Obstacle-climbing Capability Research Articles

A transformable wheel-spoke-paddle hybrid amphibious robot

AbstractThe intricate water-land intermingled nature of wild environments necessitates robots to exhibit multimodal cross-domain mobility capabilities. This paper introduces a novel wheel-spoke-paddle hybrid amphibious robot (WSP-bot) that can operate on flat and rough terrains, water surfaces, and water-land transitional zones. The proposed robot relies on a propulsion mechanism called transformable wheel-spoke-paddle (WSP), which combines the stability of wheeled robots with the obstacle-climbing capability of legged robots, while also providing additional aquatic mobility. The utilization of a crank-slider-based transformation mechanism enables seamless switching between multiple motion modes. An analysis of mode transition and ground motion in spoke mode was conducted, along with an investigation of its obstacle-crossing capability. Simulations were performed for mode transition, ground locomotion, and obstacle-crossing, as well as propulsion of a single WSP module on water. Based on the above work, a prototype robot was manufactured. Prototype tests, including mode transition and mobility tests on land and water surfaces under multimodal states, confirmed the effectiveness of the proposed WSP-bot.

Tracked Locomotion Systems for Ground Mobile Robots: A Review

The paper discusses the state-of-the-art of locomotion systems for ground mobile robots comprising tracks. Tracked locomotion, due to the large contact surface with the ground, is particularly suitable for tackling soft, yielding, and irregular terrains, but is characterized by lower speed and energy efficiency than wheeled locomotion, and lower obstacle-climbing capability than legged locomotion. Therefore, in recent years academic and industrial researchers have designed a wide variety of hybrid solutions, combining tracks with legs and wheels. The paper proposes three possible parallel taxonomies, based on body architecture, track profile, and track type, to help designers select the most suitable architecture on the basis of the operative necessities. Moreover, modeling, simulation, and design methodologies for tracked ground mobile robots are recalled.

Design and analysis of a novel octopod platform with a reconfigurable trunk

In order to enhance the terrain mobility of the close-chain leg mechanism and maximize its advantages, a novel dual degree-of-freedom (DoF) octopod platform with a reconfigurable trunk is proposed. The walking strategy of the close-chain multi-legged mechanism is adjusted through the spatial close-chain trunk mechanism. These two single-DoF close-chain mechanisms are designed and coupled to constitute whole close-chain mechanism as the walking platform. The locomotion modes of the trunk are discussed with the mobility analysis. In steering mode, the motion characteristic is analyzed under the combined action of steering linkage and elastic deformation. In climbing mode, the kinematic analysis and dimensional optimization are carried out, and the obstacle-climbing ability is evaluated through the probability model. To enhance climbing smoothness and efficiency, the assisted appendage is developed with the inner loop of Watt-Ⅰ leg linkage. A series of dynamic simulations is conducted and analyzed to test the platform performance, and a prototype is fabricated to testify the walking speed, steering property and obstacle-climbing capability. This study provides a new reference for close-chain legged platform development.

Kinematic and Dynamic Analysis of a Cable-Climbing Robot

To inspect broken cables or a cracked protective layer on cable-stayed bridges, a cable-climbing robot has been proposed and designed. In this paper, the complex 3D obstacles that may be encountered on cables are theoretically described, in order to investigate the obstacle-climbing capability of the cable-climbing robot. A climbing model is then proposed and used to design the robot. In the climbing model, two driven wheels are independently supported with a spring. Kinematics and dynamics models are further derived for the obstacle-climbing capabilities of the driving and driven wheels of the robot. In addition, the robot's obstacle-climbing tracks and its obstacle-climbing performance are simulated. Payload and obstacle-climbing experiments were conducted on the climbing robot in the laboratory. Based on the results of the simulation and the experiments, we obtained the variation of the driving torque in obstacle climbing. The contribution of this paper is intended to provide a basis for the precise motion control of the robot.