Attitude Controller Design with State Constraints for Kinetic Kill Vehicle Based on Barrier Lyapunov Function

Tao Zhang,Wanqi Li,Huaji Wang,Chuhan Xiao,Jiong Li

doi:10.1155/2018/4397548

Abstract

An adaptive attitude controller is designed based on Barrier Lyapunov Function (BLF) to meet the state constraints caused by side window detection. Firstly, the attitude controller is designed based on the BLF, but the stabilization function is complex and its time derivative will cause “differential explosion”. Therefore, Finite-time-convergent Differentiator (FD) is used to estimate the first derivative of the stabilization function. If the tracking error is outside the BLF's convergence domain, BLF controller cannot guarantee the error global convergence. Sliding mode controller (SMC) is used to make the system's error converge to set domain, and then the BLF controller could be used to ensure that the output constraint is not violated. Uncertainties and unknown time-varying disturbances usually make the control precision worse and Nonlinear Disturbance Observer (NDO) is designed for estimation and compensation uncertainties and disturbances. The pseudo rate modulator (PSR) is used to shape the continuous control command to pulse or on-off signals to meet the requirements of the thruster. Numerical simulations show that the proposed method can achieve state constraints, pseudo-linear operation, and high accuracy.

Highlights

With the development of small-size propulsion systems, accurate sensors, and precision guidance systems, the kinetic kill vehicle (KKV) is becoming both technically and economically feasible [1,2,3]
Tee [23] rigorously proved that the backstepping controller designed with symmetric Barrier Lyapunov Function (BLF) or asymmetric BLF can ensure the system output is bounded for a strict feedback nonlinear system
Motivated by the above discussions, to meet the state constraints caused by side window detection, an attempt is made to exploit Barrier Lyapunov Function to design the attitude controller

Summary

Introduction

With the development of small-size propulsion systems, accurate sensors, and precision guidance systems, the kinetic kill vehicle (KKV) is becoming both technically and economically feasible [1,2,3]. Tee [23] rigorously proved that the backstepping controller designed with symmetric BLF or asymmetric BLF can ensure the system output is bounded for a strict feedback nonlinear system This method requires the system to be in a small convergence domain and the output to be continuously differentiable, and this is usually not satisfied in the actual system. (1) This paper investigate a BLF for KKV to meet the state constraints and achieve satisfactory dynamic performance and stationary performance compared with the existing work [2, 11]. The constant thrust control is realized and the phase lag problem of the PWPF modulator is overcome compared with the existing work [2, 28, 30]

Problem Formulation and Preliminaries

Figure 1

Attitude Controller Design and Realization

Simulation Results

Conclusion