Serpentine Robot Research Articles

Memristive Circuit Implementation of Caenorhabditis Elegans Mechanism for Neuromorphic Computing.

To overcome the energy efficiency bottleneck of the von Neumann architecture and scaling limit of silicon transistors, an emerging but promising solution is neuromorphic computing, a new computing paradigm inspired by how biological neural networks handle the massive amount of information in a parallel and efficient way. Recently, there is a surge of interest in the nematode worm Caenorhabditis elegans (C. elegans), an ideal model organism to probe the mechanisms of biological neural networks. In this article, we propose a neuron model for C. elegans with leaky integrate-and-fire (LIF) dynamics and adjustable integration time. We utilize these neurons to build the C. elegans neural network according to their neural physiology, which comprises: 1) sensory modules; 2) interneuron modules; and 3) motoneuron modules. Leveraging these block designs, we develop a serpentine robot system, which mimics the locomotion behavior of C. elegans upon external stimulus. Moreover, experimental results of C. elegans neurons presented in this article reveals the robustness (1% error w.r.t. 10% random noise) and flexibility of our design in term of parameter setting. The work paves the way for future intelligent systems by mimicking the C. elegans neural system.

Neural Simulation of Actions for Serpentine Robots.

The neural or mental simulation of actions is a powerful tool for allowing cognitive agents to develop Prospection Capabilities that are crucial for learning and memorizing key aspects of challenging skills. In previous studies, we developed an approach based on the animation of the redundant human body schema, based on the Passive Motion Paradigm (PMP). In this paper, we show that this approach can be easily extended to hyper-redundant serpentine robots as well as to hybrid configurations where the serpentine robot is functionally integrated with a traditional skeletal infrastructure. A simulation model is analyzed in detail, showing that it incorporates spatio-temporal features discovered in the biomechanical studies of biological hydrostats, such as the elephant trunk or octopus tentacles. It is proposed that such a generative internal model could be the basis for a cognitive architecture appropriate for serpentine robots, independent of the underlying design and control technologies. Although robotic hydrostats have received a lot of attention in recent decades, the great majority of research activities have been focused on the actuation/sensorial/material technologies that can support the design of hyper-redundant soft/serpentine robots, as well as the related control methodologies. The cognitive level of analysis has been limited to motion planning, without addressing synergy formation and mental time travel. This is what this paper is focused on.

Design and Kinematics Analysis of Tensioning Integral Robot

In the past two decades, the technology of robots has developed rapidly. With the enrichment of social needs and applications, the functions of robots have become diversified. The tension-integrated robot designed in this paper is based on the British OC Robotics Series II X125 robot for mechanism design. The mathematical model of the tension-integrated robot is derived, and the kinematic simulation is carried out by Adams and Matlab to verify the correctness of the mathematical model, and the kinematic analysis of the tension-integrated robot is carried out. Firstly, the development and research status of tensioning integral robot is briefly summarized. Because the shape of the tensioning integral robot designed in this paper is similar to that of a snake, the development, structural characteristics and research status of the snake robot are summarized. Secondly, according to the application requirements of the tensioned integral robot, the functions and performance indexes of the tensioned integral robot are analyzed, and the overall structure of the tensioned integral robot is designed, including the body structure of the snake robot, the driving mechanism and the base. The serpentine arm of the serpentine robot is a serpentine structure with twelve joints connected in series. Finally, the mathematical model of the snake robot is derived, and the kinematic simulation of the snake robot is carried out by Adams and Matlab respectively. The obtained image results are the same, which proves that the mathematical model of the snake robot is correctly derived, laying a foundation for further research.

Design and architecture of a slender and flexible underwater robot

This paper presents the design and analysis of a biomimetic underwater snake-like robot, addressing the main limitations of current underwater robotic systems in terms of maneuverability and adaptability in complex environments. The innovative design incorporates flexible joint modules that significantly enhance the robot’s ability to navigate through narrow and irregular terrains, which is a notable limitation in traditional rigidly connected underwater robots. These flexible joints provide increased degrees of freedom and enable the robot to absorb and release energy, ensuring stability even under external impacts, thus extending the operational lifespan of the robot. Finite element analysis demonstrates the flexible joints’ superior performance in various underwater conditions, offering a greater range of motion and workspace compared to rigid connections. The results indicate that the robot’s modular design, combined with the flexible joint module, leads to improved agility and maneuverability, allowing for precise and intentional operation. The control module, equipped with advanced sensors and a CPU, manages the complex dynamics introduced by the flexible joints, ensuring effective navigation and operation. The specific advantages of this design include the robot’s enhanced structural integrity, its ability to conform to irregular surfaces, and its adaptability to environmental variations. The paper concludes with a discussion on the implications of these findings for the future design and operation of underwater serpentine robots, emphasizing the need for a balance between the effects of elastic modulus and workspace to maximize the benefits of flexible joints.

Reimagining robotic surgical precision: Reinforcement learning in swimmer-v1 environments

The current study focuses on how reinforcement learning algorithms tackle complex tasks, specifically analyzing the Swimmer-v1 environment with the reassembly of a serpentine robot in robotic surgeries. Herein, the review pays close attention to two algorithms- Proximal Policy Optimization (PPO) and Deep Deterministic Policy Gradients (DDPG)- focusing on exploration strategies in the Swimmer-v1 environment. Of particular importance here is the mentioning of the fact that the scope of exploration includes the use of parameter noise. Findings show that the DDPG learning algorithm faces outstanding difficulties with local maxima convergence. PPO emerged as the first in terms of algorithm category studied despite continuing issues of high variance. The use of a novel method which consists of tempering the range of variation of standard deviation in action noise gives promising results and can be a road to future improvement and exploration. The study provides a critical understanding of the underlying complexities that may lie hidden within the existing reinforcement learning algorithms. It brings up for repair weak points, particularly in the development of exploration capabilities and convergence stabilities.

Mathematical Modeling of Robotic Locomotion Systems

This article deals with the presentation of an alternative approach that uses methods of geometric mechanics, which allow one to see into the geometrical structure of the equations and can be useful not only for modeling but also during the design of symmetrical locomotion systems and their control and motion planning. These methods are based on extracting the symmetries of Lie groups from the locomotion system in order to simplify the resulting equations. In the second section, the special two-dimensional Euclidean group SE2 and its splitting into right and left actions are derived. The physical interpretation of the local group and spatial velocities is investigated, and by virtue of the fact that both of these velocities represent the same velocity from a physical point of view, the dependence between them can be found by means of the adjoint action. The third section is devoted to the modeling and analysis of the planar locomotion of the symmetrical serpentine robot; the positions and local group velocities of its links are derived, the vector fields for the local connections are given, and the trajectories of the individual variables in the lateral movement of the kinematic snake are shown. At the end of the article, the overall benefits of the scientific study are summarized, as is the comparison of the results from the simulation phase, while the most significant novelty compared to alternative publications in the field can be considered the realization of this study with a description of the relevant methodology at a detailed level; that is, the locomotion results confirm the suitability of the use of geometric mechanics for these symmetrical locomotion systems with nonholonomic constraints.

Path Planning and Navigation of Miniature Serpentine Robot for Bronchoscopy Application.

The miniature serpentine robot can be applied to NOTES (Natural Orifice Transluminal Endoscopic Surgery). In this paper, a bronchoscopy application is addressed. This paper describes the basic mechanical design and control scheme of this miniature serpentine robotic bronchoscopy. In addition, off-line backward path planning and real-time and in situ forward navigation in this miniature serpentine robot are discussed. The proposed backward-path-planning algorithm utilizes the 3D model of a bronchial tree constructed from the synthetization of medical images such as images from CT (Computed Tomography), MRI (Magnetic Resonance Imaging), or X-ray, to define a series of nodes/events backward from the destination, for example, the lesion, to the original starting point, for example, the oral cavity. Accordingly, forward navigation is designed to make sure this series of nodes/events shall be passed/occur from the origin to the destination. This combination of backward-path planning and forward navigation does not require accurate positioning information of the tip of the miniature serpentine robot, which is where the CMOS bronchoscope is located. Collaboratively, a virtual force is introduced to maintain the tip of the miniature serpentine robot at the center of the bronchi. Results show that this method of path planning and navigation of the miniature serpentine robot for bronchoscopy applications works.

Snake Robots for Surgical Applications: A Review

Although substantial advancements have been achieved in robot-assisted surgery, the blueprint to existing snake robotics predominantly focuses on the preliminary structural design, control, and human–robot interfaces, with features which have not been particularly explored in the literature. This paper aims to conduct a review of planning and operation concepts of hyper-redundant serpentine robots for surgical use, as well as any future challenges and solutions for better manipulation. Current researchers in the field of the manufacture and navigation of snake robots have faced issues, such as a low dexterity of the end-effectors around delicate organs, state estimation and the lack of depth perception on two-dimensional screens. A wide range of robots have been analysed, such as the i2Snake robot, inspiring the use of force and position feedback, visual servoing and augmented reality (AR). We present the types of actuation methods, robot kinematics, dynamics, sensing, and prospects of AR integration in snake robots, whilst addressing their shortcomings to facilitate the surgeon’s task. For a smoother gait control, validation and optimization algorithms such as deep learning databases are examined to mitigate redundancy in module linkage backlash and accidental self-collision. In essence, we aim to provide an outlook on robot configurations during motion by enhancing their material compositions within anatomical biocompatibility standards.

Revealing the Mechanical Characteristics via Kinematic Wave Model for Snake-Like Robot Executing Exploration of Lunar Craters

It is extremely difficult to collect deep lunar soil samples during lunar exploration, as the average thickness of lunar soils is very large, and the power of lunar soil sampling systems is inherently limited. In this paper, we propose the use of serpentine robots to explore lunar craters. Our approach is to first design a kinematic wave model that allows the serpentine robot to satisfy all the requirements of lunar exploration. The resistance encountered by each part of the robot during its motions was measured to identify the parts with the greatest influence on each mode of locomotion to maximize its locomotive efficiency. Accordingly, we have designed a serpentine robot system based on the characteristics of snakes and constructed a kinematic model for serpentine robots in lunar crater environments. In addition, we constructed a lunar soil model using a discrete element method-multibody dynamics co-simulation platform, thus optimizing the locomotion strategy of the robot. The EDEM-ADAMS co-simulation platform was used to simulate the motions of the serpentine robot in a lunar crater, which yielded the resistance, speed of motion, and displacement of the robot’s modules during its motions. The optimization analysis of the motion and environmental parameters of the serpentine robot included three variables: the inclination of the lunar crater’s walls, the crawling angle of the robot, and the amplitude of the robot’s kinematic wave. The dependence of the motions of the serpentine robot on these variables was analyzed using maximum and averaged force values. Finally, validation experiments were performed using a serpentine robot model. Thus, we have optimized the locomotion strategy of the serpentine robot for lunar craters.

Design of a soft serpentine robot with tri-tube soft actuators

Design of a soft serpentine robot with tri-tube soft actuators

ImPACTタフ・ロボティクス・チャレンジ

ImPACT Tough Robotics Challenge is a research project of Japan Cabinet Office which aims at creating disruptive disaster robotics that has enough robustness under extreme environment of disaster situations. Five types of robot platforms, i.e. aerial vehicles, cyber rescue canine, construction robots, serpentine robots and legged robots, are being developed as well as various component technologies of sensing, actuation, robot intelligence and human interface. Research fruits are evaluated at test fields twice a year at the ImPACT-TRC Field Evaluation Meetings. It helps researchers, makers and users communicate each other to promote technical innovation as well as social innovation by implementation of robotics systems, and industrial innovation by creation of new business and services. At the November Meeting in 2016, a construction robot with high control precision, teleoperation with feedback of force and touch, visual support from arbitrary point of views, and a far-infrared camera for handling hidden objects by smoke, was demonstrated. Thin serpentine robots showed high mobility in rubble piles with integration of feedback of image, sound and touch. Cyber canine showed that a cyber suit could monitor dog's motion and find things left behind.

Design and Prototyping of a Biomimetic Serpentine Robot

Objectives: In this study, a mechanism for a biomimetic serpentine robot is designed and tested. Methods/Analysis: A field survey was conducted to notice various parameters of snakes like their locomotion patterns, sizes, shape, speed, etc. Based on the observations and other important design considerations a mechanism was designed consisting of components analogous to that of snake’s anatomy. As the prototype would consist of abundant segments, analysis and simulation of a single segment was performed to validate the mechanism. After validation, the prototype was manufactured, controlled and tested. Findings: Although, there had been snake robots developed in the past, none of bot could depict the natural curve of snake’s locomotion. The bots are modular i.e. consists of abundant modules connected to each other by rigid rotating joints which disallows them to perform the perfect curve of snake. Novelty/Improvement: The mechanism developed in this study overcomes the drawbacks of previous models and hence is able to depict the serpenoid curve with maximum accuracy providing a real life curve of snake. The first prototype is cheap to manufacture and further improvement could really prove promising hypothesis.

Dynamic Modeling and Simulation of a Yaw-Angle Quadruped Maneuvering With a Planar Robotic Tail

This paper analyzes the impact a planar robotic tail can have on the yaw-angle maneuvering of a quadruped robot. Tail structures ranging from a one degree-of-freedom (1DOF) pendulum to a 6DOF serpentine robot are simulated, along with a quadruped model that accounts for ground contact friction. Tail trajectory generation using split-cycle frequency modulation is used to improve net quadruped rotation due to the tail's motion. Numerical results from the tail and quadruped models analyze the impact of trajectory factors and tail structure on the net quadruped rotation. Results emphasize the importance of both tangential and centripetal tail loading for tail trajectory planning and show the benefit of a multi-DOF tail.

Design for 1:2 Internal Resonances in In-Plane Vibrations of Plates With Hyperelastic Materials

With advances in technology, hyperelastic materials are seeing use in varied applications ranging from microfluidic pumps, artificial muscles to deformable robots. Development of such complex devices is leading to increased use of hyperelastic materials in the construction of components undergoing dynamic excitation such as the wings of a micro-unmanned aerial vehicle or the body of a serpentine robot made of hyperelastic polymers. Since the strain energy potentials of various hyperelastic material models have nonlinearities present in them, exploration of their nonlinear dynamic response lends itself to some interesting consequences. In this work, a structure made of a Mooney–Rivlin hyperelastic material and undergoing planar vibrations is considered. Since the Mooney–Rivlin material's strain energy potential has quadratic nonlinearities, a possibility of 1:2 internal resonance is explored. A finite element method (FEM) formulation implemented in Matlab is used to iteratively modify a base structure to get its first two natural frequencies close to the 1:2 ratio. Once a topology of the structure is achieved, the linear mode shapes of the structure can be extracted from the finite element analysis, and a more complete nonlinear Lagrangian formulation of the hyperelastic structure can be used to develop a nonlinear two-mode dynamic model of the structure. The nonlinear response of the structure can be obtained by application of perturbation methods such as averaging on the two-mode model. It is shown that the nonlinear strain energy potential for the Mooney–Rivlin material makes it possible for internal resonance to occur in such structures. The effect of nonlinear material parameters on the dynamic response is investigated.

Serpentine Robot Model and Gait Design Using Autodesk Inventor and Simulink SimMechanics

The authors introduce gaits of a serpentine robot with linear expansion mechanism where the robot varies its length using joints with three degrees of freedom. The 3D model of the serpentine robot is drawed in Autocad Inventor ® and exported to SimMechanics ® for straighforward modeling of the kinematics. The gaits are important for robots designed to explore ruins of disasters where the working spaces are very tight. For maximum flexibility of the serpentine robot, we adopted a joint design with three parallel actuators, where the joint is capable of linear movement in the forward axis, and rotational movements around two other axes. The designed linear expansion gaits is calculated for forward movement when the robot is posing straight or turning laterally.

Developing Serpentine Robot Control to use Lateral Affordances

This paper describes the unique challenges in developing control of complex lateral movements needed by a serpentine robot to ascend steep slopes by climbing over and around affordances/obstacles on the slope. The research extends previous serpentine robot work developing control of sagittal movements for climbing up stairs and over uneven parallel bars. Effective lateral control was developed using an iterative combination of learning, a genetic algorithm, and developer programming. The robot's many simultaneous movements were controlled mostly as a function of very local sensory inputs and little centralized coordination.

Design and Analysis of a Bio-Inspired Wire-Driven Multi-Section Flexible Robot

This paper presents a bio-inspired wire-driven multi-section flexible robot. It is inspired by the snake skeleton and octopus arm muscle arrangements. The robot consists of three sections and each section is made up of several identical vertebras, which are articulated by both spherical joints and a flexible backbone. Each section is driven by two groups of wires, controlling the bending motion in X and Y directions. This design integrates the serpentine robots' structure and the continuum robots' actuation. As a result, it is more compact than traditional serpentine robots and has a higher positioning accuracy than typical continuum soft robots, such as OctArm V. A Kinematics model and a workspace model of the robot are developed based on the piece wise constant curvature assumption. To evaluate the design, a prototype is built and experiments are carried out. The average distal end positioning error is less than 4%. Characteristics of the wire-driven robot are also discussed, including the leverage effect and the manipulability under constraint. These features makes the proposed robot well suited to confined spaces, especially for working in minimally invasive surgery, nuclear reactor pipelines, disaster debris, etc.

Implementation of serpentine locomotion

Cyclic changes in the body shape (body undulation) allow a serpent to locomote. These body undulations are most often 3D in nature and can be considered as combinations of two body waves on two orthogonal planes passing through a snake's body. This may be termed as Serpentine Shape Function (SSF). In case of an articulated serpentine robot these body waves are functions of joint orientations. This paper presents a detailed study on limbless locomotion and proposes a new concept of Coupled Orthogonal Joint Orientation Function (COJOF) and its implementation on an articulated serpentine robot. These gaits are not only inspired by snake locomotion but also can be extended to mimic other interesting gaits such as that of a caterpillar, inchworm and some synthetic gaits. These issues have been critically examined through experimental serpentine robot specially designed and extensively used for validation.

Development of a serpentine omnitread robot for searching in explosive gas atmospheres

PurposeThere is explosive gas in many disaster environments. The conventional search and rescue robots are not allowed to work in these environments, since they may cause explosion. The purpose of this paper is to describe the design and development of the serpentine omnitread robot HITSR‐I for working in these areas.Design/methodology/approachHITSR‐I consists of four segments, and each segment is equipped with crawlers in the four directions. It can be operated even under the situation of sideslip without any recovering actions. There are pressed CO2 containers and the pressurized control system inside the robot, and the shells of the robot are a fully sealed up structure. They can maintain the inside pressure higher than the outside. The robot can release the communication relay node to extend the communicating area, so it can search a large area even amid rubble.FindingsHITSR‐I was developed with the capability of climbing over 400 mm high obstacles. The maximum travel distance was 315 m. The pressurized system could enable the robot to work in Zones 1 and 2.Originality/valueDesign and development of a serpentine robot which can work in hazardous areas containing explosive gas. It can travel for a long distance in ruins by releasing the communication relay nodes.

Obstacles Perception for Serpentine Robot Based on Optical Flow Modules and Multi-Sensor Fusion

To move efficiently in an unknown environment, a mobile robot must use observations taken by various sensors to detect obstacles. This paper describes a new approach to detect obstacles for serpentine robot. It captures the image sequence and analyzed the optical flow modules to estimate the deepness of the scene. This avoids one or higher order differential in the traditional optical flow calculation. The data of ultrasonic sensor and attitude transducer sensor are fused into the algorithm to improve the real-time capability and the robustness. The detecting results are presented by fuzzy diagrams which is concise and convenient. Indoor and outdoor experimental results demonstrate that this method can provide useful and comprehensive environment perception for the robot.