Vehicle start control method and vehicle start control device

Abstract

To provide a vehicle start control method and a vehicle start control device capable of suppressing vibration generated when fastening of a clutch starts during vehicle start.SOLUTION: In a vehicle start control method and a vehicle start control device according to the present invention, by limiting the output or rotation of an internal combustion engine 1, which is a prime mover, by, for example, limiting a throttle opening, in a state where a clutch 3 is released, it is possible to reduce inertia absorption energy, which is absorption energy per unit time when the clutch 3 is fastened, and it is thus possible to suppress vibration generated when fastening of the clutch 3 starts.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle start control method and a vehicle start control device. [Background technology]

[0002] BACKGROUND ART A known conventional vehicle start control device is, for example, that described in Patent Document 1 below.

[0003] To explain briefly, this vehicle start control device assists the driver in starting the vehicle by, for example, correcting and controlling the engine speed when the driver engages the clutch, thereby achieving good starting behavior of the vehicle. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-263647 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the conventional vehicle start control device, no restrictions are placed on engine output or engine speed when the clutch is released. As a result, there is a risk of vibration, or so-called shift shock, occurring when the clutch begins to engage, particularly during a sudden start of the vehicle (during a sudden start operation), and there is still room for improvement.

[0006] Therefore, the present invention has been devised in consideration of the technical problems of the conventional vehicle start control devices, and aims to provide a vehicle start control method and a vehicle start control device that can suppress vibrations that occur when the clutch begins to engage when the vehicle starts. [Means for solving the problem]

[0007] In one aspect, the present invention provides a start control method for a vehicle equipped with a transmission and a clutch that, by engaging or disengaging, interrupts the transmission of power from the prime mover to the drive wheels when the transmission is operated to change gears, and limits the output or rotation of the prime mover in the region where the clutch is disengaged. [Effects of the Invention]

[0008] According to the present invention, by limiting the output or rotation of the prime mover while the clutch is released, it is possible to reduce the inertia absorption energy, which is the energy absorbed per unit time when the clutch is engaged, and to suppress the vibration that occurs when the clutch begins to engage. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a system configuration diagram of a vehicle start control device according to the present invention; [Figure 2] 1 is a control block diagram of a vehicle start control device according to the present invention; [Figure 3] 3 is a control map of the output restriction determination unit shown in FIG. 2. [Figure 4] 3 is a control map of the output limit amount calculation unit shown in FIG. 2. [Figure 5] 3 is a control map of the output recovery speed calculation unit shown in FIG. 2. [Figure 6] 3 is a control map of the clutch engagement start position calculation unit shown in FIG. 2. [Figure 7] 3 is a control flowchart showing a vehicle start control method according to the present invention. [Figure 8] 10 is a time chart showing changes in parameters when a vehicle starts to which output limit control of a prime mover is applied. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of a vehicle start control method and a vehicle start control device according to the present invention will be described in detail with reference to the drawings. Note that in this embodiment, as in the prior art, an example is shown in which the vehicle start control method and the vehicle start control device according to the present invention are applied to an automobile in which the prime mover is a spark ignition internal combustion engine and a manual transmission is installed as a driving force transmission device that transmits the driving force of the prime mover. Note that in this embodiment, an example is shown in which the prime mover according to the present invention is applied to the spark ignition internal combustion engine, but the prime mover according to the present invention may be configured as, for example, an electric motor in addition to the spark ignition internal combustion engine.

[0011] (System configuration of the launch control device) FIG. 1 is a system configuration diagram showing an outline of the system configuration of a vehicle start control device according to this embodiment.

[0012] For example, as shown in Fig. 1, the vehicle is an automobile having a so-called FR (front engine, rear drive) drive system in which an internal combustion engine 1 as a prime mover is disposed at the front of the vehicle, and rear wheels RW as drive wheels are driven by driving force output from a manual transmission 2 as a transmission connected to the internal combustion engine 1, with front wheels FW being driven by the driving force. A clutch 3 is interposed between an output shaft 10 of the internal combustion engine 1 and an input shaft 21 of the manual transmission 2, and the driving force of the internal combustion engine 1 is transmitted to the manual transmission 2 via the clutch 3. An output shaft 22 of the manual transmission 2 is connected to the rear wheels RW as drive wheels via a differential 4.

[0013] The internal combustion engine 1 is controlled by a control device 5, which is an engine control unit (ECU), via a fuel injection device and an ignition device (not shown), and an output is obtained according to the opening of an electronically controlled throttle valve (not shown). The engine rotation speed is detected by a crank angle sensor 61, which detects the rotation angle of a crankshaft (not shown). The vehicle speed VS, which is the vehicle speed, is detected by a vehicle speed sensor 62. The accelerator opening AO, which is the amount of depression of the vehicle's accelerator pedal, is detected by an accelerator opening sensor 63 provided on the accelerator pedal (not shown). The opening of the electronically controlled throttle valve (not shown) is detected by a throttle opening sensor 64, which detects the rotation angle of the electronically controlled throttle valve. The gear GP of the manual transmission 2 is detected by a shift position sensor 65.

[0014] The clutch 3 is a hydraulic clutch that is engaged by applying hydraulic pressure, and the internal combustion engine 1 and the manual transmission 2 are connected and disconnected in response to the driver's operation of a clutch pedal (not shown). Specifically, the clutch 3 is fully engaged, engaged, or released in response to, for example, a displacement CS in the clutch engagement direction (hereinafter abbreviated as "clutch displacement") detected by a clutch sensor (not shown), or a hydraulic pressure CH acting on the clutch 3 (hereinafter abbreviated as "clutch hydraulic pressure") detected by a hydraulic pressure sensor (not shown) provided in a clutch master cylinder (not shown). In this embodiment, "engaged" refers to a slipping state in which the clutch 3 transitions to fully engaged while slipping, and "released" refers to a state in which the clutch 3 is completely released.

[0015] (Control device configuration) 2 shows a control block diagram of a vehicle start control device according to the present invention. The functions shown in this control block diagram are realized by software or hardware executed by the control device 5.

[0016] As shown in FIG. 2, the control device 5 is configured to include an output limit determination unit 51, an output limit amount calculation unit 52, an output limit command unit 53, an output recovery speed calculation unit 54, a clutch engagement start position calculation unit 55, and an output recovery command unit 56.

[0017] An output restriction determination unit 51 determines whether or not to implement output restriction of the internal combustion engine 1. An output restriction amount calculation unit 52 calculates the output restriction amount of the internal combustion engine 1 based on the determination of the output restriction determination unit 51. An output restriction command unit 53 outputs an output restriction command signal to the electronically controlled throttle valve TV or the fuel injection device FI to limit the output of the internal combustion engine 1 based on the output restriction amount calculated by the output restriction amount calculation unit 52. Here, in this embodiment, the output restriction command unit 53 limits the output of the internal combustion engine 1 by limiting the throttle opening, which is the opening of the electronically controlled throttle valve TV. Note that the output restriction means for the internal combustion engine 1 may limit the throttle opening TO of the electronically controlled throttle valve TV, or may limit the fuel injection amount FA of the fuel injection device FI, for example.

[0018] An output recovery speed calculation unit 54 calculates an output recovery speed (output recovery timing) for recovering the limited output of the internal combustion engine 1 based on the output signal of the output restriction command unit 53. A clutch engagement start position calculation unit 55 calculates an engagement start position of the clutch 3 based on a clutch displacement CD detected by a clutch switch SW or a detection signal of a clutch oil pressure CH detected by an oil pressure sensor HS provided in an on-board master cylinder (not shown). An output recovery command unit 56 outputs an output release signal to an electronically controlled throttle valve TV or a fuel injection device FI based on the output recovery speed (output recovery timing) calculated by the output recovery speed calculation unit 54 and the clutch engagement start position calculated by the clutch engagement start position calculation unit 55, to release the output restriction of the internal combustion engine 1.

[0019] FIG. 3 shows a control map of the output restriction determination unit shown in FIG.

[0020] For example, as shown in Fig. 3, the output restriction determination unit 51 determines whether or not to restrict the output of the internal combustion engine 1 based on the vehicle speed VS [km / h] detected by the vehicle speed sensor 62 or the gear GP [gear] of the manual transmission 2 detected by the shift position sensor 65. Specifically, when the vehicle starts moving, that is, when the gear GP is in first gear and the speed is within the vehicle speed limit Vx that can be reached in first gear (output restriction implementation region shown in Fig. 3), the output of the internal combustion engine 1 is restricted. In other words, when the gear GP of the manual transmission 2 is in second gear or higher or the vehicle speed VS exceeds the vehicle speed limit Vx (output restriction prohibition region shown in Fig. 3), the output of the internal combustion engine 1 is not restricted.

[0021] FIG. 4 shows a control map of the output limit amount calculation unit shown in FIG.

[0022] For example, as shown in FIG. 4, the output restriction amount calculation unit 52 calculates the output restriction amount DV of the internal combustion engine 1 based on the road surface gradient ω ([%] or [degrees]) detected by the gyro sensor 66. In this embodiment, a throttle opening restriction amount that restricts the throttle opening, or a fuel injection restriction amount that restricts the fuel injection amount, is used as the output restriction amount DV. Specifically, when the road surface gradient ω detected based on the inclination of the vehicle is equal to or less than zero, that is, when the vehicle is horizontal or on a downward gradient, the output restriction amount DV is maximized. On the other hand, when the road surface gradient ω is greater than zero, that is, when the vehicle is on an upward gradient, the output restriction amount DV is increased as the road surface gradient ω increases.

[0023] FIG. 5 shows a control map of the output recovery speed calculation unit shown in FIG.

[0024] 5, the output recovery speed calculation unit 54 calculates the output recovery speed of the internal combustion engine 1 based on the clutch engagement speed CS, which is determined from the rate of change of the clutch displacement CD [mm] detected by the clutch switch SW or the rate of change of the clutch oil pressure CH detected by an oil pressure sensor HS [Pa] provided in an on-board master cylinder (not shown). Specifically, the higher the clutch engagement speed CS, the greater the throttle opening change rate TS [% / sec] or the engine rotation increase rate RS [rpm / sec].

[0025] Figure 6 shows a control map of the clutch engagement start position calculation unit shown in Figure 2. Note that the clutch displacement CD shown on the vertical axis of Figure 6 corresponds to the amount of depression of the clutch pedal, and the clutch oil pressure CH corresponds to the oil pressure generated in the master cylinder (not shown) when the clutch pedal is depressed, and the clutch 3 is in a fully engaged state when the clutch displacement CD and clutch oil pressure CH are zero.

[0026] 6, for example, clutch engagement start position calculation unit 55 calculates the engagement start position of the clutch 3 based on the clutch engagement speed CS ([mm / sec] or [Pa / sec]) determined from the rate of change of clutch displacement CD [mm] detected by clutch switch SW or the rate of change of clutch oil pressure CH detected by an oil pressure sensor HS [Pa] provided in an on-board master cylinder (not shown). Specifically, the clutch engagement start position SP [mm] at which engagement of the clutch 3 starts or the clutch engagement oil pressure value HP [Pa] at which engagement of the clutch 3 starts increases as the clutch engagement speed CS increases.

[0027] (Explanation of the launch control method) FIG. 7 shows a control flowchart illustrating a vehicle start control method according to this embodiment.

[0028] As shown in Fig. 7, the vehicle start control device according to this embodiment first determines whether the vehicle speed VS is equal to or less than the vehicle speed limit Vx and whether the gear position GP is first gear (step S1). If the determination in step S1 is No, the process returns to start. On the other hand, if the determination in step S1 is Yes, the process then determines whether the clutch displacement CD has reached the clutch engagement start position Cx or whether the clutch hydraulic pressure CH has reached the clutch engagement start hydraulic pressure Hx (step S2). If the determination in step S2 is No, the process returns to start.

[0029] Next, if the determination in step S2 is Yes, the output restriction amount DV of the internal combustion engine 1 is calculated based on the road surface gradient ω ([%] or [degrees]) detected by the on-board gyro sensor 66 (step S3). Then, based on this calculated output restriction amount DV, the output of the internal combustion engine 1 is restricted, that is, a restriction command signal for the throttle opening degree TO is output (step S4).

[0030] Thereafter, based on this calculated output restriction amount DV, the output restriction amount DV of the internal combustion engine 1, i.e., the throttle opening restriction amount TD, is calculated (step S5). Next, based on the clutch engagement speed CS when the clutch 3 is engaged, the output recovery speed of the internal combustion engine 1, i.e., the throttle opening change speed TS, is calculated (step S6). Then, based on this calculated throttle opening change speed TS, the output restriction of the internal combustion engine 1 is released, thereby recovering the output of the internal combustion engine 1, i.e., the throttle opening TO is restored (step S7).

[0031] Fig. 8 is a time chart showing changes in parameters when the vehicle starts moving with the application of output limit control of the prime mover (internal combustion engine 1 in this embodiment) based on the control flow shown in Fig. 7 at the start of clutch engagement during a sudden start operation. The parameters shown in Fig. 8 are, from top to bottom, (a) clutch displacement CD or clutch oil pressure CH, (b) gear GP of the manual transmission 2, (c) output limit flag FD, (d) accelerator opening AO, (e) throttle opening limit amount TD, (f) throttle opening TO, (g) engine speed RT, and (h) drive torque T transmitted from the internal combustion engine 1 to the manual transmission 2. The dashed lines in columns (f), (g), and (h) show the state when output limiting of the internal combustion engine 1 is not performed.

[0032] Up until time t1, the vehicle is stopped, the gear GP shown in column (b) is in the neutral position, the clutch 3 shown in column (a) is in the engaged state, and the engine speed RT shown in column (g) is the idle speed. After that, as shown in column (a), the clutch 3 is depressed and a predetermined clutch displacement CD is reached, that is, at time t2 when the clutch 3 begins to be released, the output restriction flag FD is turned ON, and the throttle opening restriction amount TD is set to a predetermined restriction amount TDx.

[0033] Next, after depressing the clutch 3, the gear position GP is shifted to first gear as shown in (b) and the accelerator pedal is depressed (time t3) as shown in (d), and the throttle opening TO is limited to a predetermined limit value TOx. After that, as shown in (a), the clutch pedal is released, that is, the clutch displacement CS or clutch hydraulic pressure CH is reduced, and at time t4 when the clutch 3 begins to engage, the limit on the throttle opening TO is released as shown in (f), and the engine speed RT is restored.

[0034] As described above, the timing for releasing the restriction on the throttle opening TO is increased by correcting the clutch displacement CD or clutch hydraulic pressure CH for releasing the restriction on the throttle opening TO as the clutch engagement speed CS increases. As a result, as shown by the dashed line in section (a), the clutch 3 starts to engage at an earlier timing, and as shown by the dashed line in section (f), the restriction on the throttle opening TO is released and the engine speed RT recovers (at time t5).

[0035] In this way, by performing output limit correction of the internal combustion engine 1 from the start of release of the clutch 3 to the start of engagement, the sudden increase in the driving torque T (see dashed line) is suppressed as shown in column (h), and the vibration that occurs when the clutch 3 starts to engage can be suppressed.

[0036] (Effects of this embodiment) In the vehicle start control method and vehicle start control device according to this embodiment, by limiting the output or rotation of the prime mover (the "internal combustion engine 1" in this embodiment) by, for example, limiting the throttle opening TO when the clutch 3 is released, it is possible to reduce the inertia absorption energy, which is the energy absorbed per unit time when the clutch 3 is engaged. This makes it possible to suppress vibrations that occur when the clutch 3 starts to be engaged.

[0037] Furthermore, in this embodiment, the prime mover is an internal combustion engine 1, and by limiting the throttle opening TO relative to the accelerator opening AO, it is possible to limit the output of the internal combustion engine 1 or reduce the engine speed RT associated therewith, thereby effectively suppressing vibrations that occur when the clutch 3 begins to engage.

[0038] Furthermore, when the prime mover is an internal combustion engine 1, the vibrations that occur when the clutch 3 begins to engage can also be effectively suppressed by limiting the output of the internal combustion engine 1 or reducing the engine speed associated therewith by limiting the amount of fuel injected by the fuel injection device not shown.

[0039] In another embodiment, when the prime mover is a motor 7 (see FIG. 1), the output of the motor 7 can be limited by limiting the current supplied to the motor 7, or the rotation speed of the motor 7 can be reduced accordingly, thereby effectively suppressing the vibrations that occur when the clutch 3 begins to engage.

[0040] Furthermore, in this embodiment, when it is determined that the clutch 3 is about to start engaging when the vehicle starts moving, the output restriction (restriction on the throttle opening TO) of the prime mover (internal combustion engine 1) is released. In this way, by releasing the output restriction on the internal combustion engine 1 as the clutch 3 is engaged, it is possible to suppress vibrations when the clutch 3 starts to engage and to eliminate a lack of driving force after the clutch 3 is engaged.

[0041] Furthermore, if the engagement speed of the clutch 3 is high, the load on the internal combustion engine 1 becomes steep, which makes it more likely that the rotation speed of the internal combustion engine 1 will decrease or stall. Therefore, in this embodiment, the engine rotation increase speed RS, which is the increase speed of the engine rotation speed RT, is changed according to the clutch engagement speed CS. In other words, the faster the clutch engagement speed CS, the faster the engine rotation increase speed RS after the output restriction on the internal combustion engine 1 is released, so that the rotation speed of the internal combustion engine 1 can be prevented from decreasing or stalling.

[0042] Furthermore, the faster the clutch engagement speed CS, the more the driver requests a sudden start. Therefore, by increasing the engine rotation increase speed RS after the output restriction on the internal combustion engine 1 is released, it is possible to instantly obtain the output of the internal combustion engine 1 that is necessary and sufficient for starting and accelerating after the clutch is engaged, thereby enabling powerful starting acceleration in line with the driver's intentions.

[0043] Furthermore, in this embodiment, the clutch displacement CD or clutch hydraulic pressure CH that releases the output limit of the prime mover (internal combustion engine 1) is corrected according to the rate of change of the displacement of the clutch 3 (clutch displacement CD) or the rate of change of the hydraulic pressure (clutch hydraulic pressure CH) acting on the clutch 3, thereby improving responsiveness to a driver's request for driving force. Since there is a delay in the increase characteristic of the engine speed in response to a command, when the clutch engagement speed CS is fast, that is, when a powerful driving force is required through sudden engagement, the output limit of the internal combustion engine 1 is released more quickly to reduce the delay until the driving force is generated, making it possible to obtain sufficient driving force at the time of engagement of the clutch 3, thereby improving responsiveness when the vehicle starts moving.

[0044] In this embodiment, when the vehicle speed (vehicle speed VS) is equal to or greater than a predetermined value (vehicle speed limit Vx), limiting the output of the prime mover (internal combustion engine 1) is prohibited. This makes it possible to suppress the engagement shock of the clutch 3 when the vehicle starts, and also to suppress the discomfort caused by limiting the output of the internal combustion engine 1 when the clutch 3 is released other than when the vehicle starts.

[0045] In this embodiment, the output of the prime mover (internal combustion engine 1) is limited only when the gear GP is in first gear, which is the starting gear. This makes it possible to suppress the engagement shock of the clutch 3 when the vehicle starts, and also to suppress the discomfort caused by the output of the internal combustion engine 1 being limited when the clutch 3 is released at times other than when the vehicle starts.

[0046] Furthermore, in this embodiment, when the vehicle is positioned on an uphill gradient, the limit value of the output or rotation of the prime mover (internal combustion engine 1) is changed or output limitation of the prime mover (internal combustion engine 1) is prohibited based on road gradient information (road gradient ω) detected by the gyro sensor 66. This makes it possible to ensure the driving force required for uphill start acceleration when the vehicle starts uphill on an uphill gradient. This prevents the vehicle from deteriorating in behavior due to insufficient driving force at start, and makes it possible to start and accelerate as intended by the driver.

[0047] The present invention is not limited to the configurations exemplified in the above embodiments, and can be freely modified, for example, according to the specifications of the automobile equipped with the prime mover (internal combustion engine 1 or motor 7) to which the present invention is applied. [Explanation of symbols]

[0048] 1...Internal combustion engine (prime mover) 2...Manual transmission (transmission) 3...Clutch 4...Control device (control unit) 7...Motor (prime mover)

Claims

1. The gearbox and a clutch that, when engaged or disengaged, interrupts the transmission of power from the prime mover to the drive wheels during a gear change operation by the transmission; A vehicle start control method comprising: In a region where the clutch is released, the output or rotation of the prime mover is limited. A method for controlling vehicle start-up.

2. 2. The vehicle start control method according to claim 1, the prime mover is an internal combustion engine, The output of the prime mover is limited by limiting the throttle opening relative to the accelerator opening. A method for controlling vehicle start-up.

3. 2. A vehicle start control method according to claim 1, the prime mover is an internal combustion engine, The output of the prime mover is limited by limiting the amount of fuel injection. A method for controlling vehicle start-up.

4. 2. A vehicle start control method according to claim 1, the prime mover is a motor, The output of the prime mover is limited by limiting the current supplied to the motor. A method for controlling vehicle start-up.

5. The vehicle start control method according to any one of claims 1 to 4, The clutch is a hydraulic clutch that is engaged by applying hydraulic pressure, When it is determined that the clutch has started to be engaged in accordance with the displacement of the clutch in the engagement direction or the hydraulic pressure acting on the clutch, the output restriction of the prime mover is released. A method for controlling vehicle start-up.

6. 6. A vehicle start control method according to claim 5, changing an increase rate of the rotation speed of the prime mover after the output restriction of the prime mover is released in accordance with a change rate of the displacement of the clutch or a change rate of the oil pressure acting on the clutch; A method for controlling vehicle start-up.

7. 6. A vehicle start control method according to claim 5, The displacement of the clutch that releases the output restriction of the prime mover or the oil pressure acting on the clutch is corrected according to the rate of change of the displacement of the clutch or the rate of change of the oil pressure acting on the clutch. A method for controlling vehicle start-up.

8. The vehicle start control method according to any one of claims 1 to 4, When the vehicle speed is equal to or greater than a predetermined value, limiting the output of the prime mover is prohibited. A method for controlling vehicle start-up.

9. The vehicle start control method according to any one of claims 1 to 4, limiting the output of the prime mover only when the transmission is in a starting gear position; A method for controlling vehicle start-up.

10. The vehicle start control method according to any one of claims 1 to 3, When the vehicle is located on a predetermined uphill gradient based on gradient information detected by an on-board sensor, the limit value of the output or rotation of the prime mover is changed, or the output limit control of the prime mover is prohibited. A method for controlling vehicle start-up.

11. The gearbox and a clutch that, when engaged or disengaged, interrupts the transmission of power from the prime mover to the drive wheels during a gear change operation by the transmission; a control unit that limits the output or rotation of the prime mover in a region where the clutch is released; A vehicle start control device comprising:

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