Thus , efci algorithm is improved and the oscillation is overcome validly . and further , a linear pid controller is designed to replace the nonlinear component in the standard efci algorithm , it makes flow control system more robust , at same time , controls the queue length to expected value , which is beneficial to decrease delay in queue 为了进一步克服系统振荡问题，提出采用一种线性的pid控制器来替换标准efci算法中的非线性环节，增强了系统的鲁棒性，并实现了队列长度的定点控制，有效地减少了排队延时。
Changing main performance parameter is the feature of mechanism transmission system , in other words , inertia . , hardness and dump can be changed in certain range . at the same time , in order to let students realize how non - linearity influences dynamic performance of mechanism transmission system , design two kinds of non - linearity , these are friction and clearance 该实验台机械传动系统的特点是能实现传动系统主要性能参数在一定范围可调，即：传动系统的惯量、刚度和阻尼可调，同时，为了让同学们了解非线性环节对传动系统动态性能的影响，设计了摩擦和间隙两种非线性环节。
On the basis of the model , we employ matlab to simulate the system experiment . and we compare dynamic and static characteristic of pid control , fuzzy control and based - on ga fuzzy control . the results of simulation for model of simulation are proved that the approach of based - on ga fuzzy control is more efficient than other control methods because of its non - adjust value and shorter time of control 仿真实验中采用模拟对象仿真模型，主要为等效二阶系统模型加一些非线性环节，然后对仿真模型进行pid控制、模糊控制以及基于ga的模糊控制，比较三者的控制动静态特性，由于基于ga的模糊控制无超调和调整时间短，证明了其控制特性优于前二者。
Subsequently , the nonlinear model is locally linearized at equilibrium point . with this linear model , the performance of standard efci algorithm that is used in brf scheme is evaluated . the conclusion is that oscillations are caused by the nonlinear component existed in efci algorithm , but not intrinsic attribute of the binary congestion control mechanism 在对该模型线性化后，本文对二进制abr拥塞控制广泛采用的显示前向拥塞指示( efci )算法进行了性能分析，结果表明二进制efci算法导致系统振荡的主要原因在于判定和解除拥塞状态时引入了非线性环节，而非二进制机制的内在属性。
