joint 6, and a robot 7 , pull sensor cable 8, robot cable 9, inclination sensor cable 10, computer 11;

The magnetic base 2 is mounted on the fixed platform 1 by magnetic force, the magnetic base 2 and the wire sensor 4 are connected together through the connecting rod 3, the end of the wire of the wire sensor 4 is installed on the universal joint 6, and on the universal joint 6 Attached with an inclination sensor 5, the inclination sensor 5 moves with the universal joint 6, and the universal joint 6 is installed on the robot 7; the pull wire sensor 4 and the inclination sensor 5 are respectively connected to the computer 11 through the pull wire sensor cable 8 and the inclination sensor cable 10. , the robot 7 is connected and communicated with the computer 11 through the robot cable 9;

The working principle of the present utility model is: connect backguy sensor 4, inclination sensor 5, universal joint 6, robot 7, collect the length of backguy sensor 4, the angle of inclination sensor 5 and the joint rotation angle of robot 7 by computer 11, and Change the pose of the robot 7 according to the joint transformation order, so that sufficient data can be collected; first, determine the direction vector of the backguy according to the angle collected, and then calculate the angle between any two backguys according to the direction vector, and finally according to the calculated The distance between two points in space at the end of the robot 7 is calculated from the included angle and the length of the cable collected twice. According to the distance between two points at the end of the robot 7 and the kinematic equation of the robot 7, an equation with the structural parameters of the robot 7 as unknown quantities is obtained, and the calibration of the robot is realized by solving the equation.

Specific steps are as follows:

Step1, paste the inclination sensor 5 on the universal joint 6, and install the universal joint 6 on the end of the robot 7;

Step2, install the pull wire sensor 4 on the magnetic watch base 2 through the connecting rod 3, and fix the magnetic watch base 2, and connect the pull wire of the pull wire sensor 4 to the end of the universal joint 6;

Step3, power on, turn on the inclination sensor 5, the cable sensor 4, and the robot 7, and move the robot 7 to the initial pose and satisfy the initialization count variable v=0;

Step4, judging whether to complete the data acquisition operation;

If the data collection has been completed, go to Step7; if not, go to Step4;

Step5. The counting variable is incremented by 1: v=v+1;

Step6, collect the backguy length of backguy sensor 4, the angle data of inclination sensor 5 and the joint rotation angle data of robot 7 by computer 11;

Step7. Transform the pose of robot 7. The principle of transformation is: transform the rotation angle of each joint in turn according to the size of the joint sequence (such as: move in sequence according to the principle of joints from small to large, joint one changes from 0° to 20°, and the next Change from 20° to 40° once again, and so on. Each time the joint angle is increased by 20° until it reaches 340°, that is, the pose transformation of this joint is completed, and the rest of the joints can also move in this way, so that Each joint of the robot 7 is fully moved, and the user can also increase or decrease the number of transformations of the pose to obtain more data); wherein the number of transformations of all joints is t, and the judgment is returned to step Step4 every time the transformation is performed;

Step8, make t=v after completing the data collection;

Step9. Calculation of the distance between two consecutive points i and j in the end space of robot 7:

After the data collection is completed, the collected data can be used to calculate the distance l _i,j between two consecutive points i and j in the space at the end of the robot 7; since the wire of the wire sensor 4 is always perpendicular to the plane where the inclination sensor 5 is located, and the inclination sensor 5 and the wire together As the gimbal 6 moves, the angle collected by the inclination sensor 5 is the angle α between the stay wire and the x-axis of the horizontal plane, and the angle β between the stay wire and the y-axis. Calculate the angle between the cable at position i and the cable at position j, and finally according to the angle between the cable at position i and the cable at j position and the length of the cable at position i and the cable at j position Calculate the distance between two points at the end i of the robot 7 and at the end j of the robot 7;

Calculation of the direction vector:

The direction vector of the guy wire at position i:

Use the direction cosine cosα _i ² +cosβ _i ² +cosγ _i ² =1 to calculate the angle γ _i so as to determine the direction vector m of the guy wire at position i, m=(cosα _i , cosβ _i , cosγ _i );

The direction vector n of the pull wire at position j is: n=(cosα _j , cosβ _j , cosγ _j );

Angle between the wire at position i and the wire at position j for:

Calculation of the distance between two points i and j at the end of the robot 7:

According to the law of cosines Calculate the distance l _i, j between the end point i and j in space; where l _i , l _j represent the wire length of the wire sensor 4 when the end position of the robot 7 is i, j respectively; α _i , β _i and γ _i represent the angles between the cable and the x-axis, the y-axis, and the z-axis respectively when the end position of the robot 7 is i; α _j , β _j , and γ _j respectively represent the When the end position of the robot 7 is j, the included angle between the pull wire and the x-axis of the horizontal plane, the included angle with the y-axis, and the included angle with the z-axis;

Step10, the solution of the structural parameters of the robot 7 to be calibrated:

Using the collected joint rotation angle data of the robot 7, the calculated distance l _i,j , and the kinematic equations of the robot 7 to list t equations, each equation is in the form of:

${\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; =</span>\sqrt{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; j</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}$

in, $\begin{array}{c}{x}_i=f_x({\mathrm{\&theta;}}_{i,1},{\mathrm{\&theta;}}_{i,2},...,{\mathrm{\&theta;}}_{i,w},q)\\ {\mathrm{the\; y}}_i=f_{\mathrm{the\; y}}({\mathrm{\&theta;}}_{i,1},{\mathrm{\&theta;}}_{i,2},...,{\mathrm{\&theta;}}_{i,w},q)\\ z_i=f_z({\mathrm{\&theta;}}_{i,1},{\mathrm{\&theta;}}_{i,2},...,{\mathrm{\&theta;}}_{i,w},q)\end{array}$ Indicates the coordinate value when the end position of the robot 7 is at i, θ _i,1 , θ _i,2 ,...,θ _i,w indicate the w joint rotation angle values when the end position of the robot 7 is at i, q is the robot 7 to be identified structure parameter vector;

$\begin{array}{c}{x}_j=f_x({\mathrm{\&theta;}}_{j,1},{\mathrm{\&theta;}}_{j,2},...,{\mathrm{\&theta;}}_{j,w},q)\\ {\mathrm{the\; y}}_j=f_{\mathrm{the\; y}}({\mathrm{\&theta;}}_{j,1},{\mathrm{\&theta;}}_{j,2},...,{\mathrm{\&theta;}}_{j,w},q)\\ z_j=f_z({\mathrm{\&theta;}}_{j,1},{\mathrm{\&theta;}}_{j,2},...,{\mathrm{\&theta;}}_{j,w},q)\end{array}$ Indicates the coordinate value when the end position of the robot 7 is located at j, θ _j,1 , θ _j,2 ,...,θ _j,w indicate the w joint rotation angle values when the end position of the robot 7 is located at j;

Step10. Solve the equation system composed of t equations:

$\begin{array}{c}{\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\sqrt{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}\\ {\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; =</span>\sqrt{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; 3</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}\\ <span\; class="notranslate">\; ...</span>\\ {\mathrm{<span\; class="notranslate">\; l</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; =</span>\sqrt{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; z</span>}}_{\mathrm{<span\; class="notranslate">\; t</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}\end{array}$

In the above equations, only the structural parameter vector q of the robot 7 to be identified is uncertain, which can be solved by using the nonlinear least square method to obtain the exact value of the structural parameter vector q;

Step11. Substitute the structural parameter vector q into the kinematic equation of the robot 7 to verify the validity of the calibration results and complete the calibration of the robot 7.

The beneficial effects of the utility model are:

1. Using a pull wire sensor with a variable length, the movement space of the robot becomes larger when collecting data, and the movement of each joint of the robot is more sufficient, providing more robust data support for the calculation of structural parameters and more flexible calibration operations light.

2. The distance between the end of the robot and two points in space can be accurately calculated according to the readings of the cable sensor and the inclination sensor, which improves the reliability and accuracy of the structural parameter calculation.

3. Since there is no need to measure the coordinate value of the end of the robot, the operation steps are simplified and the calibration efficiency is improved.

Description of drawings

Fig. 1 is the pose diagram when the device of the present invention collects data in the calibration process;

Fig. 2 is a schematic diagram of the length and angle of the end of the robot of the present invention in poses i and j;

Each label in the figure: 1-fixed platform, 2-magnetic table base, 3-connecting rod, 4-pull sensor, 5-tilt sensor, 6-universal joint, 7-robot, 8-pull sensor cable, 9-robot Cable, 10-inclination sensor cable, 11-computer.

detailed description

Embodiment 1: As shown in Figure 1-2, a robot calibration system based on incomplete coordinate information at the end, including a fixed platform 1, a magnetic table base 2, a connecting rod 3, a cable sensor 4, an inclination sensor 5, and a universal joint 6. Robot 7, pull sensor cable 8, robot cable 9, inclination sensor cable 10, computer 11;

The magnetic base 2 is mounted on the fixed platform 1 by magnetic force, the magnetic base 2 and the wire sensor 4 are connected together through the connecting rod 3, the end of the wire of the wire sensor 4 is installed on the universal joint 6, and on the universal joint 6 Attached with an inclination sensor 5, the inclination sensor 5 moves with the universal joint 6, and the universal joint 6 is installed on the robot 7; the pull wire sensor 4 and the inclination sensor 5 are respectively connected to the computer 11 through the pull wire sensor cable 8 and the inclination sensor cable 10. , the robot 7 is connected and communicated with the computer 11 through the robot cable 9;

The specific implementation of the utility model has been described in detail above in conjunction with the accompanying drawings, but the utility model is not limited to the above-mentioned implementation. Various changes are made.

Claims (1)

1. A robot calibration system based on terminal incomplete coordinate information is characterized in that: the device comprises a fixed platform (1), a magnetic gauge stand (2), a connecting rod (3), a stay wire sensor (4), an inclination angle sensor (5), a universal joint (6), a robot (7), a stay wire sensor cable (8), a robot cable (9), an inclination angle sensor cable (10) and a computer (11);

the magnetic gauge stand (2) is installed on the fixed platform (1) through magnetic force, the magnetic gauge stand (2) is connected with the stay wire sensor (4) through the connecting rod (3), the tail end of a stay wire of the stay wire sensor (4) is installed on the universal joint (6), the inclination angle sensor (5) is attached to the universal joint (6), the inclination angle sensor (5) moves along with the universal joint (6), and the universal joint (6) is installed on the robot (7); the pull wire sensor (4) and the tilt angle sensor (5) are respectively connected with and communicated with a computer (11) through a pull wire sensor cable (8) and a tilt angle sensor cable (10), and the robot (7) is connected with and communicated with the computer (11) through a robot cable (9); the computer (11) is used for acquiring the stay wire length of the stay wire sensor (4), the angle of the inclination angle sensor (5) and the joint rotation angle of the robot (7).