human-interactive autonomous flight manager for precision lunar landing

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Human-Interactive Autonomous Flight Manager for Precision Lunar Landing. Lauren J. Kessler Laura Major Forest [email protected] [email protected] Agenda. ALHAT Overview Background Definitions Landing architecture for Apollo Autonomy Roadmap Initial Architecture & Design Functions - PowerPoint PPT Presentation

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Human-Computer AutonomyHuman-Interactive Autonomous Flight Manager for Precision Lunar Landing
Lauren J. Kessler
Laura Major Forest
Agenda
ALHAT Project Overview
Lunar descent and landing GNC technology development project
The Project includes:
Definition, design, development, test, verification, validation and qualification of an integrated GNC lunar descent and landing system to TRL 6 capable of supporting lunar crewed, cargo, and robotic missions
Slide *
ALHAT System Level 0 Requirements
1. Landing Location
The ALHAT System shall enable landing of the vehicle at any surface location certified as feasible for landing.
2. Lighting Condition
The ALHAT System shall enable landing of the vehicle in any lighting condition.
3. Landing Precision
The ALHAT System shall enable landing of the vehicle at a designated landing point with a 1 sigma error of less than 30 meters
4. Hazard Detection and Avoidance
The ALHAT System shall detect hazards, 30 cm and larger objects and slopes 5 degrees and greater, and provide surface target re-designation.
5. Vehicle Versatility
The ALHAT System shall enable landing of crewed (humans on board), cargo (human scale without humans onboard) and robotic (smaller exploration vehicles without humans onboard) vehicles.
6. Autonomy
The ALHAT System shall have the capability to operate autonomously (without command and control intervention from sources external to the vehicle).
7. Crewed Vehicle
The ALHAT System shall accept supervisory control from the onboard crew.
8. Interoperability
The ALHAT System shall be interoperable with other elements of the Constellation Architecture.
9. Standards
The ALHAT System will adhere to the applicable set of measurement units, data and data exchange protocols defined by the Constellation Program.
Slide *
AFM Task Motivation
[A]LHAT
Put some definition, thought, and FY07 planning towards the “A” in ALHAT (A=autonomous)
Desire is to formulate and document an understanding WRT
Defining an overall role of the autonomous flight manager (AFM)
Defining a top level design architecture appropriate to ALHAT needs
What is an appropriate split between the AFM and Guidance?
What is an appropriate split between the AFM and HDA?
What is the functional division between the AFM and the human?
Suggesting a top level implementation architecture appropriate to ALHAT needs
Slide *
Background
Slide *
ESMD Requirements
There is a desire for increasing levels of operational autonomy capabilities in order to prepare for exploration beyond the Moon
However, there is also a requirement for manual intervention of automated functions critical to mission success and crew safety
NASA Autonomy definition:
Exploration Systems Mission Directorate; ESMD-RQ-0011 Preliminary (Rev. E) Exploration Crew Transportation System Requirements Document (Spiral 1); Effective Date: 24 Mar 2005. Page 31 of 45.
Slide *
Level of Automation
Apollo
The importance of choosing the correct level of automation was recognized in the development of the Apollo program.
Balance between overloading the astronauts and providing enough information and tasking so they are prepared for decision making if necessary.
Human control in a lunar lander
Highly automated lunar lander
Background
Parasuraman, Sheridan, Wickens."A Model for Types and Levels of Human Interaction with Automation." IEEE Transactions on Systems, Man, and Cybernetics-Part A: Systems and Humans, Vol. 30, No. 3., 2000.
The roles of the computer and the human depend upon
Frequency of operator interaction
Complexity of operator interaction
Slide *
Functional Flow of Apollo Astronauts and System
Crew input
GN&C
Vehicle
Draper, C.S., Whitaker, H.P., Young, L.R. “The Roles of Mend and Instruments in Control and Guidance Systems for Spacecraft.” 15th International Astronautical Congress, Poland, 1964.
Slide *
Apollo Function Allocation
Hazard Detection and Avoidance (HDA)
Determine if there are hazards in the landing zone via the reticle on the window
Scheduling functions
Astronauts gave the commands to change modes, start accepting radar data, etc
Monitoring and diagnosis
Manual control
Nevins, J.L., “Man-Machine Design for the Apollo Navigation, Guidance, and Control System-Revisited.” NASA report, January 1970.
Klump, A.R., “A Manually retargeted automatic descent and landing system for LEM.” Report-539, March 1966.
Traditional GN&C functions
Command examples: rate of descent, attitude, etc
Control
Role of Computer System
Types of Astronaut Input
Designate a new landing aim point (via rotational hand controller)
Inputs to Control (P66 – “semi-auto mode”)
Crew controlled the attitude to maneuver the vehicle by commanding the nozzles in the form of an angular acceleration command signal
Altitude or altitude rate were held constant by the computer, the crew could change these through the Rate of Descent switch
Vehicle commands (P67 - “full manual mode”)
Crew controlled engine throttle manually
Attitude was controlled by the Digital Autopilot
This mode was rarely used because of the high workload required
Nevins, J.L., “Man-Machine Design for the Apollo Navigation, Guidance, and Control System-Revisited.” NASA report, January 1970.
Klump, A.R., “A Manually retargeted automatic descent and landing system for LEM.” Report-539, March 1966.
Slide *
AFM Requirements
ALHAT Program
Determine vehicle commands needed to reach next state target condition
Hazard Detection and Avoidance Functions
Detailed sensor input on landing site
Algorithms determine the characteristics of the landing site
Identified Autonomy Need
Reduce onboard crew workload and error probability
Slide *
Need for Autonomous Flight Manager
Apollo design resulted in high crew workload and room for human error:
Landing footprint capability was primarily a mental calculation and rough estimate
Astronauts had to rely on memory stores developed through extensive training for vital information
No relative size indicators…astronauts reported significant difficulty sensing sink rates and lateral motion
Limited redesignation options due to LM window constraints
New Landing Requirements:
Higher precision
Tighter budget
Need for lower cost training
Technology improvements enable automating many of the tasks required by Apollo astronauts to help in achieving the new requirements:
Example technologies that have paved the way:
Flight management systems & autopilots
Autonomous vehicles (e.g., UUVs)
Autonomy Requirements
Autonomously provide adaptive behavior for unmanned operations…
Handle the dynamic nature of the missions within the boundaries of the pre-mission planning
Un-assisted by earth-based support
In accordance with the Human Rating Requirements
Allow for manual intervention of safety critical functions
Slide *
Proposed Level of Autonomy
Supervisory Control
Computer
Computer
Supervisory control: the human operator has the authority to inhibit and/or override any safety-critical automated function of the descent and landing system
Slide *
Types of Autonomy
Premise
Autonomous systems are an aid to humans rather than a replacement
Focuses on the attributes of planning, perception, adaptation, learning and diagnosis
Types of Autonomy
Perform preplanned scripts of actions based on anticipated events
Supervised
Intelligent
Accommodates (adapts) to unplanned events
Slide *
ALHAT Autonomy Challenge
Dovetails with the goal of Human-supervisory control
ALHAT System exchanges data with the landing vehicle’s cockpit
Helps the ALHAT System to achieve the low level of risk required for a crewed vehicle
Onboard human supervisory awareness is directly supported by the ALHAT System design
Does not try to tackle the higher complexity and abstraction of evolving mission objectives
Allows for real-time human insertion (in the crewed and cargo missions) while being flexible enough to replace the human (in robotic missions), with pre-planned decision rules.
Types of Autonomy:
Supervised
Intelligent
Slide *
ALHAT Function Allocation
Example: Begin de-orbit
Monitor the following and diagnose any deviations from expectations:
Vehicle behavior, trajectory, surface landmarks, landing zone hazards, vehicle health and status
Redirect AFM
If there are unexpected deviations or changes to the mission goals, the crew can redirect the vehicle
Input new target conditions
Issue an abort
Sensor data acquisition
Monitoring and diagnosing
AFM will compare current state against predicted state along the trajectory (including human input, health & status)
AFM will determine if state deviations require re-planning of landing sequence
Re-planning
AFM will adjust target conditions to create a new feasible plan (when triggered by diagnosis)
Role of Computer System
Functional Role of AFM
Optional guidance commands
AFM Architecture
Autonomy Software Architecture
Diagnoser
Determine root cause & impact on capabilities of system being controlled
External Coordination Module
Provides interface between system being controlled and other control elements – e.g. humans, other systems
Draper’s implementation: All-Domain Execution and Planning Technology (ADEPT)
Planner
Creates plan and modifies current plan when necessary (triggered by Diagnoser)
Can generate multiple plans, especially in a decision support role for human interaction
Execution
Plan
Implementation
Situation
Assessment
Plan
Selection
Plan
Execution
Hierarchical Decomposition
Simplify implementation of solution to real-time, closed-loop planning problems
Higher levels create plans with greatest temporal scope, but low level of detail in planned activities
Lower levels’ temporal scope decreases, but detail of planned activities increases
Functional Decomposition
Each level of the planning hierarchy is decomposed into key functional components
Inputs and outputs
Produce new mission plan
Hierarchy
Activity Hierarchy
DeOrbitBurn
Coast
PreDescentPlan
Mission
Orbit
Startup
Transit
PreBurnPlan
Abort
TransferOrbit
PoweredDescent
EndMission
Abort
Abort
Shutdown
BreakingBurn
PitchOver
TerminalDescent
Slide *
Trajectory Monitoring & Planning
The execution of the precision landing sequence will be governed by the use of state “corridors”
Union of a family of possible state trajectories with associated guidance target conditions
State includes such things as velocity, attitude, fuel usage, position, etc.
Developed far in advance of the mission
If there are deviations outside the nominal corridor, then AFM re-planning is triggered
Re-planning consists of selecting new target conditions relative to preplanned state corridor options
Slide *
Nature of Pre-calculated Trajectory Corridors
GN&C analysis and trade studies will be used to determine corridor approach and target conditions, including:
How the trajectory corridors will be defined:
Pre-calculated, or predict-ahead, or combination
The hard target conditions used to define the phase transitions:
e.g. altitude, velocity, attitude, fuel state…
The AFM will not select from an infinite amount of options, only the set of contingencies will be considered
Defining the corridors up-front …
Reduces required on-board computing
Narrows the V&V of the re-planning options to data developed far in advance of the mission
Slide *
AFM Astronaut Insertion
Types of Astronaut Input
Management by Interruption (changes to the target conditions)
Crew can update the conditions used by the AFM based on the evolving mission, within specified bounds (e.g., input a new landing aimpoint)
Management by consent (Authority to Proceed)
Execution will not occur unless the crew consents to a proposed action (e.g., de-orbit burn)
Management by exception (time-outs)
Execution will occur within a specified timeframe if the crew does not prevent the AFM from proceeding (e.g., phase change out of a non-sustainable orbit)
Map the 5 interactions from OpsCon to these types of insertion capabilities
Slide *
Called out by the Level 0 Comments
Landing site re-designation
Mission phase initiation and approval
Abort decisions
Types of Human Insertion
Management by consent (Authority to Proceed)
Management by exception (time-outs)
Crew Landing Site Re-designation
HDA sensors & algorithms will identify hazardous regions
AFM will determine alternate landing sites and present the top 5 alternate options with key information about each option
Crew will not have to integrate data across multiple instruments to determine key decision criteria
During landing, the crew can redesignate to any of the alternate landing sites
New landing aimpoint will become an input to the AFM
Notional display for terminal descent
Slide *
Crew Landing Site Re-designation
DeOrbitBurn
Coast
PreDescentPlan
PoweredDescent
TerminalDescent
Mission
The constraints of the lowest level controller are updated based on crew input
This is handled similar to something in the environment causing a local re-plan
New landing aimpoint
Crew Landing Site Re-designation
DeOrbitBurn
Coast
PreDescentPlan
TransferOrbit
TerminalDescent
Mission
New landing aimpoint
If human change is outside the capability of the planner, the activity will require re-planning from its parent
Orbit
Startup
Transit
PreBurnPlan
Abort
PoweredDescent
EndMission
Abort
Abort
Shutdown
BreakingBurn
PitchOver
Slide *
Conclusions
New landing and safety requirements necessitate an additional technology to handle mission planning and monitoring activities
GN&C will provide the detailed maneuver and control commands
AFM will update GN&C target conditions as necessary
AFM must provide mechanism for human redirection and interruption
Real-time autonomy architecture will need to support human insertion at multiple levels and quickly adapt to human input
Design of AFM architecture and Crew Interface design are tightly coupled
Technology development to mature AFM to TRL6 will continue as part of the ALHAT program
Slide *
References
Slide *
References
Parasuraman, Sheridan, Wickens."A Model for Types and Levels of Human Interaction with Automation." IEEE Transactions on Systems, Man, and Cybernetics-Part A: Systems and Humans, Vol. 30, No. 3., 2000.
Exploration Systems Mission Directorate; ESMD-RQ-0011 Preliminary (Rev. E) Exploration Crew Transportation System Requirements Document (Spiral 1); Effective Date: 24 Mar 2005. Page 31 of 45.
Draper, C.S., Whitaker, H.P., Young, L.R. “The Roles of Men and Instruments in Control and Guidance Systems for Spacecraft.” 15th International Astronautical Congress, Poland, 1964.
Sheridan, T.B. Humans and Automation: System Design and Research Issues, 2002
Boff, K.R. Ch. 40, Handbook of Perception and Human Performance, Moray, 1986.
Nevins, J.L., “Man-Machine Design for the Apollo Navigation, Guidance, and Control System-Revisited.” NASA report, January 1970.
Klump, A.R., “A Manually retargeted automatic descent and landing system for LEM.” Report-539, March 1966.
Card, S. K., Moran, T. P., & Newell, A. (1983). The psychology of human-computer interaction. Hillsdale, NJ: Lawrence Erlbaum Associates.
Ricard, M., Kolitz, S., “The ADEPT Framework for Intelligent Autonomy”, presented at NATO Research and Technology Organization Workshop on Intelligent Systems for Aeronautics, April 2002.
DeorbitBurn
Landing