Meeting the challenges of modern interceptor guidance by non-conventional approaches
The challenge of intercepting threats with non conventional warheads, the major drive for the development of ballistic missile defense systems since the first Gulf War of 1991, became even more serious when the reentry vehicles were assumed to be capable of maneuvering. Successful interception of such targets, requiring very small miss distances, cannot be guaranteed by the classical guidance and estimation methods that have been used against manned aircraft. Future interceptor guidance strategy has to be based on pursuit-evasion game concepts and the estimator design has to be integrated with the guidance law. Following such non conventional approaches has the potential to achieve the requirement of hit-to-kill accuracy against randomly maneuvering threats.
DIFFERENTIAL GAME GUIDANCE LAWS FOR INTERCEPT MISSILES
Guidance laws for intercept missiles are derived using zero-sum, perfect-information differential game theory and optimal control theory. The differential game laws are derived using both a linear constant coefficient missile model and a time varying linear model, which uses an open loop profile of the missile speed. The optimal control law is derived only using the variable velocity missile model. A series of six-degree-of-freedom simulations were used to compare missile performance for these three guidance laws. The results show that both differential game laws result in equivalent missile performance. The differential game laws, in turn, perform slightly better than the optimal control law. I. Introduction Intercept missile guidance laws derived using optimal control theory require an assumption on future action by the target in order to generate the optimal control for that specific projected target action. The feedback characteristic of missile guidance laws allows the missile to compensate for incorrect target action assumptions. In contrast, intercept missile guidance laws derived using zero-sum perfect information differential game theory do not require any assumptions on future target actions. Instead the controls are based on the lateral acceleration maneuver capabilities of the target relative to the missile.
The Analysis on Fire Smoke Exhausting Robot Vibration Based on Wavelet Transform
Belt relaxation, which affects a lot on operation reliability of the fire smoke exhausting robot, is hard to detect. In this paper, a new method for belt relaxation feature recognition based on continuous wavelet transform (CWT) is proposed, and a vibration model which simplified the robot as a 2-dof forced vibration system under harmonic excitation is established. The vibration acceleration signal has been collected using the IEPE sensor and data acquisition card, experimental results verified the accuracy of the vibration model, and weak impact signal caused by the belt relaxation was distinguished, that testify the practicability of the CWT method in belt relaxation feature recognition.