Planar locomotion of earthworm-like metameric robots

Abstract

The goal of this research is to develop a generic earthworm-like locomotion robot model consisting of a large number of segments in series and based on which to systematically investigate the generation of planar locomotion gaits and their correlation with a robot’s locomotion performance. The investigation advances the state-of-the-art by addressing some fundamental but largely unaddressed issues in the field. These issues include (a) how to extract the main shape and deformation characteristics of the earthworm’s body and build a generic model, (b) how to coordinate the deformations of different segments such that steady-state planar locomotion can be achieved, and (c) how different locomotion gaits would qualitatively and quantitatively affect the robot’s locomotion performance, and how to evaluate them. Learning from earthworms’ unique morphology characteristics, a generic kinematic model of earthworm-like metameric locomotion robots is developed. Left/right-contracted segments are introduced into the model to achieve planar locomotion. Then, this paper proposes a gait-generation algorithm by mimicking the earthworm’s retrograde peristalsis wave, with which all admissible locomotion gaits can be constructed. We discover that when controlled by different gaits, the robot would exhibit four qualitatively different locomotion modes, namely, rectilinear, sidewinding, circular, and cycloid locomotion. For each mode, kinematic indexes are defined and examined to characterize their locomotion performances. For verification, a proof-of-concept robot hardware is designed and prototyped. Experiments reveal that with the proposed robot model and the employed gait controls, locomotion of different modes can be effectively achieved, and they agree well with the theoretical predictions.

Rapidly Exploring Random Tree Algorithm-Based Path Planning for Worm-Like Robot

“…As a result of these characteristics, the smoothness of acceleration has little impact on kinematics. A simpler and less costly path smoothing patterns [5]. To achieve such a goal, a modified rapidly exploring random tree (RRT) algorithm has been developed to form a feasible path from an initial position and orientation to a desired position and orientation.…”

“…Through this study, we are intending to develop and implement an efficient and robust path planning method for the CMMWorm-S robot as well as other robots following similar locomotion patterns [5]. To achieve such a goal, a modified rapidly exploring random tree (RRT) algorithm has been developed to form a feasible path from an initial position and orientation to a desired position and orientation.…”

“…patterns [5]. To achieve such a goal, a modified rapidly exploring random tree (RRT) algorithm has been developed to form a feasible path from an initial position and orientation to a desired position and orientation.…”

Mechanical Design and Simulation of a Water Pipes Cleaning Robot

“…In-pipe robots can be categorized into many forms based on patterns of movement, as shown in Figure 1 [13]. These categories are wheels [15], [16], track/caterpillar [17], [18], inchworm [19], [20], walking [21], [22], screw [23], [24] and pig [25] types based on their motion mechanisms [14]. The most widely spread categories are wheeled, inchworm, snake and legged.…”

Yoshimura-origami Based Earthworm-like Robot With 3-dimensional Locomotion Capability

“…For example, with three independent servomotor arms in each segment, Omori et al developed a four-segment earthworm-like robot that is able to turn on a plane surface and move upward/downward in a vertical pipe ( Omori et al, 2009 ). Similarly, via embedding more actuators into the robot, planar locomotion has also been verified to be feasible in the CMMWorm-S robot ( Kandhari et al, 2018 ), the metameric robot ( Zhan et al, 2019 ), and the Meshworm ( Seok et al, 2013 ). In these successful prototypes, antagonistic axial and radial deformations of the robot segment/part play an important role in achieving locomotion.…”