A fiva valve testing system and method

Abstract

The application relates to a FIVA valve testing system and method, which comprises a host computer, a lower computer control board and a lower computer; the lower computer control board comprises an Ethernet communication module, a main control module, a current output module and an acquisition module; the main control module exchanges data with the host computer through the Ethernet communication module, and transmits host computer information to the main control module through SPI communication; the main control module controls the current output module to control the FIVA valve through output pilot valve current; the acquisition module adopts serial communication to communicate data with the main control and receives FIVA valve and lower computer feedback information. Compared with the prior art, the application improves the resolution and control period of the controller, solves the problem of instability caused by high system servo oil pressure and untimely valve adjustment, improves stability and detection precision, adopts a fuzzy PID control algorithm to realize real-time adjustment of PID parameters, and has multiple test modes.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of testing of low-speed diesel engines for ships, and particularly to a FIVA valve testing system and method. BACKGROUND

[0002] With the increasing requirements of the International Maritime Organization on ship emissions, economy has become the primary requirement for diesel engines. High-pressure common rail electronically controlled fuel injection systems have gradually become the mainstream technology for current low-speed diesel engines for ships. Among them, the FIVA valve (Fuel Injection Valve Activation) is an electro-hydraulic proportional throttling type reversing valve with an electromagnetic pilot valve, which consists of a pilot valve, a main valve, and a displacement sensor. The cylinder control unit (CCU) controls the valve throughout the process, and the main valve core displacement sensor feeds back the valve core displacement signal to the CCU, which compares and then outputs a new signal to correct the stroke of the main valve core. Among them, the electromagnetic pilot valve receives the current signal from the CCU and changes the valve core opening and direction to control the flow and direction into the main valve, ultimately achieving the purpose of controlling the main valve.

[0003] Under high pressure, the FIVA valve performs high-frequency reciprocating action, so the failure rate of the valve is relatively high. In the design, the valve has very high requirements for material, precision, and gap, and it is urgent to develop a corresponding testing system and carry out regular valve testing, and the controller of the testing system is a key core component. The existing general controller: the control speed is 50 ms per cycle, the reaction is not timely when the oil pressure is high, and the stability is poor; the precision is insufficient, and the resolution is 12 bits, and the resolution of the pilot valve current is insufficient. SUMMARY

[0004] The purpose of the present application is to overcome the defects of the prior art and provide a FIVA valve testing system and method.

[0005] The purpose of the present application can be achieved by the following technical solutions:

[0006] As a first aspect of the present application, a FIVA valve testing system is provided, which comprises an upper computer, a lower computer control board, and a lower computer for detecting hydraulic oil data;

[0007] The lower computer control board comprises an Ethernet communication module, a main control module, a current output module, and an acquisition module;

[0008] The upper computer exchanges data with the main control module through the Ethernet communication module;

[0009] The acquisition module is connected with the FIVA valve and the lower computer respectively and communicates data with the main control module through serial communication, and is used for receiving feedback information of the FIVA valve and the lower computer.

[0010] The master module controls the current output module to output the pilot valve current to control the FIVA valve based on the pilot valve mode, the host computer data and the feedback signal of the acquisition module.

[0011] The master module refreshes the interval between input and output less than 5 ms, and integrates the acquisition information in multiple control cycles into a linked list and sends to the host computer.

[0012] Further, the lower computer control board is further provided with an initialization indicator light and a watchdog.

[0013] Further, the lower computer detection hydraulic oil data includes the oil pressure, temperature and flow of the hydraulic oil.

[0014] Further, the current output module adopts a 16-bit DAC856x series chip.

[0015] As a second aspect of the application, a FIVA valve testing method is provided, which adopts the testing system as described above, and comprises the following steps:

[0016] The master module checks and analyzes the data sent by the host computer after receiving the data, and clears the data linked list after sending the required data coding;

[0017] The master module identifies the mode of the pilot valve in the FIVA valve;

[0018] The master module outputs different current signals to the current output module according to different pilot valve modes;

[0019] The current output module outputs current based on the received different current signals to control the FIVA valve;

[0020] The acquisition module queries the modbus master station according to the information fed back by the FIVA valve, and analyzes the feedback current of the FIVA main valve;

[0021] The above testing steps are repeatedly cycled.

[0022] Further, the host computer and the lower computer control board are connected before the testing, and the steps comprise:

[0023] Initializing the network module;

[0024] Configuring the IP address and MAC address of the network module;

[0025] The indicator light on the lower computer control board indicates whether the initialization is normal;

[0026] If the initialization is abnormal, the watchdog is used for recovery.

[0027] Further, the check specifically is that the main control module accepts the data of specific format and byte length sent by the upper computer and carries out crc check.

[0028] Further, the mode of the pilot valve includes an automatic mode and a direct current mode.

[0029] When the pilot valve is in the automatic mode, the main control module adopts fuzzy PID operation to pilot valve control current.

[0030] When the pilot valve is not in the automatic mode, it is judged whether the pilot valve is in the direct current mode.

[0031] When the pilot valve is in the direct current mode, the pilot valve control current is equal to the set current of the upper computer.

[0032] When the pilot valve is not in the direct current mode, the pilot valve control current is first set to zero, and then the pilot valve control current is equal to the set current of the upper computer.

[0033] Further, the specific steps of adopting fuzzy PID operation to pilot valve control current include:

[0034] The error e of the reference value of the hydraulic oil pressure and the real-time collected oil pressure feedback value of the lower computer is taken as the input of PID.

[0035] The error e and the error change rate are linearly quantified and fuzzified, then fuzzy rule reasoning is carried out, and then the gravity method is adopted to carry out real-time optimization of the parameters of PID after defuzzification.

[0036] Finally, the pilot valve control current is output by PID operation.

[0037] Further, the upper computer is provided with function modes, including:

[0038] A manual mode, which manually reads FIVA valve parameters;

[0039] A tuning mode, including zero point adjustment, extreme value test, calibration rod installation test, default position test and saving function;

[0040] A function test mode, which displays the control speed of the controller and is used for reference point test, function test and leakage test.

[0041] Compared with the prior art, the present application has the following beneficial effects:

[0042] 1) Because the test system provided by the application is controlled by the hydraulic pressure feedback of the hydraulic oil to the FIVA valve. When the oil pressure is low, the control system outputs slowly, and the system can still be stably controlled. But when the oil pressure is high, the pushing force is large, and the output frequency is slow, which cannot be adjusted in time, and cannot meet the control requirements. Through testing, the cycle time is at least less than 5ms, so as to obtain timely response. The control cycle of the general input and output module on the market is 50ms or even 100ms, which cannot meet the control rate requirement. The controller of the FIVA valve in the original main engine system of the real ship outputs with a 1ms cycle, but the price is expensive, and it is not suitable for testing. The system uses STM32F4 series chip as the system main control, and the main function is refreshed once every 1ms. The output DAC module selects the DAC856x series chip with fast update frequency. And in communication, because the refresh frequency of the upper computer is slow, the lower computer controller integrates the information in multiple control cycles into a linked list and sends it to the upper computer, instead of using the synchronous mode of the upper computer and the lower computer. Through the above three ways, the main clock cycle frequency of the lower computer controller is improved, so that the control cycle reaches 1ms. The problem of slow oil pressure response is solved, and the stability is improved.

[0043] 2) The resolution of the controller is improved, and the resolution of the DAC856x series chip is higher, which improves the original 12-bit resolution to 16-bit, solving the problem of insufficient resolution of the pilot valve.

[0044] 3) The fuzzy PID control algorithm is adopted, the PID control and the fuzzy control are combined, and the self-tuning fuzzy PID algorithm is adopted to control the FIVA valve and adjust the PID parameters in real time.

[0045] 4) A variety of test modes of the FIVA valve are designed, including manual, calibration, function test and other modes, which are convenient for carrying out various test and verification work on the valve. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 It is a structure schematic view of the FIVA valve test system of the application;

[0047] Figure 2 It is an error comparison diagram between the set value and the real-time feedback value of the FIVA valve of the FIVA valve test system of the application;

[0048] Figure 3 It is a flowchart of the FIVA valve test control method of the application;

[0049] Figure 4 It is a schematic diagram of the fuzzy PID control principle of the application. DETAILED DESCRIPTION

[0050] The application will be described in detail below in combination with the drawings and specific embodiments. The embodiments are implemented on the premise of the technical solutions of the application, and detailed implementation modes and specific operation processes are given, but the protection scope of the application is not limited to the following embodiments.

[0051] Embodiment 1

[0052] As a first aspect of the application, the embodiment provides a FIVA valve test system.

[0053] As Figure 1 shown, the test system comprises an upper computer, a lower computer control board and a lower computer. The composition of the lower computer control board comprises an Ethernet communication module, a main control module, a current output module and a collection module. The Ethernet communication module is a W5500 chip. The SPI of W5500 supports a speed of 80MHz and a new efficient SPI protocol, is used for high-speed network communication, exchanges data with the upper computer through Ethernet communication, and transmits information to the main control module through SPI communication. The main control module is an STM32F4 type chip. The current output module is an isolation DAC chip, which controls the FIVA valve by outputting a pilot valve current. The collection module is a DAM-3054p, which communicates data with the main control module through 485 communication, receives the oil pressure, temperature and flow of the hydraulic oil feedback by the lower computer, and receives the feedback current of the FIVA valve, and analyzes the current.

[0054] The test system provided by the application controls the main valve by the oil pressure feedback of the hydraulic oil to the FIVA valve. Through testing, in order to meet the control requirements, the control cycle time is at least less than 5ms to obtain timely response, so the time interval of the main function of the main control module is set to be less than 5ms for refreshing input and output, and the DAC856x series chip is selected for the current output module, which has a fast update frequency. In communication, because the upper computer has a slow refresh frequency, the main control module of the lower computer integrates the information in multiple control cycles into a linked list and then sends it to the upper computer, instead of using the synchronous mode of the upper computer and the lower computer.

[0055] Preferably, the test cycle period is the same as the controller cycle output period of the FIVA valve in the original host system on the actual ship, and the main function of the main control module refreshes input and output at 1ms.

[0056] The main clock cycle frequency of the lower computer controller is improved through the above three ways, common components are used, and the control period reaches 1ms at a low cost. The problem of untimely oil pressure response of the existing general controller is solved, and the control stability is improved.

[0057] The main control module adopts fuzzy PID control to output current signals, and the coefficients of kp, ki and kd in the PID control can be adjusted according to the fuzzy rules, and the data transmitted from the upper computer can be modified in real time.

[0058] The host computer has three functional modes: manual mode, adjustment mode, and functional test mode. In manual mode, valve parameters need to be read manually. Adjustment mode includes zero-point adjustment, extreme value testing, calibration rod installation test, default position test, and save functions. It can measure hydraulic oil pressure, flow rate, and oil temperature. Functional test mode can display the controller's control speed and perform reference point testing, functional testing, and leakage testing. This facilitates various testing and verification tasks for the valve.

[0059] Example 2

[0060] As a second aspect of the present invention, as shown in the appendix Figure 3 As shown, a test control method for the FIVA valve test controller as described in the above embodiment is provided, and the steps are as follows:

[0061] Initialize the network module, configuring its IP and MAC addresses. Then observe the indicator lights on the lower-level control board. Flashing indicates normal initialization; a constantly lit indicator light indicates a program crash, requiring watchdog timer recovery. After successful initialization, the main control module receives two bytes of data in 0xcc format, performs CRC check and parsing, sends the required data encoding, and clears the data list. The main control module then identifies the pilot valve's mode and outputs different current signals to the current output module based on the mode. The current output module then outputs different currents to control the FIVA valve. The ADC sampling module queries the Modbus master station based on the information fed back from the FIVA valve, parses the main valve feedback current, and collects the hydraulic oil pressure, temperature, and flow rate fed back from the lower-level machine. This detection cycle is repeated, with a cycle time of 1ms, the same as the actual shipboard controller cycle.

[0062] The pilot valve has two modes: Auto (automatic) and Direct Current (direct current). The main control module outputs different current signals to the current output module according to the different modes. The specific output identification steps include:

[0063] First, determine if the pilot valve is in automatic mode;

[0064] When the pilot valve is in automatic mode, the main control module uses fuzzy PID calculation to control the pilot valve current based on the reference value of the hydraulic oil pressure and the actual oil pressure value fed back by the acquisition module.

[0065] If the pilot valve is not in automatic mode, determine whether the pilot valve is in direct current mode.

[0066] When the pilot valve is in direct current mode, set the pilot valve control current to be equal to the current set by the host computer.

[0067] When the pilot valve is not in the direct current mode, the pilot valve control current is first set to zero, and then the pilot valve control current is equal to the set current of the upper computer.

[0068] Figure 4 The schematic diagram of fuzzy PID control is shown, and the specific control steps include:

[0069] The error e between the reference value of the hydraulic oil pressure and the real-time collected oil pressure feedback value of the lower computer is taken as the input of the PID;

[0070] The error e and the error change rate ec are linearly quantified and fuzzified, the fuzzy rules are determined, the fuzzy rule reasoning is carried out, the gravity method is used to solve the fuzzy PID parameters, and finally the pilot valve control current is output by the PID operation. The fuzzy PID control is based on the fuzzy logic and the real-time optimization of the PID parameters according to certain fuzzy rules, which overcomes the disadvantage that the traditional PID parameters cannot be adjusted in real time.

[0071] The upper computer is provided with three test modes:

[0072] 1. The valve parameters need to be read in the manual mode.

[0073] 2. The calibration test is included in the calibration mode, and the functions include zero point adjustment, extreme value test, calibration rod installation test, default position test and saving function. The oil pressure, flow, oil temperature and zero point position of the hydraulic oil can also be measured.

[0074] 3. The control speed of the controller can be displayed in the function test mode, and three functions including reference point test, function test and leakage test are included.

[0075] The above describes the preferred embodiments of the application in detail. It should be understood that those skilled in the art can make many modifications and changes without creative labor according to the concept of the application. Therefore, any technical solution obtained by logical analysis, reasoning or limited experiment on the basis of the prior art according to the concept of the application shall be within the protection scope determined by the claims.

Claims

1. A FIVA valve testing system, characterized in that, The system includes a host computer, a slave computer control board, and a slave computer for detecting hydraulic oil data; The lower-level control board includes an Ethernet communication module, a main control module, a current output module, and a data acquisition module. The host computer exchanges data with the main control module via an Ethernet communication module; The acquisition module is connected to the FIVA valve and the lower-level machine respectively, and communicates with the main control module via serial communication to receive feedback information from the FIVA valve and the lower-level machine. The main control module, based on the pilot valve mode, host computer data and feedback signals from the acquisition module, controls the current output module to output the pilot valve current to control the FIVA valve. The main control module refreshes the input and output interval by less than 5ms and integrates the collected information from multiple control cycles into a linked list and sends it to the host computer.

2. The FIVA valve testing system according to claim 1, characterized in that, The lower-level control board is also equipped with an initialization indicator light and a watchdog timer.

3. The FIVA valve testing system according to claim 1, characterized in that, The lower-level machine detects hydraulic oil data including hydraulic oil pressure, temperature, and flow rate.

4. The FIVA valve testing system according to claim 1, characterized in that, The current output module uses a 16-bit DAC856x series chip.

5. A FIVA valve testing method, characterized in that, The method employs the testing system as described in any one of claims 1-4, and includes the following steps: After receiving data from the host computer, the main control module verifies and parses the data, and clears the data list after sending the required data encoding. The main control module identifies the mode of the pilot valve in the FIVA valve; The main control module outputs different current signals to the current output module according to different pilot valve modes; The current output module outputs current to control the FIVA valve based on the different current signals received. The acquisition module queries the Modbus master station based on the information fed back from the FIVA valve and analyzes the feedback current of the FIVA main valve. Repeat the above test steps.

6. The FIVA valve testing method according to claim 5, characterized in that, Before conducting the aforementioned test, a connection must be established between the host computer and the slave computer control board. The steps include: Initialize the network module; Configure the network module's IP address and MAC address; The indicator lights on the lower-level control board indicate whether the initialization is normal. If initialization fails, recovery is achieved via the watchdog timer.

7. The FIVA valve testing method according to claim 5, characterized in that, The verification process specifically involves the main control module receiving data of a specific format and byte length sent by the host computer and performing CRC verification.

8. The FIVA valve testing method according to claim 5, characterized in that, The pilot valve can be configured in two modes: automatic mode and direct current mode. When the pilot valve is in automatic mode, the main control module uses fuzzy PID calculation to control the pilot valve current. If the pilot valve is not in automatic mode, determine whether the pilot valve is in direct current mode. When the pilot valve is in direct current mode, set the pilot valve control current to be equal to the current set by the host computer. When the pilot valve is not in direct current mode, first set the pilot valve control current to zero, and then set the pilot valve control current to equal the current set by the host computer.

9. A FIVA valve testing method according to claim 8, characterized in that, The specific steps for controlling the current using a pilot valve with fuzzy PID calculation include: The error e between the reference value of hydraulic oil pressure and the real-time oil pressure feedback value collected by the lower-level machine is used as the input of the PID controller; The error e and the rate of change of error are linearly quantized and fuzzified; then fuzzy rule reasoning is performed; and finally, the PID parameters are optimized in real time after defuzzification using the gravity method. Finally, the PID controller outputs the pilot valve control current.

10. A FIVA valve testing method according to claim 5, characterized in that, The host computer is equipped with the following functional modes: Manual mode allows you to manually read FIVA valve parameters. The calibration modes include zero-point adjustment, extreme value testing, calibration rod installation test, default position test, and save function; Functional test mode displays the controller's control speed and is used for reference point testing, functional testing, and leakage testing.

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