本帖最后由 chlh_jd 于 2012-7-14 02:32 编辑
我简单写了个,实例可以把精度设得更高些,另外通过grread和总用时控制退出机制可以改进下。
 - ;;测试(defun c:test
- (/ ss tl gz cz c r p10 p11 c0 r0 lm zsc tt0 t0 t1 tzs tl_p0)
- (prompt "\n选择凸轮转动对象集:")
- (if (and
- (setq ss (ssget))
- (setq
- tl (cadar
- (vl-remove-if-not
- (function
- (lambda (x)
- (and (= (type (cadr x)) 'ENAME)
- (= (cdr (assoc 0 (entget (cadr x)))) "SPLINE")
- )
- )
- )
- (ssnamex ss)
- )
- )
- )
- (setq tl_p0 (getpoint "\n选择凸轮转心:"))
- (listp tl_p0)
- (or (setq zsc (getreal "\n输入凸轮每转过1度的用时(ms毫秒)<10>:"))
- (setq zsc 10.)
- )
- (setq gz (car (entsel "\n选择滚子圆"))
- cz (car (entsel "\n选择传力轴直线:"))
- )
- )
- (progn
- (setq gz (entget gz)
- cz (entget cz)
- c (cdr (assoc 10 gz))
- r (cdr (assoc 40 gz))
- p10 (cdr (assoc 10 cz))
- p11 (cdr (assoc 11 cz))
- R0 (distance p10 p11)
- )
- (if (< (distance p10 c) (distance p11 c))
- (setq lm 10
- C0 p11
- )
- (setq lm 11
- C0 p10
- )
- )
- (setq tt0 (getvar "MilliSecs")
- t0 tt0
- tzs (* 360. 4. zsc)
- )
- (while (and (setq pt (grread t 4 2))
- (= (car pt) 5)
- (setq t1 (getvar "MilliSecs"))
- (< (- t1 tt0) tzs)
- )
- (if (> (- t1 t0) zsc)
- (progn
- (setq t0 t1)
- (command "_rotate" ss "" tl_p0 1.)
- (setq c (ss:get_c c0 r0 c r tl 1e-1))
- (entmod (subst (cons 10 c) (assoc 10 gz) gz))
- (entmod (subst (cons lm c) (assoc lm cz) cz))
- )
- )
- )
- )
- (princ "\n参数错误或对象不足!")
- )
- (princ)
- )
- ;;;核心函数
- ;;;滚子与凸轮求切
- (defun ss:get_c (c0 r0 c r tl eps / p p1 d a b)
- ;;高效求凸轮滚子与凸轮切点函数
- ;; get_c
- ;; c0 —— 传力轴转心
- ;; r0 —— 滚子到传力转心的距离
- ;; c —— 滚子初始圆心
- ;; r —— 滚子半径
- ;; tl —— 凸轮外轮廓线图元名
- ;; eps —— 允许误差
- ;; by GSLS(SS) 2012-07-14
- (setq a (angle c0 c))
- (while (and (setq p (polar c0 a r0))
- (setq p1 (vlax-curve-getclosestpointto tl p))
- (not (equal (setq d (distance p p1)) r eps))
- )
- (setq b (/ (- d r) 2. pi r0))
- (setq a (+ a b))
- )
- p
- )
-
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