CN105081524B - In welding process, the online dynamic programming of track follows the tracks of collaborative control method with welding bead - Google Patents

Abstract

The invention provides the online dynamic programming of track in a kind of welding process and follow the tracks of collaborative control method with welding bead, belong to mobile welding robot technical field.The present invention abundant integrated structure light sensors region is ahead of electric arc and realizes the detection of front, weld zone seam welds groove and arc sensor obtains the advantage of welding torch pose in real time, realizes, based on welding bead Isometric Approximation thought, the collaborative uneoupled control that the online dynamic programming of robot body track is followed the tracks of with welding bead.The present invention can improve mobile welding robot speed of welding stability in large-scale component complicated track weld seam welding process and welding bead tracking accuracy, improve joint trajectory local deep camber and the quality of weld seam molding in knuckle region, can be applicable to, in the mobile robot welding process of the equipment manufacturing such as boats and ships, the energy and track traffic, be particularly suited for the welding occasion of large turn or deep camber curved welding seam.

Description

Cooperative control method of trajectory online dynamic planning and weld bead tracking in welding process

technical field

The invention belongs to the technical field of mobile (type) welding robots. The invention relates to a control method for the coordination of trajectory online dynamic planning and welding bead tracking in the welding process, and can be widely used in automatic welding of mobile robots and the like.

Background technique

In the welding of large components in the fields of energy equipment, heavy machinery, and shipbuilding, mobile welding robots have become an effective method for automatic welding of large-scale and complex space curve welds due to their advantages in large-scale motion capabilities. Limited by the working stroke of the airborne actuator device (such as the mechanical arm, Cartesian coordinate system X-Y carriage, etc.) installed on the robot body of the mobile welding robot, it is necessary to adjust its position and posture in real time in combination with the robot body to ensure that the welding torch is aligned. In the center of the welding seam, the welding operation is performed under the coordinated control of the robot body and the onboard actuator.

Existing mobile welding robots mainly use a single type of seam tracking sensor, including arc sensors and vision sensors. The mobile welding robot using arc sensors only detects the molten pool area and obtains welding deviation information from it. The real-time welding deviation information or the actual correction behavior of the airborne actuator to adjust the pose requires the airborne actuator to have a large effective working stroke; moreover, the following motion of the robot body to the welding bead is easily affected by the electromechanical inertia of the mobile welding robot system The impact leads to control lag, especially in areas with large curvature of the curved weld trajectory and knuckle areas where the mobile welding robot needs to perform large-angle turning motions to track the weld trajectory. Because it is difficult to adjust the pose in time, it is easy to produce partial welding defects , or the welding seam is poorly formed due to changes in welding speed; in order to avoid strong arc light interference, the mobile welding robot using visual sensors usually has a certain distance between the detection area of the visual sensor and the arc molten pool area, and it is difficult to compensate in real time. Seam position and size changes.

To sum up, the existing technologies are difficult to take into account the dynamic response and static accuracy of the mobile welding robot in the welding process of large-scale complex trajectory welds, and it is difficult to solve the technical problem of coupling the motion control of the robot body and the airborne actuator.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art, and propose a control method in which trajectory online dynamic planning and weld bead tracking are coordinated in order to realize accurate tracking of weld bead in large-scale complex trajectory weld welding while ensuring Weld form quality.

In order to achieve the above object, the present invention takes the following technical solutions:

A control method for the coordination of trajectory online dynamic planning and weld bead tracking in the welding process, comprising the following steps:

1) Establish the coordinate system of the mobile welding robot system, including: the basic Cartesian coordinate system O _xyz , the robot body coordinate system M _xyz , the airborne actuator coordinate system U _xyz and the structured light sensor coordinate system L _xyz , where the airborne actuator The positive direction of the x-axis of the coordinate system U _xyz and the coordinate system L _xyz of the structured light sensor is consistent with the direction of the robot body moving straight forward, the positive direction of the z-axis is consistent with the direction of the ground normal, and the positive direction of the y-axis is determined by the left-hand rule. The origin of the mechanism coordinate system U _xyz is located at the fixed connection between the airborne actuator and the robot body;

2) When the welding arc scans the groove in the form of swinging, rotating or swinging-rotating compound motion, the structured light sensor is used to extract the position information of the welding groove feature point i in the front of the welding zone, including the welding groove feature point i and the welding groove feature point i. The deviation distance E _i of the torch in the y-axis direction in the structured light sensor coordinate system L _xyz and the coordinates of the welding groove feature point in the structured light sensor coordinate system L _xyz , and the arc sensor is used to collect the arc energy signal in real time, and the integral The difference method, the characteristic harmonic method or the extreme value method extract the real-time welding torch position and orientation information in the arc energy signal after signal filtering and amplification processing, and the airborne actuator adjusts the welding torch position and orientation information according to the obtained real-time welding torch position and orientation information. Torch position and posture, while the airborne actuator adjusts the welding torch position and posture, the arc sensor starts the next cycle of arc energy signal acquisition, and this cycle realizes welding bead tracking;

3) According to the coordinates of the welding groove feature points in the structured light sensor coordinate system L _xyz , the coordinates are transformed to the basic Cartesian coordinate system O _xyz to obtain the coordinates G _{i of the welding groove feature point i} = ( _xi , y _i );

4) According to steps 2) and 3), the coordinates of a series of welding groove feature points are solved sequentially, and a welding groove feature point coordinate sequence {G ₁ ,G ₂ ,...,G _N } and a deviation distance array { E ₁ ,E ₂ ,...,E _N }, where

$\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}{{\mathrm{<span\; class="notranslate">\; vT</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; p</span>}}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}$

In the formula: λ is the distance between the structured light sensor and the welding torch, v is the welding speed, and T _op is the extraction cycle of the feature point position information of the welding groove;

5) Use spline curves to fit and calculate the coordinate sequence of welding groove feature points, obtain the trajectory function S(x) to be welded and perform derivation, and solve the welding groove feature point coordinate sequence for each welding groove feature point to be welded The tangent slope k _i on the welding trajectory function S(x), i=1,2,...,N, obtains the pose matrix P _i =[x _i y _i arctan(k _i )], the set of i=1,2,...,N;

6) Set the threshold σ and to compare and set the threshold ζ to compare with ΔE when Or when ΔE>ζ, the robot body executes continuous path motion trajectory planning; when Or when ΔE<-ζ, the robot body executes in-situ turning trajectory planning around the center of the car body; when And when -ζ≤ΔE≤ζ, the robot body executes point-to-point straight trajectory planning, where:

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ \mathrm{<span\; class="notranslate">\; \&sigma;</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; ,</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\\ \mathrm{<span\; class="notranslate">\; \&zeta;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\end{array}\right.$

In the formula: E ₁ and E _N are the deviation distances between the first and Nth welding groove feature points and the welding torch in the y-axis direction in the structured light sensor coordinate system L _xyz , and L _s is the welding torch on-machine y coordinate in the coordinate system U _xyz of the onboard actuator, L _a is the maximum working _stroke of the onboard actuator in the direction of the y axis in the coordinate system U _xyz of the The preset working stroke in the direction of the y-axis in the coordinate system U _xyz ;

7) The robot body performs pose adjustment according to the continuous path motion trajectory planning, the in-situ turning trajectory planning around the center of the car body, or the point-to-point straight trajectory planning, and at the same time repeat steps 2) to 6) to perform the next trajectory planning, that is, to realize Coordinated control of trajectory online dynamic planning and weld bead tracking during welding.

In the above-mentioned technical scheme, step 6) described in the continuous path motion locus planning, the method that adopts is:

According to the collection of welding groove feature point pose matrix described in step 5), adopt the following formula:

$\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}\mathrm{<span\; class="notranslate">\; i</span>}}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}\mathrm{<span\; class="notranslate">\; i</span>}}\\ {\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]<span\; class="notranslate">\; =</span>\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</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>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>\\ \mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; )</span>\end{array}\right]<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; ...</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; N</span>}$

Calculate the pose matrix of the i-th point of the robot body on the trajectory of the robot body: U _pi :[x _pi ,y _pi ,θ _pi ],(i=1,2,...,N), where: S(x _i ) is the function value of the i-th point on the track function S(x) to be welded, x _pi and y _pi are the coordinates of the i-th point on the robot body motion track in the basic Cartesian coordinate system O _xyz respectively, and θ _pi is The azimuth angle of the i-th point of the robot body on the robot body trajectory, using the spline curve to interpolate the coordinates (x _pi , y _pi ) of all points on the robot body trajectory, i=1,2,...,N Calculate and generate continuous and smooth robot body motion trajectory;

In the above-mentioned technical scheme, in step 6) described in step 6), the method of turning track planning around the center of the car body in situ is:

Control the driving wheels on the left and right sides of the robot body so that the speeds of the driving wheels are equal and opposite, so that the robot body turns around the center of the car body in situ. The turning angle θ _R of the robot body is calculated by the following formula:

${\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; )</span>$

In the above-mentioned technical scheme, point-to-point straight track planning described in step 6), the method that adopts is:

Keep the speed of the driving wheels on the left and right sides of the robot body stable, so that the robot body moves a distance of λ along the current direction, and the moving speed remains unchanged.

The welding torch in the present invention adopts one of a magnetically controlled rotary welding torch, a mechanical rotary welding torch, an electronically controlled swing welding torch or a mechanical swing welding torch.

The present invention has the following advantages and outstanding technical effects: fully combining the detection area of the structured light sensor ahead of the arc to realize the detection of the seam welding groove in front of the welding zone and the advantages of the arc sensor obtaining the position and posture of the welding torch in real time through the robot body and the airborne The cooperative decoupling control of the actuator can effectively solve the technical problems of tracking control lag caused by electromechanical inertia and difficulty in taking into account dynamic response and static accuracy during the welding process of large-scale complex space curve welds by mobile welding robots; The welding speed stability and the smoothness of the welding trajectory can be improved, especially the weld forming quality in the local large curvature area of the curved welding seam trajectory and the knuckle area of the broken line welding seam can be improved. This method has obvious advantages over traditional methods in the automatic welding of large components with complex trajectory welds, and has important practical application value. It can be widely used in the welding process of mobile robots in the manufacture of ships, heavy machinery, energy and rail transit equipment. It is especially suitable for the welding of large-scale cylinder girder welds, gantry crane girder side welds, bucket wheel stacker reclaimer bucket wheel welds, locomotive center beam and side chord beam welds and other large turning or large curvature curve welding seams occasion.

Description of drawings

Fig. 1 is a flow chart of a control method for the coordination of trajectory online dynamic planning and weld bead tracking in the welding process.

Fig. 2 is a schematic diagram of the kinematics model of the robot body of the present invention.

Fig. 3 is a schematic diagram of continuous path motion trajectory planning in the present invention.

In Fig. 3-Fig. 5: a and b are the two ends of the weld track respectively.

Fig. 4 is a schematic diagram of planning the in-situ turning trajectory around the center of the car body according to the present invention.

Fig. 5 is a schematic diagram of point-to-point straight track planning in the present invention.

Fig. 6 is a schematic diagram of the structural principle of the mobile welding robot system for realizing the method of the present invention.

In the figure: 1—mobile robot; 2—structured light sensor; 3—image acquisition card; 4—welding torch; 5—Hall sensor or signal transmitter; 6—signal acquisition and processing module; 7—industrial computer; 8— Motion control card; 9—airborne actuator; 10—mobile robot controller; 11—welding power supply; 12—workpiece.

detailed description

The principle and working process of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

Fig. 1 shows the flow chart of the control method of trajectory online dynamic planning and weld bead tracking coordination in the welding process of the present invention, including the following steps:

1) Establish the coordinate system of the mobile welding robot system, including: the basic Cartesian coordinate system O _xyz , the robot body coordinate system M _xyz , the airborne actuator coordinate system U _xyz and the structured light sensor coordinate system L _xyz , where the airborne actuator The positive direction of the x-axis of the coordinate system U _xyz and the coordinate system L _xyz of the structured light sensor is consistent with the direction of the robot body moving straight forward, the positive direction of the z-axis is consistent with the direction of the ground normal, and the positive direction of the y-axis is determined by the left-hand rule. The origin of the mechanism coordinate system U _xyz is located at the fixed connection between the airborne actuator and the robot body. The robot body of the present invention has two degrees of freedom of displacement on the XOY plane and an angle of rotation around the Z axis in the basic Cartesian coordinate system;

To set up the kinematics model of the robot body of the present invention, the method adopted is: since the robot body of the present invention is driven in parallel with the same side wheels, the robot body model is simplified to a two-wheel model when calculating the two-dimensional plane motion pose , and ignore tire deformation and longitudinal sliding of the car body. As shown in Figure 2, the robot body moves from point p to p′, R is the turning radius, b is the distance between the left and right wheels, θ, θ′, and Δθ are the initial azimuth angle of the robot body, the azimuth angle after steering, and the turning distance. Angle, the pose (x ^k+1 , y ^k+1 , θ ^k+1 ) of the center of the robot body in the basic Cartesian coordinate system O _xyz at the moment (k+1) is given by the following formula (1) or the following formula ( 2) calculated,

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}^{\mathrm{<span\; class="notranslate">\; k</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">\; k</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; r</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}}^{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; cos\&theta;</span>}}^{\mathrm{<span\; class="notranslate">\; k</span>}}\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}^{\mathrm{<span\; class="notranslate">\; k</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">\; k</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; r</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}}^{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; )</span>{\mathrm{<span\; class="notranslate">\; sin\&theta;</span>}}^{\mathrm{<span\; class="notranslate">\; k</span>}}\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}\\ {\mathrm{<span\; class="notranslate">\; \&theta;</span>}}^{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; r</span>}}{\mathrm{<span\; class="notranslate">\; b</span>}}{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}}^{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; \&omega;</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}^{\mathrm{<span\; class="notranslate">\; k</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">\; k</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&pi;rcos\&theta;</span>}}^{\mathrm{<span\; class="notranslate">\; k</span>}}{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}}^{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}^{\mathrm{<span\; class="notranslate">\; k</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">\; k</span>}}<span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; \&pi;rsin\&theta;</span>}}^{\mathrm{<span\; class="notranslate">\; k</span>}}{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}}^{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; (</span>{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}\\ {\mathrm{<span\; class="notranslate">\; \&theta;</span>}}^{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; \&pi;</span>}\mathrm{<span\; class="notranslate">\; r</span>}}{\mathrm{<span\; class="notranslate">\; b</span>}}{<span\; class="notranslate">\; \&Integral;</span>}_{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}}^{{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}<span\; class="notranslate">\; |</span>{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; no</span>}}_{\mathrm{<span\; class="notranslate">\; l</span>}}}^{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; |</span>\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; t</span>}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; )</span>$

In the formula: T is the motion period, r is the radius of the wheel, ω _l and ω _r are the angular velocities of the left and right wheels respectively, n _l and n _r are the speeds of the left and right wheels respectively;

2) In this embodiment, the structured light sensor is used to obliquely project the structured light on the seam welding groove, and when the welding arc scans the groove in the form of a rotating motion under the control of an externally applied transverse rotating magnetic field, the data including the geometric structure features of the groove are collected. For the structured light fringe image, the steps of adaptive threshold segmentation, median filtering, thinning and slope calculation are used to process the image and extract features in order to obtain the position information of the welding groove feature point i, including the welding groove feature point i and The deviation distance E _i of the welding torch in the y-axis direction in the structured light sensor coordinate system L _xyz and the coordinates of the welding groove feature point in the structured light sensor coordinate system L _xyz ; when the welding arc is controlled by an externally applied transverse rotating magnetic field to rotate When scanning the groove in the motion form, the arc sensor starts to use the Hall sensor to collect the welding current signal, and uses the Butterworth low-pass filter and wavelet filter to preprocess the welding current signal to filter out the interference signal and perform signal amplification. The difference method, characteristic harmonic method or extreme value method extracts the processed welding current signal to obtain real-time welding torch pose information, and the airborne actuator adjusts the welding torch pose according to the obtained real-time welding torch pose information, so that Align the center of the welding seam and maintain a constant welding torch height. When the onboard actuator adjusts the welding torch position and posture, the arc sensor starts the next cycle of arc energy signal collection, and this cycle realizes automatic tracking of the welding bead;

3) According to the coordinates of the welding groove feature points in the structured light sensor coordinate system L _xyz , the coordinates are transformed to the basic Cartesian coordinate system O _xyz to obtain the coordinates G _{i of the welding groove feature point i} = ( _xi , y _i );

4) According to steps 2) and 3), the coordinates of a series of welding groove feature points are solved sequentially, and a welding groove feature point coordinate sequence {G ₁ ,G ₂ ,...,G _N } and a deviation distance array { E ₁ ,E ₂ ,...,E _N }, where

$\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}{{\mathrm{<span\; class="notranslate">\; vT</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; p</span>}}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

In the formula: λ is the distance between the structured light sensor and the welding torch, which is determined according to the geometric structure characteristics of the weld bead track and the welding process requirements, and λ is set as a value between 30mm and 50mm, v is the welding speed, T _op is the welding Groove feature point position information extraction cycle;

5) Use the spline curve (Catmull-Rom curve) to fit and calculate the coordinate sequence of the welding groove feature points, obtain the trajectory function S(x) to be welded and perform derivation, and solve each weld in the welding groove feature point coordinate sequence The tangent slope k _i of the groove feature points on the track function S(x) to be welded, i=1,2,...,N, and the pose matrix P _i =[ _xi y _i arctan(k _i )], the set of i=1,2,...,N;

6) Set the threshold σ and to compare and set the threshold ζ to compare with ΔE when Or when ΔE>ζ, the robot body executes the turning motion planning on the side where the welding torch is located, that is, the continuous path motion trajectory planning; when Or when ΔE<-ζ, the robot body executes the turning motion planning of the side where the welding torch is not located, that is, the turning trajectory planning around the center of the car body; when And when -ζ≤ΔE≤ζ, the robot body executes point-to-point straight trajectory planning; where

$\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ \mathrm{<span\; class="notranslate">\; \&sigma;</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; ,</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\\ \mathrm{<span\; class="notranslate">\; \&zeta;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\end{array}\right.<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 4</span>}<span\; class="notranslate">\; )</span>$

In the formula: E ₁ and E _N are the deviation distances between the first and Nth welding groove feature points and the welding torch in the y-axis direction in the structured light sensor coordinate system L _xyz , and L _s is the welding torch on-machine y coordinate in the coordinate system U _xyz of the onboard actuator, L _a is the maximum working _stroke of the onboard actuator in the direction of the y axis in the coordinate system U _xyz of the The preset working stroke in the y-axis direction in the coordinate system U _xyz is set according to the actual welding structure and the size of the airborne actuator;

7) The robot body performs pose adjustment according to the continuous path motion trajectory planning, the in-situ turning trajectory planning around the center of the car body, or the point-to-point straight trajectory planning, and at the same time repeat steps 2) to 6) for the next trajectory planning, that is, to realize Coordinated control of trajectory online dynamic planning and weld bead tracking during welding.

Step 6) described in continuous path motion locus planning, the method that adopts is:

According to the collection of welding groove feature point pose matrix described in step 5), adopt the following formula:

$\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}\mathrm{<span\; class="notranslate">\; i</span>}}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}\mathrm{<span\; class="notranslate">\; i</span>}}\\ {\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]<span\; class="notranslate">\; =</span>\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</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>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>\\ \mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; )</span>\end{array}\right]<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; ...</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 5</span>}<span\; class="notranslate">\; )</span>$

Calculate the pose matrix U _pi of the i-th point of the robot body on the trajectory of the robot body: [x _pi ,y _pi ,θ _pi ],(i=1,2,...,N), where: S( _xi ) is the function value of the i-th point on the track function S(x) to be welded, x _pi and y _pi are the coordinates of the i-th point on the robot body motion track in the basic Cartesian coordinate system O _xyz , and θ _pi is the robot The azimuth of the i-th point of the body on the trajectory of the robot body, using the spline curve (Catmull-Rom curve) to coordinate (x _pi , y _pi ) of all points on the trajectory of the robot body, i=1,2,.. ., N performs interpolation calculations to generate a continuous and smooth trajectory of the robot body; uses the differential speed control method to control the left and right wheels of the robot to complete the continuous path movement along the path nodes, as shown in Figure 3.

U _p1 :[x _p1 ,y _p1 ,θ _p1 ] is the pose matrix of the starting point of the robot body on the trajectory of the robot body,

U _pN :[x _pN ,y _pN ,θ _pN ] is the end point pose matrix of the robot body on the trajectory of the robot body,

U _pi :[x _pi ,y _pi ,θ _pi ], (i=2,3,...,N-1) is the path node pose matrix of the robot body on the robot body trajectory;

Step 6) described in the in-situ turning track planning around the center of the car body, the method adopted is:

As shown in Figure 4, control the driving wheels on the left and right sides of the robot body so that the speeds of the driving wheels are equal and opposite in direction, so that the robot body turns in situ around the center of the car body, and the center speed directions of the robot body are separated at the beginning and end of the turn. Consistent with the tangent direction of the fitted weld trajectory, the turning angle θ _R of the robot body is calculated by the following formula:

${\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 6</span>}<span\; class="notranslate">\; )</span>$

Point-to-point straight track planning described in step 6), the method that adopts is:

As shown in Figure 5, U _p1 is the initial pose of the robot body, U _pN is the target pose of the robot body, keep the speed of the driving wheels on the left and right sides of the robot body stable, and make the robot body move along the current direction with a distance of λ , the movement speed remains unchanged.

Realize the mobile welding robot system of the method described in this embodiment, as shown in Figure 6, it is characterized in that: it comprises a mobile robot (namely said robot body) 1, a structured light sensor 2 (comprising light source, video camera, filter filter , not shown in the figure), an image acquisition card 3, an arc sensor (including a welding torch 4, a Hall sensor or signal transmitter 5), a signal acquisition and processing module 6, an industrial computer 7, an A motion control card 8, a set of onboard actuators 9 (including a carriage, a slider, a motor, and a motor driver), a mobile robot controller 10, and a welding power source 11. The on-board actuator is fixedly arranged on the mobile robot 1 . The end on one side of the onboard actuator 9 is fixedly connected with the welding torch 4 . An interface of the welding power source 11 is connected to the workpiece 12 through the Hall sensor or the signal transmitter 5 . Another interface of the welding power source 11 is connected with the welding torch 4 to form a welding current loop. The output end of the Hall sensor or signal transmitter 5 is connected to the input end of the signal acquisition and processing module 6 , and the output end of the signal acquisition and processing module 6 is connected to the other input end of the industrial computer 7 . The structured light sensor 2 is fixedly arranged on one side of the welding torch 4 via a bracket, the output end of the structured light sensor 2 is connected to the input end of the image acquisition card 3, and the output end of the image acquisition card 3 Connect to an input terminal of the industrial computer 7 . An output end of the industrial computer 7 is connected to an input end of the motion control card 8 to control its operation, and an output end of the motion control card 8 is connected to the onboard actuator 9 . The other output end of the industrial computer 7 is connected to the input end of the mobile robot controller 10 to control its work, and the output end of the mobile robot controller 10 is connected to the mobile robot 1 .

Described mobile robot adopts a kind of wheeled mobile robot, mobile platform or mobile dolly, is characterized in that: can realize turning radius to be zero turning in situ, adopt ActivMedia company and Stanford University SIR laboratory to jointly develop in the present embodiment The Pioneer3-AT robot car.

The welding torch is one of magnetron rotary torch, mechanical rotary torch, electric control swing torch or mechanical swing torch. In this embodiment, magnetron rotary torch is used.

The industrial computer can be replaced by one of single-chip microcomputer, DSP, PLC, ARM, FPGA or computer according to actual needs.

Claims (5)

1. a control method for trajectory online dynamic programming and weld bead tracking coordination in a welding process, characterized in that said method comprises the steps: 1) Establish the coordinate system of the mobile welding robot system, including: the basic Cartesian coordinate system O _xyz , the robot body coordinate system M _xyz , the airborne actuator coordinate system U _xyz and the structured light sensor coordinate system L _xyz , where the airborne actuator The positive direction of the x-axis of the coordinate system U _xyz and the coordinate system L _xyz of the structured light sensor is consistent with the direction of the robot body moving straight forward, the positive direction of the z-axis is consistent with the direction of the ground normal, and the positive direction of the y-axis is determined by the left-hand rule. The origin of the mechanism coordinate system U _xyz is located at the fixed connection between the airborne actuator and the robot body; 2) When the welding arc scans the groove in the form of swinging, rotating or swinging-rotating compound motion, the structured light sensor is used to extract the position information of the welding groove feature point i in the front of the welding zone, including the welding groove feature point i and the welding groove feature point i. The deviation distance E _i of the torch in the y-axis direction in the structured light sensor coordinate system L _xyz and the coordinates of the welding groove feature point in the structured light sensor coordinate system L _xyz , and the arc sensor is used to collect the arc energy signal in real time, and the integral The difference method, the characteristic harmonic method or the extreme value method extract the real-time welding torch position and orientation information in the arc energy signal after signal filtering and amplification processing, and the airborne actuator adjusts the welding torch position and orientation information according to the obtained real-time welding torch position and orientation information. Torch position and posture, while the airborne actuator adjusts the welding torch position and posture, the arc sensor starts the next cycle of arc energy signal acquisition, and this cycle realizes welding bead tracking; 3) According to the coordinates of the welding groove feature points in the structured light sensor coordinate system L _xyz , the coordinates are transformed to the basic Cartesian coordinate system O _xyz to obtain the coordinates G _{i of the welding groove feature point i} = ( _xi , y _i ); 4) According to steps 2) and 3), the coordinates of a series of welding groove feature points are solved sequentially, and a welding groove feature point coordinate sequence {G ₁ ,G ₂ ,...,G _N } and a deviation distance array { E ₁ ,E ₂ ,...,E _N }, where $\mathrm{<span\; class="notranslate">\; N</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; \&lambda;</span>}}{{\mathrm{<span\; class="notranslate">\; vT</span>}}_{\mathrm{<span\; class="notranslate">\; o</span>}\mathrm{<span\; class="notranslate">\; p</span>}}}<span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; 1</span>}$ In the formula: λ is the distance between the structured light sensor and the welding torch, v is the welding speed, and T _op is the extraction cycle of the feature point position information of the welding groove; 5) Use spline curves to fit and calculate the coordinate sequence of welding groove feature points, obtain the trajectory function S(x) to be welded and perform derivation, and solve the welding groove feature point coordinate sequence of each welding groove feature point The tangent slope k _i on the welding trajectory function S(x), i=1,2,...,N, obtains the pose matrix P _i =[x _i y _i arctan(k _i )], the set of i=1,2,...,N; 6) Set the threshold σ and to compare and set the threshold ζ to compare with ΔE when Or when ΔE>ζ, the robot body executes continuous path motion trajectory planning; when Or when ΔE<-ζ, the robot body executes in-situ turning trajectory planning around the center of the car body; when And when -ζ≤ΔE≤ζ, the robot body executes point-to-point straight trajectory planning; where $\left\{\begin{array}{c}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; E.</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ \mathrm{<span\; class="notranslate">\; \&sigma;</span>}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; the\; s</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; ,</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}}<span\; class="notranslate">\; <</span>{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\\ \mathrm{<span\; class="notranslate">\; \&zeta;</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 4</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\end{array}\right.$ In the formula: E ₁ and E _N are the deviation distances between the first and Nth welding groove feature points and the welding torch in the y-axis direction in the structured light sensor coordinate system L _xyz , and L _s is the welding torch on-machine y coordinate in the coordinate system U _xyz of the onboard actuator, L _a is the maximum working _stroke of the onboard actuator in the direction of the y axis in the coordinate system U _xyz of the The preset working stroke in the direction of the y-axis in the coordinate system U _xyz ; 7) The robot body performs pose adjustment according to the continuous path motion trajectory planning, the in-situ turning trajectory planning around the center of the car body, or the point-to-point straight trajectory planning, and at the same time repeat steps 2) to 6) to perform the next trajectory planning, that is, to realize Coordinated control of trajectory online dynamic planning and weld bead tracking during welding. 2. according to claim 1, a kind of control method of track online dynamic planning and weld bead tracking coordination in the welding process, it is characterized in that: step 6) described in the continuous path motion track planning, the method that adopts is: According to the collection of welding groove feature point pose matrix described in step 5), adopt the following formula: $\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}\mathrm{<span\; class="notranslate">\; i</span>}}\\ {\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}\mathrm{<span\; class="notranslate">\; i</span>}}\\ {\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; p</span>}\mathrm{<span\; class="notranslate">\; i</span>}}\end{array}\right]<span\; class="notranslate">\; =</span>\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; +</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\mathrm{<span\; class="notranslate">\; the\; s</span>}\mathrm{<span\; class="notranslate">\; i</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</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>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; L</span>}}_{\mathrm{<span\; class="notranslate">\; a</span>}}\mathrm{<span\; class="notranslate">\; cos</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; )</span>\\ \mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; )</span>\end{array}\right]<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; i</span>}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; ,</span><span\; class="notranslate">\; ...</span><span\; class="notranslate">\; ,</span>\mathrm{<span\; class="notranslate">\; N</span>}$ Calculate the pose matrix of the i-th point of the robot body on the trajectory of the robot body: U _pi :[x _pi ,y _pi ,θ _pi ],(i=1,2,...,N), where: S(x _i ) is the function value of the i-th point on the track function S(x) to be welded, x _pi and y _pi are the coordinates of the i-th point on the robot body motion track in the basic Cartesian coordinate system O _xyz respectively, and θ _pi is The azimuth angle of the i-th point of the robot body on the robot body trajectory, using the spline curve to interpolate the coordinates (x _pi , y _pi ) of all points on the robot body trajectory, i=1,2,...,N Calculate and generate continuous and smooth robot body motion trajectory. 3. The control method for the online dynamic planning of the trajectory in the welding process and the coordination of the welding bead tracking according to claim 1, characterized in that: in the step 6), the method of turning trajectory around the center of the car body in situ is adopted yes: Control the driving wheels on the left and right sides of the robot body so that the speeds of the driving wheels are equal and opposite, so that the robot body turns around the center of the car body in situ. The turning angle θ _R of the robot body is calculated by the following formula: ${\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; R</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; N</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; r</span>}\mathrm{<span\; class="notranslate">\; c</span>}\mathrm{<span\; class="notranslate">\; t</span>}\mathrm{<span\; class="notranslate">\; a</span>}\mathrm{<span\; class="notranslate">\; no</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; S</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>}{\mathrm{<span\; class="notranslate">\; d</span>}\mathrm{<span\; class="notranslate">\; x</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; .</span>$ 4. The control method for online dynamic planning of trajectory and coordination of weld bead tracking in a kind of welding process according to claim 1, characterized in that: point-to-point straight trajectory planning described in step 6), the method adopted is: Keep the speed of the driving wheels on the left and right sides of the robot body stable, so that the robot body moves a distance of λ along the current direction, and the moving speed remains unchanged. 5. The control method for the coordination of trajectory online dynamic planning and weld bead tracking in the welding process according to claim 1, characterized in that: the welding torch adopts a magnetically controlled rotary welding torch, a mechanical rotary welding torch, an electric welding torch A kind of controlled swing welding torch or mechanical swing welding torch.