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inclination的数学模型

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面条雪

发布时间: 2011-4-21 12:07

正文摘要:

I used two lateral moments, the one caused by the body weight, m x g x sin(alpha) x COMposition, and the other one from centripetal force, m x v^2/(r x cos(alpha+tipping)) x cos(alpha) x COMpos r is s ...

jluo 发表于 2011-4-22 19:08:36

iEngineer ;)

jluo 发表于 2011-4-22 17:31:23

that is why there are we engineers :D

点评

面条雪

you engineers ;) 发表于 2011-4-22 18:07

jluo 发表于 2011-4-22 16:45:09

let's just leave it to the pros :D ...

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面条雪

of course. although i don't think any pro (of this kind) will be interested in this topic (and nerdy enough to actually pursue it) 发表于 2011-4-22 16:50

lupo 发表于 2011-4-22 16:15:29

你们都学过matlab的？大学的时候学过一年，博士前的时候用这个做数据分析，当时的课题是温度及地理位置对购车者得影响，还有癌症病例分析成活率等，这个软件牛叉的。

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面条雪

"温度及地理位置对购车者得影响"=>结果是：冬天越长离雪山越近的地方，购车的人越多，因为要滑雪啊！发表于 2011-4-22 16:31

面条雪

没学过，昨天为了算这个现炒现卖来的发表于 2011-4-22 16:22

jluo 发表于 2011-4-22 16:14:36

I didn't mean the formula was wrong, I just think the formula is presentation of forces, and the consideration of moment arms are also important, but skiing is very dynamic and complex, so if you balance, you are doing it right :D I leave the real deal to the pros,

点评

面条雪

and COMpos x cos(alpha) is the moment arm of centripetal force. so the 'balance' here means the torque produced by weight and that by centripetal are equal, that is, laterally balanced 发表于 2011-4-22 16:38

面条雪

sorry but just for the sake of clarity: I still think you misunderstood it. if COMpos is the distance between ski edge and CG, then COMpos x sin(alpha) is really exactly the moment arm of weight force 发表于 2011-4-22 16:37

面条雪

if a simplified model gives you some meaningful results (which can be confirmed in reality) then it's a good model. otherwise, it's pointless even if it's more complex and closer to reality. 发表于 2011-4-22 16:24

jluo 发表于 2011-4-22 16:01:43

noodle snow ==>

"the moment arm for both forces are both roughly the length between edge of ski to cg" this is wrong. for weight it's sin(alpha) x that length, and for centripetal force it's cos(alpha) x that len

the sin/cos are the composition of the force, which I think I conveniently left out the composition. to me the weight force component is actually mg.cos(a), and the centripetal has 3 components, the balance force, the normal support, and the angular acceleration (turning force)

点评

面条雪

change than with only body inclination). for this his model is good enough. if you can get more interesting results from a more complex model, i would love to see. otherwise, i'll skip :P 发表于 2011-4-22 16:18

面条雪

anyway, i think the original author's main point is that foot tipping and angulation (CB) can potentially give you a higher inclination angle that is more stable (e.g., less vulnerable to terrain cha 发表于 2011-4-22 16:16

面条雪

of coz we assume for simplicity a constant velocity and the balance is achieved as long as (weight force+centripetal force) is parallel to supporting force (i.e., we are talking about lateral balance) 发表于 2011-4-22 16:11

bullpower 发表于 2011-4-22 10:08:03

本帖最后由 bullpower 于 2011-4-22 10:08 编辑

Bingster 发表于 2011-4-22 09:53
这个 Topic 太学究气了。用数学物理来算滑雪？我不信会有帮助。
到是从另一个角度看文题。
...

那是你水平还没到那个级别。

所有体育运动到达顶尖标准，全是在拼高科技，我就列举几个我熟悉的运动：

球类运动：
               球路分析，习惯性的进攻路线和得分手段=== 都是从大量比赛录像里DATA MINING出来的
            球拍的性能，最佳挥拍动作，击球点。。都是算出来的。。。我知道排球比赛：现在比赛里，
            多台摄像机在观众席上实时拍摄，助理教练用计算机随时统计对方的进攻路线，二传的组织球路。。
            主教练戴着耳机，随时听数据反馈

游泳：在静止池里游，就是为了一个动作一个动作的细扣，合理性。

这些都是数学/物理。你去看看体育专业的论文，里面数学，物理的东东不少地。
我认识一个高中球友（ONTARIO U19铜牌哦），他高中就写过论文，论证劈吊时，球的转速与落点的关系。。。。

滑雪需要理论和高科技的地方一定不少。

想咱这样的业余水平，当然用不到，也烧不起那粪土，主要是数学物理都忘了，基本看不明白。。。。

我想真到LEVEL 4了，自然也需要了。