Unmanned Systems Technology 002 | Scion SA-400 | Commercial UAV Show report | Vision sensors | Danielson Trident I Security and safety systems | MIRA MACE | Additive manufacturing | Marine UUVs

64 Dossier | MIRA MACE the sensor systems, and the experience with all three generations of the MACE platform highlights the different levels of autonomy for different uses. In a military context, the use cases are driven by three Ds – tasks that are dull, dirty or dangerous. On land, that tends to mean mechanical operations such as digging ditches or building banks, as well as rescue and retrieval operations, and for these applications the operation of a vehicle is unlikely to be completely autonomous. For example, if you wanted to do unmanned construction tasks or create a secure base in a potentially hostile area, you could send out unmanned heavy equipment or heavy engineering vehicles to travel to the location autonomously. Once there, the vehicles would probably then have to be controlled remotely to achieve the task. All this means that the development of platforms such as MACE has to take into account comms issues such as data rates, latency and power consumption to achieve autonomous as well as remote operations. Sensor suite The main sensor is a camera suite, from UK company Chess Dynamics. This handles the optical detection so that the vehicle can follow a set of waypoints on the navigation system, such as the perimeter of a military base, while all the time checking for obstacles on the route. One of MACE 3’s camera systems, called Piranha, provides a field of view of up to 100 º and is encased in a rugged housing that is designed to withstand vehicle vibrations. It provides images in temperatures from -40 to +70 C, and an integrated mounting bracket allows precise elevation and azimuth alignment to within 2 º . The Piranha also uses cooling to remove heat from the charge coupled device (CCD) sensor. This reduces random noise in the sensor, resulting in improved image quality, particularly in low-light conditions. It also supports Expanded Hi-Dynamic Range, which amplifies the signal level in dark areas and reduces it in very bright areas, improving the visibility of objects in the image. Other cameras are sourced from Sick, in Germany, which provides cameras for industrial applications such as production line monitoring. MIRA has used these to demonstrate that commercial off-the-shelf imaging systems can be used as well as ruggedised systems such as Piranha. The engine transmission is automatic, which is easily adapted for autonomous operation, although the control software does not use feedback from the transmission to the control electronics for engine braking, for example. The steering, braking and acceleration are all controlled by small actuators inside the footwell so that a driver can also Spring 2015 | Unmanned Systems Technology MIRA has developed a vehicle platform capable of adapting throttle and brake control in response to messages received over a wireless network. Using accurate positioning techniques, suitable control commands can be generated remotely to accurately execute predefined test scenarios. This Network Assisted Vehicle (NAV) has a number of advantages over the two main alternatives for pre-crash testing. These rely on full driver control of the vehicle, or a fully automated vehicle. The increasingly complex test requirements for advanced driver assistance systems (ADAS) also means that multiple vehicles or related events need to be synchronised. The option of using fully automated vehicles is appealing for safe and repeatable testing, but the current costs are prohibitively high because of the need for accurate sensor systems for all parts of the vehicle. MIRA’s NAV has already completed system development and testing, and is being used in evaluation projects such as UK Autodrive in Coventry and the connected cyber security collaboration group. The cooperative car The three cameras on MACE 3 provide a wide field of view and are the key obstacle detection system