Engine speed control method and related device

Abstract

The application discloses an engine rotating speed control method and related device, and relates to the field of engines, and comprises the following steps: determining a rotating speed rising slope in an engine rotating speed rising process and taking the rotating speed rising slope as an engine load estimation value; when the engine rotating speed meets a preset rotating speed control condition, searching for a corresponding steady-state torque self-learning value according to a target engine load interval to which the engine load estimation value belongs; determining a transient torque correction value corresponding to the rotating speed rising slope from a transient torque correction curve; correcting the steady-state torque self-learning value to obtain an integral torque initial value; and taking the integral torque initial value as an initial value of an integral control item to perform engine rotating speed control. The application determines the steady-state torque self-learning value of the engine based on the engine load estimation value, determines the required transient torque correction value based on the rotating speed rising slope, superimposes the transient torque correction value on the steady-state torque self-learning value to compensate for torque dynamic deviation, and improves the stability and accuracy of the engine rotating speed control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of engine, more particularly, to an engine speed control method and related device. BACKGROUND

[0002] The current engine speed control adopts a PI (Proportional-Integral) control method, and the control structure is a combination of feedforward and closed loop. The parameters of the feedforward controller and the closed loop controller are determined by calibration. However, when the external boundary conditions (for example, vehicle load, road slope, gearbox gear position, fan / air conditioner start-stop and other factors affecting engine load) change, the calibrated parameters may not match the actual working conditions, thereby causing the control system to oscillate, and ultimately affecting the stability and accuracy of engine speed control. SUMMARY

[0003] Therefore, the present application discloses an engine speed control method and related device to improve the stability and accuracy of engine speed control.

[0004] An engine speed control method, comprising:

[0005] determining a speed rise slope in an engine speed rise process;

[0006] determining the speed rise slope as an engine load estimation value;

[0007] when the engine speed meets a preset speed control condition, according to a target engine load interval to which the engine load estimation value belongs, searching for a corresponding steady-state torque self-learning value;

[0008] determining a transient torque correction value corresponding to the speed rise slope from a preset transient torque correction curve;

[0009] correcting the steady-state torque self-learning value by using the transient torque correction value to obtain an integral torque initial value;

[0010] using the integral torque initial value as an initial value of an integral control item to perform engine speed control.

[0011] Optionally, the determination of the speed rise slope in the engine speed rise process comprises:

[0012] starting from the time when the engine demand torque reaches the external characteristic torque at the current engine speed, recording each speed rise time period in the engine speed rise process and the speed change amount in each speed rise time period;

[0013] When the engine speed rises to a speed set value, sum all the recorded speed rising time periods to obtain a total change time period;

[0014] Sum all the recorded speed changes to obtain a total speed change rate;

[0015] Calculate the ratio of the total speed change rate and the total change time period to obtain the speed rising slope.

[0016] Optionally, further comprising:

[0017] In the engine speed control process, when the engine speed exceeds the speed set value and enters a steady state, calculate a speed deviation value of the speed set value and the actual engine speed;

[0018] When the speed deviation value is negative and the absolute value of the speed deviation value reaches a speed deviation maximum value, determine the speed deviation value as a speed overshoot value;

[0019] When the speed overshoot value exceeds a speed overshoot threshold value, decrease the steady state torque self-learning value by a first step size.

[0020] Optionally, further comprising:

[0021] The steady state torque self-learning value obtained after the steady state torque self-learning value is decreased by the first step size is taken as the latest steady state torque self-learning value corresponding to the target engine load interval.

[0022] Optionally, further comprising:

[0023] When the speed overshoot value does not exceed the speed overshoot threshold value, if the speed deviation value is positive and the speed deviation value reaches a speed deviation maximum value, determine the speed deviation value as a speed dip value;

[0024] When the speed dip value exceeds a speed dip threshold value, increase the steady state torque self-learning value by a second step size.

[0025] Optionally, further comprising:

[0026] The steady state torque self-learning value obtained after the steady state torque self-learning value is increased by the second step size is taken as the latest steady state torque self-learning value corresponding to the target engine load interval.

[0027] Optionally, further comprising:

[0028] When it is determined that the target engine load interval to which the engine load estimate value belongs is inconsistent with the engine load interval determined by the last engine speed control, return and repeatedly determine the latest engine load estimate value in the engine speed rising process;

[0029] If the deviation of the latest engine load estimation value re-determined multiple times and the engine load estimation value currently determined is within a preset deviation range, it is determined that the engine load estimation value is a reliable value, and the corresponding steady-state torque self-learning value is searched according to the target engine load interval to which the engine load estimation value belongs.

[0030] An engine speed control device comprises:

[0031] A slope determination unit is configured to determine a speed-up slope during a speed-up process of an engine speed;

[0032] A load estimation value determination unit is configured to determine the speed-up slope as an engine load estimation value;

[0033] A steady-state torque determination unit is configured to search for a corresponding steady-state torque self-learning value according to a target engine load interval to which the engine load estimation value belongs when the engine speed meets a preset speed control condition;

[0034] A torque correction value determination unit is configured to determine a transient torque correction value corresponding to the speed-up slope from a preset transient torque correction curve;

[0035] A correction unit is configured to correct the steady-state torque self-learning value to obtain an integral torque initial value by using the transient torque correction value;

[0036] A speed control unit is configured to perform engine speed control by taking the integral torque initial value as an initial value of an integral control term.

[0037] A computer storage medium stores at least one instruction, and the at least one instruction is executed by a processor to implement any one of the engine speed control methods.

[0038] An engine controller comprises a memory and a processor;

[0039] The memory is configured to store at least one instruction;

[0040] The processor is configured to execute the at least one instruction to implement any one of the engine speed control methods.

[0041] From the above technical solution can be known, the application discloses an engine speed control method and related device, determine the speed rising slope in the engine speed rising process, the speed rising slope is determined as the engine load estimation value, when the engine speed meets the preset speed control condition, according to the target engine load interval to which the engine load estimation value belongs, look up the corresponding steady-state torque self-learning value, determine the transient torque correction value corresponding to the speed rising slope from the preset transient torque correction curve, modify the steady-state torque self-learning value using the transient torque correction value to obtain the integral torque initial value, and the integral torque initial value is used as the initial value of the integral control item for engine speed control. The application takes the speed rising slope as the engine load estimation value, and determines the steady-state torque self-learning value under the stable working condition of the engine based on the engine load estimation value. At the same time, based on the speed rising slope, the transient working condition triggered by the change of external boundary condition is identified, and the transient torque correction value required by the current working condition is determined through the transient torque correction curve. By superimposing the transient torque correction value on the steady-state torque self-learning value, the dynamic deviation of the steady-state torque self-learning value can be compensated, thereby improving the stability and accuracy of the engine speed control. BRIEF DESCRIPTION OF DRAWINGS

[0042] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only embodiments of the application, and for those skilled in the art, other drawings can also be obtained without creative labor based on the disclosed drawings.

[0043] Figure 1 A flow chart of an engine speed control method disclosed by the embodiments of the application is shown in the figure.

[0044] Figure 2 A calculation schematic diagram of the speed rising slope disclosed by the embodiments of the application is shown in the figure.

[0045] Figure 3 A flow chart of an integral torque initial value adaptive strategy method disclosed by the embodiments of the application is shown in the figure.

[0046] Figure 4 A speed overshoot and speed notch schematic diagram disclosed by the embodiments of the application is shown in the figure.

[0047] Figure 5 A structural schematic diagram of an engine speed control device disclosed by the embodiments of the application is shown in the figure.

[0048] Figure 6 A structural schematic diagram of an engine controller disclosed by the embodiments of the application is shown in the figure. DETAILED DESCRIPTION

[0049] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described, obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0050] The embodiments of the present application disclose an engine speed control method and related device, taking a speed rising slope as an engine load estimation value, determining a steady state torque self-learning value in a stable working condition of the engine based on the engine load estimation value; at the same time, identifying a transient working condition triggered by an external boundary condition change based on the speed rising slope, determining a transient torque correction value required by a current working condition through a transient torque correction curve. By superimposing the transient torque correction value to the steady state torque self-learning value, the dynamic deviation of the steady state torque self-learning value can be compensated, so as to improve the stability and accuracy of the engine speed control.

[0051] Referring to Figure 1 The embodiments of the present application disclose an engine speed control method flow chart, and the method comprises:

[0052] Step S101, determining a speed rising slope in an engine speed rising process.

[0053] The inventor has found through research that, according to the automobile driving equation, the balance relationship between driving force and resistance of the vehicle in the acceleration process can be expressed as the following equation:

[0054] (1);

[0055] In the formula, is the driving force, is the rolling resistance, is the air resistance, is the slope resistance, is the acceleration resistance.

[0056] According to formula (1), the inventor has further found that the total resistance in the vehicle driving process is equivalent to the engine load, and the intuitive quantitative index of the engine load acting on the engine is the speed rising slope of the engine. The advantage of this method is that by including the gear factor in the engine load estimation value, the control dimension of the control system can be effectively reduced.

[0057] Based on the above idea, the present application designs an engine load estimation strategy, that is, determining the speed rising slope in the engine speed rising process, and determining the speed rising slope as the engine load estimation value.

[0058] Step S102: Determine the speed increase slope as the engine load estimate.

[0059] Step S103: When the engine speed meets the preset speed control conditions, find the corresponding steady-state torque self-learning value according to the target engine load range to which the engine load estimate belongs.

[0060] Among them, the engine speed meeting the preset speed control condition can be triggered when the engine speed enters the preset speed range.

[0061] It should be noted that this application adopts a steady-state torque self-learning strategy based on engine load, and stores the adapted steady-state torque self-learning values ​​according to the engine load range. In subsequent applications under the same engine load conditions, the pre-stored steady-state torque self-learning values ​​can be directly called as the feedforward input of the integral torque controller, thereby improving the engine control response speed.

[0062] In other words, this invention employs a steady-state torque self-learning strategy that pre-sets the correspondence between engine load ranges and steady-state torque self-learning values, and this correspondence can be stored in tabular form. When the determined engine load estimate falls within any engine load range, the engine load range to which the engine load estimate belongs is determined as the target engine load range, and the steady-state torque self-learning value corresponding to the target engine load range is found from the correspondence between engine load ranges and steady-state torque self-learning values.

[0063] It should be noted that when the engine speed does not meet the preset speed control conditions, the process returns to step S101 to redetermine the speed increase slope during the engine speed increase process.

[0064] Step S104: Determine the transient torque correction value corresponding to the speed increase slope from the preset transient torque correction curve.

[0065] Through research, the inventors discovered that under the same engine load, different torque demands result in different engine speed surge accelerations, and these different surge accelerations ultimately require different initial values ​​of integral torque. A large surge acceleration may lead to excessive speed overshoot, in which case the initial value of integral torque needs to be appropriately reduced; conversely, a small surge acceleration may cause speed dips, requiring the initial value of integral torque to be appropriately increased.

[0066] Different accelerations during engine speed rise result in different speed rise slopes. Based on this, this application pre-determines a transient torque correction curve based on the speed rise slope through experimental calibration. This transient torque correction curve represents the correspondence between the speed rise slope and the transient torque correction value, and is used to correct the steady-state torque self-learning value according to the transient degree during the engine speed rise process.

[0067] Step S105, the steady state torque self-learning value is corrected by the transient torque correction value to obtain an integral torque initial value.

[0068] The steady state torque self-learning value is a long-term calibrated data based on a stable working condition (such as uniform driving), and reflects the torque output characteristics of the engine under static or quasi-static conditions. However, under transient conditions (such as sudden acceleration, load mutation), the dynamic factors such as intake efficiency, combustion state and friction loss of the engine will deviate significantly from the steady state condition, resulting in torque output deviation from the actual demand when only the steady state value is controlled. Based on this, the application quickly calculates the transient torque correction value required for the current working condition by real-time monitoring of dynamic signals such as speed change, accelerator pedal action and load mutation, and adds the transient torque correction value to the steady state torque self-learning value, which can compensate for the dynamic deviation of the steady state value and improve the control accuracy of the engine speed.

[0069] In other words, the application corrects the steady state self-learning value by using the transient torque correction value, and the essence is to solve the pain point of the traditional steady state control "static precision but dynamic lag" through the architecture of "steady state basis + dynamic compensation".

[0070] Step S106, the integral torque initial value is used as the initial value of the integral control item for engine speed control.

[0071] The application corrects the steady state torque self-learning value by using the transient torque correction value to obtain the integral torque initial value, which is used as the initial value of the integral control item, so that the stability and accuracy of the engine speed control can be ensured when the external boundary condition changes.

[0072] In summary, the application discloses an engine speed control method, determines a speed rising slope in an engine speed rising process, determines the speed rising slope as an engine load estimation value, when the engine speed meets a preset speed control condition, according to a target engine load interval to which the engine load estimation value belongs, looks up a corresponding steady state torque self-learning value, determines a transient torque correction value corresponding to the speed rising slope from a preset transient torque correction curve, corrects the steady state torque self-learning value by using the transient torque correction value to obtain an integral torque initial value, and uses the integral torque initial value as an initial value of an integral control item for engine speed control. The application uses the speed rising slope as the engine load estimation value, determines the steady state torque self-learning value of the engine under stable working conditions based on the engine load estimation value, and at the same time, identifies a transient working condition triggered by a change in an external boundary condition based on the speed rising slope, and determines the transient torque correction value required for the current working condition through the transient torque correction curve. By superimposing the transient torque correction value on the steady state torque self-learning value, the dynamic deviation of the steady state torque self-learning value can be compensated, thereby improving the stability and accuracy of the engine speed control.

[0073] In one embodiment, step S101 can specifically include:

[0074] (1) From the time when the demand torque of the engine reaches the external characteristic torque at the current engine speed, record each speed-up time period in the engine speed-up process and the speed change amount in each speed-up time period.

[0075] Specifically, in the engine speed-up process, the demand torque of the engine is monitored in real time, and when the demand torque of the engine reaches the external characteristic torque at the current engine speed, the engine speed is recorded from this time. When the engine speed rises, the speed-up time period and the speed change amount in the speed-up time period are recorded; when the engine speed is disturbed and the speed drops, the recording is stopped; when the engine speed continues to rise, the next speed-up time period of the engine and the speed change amount in the speed-up time period are continuously recorded, and finally when the engine speed rises to the speed setting value, a plurality of speed-up time periods and a plurality of speed change amounts are recorded.

[0076] (2) When the engine speed rises to the speed setting value, sum all the recorded speed-up time periods to obtain the total change time period.

[0077] (3) Sum all the recorded speed change amounts to obtain the total speed change rate.

[0078] (4) Calculate the ratio of the total speed change rate to the total change time period to obtain the speed-up slope.

[0079] The external characteristic refers to: the maximum torque that the engine can reach at each speed under the influence of intake air volume, ignition angle, and fuel injection volume calibration when the throttle is fully open.

[0080] The external characteristic torque in the embodiment refers to: the maximum torque that the engine can reach at the current engine speed.

[0081] When the demand torque of the engine reaches the external characteristic torque at the current engine speed, it means that the torque requested by the engine control system has reached the maximum torque that can be output at the current engine speed, and at this time the engine speed is in the low speed stage.

[0082] For example, the process of the speed-up slope is illustrated in Figure 2 , a calculation diagram of the speed-up slope disclosed in the embodiment of the application, Figure 2 , wherein 10 represents the engine speed and 20 represents the speed setting value.

[0083] When the demand torque of the engine reaches the external characteristic torque at the current engine speed, the first time period and the corresponding first section speed change amount wherein the first time period starts at the time when the required torque of the engine reaches the external characteristic torque at the current engine speed.

[0084] The recording is stopped when the engine speed is disturbed to drop.

[0085] The second time period is recorded when the engine speed continues to rise. wherein the second time period ends at the time when the engine speed 10 reaches the speed setting value 20.

[0086] The speed rise slope is calculated according to the following formula :

[0087] (2).

[0088] The present application finds that, when the external boundary conditions (for example, vehicle load, road slope, gearbox gear, fan / air conditioner start-stop and other factors affecting the engine load) change, the control effect of the engine speed may also be different under the same engine load and acceleration.

[0089] To further improve the accuracy of engine speed control, the present application also provides an integral torque initial value adaptive strategy for speed overshoot and speed dip. That is, after the integral torque initial value is taken as the initial value of the integral control item in step S106 for engine speed control, the integral torque initial value adaptive strategy is executed.

[0090] Referring to Figure 3 , the integral torque initial value adaptive strategy method flow chart disclosed by the embodiment of the present application comprises:

[0091] Step S201, in the engine speed control process, when the engine speed exceeds the speed setting value and enters a steady state, the speed deviation value of the speed setting value and the actual engine speed is calculated.

[0092] Speed deviation value = speed setting value - actual engine speed.

[0093] Wherein, the value of the speed setting value is determined according to actual needs, which is not limited in the present application.

[0094] It should be noted that, when the engine speed does not exceed the speed setting value and enters a steady state, it is continued to wait until the engine speed exceeds the speed setting value and enters a steady state, and then the speed deviation value of the speed setting value and the actual engine speed is calculated.

[0095] Step S202, when the speed deviation value is negative and the absolute value of the speed deviation value reaches the maximum speed deviation value, the speed deviation value is determined as the speed overshoot value.

[0096] Referring to Figure 4 The speed overshoot and speed dip schematic diagram shown in the figure, when the speed deviation value obtained by the speed setting value 20 and the actual engine speed 30 is negative, and the absolute value of the speed deviation value reaches the maximum speed deviation value m1, the speed deviation value is determined as the speed overshoot value.

[0097] Step S203, judging whether the speed overshoot value exceeds the speed overshoot threshold value, if yes, executing step S204.

[0098] Wherein, the value of the speed overshoot threshold value is determined according to actual needs, which is not limited in the present application.

[0099] Step S204, reducing the steady state torque self-learning value according to the first step length.

[0100] Wherein, the value of the first step length is determined according to actual needs, which is not limited in the present application.

[0101] From the above, it can be known that when the engine speed overshoot phenomenon is determined, in the case that the speed overshoot value exceeds the speed overshoot threshold value, the steady state torque self-learning value is reduced according to the first step length, so as to realize the adaptive adjustment of the integral torque initial value, thereby improving the accuracy of the engine speed control.

[0102] In one embodiment, after step S204, it can also include:

[0103] Step S205, taking the steady state torque self-learning value obtained after reduction as the latest steady state torque self-learning value corresponding to the target engine load interval.

[0104] In actual application, the latest steady state torque self-learning value can be used to update the steady state torque self-learning value in the corresponding relationship between the engine load interval and the steady state torque self-learning value.

[0105] In one embodiment, in the case that step S203 judges no, it can also include:

[0106] Step S206, if the speed deviation value is positive and the speed deviation value reaches the maximum speed deviation value, the speed deviation value is determined as the speed dip value.

[0107] Referring to Figure 4The speed overshoot and speed notch diagram shown, when the speed set value 20 and the actual engine speed 30 get a positive speed deviation value, and the absolute value of the speed deviation value reaches the maximum speed deviation value m2, the speed deviation value is determined as the speed notch value.

[0108] Step S207, determine whether the speed notch value exceeds the speed notch threshold value, if yes, execute step S208.

[0109] Wherein, the value of the speed notch threshold value is determined according to actual needs, which is not limited herein.

[0110] Step S208, increase the steady state torque self-learning value according to the second step length.

[0111] Wherein, the value of the second step length is determined according to actual needs, which is not limited herein.

[0112] As can be seen from the above, in the case of determining that the engine speed notch value exceeds the speed notch threshold value, the steady state torque self-learning value is reduced according to the second step length, the initial value of the integral torque is adaptively adjusted, and the accuracy of the engine speed control is improved.

[0113] In one embodiment, after step S208, it can also include:

[0114] Step S209, the steady state torque self-learning value obtained after increasing is taken as the latest steady state torque self-learning value corresponding to the target engine load interval.

[0115] In actual application, the latest steady state torque self-learning value can be used to update the steady state torque self-learning value in the corresponding relationship between the engine load interval and the steady state torque self-learning value.

[0116] In one embodiment, in the case of no in step S207, it can also include:

[0117] Step S210, determine that the engine is in the speed control steady state working condition.

[0118] When it is determined that the engine is in the speed control steady state working condition, the actual engine torque can be recorded under the corresponding engine load and stored.

[0119] In one embodiment, the engine speed control method can also include:

[0120] When it is determined that the target engine load interval to which the engine load estimation value belongs is inconsistent with the engine load interval determined by the last engine speed control, return and determine the latest engine load estimation value in the engine speed rising process multiple times;

[0121] If the deviations of the latest engine load estimation values re-determined multiple times from the engine load estimation value currently determined are all within a preset deviation range, it is determined that the engine load estimation value is a credible value, and the corresponding steady-state torque self-learning value is searched according to the target engine load interval to which the engine load estimation value belongs.

[0122] After the engine load estimation value is determined, the target engine load interval to which the engine load estimation value belongs and the engine load interval determined by the last engine speed control are compared for consistency. When the two are inconsistent, the credibility of the currently calculated engine load estimation value needs to be determined. Specifically, the latest engine load estimation value in the engine speed rising process is re-determined multiple times. If the deviations of the latest engine load estimation values re-determined multiple times from the engine load estimation value currently determined are all within a preset deviation range, it is determined that the currently calculated engine load estimation value is credible. At this time, the step of searching for the corresponding steady-state torque self-learning value according to the target engine load interval to which the engine load estimation value belongs is continued to be executed. In addition, when the engine speed control is executed next time, the integral torque initial value determined by the steady-state torque self-learning value corresponding to the current engine load estimation value and the transient torque correction value is assigned to the integral torque controller as an initial value.

[0123] Corresponding to the method embodiment, the application further discloses an engine speed control device.

[0124] Referring to Figure 5 The engine speed control device disclosed by the embodiment of the application can include:

[0125] The slope determination unit 301 is configured to determine a speed rising slope in the engine speed rising process.

[0126] The load estimation value determination unit 302 is configured to determine the speed rising slope as an engine load estimation value.

[0127] The steady-state torque determination unit 303 is configured to search for a corresponding steady-state torque self-learning value according to a target engine load interval to which the engine load estimation value belongs when the engine speed meets a preset speed control condition.

[0128] The engine speed meeting the preset speed control condition can be triggered when the engine speed enters a preset speed range.

[0129] It should be noted that the application adopts a steady-state torque self-learning strategy based on engine load, and the adaptive steady-state torque self-learning values are classified and stored according to engine load intervals; in the same engine load condition, the pre-stored steady-state torque self-learning values can be directly called as the feedforward input of the integral torque controller, so as to improve the engine control response speed.

[0130] In other words, the application adopts a steady-state torque self-learning strategy to pre-set the corresponding relationship between the engine load interval and the steady-state torque self-learning value, and the corresponding relationship can be stored in the form of a table. When the determined engine load estimation value is in any engine load interval, the engine load interval to which the engine load estimation value belongs is determined as the target engine load interval, and the steady-state torque self-learning value corresponding to the target engine load interval is searched from the corresponding relationship between the engine load interval and the steady-state torque self-learning value.

[0131] The torque correction value determination unit 304 is configured to determine the transient torque correction value corresponding to the speed rise slope from the preset transient torque correction curve.

[0132] The inventors have found through research that, under the same engine load, different demand torques will result in different engine speed uprush accelerations, and different uprush accelerations require different initial values of the integral torque. A large speed uprush acceleration may result in a large speed overshoot value, and in this case, the initial value of the integral torque needs to be appropriately reduced; a small speed uprush acceleration may result in a speed concave pit, and the initial value of the integral torque needs to be appropriately increased.

[0133] Different engine speed uprush accelerations eventually result in different speed rise slopes, and based on this, the application pre-determines a transient torque correction curve based on the speed rise slope through test calibration, the transient torque correction curve being a corresponding relationship between the speed rise slope and the transient torque correction value, and being used to correct the steady-state torque self-learning value according to the transient degree in the engine speed uprush process.

[0134] The correction unit 305 is configured to correct the steady-state torque self-learning value by using the transient torque correction value to obtain the initial value of the integral torque.

[0135] The steady-state torque self-learning value is data calibrated for a long time based on a stable working condition (such as uniform driving), and reflects the torque output characteristics of the engine under static or quasi-static conditions. However, under a transient working condition (such as sudden acceleration or load mutation), dynamic factors such as intake efficiency, combustion state and friction loss of the engine will significantly deviate from the steady-state condition, resulting in torque output deviation from the actual demand when only the steady-state value is used for control. Based on this, the application quickly calculates a transient torque correction value required for the current working condition by monitoring dynamic signals such as speed change, accelerator pedal action and load mutation in real time, and adds the transient torque correction value to the steady-state torque self-learning value, which can compensate for the dynamic deviation of the steady-state value and improve the control accuracy of the engine speed.

[0136] In other words, the application uses the transient torque correction value to correct the steady-state self-learning value, and the essence is to solve the pain point of the traditional steady-state control "static precision but dynamic lag" through the architecture of "steady-state basis + dynamic compensation".

[0137] The speed control unit 306 is configured to use the integral torque initial value as an initial value of an integral control item to perform engine speed control.

[0138] By using the transient torque correction value to correct the steady-state torque self-learning value to obtain the integral torque initial value as the initial value of the integral control item, the stability and accuracy of the engine speed control can still be ensured when the external boundary condition changes.

[0139] In summary, the application discloses an engine speed control device, determines a speed rising slope in an engine speed rising process, determines the speed rising slope as an engine load estimation value, when the engine speed meets a preset speed control condition, according to a target engine load interval to which the engine load estimation value belongs, searches for a corresponding steady-state torque self-learning value, determines a transient torque correction value corresponding to the speed rising slope from a preset transient torque correction curve, corrects the steady-state torque self-learning value by using the transient torque correction value to obtain an integral torque initial value, and uses the integral torque initial value as an initial value of an integral control item to perform engine speed control. The application uses the speed rising slope as the engine load estimation value, determines the steady-state torque self-learning value of the engine under a stable working condition based on the engine load estimation value, and simultaneously identifies a transient working condition triggered by a change in an external boundary condition based on the speed rising slope, and determines a transient torque correction value required for the current working condition through a transient torque correction curve. By superimposing the transient torque correction value on the steady-state torque self-learning value, the dynamic deviation of the steady-state torque self-learning value can be compensated, and the stability and accuracy of the engine speed control can be improved.

[0140] In one embodiment, the slope determination unit 301 can be specifically configured to:

[0141] record each speed-up time period in the process of the engine speed rising and the speed variation in each of the speed-up time periods, starting from the time when the demanded torque of the engine reaches the external characteristic torque at the current engine speed;

[0142] when the engine speed rises to the speed setting value, sum all the recorded speed-up time periods to obtain a total variation time period;

[0143] sum all the recorded speed variations to obtain a total speed variation rate;

[0144] calculate the ratio of the total speed variation rate to the total variation time period to obtain the speed-up slope.

[0145] In one embodiment, the engine speed control device can further comprise:

[0146] a calculation unit configured to calculate a speed deviation value between the speed setting value and the actual engine speed when the engine speed exceeds the speed setting value and enters a steady state during the engine speed control process;

[0147] a speed overshoot value determination unit configured to determine the speed deviation value as a speed overshoot value when the speed deviation value is negative and the absolute value of the speed deviation value reaches a maximum speed deviation value;

[0148] a torque reduction unit configured to reduce the steady state torque self-learning value by a first step size when the speed overshoot value exceeds a speed overshoot threshold value.

[0149] In one embodiment, the engine speed control device can further comprise:

[0150] a first update unit configured to use the steady state torque self-learning value obtained after the steady state torque self-learning value is reduced by the first step size as the latest steady state torque self-learning value corresponding to the target engine load range.

[0151] In one embodiment, the engine speed control device can further comprise:

[0152] a speed dip value determination unit configured to determine the speed deviation value as a speed dip value when the speed deviation value is positive and the speed deviation value reaches the maximum speed deviation value if the speed overshoot value does not exceed the speed overshoot threshold value.

[0153] a torque increase unit configured to increase the steady state torque self-learning value by a second step size when the speed dip value exceeds a speed dip threshold value.

[0154] In one embodiment, the engine speed control device can further comprise:

[0155] The second updating unit is configured to increase the steady-state torque self-learning value by the second step length, and take the increased steady-state torque self-learning value as the latest steady-state torque self-learning value corresponding to the target engine load range.

[0156] In one embodiment, the engine speed control device can further comprise:

[0157] The re-determining unit is configured to return and re-determine the latest engine load estimation value during the engine speed rising process for multiple times when the target engine load range to which the engine load estimation value belongs is inconsistent with the engine load range determined by the last engine speed control.

[0158] The determining unit is configured to determine that the engine load estimation value is a reliable value and continue to search for the corresponding steady-state torque self-learning value according to the target engine load range to which the engine load estimation value belongs if the deviation of the latest engine load estimation value re-determined for multiple times and the engine load estimation value determined currently is within a preset deviation range.

[0159] It should be noted that the specific working principles of the components in the device embodiment can be referred to the corresponding parts of the method embodiment, which will not be repeated here.

[0160] Corresponding to the above-mentioned embodiments, the present application further discloses a computer storage medium, which stores at least one instruction, and the at least one instruction is executed by a processor to realize the steps shown in the engine speed control method embodiment.

[0161] Corresponding to the above-mentioned embodiments, as shown in Figure 6 The present application further provides a structural diagram of an engine controller, which can comprise a processor 1 and a memory 2.

[0162] The processor 1 and the memory 2 complete the communication between each other through a communication bus 3.

[0163] The processor 1 is configured to execute at least one instruction.

[0164] The memory 2 is configured to store at least one instruction.

[0165] The processor 1 can be a central processing unit (CPU), or an application specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present application.

[0166] The memory 2 can comprise a high-speed RAM memory and possibly also a non-volatile memory, for example at least one disk memory.

[0167] The processor executes at least one instruction to implement the steps shown in the engine speed control method embodiment.

[0168] Finally, it should be noted that the terminology used herein, such as first and second, is merely used to differentiate one entity or operation from another entity or operation and is not necessarily required or implied to indicate any such actual relationship or order between the entities or operations. Also, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises a" does not, without more constraints, foreclose the existence of additional identical elements in the process, method, article, or apparatus that comprises the recited element.

[0169] The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be mutually referred to.

[0170] The above description of the disclosed embodiments enables a person skilled in the art to implement or use the invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An engine rotation speed control method characterized by comprising: The method comprises the following steps: determining a speed rise slope in a process of engine speed rise; determining the speed rise slope as an engine load estimation value; when the engine speed meets a preset speed control condition, searching for a corresponding steady-state torque self-learning value according to a target engine load interval to which the engine load estimation value belongs; determining a transient torque correction value corresponding to the speed rise slope from a preset transient torque correction curve; correcting the steady-state torque self-learning value by using the transient torque correction value to obtain an integral torque initial value; using the integral torque initial value as an initial value of an integral control item to perform engine speed control; The method further comprises the following steps: during the engine speed control process, when the engine speed exceeds a speed setting value and enters a steady state, calculating a speed deviation value of the speed setting value and an actual engine speed; when the speed deviation value is negative and an absolute value of the speed deviation value reaches a maximum speed deviation value, determining the speed deviation value as a speed overshoot value; when the speed overshoot value exceeds a speed overshoot threshold, reducing the steady-state torque self-learning value according to a first step length; when the speed overshoot value does not exceed the speed overshoot threshold, if the speed deviation value is positive and the speed deviation value reaches the maximum speed deviation value, determining the speed deviation value as a speed dip value; when the speed dip value exceeds a speed dip threshold, increasing the steady-state torque self-learning value according to a second step length.

2. The engine rotation speed control method according to claim 1, characterized by, The determination of the speed rise slope in the process of engine speed rise comprises the following steps: starting from a time point at which a required torque of the engine reaches an external characteristic torque at a current engine speed, recording each speed rise time period in the process of engine speed rise and a speed change amount in each speed rise time period; when the engine speed rises to the speed setting value, summing all the recorded speed rise time periods to obtain a total change time period; summing all the recorded speed change amounts to obtain a total speed change rate; calculating a ratio of the total speed change rate to the total change time period to obtain the speed rise slope.

3. The engine rotation speed control method according to claim 1, characterized by, The method further comprises the following steps: using the steady-state torque self-learning value obtained after the steady-state torque self-learning value is reduced according to the first step length as a latest steady-state torque self-learning value corresponding to the target engine load interval.

4. The engine rotation speed control method according to claim 1, characterized by, The method further comprises the following steps: using the steady-state torque self-learning value obtained after the steady-state torque self-learning value is increased according to the second step length as a latest steady-state torque self-learning value corresponding to the target engine load interval.

5. The engine rotation speed control method according to any one of claims 1 to 4, characterized by The method further comprises the following steps: when it is determined that the target engine load interval to which the engine load estimation value belongs is inconsistent with an engine load interval determined in a previous engine speed control, returning and repeatedly determining a latest engine load estimation value in the process of engine speed rise; if deviations of the repeatedly determined latest engine load estimation values and the currently determined engine load estimation value are within a preset deviation range, determining the engine load estimation value as a credible value, and continuing to search for a corresponding steady-state torque self-learning value according to a target engine load interval to which the engine load estimation value belongs.

6. An engine rotation speed control device characterized by comprising: The method comprises the following steps: A slope determination unit is configured to determine a speed-up slope in a process of increasing the engine speed; A load estimation value determination unit is configured to determine the speed-up slope as an engine load estimation value; A steady-state torque determination unit is configured to, when the engine speed meets a preset speed control condition, look up a corresponding steady-state torque self-learning value according to a target engine load interval to which the engine load estimation value belongs; A torque correction value determination unit is configured to determine a transient torque correction value corresponding to the speed-up slope from a preset transient torque correction curve; A correction unit is configured to correct the steady-state torque self-learning value by using the transient torque correction value to obtain an integral torque initial value; A speed control unit is configured to use the integral torque initial value as an initial value of an integral control item to perform engine speed control; Further comprising: A calculation unit is configured to, in a process of engine speed control, calculate a speed deviation value of the speed set value and the actual engine speed when the engine speed exceeds the speed set value and enters a steady state; A speed overshoot value determination unit is configured to, when the speed deviation value is negative and an absolute value of the speed deviation value reaches a maximum speed deviation value, determine the speed deviation value as a speed overshoot value; A torque reduction unit is configured to, when the speed overshoot value exceeds a speed overshoot threshold, reduce the steady-state torque self-learning value by a first step, and when the speed overshoot value does not exceed the speed overshoot threshold, if the speed deviation value is positive and the speed deviation value reaches the maximum speed deviation value, determine the speed deviation value as a speed dip value; and when the speed dip value exceeds a speed dip threshold, increase the steady-state torque self-learning value by a second step.

7. A computer storage medium, characterized in that The computer storage medium stores at least one instruction, and the at least one instruction is executed by the processor to implement the engine speed control method according to any one of claims 1-5.

8. An engine controller characterized by, The engine speed control device comprises a memory and a processor; The memory is configured to store at least one instruction; The processor is configured to execute the at least one instruction to implement the engine speed control method according to any one of claims 1-5.

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