Soft Robotic Snake with Variable Stiffness Actuation (original) (raw)
Related papers
Design, fabrication and experimental analysis of a 3-D soft robotic snake
2018 IEEE International Conference on Soft Robotics (RoboSoft), 2018
Snake robots are an emerging approach for navigating complicated and constrained environments. While existing snake robots rely on traditional articulated joints, we have been investigating the use of soft robotic modules which can allow for better compliance with the environment. In this article we present the first soft-material snake robot capable of non-planar locomotion. We performed experiments on the modules that make up the snake robot to determine the ideal material, settling on Ecoflex 0050. Combining 4 modules into the full soft snake, we performed locomotion experiments using both serpentine and sidewinding gaits. We determined that its maximum speed under serpentine locomotion was 131.6 mm/s (0.25 body lengths per second) while under sidewinding it was 65.2 mm/s (0.12 body lengths per second). Finally, we tested these gaits on other surfaces and found that the sidewinding could move more reliably on different surfaces.
2019 5th International Conference on Control, Automation and Robotics (ICCAR)
Even though a few examples of elastic snake robots exist, they are generally expensive and tailored to custom-made hardware/software components that are not openly available. In this work, Serpens, a newly-designed low-cost, open-source and highly-compliant modular snake robot with series elastic actuator (SEA) is presented. Serpens features precision torque control and stereoscopic vision. Only low-cost commercial-off-the-shelf (COTS) components are adopted. The robot modules can be 3Dprinted by using Fused Deposition Modelling (FDM) manufacturing technology, thus making the rapid-prototyping process very economical and fast. A screw-less assembly mechanism allows for connecting the modules and reconfigure the robot in reliable and robust manner. By using a low-cost sensing approach, functions for torque sensing at the joint level, sensitive collision detection and joint compliant control are possible. The concept of modularity is also applied to the system architecture on both the software and hardware sides. The software architecture is based on the Robot Operating System (ROS). This paper describes the design of Serpens and presents preliminary simulation and experimental results which illustrate its potential.
The Redesigned Serpens, a Low-Cost, Highly Compliant Snake Robot
Robotics, 2022
The term perception-driven obstacle-aided locomotion (POAL) was proposed to describe locomotion in which a snake robot leverages a sensory-perceptual system to exploit the surrounding operational environment and to identify walls, obstacles, or other structures as a means of propulsion. To attain POAL from a control standpoint, the accurate identification of push-points and reliable determination of feasible contact reaction forces are required. This is difficult to achieve with rigidly actuated robots because of the lack of compliance. As a possible solution to this challenge, our research group recently presented Serpens, a low-cost, open-source, and highly compliant multi-purpose modular snake robot with a series elastic actuator (SEA). In this paper, we propose a new prototyping iteration for our snake robot to achieve a more dependable design. The following three contributions are outlined in this work as a whole: the remodelling of the elastic joint with the addition of a damp...
Design and Development of Snake Inspired Robot
Snake-inspired robot is a promise in potential areas of search, rescue and inspection. There are several specific issues to be addressed through analysis for designing it better for deriving comprehensive utility and effectiveness. This project tries to develop a modular snake with repetitive modules by using a single motor to propel one unit of four modules. This aim is achieved by developing a link mechanism to produce a snake-like motion. The modules are connected together using hinged joints. Moreover, a vault mechanism was developed for the snake robot to negotiate small objects on its path. The vault mechanism is connected to a control system consisting of microcontroller and IR sensor for the purpose of actuating the motor on detection of the object in front of the robot. The whole assembly is powered by lead-acid battery. Apart from designing and developing the snake-inspired robot, its performance characteristics were determined and the robot was successfully tested for its capability to traverse through plane surface in a snake-like fashion as well as its ability to negotiate objects of heights up to 150 mm. Future improvisations that can be done to better the capabilities of the robot are also attempted to describe briefly.
Development of Tough Snake Robot Systems
Springer Tracts in Advanced Robotics, 2019
In the Tough Snake Robot Systems Group, a snake robot without wheels (nonwheeled-type snake robot) and a snake robot with active wheels (wheeled snake robot) have been developed. The main target applications of these snake robots are exploration of complex plant structures, such as the interior and exterior of pipes, debris, and even ladders, and the inspection of narrow spaces within buildings, e.g., roof spaces and underfloor spaces, which would enable plant patrol and inspection. At the head of each robot, a compact and lightweight gripper is mounted to allow
Motion Planning and Iterative Learning Control of a Modular Soft Robotic Snake
Frontiers in Robotics and AI, 2020
Snake robotics is an important research topic with a wide range of applications, including inspection in confined spaces, search-and-rescue, and disaster response. Snake robots are well-suited to these applications because of their versatility and adaptability to unstructured and constrained environments. In this paper, we introduce a soft pneumatic robotic snake that can imitate the capabilities of biological snakes, its soft body can provide flexibility and adaptability to the environment. This paper combines soft mobile robot modeling, proprioceptive feedback control, and motion planning to pave the way for functional soft robotic snake autonomy. We propose a pressure-operated soft robotic snake with a high degree of modularity that makes use of customized embedded flexible curvature sensing. On this platform, we introduce the use of iterative learning control using feedback from the on-board curvature sensors to enable the snake to automatically correct its gait for superior loc...
Design and control of a snake robot according to snake anatomy
… , 2008. ICCCE 2008. …, 2008
Serpentine robots are multi-segmented vehicles. Based on their physical structure and design, these robots could have great mobility in their movements. This mobility can enable the robot to move around in more complex environments. The application of these kind of robots could be very useful in hard to reach places or hazardous environments. In this paper we investigated and implemented a serpentine robot. Inspired from snake motion, we implemented the structure of our robot based on the snakepsilas physical mechanism. In spite of most designed snake robots, our robot makes use of the friction between the body of the robot and the environment it encompasses to move in. This kind of movement requires a considerable amount of accuracy and synchronization among all segments. For this purpose we utilized a master and slave routine. The master is located in the head of the snake and is able to change each of the slaves status located in every segment of the snake according to the snakepsilas controlling algorithm and the feedback signals received from each slave unit. The communications to these segments are accomplished by the serial interface of the micro-controllers located in each segment. The joints between each neighboring segment are constructed of an elastic rubber and a cord, similar to the body structure of a real snake. The relative movements of the neighboring segments are the result of the wrapping and unwrapping of this cord. Utilizing this cord system, we obtained 3-degree-of freedom joints which enable the snake to move in any desired direction.
Snake robot locomotion in a cluttered environment where the snake robot utilises a sensory-perceptual system to perceive the surrounding operational environment for means of propulsion is defined as perception-driven obstacle-aided locomotion (POAL). From a control point of view, achieving POAL with traditional rigidly-actuated robots is challenging because of the complex interaction between the snake robot and the immediate environment. To simplify the control complexity, compliant motion and fine torque control on each joint is essential. Accordingly, intrinsically elastic joints have become progressively prominent over the last years for a variety robotic applications. Commonly, elastic joints are considered to outperform rigid actuation in terms of peak dynamics, robustness, and energy efficiency. Even though a few examples of elastic snake robots exist, they are generally expensive to manufacture and tailored to custom-made hardware/software components that are not openly available off-the-shelf. In this work, Serpens, a newly-designed low-cost, open-source and highly-compliant multipurpose modular snake robot with series elastic actuator (SEA) is presented. Serpens features precision torque control and stereoscopic vision. Only low-cost commercial-off-the-shelf (COTS) components are adopted. The robot modules can be 3D-printed by using Fused Deposition Modelling (FDM) manufacturing technology, thus making the rapid-prototyping process very economical and fast. A screw-less assembly mechanism allows for connecting the modules and reconfigure the robot in a very reliable and robust manner. The concept of modularity is also applied to the system architecture on both the software and hardware sides. Each module is independent, being controlled by a self-reliant controller board. The software architecture is based on the Robot Operating System (ROS). This paper describes the design of Serpens and presents preliminary simulation and experimental results, which illustrate its performance.
Bioinspiration & biomimetics, 2015
Soft robotic snakes promise significant advantages in achieving traveling curvature waves with a reduced number of active segments as well as allowing for safe and adaptive interaction with the environment and human users. However, current soft robot platforms suffer from a lack of accurate theoretical dynamic models and proprioceptive measurements, which impede advancements toward full autonomy. To address this gap, this paper details our recent results on the design, fabrication, and experimental evaluation of a new-generation pressure-operated soft robotic snake platform we call the WPI SRS, which employs custom magnetic sensors embedded in a flexible backbone to continuously monitor the curvature of each of its four bidirectional bending segments. In addition, we present a complete and accurate dynamic undulatory locomotion model that accounts for the propagation of frictional moments to describe linear and rotational motions of the SRS. Experimental studies indicate that on-boa...
Two new design concepts for snake robot locomotion in unstructured environments
Paladyn, 2010
This communication presents and justifies ideas related to motion control of snake robots that are currently the subject of ongoing investigations by the authors. In particular, we highlight requirements for intelligent and effcient snake robot locomotion in unstructured environments, and subsequently we present two new design concepts for snake robots that comply with these requirements. The first design concept is an approach for sensing environment contact forces, which is based on measuring the joint constraint forces at the connection between the links of the snake robot. The second design concept involves allowing the cylindrical surface of each link of a snake robot to rotate by a motor inside the link in order to induce propulsive forces on the robot from its environments. The paper details the advantages of the proposed design concepts over previous snake robot designs.