Title of the invention
System for Adaptive Guided Amphibian Rowing (SAGAR)
Field of invention
This invention relates to an integrated adaptive recontlgurable control system for rowing or paddling on water under different sea state conditions, with the provisions for additional lift generation and aiding hydrostatic and.hydrodynamic stability and controllability of the amphibious aircraft.
Use of invention
This invention can be used in amphibious aircraft or seaplane or flying boat or ship as an integrated adaptive control system to obtain optimum water performance of the craft, in terms of hydrostatic & hydrodynamic stability and controllability, under different sea state conditions.
This invention can be used in amphibious aircraft or seaplane or flying boat for additional lift generation and optimum performance on water while aerodynamic characteristics of the aircraft are not degraded.
This invention can be used in amphibious aircraft or seaplane or flying boat for achieving short take-off and landing features in conjunction with other devices on the aircraft.
Prior art
Not Applicable.
Drawbacks of prior art
Not Applicable.
Comparison between prior art and present invention
Not Applicable.

Aim of the invention
This invention aims:
(i) To provide stability and controllability of amphibious aircraft on water, without compromising the flying characteristics (or aerodynamic characteristics) of the aircraft and its land based take-off or landing;
(ii) To provide a controller for optimum hydrostatic and hydrodynamic performance of the amphibious aircraft under different sea state conditions;
(iii) To provide additional lift generation to aid take-off and landing performance of the amphibious aircraft on water as well as for land based applications;
(iv) To provide an add-on device to achieve Short Take-Off and Landing (STOL) performance of the amphibious aircraft on water and land, to facilitate its usage under different sea state and terrain conditions;
(v) To provide an integrated adaptive reconfigurable control system for amphibious aircraft which comprises of pilot commands, measuring sensors, actuators, control surfaces, .and embedded fault tolerant artificial intelligence based adaptive controllers and data fusion.
Summary of the present invention
The primary problem with amphibious aircraft is its performance degrading due to the adaptation for water operations. The conventional design of amphibious ■ aircraft which include hull, floats, hydrofoil, sponsons, pontoons etc. will negatively mpact the aerodynamic characteristics of the aircraft and also have stability ssues, problems due to loading of wave slap, and problems with operation from sea other than calm state. This indicates a strong need of an innovative approach while adapting the aircraft for land and water operations.
Hydrodynamic stability of ships and seaplanes or flying boat or amphibious aircraft depend on Weight (in air and water), Geometry, Centre of Gravity, Centre of Buoyancy, Metacentre and the restoring moment created thereby when disturbed From rest. Conventionally this is addressed by floats suitably sized and located along with the hull or the fuselage. While the floats are a proven way of handling :he operations in water, the associated penalties in terms of weight, drag etc. are :he areas wherein improvements can' still be made. Without compromising the Flying characteristics of a proven aircraft, meeting the requirements of operations n and out of water is challenging for the amphibious aircraft design. The amphibious aircraft needs to takeoff, land and dock in still and moving water Dodies like sea, lakes, rivers etc. where the characteristics of the water body plays major role in the dynamics of the amphibian. Keeping these key aspects of

operational requirements, the conceptual invention of a System for Adaptive ■ Guided Amphibian Rowing (SAGAR), helps the amphibious aircraft to maintain its stability, augment its controllability and handling when in water. The concept uses a feedback controller which works on Artificial Intelligence technique such as Artificial Neural Network based adaptive reconfigurable control system taking into consideration of various parameters such as speed, sea state, wave height, etc. to manoeuvre the seaplane with adequate safety for passengers and freight. This system drives a retractable Rowing or paddle mechanism with actuators and associated sensors and will be located within the fuselage. The requirement of float or sponsons or pontoons is avoided by utilizing the benefits offered by SAGAR. This ensures that aerodynamic characteristics of the aircraft are not affected much due to the adaptation for water operations. The SAGAR mechanism offers a scheme in order to improve hydrostatic stability, hydrodynamic stability, water performance, wave performance and also aerodynamic performance of the aircraft. The retractable/ rowing control surfaces of the SAGAR can aid in additional lift generation which would be beneficial to enhance STOL (short take-off and landing) performance of the aircraft on water as well as for land based applications. The SAGAR can be used in amphibious aircraft or seaplane or flying boat for optimum performance on water, land based runway, and in air. This concept can also be used in ships for enhanced water performance under different sea state conditions.
Statement of invention
This invention pertains to the concept of integrated adaptive reconfigurable control system comprising of: pilot commands, measuring sensors, actuators, retractable/rowing control surfaces, and embedded fault tolerant artificial intelligence based adaptive controllers and data fusion, for stability, controllability, and short take-off and landing of the amphibious aircraft on water without compromising the aerodynamic characteristics of the aircraft.

10. Detailed description of invention
The airplanes designed to operate from water are commonly known as seaplanes and there are three kinds of seaplanes in general. They are floatplanes, flying boats, and amphibians. While a floatplane is actually a landplane with landing gears removed and installed with pontoons that are partially submerged floats, the flying boat is a seaplane version in which the payload is carried inside a fuselage designed to function as a hull for operation on the water. The amphibian is an aircraft that has features for water operations by using hull type fuselage and for land based operations by using retractable landing gear. An amphibious aircraft combines the speed and range benefits of a conventional aircraft with the additional ability to land and take-off on open water.
Most of the existing seaplanes/flying boats and amphibians have weight and ■ aerodynamic penalties, which in turn is related to fuel efficiency, thus affecting range and . endurance of the aircraft. Tip floats or sponsons, used in contemporary flying boat amphibians in order to provide hydro-dynamic stability, increase the drag and weight of the aircraft, thereby affecting its range, endurance, and payload capabilities. To overcome such limitations, a unique float/sponson-less design of amphibious aircraft providing improved performance in water and air, without compromising on stability, control, and guidance is conceptualized in this invention. An optimized design approach, addressing key features like hydrostatic stability, dynamic stability, wave handling, and water performance is conceptualized with due care for aerodynamic characteristics and overall performance figures. This innovative concept is named as System for Adaptive Guided Amphibian Rowing (abbreviated as SAGAR).
The SAGAR aims to provide.stability and controllability of amphibious aircraft on water, without degrading the aerodynamic characteristics of the aircraft and its performance pertaining to land based take-off or landing. Provisions for additional lift generation, . optimum hydrostatic and hydrodynamic performances under different sea state conditions, and aid for short take-off and landing characteristics are conceptualized under the SAGAR. An integrated controller comprising of pilot commands, measuring sensors, actuators, control surfaces, and embedded fault-tolerant artificial intelligence based adaptive reconfigurable controllers are the key elements of the SAGAR.
The schematic of SAGAR is shown in Figure 1.0. The schematic diagram of SAGAR Controller Module is shown in Figure 2.0. A typical architecture of SAGAR Reconfigurable Controller is shown in Figure 3.0.