Space subsystems design: (navigation, control, structure and…)
Amirhossein Mirzaei; S. Hamid Jalali-Naini; Ali Arabian Arani
Volume 15, Issue 4 , December 2022, , Pages 1-18
Abstract
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 ...
Read More
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.
Space subsystems design: (navigation, control, structure and…)
S. Hamid Jalali Naini; Ali Arabian Arani
Volume 13, Issue 4 , December 2020, , Pages 1-13
Abstract
In this paper, a modified proportional navigation (PN) with weighted combination of linear acceleration and line-of-sight (LOS) acceleration feedback is suggested. For this purpose, a comprehensive miss distance analysis is carried out for PN with linear acceletation feedback and PN with LOS acceleration ...
Read More
In this paper, a modified proportional navigation (PN) with weighted combination of linear acceleration and line-of-sight (LOS) acceleration feedback is suggested. For this purpose, a comprehensive miss distance analysis is carried out for PN with linear acceletation feedback and PN with LOS acceleration feedback using a fifth-order binomial guidance and control system. The miss distance (MD) due to initial heading error, target acceleration, and seeker noise is separately analysed. As a special case, a modified PN with acceleration feedback using variable gains is suggested based on MD analysis for infra red seekers. The comparison of PN strategies is carried out using an equivalent effective navigation ratio, defined by using LOS rate profile solution. In addition, the first-order optimal guidance law is converted into PN with PD block with variable gains.
Space subsystems design: (navigation, control, structure and…)
S. Hamid Jalali-Naini; Ali Arabian Arani
Volume 13, Issue 2 , June 2020, , Pages 1-12
Abstract
In the present work, the performance of True Proportional Navigation (TPN) with different profiles for effective navigation ratio in terms of the relative velocity angle with respect to line-of-sight is investigated due to initial heading errors and target maneuvers. Since an appropriate profile of effective ...
Read More
In the present work, the performance of True Proportional Navigation (TPN) with different profiles for effective navigation ratio in terms of the relative velocity angle with respect to line-of-sight is investigated due to initial heading errors and target maneuvers. Since an appropriate profile of effective navigation ratio for heading error is almost in contrary with the appropriate profile for maneuvering targets, a variable effective navigation ratio in terms of the relative velocity angle and its rate is introduced. In this way, the miss distance (MD) for the first two peaks of the normalized MD graph versus normalized final time, for example under an effective navigation ratio of 4, is reduced together. The analysis is carried out using normalized equations in polar coordinates for perfect and binomial fifth-order control systems without acceleration limit. Due to practical consideration, the effective navigation ratio is tuned and limited between 3 and 5.
