The University of Tokyo · Engineering
Professor Moju Zhao's research lab specializes in the design, control, and application of transformable aerial robots for enhanced mobility and manipulation in complex environments. The lab focuses on developing multirotor systems with multi-degree-of-freedom (DoF) aerial transformation capabilities, integrating advanced flight control, whole-body manipulation, and real-time grasping strategies. Key innovations include the DRAGON robot with dual-rotor gimbal modules for vectorable thrust and pose control, enabling stable flight and dynamic manipulation without external appendages. The lab also explores intelligent perception and planning, such as attention-based tracking and optimized grasp form search, to support autonomous operation in challenging scenarios like disaster response.
Figures are computed from collected data and may differ slightly.
In this letter, we introduce a novel transformable aerial robot called DRAGON, which is a dual-rotor-embedded multilink robot with the ability of multi-degree-of-freedom (DoF) aerial transformation. The new aerial robot can control the full pose in SE(3) regarding the center of gravity (CoG) of multilinks and can render the multi-DoF aerial transformation, which is accomplished by the original two-DoF force vectoring mechanism on each link called the dual-rotor gimbal module. The dynamics is der
In this paper, we introduce the achievement of the aerial manipulation by using the whole body of a transformable aerial robot, instead of attaching an additional manipulator. The aerial robot in our work is composed by two-dimensional multilinks which enable a stable aerial transformation and can be employed as an entire gripper. We propose a planning method to find the optimized grasping form for the multilinks while they are on the air, which is based on the original planar enveloping algorit
Template-based discriminative trackers are currently the dominant tracking methods due to their robustness and accuracy, and the Siamese-network-based methods that depend on cross-correlation operation between features extracted from template and search images show the state-of-the-art tracking performance. However, general cross-correlation operation can only obtain relationship between local patches in two feature maps. In this paper, we propose a novel tracker network based on a powerful atte
A multirotor with two-dimensional multilinks is proposed to perform aerial transformation and aerial manipulation. First, a modular link structure that comprises a multirotor with a reliable internal communication system was initially developed. Second, a flight control method was further introduced on the basis of linear–quadratic–integral optimal control for aerial transformation. A relaxed hovering solution that neglects the yaw motion stability is proposed to enable stable flight under a cer
In this study, we investigated a novel type of the multirotor aerial vehicle with two-dimensional multilinks to demonstrate stable aerial transformation for high mobility in three-dimensional environments. Our goal was to tackle the challenge of traversing narrow spaces or gaps, which is one of the difficulties for existing structure of multirotors, especially in the cluttered indoor environment of disaster sites. The research involved three steps. First, we developed the modeling of the link mo
Various state-of-the-art works have achieved aerial manipulation and grasping by attaching additional manipulator to aerial robots. However, such a coupled platform has limitations with respect to the interaction force and mobility. In this paper, we present the successful implementation of aerial manipulation and grasping by a novel articulated aerial robot called DRAGON, in which a vectorable rotor unit is embedded in each link. The key to performing stable manipulation and grasping in the air
State-of-the-art work on deformable multirotor aerial robots has developed a strong maneuvering ability in such robots, whereas there is no versatile aerial robot that can perform both deforming maneuvering and aerial manipulation yet. However, a novel multilinked aerial robot presented in our previous work, called DRAGON, has both potential because of its serial-link structure. Therefore, an online motion planning method for such a multilinked aerial robot is required. In this letter, we first
Multimodal locomotion capability is an emerging topic in robotics field, and various novel mobile robots have been developed to enable the maneuvering in both terrestrial and aerial domains. Among these hybrid robots, several state-of-the-art bipedal robots enable the complex walking motion which is interlaced with flying. These robots are also desired to have the manipulation ability; however, it is difficult for the current forms to keep stability with the joint motion in midair due to the cen
Aerial manipulation is a growing field of research, and multirotors with attached arm manipulator have shown practical utility in contact-based inspection. However, theses coupled platforms limit the pose reachability of the end-effector, which then motivates the development of omni-directional designs for aerial robots. Although the full pose tracking can be achieved by these omni-directional models, the large amount of internal thrust force constrains wrench exertion for forceful manipulation
In this paper, we introduce the achievement of the flight motion to pass through small opening by the multilinked and transformable aerial robot. Previous works about such motion are based on under-actuated multirotors, indicating that aggressive maneuvering is necessary condition. This involves two crucial problems: i) enough free space for deceleration is necessary, otherwise the robot would collide with unknown obstacle after exiting opening; ii) the multirotor can not traverse the openings t
Abstract A multilinked structure can benefit aerial robots in terms of both maneuvering and manipulation owing to its ability of aerial transformation. A coplanar multilinked model was developed in our previous study. However, the maneuvering and manipulation performances of that model were limited owing to the weak controllability. Therefore, we adopt tilted propellers in this study to enhance controllability. The related design, modeling, and control method are developed to achieve stable hove
Two-dimensional multilinked structures can benefit aerial robots in both maneuvering and manipulation because of their deformation ability. However, certain types of singular forms must be avoided during deformation. Hence, an additional 1 Degrees-of-Freedom (DoF) vectorable propeller is employed in this work to overcome singular forms by properly changing the thrust direction. In this letter, we first extend modeling and control methods from our previous works for an under-actuated model whose
The multilinked or modular structure is one of the state-of-the-art topics in aerial robot field. One type of the multilinked aerial robot called DRAGON containing a two degree-of-freedom (DoF) force vectoring apparatus in each link has been developed in our previous work to augment both maneuvering and manipulation ability. However, several types of invalid robot poses, which are due to the mechanical structure, the previous control method and the interrotor aerodynamic interference, significan
State‐of‐the‐art aerial robots often prioritize maneuverability or manipulation capabilities, making it difficult to achieve both. The issue arises because aerial robots with agile mobility lack sufficient rotors for manipulation tasks, while those with manipulation ability are too large for agile mobility. To tackle this problem, a novel aerial robot unit named TRADY, tilted‐rotor‐equipped aerial robot with autonomous in‐flight assembly and disassembly capability, is introduced. The TRADY unit
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