northwolves 发表于 2014-3-4 07:34:06

这个怎么计算？

计算？的值

northwolves 发表于 2014-3-4 07:34:59

图片怎么变形了？

sheng_jianguo 发表于 2014-3-4 13:06:23

AV(P21)是怎样定义的？看不明白。

northwolves 发表于 2014-3-4 14:55:32

我的当前计算方法：

    Function Translating_offset_convex(ByVal s1 As Single, ByVal RC As Single, ByVal RF As Single, ByVal AC As Single, ByVal AV As Single, ByVal LOF As Single, Optional ByVal XOF As Single = 0) As Single
      Dim R As Single, ox As Single, oy As Single, L As Single, L2 As Single, Fpi As Single, alpha As Single, ac2 As Single
      Fpi = Atan(1) / 45
      ox = RC * Cos(AV * Fpi) - s1
      oy = RC * Sin(AV * Fpi)

      L = (RF + RC) ^ 2
      For alpha = 0.01 To AC Step 0.01
            If Abs(L - L2) < 0.01 Then Exit For
            ac2 = AC - alpha
            R = LOF / Sin(alpha * Fpi)
            L2 = (-R * Cos(ac2 * Fpi) - ox) ^ 2 + (R * Sin(ac2 * Fpi) - oy) ^ 2
      Next
      Return R * Cos(alpha * Fpi)
    End Function

northwolves 发表于 2014-3-4 15:04:33

需要一个几何学的计算方法。我的思路是：

分别求出两个圆的圆心坐标：

大圆ox = RC * Cos(AV) - s1
      oy = RC * Sin(AV)
小圆：
         所求线段与半径的夹角alpha
         半径R
            ac2 = AC - alpha
            R = OF / Sin(alpha * Fpi)
         圆心(-R * Cos(ac2) ，R * Sin(ac2))
两圆外切，故圆心距=RC+RF

解出alpha.OF/TAN(ALPHA)即所求

northwolves 发表于 2014-3-4 15:06:18

想得到结果的几何表达式，而不是编程计算的结果

northwolves 发表于 2014-3-4 15:11:31

解方程求$alpha$ : $(RC *cos(AV) - s1+OF*cos(AC-alpha) /sin(alpha))^2+(RC * sin(AV)-OF* sin(AC - alpha) /sin(alpha))^2=(RF+RC)^2$

northwolves 发表于 2014-3-4 20:11:13

已解决$?=-sin(AC) * (RC *cos(AV) - s1 + OF * sin(AC)) + cos(AC ) * (RC * sin(AV) + OF * cos(AC))+sqrt((-sin(AC ) * (RC * Cos(AV) - s1 + OF * sin(AC)) + cos(AC ) * (RC * sin(AV) +OF * cos(AC)))^2-4*((RC * cos(AV) - s1 + OF * sin(AC)) ^ 2 + ( -RC * sin(AV) +OF * cos(AC)) ^ 2 - (RF + RC) ^ 2)$
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