Continual Learning for Addressing Optimization Problems with a Snake-Like Robot Controlled by a Self-Organizing Model

We have entered a new era, “Industry 4.0”, that sees the overall industry marching toward an epoch of man–machine symbiosis and intelligent production. The developers of so-called “intelligent” systems must attempt to seriously take into account all possible situations that might occur in the real world, to minimize unexpected errors. By contrast, biological systems possess comparatively better “adaptability” than man-made machines, as they possess a self-organizing learning that plays an indispensable role. The objective of this study was to apply a malleable learning system to the movement control of a snake-like robot, to investigate issues related to self-organizing dynamics. An artificial neuromolecular (ANM) system previously developed in our laboratory was used to control the movements of an eight-joint snake-like robot (called Snaky). The neuromolecular model is a multilevel neural network that abstracts biological structure–function relationships into the system’s structure, in particular into its intraneuronal structure. With this feature, the system possesses structure richness in generating a broad range of dynamics that allows it to learn how to complete the assigned tasks in a self-organizing manner. The activation and rotation angle of each motor are dependent on the firing activity of neurons that control the motor. An evolutionary learning algorithm is used to train the system to complete the assigned tasks. The key issues addressed include the self-organizing learning capability of the ANM system in a physical environment. The experimental results show that Snaky was capable of learning in a continuous manner. We also examined how the ANM system controlled the angle of each of Snaky’s joints, to complete each assigned task. The result might provide us with another dimension of information on how to design the movement of a snake-like robot.

Immobilization-Based Control of Spider-Like Robots in Tunnel Environments

This paper presents an immobilization-based control method for spider-like robots that move quasi-statically in tunnel environments. The control method is based on a recent immobilization theory of bodies in contact. This theory ensures that when a spider-like mechanism is bracing against the environment at an immobile posture, the naturally occurring compliance at the contacts stabilizes the mechanism as a single body. Based on this result, we present two versions of a position control law for general k-limbed robots. We show that if the controller’s stiffness (i.e., proportional gain) is above a lower limit determined by the robot and environment parameters, stability of the closed-loop spider system is guaranteed. Next, we present dynamic simulations of a spider robot moving in a tunnel under the influence of the immobilization-based control law. The simulations show excellent convergence properties of the control algorithm. A four-legged spider prototype has been built, and we conclude with a description of initial experiments with this prototype.

Engineering observation of lateral undulation in colubrid snakes for wheel-less locomotion

Nature has always inspired engineers. This research tries to understand the contribution of snake anatomy in its locomotion from engineering point of view to be adopted in the design of snake robots. Rib design and muscular structure of snake robots will have a great impact on snake robot flexibility, weight, and actuators' torque. It will help to eliminate wheels in snake robots during serpentine locomotion. The result of this research shows that snakes can establish the required peg points on smooth surfaces by deflecting the body and ribs. The results are verified by both field observations and simulation.

A survey of snake-inspired robot designs

Body undulation used by snakes and the physical architecture of a snake body may offer significant benefits over typical legged or wheeled locomotion designs in certain types of scenarios. A large number of research groups have developed snake-inspired robots to exploit these benefits. The purpose of this review is to report different types of snake-inspired robot designs and categorize them based on their main characteristics. For each category, we discuss their relative advantages and disadvantages. This review will assist in familiarizing a newcomer to the field with the existing designs and their distinguishing features. We hope that by studying existing robots, future designers will be able to create new designs by adopting features from successful robots. The review also summarizes the design challenges associated with the further advancement of the field and deploying snake-inspired robots in practice.

A survey on snake robot modeling and locomotion

Snake robots have the potential to make substantial contributions in areas such as rescue missions, firefighting, and maintenance where it may either be too narrow or too dangerous for personnel to operate. During the last 10–15 years, the published literature on snake robots has increased significantly. The purpose of this paper is to give a survey of the various mathematical models and motion patterns presented for snake robots. Both purely kinematic models and models including dynamics are investigated. Moreover, the different approaches to biologically inspired locomotion and artificially generated motion patterns for snake robots are discussed.

Colonoscopy: new designs for the future

The main purpose of this article is to outline various devices of varying practicality that have been described that might allow the examination of the colon by other means. These methods include tip propulsion by various methods, robotics, wireless endoscopy, free capsule endoscopy, specialized overtube use, and toposcopy.