Design And Implementation Of Spacecraft Data Acquisition Wireless Sensor Network Gateway

Wireless Sensor Network(WSN)is a wireless distributed network composed of a large number of sensors through self-organizing and multi-hop.When used to replace the existing wired transmission network,WSN can greatly reduce the number of transmission lines and improve the aircraft's carrying capacity.In order for the real-time and high-speed acquisition of sensing information at the same terminal,it is necessary and significant to design a WSN Gateway with high reliability after the rational deployment of sensor nodes and establishment of network.In order to meet the function and performance requirements of data acquisition in the spacecraft,a WSN gateway is designed in this thesis.Due to high requirements on the volume and power consumption of the devices,the spacecraft data acquisition WSN Gateway can only be implemented using a lightweight and low-power embedded microcontroller.Based on this condition,the overall structure of the spacecraft data acquisition WSN gateway is given firstly.On this basis,the data collection gateway protocol stack based on 6LoWPAN is adopted to enable WSN to IP network access;And also,the network layer routing forwarding mechanism is designed so that the sensor node-to-gateway routing can be implemented.In terms of the performance: a multi-process communication method is designed based on ContikiOS to achieve concurrent data acquisition and ensure the reliability of communication;And also,a multi-task scheduling strategy is designed based on FreeRTOS to achieve high-speed data transmission and guarantee real-time scheduling.Finally,a spacecraft data acquisition WSN Gateway is designed and implemented based on a lightweight and low-power embedded microcontroller.It is indicated in the function and performance test results of the gateway that in terms of network access function,the connectivity between sensor nodes and the gateway is good and the interconnection between the WSN and the IP network can be realized;in terms of the packet loss rate and throughput performance of the gateway,the packet loss rate is 0.5 ‰ under the maximum transmission and the overall gateway throughput is 1.6 Mbps.The indicators of the gateway have reached expectations and have good functions and performance.