This paper advances a neural-network-based approximate dynamic programming control mechanism that can be applied to complex control problems such as helicopter flight control design. Based on direct neural dynamic programming (DNDP), an approximate dynamic programming methodology, the control system is tailored to learn to maneuver a helicopter. The paper consists of a comprehensive treatise of this DNDP-based tracking control framework and extensive simulation studies for an Apache helicopter. A trim network is developed and seamlessly integrated into the neural dynamic programming (NDP) controller as part of a baseline structure for controlling complex nonlinear systems such as a helicopter. Design robustness is addressed by performing simulations under various disturbance conditions. All designs are tested using FLYRT, a sophisticated industrial scale nonlinear validated model of the Apache helicopter. This is probably the first time that an approximate dynamic programming methodology has been systematically applied to, and evaluated on, a complex, continuous state, multiple-input multiple-output nonlinear system with uncertainty. Though illustrated for helicopters, the DNDP control system framework should be applicable to general purpose tracking control.

http://www.cmap.polytechnique.fr/~munos/MVA/helicoptrek/articles/direct%20NDP/part2_12_ndptrim.pdf

Helicopter trimming and tracking control using direct neural dynamic programming

This 2007 book concerns the vibration and the stability of slender structural components. The loss of stability of structures is an important aspect of structural mechanics and is presented here in terms of dynamic behavior. A variety of structural components are analyzed with a view to predicting their response to various (primarily axial) loading conditions. A number of different techniques are presented, with experimental verification from the laboratory. Practical applications are widespread, ranging from cables to space structures. The book presents methods by which the combined effects of vibration and buckling on various structures can be assessed. Vibrations and buckling are usually treated separately, but in this book their influence on each other is examined together, with examples when a combined approach is necessary. The avoidance of instability is the primary goal of this material.

https://assets.cambridge.org/97805218/80428/frontmatter/9780521880428_frontmatter.pdf

Vibration of Axially-Loaded Structures

A review of safety strategies of a Li-ion battery

Modeling rotorcraft dynamics with finite element multibody procedures

Evidence suggests that the proportion of the human population living in cities will continue to grow, to the point where over 90% of the world’s population will be living in one form of city or ano...

https://www.tandfonline.com/doi/pdf/10.1080/13658816.2019.1673397

Real-time GIS for smart cities

In this paper we offer a general theory of rotorcraft trim. The theory is set in the context of control theory. It allows for completely arbitrary trim controls and trim settings for multi-rotor aircraft with tests to ensure that a system is trimmable. In addition, the theory allows for “optimal trim” in which some variable is minimized or maximized rather than set to a specified value. The theory shows that sequential trim cannot work for free flight. The theory is not tied to any particular trim algorithm; but, in this paper, it is exercised with periodic shooting to show how free-flying rotorcraft can be trimmed in a variety of ways (zero yaw, zero pitch, zero roll, minimum power, etc.) by use of the general theory. The paper also discusses applications to harmonic balance and 
auto-pilot trim techniques.

/pdf/a-general-theory-of-rotorcraft-trim-1oa6y2zuz8.pdf

Dinesh Barwey

Papers

A general theory of rotorcraft trim

A general theory of rotorcraft trim

Orthogonal Polynomials for Energy Methods in Rotary Wing Structural Dynamics