U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Electrical and Computer Engineering.
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Transcript of U NIVERSITY OF M ASSACHUSETTS, A MHERST Department of Electrical and Computer Engineering.
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS, A, AMHERST • MHERST • Department of Electrical and Computer Engineering Department of Electrical and Computer Engineering
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS, A, AMHERST • MHERST • Department of Electrical and Computer Engineering Department of Electrical and Computer Engineering
Agenda
• Background & Motivation
• Deliverables
• Principle of Operation
• System Block Diagram
• Design Alternatives
• Proposed MDR Specifications
• Summary
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS, A, AMHERST • MHERST • Department of Electrical and Computer Engineering Department of Electrical and Computer Engineering
Background
• ~60 Amateur rocket hobbyists from 15 countries• 27 foot tall rocket• Max velocity ~mach 5.2 (3440 mph)• Max altitude >100km (100km = “space”)• Powered with sucrose fuel (sugar)• Low budget volunteer program
Our design project
• A sensor control system, providing data to flight control system• Resilient to power problems• Providing data even in the event of sensing element failure
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS, A, AMHERST • MHERST • Department of Electrical and Computer Engineering Department of Electrical and Computer Engineering
Motivation
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS, A, AMHERST • MHERST • Department of Electrical and Computer Engineering Department of Electrical and Computer Engineering
Deliverables– Gerber plot files– Schematic– Documented source code– Hardware prototypes (not flight qualified)
User manual– Program the flight plan– Edit config file– Installation verification
Acceptability Tests
- Test broad temperature range - Simulate bad sensor readings - Power disturbance
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS, A, AMHERST • MHERST • Department of Electrical and Computer Engineering Department of Electrical and Computer Engineering
Principle of Operation
• Power Buffering• Premature to design this component now• Specifications based on operating times after power failure
• Sensors may have different power profiles• Final output requires long duration of power supply
• Computational Persistence• Approximation Algorithm• Validity Checking Algorithm• Persistent Output
• Inputs to algorithms:• Multiple sensors• Pre-programmed flight plan• Flight history
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS, A, AMHERST • MHERST • Department of Electrical and Computer Engineering Department of Electrical and Computer Engineering
• Computational Persistence– Approximation Algorithm
• Algorithm design– Laws of Physics– Flight history– Flight plan
• Output– Expected sensor values– Crude uncertainty measure
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS, A, AMHERST • MHERST • Department of Electrical and Computer Engineering Department of Electrical and Computer Engineering
• Computational Persistence– Crosschecking Algorithm
• Algorithm design– Multiple sensor values– Compare data from sensors of same type– Compare data from sensors of other types– Compare data to Expected Value from approximator
• Output– Single most probable data for each sensor type– Crude uncertainty measure
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS, A, AMHERST • MHERST • Department of Electrical and Computer Engineering Department of Electrical and Computer Engineering
• Computational Persistence– Persistent Output
• Design– Arbitrates data from Approximator and Crosschecker– Power buffered to sustain output for length of flight
• Output– Single set of data for each sensor type– Data is provided to flight computer– Data is also stored in Flight History
» History stores uncertainty values with data
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS, A, AMHERST • MHERST • Department of Electrical and Computer Engineering Department of Electrical and Computer Engineering
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS, A, AMHERST • MHERST • Department of Electrical and Computer Engineering Department of Electrical and Computer Engineering
Design Alternatives
UUNIVERSITY OF NIVERSITY OF MMASSACHUSETTSASSACHUSETTS, A, AMHERST • MHERST • Department of Electrical and Computer Engineering Department of Electrical and Computer Engineering
For MDR:
- Purchased and Tested Sensors
- Simulate and Verify approx Algorithm (Proof of Concept)
- Estimated Resources (Power, Mass, Volume, Memory etc)
- Purchased Microprocessors
- Power Buffer design idea and possibly simulate