中文摘要：

受自然界中变形虫和生物蛇启发，将可变形和链式构型特性引入两栖机器人。通过运动特性、水环境适应性和可变形能力扩展等综合分析，设计了没有添加额外水下推进机构的非叠加型两栖机器人链式可变形构型。该机器人在陆地环境具有较高机动性外，还具有履带划水和仿生划水组合的复合推进方式。提出基于理想推进器的履带划水推进模型；针对仿生划水时运动学与流体力的耦合关系，提出基于拉格朗日方程的运动学-动力学联合运动模型，并建立了转向模型，完成仿生推进方式的水中机动性能分析。通过仿真分析了履刺高度和分布等机构参数以及幅值、频率等运动参数对水下推进性能的影响。利用基于链式可变形构型研制的机器人样机Amoeba-II进行了水环境试验，验证该构型在水下推进中的有效性，并对履带划水和仿生划水的推进效率、稳定性进行对比。

英文摘要：

Inspired by amoebae and snake in the nature, the transformable capability and link-type structure is brought in an amphibious robot. The link-type transformable configuration without adding extra underwater propulsion mechanism is designed for an amphibious robot through analysis on the movement characteristics, extending on the water environment adaptability and transformable ability, which has crawler-swimming propulsion mode and the bionic propulsion mode. The model of the crawler-swimming propulsion mode is established based on the ideal propeller. Aiming at the coupling relationship between the kinematics and fluid force in the fish-like propulsion mode, the associated model on the kinematics and dynamics is put forward based on the Lagrange equation. Together with the steering model, the motion performance of the bionic propulsion is analyzed. The simulation demonstrates the influence of the mechanism parameters such as height and distribution of the track grouser and motion parameters such as amplitude and frequency on the underwater propulsion. The experiments in the water environment performed on the robot prototype Amoeba-II verify the effectiveness of the amphibious link-type transformable configuration, and compare the propulsion efficiency and stability between crawler-swimming propulsion mode and the bionic propulsion mode.