Method for pressure signal alignment at engine shutdown

Abstract

The application discloses a method for checking pressure signals when an engine stops, which comprises the following steps: reading a throttle inlet pressure signal and a throttle rear pressure signal in real time when a throttle pressure checking condition is met; and judging whether the throttle inlet pressure signal is faulty according to the throttle inlet pressure signal, the throttle rear pressure signal and a preset time. The method provided by the application can check the rationality of a pressure signal of a pressure sensor before a throttle when an engine stops.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engine control, and particularly relates to a pressure signal checking method when an engine is stopped. BACKGROUND

[0002] When the engine is stopped, each pressure signal should be less different from the atmospheric pressure, so it is necessary to check whether the pressure signal when the engine is stopped is reasonable.

[0003] A patent with the application number 202110982953.2 discloses a throttle flow calculation method, device and equipment and readable storage medium, which estimates EGR method flow by using throttle front pressure (inlet pressure) and rear pressure (outlet pressure), but does not propose a pressure signal checking method when the engine is stopped.

[0004] A patent with the application number 202110518171.3 discloses a measurement method and device of EGR mass flow and exhaust gas treatment system, which estimates EGR method flow by using throttle front pressure (inlet pressure) and rear pressure (outlet pressure), but does not propose a pressure signal checking method when the engine is stopped. SUMMARY

[0005] The present application solves the technical problems of the prior art and provides a pressure signal checking method when the engine is stopped, which can check the rationality of the throttle front pressure sensor pressure signal when the engine is stopped.

[0006] To achieve the above-mentioned purpose, according to one aspect of the present application, a pressure signal checking method when the engine is stopped is provided, comprising: when the throttle pressure checking condition is met, reading the throttle inlet pressure signal and the throttle rear pressure signal in real time;

[0007] According to the throttle inlet pressure signal, the throttle rear pressure signal and the preset time, it is judged whether the throttle inlet pressure signal is faulty.

[0008] In the above-mentioned scheme, the specific method for judging whether the throttle inlet pressure signal is faulty is: when the throttle pressure checking condition is met, the throttle inlet pressure signal p ThrBfAct and the throttle rear pressure signal p ThrAftAct If the following conditions occur: and the continuous occurrence time exceeds the preset time t1, it is determined that the throttle inlet pressure signal is faulty; otherwise, it is determined that the throttle inlet pressure signal is not faulty.

[0009] In the above-mentioned scheme, the throttle pressure checking condition is:

[0010] (1) The length of time that the engine speed does not exceed the preset value exceeds the preset time t EngMovingDelay ; wherein the engine speed preset value is 30 rpm;

[0011] (2) Neither the atmospheric pressure sensor nor the throttle valve post-pressure sensor has failed;

[0012] (3) The difference between the atmospheric pressure signal and the throttle valve post-pressure signal is within a preset range; wherein the preset range is ±0.3 kPa.

[0013] (4) The fluctuations of the atmospheric pressure signal and the throttle valve post-pressure signal are both not more than a preset range; wherein the preset range is ±0.1 kPa.

[0014] wherein t EngMovingDelay = t EngMovingDelayRaw × (1 + r Delay ), t EngMovingDelayRaw is the preset time initial value, r Delay is the preset time learning correction coefficient, the initial value of which is 0 and is constantly learned and updated, and can be saved after the vehicle is powered off.

[0015] The throttle valve opening degree pct ThrActOff is more and more away from the natural opening degree (the natural opening degree refers to the opening degree of the throttle valve motor when it is not controlled, i.e. the opening degree by default when it is not powered on), the intake system airflow is still flowing, and therefore more time needs to be delayed before entering the throttle valve inlet pressure signal check. Based on test verification, the accuracy of the throttle valve inlet pressure signal check is ensured, and the preset time initial value t EngMovingDelayRaw is calibrated in connection with the throttle valve opening degree pct ThrActOff . The results are shown in the preset time initial value t EngMovingDelayRaw vs. the throttle valve opening degree pct ThrActOff table.

[0016] The preset time initial value t EngMovingDelayRaw depends on the throttle valve opening degree pct ThrActOff at the time when the engine speed does not exceed the preset value, wherein the preset time initial value t EngMovingDelayRaw vs. the throttle valve opening degree pct ThrActOff table is as follows:

[0017]

[0018] The reason for only focusing on the throttle valve opening degree between 0% and 9% is that when the engine requests to stop, the throttle valve is preferentially fully closed and then slowly enters the natural opening degree to quickly reduce the engine torque and achieve rapid stopping. t EngMovingDelayRaw The shorter the time, the greater the throttle valve inlet pressure fluctuation at this time and the greater the fluctuation from the stable pressure value at the engine stop time. If tEngMovingDelayRaw Too long time, may cause pressure signal check detection late, pressure signal check efficiency is lower, controller needs power supply time long and leads to power consumption.

[0019] The throttle opening degree pct ThrActOff Determined by adopting a control method of electronic throttle valve of exhaust turbocharged engine (for reference to CN111255581A Chinese patent), the control method of electronic throttle valve of exhaust turbocharged engine is:

[0020] Step 1: Set throttle full opening exit flag, throttle full opening preparation exit flag and transient throttle full opening flag in throttle controller;

[0021] Throttle full opening exit flag is 1 when the difference between throttle inlet pressure and throttle target inlet pressure is greater than the calibrated value A1, and 0 when it is less than the calibrated value A2, A1 is greater than A2;

[0022] Throttle full opening preparation exit flag is 1 when the difference between estimated throttle inlet pressure and estimated throttle target inlet pressure is greater than the calibrated value B1, and 0 when it is less than the calibrated value B2, B1 is greater than B2;

[0023] Transient throttle full opening flag is 1 when the difference between throttle inlet pressure and throttle outlet pressure is less than the calibrated value C1, and 0 when it is greater than the calibrated value C2, C1 is less than C2;

[0024] Step 2: When the throttle full opening exit flag is 1, the throttle control mode is the normal throttle control mode, in which the effective area of the throttle is the target throttle effective area A Eff ;

[0025] Step 3: When the throttle full opening exit flag is 0, the throttle control mode at the last time is the normal throttle control mode, and the transient throttle full opening flag is 0, the throttle enters the normal throttle control mode;

[0026] Step 4: When the throttle full opening exit flag is 0, and the transient throttle full opening flag is 1, and the throttle full opening preparation exit flag is 1, the throttle enters the throttle anti-hunting control mode, in which the effective area of the throttle is the adjusted target throttle effective area min(A Eff1 ,A Eff2 ), and the adjusted target throttle effective area is not less than A Eff , wherein A Eff1 is obtained by multiplying A Eff by a preset compensation coefficient, A Eff2 is obtained by multiplying A EffThe preset compensation amount is added to obtain;

[0027] Step 5: when the full throttle exit flag bit is 0, the full throttle allowed flag bit is 1, and the full throttle preparation exit flag bit is 0, the throttle enters the full throttle control mode, and the effective area of the throttle in the full throttle control mode is the target full throttle effective area A EffMax , and the target throttle effective area change rate is the maximum change rate allowed by the throttle when the throttle is fully open;

[0028] The throttle opening pct ThrActOff = (A eff '-A0) / (A 100 -A0) x 100%; wherein A eff ' is the final throttle effective area after processing by different throttle control modes, the minimum throttle opening 0% and the maximum throttle opening 100% correspond to the throttle effective areas A 100 and A0.

[0029] In the above scheme, the preset time learning correction coefficient r Delay is obtained by the following method:

[0030] When it is determined that the throttle inlet pressure signal has no fault, the throttle inlet pressure signal is recorded from when the engine enters the shutdown working condition and the engine speed does not exceed the preset value, and the throttle inlet pressure signal is filtered:

[0031] p ThrBfActFilter (N) = K ThrBf x [p ThrBfAct (N)-p ThrBfActFilter (N-1)] + p ThrBfActFilter (N-1); wherein

[0032] p ThrBfAct is the throttle inlet pressure, p ThrBfAct (N) is the throttle inlet pressure in the Nth sampling period, p ThrBfActFilter is the first-order low-pass filtered throttle inlet pressure, p ThrBfActFilter (N) is the filtered throttle inlet pressure in the Nth sampling period, p ThrBfActFilter (N-1) is the filtered throttle inlet pressure in the (N-1)th sampling period, N = 1, 2, 3,..., and p ThrBfActFilter (0) is equal to the throttle inlet pressure p ThrBfAct (0) in the 0th sampling period; wherein the 0th sampling period is the sampling period at the time when the engine enters the shutdown working condition and the engine speed does not exceed the preset value, and the sampling period interval time is Δt; K ThrBf is the filtering coefficient.

[0033] Record the time from when the engine enters the shutdown condition and the engine speed does not exceed the preset value until p no longer occurs. ThrBfAct (N)-p ThrBfActFilter (N)>min[p ThrBfAct (N), p ThrBfActFilter (N)]×r ThrBfActLim The shortest time is t0, and the throttle opening pct is recorded at the moment when the engine enters the shutdown condition and the engine speed does not exceed the preset value. ThrActOff0 and atmospheric pressure; where r ThrBfActLim The preset value is used; the preset time learning correction coefficient r is set to... Delay The update methods are as follows:

[0034] First scenario: If the engine enters a shutdown state and the engine speed does not exceed the preset throttle opening value (pct) at that moment. ThrActOff0 When it is greater than 9%, and the previous preset time learning correction coefficient r Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure exceeds a preset value, then only the preset time learning correction coefficient r at a throttle opening of 9% will be updated. Delay The preset time learning correction coefficient r is not updated at other throttle openings. Delay The update calculation formula is: Where, r Delay (z) represents the preset time learning correction coefficient of the last self-learning update, and k1 is the weighting coefficient; if the engine enters the shutdown condition and the engine speed does not exceed the preset value of the throttle opening pct at that time. ThrActOff0 When it is greater than 9%, and the previous preset time learning correction coefficient r Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure does not exceed a preset value, then the preset time learning correction coefficient r under any throttle opening will not be updated this time. Delay ;

[0035] Second scenario: If the engine enters a shutdown state and the engine speed does not exceed the preset throttle opening value (pct) at that time. ThrActOff0 The value can be one of 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, or 9%, if the previous preset time learning correction coefficient r Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure exceeds a preset value, then only the preset time learning correction coefficient r at the corresponding throttle opening is updated. Delay The preset time learning correction coefficient r is not updated at other throttle openings. Delay The preset time learning correction coefficient r Delay The update calculation formula is: Where, r Delay (z) represents the preset time learning correction coefficient from the previous self-learning update, and k1 is the weighting coefficient; if the preset time learning correction coefficient r Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure does not exceed a preset value, then the preset time learning correction coefficient r under any throttle opening will not be updated this time. Delay ;

[0036] Third scenario: If the engine enters a shutdown state and the engine speed does not exceed the preset throttle opening value (pct) at that time. ThrActOff0 The value is located between two adjacent values ​​in the range of 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, and 9%. If the previous preset time learning correction coefficient r... Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure exceeds a preset value, then only the preset time learning correction coefficient r for the corresponding throttle opening will be updated. Delay The preset time learning correction coefficient r is not updated at other throttle openings. Delay If the learning correction coefficient r for the previous preset time is... Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure does not exceed a preset value, then the preset time learning correction coefficient r under any throttle opening will not be updated this time. Delay The method for determining the corresponding throttle opening range is as follows: Assuming the engine enters a shutdown state and the engine speed does not exceed a preset value, the throttle opening is pct at that moment. ThrActOff0 The value is between throttle opening A and B, where A and B are a pair of adjacent values ​​from 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, and 9%. If the preset time t corresponds to the throttle opening A read before this update... EngMovingDelay For t A The preset time t corresponding to the throttle opening B read before this update EngMovingDelay For t B Determine the throttle opening pct ThrActOff The corresponding preset time learning correction coefficient r Delay Use r Delay (pct ThrActOff If ) indicates that:

[0037] Where r Delay (pct ThrActOff (z) represents the throttle opening value updated during the last self-learning process, which is pct. ThrActOff The preset time learning correction coefficient is set below, and k2 is the weighting coefficient; simultaneously, the preset time learning correction coefficients for throttle opening A and throttle opening B are updated, respectively using r Delay(A) and r Delay (B) represents:

[0038]

[0039] wherein k3, k4 are preset weighting coefficients.

[0040] The updated stop working condition of each throttle opening pct ThrActOff The preset time learning correction coefficient r Delay According to the stop working condition of the throttle opening pct ThrActOff Separately stored, and the preset time t EngMovingDelay For the judgment of the throttle pressure checking condition.

[0041] Overall, the above technical solutions conceived by the present application compared with the prior art, the following beneficial effects can be achieved:

[0042] The present application provides a method for pressure signal calibration when the engine stops, which improves the speed and accuracy of subsequent throttle inlet pressure signal verification by calibrating the pressure under engine stop working condition and constantly updating self-learning parameters during pressure signal verification. BRIEF DESCRIPTION OF DRAWINGS

[0043] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become apparent to those of ordinary skill in the art. The drawings are for the purpose of illustrating the preferred embodiments only and are not to be considered as limiting of the present application. Moreover, the same reference numerals are used throughout the several views to designate the same or similar parts. In the drawings:

[0044] Figure 1 The figure is a schematic diagram of the intake system of a waste gas turbocharged engine in the embodiment of the present application.

[0045] Figure 2 The figure is a schematic diagram of the flow of the method for pressure signal calibration when the engine stops in the embodiment of the present application. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application. In addition, the technical features involved in each embodiment of the present application described below can be combined with each other as long as they do not conflict with each other.

[0047] It should be understood that the sequence number of each step in the embodiment does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0048] Example 1

[0049] The main components of the intake system of the turbocharged exhaust engine upon which this invention is based include: atmospheric pressure sensor, turbocharger, electronic wastegate, intercooler, pre-throttle temperature and pressure sensor, throttle body, post-throttle intake temperature and pressure sensor, carbon canister solenoid valve, EGR, VVT system, etc. Figure 1 As shown in the diagram. The atmospheric pressure sensor reads atmospheric pressure and is installed on the PCB board of the ECU controller. The turbocharger includes the turbocharger body and a wastegate valve; the boost pressure is controlled by adjusting the opening of the wastegate valve. The electronic pressure relief valve opens to prevent airflow from oscillating within the turbocharger compressor when the engine requests reduced torque, thus improving turbocharger surge, engine life, and NVH (noise, vibration, and harshness). The throttle body temperature and pressure sensor reads the temperature and pressure of the boosted gas before the throttle body. The intercooler is a mechanical component, uncontrolled, located between the turbocharger compressor and the throttle body, cooling the boosted gas. The throttle body intake air temperature and pressure sensor reads the temperature and pressure of the boosted gas before the throttle body. The carbon canister solenoid valve introduces fuel vapor into combustion and prevents it from evaporating into the atmosphere.

[0050] EGR, or Exhaust Gas Recirculation, returns a portion of the exhaust gas from the engine to the intake manifold, where it mixes with fresh air and re-enters the cylinders. VVT is used to adjust the intake (exhaust) volume, valve opening and closing time, and angle to regulate the amount of air entering the cylinders. The throttle inlet pressure signal verification in this invention verifies the validity of the pressure signal from the throttle inlet pressure sensor.

[0051] This application, according to one aspect of the present invention, provides a method for calibrating pressure signals when an engine is stopped. (See attached document.) Figure 2 ,include:

[0052] S1, when the throttle pressure check conditions are met, read the throttle inlet pressure signal and the throttle outlet pressure signal in real time;

[0053] S2 determines whether the throttle inlet pressure signal is faulty based on the throttle inlet pressure signal, the throttle outlet pressure signal, and the preset time.

[0054] Specifically, in this embodiment, the method for determining whether the throttle inlet pressure signal is faulty is as follows: when the throttle pressure check conditions are met, the throttle inlet pressure signal p is read in real time. ThrBfAct With the pressure signal p after the throttle valve ThrAftAct If the following occurs: and the continuous occurrence time exceeds a preset time t1 (0.5s in this example), it is determined that the throttle inlet pressure signal is faulty; otherwise, it is determined that the throttle inlet pressure signal is not faulty.

[0055] In this embodiment, the throttle pressure checking condition is:

[0056] (1) The length of time during which the engine speed does not exceed a preset value (30rpm in this example) exceeds a preset time t EngMovingDelay ;

[0057] wherein t EngMovingDelay =t EngMovingDelayRaw ×(1+r Delay ), t EngMovingDelayRaw is a preset time initial value, r Delay is a preset time learning correction coefficient, which has an initial value of 0 and is constantly updated and saved after the vehicle is powered off.

[0058] The greater the difference between the throttle opening pct ThrActOff and the natural opening (the opening of the throttle motor when it is not controlled, i.e., the opening when it is not powered on, which is between 7% and 9% in this example), the longer the intake system airflow needs to be delayed to enter the throttle inlet pressure signal checking. Based on test verification, the preset time initial value t EngMovingDelayRaw is calibrated in relation to the throttle opening pct ThrActOff , and the results are shown in the preset time initial value t EngMovingDelayRaw vs. throttle opening pct ThrActOff table.

[0059] The preset time initial value t EngMovingDelayRaw depends on the throttle opening pct ThrActOff at the moment when the engine speed does not exceed a preset value, and the preset time initial value t EngMovingDelayRaw vs. throttle opening pct ThrActOff table is as follows:

[0060]

[0061] The reason for only focusing on throttle openings between 0% and 9% is that when the engine requests to stop, the throttle is preferentially fully closed and then slowly enters the natural opening to quickly reduce engine torque and achieve rapid stopping. The shorter the t EngMovingDelayRaw time, the greater the throttle inlet pressure fluctuation at this time and the stable pressure value is not maintained at the engine stop moment. If t EngMovingDelayRawIf the time is too long, the pressure signal verification and detection may be delayed, the pressure signal verification efficiency may be low, and the controller may need to be powered for a long time, resulting in power consumption.

[0062] Throttle opening PCT ThrActOff The method was determined by using the electronic throttle control method of an exhaust gas turbocharged engine (see Chinese Patent Publication No. CN111255581A for details).

[0063] (2) Neither the atmospheric pressure sensor nor the throttle body pressure sensor malfunctioned;

[0064] (3) The difference between the atmospheric pressure signal and the pressure signal after the throttle valve is within the preset range, which is ±0.3 kPa in this example;

[0065] (4) The fluctuations of atmospheric pressure signal and throttle body pressure signal do not exceed the preset range. In this example, the range is ±0.1 kPa.

[0066] In this embodiment, the preset time learning correction coefficient r Delay The method for obtaining it is as follows:

[0067] When the throttle inlet pressure signal is determined to be fault-free, the throttle inlet pressure signal is recorded starting when the engine enters a shutdown state and the engine speed does not exceed a preset value (30 rpm in this example), and the throttle inlet pressure signal is filtered: p ThrBfActFilter (N)=K ThrBf ×[p ThrBfAct (N)-p ThrBfActFilter [(N-1)]+p ThrBfActFilter (N-1); where p ThrBfAct p is the throttle inlet pressure. ThrBfAct (N) represents the throttle inlet pressure during the Nth sampling period, p ThrBfActFilter p is the throttle inlet pressure after first-order low-pass filtering. ThrBfActFilter (N) represents the filtered throttle inlet pressure during the Nth sampling period, p ThrBfActFilter (N-1) represents the filtered throttle inlet pressure during the (N-1)th sampling period, where N = 1, 2, 3, ..., p ThrBfActFilter (0) equals the throttle inlet pressure p at the 0th sampling period. ThrBfAct (0); where the 0th sampling period is the sampling period when the engine enters the shutdown condition and the engine speed does not exceed the preset value (30 rpm in this example), and the sampling period interval is Δt, which is 10 ms in this example; K ThrBf The filter coefficient is 0.02 in this example;

[0068] Record the time from when the engine enters the shutdown condition and the engine speed does not exceed the preset value (30 rpm in this example) until the occurrence of |p ThrBfAct (N)-p ThrBfActFilter (N)>min[p ThrBfAct (N), p ThrBfActFilter (N)]×r ThrBfActLim The shortest time is t0, and the throttle opening pct is recorded at the moment when the engine enters the shutdown condition and the engine speed does not exceed the preset value (30 rpm in this example). ThrActOff0 and atmospheric pressure; where r ThrBfActLim The preset value is 0.05 in this example; the preset time learning correction coefficient r is... Delay The update methods are as follows:

[0069] First scenario: If the engine enters a shutdown state and the engine speed does not exceed the preset throttle opening value (pct) at that moment. ThrActOff0 When it is greater than 9%, and the previous preset time learning correction coefficient r Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure exceeds a preset value (±3 kPa in this example), then only the preset time learning correction coefficient r at a throttle opening of 9% will be updated. Delay No updates are made at other throttle openings; the preset time learning correction coefficient r is used. Delay The update calculation formula is: Where, r Delay (z) represents the preset time learning correction coefficient of the last self-learning update, and k1 is the weighting coefficient, which is 0.01 in this example; if the engine enters the shutdown condition and the engine speed does not exceed the preset value, the throttle opening pct is... ThrActOff0 When it is greater than 9%, and the previous preset time learning correction coefficient r Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure does not exceed a preset value, then the preset time learning correction coefficient r under any throttle opening will not be updated this time. Delay ;

[0070] Second scenario: If the engine enters a shutdown state and the engine speed does not exceed the preset throttle opening value (pct) at that time. ThrActOff0 The value can be one of 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, or 9%, if the previous preset time learning correction coefficient r Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure exceeds a preset value (±3 kPa in this example), then only the preset time learning correction coefficient r at the corresponding throttle opening is updated. Delay The preset time learning correction coefficient r is not updated under other throttle opening conditions. Delay Let the time learning correction coefficient be r.Delay The update calculation formula is: Where, r Delay (z) represents the preset time learning correction coefficient of the last self-learning update, and k1 is the weighting coefficient, which is 0.01 in this example; if the preset time learning correction coefficient r Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure does not exceed a preset value, then the preset time learning correction coefficient r under any throttle opening will not be updated this time. Delay ;

[0071] Third scenario: If the engine enters a shutdown state and the engine speed does not exceed the preset throttle opening value (pct) at that time. ThrActOff0 The value is located between two adjacent values ​​in the range of 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, and 9%. If the previous preset time learning correction coefficient r... Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure exceeds a preset value (±3 kPa in this example), then only the preset time learning correction coefficient r for the corresponding throttle opening will be updated. Delay The preset time learning correction coefficient r is not updated at other throttle openings. Delay If the learning correction coefficient r for the previous preset time is... Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure does not exceed a preset value, then the preset time learning correction coefficient r under any throttle opening will not be updated this time. Delay The method for determining the corresponding throttle opening range is as follows: Assuming the engine enters a shutdown state and the engine speed does not exceed the preset value, the throttle opening is pct at that moment. ThrActOff0 Between throttle openings A and B, where A and B are a pair of adjacent values ​​from 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, and 9%, if the preset time t corresponding to the throttle opening A read before this update... EngMovingDelay For t A The preset time t corresponding to the throttle opening B read before this update EngMovingDelay For t B Determine the throttle opening (pct) ThrActOff The corresponding preset time learning correction coefficient r Delay Use r Delay (pct ThrActOff If ) indicates that:

[0072] Where r Delay (pct ThrActOff (z) represents the throttle opening value updated during the last self-learning process, which is pct. ThrActOffk2 is a weighting coefficient, and in the example, 0.01 is taken; meanwhile, the preset time learning correction coefficient of the throttle opening A and the throttle opening B is updated, and r Delay (A) and r Delay (B) are represented as follows:

[0073]

[0074] wherein k3 and k4 are preset weighting coefficients, and in the example, k3 is taken as 0.85, and k4 is taken as 0.85.

[0075] In summary, the method for checking the pressure signal of the engine at the time of shutdown can check the rationality of the pressure signal of the pressure sensor before the throttle at the time of engine shutdown.

[0076] It should be noted that, according to the needs of implementation, each step described in the present application can be split into more steps, or two or more steps or part of the operation of the step can be combined into a new step to achieve the purpose of the present application.

[0077] Those skilled in the art will readily understand that the above description is only the preferred embodiment of the present application, and is not intended to limit the present application, and any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. An engine shutdown time pressure signal correlation method, characterized by, The method comprises the following steps: When the throttle pressure checking condition is met, the throttle inlet pressure signal and the throttle outlet pressure signal are read in real time; According to the throttle inlet pressure signal, the throttle outlet pressure signal and a preset time, it is judged whether the throttle inlet pressure signal is faulty or not; The throttle pressure checking condition is: (1) the length of time that the engine speed does not exceed the preset value exceeds the preset time t EngMovingDelay ; (2) The atmospheric pressure sensor and the throttle outlet pressure sensor are not faulty; (3) The difference between the atmospheric pressure signal and the throttle outlet pressure signal is within a preset range; (4) The fluctuations of the atmospheric pressure signal and the throttle outlet pressure signal are not more than a preset range; The preset time t EngMovingDelay = t EngMovingDelayRaw × (1 + r Delay ), t EngMovingDelayRaw is a preset time initial value, wherein r Delay is a preset time learning correction coefficient, an initial value of which is 0 and is constantly learned and updated, and can be saved after the vehicle is powered off; The preset time learning correction coefficient r Delay The acquisition method is that: If the engine enters the stop working condition and the throttle opening pct at the moment when the engine speed does not exceed the preset value is greater than 9% ThrActOff0 and the difference between the atmospheric pressure corresponding to the update of the preset time learning correction coefficient r Delay and the current atmospheric pressure exceeds the preset value, only the preset time learning correction coefficient r at the throttle opening of 9% is updated Delay and the preset time learning correction coefficient r Delay at other throttle openings is not updated, and the update calculation formula of the preset time learning correction coefficient r is: wherein, r Delay (z) is the preset time learning correction coefficient updated last time, and k1 is a weighting coefficient; if the engine enters the stop working condition and the throttle opening pct at the moment when the engine speed does not exceed the preset value is greater than 9% ThrActOff0 and the difference between the atmospheric pressure corresponding to the update of the preset time learning correction coefficient r Delay and the current atmospheric pressure does not exceed the preset value, the preset time learning correction coefficient r at any throttle opening is not updated this time Delay .

2. The engine off pressure signal to flag method of claim 1, wherein, The specific method for judging whether the throttle inlet pressure signal is faulty or not is: When the throttle pressure check condition is met, the throttle inlet pressure signal p is read in real time ThrBfAct and the throttle post-pressure signal p ThrAftAct If: and the continuous occurrence time exceeds the preset time t1, it is determined that the throttle inlet pressure signal has a fault; otherwise, it is determined that the throttle inlet pressure signal does not have a fault.

3. The engine off pressure signal to flag method of claim 1, wherein, The preset time initial value t EngMovingDelayRaw The throttle opening degree pct at the time when the engine rotation speed does not exceed the preset value ThrActOff The preset time initial value t ThrActOff The preset time initial value t EngMovingDelayRaw Corresponding values 12000ms, 10000ms, 6000ms, 4000ms, 2000ms, 1200ms, 1000ms, 500ms, 500ms.

4. The engine off pressure signal to flag method of claim 3, wherein, The preset time learning correction coefficient r Delay The acquisition method is that: when it is determined that the throttle inlet pressure signal is not malfunctioning, recording the throttle inlet pressure signal from when the engine enters a shutdown operating condition and the engine speed does not exceed a preset value, and filtering the throttle inlet pressure signal: p ThrBfActFilter (N) = K ThrBf × [p ThrBfAct (N) - p ThrBfActFilter (N-1)] + p ThrBfActFilter (N-1); wherein p ThrBfAct is the throttle inlet pressure, p ThrBfAct (N) is the throttle inlet pressure in the Nth sampling period, p ThrBfActFilter is the first-order low-pass filtered throttle inlet pressure, p ThrBfActFilter (N) is the filtered throttle inlet pressure in the Nth sampling period, p ThrBfActFilter (N-1) is the filtered throttle inlet pressure in the (N-1)th sampling period, N = 1, 2, 3, …, p ThrBfActFilter (0) is the throttle inlet pressure at the 0th sampling period, p ThrBfAct (0); wherein the 0th sampling period is the sampling period at the time when the engine enters a shutdown operating condition and the engine speed does not exceed a preset value, and the sampling period interval time is Δt; K ThrBf is the filtering coefficient; Record the time from when the engine enters the shutdown condition and the engine speed does not exceed the preset value until the occurrence of |p ThrBfAct (N)-p ThrBfActFilter (N)|>min[p ThrBfAct (N), p ThrBfActFilter (N)]×r ThrBfActLim The shortest time is t0, and the throttle opening pct is recorded at the moment when the engine enters the shutdown condition and the engine speed does not exceed the preset value. ThrActOff0 and atmospheric pressure; where r ThrBfActLim The preset value is used; the preset time learning correction coefficient r Delay The update method is as follows: If the engine enters a shutdown state and the engine speed does not exceed the preset value of throttle opening pct at that time. ThrActOff0 The value can be one of 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, or 9%, if the previous preset time learning correction coefficient r Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure exceeds a preset value, then only the preset time learning correction coefficient r at the corresponding throttle opening is updated. Delay The preset time learning correction coefficient r is not updated at other throttle openings. Delay The preset time learning correction coefficient r Delay The update calculation formula is: Where, r Delay (z) represents the preset time learning correction coefficient from the previous self-learning update, and k1 is the weighting coefficient; if the preset time learning correction coefficient r Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure does not exceed a preset value, then the preset time learning correction coefficient r under any throttle opening will not be updated this time. Delay ; If the engine enters a shutdown state and the engine speed does not exceed the preset value of throttle opening pct at that time. ThrActOff0 The value is located between two adjacent values ​​in the range of 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, and 9%. If the previous preset time learning correction coefficient r... Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure exceeds a preset value, then only the preset time learning correction coefficient r for the corresponding throttle opening will be updated. Delay The preset time learning correction coefficient r is not updated at other throttle openings. Delay If the learning correction coefficient r for the previous preset time is... Delay If the difference between the atmospheric pressure at the time of update and the current atmospheric pressure does not exceed a preset value, then the preset time learning correction coefficient r under any throttle opening will not be updated this time. Delay The method for determining the corresponding throttle opening range is as follows: Assuming the engine enters a shutdown state and the engine speed does not exceed a preset value, the throttle opening is pct at that moment. ThrActOff0 The value is between throttle opening A and B, where A and B are a pair of adjacent values ​​from 0%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, and 9%. If the preset time t corresponds to the throttle opening A read before this update... EngMovingDelay For t A The preset time t corresponding to the throttle opening B read before this update EngMovingDelay For t B Determine the throttle opening pct ThrActOff The corresponding preset time learning correction coefficient r Delay Use r Delay (pct ThrActOff If ) indicates that: wherein r Delay (pct ThrActOff ) is the preset time learning correction coefficient of the throttle opening degree p ThrActOff ct under the last self-learning update, k2 is a weighting coefficient; at the same time, the preset time learning correction coefficients of the throttle opening degree A and the throttle opening degree B are updated, which are represented by r Delay (A) and r Delay (B), respectively. Wherein k3 and k4 are preset weighting coefficients.

5. The engine shutdown time pressure signal correlation method of claim 1, wherein, The preset value of the engine speed is 30 rpm.

6. The engine off pressure signal to flag method of claim 1, wherein, The preset range of the difference between the atmospheric pressure signal and the throttle outlet pressure signal is ±0.3 kPa.

7. The engine off pressure signal to flag method of claim 1, wherein, The preset range of the fluctuations of the atmospheric pressure signal and the throttle outlet pressure signal is ±0.1 kPa.

8. The engine off pressure signal to flag method of claim 3, wherein, the throttle opening pct ThrActOff The throttle opening pct is determined by using an electronic throttle control method for an exhaust turbo engine, which is Step 1: setting a throttle full opening exit flag, a throttle full opening preparation exit flag and a transient throttle full opening flag in a throttle controller; The throttle full opening exit flag is set to 1 when the difference between the throttle inlet pressure and the throttle target inlet pressure is greater than a calibrated value A1, and is set to 0 when the difference is less than a calibrated value A2, A1 being greater than A2; The throttle full opening preparation exit flag is set to 1 when the difference between the estimated throttle inlet pressure and the estimated throttle target inlet pressure is greater than a calibrated value B1, and is set to 0 when the difference is less than a calibrated value B2, B1 being greater than B2; The transient throttle full opening flag is set to 1 when the difference between the throttle inlet pressure and the throttle outlet pressure is less than a calibrated value C1, and is set to 0 when the difference is greater than a calibrated value C2, C1 being less than C2; Step 2: When the throttle full open exit flag is set to 1, the throttle control mode is the normal throttle control mode, and in the normal throttle control mode, the effective area of the throttle is the target throttle effective area A Eff ; Step 3: when the throttle full opening exit flag is set to 0, the throttle control mode at the last time is the normal throttle control mode, and the transient throttle full opening flag is set to 0, the throttle enters the normal throttle control mode. Step 4: when the full opening of the throttle valve exit flag bit is 0, and the transient throttle valve full opening flag bit is 1, and the throttle valve full opening preparation exit flag bit is 1, the throttle valve enters the throttle valve anti-hunting control mode, in the throttle valve anti-hunting control mode, the effective area of the throttle valve is the adjusted target throttle valve effective area min(A Eff1 ,A Eff2 ), and the adjusted target throttle valve effective area is not less than A Eff , wherein A Eff1 is obtained by multiplying A Eff by a preset compensation coefficient, and A Eff2 is obtained by adding a preset compensation amount to A Eff ; Step 5: When the full throttle exit flag is 0, the transient full throttle flag is 1, and the full throttle preparation exit flag is 0, the throttle enters the full throttle control mode, and the effective area of the throttle is the target full throttle effective area A EffMax and the target throttle effective area change rate is the maximum change rate allowed by the throttle when the throttle is fully open. the throttle opening degree pct ThrActOff = (A eff -A0) / (A 100 -A0) x 100%; wherein A eff ' is the final throttle effective area after processing by different throttle control modes, and the minimum throttle opening degree 0% and the maximum throttle opening degree 100% correspond to the throttle effective areas A 100 and A0, respectively.

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