Study On Key Problems In Autoloader Of A Self-Propellant Howitzer

Autoloader is one of the most important subsystems in modern self-propellant howitzer. Because of the interactions between autoloader system and the self-propellant howitzer system, a great deal of technical problems needs to be solved urgently. Based on the key beforehand project of the "twelfth five-year", autoloader system and the key technologies are studied in depth employing the theory of multi-body dynamics, deterministic optimization, robustness optimization, fuzzy mathematic, sliding mode control and so on, which provide theoretical foundation for engineering practice problems. The main research contents in this dissertation are as follows:(1) The structure styles and system composition of autoloaders are expatiated, and basic functions and operational principle of various subsystems are narrated. The dynamic characteristics and computation of the key structural member of autoloader are analysed and studied, which build theroretical foundation for the coming research. And problems of autoloders, which are studied and solved in the following chapters, are brought forward.(2) Considering the problem that the control force of shell transfer arm of autoloader system is so large, deterministic engineering optimization technology is employed to improve the dynamic response performance. Multi-objective optimization model and Pareto optimal solution are introduced, and handling methods for the multi-objective optimization problem are summarized. Combining multi-objective evolutionary algorithm, all-in-one design optimization for multi-objective and multidisciplinary model of gun manipulator is analysed and studied, and the better dynamic response performance is obtained after optimizing.(3) For the existent problems of deterministic optimization, robust optimization technology with parameter interval uncertainties is proposed, and then applied to multidisciplinary optimization problem for the shell transfer arm of autoloader system. The parameter perturbations are mapped from variation space into objective and constraint space, then the degraded-estimation of objective and constraint, which is acted as an additional constraint of original optimization problem, is obtained, and a new robust optimization with an outer-inner optimization structure is established. Ten bar truss problem, structural optimization problem and bi-objective numerical problem are studied, and the ideal results are obtained. Then the multidisciplinary optimization problem for the shell transfer arm of autoloader system is studied, and the results show that the presented approach can fix complex engineering optimization problems with parameter uncertainties effectively. (4) According the shortcomings of PD controller for ammunition cabins, combining fuzzy turning method, Sliding mode control with high robustness is proposed. Nonsigular terminal sliding mode (TSM) control and global fast terminal sliding mode control are introduced. Combining the characteristic of nonsingular and fast response, the fuzzy moving terminal sliding mode control is proposed employing fuzzy mathematics. Compare study of "Stanford" manipulator is conducted, and the better control performance is obtained. For dynamic control system of ammunition cabins, comparing with traditional PD control, the better control performance is obtained employing the proposed control strategy with simple deterministic model conducted and the perturbation value established.(5) The consistency problem of bayonet-chamber of gun is studied, which affect the kinetic characteristic of projectile and firing accuracy of self-propellant howitzer. Considering the force of ammunition ramming, the velocity of ammunition ramming bayonet-chamber and contact-impact between projectile and barrel in the process of ammunition ramming, the dynamic model of ammunition ramming bayonet-chamber was constructed. The effects of the force of ammunition ramming, gap and contact-impact between projectile and barrel on the consistency of bayonet-chamber were analyzed and studied. The results show that the consistency of ammunition ramming bayonet-chamber can be improved effectively to adopt variable-force ammunition ramming and to lower the location of rammer.