Development of a Robotic Wireless Network for Underground Mine Rescue
HADES is a mine scout robot designed to be deployed by first responders to assess mine conditions post-disaster. HADES requires the capability of wireless communication between HADES and the operators on the surface station. Post-disaster mine conditions pose significant challenges to communication systems. This thesis discusses a wireless solution using 802.11b ad-hoc radios. The system developed in this thesis, named HERMES, comprises of the node system RF electronics, internal firmware, and ROS interface to the endpoints. A node design is developed in conjunction with a 2.4 GHz radio module capable of transmitting basic video data. The wireless HERMES nodes are stacked in the HADES robot and deployed as the robot traverses the mine. These wireless nodes are operable for at least 8 hours and have a range of 80 m. The wireless network formed by HERMES allows both video data and sensor data to return to a base station outside the mine. A bespoke decimation in time compression video compression strategy is implemented which provides a basic monochrome video stream with 320 x 240 resolution. This enables video to be streamed through the HERMES network with an overall through-put of 160 kbps on the application level. This basic compression is investigated and evaluated and a video stream with a peak refresh-rate of 40 frames per second with an 800 millisecond response delay is achieved.