CN114542301A - Control device, control method, and computer program product for engine - Google Patents

Abstract

The invention proposes a control device (10) for an engine of a vehicle, the control device (10) comprising a generating unit (12) for generating a final torque request and an output unit (14) for outputting a control signal depending on the final torque request, wherein the generating unit (12) is configured to be able to: acquiring a plurality of operating parameters of a vehicle; determining a first torque request based on an accelerator pedal displacement and at least one additional operating parameter of the operating parameters; determining a second torque request according to a predetermined mapping based only on the accelerator pedal displacement; and selectively treating the first torque request or the second torque request as a final torque request based on at least one operating parameter. The invention also proposes a control method using the control device (10) according to the invention and a computer program product. By means of the invention, abnormal situations in which the final torque request does not meet the operator's intention can be reduced or even avoided.

Description

Control device, control method, and computer program product for an engine

technical field

The invention relates to the control field of vehicles, especially construction machinery vehicles, in particular to a control device for an engine of a vehicle, a corresponding control method and a computer program product.

Background technique

Vehicles powered by an internal combustion engine, such as a diesel engine, are often equipped with controls for the engine. Typically, when the operator depresses the accelerator pedal of the vehicle, the engine control device determines a torque request based on accelerator pedal displacement and a number of additional operating parameters, such as engine speed or vehicle load, and controls fuel, For example the injection of diesel. Fuel is injected into the cylinders of the engine and combustion occurs, the engine converts energy and outputs power. During this process, the torque request determined by the control device is related both to accelerator pedal displacement and to additional operating parameters. Thus, a combination of factors is taken into account to determine a torque request that matches the operating state of the vehicle.

However, during the operation of the vehicle, there may be an abnormal situation in which the power generated by the engine does not match the operation of the accelerator pedal by the operator. For example, when the operator slams on the accelerator pedal, the torque request determined by the control device after taking into account multiple factors may instead drop or fluctuate, resulting in a subsequent drop or fluctuation in the fuel injection quantity. Therefore, the operator may feel that the engine does not provide the expected power after pressing the accelerator pedal. This abnormality of torque request can adversely affect the operating experience.

SUMMARY OF THE INVENTION

It is an object of the present invention to improve a control device and a control method for an engine of a vehicle in order to reduce or even avoid abnormal situations where the torque request does not conform to the operator's intention.

According to a first aspect of the present invention, there is provided a control device for an engine of a vehicle, the control device comprising a generation unit for generating a final torque request and an output unit for outputting a control signal according to the final torque request, wherein , the generating unit is configured to be able to: acquire a plurality of operating parameters of the vehicle; determine a first torque request based on the accelerator pedal displacement and at least one additional operating parameter in the operating parameters; based only on the accelerator pedal displacement, according to a predetermined mapping relationship, determining a second torque request; and selectively using the first torque request or the second torque request as the final torque request based on at least one operating parameter.

According to a second aspect of the present invention, there is provided a control method using the control device of the present invention, wherein the control method includes at least the following steps: a generating unit acquires operating parameters of the vehicle; The accelerator pedal displacement and at least one additional operating parameter determine the first torque request; the generating unit determines the second torque request based only on the accelerator pedal displacement and according to a predetermined mapping relationship; the generating unit selectively converts the first torque request according to the at least one operating parameter The torque request or the second torque request is used as the final torque request; and the output unit outputs the control signal according to the final torque request.

According to a third aspect of the present invention, there is provided a computer program product comprising computer program instructions, wherein the computer program instructions, when executed by one or more processors, cause the processors to perform a Control Method.

The control device and control method according to the present invention can reduce or even avoid abnormal situations in which the final torque request does not conform to the operator's intention by causing the generating unit to selectively use the first torque request or the second torque request as the final torque request. Since the second torque request is only related to the accelerator pedal displacement and is not affected by additional operating parameters, the operator's intention can be more directly reflected.

Description of drawings

The principles, features and advantages of the present invention may be better understood by describing the present invention in more detail below with reference to the accompanying drawings. The accompanying drawings include:

FIG. 1 schematically shows a control device for an engine according to an exemplary embodiment of the present invention;

FIG. 2 schematically shows the variation curve of accelerator pedal displacement and final torque request in a control device of the prior art;

FIG. 3 schematically shows a predetermined mapping relationship in an exemplary embodiment; and

FIG. 4 schematically shows a control method according to an exemplary embodiment.

Detailed ways

In order to make the technical problems, technical solutions and beneficial technical effects to be solved by the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and multiple exemplary embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the protection scope of the present invention.

The present invention is suitable for vehicles, especially for construction machinery vehicles, such as excavators, forklifts, cranes and the like. These vehicles are in operation to dig, carry or move, lift or turn heavier loads such as sand, bricks, dirt, etc. Although the principles of the present invention are described in detail below by taking an excavator as an example, those skilled in the art will understand that the present invention is not only applicable to excavators, but to any vehicle powered by an engine, such as a diesel engine.

FIG. 1 schematically shows a control device 10 for an engine of a vehicle according to an exemplary embodiment of the present invention.

In the embodiment shown in FIG. 1 , the control device 10 according to the invention comprises a generating unit 12 for generating a final torque request and an output unit 14 for outputting a control signal according to the final torque request.

Construction machinery vehicles that operate against large loads, such as excavators, are mostly powered by diesel engines. Typically, an operator (eg, a driver of an excavator) can control the rotational speed and output torque of the engine by depressing and releasing the accelerator pedal. To this end, the generating unit 12 is able to acquire a number of operating parameters of the vehicle and determine a final torque request from the accelerator pedal displacement therein and a number of additional operating parameters, according to which the output unit 14 controls the injection of fuel, eg diesel . For example, the output unit 14 is configured to output a control signal for the fuel injection quantity to the fuel injection unit 20 of the engine in accordance with the final torque request. Fuel is injected into the cylinders of the engine and combustion occurs, the engine converts energy and outputs power. The engine transmits power to the hydraulic system, eg via a transmission system. The hydraulic system generates and transmits the force to the action mechanism of the excavator, such as a bucket or bucket, to act on the load. Of course, the hydraulic system can also actuate other action mechanisms of the excavator, including, but not limited to, a running mechanism for driving on the ground, a slewing mechanism for rotating the body, and the like.

As discussed above, the control device may combine a number of factors to determine the final torque request. FIG. 2 schematically shows the curve of the accelerator pedal displacement d versus the final torque request T in the control device of the prior art. Since the final torque request T is related not only to accelerator pedal displacement, but also to a number of additional operating parameters, such as engine speed or load of the excavator, it may occur that the final torque request T does not match the operator's intent. For example, when the operator steps, especially hard, on the accelerator pedal, the final torque request may instead drop or fluctuate, as shown by the circled portion in FIG. 2 . This in turn causes the fuel injection quantity to drop or fluctuate undesirably. At this time, although the operator steps on the accelerator pedal, the power output by the engine may not increase accordingly, but may instead decrease.

Therefore, in the embodiment shown in FIG. 1 , the generating unit 12 of the control device 10 is configured to be able to: acquire a plurality of operating parameters of the excavator; determine the accelerator pedal displacement and at least one additional operating parameter based on the operating parameters a first torque request; determining a second torque request according to a predetermined mapping based solely on accelerator pedal displacement; and selectively using either the first torque request or the second torque request as a final torque request according to at least one operating parameter. Since the second torque request is only related to the accelerator pedal displacement and is not affected by additional operating parameters, the operator's intention can be more directly reflected. By selectively using either the first torque request or the second torque request as the final torque request, abnormal situations in which the final torque request does not conform to the operator's intent can be reduced or even avoided. For example, in the event that the operator depresses the accelerator pedal and the first torque request falls instead, the generating unit 12 may use the second torque request as the final torque request. It should be understood that in addition to the abnormal drop in the final torque request described above, the control device 10 may also be applied to avoid other abnormal conditions of the final torque request, such as abnormal rises that are not intended by the operator.

As shown in FIG. 1 , the control device 10 may further include a storage unit 16 , and a predetermined mapping relationship may be stored in the storage unit 16 .

The generating unit 12 is in particular configured to be able to execute the first mode and the second mode for generating the final torque request. In the first mode, the generating unit 12 takes the first torque request as the final torque request. In the second mode, the generating unit 12 uses the second torque request as the final torque request or the larger of the first torque request and the second torque request as the final torque request. Thus, the generating unit 12 can not only determine an appropriate final torque request in the first mode considering various factors (eg, including engine speed, vehicle load, etc.), but also switch to the second mode to make the operation of the engine more efficient. conforms to the operator's intent. In the second mode, the generating unit 12 takes the larger one of the first torque request and the second torque request as the final torque request, which is particularly beneficial to avoid abnormal drop in the final torque request.

The generating unit 12 may, for example, execute the first mode in most cases, and switch to the second mode only in cases where the first torque request may be abnormal.

The generating unit 12 is in particular configured to be able to switch between the first mode and the second mode according to a trigger parameter comprising at least one, in particular a plurality of the following operating parameters: accelerator pedal displacement, accelerator pedal displacement rate of change , the first torque request, the fuel injection amount of the engine, the engine speed. The trigger parameters may include, for example, the above five parameters. Alternatively, the trigger parameter may also only include the accelerator pedal displacement. Through the above trigger parameters, the generating unit 12 can selectively execute the first mode or the second mode according to the operating state of the vehicle, thereby generating a final torque request adapted to the operating state of the vehicle. In the case where the generation unit 12 switches according to a plurality of trigger parameters, the operation state of the vehicle can be more accurately determined. It should be understood that these trigger parameters are only exemplary and not exclusive, and any other operating parameters that can reflect the operating state of the vehicle or reflect the operator's intent may be used.

For this purpose, the generating unit 12 can be communicatively connected, for example, with the measuring unit 30 of the excavator. The measurement unit 30 includes at least one sensor for measuring at least one operating parameter of the excavator, including, but not limited to, an engine speed sensor for measuring engine speed; an accelerator pedal displacement sensor for measuring the displacement of an accelerator pedal of the excavator ; Fuel injection quantity sensor for measuring the fuel injection quantity of the engine. These sensors can be supplied individually or configured as a combined sensor capable of simultaneously measuring these operating parameters.

The generating unit 12 is particularly configured to: when each trigger parameter is respectively smaller than its first threshold, determine that the first condition is satisfied, and execute the first mode; when each trigger parameter is respectively greater than its second threshold, determine that the second condition is satisfied , and execute the second mode; and when neither the first condition nor the second condition is satisfied, continue to execute the currently executed first mode or the second mode. Thus, the generating unit 12 can more accurately determine the timing of switching between the first mode and the second mode, so as to reduce or even avoid abnormal drop or fluctuation of the final torque request. When the excavator operates a large load, the operator usually presses the accelerator pedal urgently and violently to increase the fuel injection amount of the engine, in order to increase the engine speed and the output torque of the engine. The inventors found that, in this case, the first torque request that comprehensively considers multiple factors is prone to abnormal drop or fluctuation. When the accelerator pedal displacement, the rate of change of the accelerator pedal displacement, and the optional first torque request, the optional fuel injection amount, and the optional engine speed are greater than their second thresholds, the generating unit 12 can very accurately determine that the accelerator pedal is being Press down hard and hard, and execute the second mode. This design is very targeted to avoid unusual drops or fluctuations in the final torque request when the accelerator pedal is slammed hard.

The first threshold value and the second threshold value may be stored in the storage unit 16 .

Optionally, the first threshold of each trigger parameter is equal to the corresponding second threshold.

In particular, the first threshold value of each trigger parameter can be configured to be smaller than the corresponding second threshold value, whereby too frequent switching between the first mode and the second mode can be avoided. For this purpose, the generating unit 12 can determine whether the first condition or the second condition is satisfied by means of a hysteresis curve function.

Specifically, for example, the trigger parameters include accelerator pedal displacement, accelerator pedal displacement rate of change, and a first torque request, and the first threshold value of each trigger parameter is less than the corresponding second threshold value. The generating unit 12 executes the first mode when the accelerator pedal displacement, the accelerator pedal displacement rate of change and the first torque request are each less than their first thresholds. If the accelerator pedal displacement increases above its second threshold value, but the accelerator pedal displacement rate of change and the first torque request are respectively smaller than their second threshold values, the generating unit 12 remains executing the first mode. If the accelerator pedal displacement, the accelerator pedal displacement rate of change, and the first torque request all increase and are greater than their second thresholds, respectively, it indicates that the operator is pressing the accelerator pedal hard and hard to increase engine speed and increase engine output torque. At this time, the generating unit 12 switches to the second mode. Then, if the accelerator pedal displacement rate of change decreases to less than its first threshold value, but the accelerator pedal displacement and the first torque request are still respectively greater than their first threshold values, the generating unit 12 remains executing the second mode. If the accelerator pedal displacement, the accelerator pedal displacement rate of change and the first torque request all decrease and are respectively smaller than their first thresholds, the generating unit 12 switches from the second mode to the first mode again.

The generating unit 12 is particularly configured to be able to determine which one or some of the accelerator pedal displacement, the accelerator pedal displacement rate of change, the first torque request, the fuel injection quantity of the engine and the engine speed are used as trigger parameters according to a predetermined selection mask. Thereby, the control device 10 can be adapted to various requirements, for example to different vehicle models, by simply changing the selection mask. The selection mask may be stored, for example, in the storage unit 16 and may be changed by writing data to the storage unit 16 .

The generating unit 12 is particularly configured to switch to the first mode regardless of whether the first condition is satisfied or not when the second mode is executed for more than a predetermined period of time. For example, the predetermined duration may be less than 30ms, in particular may be between 10ms and 20ms, eg 15ms. Thereby, the generation unit 12 can be prevented from executing the second mode for a long time, and the security can be improved.

The generating unit 12 is in particular configured such that the first torque request and/or the second torque request are respectively not greater than a torque request threshold. The torque request threshold is, for example, a maximum torque request allowed while meeting exhaust emission related standards.

In an exemplary embodiment, the predetermined mapping relationship is determined based on the acceleration pedal displacement and the first torque request collected on a light-duty vehicle, such as a forklift, which is running smoothly. In particular, the smooth operation means operation in such a manner that the displacement of the accelerator pedal does not change abruptly, that is, the operator does not perform an operation for rapidly depressing the accelerator pedal. For this reason, during the acquisition process, for example, the rate of change of the accelerator pedal displacement of the vehicle may be limited to be lower than a certain limit value. When the vehicle runs smoothly and does not bear a heavy load, the collected first torque request can usually reflect the torque demand corresponding to the displacement of the accelerator pedal, without abnormal rise, fall or fluctuation that does not meet the operator's expectations.

FIG. 3 shows a predetermined mapping relationship in an exemplary embodiment. In Figure 3, x represents accelerator pedal displacement and y represents torque request. Each discrete point represents a set of acquired accelerator pedal displacements and corresponding first torque requests. By performing curve fitting on multiple sets of data, the mapping relationship between the accelerator pedal displacement and the torque request can be obtained, as shown in the curve in FIG. 3 . The mapping relationship may be stored in the storage unit 16 of the control device 10 as the predetermined mapping relationship.

The predetermined mapping relationship shown in Figure 3 can be represented by the following formula:

y=kln(x+b)

where y represents the second torque request, x represents the accelerator pedal displacement, and k and b are predetermined coefficients. By curve fitting, the coefficients k and b can be determined. The coefficients k and b may be stored in the storage unit 16 for use in determining the second torque request based on the accelerator pedal displacement. It should be understood that the coefficients k and b may also be determined in other ways, for example by a skilled person empirically.

As shown in Figure 3, curve fitting using the natural logarithmic function can obtain fitting results with high correlation. The mapping relationship thus obtained is very close to the collected accelerator pedal displacement and the first torque request, so the switching between the first mode and the second mode is relatively smooth, and the operation comfort is high.

For example, by adjusting the coefficients k and b, the predetermined mapping relationship can be further adjusted to suit the type, model and/or operating conditions of the vehicle.

In further embodiments, the mapping relationship between accelerator pedal displacement and the second torque request may be represented by the following equation:

y=k _n x ⁿ +k _n-1 x ^n-1 +…+k ₀

Wherein, y represents the second torque request, x represents the accelerator pedal displacement, k _n , k _n-1 , . . . , k ₀ are predetermined coefficients, and n is an integer greater than 0.

For example, when n is 1, y=k ₁ x+k ₀ . Under this mapping relationship, the second torque demand will be linearly related to the accelerator pedal displacement, so that when the second mode is used, the power output by the engine can be significantly increased as the accelerator pedal is depressed.

Accordingly, by adjusting the coefficients k _n , k _n-1 , . . . , k ₀ , the predetermined mapping relationship can be further adjusted to suit the type, model and/or operating conditions of the vehicle.

In another embodiment, the mapping relationship between the accelerator pedal displacement and the second torque request may also be stored in the storage unit 16 in the form of a table.

In an exemplary embodiment, the storage unit 16 is configured such that the predetermined mapping relationship can be written to the storage unit 16 at least in part by a user. Different users may need to use the engine for different models or different operating conditions. For example, the user may empirically calibrate the mapping relationship between the accelerator pedal displacement and the second torque request, and then write and store it in the storage unit 16 as the mapping relationship used to determine the second torque request. Optionally, the type of the predetermined mapping relationship can be set before leaving the factory, for example, represented by y=kln(x+b), but the coefficients k and b can be written into the storage unit 16 by the user. This makes the function of the control unit more flexible, more adaptable to the applied vehicle, and more responsive to the needs of the user.

Alternatively or additionally, the storage unit 16 stores at least two mappings between the accelerator pedal displacement and the torque request, and the generating unit 12 is configured to be able to select one of the mappings for determining the second torque request. For example, one of the at least two mapping relationships can be written into the storage unit 16 at least in part by the user, while the other is set before leaving the factory. Optionally, the at least two mapping relationships can also be set before leaving the factory, and the generating unit 12 can select a mapping relationship that is more suitable for the applied vehicle model to determine the second torque request. This makes the functions of the control unit more flexible and diverse.

Figure 4 schematically shows a control method using the control device 10 according to the present invention according to an exemplary embodiment. The control method includes at least the following steps:

S1: the generating unit 12 obtains the operating parameters of the vehicle;

S2: the generating unit 12 determines a first torque request based on the accelerator pedal displacement among the operating parameters and at least one additional operating parameter;

S3: The generating unit 12 determines the second torque request only based on the accelerator pedal displacement and according to a predetermined mapping relationship;

S4: The generating unit 12 selectively uses the first torque request or the second torque request as the final torque request according to the at least one operating parameter; and

S5: The output unit 14 outputs a control signal according to the final torque request.

It should be understood that the features and advantages described herein for the control device 10 apply equally to the control method.

In addition, the present invention also provides a computer program product comprising computer program instructions which, when executed by one or more processors, cause the processors to perform the control method according to the present invention. The computer program instructions may be stored in a computer-readable storage medium, which may include, for example, any electronic, magnetic, optical, or other physical storage device. For example, a computer-readable storage medium may be: RAM, volatile memory, non-volatile memory, flash memory, storage drives (eg, hard drives), solid-state drives, any type of storage disks (eg, optical disks), or similar storage media , or their combination.

It should be understood that, herein, the expressions "first", "second", etc. are only used for descriptive purposes, and should not be construed as indicating or implying relative importance or implying the number of indicated technical features. Thus, a feature delimited with "first", "second" may expressly or implicitly include at least one of that feature. As used herein, "plurality" means at least two, such as two, three, etc., unless expressly and specifically limited otherwise.

Although specific embodiments of the present invention are described in detail herein, they are presented for purposes of explanation only and should not be considered as limiting the scope of the invention. Various substitutions, alterations and modifications may be devised without departing from the spirit and scope of the present invention.

List of reference signs

10 Controls

12 Generating Units

14 Output unit

16 memory cells

20 fuel injection unit

30 Measuring units

Claims (10)

1. A control device (10) for an engine of a vehicle, the control device (10) comprising a generating unit (12) for generating a final torque request and an output unit (14) for outputting a control signal in dependence of the final torque request, wherein the generating unit (12) is configured to be able to:

acquiring a plurality of operating parameters of a vehicle;

determining a first torque request based on an accelerator pedal displacement and at least one additional operating parameter of the operating parameters;

determining a second torque request according to a predetermined mapping based only on the accelerator pedal displacement; and

the first torque request or the second torque request is selectively made the final torque request based on at least one operating parameter.

2. The control device (10) according to claim 1, wherein the generating unit (12) is configured to be able to generate the final torque request in a first mode and a second mode, wherein in the first mode the generating unit (12) takes the first torque request as the final torque request and in the second mode the generating unit (12) takes the second torque request as the final torque request or the larger one of the first and second torque requests as the final torque request.

3. The control device (10) according to claim 2,

the generation unit (12) is configured to be switchable between a first mode and a second mode depending on a trigger parameter, the trigger parameter comprising at least one of the following operating parameters: -an accelerator pedal displacement, -a rate of change of accelerator pedal displacement, -a first torque request, -a fuel injection quantity of the engine, -an engine speed, wherein the generating unit (12) is especially configured to be able to determine which one or which of the accelerator pedal displacement, the rate of change of accelerator pedal displacement, the first torque request, the fuel injection quantity of the engine and the engine speed is/are to be used as a triggering parameter according to a predetermined selection mask; and/or

The generation unit (12) is configured to switch to the first mode when the second mode is executed for more than a predetermined period of time, regardless of whether the first condition is satisfied; and/or

The generation unit (12) is configured such that the first torque request and/or the second torque request is not greater than a torque request threshold.

4. The control device (10) according to claim 3, wherein the generating unit (12) is configured to:

when each trigger parameter is smaller than the first threshold value of the trigger parameter, judging that a first condition is met, and executing a first mode;

when each trigger parameter is respectively larger than the second threshold value, judging that a second condition is met, and executing a second mode; and

and when the first condition and the second condition are not met, continuing to execute the currently executed first mode or second mode.

5. The control device (10) according to claim 4,

the triggering parameters at least comprise accelerator pedal displacement and accelerator pedal displacement change rate; and/or

The first threshold value of at least one of the trigger parameters is less than the corresponding second threshold value.

6. The control device (10) according to any one of claims 1-5, wherein the predetermined mapping is represented by:

kln (x + b), where y represents the second torque request, x represents the accelerator pedal displacement, and k and b are predetermined coefficients; or

y＝k_nxⁿ+k_n-1x^n-1+…+k₀Where y represents the second torque request, x represents the accelerator pedal displacement, k_n、k_n-1、……、k₀N is an integer greater than 0, which is a predetermined coefficient.

7. The control device (10) according to any one of claims 1-6,

the predetermined mapping relationship is determined according to the accelerator pedal displacement and the first torque request which are acquired from a light-load vehicle which operates in a mode that the accelerator pedal displacement does not change sharply; and/or

The predetermined mapping can be adjusted to suit the type, model and/or operating conditions of the vehicle.

8. The control device (10) according to any one of claims 1-7, wherein the control device (10) comprises a storage unit (16), wherein:

the predetermined mapping relation is stored in a storage unit (16); and/or

The storage unit (16) is configured such that the predetermined mapping relationship is at least partially writable by a user to the storage unit (16); and/or the storage unit (16) stores at least two mappings between accelerator pedal displacement and torque request, the generation unit (12) being configured to be able to select one of the mappings as the mapping for determining the second torque request.

9. A control method using a control device (10) according to any of claims 1-8, wherein the control method comprises at least the following steps:

a generation unit (12) acquires an operation parameter of the vehicle;

a generating unit (12) determines a first torque request based on an accelerator pedal displacement and at least one additional operating parameter of the operating parameters;

the generation unit (12) determines a second torque request according to a predetermined mapping relation based only on the accelerator pedal displacement;

a generating unit (12) selectively takes the first torque request or the second torque request as a final torque request according to at least one operating parameter; and

an output unit (14) outputs a control signal in accordance with the final torque request.

10. A computer program product comprising computer program instructions, wherein the computer program instructions, when executed by one or more processors, cause the processors to perform the control method of claim 9.

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