CN-121976749-A - Calculation method of excavation track

CN121976749ACN 121976749 ACN121976749 ACN 121976749ACN-121976749-A

Abstract

The application discloses a method for calculating a cutting track, which is applied to a cutting tool to cut a pipeline, and comprises the steps of setting a cutting direction and a cutting depth, and constructing a parameterized transition curve; according to the parameterized transition curve, a cutting track is planned, wherein the method comprises the steps of calculating the deflection angle of a cutting tool according to the cutting depth and the parameterized transition curve, and controlling the cutting tool to cut a pipeline along the set cutting direction according to the calculated deflection angle so as to ensure that the cutting track of the cutting tool is consistent with the parameterized transition curve. According to the method, a parametric transition curve is constructed according to the excavation direction and the excavation depth, and the excavation track is quantized. And the deflection angle of the excavating tool is calculated according to the parameterized transition curve and the excavating depth, so that the excavating tool is prevented from damaging a pipeline body outside an excavating track in the excavating process, the excavating precision is improved, the excavating forming quality is ensured, and the guarantee is provided for the subsequent pipeline welding.

Inventors

LI YAONAN
FANG SIWEN
CHEN HEPING
XI NING

Assignees

辽宁沈抚辽港智能技术创新研究院有限公司

Dates

Publication Date: 20260505
Application Date: 20251229

Claims (10)

1. A method of calculating a cutting trajectory, applied to a cutting tool for cutting a pipe, comprising: Setting a digging direction and a digging depth, and constructing a parameterized transition curve; planning a cutting track according to the parameterized transition curve, including: calculating the deflection angle of the excavation tool according to the excavation depth and the parameterized transition curve; and controlling the cutting tool to cut the pipeline along the set cutting direction according to the calculated deflection angle so as to ensure that the cutting track of the cutting tool is consistent with the parameterized transition curve.
2. The method of claim 1, wherein the setting the excavation direction and the excavation depth comprises: The gouging direction includes a first direction that is a radial direction of the pipe and a second direction that is a circumferential direction of the pipe, and the gouging depth is a distance from an outer wall surface to an inner wall surface of the pipe along the first direction.
3. A method of calculating a cutting trajectory according to claim 1, wherein said constructing a parametric transition curve comprises: establishing a polar coordinate system about the radius and the angle of the pipeline by taking the circle center of the cross section of the pipeline as the origin of coordinates; Setting the parameterized transition curve as a continuous function of pipe radius and angle; performing discrete sampling on the continuous function to obtain a plurality of polar coordinate points; and mapping a plurality of polar coordinate points into a Cartesian coordinate system taking the center of the pipeline as the origin of coordinates through coordinate transformation, so as to form the parameterized transition curve.
4. The method of claim 2, wherein the cutting depth is divided into a plurality of cutting layers, each cutting layer is stacked layer by layer according to a set feed depth, the cutting tool determines a movement limit position of the cutting tool in the second direction on each cutting layer according to a current deflection angle corresponding to the cutting layer, and the cutting tool reciprocates in the second direction between the movement limit positions.
5. The method of claim 4, wherein calculating the yaw angle of the excavation tool based on the excavation depth and the parametric transition curve comprises: selecting that the excavation tool intersects the parameterized transition curve at a first location; the excavation tool and the parameterized transition curve are intersected at a first intersection point and a second intersection point respectively at a first position; Determining a first included angle of the first intersection point in a polar coordinate system and coordinates in a Cartesian coordinate system; Calculating the coordinate of the center of the excavating tool in the Cartesian coordinate system according to the first included angle and the first intersection point coordinate; dividing the arc between the first intersection point and the second intersection point into n sections of arcs according to arc length step sizes; calculating the intersection point of each of the n-section arcs and the parameterized transition curve, and determining a second included angle of the intersection point in the polar coordinate system and coordinates in the Cartesian coordinate system; Constructing a reference circle with the current excavation depth of the excavation layer as a radius, wherein each of the n-section arcs has an intersection point with the reference circle and the excavation tool respectively, namely a third intersection point and a fourth intersection point; Respectively calculating coordinates of the third intersection point and the fourth intersection point in the Cartesian coordinate system, and selecting an intersection point with larger numerical value in the X-axis direction, wherein an included angle corresponding to a connecting line of the intersection point and the circle center of the pipeline is a third included angle; And calculating the deflection angle according to the first included angle, the second included angle and the third included angle.
6. The method of claim 5, wherein the cutting tool is positioned to a first position such that one side edge of the cutting tool intersects the parametric transition curve at a first intersection point and the other side edge has exceeded the parametric transition curve and entered the pipe body, the other side edge intersecting the parametric transition curve at a second intersection point.
7. The method of claim 5, wherein the yaw angle is calculated according to the formula: Wherein beta is a deflection angle, theta is a first included angle, e i is a second included angle, and m i is a third included angle.
8. The method of claim 7, wherein a yaw angle of the cutting tool at each of the layers is calculated, and wherein a limit of movement of the cutting tool in the second direction is determined based on the yaw angle, the cutting tool reciprocating between the limit of movement to achieve a smooth transition from the outer diameter to the inner diameter of the pipe.
9. The method of claim 7, wherein the third included angle is calculated according to the formula: and the X and the y are respectively the abscissa and the ordinate of the coordinates of the third intersection point and the fourth intersection point with larger numerical values in the X-axis direction in the Cartesian coordinate system.
10. A method of calculating a gouge trajectory according to claim 3, wherein the pipe has a point S 1 on its inside diameter, a point E 1 on its outside diameter, a point a on the line between the point S 1 and the point E 1 , the slope of the line being k, The coordinates of the point a in the polar coordinate system are expressed as: R A =kt 1 Wherein R A represents the position of a on the line, t 1 represents the polar angle of point a in the polar coordinate system; the coordinates of point a in the cartesian coordinate system are expressed as: X A =kt 1 *cos(t 1 ) Y A =kt 1 *sin(t 1 ) X A is the coordinate value of the point A on the X-axis in the Cartesian coordinate system, and Y A is the coordinate value of the point A on the Y-axis in the Cartesian coordinate system.

Description

Calculation method of excavation track Technical Field The application relates to the technical field of pipeline excavation, in particular to an excavation track calculation method. Background In the installation and repair of industrial piping systems (e.g., petrochemical, natural gas, electric power, etc.), pipe butt welds are a critical form of connection between the pipe sections and the most basic plates that make up the pressure-bearing system, and especially where high temperature, high pressure, flammable, explosive, or toxic media are being delivered, the quality of the butt welds is directly related to the safety and reliability of the overall piping system. When the welding quality of the butt welded junction of the pipeline fails to meet the standard requirement, the original welding line is removed and the welding is performed again. The concrete operation is that the surface of the welding seam is polished to be smooth, and then the cutting tool is used for further cutting to form an opening shape for subsequent repair welding work. The openings generally run in the circumferential direction of the pipe, and need to gradually transition from the innermost, i.e. bottom, side of the pipe to the outer wall, so as to ensure the quality of repair welding and the safety of the pipe structure. At present, the work is usually manually completed by a hand-held angle grinder of a worker, the whole working process is time-consuming and labor-consuming, and due to lack of accurate control, the excavated curved surface is difficult to quantify, the surface of an opening is uneven, and the molding quality after secondary welding is difficult to control. Although the cutting robot is used for cutting welding seams instead of a manual hand-held angle grinder, a cutting path with high precision is still lacking so as to quantify a cutting curved surface and ensure the molding quality after secondary welding. Disclosure of Invention The present application aims to solve at least one of the above technical problems in the prior art. The application aims to provide a calculation method of a cutting track, which aims to solve the problem that the quality of formed pipes after cutting is difficult to control due to the lack of cutting curved surface quantification in the prior art. In order to achieve the above purpose, the technical scheme adopted by the application is as follows: A method of calculating a cutting trajectory for use with a cutting tool for cutting a pipe, comprising: Setting a digging direction and a digging depth, and constructing a parameterized transition curve; planning a cutting track according to the parameterized transition curve, including: calculating the deflection angle of the excavation tool according to the excavation depth and the parameterized transition curve; and controlling the cutting tool to cut the pipeline along the set cutting direction according to the calculated deflection angle so as to ensure that the cutting track of the cutting tool is consistent with the parameterized transition curve. According to some embodiments of the application, the setting the cutting direction and the cutting depth comprises: The gouging direction includes a first direction that is a radial direction of the pipe and a second direction that is a circumferential direction of the pipe, and the gouging depth is a distance from an outer wall surface to an inner wall surface of the pipe along the first direction. According to some embodiments of the application, the constructing a parameterized transition curve comprises: establishing a polar coordinate system about the radius and the angle of the pipeline by taking the circle center of the cross section of the pipeline as the origin of coordinates; Setting the parameterized transition curve as a continuous function of pipe radius and angle; performing discrete sampling on the continuous function to obtain a plurality of polar coordinate points; and mapping a plurality of polar coordinate points into a Cartesian coordinate system taking the center of the pipeline as the origin of coordinates through coordinate transformation, so as to form the parameterized transition curve. According to some embodiments of the application, the cutting depth is divided into a plurality of cutting layers, each cutting layer is stacked layer by layer according to a set feeding depth, the cutting tool determines a movement limit position of the cutting tool in the second direction on each cutting layer according to a deflection angle corresponding to the current cutting layer, and the cutting tool reciprocates in the second direction between the movement limit positions. According to some embodiments of the application, the calculating the yaw angle of the excavation tool from the excavation depth and the parameterized transition curve includes: selecting that the excavation tool intersects the parameterized transition curve at a first location; the excavation tool an