The lab of week 3

1.The objectives of week 3

After completing the individual test of the car and the board, today the group plans to combine them to test the whole system. So in this lab, the task will be divided into the following parts.

1) We need to add sensors into the board and add black tapes as road on the board where the car can be tested on it.
2) The car is still be added some sensors.
3) We plan to test the result of the car running on the parking board after the first two steps.

2.The experimental process

Figure 1. the complete car

As is shown in figure 1, we used a utility knife to dig small holes on the board at a certain distance where we can install infrared sensors. It is used to detect the position of the car. It can also be seen that the group put some black tape on the board to test the movement of the car.

Figrue 2. the installed infrared sensors

Next, we tidied up the wiring of the infrared sensors by pasting black tape. The reason why we did this is that it is easy for us to find connection problems when sensors have problems.

Figure 3. test on the desk

We installed two infrared sensors into the smart car. As can be seen in figure 3, we used two sponge to connect the sensor and the car because it could reduce the distance of detection to increase accuracy. In reality, we will choose the ultrasonic sensor instead of the infrared sensor because its detection distance can reach height of wheels. Then we let it run on the desk first to check its motion condition.

Figure 4. test on the board

After completing the above steps, we could start to test the car running on the board. First we set some simple orders to observe whether it can move on the board. It is shown in figure 4.

3. Results and discussion

When the car was tested on the desk, it could finish direct and turn commands. The phenomena we observed is that the car wobbles slightly in a straight line because it exists a distance for the detection of infrared sensor on the car. However, the car could not walk smoothly on the board. So the team did a deep research to this problem. After discussion and test, the group found that the same parameters of program was not suitable for different ground. So the group changed the parameters so that it is suitable for the board.

4. Summary

1) We have successfully finished building the smart car by adding two infrared sensors.

2) The group has completed part of the road construction on board by sticking black tape and added infrared sensors, but it is not finished. So it still needs to add parking lot and routes.
3) In the test of movement of the car, it could go straight and make a turn as we expected. So we can add more program into it in next week.