Figure 2 - uploaded by Stefano Mintchev
Content may be subject to copyright.
![Examples of terrestrial robots with morphing structures. (a) A robot equipped with circular wheels that can morph in whegs to negotiate obstacles [33]. (b) A robot with controllable sprawl angle to combine the benefit of vertical and in-plane locomotion [38]. (c) A GoQBot during rolling locomotion [40].](profile/Stefano-Mintchev/publication/308083555/figure/fig1/AS:416720037662723@1476365207969/Examples-of-terrestrial-robots-with-morphing-structures-a-A-robot-equipped-with.png)
Examples of terrestrial robots with morphing structures. (a) A robot equipped with circular wheels that can morph in whegs to negotiate obstacles [33]. (b) A robot with controllable sprawl angle to combine the benefit of vertical and in-plane locomotion [38]. (c) A GoQBot during rolling locomotion [40].
Source publication
Morphology plays an important role in behavioral and locomotion strategies of living and artificial systems. There is biological evidence that adaptive morphological changes can not only extend dynamic performances by reducing tradeoffs during locomotion but also provide new functionalities. In this article, we show that adaptive morphology is an e...
Contexts in source publication
Context 1
... instance, similar to cockroach- es [31], the latest versions are equipped with a passive body flex- ion joint to bend the front half of the body down to avoid high cen- tering during climbing [32]. Inspired by Whegs, Kim et al. [33] developed a robot equipped with passively morphing wheels that combines the advantage of both circular and legged wheels [ Figure 2(a)]. On flat sur- faces, the wheels have a circular shape but can passive- ly morph in whegs to negotiate obstacles. ...
Context 2
... has under- gone multiple series of design itera- tions, some of which embed mor phing appendages to increase adaptability. For example, Sprawl-Hex [37] and a sprawl tuned autonomous robot (STAR) [38] [ Figure 2(b)] are six-legged robots with a variable sprawl angle that combines the advantages of both vertical and in- plane locomotion. At low sprawl angles, the robots' stability and veloci- ty are comparable to a similar wheeled robot, but, at higher sprawl angles, they have better grip and can overcome higher obstacles. ...
Similar publications
The recent interest in human-robot interaction requires the development of new gripping solutions, compared to those already available and widely used. One of the most advanced solutions in nature is that of the human hand, and several research contributions try to replicate its functionality. Technological advances in manufacturing technologies an...
Citations
... The design of the robot's shield in this work was bioinspired and was based on the morphology of the terrestrial isopod Armadilium Vulgare since its shape has multi-purpose advantages such as protecting its inner area during conglobation (rolling-up behavior) as a mechanism of self-protection [22][23][24]. Each segment of the soft robot should have a sensory-motor based on the soft sensory-motor system based on ionic solution (SSMS-IS) to actuate in the environment when expanded and to sense when compressed. ...
... The design of the robot's shield in this work was bioinspired and was based morphology of the terrestrial isopod Armadilium Vulgare since its shape has mu pose advantages such as protecting its inner area during conglobation (rolling-up ior) as a mechanism of self-protection [22][23][24]. Each segment of the soft robot shou a sensory-motor based on the soft sensory-motor system based on ionic solution IS) to actuate in the environment when expanded and to sense when compres shown in Figure 1, both states integrated into only one component allow the syst formance in a sensory-motor coordination mode, i.e., in a dynamic and recipro pling among the brain (control), the body, and the environment [25]. ...
... Once the sensor actuation can achieve different levels of expansion, the robot can be able to walk in different types of terrains or improve the mechanical energy of the system. Also, the locomotion can be monitored simultaneously from the same component, since in the SSMS-IS, the actuation and sensing characteristics are integrated, as discussed in [24]. Moreover, robot prosthetics using soft materials can benefit from using the SSMS-IS. ...
Soft robots claim the architecture of actuators, sensors, and computation demands with their soft bodies by obtaining fast responses and adapting to the environment. Sensory-motor coordination is one of the main design principles utilized for soft robots because it allows the capability to sense and actuate mutually in the environment, thereby achieving rapid response performance. This work intends to study the response for a system that presents coupled actuation and sensing functions simultaneously and is integrated in an arbitrary elastic structure with ionic conduction elements, called as soft sensory-motor system based on ionic solution (SSMS-IS). This study provides a comparative analysis of the performance of SSMS-IS prototypes with three diverse designs: toroidal, semi-toroidal, and rectangular geometries, based on a series of performance experiments, such as sensitivity, drift, and durability. The design with the best performance was the rectangular SSMS-IS using silicon rubber RPRO20 for both internal and external pressures applied in the system. Moreover, this work explores the performance of a bioinspired soft robot using rectangular SSMS-IS elements integrated in its body. Further, it investigated the feasibility of the robot to adapt its morphology online for environment variability, responding to external stimuli from the environment with different levels of stiffness and damping.
... B Iological creature's capacity to adapt to a variety of environments is greatly facilitated by morphological changes that increase its robustness [1]- [3]. The creatures adopt many different kinds of morphological changes to adapt themselves to the changing environment [4]. Pigeons are known to use a strategy of folding their wings to navigate through obstacles [5]. ...
Adaptation of morphology in response to varying environments is a crucial feature seen in biological organisms. While some robots emulate adaptability through the use of adaptive body parts, practical implementation of morphological transformations in robotics remains limited. This limitation arises due to the complexity of such transformations, demanding the fusion of advanced materials, control systems, and design approaches. In our paper, we introduce a bioinspired quadruped robot equipped with a laterally undulating spine, designed to adapt its posture specifically for navigating complex terradynamic environments. Leveraging a symmetrical parallelogram mechanism, this robot can alter both height and width, enabling traversal across varied surfaces, collision avoidance, passage through narrow channels, and obstacle negotiation. Additionally, our robot’s innovative design strategically positions its center of gravity within its support triangle throughout the gait cycle using lateral undulation, eliminating the need for posture-stabilizing sensors or learning algorithms.
... Second, this research has explored a worthwhile new method to achieve multimodal robots, which does not seem to exactly fall into one of the two common principles: the reconfigurable and modular method, and the adaptive morphology. 59 Specifically, for the in-line triple configuration, although without reorganizing its pattern or reshaping its morph, it still manifests the best adaptability: crawling on ground, horizontally and vertically climbing the pole-like structure. Generally speaking, it is highly challengeable for a single robot to achieve multimode locomotion because it must simultaneously meet two competing and even conflicting criteria. ...
The reconfigurable and modular method, and the adaptive morphology method are two main methodologies to achieve the multimodal robots. Basically, the former method mimics the biological multicellular systems, while the latter is mostly inspired by the multimodal animals. Herein inspired by the rhombic dodecahedron (RDD) origami model, a novel type of soft multicellular robots with multimodal locomotion is presented. Morphologically, the combinable and expandable three-dimensional (3D)-printed soft RDD cells are assembled into several typical patterns: in-line, cross shaped, oblong shaped, and parallelogra shaped. The kinematics based on the sequential monolithic deformations of soft RDDs is analyzed to generate multimodal locomotion: peristaltic crawling, two-anchor crawling, crawling with turning functions, and omnidirectional crawling through the propagating waves in two orthogonal directions. More encouragingly, without reorganizing the pattern or reshaping the morph, the in-line multicellular robots manifest excellent climbing abilities, where the built-in rhombic meshes alternately tighten and loosen the pole-like structures to provide the gripping forces reliably without sacrificing mobility. To wrap up, owing to the monolithic and hierarchical deformability, high reconfigurability, and 3D-printable manufacturability of the RDD, we anticipate that the soft multicellular robot can potentially manifest further contributions to the advanced robotics with embodied intelligence, such as task-oriented self-assembly robots, self-reconfigurable robotic systems, and goal-directed metamorphosis robots.
... Another interesting area of research where quantification of embodiment will be useful is in the development of highly re-configurable intelligent systems with adaptive morphologies [35]. Inspired by biology, where many animals have evolved morphable bodies to extend their operational range, several terrestrial and aerial robots have been developed. ...
... Examples are GoQBot [36] that morphs before rolling, RHex [37] with legs that adapt their stiffness when morphed to run effectively over a broad range of terrains, and a few others. These systems are developed using programmable matter [35], which is concerned with the theory, design, and manufacturing of systems that reconfigure assuming different morphological configurations. This programmable matter is developed in a modular way as building blocks, starting from the simplest elements. ...
In recent years, researchers have investigated different methods to quantify embodiment for a variety of robotic systems including robotic arms, grippers and legged robots. This paper will discuss some of these methods, focusing on their potential contribution to designing robotic systems based on muscle-driven models. We start with the definition of embodiment based on the relational dynamics between the system and its environments by drawing upon the idea of mutual perturbation and structural coupling between the two. We will discuss how such an understanding can provide potential approaches to quantify embodiment. These includes two information-theoretic measures which are particularly suitable for muscle-driven models. The two methods are based on (i) comparing the controller and behaviour complexity and (ii) Conditional Mutual Information, which compares the difference in distribution of the action conditional on the actuated state and purely on its morphological properties. These methods were used on muscle-driven, biologically realistic hopping models to quantify embodiment at different stages of the hopping gait. The results clearly demonstrate the contribution of morphology of the muscle fibers at different points in the hopping cycle. Furthermore, these methods have been used in latter studies to measure the contribution of embodiment across different levels in a hierarchical control system of a neuro-musculoskeletal model and also to quantify the effects of information cost during various actions in a muscle-driven robotic system. We discuss the practical implications as well as limitations and the future work in the application of these quantification methods.
... However, in the wheeled mode, the robot cannot climb stairs and overcome large obstacles, resulting in an infinite cost. Thus when steering the robot from an uneven terrain to an even terrain, TurboQuad's morphology changes from wheeled to legged, demonstrating execution- In addition to locomotion, kinematically changing the shape of the system can enhance the robot's workspace, adding other functionality such as transportability, protection, and viable transmission [33]. Similar shape changes have been achieved in manipulation, for example, where changing finger geometries results in a system that can transition between different grasps repeatably [34] or perform reliable perching in aerial vehicles [35]. ...
While there has been much work in the space of embodied intelligence, we as a field have struggled to define what exactly embodied intelligence is and how it should be used. In this paper, we propose that there are multiple types of embodied intelligence, and that these different types of embodied intelligence are suited to different types of tasks. We introduce a method for classifying tasks according to their objective and occurrence, and we describe how existing work in embodied intelligence fits into this framework. We hope that this proposed framework will initiate a discussion to more formally think about the role that embodied intelligence plays and the value that it brings to engineering and robotics.
... Living organisms can exhibit programmed functional responses to protect themselves against external dangers and threats [219], through defensive strategies. Many defensive strategies exist in nature, some of which have been already recalled in the previous sections. ...
... Pillbugs (Armadillidum vulgare) represent another relevant example in this context: they are capable of morphing their body shape by rolling and closing (conglobation mechanism) when triggered by strong vibrations or pressure typically produced by predators [219]. A similar mechanism has been obtained in silicon-based shell structures patterned with a regular array of circular voids and mechanically deformed by controlling the difference between internal and external pressure [236]; below a critical pressure, the ligaments placed between voids exhibit buckling, leading to the closure of the structures (encapsulation, a mechanism similar to the conglobation exhibited by the Armadillidum vulgare, [236]). ...
Living organisms and, in general, bio-materials respond to external stimuli exhibiting specific functionalities (such as shape-morphing, color change, tissue growth and remodeling, programmed mechanical responses, adaptation of material properties, etc.) required for different needs (camouflage, locomotion, defense, food supply, biological processes, etc.). Functionalities in nature come from bio-chemo-physical-mechanical responsiveness of the complex architectures in which natural structures are organized across the nano-, micro- and meso-scales. Often inspired by natural structures and bio-functionalities, in recent years the development of synthetic responsive materials has attracted a huge interest, and increasingly still attracts the efforts of scientists to synthesize new smart materials and devices.
The paper illustrates the most compelling morphing and functional responses observable in nature – displayed by biological matter, living individuals or by the collective behavior of large groups of organisms – developed for different functional purposes, and discusses the related underlying mechanisms. In parallel, the most relevant functional materials being developed in the last decades are presented with the related mathematical models, and their underlying driving mechanisms are compared with those observable in nature. The study is aimed at providing a broad overview and to explain the strategies used in nature to obtain functionalities; the analogies with those shown by artificial functional materials, with a particular emphasis on polymer-based or polymer-like materials, are investigated. Some multi-physics models, describing the response and enabling the systematic design, optimization and synthesis of functional materials suitable to the development of new advanced applications, are also illustrated. The knowledge of natural cunning can push forward the research in the field, offers new possibilities worth of investigation by materials scientists, physicists and engineers, and opens unexplored scenarios not yet fully considered in the existing literature.
... This new class of systems with adaptive morphology is primarily inspired by nature [6]. Biological species exploit similar variable shape principles to extend functionalities and facilitate locomotion in dynamic environments [7]. These benefits promoted research efforts in developing highly reconfigurable systems, including mobile robots [8], [9], [10]. ...
In this paper, we propose a novel design of a hybrid mobile robot with controllable stiffness and deformable shape. Compared to conventional mobile agents, our system can switch between rigid and compliant phases by solidifying or melting Field's metal in its structure and, thus, alter the shape through the motion of its active components. In the soft state, the robot's main body can bend into circular arcs, which enables it to conform to surrounding curved objects. This variable geometry of the robot creates new motion modes which cannot be described by standard (i.e., fixed geometry) models. To this end, we develop a unified mathematical model that captures the differential kinematics of both rigid and soft states. An optimised control strategy is further proposed to select the most appropriate phase states and motion modes needed to reach a target pose-shape configuration. The performance of our new method is validated with numerical simulations and experiments conducted on a prototype system. The simulation source code is available at
https://github.com/Louashka/2sr-agent-simulation.git</uri
... They can change their morphology in flight to the appropriate one. They present many advantages, such as helping firefighting units to assess faster and more safely, and they are required in cave discovery and infrastructure inspection [4,6]. Moreover, they prevent obstacle collisions [7,8]. ...
Controlling nonlinear systems is an important and serious task, especially in the presence of external disturbances and uncertain parameters. The main aim of this paper is to design a robust controller that ensures good trajectory tracking of a new quadrotor with rotating arms subjected to external disturbances. Before proceeding to the quadrotor control, it is necessary to first develop a dynamic model of the studied system that takes into account the variation of: the Center of Gravity (CoG), the inertia, and the allocation matrix. Then, based on the finite time Lyapunov stability theory, the theoretical basis of backstepping control integrated with disturbance observer is explained. The observer estimates online the external disturbances and compensates them in the internal loop that contains the attitude and the position backstepping controllers. Numerical simulations are performed to illustrate the efficiency of the proposed control technique, where the controller’s parameters are tuned using a Genetic Algorithm (GA). Finally, qualitative and quantitative comparison of the suggested controller with the conventional backstepping controller is carried out. Overall, the findings show that the proposed control technique outperforms in terms of accuracy and robustness.
... This new class of hybrid systems with adaptive morphology is primarily inspired by nature [6]. Biological species exploit similar variable shape principles to gain additional functionalities and facilitate locomotion in dynamic environments [7]. These benefits promoted research efforts in developing a new class of highly reconfigurable systems, including mobile robots [8]- [10]. ...
... Add ς[i * ] to Ω; Add υ[i * ] to V A sequence of 2SRA velocities returned by the Motion Planner is converted into the wheels' velocities by Wheel Drive defined by the model derived in (1)- (7). A sequence of VSSs' stiffness values is mapped to the temperature values that are required to either melt the Field's metal (taken with margin) for the soft state or to cool it down for the rigid state: ...
In this paper, we propose a novel design of a hybrid mobile robot with controllable stiffness and deformable shape. Compared to conventional mobile agents, our system can switch between rigid and compliant phases by solidifying or melting Field's metal in its structure and, thus, alter its shape through the motion of its active components. In the soft state, the robot's main body can bend into circular arcs, which enables it to conform to surrounding curved objects. This variable geometry of the robot creates new motion modes which cannot be described by standard (i.e., fixed geometry) models. To this end, we develop a unified mathematical model that captures the differential kinematics of both rigid and soft states. An optimised control strategy is further proposed to select the most appropriate phase states and motion modes needed to reach a target pose-shape configuration. The performance of our new method is validated with numerical simulations and experiments conducted on a prototype system. The simulation source code is available at the GitHub repository.
... Many studies addressed this issue by carefully considering the robot's embodiment [8], [9], [10]. Such robots exploit their natural dynamics by implementing adjustable impedance actuators [11], [12], soft materials [13], adaptive mechanisms [14], [15], and so on. ...
For robots to operate in real environments where humans live, they should be able to interact safely and adequately with humans and their surroundings due to the inevitability of physical contact in such unstructured environments. However, although this is a crucial and essential skill, it is still an unsolved problem in the robotics field. Modeling all the events in a real situation is impossible, and the necessity to have explicit models of the robot's body and the environment does not suit continuously changing conditions. Therefore, robots should have flexible bodies capable of producing proper spontaneous reactions to unexpected stimuli instead of having active control of every joint angle of the robot's body at all times. In this regard, this paper introduces the development of a prototype robot that utilizes the mechanical structure of its body to realize adaptable passive dynamics. The implemented mechanisms allow safe interactions with the robot, whether it is passively or actively actuated. Here, we demonstrate the mechanical design of the robot, validate its performance through two experiments of physical human-robot interaction, and discuss its potential advantages for future research.
