摘要此次毕业设计的课题是“8字无碳小车”。
在设计小车过程中特别注重设计的方法，力求通过对命题的分析得到清晰开阔的设计思路；作品的设计做到有系统性规范性和创新性；设计过程中综合考虑材料、加工、制造成本等给方面因素。
我们借鉴了参数化设计、优化设计、系统设计等现代设计发发明理论方法；采用了MATLAB、PROE等软件辅助设计。
我把小车的设计分为三个阶段：方案设计、技术设计、制作调试。
通过每一阶段的深入分析、层层把关，是我们的设计尽可能向最优设计靠拢。
方案设计阶段根据小车功能要求我们根据机器的构成（原动机构、传动机构、执行机构、控制部分、辅助部分）把小车分为车架、原动机构、传动机构、转向机构、行走机构、微调机构等六个模块，进行模块化设计。
分别针对每一个模块进行多种方案设计，通过综合对比选择出其中的最优的方案组合。
我们的方案为：车架采用三角底板式、原动机构采用了锥形轴、传动机构采用齿轮或没有该机构、转向机构采用曲柄连杆+槽轮机构、行走机构采用单轮驱动实现差速、微调机构选用微调螺母螺钉。
其中转向机构利用了调心轴承、关节轴承。
技术设计阶段我们先对方案建立数学模型进行理论分析，利用MATLAB分别进行了能耗规律分析、运动学分析、动力学分析以及灵敏度分析。
从而得到了小车的具体参数和运动规律。
然后应用PROE软件进行了小车实体建模和小车部分运动仿真。
在实体建模的基础之上对每一个零件进行了详细的设计，综合考虑零件材料性能、加工工艺、成本等各种因素。
小车使用的零件大多是是标准件、可以购买，同时除部分要求加工精度高的部分需要特殊的加工外，大多数零件都可以通过手工加工出来。
对塑料可采用切割。
且因为小车受到的力都不大，因此大量采用胶接，这样可简化零件及零件装配。
调试过程会通过微调等方式改变小车参数进行试验，在试验的基础上验证小车运动规律，同时确定小车最优的参数。
关键字：无碳小车参数化设计软件辅助设计微调机构灵敏度分析ABSTRACTThe graduation design topic is "eight words carbon-free car". In the process of design of the car with a special focus on design methods, strive to based on the analysis of the proposition have clear and open design ideas; Work design do have systemic standardization and innovation; Considered in the design process to factors such as material, processing, manufacturing cost. We draw lessons from the parametric design, optimized design, system design and other modern design theory of invention method; Used the software such as MATLAB, PROE, cad.I put the car design can be divided into three stages: project design, technical design and production of debugging. Through every stage of thein-depth analysis, cengcengbaguan, as far as possible to the optimal design is our design.Scheme design stage according to the car function requires us based on the composition of the machine (prime mover structure, transmission mechanism, actuator and control section, auxiliary part) put the car into the frame, engine structure, transmission mechanism, steering mechanism, travel mechanism, adjustment mechanism and so on six modules, carries on the modular design. Separately for each module for a variety of scheme design, through the comprehensive comparison choose the combination of optimal solution. Our solution is: the frame USES triangle plate type, engine structure adopted the conical shaft, transmission mechanism adopts gear or not the institutions, steering mechanism adopts the crank connecting rod + tank with one wheel drive wheel mechanism, travel mechanism to achieve differential, selects theadjustment nut screw fine-tuning mechanism. The steering mechanism takes advantage of the self-aligning bearings, joint bearings.Technical design phase we to plan through theoretical analysis, the mathematical model is established using MATLAB, respectively, the rule of energy consumption analysis, kinematics analysis, dynamics analysis and sensitivity analysis. To get the specific parameters of the car and the motion law. Then using PROE software on the car movement simulation entity modeling and car parts. Based on solid modeling for each part has carried on the detailed design, considering the parts material performance, processing technology, cost and other factors.Used car parts are mostly is standard parts, can buy, at the same time, in addition to the part machining precision demanding part need special processing, most of the parts can be covered by the manual processing. The plastic can be used. And because the car by the force is not large, so large with glue, which can simplify the parts and components assembly. Debugging process will test byfine-tuning ways such as changing the parameters of the car, on the basis of the experiment verify the car motion law, determine the car at the same time the optimal parameters.Key words: carbon-free car parametric design sensitivity analysis software aided design fine tuning mechanism目录摘要 (1)一论述 (6)1.1设计布置方案 (6)1.2功能设计要求 (6)1.3整体方案设计 (7)1.4小车的设计方法 (8)二方案设计 (9)2.1车架 (12)2.2原动机构 (12)2.3传动机构 (12)2.4转向机构 (13)2.5行走机构 (16)2.6微调机构 (17)三技术设计 (19)3.1建立数学模型及参数确定 (19)3.1.2运动学分析模型 (23)3.1.3动力学分析模型 (27)3.2整体设计 (29)3.3.1整体装配图 (29)3.3.2设计过程 (30)3.3.3小车的零件设计 (39)四小车调试及改进 (40)4.1小车调试方法 (40)4.2小车改进方法 (40)五评价分析 (41)5.1小车优缺点 (41)5.2自动行走比赛时的前行距离估计 (41)5.3改进方向 (41)结论 (42)参考文献 (42)附录A (42)致谢 (42)一论述小车功能设计要求无碳小车走“8”字形越障的设计1.1设计布置方案图1 无碳小车示意图1.2功能设计要求以重力势能驱动的具有方向控制功能的自行小车。
给定一重力势能，根据能量转换原理，设计一种可将该重力势能转换为机械能并可用来驱动小车行走的装置。
小车在半张标准乒乓球台（长1525mm、宽1370mm）上，绕相距300mm距离的两个障碍沿8字形轨迹绕行，绕行时不可以撞倒障碍物，不可以掉下球台。
障碍物为直径20mm、长200mm的2个圆棒，相距500mm距离放置在半张标准乒乓球台的中线上，以小车完成8字绕行圈数的多少来综合评定成绩。