1、Application of Opto-tactile Sensor in Shearer MachineDesign to Recognise Rock Surfaces in UndergroundCoal Mining Abstract the success of automation applications in the mining industry traditionally has not been well. In many of these cases the benefits of automation have been advertised as thedefini
2、tive solution to a wide variety of problems faced by themining industry, such as increased safety and improvedproductivity. These applications have in many cases been introduced prematurely without adequate consideration of the rigors of the mining environment. As a result, effective technology has
3、often been labeled as a failure before it has had a chance to demonstrate its true capability. Therefore, we believe that a major requirement is essential to develop automation technologies for mining systems or sub-systems, which needs minimal operator input requirement. This can be achieved in sev
4、eral ways. First, by narrowing the domain in which the automated mining system must operate such that less complex automation technology can be applied robustly. Alternately, more sophisticated control technologies are required that can react to the wider range of operating mining scenarios resultin
5、g from an uncertain, dynamic and very unstructured geological highly variable and unpredictable environment. Automation of shearer machines, with the help of an opto-tactile sensor, should make the machine capable to detect the coal-rock interface in the roof and the floor. In this article an attemp
6、t has been made to apply, in association with an existing shearer machine, a newly developed opt-tactile sensor to detect different types of material layers where a shearer machine can operate at the longwall face of underground coal mines. The proposed tactile sensor should be capable to detect dif
7、ferent types of materials (coal, limestone, sandstone, and shell) recognizing their surface textures.Keywordsshearer machines, coalmining, rock/coal interface, automation, opto-tactile sensor I. INTRODUCTION AND PROBLEM ORIENTATION Shearer machines used in Australian underground longwallcoal mining
8、operations, consists of, as major units (Fig. 1), adriven rotating cutting head (cutting drum), range arm,hallway section (armoured face chain conveyor AFC), control section, main body, squirrel cage induction motor, and speed reducer. The 5m long high torque rotating cutting head removes coal seams
9、 up to five meters thick from the coal-wall. The environment is noisy, dusty and potentially explosive. Making longwall coal mining safer and more productive has been the subject of a long-running CSIRO project funded by the Australian Coal Association Research Program, which has also come up with n
10、ew technology designed to locate and guide coal-cutting equipment in longwall mines. The downtime statistics of Australian longwall mining operations showed that 10 categories of machine-related failures accounted for 50 percent downtime 1. Amongst the major ones are face alignment, horizon control,
11、 information system and open communication between subsystems. A fully automated shearer machine must include and address these issues. Currently, shearer automation refers mainly to horizon control, i.e. how to automatically control the shearers cutting horizon so that it always stays in-seam and c
12、uts a uniform thickness. In order to achieve this, the shearer must be able to recognize the coal-rock interface in the roof and floor of coal mines. Furthermore, once it determines the horizon of coal-rock interface, it must immediately adjust its cutting drum position. In addition to an onboard mi
13、croprocessor that stores and analyses data and issues commands, an automated shearer system needs a coal-rock interface detection system and inclinometers for measuring and adjusting the drum height and body pitch. The gamma ray coal thickness measurement system has been used to detect the coal-rock
14、 interface 2. Gamma radiation is high in shale, lower in sandstone, almost absent in limestone and virtually undetectable in coal 3. Natural gamma ray background (NGB) sensors are used in longwall coal mining operation for the detection of coal-rock interface. Many coal-rock interface detectors have
15、 been developed and tested, but all of them are still in the experimental stage. These are based on pick force, rock vibration and video camera 4 principles. A pick force measurement system determines thevariation of cutting forces on instrument bits by identifying the special characteristics of the
16、 cutting force required to cut the immediate roof. This system is based on the principle that the cutting force required to cut the immediate roof in a coal seam differs from that for the coal. By processing the variation in pick force with an onboard computer, the coal-rock interface can be identified. To distinguish coal-rock interface a vibration assessment system utilizes the principle of differences between the vibration characteris
