Enabling Limited Resource-Bounded Disjunction in Scheduling

We describe three approaches to enabling aseverelycomputationally limited embeddedscheduler to consider a small number of alternative activities based on resource availability.We consider the case where the scheduler is so computationally limited that it cannot backtracksearch. The first two approaches precompile resource checks (called guards) that only enableselection of a preferred alternative activity if sufficient resources are estimated to be availableto schedule the remaining activities. The third approach mimics backtracking by invokingthe scheduler multiple times with the alternative activities. We present an evaluation of thesetechniques on Mars mission scenarios (called sol types) from NASA’s next planetary roverwhere these techniques have been evaluated for inclusion in an onboard scheduler.