Van Anh Ho

RO
h-index20
5papers
9citations
Novelty43%
AI Score41

5 Papers

5.5ROMay 25
HoLoArm: Deformable Arms for Collision-Tolerant Quadrotor Flight

Quang Ngoc Pham, Jonas Eschmann, Yang Zhou et al.

The increasing use of drones in human-centric applications highlights the need for designs that can survive collisions and recover rapidly, minimizing risks to both humans and the environment. We present HoLoArm, a quadrotor with compliant arms inspired by the nodus structure of dragonfly wings. This design provides natural flexibility and resilience while preserving flight stability, which is further reinforced by the integration of a Reinforcement Learning (RL) control policy that enhances both recovery and hovering performance. Experimental results demonstrate that HoLoArm can passively deform in any direction, including axial one, and recover within 0.3-0.6 s depending on the direction and level of the impact. The drone can survive collisions at speeds up to 7.6 m/s and carry a 540 g payload while maintaining stable flight. This work contributes to the morphological design of soft aerial robots with high agility and reliable safety, enabling operation in cluttered and human shared environments, and lays the groundwork for future fully soft drones that integrate compliant structures with intelligent control.

1.4CVJul 20, 2021Code
Registration of 3D Point Sets Using Correntropy Similarity Matrix

Ashutosh Singandhupe, Hung La, Trung Dung Ngo et al.

This work focuses on Registration or Alignment of 3D point sets. Although the Registration problem is a well established problem and it's solved using multiple variants of Iterative Closest Point (ICP) Algorithm, most of the approaches in the current state of the art still suffers from misalignment when the \textit{Source} and the \textit{Target} point sets are separated by large rotations and translation. In this work, we propose a variant of the Standard ICP algorithm, where we introduce a Correntropy Relationship Matrix in the computation of rotation and translation component which attempts to solve the large rotation and translation problem between \textit{Source} and \textit{Target} point sets. This matrix is created through correntropy criterion which is updated in every iteration. The correntropy criterion defined in this approach maintains the relationship between the points in the \textit{Source} dataset and the \textit{Target} dataset. Through our experiments and validation we verify that our approach has performed well under various rotation and translation in comparison to the other well-known state of the art methods available in the Point Cloud Library (PCL) as well as other methods available as open source. We have uploaded our code in the github repository for the readers to validate and verify our approach https://github.com/aralab-unr/CoSM-ICP.

4.0ROFeb 15, 2022Code
Tombo Propeller: Bio-Inspired Deformable Structure toward Collision-Accommodated Control for Drones

Son Tien Bui, Quan Khanh Luu, Dinh Quang Nguyen et al.

There is a growing need for vertical take-off and landing vehicles, including drones, which are safe to use and can adapt to collisions. The risks of damage by collision, to humans, obstacles in the environment, and drones themselves, are significant. This has prompted a search into nature for a highly resilient structure that can inform a design of propellers to reduce those risks and enhance safety. Inspired by the flexibility and resilience of dragonfly wings, we propose a novel design for a biomimetic drone propeller called Tombo propeller. Here, we report on the design and fabrication process of this biomimetic propeller that can accommodate collisions and recover quickly, while maintaining sufficient thrust force to hover and fly. We describe the development of an aerodynamic model and experiments conducted to investigate performance characteristics for various configurations of the propeller morphology, and related properties, such as generated thrust force, thrust force deviation, collision force, recovery time, lift-to-drag ratio, and noise. Finally, we design and showcase a control strategy for a drone equipped with Tombo propellers that collides in mid-air with an obstacle and recovers from collision continuing flying. The results show that the maximum collision force generated by the proposed Tombo propeller is less than two-thirds that of a traditional rigid propeller, which suggests the concrete possibility to employ deformable propellers for drones flying in a cluttered environment. This research can contribute to morphological design of flying vehicles for agile and resilient performance.

3.0ROMar 22, 2021
Multi-directional Bicycle Robot for Steel Structure Inspection

Son Thanh Nguyen, Hai Nguyen, Son Tien Bui et al.

This paper presents a novel design of a multi-directional bicycle robot, which targets inspecting general ferromagnetic structures including complex-shaped structures. The locomotion concept is based on arranging two magnetic wheels in a bicycle-like configuration with two independent steering actuators. This configuration allows the robot to possess multi-directional mobility. An additional free joint helps the robot naturally adapt to non-flat and complex surfaces of steel structures. The robot has the biggest advantage to be mechanically simple with high mobility. Besides, the robot is equipped with sensing tools for structure health monitoring. We demonstrate the deployment of our robot to perform steel rust detection on steel bridges. The final inspection results are visualized as 3D models of the bridges together with marked locations of detected rusty areas.

5.3ROMar 2, 2021
BPActuators: Lightweight and Low-Cost Soft Actuators by Balloons and Plastics

Qiukai Qi, Shogo Yoshida, Genki Kakihana et al.

To increase the awareness and impact, soft robotics needs to go beyond the lab environment and should be readily accessible to those even with no robotic expertise. However, most prevailing manufacturing methodologies require either professional equipment or materials that are not usually available to common people, thereby constraining the accessibility of soft robotics. In this communication, we propose a lightweight and low-cost soft bending actuator, called BPActuator, that can be easily fabricated with plastics and balloons. We fabricated a range of actuators with various morphology for characterization in terms of deformation and load-bearing capacity, and demonstrated that they can bend up to 35 degrees and exert force at the tip around 0.070$\pm$0.015N, which is over 5 times higher than their average gravity. We further implemented a gripper with three fingers using the proposed actuators, and found that the gripper can realize human-like grasp of a range of daily objects. The gripper can lift objects at least 8 times heavier than its own weight. Furthermore, the BPActuator is cost effective and each costs about 0.22 USD. Given these advantages, the BPActuators are expected to significantly improve the accessibility of soft robotics to a wider group without robotic expertise.