Engine control method and device based on vehicle acceleration request

Abstract

The application discloses an engine control method based on vehicle acceleration request, and steps are as follows: vehicle acceleration request trigger condition; optimizing engine request air path torque M AirReq : obtaining engine original request air path torque M AirReqRaw , combining engine speed n, throttle opening degree pct, throttle opening degree change rate dpct, required time t Delay of fresh air entering the cylinder via the throttle, determining engine request air path torque M AirReq ; determining final engine request air path torque: obtaining the final engine request air path torque after arbitrating the air path torque requested by the driver throttle with other torque requests, controlling engine intake density based on the final engine request air path torque, improving engine air volume, and improving engine actual air path torque. The application further discloses an engine control device based on vehicle acceleration request. The application can quickly respond to vehicle acceleration power demand, thereby improving power response capability, and can be widely applied in the field of engine control.

Description

Technical Field

[0001] This invention relates to the field of engine control, and in particular to an engine control method and apparatus based on vehicle acceleration requests. Background Technology

[0002] Vehicle power performance is one of the most important performance development indicators. When the vehicle requests acceleration, it needs to respond to the power torque request for acceleration as soon as possible. However, because there is a certain distance between the throttle valve and the cylinder in the engine intake system, there is a certain delay in the fresh air entering the cylinder from the throttle valve.

[0003] In light of this, a manufacturer has filed an invention patent application with application number CN202211355696.0, entitled "A Pedal Control Method, Device, Equipment, and Vehicle." This patent discloses a method for obtaining the target pedal torque when the target pedal position change rate does not meet a preset change rate, and obtaining a first change rate of the target pedal torque based on the target pedal torque. Then, the first change rate is converted into a second change rate within a change rate threshold, where the second change rate is less than the first change rate, and the target pedal torque is output based on the second change rate. After a preset time has elapsed since the second change rate was used to output the target pedal torque, the target pedal torque continues to be output based on the first change rate. This application controls the first change rate of the target pedal torque within a certain range within a certain time, thereby avoiding rapid torque changes that could endanger the driver or passengers, and giving the driver sufficient reaction time to deal with potential dangers. However, this invention delays the request for the target pedal torque when the pedal change rate is too rapid, limiting the power request of the pedal torque, and does not consider improving acceleration performance from the perspective of vehicle dynamics.

[0004] Consequently, related companies filed another invention patent application with application number CN202211339913.7, entitled "A Vehicle Acceleration Determination Method, Control Method, System, Device, and Medium." This invention's vehicle acceleration determination method includes acquiring vehicle travel and target object information; dividing multiple danger zones based on the expected trajectory and environmental image information; determining the danger level of each danger zone; determining the current danger zone of each target object based on longitudinal distance, vehicle speed information, lateral speed information, and current position information; predicting the future danger zone of each target object; and determining the acceleration of the vehicle to be controlled based on the danger level, longitudinal distance, and lateral speed information corresponding to the current and future danger zones of each target object. Controlling the vehicle based on the determined acceleration avoids misjudging the target object's behavioral intentions and improves driving safety. However, similarly, it does not propose improving acceleration performance from the perspective of vehicle power and economy.

[0005] In order to quickly respond to the vehicle's acceleration power demand and improve power response capability, an engine control method and device based on the vehicle's acceleration request are proposed. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide an engine control method and device based on vehicle acceleration requests, enabling it to quickly respond to vehicle acceleration power demands, thereby improving power response capability.

[0007] This invention provides an engine control method based on vehicle acceleration requests, comprising the following steps: Vehicle acceleration request triggering conditions include: a first engine closed-loop control, a first engine operating state, a first engine coolant temperature range, a first brake pedal not being depressed, a first exhaust system heating requirement, a first fuel cut-off request not being triggered, a first absence of knocking or pre-ignition, and a first engine request for a change rate of airflow torque; optimizing the engine request for airflow torque M. Air Req Based on the obtained original engine request air path torque M Air ReqRaw Based on this, and combined with engine speed n, throttle opening pct, throttle opening change rate dpct, and the time t required for fresh air to enter the cylinder through the throttle valve, the following parameters are considered. Delay Determine the engine's requested airflow torque M Air Req This is used as the air path torque requested by the driver's throttle; the final engine requested air path torque is determined by arbitrating the air path torque requested by the driver's throttle along with other torque requests to obtain the final engine requested air path torque. Based on the final engine requested air path torque, the engine intake air density is controlled to increase the engine air volume and improve the actual engine air path torque, thereby meeting the vehicle's acceleration requirements.

[0008] In the above technical solution, the conditions for the vehicle acceleration request triggering step are as follows: First engine closed-loop control: The engine is not performing closed-loop speed control; First engine operating state: The engine is in operation; First engine coolant temperature range: The engine coolant temperature is within the first preset range; First brake pedal depressed: The brake pedal is not depressed; First exhaust system heating requirement: The engine does not perform the exhaust system heating requirement; First fuel cut-off request not triggered: The engine does not trigger the fuel cut-off request; First no knocking or pre-ignition: The engine does not experience knocking or pre-ignition; First engine request airflow torque change rate: Before optimization, the engine request airflow torque change rate exceeds the first preset value; All of the above conditions are met.

[0009] In the above technical solution, the optimized engine requests the airflow torque M Air ReqThe specific steps are as follows: Boost control closed loop not activated: When the boost control closed loop is not activated, it is necessary to increase the engine's requested airflow torque more quickly: M Air Req (N)=M Air Req (N-1)+k×k C ×[M Air ReqRaw (N)-M Air Req [(N-1)], Boost control closed loop activated: When boost control closed loop is activated: M Air Req (N)=M Air Req (N-1)+k×[M Air ReqRaw (N)-M Air Req [(N-1)], where M Air ReqRaw == f(n, pct + dpct × t) Delay That is, pct + dpct × t Delay For "throttle opening at which the engine requests airflow torque"; M Air Req (N) represents the engine's requested airflow torque during the Nth sampling period; M Air Req (N-1) represents the engine's requested airflow torque during the (N-1)th sampling period; M Air ReqRaw M is the engine's original request for air circuit torque. Air ReqRaw (N) represents the engine's original requested airflow torque M during the Nth sampling period. Air ReqRaw ;k C is a constant filter coefficient; k is the air path filter coefficient.

[0010] In the above technical solution, the method for obtaining the throttle opening change rate dpct in the steps of boost control closed loop not being activated or boost control closed loop being activated is as follows: Where dpct(N) is the rate of change of throttle opening in the Nth sampling period, dpct(N-1) is the rate of change of throttle opening in the (N-1)th sampling period, pct(N) is the throttle opening in the Nth sampling period, pct(N-1) is the throttle opening in the (N-1)th sampling period, N is a positive integer, pct(0) occurs when all conditions are met; dpct(0) occurs when all conditions are met, Δt is the sampling period, t c is the time constant.

[0011] In the above technical solution, in the step of not activating or activating the boost control closed loop, the value of the gas path filter coefficient k is determined as follows: k = f(n.rho) × k(pct,r) AirTrq ReqRatio )×k(dpct,d 2 pct)×k(r Sprk ,r SprkRatio )×(1+r AdaptThat is, the air path filter coefficient k is determined by engine speed n, load rho, throttle opening pct, throttle opening change rate dpct, and the second derivative of throttle opening d. 2 pct, current ignition efficiency r Sprk Current ignition angle efficiency r Sprk The ratio of efficiency to the optimal ignition angle r SprkRatio Unoptimized engine request ratio r of airflow torque to engine maximum torque AirTrq ReqRatio Learning correction factor r Adapt A joint decision.

[0012] In the above technical solution, the specific process for determining the air path filtering coefficient k is as follows: Basic value of air path filtering coefficient k: f(n.rho), determined by engine speed n and load rho, is the basic value of air path filtering coefficient k. The calibration basis is that after the above conditions are met, the actual engine firing torque is not greater than the engine requested firing torque, and the difference between the engine requested firing torque and the engine actual firing torque is not less than 5%. First correction factor for air path filtering coefficient k: After f(n.rho) is calibrated, based on the throttle opening change rate dpct and the second derivative of throttle opening d... 2 pct determines k(dpct,d) 2 pct) is the first correction factor for the air path filter coefficient k. The calibration is based on the condition that, after all conditions are met, the difference between the actual engine torque and the requested engine torque does not exceed 2%, and the difference between the requested engine torque and the actual engine torque is not less than 5%. The second correction factor for the air path filter coefficient k is determined after the above calibration, based on the throttle opening pct and the air path torque ratio r. AirTrq ReqRati o determines k(pct,r) AirTrq ReqRati o) is the second correction factor for the air path filtering coefficient k, calibrated based on the condition that the optimized engine air path torque does not exceed the engine's maximum torque, but is not limited by it either; the third correction factor for the air path filtering coefficient k: after completing the above calibration, based on the current ignition efficiency r Sprk And the ratio of ignition efficiency r SprkRatio Determine k(r) Sprk ,r SprkRatio ) is the third correction factor of the air path filter coefficient k. The calibration basis is that after the above conditions are met, the difference between the actual engine fire path torque and the engine requested fire path torque shall not exceed 2%, and the difference between the engine requested fire path torque and the engine actual fire path torque shall not be less than 5%.

[0013] In the above technical solution, in the step of either the boost control closed loop not being activated or the boost control closed loop being activated, the learning correction factor r... AdaptThe determination process is as follows: Learning trigger conditions include: second engine closed-loop control, second engine operating status, second engine coolant temperature range, second brake pedal not depressed, second exhaust system heating requirement, second fuel cut-off request not triggered, second absence of knocking or pre-ignition, second engine request for airflow torque change rate, and conditions for updating the vehicle mileage preset value; all of the above conditions must be met; learning correction factor r. Adapt Learning conditions: throttle opening, throttle opening change rate, and ignition efficiency r Sprk Divide the data into several intervals, and then divide the intervals of throttle opening, throttle opening rate of change, and ignition efficiency r into several intervals. Sprk Each interval is combined to form multiple learning correction factors r Adapt Corresponding learning conditions; learning correction factor r Adapt Update processing: Based on the distribution range of the difference between the engine's requested firing torque and the engine's actual firing torque in the learning operating conditions, a correction factor r is learned for each of the 8 operating conditions. Adapt The learning update only updates one type of function; under other operating conditions, the learning correction factor r is adjusted. Adapt The update remains unchanged; the learning correction factor r is used. Adapt Immediately after the update, the records of the difference between the engine's actual firing torque and the engine's requested firing torque for all operating conditions are updated. That is, the difference between the engine's actual firing torque and the engine's requested firing torque for any operating condition under all operating conditions is re-evaluated. Initially, it is assumed that there is no difference between the engine's actual firing torque and the engine's requested firing torque. After the next learning conditions are met, each operating condition is re-evaluated.

[0014] In the above technical solution, the learning correction factor r Adapt The specific process of learning the operating conditions is as follows: Throttle opening range: Divide the throttle opening into A ranges; Throttle opening change rate range: Divide the throttle opening change rate into B ranges; Ignition efficiency r Sprk Range: Ignition efficiency r Sprk Divide into C intervals; determine the D learning correction factors r for the A*B*C = D combinations of the above intervals. Adapt Learning and working conditions.

[0015] In the above technical solution, the learning correction factor r Adapt The specific operation process for the 8 working conditions in the update processing steps is as follows: 1) D learning correction factors r Adapt If, during the learning cycle, the difference between the engine's requested firing torque and the actual firing torque exceeds 8%, then the next vehicle driving cycle begins, and the learning correction factor r is applied. Adapt Updated to m1 times the original value; 2) D learning correction factors r AdaptIn all learning scenarios, if the difference between the engine's requested firing torque and the actual firing torque exceeds 5% but does not exceed 8%, then the next vehicle driving cycle begins, and the learning correction factor r is applied. Adapt Updated to m² times the original value; 3) D learning correction factors r Adapt If, during the learning cycle, the difference between the actual engine torque and the requested engine torque exceeds 5%, the next vehicle driving cycle begins, and the learning correction factor r is applied. Adapt Updated to m3 times the original value; 4) D learning correction factors r Adapt If, during the learning cycle, the difference between the actual engine firing torque and the requested engine firing torque exceeds 2% but does not exceed 5%, then the next vehicle driving cycle begins, and the learning correction factor r is applied. Adap t is updated to m4 times the original value; 5) D learning correction factors r Adapt If, during the learning cycle, the difference between the actual engine firing torque and the requested engine firing torque exceeds -2% but does not exceed 2%, then the next vehicle driving cycle begins, and the learning correction factor r is applied. Adapt Keep unchanged; 6) D learning correction factors r Adapt If, during the learning cycle, the difference between the actual engine firing torque and the requested engine firing torque exceeds -5% but does not exceed -2%, then the next vehicle driving cycle begins, and the learning correction factor r is adjusted. Adapt Updated to m5 times the original value; 7) D learning correction factors r Adapt If, during the learning cycle, the difference between the actual engine firing torque and the requested engine firing torque exceeds -5% but does not exceed -2%, then the next vehicle driving cycle begins, and the learning correction factor r is adjusted. Adapt Updated to m / 6 times the original value; 8) D learning correction factors r Adapt If, during the learning cycle, the difference between the actual engine firing torque and the requested engine firing torque does not exceed -5% but not more than -2%, then the next vehicle driving cycle begins, and the learning correction factor r is adjusted. Adapt Updated to 0.

[0016] The present invention also provides an engine control device based on a vehicle acceleration request, having a computer program that can execute an engine control method based on a vehicle acceleration request.

[0017] The present invention provides an engine control method and apparatus based on vehicle acceleration requests, which has the following beneficial effects: it optimizes the engine request air path torque to improve the intake control time delay caused by fresh air entering the cylinder through the throttle valve, and continuously learns and updates the engine request air path torque throughout the engine life cycle, which can improve torque response accuracy not only during the development stage, but also throughout the entire vehicle life cycle. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall process of the engine control method based on vehicle acceleration request of the present invention;

[0019] Figure 2 In step two of the engine control method based on vehicle acceleration request of the present invention, the engine request air path torque M is optimized. Air Req A flowchart illustrating the process of determining the air path filter coefficient k value;

[0020] Figure 3 In step two of the engine control method based on vehicle acceleration request of the present invention, the engine request air path torque M is optimized. Air Req Learning correction factor r Adapt A flowchart illustrating the process;

[0021] Figure 4 This is a schematic diagram of the engine control device based on vehicle acceleration request according to the present invention. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments, but these embodiments should not be construed as limiting the present invention.

[0023] The purpose of this invention is to provide an engine control method and apparatus based on vehicle acceleration requests.

[0024] Invention patent application CN202210303455.5, entitled "Method, Apparatus, Device, and Readable Storage Medium for Calculating Gas Flow Response Time," proposes a method for calculating the time required for fresh air to enter the cylinder via the throttle valve. Based on the engine torque request, the required fresh air intake volume is obtained. Since this fresh air intake volume ultimately enters through the throttle valve, there is a certain delay in the fresh air's journey from the throttle valve to the cylinder, resulting in a delay in the engine torque request. To improve torque request response capability, during vehicle acceleration, the required time t for fresh air to enter the cylinder via the throttle valve is calculated. Delay Control optimization is performed to improve vehicle dynamics requirements.

[0025] See Figure 1 The present invention provides an engine control method based on vehicle acceleration requests, comprising the following steps:

[0026] Step 1: Vehicle acceleration request triggering conditions: These include engine closed-loop control, engine operating status, engine coolant temperature range, brake pedal depressed, exhaust system heating requirements, no fuel cut-off request triggered, no knocking or pre-ignition, and the condition of requesting the rate of change of engine torque in the intake circuit before optimization. The specific process of this step is as follows:

[0027] By default, vehicle acceleration control uses existing known techniques. However, when the following conditions are met simultaneously, an optimized engine control method based on vehicle acceleration requests is adopted:

[0028] 1. The engine is not under closed-loop speed control; if the engine is under closed-loop speed control, its torque must not be disturbed to avoid affecting the accuracy of the closed-loop speed control.

[0029] 2. The engine is running;

[0030] 3. The engine coolant temperature is within the preset range, which in this embodiment refers to a coolant temperature between 60℃ and 100℃. If the coolant temperature is too low, the engine needs to warm up to improve fuel economy and emissions, resulting in relatively weak power performance; if the coolant temperature is too high, the engine is prone to knocking, etc. In order to protect the engine, it is necessary to limit the engine's power demand.

[0031] 4. Brake pedal not depressed; once the brake pedal is depressed, in order to protect the safety of the vehicle and people, engine acceleration is prohibited.

[0032] 5. The engine does not require exhaust system heating; the specific requirements for exhaust system acceleration are detailed in patent CN202110184814.5 "Ignition Efficiency Control Method Based on Engine Exhaust System Heating Requirements";

[0033] 6. The engine did not trigger a fuel cut-off request;

[0034] 7. The engine did not exhibit knocking or pre-ignition;

[0035] 8. The change rate of engine requested air path torque before optimization (engine requested air path torque before optimization refers to the engine requested torque before optimization by this invention; the change rate of engine requested air path torque refers to the engine requested air path torque in the current sampling period minus the engine requested air path torque in the previous sampling period divided by the sampling period; the sampling period in this embodiment is 10ms) exceeds the preset value, which is 15Nm / 10ms in this embodiment.

[0036] After all the above conditions are met

[0037] The engine's requested firing torque M is determined based on engine speed n and throttle opening pct. Sprk Req M Sprk Req =f(n,pct), this part is calibrated based on the vehicle's drivability requirements, and must meet both subjective drivability requirements and vehicle acceleration performance requirements. This part is a conventional technology.

[0038] Step 2: Optimize engine request for airflow torque M Air Req Based on the obtained original engine request air path torque M Air ReqRawBased on this, and combined with engine speed n, throttle opening pct, throttle opening change rate dpct, and the time t required for fresh air to enter the cylinder through the throttle valve, the following parameters are considered. Delay Determine the engine's requested airflow torque M Air Req This is then used as the air circuit torque for the driver's throttle request. The specific process of this step is as follows:

[0039] To improve the intake control time delay caused by fresh air entering the cylinder through the throttle valve, the engine control is optimized. This optimization can be achieved by optimizing the engine's requested air path torque, which is then used as the air path torque requested by the driver's throttle.

[0040] The following details the calculated and optimized engine requested airflow torque:

[0041] Based on engine speed n, throttle opening pct, throttle opening change rate dpct, and the time t required for fresh air to enter the cylinder through the throttle valve. Delay Determine the engine's requested airflow torque M Air Req .

[0042] 1. When the boost control closed loop is not activated (i.e., if the engine is a turbocharged engine, the boost pressure control is not in closed-loop control). When boost is not activated, the intake pressure and intake volume have poor responsiveness during vehicle acceleration, requiring a faster increase in the engine's requested airflow torque.

[0043] M Air Req (N)=M Air Req (N-1)+k×k C ×[M Air ReqRaw (N)-M Air Req (N-1)];

[0044] 2. When the boost control closed loop is activated (i.e., if the technology is applied to boost pressure control but closed-loop control is not achieved):

[0045] M Air Req (N)=M Air Req (N-1)+k×[M Air ReqRaw (N)-M Air Req (N-1)];

[0046] Among them, M Air ReqRaw == f(n, pct + dpct × t) Delay ), which will soon be pct+dpct×t Delay Set to "Throttle opening at which the engine requests airflow torque", where M Air ReqRaw The f function and the engine request fire torque M Sprk Req The f function uses the same algorithm; M Air Req(N) represents the engine's requested airflow torque during the Nth sampling period; M Air Req (N-1) represents the engine's requested airflow torque during the (N-1)th sampling period; M Air ReqRaw M is the engine's original request for air circuit torque. Air ReqRaw (N) represents the engine's original requested airflow torque M during the Nth sampling period. Air ReqRaw ;k C is a constant filter coefficient. If the engine is a turbocharged engine, it is 1.12 in this embodiment; if the engine is a non-turbocharged engine, it is 1 in this embodiment. k is the air path filter coefficient.

[0047] To avoid small fluctuations in throttle opening controlled by the driver and to prevent poor stability of the control system, the throttle opening change rate (dpct) is optimized. The method for obtaining the throttle opening change rate (dpct) is as follows:

[0048]

[0049] Where dpct(N) is the rate of change of throttle opening in the Nth sampling period, dpct(N-1) is the rate of change of throttle opening in the (N-1)th sampling period, pct(N) is the throttle opening in the Nth sampling period, pct(N-1) is the throttle opening in the (N-1)th sampling period, and N is a positive integer of 1, 2, 3, ...; the time when pct(0) occurs is the moment when all the above conditions are just met, and in this embodiment, pct(0) is taken as 0%; the time when dpct(0) occurs is the moment when all the above conditions are just met, and in this embodiment, Δpct(0) is taken as 0% / s, Δt is the sampling period, and t c The time constant is 40ms in this embodiment.

[0050] See Figure 2 The air path filter coefficient k is determined as follows:

[0051] k = f(n.rho) × k(pct,r) AirTrq ReqRatio )×k(dpct,d 2 pct)×k(r Sprk ,r SprkRatio )×(1+r Adapt )

[0052] That is, the air path filter coefficient k is determined by engine speed n, load rho (actual intake air density entering the cylinder), throttle opening pct, throttle opening change rate dpct, and the second derivative of throttle opening d. 2 pct(second derivative of throttle opening d) 2 PCT is obtained based on the throttle opening change rate dpct, and the method of obtaining it is the same as the calculation method of the throttle opening change rate dpct, with a corresponding time constant of 40ms and the current ignition efficiency r.Sprk Current ignition angle efficiency r Sprk The ratio of efficiency to the optimal ignition angle r SprkRatio (The current ignition angle efficiency is the actual ignition angle efficiency, while the optimal ignition angle efficiency is the ignition efficiency corresponding to the best ignition angle allowed under the current operating conditions. The optimal ignition angle is the ignition angle corresponding to the best braking torque of the MBT under the current operating conditions, and is determined by considering the ignition angle to avoid knocking. Finally, the ratio of the current ignition angle efficiency to the optimal ignition angle efficiency is referred to as the ignition efficiency ratio r.) SprkRatio The ratio r of the unoptimized engine requested airflow torque (referring to the engine requested airflow torque obtained before the optimization control of this invention, which is the original airflow torque) to the engine's maximum torque. AirTrq ReqRatio (For the engine's maximum torque, please refer to patent application CN202010632793.4, "Method for Determining the Maximum Output Torque of a Gasoline Engine." The ratio of the requested airflow torque to the engine's maximum torque is referred to as the airflow torque ratio r.) AirTrq ReqRatio Learning correction factor r Adapt Jointly determined. Among them, the learning correction factor r Adapt It will be stored after power-off, with a default value of 0. The specific learning method will be described later.

[0053] The following section details the methods for determining the various parameters of the gas path filter coefficient k, including the learning of the correction factor r during the determination process. Adapt If the value is 0, it will not be updated during the calibration of other parameters, but will be updated through self-learning at different stages of the vehicle's lifecycle after SOP.

[0054] 1) f(n.rho), determined by engine speed n and load rho, is the basic value of the air path filter coefficient k. Under different engine speeds and loads, the throttle opening pct is 20%, the throttle opening change rate dpct is 50% / s, and the second derivative of the throttle opening d 2 pct is 0% / s 2 Current ignition efficiency r Sprk The ignition efficiency ratio is 1, r SprkRatio =1, air circuit torque ratio r AirTrq ReqRatio The value was obtained from calibration at 0.5. The calibration basis is that, after the above conditions are met, the actual firing torque of the engine is not greater than the engine's requested firing torque (to ensure fuel economy), and the difference between the engine's requested firing torque and the engine's actual firing torque is not less than 5%. See Table 1 below for details:

[0055] Table 1

[0056]

[0057] 2) After f(n.rho) is calibrated, based on the rate of change of throttle opening dpct and the second derivative of throttle opening d2 pct determines k(dpct,d) 2 pct) is the first correction factor for the air path filter coefficient k, which is applied when the throttle opening pct is 20% and the current ignition efficiency r Sprk The ignition efficiency ratio is 1, r SprkRatio =1, air circuit torque ratio r AirTrqReqRatio To determine the rate of change of throttle opening dpct and the second derivative of throttle opening d at 0.5, we need to define the different rates of change of throttle opening dpct and d of throttle opening. 2 The larger the rate of change of throttle opening and the larger the second derivative of throttle opening, the larger the air path filter coefficient k. This leads to a faster increase in the engine's requested air path torque, resulting in a faster increase in the target air volume and thus a better response to changes in throttle opening. However, an excessively large air path filter coefficient k can cause excessive air volume fluctuations, affecting torque control overshoot. The calibration is based on the condition that, after meeting the above conditions, the difference between the engine's actual firing torque and the engine's requested firing torque does not exceed 2% (to ensure fuel economy), and the difference between the engine's requested firing torque and the engine's actual firing torque is not less than 5%. See Table 2 below for details.

[0058] Table 2

[0059]

[0060] The throttle opening change rate is 0% / s. The optimized engine requires a specific airflow torque M. AirReq Similar to the engine's requested airflow torque before optimization, calculations based on the previous formula show that no optimization was performed. However, the purpose of the filter coefficient in the table above when the throttle opening change rate is 0% / s is to interpolate the throttle opening change rate from 0% / s to 20% / s, ensuring that the calibration requirements are met even at throttle opening change rates less than 20% / s.

[0061] 3) After the above calibration is completed, based on the throttle opening pct and the air circuit torque ratio r AirTrq ReqRatio Determine k(pct,r) AirTrq ReqRatio ) is the second correction factor for the air path filter coefficient k, which is used when the throttle opening change rate dpct is 50% / s and the second derivative of the throttle opening d 2 pct is 0% / s 2 Current ignition efficiency r Sprk The ignition efficiency ratio is 1, r SprkRatio To determine the ratio of throttle opening (pct) and air circuit torque (r) under different conditions. AirTrq ReqRatio The effect of throttle opening being smaller, but with a lower air-to-gas torque ratio r... AirTrq ReqRatio The larger the value, the smaller the ability to optimize engine airflow torque, and the smaller the airflow filter coefficient k. Its calibration basis is that the optimized engine airflow torque does not exceed the engine's maximum torque, but is not limited by the engine's maximum torque. See Table 3 below for details:

[0062] Table 3

[0063]

[0064] 4) After the above calibration is completed, based on the current ignition efficiency r Sprk And the ratio of ignition efficiency r SprkRatio Determine k(r) Sprk ,r SprkRatio ) is the third correction factor for the air path filter coefficient k, which is applied when the throttle opening pct is 20%, the throttle opening change rate dpct is 50% / s, and the second derivative of the throttle opening d 2 pct is 0% / s 2 air circuit torque ratio r AirTrq ReqRatio To determine the throttle opening (pct) and air circuit torque ratio (r) under different conditions (0.5), AirTrq ReqRatio The impact of the current ignition efficiency r. Sprk The larger the ratio of ignition efficiency r SprkRatio The larger the value, the larger the air path filtering coefficient k. At this point, the ignition angle adjustment capability is too small, and the air path torque needs to be optimized. The calibration basis is that after the above conditions are met, the difference between the engine's actual firing torque and the engine's requested firing torque should not exceed 2% (to ensure fuel economy), and at the same time, the difference between the engine's requested firing torque and the engine's actual firing torque should not be less than 5%. See Table 4 below for details:

[0065] Table 4

[0066]

[0067]

[0068] See Figure 3 The following section details the learning correction factor r. Adapt The learning method includes the following learning trigger conditions:

[0069] 1) The engine is not under closed-loop speed control; if the engine is under closed-loop speed control, its torque must not be disturbed to avoid affecting the accuracy of the closed-loop speed control.

[0070] 2) The engine is running;

[0071] 3) The engine coolant temperature is within the preset range, which in this embodiment refers to a coolant temperature between 60℃ and 100℃. If the coolant temperature is too low, the engine needs to warm up to improve fuel economy and emissions, resulting in relatively weak power performance; if the coolant temperature is too high, the engine is prone to knocking, etc. In order to protect the engine, it is necessary to limit the engine's power demand.

[0072] 4) The brake pedal is not depressed; once the brake pedal is depressed, in order to protect the safety of the vehicle and people, the engine acceleration power request is prohibited;

[0073] 5) The engine does not perform the requirement of exhaust system heating; the specific exhaust system acceleration requirement is described in patent CN202110184814.5 "Ignition efficiency control method based on engine exhaust system heating requirement";

[0074] 6) The engine did not trigger a fuel cut-off request;

[0075] 7) The engine did not experience knocking or pre-ignition;

[0076] 8) The change rate of engine requested air path torque before optimization (engine requested air path torque before optimization refers to the engine requested torque before optimization by this patent; the change rate of engine requested air path torque refers to the engine requested air path torque in the current sampling period minus the engine requested air path torque in the previous sampling period divided by the sampling period; the sampling period in this embodiment is 10ms) exceeds the preset value, and in this embodiment it is taken as 15Nm / 10ms.

[0077] 9) Learning correction factor r Adapt If the vehicle mileage that has not been updated exceeds a preset value, this embodiment sets it to 5 kilometers to avoid excessively frequent learning.

[0078] After all the above conditions are met, proceed to learning the correction factor r. Adapt Learning process of working conditions;

[0079] Learning correction factor r Adapt Learning conditions: throttle opening, throttle opening change rate, and ignition efficiency r Sprk Divide the data into several intervals, and then divide the intervals of throttle opening, throttle opening rate of change, and ignition efficiency r into several intervals. Sprk Each interval is combined to form multiple learning correction factors r Adapt Corresponding learning conditions;

[0080] 1) Divide the throttle opening into 4 intervals: 0 ≤ pct ≤ 20%, 20% < pct ≤ 60%, 60% < pct ≤ 80%, and 80% < pct ≤ 100%.

[0081] 2) Divide the throttle opening change rate into 5 intervals: 0 ≤ dpct ≤ 20% / s, 20% / s < dpct ≤ 50% / s, 50% / s < dpct ≤ 100% / s, 100% / s < dpct ≤ 200% / s, and 200% / s < pct ≤ 500% / s.

[0082] 3) Improve ignition efficiency r Sprk Five intervals satisfying 0.1≤r Sprk ≤0.3, 0.3<rSprk ≤0.5, 0.5<r Sprk ≤0.7, 0.7<r Sprk ≤0.9, 0.9<r Sprk ≤1,

[0083] 4) The intervals that form 4*5*5=100 combinations are defined as 100 learning correction factors r. Adapt Learning and working conditions;

[0084] If the following occurs, then proceed to learning the correction factor r. Adapt Update process:

[0085] 1) 100 learning correction factors r Adapt If, during the learning cycle, the difference between the engine's requested firing torque and the actual firing torque exceeds 8%, then the next vehicle driving cycle begins, and the learning correction factor r is applied. Adapt Updated to 1.05 times the original size;

[0086] 2) 100 learning correction factors r Adapt In all learning scenarios, if the difference between the engine's requested firing torque and the actual firing torque exceeds 5% but does not exceed 8%, then the next vehicle driving cycle begins, and the learning correction factor r is applied. Adapt Updated to 1.02 times the original size;

[0087] 3) 100 learning correction factors r Adapt If, during the learning cycle, the difference between the actual engine torque and the requested engine torque exceeds 5%, the next vehicle driving cycle begins, and the learning correction factor r is applied. Adapt Updated to 0.8 times the original value;

[0088] 4) 100 learning correction factors r Adapt If, during the learning cycle, the difference between the actual engine firing torque and the requested engine firing torque exceeds 2% but does not exceed 5%, then the next vehicle driving cycle begins, and the learning correction factor r is applied. Adapt Updated to 0.95 times the original value;

[0089] 5) 100 learning correction factors r Adapt If, during the learning cycle, the difference between the actual engine firing torque and the requested engine firing torque exceeds -2% but does not exceed 2%, then the next vehicle driving cycle begins, and the learning correction factor r is applied. Adapt Keep unchanged;

[0090] 6) 100 learning correction factors r AdaptIf, during the learning cycle, the difference between the actual engine firing torque and the requested engine firing torque exceeds -5% but does not exceed -2%, then the next vehicle driving cycle begins, and the learning correction factor r is adjusted. Adapt Updated to 0.8 times the original value;

[0091] 7) 100 learning correction factors r Adapt If, during the learning cycle, the difference between the actual engine firing torque and the requested engine firing torque exceeds -5% but does not exceed -2%, then the next vehicle driving cycle begins, and the learning correction factor r is adjusted. Adapt Updated to 0.5 times the original value;

[0092] 8) 100 learning correction factors r Adapt If, during the learning cycle, the difference between the actual engine firing torque and the requested engine firing torque does not exceed -5% but not more than -2%, then the next vehicle driving cycle begins, and the learning correction factor r is adjusted. Adapt Updated to 0;

[0093] The learning correction factor r is used for each of the above 8 operating conditions. Adapt When updating learning, only one type is updated, and the priority of the above types decreases progressively.

[0094] Under other operating conditions, the learning correction factor r Adapt The update remains unchanged.

[0095] In learning the correction factor r Adapt Immediately after the update, the records of the difference between the actual engine firing torque and the requested engine firing torque for all 100 operating conditions are updated. That is, the difference between the actual engine firing torque and the requested engine firing torque for any of the 100 operating conditions needs to be re-evaluated. Initially, it is assumed that there is no difference between the actual engine firing torque and the requested engine firing torque. After the next learning condition is met, each operating condition will be re-evaluated.

[0096] Step 3: Determine the final engine airflow torque request: Arbitrate the airflow torque requested by the driver's throttle with other torque requests to obtain the final engine airflow torque request. Based on this final request, control the engine intake air density to increase the engine's airflow volume and improve the actual engine airflow torque, thereby meeting the vehicle's acceleration requirements. The specific process of this step is as follows:

[0097] Arbitrate the airflow torque requested by the driver's throttle with other torque requests (such as ESC, cruise control, etc.) to obtain the final engine airflow torque request. Based on the final engine airflow torque request, control the engine intake air density to increase the engine air volume and thus increase the engine's actual airflow torque. After the engine's actual airflow torque is increased, the engine's firing torque capability will also increase, thereby meeting the vehicle's acceleration needs.

[0098] The above describes the method for controlling the engine's requested airflow torque, ultimately limiting the engine's requested airflow torque within the engine's maximum torque range. Based on the engine's requested airflow torque, the intake volume is controlled to improve power performance.

[0099] See Figure 4 The present invention provides an engine control device based on a vehicle acceleration request, comprising the following parts:

[0100] Vehicle acceleration request trigger condition module: including engine closed-loop control, engine operating status, engine coolant temperature range, brake pedal depressed, exhaust system heating requirement, no fuel cut-off request triggered, no knocking or pre-ignition, and conditions for the engine to request the rate of change of air circuit torque before optimization.

[0101] Optimize engine request for airflow torque M Air Req Module: Based on the acquired engine raw request air path torque M Air ReqRaw Based on this, and combined with engine speed n, throttle opening pct, throttle opening change rate dpct, and the time t required for fresh air to enter the cylinder through the throttle valve, the following parameters are considered. Delay Determine the engine's requested airflow torque M Air Req And use it as the air circuit torque for the driver's throttle request;

[0102] The final engine requested air path torque module arbitrates the air path torque requested by the driver's throttle along with other torque requests to obtain the final engine requested air path torque. Based on the final engine requested air path torque, the engine intake air density is controlled to increase the engine air volume and improve the actual engine air path torque, thereby meeting the vehicle's acceleration requirements.

[0103] The technical principles and key points of this invention are as follows:

[0104] The key points of the vehicle acceleration engine control method in this application are:

[0105] Engine requests an airflow torque optimization algorithm;

[0106] Method for determining the filter coefficient for engine request airflow path torque optimization;

[0107] Engine request air path torque optimization filter coefficient learning factor learning method.

[0108] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

[0109] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

Claims

1. An engine control method based on vehicle acceleration requests, characterized in that: Includes the following steps: Vehicle acceleration request triggering conditions include: first engine closed-loop control, first engine operating state, first engine coolant temperature range, first brake pedal not depressed, first exhaust system heating requirement, first fuel cut-off request not triggered, first absence of knocking or pre-ignition, and first engine request for change rate of airflow torque. The specific details of the vehicle acceleration request triggering condition steps are as follows: First engine closed-loop control: The engine speed is not under closed-loop control; First engine operating status: The engine is running; Engine coolant temperature range: The engine coolant temperature is within the first preset range; First, the brake pedal was not pressed: The brake pedal was not pressed; First exhaust system heating requirement: The engine does not require exhaust system heating; First fuel cut-off request not triggered: The engine did not trigger a fuel cut-off request; First, no knocking or pre-ignition: The engine did not experience knocking or pre-ignition; First engine requested air path torque change rate: Before optimization, the engine requested air path torque change rate exceeded the first preset value; All of the above conditions must be met; Optimize engine request for airflow torque Based on the obtained engine's original requested airflow torque Based on this, combined with engine speed Throttle opening Throttle opening change rate Based on the time required for fresh air to enter the cylinder through the throttle valve. Determine the engine's requested airflow torque And use it as the air circuit torque for the driver's throttle request; Determine the final engine requested air path torque: Arbitrate the air path torque requested by the driver's throttle along with other torque requests to obtain the final engine requested air path torque. Based on the final engine requested air path torque, control the engine intake air density to increase the engine air volume, thereby increasing the actual engine air path torque and meeting the vehicle acceleration requirements.

2. The engine control method based on vehicle acceleration request according to claim 1, characterized in that: The optimized engine requests airflow torque The specific steps are as follows: Boost control closed loop not activated: When the boost control closed loop is not activated, the engine needs to request more torque from the intake system more quickly. ， Boost control closed-loop activation: When the boost control closed-loop is activated: ， in, ,Right now This refers to the throttle opening at which the engine requests torque from the air passage. Request the air path torque for the engine in the Nth sampling period; Request the air path torque for the engine in the (N-1)th sampling period; The engine's original requested airflow torque, The original request for the engine's airflow torque in the Nth sampling period ; The filter coefficients are constants. This represents the air path filtering coefficient.

3. The engine control method based on vehicle acceleration request according to claim 2, characterized in that: In the steps where the boost control closed loop is not activated or the boost control closed loop is activated, the throttle opening change rate... The method to obtain it is as follows: ， in, Let N be the rate of change of throttle opening during the Nth sampling period. The throttle opening change rate during the (N-1)th sampling period. For the throttle opening in the Nth sampling period, The throttle opening is the value in the (N-1)th sampling period, where N is a positive integer. It occurs when all conditions are met. It occurs when all conditions are met. The sampling period is is the time constant.

4. The engine control method based on vehicle acceleration request according to claim 3, characterized in that: In the step where the boost control closed loop is not activated or the boost control closed loop is activated, the gas path filter coefficient The value is determined as follows: That is, the air path filtering coefficient k is determined by the engine speed. ,load Throttle opening Throttle opening change rate Second-order differential of throttle opening Current ignition efficiency Current ignition angle efficiency Ratio of efficiency to optimal ignition angle Unoptimized engine request ratio of intake torque to maximum engine torque Learning correction factor A joint decision.

5. The engine control method based on vehicle acceleration request according to claim 4, characterized in that: The air path filtering coefficient The specific process for determining the value is as follows: The basic value of the air path filter coefficient k is determined by the engine speed. and load Definite This is the basic value of the air path filter coefficient k. The calibration basis is that after the above conditions are met, the actual firing torque of the engine is not greater than the engine's requested firing torque, and the difference between the engine's requested firing torque and the engine's actual firing torque is not less than 5%. First correction factor for air path filter coefficient k: After calibration, based on the rate of change of throttle opening Second derivative of throttle opening Sure It is the first correction factor for the air path filter coefficient k. The calibration basis is that when all conditions are met, the difference between the actual engine firing torque and the engine requested firing torque does not exceed 2%, and the difference between the engine requested firing torque and the engine actual firing torque is not less than 5%. Second correction factor for air path filter coefficient k: After completing the above calibration, based on throttle opening And air circuit torque ratio Sure It is the second correction factor of the air path filter coefficient k. The calibration basis is that the optimized engine air path torque does not exceed the engine maximum torque, but is not limited by the engine maximum torque. The third correction factor for the gas path filter coefficient k: After completing the above calibration, based on the current ignition efficiency and ignition efficiency ratio Sure It is the third correction factor of the air path filter coefficient k. The calibration basis is that after the above conditions are met, the difference between the actual engine fire path torque and the engine requested fire path torque shall not exceed 2%, and the difference between the engine requested fire path torque and the engine actual fire path torque shall not be less than 5%.

6. The engine control method based on vehicle acceleration request according to claim 5, characterized in that: In the step where the boost control closed loop is not activated or the boost control closed loop is activated, the learning correction factor The determination process is as follows: Learning trigger conditions include: second engine closed-loop control, second engine operating status, second engine coolant temperature range, second brake pedal not pressed, second exhaust system heating demand, second fuel cut-off request not triggered, second knock or pre-ignition, second engine request for air circuit torque change rate, and conditions for updating vehicle mileage preset value. Among them, 1) the engine speed was not under closed-loop control; 2) The engine is running; 3) Engine coolant temperature is within the preset range; 4) The brake pedal was not depressed; 5) The engine does not meet the requirement for exhaust system heating; 6) The engine did not trigger a fuel cut-off request; 7) The engine did not exhibit knocking or pre-ignition; 8) Before optimization, the engine requested a change rate of torque in the air path exceeding the preset value; 9) Learning correction factor The vehicle's mileage has exceeded the preset value. All of the above conditions must be met; Learning correction factor Learning conditions: throttle opening, throttle opening change rate, and ignition efficiency. Divide the data into several intervals, including the intervals for throttle opening, the intervals for the rate of change of throttle opening, and ignition efficiency. Each interval is combined to form multiple learning correction factors Corresponding learning conditions; Learning correction factor Update processing: Based on the distribution range of the difference between the engine's requested firing torque and the engine's actual firing torque in the learning operating conditions, a correction factor is learned for each of the 8 operating conditions. The learning update only updates one type of function; under other operating conditions, the learning correction factor is adjusted. The update remains unchanged; the learning correction factor is used. Immediately after the update, the records of the difference between the engine's actual firing torque and the engine's requested firing torque for all operating conditions are updated. That is, the difference between the engine's actual firing torque and the engine's requested firing torque for any operating condition under all operating conditions is re-evaluated. Initially, it is assumed that there is no difference between the engine's actual firing torque and the engine's requested firing torque. After the next learning conditions are met, each operating condition is re-evaluated.

7. The engine control method based on vehicle acceleration request according to claim 6, characterized in that: The learning correction factor The specific process for learning operating conditions is as follows: Throttle opening range: Divide the throttle opening into A ranges; Throttle opening change rate range: Divide the throttle opening change rate into B ranges; Ignition efficiency Range: Ignition efficiency Divide into C intervals; The above constitutes A B The intervals for C=D combinations are determined as D learning correction factors. Learning and working conditions.

8. The engine control method based on vehicle acceleration request according to claim 7, characterized in that: The learning correction factor The specific operation procedures for the eight working conditions in the update processing steps are as follows: 1) D learning correction factors If, during the learning cycle, the difference between the engine's requested firing torque and the actual firing torque exceeds 8%, then the next vehicle driving cycle begins, and the correction factor is learned. Updated to m1 times the original value; 2) D learning correction factors In all learning scenarios, if the difference between the engine's requested firing torque and the actual firing torque exceeds 5% but does not exceed 8%, then the next vehicle driving cycle begins, and the correction factor is learned. Updated to m2 times the original value; 3) D learning correction factors If, during the learning cycle, the difference between the engine's actual firing torque and the engine's requested firing torque exceeds 5%, then the next vehicle driving cycle begins, and the learning correction factor is activated. Updated to m3 times the size of the previous version; 4) D learning correction factors If, during the learning cycle, the difference between the actual engine torque and the requested engine torque exceeds 2% but does not exceed 5%, then the next vehicle driving cycle begins, and the correction factor is learned. Updated to 4 times the size of the previous version; 5) D learning correction factors If, during the learning cycle, the difference between the engine's actual firing torque and the engine's requested firing torque exceeds -2% but does not exceed 2%, then the next vehicle driving cycle begins, and the learning correction factor is activated. Keep unchanged; 6) D learning correction factors If, during the learning cycle, the difference between the actual engine firing torque and the requested engine firing torque exceeds -5% but does not exceed -2%, then the next vehicle driving cycle begins, and the learning correction factor is activated. Updated to 5 times the size of the previous version; 7) D learning correction factors If, during the learning cycle, the difference between the actual engine firing torque and the requested engine firing torque exceeds -5% but does not exceed -2%, then the next vehicle driving cycle begins, and the learning correction factor is activated. Updated to 6 times the size of the previous version; 8) D learning correction factors If, during the learning cycle, the difference between the actual engine firing torque and the requested engine firing torque does not exceed -5% but does not exceed -2%, then the next vehicle driving cycle begins, and the correction factor is learned. Updated to 0.

9. An engine control device based on vehicle acceleration requests, comprising a computer program, characterized in that: The computer program is capable of executing the engine control method based on vehicle acceleration requests as described in any one of claims 1 to 8.

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