Pure Inertial Navigation Data (IMU) Position Calculation

Pure inertial data (IMU) position calculation is a common positioning technology. It calculates the target object in real time by using the acceleration and angular velocity information obtained by the Inertial Measurement Unit (IMU), combined with the initial position and attitude information. s position. This article will introduce the principles, application scenarios and some related technical challenges of pure inertial navigation data position calculation.

1. Principle of position calculation based on pure inertial navigation data

Pure inertial navigation data position calculation is a positioning method based on the principle of inertial measurement. IMU is a sensor that integrates an accelerometer and a gyroscope. By measuring the acceleration and angular velocity of the target object in three directions, the position and attitude information of the target object can be derived.

In pure inertial navigation data position calculation, it is first necessary to obtain the initial position and attitude information of the target object. This can be achieved by introducing other sensors (such as GPS, compass, etc.) or manual calibration. The initial position and attitude information play an important role in the solution process. They provide a starting point so that the acceleration and angular velocity data measured by the IMU can be converted into the actual displacement and attitude changes of the target object.

Then, based on the acceleration and angular velocity data measured by the IMU, combined with the initial position and attitude information, numerical integration or filtering algorithms can be used to calculate the position of the target object in real time. The numerical integration method obtains the speed and displacement of the target object by discretizing and integrating the acceleration and angular velocity data. The filtering algorithm uses methods such as Kalman filtering or extended Kalman filtering to filter the data measured by the IMU to obtain the position and attitude estimation of the target object.

2. Application scenarios of pure inertial navigation data position calculation

Position calculation based on pure inertial navigation data is widely used in many fields. Among them, indoor navigation is one of the typical application scenarios for pure inertial navigation data position calculation. In indoor environments, GPS signals are usually unable to reach, and pure inertial navigation data position calculation can use the data measured by IMU to achieve accurate positioning of target objects indoors. This is of great significance in fields such as autonomous driving and indoor navigation robots.

Pure inertial navigation data position calculation can also be used in the aerospace field. In aircraft, since the GPS signal may be interfered at high altitudes or far from the ground, pure inertial navigation data position calculation can be used as a backup positioning method. It can calculate the position and attitude of the aircraft in real time through the data measured by the IMU, and provide it to the flight control system for attitude stabilization and flight path planning.

3. Challenges of position calculation using pure inertial navigation data

Position calculation based on pure inertial navigation data still faces some challenges in practical applications. First of all, the IMU sensor itself has errors and noise, which will affect positioning accuracy. In order to improve the solution accuracy, the IMU sensor needs to be calibrated and error compensated, and an appropriate filtering algorithm is used to reduce the error.

Position calculation based on pure inertial navigation data is prone to cumulative errors during long-term movements. Due to the characteristics of the integration operation, even if the measurement accuracy of the IMU sensor is high, long-term integration will lead to the accumulation of positioning errors. In order to solve this problem, other positioning means (such as GPS, visual sensors, etc.) can be introduced for auxiliary positioning, or a tightly coupled inertial navigation method can be used.

Position calculation based on pure inertial navigation data also needs to consider the impact of the dynamic environment. In a dynamic environment, the target object may be affected by external forces, causing deviations in the data measured by the IMU. In order to improve the robustness of the solution, the effects of dynamic environments can be compensated through methods such as motion estimation and dynamic calibration.

Summarize

Pure inertial data position calculation is a positioning method based on IMU measurement. By acquiring acceleration and angular velocity data, combined with initial position and attitude information, the position and attitude of the target object are calculated in real time. It has wide applications in indoor navigation, aerospace and other fields. However, pure inertial navigation data position calculation also faces challenges such as calibration error, cumulative error and dynamic environment. In order to improve the solution accuracy and robustness, appropriate calibration methods, filtering algorithms and auxiliary positioning methods need to be adopted. The MEMS IMU independently developed by ERICCO has relatively high accuracy, such as ER-MIMU-01 and ER-MIMU-05, which have higher accuracy and are navigation-grade products. If you want to know more about IMU, please contact our professional technicians as soon as possible.