The Design And Simulation Of Intelligent Guidance Law

Guided weapons are required to be able to adapt to the complex operationalenvironment in the modern warfare, at the same time have the ability to hit high-speedand large maneuvering targets, which makes a higher requirement for theanti-interference ability and precise technical ability of guided technology. Variableuniverse fuzzy control is not based on an accurate model of the controlled object,meanwhile, it has strong robustness and high control precision, and thus it is suitable forthe design of missile guidance law. Due to the sliding mode variable structure controlhas invariance to parameter uncertainties and external disturbance, guidance law whichis based on the theory of variable structure control, has been widespread concerned, butthe chattering problem seriously limits the application and promotion of variablestructure guidance law. On the basis of further study of this missile guidance technology,variable universe fuzzy control theory and the theory of variable structure control, thispaper designs intelligent variable universe fuzzy guidance law and intelligent variablestructure guidance law. Main contents of this paper are as follows:First, based on the missile and target movement, the paper establishes a model ofguided simulation, and based on the amount of off-target calculation accuracy sets up asuitable simulation step size.Secondly, in the deep analysis of the variable universe and the essentialcharacteristics of the variable quantification factor, the paper uses theoretical analysisand graphical comparison to reveal the differences and connections between variableuniverse and the variable quantification factor, and proposes the conclusion that variablequantification factor is a realization way of the variable universe.Furthermore, this paper discusses the problems of contraction-expansion factor,analyzes the influence of the various components to the system control performance inthe theory and verifies the results by simulation. Based on the above analysis, animproved design of the contraction-expansion factor methodology is proposed,coordinating the error and the error rate, thereby improving the control performance.Then the improved variable universe fuzzy control design is applied for the guidancelaw to design an intelligent variable universe fuzzy guidance law. Through thesimulation, the paper compares the intelligent variable fuzzy guidance law withtraditional proportional navigation law and common variable universe fuzzy guidancelaw, and simulation results show that the guidance law for a variety of maneuveringtargets have good interception performance.Finally, the paper designs a new variable structure guidance law. Selecting theswitching function as relative velocity declination and using power reaching law to design a variable structure controller, in order to ensure the system status can reach thesliding mode before hitting the target, the parameters for reaching law are designed.Then in order to weaken the chattering of variable structure items, the paper proposes aintelligent gain design method, and because the method is not based on the guidancesystem model, it can be extended to a general variable structure design. Through thecomparison of simulation with several other guidance laws, the simulation results showthat the designed variable structure guidance law can be achieve effective interceptionof a variety of maneuvering targets on the basis of no chattering.