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Smart Lighting Solution
With the development of society and the improvement of people's living standards, everyone's pursuit of quality of life is also increasing. Lighting is an indispensable part of life. Traditional lighting control and maintenance methods are far from being able to adapt to the speed of urban modernization. Traditional methods lack intelligent control functions such as total on, total off, and dimming. People often look for switch panels everywhere when they need to turn off all lights. The operation is closed, and the brightness of the lamp cannot be adjusted, which is inconvenient. People hope to control the luminous brightness as they like, realize various scene functions as required, and the operation is simple, requiring the system to have good scalability and maintainability. Therefore, the intelligent lighting control system came into being. The research on the lighting control system will help to promote the development of the whole smart home system.
1. Brief Introduction of Intelligent Lighting and Intelligent Building
At present, the lighting system of most buildings in China is still in the early stage of lighting control, that is, the on and off control of lighting appliances is realized by manually operating switches, circuit breakers and other electrical equipment located in the load circuit. It is very common to use one switch to control multiple lighting devices at the same time, and the waste of resources caused by the inability to individually control each light cannot be underestimated. Along with the economic development and the continuous improvement of the modernization level, the application range of the lighting system is getting wider and wider, and the requirements for the lighting system are getting higher and higher. Lighting no longer just stays at the most basic to meet the user's visual light and shade requirements. People hope that the lighting system can be applied to different application scenarios and bring a richer, more comfortable experience and visual enjoyment. For example, the simplest light is on when people come, and the light is dark or off when people leave; Completely different lighting environments; the lighting control of the underground garage needs to be decided according to the real-time situation, etc. The early lighting control system has been far from meeting the requirements of these practical applications.
The concept of intelligent building has been widely concerned since it was put forward. Building intelligence is based on various information technologies, and fully applies advanced technologies in the fields of construction, automation, artificial intelligence, network, communication, and system integration to build an integrated, automated, and intelligent system that covers the entire building and even building complexes. The platform provides people with a comfortable, energy-saving, environmentally friendly, safe, convenient, and humanized office or living environment; at the same time, people can easily monitor, manage, and control various systems in the building through the intelligent platform to meet various requirements. Different scene requirements. Intelligent lighting system is an important part of intelligent building, but compared with access control, video surveillance and other systems, the development of intelligent lighting control system is relatively slow. Many intelligent buildings installed with advanced building automation, office automation, and communication automation systems are still using the traditional manual lighting control method, which seems out of tune with the surrounding environment. Therefore, the intelligent lighting control system has a very broad development prospect, and at the same time it has reached a period when it must be vigorously developed.
2. Development and Research Status of Intelligent Lighting Control System
The development of lighting control has mainly gone through the following three stages:
(1) Manual control stage: manual control is the initial control mode of lighting control, that is, through manual operation of switches and circuit breakers installed in the load circuit to realize the switch control of lighting fixtures, to achieve the purpose of control, the control is completely dependent on human . Because of its reliability, this most primitive control method still appears in most buildings, even intelligent buildings with a high degree of modernization. However, this control method cannot meet the dimming requirements in a specific environment, cannot provide personalized lighting, and cannot conveniently carry out centralized management of the lighting system.
(2) Automatic control stage: The continuous development of electrical and electronic technologies has made the integration of various sensors, microcontrollers and other electronic components higher and higher, making it possible for these devices to be used in lighting control systems. The sign that the lighting control system enters the automatic control stage is to control lighting devices with technologies such as sound, light, and electricity. Although the degree of automation of the lighting control system has been improved, it is limited to the control of a single or a single group of lamps, making it difficult to achieve networked monitoring and control.
(3) Intelligent control stage: The development of control science has now entered the stage of intelligent control. Intelligent control combines control theory with artificial intelligence technology, theory and optimization methods of operations research, and imitates human intelligence in an unknown environment. To achieve control of the system. With the continuous development and improvement of intelligent control technology, it has been applied in many aspects, and intelligent lighting control is one of the application fields. The intelligent lighting control system integrates computer, network communication, microprocessor, automatic control and other technologies to analyze and process the real-time lighting data collected by sensors and generate control signals through control algorithms to control the corresponding equipment in the lighting circuit to achieve To meet the user's lighting needs and create a good lighting environment and atmosphere. The intelligent lighting control system can reduce the power consumption of the lighting system while providing users with a good lighting environment through the automatic control of the electrical lighting. Compared with manual lighting control, intelligent lighting control system has the advantages of creating different lighting environment atmospheres, improving working environment, improving work efficiency, saving energy, prolonging the service life of light sources, facilitating centralized management, and convenient maintenance.
At present, the main intelligent lighting control system still uses wired communication, which brings difficulties to the renovation of the lighting system of old houses. In order to add an intelligent control system to the lamps, it is necessary to rewire and add new lamps to the original system. All of them also need to be re-wired, which hinders the promotion of intelligent lighting control systems; secondly, when the structure of the lighting system changes, the control system cannot adaptively adjust the controller parameters to adapt to the new environment, and it is necessary for professionals to reset the controller parameters and It was finally determined through continuous debugging; in addition, natural light has a natural color and texture, and can provide a lighting experience that artificial light sources cannot provide. Natural light should be fully utilized. When natural light cannot meet the needs of indoor lighting, artificial lighting should be supplemented, so that It can not only save electricity, but also allow people to enjoy a more comfortable lighting environment. Unfortunately, the existing intelligent lighting control system still lacks similar functions; finally, the intelligent lighting control system cannot accurately determine the specific location and number of people, and lacks the ability to A method for accurately detecting a human body indoors and positioning it in real time.
3. Scheme design of wireless sensor network and intelligent lighting control system
1. Introduction to Wireless Sensor/Actuator Networks
Wireless sensor networks (Wireless Sensor Networks, WSNs) are composed of a large number of sensor nodes deployed in the monitoring area. The sensor nodes communicate wirelessly to form an ad hoc network, which has functions such as ubiquitous perception, data collection and processing, and wireless transmission. The purpose is to allow observers to obtain information about perceived objects in the monitored area. Although wireless sensor networks have been widely used in fields such as military affairs, modern agriculture and animal husbandry, environmental monitoring and forecasting, medical care, intelligent buildings, bridge status monitoring, etc., there are no actuators in wireless sensor networks, so monitoring cannot be changed. The physical environment of the area.
Wireless Sensor and Actuator Networks (WSANs) are derived from WSNs. The wireless sensor/actuator network is composed of a large number of sensor nodes and a small number of actuator nodes. The biggest difference from WSNs is the introduction of actuator nodes, so that WSANs not only have the function of monitoring, but also have the ability to change the environment. Interaction to achieve control goals. Collaboration is an important feature of WSANs. Wireless sensor/actuator networks not only require communication between sensors, but also require collaborative communication between sensors and actuators, and between actuators to achieve control goals. The collaboration between sensors and actuators is mainly used to establish a data transmission path from sensors to actuators to support data transmission from sensor nodes to actuator nodes; when an event is detected in the monitoring area and the event is reported to the actuator node Finally, the executors need to cooperate to reconstruct events, estimate event characteristics, and make the most accurate control decisions on action plans and how to implement joints. This is the collaboration between executors. WSANs have the advantages of easy deployment, low power consumption, low cost, strong real-time performance, strong fault tolerance, and flexibility, and are especially suitable for intelligent lighting control systems.
2. Research status of intelligent lighting control system based on WSANs
Applying wireless sensor/actuator network technology to the intelligent lighting control system can reduce the burden of wiring of the control system and reduce installation and maintenance costs. In addition, WSANs adopts the idea of cooperative control, and can adapt to changes without overall reconfiguration in the case of network topology changes, node addition or removal, etc., making the system more flexible. At present, intelligent lighting control based on WSANs has become a hot research topic.
All the above studies involving lighting control schemes are based on the premise that the system model is accurate. When the system model changes greatly, the controller needs to be re-tuned. But in practice, the external natural light changes with time, weather and other factors, and the control target point changes, which will change the model of the controlled object. Designing a control algorithm that is suitable for intelligent lighting control and can adaptively change the control strategy when the system structure changes still requires extensive research by researchers.
3. Research status of indoor human detection and positioning technology
Human detection and positioning technology occupies an important position in the intelligent lighting control system, and it is the eyes of the entire control system. Accurately judging whether there are people in the room and determining the location of people is an important guarantee for the correct subsequent control decisions. Many lighting control strategies are based on human detection. Common sensors used for human detection include passive infrared sensors (PIR), ultrasonic sensors, and RFID, but they all have shortcomings. The passive infrared sensor can perceive the change of the temperature field in the area. When the person is still or the movement is small, it may not be able to detect the existence of the person. Although the person is sitting at the workbench and working, the lamp cannot detect the presence of the person due to PIR. In the case of extinguishing, this will greatly reduce the user experience. In addition, there is a gap in the sensing area of the passive infrared sensor, and the farther away from the sensor, the larger the gap, and the movement in the gap will not be detected. Passive infrared sensors also cannot determine the exact location of a person. Ultrasonic sensors are too sensitive to moving objects. Fallen leaves outside the window or even air blown from the air conditioner will cause the sensor to move, so it cannot accurately reflect whether people are in the detection area. RFID technology usually identifies a person's identity, so if RFID technology is used to detect a person's location, there is a problem of privacy protection.
Traditional human detection sensors have problems such as false detection, and researchers have gradually shifted their attention to new detection methods, such as image processing technology. The camera is used as a sensor to detect the presence or absence of a person and determine the position coordinates through image processing and other related technologies. By learning the characteristics of the human head and using the surveillance cameras installed in many open office spaces, the number of human heads in the video screen is determined. The experimental results show that the method has high accuracy. Many researchers remove the background from the video image obtained by the camera by establishing a background model, so as to obtain the image information of the foreground, that is, the person, and realize human body detection.
4. Scheme design ideas of intelligent lighting system
1. Working principle of intelligent lighting controller system
The working principle of the system is shown in Figure 1. The system includes a switch controller panel and a base plate. The base plate mainly includes a switch execution unit, a zero-crossing detection circuit and a power module. The bottom board mainly completes the functions of switch execution, zero-crossing detection and power supply. The panel mainly includes functions such as RF data receiving, data processing, key processing, transmission of switch control signals, and operation prompts. The system can realize the opening and closing operation of the switch controller through manual buttons and RF remote control.
2. Selection of smart lighting hardware solutions
1) Power management module: realize the function of DC power conversion (5 V to 3.3 V). This design uses SMD package linear DC power supply IC, the input voltage range is: 4.25V ~ 10V; the output voltage range is: 3.267V ~ 3.365V; the maximum output current can reach 800mA. Add a diode at the input end of the power supply to prevent reverse connection of the power supply, and use magnetic beads, tantalum capacitors, and magnetic chip capacitors to reduce the ripple of the input power supply in order to obtain a clean power supply.
2) MCU and peripheral circuits: the main functions are data analysis, data processing, and transmission of control signals. Based on future upgrades and expansion considerations, the MCU is selected to include 8K Byte FLASH, 512 ByteEEPROM, 1K Byte SRAM, and supports ISP functions with high integration, high cost performance, and low power consumption ATMEGA8L AVR microcontroller (ATMEGA16L for dual-channel dimming). Hardware resources can meet the design requirements of this product and be used for future system upgrades. Its peripheral circuit adopts resistance-capacitance reset circuit; at the same time, an external crystal oscillator circuit is reserved.
3) RF module: The RF module adopts the existing CC1101 radio frequency module.
4) Button circuit: mainly completes the function of manual control. Based on the ultra-thin design concept of the product and considering the appearance of the product, the SMD light touch button is used in the design, the button pressure is 180g, and the button life can reach 100,000 times.
3. Realization of key performance indicators of intelligent lighting
1) Low power consumption: When designing this system, focus on low power consumption and environmental protection design. In the selection of devices, try to use low-power and environmentally-friendly components, such as high-integration, cost-effective, and low-power modules.
2) RF remote control distance: The design of this system comprehensively considers the RF module layout and the influence of the bottom plate on it, and adopts measures such as separate power supply, away from interference sources, circuit board emptying, module power supply and filter capacitors to improve RF receiving sensitivity, so as to achieve remote control. Distance remote control function.
3) Action response speed: The design of this system adopts a higher working frequency to achieve the highest command processing speed, so as to realize the rapid response of remote control and manual control (response time ≤ 0.2S).
4) Protection circuit design: Add varistors and NTC to the bottom plate to effectively suppress the surge current, so as to protect the product.
4. Safety design of intelligent lighting system
The minimum creepage distance of the live wire is not less than 3MM. The minimum creepage distance between the high-voltage area and the low-voltage area is not less than 8MM, less than 8MM or equal to 8MM. A 2MM safety slot must be opened. The minimum safe distance between positive and negative of high voltage rectification filter is not less than 2MM.
5. Electromagnetic compatibility design of intelligent lighting
1) Connect a 0.01-0.1μF high-frequency capacitor to each IC on the circuit board in parallel to reduce the impact of the IC on the power supply. But attention should be paid to the wiring of high-frequency capacitors. The wiring should be close to the power supply terminal and as thick and short as possible. Otherwise, the equivalent series resistance of the capacitor will be increased, which will affect the filtering effect. 2) Avoid 90° broken lines when wiring, and minimize high-frequency noise emissions. 3) Pay attention to the crystal oscillator wiring. The pins of the crystal oscillator and the microcontroller should be as close as possible, and the clock area should be isolated with a ground wire, and the shell of the crystal oscillator should be grounded and fixed. It is best to choose a low-speed crystal oscillator as much as possible where a low-speed crystal oscillator can be used. 4) Connect electrolytic capacitors and ceramic capacitors between VCC and GND to remove high and low frequency interference signals.
6. The realization of the environmental conditions of the intelligent lighting system
When selecting components, fully consider the use environment of each component, and can meet the following requirements: operating temperature: 0-50°C; storage temperature: -20-70°C; relative humidity: 45%-80%; atmospheric pressure : 90~110kPa;
7. Scalability and ultra-small design of intelligent lighting solutions
1) An I/0 pin is reserved for the panel MCU board interface, which is convenient for future expansion. 2) In the PCB layout, the position and structure of the components placed on the circuit board make the product ultra-thin, so that it can be applied to the size of various 86 pre-embedded bottom boxes on the market.
5. PCB layout design of intelligent lighting controller
The layout of panel components is shown in Figure 2.
1. The interfaces of each PCB module are defined as follows
(1) Physical connection: the connection line between the panel and the bottom plate includes power lines and control lines; the RF module interface includes power lines and data communication lines.
(2) Data communication: Data communication includes the above-mentioned control line and data communication line, which all adopt simplex communication mode and are managed and maintained by MCU.
2. PCB board design
(1) Definition of interface position: The wiring terminals of the panel and the bottom plate have been made to comply with the principle of placing the connector on the edge of the circuit board, so as to facilitate production and installation operations and increase production capacity.
(2) Chip layout: MCU is placed in the lower left corner of the circuit board because it needs to cooperate with the structure to make the product ultra-thin. The voltage regulator chip is not only close to the power terminal, but also close to the MCU, so as to achieve the effect of small ripple. Keep the RF module away from interference sources such as buzzers to improve the sensitivity of data reception.
3. Principles of PCB routing
1) The high-frequency digital circuit traces are thin and short in the PCB design. 2) Pay attention to the isolation between high-current signals, high-voltage signals and small signals in pcb design (the isolation distance is related to the withstand voltage, usually at 2KV, the distance on the board is 2mm, and above that, it is calculated proportionally Large, for example, if you want to withstand a 3KV withstand voltage test, the distance between the high and low voltage lines should be more than 3.5mm. In many cases, in order to avoid creepage, slots are also slotted between the high and low voltage on the printed circuit board.) 3) When wiring on double-sided boards, the wires on both sides should be perpendicular to each other, oblique, or bent in the pcb design, and avoid parallel to each other to reduce parasitic coupling; as the input and output of the circuit, the wiring should be avoided as much as possible Adjacent to parallel, to avoid feedback, add a ground wire between these wires for isolation. 4) As much as possible, take the wiring at a 45-degree angle. 5) The wiring should be avoided to pass through the RF module as much as possible, and the circuit board under the RF module should be cleaned out. 6) Avoid wiring under the optocoupler as much as possible, so as not to interfere with the optocoupler.
6. Summary of Intelligent Lighting System Scheme
This paper mainly studies the two major contents of human detection, real-time positioning and intelligent lighting control. And it mainly introduces the hardware design part of the lighting control system. The whole control system adopts a modular design, and its main advantage is that it can expand flexibly and increase the compatibility of the system. The hardware circuit design of the controller is reliable and works well. It enables people to control the lights according to their own needs, and at the same time prolongs the life of the bulbs and achieves the effect of energy saving. Today, with the rapid development of science and technology, smart home products have very broad social and commercial prospects.
The above are the details of the smart lighting controller solution introduced by Shenzhen Zuchuang Microelectronics Co., Ltd. for you. If you have electronic function development needs for smart home control systems, you can trust us. We have rich experience in customized development of electronic products. We can evaluate the development cycle and IC price as soon as possible, and can also calculate PCBA quotations. We are a number of chip agents at home and abroad, including MCU, voice IC, Bluetooth IC and modules, wifi modules. Our development capabilities cover PCB design, single-chip microcomputer development, software custom development, APP custom development, WeChat official account development and other hardware and software design. It can also undertake the research and development of smart electronic products, household appliances scheme design, beauty equipment development, Internet of Things application development, smart home scheme design, TWS scheme development, Bluetooth audio development, children's toy scheme development, and electronic education product development.
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