Calculates the lab test required for electric motors.
Imagine you’re at work. A lab test engineer comes into your office and says, ‘Bob, I need your help solving a puzzle.’ He presents you with a spreadsheet; an excel file. He calls it ‘the matrix’. You’re intrigued. In it contains a long list of varying combinations of different motor characteristics like speed, voltage, phase, frequency, and many others, combined with various types of certified motor test, such as performance test, timed heat run, DDF’s and LR Single and LR Three phase (22 different types of test in total), all in a 300+ line excel grid. He explains how the lab engineer had to vertically scroll through the various combinations of motor characteristics values (the different spreadsheet lines) until he or she finds which line represented the motor he needed to test. Then they would horizontally scroll through the line to copy down which test had to be performed on that particular motor. Although the task was not overly difficult it was unnecessarily time consuming and particularly vulnerable to human error.
Now the question becomes, what route do you take to answer the question. How do you solve ‘the matrix’? Something like the following did get presented to me a number of years ago. I used a tool I had only recently been introduced to, C#. Although this is not at all the solution I came up with at the time the following should always give you the correct result for the motor you input. The excel file needed to understand the solution to the algorith is defined in the spreadsheet named 'Lab Testing Rules.xlsx' contained at the root of this project. This file is key to understanding the premise of the project.
Since the original solution, I have grown in my understanding of the C# language and attempted to improve the original version so it was easier to read and understand. My solution contains many objects. These objects mimic all the various entitys you'll find in the spreadsheet, the different characteristics like hertz, voltage, frequency, and all the test like running heating, performance ext. Then you'll find other objects that deal with connection which objects go together. The algortih solution for determining which test to run can be found in the class ‘TestCalculation.cs’ and function ‘RequiredTest’ which returns an IEnumerable of IMotorTest (An overly simple interface for storing the test name). Although this particular function might not look overly difficult, understanding which combinations of characteristics give rise to which test is not at all easy.
Also, for a simple ui to retreive the users input and display the results i've added a .NET console application 'LabMotorTest' which uses the library 'ConsoleInterpreter' as the user interface for retrieving the required parameters for the calculation and displaying the results. Although obviously a web interface is a more logical choice, I’ll leave that piece for you. In this project, I've attempted to decouple responsiblity of knowing what is invalid data from knowing how to handle the invalid response. If we attempt to pass 'maybe' as the overload type we might expect the program to not work properly but what should the program actually do? For me, I expect it to work properly. That is, I expect it to alert me that 'maybe' is not a valid option and allow me to change my input. To see how my solution works, take a look at the class ConsolePromptValidation.cs inside ConsoleInterpreter library. In it I force the console input to pass the validation function provided in the implementation of the IConsoleInputValidator.cs interface given to the constructor of ConsolePromptValidation.cs. Essentially this object places unending console.Read()'s on the console until the user provides a valid value defined by the creator of IConsoleInputValidators' implementer. This makes it the callers' responsibility to properly communicate the possible valid options the end user can use by adding them to the InputPrompt getter property defined on the object, and to determine if the users input is valid by implementing the Validate function also defined on the interface.
Take a look, try it out, make a branch, see if you can make any sense of it. Let me know if you have any questions or input.
Thanks, Jeremy Christman Jchristman129@gmail.com