【作者】 张朋；

【导师】 邓宗全；

【作者基本信息】 哈尔滨工业大学 ， 机械设计及理论， 2010， 博士

【摘要】 月球车移动系统是探月二期工程的重要工具和载体,其性能的好坏具有举足轻重的作用。近几年各种各样的月球车移动系统涌现,但大部分移动系统的功能、结构和尺寸等各不相同,这些移动系统具有各自的优缺点,设计过程中遵循的原则更是各不相同。到目前为止尚未有完善的理论和准则来指导月球车移动系统的设计,对月球车移动系统应具有哪些性能,哪些技术更满足月球车要求缺乏统一的评判标准。因此开展月球车移动系统构型综合的研究,研制出高性能的月球车移动系统,具有重要的研究意义和应用价值。按照移动系统的结构组成分别对车轮、悬架和差动机构的构型展开研究。应用图论理论建立悬架子系统的拓扑图,在分析铰接式悬架拓扑图的基础上添加车轮等约束构成新的拓扑图,对四轮、六轮和八轮月球车移动系统悬架子系统进行拓扑构型综合,提出了ALR(Articulated Lunar Rover)移动系统悬架新构型和其他几种性能优越的悬架子系统新构型;应用图论理论对齿轮式差动机构进行拓扑构型综合,综合出三种齿轮式月球车差动机构新构型,提出了分离式绳索差动机构构型,分析了分离式差动机构的特点,并利用构型组合的方法衍生几种新型月球车差动机构;从地面力学角度出发,分析了提高车轮牵引力的方法,提出两种月球车车轮新构型。针对ALR移动系统悬架构型,以其最小越障力矩和载荷平台俯仰角为优化目标,建立了ALR移动系统悬架结构参数的多目标优化数学模型,利用双权因子法将多目标优化模型转换成单目标优化模型,利用序列二次规划法进行了悬架结构参数的优化,得到了ALR移动系统悬架的最优结构参数。根据优化后的悬架结构尺寸参数对ALR移动系统进行了结构设计,包括车轮、绳索式差动机构、转向机构的设计和驱动元件的选择等,研制了ALR移动系统地面试验原理样机(简称ALR原理样机)。对ALR原理样机性能分析的仿真地形进行了研究,给出了典型地形和随机地形的建立方法,建立了ALR原理样机性能分析的虚拟仿真模型,分析了其在松软地形下的通过性能、稳定性能、越障性能和差动性能,将其和采用摇臂-转向架式悬架的FAYC(Fang An Yang Che)移动系统的性能进行了对比,分析结果发现ALR移动系统在载荷平台倾角、行驶效率、最大越障力矩和滑转率等方面的性能要优于FAYC移动系统。基于地面力学理论分析了月球车移动系统性能和构型参数间的关系,根据分析结果和月球车移动系统的性能技术准则,建立了ALR原理样机移动系统的性能评价的指标体系。基于熵权层次分析评价方法,建立了ALR原理样机移动系统性能评价体系。在确定指标的权重系数时结合主观分析和客观分析的方法,既借鉴了专家的经验,又尊重指标间的客观联系,评价结果更可信。利用VC编写了性能评价软件,利用该软件对ALR原理样机的性能进行了自定义指标的评价。为了更好的评价ALR移动系统的性能,将其和采用Rocker-bogie悬架的FAYC的移动系统的性能进行了自定义指标的对比评价,评价结果表明ALR具有更好的移动性能。对研制的ALR原理样机进行了室内沙场试验,搭建移动系统的控制系统和力/力矩参数的测量系统,利用六维力传感器测量ALR的牵引力和转向力矩等参数。在相同包络尺寸的约束条件下,研制了FAYC移动系统原理样机,对其同样进行了相关性能的试验,并将试验结果和ALR试验结果进行对比,分析两种移动系统的性能。试验结果表明ALR原理样机在越障性能、车轮载荷分配和滑转率等方面较FAYC原理样机具有较好的性能。更多还原

【Abstract】 Rover locomotion system is one of the important tools for lunar exploration and carrier, which plays an important role in the lunar exploration. Recently many new types of rover locomotion system are proposed, but most of them aren’t consistent, such as function, structure and dimension. These locomotion systems have their respective advantages and disadvantages. The design principles are also different. There is no theory and criterion for the design of lunar rover locomotion system. It is lack of unified evaluation criterion such as which performances lunar rover should have, which technologies meet the requirements of lunar exploration. So there are important research significance and application value in the aspects of research on configuration synthesis of lunar rover locomotion system and developing high performance locomotion system.According to structure composition of locomotion system this paper do some research on the configuration of wheel, suspension subsystem and differential mechanism. The topology graphs of the suspension subsystem are built based on graph theory. New topology graphs are rebuilt by adding wheel to the suspension subsystem. ALR (Articulated Lunar Rover) locomotion system suspension configuration is proposed through the mechanism synthesis of suspension subsystem for 4, 6 and 8-wheel rover locomotion system. Configuration synthesis of gear differential is carried out based on graph theory. Three types of gear differentials are found. A separating rope differential is proposed in this paper. Also configuration characteristics of separating type differential are summarized. Some other differential configurations are obtained by configuration combination. The method for improving draw-bar pull is analyzed according to theory of mechanism and two kinds of wheel configurations are put forward.Multi-objective optimization mathematical model is established, which takes minimum torque surmounting obstacle and load platform pitch angle as optimization objection for ALR suspension. Then structure parameters of ALR are optimized by sequential quadratics programming and suspension parameters of ALR suspension are determined. According to the results ALR locomotion system is designed including wheel, rope differential and steering gear. At last ALR locomotion system principle prototype used in ground test is developed (shortened name is ALR principle prototype). Simulation terrain has been studied for performance analysis of ALR locomotion systems principle prototype, the ways of establishing the typical and random terrain are given. ALR principle prototype virtual simulation model is built, analysis of its trafficability, stability, surmounting obstacle capability and differential performance on soft terrain are carried out. Then the capability of ALR and FAYC(Fang An Yang Che) which adopts the locomotion system of rocker-bogie is analyzed and compared. Simulation results indicated ALR locomotion system have better performance on load platform pitch angle, driving efficiency, obstacle-crossing capability and slip ratioThe relationship between performance and configuration parameters is analyzed based on terramechanics. According to the analysis results and the rule of technique, the index system of the performance evaluation for the rover locomotion system is established. To evaluate the performance of ALR principle prototype, the evaluation system is established based on the method of entropy weight and analytical hierarchy process comprehensive evaluation. The evaluation result is creditable, for the index of weight coefficient is confirmed by the methods of subjective and objective analysis, which use the experience of experts for references and respect the objective relationships of index. A software is developed based on the evaluation model. The performance of ALR principle prototype is evaluated by the software. For comprehensive evaluation ALR performance, evaluation comparison between ALR and FAYC locomotion system is carried out and analysis result indicates ALR locomotion system principle prototype has better mobility performance.To implement indoor experiment, the control and measure system is established. The tractive force and turning torque of ALR principle prototype is measured with the six-axis force/torque sensor. To analysis the locomotion performance of FAYC and ALR principle prototype, the rover locomotion system FAYC is developed. Also, the experiment of FAYC is done. The results show that ALR possesses higher performance of obstacle-crossing, wheel load-distributing and slip ratio.更多还原