Research On Locomotive Communication Behavior Strategy Of Underground Unmanned System

The mine locomotive unmanned system can reduce the number of underground workers, and avoid the transportation accident caused by scheduling and operation errors effectively. The system will bring prominent benefits to the society and economy based on above advantages. Realizing the unmanned system is on the premise of the reliable wireless data transmission. The thesis studied the communication behavior issues of the driving locomotive with access points (AP), and proposed the access and handoff strategies. The specific work is as follows.(1)The underground mobile access network model which was bilateral symmetry redundant was presented to improve the reliability of wireless communication. The access points were symmetrically installed on the both sides of the roadway, and they were reasonably arranged based on the need of the wireless access and handoff. Thus, the redundant structure of the underground wireless communication was constituted, and the favorable wireless communication condition was provided for the unmanned system.(2)The locomotive access optimization strategy based on the AP coverage region partition was proposed to optimize the total effect of locomotives’total passing time and AP coverage utilization. Firstly, the region partition model was constructed in the AP communication coverage, and then the interference constraint condition and the optimization goal were received according to relevant analysis. Secondly, according to the theoretical derivation, the correlation between the number of region partitions and the AP communication coverage radius and the correlation between the locomotive position in the partition and the transmission power were found respectively. Finally, the Successive Interference Cancellation (SIC) region partition strategy was proposed. The simulation results show that the access strategy can make one AP access three locomotives at the same time, and the total optimization effect increases at least 50%.(3)The AP handoff strategy based on Markov Decision Process (MDP) model was proposed to maximize the network expected total utility composed of bandwidth, delay, signaling overhead. Firstly, the underground wireless handoff model was built. Secondly, the compromise factor was introduced, which combined the available bandwidth and handoff delay to get the revenue function, and then the communication revenue was connected with the signaling overhead to define the utility function. Finally, the handoff strategy based on MDP could be got by using the discount model of infinite stage and the Bellman Equation. The simulation results show that the expected total utility of the handoff strategy is superior to the ipsilateral AP handoff scheme and the high bandwidth handoff scheme.