: This talk is to share our experience on development of a bio-inspired insect-like tailless flapping-wing robot, named KUBeetle. The flying robot has no control surface at tail and mimics flapping wing motion of rhinoceros beetle. For design of the KUBeetle, we began with observation of beetle flight using digital high-speed cameras, which was nontrivial because the beetle is nocturn. From the acquired images of wing motion, we could extract key features of the beetle flight, which became design parameters for flapping mechanism. Since the flapping angle of the beetle reached 180 degrees, we should have created a new flapping mechanism, which was totally different from existing flapping mechanisms used for typical bird-mimicking flyers. Design of the flapping mechanism was evolved to a most recent one that can create a flapping angle of larger than 180 degrees to passively implement the clap-fling effect in between the outboards of the two flapping wings. Since there is no control surface at tail, the KUBeetle should be able to modify flapping wing kinematics in the middle of flapping motion, so that asymmetric forces can be produced in the two wings generating control moment for attitude control. Several designs were proposed for this purpose, which are the flapping-angle-change(FAC) mechanism, trailing-edge-change mechanism(TEC), and stroke-plane change (SPC) mechanism. For controlled flight, we first implemented the TEC mechanism with micro servos. The PD control theory was used to set up control logics. The prototype KUBeetle weighing 21g could fly for 40 seconds in 2016. As an effort to extend endurance, we focused on reduction of weights of components installed to the KUBeetle. Particularly, a one-gram integrated control board was developed and installed by the control group at Konkuk University. A modified KUBeetle could record an endurance of 8.8 minutes in 2019. Recently, inspired by a collision energy absorbing mechanism in hindwings of the rhinoceros beetle, artificial wings equipped with elastic energy storage mechanism were fabricated and installed into a KUBeetle. The robot successfully demonstrated stable flight even after the wing tip is collided with an obstacle, just like the rhinoceros beetle.
Bio: Professor Hoon Cheol Park received his BS (1985) and MS(1987) degrees from Seoul National University in Seoul, Korea and Ph.D. degree from the University of Maryland at College Park, MD, USA(1994). He joined Department of Aerospace Engineering, Konkuk University in Seoul, Korea in 1995. Dr. Hoon Cheol Park is currently professor at Department of Smart Vehicle Engineering, Konkuk University, Seoul, Korea. His professional experience includes research engineering at Kia Motors (1986-1988) and senior researcher at Korea Aerospace Research Institute (1994-1995). His specialty is the finite element analysis, and his recent research focus is mainly biomimetics and bio-inspired flight. His research team published more than 100 SCI/SCIE journal papers on design and demonstration of bird/insect-mimicking flying robots, locust-mimicking jumping plus flight robot, and fish-mimicking swimming robot, including a research article published in Science, December 2020. He has been an editorial board member of Journal of Bionic Engineering since 2007 and the associate editor of International Journal of Advanced Robotic Systems since 2013. He is serving Bioinspiration and Biomimetics as an editorial board member since 2019 and Journal of Bionic Engineering as associate editor since 2021. He also served Korea Society of Mechanical Engineers, Division of Bio-engineering as president in 2015 and as vice president for several years. As an international activity, he led International Society of Intelligent Unmanned Systems (ISIUS) as president (2017-2019). His research team was recognized as one of the most active teams in biomimetic flying robot research according to two review papers published in International Journal of Micro Air Vehicles in 2015 and 2017.