Research On Speed Planning And Software Architecture Design Of Embedded CNC Interpolation System

In laser engraving,surface mount,3D printing and other equipment,embedded CNC system software is widely used,so improving its performance is of great significance.In order to further improve the performance and reliability of the embedded CNC system,this article mainly does the following related research:(1)The common functions and principles of the embedded numerical control system including display,decoding,arc processing,speed planning,interpolation and acceleration/deceleration discretization and driving,etc.are studied;at the same time,the inter-function modules are studied.Calling relationship,parameter transfer,structure and type of transferred data,and embedded CNC system software framework.(2)In order to further take into account the efficiency and stability of processing,a dynamic forward-looking backward planning algorithm and a relatively complete set of acceleration and deceleration planning processes are given.First,calculate the speed of convergence between two adjacent segments based on the angle between two adjacent segments;second,use the look-ahead algorithm to further restrict the speed of convergence between two adjacent segments to strictly ensure the exit speed of the last segment Is zero,and get the entrance velocity and exit velocity of each straight line;finally,according to the entry velocity,exit velocity,acceleration and displacement of each straight line,refine the speed change process with time,prepare conditions for calculating the interpolation period.Simulation shows that the proposed dynamic look-ahead algorithm can effectively improve the smoothness and efficiency of processing.(3)In the case of long processing paths and low precision requirements,in order to reduce the amount of calculation,and to adjust the height of the "step" for different processing precisions,the calculation amount and accuracy can be optimized,and the acceleration and deceleration discrete algorithm Some improvements have been made,and the interpolation period can be calculated every multiple steps.The simulation results show that the improved discrete algorithm can significantly reduce the number of iterations,and can more accurately describe and restore the relationship between speed and displacement over time.The physical processing results show that selecting algorithm parameters within a suitable range has little effect on the surface quality of the workpiece.(4)In order to further reduce the degree of coupling between functional modules and improve the efficiency of program execution,a multi-threaded software framework based on circular queue and production-consumption model is established,and a parallel design scheme for embedded CNC system is given.The embedded CNC system is divided into 5 threads according to different functions and execution order,which reduces the coupling degree between modules,can be executed concurrently,and improves the utilization of hardware resources such as CPU.Finally,an experimental software and hardware platform is built.The experiment shows that the newly proposed software architecture is feasible.