| With the continuous development of science and technology,inertial navigation technology is more and more widely used in the military and in our daily life.Traditional inertial navigation will accumulate over time,and the accumulation of errors will slowly increase,resulting in a decrease in orientation accuracy.Geomagnetic orientation system can effectively make up for this defect and improve the measurement accuracy.However,in the geomagnetic orientation platform,the accelerometer and gyroscope in the inertial measurement unit will be affected by external noise during the work process,and the geomagnetic sensor will also be affected by the soft and hard magnetic interference and temperature drift in the surrounding environment,reducing the Correctness.This topic designs a high-precision geomagnetic orientation platform hardware circuit,through anti-interference processing of the error analysis of the inertial measurement unit,and temperature compensation algorithm design for the geomagnetic sensor,on this basis,the use of high-precision attitude calculation algorithm To achieve geomagnetic orientation.First,according to the functional requirements of the geomagnetic orientation platform,the hardware circuit design of the microprocessor module,inertial measurement unit module,geomagnetic sensor module,temperature sensor module,data storage module and data transmission module is implemented.The directional platform realizes the requirements of low power consumption,small area and high reliability,which is convenient for outdoor use and portable.Then according to the design of the functional modules of each part,the driver design of the module is completed,so that each part of the module can realize the basic functions of data acquisition,transmission and storage.Because the geomagnetic directional platform is working,the sensor module is susceptible to interference from external noise during the data collection process,so that the output has drifts and unstable signals.Therefore,the first-order low-pass filter and IIR filter are used to reduce the noise of the inertial measurement unit.And use PSO-LSSVM algorithm to compensate the temperature of geomagnetic sensor,so as to reduce the influence of external temperature on geomagnetic sensor.After obtaining the sensor data after noise reduction,the initial attitude angle value is obtained by the gradient descent method using the geomagnetic field data and the acceleration data,and then the final attitude angle information is obtained by using the data fusion method and the angular velocity data.Finally,the hardware and software testing and algorithm simulation of the geomagnetic orientation platform are carried out.Build a test platform and design a test program for functional modules.After testing,all functional modules can work normally.The sensor module can send the data to the main control module for data processing after the data collection,and the main control module can send the processed data To external equipment.Through algorithm simulation,the accuracy of the data collected by the sensor is improved after filtering and temperature compensation.The rms error of the acceleration signal decreases from 0.0051 g to0.0015 g,and the rms error of the angular velocity signal decreases from0.1732 °/sto 0.0618 °/s.The fluctuation range of the geomagnetic sensor is controlled within 0.003 μT by the temperature.Finally,the post-noise data is used to solve the attitude,and stable and high-precision attitude information can be obtained,and the accuracy of the attitude angle during the static test can be achieved within 0.131°.Meet the requirements of the subject. |
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