来源：
https://goo.gl/fFjgTH
The secret tech behind the Tesla Model 3
标题：Tesla Model 3 背后的秘密技术
When it comes to Tesla, attention is usually focused on its production
struggles, the latest actions of company founder Elon Musk or, from a
technology perspective, its pure-electric powertrains. But with the Model 3,
the firm is also aiming to pioneer a new approach to chassis and suspension
design.
谈到Tesla，人们的注意力通常集中在其挣扎于产能，公司创始人Elon Musk 的
最新言行，或者从技术角度来看，其纯电动力系统。 但借由Model 3，该公司还
致力于开创一种新的底盘和悬架设计方法。
Tesla’s approach to designing those areas, which are crucial elements in
defining a car’s character and desirability, didn’t follow usual automotive
industry practice for volume car production. Autocar spoke exclusively with a
number of Tesla engineers to gain an insight into that development process.
Tesla 设计这些部件的方法，是确定车辆个性和可取性的关键因素，他们并没有
遵循汽车行业一般量产汽车的做法。 Autocar 专门和众多Tesla 工程师进行了
交流，以深入了解该开发过程。
Most manufacturers these days build major new models from a platform or
architecture, but when it came to the design of the Model 3’s chassis and
suspension, Tesla engineer stuck with a ‘first principles’ clean-sheet
approach. The starting point were the tyres, which Tesla describes as the
unsung heroes of its cars and crucial to feel and drivability. Development
started in 2015 and Tesla worked with tyre manufacturers for almost three
years, which is longer than the time spent on the Model S’s tyres.
如今大多数制造商都是从平台或架构中构建主要的新车型，但在设计Model 3 车
架和悬吊时，Tesla 工程师坚持使用"第一性原理"达到其需求。起点是轮胎，Tesla
称其为车辆的无名英雄，对驾驶感觉和性能至关重要。开发于2015年开始，Tesla
与轮胎制造商合作将近三年，这比花在Model S 轮胎上的时间更长。
https://i.imgur.com/V80QZE0.jpg
Tesla says tyres for a high-performance electric vehicle are challenged in a
way that those on a car powered by an internal combustion engine (ICE) are
not. A two-wheel-drive Model 3 with a long-range battery weighs just over
1700kg, so tyres have to cope with high loads as well as a 155mph top speed
(for dual motor versions) plus continual torque input, either when
accelerating or during regenerative braking.
Tesla 表示，高性能电动车的轮胎受到的挑战是现在的轮胎是为了装在内燃机(ICE)
驱动的汽车上的。配备远程电池组的两轮驱动Model 3 重量超过1700kg，因此轮
胎必须应对高荷重、250km/h 的最高速度(双电机版本)、以及无论是在加速时还
是在再生刹车时所带来的持续扭矩输入。
The bulk of mass of an EV is usually located lower than in an ICE-powered car
due to the battery packs being mounted under the floor. As a result, there is
less vertical force build-up through the outside pair of tyres to generate
grip when they corner. To tackle that, Tesla focused on tread stiffness,
developing new compounds to deliver the desired combination of cornering grip
and low rolling resistance. The tyres are filled with sound-absorbing foam to
suppress noise amplified inside the tyre cavity.
由于电池组安装在地板下，电动车大部分的质量通常低于内燃机所驱动的汽车。
所带来的结果是，转弯时外侧轮胎用来产生抓地力的垂直力较小。为了解决这个
问题，Tesla 专注于胎面刚度，开发新的化合物，以提供所需的转弯抓地力和低
滚动阻力。轮胎内贴满吸音泡棉，以抑制轮胎腔内放大的噪音。
Each rear wheel has six degrees of freedom – five links and one damper,
similar to a double wishbone – but the links have been split to give better
control over the forces transmitted through the tyre’s contact patch. The
front suspension has also been designed to provide maximum protection in the
stringent, small-overlap frontal collision crash test.
每个后轮都有六个自由度 - 五个连杆和一个阻尼器，类似于双A臂 - 但是连杆
已被拆分，以便更好地控制通过轮胎接触面所传递的力。前悬架的设计还用于在
严格的小范围正面碰撞试验中提供最大程度的保护。
https://i.imgur.com/GMPvnzW.jpg
Apart from the direct injury that can occur in accidents, doors can jam and
EV batteries can be threatened too. To counter this, sacrificial links are
designed to snap when the front wheel and suspension takes a hit.
除了事故中可能发生的直接伤害外，车门也会卡住，电池也可能受到威胁。为了
解决这个问题，连杆设计成在前轮和悬架受到撞击时可被牺牲折断。
That allows the wheel to rotate around a third link, moving the wheel outside
of the body and pushing the car, the occupants and the batteries away from
the point of impact.
这可使得车轮围绕第三连杆旋转，将车轮移动到车身外部并且将车辆，乘员和电
池推离撞击点。
The additional motor in all-wheel-drive variants sits on two mounts in the ‘V
’ of the front subframe and pivots backwards into a void in the event of a
collision. The electric power steering system has a rapid 10:1 ratio, giving
two turns lock-to-lock. The system has full redundancy with separate power
feeds taken directly from the high-voltage battery, two electronic control
modules and two inverters providing ‘hot backup’ if one fails.
全轮驱动车型中的另一个电机位于前副车架两个骨架的"V"中，并在发生碰撞时
随枢轴向后转到空隙中。电动转向系统具有10：1的快速转向比，可以两圈打死。
系统具有完全冗余，可直接从高压电池获取独立的电源，两组电子控制模块和两
个逆变器提供了"hot backup"以防其中一组失效。
https://i.imgur.com/JJ6Supx.jpg
Tesla’s engineering team opted to fit more expensive four-pot brake calipers
at the front of the Model 3 rather than a cheaper, single-piston sliding
version for superior pedal response. That also allowed the firm to design its
own piston seals that fully retract the brake pads after braking, cutting
drag and boosting the available driving range.
Tesla 的工程团队选择在Model 3 的前轮安装更昂贵的四活塞卡钳，而不是更便
宜的单活塞版本，以获得出色的踏板反应。这也使得该公司能够设计自己的活塞
油封，在刹车后能完全缩回刹车片，减少阻力并提高可用的行驶里程。
The discs themselves have been designed to last for the life of the car
(about 150,000 miles), which is possible because the Model 3’s regenerative
braking system reduces how much the conventional brakes are used. Rust could
be an issue over that time, so engineers developed new anti-corrosion
techniques. Such attention to detail is indicative of the development team’s
‘more and’ mantra: if an improvement is made in one area, whether for
performance or cost reasons, Tesla’s team commits to making another
improvement elsewhere.
这些盘片本身的设计可以延长汽车的使用寿命(约150,000英里)，这是可能的，
因为Model 3 的再生刹车系统减少了传统刹车的使用量。生锈可能是一个问题，
因此工程师开发了新的防锈技术。对细节的这种关注解释了开发团队的"more and"
口头禅：如果在一个领域做出改进，无论是出于性能还是成本原因，Tesla 的团
队保证会在其他地方做到另一项改进。
What’s the frequency, Elon?
Tesla drew on learnings from Nasa when refining the Model 3’s suspension
settings to ensure the car would be comfortable.
Tesla 在改进Model 3 的悬架设置时藉鉴了美国NASA 的经验，以确保车辆舒适。
The Californian company’s engineers turned to a study by the space agency on
the limits of human capability, which included research into how long the
body can be subjected to a certain frequency without feeling uncomfortable.
这家加州公司的工程师们为了学习了解人类能力的极限而向太空机构求助，其中
包括研究人体在受到特定频率影响下有多长时间不会感到不适。
The vertical frequency (measured in hertz) at which the suspension moves
affects not just comfort but how a car feels to drive, whether it be relaxed
and serene or sharp and edgy.
悬架移动的垂直频率(以赫兹为单位)不仅影响舒适性，还影响驾驶感受，无论是
放松平静或是激烈急躁的。
Tesla says the suspension of most cars is sprung and damped to move at
between 1.0Hz and 3.0Hz. For the Model 3, engineers settled on a vertical
frequency for the suspension that is equivalent of a brisk walk or a slow run
to give a chassis feel that was comfortable yet sporty enough to harmonise
with the performance of the powertrain.
Tesla 表示，大多数汽车的悬架弹簧和阻尼都会在1.0Hz 到3.0Hz 之间。对于
Model 3，工程师对于悬架的垂直频率设定采用了相当于快走或慢跑，使底盘感
觉舒适而又运动，足以与动力总成的性能相协调。