A little bit intro...

Automated vehicle convoys have been proposed as an alternative to human drivers in private, commercial and military convoys [1]. These autonomous vehicles are able to safely reduce the spacing between vehicles, which would increase overall driving effectiveness of traffic patterns [2]. There are various fields application of autonomous cars. Compared to human drivers, the system could be more reliable, can react faster and observe up to the whole 360-degree environment [3]. Fewer traffic collisions, better traffic flow, higher traffic economy and free time for human drivers are some benefits of autonomous following car [4].

There are so many factors that can lead to car collision during convoying. Human error like sleepy and drinking driver ability to open the portion of accident. In order, space between adjacent cars can lead to road congestion. By using the application of autonomous following car, communication and sensor will react faster to reduce the space which allowing greater density on the highway [5].

Prototype of vehicle following system (POVFS) is designed to develop automated convoy system with constant motion. This system which can ensure the safe distance between vehicles during following. It is designed with two important features which are Bluetooth module and ultrasonic sonar. The implementation of Bluetooth signal assists a communication between Master and slave car. Lastly, ultrasonic sensor emit sound waves, respectively and detect occupancy by analysing the frequency of the received waves.

  Problem...?

Accident due to collision is a common problem happened in highway road [6]. Those problems can lead to road congestion and worst traffic flow. One of the factor that lead to car collision is people felt tired and sleepy when driving [7]. Driver following vehicle in front very closely are very dangerous especially when the driver is tired. Lot of cases of car collision accidents tend to happen in every year and everywhere. Based on the statistic of PDRM Malaysia 2012, the total number of vehicle accident from 2008-2011 are about 1,633,862 [8].

Car jumping queues could be one of the factor that can lead to road congestion . Mostly drivers nowadays felt impatient for them to reach their destination. These behaviours can lead to road congestion.

Others, bumper to bumper collision tend to occur problem of road congestion. Ghost slowdown can lead bumper collision as car in front do emergency brake during convoy [9]. Those problems could be solved by applying automated vehicle following system.

  My Pure Objective...?

• To develop automated vehicle system that can make them follow each other’s.
• To develop Bluetooth communication between the cars.
• To develop the constant velocity motion of the system during the following movement.

  I Will Be Focusing On...?

The aim of this project is to develop Prototype of Vehicle Following System (POVFS) where the slave vehicle will automated follow the motion of the first master vehicle. Slave car will move according to the command given by the Bluetooth signal in constant speed motion. The aim of ultrasonic sonar sensor is to calculate distance between Master and slave car to provide safe distance during convoy.

POVFS is divided into three main parts which are overall system development, hardware design and programming development. For the first part which is system development that will focus on how to develop automated following system between the vehicles in constant velocity. The second part, hardware development that will focus on developing a prototype car. A small and movable prototype car will be designed according to the size of Arduino Uno and Bluetooth module.

The third part is developing the programming and algorithm for POVFS. The development of programs is focused on how the master mode will sent the data to the slave mode. Communication of Bluetooth is used as medium to communicate between them. Algorithm and motion of Master prototype car also being developed at this part.

  So, It Is A Success...?

In order to live test, two prototype cars are placed in a straight line with master prototype car in front of the slave prototype car. There is non-ultrasonic sonar sensor at master car because master car supposedly leads the path. Motor driver and controller was put on the top of the car. Bluetooth transmitter module are used to transmit a signal to slave prototype car and battery with the input voltage 7.4 is used as the power source. Figure 4.1 below shows prototype Master car for POVFS. Figure 4.2 shows circuit design for master car.

Figure 4.1: prototype Master car for POVFS.

Figure 4.2: Circuit design Master Car using Altium software

In order to control the movement of the prototype car, small remote controller was created in this project. Meanwhile, 4 small push buttons are used as the input movement of the controller. The buttons are soldered at the small donut board.  The 1800pF capacitor was connected parallel to each of the button as to make sure the signal smoother by reducing the environment noise. Push button was connected as active low configuration input. Figure 4.3 shown hardware implemented for wired controller. Connection circuit of the controller was shown at Figure 4.3 below.

Figure 4.3: Wired Controller implemented on Master Car

Figure 4.4: Circuit design for controller using Altium software

For the slave car, different features are used to this car. Slave car aim to follow the movement of the master car in a safe distance. One ultrasonic sonar sensor is installed in front of the car to calculate the safe distance when following. Meanwhile, the sonar sensor also functions as to prevent from bumper to bumper collision. Receiver Bluetooth module is used to detect the signal from the master car. The movement and motion of the Master car will always follow by Slave car. Figure 4.3 below shows prototype of the slave car. Circuit connection of Slave car shown at Figure 4.4.

Figure 4.5: Prototype Slave car for POVFS

Figure 4.6: Circuit design for prototype slave car.

For the live test of prototype car, the experiment is conducted to test the stability of the Bluetooth signal. The experiment is conducted in open area which is at Stadium Azman Hashim, UTM. To test the stability of the Bluetooth signal, 5 different range of distance are being experimented. Table 4.1 shows Sensor stability of POVFS.

Table 4.1: Sensor stability of POVFS.

Based on the data provided, when the distance between the cars is about 1-5 m, the signal is very strength. Time responded of slave car is very fast. This kind of range are very suitable to function the system. Both car convoy at constant velocity as slave car follow the motion of Master Car.

For distance 6-10 m, stability of sensor shows a moderate stable. Slave car still can detect the signal and follow Master’s motion. At distance of 11-15m, the result shows stability of Bluetooth are weak. The unstable of signal occur at this range. This caused the motion of convoy slave car is unstable in order the non-stable of the signal.

Next, for distance 16-29 m, the data shows the signal is very weak. There are sometime lost connection occur during following. This distance is not good when functioning the system. Noise of the environment can be one of the factor for weak signal. Lastly, when range more than 30m is tested, the data shows no signal. Bluetooth sensor failed to detect the signal for distance more than 30 m. The cars are not following each other.

Hence, in order to provide functioning the system as good, range 1-5 m are choosing. Car will follow the motion very well in constant velocity as the Bluetooth signal are at very stable. A good convoy system can be provided in the range of 1-5 m.

Based on the results being shown in the above tables, we can conclude that the POFVS will functioning well at distance 1-5 m. Both Master and Slave prototype car can travel each other in constant velocity without any collision. Strength of Bluetooth are very good at this range to help functioning POVFS very well. Conversely, POVFS is not able to communicate each other in long distances due to factor loss of signal.

  Hence...?

Prototype of Vehicle Following System (POVFS) is designed to develop a prototype car system which can make them follow each other in constant velocity. This prototype car can lead to systematic following motion car which can prevent collision happened on the road. Communication and sensor of POVFS can react faster either than human error which can reduce the space and allowing a greater density on the road. POFVS also can reduce human error like sleepy and drinking which can open the portion of accident especially when following the car in front.

Besides, POVFS provides a systematic constant motion on road as the vehicle installed with the system will follow all the programming code that have been programmed. POVFS also equipped with ultrasonic sonar sensor. The function of the sensor is to reduce ghost down as the car in front do emergency break which can lead bumper to bumper collision. At last, this system can provide a systematic car following system which can be implanted to the real car as to reduce energy and power of human.