CN-121615374-B - Fixed-point resampling method for chain system

CN121615374BCN 121615374 BCN121615374 BCN 121615374BCN-121615374-B

Abstract

The invention relates to a fixed-point resampling method of a chain system, belongs to the technical field of rotary mechanical signal processing, and aims to solve the problems that the regularity of time domain signals of single chain links is poor, the dynamics characteristic of the whole system is difficult to directly reflect, and frequency domain feature extraction cannot be carried out. The method comprises the steps of extracting original data of discrete motion units from a multi-body dynamics simulation result, presetting data monitoring point positions in a system, searching the nearest discrete motion units in real time by calculating distance to serve as monitoring units, processing the original data of the monitoring units according to data types by adopting one of a direct method, a synthesis method and an average method to generate characteristic data representing dynamics states of the fixed positions, and finally writing the characteristic data into a file according to time sequence. The invention collects time sequence data of fixed positions by a fixed-point resampling method, and solves the problems of strong data contingency, poor regularity and difficult deep frequency domain and statistical analysis caused by tracking a single motion unit.

Inventors

JIANG YUJIE
FENG ZENGMING
XU KAI
ZHOU ZHIJIE
LI FAN

Assignees

吉林大学
长春瑞百惠科技有限公司

Dates

Publication Date: 20260508
Application Date: 20260130

Claims (8)

1. The fixed-point resampling method for the chain system is characterized by being suitable for the post-processing of multi-body dynamics simulation data of a transmission system comprising a plurality of discrete motion units, wherein the discrete motion units sequentially and continuously move along a preset track and do not overlap in a motion plane; the method comprises the following steps: Step one, extracting simulation result data, namely extracting dynamics data of the discrete motion units from a completed multi-body dynamics simulation result file and storing the dynamics data into an intermediate file; Step two, searching fixed-point chain links, setting at least one fixed data monitoring point in the transmission system, calculating the relative distance between all discrete motion units at each moment and the data monitoring point in a plane, and selecting the discrete motion unit closest to the data monitoring point as the monitoring unit at the current moment of the corresponding data monitoring point; The method comprises the steps of monitoring the data monitoring points, carrying out fixed-point chain link data processing, adopting a corresponding processing method to acquire characteristic data representing the data monitoring points according to the original dynamic data type corresponding to each data monitoring point obtained by monitoring in the step two, and executing fixed-point chain link searching and fixed-point chain link data processing processes by adopting a multi-thread parallel processing method when a plurality of data monitoring points exist; Writing fixed-point data result files, and respectively writing characteristic data acquired by various data of each data monitoring point according to time sequence into the result files; the fixed point chain link data processing in the third step comprises the following steps: a direct method, namely directly adopting the monitored instantaneous value of the nearest chain link when the characteristic data is a physical quantity which can be directly acquired under an absolute coordinate system; when the characteristic data is a physical quantity to be expressed under a relative coordinate system, carrying out coordinate transformation on the monitored data according to the phase angle of the movement direction of the chain; And an averaging method of calculating an average value of the dynamic quantity at both ends of the discrete motion unit as the characteristic data when the characteristic data is a physical quantity indirectly reflected on the unit.
2. The method of claim 1, wherein the step one of extracting the simulation result data includes starting a post-processing module, importing a simulation result file, importing a desired data path, and exporting data to the file.
3. A method of fixed point resampling of a chain system according to claim 1 or 2, wherein the simulation result data meets the following requirements according to different requirements of the chain system: When all simulation boundary conditions are in a stable state and are not changed with time, the steady-state simulation duration is at least 6 meshing periods; when the simulation boundary conditions are in an unstable state, the steady state simulation duration is at least 2 times the time period of the boundary condition change.
4. The method of claim 1, wherein the dynamics data of step one includes discrete motion element position, velocity, acceleration and inter-element interaction force data.
5. The method for resampling a chain system fixed point according to claim 1, wherein the data monitoring points in the second step are arranged on a chain link running track, and the position information of the data monitoring points comprises an abscissa, an ordinate and a phase angle in a chain plane.
6. The method of claim 5, wherein the data monitoring point position information comprises a phase angle that is an angle between a link movement direction and a horizontal positive direction.
7. The method of claim 1, wherein the fixed-point link searching in the second step comprises two methods of global searching and local searching: The global search is to calculate the relative distance of all the chain links relative to the data monitoring points in the plane, and the data of the chain links closest to the data monitoring points are selected as monitoring data; After the global search is completed for the first time to confirm the nearest chain link of the corresponding data monitoring point, the chain link is taken as the center, the chain link in the search range R is determined, the distance between the chain link in the search range R and the corresponding data monitoring point is calculated only and compared, and the data of the nearest chain link is selected as the monitoring data; And searching the fixed-point chain links, adopting the global search when the chain links are selected for the first time for each data monitoring point, and selecting the local search in the follow-up search.
8. The method for resampling a chain system set point of claim 7 wherein the local search calculates the number of links passing through the data monitoring point in each simulated output interval time based on the simulated output interval time, the number of teeth of the sprocket, and the maximum rotational speed of the sprocket, and wherein the search range R of the local search method is dynamically determined based on the simulated output interval time, the number of teeth of the sprocket, and the maximum rotational speed of the sprocket, and the search range R is a positive integer greater than the calculated number of links.

Description

Fixed-point resampling method for chain system Technical Field The invention belongs to the technical field of rotary mechanical signal processing, and particularly relates to a fixed-point resampling method of a chain system. Background The chain transmission system is widely used for mechanical transmission and is practically applied in the fields of transportation, material conveying, hauling lifting and the like. At present, the multi-body dynamics simulation technology has become an indispensable part of chain transmission system design, optimization and verification. In particular to a chain transmission system (such as an engine timing chain system, a mining scraper conveyor and a large crane) with complex structure, complex boundary conditions and high speed and heavy load, the time and money cost required by the design and test are high, and the efficient high-speed scheme iteration cannot be performed. The complex mechanical system is abstracted into entity models which are connected with each other through kinematic pairs and force actions by the multi-body dynamics simulation, and the dynamic time sequence signals of each entity are obtained by solving based on a computer numerical method. Based on the time sequence signals, the whole system can be deeply analyzed to judge whether the system can reach the design and optimization targets. In the field of chain system design, the dynamic quantities of tension, displacement, speed and the like when the chain system runs are parameters which must be considered in design. However, since the chain system is a slewing system, the position of the individual links changes with the movement of the chain. In a complex system, the time domain signal regularity of a single chain link is poor, the dynamics characteristic of the whole system is difficult to directly reflect, and the extraction of the frequency domain characteristics cannot be carried out. Therefore, a method for resampling a chain system at a fixed point is needed by those skilled in the art, and a method for extracting data reflecting the dynamics of the system at a fixed spatial location from the results of the multi-body dynamics simulation is needed. Signals which are stable near a certain fixed point and can reflect the dynamic characteristics of a local area are collected so as to supplement and perfect a simulation data analysis means of a chain transmission system and establish a multi-dimensional evaluation system of the chain system. Disclosure of Invention The invention aims to provide a fixed point resampling method of a chain system, which solves the problems that in the prior art, the time domain signal regularity of a single chain link is poor, the dynamics characteristic of the whole system is difficult to directly reflect, and the extraction of frequency domain characteristics cannot be carried out, and continuous and stable characteristic time sequence data at a preset fixed monitoring point is reconstructed from simulation data of a discrete motion unit (such as a chain link), so that the subsequent frequency domain, statistics and multidimensional analysis are convenient to carry out. In order to achieve the above purpose, the fixed-point resampling method of the chain system is suitable for post-processing of multi-body dynamics simulation data of a transmission system comprising a plurality of discrete motion units, wherein the discrete motion units sequentially and continuously move along a preset track and do not overlap in a motion plane; the method comprises the following steps: Step one, extracting simulation result data, namely extracting dynamics data of the discrete motion units from a completed multi-body dynamics simulation result file and storing the dynamics data into an intermediate file; Step two, searching fixed-point chain links, setting at least one fixed data monitoring point in the transmission system, calculating the relative distance between all discrete motion units at each moment and the data monitoring point in a plane, and selecting the discrete motion unit closest to the data monitoring point as the monitoring unit at the current moment of the corresponding data monitoring point; step three, fixed-point chain link data processing, namely acquiring characteristic data representing each data monitoring point by adopting a corresponding processing method according to the original dynamic data type corresponding to each data monitoring point obtained by monitoring in the step two; And fourthly, writing the fixed-point data result file, and respectively writing the characteristic data acquired by various data of each data monitoring point according to time sequence into the result file. The step one of the simulation result data extraction includes a post-start processing module, importing a simulation result file, importing a required data path and exporting data to the file. The simulation result data meets the following requirements according to di