Development And Implementation Of The Multi-axis Motion Control Block Based On PLCopen Standard

Aiming at the problems of the traditional multi-axis motion control system,such as none unified programming language,poor universality and over reliance on the hardware platform,an upper computer motion control system with the multi-axis motion control function is developed based on IEC61131-3 standard and PLCopen standard,and a set of PLCopen multi-axis function blocks are built.The upper computer motion control system provides the program editing interface which takes the PLCopen standard function block diagram as its programming language,and after compiling and executing the multi-axis function block programs,the real-time motion control parameters of each control cycle are output to the lower computer hardware platform in the end.According to its function,the control system can be divided into analytic system and executive system.The main work of this paper is summarized as follows:First,the editing interface and compiler conversion of multi-axis function block diagram program are achieved in the analysis system.Due to the problem of multi-axis function block diagram program with multiple input axes and output axes,a compiler conversion algorithm for multi-axis function block diagram is proposed which establishes vertical line class.By means of the virtual object decomposition and reorganization of the vertical line,the complex multi-axis function block diagram can be converted into a collection of simple ordered tree structures.The tree structures are sequentially visited in the post-order traversal way to generate the instruction list(IL)language.After optimizing the IL language,the hexadecimal target file is generated.The results show that the algorithm can achieve the compiler conversion of the multi-axis function block program and optimize the results to improve the efficiency of the system.Then,the execution and output of the multi-axis function block program are realized in the execution system.There is no explicit series-parallel relation in the multi-axis function block program,with the BufferMode function added into the execution system,non-sequential execution manner of multiple speed control modes is implemented by establishing the information queue.Aiming at the problem of more motion parameters in the multi-axis function block,the structure object is established to package the motion parameters and given a unique identifier to be identified,which can avoid wasting time caused by repeatedly scanning the parameters and improve the efficiency of the system.According to the practical control requirements,the PLCopen function library is established in the system.Finally,based on the hardware platform with IPC and UMAC motion control card,experimental verification of the upper computer motion control system is carried out.The results indicate that the multi-axis function block which executes accurately is able to achieve the multi-axes coordinated motion control in multiple speed control modes and meet the requirements in practical application.