Tatiana Kichkaylowith Dave Barnhart and Lucy Hoag

USC Information Sciences Institute

BackgroundFunded as ISI Inter-divisional seedling

Space Engineering Research Center+Artificial Intelligence

= Spacecraft Portal for Integrated Design in Real time

Driven by user needs SERC is building satellites, fast, cheap, with student power

("teaching hospital" model) SPIDR is there to help

Systems Platform for Integrated Design in Real time

Design problem Spacecraft missions are typically “one-off” designs, requiring high degree

of non-recurring engineering between even similar design states Spacecraft design is highly interdisciplinary, and follows many sets of

constraints and rules dictated by environment, payload and mission sets

Components and design approaches can be reused Engineering knowledge can be encoded to automate many design choices

and analysis steps "Paperless" design helps directly and also provides basis for further

automation

Ultimately want to let individual engineers bounce ideas of a computer system, leading to faster, cheaper and better designs

BlueprintsPurchase ordersLaunch dates…

BlueprintsPurchase ordersLaunch dates…

Magic

BlueprintsPurchase ordersLaunch dates…

Design

Geometry/mass

Power

Thermal

Launch

Orbit

Flight software

Mission goals

Vibration

Component providersExport regulations

Delivery schedules

Manufacturing capabilities

Validation and testing(software and hardware)

Payload

What does it take to build a spacecraft?

Bigger pictureCollaborative design

Information sharing and clash detectionOptimization of parameters

Limited number of parameters but with high fidelityProject management

Schedules and resources

SPIDR Automate roll out and propagation of dependencies Optimize over structures given high-level specification Very lightweight and driven by project needs

Idea: Use planningAI planning is about finding a sequence (DAG) of

actions that achieve a goal Methods have preconditions Methods expand parts of the plan

Design is about finding a set of recipes that convert a specification into a complete design Recipes have applicability conditions Recipes modify (expand) design

Both methods and recipes have parametersBoth plans and designs have constraints

Constraints in design are often represented as models

User revises requirements and metrics as needed

Reusable knowledge base of engineering

rules

Mission requirement

s, orbit

N best designs(component lists and

system budgets)

Reusable component database

Optimization metrics

SPIDR

Reusable data

Mission-specific data

Automated design synthesis

Design loop

Rule example

Semantic entities

Query engine

Variables and

constraints

Constraint propagation

Tokens and rules

Planner

Semantic layer

Constraint layer

Planning layer

Data representation Algorithms

Optimization engine

User interface

iLan

ds

SP

IDR

Mission req's

Constants

P. battery

Implementation

SPIDR meets real world

Nanosatellite project at USC ISI Low costs Unusual constraints

Reality alters trajectory Initial "vision" for SPIDR

Single optimization tool with models in the loop Actual use

Run every several days with design files (XML etc.) posted online

Got several extensions, model tweaked constantly Useful for dealing with ripple effects and ensuring consistency Users want more

ObservationsNo way to close all loops

Extended to dynamic models (e.g., power profile) Stuck on thermal and geometry due to

Lack of APIs Licensing issues Need for user interaction

One shot is not enough – need Living Design Feed back from out-of-the-loop models, version control Side-by-side designs Project structure and scheduling roll out Still want the optimization loop

Observations (2)Rule design is not easy

Engineers understand the concept Tools help: Eclipse plug-in

Crossing domain boundary is hard Tweaks and overrides encourage local thinking SPIDR Lite to study the knowledge engineering problem

Other applications:Trade space studies and tools for acquisition SPIDR-Energy for undersea surveillance (DARPA)

Last slideSPIDR is about rolling out engineering recipes and

optimizing over high-level structures Glue for collaborative design, optimization, and project

managementSPIDR is driven by real project(s)

Some ambitions got scaled down New extensions and ideas emerged

Next steps New [engineering] domains New applications More users (students?)

Tatiana Kichkaylotatiana@isi.edu