Research On Intelligent Control Technology Of Gas Valve Automatic Assembly Line

With development of automation technologies,all industrial fields impose higher requirements on performance indicators such as production quality and efficiency.In recent years,initiatives such as Industry 4.0 and Made in China 2025 all have started.These initiatives are aimed at improving intelligence level of the manufacturing industry and building modernized intelligent plants.In such a context,automatic assembly technologies are widely used in all kinds of industries.In this paper,based on the engineering background of automatic assembly production line of liquefied petroleum gas cylinder valves,an automatic assembly control system of gas valve was studied and designed.In order to realize accurate positioning of conveyor chain,reliable tightening of threaded parts and overall stable operation of the system of the production line,following aspects were analyzed and studied:(1)Fuzzy-PID full closed-loop position controller is designed.In order to solve the problem of low positioning accuracy in existing conveyor chains,a full closed-loop control solution was proposed.In this solution,an AC servo system was adopted for the inter loop to improve operation stability of the system;in addition,in order to improve positioning accuracy and efficiency,control algorithms such as approximation algorithm,PID algorithm and fuzzy-PID algorithm were adopted to construct the motion system model.Then,the simulation results were analyzed to verify that fuzzy-PID algorithm had better control performance and great engineering application value.(2)The research on the method of tightening of the workpiece.A comparative analysis of several tightening control methods was completed.Based on the angle control method,the mechanism of threaded part tightening was analyzed to work out the optimal tightening angle and fitting torsion value,so as to provide reliable control target values,laying a firm foundation for realizing tightening control.Meanwhile,a phased control method was further proposed to improve reliability of threaded part tightening and ensure zero-damage to parts,reducing the semi-finished product rate.(3)The research on the fault-tolerant control system.Predictable failures that can easily occur in the system after long-term usage were analyzed.For failures such as single-station and abnormal power cut,an idea of software redundancy and fault tolerance was proposed to improve stability and operability of system operation through corresponding software programming control.(4)The overall design of the production line control system.Taking into consideration practical requirements,functions of the control system were designed.In order to enable these functions,other works such as electrical element selection,slave computer software design and monitoring program design were completed.