Research On Motion Algorithm And Software Control System For Six-axis Robot Based On LinuxCNC.

With the changes in global manufacturing competition,the competitiveness of manufacturing has shifted from a cost advantage to a productivity advantage.Therefore,advanced manufacturing technology will become a key factor in improving the competitiveness of manufacturing industries in each country.Industrial robots,as the basic equipment to achieve digitalization,automation,integration,and networking in high-end manufacturing,have widespread market application foreground and important strategic positions.The industrial robot integrates the mechanical structure,the drive system,the perception system and the control system.This paper takes the 6-axis robot's software control system as the research object,and designs a fully functional robot software control system.The main research work and results of this article include the following sections:(1)Analyze the functional requirements of the robot software control system.At the same time,complete the overall design of the 6-axis robot software control system based on the Linux CNC software platform.(2)Based on the D-H modeling theory,the forward and inverse kinematics of 6-axis robots are analyzed.And the analytical solution of inverse kinematics of STR6-06 robots is derived.The optimal solution in multiple solutions of inverse kinematic is established according to the shortest-stroke method with weights.And using the Matlab platform to simulate positive and negative kinematics and work space of STR6-06 robot.(3)In order to make the 6-axis robot capable of processing NURBS curves,this paper firstly analyzes the recursive expressions of the NURBS curve and the calculation method of interpolation points,and proposes a new discrete S-type speed planning algorithm that can eliminate the residual velocity and residual distance.In addition,to achieve the contour accuracy of NURBS and overcome the shortcomings of the feed-speed oscillation and hysteresis in the adaptive algorithm based on chord error,a segmented discrete S-type velocity planning algorithm for NURBS curve is proposed.The algorithm segmented the NURBS curve at the point of extreme curvature,and discrete S-type velocity planning algorithm was applied to the segmented curve respectively,thus achieving a better control of the chord error under continuous acceleration.Finally,the NURBS Trident curve is used as an example to simulate and compare different interpolation algorithms in Matlab.(4)Study the working mode of EtherCAT communication protocol and the transmission process of data frame between master and slave station.And design the real-time communication module with the help of application layer protocol Co E.On the industrial PC,the open source software Ether Lab and the Linux CNC HAL design method are used to implement the application development of the Ether CAT master station.Finally,an experimental platform for robot control was set up.By analyzing and modifying Linx CNC numerical control software source code,the design of the software control system was completed.Experiments on real-time communication,positive-inverse kinematics and NURBS curve interpolation were conducted in the experimental platform.The results show that the 6-axis robot software control system designed in this paper achieves the desired goal.