Research And Implementation Of Key Technologies Of Mechatronics Virtual Commossioning System

As an important application of digital twin technology in manufacturing industry,virtual mechatronic commissioning(VMC)technology makes it possible to fully simulate,verify and optimize the design scheme and control program in a virtual environment.The VMC technology has obvious advantages over the traditional commissioning method,which depends on the physical equipment for commissioning,especially for some innovative or highly complex automation equipment.At present,only a few foreign software enterprises have developed some VMC software.But expensive prices and closed hardware and software ecology hinder the promotion of these software.In order to promote and widen the application of VMC technology in the domestic automation equipment industry,a set of VMC software was developed after solving some key technical problems such as real-time motion,dynamic interference checking and workpiece transferring.The main work of this paper is summarized as follows:(1)The kinematic modeling and solving technology for open-and closed-loop mechanisms are implemented.For open-loop mechanism of tree-topology,the real-time motion is calculated based on the theory of kinematics of rigid bodies by transforming the control signals of a kinematic pairs(KPs)into the relative transformation matrices.Using the maximum spanning tree algorithm,the non-tree topology of closed-loop mechanisms are transformed to the tree topology by cutting off some KPs.After replacing the cut-off KPs with constraint equations and solving these equations,a closed-loop mechanism is converted to an open-loop mechanism,and can be treated in the same way.(2)In order to meet the real-time requirements of VMC,an offline dynamic interference detection algorithm is proposed.The algorithm consists of three parts: motion recording,offline interference calculation and interference playback.First,during the commissioning process,the generalized coordinates of all KPs in each time step are recorded;then,the position and pose of each part in a time step are restored and the interference in each step are calculated;finally,the dynamic commissioning process and the interference detected are replayed.In this way,the accuracy interference calculation can be guaranteed without blocking the commissioning process.(3)The commonly used dynamics-based methods are time-consuming and instable in simulating the transferring of workpieces.To avoid these problems,a kinematics-based transfer method is proposed.This method introduces a concept of contact pair.When a moving part closes to a workpiece,the contact pair is triggered and the workpiece will move with the moving part.When the moving part leaves the workpiece,the contact pair is released.The transferring of the workpieces is simulated by inspecting the status of the contact pairs and using a special algorithm for update the position and pose of workpieces.(4)A set of VMC software was developed on the Solid Works platform,which supports both software-in-the-loop commissioning and hardware-in-the-loop commissioning.A desktop automated storage system,as a physical equipment,was operated with digital model in a parallel way.The movement of the physical equipment and the digital model remained consistent throughout the whole process,which proved the feasibility of virtual commissioning of equipment in the digital space.