Study On Performance Analysis And Tracking Control Of Hybrid Airship Based On Multi-vector Control

The airship is a high-altitude aerial vehicle that can be lifted and stay in the air for a long time,it relies mainly on static buoyancy.It is characterized by its large load and low energy consumption.and has unique advantages in the military and civilian fields.The aircraft can be used for ground monitoring,forest fire monitoring for example,communication relays and heavy-duty transport.However,the flying environment of conventional airships is relatively complex and the way taking off and landing of it is single.It is very vulnerable to the external environment during flight.The buoyant hybrid airship is a new type aircraft.This aircraft has both the aerodynamic characteristics of conventional aircrafs and airships.Flight height of the hybrid airship is between 500 meters and 3 kilometers,and it has a good flying environment.The external environment interferes less during the flight.During the flight it is necessary to ensure the stability and controllability of the aircraftTherefore,the stability of the hybrid airship when flighting and the design of the tracking control law have become the key to research on buoyant hybrid airship.Buoyant hybrid airship has huge volume and relatively slow running speed,as well as unique aerodynamic shape.All this increase the difficulty of designing the control law.Considering these conditions,this paper will take the buoyant hybrid airship as a research object,establish a mathematical model,and design a trajectory tracking control method and a guided path tracking control method on the basis of the model to perform flight performance analysis and tracking control design.The main work of this article is as follows:1.The construction of model of the buoyant hybrid airship.Constructing a coordinate system by analyzing the force of the buoyant hybrid airship,by the way referencing the conventional airship modeling method,Gravity,static buoyant force,aerodynamic force,additional inertial force and thrust vector in different coordinate systems are converted into a unified coordinate system through coordinating conversion.A nonlinear mathematical model for six degrees of freedom of a hybrid airship was established.On this basis,the small disturbance linearization method was used to analyze the influence of additional mass on the flight stability of the hybrid airship.2.Design of trajectory tracking control law for buoyant hybrid airship.The trajectory tracking control method is used to divide the mathematical model into four loops,which are the attitude kinematics loop,attitude dynamics loop,positional kinematics loop and positional dynamics loop,and the virtual control volume is designed.The method of dynamic control allocation based on quadratic programming is used to allocate redundant control quantity,and the actual control quantity is obtained.The tracking effect is verified by Matlab simulation software.3.Design of path following control law for the buoyant hybrid airship.The guidance path tracking control method is used to obtain the desired attitude angle when tracking the desired path.The trajectory tracking control is used to divide the mixed airship model into three loops,and a virtual control quantity is obtained.Based on this,redundant allocation of control quantity is performed,and the actual control quantity is obtained by using a dynamic control allocation method based on quadratic programming.Finally,using Matlab to verify the feasibility and effectiveness of the designed control law.