阅读说明：本技术 车辆控制装置、车辆和车辆控制方法 (Vehicle control device, vehicle, and vehicle control method ) 是由 小清水翔一 山下觉嗣 福留弘幸 永坂庄司 小川诚一 桥本友希 长尾和也 于 2019-11-15 设计创作，主要内容包括：本发明提供一种车辆控制装置、车辆和车辆控制方法。车辆控制装置(122)具有相位差判定部(188)和控制部(186),所述相位差判定部判定第一时间序列数据与第二时间序列数据之间的相位差是否为相位差阈值以上,其中,所述第一时间序列数据表示分动箱/(38)所具有的驱动侧齿轮(82)的转速的经时变化,所述第二时间序列数据表示分动箱所具有的从动侧齿轮(84)的转速的经时变化；所述控制部在相位差判定部判定为相位差为相位差阈值以上的情况下,使离合器(42)的接合度增加,据此使被传递到第二驱动轮(48l、48r)的驱动力增加。根据本发明,能够更好地抑制在分动箱中产生齿碰撞声。(The invention provides a vehicle control device, a vehicle, and a vehicle control method. The vehicle control device (122) is provided with a phase difference determination unit (188) and a control unit (186), wherein the phase difference determination unit determines whether or not a phase difference between first time-series data and second time-series data is equal to or greater than a phase difference threshold value, wherein the first time-series data represents a temporal change in the rotation speed of a driving side gear (82) of the transfer case/(38), and the second time-series data represents a temporal change in the rotation speed of a driven side gear (84) of the transfer case; when the phase difference determination unit determines that the phase difference is equal to or greater than the phase difference threshold value, the control unit increases the degree of engagement of the clutch (42), thereby increasing the driving force transmitted to the second drive wheels (48l, 48 r). According to the present invention, the generation of the tooth collision sound in the transfer case can be suppressed more effectively.)

1. A vehicle control device that controls a vehicle having a drive source, first and second drive wheels, a transfer case, a drive force transmitting shaft, and a clutch, wherein the first and second drive wheels are driven by the drive source; the transfer case is provided on a drive force transmission path between the drive source and the second drive wheels, has a drive-side gear and a driven-side gear, and switches a direction of a rotary shaft that transmits drive force from the drive source; the drive power transmitting shaft transmits the drive power transmitted through the transfer case to the second drive wheel; the clutch adjusts the driving force transmitted to the second driving wheel through the driving force transmission shaft,

comprises a first rotation speed calculation unit, a second rotation speed calculation unit, a first time-series data acquisition unit, a second time-series data acquisition unit, a phase difference determination unit, and a control unit,

the first rotation speed calculation section calculates a rotation speed of the drive side gear based on a signal supplied from a first rotation sensor for detecting the rotation speed of the drive side gear;

the second rotation speed calculation portion calculates the rotation speed of the driven side gear based on a signal supplied from a second rotation sensor for detecting the rotation speed of the driven side gear;

the first time-series data acquiring unit acquires first time-series data indicating a temporal change in the rotational speed of the drive-side gear, based on the rotational speed of the drive-side gear sequentially supplied from the first rotational speed calculating unit;

the second time-series data acquiring unit acquires second time-series data indicating a change with time of the rotation speed of the driven gear, based on the rotation speed of the driven gear sequentially supplied from the second rotation speed calculating unit;

the phase difference determination unit determines whether or not a phase difference between the first time-series data and the second time-series data is equal to or greater than a phase difference threshold;

the control unit increases the degree of engagement of the clutch when the phase difference determination unit determines that the phase difference is equal to or greater than the phase difference threshold, thereby increasing the driving force transmitted to the second driving wheel.

2. The vehicle control apparatus according to claim 1,

further comprising a differential rotation speed determination unit that determines whether or not a differential rotation speed, which is a difference between the rotation speed of the drive-side gear and the rotation speed of the driven-side gear, is equal to or greater than a differential rotation speed threshold,

when the rotational speed difference determination unit determines that the rotational speed difference is equal to or greater than a rotational speed difference threshold value and the phase difference determination unit determines that the phase difference is equal to or greater than the phase difference threshold value, the control unit increases the degree of engagement of the clutch, thereby increasing the driving force transmitted to the second driving wheel.

3. The vehicle control apparatus according to claim 1,

the drive force transmission path is also provided with a continuously variable transmission having a drive pulley, a driven pulley, and a belt wound around the drive pulley and the driven pulley.

4. The vehicle control apparatus according to claim 1,

the driving source is an internal combustion engine.

5. The vehicle control apparatus according to claim 1,

the first drive wheel is a main drive wheel,

the second driving wheel is an auxiliary driving wheel.

6. A vehicle having the vehicle control device according to any one of claims 1 to 5.

7. A vehicle control method that is a method of controlling a vehicle having a drive source, first and second drive wheels, a transfer case, a drive power transmitting shaft, and a clutch, wherein the first and second drive wheels are driven by the drive source; the transfer case is provided on a drive force transmission path between the drive source and the second drive wheels, has a drive-side gear and a driven-side gear, and switches a direction of a rotary shaft that transmits drive force from the drive source; the drive power transmitting shaft transmits the drive power transmitted through the transfer case to the second drive wheel; the clutch adjusts the driving force transmitted to the second driving wheel through the driving force transmission shaft, the vehicle control method being characterized in that,

comprises the following steps:

determining whether or not a phase difference between first time-series data indicating a temporal change in the rotational speed of the driving gear and second time-series data indicating a temporal change in the rotational speed of the driven gear is equal to or greater than a phase difference threshold value; and

and increasing the degree of engagement of the clutch when the phase difference is equal to or greater than the phase difference threshold value, thereby increasing the driving force transmitted to the second driving wheel.

8. The vehicle control method according to claim 7,

further comprising a step of determining whether or not a difference between the rotational speed of the drive-side gear and the rotational speed of the driven-side gear, that is, a rotational speed difference, is equal to or greater than a rotational speed difference threshold,

when the rotational speed difference is equal to or greater than a rotational speed difference threshold value and the phase difference is equal to or greater than the phase difference threshold value, the degree of engagement of the clutch is increased, whereby the driving force transmitted to the second driving wheel is increased.

9. The vehicle control method according to claim 8,

the step of determining whether the rotational speed difference is equal to or greater than the rotational speed difference threshold is executed before the step of determining whether the phase difference is equal to or greater than the phase difference threshold.

Technical Field

The invention relates to a vehicle control device, a vehicle, and a vehicle control method.

Background

Japanese patent application laid-open No. 6056891 discloses that when the accelerator is returned so that the throttle opening is equal to or less than a predetermined opening, the engagement force of the frictional engagement mechanism is increased. According to japanese patent application laid-open No. 6056891, when the throttle opening degree is equal to or less than a predetermined opening degree, the drive system from the engine to the four wheels is in a connected state. Therefore, according to japanese patent laid-open publication No. 6056891, when the vehicle is accelerated by depressing the accelerator again, the generation of the tooth collision sound (rattlnoise) can be suppressed.

Disclosure of Invention

However, a technique capable of more effectively suppressing the generation of the tooth collision sound in the transfer case has been desired.

An object of the present invention is to provide a vehicle control device, a vehicle, and a vehicle control method that can better suppress the generation of tooth collision sound in a transfer case.

A vehicle control device according to an aspect of the present invention controls a vehicle having a drive source, first and second drive wheels, a transfer case, a drive force transmission shaft, and a clutch, wherein the first and second drive wheels are driven by the drive source; the transfer case is provided on a drive force transmission path between the drive source and the second drive wheels, has a drive-side gear and a driven-side gear, and switches a direction of a rotary shaft that transmits drive force from the drive source; the drive power transmitting shaft transmits the drive power transmitted through the transfer case to the second drive wheel; the clutch adjusts the driving force transmitted to the second driving wheel through the driving force transmission shaft, the vehicle control device has a first rotation speed calculation section that calculates a rotation speed of the driving side gear based on a signal supplied from a first rotation sensor for detecting the rotation speed of the driving side gear, a second rotation speed calculation section, a first time-series data acquisition section, a second time-series data acquisition section, a phase difference determination section, and a control section; the second rotation speed calculation portion calculates the rotation speed of the driven side gear based on a signal supplied from a second rotation sensor for detecting the rotation speed of the driven side gear; the first time-series data acquiring unit acquires first time-series data indicating a temporal change in the rotational speed of the drive-side gear, based on the rotational speed of the drive-side gear sequentially supplied from the first rotational speed calculating unit; the second time-series data acquiring unit acquires second time-series data indicating a change with time of the rotation speed of the driven gear, based on the rotation speed of the driven gear sequentially supplied from the second rotation speed calculating unit; the phase difference determination unit determines whether or not a phase difference between the first time-series data and the second time-series data is equal to or greater than a phase difference threshold; the control unit increases the degree of engagement of the clutch when the phase difference determination unit determines that the phase difference is equal to or greater than the phase difference threshold, thereby increasing the driving force transmitted to the second driving wheel.

A vehicle according to another aspect of the present invention includes the vehicle control device described above.

A vehicle control method according to another aspect of the present invention is a method of controlling a vehicle having a drive source, first and second drive wheels, a transfer case, a drive force transmission shaft, and a clutch, wherein the first and second drive wheels are driven by the drive source; the transfer case is provided on a drive force transmission path between the drive source and the second drive wheels, has a drive-side gear and a driven-side gear, and switches a direction of a rotary shaft that transmits drive force from the drive source; the drive power transmitting shaft transmits the drive power transmitted through the transfer case to the second drive wheel; the clutch adjusts the driving force transmitted to the second driving wheel through the driving force transmission shaft, the vehicle control method having the steps of: determining whether or not a phase difference between first time-series data indicating a temporal change in the rotational speed of the driving gear and second time-series data indicating a temporal change in the rotational speed of the driven gear is equal to or greater than a phase difference threshold value; and a step of increasing the degree of engagement of the clutch when the phase difference is equal to or greater than the phase difference threshold value, thereby increasing the driving force transmitted to the second driving wheel.

According to the invention, it is possible to provide a vehicle control apparatus, a vehicle, and a vehicle control method that can better suppress generation of a tooth collision sound in a transfer case.

The above objects, features and advantages will be readily understood by the following description of the embodiments with reference to the accompanying drawings.

Drawings

Fig. 1 is a block diagram showing a vehicle according to an embodiment.

Fig. 2A is a timing chart showing an example of the rotation speed of the driving side gear, and fig. 2B is a timing chart showing an example of the rotation speed of the driven side gear.

Fig. 3A is a timing chart showing an example of the rotation speed of the driving side gear, and fig. 3B is a timing chart showing an example of the rotation speed of the driven side gear.

Fig. 4A is a timing chart showing an example of first time-series data on which the filter unit has performed the filter process, and fig. 4B is a timing chart showing an example of second time-series data on which the filter unit has performed the filter process.

Fig. 5A is a timing chart showing an example of the rotation speed of the driving side gear, and fig. 5B is a timing chart showing an example of the rotation speed of the driven side gear.

Fig. 6 is a flowchart showing an operation of the vehicle control device according to the embodiment.

Fig. 7 is a time chart showing the evaluation results of the vehicle control device according to the reference example.

Fig. 8 is a time chart showing the evaluation results of the vehicle control device according to the embodiment.

Detailed Description

Hereinafter, a vehicle control device, a vehicle, and a vehicle control method according to the present invention will be described in detail with reference to the accompanying drawings.

[ one embodiment ]

A vehicle control device, a vehicle, and a vehicle control method according to an embodiment will be described with reference to the drawings. Fig. 1 is a block diagram showing a vehicle according to the present embodiment.

The vehicle 10 according to the present embodiment is a four-wheel drive vehicle. The vehicle 10 has a powertrain 20, a hydraulic system 22, and a control system 24.

The powertrain 20 has a drive source (power source) 30, a front axle 34, main drive wheels (first drive wheels) 36l, 36r, a rear axle 46, and sub drive wheels (second drive wheels) 48l, 48 r. The drive source 30 is, for example, an internal combustion engine (engine), but is not limited thereto. The drive source 30 generates a drive force (drive torque) for running the vehicle 10.

The power system 20 has a driving force transmission path (driving force transmission mechanism) 11, and the driving force transmission path (driving force transmission mechanism) 11 transmits the driving force from the driving source 30 to main driving wheels (front wheels) 36l, 36r and sub driving wheels (rear wheels) 48l, 48 r.

On the drive power transmission path 11, there are provided a transmission unit 32, a transfer case 38, a propeller shaft (drive power transmitting shaft) 40, a clutch 42, and a rear differential 44.

The Transmission unit 32 has a torque converter 60 and a Continuously Variable Transmission (CVT) 64. The transmission unit 32 also has an intermediate gear 66 and a final reduction gear (final gear) 68. The continuously variable transmission 64 has a drive pulley 70, a driven pulley 72, and an endless belt 74. The intermediate gear 66 includes a drive-side gear not shown and a driven-side gear not shown, but the intermediate gear 66 is conceptually shown here.

The transfer case 38 is provided on the drive force transmission path 11 between the drive source 30 and the sub-drive wheels 48l, 48 r. There is an input gear 80 at the forward section of the transfer case 38. The direction of the rotation axis of the input gear 80 is the same as the direction of the rotation axis of the final reduction gear 68, that is, the direction of the rotation axis of the front shaft 34. The driving force output from the final reduction gear 68 is transmitted to the transfer case 38 through the input gear 80.

The transfer case 38 has a drive side gear (drive gear) 82 as a bevel gear and a driven side gear (driven gear) 84 as a bevel gear. The direction of the rotation axis of the driving side gear 82 is the same as the direction of the rotation axis of the input gear 80, that is, the direction of the rotation axis of the front axle 34. The direction of the rotational axis of the driven side gear 84 is the same as the direction of the rotational axis of the propeller shaft 40, i.e., the same as the front-rear direction of the vehicle 10. In this way, the direction of the rotation axis can be changed by 90 ° by the transfer case 38. The transfer case 38 transmits the driving force input from the final reduction gear 68 through the input gear 80 to the propeller shaft 40.

The propeller shaft 40 is used to transmit the driving force transmitted from the main driving wheels 36l, 36r side through the transfer case 38 to the sub driving wheels 48l, 48r side. As described above, the direction of the rotation axis of the propeller shaft 40 is the same as the front-rear direction of the vehicle 10.

At the rear section of the propeller shaft 40 there is a rear differential 44. Rear differential 44 has an input gear 90 as a bevel gear and an output gear 92 as a bevel gear. The direction of the rotation axis of the input gear 90 is the same as the direction of the rotation axis of the propeller shaft 40. The direction of the rotational axis of the output gear 92 is the same as the direction of the rotational axis of the rear axle 46. In this way, the direction of the rotation axis can be changed by 90 ° by the rear differential 44. The rear differential 44 transmits the driving force transmitted from the main drive wheels 36l, 36r side through the propeller shaft 40 to the auxiliary drive wheels 48l, 48r side.

A clutch (rear differential clutch, coupling) 42 is provided between the propeller shaft 40 and the auxiliary drive wheels 48l, 48 r. Here, the case where the clutch 42 is disposed between the propeller shaft 40 and the sub-drive wheels 48l and 48r will be described as an example, but the present invention is not limited to this. The clutch 42 can change the degree of engagement (tightness). The degree of engagement of the clutch 42 can be controlled by, for example, a hydraulic pressure supplied to the clutch 42, but is not limited thereto.

The hydraulic system 22 supplies hydraulic pressure to the transmission unit 32. More specifically, the hydraulic system 22 supplies hydraulic pressure to the torque converter 60, the drive pulley 70, and the driven pulley 72. The hydraulic system 22 supplies hydraulic pressure to the clutch 42. The hydraulic system 22 includes a hydraulic pump 110, oil passages 112a, 112b, 112c, and 112d, and control valves 114a, 114b, 114c, and 114 d. The hydraulic pump 110 can be operated by a driving force (driving torque) generated by the driving source 30. The drive source 30 can function as a part of the mechanical pump. The hydraulic pump 110 may be configured by combining the drive source 30 and an electric motor, not shown. The hydraulic pump 110 may be constituted by only an electric motor.

Control system 24 controls power system 20 and hydraulic system 22. The control system 24 has a sensor group 120 and a vehicle control device 122.

The sensor group 120 has an accelerator pedal sensor 130, a vehicle speed sensor 132, rotation sensors 134A, 134B, a first hydraulic pressure sensor 136, a second hydraulic pressure sensor 138, a third hydraulic pressure sensor 140, and a fourth hydraulic pressure sensor 142.

The accelerator pedal sensor 130 detects an operation amount of an accelerator pedal. The vehicle speed sensor 132 detects the speed of the vehicle 10.

The rotation sensor (first rotation sensor) 134A is disposed, for example, so as to face the teeth of the drive side gear 82. The rotation sensor 134A detects the rotation of the driving side gear 82. The rotation sensor (second rotation sensor) 134B is disposed, for example, so as to face the teeth of the driven gear 84. The rotation sensor 134B detects rotation of the driven side gear 84. Here, a case where the rotation sensor 134A detects the rotation of the driving side gear 82 is described as an example, but the present invention is not limited to this. The rotation sensor 134A may detect the rotation of the rotating body connected to the rotation shaft of the driving gear 82. Here, a case where the rotation sensor 134B detects the rotation of the driven gear 84 is described as an example, but the present invention is not limited to this. The rotation sensor 134B may detect the rotation of the rotating body connected to the rotation shaft of the driven gear 84.

The first hydraulic pressure sensor 136 detects a torque converter hydraulic pressure, which is a pressure of oil supplied to the torque converter 60. The second hydraulic pressure sensor 138 detects the pressure of the oil supplied to the drive pulley 70, i.e., the drive pulley hydraulic pressure. The third hydraulic pressure sensor 140 detects the pressure of the oil supplied to the driven pulley 72, that is, the driven pulley hydraulic pressure. The fourth hydraulic pressure sensor 142 detects clutch hydraulic pressure, which is pressure of oil supplied to the clutch 42.

The vehicle Control device 122 is constituted by, for example, an ecu (electronic Control unit). Vehicle control device 122 includes an arithmetic unit 162 and a storage unit 164. The arithmetic Unit 162 may be configured by a Processor such as a CPU (Central Processing Unit), DSP (Digital Signal Processor), etc., not shown. The storage section 164 includes, for example, a non-volatile memory not shown and a volatile memory not shown. Examples of the nonvolatile Memory include a ROM (Read Only Memory), a flash Memory, and the like. Examples of the volatile Memory include a RAM (Random Access Memory). The arithmetic unit 162 can perform predetermined control based on a program, data, or the like stored in the storage unit 164.

The calculation unit 162 includes an engine control unit 170, a transmission unit control unit 172, a control unit 186, a rotational speed difference determination unit 187, and a phase difference determination unit 188. The arithmetic unit 162 further includes rotation speed calculation units 189A and 189B, time-series data acquisition units 190A and 190B, and filter units 192A and 192B.

Engine control unit 170, transmission unit control unit 172, and control unit 186 can be realized by calculation unit 162 executing a program stored in storage unit 164. More specifically, the engine control portion 170, the transmission unit control portion 172, and the control portion 186 can be realized by, for example, executing a program stored in the storage portion 164 by a CPU.

The rotational speed difference determination unit 187, the phase difference determination unit 188, and the rotational speed calculation units 189A and 189B can be realized by the arithmetic unit 162 executing a program stored in the storage unit 164. More specifically, the rotational speed difference determination unit 187, the phase difference determination unit 188, and the rotational speed calculation units 189A and 189B can be realized by executing a program stored in the storage unit 164, for example, by a DSP. The time-series data acquisition units 190A and 190B and the filter units 192A and 192B can be realized by the arithmetic unit 162 executing a program stored in the storage unit 164. More specifically, the time-series data acquisition units 190A and 190B and the filter units 192A and 192B can be realized by executing a program stored in the storage unit 164, for example, by a DSP.

The engine control unit 170 controls the drive source 30 based on a signal supplied from the sensor group 120, for example, the accelerator pedal sensor 130.

The transmission unit control section 172 controls the transmission unit 32 based on the signal supplied from the sensor group 120. Transmission unit control portion 172 has a torque converter control portion 180 and a continuously variable transmission control portion 182. Torque converter control unit 180 and continuously variable transmission control unit 182 can be realized by operating unit 162 executing a program stored in storage unit 164.

The torque converter control portion 180 controls the control valve 114c to supply a desired hydraulic pressure to the torque converter 60. The continuously variable transmission control portion 182 controls the gear ratio of the continuously variable transmission 64 by controlling the control valves 114a, 114b to supply a desired hydraulic pressure to the drive pulley 70 and the driven pulley 72. The control portion 186 controls the degree of engagement of the clutch 42 by controlling the control valve 114d to supply a desired hydraulic pressure to the clutch 42, thereby controlling the driving force supplied to the sub-drive wheels 48l, 48 r.

The rotation speed calculation unit (first rotation speed calculation unit) 189A can calculate the rotation speed of the driving side gear 82, that is, the rotation speed of the driving side gear 82 per unit time, based on the signal supplied from the rotation sensor 134A. The calculation of the rotation speed of the drive side gear 82 is repeatedly executed at a predetermined processing cycle. The rotation speed calculator (second rotation speed calculator) 189B can calculate the rotation speed of the driven gear 84, that is, the rotation speed of the driven gear 84 per unit time, based on the signal supplied from the rotation sensor 134B. The calculation of the rotation speed of the driven gear 84 is repeatedly executed at predetermined processing cycles. The predetermined processing cycle can be set to, for example, 1msec or less, and more preferably 100 μ sec or less.

Fig. 2A is a timing chart showing an example of the rotation speed of the driving side gear. The horizontal axis of fig. 2A represents time, and the vertical axis of fig. 2A represents the rotational speed of the driving gear 82. Fig. 2B is a timing chart showing an example of the rotation speed of the driven gear. The horizontal axis of fig. 2B represents time, and the vertical axis of fig. 2B represents the rotational speed of the driven gear 84. Fig. 2A and 2B show an example in which a large phase difference is not generated between a rotation speed waveform indicating a temporal change in the rotation speed of the driving side gear 82 and a rotation speed waveform indicating a temporal change in the rotation speed of the driven side gear 84.

Fig. 3A is a timing chart showing an example of the rotation speed of the driving side gear. The horizontal axis of fig. 3A represents time, and the vertical axis of fig. 3A represents the rotational speed of the driving gear 82. Fig. 3B is a timing chart showing an example of the rotation speed of the driven gear. The horizontal axis of fig. 3B represents time, and the vertical axis of fig. 3B represents the rotational speed of the driven gear 84. Fig. 3A and 3B show an example in which a large phase difference is generated between a rotation speed waveform indicating a temporal change in the rotation speed of the driving side gear 82 and a rotation speed waveform indicating a temporal change in the rotation speed of the driven side gear 84.

Each time the rotation speed calculator 189A calculates the rotation speed of the driving gear 82, it supplies information indicating the calculated rotation speed to the rotation speed difference determination unit 187. Further, the rotation speed calculator 189A supplies information indicating the calculated rotation speed to the filter unit 192A each time the rotation speed of the driving gear 82 is calculated.

Each time the rotation speed calculator 189B calculates the rotation speed of the driven gear 84, it supplies information indicating the calculated rotation speed to the rotation speed difference determination unit 187. Further, the rotation speed calculator 189B supplies information indicating the calculated rotation speed to the filter 192B each time the rotation speed of the driven gear 84 is calculated.

The rotation speed difference determination unit 187 can determine whether or not the difference between the rotation speed of the driving gear 82 and the rotation speed of the driven gear 84, that is, the rotation speed difference is equal to or greater than a rotation speed difference threshold. More specifically, the rotational speed difference determination unit 187 acquires information indicating the rotational speed supplied from the rotational speed calculation unit 189A. Further, the rotational speed difference determination unit 187 acquires information indicating the rotational speed supplied from the rotational speed calculation unit 189B. Then, the differential rotation speed determination unit 187 determines whether or not the differential rotation speed is equal to or greater than a differential rotation speed threshold value based on the information. The rotation speed difference threshold value is a threshold value for determining whether or not a difference of some degree is generated between the rotation speed of the driving side gear 82 and the rotation speed of the driven side gear 84. The rotational speed difference threshold value is stored in the storage unit 164 in advance, for example. The rotation speed difference threshold value may be a fixed value or a value that varies depending on the rotation speed of the driving side gear 82 or the driven side gear 84.

The filter unit 192A performs a filtering process, more specifically, a band pass filter (Bandpass filter) process on the information (data and signals) sequentially supplied from the rotational speed calculation unit 189A. That is, the filter unit 192A performs filter processing on a signal indicating a temporal change in the rotation speed of the drive side gear 82. The center frequency, the cutoff frequency, and the like of the band-pass filter included in the filter unit 192A can be appropriately set in accordance with the rotation speed of the drive side gear 82 and the like. The filtering unit 192A supplies information obtained by the bandpass filtering process performed by the filtering unit 192A to the time-series data acquisition unit 190A.

The filter unit 192B performs a filtering process, more specifically, a band-pass filtering process on the information sequentially supplied from the rotational speed calculation unit 189B. That is, the filter unit 192B performs filter processing on a signal indicating a temporal change in the rotation speed of the driven gear 84. The center frequency, the cutoff frequency, and the like of the band-pass filter included in the filter unit 192B can be appropriately set in accordance with the rotation speed of the driven gear 84 and the like. The filtering unit 192B supplies information obtained by performing the band-pass filtering process by the filtering unit 192B to the time-series data acquisition unit 190B.

The time-series data acquisition unit (first time-series data acquisition unit) 190A can acquire time-series data supplied from the filter unit 192A, that is, first time-series data (first rotation speed waveform) indicating a temporal change in the rotation speed of the drive-side gear 82. The time-series data acquisition unit (second time-series data acquisition unit) 190B can acquire time-series data supplied from the filter unit 192B, that is, second time-series data (second rotation speed waveform) indicating a temporal change in the rotation speed of the driven gear 84.

Fig. 4A is a timing chart showing an example of first time-series data on which the filtering process is performed by the filtering unit. Fig. 4B is a timing chart showing an example of the second time-series data on which the filtering process is performed by the filtering unit. Fig. 4A and 4B show an example of a case where a large phase difference is generated between the first time-series data representing the temporal change in the rotational speed of the driving side gear 82 and the second time-series data representing the temporal change in the rotational speed of the driven side gear 84.

The time-series data acquisition unit 190A stores the first time-series data thus acquired in the storage unit 164. The time-series data acquisition unit 190B stores the second time-series data thus acquired in the storage unit 164.

The phase difference determination unit 188 can determine whether or not the phase difference between the first time-series data and the second time-series data is equal to or greater than a phase difference threshold value. The phase difference threshold is a threshold for determining whether or not a phase difference occurs to some extent between the first time-series data and the second time-series data.

For example, whether or not the phase difference between the first time-series data and the second time-series data is equal to or greater than a phase difference threshold value can be determined by the following method. That is, the phase difference determination unit 188 acquires the rotation speed N1 of the driving side gear 82 at the time t1 (see fig. 4A) when the first time-series data reaches the maximum value, based on the first time-series data. The phase difference determination unit 188 acquires the rotation speed N2 of the driving side gear 82 at the time t2 (see fig. 4A) when the first time-series data reaches the minimum value, based on the first time-series data. The phase difference determination unit 188 acquires the rotation speed N1' of the driven gear 84 at time t1 (see fig. 4B) based on the second time-series data. The phase difference determination unit 188 acquires the rotation speed N2' of the driven gear 84 at time t2 (see fig. 4B) based on the second time-series data. When | (N2-N1) - (N2'-N1') | is equal to or greater than the phase difference threshold value, the phase difference determination unit 188 determines that the phase difference between the first time-series data and the second time-series data is equal to or greater than the phase difference threshold value. The phase difference determination section 188 determines that the phase difference between the first time-series data and the second time-series data is less than the phase difference threshold value when | (N2-N1) - (N2'-N1') | is less than the phase difference threshold value. In this way, it is possible to determine whether or not the phase difference between the first time-series data and the second time-series data is equal to or greater than the phase difference threshold.

In addition, it may be: whether or not the phase difference between the first time-series data and the second time-series data is equal to or greater than a phase difference threshold value is determined by the following method. Fig. 5A is a timing chart showing an example of the rotation speed of the driving side gear. The horizontal axis of fig. 5A represents time, and the vertical axis of fig. 5A represents the rotational speed of the driving side gear 82. Fig. 5B is a timing chart showing an example of the rotation speed of the driven side gear. The horizontal axis of fig. 5B represents time, and the vertical axis of fig. 5B represents the rotation speed of the driven gear 84. Fig. 5A and 5B show an example of a case where a large phase difference is generated between the first time-series data representing the temporal change of the driving side gear 82 and the second time-series data representing the temporal change of the driven side gear 84. The phase difference determination unit 188 determines the time t11 at which the first time-series data reaches the maximum value, based on the first time-series data. The phase difference determination unit 188 determines the time t12 at which the second time-series data reaches the maximum value, based on the second time-series data. The phase difference determination unit 188 determines the cycle T of the first time-series data or the second time-series data based on the first time-series data or the second time-series data. When | T11-T12|/T is equal to or greater than the phase difference threshold value, the phase difference determination unit 188 determines that the phase difference between the first time-series data and the second time-series data is equal to or greater than the phase difference threshold value. It is also possible to determine whether or not the phase difference between the first time-series data and the second time-series data is equal to or greater than a phase difference threshold value by this method.

The control section (driving force control section, driving force distribution control section) 186 controls the distribution of the driving force to the main driving wheels 36l, 36r and the sub-driving wheels 48l, 48 r. When the phase difference determination unit 188 determines that the phase difference is equal to or greater than the phase difference threshold, the control unit 186 increases the supply of the driving force to the sub-driving wheels 48l, 48 r. More specifically, when the differential rotation speed determination unit 187 determines that the differential rotation speed is equal to or greater than the differential rotation speed threshold and the phase difference determination unit 188 determines that the phase difference is equal to or greater than the phase difference threshold, the control unit 186 performs the following processing. That is, in this case, the control unit 186 increases the supply of the driving force to the sub-drive wheels 48l, 48 r. The control unit 186 may increase the supply of the driving force to the sub-drive wheels 48l, 48r without changing the supply of the driving force to the main drive wheels 36l, 36 r. The control unit 186 may decrease the supply of the driving force to the main driving wheels 36l and 36r and increase the supply of the driving force to the sub driving wheels 48l and 48 r. The control unit 186 increases the degree of engagement of the clutch 42 to increase the supply of the driving force to the sub-drive wheels 48l, 48 r.

The supply of the driving force to the sub-driving wheels 48l, 48r is increased when the phase difference between the first time-series data and the second time-series data is equal to or greater than the phase difference threshold value for the following reason. That is, when the rotation speed of the drive source 30 changes, the variation amount of the rotation speed of the propeller shaft 40 becomes large, and the variation amount of the torque transmitted from the transfer case 38 to the propeller shaft 40 also becomes large. The large variation in the torque transmitted from the transfer case 38 to the propeller shaft 40 is caused by resonance. In the four-wheel drive vehicle configured as described in the present embodiment, the rotational fluctuation of the drive source 30, the string vibration of the continuously variable transmission 64, the vibration of the propeller shaft 40, and the like affect each other, and large resonance tends to occur in the propeller shaft 40 and the like. The resonance frequency of the propeller shaft 40 is, for example, about 70 to 90 Hz. If the amount of variation in the torque transmitted from the transfer case 38 to the propeller shaft 40 is too large, a state may occur in which the torque transmitted from the transfer case 38 to the propeller shaft 40 is momentarily below zero. That is, a state occurs in which the torque transmitted from the transfer case 38 to the propeller shaft 40 instantaneously changes from positive to negative. When the torque transmitted from the transfer case 38 to the propeller shaft 40 instantaneously drops, for example, tooth surface separation occurs in the drive-side gear 82 and the driven-side gear 84 of the transfer case 38, and a tooth collision sound is generated when the separated tooth surfaces come into contact again. On the other hand, if the supply of the driving force to the sub-drive wheels 48l and 48r is increased at a stage before the fluctuation amount of the torque transmitted to the propeller shaft 40 becomes excessively large, the following situation occurs. That is, the occurrence of a state in which the torque supplied to the propeller shaft 40 is momentarily reduced can be suppressed. This can suppress the occurrence of tooth surface separation or the like of the gear, and further suppress the occurrence of tooth collision noise. It is possible to determine that the fluctuation amount of the torque transmitted to the propeller shaft 40 is large based on the phase difference between the first time-series data and the second time-series data being large. For this reason, in the present embodiment, when the phase difference between the first time-series data and the second time-series data is equal to or greater than the phase difference threshold value, the supply of the driving force to the sub-driving wheels 48l, 48r is increased. The phase difference threshold value can be set to ensure a predetermined margin.

Fig. 6 is a flowchart showing the operation of the vehicle control device according to the present embodiment.

In step S1, the rotation speed difference determination unit 187 determines whether or not the difference between the rotation speed of the driving side gear 82 and the rotation speed of the driven side gear 84, that is, the rotation speed difference is equal to or greater than a rotation speed difference threshold. If the rotational speed difference is equal to or greater than the rotational speed difference threshold value (yes in step S1), the process proceeds to step S2. If the rotational speed difference is smaller than the rotational speed difference threshold value (no in step S1), the processing shown in fig. 6 is completed.

In step S2, the phase difference determination unit 188 determines whether or not the phase difference between the first time-series data and the second time-series data is equal to or greater than a phase difference threshold value. When the phase difference between the first time-series data and the second time-series data is equal to or greater than the phase difference threshold value (yes in step S2), the process proceeds to step S3. In a case where the phase difference between the first time-series data and the second time-series data is smaller than the phase difference threshold value (no in step S2), the processing shown in fig. 6 is completed.

In step S3, the control unit 186 increases the supply of the driving force to the sub-drive wheels 48l, 48 r. Thus, the processing shown in fig. 6 is completed.

Fig. 7 is a time chart showing the evaluation results of the vehicle control device according to the reference example. Fig. 8 is a time chart showing the evaluation results of the vehicle control device according to the present embodiment. Fig. 7 and 8 show the vehicle speed, the accelerator opening, the rotation speed of the drive source 30, and the rotation speed of the propeller shaft 40. The horizontal axis in fig. 7 and 8 represents time. In the reference example, even if a phase difference of a phase difference threshold value or more is generated between the first time-series data and the second time-series data, the driving force transmitted to the sub-driving wheels 48l, 48r is not increased.

As shown in fig. 7, in the case of the reference example, when the rotation speed of the drive source 30 sharply decreases with a decrease in the accelerator opening degree, the amount of variation in the rotation speed of the propeller shaft 40 becomes large. As described above, when the amount of variation in the rotational speed of the drive shaft 40 becomes large, tooth surface separation or the like occurs at the drive-side gear 82 and the driven-side gear 84 of the transfer case 38, and a tooth collision sound is generated when the separated tooth surfaces again abut.

On the other hand, as shown in fig. 8, in the case of the present embodiment, even if the rotation speed of the drive source 30 is rapidly reduced as the accelerator opening degree is reduced, the variation amount of the rotation speed of the propeller shaft 40 is not so large. Thus, in the present embodiment, the generation of tooth collision noise can be suppressed.

As described above, in the present embodiment, the first time-series data indicating the temporal change in the rotation speed of the drive side gear 82 is acquired. In the present embodiment, second time-series data indicating a change with time in the rotation speed of the driven gear 84 is acquired. In the present embodiment, it is determined whether or not the phase difference between the first time-series data and the second time-series data is equal to or greater than a phase difference threshold value. In the present embodiment, when the phase difference is equal to or greater than the phase difference threshold value, the degree of engagement of the clutch 42 is increased, and the driving force transmitted to the sub-drive wheels 48l, 48r is increased accordingly. When the supply of the driving force to the sub-drive wheels 48l, 48r is increased, the tooth surfaces of the driving side gear 82 and the driven side gear 84 of the transfer case 38 can be suppressed from being separated. When the tooth surface separation of the driving side gear 82 and the driven side gear 84 is suppressed, the generation of the tooth collision sound due to the re-abutment of the separated tooth surfaces can be suppressed. Therefore, according to the present embodiment, it is possible to provide the vehicle control device 122 that can favorably suppress the occurrence of the tooth collision sound in the transfer case 38.

The preferred embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments, and various modifications can be made without departing from the scope of the present invention.

The above embodiments can be summarized as follows.

A vehicle control device (122) that controls a vehicle (10) having a drive source (30), first and second drive wheels (36l, 36r, 48l, 48r) that are driven by the drive source, a transfer case (38), a drive force transmitting shaft (40), and a clutch (42); the transfer case is provided on a drive force transmission path (11) between the drive source and the second drive wheel, has a drive side gear (82) and a driven side gear (84), and switches the direction of a rotary shaft that transmits the drive force from the drive source; the drive power transmitting shaft transmits the drive power transmitted through the transfer case to the second drive wheel; the clutch adjusts the driving force transmitted to the second driving wheel through the driving force transmission shaft, and the vehicle control device has a first rotation speed calculation section (189A), a second rotation speed calculation section (189B), a first time-series data acquisition section (190A), a second time-series data acquisition section (190B), a phase difference determination section (188), and a control section (186), wherein the first rotation speed calculation section calculates the rotation speed of the driving side gear based on a signal supplied from a first rotation sensor (134A) for detecting the rotation speed of the driving side gear; the second rotation speed calculation portion calculates the rotation speed of the driven side gear based on a signal supplied from a second rotation sensor (134B) for detecting the rotation speed of the driven side gear; a first time-series data acquiring unit that acquires first time-series data indicating a temporal change in the rotational speed of the drive-side gear, based on the rotational speed of the drive-side gear sequentially supplied from the first rotational speed calculating unit; the second time-series data acquiring unit acquires second time-series data indicating a change with time of the rotation speed of the driven gear, based on the rotation speed of the driven gear sequentially supplied from the second rotation speed calculating unit; the phase difference determination unit determines whether or not a phase difference between the first time-series data and the second time-series data is equal to or greater than a phase difference threshold; the control unit increases the degree of engagement of the clutch when the phase difference determination unit determines that the phase difference is equal to or greater than the phase difference threshold, thereby increasing the driving force transmitted to the second driving wheel. According to this configuration, when the phase difference between the first time-series data and the second time-series data is equal to or greater than the phase difference threshold value, the degree of engagement of the clutch is increased, and the driving force transmitted to the second driving wheel is thereby increased. When the supply of the driving force to the second driving wheels is increased, the tooth surface separation of the driving-side gear of the transfer case can be suppressed. When the tooth surface separation of the drive-side gear is suppressed, the generation of tooth collision sound due to the separated tooth surfaces coming into contact again can be suppressed. Therefore, according to such a configuration, it is possible to provide a vehicle control device that can favorably suppress the occurrence of tooth collision noise in the transfer case.

Can be as follows: the vehicle control device further includes a differential rotation speed determination unit (187) that determines whether or not a differential rotation speed, which is a difference between the rotational speed of the drive-side gear and the rotational speed of the driven-side gear, is equal to or greater than a differential rotation speed threshold value, and when the differential rotation speed determination unit determines that the differential rotation speed is equal to or greater than the differential rotation speed threshold value and the phase difference determination unit determines that the phase difference is equal to or greater than the phase difference threshold value, the control unit increases the engagement degree of the clutch, thereby increasing the driving force transmitted to the second drive wheel. According to such a configuration, since the phase difference is not determined when the rotation speed difference is lower than the rotation speed difference threshold value, the processing load can be reduced.

Can be as follows: the vehicle control device further includes a continuously variable transmission (64) having a drive pulley (70), a driven pulley (72), and a belt (74) wound around the drive pulley and the driven pulley on the drive force transmission path.

Can be as follows: the driving source is an internal combustion engine.

The following steps can be also included: the first driving wheel is a main driving wheel, and the second driving wheel is an auxiliary driving wheel.

The vehicle includes the vehicle control device as described above.

A vehicle control method that is a method of controlling a vehicle having a drive source, first and second drive wheels, a transfer case, a drive power transmitting shaft, and a clutch, wherein the first and second drive wheels are driven by the drive source; the transfer case is provided on a drive force transmission path between the drive source and the second drive wheels, has a drive-side gear and a driven-side gear, and switches a direction of a rotary shaft that transmits drive force from the drive source; the drive power transmitting shaft transmits the drive power transmitted through the transfer case to the second drive wheel; the clutch adjusts the driving force transmitted to the second driving wheel through the driving force transmission shaft, the vehicle control method having the steps of: a step (S2) of determining whether or not a phase difference between first time-series data and second time-series data is equal to or greater than a phase difference threshold value, the first time-series data indicating a temporal change in the rotational speed of the drive-side gear, the second time-series data indicating a temporal change in the rotational speed of the driven-side gear; and a step (S3) of increasing the degree of engagement of the clutch when the phase difference is equal to or greater than the phase difference threshold value, thereby increasing the driving force transmitted to the second driving wheel.

Can be as follows: the vehicle control method further includes a step (S1) of determining whether or not a difference between the rotation speed of the drive-side gear and the rotation speed of the driven-side gear, that is, a rotation speed difference, is equal to or greater than a rotation speed difference threshold value, and when the rotation speed difference is equal to or greater than the rotation speed difference threshold value and the phase difference is equal to or greater than the phase difference threshold value, increasing the degree of engagement of the clutch, thereby increasing the driving force transmitted to the second driving wheel.

Can be as follows: the step of determining whether the rotational speed difference is equal to or greater than the rotational speed difference threshold is executed before the step of determining whether the phase difference is equal to or greater than the phase difference threshold.