研究了非线性系统的时变参数估计问题 ,给出了基于新的估计准则的非线性系统投影算法———梯度投影算法的改进形式 ,证明了算法的收敛性 ,并讨论了算法的优缺点 .最后给出一个仿真算例 ,验证了所给算法的有效性 . The problem of time-varying parameter estimation for nonlinear systems is studied. An improved version of the gradient projection algorithm is proposed based on the new estimation criterion, which proves the convergence of the algorithm. The advantages and disadvantages of the algorithm are also discussed Finally, a simulation example is given to verify the effectiveness of the proposed algorithm.