Research On Several Key Techniques Of Mins/gnss Integrated Navigation System In The Guided Projectiles

Based on the advantages of rapid reaction speed,high attack ability of a point target with little damage,the precision guided projectile has become one of the indispensable weapons in the modern battlefield.With the development of MEMS technology,MINS made up of these sensors has been widely used in the application of the smart weapons.The smart weapons based on MINS/GNSS can fully take the advantages of small size,high precision and low cost.Thus,the development of precision guided projectile based on MINS/GNSS can improve the operational performance of the conventional artillery weapon system.Aiming at the application background of the guided projectile,this paper used domestic developed MEMS inertial sensors to construct the MINS/GNSS integrated navigation system for the guided projectiles.In order to improve the guided precision of the projectile,several key techniques for the system have been studied.The major research contents are as follows:(1)Designed the MINS/GNSS integrated navigation system for the guided projectile.According to the features of high initial speed and high impact of the guided projectile,and considering the complexity of the navigation algorithm,reaction speed,output frequency and the volume of the system,MIMU data acquisition module,differential GNSS receiver and MINS/GNSS navigation system have been designed.This hardware system can be used for the turntable tests and the projectile tests,which provided a test platform for the following research algorithms.(2)A novel network calibration method for inertial measurement units was studied.Since the output model for the angular rate and the specific force of the MIMU calibrated in the laboratory can be changed by the actual application environment,such as the temperature,humidity and so on,a network calibration algorithm for multi MIMU was proposed,which includes the inner and outer filter algorithms.According to the different installation of the system,the observability of the parameters for the output model of angular rate and specific force has been discussed emphatically.Also,the detail calibration procedure has been arranged.Simulation experiment demonstrated the validity of the network calibration method.(3)Aiming at the projectiles with large spin angular velocity,an in flight alignment algorithm based on the characteristic parameter of the projectile was studied.First,the feature of the projectile in stable flight is analyzed.And then,on the base of the angular motion theory for the exterior ballistics and its simplify model,the in flight alignment model was established.Error analysis for the established alignment model was also discussed.The simulation was carried out to evaluate the performance of this algorithm.(4)Aiming at the projectiles with low spin angular velocity,an in flight alignment algorithm based on large acceleration and deceleration maneuver using dual vectors was studied.According to the attitude determination principle of the dual vectors,the Request algorithm was applied for the alignment of MINS in the projectile by the dual vectors which were derived from the velocity differential equation for the navigation.And then,error analysis was discussed,therefore putting forward the large acceleration and deceleration maneuver for the in flight alignment.Simulations were performed and errors were analyzed.(5)Attack angle detection for the guided projectiles was studied.To solve the problem that the direct detection of the attack angle for the guided projectile in flight is difficult,a new method based on the coordinate cascade was proposed to estimate the attack angle.This method utilized the transform relationship among the coordinate systems,and then the detection model for the attack angle was established.Based on the trajectory data of a a fin-stabilized precision guided projectile,the simulation was applied.(6)Vehicle test and semi-physical simulation experiments for the guided projectile have been carried out.Vehicle test was designed to demonstrate the validity of the network calibration method.Semi-physical simulation experiments for the guided projectile were carried out by the three axis flight attitude simulation turntable,which verified the performance of the aforementioned algorithms.What's more,the experiment errors were analyzed.