The Design And Performance Analysis Of Flexible Wheel For Planetary Rover

As the main platform and carriers for deep space exploration, planetary rover must have good mobility, trafficability, mobility and smooth-going characteristic.So that it can smoothly through the soft and bumpy surfaces of planet, such as Mars and Moon.And the wheel as a direct contact parts with the planet’s surfaces is the most important components of the moving system. For the complex state of the planet’s surface, the research of excellent trafficability and vibration damping wheel is important to rover’s mobile system design and path planning.This paper based on the principle of engineering bionics, conducted the bionic design and performance analysis of the flexible wheel, in order to provide the new ideas and methods for the design of our country’s planetary rover’s flexible wheel.Through the similarity analysis, I chose pine cone as the biological design prototype of flexible wheel. Using the measuring instruments to measure the pine cone structure, we gained the relationship of height, mass and large diameter of the pine cone, and discovered the change rules of the pine cone’s seed scales, core angle and the bottom helix. By using high-speed cameras and compression testing machine conducted the drop and compression performance testing of pine cone respectively, and analyzed the characteristics of felxible deformation in pine cone’s three kinds of typical structure. And discussed the influence of the structure of pine cone’s scales to its deformation.Based on the bionic structure, and combined with the the structural of pine cone. We selected the morphology sructure characteristics of the pine cone’s overall shape, open architecture shape, scale grain distribution structure, bottom shape and semiexpand external contours as the reference factors of flexible wheels’ bionic design.And designed similar structure bionic flexible wheel respectively. Using CATIA to establish the three-dimensional model for all wheels and using FEM software Hypermesh and ANSYS to analyze the Statics characteristic of designed flexble wheels. Finally, we chose semi-expand external contours structure bionic wheel as the bionc model.Using the FEM software to simulate the change of thickness, parallel spacing and tilt spacing of felxible wheel’s sheet, and analyze its influence on the deformation, stiffness and stress of felxible wheels. Taking the duplicate modeling into account, we used the function of CATIA parametric modeling to establish wheels model. The simulation results show that with the increase of the thickness of the wheel sheets,wheel’s deformation and stress increased, and the stiffness reduced. As the increase of the parallel spacing and tilt spacing of wheel sheets, the wheel’s deformation and stress increased, and the stiffiness decreased. And the change of the thickness of wheel sheet has the most obvious influence on wheel’s performance.Using FEM software to simulate and analyze the model performance of the flexible wheel. We chose the wheel three typical states: freedom without constraints, ground constraints, and prestressed ground constraint. The analysis result shows that the wheel’s natural frequency and vibration mode will be changed in different states. For analyzing the affect of the wheel sheet material properties on the wheel modes. We solve the modes by using six different elastic modulus in the state of freedom without constraints and ground constraints. The analysis result shows that the natural frequency of the wheel increased with the increase of material elastic modulus in different states. And the change of materials has small affect on wheel vibration mode, mainly affects the wheel vibration amplitude.This paper analyzed the bionic flexible wheel preliminary, and will provide reference for the design and research of flexible wheel.