Launch control device

Abstract

A starting control device that improves the driver's acceleration feeling when starting a vehicle. [Solution] The starting control device has an acquisition unit that acquires the torque required by the vehicle driver and the degree of engagement of the clutch device, and a control unit that controls the engine to assist the engine output torque based on the required torque and the degree of engagement acquired by the acquisition unit when the vehicle starts and the clutch device is switched from a disengaged state to an engaged state, and when a predetermined condition for terminating the assist is satisfied, the control unit determines whether to extend the assist based on the difference between the engine output torque and the required torque.

Description

[Technical field]

[0001] The present disclosure relates to a starting control device. [Background technology]

[0002] Conventionally, a start control device has been disclosed that assists engine torque in order to suppress engine stall when a vehicle starts. Here, the start control device is required to improve the responsiveness of engine control.

[0003] Therefore, for example, Patent Document 1 discloses a vehicle start control device that effectively improves the responsiveness of the start assist control to improve the starting performance of the vehicle. This start control device performs start assist control to increase the engine speed to a target speed according to the accelerator opening and the clutch engagement rate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-014833 Summary of the Invention [Problem to be solved by the invention]

[0005] However, with the starting control device of Patent Document 1, when the assist control is stopped, the driver may feel uncomfortable with the acceleration of the vehicle depending on the difference between the engine torque and the torque required by the driver.

[0006] An object of the present disclosure is to provide a starting control device that improves the acceleration feeling experienced by a driver when a vehicle starts. [Means for solving the problem]

[0007] The launch control device according to the present disclosure is a vehicle and the speed of said vehicle The torque required by the driver and A gear shifter that can switch between a disengaged state in which power from the engine is cut off and an engaged state in which the power is transmitted. Clutch device Conclusion rate and 、 An acquisition unit for acquiring The above The clutch device The above From a disconnected state The above When the vehicle starts moving and the engagement state is switched to, The above Engine output torque Add assist torque to Assist Control Do A control unit, A first mode is set in which the assist control is performed by feedback-controlling the output torque of the engine, and a second mode is set in which the assist control is performed by feedback-controlling the output torque of the engine with a gain smaller than that in the first mode, and the vehicle is determined to be stopped based on at least one of the speed of the vehicle and the gear stage of the transmission, and when the clutch device is switched to the disengaged state while the vehicle is stopped, the vehicle is determined to have started moving and the assist control in the first mode is started, and the assist control in the first mode is performed in which the assist torque is added so as to increase the rotation speed of the engine according to the engagement rate that increases as the clutch device transitions from the disengaged state to the engaged state, and the clutch device The above When the fastening state is reached, the first mode Finish the above assist death, The difference between the output torque of the engine and the required torque When the difference between the output torque of the engine and the required torque becomes equal to or smaller than the threshold value, the assist control in the second mode is started. The assistant control of Quit It is something. Effect of the Invention

[0008] According to the present disclosure, it is possible to improve the acceleration feeling experienced by the driver when the vehicle starts moving. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a configuration of a vehicle equipped with a starting control device according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a diagram showing the configuration of the starting control device. [Diagram 3] FIG. 3 is a flow chart illustrating the operation of one embodiment. [Figure 4] FIG. 4 is a diagram showing the assistance of the output torque of the engine by the starting control device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0011] 1 shows the configuration of a vehicle equipped with a starting control device according to an embodiment of the present disclosure. The vehicle has an engine 1, and a crankshaft of the engine 1 and an input shaft of a transmission 3 are connected in a disconnectable manner by a clutch device 2. Left and right driving wheels are connected to output shafts of the transmission 3 via differential gears. The vehicle also has an accelerator pedal 4, a clutch pedal 5, a gear shift operation device 6, a required torque sensor 7a, a clutch stroke sensor 7b, a shift position sensor 7c, an engine speed sensor 7d, a vehicle speed sensor 7e, and a starting control device 8.

[0012] The engine 1 burns fuel to generate driving force for running a vehicle, and is, for example, a so-called four-stroke engine that repeats four strokes: an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke. Examples of the engine 1 include a diesel engine and a gasoline engine. The engine 1 is not limited to a direct injection engine, and may be a premixed engine. The engine 1 may be either a single-cylinder or multiple-cylinder engine.

[0013] The clutch device 2 is disposed between the engine 1 and the transmission 3, and is configured to be switchable between a "disengaged state" in which the transmission of power from the engine 1 to the transmission 3 is interrupted, and an "engaged state" in which the transmission of power from the engine 1 to the transmission 3 is engaged. Specifically, when the driver depresses the clutch pedal 5, the clutch device 2 strokes a piston together with a push rod due to hydraulic pressure supplied from a master cylinder to a release cylinder, and the release fork rotates to press a release bearing, thereby switching from the "engaged state" to the "disengaged state." In addition, when the driver releases the clutch pedal 5, the clutch device 2 is switched from the "disengaged state" to the "engaged state" by the clutch facing of the clutch disc being pressed against the flywheel by the elastic force of a diaphragm spring.

[0014] The transmission 3 is a manual transmission that changes gears in response to the operation of a gear change device 6 provided in the driver's cab, and has a plurality of gear change gear trains. Specifically, the plurality of gear change gear trains are coupled (geared in) to be integrally rotatable with an output shaft or a countershaft in response to the operation of the gear change device 6. The plurality of gear change gear trains include, for example, a starting gear train (starting gear stage) such as a low-speed gear train (e.g., 1st gear, 2nd gear) for starting forward or a reverse gear train for going backward.

[0015] Accelerator pedal 4 is arranged so as to be operable by the driver, and controls the amount and timing of fuel injection in engine 1 according to the amount of depression by the driver.

[0016] The clutch pedal 5 is disposed so as to be operable by the driver, and is connected to the clutch device 2 so as to switch the clutch device 2 between a "disengaged state" and an "engaged state" in response to the driver's depression of the clutch pedal 5.

[0017] The gear shift operation device 6 is disposed so as to be operable by the driver, and controls the transmission 3 so as to perform gear shifting in response to the driver's operation.

[0018] The required torque sensor 7a detects the depression amount of the accelerator pedal 4. The clutch stroke sensor 7b detects the clutch stroke amount according to the depression amount of the clutch pedal 5. For example, the clutch stroke sensor 7b detects the clutch stroke amount from the movement amount of a rod of a master cylinder connected to the clutch pedal 5. The shift position sensor 7c detects the operation position of the gear shift operation device 6. The engine speed sensor 7d detects, for example, the rotation speed of a crankshaft connected to the engine 1. The vehicle speed sensor 7e detects, for example, the rotation speed of a propeller shaft. The required torque sensor 7a, the clutch stroke sensor 7b, the shift position sensor 7c, the engine speed sensor 7d, and the vehicle speed sensor 7e each output detection values ​​to the starting control device 8 electrically connected thereto.

[0019] 2 shows the configuration of the starting control device 8. The starting control device 8 has an acquisition unit 9, a control unit 10, and a storage unit 11.

[0020] The acquisition unit 9 acquires the torque required by the driver (accelerator opening) based on the depression amount of the accelerator pedal 4 detected by the required torque sensor 7a. The acquisition unit 9 also acquires the clutch engagement rate (degree of engagement) of the clutch device 2 based on the clutch stroke amount detected by the clutch stroke sensor 7b. The acquisition unit 9 also acquires the current gear stage of the transmission 3 based on the operation position of the gear shift operation device 6 detected by the shift position sensor 7c. The acquisition unit 9 also acquires the rotation speed of the engine 1 based on the rotation speed of the crankshaft detected by the engine rotation speed sensor 7d. The acquisition unit 9 also acquires the speed of the vehicle based on the rotation speed of the propeller shaft detected by the vehicle speed sensor 7e.

[0021] When the vehicle starts moving and the clutch device 2 is switched from the "disengaged state" to the "engaged state", the control unit 10 controls the amount or timing of fuel injection in the engine 1 so as to assist the output torque of the engine 1 based on the driver's required torque and the engagement degree of the clutch device 2 acquired by the acquisition unit 9. Specifically, the memory unit 11 stores a target rotation speed map that specifies the target rotation speed of the engine 1 that changes according to the driver's required torque and the engagement degree of the clutch device 2. For example, the target rotation speed of the engine 1 is set in the target rotation speed map so that it increases as the driver's required torque increases and increases as the engagement degree of the clutch device 2 increases.

[0022] When the vehicle starts moving, the control unit 10 calculates the target rotation speed of the engine 1 by referring to a target rotation speed map stored in the storage unit 11 based on the torque required by the driver and the degree of engagement of the clutch device 2. Then, the control unit 10 controls the amount of fuel injected into the engine 1, etc., so that the engine 1 rotates at the target rotation speed. For example, the control unit 10 may feedback control the amount of fuel injected into the engine 1 based on the deviation between the target rotation speed and the actual rotation speed of the engine 1. As a result, when the torque required by the driver is insufficient for the target rotation speed of the engine 1, the control unit 10 assists the output torque of the engine 1 so as to make up for the insufficient rotation speed (to increase the rotation speed).

[0023] Then, when a predetermined condition for ending the assist of the engine 1 is satisfied, the control unit 10 determines whether or not to extend the assist of the output torque of the engine 1 based on the difference between the output torque of the engine 1 and the torque required by the driver. For example, the control unit 10 may extend the assist of the engine 1 until the difference between the output torque of the engine 1 and the torque required by the driver indicates a predetermined value or less. Note that the predetermined condition may include, for example, the clutch device 2 entering an "engaged state" or the vehicle speed exceeding a predetermined threshold.

[0024] The starting control device 8 may be composed of one or more processors, and the functions of the control device may be realized by one or more processors executing a computer program. For example, a computer reading device reads a program for realizing the functions of the starting control device 8 from a recording medium on which the program is recorded, and stores the program in a storage device. Then, a CPU (Central Processing Unit) copies the program stored in the storage device to a RAM (Random Access Memory), and sequentially reads and executes the instructions contained in the program from the RAM, thereby realizing the functions of the starting control device 8.

[0025] Next, the operation of this embodiment will be described with reference to the flowchart of FIG.

[0026] First, as shown in Fig. 1, when the driver operates the accelerator pedal 4, the required torque sensor 7a detects the depression amount of the accelerator pedal 4. In addition, when the driver operates the clutch pedal 5, the clutch stroke sensor 7b detects the clutch stroke amount corresponding to the depression amount of the clutch pedal 5. The required torque sensor 7a and the clutch stroke sensor 7b then output the detected depression amount of the accelerator pedal 4 and the clutch stroke amount to the start control device 8.

[0027] In addition, the shift position sensor 7c outputs the detected operating position of the gear change operation device 6 to the starting control device 8. In addition, the engine rotation speed sensor 7d outputs the detected rotation speed of the crankshaft to the starting control device 8. In addition, the vehicle speed sensor 7e outputs the detected rotation speed of the propeller shaft to the starting control device 8.

[0028] 2, the detection data output from the required torque sensor 7a, clutch stroke sensor 7b, shift position sensor 7c, engine speed sensor 7d, and vehicle speed sensor 7e are input to an acquisition unit 9 of the starting control device 8. As a result, in step S1, the acquisition unit 9 acquires the torque required by the vehicle driver based on the depression amount of the accelerator pedal 4 detected by the required torque sensor 7a, and acquires the degree of engagement of the clutch device 2 based on the clutch stroke amount detected by the clutch stroke sensor 7b.

[0029] The acquisition unit 9 also acquires the current gear position of the transmission 3 based on the operating position of the gear shift operation device 6 detected by the shift position sensor 7c. The acquisition unit 9 also acquires the rotation speed of the engine 1 based on the rotation speed of the crankshaft detected by the engine rotation speed sensor 7d, and acquires the vehicle speed based on the rotation speed of the propeller shaft detected by the vehicle speed sensor 7e. The acquisition unit 9 outputs the acquired data, such as the driver's required torque, the engagement degree of the clutch device 2, the gear position of the transmission 3, the rotation speed of the engine 1, and the vehicle speed, to the control unit 10.

[0030] When the control unit 10 receives the acquired data acquired by the acquisition unit 9, it determines in step S2 whether or not the vehicle is starting and the clutch device 2 is switched from the "disengaged state" to the "engaged state".

[0031] Specifically, the control unit 10 may determine whether the vehicle is stopped or not based on the vehicle speed or the gear stage of the transmission 3 acquired by the acquisition unit 9. For example, as shown in Fig. 4, the control unit 10 can determine that the vehicle is stopped when the gear stage of the transmission 3 is in neutral at time t0.

[0032] Here, the control unit 10 may be preset with a first mode in which the output torque of the engine 1 is feedback-controlled with a common setting (a common setting for normal control and assist control) throughout the operation of the engine 1, and a second mode in which the output torque of the engine 1 is feedback-controlled with a setting dedicated to starting the vehicle (a dedicated setting for assist control).When the control unit 10 determines that the vehicle is stopped, it normally controls the engine 1 based on the first mode so as to maintain a predetermined idling speed.

[0033] Furthermore, when the control unit 10 determines that the vehicle is stopped, it determines whether the clutch device 2 has been switched to a "disengaged state" based on the degree of engagement of the clutch device 2 acquired by the acquisition unit 9, and determines whether the transmission 3 has been shifted into a starting gear based on the gear stage of the transmission 3 acquired by the acquisition unit 9. Here, the control unit 10 can determine that the vehicle has started if, at time t1, the clutch device 2 has been switched to a "disengaged state" (the clutch pedal has been depressed) and has been shifted into a starting gear. At this time, the control unit 10 repeats the determination in step S2 until it determines that the vehicle has started.

[0034] When the control unit 10 determines that the vehicle has started, the process proceeds to step S3, and the assist control of the first mode is started. For example, the control unit 10 can feedback control the amount of fuel injected into the engine 1 based on the deviation between the target rotation speed and the actual rotation speed of the engine 1. Specifically, the control unit 10 calculates the target rotation speed R1 of the engine 1 by referring to a target rotation speed map stored in the storage unit 11 based on the torque required by the driver (accelerator opening) and the engagement degree of the clutch device 2. Then, the control unit 10 assist-controls the output torque T1 of the engine 1 so as to add an assist torque T2 corresponding to the difference between the target rotation speed R1 and the actual rotation speed R2 of the engine 1.

[0035] At this time, the target rotation speed R1 of the engine 1 is calculated so that the actual rotation speed R2 of the engine 1 increases from the idling rotation speed in response to an increase in the engagement degree of the clutch device 2 (a transition from the "disengaged state" to the "engaged state"). Therefore, the control unit 10 generates the assist torque T2 so that the actual rotation speed R2 of the engine 1 increases in response to an increase in the engagement degree of the clutch device 2 before time t2 when the torque required by the driver is not generated (the accelerator pedal 4 is not depressed). This allows the control unit 10 to increase the actual rotation speed R2 of the engine 1 in accordance with the target rotation speed R1. Furthermore, the control unit 10 can increase the actual rotation speed R2 of the engine 1 to a predetermined value or more before the clutch device 2 is completely engaged, thereby suppressing engine stall.

[0036] When the control unit 10 increases the actual rotation speed R2 of the engine 1 to a predetermined value or more at time t2, the control unit 10 controls the output torque T1 of the engine 1 so as to maintain the actual rotation speed R2 at a predetermined value based on the deviation between the target rotation speed R1 and the actual rotation speed R2 of the engine 1. Therefore, when the driver's required torque T3 is input, the control unit 10 controls the output torque T1 of the engine 1 so as to reduce the assist torque T2 in response to an increase in the required torque T3.

[0037] Next, in step S4, the control unit 10 determines whether or not a predetermined condition for ending the assist of the engine 1 is satisfied. For example, the control unit 10 may determine that the predetermined condition is satisfied when the clutch device 2 is in a completely "engaged state" or the vehicle speed exceeds a predetermined threshold. The control unit 10 repeats the determination in step S4 until the predetermined condition is satisfied. Here, it is assumed that the control unit 10 determines that the predetermined condition for ending the assist of the engine 1 is satisfied at time t3.

[0038] In this way, even when a predetermined condition for ending the assist of the engine 1 is satisfied, a large difference D exceeding a predetermined value may occur between the output torque T1 of the engine 1 and the torque T3 required by the driver. In such a case, when the assist of the engine 1 is ended, the driver may feel an uncomfortable sensation in the acceleration of the vehicle according to the difference D between the output torque T1 and the torque T3 required. For example, the driver may feel a flat feeling, sluggishness, delayed response, or drop in the acceleration of the vehicle.

[0039] Therefore, when a predetermined condition for ending the assist of the output torque T1 of the engine 1 is satisfied, the control unit 10 proceeds to step S5 and determines whether or not to extend the assist of the output torque T1 of the engine 1 based on the difference D between the output torque T1 of the engine 1 and the torque T3 required by the driver. For example, the control unit 10 may determine whether or not to extend the assist of the output torque T1 of the engine 1 based on whether or not the difference D between the output torque T1 of the engine 1 and the torque T3 required by the driver is equal to or smaller than a predetermined value. The predetermined value can be set based on, for example, an evaluation of the acceleration feeling by the rider.

[0040] When the control unit 10 determines not to extend the assist of the output torque T1 of the engine 1 (determines that the difference D is equal to or smaller than a predetermined value), the control unit 10 proceeds to step S7 and ends the assist of the output torque T1 of the engine 1. Then, the control unit 10 controls the output torque T1 of the engine 1 based on the driver's required torque T3.

[0041] On the other hand, when the control unit 10 determines that the assist of the output torque T1 of the engine 1 should be extended (determines that the difference D exceeds the predetermined value), the control unit 10 extends the assist of the output torque T1 of the engine 1. That is, the control unit 10 controls the assist of the output torque T1 of the engine 1 so as to add an assist torque T2 corresponding to the deviation between the target rotation speed R1 and the actual rotation speed R2 of the engine 1. In this way, the start control device 8 can suppress the feeling of reduction in the output torque T1 and improve the driver's acceleration feeling when the vehicle starts.

[0042] At this time, the control unit 10 can switch from the first mode to the second mode and assist control the engine 1 in the second mode. Here, the assist torque T2a in the second mode is set to decrease more gradually than the assist torque T2 in the first mode in response to an increase in the torque T3 required by the driver. For example, the assist torque T2a in the second mode can be decreased more gradually by making the gain of the feedback control in the second mode smaller than that in the first mode. As a result, the control unit 10 can suppress the occurrence of a step in the output torque of the engine 1 when switching from the first mode to the second mode, and can smoothly connect the output torque of the engine 1. Therefore, the starting control device 8 can reliably improve the acceleration feeling of the driver when the vehicle starts.

[0043] In addition, by providing separate first and second modes, it is easy to set the second mode to perform feedback control with settings dedicated to starting the vehicle (settings dedicated to assist control) in contrast to the first mode, which performs feedback control with common settings (settings common to normal control and assist control) throughout the operation of the engine 1.

[0044] Next, in step S6, the control unit 10 judges whether or not the difference D between the output torque T1a of the engine 1 and the torque T3 required by the driver is equal to or less than a predetermined value. The control unit 10 repeats the judgment in step S6 until the difference D between the output torque T1a of the engine 1 and the torque T3 required by the driver is equal to or less than the predetermined value. In this way, the starting control device 8 can suppress the occurrence of a step in the output torque of the engine 1, and reliably improve the acceleration feeling of the driver when the vehicle starts.

[0045] The predetermined value may be set to the same value as that used in the determination in step S5. Alternatively, the predetermined value may be set to zero, at which point the output torque T1a of the engine 1 coincides with the torque T3 required by the driver.

[0046] When the control unit 10 determines at time t4 that the difference D between the output torque T1a of the engine 1 and the torque T3 required by the driver is equal to or smaller than a predetermined value, the control unit 10 proceeds to step S7 and ends the assist of the output torque T1 of the engine 1. As a result, the control unit 10 controls the output torque T1 of the engine 1 based on the torque T3 required by the driver. At this time, the control unit 10 may switch from the second mode to the first mode.

[0047] According to this embodiment, the acquisition unit 9 acquires the torque T3 required by the driver of the vehicle and the degree of engagement of the clutch device 2. Furthermore, when the clutch device 2 is switched from a disengaged state to an engaged state when the vehicle starts, the control unit 10 controls the engine 1 so as to assist the output torque T1 of the engine 1 based on the torque T3 required by the acquisition unit 9 and the degree of engagement of the clutch device 2. When a predetermined condition for ending the assist is satisfied, the control unit 10 determines whether or not to extend the assist based on the difference between the output torque T1 of the engine 1 and the torque T3 required. Therefore, the start control device 8 can improve the acceleration feeling of the driver when the vehicle starts.

[0048] In the above embodiment, the gear shift operation device 6 is configured as a manual transmission, but it may be configured as an automatic transmission.

[0049] In addition, the above-mentioned embodiments are merely examples of the embodiment of the present invention, and the technical scope of the present invention should not be interpreted as being limited by these. That is, the present invention can be implemented in various forms without departing from the gist or main features of the present invention. For example, the disclosure of the shape and number of each part described in the above-mentioned embodiments is merely an example, and can be implemented by appropriately changing them. [Industrial Applicability]

[0050] The starting control device according to the present disclosure can be used as a device that assists the output torque of an engine. [Explanation of symbols]

[0051] 1 Engine 2 Clutch device 3. Gearbox 4. Accelerator pedal 5. Clutch pedal 6. Gear shifting device 7a Torque sensor requirements 7b Clutch stroke sensor 7c Shift position sensor 7d Engine speed sensor 7e Vehicle speed sensor 8. Starting control device 9 Acquisition Department 10 Control section 11 Storage section D difference R1 Target RPM R2 Actual rotation speed t0~t4 time T1, T1a output torque T2, T2a Assist torque T3 Required torque

Claims

1. an acquisition unit that acquires a vehicle speed, a torque required by a driver of the vehicle, a gear stage of a transmission, and an engagement rate of a clutch device that can switch between a disengaged state in which power from the engine is cut off and an engaged state in which the power is transmitted; a control unit that performs assist control to add an assist torque to an output torque of the engine when the clutch device is switched from the disengaged state to the engaged state to start the vehicle, the control unit is set to a first mode in which the assist control is performed by feedback-controlling an output torque of the engine, and a second mode in which the assist control is performed by feedback-controlling the output torque of the engine with a gain smaller than that in the first mode, determining that the vehicle is stopped based on at least one of a speed of the vehicle and a gear stage of the transmission, and when the clutch device is switched to the disengaged state while the vehicle is stopped, determining that the vehicle has started moving and starting the assist control in the first mode; performing the assist control in the first mode in which the assist torque is added so as to increase a rotation speed of the engine in accordance with the engagement rate that increases as the clutch device transitions from the disengaged state to the engaged state; When the clutch device is in the engaged state, the assist in the first mode is terminated. When a difference between the output torque of the engine and the required torque is greater than a threshold value, the assist control in the second mode is started. When the difference between the output torque of the engine and the required torque becomes equal to or less than the threshold value, the assist control in the second mode is terminated. Launch control device.

2. The control unit increases the rotation speed of the engine in response to the engagement ratio of the clutch device transitioning from the disengaged state to the engaged state, and performs the assist control in the first mode so that the rotation speed of the engine is maintained within a predetermined range even if the required torque increases. The starting control device according to claim 1 .

3. The control unit terminates the assist control of the second mode when the engagement rate of the clutch device reaches the complete engagement state and the output torque of the engine and the required torque become zero. The starting control device according to claim 1 .

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