Theoretical Analysis And Experimental Study Of Two-dimensional Contactless Transport Platform

With the continuous advancement of precision manufacturing technology,industrial products are rapidly developing towards high cleanliness and high precision,and their transportation requirements have also increased accordingly.The traditional transportation method of direct contact is very easy to cause scratches on the surface of precision workpieces and cannot meet the demand.At the same time,the logistics industry has made rapid progress in recent years,but a large number of manual sorting and handling links have reduced the efficiency of modern logistics.Contactless air flotation transportation based on pneumatic technology has become a research hotspot with the advantages of no pollution,safe,and high automation.In this paper,a contactless two-dimensional air floatation transportation control system is designed,which breaks through the defect that the traditional one-dimensional air floatation transportation can only reciprocate linearly,and realizes two-dimensional movement and positioning of the object plane.The main research is as follows:Firstly,design a new type of non-contact air flotation transportation platform,and explain the working principle of two-dimensional air flotation transportation: the air flow and the surface of the object contact to form a gas film to generate supporting force,The horizontal and vertical units generate a controlled air flow,providing horizontal and vertical viscous driving forces.Establish a three-dimensional model of the fluid,and use CFD simulation to study the gas flow velocity between the surface of the suspended object and the platform.The region division and viscous force distribution of a typical driving unit are preliminarily obtained.Analyze the influence of the combination of drive unit array,inspiratory flow and gas film gap height on the viscous force;Secondly,Based on the simulation results,the key parameters are extracted and the simplified viscous force mathematical model of two-dimensional platform gap flow is established.Study the sensitivity of each parameter to the viscous force,and compare the mathematical model with the simulation results.The model studies the sensitivity of each parameter to the viscous force,and compares the mathematical model with the simulation results.This paper designs and builds an airflow viscous force test device,compares the viscous force model and the test results,verifies the correctness of the mathematical model under actual conditions,and determines the optimal design criteria for the air floating platform device;Next,The relationship between the driving force (F_X,F_Y) and the object position parameter (x,y,?) is analyzed to determine the two control variables of the transport unit array combination and the inspiratory flow.This paper establishes an effective coding method for the combination of drive unit arrays,formulates multi-valve coordination rules,and analyzes the corresponding methods of inspiratory flow and viscous force.Two control methods are proposed: one is the use of transport unit array combination and fixed inspiratory flow single variable control method,and the other is the use of transport unit array combination and variable inspiratory flow dual variable control method.One is the use of a combination of transport unit array combination and fixed suction flow single variable control method,and the second is the use of a combination of transport unit array combination and variable suction flow control method.This paper studies the method of control quantity input,combines the mathematical model of viscous force with Newton's second law,and uses C++ language to write PID controller and simulation program.It is found that the bivariate control method with variable suction flow can effectively reduce the motion error.Finally,a two-dimensional air floating transport test device is designed and built,which uses the switching of solenoid valve to realize the combination of driving unit array,changes the direction of driving force,and uses the proportional direction solenoid valve to adjust the suction flow to change the size of driving force.The linear positioning motion and two-dimensional circular trajectory motion of the object are designed,and the experiment and data analysis are carried out respectively.The results show that the designed two-dimensional air floating transportation system can not only achieve good linear motion,but also meet the simple two-dimensional trajectory motion requirements.