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Jillian Redfern Orbital Express Presentation TITAN All-Hands 07/08/2003. Orbital Express and Mission Manager TITAN’s role Progress Future work Suggestions. Topics to be Discussed. DARPA’s Motivation. Movie of Robotic Arm. Movie of Direct Capture. Program Plans
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Jillian Redfern Orbital Express Presentation TITAN All-Hands 07/08/2003
Orbital Express and Mission Manager TITAN’s role Progress Future work Suggestions Topics to be Discussed
Program Plans Develop and validate software for autonomous mission planning, rendezvous, proximity operations and docking. Design, fabricate, and test on-orbit robotic satellite servicing, including fuel and electronics transfer, deployment of and operations with a micro-satellite. Design, fabricate, and test on orbit a modular micro-satellite for protection of stationary satellites. Perform utility assessments of on-orbit servicing in conjunction with operational customers and plan for technology transition.
Guidance, Navigation, & Control Capture Free Fly Capture (With Robotic Arm) Direct Capture (With Grappling Mechanism) ORU Transfer NextSat to ASTRO (With Robotic Arm) ASTRO to NextSat (With Robotic Arm) Fluid Transfer NextSat to ASTRO ASTRO to NextSat Mission Manager (Draper Lab’s part) Main Operations
Top 12 Failures Which Require Autonomous Response Fail to direct capture Fail to free-flyer capture AC1 fault which results in reboot AC2 fault which results in reboot AVGS fails during prox ops MCU fail during arm use Battery DOD above 75 (TBR) % Fluid coupler fails to engage Fluid coupler fails to disengage Pump fails on RCS jet fail during prox ops Selected valves fail open or closed Failure Concerns
Draper’s Mission Manager “looks” a lot like TITAN at the high levels Current thinking for fault diagnosis: rule-based -- system engineer generated fault response system which is pre-determined (simplifies Diagnosis and Planning step through database utilization) I want to add in a Diagnosis step through either TITAN or MINI-ME Draper’s Mission Manager
AutoNav AutoGd OEDMS CM FTAPS NEXTSat ASTRO Mission Manager Database MM Executive Monitor Contingency Responder Resource Predictor Sequencer Commands Response Messages
TITAN Titan Model-based Executive Model-based Program Activity goals (from planner) Control Program Sequencer Configuration goals State estimates Plant Model Deductive Controller Mode Estimation Mode Reconfiguration CCAs Observations Control actions Flight Control Software Physical Plant
P1 F1 Tank1 Valve1 Tank2 F2 Pump Valve2 System (Extremely simplified) 2 Valves (not pyro) 2 Fluid Transfer Tanks 1 Pump 1 Pressure Sensor 2 Flow Sensor Flow in both directions *Assume valves open individually
Filling/Emptying Full Empty Broken Fluid Transfer Tank Level (Tank1) Pump = 1to2 Pump = Off Pump = Off Pump = 2to1 (P1 = Nominal) Pump = 1to2 Pump = 2to1 (P1 = High) (P1 = Low) Pump = Off
Filling/Emptying Full Empty Broken Fluid Transfer Tank Level (Tank2) Pump = 2to1 Pump=Off Pump=Off Pump = 1to2 (P1 = Nominal) Pump = 2to1 (P1 = Low) Pump = 1to2 (P1 = High) Pump=Off
Unknown Propellant Isolation Valve Number 1 F1 = forward Open F1 = reverse Leaking Cmd=CloseV1 Cmd=OpenV1 Closed F1 = stagnant
Unknown Propellant Isolation Valve Number 2 F2 = forward Open F2 = reverse Leaking Cmd=CloseV2 Cmd=OpenV2 Closed F2 = stagnant
Pump (NOT Valve2=open) OR (Valve2=open AND F2=forward) (NOT Valve1=open) OR (Valve1=open AND F1=forward) 1to2 2to1 Broken Cmd=PumpOff Cmd = PumpLeft Cmd=PumpRight Cmd=PumpOff Off (F1 = Stagnant) AND (F2 = Stagnant)
Pump = Off V1 = Closed V2 = Closed Tank1Level = Full Tank2Level = Empty Pressure = High Flow1 = Stagnant Flow2 = Stagnant Initial State
When Tank1Level = Full, turn pump on right and open valve V1 and close valve V2 When Tank1Level = Empty, turn pump off and close valve V1 and open valve V2. Turn the pump on left. Nominal Scenarios
At t = 1 Pump = Off Flow1 = Stagnant Flow2 = Stagnant V1 = Closed V2 = Closed Tank1Level = Empty Tank2Level = Full Pressure = Low At t = 2 Valve2_Command = open Pump_Command = PumpLeft At t = 3 Pump = 2to1 Flow1 = Reverse Flow2 = Forward V1 = Closed V2 = Open Tank1Level = Filling Tank2Level = Filling Pressure = Nominal At t = 4 Valve1 = Leaking (Can I think of this as a fail to close?) Off-Nominal Scenario
At t = 1 Pump = 1to2 Flow1 = Forward Flow2 = Stagnant V1 = Open V2 = Closed Tank1Level = Filling Tank2Level = Filling Pressure = Nominal At t = 2 Pump_Command = Off At t = 3 Pump = Off Flow1 = Forward Flow2 = Stagnant V1 = Open V2 = Closed Tank1Level = Filling Tank2Level = Filling Pressure = Nominal At t = 4 Pump = Broken Another Off-Nominal Scenario
Valve1 – equal probability of failure Valve2 – equal probability of failure Pump – higher probability of failure Tank1 – low probability of failure Tank2 – low probability of failure Failure Probabilities
Extremely simple model has just now been compiled successfully I have not run the mof file through TITAN or even Mode Estimation Progress
Model the rest of the system accurately FTAPS Capture Direct Free-Flyer ORU Transfer Adapt TITAN/MINI-ME to my needs or at least demonstrate its diagnosis is better than a system engineer Help improve the utility of TITAN to other programs Goals for Thesis/Project
The monitor: I receive a lot of status updates from software and general system statuses. What can I do with those? Do I always assume the commands are getting to the correct components? Not sure whether I have hybrid capabilities with the monitor Is there someone who is a better modeler than I in this group? Why do we code it like this: (off :documentation "The OFF mode." :model (and (= (flow ?valveName1) stagnant) (= (flow ?valveName2) stagnant) (= (pump_mode ?pumpName) off)) My questions to the group