Scheduling with Complex Consumptive Resources for a Planetary Rover

Wayne Chi, Steve Chien, Jagriti Agrawal

Keywords: Mars2020, Consumptive, Resources, Power, Sleep

TL;DR: This paper describes and analyzes three methods to schedule non-fixed duration activities in the presence of consumptive resources.

Abstract:

Generating and scheduling activities is particularly challenging
when considering both consumptive resources and
complex resource interactions such as time-dependent resource
usage.We present three methods of determining valid
temporal placement intervals for an activity in a temporally
grounded plan in the presence of such constraints. We introduce
the Max Duration and Probe algorithms which are
sound, but incomplete, and the Linear algorithm which is
sound and complete for linear rate resource consumption.
We apply these techniques to the problem of scheduling
awakes for a planetary rover where the awake durations
are affected by existing activities. We demonstrate how the
Probe algorithm performs competitively with the Linear algorithm
given an advantageous problem space and well-defined
heuristics. We show that the Probe and Linear algorithms
outperform the Max Duration algorithm empirically.
We then empirically present the runtime differences between
the three algorithms. The Probe algorithm is currently base-lined
for use in the onboard scheduler for NASA’s next planetary
rover, the Mars 2020 rover.