Conducting Research: A Personal Technical Experience
-Part IV: At the National Aerospace Laboratories
By JIRARA
© JIRARA, August 2022
Published by JIRARA
on matrubharti.com
All rights reserved. No parts of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, for any commercial purposes without the prior permission of the author and/or publisher.
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Disclaimer: This is the work of fiction as far as all the characters, their names and the names of all the events are concerned and all these are imaginary and hence any resemblance to the persons (and their lives) dead or alive, and any places are coincidental. Even if a few events might look realistic/’real’, these are fictionalised and the associated names are changed in order to maintain their privacy, honour, and security. No intention whatsoever is meant to hurt any feelings of whosoever, irrespective of their personal/cultural beliefs, social or political inclinations, religion-orientations/practicing/philosophy, life styles, and work/business. The ‘I’, ‘my’, ‘me’, and ‘mine’ (if any used) do not necessarily mean the author of this book/story/article, and these and other such pronouns: her, hers, his, he, she, him, you, your, yours, ours, theirs…; are used for effective personification and dramatization, and the readers should not take these on their ‘own persons’.
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The readers should take these stories/verses/thoughts with/in good spirit. The presented ideas and material are based, where feasible, on readings and (thought-) analyses of scientific/other open literature (which seemed most profound and trustworthy), with as much care as possibly taken. The readers are requested to verify these notions on their own, and use their own discretion. However, these stories/verses/thoughts/ideas (mostly original) are expressed here with an intention of increasing awareness of the readers with a hope that in an overall sense, their (and ours) consciousness would be heightened (in all and multiple directions), so that we all can live our lives on this planet with true happiness, ever-lasting peace and real joy (irrespective of our orientations). The author and the publisher will not be responsible for any negative effects/situations arising as a result of reading these stories/verses and/or following the suggestions if any; and no discussions/dispute of any kind will be entertained at any time and in any way, manner, and/or forum; because the dictum is that if you like(-d) you read, otherwise ignore, what is the point in making a fuss about it?; anyway you are independent to judge the messages in the articles/stories and utilize for your benefits if found useful, since here the idea is in the direction of ‘consciousness raising’. JIRARA.
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Dedication
This and the next story-article is dedicated to Dr. S. Balakrishna (Now with Vigyan Research, USA), and Dr. S. Srinathkumar (late) for being the originators (~in early seventies, 1970) and the pillars of the flight mechanics and control activity in the county, and nurturing and nourishing dozens of scientists and engineers who had have worked in various R&D areas like: building of flight simulators, flight control, system identification, and wind tunnel experiments; they themselves contributed to these and more areas like: pressure regulating valve for the NAL-wind tunnel, wind tunnel control systems, control of filament winding machine, computer control for non-destructive testing facility, hydraulics, and many more fields as a part of the systems engineering activities. For their exemplary work carried out at NASA, they both, at different times, had received some NASA awards. Dr. S. Srinathkumar led the national CLAW team for nearly decade for the analysis, design and synthesis of flight control laws (automatically stabilizing control systems) for the LCA.
Today, the FMCD is one of the best divisions of the country, and this is thanks to their discipline, guidance, commitment to the common goals, highest kind of sincerity and honesty of the purpose. These selfless scientists were/are highly committed individuals, and I consider them as high calibre engineers-cum-scientists/professional engineers; they have created a formidable and high science-high technology group of contemporary activities of the world class research.
They deserve some suitable high order of awards from the Federal Democratic Government of India.
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Conducting Research: A Personal Technical Experience
-Part IV: At the National Aerospace Laboratories
Preamble: When I was nearing the completion of my doctoral studies (at the McMU, Canada), I had written to Dr. S. Balakarishna, who was in NAL (now National Aerospace Laboratories) that time, that if I came (gone) back to India, I would like to join NAL, to which he had agreed to.
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After coming back to India, I had gone to Bangalore to meet Dr. S. Balakrishna, and the NAL director, Prof. R. Narasimha, in early July 1986, for getting a position in NAL; and then I had gone to Delhi to appear for an interview at UPSC (union publish service commission) in July 1986; at both the places I had got the affirmative answers for my job, but I had selected NAL; this again because I was familiar with the set up (and some colleagues) having worked therein for six years before I had left NAL in August 1981 to pursue my doctoral work at McMU (from Sept. 1981-April 1986).
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So, I joined NAL in October 1986 as a Scientist C (ad hoc); and I found that the scope of the research had further changed and had expanded in some other directions that I was not much aware of; I was attached to the flight mechanics and control group (FMC) of the systems engineering division (SED), which was then formed by combining three previous smaller divisions: i) instrumentation, ii) electronics, and iii) computer. This SED had four groups: i) FMCG, ii) aerospace electronics, iii) flight research, and iv) computer systems; which after some years were separated and came to be known as the independent divisions with nearly the same names. So, I remained as a scientist attached to the FMCD till I retired in July 2007, as a head of this division after serving it for six and half years.
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The new activities of the FMCG/FMCD were: a) system identification (SID), b) flight control (FC), c) flight simulation (FS), and d) dynamic wind tunnel experiments (DWT); this was a sort of shock for me to get adjusted to, since except the first two I had not heard other terminologies and what it meant doing R&D in those fields, it took quite some time for me to understand this, as well as application of SID to aircraft parameter estimation and FC to design of flight control laws for LCA (Light Combat Aircraft to be developed, using indigenous technologies, primarily for the Indian Air Force). It was a sea change for me to get into this new phase of activities, but I was asked to focus on only SID, which was my specialisation at my masters and doctoral research levels.
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The events presented in the following are not necessarily in the chronological order.
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As a Scientist C for a year or so:
Soon as I joined NAL, I was asked to work with V. S. Mohan Ram, a scientist who was working on two projects sponsored from DRDL, Hyderabad (a defence R&D lab): a) analysis of the data from the aeroballistic range facility of the lab, and b) to develop a methodology of conducting system identification experiments to obtain real-flight (test) data of Prithvi missile (SSM, a surface to surface missile), and subsequently analyse these data (when obtained in future) to estimate the parameters of the math model of the missile; both looked formidable tasks to me, because I had not studied anything of the kind, and I did not have any aero-degree at any UG/PG level.
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So, first I started reading books and reports on missile aerodynamics, and also started attending some classes on flight mechanics offered by the aerospace dept. of the IISc (Indian Institute of Science, Bangalore).
First, I would go to NAL by the NAL’s own bus transit facility from nearby stop, from my house, and after some time I would leave the lab and by NAL’s another service go to IISc., and attend one hour class, then go back to NAL by return bus; I could do this only for a few classes, because sometimes when I reached the IISc., the class was declared cancelled, and for this I would not have got any advanced information, no mobiles, and no internet at that time! So, I could learn only certain basics on stability and control of an aircraft, and then many more details on flight mechanics, I learnt from several books, and also learnt about aircraft parameter estimation from the reports of NASA, DLR (Germany), and NLR (The Netherlands); it was much more arduous journey for me because I had only background in electrical engineering with a specialisation in automatic control, and system identification; and I had no idea of signal processing and aerodynamics.
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After one year I was regularised as Scientist C without any interview, and then since the two bosses had to go to USA for their respective fellowships (~1988-1990) to work on the projects sponsored from NASA, they had thought to install me in some better and a firm position since I had a Ph.D. For this a position of Scientist E1 was advertised for me, with the job description that read like my own short biodata, to which some colleagues felt that only my photo was missing from the advertisement in the newspaper! Nobody from the division had attended the interview, and there were no external candidates, because the job requirements were stringently specified.
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After I was promoted to the position of Scientist E1, both the bosses left to USA on sabbatical leave with a time lag of six months, and they handed over to me the coordination of the FMC group of the SED for next two years, and this was unexpected by me; there were a few new members, and a few were seniors to me; and I was told to allow them to do whatever they wanted to do, so then I would not face any problem; the second boss who went after six months had outlined, in his own handwriting on four pages, all the major activities to be carried out and monitored by me, and certain confidential things he had told me verbally and to be remembered well.
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As a Scientist E1 to G (1987-2007):
My journey and task became more and more involved for me and since the FMC had already made a good progress during the then last intervening seven/eight years, we had started getting new sponsored projects from some external organisations; and I started learning art and logistics of sponsoring new projects, taking the responsibility of the sponsored projects, and coordinating the technical affairs, assessments-interviews of my own junior colleagues, related financial/budget management aspects, and attending some meetings as a group leader of the FMC.
During the two years, things went well, with only a very few unpleasant but minor events for me; by and large I had attended to all the items that were specified my second boss to me; except a few for which the proper time had not come, or the opportunity did not come.
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Then the new division was formed in 1990-91, after the bosses returned from USA, with the same name, and was called Flight Mechanics and Control division, FMCD, and I was made the coordinator of the SID group.
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The FMCD’s activities had increased in several directions, and we had key sponsored projects on the following areas, at different and even overlapping times for various periods and for various budgets (of lakhs of rupees): i) advanced flight mechanics analysis, ii) development of flight control laws for LCA, iii) development of engineer-in-loop simulator for LCA, iv) flight test data analysis of Jaguar aircraft, v) development of analytical redundancy, vi) development of methods for analysis of data from inherently unstable aircraft, vii) flight test data analysis of basic aircraft (HS748) and the one with pylons, viii) the study of effects on static stability of the AVRO/HS748 aircraft due to rotodome, ix) parameter estimation from flight data of Ajeet aircraft and a helicopter (Chetak?), and x) DWT based experimental projects; and a few more research projects.
These projects were carried out under the leadership of one or two principal investigators, by the teams of scientists/engineers and scientific assistants. Various sponsoring agencies were: a) aeronautical development agency (ADA), b) centre for airborne systems (CABS), c) aeronautical research and development board (New Delhi), d) Hindustan aeronautics limited (HAL), and e) DRDL. The activities were full of lot of work: development of algorithms/software, development of hardware facilities, various review meetings, and frequent visits to the sponsoring agencies.
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Historic moment:
The period of 1991-2001 was a very hectic one because the LCA programme was going ahead with a rapid rate, and finally with the successful implementation of the control law on this fighter aircraft, the LCA had a maiden flight on 4th January 2001. Most of us went on the roof-top of a building nearby the HAL airport (old airport road), and witnessed this flight which was very successful and it was a historic moment for the country and the aeronautical industry, because it had a fly-by-wire technology and built indigenously, except a few components from abroad, e.g. with a GE engine.
As far as the control law was concern it was another triumph of the CLAW team that constituted of the scientists of ADA, HAL, ADE, and NAL; for the latter it was a team of engineers and scientists of FMCD, and the team was led by Dr. S. Srinathkumar as a project director of the CLAW. Except for some consultancy from British Aerospace, the complete control law analysis, development, design, and synthesis was accomplished by the team; it was an extraordinary feat and had taken nearly a decade to achieve this, because any failure of the control law would be the failure of the flight of the LCA; the aircraft cannot fly without control law; of course for any emergency the pilot could take over the commands. LCA is a highly sophisticated, single engine, jet aircraft with very advanced avionics, and lot of redundancy systems in sensor suits and controls, etc. It has also quadraplex computers developed/built indigenously that in fact fly the aircraft. It is a supersonic jet aircraft and perhaps one of its kind in the world.
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Subsequently, some more projects came up especially on parameter estimation of the LCA (and its some later versions) from its flight test data for which the aircraft was flown with special maneuvers. It was necessary to obtain the math models of the aircraft from the real-flight-test-data to validate the math models already used by the control engineers for the LCA; and the SID group was fully prepared to take up this task. Various parameter estimation techniques were validated with MATLAB based simulated data, LCA flight-simulator based data, and the real flight-test data of some other aircraft. As a result of these exercises, the success rate of determination of math models of the LCA from various test maneuvers at several flight test points in the flight envelop (Mach v/s speed) of the LCA, at various conditions of longitudinal and lateral-directional flights was very high, though the analysis of the real flight test data was a very difficult and involved tasks; it required: i) several repeat maneuvers, ii) checking of the kinematic consistency from these data, iii) several runs of the estimation algorithm, iv) reconciling the estimation results with the theoretical predictions, and v) preparations and presentations of the results to the sponsoring agency in their review meetings.
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ESTIMA package
Since, it was very important that when we estimate the parameters of math models of the LCA, they should make sense, as well as they add new information to the existing data base of aerodynamics of the aircraft, and we had to be doubly sure that the results of our estimation exercises from the flight-generated data are trustworthy; and hence we wanted to build a redundancy in our estimation technology, so we had bought the ESTIMA SW from the DLR, Germany (we had a scientific collaboration with them) at a reduced cost from our project money, and then had utilised ESTIMA to generate the results from the same flight test data that we had used earlier, and confirm that the results from both the packages are almost the same; this we had to do only a few times, since if it had worked on some cases, then surely would work for all the cases. With this we were very confident in the estimation results and math models of the LCA.
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New activity on sensor data fusion (1999-2007…)
Once, there was a call from ITR (integrated test range facility of DRDO) and a scientist told me that I should take up some work on sensor data fusion for their requirement; to which I had said that I did not know what it meant, let alone doing any research in that area. Then, he told me that he had read a paper in the Defence Science journal (New Delhi) authored (jointly) by a MTech student guided by me, and in that paper we had given some suggestions for futuristic research that hinted in a way ‘multi sensor data fusion’; then I read our own paper again and reconciled that his observation was true; and then I started working on the problem of sensor data fusion; and in a process of six/seven years just before I retired, we had completed nearly 5 projects sponsored by DRDO (two from ITR, Chandipur; two from DRDL, Hyderabad; and one from ARDB, New Delhi). In meantime I had also built up a group with the same name and trained scientists to do work on data fusion at various levels: kinematic fusion, fuzzy logic/decision fusion, and image fusion; and two Ph.D.’s came out in the latter two areas under my guidance.
I suspect that since, I had retired, the soft credit of starting the activity went to some other scientist of the group! Now, in the FMCD, they are doing sponsored projects in this area with budgets of the order of several lakhs of rupees.
Continued…
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