Experts recommend purchasing systems of parking occupancy sensor with a self-diagnostic capability: such a check is carried out by the radar itself each time before turning it on, and this minimizes the danger of a sensor failure in front of an obstacle or a signal failure due to wiring faults.
An important selection criterion is the speed of the parking sensors: in heavy traffic, this characteristic becomes even more important. In addition, the margin of error must come into account. This parameter is called “measurement accuracy”. Under normal conditions, the error can be, for example, 10 cm.
That is, when the parking sensor reports that the distance to the obstacle is half a meter, then in reality it can be 40, 50, and 60 cm. But if the parking conditions cramp, then the measurement accuracy must be high.
A quality parking occupancy sensor should work properly and stably in various weather conditions-during rain, temperature changes, etc. Everyone chooses the type of notification to his liking, but you should know that sound is the most effective-it is the sound indication that comes in all products of the BMW, Renault, Audi and other giants.
The display is certainly convenient, but if not too overloaded with information, otherwise the parking will take longer. The optimal position of the display is at the rear-view mirror, in the side-vision zone. If you decide to purchase a rear- view camera, then it should have good light sensitivity and a large viewing angle.
Now let’s talk about the disadvantages of parking occupancy sensor that need to be considered when choosing. The first is a minus that is not too important for most car owners. The device must come in the front therefore; the sensors should be selected in the color of the car bumpers.
Accordingly, the display unit is selected to match the interior. If the sensors are not overhead, but mortise-for their installation you need to make a niche in the bumper. The second disadvantage is much more serious. Parking sensor may not work correctly under certain conditions. Malfunctions are guaranteed if the sensors are dirty, in snow or ice-then they simply do not react to obstacles. \
Failures are also possible at low temperatures (usually the devices begin to “glitch” at -35 degrees) and at high temperatures (above 50 degrees). The parking occupancy sensor can incorrectly show the distance to the object on uneven terrain, with descents, ascents, as well as in conditions of a large amount of interference, if there are sound-reflecting and sound-absorbing objects nearby.
In addition, open hatches, holes, thin and small objects, for example, tensioned chains, and are out of the field of view of the parking sensors. When towing a trailer, do not rely on the readings of the rear sensors.
Parking radars are divided into types according to several criteria. By the method of mounting the sensors:
This parking occupancy sensor installs quickly and easily. The fastening method allows for minimal changes in the design of the machine;
It is the most common. To install them, you need to drill technological holes, paint areas. Moreover, the fastening method is very reliable. All these methods are easy to combine in various ways or common independently.
At the place of installation:
By the type of signal transmission to the driver:
In rear parking sensors, sensors come on the rear bumper. Such systems are in greatest demand. Usually these are 4 parking occupancy sensors ; the equipment connects to the power supply of the reversing lights. Activation occurs when the gearbox is switched to the position for reversing.
In the front sensors install, respectively, on the front bumper of the car. Devices start to work when braking. The driver’s vision is better in front than in the back, so two sensors are enough for normal operation.
They differ from the rear ones-it is not recommended to swap places. The front ones have an input in their design-they are easy to connect to a speed sensor.
This is done so that when driving, when the speed exceeds, for example, 20 km / h, the parking system disables. And already during the trip, the radar will not react to surrounding objects.
The rear parking occupancy sensor is easy put on the front bumper, otherwise there will be constant false alarms while driving. In addition, the ECU is not good for installation under the hood, and the wires of the rear parking sensors simply will not be enough to connect on the front hood.
The range of the rear ones is usually greater than that of the front ones; such a distance for the perception of interference will be simply excessive.
A common set of rear and front parking sensors has a single electronic control unit; usually 6 or 8 sensors are included in the kit-4 for the rear bumper and 2 or 4 for the front one. In addition, in some systems, it is possible to install devices on the sides-in the corners.
Beeper signals in such systems are usually tuned to different sounds, so that it is immediately clear by the sound of the beeper-a potential danger from behind or in front. In addition, there may be one screen or two displays of parking occupancy sensor .
Combined parking radars cover the area well, they are reliable, allow safe maneuvers, but they are more expensive than conventional rear ones. Such systems are in special demand among two categories of drivers-beginners who still do not feel very well the dimensions of the car, as well as among the owners of SUVs and other cars with a high seating position.
The most expensive and by far the most comfortable is the parking occupancy sensor with a rear view camera. In such models, the display is easy to display. When choosing this option, the quality of the image is decisive, this is transmitting from the rear view camera from different viewing angles.