机械设计的基本原理1.7
Deterministic Design: Reverse Engineering
确定性设计：逆向工程
Everyone always seems to remember after the fact that history repeats itself and those who do not study history will forever walk around with backside binocular syndrome! Therefore, a critical step in developing new technologies is the study of competing designs in order to understand their design intent, and to hopefully identify and exploit a weakness or an opportunity that your competition missed! This process is called reverse engineering and it is considered a critical part of the product development process.1 2 It can also be thought of as a “prior art” search, which is the term used by the patent office.
每个人其实都似乎记得，历史的车轮是不断重复的。那些不研究历史的人，只会紧盯远方，而忽略了眼下已经存在的故事。因此，研发新技术的最关键步骤应该是先研究竞争对手的设计，从而发现其设计功能。通过分析其产品的优缺点，来促进自己对产品设计的思考。这个过程，就是逆向工程，是产品开发阶段最重要的阶段之一。在专利办公室中，这个过程叫做已有技术搜寻。
Reverse engineering involves physically taking apart a competitor’s product in a very systematic manner. Each component and its function are analyzed to understand each part’s function and why it was designed the way it was. In fact, in order to effectively reverse engineer something, you merely have to follow good engineering practice, as discussed earlier, in reverse. Whenever you get stuck, go back a few steps and then try to move back forward. In the case of a design contest, reverse engineering of the contest table itself can help to develop a better physical and analytical intuitive feel for the contest, as well as potentially uncover “keys” to winning.
逆向工程需要系统性的拆解竞争对手的产品，一件件的分析其功能。通过理解其各部件的功能，了解设计意图。事实上，有效的逆向工程拆解方法只需要参考产品设计过程，反过来就可以了。无论卡在哪里了，后退几步，然后再重新出发。对于设计竞赛来说，通过逆向工程分析竞赛场地有助于加深对比赛的理解，同样有可能指引你找到制胜的关键。
The ultimate goal of the reverse engineering process is to find a eureka! element that was overlooked by the original designer (or placed there by the contest designer for the astute competitor to find). Eureka! elements have the potential to be disruptive technologies, which are the holy grails of the design world. Given the tremendous potential of reverse engineering, consider the contest The MIT and the Pendulum and pretend you are reverse engineering the contest table and the winning machine:
逆向工程的最终目的还是要找到产品设计的诀窍，尤其是那些产品设计师所忽略的地方（或者是竞赛设计者设置给最敏锐设计者的奖励）。设计的诀窍有可能会产生新的颠覆性技术，是设计问题中最璀璨的皇冠。只要有了逆向工程的分析工具，我们就可以努力分析竞赛要求，通过技术来赢得比赛。
• Play with the contest table and kit parts to activate your bio neural net so the ideas begin to flow:
边熟悉竞赛场地和工具箱里的零件，边在脑海里想象一些方案
• Look at the contest table and your kit parts and create mental 3D images and movies of all the elements and practice manipulating them in your mind so your bio neural net can work on solutions while you do the laundry. In your mind, disassemble and reassemble the table.
在脑海中假想需要所有场地和工具箱零件的3D图形，即使洗衣服时，你也可以想象可能的解决方案。
• Touch the parts of table and kit and experience their mass and inertia. Connect a motor to a power supply and feel its torque. Can it rotate one of the pendulums? How could power from the motor be applied to the pendulum? Measure the period of the pendulums. Feel the weight of the scoring parts and roll them around on the table and up over the wall and into the scoring bin. Measure the coefficient of friction between each potential wheel material and different surfaces on the table. Feel the stiffness and apparent strength of each of the structural elements in the table and the contest kit.
通过直接的感官接触，实物的重力和惯性矩会给大脑提供理性的认识。给电机接上电源，可以感性认识它的扭矩大小。判断这个扭矩是否能驱动钟摆结构，怎么把电机的动力传给钟摆结构？通过实验，记录钟摆的周期。熟悉小球的质量，用纯手动的方式，模拟小球的运动和得分方式。测量不同轮子材料和不同表面之间的摩擦系数，感性认识下所有零件和场地的刚度以及强度。
• Listen to the sounds of the pendulums as they swing, the scoring elements as they are pushed around the table, and to the kit motors.
仔细聆听机械的声音，钟摆的摆动、小球的滚动和电机的旋转。
• Smell the contest table and the kit elements. Scent is one of the most powerful senses for recall!
仔细闻竞赛场地和工具箱零件，味觉是刺激大脑运作的元素之一。
• Taste victory (or the resources if this is a food-based challenge) by imagining your solution is the one that wins!
品尝胜利吧，就好像你的解决方案成功了一样（这些都是为了调动大脑，虽然看起来很“土”）。
• Sketch the table and draw motion path arrows to illustrate the motions you observed that were possible. Sketch in kit actuators to imagine them causing the motion paths to happen…
画草图，分析可能的运动方式，直观的验证自己的方案。同样，在草图上绘制工具箱里的驱动器，假设驱动器驱动钟摆的情况。
• Model the motions of the table elements in terms of time and motion potential and the forces and torques required. A spreadsheet or MatLab model will allow you to compare different scenarios that the kit motors could make happen; consequently you may discover the true design intent of the contest creators.
对竞赛涉及到的时间、运动、力以及扭矩进行计算分析。计算表单或者MatLab程序，都可以很好的模拟不同的情况，决定电机的效用。最终，你才有可能发现比赛设计者的真正意图。
• Create a simple physical model, perhaps a sketch model from cardboard, of a reasonable idea you have thus since identified, and play with it on the table, using your hands in place of the kit motors to move the elements. You can rapidly make many different sketch models, and then if one seems to be promising, you could even create a working physical model in order to run a bench level experiment on the table using the kit motors for power.
可以用简单的硬纸板建立实体模型验证自己的方案，甚至可以用手驱动一些运动部件。通过建立不同的简单模型，可以找一个觉得可行的方案。通过搭建实体模型，安装电机后进行测试。
• Detailed concepts should NOT be a part of this initial process, but rather they should enable you to discover the design intent of the contest creators, and help you to formulate different strategies for exploiting it. Building and testing whatever best concept finally evolves from the completion of your design process will be totally dependent on how well you executed the above.
. 在方案初期，最好不要深入到细节设计，但是通过方案细节的分析，可以帮助你理解比赛设计者的意图，从而帮助你产生不同的战略来利用设计意图。最后实际机器的搭建和测试，都源于你自己最佳设计方案的演化。而机器的好坏，完全取决于你是否很好的执行了上述原则。
1.Otto, K. Wood, Product Design, Prentice Hall, Upper Saddle River, NJ, USA 2001
2.Karl T. Ulrich, Steveen D. Eppinger Product Design And Development, 2000 The McGraw-Hill Companies, Inc. Boston, MA, USA
