In support of military operations and civil applications, the Unmanned Aerial Vehicles (UAVs) have quickly emerged as useful and versatile tools with extensive scope of mission profiles. Examples range from small-sized UAVs like Wasp and Black Widow, to medium-sized UAVs like Pioneer and RMAX, to large-sized UAVs like Global Hawk and A160. Flying platforms vary from fixed-wing, rotary-wing, flapping wing, or a hybrid of various concepts. Their missions include but no limited to surveillance, reconnaissance, target acquisition, datalink relay, sensor shooting, border patrol, and highway monitoring.
Operating environments play an important role in formulating design features. In particular, challenges involving operations in the urban settings may include hostile environments, loss of line-of-sight, poor GPS reception, fast maneuver in narrow urban corridors, perch and stare, and even flying into the buildings. On the other hand, UAVs for naval applications may require VTOL (Vertical Take-Off and Landing) capability, extended payload capacity, longer range, and operating under various sea conditions. These challenges in turn affect the design of autonomous control system.
Classical features of autonomous control design involve stability enhancement and waypoint flight. However, new requirements in the recent development of UAVs demand robust and adaptive control techniques for various flight conditions, aggressive maneuvers, non-traditional sensor selections like cameras, obstacle avoidance, fault detection and tolerance, power management for perch and stare, team formation and coordinate flight. In order to achieve these ambitious requirements, a systematic and innovative thinking needs to be in place. Moreover, concerted efforts are critical on issues related to practical implementation.
The aim of this special issue is to bring together researchers and practitioners in the fields of unmanned systems, with a common interest in the new challenges in platform design and autonomous control development. We hope to attract contributions on novel ideas in the design of non-conventional UAVs, autonomous control, navigation, guidance, and implementation considerations such as miniature flight computer and computational efficiency.
In this special issue, two papers are dedicated to design of unconventional and micro UAVs. First, Bermes et al. propose design of two prototypes of autonomous micro helicopter muFly. Rotor configuration and steering selection criteria are discussed in details. Adopting a coaxial configuration with a swashplate steering from the lower rotor, these prototypes are built and flown in untethered test flights. The second paper by Andersh et al. describes development and integration of an UAV. Choice of flying platform, onboard electronics and sensing unit, and system integration are carefully elaborated. An overview of