机械设计的基本原理1.11
Deterministic Design: Risk Management
确定性设计：风险管理
Imagine the first time you thought to ask someone out on a date (if you never have, maybe this will help)! Popular media parodies the pleasures and perils; however, we exist and that means we have parents; therefore the process must work and be worth it! That first luscious lackadaisical life form that caught your eye, the uncertainty, what if you were rejected? The shame, the embarrassment, oh how could you do it?! Finally, one day, you just did it, and you know what? The life form laughed and ran away! At that point you thought to become a hermit, but then a voice inside you said “Hey, that wasn’t so hard, and even though I got laughed at, it means I can do it again because I have parents so it’s bound to work sooner or later!” The next time, you focus on a life form in shop class with a very high IQ, and before you finish asking the question, they ask you what time they should meet you for a game of chess!
设想下你第一次跟别人约会的情况（如果你还是单身狗，也许接下来的内容会帮助到你）。媒体总是嬉笑怒骂的调侃人生的愉悦和黑暗，但是我们作为父母创造的人，是活生生存在的。所以，整个社会只不过是要求一个好的成功过程罢了。作为不可避免的花式未知情况，我们总是害怕万一被拒绝会怎么样？太丢脸了，怎么应对？最终，有一天你克服了未知，你猜怎么着？那种对未知的恐惧和不安，马上烟消云散了。那时候，虽然内心打着退堂鼓想“我出家算了”，但是内心却想着“应该不难啊，即使我被人嘲笑，我也是我父母的好儿子，他们能做到，我也可以啊”。下一次，你和高智商人群在一起的时候，就是他们来问你是否有时间一起下象棋的时候（角色反转）。
Thus it often is with engineering design. Too often we get enamored with a sexy design that tempts us to run after it, while it remains aloof and unobtainable, when a little bit of forethought would have made us realize the futility of our fantasies. Once again, applying good engineering practice prevails: Dream your wildest fantasies, but then carefully evaluate them, including performing analysis. Which classes and clubs are they in? What chat rooms do they visit? Who are their friends? What is their favorite machine tool? What CAD program do they like best? What languages can they code? Run some experiments such as ask a friend to see help casually determine if there might be any interest. Then make casual conversation about what a great time you had in the shop this weekend. All projects have risks, which represent the potential to succeed, so learn to identify and assess risks, and manage them by best engineering practice, having a contingency plan, and learning when to use it.
同样，机械设计也有这些尴尬之处。曾几何时，我们执念于一个完美的设计而不敢自拔。但是设计本身玄而又玄，我们又不得其法。只要冷静下里，提早分析，就会发现这样的完美设计只不过是幻想罢了。再一次，最佳工程实践还是更靠谱：尽情狂想，但是要仔细客观的审视他们。整个比赛，就是一场约会而已。花点时间，了解自己的队员和同学吧。大家都有什么爱好？他们喜欢去哪个教室?他们有哪些朋友圈？他们最爱的机床是哪个？他们喜欢用什么设计软件？他们喜欢那种程序语言? 勇敢的找一些感兴趣的朋友，在实验过程中稍微的聊上那么几句，并告诉对方你很享受这周在实验室的时间。所有的项目都有风险，但也是机遇。只要你学会发现和决定风险，通过最佳工程实践加以管理，想一些备选方案来应急的话，你就不必担心失败了。
Risk is inherent in every project and good engineers must never make decisions based on hope or hype. If you find yourself praying for success, you likely did not design deterministically! Religion can be a wonderful part of your life, but it should not be part of the engineering design process. Facts, calculations and data are essential to making good decisions:
每个项目都有风险，好的工程师从来都不会寄托于希望。如果你双手祈祷设计成功，那这个产品有可能并不是按照确定性设计进行的。宗教和信仰确实很重要，但是机械设计过程可不是凭空捏造的。事实上，计算和数据是做好机械设计的根本。
• First and foremost, do a safety assessment to ensure that the concept is inherently safe, or make sure that you have plans for safety devices.
首先，对方案进行判断，确定方案本身是安全的。或者，至少有一个安全装置的方案。
• Search and see if someone else has already solved the problem, and if they have, reverse engineer their solution to see if you can create a better idea:
搜寻可能的解决方案，如果别人已经解决了类似的问题，你可以逆向工程分析下自己是否有可能有更好的办法。
• Use the Internet or the scientific method to get the facts:
利用网络或者科学的方法来获取事实数据：
• Formulate a hypothesis, analyze or experiment, torture the data, and draw conclusions.
假想一个理论，通过分析或者实验来检验数据，从而得到最终的结论。
• Preliminarily analyze the idea for power, geometry, and complexity:
初步分析动力、形状和复杂性：
• Create a power and force analysis to see if you have enough to do what's required in the time allotted.
分析系统的动力和力学要求，确定该设计是否能在足够的时间内，提供足够的能量
• Evaluate motion and space (packaging) requirements.
评价运动和空间（包装）的要求
• Estimate the number and types of modules and parts that will be required, and seek to minimize their numbers!
估算系统的模块和零件数量，优化至最小值
Deterministic design requires continuous risk assessment and identification of contingencies should the risk prove too great or the schedule not allow further investigation:
确定性设计要求贯穿整个设计的风险评价，并确定应急预案。这样才能判断，风险本身是否过大，或者时间要求是否太短。
• Lower Risk Design:
低风险的设计
• If you can confidently create an analytical model for a design, then it is likely that the path you are following is "safe" and is low risk.
如果设计本身有相应的分析模型，那么你的设计是安全的，风险应该很低。
• The design has been done many times before, and you merely have to scale or copy the solution and focus on implementation
设计本身已经很成熟，你要做的只不过是变形设计，专注于整个过程本身。
. • Higher Risk Design
高风险的设计
• If it is hard to analytically model a design, BUT the design has fewer parts and has the promise of elegance, it is a risky design that is worth investigating
很难建立设计的分析模型，但是该设计零件数量并不多。那么整个设计是一个值得研究，进一步优化的设计。
• Such designs might be developed using advanced computer models and/or bench level experiments or prototypes
这种设计需要电脑建模或者一次实验才能决定其风险。
• Continually evaluate the risk to see if it is subsiding as engineering progresses. Keep an eye on the schedule and be prepared to revert to your contingency plan.
一直对风险保持警惕，确实你的设计过程没有因为存在风险而引起不确定性。总是按照时间计划表进行，适当的时候采取备用方案。
• Always have a lower-risk alternate design as a contingency plan!
总要有一个低风险的可替换方案。
Review your different strategies and reassess risks and possible countermeasures to minimize risk. Where risk has the potential for big payoff, make sure you have a solid easy-to-implement contingency plan. This often can be accomplished with redundant or alternative modules that can be incorporated into the risky strategy.
审查自己的策略和方案，重新评估风险的大小，从而确定一些反制措施来降低风险。当风险有可能产生高回报时，也不要忘记定制应急计划。通常，高风险设计本身会额外附带一个可替换模块。
