This work is part of ongoing research conducted at Virginia Commonwealth University relating to unmanned aerial vehicles. The primary objective of this thesis was to develop a flexible, high-performance autopilot platform in order to facilitate research on advanced flight control algorithms. A dual FPGA-based system architecture utilizing a stacked, multi-board design was created to meet this goal. Processing tasks were split between the two FPGA devices, allowing for improved system timing and increased throughput. A combination of analog and digital filtering techniques were employed in the new system, resulting in enhanced sensor accuracy and precision compared to the previous generation autopilot system. Several important improvements to the safety and reliability of the overall system were also achieved.

Techn. Univ., Diss.--Braunschweig, 2005.

This thesis details the development of a custom autopilot system designed specifically for multi-agent robotic missions. The project was motivated by the need for a flexible autopilot system architecture that could be easily adapted to a variety of future multi-vehicle experiments. The development efforts can be split into three categories: algorithm and software development, hardware development, and testing and integration. Over 12,000 lines of C++ code were written in this project, resulting in custom flight and ground control software. The flight software was designed to run on a Gumstix Overo Fire(STORM) computer on module (COM) using a Linux Angstrom operating system. The flight software was designed to support the onboard GN&C algorithms. The ground control station and its graphical user interface were developed in the Qt C++ framework. The ground control software has been proven to operate safely during multi-vehicle tests, and will be an asset in future work. Two TSH GAUI 500X quad-rotors and one Gears Educational Systems SMP rover were integrated into an autonomous swarm. Each vehicle used the Gumstix Overo COM. The C-DUS Pilot board was designed as a custom interface circuit board for the Overo COM and its expansion board, the Gumstix Pinto-TH. While the built-in WiFi capability of the Overo COM served as a communication link to a central wireless router, the C-DUS Pilot board allowed for the compact and reliable integration of sensors and actuators. The sensors used in this project were limited to accelerometers, gyroscopes, magnetometers, and GPS. All of the components underwent extensive testing. A series of ground and flight tests were conducted to safely and gradually prove system capabilities. The work presented in this thesis culminated with a successful three-vehicle autonomous demonstration comprised of two quad-rotors executing a standoff tracking trajectory around a moving rover, while simultaneously performing GPS-based collision avoidance. / text

Universiẗat, Diss., 2002--Giessen.

This project is part of research funded by NASA Langley in field of Unmanned Aerial Vehicles (UAVs) and is based on past work conducted at Virginia Commonwealth University. Dr. Mark A. Motter of NASA Langley intends to use the new autopilot system to test aircraft with many control surfaces. The goal of this project is to port an existing UAV autopilot system that has more computing power than the previous generation system to allow for more advanced flight control algorithms.The steps taken to complete this project include choosing a new hardware platform, porting C flight control software from a MicroBlaze platform to a PowerPC platform, and developing FPGA based hardware to interface with external sensors. The Suzaku-V based system was shown to have much better computing performance than the previous system, and several successful test flights have proved the viability of the new autopilot system.

Unmanned aerial vehicles and unmanned ground vehicles, or UAVs and UGVs respectively, currently perform a large variety of missions usually centered around reconnaissance. Because the platforms may vary for a particular type of mission--everything from small unmanned airplanes and remote control vehicles to large vehicles such as the Yamaha R-MAX helicopter and Hummer--flight and navigation controllers must be changed to allow proper control of the selected platform. Currently, controllers are designed and tested in MATLAB/SIMULINK, but then rewritten in C or Assembly for a specific target platform. When designing controllers in a programming language, changes are often tedious, so producing a working controller takes considerable time. MATLAB/SIMULINK provides a GUI interface and SIMULINK provides excellent testing capabilities, so changes may be quick and easy. However, no automated method for converting a simple controller, such as a PID for example, from MATLAB to implementation on a microcontroller has been presented in literature. To implement current in-house controllers designed in MATLAB/SIMULINK, a system consisting of Real-Time Workshop and a C compiler has been used to produce assembly code for a target microcontroller. To aid in verification of the controllers and C code produced by Real-Time Workshop targeted toward aerial platforms, an interface for the controllers in SIMULINK and a flight simulator (X-Plane) has been created. Thus the overall system allows for rapid changes and implementation on a variety of platforms as well as plug-in/plug-out capabilities in the field for diverse missions. Functionality and diversity of the system is demonstrated through testing of PID VTOL controllers in SIMULINK with X-Plane as well as implementation of UGV controllers onboard a small radio controlled truck.

<p><em>This bachelor thesis is dedicated to assemble the hardware system of a UAV (Unmanned Aerial Vehicle) in order to prepare the platform for an autonomous flight in the air for a given path through the pre-programmed check points. A UAV is an aircraft that contains sensors, GPS, radio system, servomechanisms and computers, which provide the capability of an autonomous flight without a human pilot in the cockpit. A stable flight requires sensing the roll, pitch, and yaw angles of aircraft. Roll and pitch angles were ensured by a sensor system of FMA Direct Company called co-pilot flight stabilization system (CPD4), which allows controlling ailerons and elevator manually.</em></p><p><em>An autopilot is required for steering the aircraft autonomously according the GPS data and the establish waypoints that the airplane have to pass by. The GPS gives heading information to the autopilot, and this uses the information of the next waypoint to decide which direction to go. Hereby an autonomous flight is provided. In this project a lego mindstorm NXT was used as an autopilot that is product of LEGO Company [1]. The output of the autopilot is used to control the airplane servos to fly in the desired direction. A software and hardware interface was designed to allow the autopilot to receive the data from the co-pilot sensor and to transmit data to the co-pilot processor, which will finally steer the actuator servos. Experiments were performed with different parts of the system and the results reported.</em></p>

In unmanned aerial systems an autopilot controls the vehicle without human interference. Modern autopilots use an inertial navigation system, GPS, magnetometers and barometers to estimate the orientation, position, and velocity of the aircraft. In order to make correct decisions the autopilot must rely on correct information from the sensors. Fault diagnosis can be used to detect possible faults in the technical system when they occur. One way to perform fault diagnosis is model based diagnosis, where observations of the system are compared with a mathematical model of the system. Model based diagnosis is a common technique in many technical applications since it does not require any additional hardware. Another way to perform fault diagnosis is hardware diagnosis, which can be performed if there exists hardware redundancy, i.e. a set of identical sensors measuring the same quantity in the system. The main contribution of this master thesis is a model based diagnosis system for a fixed wing UAV autopilot. The diagnosis system can detect faults in all sensors on the autopilot and isolate faults in vital sensors as the GPS, magnetometer, and barometers. This thesis also provides a hardware diagnosis system based on the redundancy obtained with three autopilots on a single airframe. The use of several autopilots introduces hardware redundancy in the system, since every autopilot has its own set of sensors. The hardware diagnosis system handles faults in the sensors and actuators on the autopilots with full isolability, but demands additional hardware in the UAV.

This bachelor thesis is dedicated to assemble the hardware system of a UAV (Unmanned Aerial Vehicle) in order to prepare the platform for an autonomous flight in the air for a given path through the pre-programmed check points. A UAV is an aircraft that contains sensors, GPS, radio system, servomechanisms and computers, which provide the capability of an autonomous flight without a human pilot in the cockpit. A stable flight requires sensing the roll, pitch, and yaw angles of aircraft. Roll and pitch angles were ensured by a sensor system of FMA Direct Company called co-pilot flight stabilization system (CPD4), which allows controlling ailerons and elevator manually. An autopilot is required for steering the aircraft autonomously according the GPS data and the establish waypoints that the airplane have to pass by. The GPS gives heading information to the autopilot, and this uses the information of the next waypoint to decide which direction to go. Hereby an autonomous flight is provided. In this project a lego mindstorm NXT was used as an autopilot that is product of LEGO Company [1]. The output of the autopilot is used to control the airplane servos to fly in the desired direction. A software and hardware interface was designed to allow the autopilot to receive the data from the co-pilot sensor and to transmit data to the co-pilot processor, which will finally steer the actuator servos. Experiments were performed with different parts of the system and the results reported.

This thesis has been written at Linköping University for the company Instrument Control Sweden AB (ICS). ICS is a small company located in Linköping that develops software and hardware for Unmanned Aerial Vehicles, UAV. At present, ICS has a fully functional autopilot called EasyPilot but they want to reduce the autopilot’s size to make it more attractive. The purpose of this thesis was to investigate if it was possible to reduce the size of the autopilot and how, in that case, it would be done. It was also necessary to examine whether the old processors should be replaced by new ones and how hard it would be to convert the old software to these new processors. To succeed with the goals many of the old components had to be changed for new, smaller ones. Some less necessary parts were also completely removed. The results showed that the size could be reduced quite a bit, exactly how much is hard to say since no PCB-layout were done. By doing some programming tests on the new components it could be shown that some parts of the old code could be reused on the new design. It was mainly algorithms and other calculations. However, a lot of new code still had to be written in order to successfully convert the old software to the new hardware.