The lab of week 2

1. The objectives of week 2

In this lab, the team decides to install a small car and improve the functions of each component to make them perform independently. In addition, another task today is to discuss out the reasonable parking planning map where the smart car can avoid obstacles and park automatically. So the division of the work is as follows.

1) Shuorong.Guo and Hongqian.Zhou are responsible to install the small car.
2) Zijie.Di is responsible to improve the functions of all the cmponents.
3) Four members of the group design out the parking lot structure and Boyuan.Li is responsible to draw the flowchart to explain it.

 2. The experimental process and experimental results

Figure 1. the smart car

The figure 1 shows that the installed car. Shuorong.Guo and Hongqian.Zhou mounted two speed sensors and L293d ic chip that can control direction on the motors.

Figure 2. the infrared sensors

As shown in figure 2, the infrared sensors can detect the objects and the detection distance we measured is about 25mm, which is enough to this lab. In reality, we will choose the ultrasonic sensor instead of the infrared sensor because its detection distance can reach height of wheels. And the reason why we choose it is that the infrared sensor has small volume that is more suitable for smart car model.

Figure 3. the parking structure

The figure 3 shows the parking lot structure we design. There are three parking spaces in the right column and it can be expanded in the future. The black line of left part is parking road where the car can go straight and make a turn. The point at the center of the square represents the infrared sensors that are used to detect the position of the car.

Figure 4. flow chart

The figure 4 shows the parking process and parking principle.

3. Problems and Solutions

In the test of the wireless sensor, the group found that the detection distance of the wireless sensor was so short that it only transmitted about 10 centimetres, which cannot reach the requirement of the experiment.

 

Figure 5. the wireless sensor with antennas

In order to solve this problem, the group decided to add antennas to both transmitters and receivers. Therefore, the group welded the wire to the end of the sensor and turned it into a helix shape, which is shown in figure 5. As the result, the receiving distance is long enough to meet the requirements of this simulation experiment. The group thinks that it is also not a problem in reality because of using more advanced wireless transmitter.

 4. Summary


1) We have constructed the smart car. It can be tested on the board but it is still improved because some sensors are not installed.
2) We have successfully tested all the functions of each independent component, which will be combined to work together in next week.
3) The parking lot structure has been determined.
4) The group has drawn out the flowchart of car movement to help others understand principle.