Ⅰ Requirements
Taking an elevator in a high-rise building in a big city, the following situations can happen:
(1) Someone on certain floors presses the elevator, but then suddenly leaves for something else, causing the elevator to stay, which is very common in life.
(2) It is also common in life that the elevator is already packed with people but still stays on the floor where someone pressed the elevator but can no longer carry anyone else.
(3) Some high-rise buildings will exist 4 to 6 elevator devices, multiple button operation, will lead to the existence of multiple elevators to the same floor, but at this time the passengers have been carrying the first to arrive at the elevator to leave, after arriving at the elevator belongs to an empty trip.
(4) Some people will press the wrong elevator but will not cancel it in time, but the elevator will still lift to the wrong floor after stopping at the right floor, which is more common when going up the stairs.
Although the current elevator is smart enough, it has not completely solved the above problems, as well as other problems that the blogger has not thought of.
 
Ⅱ Solution
It just occurred to me that millimeter-wave radar for human detection has been studied for more than 10 years, especially in the last 5 years the outbreak of a large number of human presence detection radar, multi-target tracking and head counting radar, etc., their costs have been very low. If the characteristics of millimeter wave radar can be used, it should be able to solve the problem of elevator intelligent linkage to a certain extent:
(1) If the elevator is already stuffed with people, it will only go down but not up;
(2) If there is no one outside the elevator door, then don't stay;
(3) If there is no one inside the elevator, then keep silent.
This not only saves electricity, but also accelerates the passengers' riding experience, so that they will not be annoyed because the elevator is always doing some useless work, especially during the peak period of commuting.
 
Ⅲ Implementation Program
(1) Install a headcount radar inside the elevator, which requires high-resolution radar. Do better with cameras.
(2) Each floor to install a low-cost human presence detection radar can be, 24GHz radar sensor can be, after all, a lot of floors, the deployment of the cost is very high.
(3) Finally, link the data from the radar with the elevator control system, while ensuring the stability of the system and the correct functionality of the system can be.

Parking assistance sensors are integrated into vehicles to help drivers park more accurately by detecting surrounding obstacles. These sensors provide real-time feedback, often through visual or audible alerts, to help the driver find a parking space. The goal is to minimize the chance of a collision, even in challenging conditions with multiple moving objects around the vehicle.
 
Parking assistance systems typically use various technologies, each with its own advantages and disadvantages. Currently, one of the most popular technologies is ultrasonic sensors, which can detect objects at close range but have some performance drawbacks. Radar sensors, an emerging parking technology, offer more advanced features that help overcome the performance drawbacks of ultrasonic sensors and lead to new features and applications.
 
The ultrasonic parking sensor emits high-frequency sound waves that are undetectable to the human ear. When sound waves hit an object, such as a wall or another vehicle, they bounce back to the sensor. By measuring the time it takes for the sound waves to return, the sensor can determine the object's distance based on the known speed of sound. If the object is within a critical distance, the system alerts the driver with an audible alarm. Typically, four or six ultrasonic sensors are integrated into the bumper to provide a 180-degree field of view.
 
Radar sensors emit electromagnetic waves and analyze the reflected signals to determine the distance, horizontal and vertical angles, and speed of objects within the vehicle. Millimeter-wave radar technology uses electromagnetic waves in the millimeter wavelength range, with the standard frequency being 79 GHz for exterior automotive applications. Once the sensor emits waves, they propagate through the air and reflect off objects in their path, such as other vehicles, walls, or pedestrians.

The sensor receives the reflected waves and calculates the distance of each detected object from the vehicle based on the time it takes for the reflected waves to return. Today's radar sensors use MIMO (Multiple Input Multiple Output) technology with multiple transmitters and receivers, providing a larger field of view and the ability to detect all objects in a single scan, including distance, angle to the sensor, and their relative speed.
​
When comparing ranges, millimeter wave radar outperforms ultrasonic sensors at both minimum and maximum detectable distances. Millimeter-wave radar sensors can detect objects up to 5 centimeters from the vehicle, while ultrasonic sensors have a detection distance of 10-20 centimeters. Ultrasonic sensors have a maximum range of about 8 meters, with some systems reaching 20 meters. In comparison, radar sensors can detect objects up to 60 meters away from a person and up to 100 meters away from a vehicle with a field of view (FoV) of 180°.
 
Field of View (FoV) is the width of a sensor's field of view and is typically measured in degrees. Radar parking sensors typically have a 120°horizontal FoV, but the new generation of millimeter-wave radar sensors have a horizontal FoV of up to 180°, covering the entire area behind the vehicle. 

I. Introduction
What is radar? Radar is the abbreviation of Radio Detection and Ranging. It detects targets through radio waves and determines their location in space. Millimeter-wave radar refers to a type of radar sensor operating in the millimeter wave band. According to the "Radio Regulations" promulgated by the International Telecommunication Union (ITU), the radio frequency range of 30-300 GHz (wavelength 1-10 mm) is called the millimeter wave frequency band. The 24G radar is close to 30G, and we also call it mmw radar.
 
Note: 24G is not sub-millimeter wave. Sub-millimeter wave refers to a frequency band with a wavelength shorter than millimeter wave and close to terahertz, such as 220GHz. Strictly speaking, 24G should be centimeter wave (λ = 1.25 cm = 12.5 mm), or sub-centimeter wave, close to the millimeter wave frequency band. In the industry, it is generally accustomed to calling it millimeter wave.
 
Radar is a high-quality sensor using FMCW technology. In recent years, its usage in various applications has increased rapidly. Compared with PIR solutions, radar sensing is not affected by temperature, brightness, humidity or light fluctuations. It has good penetration and is very suitable for privacy-sensitive applications.
 
Ⅱ Application Scenarios 
1. Smart Mirror
When the mirror senses someone, the light will turn on automatically. When people sit quietly in front of the mirror or move slightly, the light will stay on. If more functions are needed, the combination of WIFI + Bluetooth + radar module is a good solution, allowing you to know the time, temperature, weather, etc. at any time. Such smart mirrors are especially suitable for hotel or home bathrooms, dressing tables, makeup rooms, barbershops, fitting rooms, etc. If it can be combined with a breathing and heart rate detection radar, it can be further made into a medical experience product.
 
2. Gesture Sensing Radar: Kitchen Range Hood and Faucet
When cooking, there are oil stains and water stains on the hands, which is not convenient to operate touch or button-type range hoods. If gesture sensing radar is used, the range hood can be started and closed through the air. Faucets can also be opened and closed by radar. For other human body sensing applications, such as smart toilets, pet feeders, water dispensers, air conditioners, electric fans, etc.
 
3.Smart Lighting
Smart lighting is a relatively wide application. Through non-contact switch control, microwave sensing realizes the function of turning on the light when people come and turning off the light when people leave. Thus, it avoids the cost of double-control switches and wiring, and also reduces the user's dependence on switches. There is no need to look for the switch in the dark environment and then touch it.
 
4.Human Body Sensing Billboard
Outdoor electronic billboards add color to the night but also bring troubles to citizens' travel. The billboards that are on all day and night have gradually changed from initially attracting attention to harming people's eyes. At night, they also cause serious light pollution and waste precious electric resources. Use sensors to detect pedestrians within the billboard range. When there are no pedestrians passing by the billboard within the sensing range, it does not work. When there are pedestrians passing by the billboard, it starts to work. Such inductive billboards can not only save energy and electricity but also improve the light pollution caused by the abuse of billboards. Outdoor advertising is possible, and indoor advertising is also possible. When someone is sensed, the advertisement will be played automatically. When there is no one, it will not be played. It is mainly used in enclosed spaces, such as elevators, taxi rear screen advertisements, etc.
 
5.Smart Television and Computer Screens
When children are too close to the TV, an alarm will sound or the TV will be forced to standby. When no one is in front of the computer screen, it will automatically lock or hibernate to enhance enterprise information security or personal information security.
 
6.Smart Access Control
Smart door opening and smart camera security. When sensing people, the entrance control screen wakes up for face recognition or other functions.
 
7.Barrier Gate Radar
It is mainly used at vehicle entrances and exits of parks and companies, highway entrances and exits, and parking lot management. It replaces the existing ground induction coil and controls the lowering function of the barrier gate to prevent accidents such as "hitting cars" and "hitting people". Barrier gate radar has the advantages of convenient installation and maintenance, no need to damage the road surface, no impact on vehicle access, advanced technology, flexible setting of action distance, working all day and all weather, and being able to adapt to barrier gate poles.
 
8.Parking Space or Charging Pile Occupancy Detection
Drivers entering large multi-story parking buildings often find it difficult to find unoccupied parking areas. In order to improve efficiency, a method is needed to inform about real-time parking conditions and guide them to unoccupied parking areas. In the field of new energy charging, 24G radar can be used to monitor the occupancy status of charging piles and detect the activities of people around to ensure the safety of the charging process.
 
9.Intrusion Detection and Intelligent Monitoring System
​24G millimeter-wave radar can be used in intrusion detection systems in the field of security. It can monitor dynamic targets in the area in real time, such as people, vehicles, etc. Once abnormal situations are found, an alarm will be issued immediately, thus realizing effective protection of important areas. 24G millimeter-wave radar can also be combined with intelligent monitoring systems to achieve accurate tracking and identification of targets. Through the collaborative work of radar and camera, omni-directional monitoring of targets can be realized, improving the intelligent level of the monitoring system.

Dear ALL Clients,

Due to the National Holiday, our office will be temporarily closed from Oct 1st to Oct 7th, 2024. We will resume work on Oct 8th, 2024.
For urgent issues, feel free to contact  +8613656000291 (Tank) or +8617700087816 (Jasmine).

Best Regards,
Xiamen Kegan IoT Technology Co., Ltd.

​Ⅰ Requirements
Taking an elevator in a high-rise building in a big city, the following situations can happen:
(1) Someone on certain floors presses the elevator, but then suddenly leaves for something else, causing the elevator to stay, which is very common in life.
(2) It is also common in life that the elevator is already packed with people but still stays on the floor where someone pressed the elevator but can no longer carry anyone else.
(3) Some high-rise buildings will exist 4 to 6 elevator devices, multiple button operation, will lead to the existence of multiple elevators to the same floor, but at this time the passengers have been carrying the first to arrive at the elevator to leave, after arriving at the elevator belongs to an empty trip.
(4) Some people will press the wrong elevator but will not cancel it in time, but the elevator will still lift to the wrong floor after stopping at the right floor, which is more common when going up the stairs.
Although the current elevator is smart enough, it has not completely solved the above problems, as well as other problems that the blogger has not thought of.
 
Ⅱ Solution
It just occurred to me that millimeter-wave radar for human detection has been studied for more than 10 years, especially in the last 5 years the outbreak of a large number of human presence detection radar, multi-target tracking and head counting radar, etc., their costs have been very low. If the characteristics of millimeter wave radar can be used, it should be able to solve the problem of elevator intelligent linkage to a certain extent:
(1) If the elevator is already stuffed with people, it will only go down but not up;
(2) If there is no one outside the elevator door, then don't stay;
(3) If there is no one inside the elevator, then keep silent.
This not only saves electricity, but also accelerates the passengers' riding experience, so that they will not be annoyed because the elevator is always doing some useless work, especially during the peak period of commuting.
 
Ⅲ Implementation Program
(1) Install a headcount radar inside the elevator, which requires high-resolution radar. Do better with cameras.
(2) Each floor to install a low-cost human presence detection radar can be, 24GHz can be, after all, a lot of floors, the deployment of the cost is very high.
(3) Finally, link the data from the radar with the elevator control system, while ensuring the stability of the system and the correct functionality of the system.

The application of millimeter-wave radar sensors in self-driving mainly includes real-time monitoring of the surrounding environment of the vehicle.

​By emitting millimeter waves and receiving reflected signals, information such as the distance, speed, and angle of target objects can be detected. In autonomous driving, millimeter-wave radar can help vehicles achieve functions such as adaptive cruise control, automatic emergency braking, and lane departure warning, improving driving safety and comfort.

Indoor millimeter wave radar sensors seem to be small in size and simple in hardware structure, but it is still very difficult to do in practice, and the complexity of the radar should not be trivialized because of its small size. Specifically manifested in:
(1) The algorithmic scheme has the requirements of the arithmetic power to be low but also requires the algorithmic performance to be very good.
(2) The hardware cost should be low, need to cooperate with the low arithmetic processor to complete the balance between real-time and accuracy.
(3) Engineering landing needs to face a lot of potential problems that need to be solved, such as a variety of interference, blind zones, false alarms, omissions, and other issues.
(4) The indoor environment is complex, and the targets have different characteristics, which requires good performance of radar processing algorithms.
(5) The consistency of the hardware is also important. Millimeter wave radar sensor is very small, but some manufacturers make a board, the consistency of performance is not very good, some boards have better signal quality, some boards have poorer signal quality. In addition, power spurious is also a problem.
(6) Human presence detection is simply the human presence detection function. For example, human presence detection, while combining gesture recognition, head count, sleep monitoring, fall monitoring, and so on. To unify and integrate these functions is actually a relatively difficult thing.
(7) Some indicators and precision data are difficult to achieve.

​Millimeter-wave radar sensor applications have gradually expanded and are now mainly focused on automotive radar , transportation security, indoor homes, and other popular areas. Demand is also growing in other niche areas. Although both are millimeter wave radars, the processing method and focus differ in different ways. For example, in automotive radar sensors :
 
(1) Most of the targets are cars belonging to the rigid body target, do not need to pay too much attention to the details of the target's movement information, such as wheel rotation;
 
(2) Generally, an automobile radar needs to detect targets within 300m at the farthest, and needs to realize stable tracking of targets and estimate the direction of target movement;
 
(3) Even in the face of pedestrians and other non-rigid targets, automotive radar does not need to pay attention to the target's specific attitude changes, such as pedestrian detection does not need to pay attention to the specific posture of the person (running, walking, falling), as long as the car is told someone and their movement direction.
 
However, indoor radar and automobile radar sensor are significantly different. Indoor radar sensor ​has many scenarios, such as human presence sensing, respiratory heartbeat detection, gesture recognition, gesture recognition, fall detection, number of people, etc., as well as based on these basic functions of the expansion of the application, such as smart lights, air conditioning, TV, toilet seat and so on. In these scenarios, it is necessary to sense information about the human body or human limbs, and academics have categorized the different levels of motion on the human body into three types, as shown in Figure 1.

Figure 1: Classification of Human Body Motion

​In the dynamic world of industrial automation, precision and customization are key to meeting the unique demands of our clients. This June, we were honored to connect with a distinguished client from Australia on Alibaba, who sought a specialized radar sensor for their car wash facility. Embracing the challenge, our team at KeGan embarked on a journey to deliver a solution that not only met but exceeded their expectations.

Understanding the Need
Our first step was to delve deep into understanding the client's specific requirements. Through meticulous discussions and real-time feedback, we ensured that every detail of their vision was captured and translated into a tailored product design.

Customization at its Best
The radar sensor we custom-developed is not just a product; it's a testament to our commitment to innovation and client satisfaction. Designed to seamlessly integrate into the client's car wash setup, the sensor offers unparalleled accuracy and reliability. It is equipped to handle various car sizes and models, ensuring optimal performance in every wash cycle.

Adapting to Perfection
Throughout the development process, we maintained an open channel of communication with our client. Any minor adjustments or modifications they requested were promptly addressed, demonstrating our agility and dedication to refining the product to the highest standards.

Real-time Feedback: A Key to Success
Constant feedback loops were established to keep our client informed at every stage of the development. This transparency not only built trust but also allowed for a collaborative approach, ensuring that the final product was a perfect match for their needs.

The Result: A Seamless Integration
The end result is a radar sensor that has been seamlessly integrated into the Australian client's car wash operations, enhancing efficiency and delivering a superior washing experience. This project is a proud milestone for us, showcasing our ability to provide bespoke solutions that are both innovative and practical.

Looking Forward
We are thrilled to have had the opportunity to work with our Australian client and are excited about the possibilities that lie ahead. As we continue to innovate and push the boundaries of what's possible with radar technology, we look forward to serving more clients with the same level of dedication and excellence.

About KeGan
KeGan is a leading provider of advanced sensor technology, committed to delivering customized solutions that drive automation and efficiency in various industries. Our team of experts is always ready to take on new challenges and create impactful solutions for our clients worldwide.