Articles written in Sadhana

    • On high-resolution manoeuvres control via trajectory optimization


      More Details Abstract Fulltext PDF

      This research is on a realization of control approach in line with the trajectory optimization for the purpose of dealing with overactuated spacecraft in the process of the high-resolution manoeuvres. The idea behind the research is to realize closed control loops to cope with the rotational angles and the corresponding angular rates,synchronously, to handle the spacecraft manoeuvres. It is to be noted that the traditional techniques may not have sufficient merit to deal with such a complicated process, suitably. The proposed trajectory optimization is designed to provide the three-axis referenced commands, in finite burn, for transferring the aforementioned overactuated spacecraft from the initial orbit to its final outcomes in the orbital transfer process. The outcomes are realized through the variations of the orbital parameters, including the inclination, the eccentricity, the angular momentum, the semi-major axis and so on, in the high-resolution manoeuvres. It aims to get the system under control to guarantee the performance of the three-dimensional rotational angles tracking to be desirable, instantly. The contribution of the research is to make the high-thrust optimization trajectory,which is organized in association with the new configuration of the three-axis attitude control approach, to be applicable to manage the present overactuated spacecraft in the procedure of high-resolution orbital transfer process. The investigated outcomes of the research are efficient and competitive along with the potential materials through a series of experiments, as long as the desirable tracking performance in the three-dimensional space manoeuvres is apparently guaranteed.

    • Control of the inverted pendulum system: a Smith fractional-order predictive model representation


      More Details Abstract Fulltext PDF

      The inverted pendulum system in the presence of uncertainties and external disturbances with delay is considered as one of the most applicable nonlinear systems to be used in real environments and industrial domains, extensively. The subject behind the research is to design a state-of-the-art fractional-order slidingmode control approach to stabilize the inverted pendulum angle. Subsequently, a consideration of uncertainties and external disturbances in the pendulum dynamic’s parameters such as pendulum length and chariot’s massaims us to find an efficient technique to decrease chattering and correspondingly increase system’s performance as well. In addition, the Smith predictive model representation along with the control approach is realized as asolution of eliminating time delay. In a word, the realization of sliding mode control to deal with uncertainties and external disturbances in line with an application of fractional-order sliding surfaces for decreasing chattering under the aforementioned Smith predictive model representation to eliminate delay is taken into real consideration as remarkable novelty of research proposed. Finally, the effectiveness of the approach analyzed here is verified in the form of numerical simulations through MATLAB software, tangibly

    • Super-twisting sliding mode control approach for tumor growth by immunotherapy


      More Details Abstract Fulltext PDF

      Cancer is the second leading cause of death after heart disease in the world and the third leading cause of death after heart disease and accidents in Iran. In general, cancer is a disorder of the rate of proliferation and cell differentiation that can occur in any tissue of the body and at any age and by invading healthy tissues may exacerbate the disease and eventually cause death. In a word, one of the most commonly used treatments for cancer is the use of chemotherapy. The drugs of the aforementioned chemotherapy are transported throughthe blood to cancer cells and all parts of the body. In addition to cancer cells, these drugs also have a detrimental effect on healthy cells, which can be seen as side effects. It is to note that they are temporary and can stop at the end of treatment. The subject behind this research is to propose super-twisting sliding mode control approach without chattering for mathematical model of cancer by immunotherapy with the aim of stabilizing the closedloop system, as long as determining the optimal drug dose is taken into consideration as the innovation of this study to conclude which controller has the better performance in the presence of uncertainties and disturbances

    • On pulse-width pulse-frequency modulator control strategy: An adaptation-based describing function representation


      More Details Abstract Fulltext PDF

      This research describes an adaptation-based control strategy to deal with the pulse-width pulsefrequency modulator. The subject behind the research is to control the above-referenced modulators the hard limiter block via closed-loop describing function representation. In a word, this modulator has a set ofparameters, which are all in need of adjusting, accurately, in order to guarantee its high performance, in the entire areas of overall systems under control. The investigated results indicate that parameter’s adjustment of the aforementioned pulse-width pulse-frequency modulator can be recognized as the state-of-the-art outcomes via adaptation rules

  • Sadhana | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2021-2022 Indian Academy of Sciences, Bengaluru.