【作者】 杨飞；

【导师】 邓宗全； 陶建国；

【作者基本信息】 哈尔滨工业大学 ， 机械设计及理论， 2014， 博士

【摘要】 为更好地执行行星探测任务，世界各国都在发展不同类型的行星漫游车，以此携带科学仪器进行实地勘测从而得到详实的地貌、地质等相关信息。现阶段的研究还主要处在针对某一特定构型的漫游车进行各种性能研究的阶段，缺乏系统的理论或方法来指导漫游车从功能到结构化的设计。由于现阶段运载工具运输能力和容纳能力的限制，具有折展性能的漫游车渐成研究热点，很多不同构型的具有折展功能的漫游车也越来越多地出现于相关文献之中，但如何指导漫游车进行很好地折叠与展开设计仍是一个未被很好解决的问题。因此，研究漫游车从功能到结构化设计以及提出一种解决漫游车折展的方法对于我国深空探测具有很好的促进作用。考虑轮刺效应的影响，建立加装轮刺的沙土对车轮驱动力矩和阻力力矩数学模型，得到轮宽、轮径及轮刺高度在一定范围内时车轮沉陷与沙土对车轮驱动效率间的关系，并给出合理确定车轮数目的方法。分别研究车轮运动具有自适应性能的单轮、两轮及三轮悬架系统所需自由度，应用单开链叠加法对漫游车悬架进行运动链构型综合。在综合过程中基于构型拓扑图的关联矩阵，提出一种同构判别的方法，并给出进行同构判别的规则和步骤。在生成六轮漫游车悬架运动链拓扑图的顶点类配后，应用直接综合和组合综合的方法产生大量新悬架构型图谱，为悬架基本构型的选择奠定基础。研究漫游车的理想悬架机构，从悬架基本构型中选出一种名为多约束四边形悬架（MCQS，Muti-constraint quadrilateral suspension）进行折展研究。建立漫游车翻越台阶障碍、跨越壕沟及自身稳定性能的数学模型，得到这些性能与车体结构参数之间的关系，并给出保证这些性能顺利实现的约束条件。从降低能耗和保护车载仪器安全角度考虑，以越障时各车轮提供的合力矩和车体质心的平顺性能为优化目标，建立多目标优化函数并在ADAMS软件中进行漫游车的结构参数优化，得到悬架的最优结构尺寸。对MCQS悬架机构运动链进行分解，得到组成这些运动链的三种基本结构单元。借鉴变胞机构构态变换的描述以及生物学中细胞融合和变异的理论，研究悬架机构运动链基本单元的变异和融合方式。按照排列组合的方式将这些变异后有不同变异方案的基本运动链融合成一个悬架整体，筛选并得到15种折展方案并从中优选出一种方案进行后续研究。从一般机构入手，给出其构态发生变化时描述系统动能和势能的数学模型，并得到可展开机构展开过程中的动力学方程。针对MCQS的展开过程，给出杆件发生碰撞的三种分类方法并得到杆件碰撞前后速度变化表达式。建立发生构态变化的杆件质量和惯量数学模型，借鉴机器人学知识，建立所关心杆件质心点速度和位置的矩阵变换数学模型。规划MCQS的两种展开方式，对悬架展开过程中发生碰撞的杆件进行动力学研究，确定其整个过程杆件之间碰撞的持续时间以及受到的冲击力，计算结果表明产生的冲击力不会影响悬架结构的安全性。给出一般漫游车仿真时的地形信息和相关仿真参数的设定。建立MCQS漫游车虚拟仿真的三维模型，在多体系统动力学软件ADAMS中进行漫游车展开过程分析，检验其是否能顺利展开；模拟漫游车行驶过程中遇到的一些地形障碍，对漫游车在不同连接模式下的相关运动性能进行分析。根据仿真结果和优化后的结构尺寸，对漫游车原理样机进行结构设计并利用研制的原理样机进行了相关折展和运动性能实验研究。实验结果表明MCQS漫游车在顺利展开的同时也满足折叠比要求，能顺利越过大于车轮半径的垂直台阶障碍和25°倾角的斜坡。更多还原

【Abstract】 To better implement planetary exploration missions, various rovers withdifferent configurations are presented to obtain detailed topography, geology andother related information with the help of scientific instruments. Now manyresearchers mainly focus on various performances of one specific rover and fewtheories or methods are employed to guide the design from function to structure.Constrainted by transport capacity of current rockets, planetary rover having foldingfunction has recently become a research focus. However, how to instruct designersin realizing folding function is still an unsolved problem. For deep spaceexploration, it will be a promotion if one folding method is proposed.Considering the effect of wheel grousers, mathematic model of single wheel isestablished using wheel-soil interaction terramechanics, and the relationshipbetween sinkage and drive efficience caused by soil is obtained while wheel width,wheel radius and height of wheel grouser all locate in certain range, and then oneapproach is presented to determine reasonable numbers of wheels. DOFs requiredfor single, double and three wheel suspension systems with self-adaptiveperformance are analyzed, and structural synthesis of rover suspension is carriedout based on single-open chain method. A new isomorphism identification methodis presented and used in the synthesis process using incident matrixes of topologicalgraph with identification rules and steps. After obtaining vertice combinations ofsix-wheel rover suspension topology, lots of new suspension configurations arecreated by direct synthesis and combination synthesis methods.Ideal suspension mechanism has been studied and MCQS (Muti-constraintquadrilateral suspension) is chosen for further research from all synthesizedconfigurations. Mathematic models of step-climbing performance, ditch-crossingperformance and the stability of the rover are established, and the relationshipbetween motion performances and structural parameters is achieved. Someconstraint conditions are goven to realize rover perfprmances well. For lowingenergy consuming and safing instruments, resultant torque provided by wheels andsmooth performance of rover mass center are used as the optimization objective.Muti-objective function is established in ADAMS to optimize the structural parameters of MCQS rover for optimal structure size.MCQS is decomposed and three basic kinematic chains are obtained. Based onstructure change in metamorphic mechanisms and cell fusion and variation theory inbiology, fusion and variation manners of some basic units are studied. Three basicchains with various variation manners have been fused into one suspensionaccording to the permutation and combination mode. Thus one is determined forfurther research by optimal selection in all obtained15folding schemes.For general mechanisms, mathematical models of kinetic and potential energyare established and dynamic equations used for unfolding course of deployablemechanisms are developed. Especially for the unfolding process, three collisionclassifications are given followed by velocity change expressions. Model mass andinertia of changed links and the matrix transformations for velocity and position ofmass center are given. Two unfolding modes of MCQS are presented and dynamicanalysis of collided links in the unfolding process are carried out to determine theimpact time and force. The result shows that impact force has little influence on thesafety of rover structure.Lunar terrain and parameter settings for simulation are introduced, virtual3DMCQS rover is built in ADAMS and then is simulated to determine whether foldedrover can unfold successfully or not. Simulating some lunar obstacles and relatedlocomotion performances of MCQS rover under two different connection modes areanalyzed. Based on simulation results and optimized structure size, the structuraldesign of rover sample is completed. Unfolding and some locomotion performanceexperiments are carried out, these results show MCQS rover can unfold well withmeeting the required folding ratio and can also pass over step-obstacle whose heightis larger than wheel radius and slope with25°inclination angle.更多还原