Radio Remote Monitoring of Environmental and Conditional Data

This report presents the results of the development of a radio based system for the reliable transmission of condition monitoring data of a bandwidth of up to 10 kHz from a piece of mobile mining machinery to a location outside of the operations path of the unit and associated equipment. Alternatives for transmitting condition monitoring data from mobile mining machinery include power line systems (trailing cables). A radio based system offers greater flexibility and allows any piece of machinery to be monitored, potentially at lower cost.

This work was conducted under three ACARP projects entitled "Intrinsically Safe Remote Sensor for Monitoring the Condition of Underground Mining Equipment" (C3062), "Interfacing Radio Transmitted Machine Condition Data to Mine Communication Systems" (C4021) and "Radio Remote Monitoring of Environmental and Condition Data - Extension of C4021 and C3062" (C5421).

Test work during the project determined that a digital transmission system, operating in the 900 MHz to 1 GHz frequency range, offered the best combination of bandwidth, transmission in the underground environment, avoidance of noise from electrical equipment underground, and transmission power allowable under Australian broadcasting regulations. A prototype Remote Sensor system for the collection and radio transfer of condition based monitoring (CBM) data based on a digital radio system was completed. The system:

• reliably transmits realistic CBM vibration data over a distance of > 65 m on line-of-sight and 40 m off line-of-sight,
• transmits reliably in areas with moderate levels of electrical noise,
• is capable of simultaneously capturing and transmitting data from multiple locations on a mobile machine to a single monitoring station,
• is designed to meet Intrinsic Safety requirements.

Recommended further steps include:

• evaluation of the system in an active continuous mining operation, with the objective of determining the transmission performance in the high electrical interference environment and identifying the range of safe positions for locating the Receiver unit in normal operation,
• assess the transmission characteristics in a variety of seam conditions, to confirm the conclusion that the system will transmit with acceptable levels of attenuation in the full range of conditions found in Australian underground coal mines,
• commercialise the technology through an established supplier of electrical equipment to the underground mining industry. Discussions have already been held with potential suitable companies.