Insertion method for guiding robot to clamp long cylinder characteristics of cabin section based on 2D measurement

Abstract

The invention relates to the field of robots, cylinder axis measurement guiding methods and cylinder insertion long-distance decoupling alignment assembly, in particular to a long-distance insertion automatic assembly method for guiding a robot to clamp a cylinder based on 2D measurement. Comprising the following steps: 1) respectively constructing a measurement coordinate system c-xyz, a position adjustment coordinate system b-xyz and a direction adjustment coordinate system a1-xyz; 2) measuring the axis of the cabin section through a contourgraph; 3) performing coaxial adjustment on the cabin section A according to a measurement result; and 4) carrying out plug-in mounting work based on the adjusted position. According to the insertion method for guiding the long cylinder characteristics of the clamping cabin section of the robot based on 2D measurement, single measurement is carried out by adopting the axis of the section of a fixed cabin section B, the robot is guided to clamp a moving cabin section A by adopting center alignment and direction alignment decoupling alignment of two sections, and real-time closed-loop feedback adjustment can be realized during center alignment and axial alignment; the method improves the detection flexibility, and has the advantages of efficient decoupling and high matching precision.

Description

TECHNICAL FIELD

[0001] The application relates to the fields of robots, a cylindrical axis measurement guiding method and a long-distance decoupling alignment assembly of a cylindrical plug-in, in particular to a long-distance plug-in automatic assembly method of a robot clamping a cylinder based on 2D measurement guiding. BACKGROUND

[0002] Long-distance plug-in of a cylinder is a necessary link and a key technology of a shell assembly, and long-characteristic cylinder plug-in has the characteristics of small matching gap, long plug-in distance and multi-degree-of-freedom matching, so that the assembly has the requirements of high measurement accuracy and great assembly difficulty, and currently, manual butt joint is mostly adopted, which has the problems of low assembly efficiency and poor consistency, and does not meet the requirements of automatic assembly of the whole line. Researchers butt joint through forms such as scanning a three-dimensional model, reverse modeling and indirect target, but the research objects are all short-distance matching spigots, and the long-distance cylinder plug-in is not applicable. A 2D profile gauge can realize fitting of a cross-section circle center and fitting of a cylindrical axis by identifying the characteristics of a cylinder part, and a serial robot has the advantages of large moving range and high repeat accuracy, so that the robot can be guided by the 2D profile gauge, the multi-degree-of-freedom adjustment and matching problem can be solved by using the degree-of-freedom split matching, and the long-characteristic cylinder plug-in problem can be solved, and the assembly efficiency and the consistency of product quality are improved. SUMMARY

[0003] The application aims to provide a long-distance plug-in automatic assembly method of a robot clamping a cylinder based on 2D measurement guiding, so as to overcome the above defects.

[0004] The technical scheme adopted by the application to achieve the above-mentioned purpose is:

[0005] The long-distance plug-in method of a robot clamping a cylinder characteristic of a cabin section based on 2D measurement guiding comprises a cabin section A with a long-cylinder-hole characteristic and a cabin section B with a long-cylinder-shaft characteristic, wherein the cabin section A is clamped by a robot tool, and the cabin section B is fixedly connected through a support, and comprises the following steps.

[0006] 1) respectively construct a measurement coordinate system c-xyz, a position adjustment coordinate system b-xyz and a direction adjustment coordinate system a1-xyz;

[0007] 2) measure the cabin axis through a profile gauge;

[0008] 3) coaxially adjust the cabin A according to the measurement result;

[0009] 4) perform plug-in work based on the adjusted position.

[0010] The step 1) comprises the following steps:

[0011] 1.1) construct the measurement coordinate system c-xyz:

[0012] The measurement coordinate system c-xyz is a fixed system. When its origin is located at the initial position of the external axis of the 2D profilometer, y=0, x=0, z=0. That is, when the external axis is 0, the coordinate system coincides with the centroid of the sensor. The y direction is along the external axis, and the xz direction coincides with the inherent coordinate system of the profilometer.

[0013] 1.2) Constructing a position adjustment coordinate system b-xyz:

[0014] The position adjustment coordinate system b-xyz is a fixed system, with its origin coinciding with the origin of the robot base and its coordinate axis direction coinciding with the c-xyz direction. The y-axis movement of the serial robot and the external axis of the 2D profilometer move synchronously to keep the same position and the measured value of the fitted circle center remains unchanged, thus completing the same-direction calibration of the measurement coordinate system and the position adjustment coordinate system.

[0015] 1.3) Construct the orientation adjustment coordinate system a1-xyz:

[0016] The angle adjustment coordinate system a1-xyz is a moving system, with its origin coinciding with the center of the clamping compartment A at section a1. The x, y, and z directions are all consistent with the end flange system.

[0017] Step 2) includes the following steps:

[0018] 2.1) Measure the center coordinates of the axis of compartment B at fixed ends b1 and b2 using a 2D profilometer. , ;

[0019] 2.2) Measure the position of the B-axis of compartment based on the fixed end sections b1 and b2. and The positions of the A-axis of the measuring section are measured at sections a1 and a2. and Using the coaxial principle, the coordinates of the target's center at cross-sections a1 and a2 are calculated. , .

[0020] Step 2.2) specifically refers to:

[0021] The coordinates of position a1 are:

[0022] ;

[0023] ;

[0024] The coordinates of position a2 are:

[0025] ;

[0026] .

[0027] The step 3) comprises the following steps:

[0028] 3.1) In the cross section a1, the deviation of the current position measurement value from the target position is The deviation is made to tend to 0 by adjusting x and z in the position adjustment coordinate system b-xyz coordinate system And The adjustment amount is ;

[0029] 3.2) In the cross section a2, the x and z measurement deviation is made to tend to 0 by adjusting the angles rx and rz in the angle adjustment coordinate system a1-xyz And The adjustment amount is , adjustment amount Finally, the direction alignment of the cabin section A and the cabin section B is realized.

[0030] The present application has the following advantages and benefits:

[0031] 1. The method for inserting the long cylindrical feature of the cabin section based on the 2D measurement guided robot clamping of the present application only uses a 2D profiler, which has the advantages of fewer measurement parameters, low cost and easy use.

[0032] 2. The method for inserting the long cylindrical feature of the cabin section based on the 2D measurement guided robot clamping of the present application does not need scanning, reverse modeling and other methods, greatly simplifying the process of automatic assembly and improving the assembly efficiency.

[0033] 3. The method for inserting the long cylindrical feature of the cabin section based on the 2D measurement guided robot clamping of the present application adopts single measurement of the fixed cabin section B cross section axis, and the guided robot clamping motion cabin section A adopts two cross section center alignment and direction alignment decoupling alignment. The center alignment and axial alignment can realize real-time closed-loop feedback adjustment, improve the flexibility of detection, have the advantages of efficient decoupling and high matching precision. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 It is a schematic diagram of the cabin section A and the cabin section B feature, measurement coordinate system and adjustment coordinate system of the present application.

[0035] Figure 2 It is a principle diagram of the 2D profiler measurement cylindrical cross section feature fitting circle center.

[0036] Figure 3 It is an assembly flowchart of the present application. DETAILED DESCRIPTION

[0037] The present application will be further described in detail below in combination with the drawings and examples.

[0038] The method for guiding the robot to clamp the cylinder for long-distance insertion and automatic assembly based on 2D measurement comprises the following steps: firstly, measurement, position adjustment, coordinate system establishment and calibration. The measurement coordinate system c-xyz is established at the original point of the starting position of the 2D profiler, and the position adjustment coordinate system b-xyz is established at the robot base. The angle relationship between the external motion axis y of the profiler and the motion axis y of the robot is calibrated through the synchronous movement of the external axis of the profiler and the y axis of the robot, so that the rx / rz angle derivation is not caused when the x / z direction position is adjusted in the b-xyz system. Secondly, the angle adjustment coordinate system a1-xyz is established at the center position of the motion cabin section a1. When the rx and rz angles of the cabin section A are adjusted according to the position a2 deviation, the position and angle coupling adjustment of the position a1 is not caused. Thirdly, the axis measurement of the fixed cabin section B and the target position calculation of the cabin section A are realized by moving the 2D profiler. The specific method is to use the profiler to fit and measure the center position of the B1 cross section circle (x b1 ,y b1 ,z b1 ), the center position of the B2 cross section circle (x b2 ,y b2 ,z b2 ), wherein y is measured by the external axis, and x / z is measured by the profiler fitting. The 2D fitting center value (x a1 ,z a1 ) of the section a1 of the cabin section A and the 2D fitting center value (x a2 ,z a2 ) of the section a1 can be calculated by using the collinear principle and the known coordinates ya1 and ya2. Then, the center alignment and direction alignment are realized by using the two-section adjustment method. The specific method is to adjust x and z in the position adjustment coordinate system b-xyz according to the target value (x a1 ,z a1 ) at the position a1 so that the measurement deviations dx a1 and dz a1 tend to 0. At the section a2, the angles rx and rz are adjusted in the angle adjustment coordinate system a1-xyz so that the measurement deviations dx a2 and dz a2 tend to 0, and finally the direction alignment of the cabin section A and the cabin section B is realized. Finally, the axis alignment of the robot clamped motion cabin section A and the fixed cabin section B is realized by using the 2D profiler, and then the long-cylinder feature automatic insertion method is realized.

[0039] As shown in Figure 1 , the cabin section B has the feature of a long-cylinder "axis" fixedly connected by a support, and the cabin section A has the feature of a long-cylinder "hole" clamped by a robot tool. The figure contains three coordinate systems, namely the measurement coordinate system c-xyz, the position adjustment coordinate system b-xyz and the direction adjustment coordinate system a1-xyz. The specific coordinate system establishment method is:

[0040] 1) Measurement coordinate system c-xyz is fixed, the origin is located outside the initial position of the 2D profile instrument axis, y=0, x=0, z=0, that is, the external axis is 0, the coordinate system coincides with the sensor center, the y direction is along the external axis, and the xz direction coincides with the inherent coordinate system of the profile instrument.

[0041] 2) Position adjustment coordinate system b-xyz is fixed, the origin coincides with the base origin of the Kuka robot, and the coordinate axis direction coincides with the c-xyz direction. When the specific calibration method is fitted, the y axis movement of the serial robot is synchronized with the external axis movement to keep the same position and the measurement value of the circle center is unchanged.

[0042] 3) Angle adjustment coordinate system a1-xyz is a moving system, the origin coincides with the circle center of the holding cabin section A at the a1 position, and the x / y / z direction coincides with the end flange system, that is, when the holding cabin section angle posture is adjusted in a1-xyz, the a1 position will not be derived.

[0043] As shown in Figure 2 , the 2D profile instrument has laser emission and laser reception, the x axis is the light direction, and the z axis represents the distance between the current object and the sensor. The partial section of the cylinder is a partial arc, and the arc can fit the cylinder section circle center x / z coordinates and radius r. Therefore, the 2D profile instrument can be used to measure the circle center coordinates of the cylinder section in real time, which is beneficial to real-time closed-loop adjustment of the current cylinder section center position.

[0044] As shown in Figure 3 , the long cylinder "axis" and "hole" specific operation process is coordinate system establishment, cabin section axis measurement and cabin section coaxial adjustment, which is specifically:

[0045] 1) Coordinate system establishment, which is measurement coordinate system c-xyz, position adjustment coordinate system b-xyz and direction adjustment coordinate system a1-xyz;

[0046] 2) Cabin section axis measurement operation is to measure the axis center coordinates , using the profile instrument at fixed ends b1 and b2, and according to the b1 and b2 measured axis positions y b1 and y b2 , a1 and a2 measured axis positions y a1 and y a2 , the target position in the section a1 and section a2 target circle center coordinates , can be calculated using the coaxial principle. The a1 position coordinates are , ; the a2 position coordinates are , .

[0047] 3) Cabin section axis adjustment adopts two-step adjustment method, in a1 section, according to the deviation between the current position measurement value and the target position of the position , by adjusting x and z in b-xyz coordinate system, the deviation dz a1 and dx a1 tends to 0, wherein the adjustment amount ; in section a2, by adjusting the angle rx and rz in the angle adjustment coordinate system a1-xyz, wherein the adjustment amount , the measurement deviation x and z , dx a2 and dz a2 tends to 0, and finally realizes the direction alignment of cabin section A and cabin section B.

[0048] The above is the preferred embodiment of the present application, it should be pointed out that for ordinary skilled in the art, without departing from the principles of the present application, can also make a number of improvements and refinements, these improvements and refinements should be considered as the protection scope of the present application.

Claims

1. A method for guiding a robot to clamp a long cylindrical feature of a segment based on 2D measurements, comprising a segment A having a feature of a long cylindrical "hole" and a segment B having a feature of a long cylindrical "shaft", wherein, The cabin section A is clamped by a robot tool, and the cabin section B is fixedly connected by a support, characterized in that the method comprises the following steps: 1) constructing a measurement coordinate system c-xyz, a position adjustment coordinate system b-xyz and a direction adjustment coordinate system a1-xyz respectively; 2) measuring the cabin section axis by a profiler; 3) performing coaxial adjustment on the cabin section A according to the measurement result; 4) performing insertion work based on the adjusted position.

2. The method of claim 1, wherein, The step 1) comprises the following steps: 1.1) constructing the measurement coordinate system c-xyz: The measurement coordinate system c-xyz is a fixed system, when the origin point is located at the initial position of the external axis of the 2D profiler, y=0, x=0, z=0, that is, the external axis is 0, the coordinate system coincides with the sensor center, the y direction is along the external axis, and the xz direction coincides with the inherent coordinate system of the profiler; 1.2) constructing the position adjustment coordinate system b-xyz: The position adjustment coordinate system b-xyz is a fixed system, the origin point coincides with the origin point of the robot base, the coordinate axis direction coincides with the direction of c-xyz, the synchronous movement of the y axis of the serial robot and the external axis of the 2D profiler keeps the same position fitting circle center measurement value unchanged, and the same direction calibration of the measurement coordinate system and the position adjustment coordinate system is completed; 1.3) constructing the direction adjustment coordinate system a1-xyz: The angle adjustment coordinate system a1-xyz is a dynamic system, the origin point coincides with the circle center of the clamped cabin section A at the cross section a1 position, and the x, y and z directions all coincide with the end flange system.

3. The method of claim 1, wherein, The step 2) comprises the following steps: 2.1) Measure the axis center coordinates of the cabin section B at the fixed ends bl and b2 with a 2D profilometer , ; 2.2) Measure the cabin section B axis position according to fixed end sections bl and b2 and , Measure the cabin section A axis position according to sections al and a2 and , Calculate the target center coordinates of the target position in section al and section a2 using the coaxial principle , .

4. The method of claim 3, wherein, The step 2.2) is specifically: The a1 position coordinate is: ； ； The a2 position coordinate is: ； 。 5. The method of claim 1, wherein, The step 3) comprises the following steps: 3.1) At the cross section a1, the deviation of the current position measurement from the target position is measured according to the position By adjusting x and z in the position adjustment coordinate system b-xyz coordinate system, the deviation and tends to 0, wherein the adjustment amount ; 3.2) At cross-section a2, the x and z measurement biases are adjusted by adjusting angles rx and rz in the angle-adjusted coordinate system a1-xyz and tend to 0, where, the adjustment amount eventually achieving directional alignment of the cabin section A and the cabin section B.

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