Side-Mounted Window Orientation Algorithm and Attitude Controller Design for Kinetic Kill Vehicle

Side-window detection technology is adopted by the kinetic kill vehicle (KKV) to solve the problem of aerodynamic heat induced by the high speed. A new side-window orientation algorithm is proposed to adjust the KKV attitude angles according to the line-of-sight (LOS) angles to achieve stable and accurate tracking of the target. The time-scale separation methodology is adopted to implement the side window algorithm. The attitude thrusters are activated in pulse mode, and the pulse-width pulse-frequency (PWPF) modulation is adopted to control the thrusters firing. PWPF modulation is a control method that provides pseudo-linear operation for an on-off thruster. PWPF modulator holds several advantages over classical bang-bang controllers such as close to linear operation, high accuracy, and reduced propellant consumption. A modified PWPF modulator with threshold limitation is adopted in this paper to reduce the number of thruster firings and fuel consumption at a possible cost of control accuracy. The control scheme is verified using computer simulation. The results have been proven the potential of this scheme.