Objective

The objective is to explore the use of data and the development of temperature conversion and linear interpolation algorithms for calculating psi from a given temperature.

Introduction

Your program will calculate the resultant saturated pressure of our mythical vessel of special fluid and air to a global variable vesselPressPsi, from a temperature (degrees Fahrenheit, global variable vesselTempFahr). This temperature represents an electrical sensor input that was converted to engineering units. The linear interpolation algorithm is based on degrees Celsius.

Requirements

Design, Code, Test a C program which will loop forever calculating the resultant saturated pressure of our mythical vessel of special fluid and air to a global variable; vesselPressPsi, from a temperature (degrees Fahrenheit, global variable vesselTempFahr). Temperature will be provided by using a random number generator. Use the modulus operator to place your random number closer to the range vesselTempFahr (100-1800F). This temperature represents an electrical sensor input that was converted to engineering units. The linear interpolation algorithm and corresponding data tables are based on degrees Celsius (local variable vesselTempCelsius). The program will use the data tables in Appendix A, which provide corresponding pressure for a given Celsius temperature. One data pair is the upper and lower degree Celsius and the other pair is the upper and lower relative saturated pressure for the corresponding temperature. Compute the saturated pressure from the temperature input.

Since temperature in this assignment represents an electrical sensor input, we need to understand some basic constraints with sensors. Sometimes sensors are saturated or at their limits of operations, the sensor may respond (signal) with unknown values outside its working range. This could cause erratic or catastrophic conditions for control systems. This is solved by placing limiter testing at saturation points of sensors. Saturation testing imposes upper and lower bounds on a signal. When the input signal is within the range specified by lower limit and upper limit parameters, the input signal passes through unchanged. When the input signal is outside these bounds, the signal is clipped to the upper or lower bound values.

Algorithm

Not every Temperature input will have a direct corresponding pressure. For example if vesselTempCelsius = 65, which is neither of the known Celsius limits in Appendix A. Linear interpolation is a way to fill in the holes'' in tables. Linear Interpolation is a method of constructing new data points within the range of a discrete set of known data points. Linear interpolation is quick and easy, but at times not very precise, to increase precision is to increase the number of data points with in the know set of data points.

In this assignment, you only have two data points, which represent the upper and lower data range.

Interpolation example with Appendix A:

vesselTempFahr = 147.0

Result of hand test is psi= 0.2978 psi

Design considerations:

1. IFF, your Hw5 was buggered, you may use the Hw5 solution as a baseline for Hw6.

2. Notice, not much seems to have changed from Hw5

a. Make sure you can see the comments in this document for change notifications

b. Tables, aka arrays saturation/bounds are based on the first and last index values

i. You will need to calculate them for your If statements and loops

c. for-loops are better than while-loops to scan through the array to find a data pair for your algorithm

3. Setup your testing to make sure all requirements are still met.

4. Notice the tables arrays requirements do not include identifier naming, types, and whether the data is to be local or global.

a. Since they are tables and never to change, try defining them as constants

b. There are reasons why we do this, but that is for another class/course.

5. When scanning though the data table, place break statements to exit loops once data and calculations are completed.

a. Lookup reserved word break to understand use-case.

6. There will be changes to the design which should show-up in your traceability form.

7. The code must perform Saturation testing. Provide your test plan for verifying Saturation testing in your header comment.

8. The data used to validate your hand calculations become your known data inputs to your code. That is a step in validating your code algorithm.

Deliverables 40pts

1. Fill out the Simple Requirements tractability form.

a. This is an engineering process of design and test (V&V)

b. To identify requirements, a conceptual design and how to verify/validate the design meets the requirement

c. Submit as Hw5a document (PDF, Word, or Excel compatibility)

2. You are to follow the Programming Standards for this class.

Appendix A

Temperature

- t -

(oc)

Pressure

- pv -

(psia, lb/in2)

10

0.1317

30

0.1881

60

0.2563

70

0.3631

80

0.5069

90

0.6979

110

0.9493

130

1.692

140

2.888

160

4.736

190

7.507

220

11.52

240

14.69

250

17.19

260

24.97

270

35.43

280

49.20

350

67.01

400

134.60

450

247.26

500

422.55

575

680.86

650

1045.43

700

1543.20

800

2308.40

950

3194.30