Research on Ultrasonic Transducers to Accurately Determine Distances in a Coal Mine Conditions

Determining the location of objects, for example roadheader in a hard coal mine, is a task that should be automated in the conditions of state-of-the-art mining. Current solutions do not meet the user’s expectations due to the lack of the possibility of automation, maladjustment to the environment of a hard coal mine or not meeting the legal requirements. The article describes the initial stage of work on an automatic system for determining the position of machines in difficult underground conditions, including the analysis of requirements and constraints, an overview of available solutions, technologies and algorithms, as a result of which devices were selected for further tests. To determine the location, it is necessary to take distance measurements with high accuracy, despite the disturbances resulting from the working environment. Ultrasonic devices were selected and then tested under various operating conditions, including different distances between the transmitter and receiver as well as different directions and intensities of air movement that could distort the measurement results. During tests, sufficient accuracy, as well as other parameters, of the ultrasonic transducers were confirmed, allowing for distance measurements in the required range, suitable for use in the real-time locating system (RTLS) being developed.