In this paper, a new optimization method named surround method is introduced. and Its bases upon isoclines of function are closed and doesn't intersect with each other.
介绍了一种优化方法——围法，该方法的基本原理是利用函数等值线封闭且互不相交。
2
In this paper a new concept of phase contrail of phase plane for higher order nonlinear control system based on isoclines method of second-order linear system is proposed.