CN-118727871-B - Method and system for checking motion interference of loader working device

CN118727871BCN 118727871 BCN118727871 BCN 118727871BCN-118727871-B

Abstract

The invention discloses a motion interference checking algorithm and a motion interference checking system for a working device of a loader, which comprise the steps of obtaining parameters such as the coordinates of each hinge point and the diameters of pin shafts at corresponding positions, generating a two-dimensional profile of the working device according to the coordinates of each hinge point and the diameters of the pin shafts at corresponding positions, determining an interference position which is easy to occur according to design experience, calculating the minimum distance of an interference curve pair under the current gesture, comparing the calculated minimum distance between the curves with a minimum clearance value allowed by the design, recording the lengths of a tipping bucket cylinder and a movable arm cylinder under the current gesture if the minimum distance of the curve pair is smaller than the minimum clearance allowed by the design, updating the positions of the profile when the lengths of the tipping bucket cylinder and/or the movable arm cylinder are changed, and repeating the steps until the motion is completed. Compared with the prior art, the product development efficiency can be effectively improved.

Inventors

MENG LINGCHAO
LIU HUIBIN
LI XIAOFENG
SHEN MENGQING
ZHANG MENGLONG
Chang Lizhuang
ZHANG CHAOYONG

Assignees

徐工集团工程机械股份有限公司科技分公司

Dates

Publication Date: 20260512
Application Date: 20240628

Claims (8)

1. A method of motion interferometry of a loader operating device, comprising: acquiring the coordinates of each hinge point and the diameter parameters of the pin shaft at the corresponding position; generating a two-dimensional profile of the working device according to the coordinates of each hinge point and the diameter parameters of the pin shaft at the corresponding position; determining the position easy to interfere according to design experience, and calculating the minimum distance between easy-to-interfere curves under the current gesture; comparing the calculated minimum distance of the curve pair with a minimum clearance value allowed by design, and recording the lengths of the tipping bucket cylinder and the movable arm cylinder under the current gesture if the minimum distance of the curve pair is smaller than the minimum clearance allowed by design; when the length of the tipping bucket cylinder and/or the movable arm cylinder is changed, updating the position of the profile, and repeating the steps until the movement is completed; when the length of the tipping bucket cylinder and/or the movable arm cylinder is changed, the position of the profile is updated, specifically: Deducing a kinematic formula of a working device of the loader based on a D-H method or a vector method according to the lengths of the skip bucket cylinder and the movable arm cylinder, and calculating the rotation angles of the bucket, the pull rod, the rocker arm and the movable arm part relative to the initial posture and the coordinates of all hinge points; According to the calculated rotation angle of the component relative to the initial gesture and the coordinates of each hinge point, calculating the positions of the key points by a coordinate transformation matrix: , Wherein KP init 、KP new is the initial coordinate and the updated coordinate of the key point respectively, RP init 、RP new is the initial coordinate and the updated coordinate of the reference point respectively, the reference point is any hinge point on the same component as the key point, and T is a coordinate transformation matrix , Where θ is the angle of rotation of the component relative to the initial pose.
2. The method for checking the motion interference of the working device of the loader according to claim 1, wherein the two-dimensional profile of the working device is generated according to the coordinates of each hinge point and the diameter parameters of the pin shaft at the corresponding position, specifically: firstly, according to the diameter of a pin shaft, respectively taking each hinge point as a circle center and taking the product of the diameter of the pin shaft and a certain proportion coefficient as a radius to make a circle; Then drawing the outline of the key feature according to the feature size of each component; and then, calculating a mathematical expression of a transition curve connecting the key feature profile and a circle taking the hinge point as a center according to the tangent relation.
3. The method for checking motion interference of loader working device according to claim 2, wherein the drawing of the outline of the key feature is based on the feature size of each part, the drawing of the outline of the key feature is based on the feature size of the bucket, the drawing of the outline of the key feature is based on the feature size of the pull rod, and the drawing of the outline of the key feature is based on the feature size of the movable arm.
4. A method for checking motion interference of a loader working device according to claim 3, wherein the outline of the key feature is drawn according to the feature size of the bucket, specifically, the bottom plate and the main cutter are drawn according to the length L d1 、L d2 of the bottom plate and the vertical distance H c between the center of the bucket and the hinge center of the movable arm, and then the side cutting edge is drawn according to the height H d of the bucket and the angle psi z of the cutting edge.
5. A motion interference checking method for a loader working device according to claim 3 is characterized in that the outline of the key feature is drawn according to the feature size of the pull rod, specifically, a line segment connecting hinge points at two ends of the pull rod is firstly made, then two line segments which are parallel to the line segment and symmetrical to each other are made, and the distance between the line segments is equal to the width W l of the pull rod.
6. A motion interference checking method for a loader working device according to claim 3, wherein the outline of the key feature is drawn according to the feature size of the movable arm, specifically, a line segment connecting the upper and lower hinge points of the movable arm is firstly made, a rounded rectangle parallel to the line segment is made according to the parameters of the length W z and the width L z of the section of the seat beam, then the rounded rectangle is rotated around the geometric center of the rounded rectangle according to the offset angle psi z of the seat beam, then two line segments a and b parallel to the upper side of the seat beam and with the length Lz are made, the distances between the two line segments a and b and the upper side of the seat beam are W d1 、W d2 respectively, and finally a circle which is tangent to the line segment a and passes through the two end points of the line segment b is made.
7. The method for checking the motion interference of the loader working device according to claim 1, wherein the method is characterized in that the position where the interference is easy to occur is determined according to design experience, and the minimum distance between the easy-interference curves in the current posture is calculated, specifically: Firstly, the outline of each component is decomposed into a line segment and an arc primitive, wherein the key points of the line segment are the endpoints of two sides of the line segment, and the key points of the arc are the endpoints and the circle center of the arc; marking a curve corresponding to the position easy to interfere according to design experience, and calculating a mathematical expression of the curve according to the coordinates of the key points; finally, solving the following problems through an optimization algorithm to obtain the minimum distance of each curve pair under the current gesture; min , s.t. , , , , The curve i A 、i B represents a curve combination corresponding to the i-th easy-to-interfere position, (x iA ,y iA )、(x iB ,y iB ) is a point on the i-th easy-to-interfere curve, f (x iA ,y iA )、g(x iB ,y iB ) is a mathematical expression of the i-th easy-to-interfere curve, and [ x iA,min ,x iA,max ]、[x iB,min ,x iB,max ] is a value range of an abscissa of the point on the i-th easy-to-interfere curve.
8. A motion interference checking system of a loader working device, which is characterized by comprising a storage medium and a processor; The storage medium is used for storing instructions; the processor being operative according to the instructions to perform the method of any one of claims 1-7; selecting coordinates of corresponding hinge points as design variables according to design requirements; taking the component clearance along with other performance indicators as a target or constraint function; the iterative solution is carried out by an optimization algorithm, each iteration needs to execute the calculation step of claim 1, wherein when parameterizing to generate the two-dimensional contour of the working device, other iterative processes only need to execute the mathematical expression of the transition curve connecting the key feature contour and the circle taking the hinge point as the center according to the tangent relation, except that the first iteration needs to execute all the steps of claim 2.

Description

Method and system for checking motion interference of loader working device Technical Field The invention belongs to the technical field of loader optimization design, and particularly relates to a method and a system for checking motion interference of a loader working device. Background The loader can complete various operations such as shoveling, unloading and the like by controlling a series of actions of the working device, when the existing connecting rod parameters cannot meet the requirements, the working device needs to be optimally designed according to new design input, and meanwhile, in order to ensure that the working device can work normally, all parts of the working device are prevented from interfering in the movement process. In the prior art, when a working device is optimally designed, a clearance of a simple contour is restrained through a circle drawing method, the design margin is often larger, the clearance of a part with a complex shape is difficult to be added into a constraint condition, after the parameters of a working connecting rod are confirmed, the interference condition of the working device in the moving process is checked through establishing a three-dimensional model of the working device and based on three-dimensional modeling software, when interference exists among components, the optimal design is needed to be carried out again, and the steps are repeated until the requirements of various performance indexes in design input and the clearance of the contour of the component are met at the same time, so that the product development efficiency is lower and the period is longer. Disclosure of Invention In order to solve the problems, the invention provides a motion interference checking method and a motion interference checking system for a loader working device, which are used for converting the interference checking problem between components into the minimum distance calculation problem of a two-dimensional contour by establishing a parameterized model of the two-dimensional contour of the working device, and simultaneously, the parameterized two-dimensional contour can be updated along with the change of the hinge point position, so that the product development efficiency can be effectively improved compared with the prior art. In order to achieve the technical purpose and achieve the technical effect, the invention is realized by the following technical scheme: in a first aspect, the present invention provides a method for motion interferometry of a loader working device, comprising: Acquiring the coordinates of each hinge point and parameters such as the diameter of a pin shaft at a corresponding position; Generating a two-dimensional profile of the working device according to the coordinates of each hinge point, the diameter of a pin shaft at the corresponding position and other parameters; determining the position easy to interfere according to design experience, and calculating the minimum distance between easy-to-interfere curves under the current gesture; comparing the calculated minimum distance of the curve pair with a minimum clearance value allowed by design, and recording the lengths of the tipping bucket cylinder and the movable arm cylinder under the current gesture if the minimum distance of the curve pair is smaller than the minimum clearance allowed by design; when the length of the skip cylinder and/or the boom cylinder changes, the position of the profile is updated, and then the steps are repeated until the movement is completed. Optionally, the generating a two-dimensional profile of the working device according to the coordinates of each hinge point and parameters such as the diameter of the pin shaft at the corresponding position specifically includes: firstly, according to the diameter of a pin shaft, respectively taking each hinge point as a circle center and taking the product of the diameter of the pin shaft and a certain proportion coefficient as a radius to make a circle; Then drawing the outline of the key feature according to the feature size of each component; and then, calculating a mathematical expression of a transition curve connecting the key feature profile and a circle taking the hinge point as a center according to the tangent relation. Optionally, the drawing the outline of the key feature according to the feature size of each component specifically comprises the following steps: For the bucket, firstly, drawing the bottom plate and the main cutter plate according to the length L d1、Ld2 of the bottom plate and the vertical distance H c between the bucket and the hinged center of the movable arm and the main cutter plate, and then drawing the side cutting edge according to the height H d of the bucket and the angle phi z of the cutting edge; For the pull rod, firstly, a line segment connecting hinge points at two ends of the pull rod is made, then two line segments which are parallel to the line segment and symmetrical to each o