Parking has become one of the biggest problems in modern cities. When the vehicle growth rate is faster than street development rate, there will be issues with how these vehicles will be parked. A smart parking system becomes an alternative solution to addressing parking problems.

In general, a smart parking system will address problems shown in the following figure:

• Vehicle In/Out stands for detecting when a vehicle comes in and goes out. It will affect the number of vacant parking spaces and parking duration.
• Vehicle plate number detection aims at minimizing human errors in entering vehicle plate numbers into a system.
• Vacant parking space aims at optimizing parking space by knowing the number of vacant parking spaces.
• Parking management system is the main system to manage all activities in a parking system. It also provides information about...

To build a smart parking system, we should know about some sensors related to a smart parking system. In this section, we will review the main sensors that are used in one.

Let's explore!

The HC-SR04 is a cheap ultrasonic sensor. It is used to measure the range between itself and an object. Each HC-SR04 module includes an ultrasonic transmitter, a receiver, and a control circuit. You can see that the HC-SR04 has four pins: GND, VCC, Triger, and Echo. You can buy HC-SR04 from SparkFun, at https://www.sparkfun.com/products/13959, as shown in the next image. You can also find this sensor at SeeedStudio: https://www.seeedstudio.com/Ultra-Sonic-range-measurement...

A parking lot usually has an in-gate and out-gate. When a vehicle comes in, a driver presses a button to a get parking ticket. Then, the gate opens. Some parking places use a card as driver identity. After it is tapped, the gate will open.

Here's a real parking gate:

To build a parking in-gate, we can design one as shown in the following figure. We put sensor devices on the left, right, and a front of a vehicle. You can use sensor devices that we have learned about.

For instance, we can use an ultrasonic sensor. We'll put some sensor devices on the right, left, and front of the vehicle. The sensor device position in the gate is shown in the following figure. All sensors acquire and obtain distance values, dx. Then, we set a threshold value from a collection of distance values to indicate whether...

A smart parking system ensures all activities take place automatically. Rather than reading a vehicle plate number manually, we can make it read a vehicle plate number using a program through a camera. We can use the OpenALPR library for reading vehicle plate numbers.

OpenALPR is an open source automatic license plate recognition library written in C++ with bindings in C#, Java, Node.js, Go, and Python. You can visit the official website at https://github.com/openalpr/openalpr.

We will install OpenALPR and test it with vehicle plate numbers in the next section.

In this section, we will deploy OpenALPR on the Raspberry Pi. Since OpenALPR needs more space on disk, make sure...

In a smart parking system, information about vacant parking spaces is important. A simple method to identify how many vacant spaces are available is to count the difference between the parking lot capacity and the number of vehicles currently in the lot. This approach has a disadvantage because we don't know which parking areas are vacant. Suppose a parking lot has four levels. We should know whether a parking area level is full or not.

Suppose we have a parking area as shown in the next image. We can identify how many vacant parking spaces there are using image processing and pattern recognition.

A simple way to detect vacant parking spaces is to apply the background subtraction method. If you use the OpenCV library, you can learn this method with this tutorial...

We have built sensors for detecting vehicle entry/exit and plate numbers. All those systems should be connected to a central system. This could be called a core system. To build a core system for parking, we could design and develop a parking management system. It's software which can use any platform, such as Java, .NET, Node.js, Python.

In general, a parking management system can be described as follows:

From this figure, we can explain each component as follows:

• Core parking system application is the main application for the parking system. This application is responsible for processing and querying data for all vehicles and sensors.
• Web application is a public application that serves parking information, such as capacity and current vacant parking space.
• RESTful/MQTT is an application interface to serve JSON or MQTT for mobile and sensor...

Building a smart parking system needs several components to make it work. These components can be software and hardware. In general, a smart parking system can be described as follows:

A parking application system consists of application modules that manage each task. For instance, the web application is designed as an interface for user interaction. All data will be saved into a storage server, such as MySQL, MariaDB, PostgreSQL, Oracle, or SQL Server.

All sensors are connected to a board system. You can use Arduino or Raspberry Pi. The sensor will detect vehicle entry/exit and plate numbers.

Firstly, we design a smart parking system in a building. We put a camera and sensors on each floor in the building. You also build gates for vehicle entry/exit with sensors. Lastly, we deploy a core parking system in the building. Building infrastructure...

We learned what a smart parking system is and explored sensor devices that are used in a smart parking system. We also implemented core components of such a smart parking system.

In the next chapter, we'll review a vending machine and try to build a prototype.