Improvement of the measurement accuracy of the support-rotary platform of the antenna system using mems accelerometers

Abstract

Досліджено похибки, що виникають внаслідок поперечного нахилу площини корпусу сенсора кута на основі MEMS інклінометра. Наведено результати дослідження, отримані при вимірюваннях кутів опорно-поворотної платформи антени, запропоновано метод підвищення точності на основі використання трьохосьового MEMS акселерометра та процедури калібрування сенсора перед початком роботи.Summary The article is devoted to the research of errors arising from the influence of non-linear characteristics of MEMS gyroscopes, which appear at high angles deviation plane of the crystal sensor from horizontal surface, and also from the influence of cross slope plane casing MEMS inclinometer which is based on gyroscopic sensor. The research for the purpose of estimation possibility of using such sensors for precision control tasks in controlling antenna system based on support-rotary platform with paralel kinematic links and octahedral composition Hexapod type and other targeting systems have been performed. The automated laboratory stand for research of MEMS gyroscope parameters which allows to compare results of measurements and data of pecision optoelectronic angle sensor in range ±90° with presence of transverse slope influence has been developed. The results of experimental research, which shows main sources of MEMS inclinometer errors with their numerical estimation, are presented. The method of increasing the accuracy of the angular position determination by means of using three-axis MEMS accelerometer is proposed and sensor calibration procedure before commencement of operation is considered. The importance of the method based on considering information received from two other mutually-perpendicular coordinate axes to compensate the negative influence of cross slope on the main axis by creating cross interactions correcting matrix has been analysed. Due to angle calculation using 12 calibrated parameters the errors were decreased owing to crystal cross slope influence and MEMS sensor non-linearity conversation with slope angles above 45 degrees. The using of the method has practical value in the tasks of designing precision antenna complex control systems with new the Hexapod type support-rotary platforms, in robotics and many other technical targeting systems. The method allows to increase the accuracy, reliability and to reduce the cost of such systems