اثر رادوم

The miss distance analysis of the first-order explicit guidance law (EGL) is carried out using linearized equation of motion in the normalized form in order to obtain normalized miss distance curves. The initial heading error, constant target, acceleration limit, radome refraction error, and fifth-order binomial control system are considered. Moreover, body rate feedback is added to the explicit guidance law as a well-known classical compensation method of the radome effect as in proportional navigation. The analysis is performed for different values of the power of the alpha function, defined as the time decrease rate of the zero-effort miss to unit control input. As a special case, the EGL with unit power gives the first-order optimal guidance strategy for minimizing the integral of the square of the commanded acceleration during the total flight time. For the performance/stability analysis, the rms miss distance versus turning rate time constant and radome slope can be plotted for different values of the power of alpha function.

In this paper, miss distance analysis of a modified proportional navigation with lateral acceleration feedback is presented using normalized equations of adjoint method in the presence of radome effect and seeker noise. In this analysis, linear model is utilized. Also, radome error slope is assumed to be constant. Approximate formulas of miss distance are presented for second-order control system with two real distinct poles, using obtained nondimensional miss distance curves. These curves and formulas are useful for guidance system analysis and preliminary design. Moreover, using the approximate formulas, the guidance gain and time constant can be designed as variables to enhance the stability and performance of the guidance and control system in low and high altitudes.

In this paper, the effect of non-minimum phase control system on the miss distance of a class of one-dimensional guidance law due to initial heading error and also constant and time-varying target maneuvers (including ramp and sinusoidal) is presented. The guidance and control system dynamics is modeled by a fifth-order transfer function with acceleration limit and radome effect. More precisely, each of the seeker and noise filter is taken as a first-order transfer function. The control system and airframe are modeled by a third-order non-minimum phase one. Miss distance analysis is made by using normalized governing equations and plotting normalized curves, resulting in useful curves for parametric study specially the effect of zero location of airframe dynamics for analysis, modification, and design of a class of linear and nonlinear guidance laws.

In this paper، the linearized 2-D equations of proportional navigation guidance (PNG) are normalized in order to carry out the missdistance analysis considering acceleration saturation and radome effect. The control system dynamics is modeled using the first-order transfer function. To reduce the missdistance due to radome effect، the body rate feedback is added to the commanded acceleration in the analysis. Using this approach، useful normalized curves are obtained for parametric study and modification of PNG. Finally، the normalized equations of a modified PNG، having nonlinear terms consisting of line-of-sight rate with different powers، are derived.