Research On Dynamics And Control Of Ammunition Autoloaders With Uncertainty

Ammunition autoloaders, mounted on a combat vehicles such as tanks and self-propelled artillery, play an important role in modern tank and artillery weapon system. The dynamics of the autoloaders is strongly affected by nonlinear force due to the chassis’oscillation as well as the inertial changing etc, resulting in poor positioning accuracy, and has seriously deteriorated the operation accuracy and reliability of the whole weapon system. Study on dynamics and control of the autoloader has great significance from both theoretical and practical points of view, the achievements of which can be applied in various fields, such as underwater manipulators, space manipulators, manipulators installed on seaborne platforms, etc.This dissertation deals with the dynamics and control problem of a new type artillery autoloader under uncertainties such as the chassis oscillation and inertial changing etc.(1) This dissertation introduced the development of the ammunition autoloaders, and reviewed the current research situations of dynamics and control theory of which at home and aboard. Uncertain dynamic models of the ammunition transfer manipulator and the cycle-chain type magazine were obtained respectively by treating the chassis’oscillation and the inertial changing as external disturbance. The oscillating dynamic of the chassis was gained during a tank running at 40km/h on the F class road using virtual prototype technology. Based on above dynamic model and oscillation data of the chassis, the disadvantages of traditional proportion differential controller for the ammunition transfer manipulator under uncertainties were presented according numerical simulation results.(2) Based on the uncertain dynamic models of the ammunition transfer manipulator and the cycle-chain type magazine, a type of robust controller namely piecewise linear stabilizing control laws was presented. The control law does not need precise mathematics model and has good robustness to bounded disturbance due to the chassis oscillation and inertial characteristics changing. The control law present as piecewise proportion differential controls, with gains changing as a step-function of time while the system approaching the terminal state, but it’s practicality in practice needs further verification.(3) To solve above problem, another robust control law namely continuous feedback control with continuous time-varying gains was designed based on a given implicit Lyapunov function. The controller’s gains, which are differentiable functions of the state variables, increase and tend to infinity as the state variables tend to zero, but the control force always satisfies the given constrain. Finally, the continuous feedback control law was extended in order to solve the tracking control problem of the ammunition transfer manipulator via computed torque method.(3) The dynamics and control problem of the ammunition transfer manipulator considering the driving elasticity and rotational part’s structural flexibility was studied. Regarding the driving and rotational part as non-inertial spring and the Euler-Bernoulli beam respectively, the rigid-flexible dynamic model was obtained via Lagrange method and the assumed modes method. Based on the singular perturbation method, the model was decomposed into two part, a slow subsystem and a fast subsystem. For the slow subsystem, the PD controller with continuous time-varying gains was designed to achieve the positioning control of the manipulator; for the fast subsystem, a velocity difference feedback controller and a LQR controller was proposed to suppress the elastie vibration of the spring and the Euler-Bernoulli beam respectively.(4) In order to verify the effectiveness and practicability of the continuous feedback control law in engineering practice, two experimental platforms were designed to conduct the positioning control experiment:first platform, scaled model of above 2-DOF ammunition transfer manipulator; second platform, simplified model of traditional 1-DOF ammunition transfer manipulator. The results show that the designed controllers desirably attenuate the disturbance and transfer the system from an arbitrary initial state to a given terminal state, have excellent robustness.