The parking space guidance system needs to work together with a certain parking space information release system to fully play the role of parking space guidance. At present, the parking management system for large-scale use of domestic parking lots is roughly composed of three parts: vehicle detection, parking space information release and parking space information processing. The system only achieved vehicle detection and information release, and did not really realize the parking space guidance and guidance. There are two main types of mainstream parking guidance systems: one is a parking space guidance system based on ultrasonic technology, and the other is a parking space guidance system based on video technology. Parking guidance system based on ultrasonic technology Ultrasonic technology's parking guidance system is suitable for applications that are sensitive to cost and require less customer experience. The system generally combines the card to achieve regional positioning. When searching backwards, it can only be accurate to a certain area and cannot be assigned to a specific vehicle. The system uses a three-layer pyramid structure, the server is at the top, and the vehicle detector (ultrasonic probe) corresponds to each parking space at the bottom. The entire topology uses fieldbus (RS485, CAN, etc.) for data interaction, and the real-time performance is not high. Ultrasonic technology is used for the detection of the parking space, that is, the detection of the presence or absence of the vehicle on the parking space is realized by detecting the change of the ultrasonic frequency after the occlusion by the vehicle detector. The vehicle detector selects the received ultrasonic frequency, and the filter circuit performs the first filtering and the first-stage amplification on the waveform. At the same time, the ultrasonic vehicle detector will self-test and do temperature compensation. The second processed signal is then subjected to two or three stages of amplification, filtering and AD conversion. The MCU receives the signal after processing and makes a judgment that there is no car, and then outputs the result to the upper level of the system. There are many factors that affect ultrasound, and often the most common ones are misjudgments. The result of the vehicle detector output is processed by the upper level hardware and flows to the server, and the remaining parking space information is released to the designated medium to implement the vehicle induction function. In order to realize the anti-seeking function, it is necessary to acquire the vehicle information of a certain area for the first time by using the locator bound in each yard area, and generate the reverse-seeking result when acquiring the vehicle information for the second time on the designated equipment, thereby realizing the accuracy to the area. The vehicle is looking for it. Ultrasonic parking space guidance system is mature and stable, low installation and commissioning requirements, low cost and other characteristics are deeply loved by consumers. It is widely used in general commercial complexes. The disadvantage is that there is a misjudgment of sensitivity to interference. Parking guidance system based on video technology The video parking guidance system is suitable for large commercial complexes and shopping centers that require high customer experience and are not cost sensitive. When looking for a specific brand of car that is accurate to the parking space and a certain license plate number, it can directly realize the point-to-point anti-seeking function and experience well. The system is mostly based on TCP/IP mesh architecture, which has high real-time performance and is suitable for large-scale application scenarios. The video parking guide carrier is a camera, and the core is an identification algorithm based on license plate recognition technology. The realization principle is easy to understand. The image is captured by a camera installed in front of the parking space, and the license plate recognition algorithm determines whether the vehicle is present or not to give the parking space information. The general system is divided into back-end identification and front-end identification. The back-end recognition means that the camera is only responsible for video acquisition, and is transmitted to a specific identification device for recognition and output. There is a car-free result; the front-end recognition, ie, the recognition algorithm and the camera are integrated together, and the camera directly The output has no car results. Nowadays, the large-scale application of video parking space guidance is the front-end identification mode, and the back-end identification has been eliminated due to the high network bandwidth occupation. With the rapid development of semiconductor technology, the hardware of the camera is not the same, the video clarity from the initial standard definition to 720P, from 720P to today's 1080P, and even the future 2K and 4K will come soon. The higher the video clarity, the more effective information is included. Initially, the camera can only give the license plate number of the ordinary license plate. Now it can output the general license plate and special license plate information, body color and vehicle type. The camera also ranges from the original single sensor one-to-one parking space to the dual sensor one-to-one parking space, and then the single sensor one-to-many parking space to the current dual sensor one-to-many parking space. Advanced technology will also be subject to objective conditions. Although video parking guidance is mature, it has its insurmountable shortcomings. For example, the problem of decreased recognition rate due to factors such as light, stains, occlusion, and image angle. System installation and debugging requirements are high and costly, but because it can provide a peer-to-peer anti-seeking experience, it has the advantages that other systems can't match, and it is widely used in large-scale high-end commercial complexes and shopping malls. The future of parking space guidance system The current market requirements are not only usable and easy to use, but also require the system to provide an unexpected experience. Regardless of whether it is an ultrasonic or video parking guidance system, it only realizes the detection of the vehicle and the sharing of the parking space information. It is still not enough for the vehicle to guide this piece. Indoor navigation technology and mobile Internet technology have gradually penetrated into our daily lives. Combining these technologies with the guidance of parking spaces will surely produce qualitative changes and guide integration. Indoor positioning navigation, the mainstream is based on low-power Bluetooth technology, and can be combined with mobile Internet terminals to achieve optimal path point-to-point positioning and navigation. On the one hand, the guidance of the vehicle to the designated parking space is realized; on the other hand, the guidance to the designated vehicle is realized. Imagine the following scenario: Get up in the morning, pick up your phone and find the place you want to go, filter the remaining parking spaces nearby and make a reservation for the parking space. Open navigation to the specified destination, enter the parking lot camera, capture the reserved vehicle, switch to the indoor navigation system, and guide the reservation to the reserved parking space. After the shopping is completed, enter the parking lot to find your own vehicle, and the system gives the optimal path to navigate through the indoor to the designated vehicle. Some of these scenarios have been partially implemented, and some have not yet been implemented, but with the rapid update of technology, I believe these will soon be realized. (The author of this article is currently working in the product development department of Jieshun Technology Industrial Co., Ltd.) Gas Generator,4 Cycle 16 Cylinders,4 Cycle 16 Cylinders Cummins Generators,4 Cycle 16 Cylinders Generators XCMG E-Commerce Inc. , https://www.xcmg-generator.com