An engine control method, control system, device, controller, medium and vehicle
Patent Information
- Application Number
- CN202510528410.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-25
- Publication Date
- 2026-10-27
Smart Images
Figure CN122981027A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of engine control, and in particular to an engine knock control method, control system, device, controller, medium, and vehicle. Background Technology
[0002] With the development of the automotive industry, the engine, as a core component of a vehicle, directly affects the vehicle's power performance, fuel economy, and service life. During engine operation, knocking is a common abnormal combustion phenomenon that not only reduces engine power and fuel economy but also causes serious damage to engine components, shortening the engine's lifespan. Therefore, effectively controlling engine knocking is of great significance.
[0003] However, existing technologies still have some shortcomings in engine knock control, and cannot take corresponding control measures according to different degrees and types of knock, which affects engine performance, fuel economy and lifespan.
[0004] Application content
[0005] This application aims to at least address one of the technical problems existing in the prior art. Specifically, it aims to address the problem that existing technologies lack precise engine knock control strategies, failing to implement corresponding control measures based on different degrees and types of knock. The first aspect of this application discloses a vehicle control method, which includes:
[0006] An engine knock control method includes acquiring engine knock signals and background noise to determine engine state; and determining an engine control strategy based on the engine state.
[0007] Optionally, the engine knock control method is applied to the engine, and the controller is the main implementer of the engine control scheme. The engine is installed on a vehicle, and this application does not limit the type or category of the vehicle. It can be a fuel vehicle, a range-extended vehicle, a hybrid vehicle, or other construction machinery, such as tractors, trucks, and other machinery that uses an engine as a power source.
[0008] This application allows for the precise identification of engine conditions (e.g., mild or severe knocking) by combining engine knock signals and background noise, thereby determining a control strategy that matches the engine condition. For example, control strategies can differ for different vibration frequencies, different noise frequencies, or even combine vibration and noise, allowing for different control strategies based on different criteria. This refines engine control capabilities, improving engine performance, fuel economy, and lifespan.
[0009] In one possible implementation of the first aspect, acquiring engine knock signals and background noise to determine the engine state includes:
[0010] The engine status is determined based on the ratio of the engine knock signal to the background noise.
[0011] In one possible implementation of the first aspect, the acquisition of engine knock signals and background noise to determine the engine condition includes:
[0012] If the knock signal-to-noise ratio is greater than the first threshold, the engine is determined to be in the first state;
[0013] If the knock signal-to-noise ratio is greater than the second threshold and less than the first threshold, the engine is determined to be in the second state.
[0014] Optionally, determining the engine control strategy based on the engine state includes:
[0015] When the engine is in the first state, the first control strategy is executed;
[0016] The first control strategy is to determine the cylinder allocation of the engine and control the engine based on the cylinder allocation determination.
[0017] Optionally, the first control strategy involves determining the cylinder allocation of the engine, and controlling the engine based on the cylinder allocation determination includes:
[0018] If the engine experiences single-cylinder knocking, increase the fuel injection volume of that single cylinder or cut off the fuel supply.
[0019] Optionally, increasing the fuel injection quantity or cutting off the fuel supply in the single cylinder includes:
[0020] If the knocking frequency of a single cylinder is greater than the third threshold and less than the fourth threshold, the fuel injection quantity of the single cylinder shall be increased.
[0021] If the knocking frequency of a single cylinder is greater than the fourth threshold, the fuel supply to that single cylinder is cut off.
[0022] In one possible implementation of the first aspect, the first control strategy involves determining the cylinder allocation of the engine, and controlling the engine based on the cylinder allocation determination includes:
[0023] If the engine is experiencing multi-cylinder knocking, increase the fuel injection quantity of the multi-cylinder and / or increase the EGR rate and / or limit the intake charge.
[0024] Optionally, increasing the fuel injection quantity of the multi-cylinder and / or increasing the EGR rate and / or limiting the intake air volume includes:
[0025] If the knocking frequency of the multi-cylinder is greater than the fifth threshold and less than the sixth threshold, increase the fuel injection quantity of the multi-cylinder.
[0026] If the knocking frequency of the multi-cylinder is greater than the sixth threshold and less than the seventh threshold, increase the fuel injection quantity of the multi-cylinder and / or increase the EGR rate;
[0027] If the knocking frequency of the multi-cylinder is greater than the seventh threshold and less than the eighth threshold, increase the fuel injection quantity of the multi-cylinder and / or increase the EGR rate and / or limit the intake charge.
[0028] In one possible implementation of the first aspect, determining the engine control strategy based on the engine state includes:
[0029] When the engine is in the second state, the second control strategy is executed;
[0030] The second control strategy is to control the engine knock angle.
[0031] Optionally, controlling the engine knock angle includes:
[0032] Obtain the engine speed and the ratio of the engine knock signal to the background noise, and determine the knock retreat angle step size or knock retreat angle recovery step size;
[0033] The engine knock angle is controlled based on the knock angle retreat step or knock angle recovery step.
[0034] Optionally, obtaining the engine speed and the ratio of the engine knock signal to the background noise, and determining the knock retreat angle step size or knock retreat angle recovery step size includes:
[0035] The current engine status is determined based on historical engine knock retraction angle control data.
[0036] Based on the current engine status, determine the knock retraction angle step size or the knock retraction angle recovery step size.
[0037] Optionally, after controlling the engine knock retraction angle, if the engine does not knock, the second control strategy is exited;
[0038] If the engine still knocks, and the fluctuation range of the engine knock retraction angle is less than the ninth threshold, the change in engine speed is less than the tenth threshold, and the change in relative intake impulse is less than the eleventh threshold, then the knock retraction angle self-learning control is initiated.
[0039] In one possible implementation of the first aspect, the self-learning control for entering the detonation angle includes:
[0040] The self-learning range is determined based on engine speed and relative intake air volume.
[0041] Determine the initial self-learning value for the detonation retraction angle, and adjust the detonation retraction angle to the initial self-learning value;
[0042] Update the self-learning value for detonation angle.
[0043] Optionally, determining the self-learning range based on engine speed and relative intake air volume further includes determining the self-learning range based on engine load, engine speed, and relative intake air volume.
[0044] Optionally, the updated detonation recoil angle self-learning value includes:
[0045] If the engine detonates during the next power stroke, the detonation retreat angle step size is (-ninth threshold) / (n+1), and the detonation retreat angle values B1 and B2 for the current and previous cycles are recorded.
[0046] When |B1-B2| < the twelfth threshold, the self-learned detonation angle value is updated to B2;
[0047] If the engine does not experience knocking in the next power stroke, the knocking retreat angle step size is (ninth threshold) / (n+1), and the knocking retreat angle values C1 and C2 for the current cycle and the previous cycle are recorded.
[0048] When |C1-C2| < the twelfth threshold, the self-learned detonation angle value is updated to C1;
[0049] The twelfth threshold is a natural number greater than 0, and n is the number of times a certain cylinder performs a power stroke after entering the knock angle self-learning value control.
[0050] In a second aspect, embodiments of this application disclose a controller, including a processor, the processor being configured to execute a computer program or instructions, wherein when the processor executes the computer program or instructions, the method described in any of the first aspects is implemented.
[0051] Thirdly, embodiments of this application disclose an engine control system, including a detection system and a controller, wherein the detection system is used to detect engine knock signals and background noise; and the controller is used to perform the method as described in any one of the first aspects.
[0052] Fourthly, this application discloses an engine control device, comprising: a determination module for acquiring the current engine knock signal and background noise to determine the engine state; and a control module for controlling the engine to execute an engine control strategy corresponding to the engine state.
[0053] Fifthly, embodiments of this application provide a readable storage medium including program instructions that, when executed by the controller, cause the controller to perform the method described in the first aspect and any possible implementation thereof.
[0054] Sixthly, embodiments of this application provide a vehicle including a controller as described in the second aspect, and / or a computer-readable storage medium as described in the fifth aspect, and / or an engine control system as described in the third aspect, and / or an engine control device as described in the fourth aspect.
[0055] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description
[0056] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:
[0057] Figure 1 This is a schematic diagram of an engine control method disclosed in an embodiment of this application;
[0058] Figure 2 This is a schematic diagram of an engine self-learning control disclosed in an embodiment of this application;
[0059] Figure 3 This is a schematic diagram of the structure of a controller disclosed in an embodiment of this application. Detailed Implementation
[0060] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.
[0061] The terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish different objects, not to describe a specific order. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, apparatus, product, or end that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products, or ends.
[0062] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.
[0063] This application proposes a vehicle control method aimed at solving the problem that the existing engine knock control strategy is not precise enough and cannot take corresponding control measures according to different degrees and types of knock.
[0064] Please see Figure 1 , Figure 1 This is a flowchart illustrating an engine control method according to this application, including:
[0065] S01, acquire engine knock signal and background noise to determine engine status;
[0066] Engine knocking refers to an abnormal phenomenon that occurs during engine combustion. It is mainly characterized by the spontaneous combustion of the air-fuel mixture in the cylinder without proper ignition, resulting in abnormal vibrations and noise from the engine. Knocking can lead to decreased engine power output, increased fuel consumption, higher temperatures, and damage to the engine.
[0067] Knock signal refers to the high-frequency vibration signal generated by the engine under abnormal combustion conditions. It is usually an electrical signal generated after the vibration is detected by a sensor. The engine is equipped with sensors, which may include: knock sensor, coolant temperature sensor and intake air pressure sensor; the engine controller can collect knock signal, engine coolant temperature signal and intake air pressure signal, and can accurately control the ignition timing.
[0068] Background noise refers to the sound signal generated by the normal movement of mechanical parts, pressure fluctuations in the combustion chamber, or other environmental interferences during engine operation. The background noise obtained in this application can be a filtered noise signal or an unfiltered noise signal, but the filtered noise signal will be more accurate. Those skilled in the art can choose which filtering signal to use based on different application scenarios.
[0069] Specifically, the system acquires engine knock signals and background noise through sensors and sends them to the controller, which then acquires the vehicle's knock signals and background noise.
[0070] Furthermore, while engine knock signals can provide some feedback on the current engine vibration level, the lack of cross-validation can lead to inaccurate identification. Therefore, a background noise parameter is introduced to correlate the two, improving the accuracy and reliability of knock detection. Additionally, relying on only one parameter to measure knock intensity results in a lack of detection redundancy; for example, if the sensor is damaged, knocking cannot be identified. Multi-parameter identification can address the limitations of any single detection method while still allowing for the identification of the current engine knock situation based on other methods.
[0071] In one alternative implementation, the engine state is determined based on the ratio of engine knock signal to background noise.
[0072] Specifically, based on the formula engine knock signal / background noise = engine signal-to-noise ratio, the engine signal-to-noise ratio can be pre-calibrated based on different positions of the engine cylinders and different vehicle speeds.
[0073] For example, the closer the engine cylinder is to the sensor, the more accurate the signal it collects. Therefore, a higher threshold is set for its signal-to-noise ratio (SNR). Cylinders farther from the sensor collect signals of lower quality than those closer to the sensor, so a lower threshold is set for their SNR. At different vehicle speeds, the engine speed varies, resulting in different vibration magnitudes. At low speeds, the vibration caused by the engine speed is smaller, and the sensor can better identify knock signals. Therefore, a higher threshold is set for the SNR at low speeds, while a lower threshold is set at high speeds.
[0074] This enables the identification of engine knocking based on the engine signal-to-noise ratio, as well as the knocking frequency, thus accurately determining the current state of the engine.
[0075] In one optional implementation, acquiring engine knock signals and background noise to determine the engine state includes:
[0076] If the knock signal-to-noise ratio is greater than the first threshold, the engine is determined to be in the first state;
[0077] If the knock signal-to-noise ratio is greater than the second threshold and less than the first threshold, the engine is determined to be in the second state.
[0078] Specifically, engine knock can be divided into two states: normal knock and super knock. Normal knock is the mechanical vibration of a normally operating engine, mainly originating from the periodic movement of components such as the piston, crankshaft, and valves, as well as pressure fluctuations generated by normal combustion. The vibration frequency is low, and the engine can correct it by adjusting its ignition timing without requiring extensive intervention. Super knock, on the other hand, is a high-frequency shock wave caused by abnormal combustion (auto-ignition of the air-fuel mixture). It has a higher vibration frequency and significantly impacts engine structure and fuel economy, requiring additional control methods such as fuel cut-off and increased fuel injection. Therefore, this application defines a knock signal-to-noise ratio greater than a first threshold as the first state, i.e., super knock; and a knock signal-to-noise ratio greater than a second threshold but less than the first threshold as the second state, i.e., normal knock. In this application, the first threshold is greater than the second threshold.
[0079] For example, the first threshold can be set to 10, and the second threshold can be set to 5. When the knock signal-to-noise ratio is greater than 10, it indicates that the engine is in a knocking state and more stringent control measures are required; when the knock signal-to-noise ratio is between 5 and 10, it indicates that the engine is in a slight knocking state and relatively mild control measures can be taken.
[0080] Therefore, this application distinguishes the vibration state of the engine based on the knock signal-to-noise ratio and adopts different control methods under different states, which makes the control more precise, can better protect the engine, and improve the engine life.
[0081] S02, Based on the engine state, determine the engine control strategy.
[0082] In one optional implementation, determining the engine control strategy based on the engine state includes:
[0083] When the engine is in its first state, the first control strategy is executed;
[0084] The first control strategy is to determine the cylinder allocation of the engine and then control the engine based on this determination.
[0085] Specifically, when the engine is in its first state, the vibration is relatively large. It is necessary to first determine whether the engine is experiencing knocking in a single cylinder or multiple cylinders. This is because using the same control strategy for both single-cylinder and multi-cylinder knocking will increase engine consumption. For example, if a single cylinder is vibrating, but all cylinders are treated with enhanced fuel injection or fuel cut-off, although the vibration problem can be solved, the consumption will be greater for the same effect compared to treating a single cylinder individually. It may also affect the operation of other normal cylinders, thus limiting the engine's operation.
[0086] Therefore, when the engine is identified as being in its first state, this application identifies whether the knocking is occurring in a single cylinder or multiple cylinders by performing cylinder-by-cylinder analysis, and then implements different control strategies to further precisely control the engine.
[0087] In one optional implementation, the first control strategy is to determine the cylinder composition of the engine, and to control the engine based on the cylinder composition determination, including: if the engine is experiencing single-cylinder knocking, increasing the fuel injection quantity of the single cylinder or cutting off the fuel injection.
[0088] Specifically, when engine knocking in a single cylinder is detected, the fuel injection quantity in that cylinder is increased to lower the combustion temperature, thereby mitigating or preventing premature knocking. However, in some cases, the fuel quality is problematic, and increasing the fuel injection quantity may further lead to incomplete combustion, failing to mitigate knocking. Additionally, in some cases, knocking occurs frequently and rapidly; increasing the fuel injection quantity, being a gradual adjustment, may not be sufficient to promptly reduce knocking. In such situations, cutting off the fuel supply to that single cylinder instantly terminates the abnormal combustion cycle, preventing continuous high-temperature, high-pressure impact on the cylinder block, thus alleviating or stopping knocking.
[0089] Furthermore, if the knocking frequency of a single cylinder is greater than the third threshold but less than the fourth threshold, the fuel injection quantity of the single cylinder is increased; if the knocking frequency of a single cylinder is greater than the fourth threshold, the fuel injection of the single cylinder is cut off.
[0090] Specifically, by setting a third and a fourth threshold for the single-cylinder knock frequency, single-cylinder knock can be better distinguished, and different control strategies can be adopted according to different vibration frequencies, where the fourth threshold is greater than the third threshold.
[0091] Furthermore, when the vibration frequency of a single cylinder is greater than the third threshold but less than the fourth threshold, the vibration frequency is relatively low. In this case, the vibration can be alleviated by increasing the amount of fuel injection. If the effect is not good and the vibration frequency of the single cylinder continues to increase, when the frequency is greater than or equal to the fourth threshold, the fuel supply to the single cylinder is cut off. When the vibration frequency of a single cylinder is greater than the fourth threshold, the vibration frequency is relatively high. In this case, the fuel supply to the single cylinder is directly cut off to alleviate or stop the vibration of the single cylinder.
[0092] For example, when the knocking frequency of a single cylinder is between 5Hz and 10Hz, increasing the fuel injection quantity of that cylinder can reduce the combustion temperature and thus suppress knocking. When fuel injection cannot alleviate the knocking and the vibration frequency increases to 10Hz, fuel cut-off is performed. When the knocking frequency of a single cylinder exceeds 10Hz, it indicates that the knocking situation of that cylinder is serious. At this time, fuel cut-off measures need to be taken to temporarily stop the operation of that cylinder in order to protect the engine.
[0093] Therefore, this application achieves refined control by differentiating the vibration frequency of a single cylinder and adopting different control strategies at different vibration frequencies, thus solving the problem of knocking while taking into account the engine's power output and economic cost.
[0094] In one optional implementation, the first control strategy is to determine the cylinder division of the engine, and to control the engine based on the cylinder division determination includes: if the engine has multi-cylinder knocking, increasing the fuel injection quantity of the multi-cylinder and / or increasing the EGR rate and / or limiting the intake air volume.
[0095] Specifically, when knocking is detected in multiple cylinders of the engine, the fuel injection quantity of each cylinder can be increased, the EGR rate can be increased, or the charge quantity can be limited. These three methods can be used individually, in combination, or together. Increasing the fuel injection quantity has the same effect as single-cylinder knocking. However, in the case of multi-cylinder knocking, fuel cut-off of multiple cylinders cannot be performed. This is because in the case of multi-cylinder knocking, fuel cut-off of multiple cylinders will cause a precipitous drop in engine torque output (e.g., power loss exceeding 50% when two cylinders are cut off from four-cylinder fuel injection), which may cause vehicle stalling or loss of control at high speeds. At the same time, fuel cut-off of multiple cylinders will exacerbate uneven stress on the crankshaft, causing the connecting rods and crankshaft bearings to bear asymmetrical loads, which may cause mechanical resonance or structural damage. EGR (Exhaust Gas Recirculation) refers to the introduction of cooled, inert exhaust gases (CO2, H2O, etc.) to dilute the air-fuel mixture, reducing combustion speed and temperature, inhibiting auto-ignition, and mitigating knock. Increasing the EGR rate refers to increasing the percentage of recirculated exhaust gas relative to the total engine intake air volume. The inert gases (such as CO2) in the exhaust gas dilute the oxygen concentration, lowering combustion temperature and pressure, thus weakening the physical conditions for auto-ignition and significantly reducing knock. Limiting the intake impulse refers to controlling the intake air volume by reducing the throttle opening or using a turbo bypass valve, lowering cylinder pressure, weakening the conditions for auto-ignition, and mitigating knock.
[0096] Furthermore, if the knock frequency of the multi-cylinder is greater than the fifth threshold and less than the sixth threshold, the fuel injection quantity of the multi-cylinder is increased; if the knock frequency of the multi-cylinder is greater than the sixth threshold and less than the seventh threshold, the fuel injection quantity of the multi-cylinder is increased and / or the EGR rate is increased; if the knock frequency of the multi-cylinder is greater than the seventh threshold and less than the eighth threshold, the fuel injection quantity of the multi-cylinder is increased and / or the EGR rate is increased and / or the intake charge is restricted.
[0097] Specifically, by setting a fifth, sixth, seventh, and eighth threshold for the frequency of multi-cylinder knock, multi-cylinder knock can be better distinguished, and different control strategies can be adopted according to different vibration frequencies. The eighth threshold is greater than the seventh threshold, which is greater than the sixth threshold, which is greater than the fifth threshold. The value ranges of the fifth, sixth, seventh, and eighth thresholds can overlap or intersect with the value ranges of the third and fourth thresholds, or they can be non-overlapping.
[0098] For example, when the knock frequency of multiple cylinders is between 5Hz and 7Hz, knock can be suppressed by increasing the amount of fuel injected into some or all of the cylinders. When fuel injection cannot suppress the vibration, increasing the EGR rate and / or limiting the intake charge can be introduced to alleviate the vibration. When the knock frequency of multiple cylinders is between 7Hz and 9Hz, in addition to increasing the amount of fuel injected, the EGR rate can also be increased to reduce the combustion temperature by introducing more inert gas. When the above methods still cannot alleviate the vibration, limiting the intake charge can be introduced to control it. When the knock frequency of multiple cylinders is between 9Hz and 12Hz, more comprehensive measures are required, including increasing the amount of fuel injected, increasing the EGR rate, and limiting the intake charge, so that multiple methods work together to suppress knock.
[0099] Therefore, this application achieves refined control by differentiating the vibration frequencies of multiple cylinders and adopting different control strategies at different vibration frequencies, thus solving the problem of knocking while taking into account the engine's power output and economic cost.
[0100] In one optional implementation, determining the engine control strategy based on the engine state includes: when the engine is in a second state, executing a second control strategy; the second control strategy is to control the engine knock angle.
[0101] Specifically, when the signal-to-noise ratio (SNR) of engine knock is greater than the second threshold but less than the first threshold, the engine vibrates, but the vibration range is small, which is considered normal knock. Vibration can be controlled by adjusting the engine knock advance angle. The knock advance angle refers to the method of suppressing abnormal combustion by delaying the ignition timing when knock is detected in the engine.
[0102] Optionally, controlling the engine knock retreat angle includes: acquiring the engine speed and the ratio of the engine knock signal to the background noise, determining the knock retreat angle step size or the knock retreat angle recovery step size; and controlling the engine knock retreat angle based on the knock retreat angle step size or the knock retreat angle recovery step size.
[0103] The knock advance angle step size refers to the control system's reduction of the ignition advance angle when a knock signal is detected. This reduces the pressure and temperature inside the combustion chamber, preventing knock. This adjustment is achieved by gradually decreasing the ignition advance angle, with each adjustment amount called the "step size." The knock recovery angle step size refers to the control system's immediate reduction of the ignition advance angle (i.e., the advance angle) when engine knock occurs, reducing the likelihood of knock. Once the knock is eliminated, the ignition advance angle gradually returns to its original set value; this process is called the "recovery step size."
[0104] Specifically, the higher the engine speed, the shorter the combustion time of the gas in the cylinder. If the back angle step size is too large, the ignition angle adjustment may lag behind the combustion process, failing to suppress the knock pressure wave in time. Conversely, a larger back angle step size is required at low speeds. The higher the knock frequency, the stronger the pressure wave energy generated by the auto-ignition of the mixture, and the longer the required back angle step size. At the same time, high-frequency knock causes energy to accumulate rapidly in the combustion chamber. If the back angle recovery step size is too large, it may trigger secondary knock. Therefore, it is necessary to select the back angle step size and back angle recovery step size by comprehensively considering the engine speed and knock frequency. The relationship between the back angle step size and the knock frequency and engine speed can be calibrated before the vehicle goes online. During the control process, the table can be consulted based on the calibration results. This application does not limit the specific correspondence.
[0105] In one optional implementation, the knock retreat angle step size and the knock retreat angle recovery step size are limited to 3°CA, where CA represents the engine crankshaft angle. It is understood that the knock retreat angle step size and the knock retreat angle recovery step size should not be too large or too small. Based on offline measurements, 3°CA is a suitable value, but it is not limited to this value; different values can be selected depending on the engine and application scenario.
[0106] Therefore, by establishing a correlation between engine speed and knock frequency and the back angle step size and back angle recovery step size, a balance between knock suppression accuracy and power economy can be achieved.
[0107] In one optional implementation, obtaining the engine speed and the ratio of the engine knock signal to the background noise, and determining the knock retreat angle step size or knock retreat angle recovery step size includes: determining the current engine state based on historical engine knock retreat angle control; and determining the knock retreat angle step size or knock retreat angle recovery step size based on the current engine state.
[0108] Specifically, knock angle control was performed during the power stroke of the historical engine. If the engine is no longer vibrating during this power stroke, knock angle recovery is performed to approach the optimal ignition angle. If the engine is still vibrating during this power stroke, the knock angle is directly reduced based on the knock angle step size of the previous power stroke until the engine stops vibrating. Once the engine stops vibrating, knock angle recovery is performed to approach the optimal ignition angle.
[0109] In one alternative implementation, determining the knock retraction step size or knock retraction recovery step size based on the current engine state further includes: determining the interval time of the knock retraction recovery step size based on the engine speed and the knock retraction step size.
[0110] The interval time is used to observe whether the detonation angle will cause detonation to occur again.
[0111] Specifically, knock angle recovery can be divided into fast recovery mode and normal recovery mode. In fast recovery mode, the engine speed is low, the knock angle step size is small, and the delay time for the engine ignition angle is short. At this time, the interval time is also short. If no engine vibration occurs within the interval time, the knock angle recovery has reached the optimal ignition angle and no further adjustment is needed, and the second control strategy is exited. In normal recovery mode, the engine speed is higher than in fast recovery mode, the knock angle step size is larger, and the delay time for the engine ignition angle is longer. At this time, the interval time is longer. If no engine vibration occurs within the interval time, the knock angle recovery has reached the optimal ignition angle and no further adjustment is needed.
[0112] In one alternative implementation, engine output can also be used to determine the knock retraction angle recovery step size.
[0113] Specifically, the change in engine output is introduced to achieve more precise control. If there is a large change in engine output during the interval of the back angle recovery step, the engine back angle recovery step is too large and back angle processing is required until the engine power output is stable and the engine does not vibrate.
[0114] Thus, this application achieves detonation suppression through the synergistic effect of dynamic step size adjustment, stepped detonation retreat angle, and multi-parameter feedback mechanism.
[0115] In one optional implementation, after controlling the engine knock retraction angle, if the engine does not knock, the second control strategy is exited; if the engine still knocks, and the fluctuation range of the engine knock retraction angle is less than the ninth threshold, the engine speed change is less than the tenth threshold, and the relative intake impulse change is less than the eleventh threshold, the knock retraction angle self-learning control is entered.
[0116] Specifically, after controlling the engine knock reduction angle, if the engine does not knock, the engine ignition angle has already been adjusted and will not affect engine operation. Therefore, it is not necessary to perform knock reduction angle adjustment again, and the second control strategy can be exited directly. However, if the engine still knocks, and the fluctuation range of the engine knock reduction angle is less than the ninth threshold, the engine speed change is less than the tenth threshold, and the relative intake impulse change is less than the eleventh threshold, it indicates that the engine is in a steady state. In this case, it is necessary to combine multiple parameters to comprehensively judge whether there are problems such as poor fuel quality or engine aging, which may cause the knock to persist even after the knock reduction angle reaches the offline calibration value. In this case, a new reduction angle value needs to be calibrated through self-learning control. If the engine still knocks, but does not meet the conditions that the fluctuation range of the engine knock reduction angle is less than the ninth threshold, the engine speed change is less than the tenth threshold, and the relative intake impulse change is less than the eleventh threshold, then the aforementioned knock reduction angle control strategy should continue to be executed.
[0117] Furthermore, the ignition angle fluctuation range reflects the stability of the current ignition angle adjustment. When the fluctuation value is less than the ninth threshold (e.g., ±0.5°CA), it indicates that knock suppression has reached a steady state. However, if the engine still knocks, it suggests that there may be an overly conservative ignition angle (e.g., an excessively large safety margin) or long-term deviation caused by environmental factors (e.g., fuel octane rating, carbon deposits, aging, etc.). Under steady-state knock control, the ignition angle is corrected through self-learning to narrow the gap between the actual ignition angle and the theoretical optimal value. Engine speed changes less than the tenth threshold (e.g., speed changes <500 rpm / s) indicate that the engine is in a steady-state condition. At this time, parameters such as combustion chamber turbulence and in-cylinder temperature distribution are rapidly decreasing. If engine knock is still detected, the ignition angle can be compensated through self-learning control. The relative intake impulse change refers to the ratio of the actual intake volume to the theoretical maximum intake volume. Under normal circumstances, a ratio maintained between 0.6 and 0.9 indicates that the engine is in a steady state. A relative intake impulse change less than the eleventh threshold (e.g., relative intake impulse change < 0.9) indicates that the engine load has not changed abruptly, ruling out knocking artifacts caused by external interference such as throttle opening and turbocharger pressure. If engine knocking is still detected at this point, it is more likely due to long-term factors such as sensor drift, changes in fuel quality, and engine aging. Self-learning is then used to correct the ignition timing. Using the engine knocking angle fluctuation range, engine speed changes, and intake impulse changes as criteria for entering self-learning avoids false self-learning due to parameter distortion caused by a single parameter. Combining multiple parameters allows for more accurate identification of whether self-learning control has been entered.
[0118] Therefore, this application identifies the engine state after the engine knocking angle reduction, and controls the engine that is still knocking to enter self-learning mode to correct its ignition angle. This solves the problem of changes in ignition angle calibration value caused by engine aging, fuel quality issues, and mechanical wear. As a result, it can perform precise knocking angle reduction operation according to the engine condition, improve engine economic performance, and extend service life.
[0119] In one alternative implementation, entering the detonation angle self-learning control includes:
[0120] S11, determines the self-learning range based on engine speed and relative intake air volume;
[0121] Specifically, the self-learning range is determined based on engine speed and relative intake air charge. Engine speed and relative intake air charge are fundamental operating parameters of the engine, directly determining the physical state of the combustion chamber. Their standards are static, facilitating range determination. In contrast, the fluctuation range of the knock angle is dynamic and easily affected by other factors. Therefore, using engine speed and relative intake air charge as references for defining the self-learning range offers better stability. The self-learning range is an array, with different speeds and load ranges corresponding to different indices. These indices determine the position of the self-learned value under the current operating condition within the array.
[0122] Furthermore, the more self-learning ranges there are, the more accurate the knock retraction angle self-learning value will be, which can better protect the engine. However, excessively increasing the complexity of the control algorithm will reduce the response speed of the control system. This application divides the engine speed into 6 operating ranges and the relative intake charge into 4 operating ranges, which can ensure both control accuracy and control efficiency.
[0123] Specifically, firstly, multiple relative intake impulse operating condition ranges corresponding to engine speeds are determined. Then, based on the actual relative intake impulse, one of the multiple relative intake impulse operating condition ranges is selected. Thus, the index value under that speed and relative intake impulse is determined. The index value is then mapped to a pre-calibrated range to determine the range of the back angle self-learning.
[0124] In one alternative implementation, the self-learning range is determined based on engine load, engine speed, and relative intake charge.
[0125] Specifically, first determine the engine speed and operating condition, then determine the corresponding relative intake impulse threshold. It's important to note that the relative intake impulse threshold differs under different loads; for example, the threshold fluctuates under steady-state and high-pressure conditions. Therefore, the threshold is adaptively adjusted for different pressure conditions. In this application, there are four ranges: Range 1: Relative intake impulse threshold ≤ Threshold 1; Range 2: Threshold 1 < Relative intake impulse threshold ≤ Threshold 2; Range 3: Threshold 2 < Relative intake impulse threshold ≤ Threshold 3; Range 4: Relative intake impulse threshold > Threshold 3.
[0126] For example, the values for the engine speed range and relative intake impulse range can be found in the table below:
[0127] Speed range 1 Speed range 2 Speed range 3 Speed range 4 Speed range 5 Speed range 6 Speed range <2000rpm 2000-3000rpm 2000-3000rpm 3000-4000rpm 4000-5000rpm >5000rpm
[0128] As another example, the values for the engine speed range and relative intake impulse range can be found in the table below, assuming the engine is operating at atmospheric pressure.
[0129] Relative intake charge threshold 1
[0130]
[0131] As another example, the values for the engine speed range and relative intake impulse range can be found in the table below, where the engine load is between normal pressure and high pressure.
[0132] Relative intake charge threshold 2
[0133]
[0134] As another example, the values for the engine speed range and relative intake impulse range can be found in the table below, where the engine is under high pressure.
[0135] Relative intake charge threshold 3
[0136]
[0137] Index value = (speed range value + relative intake impulse range value) * n, where n is the number of engine cylinders. For example, for a 4-cylinder engine, speed range 1, relative intake impulse range 2, index value = (1 + 2) * 4 = 12. Check the self-learning range with a pre-calibrated index value of 12.
[0138] Thus, by dividing and judging multi-dimensional working conditions, more accurate self-learning is achieved.
[0139] S12, determine the initial value of the detonation retreat angle self-learning, and adjust the detonation retreat angle to the initial value of the self-learning;
[0140] In one optional implementation, the average value of the knock angle during the first time period when the fluctuation range of the engine knock angle is less than the ninth threshold, the change in engine speed is less than the tenth threshold, and the change in relative intake impulse is less than the eleventh threshold is used as the initial value for the knock angle self-learning.
[0141] Specifically, as mentioned earlier, when the fluctuation range of the engine knock retraction angle is less than the ninth threshold, the engine speed change is less than the tenth threshold, and the relative intake impulse change is less than the eleventh threshold, the engine is in a steady state. If knocking still occurs under these conditions, it is likely due to factors such as fuel quality or engine aging. Using the average knock retraction angle within the first time frame under steady state as the initial value for self-learning avoids excessive fluctuations in the knock retraction angle in some cases, which could affect the stability of self-learning. The initial value for knock retraction angle self-learning may vary for different vehicle models and engines; this application does not impose any limitations on this.
[0142] S13, update the self-learning value of detonation angle.
[0143] In one optional implementation, if the engine experiences knocking during the next power stroke, the knocking retreat angle step size is (-ninth threshold) / (n+1), and the knocking retreat angle values B1 and B2 for the current and previous cycles are recorded; when |B1-B2| < twelfth threshold, the knocking retreat angle self-learning value is updated to B2; if the engine does not experience knocking during the next power stroke, the knocking retreat angle step size is (ninth threshold) / (n+1), and the knocking retreat angle values C1 and C2 for the current and previous cycles are recorded; when |C1-C2| < twelfth threshold, the knocking retreat angle self-learning value is updated to C2; the twelfth threshold is a natural number greater than 0, and n is the number of times a certain cylinder's power stroke phase has been entered after entering the knocking retreat angle self-learning value control.
[0144] For example, if detonation occurs in the next power stroke, the ninth threshold = 0.5°CA, the twelfth threshold = 0.1, the initial self-learning value B1 = 3.0°CA, and the current cycle count: n = 3, then the backswing step size = -0.5 / 3 + 1 = -0.125°CA, B2 = B1 - 0.125°CA = 2.875°CA, |B1 - B2| = 0.125°CA > 0.1°CA, at this time no self-learning update is performed, and the cycle continues.
[0145] For example, if no knocking occurs in the next power stroke, the ninth threshold = 0.5°CA, the twelfth threshold = 0.15°, the initial self-learning value C1 = 3.0°CA, the current cycle count: n = 4, then the backswing recovery step size = 0.5 / 4 + 1 = 0.1°CA, C2 = C1 + 0.1°CA = 3.1°CA, then |C1 - C2| < 0.15. Therefore, the updated self-learning value is 3.1°CA.
[0146] Therefore, this application achieves self-learning control of the knock angle, allowing the ignition timing to be at the optimal ignition position, thereby reducing knock while improving engine fuel economy and power.
[0147] This application also provides a controller 300, such as Figure 3 As shown, it includes: a processor 310, a memory 320, and a computer program stored in the memory and executable on the processor. When the processor executes the program, the controller implements the vehicle control method of the aforementioned embodiment.
[0148] Preferably, both the memory and the processor are located inside the controller, but the memory can also be located outside the controller, and the location of the memory is not limited.
[0149] According to embodiments of this application, a computer-readable storage medium is also provided, on which program instructions are stored. When the program instructions are run by a computer or processor, they are used to execute corresponding steps of the vehicle control method according to embodiments of this application and to implement corresponding modules for vehicle control according to embodiments of this application.
[0150] The computer-readable storage medium may include, for example, the storage component of a tablet computer, a hard disk of a personal computer, a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disc read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media; for example, one computer-readable storage medium may contain computer-readable program code for randomly generating sequences of action instructions, and another computer-readable storage medium may contain computer-readable program code for controlling crystal growth.
[0151] This application also provides an engine control system, characterized in that it includes a detection system and a controller, wherein the detection system is used to detect engine knock signals and background noise; and the controller is used in the method described in any of the preceding claims.
[0152] This application also provides an engine control device comprising: a determination module for acquiring the current engine knock signal and background noise to determine the engine state; and a control module for controlling the engine to execute an engine control strategy corresponding to the engine state.
[0153] This application also provides a vehicle including the controller as described above, and / or the computer-readable storage medium as described above.
[0154] Understandably, the memory in the embodiments of this disclosure may be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory may be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory may be random access memory (RAM), which serves as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.
[0155] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.
[0156] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.
Claims
1. An engine control method, characterized in that, The method includes: Acquire engine knock signals and background noise to determine engine status; Based on the engine state, an engine control strategy is determined.
2. The method according to claim 1, characterized in that, The step of acquiring engine knock signals and background noise to determine engine status includes: The engine status is determined based on the ratio of the engine knock signal to the background noise.
3. The method according to claim 1, characterized in that, The process of acquiring engine knock signals and background noise to determine engine status includes: If the knock signal-to-noise ratio is greater than the first threshold, the engine is determined to be in the first state; If the knock signal-to-noise ratio is greater than the second threshold and less than the first threshold, the engine is determined to be in the second state.
4. The method according to claim 3, characterized in that, The process of determining the engine control strategy based on the engine state includes: When the engine is in the first state, the first control strategy is executed; The first control strategy is to determine the cylinder allocation of the engine and control the engine based on the cylinder allocation determination.
5. The method according to claim 4, characterized in that, The first control strategy involves determining the cylinder allocation of the engine, and controlling the engine based on the cylinder allocation determination includes: If the engine experiences single-cylinder knocking, increase the fuel injection volume of that single cylinder or cut off the fuel supply.
6. The method according to claim 5, characterized in that, Increasing the fuel injection quantity or cutting off the fuel supply in the single cylinder includes: If the knocking frequency of a single cylinder is greater than the third threshold and less than the fourth threshold, the fuel injection quantity of the single cylinder shall be increased. If the knocking frequency of a single cylinder is greater than the fourth threshold, the fuel supply to that single cylinder is cut off.
7. The method according to claim 4, characterized in that, The first control strategy involves determining the cylinder allocation of the engine, and controlling the engine based on the cylinder allocation determination includes: If the engine is experiencing multi-cylinder knocking, increase the fuel injection quantity of the multi-cylinder and / or increase the EGR rate and / or limit the intake charge.
8. The method according to claim 7, characterized in that, The increase in the fuel injection quantity of the multi-cylinder and / or the increase in the EGR rate and / or the restriction of the intake air volume include: If the knocking frequency of the multi-cylinder is greater than the fifth threshold and less than the sixth threshold, the fuel injection quantity of the multi-cylinder is increased; If the knocking frequency of the multi-cylinder is greater than the sixth threshold and less than the seventh threshold, increase the fuel injection quantity of the multi-cylinder and / or increase the EGR rate; If the knocking frequency of the multi-cylinder is greater than the seventh threshold and less than the eighth threshold, increase the fuel injection quantity of the multi-cylinder and / or increase the EGR rate and / or limit the intake charge.
9. The method according to claim 3, characterized in that, The process of determining the engine control strategy based on the engine state includes: When the engine is in the second state, the second control strategy is executed; The second control strategy is to control the engine knock angle.
10. The method according to claim 9, characterized in that, The control of the engine knock angle includes: Obtain the engine speed and the ratio of the engine knock signal to the background noise, and determine the knock retreat angle step size or knock retreat angle recovery step size; The engine knock angle is controlled based on the knock angle retreat step or knock angle recovery step.
11. The method according to claim 10, characterized in that, The step of obtaining the engine speed and the ratio of the engine knock signal to the background noise, and determining the knock retreat angle step size or knock retreat angle recovery step size includes: The current engine status is determined based on historical engine knock retraction angle control data. Based on the current engine status, determine the knock retraction angle step size or the knock retraction angle recovery step size.
12. The method according to claim 11, characterized in that, The step of determining the knock retraction angle step size or knock retraction angle recovery step size based on the current engine state further includes: The interval time for the detonation recovery step is determined based on the engine speed and the detonation recovery step size.
13. The method according to claim 12, characterized in that, The method further includes: After controlling the engine knock angle, if the engine does not knock, the second control strategy is exited. If the engine still knocks, and the fluctuation range of the engine knock retraction angle is less than the ninth threshold, the engine speed change is less than the tenth threshold, and the relative intake impulse change is less than the eleventh threshold, then the engine enters the retraction angle self-learning control.
14. The method according to claim 13, characterized in that, The self-learning control for entering the detonation retreat angle includes: The self-learning range is determined based on engine speed and relative intake air volume. Determine the initial self-learning value for the detonation retraction angle, and adjust the detonation retraction angle to the initial self-learning value; Update the self-learning value for detonation retreat angle.
15. The method according to claim 14, characterized in that, The method of determining the self-learning range based on engine speed and relative intake air volume also includes: The self-learning range is determined based on the engine load, the engine speed, and the relative intake charge.
16. The method according to claim 14, characterized in that, The determination of the initial value for the self-learning detonation recoil angle includes: The average value of the knock angle during the first time period when the fluctuation range of the engine knock angle is less than the ninth threshold, the change in engine speed is less than the tenth threshold, and the change in relative intake impulse is less than the eleventh threshold is taken as the initial value of the knock angle self-learning.
17. The method according to claim 14, characterized in that, The updated detonation recoil angle self-learning value includes: If the engine detonates during the next power stroke, the detonation retreat angle step size is (-ninth threshold) / (n+1), and the detonation retreat angle values B1 and B2 for the current and previous cycles are recorded. When |B1-B2| < the twelfth threshold, the self-learned detonation angle value is updated to B2; If the engine does not experience knocking in the next power stroke, the knocking retreat angle step size is (ninth threshold) / (n+1), and the knocking retreat angle values C1 and C2 for the current cycle and the previous cycle are recorded. When |C1-C2| < the twelfth threshold, the self-learned detonation angle value is updated to C1; The twelfth threshold is a natural number greater than 0, and n is the number of times a certain cylinder performs a power stroke after entering the knock angle self-learning value control.
18. A controller, characterized in that, Includes a processor for executing a computer program or instructions, which, when executed, cause the method as described in any one of claims 1 to 16 to be implemented.
19. An engine control system, characterized in that, The device includes a detection system and a controller, the detection system being used to detect engine knock signals and background noise; the controller being used to perform the method as described in any one of claims 1 to 16.
20. An engine control device, characterized in that, include: The determination module is used to acquire the current engine knock signal and background noise to determine the engine status; the control module is used to control the engine to execute the engine control strategy corresponding to the engine status.
21. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed, implements the method as described in any one of claims 1-16.
22. A vehicle, characterized in that, This includes the controller as claimed in claim 17, and / or the computer-readable storage medium as claimed in claim 20, and / or the engine control system as claimed in claim 18, and / or the engine control device as claimed in claim 19.