Application of inertial navigation for determining the slippage of agricultural tractors

Introduction. The article substantiates the necessity of determining the slippage of the tractor wheels during testing. The principle of operation and design of the sensors used to determine the slippage of the driving wheel in the testing of tractors and agricultural machines are considered; design features and characteristics of common shunting sensors based on a rotating disk with slots through a fixed angle are noted. The authors analized advantages and key disadvantages of existing sensors, such as the complexity of mounting and the need to manufacture the sensor mounting parts for a specific tractor model. The aim of the study is to develop a universal slip sensor for testing wheel and tracked tractors. Materials and Methods. The proposed solution determines the positions of the driving wheel in three-dimensional space on the basis of the inertial navigation system. The principles of operation of inertial navigation system components are described. The system consist of an accelerometer, a gyroscope and a magnetometer. The basic mathematical digital orientation filters applied for processing raw data are analyzed. Results. The design of the tractor slip determination device is developed. The main element of the mechanism is an inertial wheel position sensor. The selection of the main components of the sensor is substantiated: name and model of the inertial navigation system, the digital orientation filter and the microcontroller for the functioning the sensor. As a result of the research, the position sensor of the driving wheel was designed and manufactured on the basis of the MPU-9250 inertial navigation system and the STM32F405 microcontroller. The sensor software was developed in C language. A digital filter was based on the Madgwick algorithm for real-time data processing. Discussion and Conclusions. The result of the research was the development of a sensor for slipping the tractor wheels based on an inertial navigation system. This type of sensor is devoid of the main disadvantages of the widely used sensors of driving wheels. The advantages of the sensor are easy installation and method of wireless data transfer.