01-03-11 New GateSystem, analysis and design

Gate analysis

Emir and Jakob have come up with some solutions to the bad test result from previous tests.

The gate they have made requires some practical design of the front of the car. It will have to be flat to give a good sonic response. If the other groups make an alternative front, the gate will not function optimal.

As we see it, there is either the solution that we design a front to all the different cars, or we make an alternative gate design which seeks to support as many car designs as possible.

We will have to come up with another way to detect the incoming cars.

Gate design

The previous design is a backup which we know works with a flat front. In case we run out of time, we will add a flat front to all car designs.

We have set up two new scenarios:

1. GateSystem PD3CD3
   We will use the same design as previous version, but add some small changes to the physical design and code design.
2. GateSystem PD4CD4
   To support as many car designs as possible we will place another sonic sensor at the side of the track.  When this sensor sees the car the gate will open. The sensor on the gate will only detect the car when the car is exiting the gate.
   

Design overview

• GateSystem PD3CD3

1. Requires flat front
2. Requires extra sonic sensor

• GateSystem PD4CD4

1. Requires no specific car design
2. Requires larger operating area

- Emir and Jakob

23-02-11 Test of Gate Version2.2

After finishing the physical design and the program design we constructed a test of concept. We made 10 tests with a success rate of 40%. Here is a video of a successful test:

In order to improve the test environment, we constructed a test track of the T-cross. Here is the track:

And here we have the test setup:

We had a program from previous work with line following, and made a car with a program to follow the line. We started the program at the gate and then started the program on the car. We made 50 tests with a success rate of 15%. Here is a video of a successful test:

We thought of what the problem could be. When we took raw data from the sonic sensor it gave unstable signals from the front of the car. We tried to isolate the sonic sensor. We constructed a test with a flat surface acting as a car. We made 15 tests with a success rate of 100%. We are sure that the lack of good sonic response from the front of the car is coursing the bad test results with the car. Here is a video of a successful test with a flat surface:

 Next steps:

• Try testing with different designs of cars and programs.
• Try to make an alternative way to detect the car coming from the factory
• Make a traffic light for the M1 track
• Make a circular track for continues testing

- Emir and Jakob

23-02-11 Second test

Our gate was too heavy that’s why we change it totally with cardboard box. We also put a wheel on the bottom of the gate so it can easier open the gate. We tested and it works much better now.

Here is video of our gate:

- Emir

22-02-11 First implementation

Emir and I started to implement the gate design. We build the gate due to the design in previous posts. We build the gate so it was stable and was looking like the sketch. The model looks like this:

We used the onboard programming facilities of the intelligent brick and tried to make the gate move. It worked. We when made a simple program to see how the sensor and gate reacted. The program looked like this:

Observations:

  

• We must open the gate slowly to avoid aggressive behavior.
• The gate might be too heavy.
• The brick does not have enough mass to stay in the same place when the gate moves.
• The sensor has good response.
• When the intelligent brick is being fixed to the same point the gate responds quite well.

- Jakob

Perversion of the traffic light

Perversion of the traffic light

Right before the M1 and M2 meet there should be a traffic light.

I thought of this design:

It is connected to the warehouse computer and turns 180 degrees when there is a red light. It turns back when there are no cars at the factory. The reason it has to be on the right side is because, the line follower it following the left side of the tape, when it is following the M2. A bad thing is that it would have to be so big because the right weal on the car should be able to pass. And if the car is above the disc when it turns it would not be good.

First ideas for the system

1. First thing that comes to my mind: “Safety First”
2. All the cars should have the same physical design and the same program running.
3. The track should be a strip of 2 cm wide black tape.
4. The tape will have a unique color at every place where the cars have to make a decision.
5. To ensure that the car does not run past the mark, the color sensor must at all time be at the middle of the tape. The color sensor will look for the transfer between black to “unique color”. In front of the car should be tree sensors. A color sensor should be placed in the middle, and a light sensor on each side of the color sensor.
6. Before the cars have to decide either to go M1 or M2 the tape should be marked with a unique color. It would wait here until it gets a message from the central computer at the warehouse. If it should go to M1, it would be following the left side of the tape with the left sensor on the left side of the tape. There for turning left. And if it should go to M2 it would follow the right side of the tape with the right sensor, therefore turning right. In this manner the color sensor will always be in the center of the tape