Research On Noncommutativity Error Compensation Algorithm Of Strapdown Inertial Navigation System In High Dynamic Environment

The main factors that affect the accuracy of strapdown inertial navigation systems are: the accuracy of the inertial instrument,the accuracy of the navigation algorithm,the working environment of the navigation system,etc.Since it is very difficult to further improve the accuracy of high-precision inertial sensors and the price is very expensive,it is generally believed that the solution error of the navigation algorithm should be less than 5% of the error introduced by the inertial sensor.As the process of atomic gyroscope engineering is accelerating,the strategic applications of ultra-high-precision inertial devices such as hemispherical resonant gyroscopes and pendulum integrating gyroscope accelerometers have placed more stringent requirements on traditional navigation algorithms.At the same time,high-precision fiber strapdown inertial navigation systems and laser strapdown inertial navigation systems have been widely used in high dynamic environments,which highlights the problem of poor accuracy of traditional navigation algorithms under heavy maneuver conditions.How to optimize traditional navigation algorithms under high-precision and high-dynamic environments has become an urgent problem.The dissertation "Research on the high-precision noncommutativity error compensation algorithm of strapdown inertial navigation system under high dynamic environment" focuses on the following issues: Why does traditional attitude and velocity noncommutativity error compensation algorithm have accuracy loss in high dynamic environment,can't reach the claimed theoretical accuracy and there will be cases where the accuracy of the high sample compensation algorithm is lower than the low sample algorithm? How can we optimize the design of attitude and velocity noncommutativity error compensation,so as to improve the accuracy of the navigation algorithm and make it have the same performance in a high dynamic environment? What is the internal connection between the attitude noncommutativity error compensation algorithm and the velocity compensation algorithm? Why is there duality in the compensation coefficients derived from the two? Is there a simple way to directly convert the attitude compensation algorithm to the corresponding velocity compensation algorithm? In view of the above problems,the main research contents of this dissertation are as follows:Firstly,aiming at the problem that the traditional attitude update algorithm has poor accuracy in large cone angles or high dynamic environments,an error compensation algorithm for attitude noncommutativity with higher accuracy in high dynamic environment is proposed.In the theoretical derivation of the attitude compensation algorithm,the third-order and fourth-order terms of the Picard series of the equivalent rotation vector are considered,and the more accurate equivalent rotation vector is constructed using the angle increment information.Therefore,in the attitude calculation process has a smaller loss of accuracy.Theoretical analysis shows that the accuracy of the attitude noncommutativity error compensation algorithm proposed in this dissertation is two orders of magnitude higher than the traditional compensation algorithm,and the calculation amount per attitude calculation cycle is only 540 multiplications,which can be used in the actual navigation computer.In order to further evaluate the performance of the compensation algorithm,this dissertation also carried out simulation experiments in pure cone and high dynamic environments.The simulation experiment results show that the accuracy of the attitude noncommutativity error compensation algorithm proposed in this dissertation is better than the traditional algorithm under the two sports environments,which proves the effectiveness of the algorithm.Secondly,aiming at the problem that the traditional velocity update algorithm has poor accuracy under large maneuvering conditions or even the accuracy of the high-sample algorithm is lower than that of the low-sample algorithm,this dissertation proposes a higher accuracy velocity noncommutativity error compensation algorithm in high dynamic environment.In the optimization design process,the third-order and fourth-order terms of the Picard series of the velocity translation vector are considered for the first time.In this dissertation,the optimization design process of the compensation algorithm is given in detail and the coefficients of the three and four sub-sample error compensation algorithms are given.Since the compensation algorithm proposed in this dissertation is derived based on the more accurate velocity translation vector model,it has higher accuracy in principle.In addition,the results of simulation experiments in the pure stroke motion environment and high dynamic environment show that the speed error of the velocity compensation algorithm proposed in this dissertation is less than that of the traditional compensation algorithm,which proves the algorithm's performance effectiveness and superiority.Thirdly,this dissertation proposes a new conversion method,which can accurately convert the attitude compensation algorithm to the corresponding velocity compensation algorithm through simple calculations.This dissertation first starts with the differential equations of the equivalent rotation vector and the velocity translation vector,derives and gives the general formula of the error compensation algorithm for attitude and velocity non-commutability.The comparison shows that the algorithm compensation coefficients and expression forms are exactly the same,the general equivalence between velocity compensation algorithm and attitude compensation algorithm is proved.Then through summary and induction,the conversion method is proposed and the corresponding algorithm is given.Taking the equivalent rotation vector and the speed translation vector differential equations of the Picard series components as examples for conversion,the effectiveness of the conversion method is theoretically proved.Finally,taking the existing attitude noncommutativity error compensation algorithm as an example,the compensation algorithm is converted through the new conversion method and the conversion process and conversion result are given.The conversion results are exactly the same as the velocity error compensation algorithms derived in the corresponding literature,which further proves the effectiveness of the conversion method proposed in this dissertation.Furthermore,in order to verify the actual performance of the high-precision noncommutativity error compensation algorithm of strapdown inertial navigation system under high dynamic environment proposed in this dissertation,using the laboratory's self-developed fiber-optic strapdown inertial navigation system,the navigation algorithm accuracy verification tests were carried out in the pure conical motion environment based on the high-precision three-axis turntable,the high-line motion environment based on the vibrating table,and the live ammunition environment.The experimental results show that the noncommutativity error compensation algorithm proposed in this dissertation has higher accuracy in the high dynamic environment,which proves the effectiveness and feasibility of the algorithm proposed in this dissertation.