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.
Efficient aimpoint tracking using target range profiles of a wideband FMCW seeker
This paper proposes an efficient aimpoint tracking filter for high-range resolution FMCW radar seekers. A modified probabilistic data association scheme is devised to deal with closely located measurements generated by scatterers of an extended target and multipath clutter. In order to discriminate the aimpoint measurement from others, an approximate target range profile is used for calculating likelihoods of the validated measurements. Simulation results show the effectiveness and the superior performance of the proposed approach.
An exact solution to general 4-blocks discrete-time mixed H/sub 2//H/sub /spl infin// problems via convex optimization
The mixed H/sub 2//H/sub /spl infin// control problem can be motivated as a nominal LQG optimal control problem, subject to robust stability constraints, expressed in the form of an H/sub /spl infin// norm bound. A related modified problem consisting of minimising an upper bound of the H/sub 2/ cost subject to H/sub /spl infin// constraints was introduced in Bernstein and Haddad (1989). Although there presently exist efficient methods to solve this modified problem, the original problem remains, to a large extent, still open. Sznaier (1993) developed a method to solve exactly the simpler SISO case. In this paper the authors extend this method to general MIMO systems. As in Sznaiers' paper, the main result of this paper shows that the proposed method involves solving a sequence of problems, each one consisting of a finite-dimensional convex optimization and an unconstrained H/sub /spl infin// problem.