Research On Airtightness Detection System Of Airtight Bearing Of Extravehicular Spacesuit

With the continuous improvement of my country’s aviation equipment manufacturing industry,the independent development and testing of airtight bearings has become one of the important contents of my country’s aviation basic equipment development plan.Airtight bearings are the core components of extravehicular spacesuits.The airtightness of airtight bearings directly affects the performance of astronauts in outer space.The airtightness test is a key link to ensure the airtightness of airtight bearings.Therefore,this paper studies the detection method,air circuit control circuit and detection device.Taking the airtight bearing of the extravehicular spacesuit as the research object,a set of airtightness detection system for the airtight bearing based on the embedded industrial computer is developed to realize the airtightness of the airtight bearing.Automation and intelligence of airtightness testing of tight bearings.First of all,the airtightness detection method is studied.According to the characteristics of the airtight bearing of the extravehicular space suit,the mass flow method and the pressure drop method are used respectively under the pressure of small negative pressure and small residual pressure of 10 k Pa to 200 k Pa and-5k Pa to 5k Pa.Airtightness testing of airtight bearings.Establish the detection model of the two methods,analyze the air tightness detection process,and complete the overall plan of the air tightness detection device including the mechanical system,the gas circuit system and the control system.Secondly,according to the actual requirements of the airtightness detection system for the airtight bearing of the extravehicular suit on the control of the inflation pressure without overshoot,the step response three-point method is used for system identification,and four kinds of cabins are established: shoulder bearing,wrist bearing,arm bearing and ankle bearing.The mathematical model of the air-tight bearing inflation pressure system of the external service,through the critical ratio method,the parameters in the PID controller are self-tuned and simulated,and the inflation pressure is controlled quickly and stably without overshoot.Then,according to the actual requirements of the airtight system,the dual-machine joint control mode is designed based on the embedded industrial computer and the embedded microprocessor,and the design of the main control system,data acquisition,flow control,valve output control and communication system is completed.Realize the software and hardware design of the airtightness detection system of the extravehicular suit airtight bearing,develop the application software platform of the airtightness detection system,and realize the corresponding detection functions.Finally,the completed air tightness detection device is debugged,and the air tightness of the airtight bearing is tested on site in two different pressure ranges,and the test data is analyzed.The test results show that the air tightness detection system designed in this paper The air tightness detection in different pressure ranges is realized,and the effectiveness of the design of the air tightness detection system is verified.