Research On The Key Problems Of Autoloader Control System In A Large Caliber Howitzer

Autoloader is one of the main components in the modern large caliber howitzer;it contacts and restricts with the other components of the large caliber howitzer and has become one of the main factors in restricting the firing rate of the large caliber howitzer.Compared with the advanced autoloader of the large caliber howitzer in the world,the autoloader of the large caliber howitzer in our country is of low degree of automation and of low loading speed,and the reliability of the autoloader needs to be further enhanced.The autoloader of the large caliber howitzer is a complicated multidisciplinary system,it integrates with the technologies of mechanical engineering,electrical engineering,hydraulic engineering,computer engineering and automatic control,and a lot of technical problems need to be solved badly.This dissertation is based on the twelfth five-year pre-research project,and some key problems of the autoloader control system in a large caliber howitzer are studied in-depth by combining the theories of muti-body dynamics,sliding mode control,fuzzy mathematics,adaptive control,control system reliability and so on,and the accurate posisiotn controller design theories and methods of the rotational chain shell magazine and the ammunition manopulator in complex environments are emphatically studied,thus certain theoretical and technical supports can be provided to the solution of practical engineering problems.So far,the assembling and the debugging of the autoloader's test-bed have been finished,and the maximum loading rate of the autoloader is 11 cycles per minute in the labtory environment.The main research contents of this dissertation are as follows:(1)The basic struction and the workflow of the autoloader are introduced in detail,and a distributed real-time control system based on the CANopen network is designed and built,and the control strategy of the permanent magnet synchronous servo motor system and the hydraulic servo system is established,respectively.Combing with the problems during the system integration and the joint debugging of the autoloader,some key problems of the autoloader control system in large caliber howitzer are summarized and discussed.(2)The experimental platform of the rotational chain shell amgzine is built,and the accurate position control technologies are studied in-depth based on the experimental platform.By combining the adaptive control theory and the sliding mode control theory,the adaptive sliding mode controller design method of the shell magazine is presented.The chattering is eliminated by adaptively tuning the switch gain,and satisfactory control performance is obtained.A fuzzy sliding mode controller of the shell magazine is designed,and the mathematic model of the shell magazine does not need to be known exactlly,thus the difficulty of the controller design is significantly reduced.The discontinuous control law in the traditional sliding mode control is removed by integrating the translation-width idea,and then the chattering is effectively reduced.The application of disturbance observer to the shell magazine is investigated,and the influence of the external disturbance on the control performance is reduced by using the external disturbance's feed-forward compensation.The nonlinear friction is considered in the design of the shell magazine's adaptive robust controller,and its influence on the control performance is reduced by using adaptive compensation technonogy,and favorable control performance is obtained.(3)The co-simulation platform of the ammunition manipulator control system is built based on the Matlab/Simulink software and the AMESim software.In the accurate position controller design of the ammunition manipulator,the unknown parameters are estimated by using an adaptive algorithm,and the influence of the model uncertainty on the control performance is reduced;and the chattering is also eliminated by online tuning of the switch gain according to the system states.A fuzzy sliding mode controller is designed according to the fuzzy universal approximation theory,and thus the exact mathematic model does not need to be known.Then,not only the controller design is simplified,but also the capability of suppressing the parameter variation is improved,and the system's robustness is also enhanced.To improve the steady-state precision of the ammunition manipulator,the servovalve's input dead-zone character is considered during the controller design;and the system's control performance is improved by the adaptive compensation of the input dead-zone.(4)The reliability model of the autoloader is built,and the reliability design methods of the autoloader control system are given.The application of Falut Tree Analysis to the autoloader control system is investigated by taking the shell transfer robot as an example.The reliability weaknesses of the shell transfer robot are analyzed and summarized,and corresponding measures are given.