Ad-hoc wireless MESH network implementation for rescue robots

Urban Search and Rescue (USAR) robots have the potential to save the lives not only of trapped victims but also rescuers. Due to the nature of the environment in which USAR robots operate, there are number of challenges that must be overcome to increase their effectiveness. Natural disasters, such as earthquakes, tsunamis and cyclones, can cause wide spread damage to buildings and infrastructure resulting in an environment in which maneuverability is difficult and existing communications infrastructure is inoperable. This study is focused on creating a wireless robotic guidance system for a team of teleoperated USAR robots which are able to maneuver quickly and efficiently over rough terrain within a disaster zone. The research explores robotics and wireless communication systems that will advance the body of knowledge in USAR. Two robots with differing propulsion systems have been designed as part of this research. The ability of canine search and rescue dogs to maneuver quickly through areas strewn with rubble inspired the design of a quadruped USAR robot. A tank based USAR robot featuring a 5 DOF robotic arm was the second USAR designed. These two USAR robots are able to operate as a team. The quadruped robot performs the initial reconnaissance and may be followed by the tank based robot when the searched area has been deemed structurally sound. Both USAR robots are teleoperated across an ad-hoc 802.15.4 based wireless robotic guidance system which has been designed as part of this research. The wireless robotic guidance system utilises drop nodes to adapt to its operational environment. When the communication link to the USAR robot deteriorates a drop node is deployed, the wireless network is reconfigured and the USAR robot is able to continue moving deeper into the disaster zone. The resulting multi-hop wireless network overcomes the network coverage issues experienced by traditional single hop wireless networks. Using RSSI and TOF distance measurements and trilateration based localisation algorithms the wireless robotic guidance system is capable of accurately positioning an USAR robot within a disaster zone. This thesis records the design, experimentation and thinking undertaken to complete this research and delivers a localisation system that advances the state of the art in USAR robotics.