Attitude control for CubeSats and small satellites has been widely researched. Nonetheless, most of the literature is based on simulations, with limited availability of actual implementation results. This article tries to fill this gap by highlighting implementation difficulties and proposing appropriate workable solutions. The difficulty of direct reaction wheel (RW) torque feedback for attitude control of a 1p PocketQube (PQ) pico-satellite is noted and addressed. A simple control strategy implementable on a microcontroller is then proposed, showing how direct RW torque control can be achieved through angular velocity measurement without using derivative feedback. A linear quadratic Gaussian controller with integral action in quaternion formulation is used for attitude control, and a reference input boundary caused by the use of the standard integral action scheme is highlighted. A simple solution is then proposed, showing how using the error quaternion removes this boundary. An extended Kalman filter in quaternion formulation is used for attitude determination by fusing data from three sensors, namely, a magnetometer, solar cells, and a gyroscope. An accelerometer is used in place of the solar cells for simplified laboratory testing. Magnetometer error due to surrounding interference is addressed through calibration. A string-suspended model of the UoMBSat-1 PocketQube pico-satellite is used for attitude control testing. Preliminary single-axis tests are performed using a PID controller to determine the satellite parameters and actuators verification. The proposed linear quadratic Gaussian controller is then tested and validated experimentally in the laboratory setting.

This is a quasi-review paper which defines and then places Computational Air Traffic Management (CATM) in a historical context. CATM is presented as the natural convergence of many, seemingly disparate, air traffic technologies that have evolved over the past two decades. It is the emergent order which is derived from the collective behaviour of a number of interacting systems. A distinction is initially made between strategic air traffic management (ATM) and tactical air traffic control (ATC). This distinction ebbs in CATM and the intimately intertwined relationship between ATM and ATC is accentuated. The features of an ideal ATC system are discussed and developed objectively in contrast to current systems. The requirements are based on a high level top-down approach, but also look at the time-proven characteristics that allow the current ATC system to function so surprisingly well. An inventory of the interesting research questions in the overall CATM picture is therefore gradually drawn-up along the discussion to indicate areas with insufficient research coverage. In the second part of the paper, a clean sheet approach for devising an operational concept for a streamlined CATM system is proposed and discussed. This example describes an airborne, decentralized, fault-tolerant paradigm for a continental (and perhaps global) ATC system that readily scales up (perhaps linearly) to accommodate projected future aircraft densities. The system is broadly consistent with the proposed objectives as put forward in both NextGen (Next Generation Air Transportation System) and SESAR (Single European Sky ATM Research). Practical algorithms for several subsystems are classified, and discussed in the context of emerging computational hardware. The case is then made for a new breed of grid-oriented avionics hardware that will enable aircraft to take CATM to the skies by leveraging on the many benefits brought by pervasive inter-aircraft ad-hoc communication networks and heterogeneous, high performance grid-computing.

The CubeSat form factor was very successful at reducing development and launch costs for spacecraft. The PocketQube (PQ) - one eighth the size of a CubeSat - aims to further reduce these costs. However, the question remains on whether it is feasible to implement a fully-featured satellite within the far tighter constraints imposed by a PQ. This paper explores the implications of including a 3-axis attitude determination and control system with provisions for desaturation and detumbling within the confines of a PQ. The hardware technology available is outlined and the applicable control laws and techniques are reviewed. This paper presents the approach that is actually being adopted in the development of the UoMBSat-1 picosatellite at the University of Malta.

Cameras are excellent ways of non-invasively monitoring the interior and exterior of vehicles. In particular, high speed stereovision and multivision systems are important for transport applications such as driver eye tracking or collision avoidance. This paper addresses the synchronisation problem which arises when multivision camera systems are used to capture the high speed motion common in such applications. An experimental, high-speed tri-vision camera system intended for real-time driver eye-blink and saccade measurement was designed, developed, implemented and tested using prototype, ultra-high dynamic range, automotive-grade image sensors specifically developed by E2V (formerly Atmel) Grenoble SA as part of the European FP6 project – sensation (advanced sensor development for attention stress, vigilance and sleep/wakefulness monitoring). The developed system can sustain frame rates of 59.8 Hz at the full stereovision resolution of 1280 × 480 but this can reach 750 Hz when a 10 k pixel Region of Interest (ROI) is used, with a maximum global shutter speed of 1/48000 s and a shutter efficiency of 99.7%. The data can be reliably transmitted uncompressed over standard copper Camera-Link® cables over 5 metres. The synchronisation error between the left and right stereo images is less than 100 ps and this has been verified both electrically and optically. Synchronisation is automatically established at boot-up and maintained during resolution changes. A third camera in the set can be configured independently. The dynamic range of the 10bit sensors exceeds 123 dB with a spectral sensitivity extending well into the infra-red range. The system was subjected to a comprehensive testing protocol, which confirms that the salient requirements for the driver monitoring application are adequately met and in some respects, exceeded. The synchronisation technique presented may also benefit several other automotive stereovision applications including near and far-field obstacle detection and collision avoidance, road condition monitoring and others.