CN103648185A - Sink node of water environment wireless sensing monitoring network - Google Patents

Abstract

The invention relates to a convergence node of a water environment wireless sensor monitoring network, which includes a processor unit, a sensor unit, a communication unit and an energy supply module. The processor unit includes dual microcontrollers, dual memory and A/D conversion part; the dual microcontrollers are K60N512 of ARM architecture and MC13211 of HCS08 architecture, K60N512 is used for collecting data and forwarding data processing, MC13211 is used for wireless data communication, The Zigbee protocol is used here; the dual memory is K60N512 and MC13211 internally integrated FLASH for storing data; A/D conversion receives the data of the sensing unit for conversion. The power supply module adopts dual power supply of lithium battery and solar battery to supply power for the processor module, sensor module and Zigbee wireless communication module. The invention has the characteristics of flexible configuration, low power consumption, low cost, etc., and belongs to the field of wireless monitoring and control.

Description

Aggregation node of water environment wireless sensor monitoring network

technical field

The invention relates to a convergence node of a water environment wireless sensor monitoring network, which belongs to the field of wireless monitoring and control.

Background technique

In China, water quality analyzers with a single parameter are mostly used in the collection of water quality parameters, which are low in price, simple in operation, unable to continuously monitor water quality, high in labor intensity, poor in mobility, and slow in data collection. It cannot meet the needs of monitoring water quality parameters in large-area waters and waters with complex topography. Therefore, it is necessary to find a new technology, and it is particularly necessary to solve the monitoring and management of water quality parameters in large-area, multi-water and complex terrain water environments.

As an emerging technology, wireless sensor network is composed of a large number of cheap nodes deployed in the monitoring area, forming a multi-hop ad hoc network through wireless communication, cooperatively collecting and processing the sensing object information in the monitoring area, and sent to observers. Its appearance has produced a completely new way of information acquisition and processing. Combining different types of sensors, wireless sensor networks have broad application prospects in many fields such as environmental monitoring, military inspection, smart home, intelligent transportation, and industrial control. Water environment wireless sensor monitoring network is a typical application of wireless sensor network in the field of environmental monitoring. Compared with the existing water environment automatic monitoring system, the water environment wireless sensor monitoring network has the advantages of small impact on the ecological environment, high monitoring density and wide range, and low system cost.

The water environment wireless sensor monitoring network throws a large number of sensor nodes (the number ranges from hundreds to thousands) into the water area of interest, and the nodes quickly form a wireless network through self-organization. Nodes include ordinary nodes, aggregation nodes and base stations. The aggregation node is not only responsible for the collection of information, but also collects the information sent by ordinary nodes and forwards it, which involves processing such as routing selection and topology structure. Therefore, the aggregation node plays a key role in the water environment wireless sensor monitoring network, and its performance is directly related to the stability of the monitoring network.

Contents of the invention

In order to overcome the deficiencies of the prior art, the purpose of the present invention is to provide a water environment sensor monitoring network convergence node. The convergence node has the characteristics of large monitoring range, flexible configuration, low power consumption, little impact on the natural environment, and low cost. It can realize multi-point remote multi-parameter real-time online monitoring of the water environment, and timely discover sudden water pollution accidents. , so that relevant departments can take measures in time to find the source of pollution, reduce the impact of pollution on agricultural water, animal husbandry water and people's domestic water, and have great development prospects and practical significance for the monitoring of water environment changes and environmental protection.

The invention provides a water environment monitoring network convergence node based on a wireless sensor network, comprising: a processor module, a sensor module, a power supply module, a communication module and a storage module. All modules are waterproofed, and the power module supplies power to the processor module, sensor module, and communication module.

The sensor preprocessing circuit in the acquisition circuit is connected to the pH sensor, salinity sensor and temperature sensor in the water, which can collect the pH value, salinity value and temperature of the water area to be monitored, and then convert the collected pH signal, salinity signal and water temperature signal It is a voltage signal of 0-5V and sent to the processor module.

The processor module receives the voltage signal sent by the sensor, processes and stores the pH signal, salinity signal and water temperature signal, and then sends it to the base station through the communication module. The processor in the communication module takes the MC13211 chip produced by Freescale as the core. MC13211 is mainly responsible for node access, communication between nodes and base stations, and water quality parameter data transmission between nodes. The data volume and data processing capability of the aggregation node are much larger than that of ordinary nodes. Therefore, the aggregation node adds an independent data processor, that is, the K60N512 of the ARM architecture, to realize data processing and communication.

In order to expand the data storage capacity of the aggregation node, in addition to relying on the integrated Flash capacity of the microcontroller itself, an independent storage space should also be expanded. The electric erasable memory series 24LC1025 chip produced by Microchip Technology Inc. is used.

The monitoring node power supply module includes two parts of power supply: +3.3V and +5V. Some of the lithium batteries output +12V and output +5V DC voltage after voltage stabilization to supply power to the sensor module, serial port module and storage module. The other part is converted into +3.3V DC voltage to supply power to the MC13211 minimum system and wireless communication module through voltage regulation. In order to fully guarantee the unattended operation of the monitoring nodes, a dual-battery power supply mode of lithium batteries and solar batteries is adopted to maximize the battery life under the existing conditions and ensure the life cycle of the nodes.

Wireless communication module design. The monitoring nodes are networked through the Zigbee communication protocol and connected to the base station, and the upload data is controlled by the base station command. The mesh structure network based on the IEEE802.15.4/zighee protocol is a multi-hop topology structure, which can realize point-to-point transmission between nodes in the network. This structure is connected to each other to form a mesh. The network is very robust and has strong fault tolerance. When individual links and terminal nodes fail, the transmission path will be reselected, and the transmission distance and reliability are stronger than other structured networks.

Description of drawings

Fig. 1 is a schematic diagram of the system structure of the convergence node of the water environment wireless sensor monitoring network of the present invention;

Fig. 2 The principle connection diagram of the signal conditioning circuit of the temperature sensor;

The principle connection diagram of the signal conditioning circuit of Fig. 3PH sensor;

The schematic connection diagram of the signal conditioning circuit of Fig. 4 salinity sensor;

Fig. 5 The principle connection diagram of the minimum system reference circuit of microcontroller MC13211;

Fig. 6 Principle connection diagram of transmitting antenna and power amplifier conditioning circuit;

Figure 7 is the schematic connection diagram of the battery management module circuit.

Figure 8 is a schematic connection diagram of the storage module circuit.

Figure 9 is a schematic connection diagram of the minimum system reference circuit of the microcontroller K60N512.

specific implementation plan

The present invention is described in detail below in conjunction with accompanying drawing:

Fig. 1 is a schematic diagram of the system structure of the convergence node of the water environment monitoring network based on the wireless sensor network in the present invention. The node device includes a sensing unit, a processing unit, a communication unit and an energy supply unit.

(1) The sensing unit includes two parts: the sensor and the signal conditioning circuit.

The sensor is responsible for collecting the pH value, salinity value and water temperature of the water area to be monitored. The monitoring node is equipped with pH sensors, salinity sensors and temperature sensors, which can collect the pH value, salinity value and water temperature of the water body, and the signal conditioning circuit performs linearization and temperature compensation on the collected data.

The water temperature signal is obtained from the TMP in Figure 2, and transmitted to the TMP pin in the schematic connection diagram of the minimum system reference circuit of the microcontroller MC13211 in Figure 5; the PH value signal is obtained from the PH interface in Figure 3, and transmitted to the minimum of the microcontroller MC13211 in Figure 5 The PH pin in the principle connection diagram of the system reference circuit; the salinity value signal is obtained from the Salinity interface in Figure 4, and sent to the Salinity pin in the minimum system reference circuit principle connection diagram of the microcontroller MC13211 in Figure 5.

(2) The processing unit includes microcontroller, memory and A/D converter.

Microcontroller MC13211 is responsible for transmitting data between nodes, as shown in Figure 5; microcontroller K60N512 is responsible for data storage and forwarding, as shown in Figure 9. The water quality parameters collected and processed by the node are not immediately uploaded to the base station, so they need to be temporarily stored locally on the node according to a certain storage structure. The water quality parameters can be uploaded at regular intervals, or the corresponding historical data of water quality parameters can be uploaded according to the requirements of the host computer after passively accepting the instructions from the host computer.

The data of other nodes are wirelessly obtained from the RxD and TxD interfaces in Figure 5, and transmitted to the TxD and RxD pins in the schematic connection diagram of the minimum system reference circuit of the microcontroller K60N512 in Figure 9 respectively.

(3) The communication unit includes a transmitting antenna and a power amplifier conditioning circuit.

The monitoring network builds wireless communication based on Zigbee communication. Zigbee wireless communication technology is used for data transmission between monitoring nodes, and multi-hop transmission is used to collect the collected water quality parameters to the base station, and the base station transmits the collected parameters to the remote data center through GPRS communication. The role of the transmission power amplifier circuit is to amplify the input power of the wireless transceiver to achieve the desired output power. Since data reception and transmission are realized through the same antenna circuit, a radio frequency single-pole double-throw switch is added at the antenna end to realize data transmission and reception switching.

Obtain wireless communication data from the RFIN_P and RFIN_M interfaces in Figure 6, and transmit them to the RFIN_P and RFIN_M pins in the schematic connection diagram of the minimum system reference circuit of the microcontroller MC13211 in Figure 5, respectively.

(4) The energy module includes energy supply and energy management.

Considering that monitoring nodes need to be deployed in water for a long time, it is not easy to replace batteries frequently, and manual battery replacement will consume extra manpower and material resources, increase monitoring costs, and is not conducive to the continuity of monitoring. Therefore, an energy management module is added to the design of the monitoring node to monitor the remaining energy of the battery in real time. By collecting the remaining energy of the node, the necessary energy distribution is performed on each module of the node to achieve the purpose of extending the life cycle of the node and continuously monitoring the waters.

As shown in Figure 7, the circuit principle connection diagram of the battery management module can monitor the power of the lithium battery in real time, and can realize the charging and discharging function of the lithium battery, and provide +5V voltage for the node.

(5) Data storage management module.

Compared with ordinary nodes, the storage capacity of the aggregation node is relatively strong. It connects the wireless sensor network to the base station, and forwards the collected data to the base station and external network. Therefore, in addition to meeting the basic functions of terminal nodes such as data collection, data processing, and wireless communication, the design of the aggregation node should also have a stronger data storage function. In order to expand the data storage capacity of the aggregation node, in addition to relying on the integrated Flash capacity of the microcontroller itself, it is also necessary to expand an independent storage space. The electric erasable memory series 24LC1025 chip is used, and the data storage capacity is 1024K. This family of devices supports a 2-wire serial interface, organized in 8-bit memory blocks.

Under the SCL interface clock in Figure 8, the data is obtained from the SDA interface and sent to the SCL and SDA pins in the schematic connection diagram of the minimum system reference circuit of the microcontroller K60N512 in Figure 9.

Claims (2)

1. water environment wireless sensing monitoring net aggregation node, is characterized in that comprising: the Zigbee wireless transceiver module for connecting sensor group to obtain the sensor interface of temperature, pH value and salinity value, the data processing module being connected with sensor interface, to be connected with data processing module.

2. according to claim 1 in the water environment monitoring node of wireless sensor network, it is characterized in that: it is the K60N512 chip of Freescale Kinetis series that processing module adopts model.

Images