CN104714473A - Conduit margin cutting position computing method for flexible pipeline welding and assembling - Google Patents

Abstract

The invention provides a flexible pipeline welding and assembling scheme based on vision measurement and a robot. The scheme is characterized by comprising software and hardware, the hardware mainly comprises a vision measurement device, an industrial robot, a conduit cutter and a conduit clamp, and the software mainly comprises a margin computing module, a pose computing module and a robot movement simulating module. The conduit margin cutting position computing method comprises the steps of 1, computing the coordinates of a conduit margin end central point in a robot TCP coordinate system according to the coordinates, obtained through measurement, of the conduit margin end central point and the pose of the robot when the robot grabs a conduit for measurement; 2, computing the coordinates of the conduit margin end central point when the robot returns to the zero position according to the pose of the robot when the robot returns to the zero position; 3, computing the conduit margin cutting position according to a measured conduit margin, and the included angle, obtained from a three-dimensional conduit mathematical model, between the margin end face and the clamping right-angle section of the robot. Flexible pipeline production is achieved based on the vision measurement technique and the robot technique, cost can be reduced effectively, and efficiency can be improved.

Description

A kind of conduit surplus cutting position computing method of pipeline flexible welding and assembling

Technical field

The present invention relates to a kind of conduit surplus cutting position computing method of pipeline flexible welding and assembling, is the measurement data based on welding equipment system and device location, calculates the method for conduit surplus cutting position.Belong to computer-aided design (CAD) and manufacture field.

Background technology

Pipe system is all widely used in nearly all electronic product, the passage of its function mainly pumped (conveying) medium.Particularly at aerospace field, conduit is all the important component part of aircraft or all kinds of spacecraft, and it is determine one of properties of product and quality very important condition that pipe system can normally be run.

At present, Aero-Space class pipeline wide variety, complex interfaces and the production form mainly with single-piece or short run exist.Traditional conduit welding needs the built-up jig of design specialized, and efficiency is very low, and fixture versatility is low, and the preparatory period is long.For different welding conduits, need the unit clamp that design is different in a large number, this considerably increases development time and the cost of Aerospace Products, also bring very big inconvenience to production management simultaneously.And in process of production, owing to being subject to the impact of the factors such as operator's experience level, frock, positioning precision and measuring accuracy, larger error and distortion need be there is to after conduit welding, accuracy requirement cannot be reached, visible traditional conduit production technology cannot meet the manufacture demand of modern product, so the flexible welding and assembling system of producing towards pipeline is set up in necessary research.

Conduit can reserve certain process redundancy in producing, and needs surplus to excise before conduit assembling, so need the cutting position calculating conduit surplus according to the measurement data of system.

Summary of the invention

The object of the present invention is to provide the pipeline flexible welding and assembling scheme of the measurement of a kind of view-based access control model and robot, and based on the conduit surplus cutting position computing method of measurement data in this scheme, in order to the problem such as solve inefficiency in existing conventional catheters solder technology, the cycle is long, error distortions is large.

General system proposal: the formation of this pipeline flexible welding and assembling system as shown in Figure 1.Overall system comprises software and hardware two large divisions, wherein hardware mainly comprises visual measuring equipment, industrial robot, conduit cutting machine and catheter clamp, software section mainly comprises surplus computing module, pose computing module and robot motion's analogue simulation module.

The pipeline flexible welding and assembling scheme that the present invention proposes, comprises following workflow:

Step one: robot captures pipeline respectively and detects to visual measuring equipment place, the three-dimensional feature data obtaining pipeline are transferred to software module, data comprise the coordinate of all end points of conduit and bending point and conduit axially and radial deviation, axial deviation and conduit surplus, subsequent calculations desired data all extracts from this measurement file.

Step 2: software module reads measurement data and calculates, obtain the cutting position of pipeline surplus and the end effector pose (TCP pose) of robot, and generate robot control documents to be transferred to robot motion's emulation module and to simulate, simulate successfully and export control documents to robot.

Step 3: robot captures pipeline and moves under the control documents comprising TCP posture information drives, and realizes the cutting of pipeline surplus and the docking of two sections of pipelines.

The conduit surplus cutting position computing method comprised in the pipeline flexible welding and assembling scheme that the present invention proposes, comprise the steps:

Step one: according to measuring the conduit surplus end center point coordinate P obtained _m(x _m, y _m, z _m) and robot capture conduit measure time pose T ^m _tCP, calculate the coordinate P of conduit surplus end central point under robot TCP coordinate system _tcp(x _t, y _t, z _t).

Step 2: in conjunction with pose T during robot recurrence zero-bit ^s _l, when calculating robot returns zero-bit, conduit surplus end center point coordinate P _s(x _s, y _s, z _s).

Step 3: combine the conduit surplus A (Allowance) that measures, and the angle theta of the surplus end face obtained from the three-dimensional digital-to-analogue of conduit and robotic gripper's straight-line segment, calculating conduit surplus cutting position.

A kind of pipeline flexible welding and assembling scheme that the present invention provides and conduit surplus cutting position computing method thereof, its advantage and effect are: compared with traditional pipeline erection welding method, present invention eliminates various sample pipe and fixture, improve versatility, reduce cost; Compared with the conduit allowance cutting method of ruling with Traditional Man, the present invention is by calculating the cutting position of conduit surplus, and control gripping conduit cuts, and improves production efficiency.

Accompanying drawing explanation

Fig. 1 is flexible welding and assembling system global structure schematic diagram of the present invention.

Fig. 2 is conduit surplus cutting schematic diagram in the present invention.

Fig. 3 is conduit surplus cutting position calculation flow chart in the present invention.

Embodiment

Below in conjunction with accompanying drawing, technical scheme of the present invention is described further:

As shown in Figure 1, the present invention proposes the pipeline flexible welding and assembling scheme of the measurement of a kind of view-based access control model and robot, and concrete steps are as follows:

Step one: robot captures pipeline respectively and detects to visual measuring equipment place, the three-dimensional feature data obtaining pipeline are transferred to software module, data comprise the coordinate of all end points of conduit and bending point and conduit axially and radial deviation, axial deviation and conduit surplus, subsequent calculations desired data all extracts from this measurement file.

Step 2: software module reads measurement data and calculates, obtain the cutting position of pipeline surplus and the end effector pose (TCP pose) of robot, and generate robot control documents to be transferred to robot motion's emulation module and to simulate, simulate successfully and export control documents to robot.

Step 3: robot captures pipeline and moves under the control documents comprising TCP posture information drives, and realizes the cutting of pipeline surplus and the docking of two sections of pipelines.

Wherein, " visual measuring equipment " described in step one, meet measuring speed fast, precision is high, can just and with the feature such as robot is connected.

Wherein, " software module " described in step 2, comprises robot motion simulation software, for the analogue simulation of robot motion; Conduit surplus computing module, for calculating conduit surplus cutting position; Pose computing module, the end effector pose of primary computer device people, moves for control.Surplus calculates and pose computing module is realized by secondary development under Three-dimensional CAD Software environment.

As shown in Figures 2 and 3, the conduit surplus cutting position computing method comprised in the pipeline flexible welding and assembling scheme that the present invention proposes, embodiment is as follows:

Step one: according to measuring the conduit surplus end center point coordinate P obtained _m(x _m, y _m, z _m) and robot capture conduit measure time pose T ^m _tCP, calculate the coordinate P of conduit surplus end central point under robot TCP coordinate system _tcp(x _t, y _t, z _t).

$P_{\mathrm{tcp}}={{T^m}_{\mathrm{TCP}}}^{-1}\×P_m={\left(\begin{array}{cccc}{\mathrm{nx}}_{\mathrm{mt}}& {\mathrm{ox}}_{\mathrm{mt}}& {\mathrm{ax}}_{\mathrm{mt}}& x_{\mathrm{mt}}\\ {\mathrm{ny}}_{\mathrm{mt}}& {\mathrm{oy}}_{\mathrm{mt}}& {\mathrm{ay}}_{\mathrm{mt}}& y_{\mathrm{mt}}\\ {\mathrm{nz}}_{\mathrm{mt}}& {\mathrm{oz}}_{\mathrm{mt}}& {\mathrm{az}}_{\mathrm{mt}}& z_{\mathrm{mt}}\\ 0& 0& 0& 1\end{array}\right)}^{-1}\×\left(\begin{array}{c}{x}_m\\ y_m\\ z_m\\ 1\end{array}\right)---\left(1\right)$

Step 2: in conjunction with pose T during robot recurrence zero-bit ^s _tCP, when calculating robot returns zero-bit, conduit surplus end center point coordinate P _s(x _s, y _s, z _s).

$P_s={T^s}_{\mathrm{TCP}}\×P_{\mathrm{tcp}}=\left(\begin{array}{cccc}{\mathrm{nx}}_{\mathrm{st}}& {\mathrm{ox}}_{\mathrm{st}}& {\mathrm{ax}}_{\mathrm{st}}& x_{\mathrm{st}}\\ {\mathrm{ny}}_{\mathrm{st}}& {\mathrm{oy}}_{\mathrm{st}}& {\mathrm{ay}}_{\mathrm{st}}& y_{\mathrm{st}}\\ {\mathrm{nz}}_{\mathrm{st}}& {\mathrm{oz}}_{\mathrm{st}}& {\mathrm{az}}_{\mathrm{st}}& z_{\mathrm{st}}\\ 0& 0& 0& 1\end{array}\right)\×\left(\begin{array}{c}{x}_t\\ y_t\\ z_t\\ 1\end{array}\right)---\left(2\right)$

Step 3: combine the conduit surplus A (Allowance) that measures, and the angle theta of the surplus end face obtained from the three-dimensional digital-to-analogue of conduit and robotic gripper's straight-line segment, calculating conduit surplus cutting position, concrete grammar is as follows:

The angle theta that surplus end face normal direction and conduit clamp straight-line segment can be tried to achieve according to conduit three-dimensional information:

$\cos \mathrm{\θ}=\frac{{\mathrm{vx}}_l\·{\mathrm{vx}}_p+{\mathrm{vy}}_l\·{\mathrm{vy}}_p+{\mathrm{vz}}_l\·{\mathrm{vz}}_p}{\sqrt{{{\mathrm{vx}}_l}^2+{{\mathrm{vy}}_l}^2+{{\mathrm{vz}}_l}^2}\·\sqrt{{{\mathrm{vx}}_p}^2+{{\mathrm{vx}}_p}^2+{{\mathrm{vz}}_p}^2}}---\left(3\right)$

Wherein V _l(vx _l, vy _l, vz _l) capture by robot the direction vector of conduit straight-line segment, V _p(vx _p, vy _p, vz _p) be the normal vector of conduit surplus end face.

Surplus cutting position can represent by a plane, the intersecting point coordinate P of this plane and pipeline axis _c(x _c, y _c, z _c) can be tried to achieve by following formula:

$\left\{\begin{array}{c}{x}_c=x_s\\ y_c=y_s-d\·\cos \mathrm{\θ}\\ z_c=z_s-d\·\sin \mathrm{\θ}\end{array}\right.---\left(4\right)$

Then surplus cutting position plane equation is:

0·(x-x _c)+cosθ·(y-y _c)+sinθ·(z-z _c)＝0 (5)

The profile of conduit and this Plane intersects is a circle, this satisfactory foot formula:

(x-x _c) ²+(y-y _c) ²+(z-z _c) ²＝R ²(6)

In actual production, can represent with profile circle upper four somes P1, P2, P3, P4, simultaneous formula (5) ~ (6), by x=x _cx _c+ R x _c-R substitutes into, and can try to achieve four point coordinate.

Following table is depicted as the measurement data of pipeline flexible welding and assembling system:

Following table is depicted as the conduit surplus cut point coordinate calculated:

Claims (4)

1. the pipeline flexible welding and assembling scheme of a view-based access control model measurement and robot, it is characterized in that: protocol population comprises software and hardware two large divisions, wherein hardware mainly comprises visual measuring equipment, industrial robot, conduit cutting machine and catheter clamp, software section mainly comprises surplus computing module, pose computing module and robot motion's analogue simulation module.

2. pipeline flexible welding and assembling scheme according to claim 1, is characterized in that: it comprises the steps:

Step one: robot captures pipeline respectively and detects to visual measuring equipment place, the three-dimensional feature data obtaining pipeline are transferred to software module, data comprise the coordinate of all end points of conduit and bending point and conduit axially and radial deviation, axial deviation and conduit surplus, subsequent calculations desired data all extracts from this measurement file.

Step 2: software module reads measurement data and calculates, obtain the cutting position of pipeline surplus and the end effector pose (TCP pose) of robot, and generate robot control documents to be transferred to robot motion's emulation module and to simulate, simulate successfully and export control documents to robot.

Step 3: robot captures pipeline and moves under the control documents comprising TCP posture information drives, and realizes the cutting of pipeline surplus and the docking of two sections of pipelines.

3. pipeline flexible welding and assembling scheme according to claim 1, is characterized in that: software module comprises robot motion simulation software, for the analogue simulation of robot motion; Conduit surplus computing module, for calculating conduit surplus cutting position; Pose computing module, the end effector pose of primary computer device people, moves for control.Surplus calculates and pose computing module is realized by secondary development under Three-dimensional CAD Software environment.

4., based on conduit surplus cutting position computing method for pipeline flexible welding and assembling, it is characterized in that: it comprises following steps:

Step one: according to measuring the conduit surplus end center point coordinate P obtained _m(x _m, y _m, z _m) and robot capture conduit measure time pose T ^m _tCP, calculate the coordinate P of conduit surplus end central point under robot TCP coordinate system _tcp(x _t, y _t, z _t).

Step 2: in conjunction with pose T during robot recurrence zero-bit ^s _l, when calculating robot returns zero-bit, conduit surplus end center point coordinate P _s(x _s, y _s, z _s).

Step 3: combine the conduit surplus A (Allowance) that measures, and the angle theta of the surplus end face obtained from the three-dimensional digital-to-analogue of conduit and robotic gripper's straight-line segment, calculating conduit surplus cutting position.