Tutorial Sessions

IEEE Space, Aerospace and Defence Conference, SPACE 2025

Robust Engineering Systems Control Systems and Signal Processing (RES CSSP) Toolbox

A New, Patented Toolbox for Convex Stability Assessment of Dynamic Systems with Aero, Space and Defense Applications

Abstract:

This Tutorial presentation first gives an overview of the research carried out by Prof. Yedavalli and his group on stability and robustness of dynamic systems described by linear state space models with applications in aerospace, mechanical and electrical systems using both eigenvalue based stability assessment via Transformation Compliant (TC) methods such as the Routh-Hurwitz Criterion, Cayley-Hamilton Theorem, and Lyapunov Matrix Equation methods (which are all equivalent to each other) as well as sign pattern based Qualitative Sign Stability (QLSS) approach being used by ecology researchers. Then, by juxtaposing these two extreme viewpoints, namely TC and QLSS methods, his startup firm RES proposes a new method without using eigenvalues at all so that we achieve not only significant computational savings but also many other superior and powerful features. This new Convex Stability concept (as opposed to Hurwitz stability (for continuous time systems) and Schur stability (for discrete time and sampled data systems) is a completely different and innovative concept, essentially positively disrupting the current control systems and signal processing design algorithms, as evidenced by the issuance of an already awarded US Patent (and another potential patent to be awarded soon by the India patent office). The novel Transformation Allergic (TA) Approach and the associated Convex Stability concept invented by our firm’s RES CSSP Toolbox has emphatically proved that the current literature eigenvalue based control and signal processing methods being followed by the TC methods (mentioned above) have significant flaws and thus are leading to misleading conclusions about the actual stability of a dynamic system in all the real world applications, especially in the Defense (robotics and autonomous flight vehicle) applications and Space (satellite attitude, orbit, docking and formation flying) applications. In addition, this new concept of Convex Stability is valid equally well for not only time-invariant dynamic systems but also for Time Varying and a few mild Non-Linear dynamic systems as well. This Tutorial will discuss these concepts with concrete real life application examples. This patented Convex Stability concept does not endorse the transfer function approach and proves that the currently popular PID controller philosophy is insufficient for guaranteed safe fight in any real-life flight control/robotics/satellite control applications. Finally, RES CSSP Toolbox algorithms can stabilize and control any dynamic system declared by the current literature methods as un-controllable, un-stabilizable, un-observable and un-detectable.

Because of the issuance of two patents (one an already awarded US patent # No. 11,815,862, and another India patent under review), the contents of this tutorial presentation are IP protected and can be used only with a technology licensing agreement with the firm Robust Engineering Systems, LLC or permission from it.

Bio-sketch for Speaker:

Dr. Rama K. Yedavalli received his Ph.D degree from the School of Aeronautics and Astronautics of Purdue University in the Dynamics and Control area in 1981. His Bachelor’s and Master’s degree were both from the Indian Institute of Science (IISc), Bangalore, India. He spent his sabbatical at IISc as the “Satish Dhawan Chaired Professor” in 2017-18. He received the `Distinguished Alumnus Award’ in 2009 and the “Platinum Jubilee Award” and the “Satish Dhawan (Visiting) Chaired Professorship” in 2017-18, all, from the AE department of IISc.

Dr. Yedavalli is a (Life) Fellow of IEEE, a Fellow of ASME, a Fellow of AAAS and an Associate Fellow of AIAA. He received the O.Hugo Schuck Best Paper award from the American Automatic Control Council in 2001. In 2002, he also received the `Lumley Research Award’ by the Ohio State University’s College of Engineering. He published a graduate level text book with Springer in Jan 2014 titled: “Robust Control of Uncertain Dynamic Systems: A Linear State Space Approach” and an Undergraduate level textbook titled: “Flight Dynamics and Control of Aero and Space Vehicles” published by Wiley in 2020. A third book is under contract to be delivered to AIAA Education Series in 2025 in which he plans to discuss the Convex Stability Approach. He published in excess of 200 Journal, Book chapters and Conference papers and presented invited seminars on these topics. He holds the title of Academy Professor from the Ohio State University and currently serves as the Founder, President, CEO and CTO of the startup firm Robust Engineering Systems, LLC, which holds the patent for the contents of this tutorial presentation.