Research On Error Compensation Of SINS Based On Forward And Reverse Rotation

In the MEMS inertial measurement system,the key to improve the navigation accuracy is how to compensate the navigation error caused by the error of MEMS inertial device.The model researched in this paper is forward and reverse rotation of single axis.Then an equivalent rotation modulation scheme with the rotation of carrier is proposed to compensate error of MEMS inertial device.Firstly,the error model of inertial device are described in this paper.And the random error of MEMS is analysised with Allan variance method.And the experimental results showed that the noise in the random error mainly include: angle random walk,zero bias instability and the angular rate random walk.In order to use the carrier's forward and reverse rotation to construct the rotation modulation,the modulation mechanism of single axis rotating INS is analysis in this paper.And the errors caused by gyro drift?scale factor error and installation error are analyzed in detailed.Analysis are conducted on the error's propagation mechanism which are generated in the process of forward and reverse rotation.And according to the symmetric of carrier's attitude and velocity,a Kalman filter is constructed to estimate the constant error of inertial device.Observability analysis shows that the model is observable.In the simulation experiments,when all three gyro drifts of the SINS were 0.1(°)/h and accelerometer biases were 1mg,the gyro drift estimation precision was better than 0.035(degrees)/h,and the error of accelerometer bias estimation in the horizontal direction was less than 0.12 mg.The result shows that the scheme is feasible.The symmetric single axis forward and reverse rotation is rare in practice and can only be achieved in the laboratory.Therefore,to form a equivalent forward and reverse rotation with body frame,the carrier's equivalent reverse rotating frame is constructed.Then the attitude algorithm and velocity algorithm of the frame based on the carrier's IMU are proposed.Attitude errors and velocity errors,which are generated in the process of algorithm are also derived.Error compensation algorithm are designed with the equivalent forward and reverse rotation.Experiments shows that attitude errors were estimated accurately under the condition of static base simulation and the variation trend of attitude errors could also be estimated in the experiment of turntable.