1. Carnegie Mellon Zoë Computing Design Design Review December 19, 2003 Michael Wagner (mwagner@cmu.edu) 

2. Carnegie Mellon Computing Design Drivers Modifiability Linux Environment Minimize Power Consumption

3. Carnegie Mellon Computing Design Drivers Modifiability Year 2 field expedition is the second, not final, iteration of an astrobiology robot. Assume improvements will be made for year 3, so ease the effort required. Support technology experiments in the field. Linux Environment Minimize Power Consumption

4. Carnegie Mellon Computing Design Drivers Modifiability Linux Environment Minimize Power Consumption

5. Carnegie Mellon Computing Design Drivers Modifiability Linux Environment The team is experienced with Linux. Linux has historically had sufficient driver and application software support. Computing hardware vendors now have widespread Linux support. We can configure off-board computers identically to the onboard computers. Minimize Power Consumption

6. Carnegie Mellon Computing Design Drivers Modifiability Linux Environment Minimize Power Consumption Night operations are important, so energy must be efficiently conserved. However, complex perception and planning software calls for high-speed computers with large memories. Rover must be able to switch components on/off.

7. Carnegie Mellon Historical Lessons Research software can be optimized, but usually is not. So assume it won’t be. The I/O buses often become overcrowded with sensors and devices, both expected and unexpected. Power switching also becomes impractical. Transfer of large data sets off the robot can be very time consuming. The console is a crutch.

8. Carnegie Mellon Operating FSM Hibernate Plan Drive to Waypoint Plow Trench Acquire Panorama Full Sample Re-plan Quick Sample

9. Carnegie Mellon State Description StateDuty Cycle (480 min / day, not including night) Core CPU (PMAD) Drive MotorsAutonomy CPU(s) Science Instruments* Hibernation 0% ONOFF Plan 20 min / plan, 2 / day 40 min / day = 8% ONOFFON / PLANOFF Drive to Waypoint Remaining time = 30% ON OFF Re-plan 2.5 min / re-plan, 12 / day 30 min / day = 6% ONUNCHANGEDON / PLANOFF Plow Trench 20 min / trench, 1 / day 20 min / day = 4% ON OFF Full Sample 1 hr / sample, 2 / day 120 min / day = 25% ON Quick Sample 1 min / sample, 100 / day 100 min / day = 21% ONUNCHANGEDON Acquire Panorama 10 min / sample, 3 / day 30 min / day = 6% ONUNCHANGEDONOFF * may require significant warm-up time

10. Carnegie Mellon Power Restrictions Need low-power (<5 W) core (PMAD) computer Autonomy CPU(s) do not face similar restrictions At some times, rover will collect more solar power than it can store in batteries Battery energy density high enough to support ~1 hr of night science Try to minimize autonomy CPU power with lower-clock speed modes while: Collecting science data Not using compute intensive applications (planners, etc.) Possible under Linux w/ APM or APCI Use power relays for science instruments, buses and motion controllers

11. Carnegie Mellon High-level Computing Design Core CPU (PMAD) Battery monitoring, power relays, time server, read high- rate sensors like IMU and encoders Autonomy CPU Near-field stereo, navigator, rover executive, instrument manager, vehicle controller “Planning” CPU Mission planner, far- field sensing, low duty-cycle processes 100 Mbps Ethernet

12. Carnegie Mellon High-level Computing Design Power Relays Battery Chargers Core CPU (PMAD) Power Sensors CAN Digital I/O Analog I/O IMU Encoders Autonomy CPU “Planning” CPU

13. Carnegie Mellon High-level Computing Design Motion Controller Roll / Pitch LED Ctrl Spec Sun Sensor Nav Cams Fluor Cam Haz Cams SPI Cams GPS 9-10 Firewire RS232 Core CPU (PMAD) Autonomy CPU “Planning” CPU Digital I/O

14. Carnegie Mellon Power Management Core CPU (PMAD) can switch off other components: Autonomy CPU Planner CPU Firewire Bus 1: Used for driving Nav cams, sun sensor Firewire Bus 2: Used for science SPI cams, fluorescence camera, workspace cams

15. Carnegie Mellon Core CPU (PMAD) Candidates All core CPUs (PMADs) have PC/104+ bus interfaces, supporting expansion

16. Carnegie Mellon Autonomy and Planner CPU Candidates Specific selection depends upon: Planner RAM requirements Availability of 3U models Courage to use PowerPCs?

17. Carnegie Mellon Next Steps Autonomy CPU Contact vendors to find power consumption numbers Detail RAM requirements, operating mode, CPU resources for: Mission planner Rover executive Near-field stereo @ 4x vehicle speed Far-field perception / navigation system Create breadboard Firewire Bus Can we use two Firewire cards on the same bus? Test power switching on dual bus system

18. Carnegie Mellon Next Steps Implement core CPU (PMAD) and start using it ASAP to “ensure” reliability Test CPU / Firewire hub power switching Implement high-rate (~60 Hz) analog data collection for state estimation Implement and test data offload strategy based on removable hard drive Find an LCD flat screen / keyboard to integrate onto ebox Communications