A kinematics analysis of a biologically-inspired biped robot is carried out, and the trajectory of the robot foot is understood. For calculating the pressure distribution across a robot foot before touching the surface of water, the compression flow of air and the depression motion of the water surface are considered. The pressure model after touching the water surface has been built according to the theory of rigid body planar motion. The multi-material ALE algorithm is applied to emulate the course of the foot slapping water. The simulation results indicate that the model of the bionic robot can satisfy the water-running function. The real prototype of the robot is manufactured to test its function of running on water. When the biped robot is running on water, the average force generated by the propulsion mechanism is about 1.3N. The experimental results show that the propulsion system can satisfy the requirement of biped robot running on water.
Aerostatic bearings are the core parts of ultra-high-speed spindles with maximum running speed greater than 100,000 r/min. In this paper, the influences of herringbone grooves on the performance of aerostatic journal bearings are studied to design spindles with the features of higher precision and higher speed. Parametric studies and sensitivity analyses are executed in terms of the improved finite element method, which is specially developed to solve the compressible Reynolds equation for herringbone grooved air bearings. The calculated results indicate that herringbone grooves significantly improve the performance of aerostatic journal bearings under the conditions of ultra-high speeds and low supply pressures. Groove parameters are nonlinear dependent, and groove depth and length are the dominant influential factors for the load capacity at speed of 200,000 r/min. Experiments are designed and conducted to verify the improved finite element method, which show that the improved finite element method can be used to analyze the influences of herringbone grooves on aerostatic journal bearings and also manifest that suitable herringbone groove geometrical parameters can obviously decrease spindle radial runouts at ultra-high speeds.
A novel biped robot inspired by basilisk lizards is designed to simulate the water-running function. The kinematic analysis of the running-mechanism is brought out to get the movement equations of the mechanism, and the numerical simulation results show that the feet trajectories of the robot are similar to basilisk lizards. For calculating the pressure distribution on a robot foot before touching water surface, the compression flow of air and depression motion of water surface are considered. The calculating model after touching water surface has been built according to the theory of the plane motion of a rigid body. The multi-material ALE algorithm is applied to emulate the course of the foot slapping water. Numerical simulation results indicate that the model of the bionic robot can satisfy the water-running function.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.