[Design] University intelligent lighting system

1. The significance of applying intelligent lighting systems in colleges and universities

In the context of building a conservation-minded society, the construction of intelligent lighting control systems in colleges and universities is an inevitable choice for the development of the times, and its significance is embodied in the following aspects:

1.1 Reduce Electricity Expenses

University intelligent lighting system can greatly reduce the use of lamps and energy consumption, compared to ordinary lighting systems, can save 20% -25% of energy. The intelligent lighting system is based on the premise of ensuring students' normal learning. Automating the turning on or off of lighting equipment can reduce the school's electricity expenses and save school funding. The teaching building lighting system is an important part of the university's lighting system. It should focus on the development of a teaching building intelligent lighting control system to enhance the lighting equipment's automatic control capabilities.

1.2 Improve the intelligent management level of lighting equipment

The intelligent lighting system in colleges and universities introduces advanced science and technology, and uses electronic induction technology, electromagnetic pressure regulation technology, etc. to improve the additional power consumption caused by unbalanced load in the lighting circuit, enabling light adjustment, intelligent dimming, delay control, etc. The function can provide more comfortable lighting for teachers and students in the teaching building, and promote the management of lighting equipment more scientific and intelligent.

1.3 Promoting Intelligent Building Construction in Colleges and Universities

Intelligent lighting system is an important component of intelligent buildings. The system can operate independently, and it can automatically control lighting equipment. It can also interface with other subsystems and become a component module in building intelligent control system to improve the intelligence of building management in colleges and universities. Level.

2. Design points of college intelligent lighting system

2.1 overall system design

Energy saving and consumption reduction is the main goal of the design of this system. In the process of determining the overall design plan of the system, the realization of this goal must be taken as a precondition. Through the design of software and hardware, the basic functions of the system are ensured. In the hardware design of the system, the CAN control chip with relatively advanced performance and relatively complete technology was adopted. After considering the factors such as cost performance and scalability, after comparison and selection, the control method of connecting the AT89S51 microcontroller and the CAN control was finally decided. The CAN bus The transceiver used was a TJA1050 high-speed transceiver independently developed by Philips, and the LIN bus transceiver was a TJA1020 product compatible with the CAN bus transceiver. The MC68HC908GZ32 chip selected by the gateway can communicate with CAN and LIN at the same time. The main role of the sensor is to perform illumination detection. The TI's TSL230 product is used. The software design program adopts C language to write the relevant software program, and applies the current popular modular programming method. The following focuses on the system's hardware design and software design analysis.

2.2 System Hardware Design

2.2.1 Infrared Detection Module

In order to achieve the collection of relevant data, the infrared detection module selected in the hardware design of this system, model number is HN911L, which is a low-power chip, its working voltage is only DC6V, detection range can reach more than 10m, suitable for In the high temperature and cold environment, the module can effectively distinguish the infrared signal radiated from the human body and the ambient environmental radiation signal during the operation process, thereby ensuring the reliability of the operation of the sensor. The internal circuit structure of this detection module is shown in Figure 1.

2.2.2 Sensor layout

Pyroelectric infrared sensor is the main component of the infrared detection module. In accordance with the relevant requirements, the infrared detection module can only be arranged indoors, which makes the false alarm rate of the module has a great correlation with the installation position and layout method. When deploying infrared sensors, the following requirements must be met: Placement of sensors should be far away from sensitive areas such as air conditioners and stoves; within the range of sensor detection, large pots, homes, screens, etc. must not be installed; sensors cannot be directly Facing the glass window, if it must be set in a place with a glass window, the window curtain should be pulled up; it should not be placed in the area where the air flow activity is strong. Since the infrared sensor has a low sensitivity to a certain radial object, and has a high sensitivity to a laterally moving object, in order to prevent the false detection of the infrared probe, an appropriate position should be selected for installation.

2.2.3 CAN bus design

To effectively protect the TJA1050 CAN transceiver, the device is protected from over-current during system operation. In the hardware design of the system, a resistance of 5Ω can be connected in series at the pins of the CAN transceiver. The role of flow. At the same time, in order to further increase the EMI of the CAN bus node, two 30pF capacitors can be connected in parallel between CANH and CANL and the ground.

2.2.4LIN network node design

In the LIN bus, the network management is the main node of the host. Through the gateway, LIN and CAN can be connected. Since the local node wakeup is not used in the design of the network node, it is not necessary to pull up the resistor externally.

2.3 System Software Design

In this system, the main purpose of software design is to realize the control function of the intelligent lighting control system. The specific design points are as follows:

2.3.1 Initialization

This function is mainly completed by the program initialization module, including the following: CPU clock initialization, variable definition, timer initialization, I/O port initialization, and A/D sampling initialization.

2.3.2 Control Program Design

In this system, the design of the control program is the focus of software design, and its ultimate goal is to achieve the system's basic functions, such as automatic control and communications. When the infrared detection module detects a person in a university teaching building, the control system will turn on the lighting fixtures in the area. When the infrared detection module cannot detect the human body temperature, the lighting fixture will be turned off within a certain period of time. Can achieve the intelligent control of lamps.

in conclusion

In summary, as the size of the universities in China's major universities continues to expand, the lighting energy consumption in schools has increased. To effectively solve this problem, this paper proposes an intelligent lighting control system, and from the hardware and software The aspects of the system's design were analyzed. Currently. The intelligent lighting control system designed in this paper has been applied in a certain university. Since the application of the system, the lighting energy is greatly reduced. Therefore, the system has a certain value of promotion and application, and can be promoted and applied in major universities and colleges.

This article is taken from a thousand intelligent lighting network

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