In the vertical transportation system of modern buildings, escalators play an indispensable role and are widely used in densely populated places such as shopping malls, subway stations, and airports. Under the traditional escalator operation mode, the escalator keeps running regardless of whether there are passengers or not. This not only causes a large amount of energy waste but also accelerates the wear and tear of the equipment and increases the maintenance cost. In the context of the era that pursues high efficiency, energy conservation, safety, and comfort, the intelligent upgrade of escalator sensors is imminent. As an emerging technology, the radar module is gradually coming to the fore, bringing a new transformation to the escalator sensing system.

I. Working Principle of the Radar Module
The core operation of the radar module is based on the Doppler effect. It emits electromagnetic waves of a specific frequency into the surrounding space. When an object moves within its detection range, the frequency of the reflected electromagnetic waves will change due to the motion state of the object. For example, when a passenger approaches the escalator, the frequency of the reflected wave increases; if the passenger leaves, the frequency decreases. The built-in signal processing unit of the radar module can accurately capture and analyze these frequency changes, convert them into electrical signals for output, and then determine whether a passenger has entered the sensing area. Compared with other sensing technologies, the electromagnetic wave propagation of the radar module is not interfered by environmental factors such as light, color, smoke, and dust. Under complex lighting conditions, such as the flashing lights in a shopping mall, the strong lighting in a subway station, or the escalators near a dusty construction site, it can work stably and reliably, demonstrating excellent environmental adaptability.

II. Current Situation and Pain Points of the Escalator Sensing System
Currently, common escalator sensing devices include infrared sensors and light curtain sensors. Infrared sensors identify passengers by detecting the infrared rays emitted by the human body, but they are easily affected by changes in the ambient temperature. During the high-temperature period in summer, when the ambient temperature is close to the human body temperature, the infrared sensor may make misjudgments, resulting in unnecessary start and stop of the escalator. The light curtain sensor uses multiple beams of light to form a light curtain, and the induction is triggered when the light is blocked. However, it has extremely high requirements for installation accuracy. A slight deviation will create sensing blind areas. Moreover, once dust or water droplets adhere to the light curtain, the sensing effect will be greatly reduced. Traditional sensing devices are unable to cope with complex scenarios and cannot accurately identify diverse passenger behaviors such as rapid movement, stationary standing, or multiple people entering simultaneously. This leads to low operation efficiency of the escalator and may even cause potential safety hazards.

III. Advantages of the Radar Module in Escalator Sensors

(1) High-precision Detection
With its high-resolution detection capability, the radar module can accurately identify various states of passengers. Whether it is during peak hours when a large number of passengers pour into the escalator densely or during off-peak hours when individual passengers approach slowly, it can keenly capture subtle changes in movements and accurately determine whether there are passengers who need to use the escalator. It effectively avoids the misjudgments and missed judgments caused by the insufficient detection accuracy of traditional sensing devices.

(2) Fast Response
From the moment a passenger steps into the detection range of the radar module to the system receiving the signal and making a response, the entire process takes extremely little time. Experimental data shows that the response time of the radar module can be as low as the millisecond level, which is significantly shorter than that of traditional sensing devices. This means that passengers do not need to wait, and the escalator can start running quickly, greatly improving the convenience and smoothness of passengers using the escalator. Especially in places with a large passenger flow, it can significantly improve the passage efficiency.

(3) Convenient Installation
The radar module is small in size. Usually, it only needs to be simply fixed at a suitable position above or on the side of the escalator entrance to complete the installation, without the need for large-scale modifications to the original structure of the escalator. Its installation methods are flexible and diverse, and it can adopt wall-mounted, embedded, etc., and can easily adapt to escalators of different types and specifications. The installation process is simple and fast, which greatly reduces the equipment upgrade cost and construction difficulty.

(4) Energy Saving and Consumption Reduction
Benefiting from the characteristics of precise detection and fast response, the escalator sensor equipped with a radar module can achieve an intelligent operation mode of "starting when people come and stopping when people leave". According to statistics from practical application cases, compared with the traditional escalator that runs continuously, after adopting radar sensing control, the energy consumption of the escalator can be reduced by 30% - 50%. This not only saves a large amount of electricity expenses for the operators but also conforms to the social environmental protection concept of energy conservation and emission reduction, contributing to sustainable development.

IV. Application Examples of the Radar Module in Escalators
When a large shopping mall in Shanghai carried out intelligent renovations on multiple internal escalators, it introduced the radar module as a new sensing device. After the renovation, the operation data of the shopping mall showed that the no-load running time of the escalator during non-peak hours was greatly reduced, and the monthly electricity expenditure was reduced by about 40%. At the same time, due to the accurate detection performance of the radar module, the start and stop of the escalator are more stable and reasonable, and the passenger experience has been significantly improved. The complaint rate caused by escalator sensing problems has decreased by 80%. In a subway station in Guangzhou, the escalators equipped with radar modules have increased the passage efficiency by 25% during the morning and evening peak hours, effectively relieving the pressure of passenger flow congestion and ensuring the fast and safe passage of passengers. These practical cases fully demonstrate the remarkable effectiveness of the radar module in the application of escalators.

V. Future Outlook
With the continuous progress of science and technology, the radar module technology will continue to iterate and upgrade. In the future, its detection accuracy is expected to be further improved, and it will be able to more accurately identify the subtle movements and postures of passengers, and even distinguish different types of passengers, such as adults, children, and wheelchair users, etc., so as to achieve personalized adjustment of the escalator operation parameters and provide passengers with more intimate and safe services. In terms of communication, the radar module will be deeply integrated with the Internet of Things to achieve remote monitoring and management. Operators can view the operation status and sensing data of the escalator at any time through a mobile APP or a computer terminal, discover and deal with potential faults in a timely manner, and greatly improve the efficiency and timeliness of escalator maintenance and management. At the same time, the radar module may also be linked with other intelligent devices to build a more intelligent and efficient vertical transportation system for buildings, bringing more convenience and surprises to people's travel.
The radar module has injected strong impetus into the intelligent upgrade of escalator sensors. With its unique advantages, it has achieved remarkable results in practical applications and effectively solved the pain points of traditional sensing devices. With the continuous development and improvement of technology, the radar module will surely play a more important role in the field of escalators, leading the escalator industry into a new era of intelligence, high efficiency, and greenness, and bringing more convenience and comfort to people's lives.