JPH06289039A - Slip degree calculation device for vehicles - Google Patents

Abstract

PURPOSE:To obtain an exact slip degree even in turning time by providing a wheel revolution speed detection means, a drive wheel speed caculation means, an idle wheel speed calculation means, a slip degree calculation means, an abnormality judgment means and a revolution speed changing means. CONSTITUTION:With a wheel revolution speed detection means M1, the revolution speeds of a driving wheel and a idle wheel are detected and input to a drive wheel speed calculation means M2 and a floating wheel speed calculation means M3. In the means M2, the drive wheel speed is obtained based on the revolution speeds of left and right drive wheels. Also in the means M3, idle wheel speed is obtained based on the revolution speeds of left and right idle wheels. The drive wheel speed and the idle wheel speed from the calculation means M2 and M3 are input to a slip degree calculation means M4 and a slip degree is calculated. An abnormality judgment means M5 outputs to the means M4, the wheel speed of the drive wheel or the idle wheel of the opposit side one judged abnormal in revolution speed of either of drive wheel or idle wheel output from the means M1. The means M4 calculates a slip degree by using the wheel speed instead of the drive or idle speeds.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slip amount calculating device for a vehicle used to eliminate slip of driving wheels, and more particularly to calculating a slip amount when a rotational speed sensor becomes abnormal. Regarding means.

[0002]

2. Description of the Related Art Conventionally, there has been known a vehicle driving force control device for slip control based on a road surface condition (Japanese Patent Laid-Open No. 58-38347). This vehicle driving force control device, on a low μ road surface such as a snow road or asphalt road surface wet with rain, when the slip amount based on the drive wheel and the idle wheel is determined to be a predetermined value or more, engine output control, The slip of the driving wheels is eliminated by executing the driving force control such as the switching control of the shift stage of the transmission and the ignition timing control.

In such a driving force control device, rotation speed sensors are provided for the left and right drive wheels and the idle wheel respectively, and the average rotation speed of the left and right drive wheels and the average of the left and right idle wheels are determined from the detected values of the rotation speed sensors. The rotational speed and the average rotational speed are respectively calculated, and the slip amount is calculated based on the difference between the average rotational speeds. The use of the slip amount calculated based on the average rotational speed of the left and right wheels is characterized in that stable control can be performed even in the case of a so-called straddling road in which only one wheel rides on a low μ road surface.

Further, in the above drive force control device, as a fail-safe measure for the rotation speed sensor, when any one of the rotation speed sensors becomes abnormal, normal rotation on the opposite side of the abnormal rotation speed sensor is performed. The detection value of the speed sensor is used. For example, when the right front wheel fails, the slip amount is calculated from the rotation speed of the left front wheel and the rotation speed of the left front wheel and the average rotation speed of the left and right rear wheels.

[0005]

However, the above slip amount calculation method has a problem that an accurate slip amount cannot be calculated during turning. For example, when a sensor on the inner ring side of the rotation speed sensors that detects the rotation speed of the idle wheel becomes abnormal, the rotation speed on the outer ring side is higher than the average rotation speed, and therefore, the rotation speed on the outer ring side and the drive speed When the slip amount is calculated based on the average rotation speed of the wheels, the slip amount is calculated too small.

When the rotation speed sensor on the outer wheel side of the idle wheel becomes abnormal, the rotation speed of the rotation speed sensor of the inner wheel is smaller than the average rotation speed, and therefore the slip amount is calculated excessively.

On the other hand, when the rotational speed sensor on the drive wheel side becomes abnormal, the slip amount is calculated to be excessive due to the abnormality of the inner wheel sensor, and the slip amount is calculated to be excessive due to the abnormality of the outer wheel sensor. As described above, when the wheel rotation speed sensor becomes abnormal during turning, an appropriate slip amount cannot be obtained, and as a result, optimum driving force control cannot be performed.

The present invention solves the above-mentioned problems of the prior art. Even if one or more of the rotational speed detecting means becomes abnormal during turning, the slip amount of the vehicle can be accurately determined. An object is to provide an arithmetic unit.

[0009]

DISCLOSURE OF THE INVENTION The present invention, which has been made to solve the above-mentioned problems, provides a vehicle slip amount calculating apparatus for calculating a slip amount between a drive wheel and an idle wheel as shown in FIG. Wheel rotation speed detection means M1 for detecting the rotation speeds of the wheels and idle wheels, and a drive wheel speed representative of the drive wheels based on the rotation speeds of the left and right drive wheels among the rotation speeds from the wheel rotation speed detection means M1. Driving wheel speed calculating means M2 for calculating
Slip based on the driving wheel speed and the idler wheel speed, and the idler wheel speed calculating means M3 for calculating the idler wheel speed representing the idler wheel based on the rotational speeds of the left and right idler wheels among the rotation speeds from 1. A slip amount calculating means M for calculating the amount
4 and the abnormality determination means M5 for determining abnormality of the wheel rotation speed detection means based on the rotation speed of the wheel rotation speed detection means M1 and the wheel rotation speed detection means M1 by the abnormality determination means M5. When is determined to be abnormal, the rotational speeds of the idler wheel and the drive wheel opposite to the idler wheel or the drive wheel determined to be abnormal are obtained,
Rotational speed changing means M6 for changing and setting both rotational speeds to the drive wheel speed and idle wheel speed of the slip amount calculating means M4.
And are provided.

[0010]

In the present invention, the wheel rotation speed detecting means M1 detects the rotation speeds of the drive wheel and the idle wheel, respectively, and inputs them to the drive wheel speed calculating means M2 and the idle wheel speed calculating means M3. The drive wheel speed calculation means M2 calculates the drive wheel speed based on the rotation speeds of the left and right drive wheels, and the idle wheel speed calculation means M3 calculates the idle wheel speed based on the rotation speeds of the left and right idle wheels. The drive wheel speed and the idle wheel speed can be, for example, the average speed of the left and right wheels.
Drive wheel speed calculation means M2 and idle wheel speed calculation means M3
The driving wheel speed and the idle wheel speed are input to the slip amount calculating means M4, and the slip amount is calculated.

When the abnormality determining means M5 determines that the rotational speed of either the drive wheel or the idle wheel output from the wheel rotational speed detecting means M1 is abnormal, the rotational speed changing means M6 determines The wheel speed of the drive wheel or idler wheel opposite to the drive wheel or idler wheel determined to be abnormal is output to the slip amount calculating means M4. The slip amount calculating means M4 calculates the slip amount by using these wheel speeds instead of the driving wheel speed and the idle wheel speed.

Therefore, when any one or more of the wheel rotation speed detecting means M1 becomes abnormal, a highly accurate slip amount is calculated by comparing the rotation speeds of the inner wheels or the outer wheels even during turning. To be done.

[0013]

Preferred embodiments of the present invention will be described below in order to further clarify the structure and operation of the present invention described above.

FIG. 2 is a schematic configuration diagram showing a vehicle system in which the driving force control device according to one embodiment of the present invention is applied to a front engine / rear drive (FR type) automobile. As shown in FIG. 2, in the vehicle system, the rotational driving force of the engine 11 is the transmission 13 and the propeller shaft 1.
4, transmitted to the right drive wheel 22 and the left drive wheel 24 via the rear differential gear 16 and the rear drive shaft 18. The right idle wheel 26 and the left idle wheel 28 are non-driving wheels.

A throttle valve 36 mechanically connected to an accelerator pedal 38 is provided in the intake pipe 32 of the engine 11 and is electrically driven by a sub-throttle actuator 44 on the upstream side of the throttle valve 36. A sub-throttle valve 42 is provided.

Further, the vehicle system is provided with various sensors, that is, a vehicle speed sensor 50 for detecting the rotational speed of the output shaft of the transmission 13 and a right sensor for detecting the rotational speed of the right drive wheel 22. A rear wheel rotation speed sensor 52, a left rear wheel rotation speed sensor 54 that detects the rotation speed of the left drive wheel 24,
A front right wheel rotation speed sensor 56 for detecting the rotation speed of the right idle wheel 26 and a left front wheel rotation speed sensor 58 for detecting the rotation speed of the left idle wheel 28 are provided respectively. Further, the brake pedal 73 is provided with a foot switch 72 for detecting the stepped state thereof.

Further, the engine 11 has a crank angle sensor 66 for detecting the number of revolutions thereof and a throttle valve 36.
There is provided a main throttle position sensor 62 having an idle switch 61 for detecting the opening of the sub throttle valve 42 and an opening of the sub throttle valve 42 for detecting the opening of the sub throttle valve 42.

Further, in the present vehicle system, as a switch and an indicator, a slip control instruction switch for instructing an opening control of a sub-throttle valve, which will be described later, is provided on an instrument panel in the vehicle compartment as shown in FIG. 76, a slip control instruction indicator 82 for displaying the switch operating state, a slip control operation indicator 84 for indicating that the slip control is being performed, and the like are provided.

The detection signals of the above-mentioned sensors and the signals of the switches are sent to the electronic control unit (hereinafter referred to as ECU) shown in FIG.
100 is input. The ECU 100 is configured as a logical operation circuit centered on a microcomputer, and more specifically, the CPU 10 that executes various kinds of arithmetic processing relating to slip control and the like according to a preset control program.
2 and an RO in which a control program and control data necessary for the CPU 102 to execute various arithmetic processes are stored in advance.
M104 and R, in which various data necessary for executing various arithmetic processes in the CPU 102 are temporarily read and written
The AM 106, the backup RAM 108 that can retain data even when the power is off, the common bus 109 that connects them, the input processing circuit 110 that processes the detection signals from the sensors and the signals from the switches, and the sub throttle actuator 44. An output processing circuit 120 for outputting a drive signal and the like is provided.

The ECU 100 includes rotation speed sensors 52 to 5
8 and various detection signals from the main throttle position sensor 62, the slip amount S is calculated based on these detection signals, and the sub-throttle actuator 44 is given priority over the throttle valve 36 based on the calculation result.
To control. Further, the ECU 100 executes the calculation as the slip amount S corresponding to the abnormality of the rotation speed sensors 52 to 58.

Next, the ECU 10 constructed as described above
The engine output control process executed by the CPU 102 of No. 0 will be described in detail with reference to the flowcharts of FIGS. 4 to 7.

FIG. 4 is a flow chart for explaining the sub throttle valve opening control process, FIG. 5 is a flow chart for explaining the slip control condition judging process, FIG. 6 is a flow chart for explaining the rotational speed sensor abnormality judging process, and FIG. 7 is a flowchart illustrating a slip amount calculation process.

The ECU 100 executes the main routine shown in FIG.
The opening control processing of the sub-throttle valve shown in is executed. The opening control process of the sub-throttle valve is repeatedly executed at an interrupt every predetermined time (for example, several ms). First, after initialization of various flags, etc., in step 105, detection signals and various data of the main throttle position sensor 62, the sub throttle position sensor 64, etc. are read. In the following step 110, it is determined whether or not the slip control flag FMU is 1. The slip control in-progress flag FMU is a flag that is set to 1 or 0 according to the satisfaction of the slip control start condition or the cancellation condition in the process of FIG.

When it is determined in step 110 that the slip control flag FMU is 0, step 115
At, the high μ road surface map that defines the opening control conditions of the sub-throttle valve 42 corresponding to the high μ road surface is read.
On the other hand, when it is determined in step 110 that the slip control flag FMU is 1, the low μ road surface map that defines the opening control condition of the sub-throttle valve 42 corresponding to the low μ road surface is read in step 120. Be done. The high μ road surface map is a map that defines the normal opening control state of the sub-throttle valve 42, and the low μ road surface map is
This is a map in which the opening range of the sub-throttle valve 42 is restricted to about 30 ° or less and the opening / closing speed of the sub-throttle valve 42 is set to be slower than the high μ road surface map.

Next, in step 125, the above step 1
The target throttle opening degree of the sub-throttle valve 42 and the opening / closing speed when controlling to the target throttle opening degree are obtained based on the detection signal of 05, various data, and the map of either step 115 or step 120. In the following step 130, the output control of the engine 11 is executed by outputting a drive signal to the sub-throttle actuator 44 based on the target throttle opening degree and its opening / closing speed obtained in step 125. As a result, when it is determined that the road surface is high μ, excellent acceleration performance is obtained with normal driving force, while when the road surface is low μ, the engine 11 is driven by controlling the opening of the sub-throttle valve 42. The output is suppressed and the slip is eliminated.

Next, the slip control condition determination process of FIG. 5 will be described. This process takes a predetermined time (for example, 32 m
It is repeatedly executed every s). First, the control inhibition flag FX1 is determined in step 205, the control inhibition flag FX2 is determined in step 210, the idle control flag FID is determined in step 215, and the brake flag FST is determined in step 220. The above-mentioned control prohibition flag FX1 indicates that the driver has slip control instruction switch 76
Is a flag that is set to 1 when is set to OFF, and the control prohibition flag FX2 is a flag that is set to 1 when any of the rotation speed sensors 52 to 58 has a main abnormality in the processing of FIG. 6 described later. Yes, the idle control flag FID is a flag that is set to 1 when the idle switch 61 is turned on, and the brake flag FST is the foot switch 7 that operates when the brake pedal 73 is depressed.
This is a flag that is set to 1 when 2 is on.

If the determinations at steps 205 to 220 are all affirmative, the routine proceeds to step 225. In step 225, the slip control flag FMU is determined. The slip control in-progress flag FMU is set to 1 when the slip control start condition is satisfied, that is, when the low μ road surface is determined, and when the slip control cancellation condition is satisfied, that is, when the high μ road surface is determined. This flag is set to 0. When it is determined in this step 225 that the slip control flag FMU is 0, step 23
When the start condition is satisfied, it is determined whether the slip control start condition is satisfied or not.
At 5, the slip control flag FMU is set to 1.
On the other hand, in step 225, the slip control flag FMU
When it is determined that is 1, the process proceeds to step 240,
It is determined whether or not the slip control cancellation condition is satisfied, and when the cancellation condition is satisfied, the slip control flag FMU is set to 0 in step 245.

In the determination process of the satisfaction of the slip control start condition in the above step 230, for example, it is determined by the following equation (1) whether the slip amount S is a predetermined value or more. VWRM-VWFM ≧ max (10 km / h, VWFM × 0.10) (1) VWRM: Drive wheel control rotation speed VWFM: Idling wheel control rotation speed

Here, the drive wheel control rotational speed VWRM and the idle wheel control rotational speed VWFM are obtained by the processing of FIG. VWFM x 0.10 is the idle wheel control rotation speed VWFM
Means a rotation speed of 10%. max means a function that takes the maximum value of the two values in any one of the parentheses.
Therefore, when the difference between the drive wheel control rotation speed VWRM and the idle wheel control rotation speed VWFM is 10 km / h or more, or when the slip amount S is 10% or more of the idle wheel control rotation speed VWFM, an affirmative determination is made, and the routine proceeds to step 235. After the shift, the slip control flag FMU is set to 1.

On the other hand, in the step 240 for determining whether or not the slip control cancellation condition is satisfied, for example, when the drive wheel control rotational speed VWRM is a predetermined value (for example, 5 km / h) or more, the main throttle opening is more than a predetermined value. And the slip amount S satisfies the condition of the following expression (2), it is determined that the slip control cancellation condition is satisfied. VWRM-VWFM <max (5 km / h, VWFM × 0.05) (2)

The slip control flag FMU set in steps 235 and 245 of the process of FIG. 5 is used to determine whether or not the sub throttle valve opening control is executed in the process of FIG. 4 as described above. used.

When the control prohibition flag FX1 is set to 1 in step 205, that is, when the driver turns off the slip control instruction switch 76, and in step 210 the control prohibition flag FX2 is set to 1. If so, that is, if one of the rotation speed sensors 52 to 58 has this abnormality, the routine proceeds to step 250, where the slip control flag FMU is set to zero.

Next, the calculation process of the slip amount S shown in FIG. 7 used for the determination of the slip control start condition of step 230 and the determination of the slip control cancellation condition of step 240 will be described. In this processing, the rotation speed sensor 52
Since different slip amounts S are calculated depending on the abnormalities of ~ 58, first, the abnormality determination processing of the rotation speed sensors 52-58 of Fig. 6 will be described. The rotation speed sensor 52 to
The abnormality determination process of 58 is performed by performing the same process for each wheel at predetermined time intervals, and therefore the right rear wheel rotation speed sensor 52 will be described as a representative.

In the abnormality determination processing of the right rear wheel rotation speed sensor 52 shown in FIG. 6, first, at step 305, it is determined that the signal from the foot switch 72 is off, that is, the accelerator pedal 38 is not depressed. Then, in step 310, the estimated vehicle speed VB (= max (VWFR, VWF
L) or max (VWFR, VWFL, VWRR, VWR
L)) is determined to be 15 km / h or more and the right rear wheel speed VWRR is determined to be 0 km / h in step 315, the temporary abnormality flag FYRR is determined in step 320.
Is set to 1. In the following step 325, the counter C3 is incremented. And step 30
If it is determined in step 330 that the conditions of 5 to step 315 have continued for the predetermined time CC (for example, 10 ms) or more in step 330, the control prohibition flag FX2 indicating this abnormality is set to 1 in step 335. Set to.

In this step 335, the control prohibition flag FX2 is set and stored in a predetermined address for diagnosis in the backup RAM 108, and an abnormal state of the right rear wheel rotation speed sensor 52 is notified at the time of failure inspection. .

On the other hand, if the abnormality determination conditions in steps 305 to 315 are not satisfied, the temporary abnormality flag FYRR is reset and the counter C3 is cleared in step 340.

Next, the process of obtaining different slip amounts S according to the abnormality of the rotation speed sensors 52 to 58 will be described in detail with reference to the flowchart of FIG. In FIG. 7, first, at step 401, the wheel speeds VWFR, VWFL, VWRR and VWRL of the rotation speed sensors 52 to 58 are read. Following Step 402 to Step 426
Up to the temporary abnormality flags FYFR, FYFL, FYRR, F which are set based on the abnormality of each of the rotation speed sensors 52 to 58.
The determination of YRL is executed, and based on the determination result, the drive wheel control rotational speed VWRM and the idle wheel control rotational speed VWFM are calculated in any of steps 430 to 470, and the slip amount S is obtained in step 480. To be Here, the temporary abnormality flags FYFR, FYFL, FYRR,
FYRL is set to 0 when the rotation speed sensors 52 to 58 are normal, and is set to 1 when they are abnormal.

Steps 402 to 426,
In the processing from step 430 to step 480, the control No. 1 in FIG. 1-No. The drive wheel control rotational speed VWRM, the idle wheel control rotational speed VWFM, and the slip amount S corresponding to the combination of the temporary abnormality flags FYFR, FYFL, FYRR, FYRL as shown in 9 are obtained.

Hereinafter, steps 402 to 480
Up to the control No. 1-No. It demonstrates in order of 8. First, the control No. 1 is a temporary abnormality flag FYFR, FY
This shows a case where FL, FYRR, and FYRL are all 0, that is, the rotation speed sensors 52 to 58 are all normal.
In this case, the process proceeds to step 430 through step 402 → step 404 → step 406 → step 408.

At step 430, the drive wheel control rotational speed VWRM and the idle wheel control rotational speed VWFM are calculated by the following equations (3) and (4), respectively. VWRM = (VWRR + VWRL) / 2 (3) VWFM = (VWFR + VWFL) / 2 (4) That is, the average value of the right rear wheel speed VWRR and the left rear wheel speed VWRL is set as the drive wheel control rotational speed VWRM, and the right front wheel is used. The average value of the speed VWFR and the left front wheel speed VWFL is set to the idle wheel control rotation speed VWF.
Let's say M.

In the following step 480, step 430
The slip amount S is calculated by the following equation (5) using the drive wheel control rotation speed VWRM and the idle wheel control rotation speed VWFM obtained in step S4. S = VWRM-VWFM (5)

That is, when all the rotation speed sensors 52 to 58 are normal, the slip amount S is calculated based on the difference between the average values of the left and right front wheels and the left and right rear wheels.

Control No. 2 indicates that the temporary abnormality flag FYFR is 1
And the temporary abnormality flags FYFL and FYRL are 0,
That is, the right front wheel rotation speed sensor 56 is abnormal, and the left front wheel rotation speed sensor 58 and the left rear wheel rotation speed sensor 5 are included.
4 shows the case where it is normal. In this case, step 4
The process proceeds from 02 → step 414 → step 418 to step 440.

In step 440, the left rear wheel speed VWRL is added to the drive wheel control rotational speed VWRM and the idle wheel control rotational speed VWFM.
The left front wheel speed VWFL is respectively substituted into. In the following step 480, the slip amount S is the drive wheel control rotation speed VWR.
It is calculated based on M and the idle wheel control rotation speed VWFM. That is, the slip amount S is obtained by the difference between the left front wheel speed VWFL and the left rear wheel speed VWRL when the right front wheel rotation speed sensor 56 becomes abnormal.

Control No. 3 is a temporary abnormality flag FYFR, F
A case where YFL is 1 (that is, the right front wheel rotation speed sensor 56 and the left front wheel rotation speed sensor 58 are abnormal) is shown. In this case, step 402 → step 41
After 4, the process proceeds to step 450. In step 450, slip control stop processing is executed.

As the slip control stop processing, for example, processing in which the idle wheel control rotational speed VWFM in the previous processing is maintained for a predetermined time and then the slip amount S is gradually changed to 0 can be performed.

Control No. 4, the temporary abnormality flag FYFR is 0, the temporary abnormality flag FYFL is 1, and the temporary abnormality flag FYRR is 0.
In other words, the case where the right front wheel rotation speed sensor 56 and the right rear wheel rotation speed sensor 52 are normal, and the left front wheel rotation speed sensor 58 is abnormal is shown. In this case, the process proceeds from step 402 → step 404 → step 426 to step 460. In step 460, the right rear wheel speed VWRR is substituted into the drive wheel control rotational speed VWRM, and the right front wheel speed VWFR is substituted into the idle wheel control rotational speed VWFM. In the following step 480, the slip amount S is calculated. That is, the slip amount S is calculated by the difference between the right rear wheel speed VWRR and the right front wheel speed VWFR when the left front wheel rotation speed sensor 58 becomes abnormal.

Control No. 5, the temporary abnormality flag FYFR is 0
And if the temporary abnormality flags FYFL and FYRR are 1,
That is, a case is shown in which the right front wheel rotation speed sensor 56 is normal, and two sensors located diagonally to the left front wheel rotation speed sensor 58 and the right rear wheel rotation speed sensor 52 are abnormal. In this case, step 402 → step 404 →
After step 426, the process proceeds to step 470. In step 470, the same slip control stop processing as in step 450 is executed.

Control No. 6 is a temporary abnormality flag FYFR, F
When YFL and FYRL are 0 and the temporary abnormality flag FYRR is 1, that is, the right front wheel rotation speed sensor 56, the left front wheel rotation speed sensor 58, and the left rear wheel rotation speed sensor 54 are normal, and the right rear wheel rotation speed sensor. The case where 52 is abnormal is shown. In this case, the process proceeds from step 402 → step 404 → step 406 → step 418 to step 440.
Go to. Therefore, the processing of step 440 described above is executed, and the left rear wheel speed VWRL is added to the drive wheel control rotation speed VWRM.
The left front wheel speed VWFL is substituted into the idle wheel control rotation speed VWFM. In the following step 480, the slip amount S is the drive wheel control rotation speed VWRM and the idle wheel control rotation speed V.
Calculated based on WFM.

Control No. 7 is a temporary abnormality flag FYFR, F
When YFL is 0 and the temporary abnormality flags FYRR and FYRL are 1, that is, the right front wheel rotation speed sensor 56 and the left front wheel rotation speed sensor 58 are normal, and the right rear wheel rotation speed sensor 5
2, the case where the left rear wheel rotation speed sensor 54 is abnormal is shown. In this case, the process proceeds to step 402 → step 404 → step 406 → step 418 → step 450, and the slip control is stopped.

As a slip control stopping process, the drive wheel control rotational speed VWRM is set to the idle wheel control rotational speed VWFM. As a result, the slip amount S calculated in step 480 becomes 0 and the slip control is stopped.

Control No. 8 is a temporary abnormality flag FYFR, F
When YFL and FYRR are 0 and the temporary abnormality flag FYRL is 1, that is, the right front wheel rotation speed sensor 56, the left front wheel rotation speed sensor 58, and the right rear wheel rotation speed sensor 52 are normal, and the left rear wheel rotation speed is The case where the sensor 54 is abnormal is shown. In this case, step 402 → step 404
→ Step 406 → Step 408 and then Step 46
0, drive wheel control rotation speed VWRM to right rear wheel speed VWRR
However, the right front wheel speed VWFR is substituted into the idle wheel control rotation speed VWFM. Based on the drive wheel control rotation speed VWRM and the idle wheel control rotation speed VWFM, step 480
The slip amount S is calculated at.

Control No. 9 is a temporary abnormality flag FYFR, F
The case where YRL is 1 and the temporary abnormality flag FYFL is 0, that is, the case where the sensors located diagonally to the right front wheel rotation speed sensor 56 and the left rear wheel rotation speed sensor 54 are abnormal is shown. In this case, step 402 → step 41
4 → Go to step 450 through step 418. In step 450, the above-mentioned slip control stop processing is executed.

Therefore, the front right wheel rotation speed sensor 56
Alternatively, if any of the right rear wheel rotation speed sensor 52 becomes abnormal (control No. 2, control No. 6), only the detection values of the left front wheel rotation speed sensor 58 and the left rear wheel rotation speed sensor 54 are detected. Since the slip amount S is obtained, an accurate calculated value can be obtained as the slip amount S without causing an error due to the rotational speed difference between the inner and outer wheels as described in the related art even during turning. .

Further, when turning, the left front wheel rotation speed sensor 58
Alternatively, when any of the left rear wheel rotation speed sensor 54 becomes abnormal (control No. 4, control No. 8), the right front wheel rotation speed sensor 56 and the right rear wheel rotation speed sensor 52 are also included.
An accurate slip amount S can be obtained from the detected value of.

Therefore, even if one of the rotation speed sensors 52 to 58 fails, an accurate slip amount S can be obtained even during turning, and based on this slip amount S, an appropriate value for the sub-throttle valve 42 can be determined. Slip control can be performed.

Further, when both the left front wheel rotation speed sensor 58 and the right rear wheel rotation speed sensor 52 become abnormal (control No. 5), the right front wheel rotation speed sensor 56 and the left rear wheel rotation speed sensor 54 are operated. If both are abnormal (control No. 9), the slip control is stopped, and therefore the excessive or excessive slip amount S is not calculated.

Further, the right front wheel rotation speed sensor 56 and the left front wheel rotation speed sensor 58 become abnormal at the same time (control No. 3), or the right rear wheel rotation speed sensor 52 and the left rear wheel rotation speed sensor 54 become abnormal at the same time. If it happens (control No. 7), the slip control is immediately stopped.
Safety is further enhanced.

In the above embodiment, the rotation speed sensor 5
Although the opening degree control processing of the sub-throttle valve 42 has been described based on the calculation result of the slip amount S corresponding to the abnormalities 2 to 58, the calculation result of the slip amount S is used for acceleration slip control, brake control, fuel cut control, It can be used for various vehicle driving force controls such as transmission shift control and ignition timing control.

[0060]

As described above, according to the vehicle slip amount calculating apparatus of the present invention, the abnormality determining means determines that the rotational speed of either the drive wheel or the idle wheel output from the wheel rotational speed detecting means is abnormal. If it is determined that there is, the wheel speed of the drive wheel or idler wheel on the side opposite to the drive wheel or idler wheel determined to be abnormal is determined, and the slip amount is calculated based on these wheel speeds. Therefore, when any one or more of the wheel rotation speed detecting means becomes abnormal, the slip amount can be calculated with high accuracy by comparing the rotation speeds of the inner wheels or the outer wheels even during turning. .

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a vehicle slip amount computing device according to the present invention.

FIG. 2 is a schematic diagram showing a vehicle system according to an embodiment of the present invention.

FIG. 3 is a block diagram showing an electronic control unit and its peripheral circuit according to an embodiment.

FIG. 4 is a flowchart showing a sub-throttle valve opening control process according to the embodiment.

FIG. 5 is a flowchart showing slip control condition determination processing according to the embodiment.

FIG. 6 is a flowchart showing an abnormality determination process of the rotation speed sensor according to the embodiment.

FIG. 7 is a flowchart showing slip amount calculation processing according to the embodiment.

8 is an explanatory diagram explaining the flowchart of FIG. 7. FIG.

[Explanation of symbols]

 M1 ... Wheel rotation speed detecting means M2 ... Drive wheel speed calculating means M3 ... Idle wheel speed calculating means M4 ... Slip amount calculating means M5 ... Abnormality determining means M6 ... Rotation speed changing means 11 ... Engine 13 ... Transmission 14 ... Propeller shaft 16 ... Rear differential gear 18 ... Rear drive shaft 22 ... Right drive wheel 24 ... Left drive wheel 26 ... Right idle wheel 28 ... Left idle wheel 32 ... Intake pipe 36 ... Throttle valve 38 ... Axel pedal 42 ... Sub throttle valve 44 ... Sub throttle Actuator 50 ... Vehicle speed sensor 52 ... Right rear wheel rotation speed sensor 54 ... Left rear wheel rotation speed sensor 56 ... Right front wheel rotation speed sensor 58 ... Left front wheel rotation speed sensor 61 ... Idle switch 62 ... Main throttle position sensor 64 ... Sub throttle position Sensor 66 ... Crank angle Sensor 72 ... Foot switch 73 ... Brake pedal 76 ... Slip control instruction switch 82 ... Slip control instruction indicator 84 ... Slip control operation indicator 100 ... ECU 102 ... CPU 104 ... ROM 106 ... RAM 108 ... Backup RAM 109 ... Common bus 110 ... Input processing Circuit 120 ... Output processing circuit

Claims (1)

[Claims] 1. A vehicle slip amount calculating apparatus for calculating a slip amount between a drive wheel and an idle wheel, comprising: wheel rotation speed detecting means for detecting respective rotation speeds of the drive wheel and the idle wheel; and the wheel rotation speed detecting means. Drive wheel speed calculation means for calculating the drive wheel speed representative of the drive wheel based on the rotation speeds of the left and right drive wheels among the rotation speeds from An idle wheel speed calculation means for calculating an idle wheel speed representative of the idle wheel based on the rotation speed of the wheel; a slip amount calculation means for calculating a slip amount based on the drive wheel speed and the idle wheel speed; Based on the rotation speed of the wheel rotation speed detection means, abnormality judgment means for judging abnormality of each of the wheel rotation speed detection means, and the abnormality judgment means of the wheel rotation speed detection means When either is determined to be abnormal, the rotational speeds of the idler wheel and the drive wheel opposite to the idler wheel or the drive wheel determined to be abnormal are respectively determined, and both rotational speeds are calculated as the drive wheel of the slip amount calculating means. A vehicle slip amount computing device comprising: a rotational speed changing means for changing and setting a speed and an idle wheel speed.