Aerospace Science and Technology
Noise-Induced Miss Distance Analysis of First-Order Explicit Guidance Law

Ali Arabian Arani; S.H. Jalali Naini; mohammad hossein Hamidi nejad

Volume 15, Issue 1 , June 2022

  This study presents the miss distance analysis of the first-order explicit guidance law due to seeker noise using the adjoint method. For this purpose, linearized equations are utillized and the adjoint model is developed. Then the first-order equations are obtained and converted into nondimensional ...  Read More

Static and Dynamic Analyses of Integral Pulse-Width Pulse-Frequency Modulator with Small Error-Reset Integrator Logical Circuit

S.H. Jalali Naini; omid omidi hemmat

Volume 15, Issue 1 , June 2022

  In this study, the static and dynamic analyses of a modified integral pulse-width pulse-frequency (PWPF) modulator with small error-reset integrator (SE-RI) logical circuit are carried out using grid search method. A set of quasi-normalized equations is utilized in order to reduce the number of parameters, ...  Read More

Preliminary Design of Spacecraft Attitude Control with Pulse-Width Pulse-Frequency Modulator for Rest-to-Rest Maneuvers

S.Hamid Jalali -Naini; Sh. Ahmadi Darani

Volume 11, Issue 1 , June 2017

  In this paper, the preferred region of design parameters for quasi-normalized equations of single-axis attitude control of rigid spacecraft using pulse-width pulse-frequency modulator (PWPFM) is presented for rest-to-rest maneuvers. Using the quasi-normalized equations for attitude control reduces the ...  Read More

Approximate Solution of Sensitivity Matrix of Required Velocity Using Piecewise Linear Gravity Assumption

S.H. Jalali Naini

Volume 9, Issue 2 , September 2012

  In this paper, an approximate solution of sensitivity matrix of required velocity with final velocity constraint is derived using a piecewise linear gravity assumption. The total flight time is also fixed for the problem. Simulation results show the accuracy of the method. Increasing the midway points ...  Read More