Team develops a revolutionary unmanned aerial vehicle inspired by science fiction

Imagine a world where science fiction meets reality, where cutting edge technology brings to life the awe-inspiring scenes from movies like Prometheus. This is groundbreaking research led by Dr. Fu Zhang, Assistant Professor, Department of Mechanical Engineering at the Faculty of Engineering, The University of Hong Kong (HKU), who has developed a powered-flying ultra-underactuated LiDAR-sensing aerial robot (Pulsar) that can operate without a pilot. is set to redefine the world of unmanned aerial vehicles (UAVs).

UAVs are already playing an increasingly important role in search and rescue, cave surveying and architectural mapping. Pulsar, aptly named for its similarity to a celestial pulsar’s self-rotating and scanning patterns, takes UAV technology to new heights. With a micro-computer and a LiDAR sensor, Pulsar boasts full onboard perception, mapping, planning and control capabilities in both indoor and outdoor environments, without the need for any external equipment.

The secret to the Pulsar’s incredible functionality lies in its single actuator, which powers the swapplateless mechanism and provides both thrust and moment. Through a series of experiments, Dr. Zhang’s team demonstrated the pulsar’s ability to detect static and dynamic obstacles in real time, track complex trajectories, and navigate autonomously even in complete darkness.

The Pulsar’s robustness also extends to withstanding external wind perturbations, enabling safer and more stable flights in unpredictable conditions. At a maximum wind speed of 4.5 m/s, the Pulsar can maintain its hover position over a small area. Such a feature enables safe and stable flight in wild environments.

In addition to its aforementioned capabilities, the sensor can also expand the field of view (FoV) through self-rotating motion, which enhances the UAV’s perception and action capability. Currently, there are two main approaches to expanding the sensor FoV, but both consume significant amounts of power.

The first approach involves using sensors with large FOV, such as fisheye cameras, catadioptic cameras, or 360° lidars, which produce distortions. However, 360° LiDAR has a narrow and low-resolution FoV in the vertical direction. The second approach involves using multiple sensors such as multi-camera or multi-lidar systems, but this incurs additional cost and longer data processing time.

Pulsar’s invention can save up to 26.7% energy consumption compared to a quadrotor UAV with the same propeller disc area and payload, while still maintaining good agility. Thanks to its single actuator propulsion system, the Pulsar experiences low energy conversion losses, resulting in a high flight efficiency of 6.65g/W.

Despite its small size, with a diameter of only 37.6 cm and a battery capacity of just 41 Wh, this 1234-g UAV achieved a hover time of over 12 minutes. By removing the LiDAR sensor and adding a larger propeller and battery, the Pulsar’s hover time can be increased to more than 40 minutes.

Research findings are presented in science robotics,

Dr. Zhang said the research platform established by his team could be conducive to further exploration of self-rotating UAVs. “We believe that this will facilitate the research of UAV control methods under aggressive motion such as high-speed rotation and simultaneous localization and mapping (SLAM) techniques.”