CN104698933A - A Water Sampling Device Control System Based on Single Chip Microcomputer - Google Patents

Abstract

The invention relates to a design of a control system of a layered water sampler, wherein the control system takes a single chip microcomputer as a control core, senses water depth and pressure by using a pressure sensor, and acquires and stores sensor information by using a data acquisition unit; the electromagnetic valve is controlled to be conducted through the electromagnetic valve driving circuit, and the sampling bottle is triggered to be closed. The whole system uses the storage battery to supply power, the power management unit supplies power to each module, and the wireless communication module is used for receiving and sending data before and after sampling. The invention can complete the water sample collection of the surface layer, the middle layer and the bottom layer at one time, improves the sampling efficiency, avoids the step of connecting a cable in the using process by using the wireless communication module to transmit data, improves the sampling precision by carrying the pressure sensor, has lower manufacturing cost of the whole system and has higher economic value.

Description

A Water Sampling Device Control System Based on Single Chip Microcomputer

technical field

The invention relates to a control system for an underwater water sample collection device, which is suitable for layered collection of water samples by using a card cover type water collection device.

Background technique

With the rapid development of industry, the problem of water pollution is becoming more and more serious. Therefore, water quality monitoring has become one of the important tasks of many environmental workers. Among them, water sample collection is the basic link for water environment research and governance. To fully understand the water environment, it is usually necessary to obtain the vertical distribution information of various indicators of the water body, so it is necessary to conduct vertical stratified sampling of the water body profile.

At present, Niskin, Hosking and other water collectors are widely used water sample collection instruments. When sampling, it is necessary to manually lower the water collector with a cable. When the water collector is lowered to a predetermined sampling depth, the hammer is released from the water surface to trigger the closure of the sampling bottle. It has the following disadvantages in its working process. First of all, at least surface, middle and bottom water samples need to be collected during sampling, which is a huge workload. When using a single sampling bottle, the work is cumbersome and requires a lot of manpower and material resources. In addition, the water sampling device usually needs to be lowered with a winch, and its depth depends on the depth of the steel wire rope. However, in the actual working environment, the water sampling device usually drifts due to water flow and other effects, causing the steel wire rope to tilt. At this time, the sampling accuracy is difficult to guarantee. , Sometimes the water sampler is tilted too much, and the heavy hammer cannot trigger the closing of the water sampler, and the water sample collection cannot be completed smoothly. Pump suction is another commonly used method of water sample collection. However, during the sampling process, the floc shape in the water body is easily damaged, and the in-situ state of the sample cannot be guaranteed, which brings difficulties to the subsequent determination of water body indicators.

The CTD sunflower water sampler is a commonly used water sample collection device, which can measure water quality parameters while collecting water samples, but it needs to use a motor to drive the sampling bottle to close, which requires high power consumption and high power consumption. very expensive. The "Electric Water Sampling Device" applied by the First Oceanographic Research Institute of the State Oceanic Administration in 2005 can keep the sampling bottle closed before and after sampling, and can keep the water sample pollution-free, leak-proof, and free from organisms. impact, but it requires cables for electrical connection underwater and above water during use, which is inconvenient to use; the patent "a control device for automatic return water collection device" applied by the Institute of Oceanology, Chinese Academy of Sciences in 2006, which does not The automatic layered collection of water samples can be completed without the use of cables or cables, but it still needs to be connected to the cable for depth data transmission before sampling, and since the return is provided by the buoyancy of the water sampler itself, the water sampler The return location is uncertain and it is not easy to retrieve the water collector during winter sampling in reservoir waters.

Contents of the invention

In order to solve the above problems, the present invention provides a single-chip microcomputer-based water sampling control system, which can be used in conjunction with Niskin and other water sampling devices to improve sampling accuracy and complete automatic layered collection of water samples.

To achieve the above object, the present invention adopts the following technical solutions:

A water collector control system based on a single-chip microcomputer, including a single-chip microcomputer, a data storage unit, a power management unit, a solenoid valve drive circuit, a wireless communication module, a solenoid valve, a solenoid valve drive circuit, a pressure sensor, and an A/D conversion unit; At the core, a pressure sensor is connected to the input end of the system, and the information is collected into the single-chip microcomputer through the A/D conversion unit, and the single-chip microcomputer saves the data in the data storage unit. The output end of the system is connected to the solenoid valve drive circuit. Each solenoid valve drive circuit is composed of optocoupler, triode, diode and relay. There are three in total, which control three solenoid valves respectively. The three solenoid valves respectively control the closing of the corresponding sampling bottles.

The control system of the water collector is powered by a storage battery or a dry battery through a power management unit. The power management unit includes a step-up module and a step-down module. , A/D conversion unit, data storage unit, solenoid valve drive circuit and wireless communication module power supply. The output end of the pressure sensor is connected with the analog input end of the A/D conversion unit, and the output port and the control port of the A/D conversion unit are connected with the single chip microcomputer.

The communication serial port of the single-chip microcomputer is connected with a wireless communication module, and the single-chip microcomputer can exchange data with the outside world by controlling its working mode.

The present invention has the following beneficial effects:

1. The control system is equipped with three solenoid valve drive circuits. When sampling, it can be equipped with three sampling bottles for collection. It can complete the collection of water samples from the surface, middle and bottom layers of the water body at one time. No human intervention is required during the sampling process, saving manpower , Material resources, improved sampling efficiency;

2. The control system is equipped with a pressure sensor for position measurement, thereby avoiding the problem of inaccurate sampling depth caused by the interference of the surrounding environment and improving the sampling accuracy;

3. The control system is equipped with a wireless communication module for data interaction with the outside world, and there is no need to use cables for data transmission during use;

4. The cost of the present invention is relatively low.

Description of drawings:

1. Figure 1 is a schematic diagram of the overall structure of the control system

2. Figure 2 is the schematic diagram of the control system circuit

3. Figure 3 is a schematic diagram of using with a sampling bottle

Among them, 1 is the pressure sensor, 2 is the sampling bottle trigger mechanism, 3 is the sampling bottle, and 4 is the airtight cabin

4. Figure 4 is the flow chart of the control program

Specific implementation:

The invention is a water sampling device control system used for improving sampling precision and efficiency. As shown in Figure 1, the core of the control system is the single-chip microcomputer U1, the system input is connected to the pressure sensor, U1 collects the pressure sensor information through the A/D conversion unit U2, and stores the information in the data storage unit U3. The system can be powered by storage batteries or dry batteries, through the boost module U4 and the step-down module U5 in the power management unit. The output end of the system is connected to three solenoid valves that trigger the closure of the sampling bottle, and U1 controls the solenoid valve "on and off" through the solenoid valve drive circuit. At the same time, the communication serial port of the single-chip computer is connected with the wireless communication module, so that information can be exchanged with the outside world.

As shown in Figure 2, in this embodiment, the model of the single-chip microcomputer U1 selected is STC89C52, and its clock signal source is supplied by an external crystal oscillator, and the frequency of the crystal oscillator is 11.0592MHz. U1 collects the information of the pressure sensor through the A/D conversion unit U2, and U2 TLC2543 is selected, its analog input terminal is connected to the pressure sensor output (0~5V voltage signal), the sensor power supply voltage is 24v, the control port and data port of U2 are connected with the single chip microcomputer P1.3~P1.7, and U1 will It is stored in data storage unit U3 (AT24C64).

As shown in FIG. 2 , in this embodiment, a 12V battery is used to supply power to the system, and the power supplies power to each module through the power management unit. The power management unit includes a step-up module U4 and a step-down module U5. U4 selects TPS61175 to increase the 12V power supply voltage to 24V to supply power to the pressure sensor and solenoid valve. U5 selects TPS767D301 to reduce the power supply voltage to 5v, and its 5V output is sent to the microcontroller, The A/D conversion module U2, the data storage unit U3, the solenoid valve driving circuit and the external wireless communication module supply power.

As shown in Figure 2, the solenoid valve driving circuit is isolated by an optocoupler at the input end to protect the normal operation of the single chip microcomputer. The relay (J1~J3) is driven by the triode (Q1~Q3) to conduct, and a diode (1N4007) is connected in parallel at the input end of the relay. , can prevent the back electromotive force interference generated after the relay breakpoint. There are three contacts at the relay output terminal, normally closed contact 4, common contact 2 and normally open contact 5, 2 and 4 are connected to both ends of the solenoid valve, 4 is connected to the ground terminal at the same time, and 5 is connected to the output terminal of TPS61175 +24v .

As shown in Figure 3, the specific process of the control system controlling the closing of the electromagnetic trigger sampling bottle is as follows. The control port U1 (P1.0~P1.3) of the single chip microcomputer sends the control command "low level", the optocoupler is turned on, and the base level of the triode Connect to the +5v voltage conduction, the negative input terminal 3 of the relay conducts with the ground terminal, the relay conducts, its common contact is disconnected from the normally closed contact, and connected to the normally open contact, the solenoid valve is energized and closed, its The moving iron core moves downward under the action of suction, which drives the connected iron pin to move downward and releases the round sleeve hanging on the iron pin. The sampling bottle is automatically closed and the water sample is collected.

As shown in Figure 2, in this embodiment, the single-chip serial port (P3.0～P3.3) is externally connected to the wireless communication module (SV651). Before sampling, P3.2 sends out a "low level" to enable the configuration of the wireless communication module function, and then the MCU configures the wireless communication module to receive mode through P3.1 (TXD), the PC serial port of the upper computer is connected to the same wireless communication module, and the staff sends the collected depth data from the PC. The depth data is read from the communication module and stored in the memory of the single-chip microcomputer; during the sampling process, the pin P3.3 of the single-chip microcomputer sends a low level to make the wireless communication module in a dormant state; "Ping", and then configure the wireless communication module to be in the transmitting state through the serial port, the single-chip microcomputer reads the data from the AT24C64 and sends it to the host computer through the wireless communication module, so that the staff can observe.

The specific working process of the control system with the sampling bottle is as follows. Before sampling, hang the sampling bottle on the trigger mechanism outside the control system airtight cabin. The upper computer PC serial port is connected to a wireless communication module, and the data to be collected is input from the upper computer and sent to the connected wireless communication module through the serial port. The wireless communication module will transmit the data to the wireless communication module connected to the control system in the airtight cabin. The single-chip microcomputer U1 reads the depth data to be collected through the serial port, and saves them in the internal ROM of the single-chip microcomputer. The water collector is lowered at a constant speed through the cable. During the lowering process, the single-chip microcomputer U1 collects the pressure sensor information through the data acquisition unit U2, and compares it with the preset sampling depth received before. When the water collector reaches the preset depth, the single-chip microcomputer control port (P1.0～P1.2) Issue a control command, drive the solenoid valve to conduct, close the first sampling bottle, and continue to lower the water collector until all three sampling bottles are closed, so that the surface, middle and bottom layers of water are collected. Sample.

The present invention is a control system for Nisskin bottle, Hoskin bottle or other sampling bottles based on the principle of opening and closing. The control system can be attached to three sampling bottles at the same time, and representative water samples of the surface layer, middle layer and bottom layer can be obtained at one time. The sampling efficiency is greatly improved, and different sampling depths can also be set according to specific conditions during sampling. Before sampling, the control system receives the sampling depth data transmitted by the upper computer PC through the wireless communication module, which avoids the use of cables. During the sampling process, the pressure sensor is used to measure the water depth position of the water collector, which improves the sampling accuracy and makes the collected samples more authentic and representative.

Claims (1)

1. A water collector control system based on a single-chip microcomputer, comprising a single-chip microcomputer, a data storage unit power management unit, a solenoid valve drive circuit, a wireless communication module, a solenoid valve, a solenoid valve drive circuit, a pressure sensor, and an A/D conversion unit; The feature is that the single-chip microcomputer is the control core, the system input end is connected with a pressure sensor, the information is collected into the single-chip microcomputer through the A/D conversion unit, and the single-chip microcomputer saves the data in the data storage unit. The output end of the system is connected to the solenoid valve driving circuit, and each solenoid valve driving circuit is composed of an optocoupler, a triode, a diode and a relay to control the solenoid valve. The solenoid valve controls the closing of the corresponding sampling bottle. The control system of the water collector is powered by a storage battery or a dry battery through a power management unit. The power management unit includes a step-up module and a step-down module. , A/D conversion unit, data storage unit, solenoid valve drive circuit and wireless communication module power supply. The output end of the pressure sensor is connected to the analog input end of the A/D conversion unit, and the output port of the A/D conversion unit is connected to the control port and the single-chip microcomputer; The communication serial port of the single-chip microcomputer is connected with a wireless communication module, and the single-chip microcomputer exchanges data with the outside world by controlling its working mode.