79 research outputs found
Locomation strategies for amphibious robots-a review
In the past two decades, unmanned amphibious robots have proven the most promising and efficient systems ranging from scientific, military, and commercial applications. The applications like monitoring, surveillance, reconnaissance, and military combat operations require platforms to maneuver on challenging, complex, rugged terrains and diverse environments. The recent technological advancements and development in aquatic robotics and mobile robotics have facilitated a more agile, robust, and efficient amphibious robots maneuvering in multiple environments and various terrain profiles. Amphibious robot
locomotion inspired by nature, such as amphibians, offers augmented flexibility, improved adaptability, and
higher mobility over terrestrial, aquatic, and aerial mediums. In this review, amphibious robots' locomotion
mechanism designed and developed previously are consolidated, systematically The review also analyzes
the literature on amphibious robot highlighting the limitations, open research areas, recent key development
in this research field. Further development and contributions to amphibious robot locomotion, actuation, and
control can be utilized to perform specific missions in sophisticated environments, where tasks are unsafe
or hardly feasible for the divers or traditional aquatic and terrestrial robots
Research on obstacle performance and tipping stability of a novel wheel–leg deformation mechanism
A new type of wheel–leg deformation mechanism, based on an
electromagnetic clutch and gear rack transmission mechanism, is designed.
This mechanism has a compact structure and simple operation, which can roll on wheels and surmount obstacles with a support leg. Firstly, the walking model is established to study the kinematics characteristics of the mechanism. The
alternation of the support legs does not affect smooth obstacle crossing,
but will cause the step change of the angular velocity of the centroid of
the main body. Secondly, the obstacle-surmounting performance of roll-over
mode and obstacle-crossing mode using support legs is analyzed. For roll-over mode, the maximum climbing height is 87.36 mm. For obstacle-crossing
mode using support legs, the maximum climbing height is the maximum
extension length of the support leg. According to the climbing height, the
switching criteria of different climbing modes are obtained. In addition,
the rolling angle of the main body has a greater impact on the support force and driving torque, while the contact angle between the legs and the ground has a small impact. Finally, the tipping stability and anti-interference ability of the wheel–leg deformation mechanism is evaluated using the stability cone method.</p
Design, Actuation, and Functionalization of Untethered Soft Magnetic Robots with Life-Like Motions: A Review
Soft robots have demonstrated superior flexibility and functionality than
conventional rigid robots. These versatile devices can respond to a wide range
of external stimuli (including light, magnetic field, heat, electric field,
etc.), and can perform sophisticated tasks. Notably, soft magnetic robots
exhibit unparalleled advantages among numerous soft robots (such as untethered
control, rapid response, and high safety), and have made remarkable progress in
small-scale manipulation tasks and biomedical applications. Despite the
promising potential, soft magnetic robots are still in their infancy and
require significant advancements in terms of fabrication, design principles,
and functional development to be viable for real-world applications. Recent
progress shows that bionics can serve as an effective tool for developing soft
robots. In light of this, the review is presented with two main goals: (i)
exploring how innovative bioinspired strategies can revolutionize the design
and actuation of soft magnetic robots to realize various life-like motions;
(ii) examining how these bionic systems could benefit practical applications in
small-scale solid/liquid manipulation and therapeutic/diagnostic-related
biomedical fields
Novel Reconfigurable Walking Machine Tool Enables Symmetric and Nonsymmetric Walking Configurations
Current research on walking robots strives to achieve a higher efficiency, a better load capacity, and an increased adaptability. Parallel kinematic manipulators (PKMs) are characterized by high payload and accuracy, but conventional PKMs with fixed configurations are limited to constrained workspaces in known structured environments. In this article, we propose a parallel reconfigurable walking machine tool that overcomes these limits by adapting its configuration and gaits to different scenarios. A lightweight and compact positioning system with shape memory alloy actuation is presented to achieve reconfiguration capabilities. Furthermore, kinematic, stability, and force analyses are reported to determine the optimal walking gaits in three different scenarios (with inclined slopes at different angles) and four robot configurations. Finally, a set of experiments with the physical prototype validates the proposed models. The results show that symmetric configurations present a better performance at lower ground inclinations (0.5% error), whereas asymmetric configurations can climb on slope conditions that would prevent the use of conventional PKMs (18% or 10°)
Aquatic escape for micro-aerial vehicles
As our world is experiencing climate changes, we are in need of better monitoring technologies.
Most of our planet is covered with water and robots will need to move in aquatic environments.
A mobile robotic platform that possesses efficient locomotion and is capable of operating in
diverse scenarios would give us an advantage in data collection that can validate climate models,
emergency relief and experimental biological research. This field of application is the driving
vector of this robotics research which aims to understand, produce and demonstrate solutions
of aerial-aquatic autonomous vehicles.
However, small robots face major challenges in operating both in water and in air, as well as
transition between those fluids, mainly due to the difference of density of the media.
This thesis presents the developments of new aquatic locomotion strategies at small scales that
further enlarge the operational domain of conventional platforms. This comprises flight, shallow
water locomotion and the transition in-between. Their operating principles, manufacturing
methods and control methods are discussed and evaluated in detail.
I present multiple unique aerial-aquatic robots with various water escape mechanisms, spanning
over different scales. The five robotic platforms showcased share similarities that are compared.
The take-off methods are analysed carefully and the underlying physics principles put into light.
While all presented research fulfils a similar locomotion objective - i.e aerial and aquatic motion
- their relevance depends on the environmental conditions and supposed mission. As such, the
performance of each vehicle is discussed and characterised in real, relevant conditions.
A novel water-reactive fuel thruster is developed for impulsive take-off, allowing consecutive
and multiple jump-gliding from the water surface in rough conditions. At a smaller scale, the
escape of a milligram robotic bee is achieved. In addition, a new robot class is demonstrated,
that employs the same wings for flying as for passive surface sailing. This unique capability
allows the flexibility of flight to be combined with long-duration surface missions, enabling
autonomous prolonged aquatic monitoring.Open Acces
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A survey on evolutionary-aided design in robotics
The evolutionary-aided design process is a method to find solutions to design and optimisation problems. Evolutionary Algorithms (EAs) are applied to search for optimal solutions from a solution space that evolves over several generations. EAs have found applications in many areas of robotics. This paper covers the efforts to determine body morphology of robots through evolution and body morphology with the controller of robots or similar creatures through co-evolution. The works are reviewed from the perspective of how different algorithms are applied and includes a brief explanation of how they are implemented
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