Hardware Implementation of COTS Avionics System on Unmanned Aerial Vehicle Platforms

MUHAMMAD USMAN ALI (12063122-086)

MUHAMMAD FARAN ALI (12063122-055)

I. IntroductionII.EAV Airframe ModificationsIII. Avionics DesignIV. EAV System IdentificationV. MATLAB SimulationVI. Reflection Simulation

I. Introduction: To test novel control systems the National Institute

Of Aeronautics And Space Administration (NASA) operates two COTS (also known as Commercial Off the Shelf) aerial platforms in its EAV laboratory. The two platforms include EAV (Exploration Aerial Vehicle) and XSCAV (Experimental Sensor Controlled Aerial Vehicle).EAV is the Cessna 182 while the duties of XSCAV are performed by J3 Piper Cub. To provide low-risk testing of adaptive controllers EAV will be used but due to its limitations in limited payload capabilities other platform comes in mind. To remove this XSCAV is used. There hardware is updated regularly to provide state of the art power.

Cessna 180 and J3 Piper:

II.EAV Airframe Modifications:

To improve its capabilities aluminum rib support structure and custom avionics box was added but it resulted in the overweight of system, so to provide high- g maneuvers in the air the factory struts were replaced with stronger custom built struts. The stress was easily distributed between areas of the vehicle.

The ribs distribute the stress between the six areas of the EAV airframe with the heaviest load: the wing bar area, from which most the lift of the wings is distributed to the fuselage, the body wing strut mounts, which also distribute some of the stress from the lift, and the landing gear, which pass the impact of hard landings into the belly of the plane.

III Avionics Design:

The avionics systems use many state space and transfer functions to improve real time data processing. In addition with already using CPU an another CPU was added in the casket. The former power supply was replaced with a higher wattage DC/DC power supply. The Unmanned Aerial Vehicle (UAV) is found to have capabilities very similar to the EAV. The height of the stack was increased due to the addition of a second CPU. To address this problem instead of keeping the stack in vertical they were replaced horizontal. A custom box provided the requirement for further improvements. Various specifications were provided for the box which included its length width and height.

Main avionics were chosen in the PC/104 but the main thing kept in mind was the compatibility so considering this compatible systems were used with PC/104. Different areas were kept in mind which included electrical and mechanical.

To provide repetition of messages to reduce the probability of errors in transmission in case of signal loss and battery short circuits there was a need to redesign the actuator system.

IV.EAV System Identification:

The members of this lab carried out a detailed system identification on flight data using various principles and laws however a slight error was found but was removed using new and advanced system. Longitudinal and Lateral formulas were used for aircraft dynamic model. The result was run on multiple flight data sets but two results were obtained. First being the normalized MSE and second being the generalization score.

V. Matlab Simulation:

Model Reference Adaptive Control (MRAC) controller was used by the NASA Ames Integrated Resilient Aircraft Control (IRAC) project to study flight tests.

VI. Reflection Simulation:

The model is sent to the main software running on the avionics system which is a real time component based plug and play architecture. The results are documented

SUMMARY:

This paper tells the design modelling and testing process for two platforms. MRAC Simulation was used new results were compared with the previous ones. Some improvements were provided in systems model and hardware which will help us in the low-risk testing of adaptive controllers under IRAC.