Think of a big building or a house that for protection is surrounded with fencing and an automatic gate. Two things are important here. Firstly, if a vehicle or a person is standing in front of the gate, it is desirable the gate to open automatically. For this a vehicle detection should be performed, after which the gate can be activated. Second, it is desirable that opened gate only closes when a vehicle or person is fully passed. If this is not set up (well), this could lead to accidents. For this a security should be applied on the gate. This not only applies for applications with sliding gates, but also for automatic speedgates, swing gates and other horizontal closing access systems.
If only a selection of vehicles are allowed to pass temporarily or incidental to a building or area this can be solved by using automatic number plate recognition. For this the number plate of the approaching vehicle is detected with an ANPR (Automatic Number Plate Recognition) camera. When the number plate is present in the database the automatic gate or other automatic closing access systems are opened. The advantage of this system is that not everyone is just allowed to have access to a secured building or area.
Inductive loop detectors
When constructing a new building or house surrounded by fencing with an automatic horizontal closing access system, the installation of inductive loop detectors could be a suitable solution for performing a vehicle detection. In these cases the wiring is constructed before the concrete is dumped. Because the loop detector is processed in the ground, it has barely any influence from the environmental conditions. So a fine method to detect the presence/absence of the vehicle before the gate, after which it will open. If a barrier gate is build where the pavement is already done, it costs a lot of money and time to break everything down and to put the loops in the ground.
Photoelectric sensors of Telco Sensors
The SM3000 serie are sender & receiver photoelectric sensors from Telco Sensors which are suitable to perform a vehicle detection at automatic gates. A sender and receiver sensor are placed across each other and when a vehicle approaches the gate the light beam will be interrupted and the gate will then open. For security an extra set of photoelectric sensorrs can be installed on the gate to prevent that the gate only closes when the vehicle has passed completely. To prevent that these sensors can disturb each other, these can be placed in a channel. Because of the IP67 protection degree these sensors are resistant to harsh conditions, such as rain, wind and icing. The range of the SM3000 series is 15 meter.
The SM3000 series is also available as CAT2 photoelectric sensors.These are special certified sender & receiver safety sensors which meet the norm of a safety sensor. This sensor has furthermore a narrower beam with a range up to 10 meter.
The SP2000 series are proximity sensors with a sender and receiver within one housing which are suitable for a vehicle detection for shorter distances (range up to 5 meter). Because of the IP67 protection degree these sensors are resistant to harsh conditions, such as rain, wind and icing.
An advantage of photoelectric sensors is that these sensors perform a cheap and reliable detection of everything that interrupts the light beam. The disadvantage of these sensors is that they detect using only one beam. However when a vehicle with a trailer or caravan passes the automatic gate, it could be that these sensors do not detect anything near the towbar. In this case the sensor thinks that no vehicle is present anymore and the gate will close, which could lead to much damage.
Light grids from Telco Sensors
The SG10 series are light grids that are developed specially for performing a detection at automatic gates and other horizontal closing access systems. These light grids are available with a profile height upt to 3 meter. The advantage of this is the guaranteed detection of any vehicle that passes independent of the height. Because of the IP67 protection degree these grids are resistant to rain, wind and icing. The light grids have a range from 10 to 14 meter. Thanks to the automatic sensitivity settings there are no adaptations or configurations necessary when installing the light grids. Met the SG10 M / S series two sets of light grids are placed. One just in front of the gate and one just behind the gate. In this way, the automatic gates are fully protected against any form of entrapment, damage or injury of people, vehicles or objects.