In a narrow sense, electronic dog refers to an anti-speed measuring product based on the early wireless transceiver principle. At present, it is still widely sold in the south of the Yellow River and can only play a limited role in some areas. This electronic dog is just a wireless signal receiver, which is simpler than the principle and cost of radio. Usually, the manufacturer will bury the transmitter 300 to 1000 meters in front of the fixed camera, and as long as the passing car is equipped with a voice early warning machine, it will receive an early warning signal. Wholesale 30-50 yuan, market selling 100-500 yuan RMB, mobile phone photography without warning. Because it depends on the transmitter signal embedded in the receiver, it can only be used in areas where the transmitter is buried by the manufacturer. People in the industry also call it "mad dog and fake dog" and "radish machine". As the name implies, it's like pulling a carrot. This kind of P-frequency electronic dog is just a kind of psychological comfort for cyclists, and it has no practical effect.

The shortcomings of this product are obvious. First of all, the battery of the embedded transmitter must be replaced frequently, which is both troublesome and dangerous. Manufacturers are increasingly reluctant to do this job, and transmitters can't work without batteries, which is also the reason why some early buyers feel worse and worse. Second, due to the change of roads and fierce commercial competition, manufacturers destroy each other's transmitters, and the early warning aircraft will not give an alarm at all, which will bring huge losses to consumers, so special attention should be paid to this kind of goods. In addition, the use of radio frequency in China also needs the approval of the Committee, but the P frequency has not been submitted for approval, so it will be detected by the Committee's probe car and can be banned or interfered at any time.

Electronic dog in a broad sense

Electronic dog in a broad sense means that many people are used to calling all anti-speed measuring products electronic dogs. This kind of product is now generally called anti-speed radar, and the product package says safety drive or radar early warning device. It can be divided into the following types:

(1) full-frequency inverse velocity radar

Full-frequency anti-velocimetry radar is a kind of vehicle-mounted equipment widely used in radar velocimetry. It calculates the frequency shift of the received reflected wave to obtain the moving speed of the measured object. At present, radar speedometer is widely used in urban traffic, mainly used to measure whether cars are speeding. There are two types: fixed and mobile. Fixed speedometers are installed on bridges or intersections (the number of fixed speedometers is small), and mobile speedometers are generally installed on patrol cars.

All-frequency anti-velocimetry radar is a kind of equipment to remind drivers whether there is a radar velocimeter nearby. It is installed in the car and can detect whether there is a radar speedometer in a certain distance by receiving radar waves. When the car is driving, when the car is close to the radar speedometer, the counter tachometer will give a warning. It is enough for the car to slow down to the normal level for 2 or 3 seconds+100-300m. Full frequency can receive radar signals of all frequency bands, and the main receiver is rarely made in China, mainly imported from Taiwan Province Province, the Philippines and South Korea. Different manufacturers pay different attention to the frequency of radar signal, so it is difficult to judge whether it is good or bad.

(2)GPS electronic dog

At present, more than 80% cities in the world use pressure-sensitive coils to measure speed. This speed measurement method is to bury the induction coil on the road surface and calculate the speed by calculating the time for the vehicle to pass through the coil. There are also a few advanced multi-lane continuous shooting velocimetry methods that don't emit radar waves, so this kind of electronic eye velocimetry can't be detected by full-frequency radar for the first time.

This gave birth to the gps anti-speeding radar, which does not prompt speeding by receiving radar waves. The working principle of GPS function is: pre-store the latitude and longitude data of fixed speed measuring point or red light shooting (you can upgrade and update, or you can establish your own coordinates), and trigger an alarm when you are close to the target point through GPS positioning. Combined with electronic compass, it can calculate and display the speed and direction, without the trouble of being unable to distinguish the directionality, and can automatically mute when not speeding. This kind of products also contains a lot of traffic information and life information, with voice prompt function, which is a good helper when driving. The quality of GPS speed radar mainly depends on the data volume and accuracy of speed measuring points, but this kind of products can not play a role in mobile speed measurement.

(3)GPS radar electronic dog

GPS full-frequency anti-velocimetry radar combines the functions of the first two types of anti-velocimetry radar, which can accurately predict both fixed radar velocimetry and mobile velocimetry, and completely solve the shortcomings of the first two types of products. This kind of anti-tachometer radar can be divided into two types. One is integrated, with stable performance and simple installation. The disadvantage is that it must be placed close to the windshield, and the indoor unit is huge.

The other is the more common split type. The main engine in the car is wirelessly connected with the radar under the hood of the front car. Because the radar machine and GPS machine are separate, the indoor machine can be made a little smaller and does not need to be placed near the windshield. Good concealment, conducive to anti-theft and inspection. But the installation is a little troublesome, and the problem is not big. When you read the instructions, you should understand what is going on. It really doesn't cost much if you don't want to find a car repair.

(4)GPS navigation speed measuring radar

Connect map navigation and anti-speed-measuring functions to realize multi-function of one machine. At present, most navigation map companies also add a lot of speedometer data to their navigation software, so the common navigators now have the function of GPS anti-speedometer radar, that is, GPS navigation anti-speedometer radar from the perspective of electronic dog. At present, Yimai Digital Company combines navigation with all-frequency speed-measuring radar to realize the three-in-one function of navigation+fixed+mobile.