Improvement of Measurement Method and Design of Intelligent Sensor for Shearer Drum Height

The shearer drum height measurement plays a crucial role in the fully mechanized mining face. This paper proposes a measurement method of drum height, taking the ranging arm swing-angle and fuselage attitude angle into consideration; therefore, compared with the existing drum height measurement methods, our approach adheres more to the actual operating conditions of the shearer. Based on our approach, we further developed a shearer drum height sensor. Firstly, TLE5012B (MEMS magnetic angle chip) and MPU6050 (MEMS inertial navigation chip) are selected as the sensing elements of swing-angle and attitude angle, respectively. Secondly, a “rocker-rotating shaft” is designed to convert the swing-angle into the rotation of TLE5012B’s external magnetic field. Thirdly, an intelligent drum height sensor based on DSP-TMS320F28335 is developed, including hardware circuits and software that measure and process the angle data, calculate the drum height, store and display the data, and transmit the data by CAN or WIFI. Fourthly, the magnetic field distribution and vibration source of the shearer are simulated and analyzed, and the magnetic shielding shell and anti-vibration device are designed to reduce the influence of external factors on the sensor. Furthermore, a sensor prototype was developed and experimentally tested. The maximum absolute errors of sensor swing-angle, pitch angle, roll angle, and drum height were 0.16°, 0.07°, 0.06°, and 6.7mm, respectively. Finally, we establish a measurement error model of shearer drum height and calculate the maximum measurement error is 2.24cm. The results show that our approach and sensor meet the requirements of shearer drum height measurement.