Preliminary Design Review

Thermal Wireless Sensor

Presentation Outline

• Project Goals and Scope• Deliverables• Project Risks and Challenges• Specifications• Wireless Architecture Decision Matrix• Prototypes• Cost Estimation• Project Timeline

Project Goal

• Design and Build a wireless system that will be imbedded in a heat shield material to measure temperature on atmospheric entry.

Scope

• Primary Focus: The main focus of our project will be to design the wireless transmission of the thermocouple signal

• Secondary Considerations– Thermocouple Correction and Amplification

circuit– Data Acquisition

Deliverables

• Evolution of several designs

• Characterization of the system and how it responds to environmental noise

• Verification of signal to a similar “wired” system

• Wireless system imbedded into heat shield material

Project Risks and Challenges

• Transmission through RF non-transparent material

• Transmission through a high interference environment

• Protection of wires and circuits at high temperatures

• Machining hazardous material

• Meeting required size specifications

Specifications and Constraints

Type Specs Priority

No. of Comm. Channels 4 1

No. of Thermocouples 4 1

Sensor Placement Center Embedded 1

Data Collection Microsoft Excel 1

Data Rate Sample Every Second 1

Data Transfer Real Time 1

Power Source < 9 V 1

System Life Power 2 years 1

Bandwidth 1 – 10Hz 2

Temperature Resolution +/- 5 degrees Celsius 2

Noise Interference ??? 2

Temperature Range 0 – 1000 degrees Celsius 2

Transmitter Size 5” x 4” x 2” 3

Weight 16 oz (Heat Shield Side) 3

Vibration Low Susceptibility 3

Wireless ArchitectureDecision Matrix

RF NFMC LED

Size Comparable Comparable Comparable

Power Consumption Highest Potentially None Medium

Ability to Transmit Power No Yes No

Transmission Type RF Magnetic Coupling Light Emission

Transmission Distance 40 meters 2 meters 10 meters

Needs Line of Sight No No Yes

Noise Immunity Low High High

Cost Highest Lowest Medium

Commercial Availability Highest None Medium

Prototypes

Prototypes

Cost Estimation

Part Description Price Qnt. Total

Thermocouple Wire 22.00 1 22.00

Maxim Thermocouple CJC and A/D Converter

7.18 4 24.72

Wireless Transmitter ~50.00 4 ~200.00

Wireless Receiver ~50.00 4 ~200.00

Dataq Digital Data Acquisition

50.00 1 50.00

Total ~500.00

Project Timeline

Project Timeline