Calibration method and device for inertial measurement unit

Abstract

The invention discloses a calibration method and device for an inertial measurement unit. The method comprises the steps of respectively acquiring original values of a gyroscope and original values ofan accelerometer under different attitudes; respectively dividing the original values of the gyroscope and the original values of the accelerometer into static values and dynamic values according tothe original values of the gyroscope under different attitudes and static judgment; carrying out parameter calibration on the static values of the accelerometer according to a preset accelerometer parameter calibration model to obtain a calibration values of the accelerometer under each different attitude; carrying out parameter calibration on the gyroscope according to the calibration value of the accelerometer under each different attitude, the corresponding original value of the gyroscope and a preset gyroscope parameter calibration model so as to obtain a calibration value of the gyroscopeunder each different attitude. The calibration method realizes accurate recognition and extraction of static and dynamic data, not only can be used for multi-parameter calibration of the inertial measurement unit, but also can be used in application scenarios such as pedestrian dead reckoning and pedestrian gait recognition.

Description

technical field [0001] The invention relates to the technical field of inertial navigation, in particular to a calibration method and device for an inertial measurement unit. Background technique [0002] Mobile phone IMU (Inertial Measurement Unit, inertial measurement unit) is a consumer-grade IMU, usually including 6-axis (three-axis gyroscope + three-axis accelerometer) or 9-axis (three-axis gyroscope + three-axis accelerometer + three-axis Magnetometer) is used to measure the angular velocity and acceleration of the carrier in the inertial space (9 axes plus magnetic flux), and then the attitude and position information of the carrier can be solved. [0003] Consumer-grade IMUs are widely used in the field of navigation, especially in the field of civil navigation, especially in combination with other sensors, such as IMU and satellite navigation (GPS, BDS) fusion, or IMU and camera fusion visual inertial odometer (VIO, visual-inertialodometry), which can be widely use...

AI Technical Summary

Problems solved by technology

This method has the following deficiencies: 1. There are strict requirements on the attitude of the IMU placement. It needs to rotate 180° around a certain axis strictly between the six attitude states, which has relatively high requirements for operation; 2. This calibration method requires Equipment such as thermostats, single-axis or multi-axis turntables, and hexahedron fixtures have high requirements for calibration equipment, and it takes a lot of material and financial resources to calibrate once.

This method has the following disadvantages: 1. Only the zero offset and scale factor parameters of the IMU are calibrated, and the misalignment angle parameters between the three axes are not calibrated, which will directly affect the calculation accuracy of the IMU. The optimization method of the 12-dimensional state equation of Kalman filtering is lower than the method of nonlinear graph optimization in theoretical accuracy; 2. Without the support of any hardware equipment, it is difficult to guarantee the quality of static data collection. The handheld IMU collection proposed in the invention Static data is easily affected by hand shake, which in turn affects the accuracy of parameter calibration

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