阅读说明：本技术 一种新型柴动螺杆式空压机控制器的控制方法 (Control method of novel diesel-driven screw type air compressor controller ) 是由 吴海波 骆敏舟 康淼淼 王永 张华东 于 2020-05-21 设计创作，主要内容包括：本发明公开了一种新型柴动螺杆式空压机控制器的控制方法,属于空压机术领域,包括建立控制器,控制器包括主控单元、模拟量采集单元、开关量单元、485通信单元、人机交互界面和CAN通信单元,解决了空压机的快速响应和稳定运行的技术问题,可以通过控制器的主逻辑运算,实现空压机的上电、运行、启动、加载、卸载5种运行状态模式；该控制器使用PID控制,可以实现设备在运行过程中具有调节速度快、控制精度高的优点,同时针对连续用气和间断用气两种不同的使用模式,及时的调节柴油机转速以稳定气体压力；同时压缩机进气阀控制、涡轮增压和高压共轨油喷技术使得系统更加节能环保。(The invention discloses a control method of a novel diesel-driven screw type air compressor controller, which belongs to the technical field of air compressors and comprises the steps of establishing a controller, wherein the controller comprises a main control unit, an analog quantity acquisition unit, a switching value unit, a 485 communication unit, a man-machine interaction interface and a CAN communication unit, the technical problems of quick response and stable operation of the air compressor are solved, and 5 operation state modes of electrifying, operation, starting, loading and unloading of the air compressor CAN be realized through main logic operation of the controller; the controller uses PID control, can realize that the equipment has the advantages of high regulation speed and high control precision in the operation process, and can timely regulate the rotating speed of the diesel engine to stabilize the gas pressure aiming at two different use modes of continuous gas use and intermittent gas use; meanwhile, the system is more energy-saving and environment-friendly due to the compressor air inlet valve control, turbocharging and high-pressure common rail oil injection technologies.)

1. A control method of a novel diesel-driven screw type air compressor controller is characterized by comprising the following steps: the method comprises the following steps:

step 1: establishing a controller, wherein the controller comprises a main control unit, an analog quantity acquisition unit, a switching value unit, a 485 communication unit, a man-machine interaction interface and a CAN communication unit, and the analog quantity acquisition unit, the switching value unit, the 485 communication unit, the man-machine interaction interface and the CAN communication unit are all electrically connected with the main control unit;

the main control unit is communicated with an electronic control unit ECU of the diesel engine in real time through a CAN communication unit;

the analog quantity acquisition unit comprises an operational amplifier and an analog quantity interface, and the analog quantity interface is connected with an external sensor; the operational amplifier amplifies the signal of the analog quantity interface and inputs the amplified signal into an AD interface of the analog quantity acquisition unit;

the switching value unit comprises a relay unit and a photoelectric coupler unit, the relay unit is used for outputting an opening signal, and the photoelectric coupler unit is used for inputting an opening signal;

step 2: after power-on, the controller enters initialization, and the method comprises the following steps:

step S1: the main control unit reads parameter settings input by the human-computer interaction interface and stores prefabricated parameters input by a user through the human-computer interaction interface;

step S2: the main control unit reads the external sensor information read by the analog quantity acquisition unit, wherein the external sensor information comprises an air supply pressure value, an exhaust temperature value and a fuel oil quantity value;

step S3: the main control unit judges whether the oil level is normal or not according to the fuel flow oil quantity value: if yes, go to step S4; otherwise, go to step S2;

step S4: the main control unit sends a communication handshake signal with an electronic control unit ECU of the diesel engine through a CAN bus, and waits for a feedback signal of the electronic control unit ECU of the diesel engine: if the feedback signal exists, the initialization is finished, and the step 3 is executed; if no feedback signal exists, continuing to wait;

and step 3: the main control unit reads the actual rotating speed, oil pressure, oil consumption, water temperature, battery pack voltage and fault information of the diesel engine through the CAN bus;

and 4, step 4: the main control unit sends a preheating starting instruction to the electronic control unit ECU, the electronic control unit ECU controls the diesel engine to enter preheating starting according to the preheating starting instruction until the diesel engine enters an idling state, the preheating starting instruction comprises that an air inlet valve of an air compressor is closed when the diesel engine is started, the diesel engine runs at a low speed to preheat, the air inlet valve is fully opened after preheating, the controller sends a target rotating speed control instruction to increase the rotating speed of the diesel engine, meanwhile, the controller monitors the air pressure in the air tank through data transmitted by an air pressure sensor, and when the air pressure reaches a set air pressure value, the diesel engine stops increasing the speed;

and 5: the main control unit controls the operation of the diesel engine according to a PID control flow, and adjusts the rotating speed of the diesel engine in time to stabilize the gas pressure aiming at two different use modes of continuous gas use and intermittent gas use; meanwhile, the operation of the diesel engine is controlled by adopting the compressor air inlet valve control, turbocharging and high-pressure common rail oil injection technologies;

step 6: the main control unit monitors whether new information transmitted by a human-computer interaction interface is received in real time: if yes, executing step 7; if not, executing the step 5;

and 7: the main control unit controls the operation mode of the diesel engine according to information transmitted by the human-computer interaction interface, wherein the information transmitted by the human-computer interaction interface comprises a plurality of working mode selections, and the working mode selections comprise an intermittent operation mode and a continuous operation mode; when the continuous operation mode is normal continuous gas utilization, the air inlet valve is fully opened; the controller can adjust the air pressure in the air tank by adjusting the rotating speed of the diesel engine so as to enable the air pressure in the air tank to be stabilized at an air pressure set value, and the target rotating speed is adjusted at any time along with the air consumption;

when the intermittent operation mode is intermittent gas use, if the gas pressure in the gas tank exceeds a gas pressure set value, the controller adjusts and reduces the rotating speed of the diesel engine to reduce the gas pressure in the gas tank, and the rotating speed of the diesel engine can be reduced to an idle speed; simultaneously, the opening of the air inlet valve is reduced through the air path until the air pressure in the air tank reaches an air pressure set value;

and 8: the main control unit monitors whether the man-machine interaction interface transmits a back-off signal in real time: if yes, executing step 9; if not, executing the step 5;

and step 9: the main control unit sends a shutdown instruction to the electronic control unit ECU.

2. The control method of the novel diesel screw type air compressor controller as claimed in claim 1, characterized in that: the main control unit is an STM32F429 control chip, the 485 communication unit is an RS485 communication chip and a peripheral circuit thereof, the human-computer interaction interface is a touch screen, and the CAN communication unit is an SAE1939CAN bus communication chip and a peripheral circuit thereof.

3. The control method of the novel diesel screw type air compressor controller as claimed in claim 1, characterized in that: the starting signal output by the relay unit comprises stopping, starting, loading and discharging, and the starting signal element connected with the photoelectric coupler unit comprises an emergency stop button, a loading signal knob, a high-voltage signal knob, a stopping signal knob, a starting signal knob and an auxiliary starting button.

4. The control method of the novel diesel screw type air compressor controller as claimed in claim 1, characterized in that: the external sensor comprises a gas pressure sensor, a temperature sensor and a fuel tank liquid level sensor.

Technical Field

The invention belongs to the technical field of air compressors, and particularly relates to a control method of a novel diesel screw type air compressor controller.

Background

According to the difference of the internal design structure of the air compressor, the air compressors on the market at present are mainly divided into screw type air compressors, piston type air compressors, centrifugal type air compressors and the like. The centrifugal air compressor is mainly applied to occasions with large gas consumption, and is rarely applied by general enterprises. The piston type air compressor has low equipment investment, is adopted by many enterprises in the past, but has poor gas production efficiency and is gradually replaced by a screw type air compressor.

The movable air compressor is mainly applied to places without commercial power supply, such as the field; in the places with larger construction load, such as rock drilling, mining, open circuit and the like, a high-power diesel-driven mobile air compressor is generally required.

For a mobile screw type air compressor using a national standard second-stage non-road diesel engine, when the air compressor is started, the pneumatic control system enables the air inlet valve to be in an open state, so that the compressor has a larger load when being started, and the requirement for larger power output of a diesel engine is provided.

The diesel engine in the starting state drives a large load to operate, and the operating mode is easy to cause the engine to break down to cause flameout. The system design defect can be highlighted under the working conditions that the starting performance of a diesel engine selected by the equipment is not high or the diesel engine is started at low temperature, so that the normal operation of the equipment is influenced.

Disclosure of Invention

The invention aims to provide a control method of a novel diesel-driven screw type air compressor controller, which solves the technical problems of quick response and stable operation of an air compressor.

In order to achieve the purpose, the invention adopts the following technical scheme:

a control method of a novel diesel-driven screw type air compressor controller comprises the following steps:

step 1: establishing a controller, wherein the controller comprises a main control unit, an analog quantity acquisition unit, a switching value unit, a 485 communication unit, a man-machine interaction interface and a CAN communication unit, and the analog quantity acquisition unit, the switching value unit, the 485 communication unit, the man-machine interaction interface and the CAN communication unit are all electrically connected with the main control unit;

the main control unit is communicated with an electronic control unit ECU of the diesel engine in real time through a CAN communication unit;

the analog quantity acquisition unit comprises an operational amplifier and an analog quantity interface, and the analog quantity interface is connected with an external sensor; the operational amplifier amplifies the signal of the analog quantity interface and inputs the amplified signal into an AD interface of the analog quantity acquisition unit;

the switching value unit comprises a relay unit and a photoelectric coupler unit, the relay unit is used for outputting an opening signal, and the photoelectric coupler unit is used for inputting an opening signal;

step 2: after power-on, the controller enters initialization, and the method comprises the following steps:

step S1: the main control unit reads parameter settings input by the human-computer interaction interface and stores prefabricated parameters input by a user through the human-computer interaction interface;

step S2: the main control unit reads the external sensor information read by the analog quantity acquisition unit, wherein the external sensor information comprises an air supply pressure value, an exhaust temperature value and a fuel oil quantity value;

step S3: the main control unit judges whether the oil level is normal or not according to the fuel flow oil quantity value: if yes, go to step S4; otherwise, go to step S2;

step S4: the main control unit sends a communication handshake signal with an electronic control unit ECU of the diesel engine through a CAN bus, and waits for a feedback signal of the electronic control unit ECU of the diesel engine: if the feedback signal exists, the initialization is finished, and the step 3 is executed; if no feedback signal exists, continuing to wait;

and step 3: the main control unit reads the actual rotating speed, oil pressure, oil consumption, water temperature, battery pack voltage and fault information of the diesel engine through the CAN bus;

and 4, step 4: the main control unit sends a preheating starting instruction to the electronic control unit ECU, the electronic control unit ECU controls the diesel engine to enter preheating starting according to the preheating starting instruction until the diesel engine enters an idling state, the preheating starting instruction comprises that an air inlet valve of an air compressor is closed when the diesel engine is started, the diesel engine runs at a low speed to preheat, the air inlet valve is fully opened after preheating, the controller sends a target rotating speed control instruction to increase the rotating speed of the diesel engine, meanwhile, the controller monitors the air pressure in the air tank through data transmitted by an air pressure sensor, and when the air pressure reaches a set air pressure value, the diesel engine stops increasing the speed;

and 5: the main control unit controls the operation of the diesel engine according to a PID control flow, and adjusts the rotating speed of the diesel engine in time to stabilize the gas pressure aiming at two different use modes of continuous gas use and intermittent gas use; meanwhile, the operation of the diesel engine is controlled by adopting the compressor air inlet valve control, turbocharging and high-pressure common rail oil injection technologies;

step 6: the main control unit monitors whether new information transmitted by a human-computer interaction interface is received in real time: if yes, executing step 7; if not, executing the step 5;

and 7: the main control unit controls the operation mode of the diesel engine according to information transmitted by the human-computer interaction interface, wherein the information transmitted by the human-computer interaction interface comprises a plurality of working mode selections, and the working mode selections comprise an intermittent operation mode and a continuous operation mode; when the continuous operation mode is normal continuous gas utilization, the air inlet valve is fully opened; the controller can adjust the air pressure in the air tank by adjusting the rotating speed of the diesel engine so as to enable the air pressure in the air tank to be stabilized at an air pressure set value, and the target rotating speed is adjusted at any time along with the air consumption;

when the intermittent operation mode is intermittent gas use, if the gas pressure in the gas tank exceeds a gas pressure set value, the controller adjusts and reduces the rotating speed of the diesel engine to reduce the gas pressure in the gas tank, and the rotating speed of the diesel engine can be reduced to an idle speed; simultaneously, the opening of the air inlet valve is reduced through the air path until the air pressure in the air tank reaches an air pressure set value;

and 8: the main control unit monitors whether the man-machine interaction interface transmits a back-off signal in real time: if yes, executing step 9; if not, executing the step 5;

and step 9: the main control unit sends a shutdown instruction to the electronic control unit ECU.

Preferably, the main control unit is an STM32F429 control chip, the 485 communication unit is an RS485 communication chip and a peripheral circuit thereof, the human-computer interaction interface is a touch screen, and the CAN communication unit is an SAE1939CAN bus communication chip and a peripheral circuit thereof.

Preferably, the open-out signal output by the relay unit comprises stop, start, load and unload, and the open-in signal element connected with the photoelectric coupler unit comprises an emergency stop button, a load signal knob, a high-voltage signal knob, a stop signal knob, a start signal knob and an auxiliary start button.

Preferably, the external sensors include a gas pressure sensor, a temperature sensor and a tank level sensor.

The control method of the novel diesel-driven screw type air compressor controller solves the technical problems of quick response and stable operation of the air compressor, and can realize 5 operation state modes of electrifying, running, starting, loading and unloading of the air compressor through the main logic operation of the controller; the controller uses PID control, can realize that the equipment has the advantages of high regulation speed and high control precision in the operation process, and can timely regulate the rotating speed of the diesel engine to stabilize the gas pressure aiming at two different use modes of continuous gas use and intermittent gas use; meanwhile, the system is more energy-saving and environment-friendly due to the compressor air inlet valve control, turbocharging and high-pressure common rail oil injection technologies.

Drawings

FIG. 1 is a system architecture diagram of the present invention;

FIG. 2 is an initialization flow diagram of the present invention;

fig. 3 is a control flow diagram of the present invention.

Detailed Description

The control method of the novel diesel screw type air compressor controller shown in fig. 1-3 comprises the following steps:

step 1: establishing a controller, wherein the controller comprises a main control unit, an analog quantity acquisition unit, a switching value unit, a 485 communication unit, a man-machine interaction interface and a CAN communication unit, and the analog quantity acquisition unit, the switching value unit, the 485 communication unit, the man-machine interaction interface and the CAN communication unit are all electrically connected with the main control unit;

the application target of the controller of the invention is a diesel engine which accords with the third stage of national standard and a screw air compressor which is connected by a transmission device; other functional aids are intake valves, charge valves, turbochargers, coolers, air-oil separators, air filters, fuel filters, oil filters, etc.

The air path control of the screw air compressor is as follows: the air inlet is provided with a turbocharger and an air inlet valve, and the air inflow is accurately controlled through the ECU module; meanwhile, the given amount of fuel oil is controlled, and the fuel oil is converted into mist by a high-pressure common rail oil injection pump and is injected into the cavity; the outlet of the screw air compressor is connected with an oil-gas separator, and lubricating oil and compressed air are separated in the device; the output of the oil-gas separator is connected with a gas tank, and compressed gas meeting a certain pressure standard is output for customers to use.

The main control unit is communicated with an electronic control unit ECU of the diesel engine in real time through a CAN communication unit;

the analog quantity acquisition unit comprises an operational amplifier and an analog quantity interface, and the analog quantity interface is connected with an external sensor; the operational amplifier amplifies the signal of the analog quantity interface and inputs the amplified signal into an AD interface of the analog quantity acquisition unit;

the switching value unit comprises a relay unit and a photoelectric coupler unit, the relay unit is used for outputting an opening signal, and the photoelectric coupler unit is used for inputting an opening signal;

the chip of the main control unit adopts STM32F429 series chips of ST, can process complex logic operation and meet the requirement of an LCD module with multiple output ports; meanwhile, the minimum system is also provided with a DDR memory and a Flash memory, so that data can be cached, the processing speed is increased, and the processed data is stored; SWD is used to debug and download program code.

The controller realizes 5 running state modes of powering on, running, starting, loading and unloading the air compressor through main logic operation;

the power supply module adopts a switching power supply technology and outputs +5V voltage to supply power for the digital signal; meanwhile, the requirements of a plurality of power supply signals of +9.3V \ 10.6V \ 16V \ 7.5V and the like required by the LCD are met; and common mode protection and pressure-sensitive protection are added simultaneously, so that harmonic waves are eliminated, and meanwhile, a device is protected from being damaged by high voltage.

The communication module is divided into an SAE1939CAN bus communication module and an RS485 communication module, CAN realize main signal transmission of the system, is communicated with an ECU of a diesel engine through a CAN bus technology, and CAN transmit more important information such as rotating speed, oil pressure, oil consumption, water temperature, battery pack voltage, various fault information and the like. The function of the Internet of things can be realized through the RS485 module, real-time control and monitoring equipment operation of the computer end and the mobile phone end are realized, and subsequent services are provided.

The sensor module mainly comprises a gas pressure sensor, a temperature sensor and a liquid level sensor; the air pressure sensor is converted into a current signal of 4mA-20mA through an acquired signal, and the air temperature sensor and the oil level sensor are converted into unequal resistance signals through the acquired signal; the voltage signal with proper range is processed through filtering and operational amplification in the controller and transmitted to the control chip for corresponding processing.

The man-machine interaction module comprises two parts of contents, namely a liquid crystal display screen processing module and a touch screen processing module; the liquid crystal display screen displays real-time rotating speed signals and oil pressure, oil consumption, water temperature, battery pack voltage and various fault information of the diesel engine, and displays the air pressure in the air tank acquired by the air pressure sensor, the air temperature in the air tank acquired by the air temperature sensor and the oil level of an oil tank in the diesel engine acquired by the oil level sensor; the client can input operation information such as an air pressure set value and the like through a touch screen or a key; meanwhile, the operation configuration information can be input to realize personalized operation.

The input/output port adopts an isolation protection circuit, so that the common-mode voltage and the differential-mode voltage of the circuit board are well protected while effective input and output of signals are realized; the input port adopts an optical coupling isolation device, so that the effect of isolation protection can be well played; the output port adopts a relay device, so that the integrity and the idealization of output signals are effectively guaranteed.

Step 2: after power-on, the controller enters initialization, and the method comprises the following steps:

step S1: the main control unit reads parameter settings input by the human-computer interaction interface and stores prefabricated parameters input by a user through the human-computer interaction interface;

step S2: the main control unit reads the external sensor information read by the analog quantity acquisition unit, wherein the external sensor information comprises an air supply pressure value, an exhaust temperature value and a fuel oil quantity value;

step S3: the main control unit judges whether the oil level is normal or not according to the fuel flow oil quantity value: if yes, go to step S4; otherwise, go to step S2;

step S4: the main control unit sends a communication handshake signal with an electronic control unit ECU of the diesel engine through a CAN bus, and waits for a feedback signal of the electronic control unit ECU of the diesel engine: if the feedback signal exists, the initialization is finished, and the step 3 is executed; if no feedback signal exists, continuing to wait;

and step 3: the main control unit reads the actual rotating speed, oil pressure, oil consumption, water temperature, battery pack voltage and fault information of the diesel engine through the CAN bus;

and 4, step 4: the main control unit sends a preheating starting instruction to the electronic control unit ECU, the electronic control unit ECU controls the diesel engine to enter preheating starting according to the preheating starting instruction until the diesel engine enters an idling state, the preheating starting instruction comprises that an air inlet valve of an air compressor is closed when the diesel engine is started, the diesel engine runs at a low speed to preheat, the air inlet valve is fully opened after preheating, the controller sends a target rotating speed control instruction to increase the rotating speed of the diesel engine, meanwhile, the controller monitors the air pressure in the air tank through data transmitted by an air pressure sensor, and when the air pressure reaches a set air pressure value, the diesel engine stops increasing the speed;

the air inlet valve is closed during starting through preheating starting, so that the starting load of the diesel engine is reduced, and the phenomenon of starting and flameout is thoroughly solved;

and 5: the main control unit controls the operation of the diesel engine according to a PID control flow, and adjusts the rotating speed of the diesel engine in time to stabilize the gas pressure aiming at two different use modes of continuous gas use and intermittent gas use; meanwhile, the operation of the diesel engine is controlled by adopting the compressor air inlet valve control, turbocharging and high-pressure common rail oil injection technologies;

step 6: the main control unit monitors whether new information transmitted by a human-computer interaction interface is received in real time: if yes, executing step 7; if not, executing the step 5;

and 7: the main control unit controls the operation mode of the diesel engine according to information transmitted by the human-computer interaction interface, wherein the information transmitted by the human-computer interaction interface comprises a plurality of working mode selections, and the working mode selections comprise an intermittent operation mode and a continuous operation mode; when the continuous operation mode is normal continuous gas utilization, the air inlet valve is fully opened; the controller can adjust the air pressure in the air tank by adjusting the rotating speed of the diesel engine so as to enable the air pressure in the air tank to be stabilized at an air pressure set value, and the target rotating speed is adjusted at any time along with the air consumption;

when the intermittent operation mode is intermittent gas use, if the gas pressure in the gas tank exceeds a gas pressure set value, the controller adjusts and reduces the rotating speed of the diesel engine to reduce the gas pressure in the gas tank, and the rotating speed of the diesel engine can be reduced to an idle speed; simultaneously, the opening of the air inlet valve is reduced through the air path until the air pressure in the air tank reaches an air pressure set value;

under any one use mode, the main control unit can ensure that the air pressure in the air tank is stabilized within a reasonable range allowed by an air pressure set value, and at the moment, the air outlet of the screw air compressor and the air consumption of air consumption equipment are balanced, so that the purposes of energy conservation are achieved by balancing supply and demand.

In most operation periods, the controller needs to keep the balance between the air outlet of the screw air compressor and the air consumption of the air consumption equipment; the supply and demand balance can make the equipment more energy-saving, make the air pressure in the air tank stable, and protect the gas equipment connected with the air tank from being damaged less

The main control unit is communicated with the diesel engine ECU in real time through a CAN bus; the main control unit reads real-time rotating speed signals, oil pressure, oil consumption, water temperature, battery pack voltage, various fault information and the like of the diesel engine through the bus, and sends target rotating speed control instructions to the diesel engine.

The main control unit is designed through the Internet of things, and a Modbus communication protocol is used for realizing real-time control and monitoring of the machine by the computer end and the mobile phone end.

And 8: the main control unit monitors whether the man-machine interaction interface transmits a back-off signal in real time: if yes, executing step 9; if not, executing the step 5;

and step 9: the main control unit sends a shutdown instruction to the electronic control unit ECU.

Preferably, the main control unit is an STM32F429 control chip, the 485 communication unit is an RS485 communication chip and a peripheral circuit thereof, the human-computer interaction interface is a touch screen, and the CAN communication unit is an SAE1939CAN bus communication chip and a peripheral circuit thereof.

Preferably, the open-out signal output by the relay unit comprises stop, start, load and unload, and the open-in signal element connected with the photoelectric coupler unit comprises an emergency stop button, a load signal knob, a high-voltage signal knob, a stop signal knob, a start signal knob and an auxiliary start button.

Preferably, the external sensors include a gas pressure sensor, a temperature sensor and a tank level sensor.

The control method of the novel diesel-driven screw type air compressor controller solves the technical problems of quick response and stable operation of the air compressor, and can realize 5 operation state modes of electrifying, running, starting, loading and unloading of the air compressor through the main logic operation of the controller; the controller uses PID control, can realize that the equipment has the advantages of high regulation speed and high control precision in the operation process, and can timely regulate the rotating speed of the diesel engine to stabilize the gas pressure aiming at two different use modes of continuous gas use and intermittent gas use; meanwhile, the system is more energy-saving and environment-friendly due to the compressor air inlet valve control, turbocharging and high-pressure common rail oil injection technologies.