Life in the AtacamaCarnegie Mellon Power – Performance James Teza July 28, 2003

Life in the AtacamaCarnegie Mellon Power Performance - Overview Obtain insight into energy requirements Formulate preliminary design constraints for new robot design Measured parameters: Locomotion input currents (4) Hotel input load currents (4) Solar panel output currents (2) Bus voltages (2) Initial estimate: Integrate over each each day to obtain total energy per day Problem - aggregate measure includes all activities: driving, re- planning, etc.

Life in the AtacamaCarnegie Mellon Locomotion – Energy Required Per Operating Day Average required locomotion energy per day: 1.1 MJ/day Std dev: 0.5 MJ/day

Life in the AtacamaCarnegie Mellon Locomotion – Average Power Required Average locomotion power: 124 W Std dev: 43 W

Life in the AtacamaCarnegie Mellon Power - Results PowerEnergy (per operating day) Locomotion average std dev maximum 124 W 43 W 192 W 1.1 MJ 0.5 MJ 2.1 MJ Hotel average std dev maximum 12 W (14 W)* 4 W 21 W (21 W)* * Results of static testing 0.19 MJ 0.09 MJ 0.39 MJ Total average maximum 1.3 MJ 2.4 MJ

Life in the AtacamaCarnegie Mellon Power Requirements - Example – 24 Hour operation Energy required per 24 hour period Day (10 hrs)Night (14 hrs) (Including battery efficiency of 78%) Sub total Locomotion Average Maximum 1.1 MJ 2.1 MJ MJ 2.1 MJ Hotel Average (14W) Maximum (21W) 0.50 MJ 0.76 MJ 0.91 MJ 1.36 MJ 1.4 MJ 2.1 MJ Payload (estimate) Average (14W) Maximum (21W) 0.50 MJ 0.76 MJ 0.91 MJ 1.36 MJ 1.4 MJ 2.1 MJ Total Average Maximum 3.9 MJ 6.3 MJ

Life in the AtacamaCarnegie Mellon Performance Results - Summary Obtained rough measures of locomotion and hotel power requirements Extrapolation of results to inform initial design requirements for 24 hour operation Total energy requirement Solar panel design Battery design Further work Refine energy requirements for discrete activities Compare solar energy gain with energy consumption Problem – noisy data

Life in the AtacamaCarnegie Mellon