Model Plane- 2/14/13

Open and Closed Loop Systems (ex. 1.6)

This picture shows an open and closed loop system. It works by using an input as the variable. The input is based on a light reading from the phototransistor, which ranges from 5000(no light) to 0(max light). The variable tells the system when it should continue based on the reading from the phototransistor. It continues to loop until it has the correct reading.


Conclusion:

1. Another example of an open looped system could be a toaster oven, because it will continue to operate until the time variable reaches the specified limit. It would not benefit from feed back because time is a very specific variable.
2. The mouse on a computer is a closed loop system because it will not act until an input gives it specific feedback on how to react.

Variable Fuctions (ex. 1.5)

Here is an example of a variable function that I made using RoboPro. It works by running through the counter then updating the variable on each loop. As soon as the process runs five times the varible will read 5 which will tell the system it is time to stop.

Conclusion:

1. I might modify the plus command to reset a block to 0 by doing a [-5] counter after the system finishes.
2. An industrial need for counting could be used on an assembly line, where the system would count how many parts go through to log the output.

Branch Fuctions (ex. 1.4)

Branch functions are important in a system to provide multiple endings.

• An example of a normally open switch would be the home button.   
• An example of a normally closed switch would be a garage door opener.

In the system above it includes a switch and a motor. The motor will start once the switch is pressed, then stop when the switch is pressed again. Then the system ends.

Moneyball

The following questions correspond to the in class movie we watched, "Moneyball."

1) The "Moneyball" approach to baseball uses strictly statistics to build a good team. Billy Beane crafted a cheap but sucessful team by choosing players based on batting averages only and disregarding other factors like fielding skills. The Moneyball strategy is a science, but the way that Beane created the team was executed in an artistic fasion. The way he delegated with other teams to get the players he wanted was very elegant and creative.

2) The equation used to calculate OBP is (H + BP + HBP)

3) Design is to plan and create something in a skillfull and artistic manner.
4) Describe 3 situations where movie characters (intentionally or not) applied a step from the PLTW 12 Step Design Process:

       1 - In one of the first scenes, the board of managers and team owners were sitting around a table discussing how the Oakland A's could have a good season dispite their small budget. Many were saying that they needed a few big budget players while Billy Beane was arguing that all they needed were a few average cheat players. This shows the planning and pinpointing the problem part of the design process.

       2 - Later in the movie, Billy Beane hired the Yale graduate to use him as a draft manager. This move was significant in the design process as part of the planning stage. He was planning to make a good team so he picked up the Yale graduate to make a better team for the A's.
       3 - When the A's actually started winning was when Beane's team actually started playing. That was the execution portion of the design process.


5) What is “Leadership”? List the three aspects of leadership that we come up with in class. (In class research/discussion)
1 - Leadership is leading a group to complete a common task.
2 - It is having a vision and being able to communicate it clearly to others.
3 - It is creating a work group that can work well together.


6) Describe 3 circumstances from the story where a character exercised effective leadership:

       1 - Billy Beane organized the "Moneyball" team by executing his vision of cheap players who have values that other baseball clubs may overlook.

       2 - Billy Beane speaks to the losing A's team in the locker room to inspire them to play better.

       3 - Billy Beane decides not to move to Boston so he can stay in California and live with his daughter.


7) According to the movie, what was the A’s record at the start of their winning streak? 51 : 68

8) What does this ratio simplify to (roughly)? 1 : 1.5

9) How long was the A’s record setting winning streak? 20 games won.

10) Given the A’s win/loss ratio at the start of the streak (listed two questions above), what are the odds of winning 20 games in a row? Run the numbers. (In class research/discussion)

• Their odds of winning 20 games in a row is the A's current win percentage to the power of twenty. Raising their current performance (51:68; 57%) to the length of the win streak gives the chances of the win streak (0.57^20=.000013). So the reciprocal of 1.3x10^-5 = 76,923 games. Theoretically the A's must play 76,923 games before they reach the 20 game win streak.

11) Based on your calculation, do you think the A’s got lucky or was there something to the Moneyball approach?

• I think the Moneyball approach played a huge role in the massive win streak, although I think that luck played a huge part in their successes, as it does in everything else. There are just too many variables to measure a "good" baseball team, so luck does end up playing a large role.

12) Did Billy Beane strictly apply the “science” of Moneyball to his management approach? Was there an “art” to his efforts as well? Describe a circumstance where he broke from the Moneyball approach to make a positive change for the team.

•  Billy Beane's first approach to all player trades were Moneyball sciences, although his style of trading was a very artistic art form in the ways he negociated with other teams.

Basic Programming in Robo Pro

This week we have been working on basic programming. We are using the the computer program RoboPro, which allows you to easily create flowcharts that control the actions of a system. Here is a screenshot of our first program

This simple program starts and stops the motor for designated periods of time

Our first program included all the basic commands and was built in about 10 minutes. The little box that says "subprogram test" actually includes about 3 commands within it, allowing you to keep the work interface cleaner and organized.

This next screenshot is our second system which included a switch which terminated the program on activation. The system would loop for infinity until the open circuit was closed, allowing the program to end.

And of course an action shot to wrap up this activity:

Flowcharts

Here are some interesting flowcharts that we made to show simple tasks.

The first two are for sorting machines.

 This one is for a counting machine. Yay.

Edit: the flowchart includes an error. The final "no" arrow should redirect to "is it even or odd" instead ofo "choose a #."