RecoNode: A reconfigurable node for heterogeneous multi-robot search and rescue

Search and rescue robots can benefit from small size as it facilitates access to voids and movement in cramped quarters. Yet, small robots cannot be the entire answer for urban search and rescue because small size limits the size of actuators, sensor payloads, computational capacity and battery capacity. Nonetheless, we are attempting to alleviate these limitations by developing the hardware and software infrastructure for heterogeneous, wireless sensor/actuator/control networks that is well-suited to miniature search and rescue robots, as well as a host of other relevant applications. These networks of application-specific sensors, actuators and intelligence will be assembled from a backbone that includes scalable computing, a flexible I/O bus, and multi-hop data networking. But two things will ultimately give our wireless infrastructure its novelty: a dual-baseband communications layer and the embedded virtual machine. The dual-baseband communications layer augments the standard data communication layer with a secondary, sub-millisecond synchronization layer to permit high-fidelity, deterministic, distributed control across the network. The determinism of this dual-baseband communications layer, in turn, enables the creation of the embedded virtual machine, which is a programming construct that abstracts away the physical sensor/actuator/control nodes. With this infrastructure, programming will not be done at the node level, as in conventional wireless sensor networks. Instead, programming will be done at the task level with port-based objects distributed across physical resources as necessary at either compile-time or run-time. At compile-time, the system can assist in the specification of the physical network, while at run-time the system can react to changes in configuration, such as nodes exhausting their batteries or losing connectivity. This paper describes progress to-date on developing this scalable infrastructure, specifically the RecoNode high-performance, dynamically-reconfigurable computational node for the Terminator-Bot crawling robot and the FireFly mid-performance node, as well as their real-time software.