6 research outputs found
Bionic Collapsible Wings in Aquatic-aerial Robot
The concept of aerial-aquatic robots has emerged as an innovative solution
that can operate both in the air and underwater. Previous research on the
design of such robots has been mainly focused on mature technologies such as
fixed-wing and multi-rotor aircraft. Flying fish, a unique aerial-aquatic
animal that can both swim in water and glide over the sea surface, has not been
fully explored as a bionic robot model, especially regarding its motion
patterns with the collapsible pectoral fins. To verify the contribution of the
collapsible wings to the flying fish motion pattern, we have designed a novel
bio-robot with collapsible wings inspired by the flying fish. The bionic
prototype has been successfully designed and fabricated, incorporating
collapsible wings with soft hydraulic actuators, an innovative application of
soft actuators to a micro aquatic-aerial robot. We have analyzed and built a
precise model of dynamics for control, and tested both the soft hydraulic
actuators and detailed aerodynamic coefficients. To further verify the
feasibility of collapsible wings, we conducted simulations in different
situations such as discharge angles, the area of collapsible wings, and the
advantages of using ground effect. The results confirm the control of the
collapsible wings and demonstrate the unique multi-modal motion pattern between
water and air. Overall, our research represents the study of the collapsible
wings in aquatic-aerial robots and significant contributes to the development
of aquatic-aerial robots. The using of the collapsible wings must a
contribution to the future aquatic-aerial robot
6-DOF All-Terrain Cyclocopter
This paper presents the design of a 6-DOF all-terrain micro aerial vehicle
and two control strategies for multimodal flight, which are experimentally
validated. The micro aerial vehicle is propelled by four motors and controlled
by a single servo for the control of the cycloidal rotors(cyclorotors) speed
and lift direction. Despite the addition of the servo, the system remains
underactuated. To address the traditional underactuation problem of cycloidal
rotor aircraft, we increase the number of control variables. We propose a PID
and a nonlinear model predictive control (NMPC) framework to tackle the model's
nonlinearities and achieve control of attitude, position, and their
derivatives.Experimental results demonstrate the effectiveness of the proposed
multimodal control strategy for 6-DOF all-terrain micro aerial vehicles. The
vehicle can operate in aerial, terrestrial, and aquatic modes and can adapt to
different terrains and environmental conditions. Our approach enhances the
vehicle's performance in each mode of operation, and the results show the
advantages of the proposed strategy compared to other control strategies
Path Planning for Air-Ground Robot Considering Modal Switching Point Optimization
An innovative sort of mobility platform that can both drive and fly is the
air-ground robot. The need for an agile flight cannot be satisfied by
traditional path planning techniques for air-ground robots. Prior studies had
mostly focused on improving the energy efficiency of paths, seldom taking the
seeking speed and optimizing take-off and landing places into account. A robot
for the field application environment was proposed, and a lightweight global
spatial planning technique for the robot based on the graph-search algorithm
taking mode switching point optimization into account, with an emphasis on
energy efficiency, searching speed, and the viability of real deployment. The
fundamental concept is to lower the computational burden by employing an
interchangeable search approach that combines planar and spatial search.
Furthermore, to safeguard the health of the power battery and the integrity of
the mission execution, a trap escape approach was also provided. Simulations
are run to test the effectiveness of the suggested model based on the field DEM
map. The simulation results show that our technology is capable of producing
finished, plausible 3D paths with a high degree of believability. Additionally,
the mode-switching point optimization method efficiently identifies additional
acceptable places for mode switching, and the improved paths use less time and
energy
Giant electrically tunable magnon transport anisotropy in a van der Waals antiferromagnetic insulator
Abstract Anisotropy is a manifestation of lowered symmetry in material systems that have profound fundamental and technological implications. For van der Waals magnets, the two-dimensional (2D) nature greatly enhances the effect of in-plane anisotropy. However, electrical manipulation of such anisotropy as well as demonstration of possible applications remains elusive. In particular, in-situ electrical modulation of anisotropy in spin transport, vital for spintronics applications, has yet to be achieved. Here, we realized giant electrically tunable anisotropy in the transport of second harmonic thermal magnons (SHM) in van der Waals anti-ferromagnetic insulator CrPS4 with the application of modest gate current. Theoretical modeling found that 2D anisotropic spin Seebeck effect is the key to the electrical tunability. Making use of such large and tunable anisotropy, we demonstrated multi-bit read-only memories (ROMs) where information is inscribed by the anisotropy of magnon transport in CrPS4. Our result unveils the potential of anisotropic van der Waals magnons for information storage and processing