The invention relates to a milling machine having a replaceable milling drum, different types of milling drums being capable of being associated with the milling machine; and having a control unit for controlling the milling machine, machine parameters of the milling machine being settable by way of the control unit. Provision is made that the milling machine has associated with it at least one means that is designed to detect at least one characteristic feature of the milling drum; that the at least one means is connected to the control unit; and that the control unit is designed to specify for at least one machine parameter, indirectly or directly from the characteristic feature, a value to be set, and/or a setting range. The invention further relates to a corresponding milling drum and to a corresponding method. The milling machine, milling drum, and method allow the selection of machine parameters for operation of the milling machine to be simplified.

An apparatus includes a current excitation source, a roadheader telescopic protection cylinder, an electric rotating apparatus, auxiliary cutting teeth, a cutting head entity, a transmission shaft, an optical fiber ring protective housing, an optical fiber ring, an optical fiber current sensor control unit and a recovery electrode. The apparatus transmits an auxiliary current I.sub.e and a monitoring current I.sub.d to a coal seam. The auxiliary current I.sub.e and the monitoring current I.sub.d are homologous currents that are incompatible, and the auxiliary current I.sub.e squeezes the monitoring current I.sub.d, so the monitoring current I.sub.d monitors the environment of the coal seam. The monitoring current I.sub.d flows to the coal seam as, and a return current I.sub.f flows through the transmission shaft and a roadheader expansion part. The optical fiber ring measures the return current I.sub.f, when the roadheader is heading forward and encounters abnormal geological bodies.

An apparatus includes a current excitation source, a roadheader telescopic protection cylinder, an electric rotating apparatus, auxiliary cutting teeth, a cutting head entity, a transmission shaft, an optical fiber ring protective housing, an optical fiber ring, an optical fiber current sensor control unit and a recovery electrode. The apparatus transmits an auxiliary current I.sub.e and a monitoring current I.sub.d to a coal seam. The auxiliary current I.sub.e and the monitoring current I.sub.d are homologous currents that are incompatible, and the auxiliary current I.sub.e squeezes the monitoring current I.sub.d, so the monitoring current I.sub.d monitors the environment of the coal seam. The monitoring current I.sub.d flows to the coal seam as, and a return current I.sub.f flows through the transmission shaft and a roadheader expansion part. The optical fiber ring measures the return current I.sub.f, when the roadheader is heading forward and encounters abnormal geological bodies.

A method includes the steps of: receiving a three-dimensional model of an underground tunnel; identifying floor points among points of the three-dimensional model; extracting the floor points; and applying at least a part of the extracted floor points as a floor model of the tunnel for positioning or route planning of a mobile object in the underground tunnel.

A method includes the steps of: receiving a three-dimensional model of an underground tunnel; identifying floor points among points of the three-dimensional model; extracting the floor points; and applying at least a part of the extracted floor points as a floor model of the tunnel for positioning or route planning of a mobile object in the underground tunnel.

Methods and systems of monitoring and controlling a longwall mining system. One system includes a shearer including a cutter drum and a sensor mounted to the shearer. The system also includes an electronic controller including a processor and a memory. The electronic controller is configured to receive an impact event indication associated with an impact event of the cutter drum, the impact event indication based on vibration data collected by the sensor. The electronic controller is also configured to retrieve additional data associated with the impact event indication and link the additional data with the vibration data of the impact event indication. The electronic controller is also configured to create and store an impact event record including the vibration data and the additional data. The electronic controller is configured to, in response to receiving a maintenance request, export the impact event record for display.

Methods and systems of monitoring and controlling a longwall mining system. One system includes a shearer including a cutter drum and a sensor mounted to the shearer. The system also includes an electronic controller including a processor and a memory. The electronic controller is configured to receive an impact event indication associated with an impact event of the cutter drum, the impact event indication based on vibration data collected by the sensor. The electronic controller is also configured to retrieve additional data associated with the impact event indication and link the additional data with the vibration data of the impact event indication. The electronic controller is also configured to create and store an impact event record including the vibration data and the additional data. The electronic controller is configured to, in response to receiving a maintenance request, export the impact event record for display.

Methods and systems of monitoring and controlling a longwall mining system. One system includes a shearer including a cutter drum and a sensor mounted to the shearer. The system also includes an electronic controller including a processor and a memory, the electronic controller communicatively coupled to the sensor. The electronic controller is configured to receive vibration data from the sensor and determine a current vibration level experienced by a cutter drum of the shearer based on the vibration data. The electronic controller is also configured to compare the current vibration level to a vibration threshold. The electronic controller is also configured to detect an impact event associated with the cutter drum of the shearer based on the comparison and generate an impact event indication associated with the impact event.

Methods and systems of monitoring and controlling a longwall mining system. One system includes a shearer including a cutter drum and a sensor mounted to the shearer. The system also includes an electronic controller including a processor and a memory, the electronic controller communicatively coupled to the sensor. The electronic controller is configured to receive vibration data from the sensor and determine a current vibration level experienced by a cutter drum of the shearer based on the vibration data. The electronic controller is also configured to compare the current vibration level to a vibration threshold. The electronic controller is also configured to detect an impact event associated with the cutter drum of the shearer based on the comparison and generate an impact event indication associated with the impact event.

Various examples are provided related to methane detection in harsh environments. In one example, a method includes drawing a sample of air from at least one first location; delivering the sample to a volume within a sensor block at a second location, where the sensor block includes a gas concentration sensor in communication with the volume; and where a vacuum is applied to the volume within the sensor block to facilitate delivery of the sample to the second location. In another example, a system includes a sampling unit that houses a sensor block, where a sample tube is coupled to an inlet of the sensor block, which includes a gas concentration sensor; an ejector that facilitates delivery of a sample of air from the first location via the sample tube; and a control unit that can receive a gas concentration sensor output from the sampling unit for processing.