Research On The Stability Of Rigid Airship

During the actual flight,it is inevitable that the airship encounters disturbance problems.When the airship is disturbed after flying in a balanced state,it will reach a new equilibrium state.Therefore,the research of the intermediate process is of great significance to the stability of the airship.In this paper,the dynamic modeling method and the six-degree-of-freedom motion model of the airship is systematically established to take the rigid airship as the research object.In order to study the influence of disturbance on the stability of the airship during flight,the disturbance is divided into two types.One is the change of the engine power and the rudder angle(motorized condition),the other is the disturbance caused by the external wind field(gust condition).At the same time,the nonlinear balance equations of the airship are established to calculate by autonomous programming.After the disturbance is added,the initial balance state of the airship will be destroyed and it will reach a new equilibrium state.The process between the two equilibrium states is simulated by the autonomous programming program and then the flight path and motion attitude of the airship during the two types of disturbances can be analyzed,which is used to analyze the stability performance of the airship.It is of certain guiding significance to study the stability of the airship during actual flight.Through the self-written program combined with the dynamic equation of the airship,the stability of the airship under motorized condition and gust condition was studied and calculated.The following main conclusions were obtained through analysis:(1)For different motorized conditions,the time required from the initial equilibrium state to the end state after completion of the corresponding motorized conditions is different.At the same time,the greater the pitch angle required for the airship to complete the balance of the motorized condition,the longer the airship reaches a new equilibrium state,and the worse the stability of the airship after being disturbed.(2)For the same motorized condition,as the engine power and the rudder angle changing time reduce,the time for the airship to reach the new equilibrium state from the initial equilibrium state will be decreased,and the flight stability of the airship is improved;As the time decreases,the peak of the inertial load experienced by the airship will also increase,which is adverse for the flight process of the airship.(3)For different gust conditions,as the time of gusting on the airship is decreased,the peak value of the gust load on airship is increased,which is unfavorable for the flight of the airship under gust conditions.At the same time,as the gust speed reduce,the maximum value of the gust load on the airship will decrease,which is more favorable for the airship to return to its original stable state.