Requirements Development Autonomous MAV

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Requirements Development- Autonomous MAV
J.Jayaraman Center for Aerospace System Design
and Engineering Department of Aerospace
Engineering Indian Institute of technology,
Bombay Mumbai
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Overview of the presentation

• Introduction
• Requirements Definition
• Requirements Development Events
• Operational/ Originating Requirements
  Development Process
• Requirements Criteria
• The need for Requirements Development
• System Development Process
• Stakeholder Requirements Definition
• Autonomous MAV Requirements
• Conclusion

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Requirements - Definition

• Characteristics that identify the accomplishment
  levels needed to achieve specific objectives for
  a given set of conditions. INCOSE System
  engineering HB Version 2a June 2004
• It is a statement that identifies a product or
  process operational, functional or design
  characteristic or constraint which is
  unambiguous, testable or measurable and necessary
  for product or process acceptability ( by
  consumers or internal quality assurance
  guidelines ). IEEE 1220 1998
• Requirements provide the way points to navigate
  and realize the final product that is required

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The need for Requirements Development

• One has to begin well to finish well.
  Requirements are the beginning of the product
  development.
• Deficiencies in requirements definition have a
  Domino effect through out the product life cycle.
  Requirement deficiency leads to system design
  deficiency in turn leads to functional and
  interface deficiencies and therefore to failure

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The need for Requirements Development-2

• Project failure Statistics
  34 to 44 failures attributed to
  Requirements
• Not spelt out properly and fully
• Not anticipated
• Not realistic
• Not validated initially

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Requirements Development Events

• Language of stake holders
• Feasible design exists
• Derived from ORD
• Engineers language
• Output of Systems Engineer
• Best design selected

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Operational / Originating Requirements
Development Process
From needs statement develop operational
concepts
Ensure requirements feasibility
Define system boundaries with system context
diagram
Define the test system requirements
Develop system objectives hierarchy
Obtain approval of the ORD and issue
Analyze and refine requirements Originating and
System
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Requirements criteria

• Good requirements have five primary
  characteristics viz. FACTS
• F stands for feasible (able to be satisfied)
• A stands for ambiguity free ( no vague terms)
• C stands for complete (contains all essential
  information)
• T stands for testable (able to be verified)
• S stands for simple ( short and concise
  sentence)

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System Development Process
Operational scenarios
Develop stakeholder requirements
Statement of needs
Customer requirements
Stakeholder requirements
Lessons learnt
Legal, Safety, air-worthiness requirements
Functional analysis
Stakeholder requirements
Develop system requirements
System requirements
Interface analysis
System design architecture logical
System requirements
Subsystem requirements
Develop system design
System design architecture physical
Repeat for the next level of subsystem
Layer by layer as in peeling of onions
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Stakeholder requirements definition

• Stake holder requirements definition process is
  to define the requirements for a system that can
  provide the services needed by Users and other
  Stakeholders in a defined environment
• Perform customer value chain analysis

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Needs statement - Autonomous MAV

• Provide flight control capability to KADET mini
  UAV beyond the visual range
• Provide capability to fly accurately within ..
  Meters of preplanned route
• Additional Objectives considered
• For future applications wet the hands in systems
  engineering application for product development
• Assess the utility of CORE 3.1 trial version to
  support requirements development

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Customer value chain analysis- Autonomous MAV
components parts
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Customer value chain analysis

• It helps in identifying the stakeholders
• Through this analysis one could also assign
  weights to customers and their requirements . It
  means that one could identify which stakeholder
  has a larger say for a particular requirement

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Concept of operations (Con-Ops, Operational
scenario) Autonomous MAV
One can visualize several operational scenarios
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System Context Diagram
Engine Control System
Environment Atmosphere
Airframe
Mission payload system
Power supply system
KADET Auto-NAV system
Ground controller
Tele-command system
Telemetry system
External system impacts and gets impacted by the
system
System Context impacts but does not get impacted
by the system
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System Objectives hierarchy value curves and
weights
Provide flight beyond visual range
Provide automatic navigation capability
Provide automatic flight control capability
0.55
0.45
Provide a reliable system
Provide augmented stability for payload operation
Provide reversionary modes of flight
Provide automatic handling of flight emergencies
Provide many way points
Provide navigation accuracy of . Meters of the
planned flight path
0.2
0.1
0.4
1.0
0.5
0.3
1.0
0.5
0.0
Graphs are value curves
0.0
20 40 60 80 100
3.0
0.0
Number of way points
Roll oscillations peak to peak degrees
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Function Behavior Model Autonomous MAV
Flight plan
Output of flight emergency logics
Legend
Flight conditions
Function Input Output
Handle flight emergencies
Receive and store flight plan
Flight termination
Continue mission
Reacquire link command
Store flight plan
Control surface deflection required
Planned Touch down point
Health check navigation system
Control UAV
Health check control system
Touch down
Control surface deflection
Flight sensor output
Health check system
Necessary control commands
Provide telemetry data
Systems healthy
System not healthy
Flight sensor conditioned output
Planned flight path
Navigate
Necessary control commands
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Creation of Originating and System requirements
Start with the operational scenarios
Carry out these activities at each layer up to
the lower most level of subsystem Finally
generate Requirements document
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Conclusion

• The process for developing Operational
  Originating Requirements is applied to Autonomous
  MAV
• The use of CORE 3.1 trial version has been
  attempted for requirements development and
  producing the Systems Requirement document
• This activity is incomplete because of the
  artificial limitations imposed by CORE 3.1 trial
  version and Autonomous control and Navigation
  system design has not been attempted
• Although the exercise is not complete tremendous
  advantages are seen to develop requirements
  adopting the ORD methodology and generate the
  necessary documentation automatically with the
  help of full fledged version of CORE software