Control method and device based on low-pressure EGR system and vehicle

Abstract

The invention discloses a control method and device based on a low-pressure EGR system and a vehicle, and belongs to the technical field of vehicle control, the EGR system comprises a cooler, an electromagnetic valve, an EGR valve and a differential pressure sensor, the electromagnetic valve is arranged on a first pipeline between the cooler and the first end of the EGR valve, and the differential pressure sensor is arranged on a second pipeline between the cooler and the first end of the EGR valve; a differential pressure sensor is arranged on a second pipeline between the first end of the EGR valve and the second end of the EGR valve, and the control method comprises the steps that under the condition that an engine is started, a starting instruction of the engine for the low-pressure EGR system is obtained; under the condition that the starting instruction represents that the low-pressure EGR system is started, an electromagnetic valve is controlled to be opened, so that gas enters a differential pressure sensor through a first pipeline and a second pipeline; and under the condition that the starting instruction represents that the low-pressure EGR system is not started, the electromagnetic valve is controlled to be closed, so that gas is prevented from entering the differential pressure sensor through the first pipeline and the second pipeline. According to the scheme, the contact time of the differential pressure sensor and waste gas in the low-pressure EGR system can be shortened.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of vehicle control, and particularly relates to a control method and device based on a low-pressure EGR system and a vehicle. BACKGROUND

[0002] In order to reduce the fuel consumption of a hybrid vehicle, many vehicle manufacturers use a low-pressure exhaust gas re-circulation (EGR) technology. This technology requires exhaust gas to be taken from behind a catalyst, and the exhaust gas is cooled by a cooler and controlled by an EGR valve in sequence, and then enters an intake manifold main pipe or branch pipe to mix with fresh air and enter a cylinder for combustion, so as to achieve more sufficient combustion of in-cylinder oil-gas mixture, thereby achieving the purpose of improving the fuel consumption level. In the process of controlling the flow by using the EGR valve, a differential pressure sensor is used to detect the pressure on both sides of the EGR valve and calculate the pressure difference, and a controller controls the opening of the EGR valve according to the pressure difference, thereby controlling the flow of gas.

[0003] At present, in a hybrid vehicle, due to the increase in the number of engine start and stop, the water vapor component in the exhaust pipe is increased in proportion compared with a traditional vehicle, which causes more insufficiently combusted mixed exhaust gas to enter the low-pressure EGR system. The pressure chip element of the differential pressure sensor is directly in contact with the gas, and is subjected to the erosion of high temperature, high humidity and pollution elements for a long time, which easily causes the failure of the protective layer and the failure of the function of the differential pressure sensor. SUMMARY

[0004] Embodiments of the present application provide a control method and device based on a low-pressure EGR system and a vehicle, thereby reducing the contact time of the differential pressure sensor with the exhaust gas and improving the service life of the differential pressure sensor.

[0005] Other characteristics and advantages of the present application will become apparent from the following detailed description, or will be learned by practice of the present application.

[0006] According to a first aspect of the embodiments of the present application, a control method based on a low-pressure EGR system is provided. The low-pressure exhaust gas recirculation (EGR) system includes a cooler, an electromagnetic valve, an EGR valve, and a differential pressure sensor. The electromagnetic valve is arranged on a first pipeline between the cooler and a first end of the EGR valve. The differential pressure sensor is arranged on a second pipeline between the first end of the EGR valve and a second end of the EGR valve. The control method based on the low-pressure EGR system includes: obtaining an enabling instruction of the engine for the low-pressure EGR system in a case where the engine is started; controlling the electromagnetic valve to open, so that gas enters the differential pressure sensor through the first pipeline and the second pipeline, in a case where the enabling instruction indicates that the low-pressure EGR system is enabled; and controlling the electromagnetic valve to close, so as to block the gas from entering the differential pressure sensor through the first pipeline and the second pipeline, in a case where the enabling instruction indicates that the low-pressure EGR system is not enabled.

[0007] In some embodiments, the controlling the electromagnetic valve to open includes: determining an EGR rate of the low-pressure EGR system according to an intake demand amount of the gas; and controlling a time length for which the electromagnetic valve is opened according to the EGR rate.

[0008] In some embodiments, the controlling the time length for which the electromagnetic valve is opened according to the EGR rate includes: controlling the time length for which the electromagnetic valve is opened to be positively correlated with the EGR rate.

[0009] In some embodiments, the control method based on the low-pressure EGR system further includes: adjusting an opening degree of the EGR valve according to a temperature of a cooling liquid of the engine.

[0010] In some embodiments, the control method based on the low-pressure EGR system further includes: in a case where the differential pressure sensor is invalid, controlling the electromagnetic valve to switch between the opening and the closing at a switching frequency greater than a preset frequency, so as to clean the differential pressure sensor.

[0011] In some embodiments, the control method based on the low-pressure EGR system further includes: controlling the electromagnetic valve to switch between the opening and the closing at the switching frequency for a number of times less than or equal to a preset number of times.

[0012] In some embodiments, after the electromagnetic valve is controlled to switch between the opening and the closing at the switching frequency for the number of times less than or equal to the preset number of times, the control method based on the low-pressure EGR system further includes: in a case where the differential pressure sensor is still invalid, controlling an opening degree of the EGR valve according to a theoretical opening degree of the EGR valve output by a preset model; and in a case where the differential pressure sensor is restored to normal, controlling the opening degree of the EGR valve according to a pressure difference detected by the differential pressure sensor.

[0013] According to a second aspect of the embodiments of the present application, a control device based on a low-pressure EGR system is provided, comprising a processor and a memory, the memory storing computer program instructions capable of being executed by the processor, and the processor implements the steps of the method of any one of the above first aspect when executing the computer program instructions.

[0014] According to a third aspect of the embodiments of the present application, a computer readable storage medium is provided, the computer readable storage medium storing computer program instructions, and the computer program instructions cause a processor to implement the steps of the method of any one of the above first aspect when executed by the processor.

[0015] According to a fourth aspect of the embodiments of the present application, a vehicle is provided, comprising a low-pressure EGR system and the above control device based on the low-pressure EGR system, wherein the low-pressure EGR system comprises a cooler, an electromagnetic valve, an EGR valve and a differential pressure sensor, the electromagnetic valve is arranged on a first pipeline between the cooler and a first end of the EGR valve, and the differential pressure sensor is arranged on a second pipeline between the first end of the EGR valve and a second end of the EGR valve.

[0016] In the present application, by arranging the electromagnetic valve on the first pipeline between the cooler and the first end of the EGR valve, in the case of starting the engine, an enabling instruction of the engine for the low-pressure EGR system is obtained; in the case that the enabling instruction represents enabling the low-pressure EGR system, the electromagnetic valve is controlled to be opened, so that the gas enters the differential pressure sensor through the first pipeline and the second pipeline; in the case that the enabling instruction represents not enabling the low-pressure EGR system, the electromagnetic valve is controlled to be closed, so as to block the gas from entering the differential pressure sensor through the first pipeline and the second pipeline, which reduces the contact time of the differential pressure sensor with the exhaust gas in the low-pressure EGR system, and improves the service life of the differential pressure sensor.

[0017] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0018] The drawings incorporated in the specification and constituting a part of the specification illustrate embodiments consistent with the present application and, together with the specification, serve to explain the principles of the present application. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor. In the drawings:

[0019] Figure 1 Fig. 1 shows a structural schematic diagram of a low-pressure EGR system according to some embodiments of the present application;

[0020] Figure 2 Fig. 2 shows a structural schematic diagram of a low-pressure EGR system according to some embodiments of the present application; Figure 1 Fig. 3 shows a sectional view of a differential pressure sensor.

[0021] Figure 3 A rear view of the medium pressure difference sensor is shown. Figure 2 A rear view of the medium pressure difference sensor is shown.

[0022] Figure 4 A rear view of the medium pressure difference sensor is shown. Figure 2 A rear view of the medium pressure difference sensor is shown.

[0023] Figure 5 A flow chart of a control method of a low pressure EGR system according to some embodiments of the present application is shown.

[0024] Figure 6 A block diagram of a control device of a low pressure EGR system according to some embodiments of the present application is shown.

[0025] Figure 7 A block diagram of a control device of a low pressure EGR system according to some embodiments of the present application is shown.

[0026] Figure 8 A block diagram of a control device of a low pressure EGR system according to some embodiments of the present application is shown.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] 101 - air filter, 102 - intake manifold, 103 - supercharger, 104 - pre-stage exhaust pipe, 105 - post-stage exhaust pipe, 106 - cooler, 107 - solenoid valve, 108 - EGR valve, 109 - pressure difference sensor, 110 - temperature sensor, 201 - housing, 202 - upper cover, 203 - lower cover, 204 - pin, 205 - sealant, 206 - steel ball, 207 - PCB board, 208 - ceramic plate, 209 - pressure chip, 210 - rubber frame, and 211 - bushing. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0030] Furthermore, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. Numerous specific details are provided in the following description to give a thorough understanding of embodiments of this application. However, those skilled in the art will recognize that the technical solutions of this application can be practiced without one or more of the specific details, or other methods, components, apparatuses, steps, etc., can be employed. In other instances, well-known methods, apparatuses, implementations, or operations are not shown or described in detail to avoid obscuring various aspects of this application.

[0031] The block diagrams shown in the accompanying drawings are merely functional entities and do not necessarily correspond to physically independent entities. That is, these functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor devices and / or microcontroller devices.

[0032] The flowcharts shown in the accompanying drawings are merely illustrative and do not necessarily include all content and operations / steps, nor do they necessarily have to be performed in the described order. For example, some operations / steps can be broken down, while others can be combined or partially combined; therefore, the actual execution order may change depending on the specific circumstances.

[0033] To enable those skilled in the art to better understand this application, firstly, in conjunction with Figure 1 A brief description of the low-pressure EGR system involved in this application is provided.

[0034] Figure 1 A schematic diagram of a low-voltage EGR system according to some embodiments of this application is shown. Figure 1 As shown, the low-pressure EGR system includes an air filter 101, an intake manifold 102, a turbocharger 103, a pre-exhaust pipe 104, a post-exhaust pipe 105, a cooler 106, a solenoid valve 107, an EGR valve 108, a differential pressure sensor 109, a temperature sensor 110, and a catalytic converter (not shown). The low-pressure EGR system draws exhaust gas from after the catalytic converter. The exhaust gas is cooled by the cooler 106 and its flow is controlled by the EGR valve 108. The exhaust gas and fresh air then enter the main or branch pipe of the intake manifold 102 via the turbocharger 103 before entering the cylinder for combustion. This achieves more complete combustion of the air-fuel mixture, thereby improving fuel efficiency. During the flow control process using the EGR valve, the differential pressure sensor detects the pressure across the EGR valve and calculates the pressure difference. The controller then controls the opening of the EGR valve based on this pressure difference, thus controlling the gas flow rate.

[0035] Figure 2 It shows Figure 1 Cross-sectional view of a differential pressure sensor. Figure 3 It showsFigure 2 A rear view of the medium pressure difference sensor, Figure 4 It is shown Figure 2 A schematic diagram of the airflow direction of the medium pressure difference sensor in operation. In combination with Figure 2 、 Figure 3 and Figure 4 , the pressure difference sensor includes a shell 201, an upper cover 202, a lower cover 203, a pin 204, a sealing glue 205, a steel ball 206, a PCB board 207, a ceramic plate 208, a pressure chip 209, a glue frame 210, and a bushing 211, etc. The pressure difference sensor has two pipeline joints, which are connected to the two ends of the EGR valve respectively, to monitor the pressures at the two ends of the EGR valve, and to support the control requirements of the controller through the pressure difference between the two ends. The high-temperature exhaust gas enters the pressure difference sensor through the inlet pipeline joint of the pressure difference sensor, passes through the protective gel and contacts the pressure chip element, to realize the monitoring and control of the exhaust gas pressure. The pressure chip element is directly in contact with the gas and is subjected to the erosion of high temperature, high humidity and pollution elements for a long time, which can easily cause the failure of the protective layer and the failure of the function.

[0036] In the embodiments of the present application, an electromagnetic valve is added on the first pipeline between the cooler and the first end of the EGR valve, and the protective layer of the pressure chip in the pressure sensor is prevented from being excessively subjected to erosion and corrosion by controlling the opening and closing of the electromagnetic valve. Specifically, in the case where the low-pressure EGR system is not started, the electromagnetic valve is controlled to be closed to block the gas from entering the pressure difference sensor through the first pipeline and the second pipeline, thereby preventing the high-temperature and high-humidity exhaust gas from entering the pressure difference sensor and contacting the protective layer of the pressure chip element of the pressure difference sensor when the engine is frequently started, and avoiding the protective layer of the pressure chip element from being subjected to unnecessary gas erosion and corrosion; and in the case where the low-pressure EGR system is started, the electromagnetic valve is controlled to be opened, so that the EGR valve and the pressure difference sensor can feedback according to the control requirements of the controller, to ensure the normal operation of the low-pressure EGR system. Through the above design, the contact time of the pressure difference sensor and the exhaust gas in the low-pressure EGR system can be reduced, and the service life of the pressure difference sensor can be improved.

[0037] Figure 5 A flowchart of a control method based on a low-pressure EGR system according to some embodiments of the present application is shown. The low-pressure exhaust gas recirculation EGR system includes a cooler, an electromagnetic valve, an EGR valve, and a pressure difference sensor, and the electromagnetic valve is arranged on the first pipeline between the cooler and the first end of the EGR valve, and the pressure difference sensor is arranged on the second pipeline between the first end of the EGR valve and the second end of the EGR valve. As Figure 5 shown, a control method based on a low-pressure EGR system is provided, which can be applied to an electronic control unit (ECU) of an engine, and the method can include the following steps:

[0038] Step 501, in the case of engine starting, obtaining an engine enabling instruction for the low-pressure EGR system;

[0039] Step 502, in the case of the enabling instruction representing enabling the low-pressure EGR system, controlling the electromagnetic valve to open, so that the gas enters the differential pressure sensor through the first pipeline and the second pipeline;

[0040] Step 503, in the case of the enabling instruction representing not enabling the low-pressure EGR system, controlling the electromagnetic valve to close, so as to block the gas from entering the differential pressure sensor through the first pipeline and the second pipeline.

[0041] It can be understood that the ECU can monitor the engine enabling instruction for the low-pressure EGR system when the engine starts, and the enabling instruction includes an instruction representing enabling the low-pressure EGR system and an instruction representing not enabling the low-pressure EGR system.

[0042] If the engine requires not to enable the low-pressure EGR system, the ECU can not control the electromagnetic valve, so that the electromagnetic valve is in a closed state, and if the electromagnetic valve is open, the ECU can also control the electromagnetic valve to close, thereby blocking the high-temperature and high-humidity exhaust gas (hereinafter collectively referred to as gas) from entering the EGR valve and the second pipeline, avoiding the gas from contacting the protective layer of the pressure chip after entering the differential pressure sensor, and corroding the pressure chip, thereby prolonging the service life of the differential pressure sensor.

[0043] If the engine requires to enable the low-pressure EGR system, the ECU can control the electromagnetic valve to open, so that the electromagnetic valve is in an open state, so that the gas can enter the EGR valve and the second pipeline, and the ECU can control the opening degree of the EGR valve according to the pressure difference detected by the differential pressure sensor, so as to realize the regulation of the gas flow, and then ensure that the gas is fully burned after entering the cylinder, thereby improving the power economy of the engine.

[0044] In some embodiments, controlling the electromagnetic valve to open can include: determining an EGR rate of the low-pressure EGR system according to the intake demand amount of the gas; and controlling the opening duration of the electromagnetic valve according to the EGR rate.

[0045] In the implementation process, the relationship between the intake demand amount of the gas and the EGR rate of the low-pressure EGR system can be calibrated in advance, and a mapping table is obtained and stored in the ECU. In the use process, the ECU can find the corresponding EGR rate in the mapping table according to the intake demand amount of the gas at the current time, and determine the found EGR rate as the EGR rate of the low-pressure EGR system, and then control the opening duration of the electromagnetic valve according to the EGR rate of the low-pressure EGR system, so as to avoid excessive gas from corroding the protective layer of the pressure chip of the differential pressure sensor.

[0046] In some embodiments, the ECU can control the duration of the opening of the electromagnetic valve to be positively correlated with the EGR rate, for example, if the EGR rate is large, the ECU controls the electromagnetic valve to open for a longer duration, and if the EGR rate is small, the ECU controls the electromagnetic valve to open for a shorter duration.

[0047] In some embodiments, the ECU can adjust the opening of the EGR valve according to the temperature of the engine coolant after controlling the electromagnetic valve to open.

[0048] It can be understood that the temperature of the engine coolant refers to the temperature of the coolant in the cooling circuit of the engine. When the temperature of the coolant is low, the EGR valve is closed or has a very small opening to avoid engine stall due to low combustion efficiency. During the process of the temperature of the coolant rising, the stability of combustion is improved, and the opening of the EGR valve gradually increases with the temperature rising to introduce more gas. After the temperature of the coolant rises to a certain temperature, the opening of the EGR valve can be forcibly reduced to avoid the gas at high temperature aggravating overheating, and the ECU prioritizes protecting the engine.

[0049] In the implementation process, the ECU can also adjust the opening of the EGR valve in combination with the temperature of the coolant, self-checking humidity sensor data, etc. to increase the control accuracy of the opening of the EGR valve.

[0050] In some embodiments, the ECU can also control the electromagnetic valve to switch between opening and closing at a switching frequency greater than the preset frequency to clean the differential pressure sensor in the case of failure of the differential pressure sensor.

[0051] It can be understood that the ECU can determine whether the differential pressure sensor is failed by monitoring the pressure difference output by the differential pressure sensor. For example, if the pressure difference suddenly changes or drifts, it indicates that the differential pressure sensor is failed.

[0052] By controlling the electromagnetic valve to switch between opening and closing at a high switching frequency, the airflow in the first pipeline can be increased, and then the airflow can be used to flush and clean the first pipeline, the second pipeline, and the differential pressure sensor to clean the surface deposits of the differential pressure sensor and attempt to restore the differential pressure sensor.

[0053] In some embodiments, the ECU can also control the electromagnetic valve to switch between opening and closing at a switching frequency for a number of times less than or equal to a preset number of times.

[0054] In the implementation process, the preset number of times can be about 3 times, and the number of times of controlling the electromagnetic valve to switch between opening and closing at the above-mentioned switching frequency is less than or equal to the preset number of times, that is, the number of times of allowing the differential pressure sensor to be flushed is less than or equal to the preset number of times.

[0055] Understandably, when the number of flushing cycles of the differential pressure sensor exceeds the preset number, flushing is not very effective in restoring the differential pressure sensor. Controlling the number of flushing cycles of the differential pressure sensor can avoid ineffective flushing and improve the lifespan of the solenoid valve.

[0056] In some embodiments, the ECU can also control the opening of the EGR valve according to the theoretical opening of the EGR valve output by the preset model if the differential pressure sensor still fails after the number of times the control solenoid valve switches between opening and closing at a switching frequency is less than or equal to a preset number; and control the opening of the EGR valve according to the pressure difference detected by the differential pressure sensor if the differential pressure sensor returns to normal.

[0057] Understandably, if the differential pressure sensor still fails after flushing, it will not be able to output the correct pressure difference. In this case, the opening of the EGR valve can be controlled according to the theoretical opening of the EGR valve output by the preset model.

[0058] In the implementation process, a model for estimating the opening degree of the EGR valve can be established in advance. This model can estimate the theoretical opening degree of the EGR valve based on the EGR rate. If the differential pressure sensor still fails, the opening degree of the EGR valve can be controlled by the theoretical opening degree of the EGR valve output by the model instead of using the differential pressure to control the opening degree of the EGR valve.

[0059] If the differential pressure sensor returns to normal after flushing, it can output the correct pressure difference. At this time, the opening of the EGR valve can be controlled according to the pressure difference output by the differential pressure sensor.

[0060] If the differential pressure sensor fails after multiple driving cycles, the low-pressure EGR system should be disabled during implementation.

[0061] In the aforementioned control method based on a low-pressure EGR system, a solenoid valve is installed on the first pipeline between the cooler and the first end of the EGR valve. When the engine is started, an activation command for the low-pressure EGR system is obtained from the engine. When the activation command indicates that the low-pressure EGR system is activated, the solenoid valve is opened to allow gas to enter the differential pressure sensor through the first and second pipelines. When the activation command indicates that the low-pressure EGR system is not activated, the solenoid valve is closed to block gas from entering the differential pressure sensor through the first and second pipelines. This reduces the contact time between the differential pressure sensor and the exhaust gas in the low-pressure EGR system, thereby improving the service life of the differential pressure sensor.

[0062] The device embodiments of the present application are introduced below, which can be used to execute the control method based on the low-pressure EGR system in the above-mentioned embodiments of the present application. For details not disclosed in the device embodiments of the present application, please refer to the above-mentioned embodiments of the control method based on the low-pressure EGR system.

[0063] Figure 6 A block diagram of the control device based on the low-pressure EGR system according to some embodiments of the present application is shown. The low-pressure exhaust gas recirculation EGR system comprises a cooler, an electromagnetic valve, an EGR valve and a differential pressure sensor, the electromagnetic valve is arranged on a first pipeline between the cooler and a first end of the EGR valve, and the differential pressure sensor is arranged on a second pipeline between the first end of the EGR valve and a second end of the EGR valve, as shown in Figure 6 The control device based on the low-pressure EGR system according to the embodiments of the present application comprises an engine monitoring module 601, an electromagnetic valve opening module 602 and an electromagnetic valve closing module 603, wherein the engine monitoring module 601 is configured to acquire an enabling instruction of the engine for the low-pressure EGR system in the case of engine starting; the electromagnetic valve opening module 602 is configured to control the electromagnetic valve to open in the case that the enabling instruction represents enabling the low-pressure EGR system, so that the gas enters the differential pressure sensor through the first pipeline and the second pipeline; and the electromagnetic valve closing module 603 is configured to control the electromagnetic valve to close in the case that the enabling instruction represents not enabling the low-pressure EGR system, so as to block the gas from entering the differential pressure sensor through the first pipeline and the second pipeline.

[0064] In some embodiments, based on the foregoing scheme, the electromagnetic valve opening module 602 can be further configured to determine an EGR rate of the low-pressure EGR system according to the intake demand amount of the gas; and control the time length of the electromagnetic valve opening according to the EGR rate.

[0065] In some embodiments, based on the foregoing scheme, the electromagnetic valve opening module 602 can be further configured to control the time length of the electromagnetic valve opening to be positively correlated with the EGR rate.

[0066] In some embodiments, based on the foregoing scheme, the electromagnetic valve opening module 602 can be further configured to adjust the opening degree of the EGR valve according to the temperature of the coolant of the engine.

[0067] In some embodiments, based on the foregoing scheme, the control device based on the low-pressure EGR system can further comprise a sensor cleaning module (not shown in the figure), configured to control the electromagnetic valve to switch between opening and closing at a switching frequency greater than a preset frequency in the case that the differential pressure sensor fails, so as to clean the differential pressure sensor.

[0068] In some embodiments, based on the foregoing scheme, the sensor cleaning module can be further configured to control the electromagnetic valve to switch between opening and closing at the switching frequency for a number of times less than or equal to a preset number of times.

[0069] In some embodiments, based on the foregoing scheme, the sensor cleaning module can also be used to control the opening degree of the EGR valve according to the theoretical opening degree of the EGR valve output by the preset model in the case that the differential pressure sensor is still invalid; and control the opening degree of the EGR valve according to the pressure difference detected by the differential pressure sensor in the case that the differential pressure sensor is normal.

[0070] Based on the same inventive concept, the embodiments of the present application also provide a control device based on a low-pressure EGR system, which is used for Figure 7 , a structural schematic diagram of the control device based on the low-pressure EGR system in the embodiments of the present application is shown, the control device based on the low-pressure EGR system comprises one or more memories 704, one or more processors 702, and at least one computer program (computer program instructions) stored in the memory 704 and executable on the processor 702, and the processor 702 implements the method as described above when executing the computer program.

[0071] In the foregoing method, Figure 7 , the bus architecture (represented by the bus 700), the bus 700 can include any number of interconnected buses and bridges, and the bus 700 links various circuits including one or more processors represented by the processor 702 and the memory represented by the memory 704. The bus 700 can also link various other circuits such as peripheral devices, voltage stabilizers, and power management circuits, which are well known in the art, and thus, they will not be further described herein. The bus interface 705 provides an interface between the bus 700 and the receiver 701 and the transmitter 703. The receiver 701 and the transmitter 703 can be the same element, i.e., a transceiver, which provides a unit for communicating with various other devices on a transmission medium. The processor 702 is responsible for managing the bus 700 and general processing, while the memory 704 can be used to store data used by the processor 702 in performing operations.

[0072] Based on the same inventive concept, the embodiments of the present application provide a computer readable storage medium, the computer readable storage medium stores computer program instructions, and the computer program instructions are executed by a processor to cause the processor to implement the steps of the method as described above.

[0073] Based on the same inventive concept, the embodiments of the present application provide a computer program product, comprising a computer program, and the computer program product is executed by a processor to cause the processor to implement the steps of the method as described above.

[0074] Based on the same inventive concept, the embodiments of the present application provide a vehicle, Figure 8 , a structural schematic diagram of a vehicle according to some embodiments of the present application is shown. As Figure 8As shown, the vehicle comprises a low-pressure EGR system 801 and the above-mentioned control device based on the low-pressure EGR system 802, wherein the low-pressure EGR system 802 comprises a cooler, an electromagnetic valve, an EGR valve and a differential pressure sensor, the electromagnetic valve is arranged on a first pipeline between the cooler and a first end of the EGR valve, and the differential pressure sensor is arranged on a second pipeline between the first end of the EGR valve and a second end of the EGR valve.

[0075] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored on or transferred over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions can also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as technology evolves, the underlying functions and logic can be implemented by equivalent equivalents.

[0076] In several embodiments provided in the present application, it should be understood that the disclosed technology can be implemented in other ways. Among them, the above-mentioned device embodiments are only schematic, for example, the division of the units can be a logical function division, and actual implementation can have another division mode, for example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point, the coupling or direct coupling or communication connection between the displayed or discussed each other can be through some interface, indirect coupling or communication connection between units or modules, which can be electrical or other forms.

[0077] The units described as separate components can or can not be physically separated, and the components of the control device can or can not be physical units, that is, they can be located in one place, or they can be distributed on multiple units. According to actual needs, some or all of the units can be selected to achieve the purpose of the embodiment scheme.

[0078] The integrated unit, if implemented in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application essentially or say the part that contributes to the prior art or the whole or part of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium, including a plurality of instructions to make a computer device (which can be a personal computer, a server or a network device, etc.) execute all or part of the steps of the method described in various embodiments of the present application. The aforementioned storage medium includes: a U disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a mobile hard disk, a magnetic disk or an optical disk and various computer program instruction storage media.

[0079] The above only describes the embodiments of the present application and is not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the scope of the claims of the present application.

Claims

1. A control method based on a low-voltage EGR system, characterized in that, The low-pressure exhaust gas recirculation (EGR) system includes: a cooler, a solenoid valve, an EGR valve, and a differential pressure sensor. The solenoid valve is installed on a first pipeline between the cooler and a first end of the EGR valve, and the differential pressure sensor is installed on a second pipeline between the first end and a second end of the EGR valve. The control method includes: With the engine running, obtain the engine's activation command for the low-pressure EGR system; When the activation command indicates that the low-pressure EGR system is activated, the solenoid valve is controlled to open so that gas enters the differential pressure sensor through the first pipeline and the second pipeline; When the activation command indicates that the low-pressure EGR system is not activated, the solenoid valve is controlled to close to block the gas from entering the differential pressure sensor through the first pipeline and the second pipeline.

2. The control method based on a low-voltage EGR system according to claim 1, characterized in that, The control of opening the solenoid valve includes: The EGR rate of the low-pressure EGR system is determined based on the gas intake demand. The duration for which the solenoid valve is open is controlled based on the EGR rate.

3. The control method based on a low-voltage EGR system according to claim 2, characterized in that, The step of controlling the duration of the solenoid valve's opening based on the EGR rate includes: The duration for which the solenoid valve is open is positively correlated with the EGR rate.

4. The control method based on a low-voltage EGR system according to claim 2, characterized in that, Also includes: The opening of the EGR valve is adjusted according to the temperature of the engine coolant.

5. The control method based on a low-voltage EGR system according to any one of claims 1 to 4, characterized in that, Also includes: In the event of a failure of the differential pressure sensor, the solenoid valve is controlled to switch between opening and closing at a switching frequency greater than a preset frequency in order to clean the differential pressure sensor.

6. The control method based on a low-voltage EGR system according to claim 5, characterized in that, Also includes: The number of times the solenoid valve switches between open and closed at the switching frequency is less than or equal to a preset number.

7. The control method based on a low-voltage EGR system according to claim 6, characterized in that, After the number of times the solenoid valve switches between open and closed at the switching frequency is less than or equal to a preset number, the control method further includes: If the differential pressure sensor still fails, the opening degree of the EGR valve is controlled according to the theoretical opening degree of the EGR valve output by the preset model. When the differential pressure sensor returns to normal, the opening degree of the EGR valve is controlled according to the pressure difference detected by the differential pressure sensor.

8. A control device based on a low-voltage EGR system, comprising a processor and a memory, characterized in that, The memory stores computer program instructions that can be executed by the processor, and when the processor executes the computer program instructions, it implements the steps of the method as described in any one of claims 1 to 7.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer program instructions that, when executed by a processor, cause the processor to perform the steps of the method as described in any one of claims 1 to 7.

10. A vehicle, characterized in that, The invention includes a low-pressure EGR system and a control device based on the low-pressure EGR system according to claim 8, wherein the low-pressure EGR system includes: a cooler, a solenoid valve, an EGR valve and a differential pressure sensor, the solenoid valve is provided on a first pipeline between the cooler and a first end of the EGR valve, and the differential pressure sensor is provided on a second pipeline between the first end of the EGR valve and a second end of the EGR valve.

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