Measurement system for key attitude parameters of hydraulic support

The existing hydraulic support attitude monitoring methods have the problems of incomplete measurement parameters, low precision and reliability, and poor adaptability to working conditions. In order to solve the above problems, a key attitude parameter measurement system for hydraulic supports is proposed. The system combines direct and indirect measurement. An attitude sensor with DSP as the core, MEMS inertial navigation as the measurement element and with LoRa wireless function, is developed. The key parameters affecting the support attitude of hydraulic supports are analyzed. The parameters include the angle between the base, front connecting rod, cover beam, and top beam and the horizontal plane, as well as the displacement distance, which are directly measured. The support height, column, and balance jack length are indirectly measured. The system includes four attitude sensors installed on the base, front connecting rod, cover beam, and top beam, as well as one infrared laser ranging sensor installed on the base. The system is networked using LoRa wireless communication. The attitude sensor at the base serves is used as a gateway (i.e. gateway sensor) to measure the angle between the base and the horizontal plane, control the infrared laser ranging sensor to measure the displacement distance, and calculate the support height, column length, and balance jack length. The other three attitude sensors are served as nodes (i.e. node sensors) to measure the angle between the front connecting rod, cover beam, and top beam and the horizontal plane, and report the obtained angle information to the gateway sensor. The test results show that the maximum absolute error of attitude angle measurement is 0.2°. The maximum percentage relative errors of support height, column length, and balance jack length measurement are 0.78%, 0.72%, and 0.83%, respectively. The maximum absolute error of displacement step measurement is 1.9 mm. Taking the ZY9000/22/45D hydraulic support as an example, the error distribution under different attitude angle ranges is analyzed. The maximum measurement error of the support height is 27.4 mm, and the maximum measurement error of the column length is 16.6 mm.