P09141: ITT Thermal Heater Controller
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Target Specifications

Table of Contents

The purpose of this page is to establish the target specifications. This page contains the list of metrics and the customer needs as related to the metrics matrix.

Step 1. Prepare the List of Specifications

The table below presents the metrics, or engineering specifications, that will be used by the team to design against.

List of Specifications
Spec No. Source Description Unit of Measure Marginal Value Ideal Value
1 1.1 Production cost $ 1740 to 2070 1740
2 3.2, 3.3 Bus voltage V 20 to 36 28
3 3.2, 3.4, 3.5, 3.6 Overall power consumption maximum W 50 to 100 50
4 3.2, 3.4, 3.5, 3.7 Overall power consumption minimum W 0 to 1 0.01
5 3.2, 3.4, 3.5, 3.8 Overall energy efficiency % 75 to 100 100
6 1.4.4 Overall weight kg 2 to 5 2
7 3.2.1, 3.4, 3.5 Master slave power consumption maximum W 50 to 100 50
8 3.2.1, 3.4, 3.6 Master slave power consumption sleep W 0 to 1 0.001
9 3.4, 3.5 Master slave weight kg 0.2 to 0.5 0.2
10 1.1, 1.4, 3.4, 3.5 Master slave circuit board size cm^2 4x10 3.53x8.78
11 3.3 Master slave measurement time ms 1 to 20 1
12 3.3 Time to wake slave ms 1 to 20 1
13 3.3.2 Time to access master ms 1 to 20 1
14 3.3 Slave reconfigurability time ms 1 to 20 1
15 3.3.4 Communication protocol length bits 24 to 64 24
16 3.2, 3.6 HHC power consumption on state W 40 to 50 50
17 3.2, 3.6 HHC power consumption off state W 0 to 1 0
18 1.4.4, 3.8 HHC enclosure weight kg 0.000001 to 0.136kg smaller better
19 1.4.5, 3.8 HHC enclosure size in^3 2x3x1 smaller better
20 3.6 HHC stabilization time ms 1 to 20 1
21 3.1.2, 3.6 HHC temperature regulation deg C +/- 0.3 +/- 0.3
22 3.8.2 Enclosure vibration modeling G's RMS 10 to 30 23
23 3.8.2 Enclosure vent rate psi/s 0 to 1 (0.5 avg) bigger better
24 3.8.3 Enclosure thermal modeling deg C -40 to +55 -65 to +125
25 3.8.3 Enclosure thermal cycles Number 10 dwell 10s MIL Spec 883
26 3.3.2 Control system GUI language Any GUI lang Lab View/VB
27 3.3 Communications bandwidth Hz 12804 to 19206 12804
28 3.3 Bit error rate % 0 to 1e-4 0
29 3.3 S/N Ratio dB -40 bigger better
30 3.3 Transmitted signal amplitude over the power bus mV RMS 1 to 10 1
31 3.3 Power bus wire thickness AWG 22+ 22
32 3.3 Power bus wire length ft <50 20
33 3.7.2, 3.8.1 EMI leak KHz <100 smaller better

Step 2. Establish the Relative Importance of the Specifications

The client is flexible about the priority of many of the specifications but has established the following levels of importance.

Importance
Importance Description
1 Power consumption/efficiency
2 Mass
3 Performance
4 Communications
5 Cost

Step 3. Relate Specifications to Customer Needs

Customer Needs to Specifications Matrix
Specs/Needs Bi-dir Comm. Comm. over Bus Master/Slave GUI Adjust Set Point Enc. Design Enc. Prototype Enc. Vibration Model Enc. Thermal Model HHC Testing HHC Verification
Production cost x x x x
Bus voltage x x x
Power consumption x x x x x
Efficiency x x x x
Weight x x x x x x
Size x x x x x x
Time to wake x x x
Time to access x x x
Reconfiguration time x x x x
Stabilization time x x
Protocol length x x x x
Vibration tolerance x x x x x x
Thermal tolerance x x x x x x
GUI Design x x
Comm. bandwidth x x x
Bit error rate x x x

Step 4. Collect Competitive Benchmarking Information

Benchmark 1
Power Line communications- depending on frequency range (high, mid, or low) different limitations and benefits are encountered. High frequency is still mostly in research mode. Mid frequency is used primarily in house appliances and low frequency is used in the automatic meter reading industry. (See PLC benchmarking.doc on home page)
Benchmark 2
Implementation device- researched FPGA vs. DSP and concluded that although DSPs are slower than FPGAs in terms of performance, they are faster in terms of developing. Also, FPGAs require programming to be done in VHDL. A language with which we have little to no experience in terms of debugging. Thus, DSPs seem like the option most suited to meet our specifications. (See benchmarking.xls on home page)
Benchmark 3
Modulation techniques- Frequency Shift keying (FSK) was looked as the preferred way of modulating the signals for this application. Other techniques that were explored were PAM and PSK (Phase Shift keying). (See benchmarking.xls on home page)
Benchmarking Documentation
PLC Benchmarking
File Type: *.doc, Date Updated: 12-18-08

Step 5. Final List of Specifications

The table below represents a list of final specifications that has come from several customer engagements, relating specifications to customer needs, benchmarking analysis, and calculations.

List of Specifications
Spec No. Source Description Unit of Measure Marginal Value Ideal Value
1 1.1 Production cost $ 1740 to 2070 1740
2 3.2, 3.3 Bus voltage V 20 to 36 28
3 3.2, 3.4, 3.5, 3.6 Overall power consumption maximum W as small as possible smaller better
4 3.3 Master slave measurement time ms 1 to 20 1
5 3.3 Time to wake slave ms 1 to 20 1
6 3.3.4 Communication protocol length bits 24 to 64 24
7 1.4.4, 3.8 Enclosure Weight lb 0.01 to 0.45 < 0.45
8 1.4.5, 3.8 Enclosure Size in^3 2.0 x 3.0 x 1.0 to 2.5 x 3.75 x 1.25 < 2.5 x 3.75 x 1.25
9 3.1.2, 3.6 HHC Temperature Regulation deg C +/- 0.3 <= +/- 0.3
10 3.8.2 Enclosure Vibration Criterion G's RMS 23.1 MIL-STD-202
11 3.8.2 Enclosure Ventilation Rate psi/s 0 to 1 < 1
12 3.8.3 Enclosure Thermal Criterion deg C -40 to +55 Operational, -65 to +125 Storage MIL-STD-883
13 3.8.3 Enclosure Thermal Cycling s Dwell 10 MIL-STD-883
14 3.3.2 Control system GUI language Any GUI lang Lab View/VB
15 3.3 Communications bandwidth Hz <300K 12804 to 100K
16 3.3 Bit error rate % 0 to 1e-4 0
17 3.3 S/N Ratio dB -40 bigger better
18 3.3 Transmitted signal amplitude over the power bus mV RMS 1 to 10 1
19 3.3 Power bus wire thickness AWG 22+ 22
20 3.3 Power bus wire length ft <50 20
21 3.7.2, 3.8.1 EMI leak KHz <100 smaller better

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