Intelligent detector provides real-time information on available parking spaces

Testing of the new technology is currently underway at the Universitat Politècnica de Catalunya's North Campus, and a patent is being sought. The system can be used to provide users with information via mobile devices such as phones, laptop computers, and iPads, or using luminous panels in public thoroughfares. In the coming months it will be installed in the 22@Barcelona innovation district and in downtown Figueres.

A team at the Department of Electronic Engineering of the Castelldefels School of Telecommunications and Aerospace Engineering (EETAC), part of the Universitat Politècnica de Catalunya (UPC), has designed a new method for continuously detecting the presence of vehicles using both an optical and a magnetic sensor. The detector incorporates the two sensors in a 4 by 13 cm casing that is set into the pavement of each parking space. Urbiòtica, a company set up by UPC professors and their industrial partners, is testing the system at the UPC's North Campus prior to placing it on the market.

The device works by first detecting the sudden change in the amount of light reaching the pavement that occurs when a vehicle passes over it. The optical sensor then activates the magnetic sensor to verify that the shadow is being produced by a vehicle. This is done by detecting the slight disturbance in Earth's magnetic field that occurs when a car passes over or stops above the device. The two sensors are connected to a microcontroller that executes an algorithm to determine whether or not a vehicle is present. The system's optical sensor is always active but consumes an insignificant amount of power.

When a vehicle is detected, the microcontroller sends a radio-frequency signal, which conveys this information to an antenna connected to a transceiver. This way of transmitting signals is much more economical than using wiring. The transceiver, designed for installation on street lights, receives the information and transmits it to the database or control center within seconds (using technologies such as Wi-Fi or GPRS). Potential clients for the system include municipal services and parking lot operators.

According to Ramon Pallàs, head of the UPC team that developed the technology (for which a patent is being sought), the plan is to make the information available on luminous panels on public thoroughfares. Users will also be able to receive parking information on mobile devices such as phones, laptop computers, and iPads.

The innovative features of the product (which the UPC's AntenaLAB group also worked on) relate to the field of sensors, the circuits connecting the sensors to the microcontroller, the method for supplying power to the sensors, and management of the power supply for the system as a whole.

Continuous operation with low power consumption

The invention overcomes the shortcomings of the best existing systems for detecting stationary vehicles. There currently exist devices that emit a signal when a car passes over a sensor, but they do not detect whether the vehicle stops. In an enclosed facility these systems can be used to count vehicles entering and leaving and thus determine the number of parking spaces available, but they do not indicate where the free spaces are. Also, the magnetic sensors now in use consume too much energy to be kept running all the time.

In contrast, the system developed by the UPC group and marketed by Urbiòtica operates continuously and uses very little power because the optical sensor is the only component that is always active and the magnetic sensor is activated less frequently than in other similar systems. The fact that the sensors are connected directly to the microcontroller, without any intermediate electronic circuit, also reduces power consumption.

Practical applications

The new system can be used to manage and monitor vehicles on public and private thoroughfares, particularly in urban areas. This makes it possible to monitor points of access to centers of population, restricted zones, security zones, and grade crossings, and to manage parking on streets, at airports, and in commercial and underground parking areas. These applications can reduce the time drivers spend looking for a parking spot, resulting in lower fuel consumption and less pollution.

The characteristics of the system also facilitate other applications, such as the reservation of parking spaces for disabled drivers and payment based on the real time that a parking space is used. The system could also be used to detect areas where lighting is absent or insufficient.

Once pilot testing has been successfully completed, the system will be installed in the 22@Barcelona innovation district (from December on) as part of a Barcelona City Council project to deploy sensor systems, and in the town of Figueres (early in 2011), where it will be used to monitor traffic entering and leaving the city center.