这个怎么计算？

northwolves

计算？的值

northwolves

图片怎么变形了？

sheng_jianguo

AV(P21)是怎样定义的？看不明白。

northwolves

我的当前计算方法：

1.     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
   
2.         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
   
3.         Fpi = Atan(1) / 45
   
4.         ox = RC * Cos(AV * Fpi) - s1
   
5.         oy = RC * Sin(AV * Fpi)
   
6. 
   
7.         L = (RF + RC) ^ 2
   
8.         For alpha = 0.01 To AC Step 0.01
   
9.             If Abs(L - L2) < 0.01 Then Exit For
   
10.             ac2 = AC - alpha
    
11.             R = LOF / Sin(alpha * Fpi)
    
12.             L2 = (-R * Cos(ac2 * Fpi) - ox) ^ 2 + (R * Sin(ac2 * Fpi) - oy) ^ 2
    
13.         Next
    
14.         Return R * Cos(alpha * Fpi)
    
15.     End Function

复制代码

northwolves

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

想得到结果的几何表达式，而不是编程计算的结果

northwolves

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

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