JP2008018874A - Traveling way determination device and drive control device of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control driving of a driving wheel by detecting sand and adapting it to the sand. <P>SOLUTION: When detecting that the driving wheel is being driven (step S1) and when detecting displacement of a driving wheel to downward (step S3 or step S6), the traveling way determination device determines that a traveling way of the vehicle is sand (step S4 or step S7). When determined as sand traveling, it controls an engine torque so that the driving torque of the driving wheel does not exceed a threshold set beforehand in order to prevent a slip of the driving wheel. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a travel path determination device that determines a travel path state of a vehicle and a vehicle drive control device that controls driving of drive wheels.

In Patent Document 1, when the cumulative value of the slip amount or slip ratio of the drive wheel increases, the suppression of the drive torque is relaxed. Thereby, for example, it is possible to escape the driving wheel from sand.
JP-A-8-14075

However, in Patent Document 1, since the drive wheel is allowed to escape from the sand by controlling the drive torque of the drive wheel based on the slip amount or slip rate of the drive wheel, the drive wheel is detected in order to detect the slip amount or slip rate. Must be driven to a certain extent, and the drive wheel remains in the sand due to the drive.
An object of the present invention is to detect sandy land and control driving of driving wheels in conformity with the sandy ground.

  In order to solve the above-mentioned problem, the traveling path determination device according to claim 1 of the present invention detects the driving state of the driving wheel by the driving state detection means, and drives the vertical movement of the driving wheel relative to the vehicle body. Vehicle detected by the wheel vertical movement detection means, the drive state detection means detects that the drive wheel is driven, and the drive wheel vertical movement detection means detects the downward movement of the drive wheel, It is determined by the sandy land determining means that the traveling road is sandy.

According to a sixth aspect of the present invention, there is provided a vehicle drive control device that detects a travel path state of the vehicle by a travel path state detection means, wherein the drive control means detects the travel path state detection means and the travel path is sandy. When it is detected, the drive torque is controlled so that the drive torque of the drive wheel does not exceed a threshold value set to be equivalent to the drive torque so that the drive wheel does not slip with respect to the sand.
According to a ninth aspect of the present invention, there is provided the vehicle drive control apparatus according to the ninth aspect of the present invention, wherein the drive torque of the drive wheel does not exceed a threshold value set to be equivalent to the drive torque so that the drive wheel does not slip on the sand. The drive torque is controlled by the drive control means, and the operation state of the control by the drive control means is manually turned on and off by the operation means.
According to a tenth aspect of the present invention, there is provided a vehicle drive control method according to a tenth aspect of the present invention, wherein a threshold value set in advance corresponding to a drive torque is set so that the drive wheels do not slip with respect to the sand when the travel path is determined to be sand. The driving torque is controlled so that the driving torque of the driving wheel does not exceed.

  According to the present invention, it can be detected that the travel path is sandy. In addition, the driving torque of the driving wheel can be controlled in conformity with the sand.

The best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described in detail with reference to the drawings.
(First embodiment)
(Constitution)
FIG. 1 shows a configuration of a vehicle showing a first embodiment equipped with a driving force control apparatus according to the present invention. This vehicle shows a case where it is a front-wheel drive vehicle. In the figure, 1 is an engine, 2 is an automatic transmission, 3 and 4 are drive shafts, 5 and 6 are front wheels (drive wheels), 7 and 8 are rear wheels (driven wheels), 9 is a throttle valve, and 10 is throttle control. Motor, 11 is anti-skid control (ABS (Anti-lockBrake System) in the figure) / drive force control (TCS (Traction Control System in the figure)) control unit, 12, 13, 14, 15 are wheel speed sensors, 17 is slip Indicator, 18 is a TCS / OFF indicator, 19 is a TCS / OFF switch, 20 is an engine control unit, 21 is an automatic transmission (AT) control unit, 22 is a multiple communication line, 23 is an engine speed sensor, and 24 is an engine speed sensor. Accelerator operation amount sensor 25, throttle opening sensor 26, engine speed sensor 27, longitudinal acceleration sensor 2 , 29, 30, 31 is a stroke sensor for detecting the vertical stroke of each wheel.

  In such a configuration, a throttle control motor 10 as a throttle opening control actuator for controlling the opening of the throttle valve 9 is provided in the intake pipe of the engine 1. As the automatic transmission 2, a stepped transmission in which the gear position, that is, the gear position is changed in multiple stages, is used, and the gear ratio, that is, the gear ratio or the gear ratio is changed according to the gear shift command from the AT control unit 21. The gear position is controlled.

  In the automatic transmission 2, the gear ratio is controlled by a control signal from the AT control unit 21. As is well known, the gear ratio in the automatic transmission 2 controlled by the AT control unit 21 is based on the vehicle speed substituted for the output shaft rotation speed and the throttle opening detected by the throttle opening sensor 25 as variables. Alternatively, the engine speed is controlled with reference to the engine speed detected by the engine speed sensor 23. Incidentally, the AT control unit 21 of the present embodiment exchanges information with the engine control unit 20 to perform optimization control during normal travel of the engine 1 and the automatic transmission 2, and is selected, for example. The current gear position CURGP and the next target gear position NEXTGP changed by the shift shift operation are output to the engine control unit 20, and the gear position GRPOS for driving force control (hereinafter also referred to as TCS control) is set to ABS / Obtained from the TCS control unit 11.

  The ABS / TCS control unit 11 controls the engine torque (driving torque) as traction control in order to control the accelerator operation amount ACC from the accelerator operation amount sensor 24, the wheel speeds VwFL to VwRR from the wheel speed sensors 12 to 15, The engine rotational speed NE detected by the engine rotational speed sensor 26, the current gear position CURGP and the next target gear position NEXTGP from the AT control unit 21 are read, a TCS control gear position GRPOS is calculated, and an engine torque command value TE -Calculate COM and output them to the engine control unit 20. Accordingly, when the engine control command value TE-COM or the like is input, the engine control unit 20 controls the throttle control motor 10 so that the engine torque is achieved.

Further, the ABS / TCS control unit 11 is configured to be able to perform traction control for sandy ground separately from the traction control that is normally performed. In the traction control for sandy ground, when it is detected that the traveling path of the host vehicle is sandy, control for suppressing the drive torque within the preset upper limit engine torque _TL is performed. That is, in the normal traction control, the driving torque is controlled based on the slip state of the wheel, specifically, the driving torque is controlled when the wheel slips. In the sand traction control, The driving torque is suppressed on the condition that it is detected that the travel path is sandy, and this point is different from normal traction control. Here, the detection of the sand is performed based on the stroke amount of the wheel which is the detection value from the stroke sensors 28 to 31.

  The engine control unit 20 has a built-in microcomputer (not shown). For example, the engine speed NE detected by the engine speed sensor 23, the accelerator operation amount ACC detected by the accelerator operation amount sensor 24, and the throttle Based on the throttle opening detected by the opening sensor 25, the fuel injection device, according to the original calculation processing, or according to the request signal or information signal from the AT control unit 21 or the ABS / TCS control unit 11, The rotational state of the engine 1 is controlled by adjusting the air-fuel ratio and the intake air amount by adjusting the so-called injector ON / OFF, the timing thereof, the fuel injection amount, the throttle opening of the throttle valve 9 by the throttle control motor 10, and the like. This allows for a smooth acceleration feeling and needs Or to obtain a sufficient deceleration feeling, or optimally controlled in accordance with the ignition timing and idle speed or the like state of the vehicle.

  FIG. 2 shows a procedure of arithmetic processing for sand detection by the ABS / TCS control unit 11. In this arithmetic processing, there is no particular communication step. However, the arithmetic result calculated by the arithmetic processing device is stored in the storage device as needed, and the information stored in the storage device is stored in the arithmetic processing device as needed. It is transmitted and stored in a buffer or the like. For example, this arithmetic processing is executed by timer interruption processing every predetermined control time ΔT of about 10 msec.

  As shown in FIG. 2, when the processing is started, first, in step S1, it is determined whether or not the accelerator opening is larger than 0 based on the accelerator operation amount ACC detected by the accelerator operation amount sensor 24. That is, it is determined whether the driver is operating the accelerator. If the accelerator opening is larger than 0 (accelerator opening> 0), the process proceeds to step S2, and if the accelerator opening is 0 (accelerator opening = 0), that is, the driver is operating the accelerator. If not, the process proceeds to step S8.

In step S2, it is determined whether or not the vehicle is in a four-wheel drive state. If the vehicle is in the four-wheel drive state, the process proceeds to step S3. If the vehicle is not in the four-wheel drive state, that is, if the vehicle is driven by either the front wheels or the rear wheels (when the drive method is FF or FR), step S6 is performed. Proceed to
In step S3, it is determined whether the stroke speed of the drive wheels is 0 or less based on the detection values of the stroke sensors 28-31. Here, as shown in FIG. 3, when the stroke speed is a negative value, it means that the wheel is displaced (moved) in the direction in which the stroke (suspension) extends (increases).

If the stroke speed of the drive wheels is 0 or less (stroke speed ≦ 0) in this step S3, it is determined that the vehicle travel path is sandy, and the process proceeds to step S4. Otherwise (stroke speed> 0), the vehicle travels. Assuming that the road is not sandy, for example, an asphalt road surface, the process proceeds to step S5.
Note that when the stroke speed of at least one of the front left and right wheels is 0 or less and the stroke speed of at least one of the rear left and right wheels is 0 or less, Assuming that the stroke speed is 0 or less, the process proceeds to step S4.

In this process, it is determined whether the stroke speed of the drive wheel is 0 or less, but it is also possible to determine whether the stroke speed of the drive wheel is less than 0.
In step S4, the sand determination flag F is set to 1. Then, the process shown in FIG.
In step S5, the sand determination flag F is set to zero. Then, the process shown in FIG.

  On the other hand, in step S6, the stroke speed of the drive wheel is 0 or less and the absolute value of the stroke speed of the driven wheel (| the stroke speed of the driven wheel |) is a threshold value based on the detection values of the stroke sensors 28-31. It is determined whether it is A or less. As shown in FIG. 4, the threshold A increases with the drive torque (engine torque). Here, when the stroke speed of the drive wheel is 0 or less and the absolute value of the stroke speed of the driven wheel is less than or equal to the threshold value A (drive wheel stroke speed ≦ 0 and | stroke wheel stroke speed | ≦ A), Proceed to step S7. Otherwise (stroke speed of driving wheel> 0 or | stroke speed of driven wheel |> A), proceed to step S8.

In step S7, the sand determination flag F is set to 1. Then, the process shown in FIG.
Step S8 is also the case where the accelerator opening is 0 in step S1, and in this step S8, the sand judgment flag F is set to 0. Then, the process shown in FIG.
As described above, arithmetic processing for sand detection by the ABS / TCS control unit 11 is performed. Note that the engine control unit 20 can also perform arithmetic processing for sand detection.

  FIG. 5 shows a procedure of arithmetic processing for traction control by the ABS / TCS control unit 11. In this arithmetic processing, there is no particular communication step. However, the arithmetic result calculated by the arithmetic processing device is stored in the storage device as needed, and the information stored in the storage device is stored in the arithmetic processing device as needed. It is transmitted and stored in a buffer or the like. For example, this arithmetic processing is executed by timer interruption processing every predetermined control time ΔT of about 10 msec.

As shown in FIG. 5, when the process is started, first, in step S21, it is determined whether or not the sand land determination flag F is “1”. If the sand land determination flag F is 1, the process proceeds to step S22. If the sand land determination flag F is 0, the process proceeds to step S25.
In step S25, normal traction control is performed. That is, the drive torque is controlled based on the slip state of the wheels. Then, the process shown in FIG. 5 ends.

In step S22, an upper limit engine torque (sandy traction control intervention threshold) _TL is set. The upper limit engine torque _TL is set as a value that drives the drive wheels but does not cause the drive wheels to slide against the sand or sink into the sand. For example, the upper limit engine torque _TL is set based on experimental values, experience values, or based on vehicle specifications. Further, the upper limit engine torque _TL is set to change according to the vehicle body speed V. For example, as shown in FIG. 6, the upper limit engine torque _TL is increased as the vehicle body speed V increases. The characteristic of the upper limit engine torque _{TL with} respect to the vehicle body speed V is also obtained as an experimental value or an empirical value.

In step S23, it is determined whether or not the current engine torque is greater than the upper limit engine torque _TL set in step S22. Here, when the current engine torque is larger than the upper limit engine torque T _L set at step S22 (present engine torque> T _L), the process proceeds to step S24, otherwise (the current engine torque ≦ T _L) The process proceeds to step S25.
In step S24, sandy traction control is performed. Specifically, a process of reducing the actual engine torque (drive torque) to the upper limit engine torque _TL is performed. Then, the process shown in FIG. 5 ends.

(Operation)
The operation is as follows.
First, the sand detection is performed. That is, when the accelerator opening is larger than 0, the vehicle is in a four-wheel drive state, and the stroke speed of the drive wheel is 0 or less, the sand determination flag F is set to 1 (step S1 → step S2 → step S3 → Step S4). Further, when the accelerator opening is larger than 0 but not in the four-wheel drive state, that is, when the drive system is FF or FR, the stroke speed of the drive wheel is 0 or less and the driven wheel is the absolute value of the stroke speed. Is equal to or less than the threshold value A, the sand determination flag F is set to 1 (step S1, step S2, step S6, step S7).

  On the other hand, when the accelerator opening is 0, the sand determination flag F is set to 0 (step S1 → step S8). Further, when the accelerator opening is larger than 0 but the stroke speed of the driving wheel is not less than 0, the sand determination flag F is set to 0 (step S1 → step S2 → step S3 → step S5 or step S1 → Step S2 → Step S6 → Step S8).

Then, traction control is performed according to the sand detection result (the setting result of the sand determination flag F). That is, if the sand determination flag F is 1, the upper limit engine torque _TL is set, and if the current engine torque is greater than the set upper limit engine torque _TL , the sand traction control is performed (step S21). → Step S22 → Step S23 → Step S24). That is, as the sand traction control, the actual engine torque is controlled so as not to exceed the upper limit engine torque _TL . Further, if the current engine torque is less than the upper limit engine torque T _L, without performing a process of reducing the actual engine torque to the upper limit engine torque T _L, the process ends (step S21 → step S22 → step S23 → process End). On the other hand, if the sand determination flag F is 0, normal traction control is performed (step S21 → step S25). In normal traction control, the drive torque is controlled based on the slip state of the wheels.

(Function and effect)
The action and effect are as follows.
As described above, when the throttle opening is larger than 0 and the stroke speed of the drive wheel is 0 or less (when the drive wheel is stretched at a certain speed), that is, the drive wheel corresponding to the driver's accelerator operation. Is driven, and when the stroke speed of the drive wheel becomes 0 or less, it is determined that the traveling path of the vehicle is sandy. This is because when the driving wheel starts to rotate in the sand (even when the rotation is less than one rotation), the driving wheel starts to sink into the sand. At this time, it changes at least in the direction in which the stroke of the drive wheel extends (including the fact that the stroke of the drive wheel does not change). In this way, the timing at which the drive wheel begins to sink immediately after the rotation is detected on condition that the stroke speed of the drive wheel driven in response to the driver's accelerator operation is 0 or less. ing. This enables detection of sandy ground at an early stage when the driving wheel starts to sink into the sandy ground or until the driving wheel is rotated once.

  Further, as described above, when the drive method is FF or FR, the travel path of the vehicle is also provided that the absolute value of the stroke speed of the driven wheel (| the stroke speed of the driven wheel |) is equal to or less than the threshold value A. Is determined to be sandy. As described above, when the road is sandy, the driving wheel sinks into the sand. However, for the driven wheel, it is difficult to transmit the driving wheel to the road surface (sandy). By reducing the load movement of the vehicle body, the change in the stroke speed becomes zero or almost zero. For this reason, even if the driving wheel starts to be driven in sand, the absolute value of the stroke speed of the driven wheel (| the stroke speed of the driven wheel |) is not more than the threshold value A, Judging sand. As a result, the sand can be detected with higher accuracy.

  Further, the threshold value A increases with the driving torque. This is because if the driving torque increases, the load movement of the vehicle body by driving the driving wheels increases, that is, the stroke speed of the driven wheels also shows some change. Therefore, by increasing the threshold value A together with the driving torque, it becomes possible to determine sandy ground based on such a situation. As a result, the sand can be detected with higher accuracy.

In addition, by setting threshold value A to be smaller than the stroke speed (absolute value) of the driven wheel that is obtained when traveling on a normal road surface such as an asphalt road surface (especially when starting), the asphalt road surface is erroneously determined to be sandy. Can be prevented.
As described above, in the sand traction control, the actual engine torque is controlled so as not to exceed the preset upper limit engine torque _TL . The upper limit engine torque _TL is a value that drives the drive wheels, but does not cause the drive wheels to slide against the sand or sink into the sand. Thus, since the upper limit engine torque _TL is set at the timing when the sand is detected, the traction control for the sand is immediately after detecting the sand, without slipping or sinking into the sand. It can be driven.

Further, the upper limit engine torque _TL increases with the vehicle body speed V. For example, when running on sand, it is preferable not to suppress the vehicle speed when the vehicle speed reaches a certain level. For example, if the vehicle is decelerated, there is a greater possibility that the drive wheels will sink into sand. For this reason, by increasing the upper limit engine torque _TL together with the vehicle body speed V, it is possible to realize sandy traction control based on such a situation.

FIG. 7 shows the relationship between the driving method (FF, FR, 4WD) and the stroke displacement (displacement direction) of the wheel.
As shown in FIG. 7, the stroke displacement of the drive wheel changes in the direction in which the stroke extends in the sand, regardless of the drive method.
Note that on road surfaces other than sand, such as asphalt road surfaces, the stroke displacement of the wheel located on the traveling side of the vehicle (for example, the front wheel in the case of a forward FF vehicle) changes in the direction in which the stroke extends, regardless of the driving method. The stroke displacement of the wheel located on the opposite side (for example, the rear wheel in the case of a forward FF vehicle) changes in the direction in which the stroke contracts. This is because load movement occurs in the vehicle due to a change in driving force.

  For example, the travel route can be determined based on the relationship shown in FIG. In this case, vehicle traveling direction determining means for determining the traveling direction of the vehicle, wheel vertical movement detecting means for detecting the vertical movement of the wheel relative to the vehicle body, the determination result of the vehicle traveling direction determining means, and the wheel vertical movement detection Traveling road state determination means for determining the traveling road state of the vehicle based on the detection result of the means, the traveling road state determination means for the vehicle traveling direction side wheel determined by the traveling direction determination means The wheel vertical movement detecting means detects the downward movement, and the wheel vertical movement detecting means detects the upward movement of the wheel on the opposite side of the vehicle traveling direction determined by the traveling direction determining means. If detected, it is determined that the road of the vehicle is a road surface other than sandy land, specifically, a road surface having a road surface friction coefficient larger than that of the sandy land. Otherwise, it is determined that the vehicle road is sandy. . Here, the vehicle traveling direction determination means and the travel path state determination means are realized by the ABS / TCS control unit 11, and the wheel vertical movement detection means is realized by the stroke sensors 28 to 31.

FIG. 8 shows a change with time in the driving torque (engine torque) T ((a) in the figure) and a change with time in the vehicle body speed V ((b) in the figure) when the vehicle is started on sand. . In FIG. 8, the solid line shows the result obtained by applying the present invention (sandy traction control), and the dotted line shows the result of the conventional (normal traction control).
As shown in FIG. 6A, in the prior art (dotted line), after the drive torque T reaches a certain value (drive torque that slips) (B region shown in the figure), the drive torque T is suppressed. In other words, when a slip of the drive wheel is detected when the drive torque T is increased according to the drive torque (driver request torque) when requested by the driver, the drive torque T is decreased. On the other hand, when the present invention is applied (solid line), it is instantaneously detected as sand when starting, and the driving torque T is controlled using the set upper limit engine torque _TL as an upper limit value.

Corresponding to such a change in the driving torque T, as shown in FIG. 5B, the vehicle body speed V is once increased (B region shown in FIG. 2) in the prior art (dotted line). In contrast, when the present invention is applied (solid line), the vehicle body speed V gradually increases immediately after starting without showing such an increase.
In addition, the said embodiment can also be implement | achieved by the following structures.
That is, in the said embodiment, the movement of the up-down direction of a wheel is obtained based on the stroke speed of a wheel. On the other hand, the downward movement of the wheel can be obtained based on the stroke amount (displacement amount) and the stroke acceleration (displacement acceleration) of the wheel. In addition, the movement of the wheel can be detected by a detection other than the stroke sensor.

  Further, in the above-described embodiment, when the stroke speed of the drive wheel is 0 or less, that is, when the drive wheel is displaced in the direction in which the stroke extends, it is determined that the traveling path of the vehicle is sand. On the other hand, it is also possible to determine that the travel path of the vehicle is sandy ground, provided that the stroke speed is 0 or less and the stroke speed (absolute value) is a certain level.

  In the description of the above embodiment, the processing in step S1 of the ABS / TCS control unit 11 realizes driving state detecting means for detecting the driving state of the driving wheels, and the stroke sensors 28 to 31 are used for the vehicle body. A drive wheel vertical motion detection means for detecting the vertical displacement of the drive wheel is realized, and the drive state detection means drives the processing of step S3 and step S4 or step S6 and step S7 of the ABS / TCS control unit 11. When detecting that the wheel has been driven, and when the driving wheel vertical movement detecting unit detects a downward displacement of the driving wheel, a sandy land determining unit is provided that determines that the traveling path of the vehicle is sandy. ing.

Further, the stroke sensors 28 to 31 implement driven wheel vertical movement determining means for determining the vertical movement of the driven wheel with respect to the vehicle body.
The ABS / TCS control unit 11 realizes drive control means for controlling the drive state of the drive wheels, and the processing in step S21 of the ABS / TCS control unit 11 is a travel road that detects the travel road state of the vehicle. The state detection means is realized, and the processing of steps S22 to S24 of the ABS / TCS control unit 11 is performed when the drive control means detects that the travel path state detection means is a sand road. The driving torque is controlled so that the driving torque of the driving wheel does not exceed a threshold value set to a driving torque equivalent so that the driving wheel does not slip with respect to sand.

(Second Embodiment)
Next, a second embodiment will be described.
(Constitution)
The second embodiment includes a switch for manually turning on and off the operation of the traction control for sandy land. In other words, in the first embodiment, when the road condition of the vehicle is detected based on the detection value of the stroke sensor and the sand is detected, the traction control for the sand is activated. In the second embodiment, the sand traction control is operated manually by the driver.

FIG. 9 shows the configuration of the vehicle of the second embodiment.
As shown in FIG. 9, the basic configuration of the vehicle of the second embodiment is the same as the configuration of the vehicle of the first embodiment shown in FIG. 1, but in the vehicle of the second embodiment, In particular, a switch 41 for manually operating the sand traction control operation is provided. In the following description, in the vehicle of the second embodiment, the same reference numerals as those of the vehicle of the first embodiment are the same unless otherwise specified.

FIG. 10 shows a processing procedure in the vehicle of the second embodiment.
The basic part of the processing procedure in the second embodiment shown in FIG. 10 is the same as the processing procedure in the first embodiment shown in FIG. 1, but in the processing of the second embodiment, in particular, Step S31 is provided instead of step S21. In the following description, in the process of the second embodiment, the same reference numerals as those of the process of the first embodiment are the same unless otherwise specified.

  In step S31, it is determined whether or not the switch 41 is turned on. If the switch 41 is turned on, the process proceeds to step S22. If the switch 41 is not turned on (in the off state), the process proceeds to step S25. The processing after step S22 or the processing after step S25 is the same processing as in the first embodiment.

(Operation)
Thereby, particularly in the second embodiment, when the switch 41 is turned on by the driver, the upper limit engine torque _TL is set, and if the current engine torque is larger than the set upper limit engine torque _TL. Then, sand traction control is performed (step S31 → step S22 → step S23 → step S24). On the other hand, when the switch 41 is off, normal traction control is performed (step S31 → step S25).

(Function and effect)
Thereby, the operation state of the traction control for sandy land can be turned on and off by manual operation by the driver, and the traction control for sandy land can be operated in accordance with the driver's feeling. As a result, for example, even in a situation where sand cannot be detected based on the detection value of the stroke sensor, traction control for sand can be activated at the discretion of the driver. The traction control for sandy ground can be activated.

In the second embodiment, the switch 41 is provided instead of the stroke sensor (see FIG. 9), but the stroke sensor and the switch 41 may be provided at the same time. Thereby, for example, the sand is detected based on the detection value of the stroke sensor, the traction control for the sand is activated, and then the switch 41 is operated at the judgment of the driver, whereby the traction control for the sand is performed. Can be turned off. Thereby, the operating state of the traction control for sand can be matched with the driver's feeling.
In the description of the second embodiment, the switch 41 realizes an operating means for manually turning on and off the operation state of the control by the drive control means.

1 is a schematic configuration diagram illustrating a configuration of a vehicle according to a first embodiment of the present invention. It is a flowchart of the arithmetic processing for the sand detection by an ABS / TCS control unit. It is the figure used for description of stroke speed. FIG. 6 is a characteristic diagram showing a relationship between drive torque (engine torque) and threshold value A. A procedure of arithmetic processing for traction control by the ABS / TCS control unit will be described. FIG. 6 is a characteristic diagram showing a relationship with an upper limit engine torque _TL according to a vehicle body speed V. It is a characteristic view which shows the relationship between a drive system and the stroke displacement of a wheel. The time-dependent change ((a)) of the drive torque T and the time-dependent change ((b)) of the vehicle body speed V when the vehicle is started on sandy ground are shown. It is a schematic block diagram which shows the structure of the vehicle of the 2nd Embodiment of this invention. The procedure of the arithmetic processing for the traction control by the ABS / TCS control unit in the second embodiment will be shown.

Explanation of symbols

1 engine, 2 automatic transmission, 3 and 4 are drive shafts, 5 and 6 front wheels (drive wheels),
7, 8 Rear wheel (driven wheel), 9 Throttle valve, 10 Throttle control motor, 11 ABS / TCS control unit, 12, 13 Wheel speed sensor, 14, 15 Wheel speed sensor, 20 Engine control unit, 21 Automatic transmission control Unit, 23 engine speed sensor, 28-31 stroke sensor, 41 switch

Claims (10)

Drive state detection means for detecting the drive state of the drive wheels;
Driving wheel vertical movement detecting means for detecting vertical movement of the driving wheel relative to the vehicle body;
When the driving state detecting means detects that the driving wheel is driven, and the driving wheel vertical movement detecting means detects the downward movement of the driving wheel, it is determined that the traveling path of the vehicle is sand. A sandy land judgment means,
A travel path determination device comprising:   Driven wheel vertical movement determining means for determining vertical movement of the driven wheel with respect to the vehicle body, and the sandy land determining means is configured to detect the driven wheel when the driving state detecting means detects that the driving wheel is driven. The travel path determination device according to claim 1, wherein when the vertical movement determination means determines that the position of the driven wheel is maintained in the vertical direction, the travel path of the vehicle is determined to be sand.   The drive wheel vertical movement detecting means detects a downward movement of the drive wheel based on at least one of a vertical displacement speed and a displacement acceleration of the drive wheel. The travel path determination device according to claim 1 or 2.   The driven wheel vertical movement determining means, when at least one of the displacement speed and displacement acceleration in the vertical direction of the driven wheel is less than a threshold set corresponding to the displacement speed or displacement acceleration, The travel path determination device according to claim 2, wherein it is determined that the position of the driven wheel is maintained in the vertical direction.   The travel path determination device according to claim 4, wherein the threshold value is increased as the vehicle speed increases. Drive control means for controlling the drive state of the drive wheels;
Road state detecting means for detecting the road state of the vehicle, and
The drive control means sets the drive torque of the drive wheels to be equivalent to the drive torque so that the drive wheels do not slip with respect to the sand when the travel path state detection means detects that the travel path is sand. A drive control device for a vehicle, wherein the drive torque is controlled so as not to exceed a threshold value.   The travel path state detecting means includes a driving state detecting means for detecting a driving state of the driving wheel, a driving wheel vertical movement detecting means for detecting a vertical movement of the driving wheel, and the driving state detecting means includes a driving wheel. And a sandy land judging means for judging that the traveling path of the vehicle is sandy when the driving wheel vertical movement detecting means detects a downward movement of the driving wheel. The vehicle drive control device according to claim 6.   The vehicle drive control device according to claim 6 or 7, wherein the threshold value is increased as the vehicle speed increases. Drive control means for controlling the drive torque so that the drive torque of the drive wheel does not exceed a threshold value set corresponding to the drive torque so that the drive wheel does not slip with respect to the sand;
Operation means for manually turning on and off the operation state of the control by the drive control means;
A vehicle drive control device comprising: When it is determined that the road is sandy, the driving torque of the driving wheel is controlled so that the driving torque of the driving wheel does not exceed a preset threshold corresponding to the driving torque so that the driving wheel does not slip with respect to the sandy ground. A vehicle drive control method.

Images