Noise control method for supercharged engine of vehicle

Abstract

The present invention provides a noise control method for a vehicle's supercharged engine, applicable to a vehicle's exhaust gas turbocharged engine system. The method comprises: determining, based on status information, whether the vehicle is entering a rapid deceleration condition; if so, simultaneously performing the following operations based on the vehicle's status information: controlling the throttle to close at a preset slow closing speed; controlling the opening of the turbine's nozzle ring assembly to 100%; delaying the supercharged engine's ignition angle by a preset delay angle based on the supercharged engine's ignition angle information; and performing cylinder-by-cylinder fuel cutoff processing on the supercharged engine. Determining whether the supercharged engine meets preset turbine BPF noise generation conditions; if so, reducing the opening of the turbine's nozzle ring assembly to a preset first opening threshold corresponding to the current gear based on the current gear information. In a supercharged engine system without a pressure relief valve, this method can simultaneously control compressor surge and turbine BPF noise generation during rapid engine deceleration conditions, thereby improving the vehicle's NVH performance.

Description

Technical Field

[0001] The present invention relates to the technical field of supercharged engines, and in particular to a noise control method for a supercharged engine of a vehicle. Background Art

[0002] Modern high-performance gasoline engines in automobiles generally utilize turbocharging technology. Exhaust gas turbochargers are one of the most common turbocharging devices. They utilize high-temperature, high-pressure exhaust gas from the engine to drive the turbine in the turbocharger to rotate at high speed. This in turn drives the compressor, which is coaxial with the turbine, to rotate together, providing the engine with more combustion air, thereby improving engine performance.

[0003] During transient operation, turbocharged engines in exhaust gas turbocharged systems often struggle to avoid the inherent surge region of the turbocharger's compressor. Once the engine enters this region, not only can the turbocharger hardware be damaged, but the noise generated by the surge can also seriously impact passenger comfort. Therefore, avoiding compressor surge is a major technical challenge in the development and application of turbocharged engines.

[0004] Furthermore, with increasing engine miniaturization and power enhancement, turbocharger speeds and pressure ratios continue to rise. The turbine power and acoustic power of supercharged engines increase exponentially with the linear velocity at the impeller outlet. The high efficiency and wide flow rate of the turbine design increase the average stress on the blades, leading to an increase in turbine blade passing frequency (BPF) noise. Especially at low engine speeds, turbine BPF noise is easily perceived by the human ear, impacting the passenger experience.

[0005] To combat surge, conventional turbocharged engine systems typically incorporate a pressure relief valve (PRV) to prevent compressor surge under transient vehicle operating conditions. However, this valve presents challenges with engine layout and hardware costs, leading to ongoing research into eliminating it. However, even if surge can be mitigated through certain control measures, turbine BPF noise remains unavoidable without the PRV. Summary of the Invention

[0006] The purpose of the present invention is to solve the problem in the prior art that after the pressure relief valve is removed from the exhaust gas turbocharger engine system of the vehicle, the compressor surge and turbine BPF noise are obvious, which affects the performance of the entire vehicle and the riding experience.

[0007] To address the above-mentioned problems, embodiments of the present invention disclose a noise control method for a supercharged engine of a vehicle, applicable to an exhaust gas turbocharged engine system of the vehicle, wherein the exhaust gas turbocharged engine system includes a supercharged engine, a throttle, and a supercharger, wherein the supercharger includes a compressor and a turbine; and the noise control method includes:

[0008] S1: Obtain vehicle status information and determine whether the vehicle enters a rapid deceleration condition based on the status information;

[0009] If yes, proceed to step S2;

[0010] If not, continue to determine whether the vehicle enters a rapid deceleration condition;

[0011] S2: Perform the following operations simultaneously based on the vehicle status information:

[0012] Control the throttle valve to close at a preset slow closing speed;

[0013] The opening of the nozzle ring group of the control turbine is 100%;

[0014] Acquiring ignition angle information of the supercharged engine, and retarding the ignition angle of the supercharged engine by a preset delay angle according to the ignition angle information of the supercharged engine;

[0015] Carry out oil cut-off treatment on supercharged engines by cylinder;

[0016] S3: Obtaining vehicle speed information, current gear information, and exhaust gas turbocharger system pressure information, and determining whether the turbocharger engine meets preset turbine BPF noise generation conditions based on the vehicle status information, vehicle speed information, and exhaust gas turbocharger system pressure information;

[0017] If so, reducing the opening of the nozzle ring assembly of the turbine to a preset first opening threshold corresponding to the current gear according to the current gear information;

[0018] If not, it is further determined whether the supercharged engine meets the preset turbine BPF noise generation condition.

[0019] By adopting the above method, the compressor surge phenomenon of the exhaust gas turbocharger engine system under rapid deceleration conditions can be suppressed without setting a pressure relief valve, and the problem of turbine BPF noise can be solved at the same time, thereby improving the NVH performance of the entire vehicle.

[0020] According to another specific embodiment of the present invention, in the noise control method of the supercharged engine of a vehicle disclosed in the embodiment of the present invention, the vehicle status information includes the opening of the vehicle's accelerator pedal and the rate of change of the vehicle's accelerator pedal; and in step S2, controlling the throttle valve to close at a preset slow-closing speed includes: controlling the throttle valve to close at a preset slow-closing speed according to the comparison result of the opening of the vehicle's accelerator pedal with a preset opening threshold, and / or the comparison result of the rate of change of the vehicle's accelerator pedal with a preset rate of change threshold, until the vehicle deceleration is completed.

[0021] According to another specific embodiment of the present invention, in the noise control method of the supercharged engine of a vehicle disclosed in the embodiment of the present invention, the vehicle status information includes the opening of the vehicle's accelerator pedal and the rate of change of the vehicle's accelerator pedal; and in step S2, controlling the opening of the turbine nozzle ring group to 100% includes: controlling the opening of the turbine nozzle ring group to 100% based on the comparison result of the opening of the vehicle's accelerator pedal with a preset opening threshold, and / or the comparison result of the rate of change of the vehicle's accelerator pedal with a preset rate of change threshold, until the supercharged engine meets the preset turbine BPF noise generation condition.

[0022] According to another specific embodiment of the present invention, in the noise control method of the supercharged engine of a vehicle disclosed in the embodiment of the present invention, in step S2, the ignition angle information of the supercharged engine includes the crankshaft angle corresponding to the initial ignition angle of the supercharged engine; and delaying the ignition angle of the supercharged engine by a preset delay angle based on the ignition angle information of the supercharged engine includes: delaying the ignition angle of the supercharged engine by the preset delay angle based on the crankshaft angle corresponding to the initial ignition angle of the supercharged engine.

[0023] With the above method, since the ignition timing of the engine is determined based on the crankshaft angle, the present invention controls the ignition angle according to the crankshaft angle of the supercharged engine, thereby improving the accuracy of the ignition angle control.

[0024] According to another specific embodiment of the present invention, the noise control method of the supercharged engine of a vehicle disclosed in the embodiment of the present invention determines the ignition angle of the supercharged engine according to the following formula:

[0025] C n =C0+C Δ

[0026] Among them, C n is the ignition angle of the supercharged engine, C0 is the crankshaft angle corresponding to the initial ignition angle of the supercharged engine, C Δ is the preset delay angle.

[0027] According to another specific embodiment of the present invention, in the noise control method of the supercharged engine of a vehicle disclosed in the embodiment of the present invention, the vehicle status information includes the opening of the vehicle's accelerator pedal and the rate of change of the vehicle's accelerator pedal; the vehicle speed information includes the current vehicle speed; the pressure information of the exhaust gas turbocharger engine system includes the compressor pre-compression pressure, the compressor post-compression pressure, the turbine pre-turbine pressure, and the turbine post-turbine pressure; and, in step S3, the preset turbine BPF noise occurrence condition is: the current vehicle speed is less than the preset vehicle speed threshold; the opening of the vehicle's accelerator pedal reaches the preset opening threshold, and / or the rate of change of the vehicle's accelerator pedal reaches the preset rate of change threshold; the ratio of the compressor post-compression pressure to the compressor pre-compression pressure is less than or equal to the preset first pressure ratio; the ratio of the turbine pre-turbine pressure to the turbine post-turbine pressure is less than or equal to the preset second pressure ratio; and the above conditions must be met at the same time.

[0028] By adopting the above method, the influence of vehicle speed, accelerator pedal opening, change rate, and exhaust gas turbocharger engine system pressure is comprehensively considered, so that the time of occurrence of turbine BPF noise can be determined more accurately.

[0029] According to another specific embodiment of the present invention, in the noise control method of the supercharged engine of a vehicle disclosed in the embodiment of the present invention, the preset vehicle speed threshold range is 30 km / h to 40 km / h; the preset first pressure ratio range is 1.10 to 1.15; and the preset second pressure ratio range is 1.25 to 1.35.

[0030] According to another specific embodiment of the present invention, the embodiment of the present invention discloses a noise control method for a supercharged engine of a vehicle. In step S3, the opening of the nozzle ring group of the turbine is reduced to a preset first opening threshold corresponding to the current gear according to the current gear information, including: calibrating the opening of the nozzle ring group of the turbine of each gear of the vehicle respectively to obtain the first opening threshold corresponding to each gear; wherein the first opening threshold is the opening of the nozzle ring group of the turbine without turbine BPF noise; reducing the opening of the nozzle ring group of the turbine from 100% to the preset first opening threshold corresponding to the current gear.

[0031] According to another specific embodiment of the present invention, the noise control method for a supercharged engine of a vehicle disclosed in an embodiment of the present invention further includes, after step S3: obtaining a fuel cut-off coasting instruction issued by a vehicle controller of the vehicle, and determining whether the supercharged engine is operating in a fuel cut-off operating condition based on the fuel cut-off coasting instruction;

[0032] If so, reducing the opening of the nozzle ring group of the turbine to a preset second opening threshold corresponding to the current gear according to the current gear information; wherein the second opening threshold is smaller than the first opening threshold;

[0033] If not, continue to determine whether the supercharged engine is running in the fuel cut-off coasting condition.

[0034] According to another specific embodiment of the present invention, in the noise control method of the supercharged engine of a vehicle disclosed in the embodiment of the present invention, in step S2, a preset slow-down speed is determined according to the speed of the supercharged engine and the load of the supercharged engine; and in step S2, the preset delay angle ranges from 5° to 10°.

[0035] The beneficial effects of the present invention are:

[0036] When a vehicle enters a rapid deceleration condition, this method simultaneously controls the throttle valve to close at a preset slow closing speed; controls the turbine nozzle ring assembly to 100% opening; obtains the ignition angle information of the supercharged engine and, based on this information, delays the supercharged engine's ignition angle by a preset delay angle; and performs a cylinder-by-cylinder fuel cutoff on the supercharged engine. When the driver releases the accelerator pedal, the throttle valve closing process is controlled at a relatively low speed through a control strategy, allowing high-pressure gas in the pipeline to enter the cylinder through the throttle valve after the throttle opening is reduced, effectively suppressing the occurrence of surge. Simultaneously, by delaying the ignition angle and using a cylinder-by-cylinder fuel cutoff strategy, the number of cylinders involved in combustion is reduced, resulting in a decrease in engine torque, suppressing surge while meeting the driver's deceleration requirements. Setting the nozzle ring assembly opening to 100% reduces the supercharger's exhaust gas energy and speed, weakening the surge-driving factor. The turbine BPF noise, which is easily induced when the nozzle ring assembly is widely opened, is avoided by optimizing the nozzle ring assembly opening value in the turbine BPF noise region following the surge region. Therefore, the noise control method for a vehicle's supercharged engine, provided by the present invention, eliminates the need for a pressure relief valve in the vehicle's exhaust gas turbocharger system, saving space and cost, facilitating the layout of the exhaust gas turbocharger system, and simultaneously suppressing compressor surge and turbine BPF noise, resulting in high NVH performance for the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 1 is a schematic diagram of the structure of an exhaust gas turbocharger engine system for a vehicle provided by an embodiment of the present invention;

[0038] Figure 2 1 is a schematic structural diagram of a supercharger in an exhaust gas turbocharger engine system for a vehicle provided by an embodiment of the present invention (after removing the turbine box);

[0039] Figure 3 1 is a schematic structural diagram of a compressor housing of a supercharger in an exhaust gas turbocharger engine system of a vehicle provided by an embodiment of the present invention;

[0040] Figure 4Schematic diagram of the coordination relationship between the blades of the turbine and the nozzle ring assembly in the exhaust gas turbocharger engine system of a vehicle provided by an embodiment of the present invention;

[0041] Figure 5 is an operating characteristic curve of a supercharger in an exhaust gas turbocharged engine system of a vehicle provided by an embodiment of the present invention;

[0042] Figure 6 1 is a flow chart of a noise control method for a supercharged engine of a vehicle provided by an embodiment of the present invention;

[0043] Figure 7 This is a transient deceleration characteristic curve of a supercharger in a noise control method for a supercharged engine of a vehicle provided by an embodiment of the present invention.

[0044] Description of reference numerals:

[0045] 1. Supercharged engine; 2. Throttle valve; 3. Supercharger; 31. Compressor; 311. Air inlet; 312. Air outlet; 313. Bypass channel; 32. Turbine; 321. Turbine; 322. Spacer pin; 323. Nozzle ring assembly; 3231. Blade; 3232. Blade shaft; 33. Crank arm; 34. Push rod; 35. Electronic actuator; 4. Air filter; 5. Air flow meter; 6. Intercooler; 7. Three-way catalytic converter; 8. Pressure sensor; 81. Pre-turbulence pressure sensor; 82. Boost pressure sensor; 83. Pre-turbulence pressure sensor; 84. Post-turbulence pressure sensor; 9. Pressure relief valve. DETAILED DESCRIPTION

[0046] The following is an explanation of the embodiments of the present invention by specific specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. Although the description of the present invention will be introduced in conjunction with the preferred embodiment, this does not mean that the features of this invention are limited to this embodiment. On the contrary, the purpose of introducing the invention in conjunction with the embodiment is to cover other options or modifications that may be extended based on the claims of the present invention. In order to provide a deep understanding of the present invention, the following description will contain many specific details. The present invention can also be implemented without using these details. In addition, in order to avoid confusion or blurring the focus of the present invention, some specific details will be omitted in the description. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0047] It should be noted that in this specification, similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0048] In the description of this embodiment, it should be noted that the terms "upper", "lower", "inner", "bottom", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, or are the orientations or positional relationships in which the inventive product is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the present invention.

[0049] The terms “first”, “second”, etc. are only used for distinguishing descriptions and should not be understood as indicating or implying relative importance.

[0050] In the description of this embodiment, it should be noted that, unless otherwise specified or limited, the terms "disposed," "connected," and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this embodiment based on specific circumstances.

[0051] In order to make the objectives, technical methods and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0052] In order to solve the problem in the prior art that after the pressure relief valve is removed from the exhaust gas turbocharger engine system of a vehicle, compressor surge and turbine BPF noise are obvious, affecting the performance of the entire vehicle and the riding experience, an embodiment of the present invention provides a noise control method for a vehicle's supercharged engine, which is applicable to the exhaust gas turbocharger engine system of the vehicle.

[0053] First, refer to Figure 1 , an exhaust gas turbocharger engine system of a vehicle is described.

[0054] The vehicle's exhaust gas turbocharger engine system includes a supercharger engine 1, a throttle valve 2, and a supercharger 3. Furthermore, the supercharger 3 includes a compressor 31 and a turbine 32. Furthermore, the exhaust gas turbocharger engine system also includes devices such as an air filter 4, an air flow meter 5, an intercooler 6, a three-way catalytic converter 7, and a pressure sensor 8. Furthermore, the compressor 31 includes an air inlet 311, an air outlet 312, and a bypass channel 313. The turbine 32 includes a turbine 321, a distance pin 322, and a nozzle ring assembly 323; the nozzle ring assembly 323 includes blades 3231 and a blade shaft 3232, both of which are typically made of powder metallurgy to form an integrated nozzle ring assembly. The supercharger 3 also includes a crank arm 33, a push rod 34, and an electronically controlled actuator 35.

[0055] In this exhaust gas turbocharger engine system, reference Figure 1 The compressor 31 is located in the intake duct between the air flow meter 5 and the supercharged engine 1. When the compressor 31 rotates, it inhales the fresh air flowing in from the air filter 4 and compresses it, and then sends the compressed gas into the cylinder of the supercharged engine 1. Figure 1 The middle arrow indicates the direction of gas flow. After passing through the air filter 4 to remove impurities, the intake air flows into the intake manifold. An air flow meter 5 is located inside the air filter 4 to measure the air flow. After entering the compressor 31 of the supercharger 3, the intake air is compressed and flows out of the compressor 31. It then enters the intercooler 6, where the compressed, high-temperature gas is cooled to increase its density and reduce component thermal loads. After passing through the throttle valve 2, it flows into the intake manifold to meet the needs of the supercharged engine 1. The exhaust gas after combustion is discharged into the turbine 32 of the supercharger 3. After expanding and performing work in the turbine 32, it is treated by the three-way catalytic converter 7 to remove harmful components before being discharged into the atmosphere.

[0056] Furthermore, in the exhaust gas turbocharger engine system, the pressure sensor 8 includes a pre-compression pressure sensor 81, a boost pressure sensor 82, a pre-turbine pressure sensor 83, and a post-turbine pressure sensor 84. Specifically, in the gas flow direction, the pre-compression pressure sensor 81 is arranged in front of the compressor 31 to provide a measurement signal of the pre-compression pressure of the compressor 31; the boost pressure sensor 82 is usually arranged after the throttle valve 2 to provide a measurement signal of the post-compression pressure of the compressor 31; the pre-turbine pressure sensor 83 is arranged at the exhaust outlet of the turbocharged engine 1 to provide a measurement signal of the pre-turbine pressure of the turbine 32; and the post-turbine pressure sensor 84 is arranged at the inlet of the three-way catalytic converter 7 to provide a measurement signal of the post-turbine pressure of the turbine 32.

[0057] Further, in the exhaust gas turbocharger engine system, reference is made to Figure 2 The schematic diagram of the structure of the supercharger 3 is shown. The electronically controlled actuator 35 manipulates the rotation angle of the nozzle ring assembly 323 of the compressor 31 to control the opening of the nozzle ring assembly 323, that is, the flow area between the blades 3231. The electronically controlled actuator 35 is installed on the side of the compressor 31 where the temperature is relatively low. According to the instructions of the engine electronic control unit, the electronically controlled actuator 35 outputs torque to the push rod 34 of the supercharger 3 through its internal electric motor and gear transmission system, and the push rod 34 drives the crank arm 33. The crank arm 33 is connected to the nozzle ring assembly 323 and can drive the nozzle ring assembly 323 to rotate. That is, it can ultimately rotate the blade shaft 3232 on the back of the blade 3231 to increase or decrease the flow area between adjacent blades 3231, so as to control the opening and Figure 1The purpose of this is to increase the boost pressure of the supercharged engine 1. Exhaust gas from the supercharged engine 1 flows into the inlet of the turbine 32, passes through the closed flow channel formed by the adjacent blades 3231 of the nozzle ring assembly 323 and the turbine housing, impacts the turbine 321, and generates work for the supercharger 3 before flowing out of the turbine 32. The distance pins 322, which are in contact with the inner wall of the turbine housing, ensure a certain clearance between the blades 3231 and the turbine housing to prevent contact.

[0058] Further, in the exhaust gas turbocharger engine system, reference is made to Figure 3 The schematic diagram of the compressor housing structure of the supercharger 3 shows a bypass channel 313 disposed between the air inlet 311 and the air outlet 312 of the compressor 31. This bypass channel 313 is used to connect the air inlet and air outlet pipes of the compressor 31. In some cases, the opening and closing of the bypass channel 313 can be controlled by the pressure relief valve 9. The pressure relief valve 9 is an on-off valve and is generally in the normally closed state. Its main purpose is to deal with transient bypass pressure relief and prevent surge in the compressor 31.

[0059] Furthermore, in the exhaust gas turbocharger engine system, continue to refer to Figure 1 , the electronically controlled actuator 35 controls the opening of the nozzle ring assembly 323. When the exhaust gas energy is high, increasing the opening of the nozzle ring assembly 323 can reduce the exhaust back pressure and pumping losses of the supercharged engine 1. When the exhaust gas energy is low, decreasing the opening of the nozzle ring assembly 323 can increase the exhaust back pressure of the supercharged engine 1, thereby obtaining sufficient energy to meet the power requirements of the compressor 31 and improving the low-speed torque characteristics of the supercharged engine 1. The throttle valve 2 is used to adjust the gas flow entering the supercharged engine 1. When the supercharged engine 1 is operating at full load, the throttle valve 2 is in the fully open position. The lighter the load, the smaller the opening.

[0060] Further, in the exhaust gas turbocharger engine system, reference is made to Figure 4 The diagram shows the relationship between the turbine 321 and the blades 3231 of the nozzle ring assembly 323. The high-temperature and high-pressure exhaust gas passes through the flow channel between the adjacent blades 3231. When the opening of the nozzle ring assembly 323 changes from Figure 4The solid line position in the figure is opened to a larger opening position, that is, when the blade 3231 rotates around the blade shaft 3232 to the position shown by the dotted line, that is, the position where the airflow with a small opening changes to the airflow with a large opening. The flow passage area between adjacent blades 3231 is increased, which can accommodate more exhaust gas and effectively reduce the exhaust pressure before the turbine. The blades 3231 are evenly arranged along the circumference, but the exhaust flow flowing into the channel between the blades 3231 is unevenly arranged due to the position of the turbine box inlet. During the high-speed rotation of the turbine 321 blades, the static pressure at the tail position of individual blades 3231 on the nozzle ring 323, such as the blades 3231 located near the tongue of the turbine box flow passage, will change significantly, thereby exerting a large excitation effect on the turbine 321, causing the blades of the turbine 321 to vibrate periodically, thereby generating turbine BPF noise.

[0061] Furthermore, in the exhaust gas turbocharger engine system, reference is made to Figure 5 The operating characteristic curve of the supercharger 3 is shown. The supercharged engine 1 accelerates transiently along the dashed line A to B, reaching a stable point B. Subsequently, when the throttle is suddenly released, the throttle 2 abruptly closes, causing a sharp decrease in air flow. Due to the inertia of the supercharger 3's turbine 321, the turbine's speed cannot change dramatically within a short period of time. Therefore, the boost pressure remains stable for a period of time, with the pressure ratio remaining essentially unchanged. This is represented by the dashed line from B to C to A. The supercharger 3 enters a condition characterized by a high pressure ratio and a reduced flow rate, and is prone to surge operation, as seen from B1 to C to A1. The provision of a pressure relief valve 9 can prevent surge when the throttle 2 is closed. The operating principle of pressure relief valve 9 is that when the driver releases the accelerator pedal, pressure relief valve 9 opens, connecting the air inlet 311 and the air outlet 312 of compressor 31, and discharging the high-pressure gas in the air intake line of compressor 31, thereby effectively suppressing surge. At this time, the engine can operate along the curved solid line from B to A, avoiding the surge area. However, if pressure relief valve 9 fails, or is not installed for ease of layout or cost reduction, the noise control method provided by the present invention is required to avoid compressor surge and turbine BPF noise.

[0062] Next, refer to Figure 6 , the noise control method of the supercharged engine of a vehicle provided by the present invention is described.

[0063] In the noise control method of a supercharged engine of a vehicle according to the present invention, the noise control method includes:

[0064] S1: Obtain vehicle status information and determine whether the vehicle enters a rapid deceleration condition based on the status information;

[0065] If yes, proceed to step S2;

[0066] If not, continue to determine whether the vehicle enters a rapid deceleration condition;

[0067] S2: Perform the following operations simultaneously based on the vehicle status information:

[0068] Control the throttle valve to close at a preset slow closing speed;

[0069] The opening of the nozzle ring group of the control turbine is 100%;

[0070] Acquiring ignition angle information of the supercharged engine, and retarding the ignition angle of the supercharged engine by a preset delay angle according to the ignition angle information of the supercharged engine;

[0071] Carry out oil cut-off treatment on supercharged engines by cylinder;

[0072] S3: Obtaining vehicle speed information, current gear information, and exhaust gas turbocharger system pressure information, and determining whether the turbocharger engine meets preset turbine BPF noise generation conditions based on the vehicle status information, vehicle speed information, and exhaust gas turbocharger system pressure information;

[0073] If so, reducing the opening of the nozzle ring assembly of the turbine to a preset first opening threshold corresponding to the current gear according to the current gear information;

[0074] If not, it is further determined whether the supercharged engine meets the preset turbine BPF noise generation condition.

[0075] Furthermore, in the noise control method for a supercharged vehicle engine according to the present invention, the vehicle status information includes the degree of accelerator pedal opening and the rate of change of the accelerator pedal opening. More specifically, the degree of accelerator pedal opening can be measured by a pedal sensor, and the rate of change of the accelerator pedal opening can be calculated by combining the measurement result of the accelerator pedal sensor and time.

[0076] More specifically, in step S2, controlling the throttle valve to close at a preset slow-closing speed includes controlling the throttle valve to close at a preset slow-closing speed until vehicle deceleration is complete based on a comparison between the vehicle's accelerator pedal opening and a preset opening threshold, and / or a comparison between the vehicle's accelerator pedal rate of change and a preset rate of change threshold. The preset opening threshold can be determined through experimental calibration and refers to the accelerator pedal opening value when the vehicle enters a rapid deceleration condition. The preset rate of change threshold can also be determined through experimental calibration and refers to the rate of change of the accelerator pedal when the vehicle enters a rapid deceleration condition. Of course, in this specific embodiment, the throttle valve can be controlled solely by the accelerator pedal opening or solely by the rate of change of the accelerator pedal. This step reduces the amount of information collected and improves the efficiency of the overall control strategy. Alternatively, the throttle valve can be controlled using both the accelerator pedal opening and the rate of change of the accelerator pedal. This step comprehensively considers the effects of both the opening and the rate of change, improving the accuracy of judgment and control. The operation of controlling the throttle to close at a preset slow closing speed needs to start from when the vehicle enters a rapid deceleration condition until the vehicle deceleration is completed, that is, until the vehicle engine stops running.

[0077] Furthermore, in a preferred embodiment of the present invention, the preset slow-down speed is determined based on the speed and load of the supercharged engine. More specifically, the preset slow-down speed is determined by comprehensive experimental calibration based on the speed and load of the supercharged engine.

[0078] Furthermore, in the noise control method for a supercharged vehicle engine according to the present invention, in step S2, controlling the opening of the turbine nozzle ring assembly to 100% includes: controlling the opening of the turbine nozzle ring assembly to 100% based on a comparison between the opening of the vehicle's accelerator pedal and a preset opening threshold, and / or a comparison between the rate of change of the vehicle's accelerator pedal and a preset rate of change threshold, until the supercharged engine satisfies a preset turbine BPF noise generation condition. The preset opening threshold and the preset rate of change threshold are the same as the preset opening threshold and the preset rate of change threshold used in controlling the throttle valve to close at a preset slow closing speed, and are not further described here. Controlling the opening of the turbine nozzle ring assembly to 100% means controlling the turbine nozzle ring assembly to a fully open state. The method for controlling the turbine is essentially the same as that used in the prior art, and is not further described here. Furthermore, controlling the opening of the turbine nozzle ring assembly to 100% also begins when the vehicle enters a rapid deceleration condition and continues until the preset turbine BPF noise generation condition is met. The conditions for the occurrence of turbine BPF noise will be discussed in subsequent content.

[0079] Furthermore, in the noise control method for a supercharged engine of a vehicle according to the present invention, in step S2, the ignition angle information of the supercharged engine includes the crankshaft angle corresponding to the initial ignition angle of the supercharged engine. One rotation of the engine crankshaft is 360 degrees, and the crankshaft angle refers to the angle within 360 degrees of the crankshaft's rotation. The crankshaft angle corresponding to the initial ignition angle of the supercharged engine can be measured by an engine angle sensor. With this step, since the engine ignition timing is determined based on the crankshaft angle, the present invention controls the ignition angle based on the crankshaft angle of the supercharged engine, thereby improving the accuracy of ignition angle control.

[0080] Furthermore, retarding the ignition angle of the supercharged engine by a preset retarded angle according to the ignition angle information of the supercharged engine includes retarding the ignition angle of the supercharged engine by the preset retarded angle according to a crankshaft angle corresponding to an initial ignition angle of the supercharged engine.

[0081] Furthermore, in a preferred embodiment according to the present invention, the ignition angle of the supercharged engine is determined according to the following formula:

[0082] C n =C0+C Δ

[0083] Among them, C n is the ignition angle of the supercharged engine, C0 is the crankshaft angle corresponding to the initial ignition angle of the supercharged engine, C Δ is the preset delay angle.

[0084] Furthermore, in a preferred embodiment of the present invention, the preset delay angle ranges from 5° to 10°. For example, it can be 5°, 7.5°, 9°, 10°, or other angle values ​​within this range. The initial ignition angle of a supercharged engine is a fixed value, and therefore the crankshaft angle corresponding to this initial ignition angle is also fixed. However, in this specific embodiment, the ignition of the supercharged engine is delayed by a preset delay angle based on the crankshaft angle corresponding to this initial ignition angle. This delayed ignition reduces the engine's driving capability, preventing the engine from continuing to output power, which would violate the driver's desire to reduce the engine speed by releasing the accelerator.

[0085] Furthermore, in the noise control method of the supercharged engine of the vehicle according to the present invention, the cylinder fuel cut-off process is essentially no different from the cylinder fuel cut-off method in the prior art, and will not be described in detail here.

[0086] Furthermore, when the vehicle enters a rapid deceleration condition, the present invention simultaneously controls the throttle valve to close at a preset slow closing speed; controls the turbine nozzle ring assembly to 100% opening; obtains the ignition angle information of the supercharged engine and, based on the ignition angle information, delays the ignition angle of the supercharged engine by a preset delay angle; and performs a cylinder-by-cylinder fuel cut-off process on the supercharged engine. When the driver releases the accelerator pedal, the throttle valve closing process is controlled at a relatively low speed through a control strategy, allowing high-pressure gas in the pipeline to enter the cylinder through the throttle valve after the throttle opening is reduced, effectively suppressing the occurrence of surge. Simultaneously, the delayed ignition angle and cylinder-by-cylinder fuel cut-off strategies reduce the number of cylinders involved in combustion, reducing engine power torque, suppressing surge while meeting the driver's deceleration requirements. Setting the nozzle ring assembly opening to 100% reduces the supercharger exhaust gas energy and speed, weakening the surge driver.

[0087] Furthermore, in the noise control method of the supercharged engine of the vehicle according to the present invention, the speed information of the vehicle includes the current vehicle speed; it can be measured by a speed sensor or obtained from the vehicle controller or instrument panel. The pressure information of the exhaust gas turbocharger engine system includes the pre-compression pressure of the compressor, the post-compression pressure of the compressor, the pre-turbine pressure of the turbine, and the post-turbine pressure of the turbine, which can be obtained by Figure 1 The pressure is measured by the pre-turbocharged pressure sensor 81, the boost pressure sensor 82, the pre-turbocharged pressure sensor 83, and the post-turbocharged pressure sensor 84 shown.

[0088] Furthermore, in the noise control method of the supercharged engine of a vehicle according to the present invention, in step S3, the preset turbine BPF noise generation conditions are: the current vehicle speed is less than a preset vehicle speed threshold; the opening of the vehicle's accelerator pedal reaches a preset opening threshold, and / or the rate of change of the vehicle's accelerator pedal reaches a preset rate of change threshold; the ratio of the compressor's after-compression pressure to the compressor's before-compression pressure is less than or equal to a preset first pressure ratio; the ratio of the turbine's in-turbine pressure to the turbine's after-turbine pressure is less than or equal to a preset second pressure ratio; and the above conditions must be met at the same time.

[0089] Furthermore, in a preferred embodiment of the present invention, the preset vehicle speed threshold ranges from 30 km / h to 40 km / h; for example, it can be 30 km / h, 35 km / h, 37.5 km / h, 40 km / h, or other values. The preset first pressure ratio ranges from 1.10 to 1.15; for example, it can be 1.10, 1.125, 1.13, 1.15, or other ratios; the preset second pressure ratio ranges from 1.25 to 1.35, for example, it can be 1.25, 1.275, 1.3, 1.35, or other ratios. The preset opening threshold and the preset rate of change threshold can be obtained through experimental calibration. The opening threshold and rate of change threshold may vary for different vehicle models, and this specific embodiment does not impose any restrictions on this.

[0090] Furthermore, in the noise control method for a supercharged engine of a vehicle according to the present invention, in step S3, the nozzle ring opening of the turbine is reduced to a preset first opening threshold corresponding to the current gear based on the current gear information. This includes: calibrating the nozzle ring opening of the turbine for each gear of the vehicle to obtain the first opening threshold corresponding to each gear; wherein the first opening threshold is the nozzle ring opening of the turbine at which turbine BPF noise does not occur; and reducing the nozzle ring opening of the turbine from 100% to the preset first opening threshold corresponding to the current gear. More specifically, calibration is performed for each gear of the vehicle. That is, through testing, the nozzle ring opening is determined from 100% to the value at which turbine BPF noise does not occur. This value is then used as the first opening threshold corresponding to the current gear. In actual testing, the nozzle ring opening can be gradually reduced until the preset turbine BPF noise generation condition is met and turbine BPF noise does not occur. At this point, the nozzle ring opening is set to the calibrated value.

[0091] Furthermore, in a preferred embodiment of the present invention, after step S3, the method further includes: obtaining a fuel cut-off coasting instruction issued by a vehicle controller of the vehicle, and determining whether the supercharged engine is operating in a fuel cut-off operating condition according to the fuel cut-off coasting instruction;

[0092] If so, reducing the opening of the nozzle ring group of the turbine to a preset second opening threshold corresponding to the current gear according to the current gear information; wherein the second opening threshold is smaller than the first opening threshold;

[0093] If not, continue to determine whether the supercharged engine is running in the fuel cut-off coasting condition.

[0094] That is, under fuel cut-off conditions, the opening of the nozzle group and ring group needs to be calibrated to a smaller value. This second opening threshold can be obtained through experimental calibration, or it can be directly reduced by 8% to 10% based on the preset first opening threshold. This embodiment does not impose any restrictions on this.

[0095] Furthermore, the present invention adopts a method of optimizing and reducing the opening value of the nozzle ring group in the turbine BPF noise area after the surge area to avoid the occurrence of turbine BPF noise, which is easily induced when the nozzle ring group is widely opened.

[0096] Further, refer to Figure 7 The transient deceleration characteristic curve of the supercharger is shown. Figure 7 It can be seen that when the vehicle enters the rapid deceleration section, the boost pressure of the supercharged engine will begin to drop from the peak. When it drops to a certain value, it will enter the surge zone, and after the surge zone, it will enter the BPF noise zone. During this period, the throttle opening also slowly decreases. Transient deceleration refers to the operating characteristics of the boost pressure from the highest point B to the lowest point A when the throttle is quickly released after full throttle acceleration of the automotive supercharged engine. In this operating condition, the boost pressure rises to the peak and then drops rapidly. When the boost pressure drops rapidly, the flow rate drops relatively slowly, making it easier for the compressor operating line of the supercharger to enter the surge zone. That is Figure 5 B to B1 to C to A1 to A in the circuit, thus causing surge. Figure 7 The dashed line in the figure shows the surge fluctuation phenomenon, followed by the easily perceptible turbine BPF noise. The present invention distinguishes surge and BPF phenomena by segment and proposes a joint calibration measure and method that takes into account both surge suppression and turbine BPF noise reduction.

[0097] Although the present invention has been illustrated and described with reference to certain preferred embodiments thereof, it should be understood by those skilled in the art that the above description is provided as a further detailed description of the present invention in conjunction with specific embodiments thereof, and that the specific implementation of the present invention is not limited to these descriptions. Those skilled in the art may make various changes in form and details, including simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A method for controlling noise of a supercharged engine of a vehicle, characterized in that: An exhaust gas turbocharger engine system suitable for a vehicle, the exhaust gas turbocharger engine system comprising a supercharger engine, a throttle valve, and a supercharger, the supercharger comprising a compressor and a turbine; and The noise control method comprises: S1: Acquire status information of the vehicle, and determine whether the vehicle enters a rapid deceleration condition based on the status information; If yes, proceed to step S2; If not, continue to determine whether the vehicle enters a rapid deceleration condition; S2: Perform the following operations simultaneously according to the vehicle status information: Controlling the throttle valve to close at a preset slow closing speed; controlling the opening of the nozzle ring group of the turbine to be 100%; Acquiring ignition angle information of the supercharged engine, and retarding the ignition angle of the supercharged engine by a preset delay angle according to the ignition angle information of the supercharged engine; Performing cylinder-by-cylinder oil-cutting processing on the supercharged engine; S3: Obtaining speed information, current gear information, and pressure information of the exhaust gas turbocharger engine system of the vehicle, and determining whether the turbocharger engine meets a preset turbine BPF noise generation condition based on the vehicle status information, the vehicle speed information, and the pressure information of the exhaust gas turbocharger engine system; If so, reducing the opening of the nozzle ring assembly of the turbine to a preset first opening threshold corresponding to the current gear according to the current gear information; If not, it is further determined whether the supercharged engine meets the preset turbine BPF noise generation condition.

2. The noise control method of a supercharged engine of a vehicle according to claim 1, characterized in that: The vehicle status information includes the opening degree of the accelerator pedal of the vehicle and the rate of change of the accelerator pedal of the vehicle; and In step S2, controlling the throttle valve to close at a preset slow closing speed includes: Based on the comparison result of the opening of the vehicle's accelerator pedal and a preset opening threshold, and / or the comparison result of the change rate of the vehicle's accelerator pedal and a preset change rate threshold, the throttle valve is controlled to close at a preset slow closing speed until the vehicle deceleration is completed.

3. The noise control method of a supercharged engine of a vehicle according to claim 1, wherein: The vehicle status information includes the opening degree of the accelerator pedal of the vehicle and the rate of change of the accelerator pedal of the vehicle; and In step S2, controlling the opening of the nozzle ring assembly of the turbine to 100% includes: Based on the comparison result of the opening of the vehicle's accelerator pedal and a preset opening threshold, and / or the comparison result of the change rate of the vehicle's accelerator pedal and a preset change rate threshold, the opening of the nozzle ring group of the turbine is controlled to be 100% until the supercharged engine meets the preset turbine BPF noise generation condition.

4. The noise control method of a supercharged engine of a vehicle according to claim 1, wherein: In step S2, the ignition angle information of the supercharged engine includes a crankshaft angle corresponding to an initial ignition angle of the supercharged engine; and Delaying the ignition angle of the supercharged engine by a preset delay angle according to the ignition angle information of the supercharged engine includes: The ignition angle of the supercharged engine is retarded by a preset delay angle according to a crankshaft angle corresponding to the initial ignition angle of the supercharged engine.

5. The method for controlling noise of a supercharged engine of a vehicle according to claim 4, wherein: The ignition angle of the supercharged engine is determined according to the following formula: C n =C0+C Δ Among them, C n is the ignition angle of the supercharged engine, C0 is the crankshaft angle corresponding to the initial ignition angle of the supercharged engine, and C Δ is the preset delay angle.

6. The noise control method of a supercharged engine of a vehicle according to claim 1, wherein: The vehicle status information includes the opening degree of the accelerator pedal of the vehicle and the rate of change of the accelerator pedal of the vehicle; The vehicle speed information includes the current vehicle speed; The pressure information of the exhaust gas turbocharger engine system includes the pre-compression pressure of the compressor, the post-compression pressure of the compressor, the pre-turbine pressure of the turbine, and the post-turbine pressure of the turbine; and In step S3, the preset turbine BPF noise generation conditions are: The current vehicle speed is less than the preset speed threshold; The opening of the accelerator pedal of the vehicle reaches a preset opening threshold, and / or the rate of change of the accelerator pedal of the vehicle reaches a preset rate of change threshold; The ratio of the after-compression pressure of the compressor to the before-compression pressure of the compressor is less than or equal to a preset first pressure ratio; The ratio of the turbine pre-turbine pressure to the turbine post-turbine pressure is less than or equal to a preset second pressure ratio; and The above conditions must be met at the same time.

7. The noise control method of a supercharged engine of a vehicle according to claim 6, characterized in that: The preset speed threshold range is 30km / h to 40km / h; The preset first pressure ratio ranges from 1.10 to 1.15; The preset second pressure ratio ranges from 1.25 to 1.

35.

8. The method for controlling noise of a supercharged engine of a vehicle according to claim 1, wherein: In step S3, reducing the opening of the nozzle ring assembly of the turbine to a preset first opening threshold corresponding to the current gear according to the current gear information includes: Calibrate the opening of the nozzle ring assembly of the turbine at each gear position of the vehicle to obtain a first opening threshold corresponding to each gear position; wherein the first opening threshold is the opening of the nozzle ring assembly of the turbine at which no turbine BPF noise occurs; The opening degree of the nozzle ring assembly of the turbine is reduced from 100% to a preset first opening degree threshold corresponding to the current gear.

9. The noise control method of a supercharged engine of a vehicle according to claim 1, wherein: After step S3, the method further includes: Obtaining a fuel cut-off coasting instruction issued by a vehicle controller of the vehicle, and determining whether the supercharged engine is operating in a fuel cut-off operating condition based on the fuel cut-off coasting instruction; If yes, reducing the opening of the nozzle ring assembly of the turbine to a preset second opening threshold corresponding to the current gear according to the current gear information; wherein the second opening threshold is smaller than the first opening threshold; If not, continue to determine whether the supercharged engine is running in the fuel cut-off coasting condition.

10. The noise control method of a supercharged engine of a vehicle according to any one of claims 1 to 9, characterized in that: In step S2, the preset slow closing speed is determined according to the speed of the supercharged engine and the load of the supercharged engine; and In step S2, the preset delay angle ranges from 5° to 10°.

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