Vehicle control device

Abstract

A vehicle control device mounted in a vehicle (10) having an internal combustion engine (20), an automatic transmission (40) connected to the internal combustion engine (20) via a clutch (30) and comprising an actuator (35) engaging or disengaging the clutch (30), a clutch control unit (72) controlling the actuator (35), and a vehicle wheel speed detection sensor (53, 54) detecting a rotational speed of each of the vehicle wheels, comprising: a traction control unit (73) configured to calculate a slip amount of the vehicle wheel (13, 16) from the rotational speed of the vehicle wheel (13, 16) and to carry out a traction control process in which at least one engine torque of the internal combustion engine (20) is adjusted when the slip amount exceeds a predetermined slip amount threshold value, wherein the clutch control unit (72) controls the actuator (35) such that the clutch (30) is disengaged when an engine speed of the internal combustion engine (20) decreases, and wherein the traction control unit (73) increases the slip amount threshold value so that the traction control operation is prohibited or difficult to perform when a predetermined condition for a clutch-off mode is met during the execution of the traction control operation for a predetermined period of time.

Description

[Technical field]

[0001] The present invention relates to a vehicle control device. [Background of the invention]

[0002] Conventionally, a vehicle control device described in JP H07-108633 B2 is known, which is mounted in a vehicle such as an automobile. In the technique described in JP H07-108633 B2, in a driving force control device, when an actual slip ratio exceeds a predetermined slip ratio when a driving wheel enters a muddy road, a deep snow road, or the like and gets stuck, drive force reduction control is performed to prevent slippage of a driving wheel. Further, in the technique described in JP H07-108633 B2, when a state in which an accelerator pedal operation amount becomes a predetermined value or more and a vehicle speed becomes a predetermined value or less continues for a predetermined period of time, even if the driving force reduction control is performed. [State of the art]

[0003] EP 1 752 331 A1 discloses a vehicle control system in which reliable protection against stalling of an internal combustion engine is provided by setting a lower engagement force of a starting clutch while the power of the internal combustion engine is controlled by the traction control unit.

[0004] US 2003 / 0 144 114 A1 discloses a system and method for controlling an automated clutch system of a motor vehicle to prevent its engine from stalling by disengaging a clutch. For this purpose, conditions of the motor vehicle that indicate engine stalling are detected. In one step of the method, a threshold value for engine stalling is determined in relation to the current operating conditions of the motor vehicle. The threshold value for the engine speed is the engine speed at which the clutch opens proportionally to prevent the engine from stalling.

[0005] DE 103 51 376 A1 discloses a device that controls a clutch of a motor vehicle to be placed in a half-clutch state when there is a possibility of the engine stalling during traction control. This can prevent the occurrence of engine stall. However, this leads to the problem that a condition in which the motor vehicle cannot be accelerated or stalls continues to occur even though the driver intends to accelerate. [Summary of the invention][Problem solved by the invention]

[0006] However, in the technique described in JP H07-108 633 B2, for example, there is a problem that a state in which the vehicle cannot be accelerated or stalls even though the driver intends to accelerate the vehicle may continue when driving on a snowy uphill road for two reasons explained below.

[0007] The first reason is that, in a vehicle with a manual transmission, when an engine speed decreases due to the execution of a traction control (driving force reduction control) at the time of execution of the control described in JP H07-108 633 B2, a clutch release control is continuously executed to prevent the engine from stalling.

[0008] The second reason is that a vehicle cannot escape from a stuck condition without preventing initial slip at the time of vehicle start-up because engine torque is reduced at a vehicle speed or more, which prohibits traction control despite incipient movement of the vehicle, or traction control is prohibited at a vehicle speed of 0 km / h.

[0009] The present invention has been developed in view of the above-described problems, and the object of the invention is to provide a vehicle control device capable of preventing a start failure of a vehicle on a snowy uphill road or the like, improving an acceleration performance, and preventing a deceleration feeling for the driver. [Means of solving the problem]

[0010] According to this invention, a vehicle control device is provided that is mounted in a vehicle having an internal combustion engine, an automatic transmission connected to the internal combustion engine via a clutch and including an actuator that engages or disengages the clutch, a clutch control unit that controls the actuator, and a vehicle wheel speed detection sensor that detects a rotational speed of each of the vehicle wheels, comprising: a traction control unit configured to calculate a slip amount of the vehicle wheel from the rotational speed of the vehicle wheel and to perform a traction control operation in which at least an engine torque of the internal combustion engine is adjusted when the slip amount exceeds a predetermined slip amount threshold value, wherein the clutch control unit controls the actuator such that the clutch is disengaged when an engine speed of the internal combustion engine decreases,and wherein the traction control unit increases the slip amount threshold value so that the traction control operation is inhibited or difficult to perform when a predetermined condition for a clutch disengagement mode is met during the execution of the traction control operation for a predetermined period of time. [Effects of the invention]

[0011] In this way, according to the invention, a failure to start a vehicle on a snowy uphill road or the like can be prevented, an acceleration behavior can be improved, and a feeling of deceleration for the driver can be prevented. [Brief description of the characters] [ Fig. 1] The Fig. 1 is a configuration drawing of a vehicle including a control device according to an embodiment of the present invention. [ Fig. 2] The Fig. 2 is a flowchart illustrating an operation of a vehicle control device according to an embodiment of the present invention. [ Fig. 3] The Fig. 3 is a characteristic curve used in the vehicle control apparatus according to an embodiment of the present invention, showing a correlation between a target slip amount and a vehicle speed. [ Fig. 4] The Fig. 4(A) to 4(E) are graphs illustrating changes occurring in a case where a predetermined timing corresponding to a threshold value of a clutch release timing is changed in response to an accelerator opening degree change amount, an accelerator opening degree, a road gradient, a road friction coefficient, and a vehicle yaw rate. [ Fig. 5] The Fig. 5(A) to 5(E) are graphs illustrating changes occurring in a case where a predetermined number of times corresponding to a threshold value of the number of times a clutch is released is changed in response to an accelerator opening degree change amount, an accelerator opening degree, a road gradient, a road friction coefficient, and a vehicle yaw rate. [Embodiment(s) of the invention]

[0012] A vehicle control device according to embodiments of the present invention is mounted in a vehicle having an internal combustion engine, an automatic transmission connected to the internal combustion engine via a clutch and including an actuator that engages or disengages the clutch, a clutch control unit that controls the actuator, and a vehicle wheel speed detection sensor that detects a rotational speed of each of the vehicle wheels, and includes: a traction control unit configured to calculate a slip amount of the vehicle wheel from the rotational speed of the vehicle wheel and to perform a traction control operation in which at least an engine torque of the internal combustion engine is adjusted when the slip amount exceeds a predetermined slip amount threshold value, wherein the clutch control unit controls the actuator such that the clutch is disengaged when an engine speed of the engine decreases,and wherein the traction control unit increases the slip amount threshold value so that the traction control operation is inhibited or difficult to perform if a predetermined condition for a clutch disengagement mode is met during the execution of the traction control operation for a predetermined period of time. Accordingly, the vehicle control device according to the embodiments of the present invention can prevent a vehicle from failing to start on a snowy uphill road or the like, improve acceleration performance, and prevent a deceleration sensation for the driver. [Embodiments]

[0013] In the following, a vehicle control device according to embodiments of the present invention will be described with reference to the drawings. Fig. 1 to 5 are diagrams illustrating the vehicle control apparatus according to the embodiments of the present invention.

[0014] As in Fig. 1, the vehicle 10 includes an internal combustion engine 20, a clutch 30, an automatic transmission 40, vehicle wheels 13 and 16, an engine control unit 71, a clutch control unit 72, and a traction control unit 73. Furthermore, the vehicle wheel 13 is a front wheel and the vehicle wheel 16 is a rear wheel.

[0015] The internal combustion engine 20 is equipped with a plurality of cylinders. In the embodiment, the internal combustion engine 20 is used to rotate a crankshaft 21 by performing a series of four strokes, namely an intake stroke, a compression stroke, an expansion stroke, and an exhaust stroke, in each cylinder.

[0016] The internal combustion engine 20 is equipped with a crank angle sensor 27, and the crank angle sensor 27 detects an engine speed based on a rotational position of the crankshaft 21 and transmits a detection signal to the engine control unit 71.

[0017] The automatic transmission 40 is connected to the internal combustion engine 20 via the clutch 30 and switches a rotation transmitted by the internal combustion engine 20. The clutch 30 is designed as a single-disk dry clutch.

[0018] The automatic transmission 40 is equipped with a clutch actuator 35, which engages or disengages the clutch 30 under the control of the clutch control unit 72. The clutch actuator 35 of the embodiment constitutes an actuator of the present invention.

[0019] A vehicle wheel 13, which forms a drive wheel, is connected to the automatic transmission 40 via a differential device 11 and a drive shaft 12. The automatic transmission 40 and the internal combustion engine 20 are mounted in a front part of the vehicle 10. The vehicle 10 is thus a front-engine / front-wheel drive vehicle. Furthermore, Fig. 1 the cylinders of the internal combustion engine 20 are arranged in the longitudinal direction of the vehicle 10, but the arrangement direction of the cylinders in the internal combustion engine 20 can also be the vehicle width direction.

[0020] The vehicle 10 includes an accelerator opening degree sensor 52, and the accelerator opening degree sensor 52 detects an operation amount (an accelerator opening degree) of an accelerator pedal (not shown) and transmits a detection signal to the engine control unit 71.

[0021] The vehicle 10 includes an acceleration sensor 51 and a yaw rate sensor 50. The acceleration sensor 51 detects an acceleration in each direction of the vehicle 10 and transmits a detection signal to the traction control unit 73. The yaw rate sensor 50 detects a yaw rate of the vehicle 10 and transmits a detection signal to the traction control unit 73.

[0022] The vehicle 10 includes a vehicle wheel speed detection sensor 53 that detects a rotational speed of the vehicle wheel 13 and a vehicle wheel speed detection sensor 54 that detects a rotational speed of the vehicle wheel 16, which is a driven wheel. The vehicle wheel speed detection sensors 53 and 54 transmit detection signals to the traction control unit 73.

[0023] The vehicle includes a brake 61 that brakes the vehicle wheel 13 and a brake 62 that brakes the vehicle wheel 16, and these brakes 61 and 62 are controlled by the traction control unit 73.

[0024] The engine control unit 71, the clutch control unit 72 and the traction control unit 73 are each configured as a computer unit including a central processing unit (CPU), a random access memory (RAM), a read-only memory (ROM), a flash memory storing backup data or the like, an input port and an output port.

[0025] The ROM of the computer unit stores a program for operating the computer unit, as well as various constants and various characteristics. Each computer unit operates in such a way that the CPU executes the program stored in the ROM using the RAM as the work area.

[0026] The engine control unit 71 controls the internal combustion engine 20, which is a control target. The clutch control unit 72 controls the clutch 30 as a control target. The engine control unit 71 and the clutch control unit 72 are electrically connected to each other.

[0027] Furthermore, the engine control unit 71 and the clutch control unit 72 are electrically connected to the traction control unit 73. The detection signals of the sensors are shared by the engine control unit 71, the clutch control unit 72, and the traction control unit 73, and the control signal and the request signal are transmitted and received by them.

[0028] The engine control unit 71 and the clutch control unit 72 control the respective control targets in response to a request from the traction control unit 73.

[0029] In the embodiment, the clutch control unit 72 is configured to control the clutch actuator 35 such that the clutch 39 is disengaged when the engine speed of the internal combustion engine 20 decreases. Accordingly, engine stalling can be prevented.

[0030] Furthermore, the traction control unit 73 calculates the amount of slip of the vehicle wheels 13 and 16 from the rotational speed of the vehicle wheels 13 and 16. Since the traction control unit 73 must then release the idling of the vehicle wheels 13 and 16 at the time of starting of the vehicle 10, the traction control unit 73 executes the traction control process to release the slip (spin) of the vehicle wheels 13 and 16 when the amount of slip exceeds a predetermined slip amount threshold.

[0031] The traction control operation refers to an operation in which a braking operation of the brakes 61 and 62 and / or an engine torque reduction operation is carried out to set or limit the slip amount of the vehicle wheels 13 and 16 to the target slip amount.

[0032] In the embodiment, the traction control unit 73 adjusts at least the engine torque of the internal combustion engine 20 during the traction control process. By executing the traction control process, the spinning of the vehicle wheels 13 and 16 can be resolved.

[0033] Since the engine torque is reduced during the traction control process, it is also possible to disengage the clutch 30 intermittently or continuously to prevent the engine from stalling.

[0034] For this reason, a case where the disengagement period of the clutch 30 is long or the number of disengagement times is high corresponds to a case where the vehicle 10 repeatedly fails to escape or accelerate from the state stuck on a snowy or muddy road.

[0035] If no countermeasures are taken in a case where these problems occur, these problems will continue for a longer time because the clutch 30 is continuously disengaged or the reduction of the engine torque continues during the traction control process.

[0036] In other words, as the disengagement period of the clutch 30 or the number of disengagement times to prevent engine stalling increases, the solution of slipping the vehicle wheels 13 and 16 is exchanged for the problem of failure in attempts to escape from the stuck state or to accelerate. When this problem occurs, executing control that allows slippage is effective compared to the normal state.

[0037] Therefore, in the present embodiment, the traction control unit 73 increases the slip amount threshold value when a predetermined condition for a clutch disengagement mode is satisfied during execution of the traction control operation for a predetermined period of time, so that the traction control operation is prohibited or difficult to execute.

[0038] The target slip amount, which corresponds to the slip amount threshold value, is determined by the traction control unit 73 according to the Fig. 3 shown control characteristic curve. As shown in Fig. 3, the initial value (SL1) of the target slip amount is set to a value that is larger than the vehicle speed (V1) by a predetermined amount.

[0039] Subsequently, the traction control unit 73 sets the slip amount threshold to a target slip amount (SL2) at which the traction control operation is prohibited when a predetermined condition is met. Alternatively, the traction control unit 73 sets the slip amount threshold to a target slip amount (SL3) that gradually increases with an increase in vehicle speed when a predetermined condition is met. Alternatively, the traction control unit 73 sets the slip amount threshold to a target slip amount (SL4) that gradually increases with an increase in vehicle speed when a predetermined condition is met.

[0040] The predetermined condition is preferably that the disengagement period of the clutch 30 due to the traction control operation becomes equal to or more than a predetermined period of time. Alternatively, the predetermined condition is preferably that the number of disengagements of the clutch 30 due to the traction control operation becomes equal to or more than a predetermined number of times.

[0041] In this way, when the disengagement period of the clutch 30 or the number of disengagements is detected and compared with the threshold value to determine whether the predetermined condition is met, instead of a state in which the clutch 30 is disengaged momentarily due to the traction control operation, a state in which the clutch 30 is disengaged for a long period of time or very frequently when driving on a snowy or muddy road can be detected. Thus, a state in which a failure of the vehicle to start or accelerate occurs, or in which the driver feels deceleration when the clutch 30 is disengaged for a long period of time or very frequently, can be detected.

[0042] For example, in this embodiment, when a period of time during which the clutch 30 is continuously disengaged reaches a first predetermined period or more than the predetermined period, the traction control unit 73 determines that a predetermined condition is met. Alternatively, the traction control unit 73 determines that a predetermined condition is met when the total sum of the periods during which the clutch 30 is disengaged over a certain period of time reaches a second predetermined period or more than the predetermined period.

[0043] Since in such a case, as shown by the increase in the positive change amount of the accelerator pedal operation, the driver's intention to accelerate and start the vehicle increases, the resulting inconvenience to the driver must be eliminated, but at the same time, the driver's intention must be prioritized.

[0044] Thus, the traction control unit 73 should preferably be operated with increasing positive change amount of the accelerator pedal operation (accelerator opening degree change amount or accelerator opening degree) by the driver during the execution of the traction control operation as shown in the Fig. 4(A) and Fig. 4(B), reduce the predetermined time period.

[0045] In addition, the traction control unit 73 should preferably be operated with increasing positive change amount of the accelerator pedal operation by the driver during the execution of the traction control operation, as shown in the Fig. 5(A) and Fig. 5(B), reduce the predetermined number of times.

[0046] As the road gradient increases or the road coefficient of friction decreases, it becomes more difficult to accelerate and start the vehicle. This problem must be prevented.

[0047] Thus, the traction control unit 73 should preferably be activated with increasing gradient of the road, as in Fig. 4(C), or with decreasing friction coefficient of the road surface, as in Fig. 4(D), while performing the traction control operation, reduce the predetermined time period.

[0048] In addition, the traction control unit 73 should preferably be activated with increasing gradient of the road, as in Fig. 5(C), or with decreasing friction coefficient of the road surface, as in Fig. 5(D), while performing the traction control operation, reduce the predetermined number of times.

[0049] Since the behavior of the vehicle 10 is disturbed at a high yaw rate of the vehicle 10, it is necessary to maintain the stability of the vehicle 10 by continuing the traction control process.

[0050] Thus, the traction control unit 73 should preferably, with decreasing yaw rate of the vehicle 10, during the execution of the traction control process, the predetermined period of time, as in Fig. 4(E).

[0051] Furthermore, the traction control unit 73 should preferably, with decreasing yaw rate of the vehicle 10, during the execution of the traction control process, the predetermined number of times as in Fig. 5(D).

[0052] In addition, a change mode of the predetermined number of times or the predetermined period of time is not limited to the Fig. 4(A) to 4(D) and in the Fig. 5(A) to 5(D) is limited to a step change mode and may be a continuous change mode.

[0053] In the control system of JP H07-108 633 B2, if the vehicle speed at which the traction control operation is inhibited is set to 0 km / h, the initial slip cannot be prevented. As a result, there is a possibility that the vehicle cannot be accelerated contrary to the driver's intention, resulting in poor starting performance. Therefore, the slip amount threshold should be increased so that the traction control operation is inhibited or difficult to execute due to both the acceleration of the vehicle 10 and the vehicle speed.

[0054] Thus, during the traction control operation, when the acceleration of the vehicle 10 reaches a predetermined acceleration threshold or less, and the vehicle speed reaches a predetermined vehicle speed threshold or more, the traction control unit 73 should preferably increase the slip amount threshold over a predetermined period of time such that the traction control operation is inhibited or difficult to perform.

[0055] In this way, by using the acceleration of the vehicle 10, the slip amount threshold can be increased by detecting a start failure from the acceleration, and the traction control operation can be inhibited after the initial slip is prevented by the traction control operation. This makes it possible to improve the starting performance of the vehicle 10.

[0056] There is a possibility that if the acceleration is detected only by the acceleration sensor 51, the acceleration due to a gradient or vibration of the vehicle may not be detected correctly. Furthermore, there is a possibility that the vehicle wheel spin may not be detected if the acceleration is achieved due to the first or second fastest vehicle wheel speed among the vehicle wheel speeds of the four vehicle wheels in a four-wheel drive system or the drive wheels in a two-wheel drive system.

[0057] Thus, the acceleration of the vehicle 10 should be calculated based on the detection signal of the acceleration sensor 51 provided in the vehicle 10, the vehicle wheel speed of the vehicle wheel 16 corresponding to the driven wheel detected by the vehicle wheel speed detection sensor 53, or, if all vehicle wheels 13 and 16 are drive wheels, the third slowest vehicle wheel speed and / or the fourth slowest vehicle wheel speed among all the vehicle speeds detected by the vehicle wheel speed detection sensor 53. With such a configuration, it is possible to more accurately determine a state in which the vehicle 10 is not accelerating.

[0058] Preferably, the predetermined period of time should be defined as a period of time until a predetermined period of time elapses, and / or a period of time during which the vehicle 10 travels on a road surface without an uphill or gradient, and / or a period of time until the driving cycle of the vehicle 10 reaches a predetermined drive time, and / or a period of time until a road surface condition of a road surface on which the vehicle travels changes to another road surface condition.

[0059] Subsequently, an operation of the traction control unit 73 of the vehicle 10 having the configuration described above will be described with reference to the Fig. The flowchart shown in Figure 2 is described in more detail.

[0060] If in Fig.2 the traction control (referred to as ASR intervention in the drawings) begins (step S1), the traction control unit 73 first determines whether the rear wheel increase rate, ie an increase rate of the rotational speed of the vehicle wheel 13, is equal to a threshold value A or less (step S2).

[0061] If the rear wheel increase rate is equal to or less than the threshold value A in step S2, the traction control unit 73 proceeds to step S4 described below. If the rear wheel increase rate is greater than the threshold value A in step S2, the traction control unit 73 determines whether the number of times the clutch 30 is disengaged (hereinafter referred to as the number of disengagement times) reaches N times or more (step S3).

[0062] If the number of clutch disengagements does not reach N or more in step S3, the traction control unit 73 returns to step S1. If the number of clutch disengagements reaches N or more in step S3, the traction control unit 73 determines that a non-uphill condition exists (denoted by AN in the drawings) (step S4). Here, a non-uphill condition means that the vehicle 10 cannot climb in a current state.

[0063] After step S4, the traction control unit 73 executes the traction control restraining process (step S5) and ends the current process.

[0064] In the traction control restriction process of step S5, the traction control unit 73 temporarily prohibits the traction control, gradually increases the target slip amount, or gradually increases the target slip amount.

[0065] As previously described, the clutch control unit 73 controls the clutch actuator 35 such that the clutch 30 is disengaged when the engine speed of the internal combustion engine 20 decreases.

[0066] In addition, the traction control unit 73 increases the slip amount threshold value such that the traction control operation is prohibited or difficult to execute when a predetermined condition for the clutch release mode is satisfied during the execution of the traction control operation for a predetermined period of time.

[0067] Since the slip amount threshold is increased when the predetermined condition is met, this configuration may inhibit or make it difficult to execute the traction control operation. Therefore, the reduction of engine torque due to the traction control operation and the disengagement of the clutch due to the reduction of engine torque are interrupted.

[0068] Thus, it is possible to prevent a start failure of the vehicle 10 on a snowy uphill road or the like, improve the acceleration performance, and prevent a deceleration feeling for the driver.

[0069] Further, in the embodiment, the predetermined condition may preferably be that the disengagement period of the clutch 30 due to the traction control operation reaches a predetermined period or more.

[0070] With this configuration, since the continuous disengagement of the clutch 30 is detected based on the disengagement period of the clutch 30, rather than the intermittent disengagement of the clutch 30 due to the traction control operation, it is possible to detect a state in which a start failure or an acceleration failure occurs in the vehicle, or in which the driver feels deceleration due to running the vehicle on, for example, a snowy road or a muddy road.

[0071] Thus, as the slip amount threshold increases when a predetermined condition for the clutch 30 disengagement period is met, the traction control operation is inhibited or difficult to execute. Therefore, the reduction of engine torque due to the traction control operation and clutch disengagement due to the reduction of engine torque are interrupted.

[0072] Thus, it is possible to prevent a start failure of the vehicle 10 on a snowy uphill road or the like, improve the acceleration performance, and prevent a deceleration feeling for the driver.

[0073] Furthermore, in this embodiment, the traction control unit 73 may preferably reduce the predetermined time period as the positive change amount in the driver's accelerator pedal operation increases during the execution of the traction control operation.

[0074] Since a positive increase in the amount of change in the accelerator pedal operation indicates that the driver's intention to accelerate and start the vehicle is increasing, it is thus possible to better reduce the inconvenience to the driver by determining whether the driver's intention to accelerate and start the vehicle is strong.

[0075] Further, in the embodiment, the traction control unit 73 may preferably reduce the predetermined time period as the gradient of the road surface increases or the friction coefficient of the road surface decreases during the execution of the traction control operation.

[0076] Since acceleration and starting of the vehicle become more difficult as the gradient increases or the friction coefficient of the road decreases, it is possible to prevent the occurrence of this problem.

[0077] Furthermore, in this embodiment, the traction control unit 73 may preferably reduce the predetermined time period as the yaw rate of the vehicle 10 decreases during the execution of the traction control operation.

[0078] Accordingly, since the behavior of the vehicle 10 is disturbed at a high yaw rate of the vehicle 10, it is possible to continue the traction control process and maintain the stability of the vehicle 10.

[0079] Further, in the embodiment, the predetermined condition may preferably be that the number of disengagement times of the clutch 30 due to the traction control operation reaches a predetermined number of times or more.

[0080] With this configuration, since the continuous disengagement of the clutch 30 is detected based on the number of disengagements of the clutch 30, rather than the intermittent disengagement of the clutch 30 due to the traction control operation, it is possible to detect a state in which a start failure or an acceleration failure occurs in the vehicle, or in which the driver feels deceleration due to running the vehicle on, for example, a snowy road or a muddy road.

[0081] Thus, in a state where the engine speed continuously decreases due to the traction control operation, the slip amount threshold increases, so that the traction control operation is prohibited or difficult to execute.

[0082] Accordingly, the reduction of engine torque due to the traction control process and clutch disengagement due to the reduction of engine speed are interrupted.

[0083] For this reason, it is possible to transmit engine torque to the vehicle wheels 13 and 16 in response to the opening degree of the accelerator pedal to prevent start failure on a snowy or muddy road, improve acceleration performance, and reduce a deceleration sensation due to disengagement of the clutch 30.

[0084] As a result, it is possible to prevent a start failure of the vehicle 10 on a snowy uphill road or the like, improve acceleration performance, and reduce a deceleration feeling for the driver.

[0085] Further, in the embodiment, the traction control unit 73 may preferably reduce the predetermined number of times as the positive change amount in the driver's operation of the accelerator pedal increases during the execution of the traction control operation.

[0086] Accordingly, since a positive increase in the amount of change in the accelerator pedal operation indicates that the driver's intention to accelerate and start the vehicle is increasing, it is possible to further reduce the inconvenience to the driver by determining whether the driver's intention to accelerate and start the vehicle is strong.

[0087] Further, in the embodiment, the traction control unit 73 may preferably reduce the predetermined number of times as the gradient of the road surface increases or the friction coefficient of the road surface decreases during the execution of the traction control operation.

[0088] Since acceleration and starting of the vehicle become more difficult as the gradient increases or the friction coefficient of the road decreases, it is possible to prevent the occurrence of this problem.

[0089] Further, in this embodiment, the traction control unit 73 may preferably reduce the predetermined number of times as the yaw rate of the vehicle 10 decreases during the execution of the traction control operation.

[0090] Accordingly, since the behavior of the vehicle 10 is disturbed at a high yaw rate of the vehicle 10, it is possible to continue the traction control process and maintain the stability of the vehicle 10.

[0091] Further, in the embodiment, the traction control unit 73 may preferably increase the slip amount threshold value such that the traction control operation is prohibited or difficult to execute when, during execution of the traction control operation, for a predetermined period of time, the acceleration of the vehicle 10 reaches a predetermined acceleration threshold value or less and the vehicle speed is equal to a predetermined vehicle speed threshold value or more.

[0092] Accordingly, since it is possible to increase the slip amount threshold value due to both the acceleration of the vehicle 10 and the vehicle speed so that the traction control operation is inhibited or difficult to perform, there is no situation in which acceleration cannot be achieved even though an acceleration attempt is made.

[0093] Since the acceleration of the vehicle 10 is used in the embodiment, it is possible to inhibit the traction control operation after the initial slip is prevented by the traction control operation by detecting a start failure due to the acceleration and increasing the slip amount threshold, and to improve the start performance of the vehicle 10.

[0094] Furthermore, in the embodiment, the acceleration of the vehicle 10 may preferably be calculated from the detection signal of the acceleration sensor 51 provided in the vehicle 10, the vehicle wheel speed of the driven wheel detected by the vehicle wheel speed detection sensor 53, or, when all the vehicle wheels are drive wheels, the third slowest vehicle wheel speed and / or the fourth slowest vehicle wheel speed among all the vehicle wheel speeds detected by the vehicle wheel speed detection sensor 53.

[0095] In this case, it is possible that the acceleration due to a slope or vehicle vibration may not be correctly detected if the acceleration is detected only by the acceleration sensor. Furthermore, it is possible that the slip of the vehicle wheel may not be detected if the acceleration is determined based on the first or second fastest vehicle wheel speed among the vehicle wheel speeds of the four vehicle wheels in a four-wheel drive or the driving wheels in a two-wheel drive. In the embodiment, based on the configuration described above, it is possible to more accurately determine a state in which the vehicle 10 is not accelerating.

[0096] Furthermore, in the embodiment, the predetermined period of time may be set as a period of time until a predetermined period of time elapses, and / or a period of time in which the vehicle 10 travels on a road without an uphill or gradient, and / or a period of time until the travel cycle of the vehicle 10 reaches a predetermined drive time, and / or a period of time until a road condition of a road on which the vehicle travels becomes another road condition.

[0097] Accordingly, since a period until the condition for performing the traction control operation changes is determined based on a time period and a driving cycle, it is possible to prevent an unnecessary change in the condition for performing the traction control operation.

[0098] Although embodiments of the present invention have been described herein, it should be understood that those skilled in the art may modify this embodiment without departing from the scope of the present invention. All possible modifications or equivalents are to be considered covered by the following claims. (DESCRIPTION OF REFERENCE SYMBOLS)

[0099] 10 ... vehicle, 13 ... vehicle wheel (driven wheel), 16 ... vehicle wheel (driven wheel), 20 ... internal combustion engine, 30 ... clutch, 35 ... clutch actuator (actuator), 40 ... automatic transmission, 51 ... acceleration sensor, 53, 54 ... vehicle wheel speed detection sensor, 72 ... clutch control unit, 73 ... traction control unit

Claims

[1] A vehicle control device mounted in a vehicle (10) having an internal combustion engine (20), an automatic transmission (40) connected to the internal combustion engine (20) via a clutch (30) and comprising an actuator (35) engaging or disengaging the clutch (30), a clutch control unit (72) controlling the actuator (35), and a vehicle wheel speed detection sensor (53, 54) detecting a rotational speed of each of the vehicle wheels, comprising: a traction control unit (73) configured to calculate a slip amount of the vehicle wheel (13, 16) from the rotational speed of the vehicle wheel (13, 16) and to carry out a traction control process in which at least one engine torque of the internal combustion engine (20) is adjusted when the slip amount exceeds a predetermined slip amount threshold value, wherein the clutch control unit (72) controls the actuator (35) such that the clutch (30) is disengaged when an engine speed of the internal combustion engine (20) decreases, and wherein the traction control unit (73) increases the slip amount threshold value so that the traction control operation is prohibited or difficult to perform when a predetermined condition for a clutch-off mode is met during the execution of the traction control operation for a predetermined period of time. [2] The vehicle control apparatus according to claim 1, wherein the predetermined condition specifies that a time period in which the clutch (30) is disengaged by the traction control operation reaches a predetermined time period or more. [3] A vehicle control apparatus according to claim 2, wherein the traction control unit (73) reduces the predetermined time period as the positive change amount in the driver's operation of the accelerator pedal increases during the execution of the traction control operation. [4] A vehicle control device according to claim 2 or 3, wherein the traction control unit (73) reduces the predetermined time period as the gradient of the road surface increases or the friction coefficient of the road surface decreases during the execution of the traction control operation. [5] A vehicle control device according to any one of claims 2 to 4, wherein the traction control unit (73) reduces the predetermined time period as the yaw rate of the vehicle (10) decreases during the execution of the traction control operation. [6] The vehicle control apparatus according to claim 1, wherein the predetermined condition specifies that a number of times the clutch (30) is disengaged by the traction control operation reaches a predetermined number of times or more. [7] A vehicle control apparatus according to claim 6, wherein the traction control unit (73) reduces the predetermined number of times as the positive change amount in the driver's operation of the accelerator pedal increases during the execution of the traction control operation. [8] A vehicle control device according to claim 6 or 7, wherein the traction control unit (73) reduces the predetermined number of times as the gradient of the road surface increases or the friction coefficient of the road surface decreases during the execution of the traction control operation. [9] A vehicle control device according to any one of claims 6 to 8, wherein the traction control unit (73) reduces the predetermined number of times as the yaw rate of the vehicle (10) decreases during the execution of the traction control operation. [10] A vehicle control device mounted in a vehicle (10) having an internal combustion engine (20) and a vehicle wheel speed detection sensor (53, 54) detecting a rotational speed of each of the vehicle wheels (13, 16) as a vehicle wheel speed, comprising: a traction control unit (73) configured to calculate a slip amount of the vehicle wheel (13, 16) from the vehicle wheel speed and to carry out a traction control process in which at least one engine torque of the internal combustion engine (20) is adjusted when the slip amount exceeds a predetermined slip amount threshold value, wherein the traction control unit (73) increases the slip amount threshold value so that the traction control operation is prohibited or difficult to perform in a case where, during execution of the traction control operation for a predetermined period of time, the acceleration of the vehicle (10) is equal to or less than a predetermined acceleration threshold value or the vehicle speed is equal to or more than a predetermined vehicle speed threshold value when or after the accelerator pedal change amount becomes positive. [11] A vehicle control device according to claim 10, wherein the acceleration of the vehicle (10) is calculated from a detection signal of an acceleration sensor (51) provided in the vehicle, a vehicle wheel speed of a driven wheel (16) detected by the vehicle wheel speed detection sensor (53, 54), or, when all the vehicle wheels (13, 16) are drive wheels, the third slowest vehicle wheel speed and / or the fourth slowest vehicle wheel speed among all the vehicle wheel speeds detected by the vehicle wheel speed detection sensor (53, 54). [12] The vehicle control device according to any one of claims 1 to 9, wherein the predetermined period of time is a period of time until a predetermined period of time elapses, and / or a period of time in which the vehicle (10) travels on a road with an uphill gradient or without a gradient, and / or a period of time until a travel cycle of the vehicle (10) reaches a predetermined drive time, and / or a period of time until a road condition of a road on which the vehicle (10) travels changes to another road condition.

Images