The Flight Control System 20 (FCS20) is a compact, self-contained Guidance, Navigation, and Control system that has recently been developed to enable advanced autonomous behavior in a wide range of Unmanned Aerial Vehicles (UAVs). The FCS20 uses a floating point Digital Signal Processor (DSP) for high level serial processing, a Field Programmable Gate Array (FPGA) for low level parallel processing, and GPS and Micro Electro Mechanical Systems (MEMS) sensors. In addition to guidance, navigation, and control functions, the FCS20 is capable of supporting advanced algorithms such as automated reasoning, artificial vision, and multi-vehicle interaction. The unique contribution of this paper is that it gives a complete overview of the FCS20 GN&C system, including computing, communications, and information aspects. Computing aspects of the FCS20 include details about the design process, hardware components, and board configurations, and specifications. Communications aspects of the FCS20 include descriptions of internal and external data flow. The information section describes the FCS20 Operating System (OS), the Support Vehicle Interface Library (SVIL) software, the navigation Extended Kalman Filter, and the neural network based adaptive controller. Finally, simulation-based results as well as actual flight test results that demonstrate the operation of the guidance, navigation, and control algorithms on a real Unmanned Aerial Vehicle (UAV) are presented.

Future small UAVs will require enhanced capabilities like seeing and avoiding obstacles, tolerating unpredicted flight conditions, interfacing with payload sensors, tracking moving targets, and cooperating with other manned and unmanned systems. Cross-platform commonality to simplify system integration and training of personnel is also desired. A small guidance, navigation, and control system has been developed and tested. It employs Field Programmable Gate Array (FPGA) and Digital Signal Processor (DSP) technology to satisfy the requirements for more advanced vehicle behavior in a small package. Having these two processors in the system enables custom vehicle interfacing and fast sequential processing of high-level control algorithms. This paper focuses first on the design aspects of the hardware and the low-level software. Discussion of flight test experience with the system controlling both an unmanned helicopter and an 11-inch ducted fan follow.

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Autonomous flight of a single Unmanned Aerial Vehicle has become routine for many research teams. Our interests include multi-vehicle operation as well as developing guidance and control algorithms for each vehicle. These algorithms also need to be implemented in flight hardware and successfully flight tested. A flexible simulation environment is one of the key ingredients towards this goal, more so if heterogeneous vehicles and flight hardware are involved. This paper introduces an integrated simulation and development environment including a code generator, a standard vehicle interface library and unified hardware that enables using the same flight infrastructure for avionics ranging from over 10 lbs to just above 1 lb. The lower payload vehicles have severe restrictions on communications, and processing resources and are most often custom avionics. Reconfigurability for software-in-the-loop (SITL), hardware-in-the-loop (HITL), flight and extension to multivehicle operations is emphasized, all using a common code base.

We introduce a new benchtop microgravity simulator (MGS) that is scalable and easy to use. Its working principle is similar to that of random positioning machines (RPM), commonly used in research laboratories and regarded as one of the gold standards for simulating microgravity. The improvement of the MGS concerns mainly the algorithms controlling the movements of the samples and the design that, for the first time, guarantees equal treatment of all the culture flasks undergoing simulated microgravity. Qualification and validation tests of the new device were conducted with human bone marrow stem cells (bMSC) and mouse skeletal muscle myoblasts (C2C12). bMSC were cultured for 4 days on the MGS and the RPM in parallel. In the presence of osteogenic medium, an overexpression of osteogenic markers was detected in the samples from both devices. Similarly, C2C12 cells were maintained for 4 days on the MGS and the rotating wall vessel (RWV) device, another widely used microgravity simulator. Significant downregulation of myogenesis markers was observed in gravitationally unloaded cells. Therefore, similar results can be obtained regardless of the used simulated microgravity devices, namely MGS, RPM, or RWV. The newly developed MGS device thus offers easy and reliable long-term cell culture possibilities under simulated microgravity conditions. Currently, upgrades are in progress to allow real-time monitoring of the culture media and liquids exchange while running. This is of particular interest for long-term cultivation, needed for tissue engineering applications. Tissue grown under real or simulated microgravity has specific features, such as growth in three-dimensions (3D). Growth in weightlessness conditions fosters mechanical, structural, and chemical interactions between cells and the extracellular matrix in any direction.