Hardware for Mobile Positioning : Considerations on Design and Development of Cost-Efficient Solutions

The estimation of a moving agent's position in an unknown environment is a problem formulated in its current form already in the 1980s. Emphasis on localization and mapping problems has grown rapidly in the last two decades driven by the increased computational capability of especially handheld systems and a large number of target applications in various fields, ranging from self-driving cars and geomatics to robotics and virtual/augmented reality. Besides the algorithms for positioning, hardware plays a major role as a backbone for enabling accurate, robust and flexible position estimation solutions. This thesis gives an overview of sensors utilized in mobile positioning with a focus on passive visual-inertial sensors as an alternative to more expensive active-ranging solutions. The main research interest of the thesis is the feasibility of developing and implementing a cost-efficient hardware solution for positioning. Visual, inertial and satellite positioning sensors' advantages, performance parameters, sources of error and physical requirements are considered. Sensor integration and both sensor and system-level calibration in a multisensor setup are discussed. Levels of developer involvement and options for hardware development approaches are presented, mainly ready-made modular solutions, building on top of intermediate products and development from scratch. Hardware development processes are demonstrated by implementing a synchronized visual-inertial positioning system including two pairs of stereo cameras, an inertial measurement unit and a Real-Time Kinematic capable satellite positioning solution. The system acts as a cost-efficient example for options and decisions required on the selection of sensors and computational subsystems supporting the sensor hardware, integration and continuous temporal synchronization of sensors as well as requirements and manufacturing options for system enclosures. Even though the direct costs of the solution seem inexpensive compared to competitive solutions, accounting for the development time and associated risk makes hardware development from scratch less attractive option compared to other approaches. For a proof-of-concept or a case in which a very limited number of end products are produced, implementation from the ground up is most likely time-consuming and thus ends up being an expensive endeavor compared to other approaches. Also, the benefits of control over the details of hardware and integration may not be fully utilized

SND@LHC:The Scattering and Neutrino Detector at the LHC

SND@LHC is a compact and stand-alone experiment designed to perform measurements with neutrinos produced at the LHC in the %unexplored pseudo-rapidity region of 7.