基于模糊逻辑的现在方位导引和无干扰导引的混合导引律

在引入鱼雷导引禁区和鱼雷有利导引点的基础上，用模糊逻辑理论，提出了一种能自动实现现在方位导引和无干扰导引的混合导引律。该导引律通过两组误差信号和多目标规则库，使得鱼雷可在无干扰导引法和现在方位导引法之间自由切换，避免了传统方法需要人工切换的缺陷，所设计出的模糊导引律不受制导站、鱼雷、目标自由运动的影响，而且可以连续地适应各种工作环境

A New Hybrid Guidance Law Based on Fuzzy Logic

The traditional hybrid guidance laws 1,2] for underwater vehicle suffer from the following two shortcomings: (1) they cannot give guidance commands continuously; (2) an operator is needed to switch over between different guidance laws. We present a new hybrid guidance law to overcome these shortcomings. The key to our new hybrid guidance law lies in eqs.(1) and (2). e s in eq.(1) is used to determine whether or not the vehicle is outside the interference zone of guidance, e gp in eq.(2) is used to determine whether or not the favorable guidance point is on the present bearing line of target. Based on eqs.(1) and (2), we build two fuzzy rule bases as shown in Table (3) (for noninterference guidance) and Table (4) (for present bearing guidance). In Fig.3, a time variant gain unit is added to make the guidance law adaptive. Figs.(5) and (6) give the simulation results of present bearing guidance law and the new hybrid guidance law respectively. They show that our new hybrid guidance law can ensure that the vehicle is always outside the interference zone (Fig.6a), and that the favorable guidance point can be gradually turned to the bearing line of target(Fig.6b).