Self-reconfigurable multilegged robot swarms collectively accomplish challenging terradynamic tasks

Swarms of ground-based robots are presently limited to relatively simple environments, which we attribute in part to the lack of locomotor capabilities needed to traverse complex terrain. To advance the field of terradynamically capable swarming robotics, inspired by the capabilities of multilegged organisms, we hypothesize that legged robots consisting of reversibly chainable modular units with appropriate passive perturbation management mechanisms can perform diverse tasks in variable terrain without complex control and sensing. Here, we report a reconfigurable swarm of identical low-cost quadruped robots (with directionally flexible legs and tail) that can be linked on demand and autonomously. When tasks become terradynamically challenging for individuals to perform alone, the individuals suffer performance degradation. A systematic study of performance of linked units leads to new discoveries of the emergent obstacle navigation capabilities of multilegged robots. We also demonstrate the swarm capabilities through multirobot object transport. In summary, we argue that improvement capabilities of terrestrial swarms of robots can be achieved via the judicious interaction of relatively simple units.

Modeling and Analysis of a Modular Multilegged Robot with Improved Fault Tolerance and Environmental Adaptability

Multilegged robots can adapt to complex terrains, an ability that is highly important for their research and development. To improve the adaptability and fault tolerance of such robots, the modular design concept is applied by an increase in the number of modules. A modular multilegged robot contains a trunk with six modular leg structures that can be removed at will. The interface design of the trunk and legs can achieve good tightness and high strength, thereby ensuring quick disassembly and that the trunk and legs will not fall off while the robot walks. On this basis, the gait of a robot with different numbers of modular legs is designed. Then, kinematic and dynamic models of the robots with different gaits are established, and the motion performance, which provides reference for motion control and motor selection, is analyzed. Experiments show that the robot with different numbers of legs has good motion performance. This study serves as a useful reference for the design of modular multilegged robots.

Analysis and experiments on a novel smoothly moving low-DoF multilegged robot

SmooBot, a novel low-degree-of-freedom multilegged robot with a smoothly moving platform is proposed in the paper, which is aimed at helping people do the delivery jobs in the industrial site. Cam compensation mechanisms are applied to the robot so the platform keeps smoothly moving while the robot is walking. With the special design of the compensation mechanism, the height, velocity, and attitude of the platform almost keep constant. The motion input of the compensation mechanism shares the same continuous rotation with the mechanical legs and remain the compact structure. The cam mechanisms are designed based on the kinematics analysis of the mechanical legs. The walking simulations and prototype experiments are carried out to testify the theoretical analysis. Based on the simulation and experiment results, the enhancements of the compensation mechanisms in the platform smoothness and the energy efficiency are discussed. The study in the paper provides a new idea to enable a low-degree-of-freedom multilegged robot to have a smoothly moving platform and to carry heavy load at a high speed by using the cam compensation mechanisms.