Because of people's increasing living standards and the improvement of lighting requirements, the modern lighting system must strive towards the goal of energy saving, environmental protection and high efficiency, and at the same time, it must constantly improve in the direction of comfort, flexibility and humanization. With the rapid development of computer and network technology, the bus technology is becoming more and more mature, which promotes the industry of intelligent building, and also has a very obvious development. Under these premises, the concept of "intelligent lighting control system" appears.
1. Design scheme
This paper mainly studies and designs a set of intelligent lighting control system based on KNX bus, in which the overall design scheme, hardware equipment selection, KNX bus network construction and design are introduced in detail.
The central controller is responsible for the configuration of each extension module module, so that it can use networking normally, and control the overall system through the central computer.
The sub control station is responsible for the module control assigned to it, so as to accurately control its subordinate control modules and monitor its working status at the same time.
The control module is the key to reflect the system, and plays a crucial role, directly acting the command on the lamp.
2. System hardware design and selection
The bus is also the KNX bus used. Its control unit can carry out logic programming, store the control command in the local control unit, and has the functions of control, alarm, information collection, monitoring, etc. it can also carry out logic grouping for the control unit in the software, so as to achieve the purpose of multiple control units to complete the same scene control together.
The intelligent lighting control system in this paper mainly takes KNX system as the core. The selected KNX system components are all product modules of Schneider Electric, whose structure is shown in Figure 2.
As can be seen from Figure 2, the control module is mainly composed of power module, switch module, dimming module, intelligent panel, induction module and other relevant parts. All components of the system can work independently or in combination.
For example, the data packets sent out by KNX sensor can be received by each component on the bus, but only when the target address matches its own address, its components will carry out corresponding instructions. Of course, some additional functions are also available. For example, adding KNX / Ethernet gateway can achieve two functions: first, it completes the connection between KNX network and Ethernet network, and realizes the mutual data transmission between these two networks, and can realize remote and remote control by controlling home appliances and web access; second, it can centrally control and manage all KNX buses through the external touch screen Equipment.
3. Design of software control mode for intelligent lighting control system
Because the controlled lamps of the system are controlled by switch mode, the main control mode of the system design is as follows:
Timing control: it is based on the working time to set its control mode. It is a multiple control mode that combines scenes, time and events. Finally, different lighting control schemes will be implemented.
Brightness control: the condition is in the places where there is natural light. These places are controlled not only by timing, but also by indoor brightness and other controls according to the light intensity of outdoor natural light.
After measuring the indoor lighting intensity of the corresponding area, set the ideal lighting intensity value required by the corresponding area, so as to control the increase and decrease of the lighting intensity of the indoor lamps.
And outdoor lighting, such as awning, parking lot, road lighting, etc., can automatically switch on and off the corresponding lamps according to the change of outdoor light intensity, such as at dusk, it will automatically turn on the road lamps; at dawn, it will automatically turn off the corresponding outdoor lights.
Intelligent panel control: each distribution room shall be equipped with a button type manual control panel box, and the circuit controlled by each button can be programmed and determined by the actual use.
Scene control: This is to prepare different scene modes according to different requirements of users.
The software flow chart of intelligent lighting control system is as shown in Figure 3. It can be seen that after each start of the system, initialization is carried out first, then the parameter command to be set is sent to set the value of the system, and then the corresponding part is sent according to the type of command. The feedback state information is mainly based on the external information returned by the sensor, so as to better manually adjust the lighting value and other parameters.
In this paper, KNX bus technology is applied to intelligent lighting control system, and the software and hardware of this system are selected and designed respectively. In recent years, the application of products based on KNX technology in China is growing rapidly. Many large public facilities, such as Beijing International Airport Terminal T3, Shanghai Pudong Airport and Shanghai World Expo Park, use KNX technology. And the application of KNX in our country has the trend of development to civil residence. There are also more and more companies in China to use KNX technology, and even to develop KNX products. At present, one of the main problems of KNX is the high price, which prevents KNX from entering the field of civil construction rapidly.