Availability checking of dynamic spatial information for automobiles

We propose a formal model for availability checking of dynamic spatial information (DSI) to evaluate whether DSI can be used to determine collision possibility at intersections. As vehicles move, the DSI available to each vehicle must be updated. However, the availability is inherently not complete under the assumption that communication is unreliable and not always done within a specific period of time. A vehicle may “disappear” from the DSI no matter how frequently the DSI is updated. This disappearance may lead to incorrect conclusions of collision possibility. We show that the availability checking in our model is justified in practice by using Max-satisfiability modulo theories (Max-SMT) solvers. We illustrate our model through simple DSI examples and demonstrate that the proposed model reasonably gives availability checking results.