WO2015182112A1

WO2015182112A1 - Engine rotation speed control device

Info

Publication number: WO2015182112A1
Application number: PCT/JP2015/002637
Authority: WO
Inventors: 太郎岡田
Original assignee: アイシン精機株式会社
Priority date: 2014-05-26
Filing date: 2015-05-26
Publication date: 2015-12-03
Also published as: EP3150834A4; JP6252356B2; JP2015224543A; CN106460716A; EP3150834A1

Abstract

An engine rotation speed control device is provided with a target engine rotation speed calculation unit that calculates a target engine rotation speed depending on an accelerator opening of a vehicle, a torque gain calculation unit that calculates a torque gain on the basis of an amount of change in actual engine rotation speed and an attainment rate of the actual engine rotation speed with respect to the target engine rotation speed, and a system request torque calculation unit that calculates a system request torque on the basis of a value obtained by multiplying a driver request torque by the torque gain. The system request torque calculated in this way is requested to be output from the engine of the vehicle during engine rotation speed control.

Description

Engine speed control device

The present invention relates to an engine speed control device for controlling the engine speed of a vehicle, and more particularly to a technique for appropriately controlling the engine speed according to accelerator depression (driver operation).

Generally, in a vehicle equipped with a manual transmission, when starting, a driver first depresses a clutch pedal to shift the clutch from a transmission state to a disengagement state, and then operates a shift lever to put the transmission mechanism into the first gear. Then, while depressing the accelerator pedal to increase the engine speed, the clutch pedal is gradually returned to gradually shift the clutch from the disengaged state to the transmitting state. At this time, it is necessary for the driver to harmonize the operation of the clutch pedal and the operation of the accelerator pedal. However, this harmonizing operation cannot be easily performed for all drivers. For example, if you depress the accelerator pedal strongly before starting the transition to the transmission state when starting, the engine speed will increase more than necessary (up), fuel consumption will deteriorate, and the transmission and clutch will have a heavy load. There is a risk of taking.

Therefore, there has been proposed a control device that sets an upper limit of the engine speed when the vehicle starts to start. However, for example, if the engine speed is limited on the condition that the vehicle has started moving forward, the accelerator pedal is required before the vehicle starts moving forward (before the accelerator pedal is depressed and the clutch shifts to the transmission state). If stepped on more than this, the engine speed may increase more than necessary (swell up), and fuel efficiency may deteriorate. Also, when the driver requests higher engine torque than usual, such as when starting on an uphill road or suddenly starting, the engine speed may be limited and drivability may be reduced.

Therefore, conventionally, there has been proposed a control device that improves fuel efficiency without degrading drivability when the vehicle starts (see, for example, Patent Document 1). In this conventional control device, the initial engine speed upper limit value is determined on the condition that the vehicle speed is zero and the clutch pedal is fully depressed. Then, the correction amount of the engine speed is determined according to the amount of change in the accelerator opening, the initial engine speed upper limit value is corrected with this correction amount, and the actual engine speed is corrected and the engine speed upper limit value is corrected. When the value exceeds the value, the throttle opening is gradually decreased. *

However, in the conventional control device, the engine speed upper limit value changes in accordance with the amount of change in the accelerator opening, so that a stable engine speed cannot be maintained for each accelerator opening. For example, even when the accelerator opening is the same, if the amount of change in the accelerator opening is different (for example, when the accelerator pedal is depressed slowly or suddenly), the engine speed is controlled to be different. Will be. Further, in the conventional control device, since the throttle opening is controlled only when the actual engine speed exceeds the upper limit value (engine speed upper limit value), hunting of the engine speed near the upper limit value is performed. There is a possibility that overshoot may occur, and there is a problem in convergence to the target engine speed.

JP 2011-163233 A

The present invention has been made under the above background. An object of the present invention is to provide an engine speed control device that can arbitrarily set a target engine speed for each accelerator opening and can improve convergence to the target engine speed.

One aspect of the present invention is an engine speed control device, and the engine speed control device is an engine speed control device for controlling the engine speed of a vehicle, and the engine speed set as a target. A target engine speed calculating unit that calculates a target engine speed that is a number according to an accelerator opening of the vehicle, a change amount of an actual engine speed that is an actual engine speed of the vehicle, and the target engine Based on a value obtained by multiplying the torque request by a torque gain calculation unit that calculates a torque gain based on the arrival rate of the actual engine speed with respect to the speed, and a driver request torque that is a torque corresponding to the accelerator opening. A system required torque calculation unit that calculates a system required torque that is a torque required to output to the engine of the vehicle. To have.

As described below, there are other aspects of the present invention. Accordingly, this disclosure is intended to provide some aspects of the invention and is not intended to limit the scope of the invention described and claimed herein.

FIG. 1 is a diagram illustrating an outline of a vehicle equipped with an engine speed control device according to an embodiment of the present invention. FIG. 2 is a block diagram showing the configuration of the engine speed control device according to the embodiment of the present invention. FIG. 3 is an explanatory diagram of the target engine speed MAP value in the embodiment of the present invention. FIG. 4 is an explanatory diagram of the torque gain MAP value in the embodiment of the present invention. FIG. 5 is an explanatory diagram of the torque correction value MAP value in the embodiment of the present invention. FIG. 6 is a flowchart for explaining the operation of the engine speed control device according to the embodiment of the present invention. FIG. 7 is an explanatory diagram of engine speed control (normal time) in the embodiment of the present invention. FIG. 8 is an explanatory diagram of engine speed control (during overshoot) in the embodiment of the present invention.

The detailed description of the present invention will be described below. However, the following detailed description and the accompanying drawings do not limit the invention.

The engine speed control device of the present invention is an engine speed control device for controlling the engine speed of a vehicle, and the target engine speed, which is the engine speed set as a target, is determined by the accelerator opening degree of the vehicle. Torque gain based on a target engine speed calculation unit that is calculated according to the vehicle speed, a change amount of the actual engine speed that is the actual engine speed of the vehicle, and an arrival rate of the actual engine speed with respect to the target engine speed. Based on a value obtained by multiplying the torque required by the driver gain torque, which is a torque corresponding to the accelerator opening, and the torque gain, a system required torque, which is a torque required to output to the engine of the vehicle, is calculated. A system required torque calculation unit.

According to this configuration, the target engine speed is set according to the accelerator opening. Then, based on the value obtained by multiplying the driver request torque by the torque gain calculated based on the arrival rate of the actual engine speed with respect to the target engine speed and the change amount of the actual engine speed (engine speed change amount), A system required torque is calculated. Since the system required torque calculated in this way is output to the engine, the torque gain gradually decreases as the actual engine speed approaches the target engine speed, and the convergence to the target engine speed improves. In this case, the target engine speed can be arbitrarily set for each accelerator opening. In addition, since the target engine speed is set for each accelerator opening, the target engine speed will change as the accelerator opening changes, so as not to obstruct the request for rotation increase due to accelerator depression (driver operation). Can do. In this way, the engine speed can be appropriately controlled in accordance with the accelerator depression (driver operation). Therefore, an excessive increase in the engine speed can be prevented, and drivability when the accelerator is depressed can be improved. In addition, since the engine speed can be controlled to an appropriate level when the accelerator is depressed, the transmission and the clutch can be protected, and fuel consumption can be improved.

Further, the engine speed control device of the present invention compares the actual engine speed and the target engine speed, and determines whether or not the actual engine speed is larger than the target engine speed, A torque correction value calculator that calculates a torque correction value according to a difference between the actual engine speed and the target engine speed when the actual engine speed is greater than the target engine speed, and the system required torque calculator is The system required torque may be calculated by subtracting the torque correction value from the value obtained by multiplying the driver required torque by the torque gain.

According to this configuration, when the actual engine speed is greater than the target engine speed, the torque correction value is calculated based on the difference between the actual engine speed and the target engine speed, and the driver request torque is multiplied by the torque gain. The system required torque is calculated by subtracting the torque correction value from the value. Therefore, when the actual engine speed exceeds the target engine speed, it is possible to quickly converge to the target engine speed by reducing the system required torque (for example, by making it a negative torque).

The engine speed control device of the present invention includes a start detection unit that detects whether or not the vehicle is starting, and the system request torque calculation unit calculates the system request torque when it is detected that the vehicle is starting. Calculation may be performed.

According to this configuration, the system required torque is calculated and the engine speed is controlled when starting. As a result, it is possible to prevent an excessive increase in the engine speed at the time of starting, and to improve the drivability at the time of starting. Further, it is possible to prevent an unexpected start at a high rotational speed, and to protect the transmission and the clutch. In addition, fuel efficiency can be improved by starting at an appropriate engine speed.

According to the present invention, the target engine speed can be arbitrarily set for each accelerator opening, and the convergence to the target engine speed can be improved.

(Embodiment)
Hereinafter, an engine speed control device according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the case of an engine speed control device used for a vehicle or the like equipped with a manual transmission is illustrated.

The configuration of the engine speed control device according to the embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a diagram illustrating an outline of a vehicle equipped with an engine speed control device of the present embodiment. As shown in FIG. 1, the vehicle includes an engine 1, a clutch 2, and a transmission 3. The engine 1 is one of known internal combustion engines, and is, for example, a gasoline engine that uses gasoline as fuel and a diesel engine that uses light oil as fuel. The transmission 3 is a manual transmission having, for example, a plurality of (for example, five) forward gears, one reverse gear, and a neutral gear. The output shaft of the transmission 3 is connected to the drive wheels 4 of the vehicle via a differential (not shown). Switching of the gear position of the transmission 3 is executed by the driver operating the shift lever 5. At this time, the driver also operates the clutch pedal 6 and the accelerator pedal 7.

The transmission 3 is connected to an input rotation sensor 8 that detects the rotation speed (input rotation speed) input from the transmission 3 to the drive wheels 4. The clutch pedal 6 is connected to a clutch stroke sensor 9 that detects an operation amount (clutch stroke amount) of the clutch pedal 6. The accelerator pedal 7 is connected to an accelerator opening sensor 10 that detects an operation amount (accelerator opening) of the accelerator pedal 7.

The engine 1 includes an engine ECU 11 for electronically controlling engine operation. The engine ECU 11 is connected to an engine speed controller 12 for controlling the engine speed. Information such as the input rotational speed detected by the input rotational sensor 8 and the clutch stroke amount detected by the clutch stroke sensor 9 is input to the engine rotational speed control device 12. Information on the accelerator opening detected by the accelerator opening sensor 10 is input to the engine ECU 11. The engine ECU 11 outputs information such as driver request torque to the engine 1. Information such as actual output torque is input from the engine 1 to the engine ECU 11. Information such as engine speed (also referred to as actual engine speed), accelerator opening, driver request torque, and actual output torque is input from the engine ECU 11 to the engine speed control device 12. Further, information such as system required torque is output from the engine speed control device 12 to the engine ECU 11.

The clutch stroke sensor 9 is not limited to a sensor that directly detects the amount of displacement of the clutch 2, for example, the amount of movement of the clutch master cylinder (CMC) that operates the clutch 2, the displacement angle of the clutch pedal 6, Includes those that can detect displacement. Based on these pieces of information, the movement amount of the clutch 2 may be calculated by the calculation function of the engine speed control device 12.

The actual engine speed is the actual speed of the vehicle engine 1 (actual engine speed). On the other hand, the target engine speed is an engine speed set as a target. The driver request torque is generally torque obtained from engine characteristics (MAP of engine speed and engine output torque) according to the accelerator opening. On the other hand, the system required torque is a torque requested to be output to the engine 1 (engine ECU 11).

Next, the configuration of the engine speed control device 12 will be described in detail. FIG. 2 is a block diagram showing the configuration of the engine speed control device 12. As shown in FIG. 2, the engine speed control device 12 includes an accelerator opening input unit 20, an actual engine speed input unit 21, a driver request torque input unit 22, and a start detection unit 23. The accelerator opening (%) is input from the accelerator opening sensor 10 to the accelerator opening input unit 20. The actual engine speed input unit 21 receives the actual engine speed (rpm) from the engine ECU 11. A driver request torque (Nm) is input from the engine ECU 11 to the driver request torque input unit 22. The start detection unit 23 receives the input rotation speed from the input rotation speed sensor. The start detection unit 23 detects whether or not the vehicle is starting based on the input rotation speed and the clutch operation. The start detection unit 23 may detect whether or not the vehicle is starting based on the vehicle speed (for example, input from a vehicle sensor).

The engine speed control device 12 includes a target engine speed calculation unit 24, an engine speed comparison unit 25, an engine speed change amount calculation unit 26, and an arrival rate calculation unit 27. The target engine speed calculation unit 24 calculates the target engine speed according to the accelerator opening of the vehicle. For example, with reference to the target engine speed MAP value 28 as shown in FIG. 3, the target engine speed corresponding to the accelerator opening is obtained. The engine speed comparison unit 25 compares the actual engine speed and the target engine speed, and determines whether or not the actual engine speed is greater than the target engine speed. The engine speed change amount calculation unit 26 calculates the change amount (rpm / sec) of the actual engine speed. The arrival rate calculation unit 27 calculates, for example, the arrival rate (%) of the actual engine speed with respect to the target engine speed using the following Equation 1.
Reaching rate = (actual engine speed / target engine speed) × 100 (Formula 1)

The change speed (change time) of the engine speed generally varies depending on the engine speed. For example, in the change time from 1000 rpm to 1500 rpm and the change time from 4500 rpm to 5000 rpm, the latter tends to be shorter. This is due to the characteristics of the engine that the rotation is more likely to increase in the high rotation range than in the low rotation range. Therefore, for example, when the target engine speed is 1500 rpm and the target engine speed is 5000 rpm, even if the deviation of the actual engine speed from the target engine speed is the same (for example, 500 rpm), The degree of control will vary greatly. That is, when a torque control amount for a deviation of 500 rpm is set assuming a rapid convergence from the actual engine speed of 1000 rpm to the target engine speed of 1500 rpm, it is applied when the actual engine speed is 4500 rpm and the target engine speed is 5000 rpm. As a result, the actual engine speed may overshoot the target engine speed. On the contrary, when a torque control amount for a deviation of 500 rpm is set on the assumption that rapid convergence from the actual engine speed of 4500 rpm to the target engine speed of 5000 rpm is performed, this is applied when the actual engine speed of 1000 rpm is changed to the target engine speed of 1500 rpm. When applied, the tracking time may be long or may not converge. Therefore, in the present embodiment, the torque control amount is set in accordance with the ratio of the current actual engine speed to the target engine speed, whereby a rapid target value (target engine speed) in a wide speed range can be obtained. Convergence is achieved.

Furthermore, the engine speed control device 12 includes a torque gain calculation unit 29, a torque correction value calculation unit 30, and a system required torque calculation unit 31. The torque gain calculation unit 29 calculates the torque gain based on the change amount of the actual engine speed (engine speed change amount) and the arrival rate. For example, with reference to the torque gain MAP value 32 shown in FIG. As shown in FIG. 4, the characteristic of the torque gain with respect to the arrival rate changes depending on the engine speed change amount Δ. In this case, the torque gain calculation unit 29 sets the torque gain when the change amount of the actual engine speed is large to a smaller value than the torque gain when the change amount of the actual engine speed is small.

The torque correction value calculation unit 30 calculates a torque correction value according to the difference between the actual engine speed and the target engine speed when the actual engine speed is greater than the target engine speed. That is, the torque correction value calculation unit 30 calculates the torque correction value when the actual engine speed becomes equal to or higher than the target engine speed. For example, referring to a torque correction value MAP value 33 as shown in FIG. 5, a torque correction value corresponding to the difference between the actual engine speed and the target engine speed is obtained. When there is a rotational speed difference between the actual engine rotational speed and the target engine rotational speed, the torque correction value calculation unit 30 sets the torque correction value to a larger value as the rotational speed difference is larger. When the actual engine speed is not greater than the target engine speed, the torque correction value is zero. That is, when the actual engine speed is lower than the target engine speed, the torque correction value calculation unit 30 sets the torque correction value to zero.

The system required torque calculation unit 31 calculates the system required torque (Nm) by using, for example, the following Equation 2 (that is, by subtracting the torque correction value from the value obtained by multiplying the driver request torque by the torque gain). .
System required torque = Driver required torque x Torque gain-Torque correction value (Formula 2)

As described above, in the present embodiment, the system required torque is controlled (gain control) using the torque gain as the base characteristic to converge to the target engine speed. For example, engine output characteristics may change due to changes in the load on air conditioners and electric auxiliary equipment, changes in outside air temperature, and atmospheric pressure. However, by performing gain control, the base characteristics (driver required torque characteristics) can be reduced. Even if there is a change, the system required torque can be controlled so that it converges to the target engine speed regardless of the amount of variation in characteristics. On the other hand, when the gain control as in the present embodiment is not performed, for example, it is conceivable to control the system required torque using an absolute value (torque correction value) instead of a torque gain. However, in this case, the driver request torque is controlled by a predetermined absolute value torque (torque correction value) with respect to the target engine speed, so that the balance between the torque correction value and the characteristic variation amount is balanced. There is a risk that it will fail and not follow the target value.

The system required torque calculated in this way is output to the engine 1 and used for controlling the engine speed. It is desirable that the control of the engine speed by the system required torque is performed particularly when the vehicle starts (when the start of the vehicle is detected).

The operation of the engine speed control device 12 configured as described above will be described with reference to the flowchart of FIG.

As shown in FIG. 6, in the engine speed control device 12 of the present embodiment, first, when the start of the vehicle is detected by the start detection unit 23 (S1), the accelerator opening from the accelerator opening sensor 10 is changed. Obtained (S2), the target engine speed calculator 24 sets the target engine speed corresponding to the accelerator opening (S3). In this case, for example, the target engine speed corresponding to the accelerator opening is obtained by referring to the target engine speed MAP as shown in FIG. Then, the engine speed comparison unit 25 compares the target engine speed with the actual engine speed (S4). If the actual engine speed is not larger than the target engine speed, the torque correction value calculation unit 30 A torque correction value is calculated according to the difference between the actual engine speed and the target engine speed (S5). In this case, for example, referring to a torque correction value MAP value 33 as shown in FIG. 5, a torque correction value corresponding to the difference between the actual engine speed and the target engine speed is obtained. When the actual engine speed is larger than the target engine speed, the torque correction value is zero.

The engine speed change amount calculation unit 26 calculates the actual engine speed change amount (engine speed change amount) (S6). Further, the arrival rate calculation unit 27 calculates the arrival rate of the actual engine speed with respect to the target engine speed (S7). Then, the torque gain calculation unit 29 calculates a torque gain according to the arrival rate and the engine speed change amount (S8). In this case, for example, referring to a torque gain MAP value 32 as shown in FIG. 4, a torque gain corresponding to the arrival rate and the engine speed change amount is obtained. Finally, the system request torque calculation unit 31 multiplies the driver request torque by the torque gain (S9), and subtracts the torque correction value from the multiplied value (S10), thereby calculating the system request torque (S11). .

According to the engine speed control device 12 of this embodiment, the target engine speed is set according to the accelerator opening. Then, based on the value obtained by multiplying the driver request torque by the torque gain calculated based on the arrival rate of the actual engine speed with respect to the target engine speed and the change amount of the actual engine speed (engine speed change amount), A system required torque is calculated. Since the system required torque calculated in this way is output to the engine 1, as shown in FIG. 7, the torque gain gradually decreases as the actual engine speed approaches the target engine speed, and the target engine speed. Convergence is improved.

In this case, the target engine speed can be arbitrarily set for each accelerator opening. In addition, since the target engine speed is set for each accelerator opening, the target engine speed will change as the accelerator opening changes, so as not to obstruct the request for rotation increase due to accelerator depression (driver operation). Can do. In this way, the engine speed can be appropriately controlled in accordance with the accelerator depression (driver operation). Therefore, an excessive increase in the engine speed can be prevented, and drivability when the accelerator is depressed can be improved. Further, since the engine speed can be controlled to an appropriate value when the accelerator is depressed, the clutch 2 and the transmission 3 can be protected, and the fuel efficiency can be improved.

In this embodiment, when the actual engine speed is larger than the target engine speed, a torque correction value is calculated based on the difference between the actual engine speed and the target engine speed, and a torque gain is added to the driver request torque. The system required torque is calculated by subtracting this torque correction value from the multiplied value. Therefore, as shown in FIG. 8, when the actual engine speed exceeds the target engine speed (when overshooting), the target engine speed is quickly reduced by reducing the system required torque (for example, making it a negative torque). It can be converged to the rotational speed.

In this embodiment, the required system torque is calculated and the engine speed is controlled at the start. As a result, it is possible to prevent an excessive increase in the engine speed at the time of starting, and to improve the drivability at the time of starting. Further, it is possible to prevent an unexpected start at a high rotational speed, and to protect the clutch 2 and the transmission 3. In addition, fuel efficiency can be improved by starting at an appropriate engine speed.

The embodiments of the present invention have been described above by way of example, but the scope of the present invention is not limited to these embodiments, and can be changed or modified according to the purpose within the scope of the claims. is there.

For example, in the above description, the example in which the engine ECU and the engine speed control device are configured as separate bodies (separate ECUs) has been described. However, the engine ECU and the engine speed control device are configured as a single body (one ECU). May be.

Although the presently preferred embodiments of the present invention have been described above, it will be understood that various modifications can be made to the present embodiments and are within the true spirit and scope of the present invention. It is intended that the appended claims include all such variations.

As described above, the engine speed control device according to the present invention can arbitrarily set the target engine speed for each accelerator opening, and can improve the convergence to the target engine speed. It is useful when applied to a vehicle or the like equipped with a manual transmission.

DESCRIPTION OF SYMBOLS 1 Engine 2 Clutch 3 Transmission 4 Drive wheel 5 Shift lever 6 Clutch pedal 7 Accelerator pedal 8 Input rotation sensor 9 Clutch stroke sensor 10 Accelerator opening sensor 11 Engine ECU
DESCRIPTION OF SYMBOLS 12 Engine speed control apparatus 20 Accelerator opening input part 21 Actual engine speed input part 22 Driver demand torque input part 23 Start detection part 24 Target engine speed calculation part 25 Engine speed comparison part 26 Engine speed change amount calculation part 27 Achieving rate calculation unit 28 Target engine speed MAP value 29 Torque gain calculation unit 30 Torque correction value calculation unit 31 System required torque calculation unit 32 Torque gain MAP value 33 Torque correction value MAP value

Claims

An engine speed control device for controlling the engine speed of a vehicle,
A target engine speed calculation unit that calculates a target engine speed, which is an engine speed set as a target, according to the accelerator opening of the vehicle;
A torque gain calculating unit that calculates a torque gain based on a change amount of the actual engine speed that is an actual engine speed of the vehicle and an arrival rate of the actual engine speed with respect to the target engine speed;
A system required torque calculating unit that calculates a system required torque that is a torque to be output to the engine of the vehicle based on a value obtained by multiplying the torque required by a driver required torque that is a torque according to the accelerator opening; ,
An engine speed control device comprising:
An engine speed comparison unit that compares the actual engine speed with the target engine speed to determine whether the actual engine speed is greater than the target engine speed;
A torque correction value calculation unit that calculates a torque correction value according to a difference between the actual engine speed and the target engine speed when the actual engine speed is greater than the target engine speed;
With
The engine speed control device according to claim 1, wherein the system required torque calculation unit calculates the system required torque by subtracting the torque correction value from a value obtained by multiplying the driver required torque by the torque gain. .
A start detection unit for detecting whether or not the vehicle is starting,
The engine speed control device according to claim 1, wherein the system required torque calculation unit calculates the system required torque when it is detected that the vehicle is starting.
The torque gain calculation unit sets a torque gain when the amount of change in the actual engine speed is large to a value smaller than a torque gain when the amount of change in the actual engine speed is small. The engine speed control device described in 1.
The engine speed control device according to claim 2, wherein the torque correction value calculation unit calculates the torque correction value when the actual engine speed is equal to or higher than the target engine speed.
The engine speed control device according to claim 2, wherein the torque correction value calculation unit sets the torque correction value to zero when the actual engine speed is lower than the target engine speed.
The torque correction value calculation unit sets the torque correction value to a larger value as the rotation speed difference is larger when there is a rotation speed difference between the actual engine rotation speed and the target engine rotation speed. The engine speed control device described in 1.