DS 1 Attitude Control System PDE Flight Computer SRU He N PDU z facing thrusters x facing thrusters BC GDE PASM DSEU Livingstone reconfigured modes using one step commands. But how does the flight computer really open a valve? PEPE Requires turning on device drivers Requires repairing bus controllers Sending commands Powering down devices Massachusetts Institute of Technology
Artificial Intelligence & Space Systems Laboratories Massachusetts Institute of Technology DS 1 Attitude Control System z facing thrusters x facing thrusters 1553 bus Commands DataN2H4 He PDE SRU PDU GDE PASM DSEU PEPE BC Flight Computer PDE Livingstone reconfigured modes using one step commands. But how does the flight computer really open a valve? • Requires turning on device drivers • Requires repairing bus controllers • Sending commands • Powering down devices . .
How do we reconfigure a valve? Remote +Driver Terminal Valve Bus Computer Control Remote Driver Terminal Valve Device modes are changed through indirect commanding Communication paths are established by reconfiguring other devices The task of reconfiguring devices in the proper order generalizes state space planning to handle indirect effects To achieve reactivity all possible plans for all possible goal states should be pre-compiled (a generalization of universal plans To achieve compactness we decompose these universal plans according to a goal/ sub-goal hierarchy Massachusetts Institute of Technology
Artificial Intelligence & Space Systems Laboratories Massachusetts Institute of Technology Remote Terminal Remote Terminal Driver Bus Control Computer Valve Driver Valve • Device modes are changed through indirect commanding. • Communication paths are established by reconfiguring other devices. • The task of reconfiguring devices in the proper order generalizes statespace planning to handle indirect effects. • To achieve reactivity all possible plans for all possible goal states should be pre-compiled (a generalization of universal plans). • To achieve compactness we decompose these universal plans according to a goal/sub-goal hierarchy. How do we reconfigure a valve?
Mode reconfiguration Configuration Goal Goal Interpreter Goal state State Estimate Reactive Command (Current) Planner Model-based Programming of Intelligent Embedded Systems and Robotic EXplorers Williams et al., IEEE03 Reactive Planner for a mode/ -based Executive Williams Nayak, IJCAI 97 MERS Massachusetts Institute of Technology
MERS Massachusetts Institute of Technology Model-based Embedded & Robotic Systems Group Mode Reconfiguration Model-based Programming of Intelligent Embedded Systems and Robotic Explorers [Williams et al., IEEE’03] Reactive Planner for a Model-based Executive [Williams & Nayak, IJCAI 97] Goal Interpreter Reactive Planner Configuration Goal Command Goal State State Estimate (Current) Reactive Planner Command Goal State State Estimate (Current)
EXample: Driver Valve Command Sequence Goal: No thrust Valve driver dr Valve vlv demin din Commands Driver state Valve state MES dr= off vIv=open MS: dr= off vlv= closed MRP demin = on ME dr= on vIv=open MRP dcmdin= close ME: dr= reset failure en v=ope MRP demin reset ME dr= on vIv=open MRP demin off ME: dr= off vIv =open Artificial Intelligence e pace Systems laboratories Massachusetts Institute of Technology
Artificial Intelligence & Space Systems Laboratories Massachusetts Institute of Technology Example: Driver Valve Command Sequence Valve Driver dr Valve vlv vcmdin dcmdin Commands Driver State Valve State ME: dr = off, vlv = open MS: dr = off, vlv = closed MRP dcmdin = on ME: dr = on, vlv = open MRP dcmdin = close ME: dr = reset failure, vlv = open MRP dcmdin = reset ME: dr = on, vlv = open MRP dcmdin = off ME: dr = off, vlv = open Goal: No thrust
To achieve reactivity we eliminate all forms of search Massachusetts Institute of Technology
Artificial Intelligence & Space Systems Laboratories Massachusetts Institute of Technology To achieve reactivity we eliminate all forms of search