WO2018170790A1

WO2018170790A1 - Zigbee-based wireless continuous image transmission system

Info

Publication number: WO2018170790A1
Application number: PCT/CN2017/077681
Authority: WO
Inventors: 邹霞
Original assignee: 邹霞
Priority date: 2017-03-22
Filing date: 2017-03-22
Publication date: 2018-09-27

Abstract

The present invention provides a Zigbee-based wireless continuous image transmission system, comprising an upper computer application subsystem, an aggregation node subsystem, and an image sensor subsystem; the upper computer subsystem being connected to the aggregation node subsystem; the aggregation node subsystem being wirelessly connected to the image sensor subsystem; the aggregation node subsystem and the image sensor subsystem both comprising a wireless communication module; the image sensor subsystem further comprising a camera module; and the upper computer subsystem being connected, by means of a serial port, to the aggregation node subsystem. Compared with the prior art, the Zigbee-based wireless continuous image transmission system provided by the present invention is able to cope with longer transmission distances, is not easily affected by the image pixel size and transmission distance, produces images of a relatively high quality, and has a relatively high frame rate for continuous images.

Description

ZigBee-based wireless continuous image transmission system

[0001] The present invention relates to a ZigBee-based wireless continuous image transmission system, which belongs to the field of wireless communication and imaging.

Background technique

[0002] ZigBee is an emerging short-range, low-rate wireless network technology, which is based on a group

The IEEE802.15.4 wireless standard has developed technical standards for networking, security, and application software. It is mainly suitable for use in the fields of automatic control and remote control, and can be embedded in various devices.

[0003] ZigBee technology has the following characteristics:

[0004] 1, high reliability: Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) technology avoids competition and conflicts in sending data ;; use transmission mode with acknowledgment and weight Transmission mechanism; use Cyclic Redundancy Check (CRC) to ensure the correctness of the data.

[0005] 2. Low power consumption: tens of milliwatts in the communication state of the terminal device, and several tens of microwatts in the sleep mode. In the low-power standby mode, the No. 5 dry battery can support 1 node work for 6 months to 24 months.

[0006] 3, low cost: ZigBee chip cost only about two dollars, and ZigBee agreement is free of patent fees

[0007] 4, high security: ZigBee provides a three-level security mode, including no security settings, the use of access control lists to prevent illegal access to data and the use of advanced encryption standards (Advanced Encryption Standard with 128-bit key, AES-128 A symmetric cipher to flexibly determine its security attributes.

[0008] 5, 吋 delay: communication delay and delay from the dormant state are very short, the typical search device delay is 30ms, sleep activation delay is 15ms, active device channel access delay is 15ms.

[0009] 6. Large network capacity: Each ZigBee network can support up to 65,535 devices.

[0010] Compared with existing wireless communication technologies, ZigBee technology has the characteristics of low power consumption and low cost, and is suitable for carrying services with small data traffic.

[0011] Schematic diagram of the ZigBee protocol stack architecture is shown in Figure 1, with reference to the open system interconnection (Open System) Interconnect, OSI) model, from top to bottom, Application Layer (APL) ^ Network Layer (NWK:), Medium Access Layer (MAC), and Physical Layer (Physical Layer, PHY) ), wherein the application layer is composed of an application object (up to 240), a ZigBee Device Object (ZDO), and an Application Support Sub-layer (APS). In addition, a security service layer has been developed to provide security services for NWK and APS.

[0012] ZigBee is very suitable for control applications at low data rates and IoT-related applications for sensing signal transmission. With the efforts of scholars and engineers in various countries, ZigBee technology has gradually moved to the field of practical application after years of development. , becoming a major standard for short-range wireless transmission, and is moving toward miniaturization, multi-functionality, intelligence, and low power consumption.

technical problem

[0013] The original purpose of ZigBee technology development is not to transmit multimedia information such as voice, image and video. The traditional ZigBee technology is to implement simple environmental data (such as temperature, humidity, light intensity) on micro nodes with severe energy constraints. Acquisition, transmission and processing. However, as the demand for comprehensive monitoring of the environment continues to increase, people urgently need to transmit more data, such as voice, images, video, etc., to achieve more sophisticated environmental monitoring, such as in mountainous areas, mines and other places where there is no public network signal. , need to implement data collection and environmental monitoring, and also need to communicate between staff when necessary.

Problem solution

Technical solution

[0014] In view of the above-mentioned deficiencies of the prior art, an object of the present invention is to provide a ZigBee-based wireless continuous image transmission system, including a host computer application subsystem, a convergence node subsystem, and an image sensor subsystem. The upper computer subsystem is connected to the sink node subsystem, and the sink node subsystem is wirelessly connected to the image sensor subsystem. The sink node subsystem and the image sensor subsystem each include a wireless communication module, and the image sensor subsystem further includes a camera module. The upper computer subsystem and the aggregation node subsystem are connected through a serial port.

[0015] Preferably, the upper computer subsystem implements serial port initialization, command transmission, data receiving and verification, and image storage of the upper computer, and the upper computer and the aggregation node are connected through a serial port, and send instructions to the aggregation node through the RS-232 serial port.

[0016] Preferably, the foregoing aggregation node subsystem implements aggregation node initialization, data reception, and data transmission; The aggregation of the aggregation node includes initialization of the protocol stack and initialization of the peripheral circuit of the wireless communication module; data reception includes wirelessly receiving data sent from the image sensor node, and receiving an instruction from the upper computer through the serial port; the data transmission includes wirelessly transmitting the instruction to the image sensor node wirelessly. The communication module, and send data to the host computer through the serial port.

[0017] Preferably, the image sensor subsystem includes image sensor node initialization, data reception, and data transmission; image sensor node initialization refers to protocol stack initialization and initialization of wireless communication peripheral circuits; and data reception includes wireless reception from a sink node. Commands, and receiving data from the camera through the serial port; data transmission includes wirelessly transmitting data to the aggregation node, and sending commands to the camera through the serial port.

[0018] Preferably, the upper computer application subsystem includes a serial communication module and an image storage module. The serial communication module includes an initialization serial port, and sends a command frame for controlling the initialization and photographing of the camera to the aggregation node through the RS-232 serial cable, and also receives the camera response frame and the image data frame from the aggregation node. The image storage module saves the image to a disk file system in JPEG file format.

[0019] Preferably, the sink node in the sink node subsystem implements relay forwarding, and the host computer sends a command frame for controlling camera initialization and photographing to the sink node through the RS-232 serial line, and the sink node forwards the command frame to the sink node without a trade-off. The image sensor node receives the response frame and the image data frame wirelessly transmitted by the image sensor node, and determines the type of the frame. If it is an image data frame, the frame header is removed, and the payload is forwarded to the upper position through the RS-232 serial cable. If it is another type of data frame, it will be forwarded directly to the host computer. After receiving the image data frame, the sink node also determines whether the received image data frame is the last frame.

Advantageous effects of the invention

Beneficial effect

Compared with the prior art, the ZigBee-based wireless continuous image transmission system provided by the present invention can adapt to a long transmission distance, is not susceptible to image pixel size and transmission distance, and has high image quality and continuous image frames. The rate is also higher.

Brief description of the drawing

DRAWINGS

[0021] FIG. 1 is a schematic diagram of a ZigBee protocol stack architecture; 2 is a schematic diagram of a ZigBee-based wireless continuous image transmission system according to the present invention;

3 is a schematic diagram of the operation of a ZigBee-based wireless continuous image transmission system according to the present invention;

4 is a schematic diagram of a working process of a host computer of a ZigBee-based wireless continuous image transmission system according to the present invention; [0025] FIG. 5 is a schematic diagram of a workflow of a convergence node of a ZigBee-based wireless continuous image transmission system according to the present invention; [0026] FIG. The invention is based on the ZigBee-based wireless continuous image transmission system image sensor node workflow diagram.

Embodiments of the invention

[0027] The present invention provides a wireless continuous image transmission system based on ZigBee. The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0028] As shown in FIG. 2, the ZigBee-based wireless continuous image transmission system provided by the present invention includes:

[0029] The host computer subsystem: includes the host computer serial port initialization, command transmission, data receiving and verification, and image saving. The upper computer and the aggregation node are connected through the serial port, and send instructions to the aggregation node through the RS-232 serial port, such as a reset instruction, setting a photo picture compression rate command, reading a picture data command, etc., receiving and checking the instruction confirmation data from the aggregation node. And image data, and save the image data, mainly to achieve camera initialization and camera taking.

[0030] The wireless communication module in the aggregation node includes: aggregation node initialization, data reception, and data transmission. Aggregation node initialization refers to protocol stack initialization and initialization of wireless communication peripheral circuits. The data receiving includes wirelessly receiving data sent from the image sensor node, and receiving an instruction from the host computer through the serial port. The data transmission includes wirelessly transmitting an instruction to the image sensor node wireless communication module, and transmitting data to the upper computer through the serial port.

[0031] The wireless communication module in the image sensor node subsystem: includes image sensor node initialization, data reception, and data transmission. Image sensor node initialization refers to protocol stack initialization and initialization of peripheral circuits of the wireless communication module; data reception includes wirelessly receiving an instruction sent from the aggregation node, and receiving data from the camera through the serial port; and data transmission includes wirelessly transmitting data to the aggregation node, and Send commands to the camera through the serial port. [0032] Each module in the continuous image transmission system needs to coordinate with other modules in sequence, and the system software working diagram is shown in FIG. 3.

[0033] The user can send commands through the host computer application software to control the serial port baud rate of the camera, the size and compression ratio of the captured image, the number of consecutive photographs, etc., and can save the captured image in the JPEG format on the host computer. The upper computer application software flow chart is shown in Figure 4.

[0034] The internal communication of the entire non-continuous image transmission system is performed in accordance with a frame structure. The host computer defines the communication protocol. There are three frame structures: command frame, response frame, and image data frame.

[0035] The response frame indicates the response data returned by the camera after receiving the camera command sent by the host computer. After receiving the response frame, the upper computer checks the response frame. If it is correct, it continues to execute. If it is wrong, it resends the corresponding command frame.

[0036] The upper computer application software is composed of two parts: a serial communication module and an image storage module. The serial communication module includes an initialization serial port, and sends a command frame for controlling the initialization and photographing of the camera to the aggregation node through the RS-232 serial cable, and also receives the camera response frame and the image data frame from the aggregation node. The image storage module saves the image to a disk file system in JPEG file format.

[0037] The sink node plays the role of relay forwarding throughout the system. The host computer sends a command frame for controlling camera initialization and photographing to the sink node through the RS-232 serial line, and the sink node forwards the command frame to the image sensor node without retreat; the sink node receives the response frame and the image data frame wirelessly transmitted by the image sensor node. And determine the type of the frame. If it is an image data frame, the frame header is removed, and the payload is forwarded to the upper computer through the RS-232 serial cable. If it is another type of data frame, it is directly forwarded to the upper computer. After receiving the image data frame, the sink node also determines whether the received image data frame is the last frame. The aggregation node software flow chart is shown in Figure 5.

[0038] The specific operation flow of the image sensor node is as follows: The image sensor node is powered on, receives a command frame wirelessly sent by the sink node, parses and strips the frame header portion, sends the image to the camera through the serial port, initializes the camera, and periodically performs an image. collection. The wireless communication module reads the image data collected by the camera through the serial port. Each time it receives 100 bytes from the camera, it is encapsulated into an image data frame, and the frame header indicates whether the image data frame is the last frame. The wireless communication module of the image sensor node is wirelessly transmitted to the wireless communication module of the aggregation node every time an image data frame is encapsulated. The software flow chart of the image sensor node is shown in Figure 6. [0039] It is proved by experiments that the ZigBee-based wireless continuous image transmission system provided by the invention can adapt to a long transmission distance, is not easily affected by image pixel size and transmission distance, and has high image quality, and the frame rate of continuous images is also Higher.

[0040]

[0041] It is to be understood that those skilled in the art can make equivalent substitutions or changes in accordance with the technical solutions of the present invention and the inventive concept thereof, and all such changes or substitutions should belong to the appended claims. protected range.

Claims

Claim

A wireless continuous image transmission system based on ZigBee, characterized in that: the system comprises a host computer application subsystem, a convergence node subsystem, an image sensor subsystem, and the upper computer subsystem is connected with a sink node subsystem, and the aggregation node The subsystem is wirelessly connected to the image sensor subsystem, the sink node subsystem and the image sensor subsystem each include a wireless communication module, and the image sensor subsystem further includes a camera module, between the upper computer subsystem and the sink node subsystem Connect through the serial port.

The ZigBee-based wireless continuous image transmission system according to claim 1, wherein: said upper computer subsystem implements serial port initialization, command transmission, data reception and verification, and image storage of the upper computer, and the upper computer and the aggregation node are connected through a serial port. Send an instruction to the aggregation node through the RS-232 serial port.

The ZigBee-based wireless continuous image transmission system according to claim 1, wherein: the aggregation node subsystem implements aggregation node initialization, data reception, and data transmission; and the aggregation node initialization includes protocol stack initialization and a peripheral circuit of the wireless communication module. The data reception includes wirelessly receiving data sent from the image sensor node, and receiving an instruction from the host computer through the serial port; the data transmission includes wirelessly transmitting the command to the image sensor node wireless communication module, and transmitting the data to the upper computer through the serial port.

The ZigBee-based wireless continuous image transmission system according to claim 1, wherein: said image sensor subsystem includes image sensor node initialization, data reception, and data transmission; and image sensor node initialization refers to protocol stack initialization and wireless communication. Initialization of the peripheral circuit; data reception includes wirelessly receiving an instruction sent from the aggregation node, and receiving data from the camera through the serial port; the data transmission includes wirelessly transmitting data to the aggregation node, and sending the instruction to the camera through the serial port.

The ZigBee-based wireless continuous image transmission system according to any one of claims 1 to 4, wherein: the upper computer application subsystem comprises a serial communication module and an image storage module, and the serial communication module comprises an initialization serial port, through RS-232. The serial line sends a command frame for controlling the initialization and photographing of the camera to the sink node, and also receives the camera from the sink node. Head response frame and image data frame;

The image storage module saves the image to a disk file system in JPEG file format.

[Claim 6] The ZigBee-based wireless continuous image transmission system according to any one of claims 1 to 4, wherein: the aggregation node in the aggregation node subsystem implements relay forwarding, and the upper computer passes the RS-232 serial port. The line sends a command frame for controlling the initialization and photographing of the camera to the sink node, and the sink node forwards the command frame to the image sensor node without a trade-off; the sink node receives the response frame and the image data frame wirelessly transmitted by the image sensor node, and determines the type of the frame. If it is an image data frame, the frame header is removed, and the payload is forwarded to the upper computer through the RS-232 serial cable. If it is another type of data frame, it is directly forwarded to the upper computer; after receiving the image data frame, the aggregation node Also determine if the received image data frame is the last frame.