| With the characteristics of self-organizing,strong expansibility and convenient and flexible deployment,the mechanical vibration wireless sensor network can make up for the shortcomings of the traditional cable machinery vibration monitoring in the application environment such as closed,rotating,large displacement and so on.Mechanical vibration monitoring requires high sampling frequency and sampling precision,which will produce a large number of vibration data in a short time.It is a difficult problem to carry out a large amount of data transmission in the wireless sensor network with limited resources.In multi-hop wireless sensor networks,the expansion of the network size makes the data conflict in the transmission channel more serious,and compresses the effective data transmission time of every node,which further increases the difficulty of a large number of data transmission.In this regard,the data transmission task in multi-hop mechanical vibration wireless sensor network can be allocated to several communication channels simultaneously to improve the network transmission rate.To achieve multi-channel data transmission in multi-hop mechanical vibration wireless sensor networks,more factors should be taken into consideration,such as topological structure selection,routing protocol construction,data transmission channel allocation,multi-hop data transmission scheduling,large data transmission reliability,etc.In view of the above problems,the specific research contents are as follows:(1)A multi-hop network hierarchical routing protocol is designed based on cluster tree structure.Aiming at the issue of constructing efficient multi-hop network hierarchical routing protocol,multilevel routing nodes are used as cluster head to reduce the complexity of network topology,and the basic conditions for clock synchronization in mechanical vibration acquisition and transmission are created by using a clear hierarchical structure of cluster tree networks.The distributed node network address allocation method is used to assign the network address calculation to each routing node.At the same time,the network preset node number and the distributed network address allocation are combined to avoid the shortcomings of the existing address allocation method.And then,a distributed routing system is used to simplify the computation complexity of packet routing and distribution in multi-hop networks.(2)A Multi-channel data transmission method is designed based on clock synchronization scheduling Aiming at the problem of severe data conflict and slow transmission rate,which caused by using traditional single channel transmission method in the multi-hop mechanical vibration wireless sensor network,a mult-channel data transmission method based on clock synchronization scheduling for multi-hop networks is proposed.The synchronization trigger of the whole network transmission is realized by the time series compensation of beacon.the timing scheduling of the network transmission is completed by the father-child link timing rotation scheduling.the transmission channel allocation is completed based on the sorting of transmission link quality and the minimization of the channel interference.And the packet loss detection retrans integration mission mechanism is used to ensure the reliability of the data transmission.Finally,parallel transmission in multi-hop network is achieved and the data transmission rate is improved.(3)Monitoring system integration and multi-channel transmission application of mechanical vibration wireless sensor network.On the basis of existing hardware platform,the data communication format is normalized.A monitoring system for upper computer management platform is designed based on C# and.NET.At last,the effectiveness of the proposed multi-hop network hierarchical routing protocol and multi-channel data transmission method is verified by experiments.At the end of the paper,we summarize the work of this paper and look forward to the following research directions. |
