CN103533702A - Intelligent space art decorative light system based on internet of things - Google Patents

Abstract

An intelligent space art lighting system based on the Internet of Things. The system includes a group of wireless lighting nodes and a state control subsystem. The wireless lighting node includes a power supply subsystem, a sensor subsystem, a communication subsystem, a lighting control subsystem, and a group of lighting; the sensor subsystem is connected to the communication subsystem for Perceive the external signal to start the work of the whole system; the communication subsystem is connected with the lighting control subsystem to receive the system work start signal sent by the sensor subsystem; the lighting control subsystem converts the control signal of the communication subsystem into a driving art Lighting control signal. State control subsystem: It is used for remote control of wireless lighting nodes, and is responsible for controlling the state transition of these wireless lighting nodes to control lighting work. Each light node of the system is interconnected in the form of radio waves, and each node performs calculations separately, thereby decomposing the huge amount of calculations and realizing unique lighting effects.

Description

Intelligent Space Art Lighting System Based on Internet of Things

technical field

The invention belongs to the field of lighting control, improves the degree of information interaction in the lighting control mode, and relates to a wireless sensor network, a distributed computing method and a node dynamic positioning technology.

Background technique

Traditional LED lighting mainly has two control methods: the control methods can be roughly divided into two types: one is timing control, such as common festival flashing lights; the other is inductive control, such as sensor lights used for lighting in corridors. . Timing-controlled lamps use pre-programmed programs to control the flickering effect of the lamps. It is suitable for a group of lamps composed of a large number of lamps, but the centralized control method of wired connection is adopted between the lamps and the lamps. It is not easy to repair if there is a fault; the induction-controlled lamps control the lights by sensing changes in the surrounding environment, but the control method is single and there is no information exchange with other lamps to form a network.

With the advancement of science and technology and the improvement of people's living standards, the rising demand has caused the function and form of lamps to undergo tremendous changes from "lamps" to "lighting" and then to "smart lighting". The more humanized artistic service provided by "smart lighting" further embodies the concept of "people-oriented technology".

Contents of the invention

The main purpose of the present invention is to integrate the technology of wireless sensor network into the lighting control mode, solve the problems of low flexibility and low degree of information interaction in traditional control mode, and provide a set of intelligent control system based on the Internet of Things combined with wireless sensor network. The space art lighting system enables each light node in the lighting system to communicate with each other through radio waves, and each node distributed in the wireless sensor network performs calculations separately, thereby decomposing the huge amount of calculation and realizing unique lighting effects. And it provides the advanced technical basis for the smart home system, and builds the prototype of the smart home system based on the Internet of Things.

The intelligent space art lighting system based on the Internet of Things provided by the present invention includes a group of wireless lighting nodes and a state control subsystem. Each wireless lighting node specifically includes a power supply subsystem, a sensor subsystem, a communication subsystem, a lighting control subsystem and a set of Lighting;

Power supply subsystem: including low-power power supply module and lighting power supply module. The low-power power supply module is used for power supply of the sensor subsystem, communication subsystem and lighting control subsystem in the wireless lighting node. The lighting power supply module is used for the wireless lighting node. The power supply of a group of lighting fixtures;

In order to better reflect the flexibility and scalability of the system, the power supply of the wireless sensor network node (that is, the communication subsystem, sensor subsystem and lighting control subsystem in the wireless lighting node) is separated from the power supply of the art lighting node during design . Considering that the power supply current of the wireless sensor network node and the lighting node is quite different, the wireless sensor node only needs a few nanoamps of current when it is sleeping, and the current is only a few milliamperes when it is working, and the peak value of the wireless transmission is only a dozen milliamperes. And each wireless lighting node will flow a current of about 150 mA when the LED is fully turned on. Therefore, centralized power supply is not suitable. In addition, once the electrical parameters of the lighting node change, the power supply system of this part can be changed separately, without redesigning the wireless sensor node, which is convenient for system expansion.

Sensor subsystem: connected to the communication subsystem, mainly used to sense external signals, and input the sensed external signals into the communication subsystem to start the work of the whole system;

The design of the sensor subsystem should consider both reliability and energy saving. "This system selects a passive infrared sensor composed of a Fresnel lens, a pyroelectric infrared sensor and a BISS0001 chip as a node for sensing the outside world;" that is, the passive infrared module in Figure 2. The Fresnel lens can divide the detection area into several bright areas and dark areas, so that the moving objects entering the detection area can generate changing pyro-infrared signals on the detector in the form of temperature changes. BISS0001 is a high-efficiency infrared sensor signal processor, which is composed of digital-analog hybrid circuits such as operational amplifiers, voltage comparators, state controllers, delay controllers, and blockade time timers. signal and communicate with the processor.

Communication subsystem: connected to the lighting control subsystem, receiving the system work start signal sent by the sensor subsystem; on the one hand, the communication subsystem performs calculations, and inputs the control signals formed by the calculations to the lighting control subsystem; on the other hand, it transmits communication signals, communicates with The communication subsystems in other nodes interact to realize the interaction between wireless lighting nodes.

The lighting system adopts the CC2530 chip designed and manufactured by Texas Instruments. CC2530 is the second-generation ZigBee chip working in the 2.4GHz frequency band. It integrates a high-performance 2.4GHz DSSS (Direct Sequence Spread Spectrum) radio frequency transceiver core and a small industrial-grade 8051 controller, and can It supports ZigBee protocol. The chip is characterized by its extremely low power consumption, the voltage power supply is only 2V-3.6V, the standby current allowed by the interrupt is 0.4μA, the power consumption of the transmitter is 24mA in the receiving state, and the power consumption in the transmitting state is 29mA, which is very suitable for use. for battery-powered wireless sensor network nodes. In addition, the chip also has three timers/counters, random number generators and hardware interrupts. Considering the support of the protocol, power consumption, size, and cooperation with the algorithm, the chip is fully capable of meeting the needs of this system.

Lighting control subsystem: It is connected with the communication subsystem, and converts the control signal of the general IO port of the communication subsystem into a control signal capable of driving artistic lighting.

In order to bring out the artistic effect of lighting to the fullest, appropriate lighting control algorithms and effective and reliable hardware are necessary. The lighting control subsystem (that is, the lighting driving module in Figure 2) consists of a group of photoelectric isolation switches (AQW214S chips), current amplifiers and lighting. The distributed cluster algorithm designed for lighting introduces the concept of swarm intelligence (SwarmIntelligence) to simulate the lighting change effect of the lighting group. The so-called swarm intelligence is to use the simple intelligence of individuals to realize the high intelligence of the group, such as the route search skills of birds or fish. The lighting group built by the wireless sensor network can simulate the communication and thinking mode of the animal group, and finally simulate a similar The effect of birds flying gracefully or fish swarming flexibly forms a shocking visual experience.

State control subsystem: This subsystem is independent of the wireless lighting nodes, used for remote control of wireless lighting nodes, and is responsible for controlling the transition of these wireless lighting nodes to control lighting work.

In order to minimize the energy consumption of the lighting system, a state control subsystem is set up. The state control subsystem is composed of state remote controllers. The design of this part should consider two requirements. One is to ensure that every wireless lighting node in the system can receive the state commands issued by the state control subsystem; the other is The wireless lighting node needs to give feedback after receiving the command from the state control subsystem.

Advantage and positive effect of the present invention:

The invention adopts a novel distributed control mode by changing the centralized control mode of the traditional lighting, and builds a set of intelligent space art lighting system based on the wireless sensor network. In this system, each light node is interconnected in the form of radio waves, and each node distributed in the wireless sensor network performs calculations separately, thereby decomposing a huge amount of calculation and realizing a unique lighting effect.

The distributed computing method adopted in the present invention enables each lighting node to think independently, and communicate with other lighting nodes to form a lighting group, forming a human-light-environment trinity interactive system, bringing a new visual experience. The more humanized artistic service provided by the "intelligent lighting" constructed by the present invention further embodies the concept of "people-oriented science and technology". At the same time, it reflects the great change from "lighting" to "smart lighting", and has a good application prospect.

Description of drawings

Figure 1 is a schematic diagram of the composition of the intelligent space art lighting system.

Figure 2 is a block diagram of the basic hardware structure of the wireless lighting node.

Figure 3 is a schematic diagram of the wireless lighting node electricity.

Figure 4 is a schematic diagram of the wireless communication module circuit.

Detailed ways:

Example 1

As shown in Figure 1, the intelligent space art lighting system based on the Internet of Things includes a set of wireless lighting nodes and a state control subsystem. Each wireless lighting node specifically includes a power supply subsystem, a sensor subsystem, a communication subsystem, a lighting control subsystem and a group of lighting (see Figure 2). Power supply subsystem: including low-power power supply module and lighting power supply module. The low-power power supply module is used for power supply of the sensor subsystem, communication subsystem and lighting control subsystem in the wireless lighting node. The lighting power supply module is used for the wireless lighting node. Power supply for a group of lighting fixtures.

The intelligent space art lighting system is composed of a group of wireless lighting nodes. Many lighting nodes form an IoT sensor network. The lighting nodes are connected through the IEEE802.15.4 protocol for data interaction and become a lighting group. Through the dynamic positioning technology between nodes Realizing information exchange and self-awareness is also the basis for designing lighting control algorithms. Some of the lighting nodes are equipped with infrared sensors, through which the visitors can sense the comings and goings of the outside world, thus forming a harmonious interaction between people and the lighting environment.

In order to facilitate the layout and expansion of the system, each lighting node is powered by batteries, and the addition and deletion of independent nodes will not be affected by wiring. In order to reduce the power consumption of wireless lighting nodes and prolong the use time of the system, the system has two states of sleep and work. For nodes in a dormant state, the LED light will be disconnected from the power supply, and the radio transmission will be silent. In the working state of the node, the power supply of the LED light is in a controllable state, and can receive and transmit information at the same time.

Construction of hardware platform for wireless lighting nodes

The basic structure of the hardware is shown in Figure 2: each wireless lighting unit includes a wireless sensor network node (that is, the communication subsystem, sensor subsystem and lighting control subsystem in the wireless lighting node) and 3 artistic lighting nodes. The wireless sensor network node is small in size, powered by a low-power power supply module, and is packaged in the node box together with the battery, and the lighting node is connected to the node box through a thin cable. In order to achieve the requirements of modular design and high scalability, according to the system function, the wireless sensor network node module is designed into three parts, namely the wireless communication module, the passive infrared sensor module and the art lighting control module, which are packaged in a plastic node box middle. The infrared detection module is responsible for detecting the surrounding pedestrians. The art lighting control module is responsible for processing the detection results of the infrared detection module and implementing the algorithm of the system. The wireless communication module communicates with other lighting nodes to implement the control algorithm.

Wireless sensor network node structure: a wireless sensor network node is mainly composed of a CC2530 chip, a 32MHz patch crystal oscillator, a 32.768KHz crystal oscillator, on-board antenna, externally expanded whip antenna, power filter network, reset circuit and radio frequency Resonant network composition.

1. Design of clock crystal oscillator

The clock crystal oscillator of the wireless sensor network node adopts a dual reference design, adding a 32MHz chip crystal oscillator and a 32.768KHz crystal oscillator. The 32MHz crystal oscillator provides a high-speed clock reference for the CPU unit at full speed to meet high performance requirements, and the 32.768KHz crystal oscillator provides a low-speed clock reference for the CPU unit in a low-speed power-saving working state.

2. Antenna design

The antenna of the wireless sensor network node adopts a dual-antenna scheme of an on-board antenna and an externally expanded whip antenna to increase flexibility. The advantage of the PCB-mounted antenna is that it is low in cost and hardly increases the cost of the hardware. The disadvantage is that the performance is low and the PCB board area occupied may be large. The advantage of the whip antenna is that it has good performance, but the disadvantage is that it is expensive, large in size, and difficult to deploy in some specific applications. Therefore, the dual-antenna system we designed uses onboard antennas when long-distance transmission is not required and the nodes are compact; when long-distance transmission is required and is not sensitive to node size, whip antennas are used.

The PCB board antenna adopts an "inverted F" shaped antenna, an approximate omnidirectional antenna, with an antenna gain of 1.1dbi, and the whip antenna adopts a foldable form, with an antenna gain of 2dbi, and an omnidirectional antenna.

Topological structure design of artistic lighting group

The characteristics of the intelligent art lighting system are: there is no central node, all lighting units are on an equal footing, removing any existing lighting units or adding new lighting units will not affect the overall function of the system. Therefore, when designing the lighting unit node of this system, the functions of the coordinator, router and terminal node are properly combined, which not only ensures the function, but also increases the sleep time, which is suitable for the case of battery power supply.

In order to meet these requirements, the system modifies the Zstack protocol and adopts a two-level network structure of coordinator and router.

There are two kinds of addresses in the art lighting network, one is the 64-bit MAC address, which is unique in the world, and this address is used by the lighting nodes to communicate using the MAC layer when the ZigBee network layer is not established; the other address is 16-bit The ZigBee network address, which is unique in the lighting network, is used for the addressing of the lighting nodes inside the network when they communicate at the network layer. When the first lighting node is powered on, if no other lighting nodes are found when scanning the surrounding communication channels, it will configure itself as a coordinator lighting node to complete network initialization. Once the network is established, the coordinator lighting node becomes an ordinary router lighting node. Other lighting nodes can join this network as router nodes and request the first node to assign and save the network short address. So far, the router lighting node can not only use the MAC address to send data packets to the coordinator lighting node, but also use the network short address and the coordinator lighting node to communicate between the network layer and the application layer. The router lighting node has successfully joined the network. After that, whenever a new lighting node is powered on, it will configure itself as a router lighting node and join the lighting network one by one according to the above process. At this point, a tree-like cluster network is formed, so that the routing algorithm in Zstack can be used for point-to-point or broadcast communication. The communication letter used in this system can be divided into two ways, which are single-point transmission and broadcast transmission.

The Realization of the Control Algorithm of Art Lighting

1. Dynamic positioning algorithm

Usually, in a two-dimensional plane, the distance between nodes is known, and the coordinates (x, y) of an unknown node can be calculated from the coordinates of three or more known nodes. We define x ₀ and y ₀ as the two-dimensional coordinates of the unknown node 0 to be estimated, x _i and y _i are the two-dimensional coordinates of the known node i, i=1,2,3...N, N is the known The total number of coordinate nodes.

It can be obtained that the distance D _i0 between two points satisfies the following formula:

${\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="D.\; i"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">D.</figure-callout></span><figure-callout\; id="0"\; label="D.\; i"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}<span\; class="notranslate">\; =</span>\sqrt{{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>}^{\mathrm{<span\; class="notranslate">\; 2</span>}}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 3</span>}<span\; class="notranslate">\; )</span>$

It can be deduced from formula (3):

-x _i ² -y _i ² =(x ₀ ² +y ₀ ² )+x ₀ (-2x _i )+y ₀ (-2y _i )-D _i0 ²

For k (k≥3) such equations, the term (x ₀ ² +y ₀ ² ) can be eliminated by subtraction, for example, by subtracting from the kth formula:

-x _i ² -y _i ² +x _k ² +y _k ² =2x ₀ (x _k -x _i )+2y ₀ (y _k -y _i )+(D _ik ² -D _i0 ² )

A total of k-1 equations can be obtained, and these equations can be transformed into the following matrix form:

y=Xb (4), where

$\mathrm{<span\; class="notranslate">\; x</span>}<span\; class="notranslate">\; =</span>\left[\begin{array}{ccc}\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>& \mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="D.\; k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">D.</figure-callout></span><figure-callout\; id="0"\; label="D.\; k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="1"\; label="D.\; k"\; filenames="HDA0000292009790000021.png"\; state="\{\{state\}\}">D.</figure-callout></span><figure-callout\; id="1"\; label="D.\; k"\; filenames="HDA0000292009790000021.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ \mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>& \mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span>& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="D.\; k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">D.</figure-callout></span><figure-callout\; id="0"\; label="D.\; k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="D.\; k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">D.</figure-callout></span><figure-callout\; id="2"\; label="D.\; k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>\\ <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>\\ <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>\\ \mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>& \mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span>& {{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="0"\; label="D.\; k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">D.</figure-callout></span><figure-callout\; id="0"\; label="D.\; k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; D.</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\end{array}\right]$

$\mathrm{<span\; class="notranslate">\; the\; y</span>}<span\; class="notranslate">\; =</span>\left[\begin{array}{c}{{<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; the\; <figure-callout\; id="1"\; label="y"\; filenames="HDA0000292009790000021.png"\; state="\{\{state\}\}">y</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">k</figure-callout></span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ <span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; the\; <figure-callout\; id="2"\; label="y"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">y</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">k</figure-callout></span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; the\; <figure-callout\; id="2"\; label="y\; k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">y</figure-callout></span><figure-callout\; id="2"\; label="y\; k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ <span\; class="notranslate">\; .</span>\\ <span\; class="notranslate">\; .</span>\\ <span\; class="notranslate">\; .</span>\\ <span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; -</span>{{\mathrm{<span\; class="notranslate">\; the\; y</span>}}_{\mathrm{<span\; class="notranslate">\; k</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; <figure-callout\; id="2"\; label="k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">k</figure-callout></span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; +</span>{{\mathrm{<span\; class="notranslate">\; the\; <figure-callout\; id="2"\; label="y\; k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">y</figure-callout></span><figure-callout\; id="2"\; label="y\; k"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">\; </figure-callout>}}_{\mathrm{<span\; class="notranslate">\; </span>}}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}\end{array}\right]$

$\mathrm{<span\; class="notranslate">\; b</span>}<span\; class="notranslate">\; =</span>\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}\\ {\mathrm{<span\; class="notranslate">\; the\; <figure-callout\; id="0"\; label="y"\; filenames="51907DEST\_PATH\_HDA0000420776300000011.png,HDA0000292009790000021.png"\; state="\{\{state\}\}">y</figure-callout></span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}\\ \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right]$

Equation (4) can be obtained by matrix transformation:

b=(X ^T X) ^-1 X ^T y

The coordinate value (x ₀ , y ₀ ) of the unknown node 0 can be obtained. The other unknown nodes can be obtained by the same method.

When it is necessary to calculate the coordinates of the nodes in the three-dimensional space, it is only necessary to increase the number of nodes whose coordinates are known to four or more, and modify the above formula slightly.

The positioning function added to the lighting system is the basis for designing the lighting control algorithm later. The group intelligent lighting control algorithm mentioned in the next part will use the calculated coordinate information.

2. Lighting control algorithm

The distributed design of intelligent lighting makes the layout of lighting flexible and changeable, and the choice of control algorithms has also been greatly expanded. The intelligent art lighting system will introduce the concept of swarm intelligence and design a unique swarm intelligence lighting control algorithm.

"Swarm" is defined as a certain interactive organization or a structural collection of intelligent agents. Individuals in a group can be ants, birds or fish. What they have in common is that there is a certain relationship between individual behavior and global behavior. There is a close connection: individual behavior dominates group behavior, and group behavior also guides individual behavior. For example, in ant colonies, ants interact with other ants through the release of pheromones, so as to find the best path to find food. This behavior of collecting information from the environment and communicating with peers can be simulated in the lamp group. When the passive infrared detectors in the lighting group collect information about human activities from the environment, they will transmit the signal to the lighting node, and the node can formulate the direction and speed signal by itself according to its own coordinates and preset weight values, and then communicate with the The other nodes interact, and the nodes formulate optimized routes based on their own data and received information feedback, and finally simulate the effect similar to the graceful flight of birds or the flexible gathering and dispersal of fish, forming a novel and shocking visual experience.

After the wireless network platform is built, the design of the algorithm will have a lot of room for expansion. Here is just an example.

3. PWM art lighting modulation method with variable duty cycle

The lighting devices in the lighting system use white high-brightness LED lights.

In the working area, the light intensity of the LED lamp is basically proportional to the forward current, the greater the current, the stronger the light intensity. The dimming methods commonly used in LED drive circuits can be divided into two types: analog dimming and PWM dimming. It can be seen from the volt-ampere characteristics of the LED that in the working area, a small change in the forward voltage will cause a huge change in the current, which will cause a huge change in the brightness. The general relationship between current and voltage is:

${\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}<span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; I</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; e</span>}}^{\frac{{\mathrm{<span\; class="notranslate">\; V</span>}}_{\mathrm{<span\; class="notranslate">\; f</span>}}}{\mathrm{<span\; class="notranslate">\; KT</span>}}}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Among them, I _S is the saturation conduction current, I _S is the forward voltage, and I _F is the forward current.

A large number of studies have shown that: when the working current of the LED lamp reaches 70% to 80% of the rated current, if the current continues to increase, the brightness of the LED lamp will not continue to increase, and most of the energy will be converted into heat energy, which will accelerate the life of the LED lamp. consume.

Therefore, continuous control of LED current with analog dimming has drawbacks. The PWM dimming method adjusts the luminous brightness by repeatedly controlling the on and off of the LED current in a unit time. Since the human eye has a persistent visual effect, the stroboscopic flicker is not easy to be noticed by the human eye when the switching frequency is generally higher than 100Hz.

Radio Frequency Propagation Model

The CC2530 chip selected by this system fully supports the RSSI positioning method. As the distance between nodes increases, the RSSI value of a node receiving a signal from another node will decrease accordingly, and the two conform to a certain functional relationship, and in different environments, the parameters in the function will also change, as given below is a commonly used electromagnetic wave path loss model:

${\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; d</span>}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; =</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&eta;</span>}\mathrm{<span\; class="notranslate">\; 10</span>}\mathrm{<span\; class="notranslate">\; log</span>}<span\; class="notranslate">\; (</span>\frac{\mathrm{<span\; class="notranslate">\; d</span>}}{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>{\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}<span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; -</span><span\; class="notranslate">\; (</span>\mathrm{<span\; class="notranslate">\; 1</span>}<span\; class="notranslate">\; )</span>$

Among them, P _r (d) is the function of received signal strength and distance, the unit is dB; d ₀ is the reference distance; d is the real distance; The propagation environment; X _σ is the shielding factor in dB, which is related to the loss of the barrier. Assuming that n independent samples are used to construct a multiple regression model, the following matrix equation can be used instead of formula (1)

p=Gβ (2)

In the formula, p, G and β are respectively:

$\mathrm{<span\; class="notranslate">\; p</span>}<span\; class="notranslate">\; =</span>\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>\\ {\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>\\ <span\; class="notranslate">\; .</span>\\ <span\; class="notranslate">\; .</span>\\ <span\; class="notranslate">\; .</span>\\ {\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; P</span>}}_{\mathrm{<span\; class="notranslate">\; r</span>}}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}<span\; class="notranslate">\; )</span>\end{array}\right]$

$\mathrm{<span\; class="notranslate">\; G</span>}<span\; class="notranslate">\; =</span>\left[\begin{array}{cc}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 10</span>}\mathrm{<span\; class="notranslate">\; log</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}}{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; )</span>& \mathrm{<span\; class="notranslate">\; 1</span>}\\ <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 10</span>}\mathrm{<span\; class="notranslate">\; log</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}}{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; )</span>& \mathrm{<span\; class="notranslate">\; 1</span>}\\ <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>\\ <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>\\ <span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span>\\ <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 10</span>}\mathrm{<span\; class="notranslate">\; log</span>}<span\; class="notranslate">\; (</span>\frac{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}}{{\mathrm{<span\; class="notranslate">\; d</span>}}_{\mathrm{<span\; class="notranslate">\; 0</span>}}}<span\; class="notranslate">\; )</span>& \mathrm{<span\; class="notranslate">\; 1</span>}\end{array}\right]$

$\mathrm{<span\; class="notranslate">\; \&beta;</span>}<span\; class="notranslate">\; =</span>\left[\begin{array}{c}\mathrm{<span\; class="notranslate">\; \&eta;</span>}\\ {\mathrm{<span\; class="notranslate">\; x</span>}}_{\mathrm{<span\; class="notranslate">\; \&sigma;</span>}}\end{array}\right]$

Formula (2) can be obtained through matrix transformation:

β=(G ^T G) ^-1 G ^T p

The parameters η and X _σ can be obtained, and the node can calculate the distance information from the received RSSI strength.

Design of Lighting Drive Control Module

The drive control module can be divided into four parts: expansion interface area, photoelectric isolation switch area, control switch area, power supply and LED interface area.

1. Extended interface area

In order to consider the scalability of the nodes, the system design adopts the modular design idea. The single-function hardware is designed on an independent circuit board, so this system designs the CC2530 chip separately on a circuit board as the core board. Lead out the expansion interface to the drive control board, and connect the core board and the drive expansion board through double-row pins with a standard pitch of 2.54mm.

2. Photoelectric isolation switch area

The art lighting control module is connected to the lighting by a group of photoelectric isolating switches (AQW214S chips), which have two main functions: one is to realize the isolation of the small current of the control part from the large current of the lighting, and the power supply of the control part is separated from the power supply of the lighting, so that It can play the role of protecting the circuit; the second is to realize the effect of current amplification, and realize the amplification of primary to secondary current. In addition, the turn-on time and turn-off time of the photoelectric isolation switch (AQW214S chip) are very small, which will not affect the output power of PWM modulated light. Typical turn-on times are 0.65 ms and turn-off times are 0.08 ms.

3. Control switch area

There are three control buttons on the control module, which are the off switch S0, the test switch S1 and the start switch S2. Turn off the switch S0: After the system is powered on, it automatically enters the running state, and realizes the transformation effect of the lighting according to the preset lighting control algorithm. In order to achieve the purpose of saving electric energy, an off switch is provided. When the light and sensor nodes are in the running state, press the off switch of the remote control, and the remote control will broadcast the command of "shut down the system". LED1 of all nodes receiving this command flashes 5 times at a speed of 1 second, and then enters a dormant state, turns off each LED light, and stops requesting information from the outside world. When the node is in the dormant state, it does not respond to the "shutdown command" sent by the remote control.

Positioning switch S1: used to perform dynamic positioning between nodes. The node that receives this signal enters the positioning state. While broadcasting the "start positioning" command to the surrounding nodes, it collects the coordinate signals in the space until it can calculate its own coordinates. After the calculation, it broadcasts its own coordinates and makes the three LEDs The lights are all blinked 10 times at a rate of 100 milliseconds.

Start switch S2: In order to enable the nodes in the dormant state and positioning state to enter the running state, a start switch is set. When the light and sensor nodes are in sleep state or positioning state, press the start switch of the remote control, and the remote control will broadcast the "start node" command. The LED lights of all nodes receiving this command flash 20 times at a speed of 50ms, and then enter the normal operation state. When the node is in the running state, it does not respond to the "test node" command sent by the remote control.

4. Power supply and LED interface area

Each control board has 4 external ports, which are connected to 3 LED lights and 1 buzzer, namely P1, P2, P3 and P4. The P1 port is connected to LED light 1, the P2 port is connected to LED3, the P3 port is connected to the buzzer, and the P4 port is connected to LED4. The high-brightness white light-emitting diodes used in this system are made of blue light-emitting diodes. The forward turn-on voltage of the light-emitting diode is higher than that of ordinary diodes, about 1-2.5V, and the reverse breakdown voltage is lower than ordinary diodes, about 5V. When the forward current reaches about 1mA, it starts to emit light, and the luminous intensity is approximately proportional to the working current; but when the working current reaches a certain value, the luminous intensity gradually tends to saturation, and has a nonlinear relationship with the working current. The forward working current of the LED is 10-20mA, and the maximum forward working current is 30-50mA. In this system, the PWM pulse width modulation is used to adjust the LED light, which has been described in detail in Embodiment 4.

Claims (1)

1. the intelligent space artistic lamp-ornaments system based on Internet of Things, is characterized in that this system comprises one group of wireless lamp node and state control subsystem;

Each wireless lamp node specifically comprises supplied for electronic system, sensor subsystem, communication subsystem, lamp decoration control subsystem and one group of lamp decoration;

Supplied for electronic system: comprise low-power consumption supply module and lamp decoration supply module, low-power consumption supply module is for the power supply of sensor subsystem, communication subsystem and the lamp decoration control subsystem of wireless lamp node, and lamp decoration supply module is for the power supply of one group of lamp decoration of wireless lamp node;

Sensor subsystem: be connected with communication subsystem, be mainly used in the signal in the perception external world, and by the outer signals input communication subsystem perceiving, to start the work of whole system;

Communication subsystem: be connected the system works enabling signal that receiving sensor subsystem sends with lamp decoration control subsystem; Communication subsystem is carried out computing on the one hand, and the control signal that computing is formed inputs to lamp decoration control subsystem; Launch signal of communication on the one hand, mutual with the communication subsystem in other nodes, realize the interactive intercommunication between wireless lamp node;

Lamp decoration control subsystem: be connected with communication subsystem, the control signal of communication subsystem universal I/O port is converted into the control signal that can drive artistic lamp-ornaments;

State control subsystem: this subsystem is independent of wireless lamp node, for remote-control radio lamp decoration node, and the responsible conversion of controlling these wireless lamp node states, to control lamp decoration work.

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