JPH1164372A - Acceleration detecting device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an acceleration detecting device capable of obtaining information for determining the state of acceleration with a degree of accuracy necessary for the control of a vehicle with maintaining the performance of a controller as before without incurring any rise in cost. SOLUTION: In a low vehicle speed region β1 in which vehicle speed V does not exceed a predetermined vehicle speed Von, the state of acceleration of a vehicle is detected on the basis of pulse signals generated at time intervals responsive to vehicle speed. In a high vehicle speed region β2 exceeding the predetermined vehicle speed Von, the detection of the pulse signal is prohibited. and the state of acceleration is not detected. Therefore, it is possible to obtain information for determining the state of acceleration with a degree of accuracy necessary for the control of the vehicle with maintaining the performance of a controller as before without incurring any rise in cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an acceleration detecting device for a vehicle which determines an acceleration state of a vehicle based on pulse signals generated at time intervals corresponding to a vehicle speed.

[0002]

2. Description of the Related Art As a vehicle acceleration detecting device, a digital rotation sensor that outputs a digital signal is generally used. Such a rotation sensor is a combination of a rotating gear or a perforated disk attached to a rotating shaft and a photoelectric element attached at a fixed position, and the controller generates a pulse signal generated at time intervals corresponding to the vehicle speed. The acceleration state of the vehicle is obtained by counting the output change. In addition, as an example of the rotation sensor,
For example, those described in JP-A-8-15312 can be mentioned.

However, in such a device,
Based on pulse signals generated at time intervals corresponding to the vehicle speed, detection of the acceleration state is performed consistently in all vehicle speed ranges from low vehicle speed to high vehicle speed. The amount of calculation performed to detect the acceleration state increases, and there is no time margin in the calculation processing for detecting the acceleration state. From a vehicle speed range above a certain value, it is necessary to accurately detect the acceleration state. Operation becomes impossible.

In order to solve this, it is necessary to increase the arithmetic processing speed of the controller. However, when the arithmetic processing speed of the controller is increased in this way, there is a disadvantage that the cost of the controller increases.

[0005] By the way, the vehicle acceleration detecting device is used, for example, in lock-up control for releasing a lock-up clutch in order to prevent engine stall due to sudden deceleration in a low vehicle speed range during coasting. In most cases, it is only necessary to detect acceleration or deceleration. In other words, in a high vehicle speed region where the engine stall due to the release delay of the lock-up clutch hardly occurs, not so much accuracy is required to detect whether the vehicle is accelerating or decelerating.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above facts, and the performance of the controller is the same as that of the prior art without increasing the cost of the controller and with the precision required for vehicle control. It is an object of the present invention to provide a vehicle acceleration detection device that can obtain information for determining an acceleration state.

[0007]

According to a first aspect of the present invention, there is provided an acceleration detecting apparatus for a vehicle, which detects a vehicle based on a pulse signal generated at time intervals corresponding to a vehicle speed. The vehicle acceleration detecting device for determining the acceleration state of the above is characterized by comprising an acceleration state detection reducing means for reducing the amount of calculation performed to detect the acceleration state as the vehicle speed increases.

According to a second aspect of the present invention, there is provided a vehicle acceleration detecting apparatus according to the first aspect, wherein the acceleration state detecting / reducing means detects more and more pulse signals as the vehicle speed becomes higher. Things.

According to a third aspect of the present invention, there is provided the vehicle acceleration detecting apparatus according to the second aspect, wherein the acceleration state detecting / reducing means detects the pulse signal at least once when the vehicle speed region becomes a predetermined speed or more. The number of times is divided.

According to a fourth aspect of the present invention, there is provided a vehicle acceleration detecting apparatus according to the first aspect, wherein the acceleration state detecting / reducing means inhibits the detection of the pulse signal in a vehicle speed region above a predetermined speed, and The operation for detecting the state is not performed.

According to a fifth aspect of the present invention, there is provided an acceleration detecting device for a vehicle according to any one of the first to fourth aspects, wherein the vehicle speed is determined based on a gear ratio of the transmission and an input rotation of the transmission. It is determined based on this.

[0012]

As described above, according to the first aspect of the present invention, as the vehicle speed increases, the acceleration state detection / reduction means for reducing the amount of computation performed for detecting the acceleration state is provided, so that the performance of the controller remains unchanged. It is possible to obtain information for determining the acceleration state with an accuracy required for vehicle control without increasing the cost of the controller.

According to the invention of claim 2, in claim 1, the acceleration state detection / reduction means thins out and detects as many pulse signals as the vehicle speed increases, so that the performance of the controller remains unchanged. Thus, it is possible to obtain information for determining the acceleration state with an accuracy required for vehicle control without increasing the cost of the controller.

Further, in the invention according to claim 3, in claim 2, the acceleration state detection / reduction means is configured to divide the number of times of detection of the pulse signal at least once when the vehicle speed region exceeds a predetermined value. The acceleration state can be detected with high accuracy in a vehicle speed region lower than the predetermined vehicle speed, and the acceleration state can be detected with minimum accuracy in a vehicle speed region higher than the predetermined vehicle speed. Further, since the pulse signals are thinned out at equal intervals, the detection algorithm is simplified.

According to a fourth aspect of the present invention, in the first aspect,
Since the acceleration state detection / reduction means prohibits the detection of the pulse signal in a vehicle speed region equal to or higher than a predetermined value and does not perform the calculation for detecting the acceleration state, the CPU time and the program amount are simpler. Can be reduced.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the vehicle speed is determined by:
Since it is determined based on the input rotation of the transmission, it is effective even when the output shaft sensor cannot be used.

[0017]

An embodiment of the present invention will be described below in detail with reference to the accompanying drawings. In this embodiment, the term "deceleration (deceleration state)" means a state in which the polarity of the acceleration (acceleration state) of the vehicle is negative.

FIG. 1 is a control system diagram showing a power train including a vehicle acceleration detecting device according to the present invention. The vehicle power train includes a torque converter 10,
Power from an engine (not shown) having a transmission 11 and a final reduction gear 12 is input to the torque converter 10. The torque converter 10 has a torque increasing function and a torque fluctuation absorbing function.
c. The transmission 11 is an automatic transmission, and may be a stepped automatic transmission or a continuously variable transmission. Transmission 11
Has a vehicle speed sensor 1 on the output side. Here, the vehicle speed sensor 1 is a rotation sensor that outputs a pulse signal at predetermined time intervals by combining a rotating gear or a perforated disk attached to a rotating shaft and a photoelectric element attached at a fixed position.
The vehicle speed V is obtained by a calculation based on the pulse signal Ro from the vehicle speed sensor 1 input to the controller 100. The power output from the output shaft 13 of the transmission 11 rotates the wheels 15 from the final reduction gear 12 via the axle 14.

The lock-up clutch 10c has a front-rear differential pressure (= PA-P) caused by a torque converter apply pressure PA applied to both sides thereof and a torque converter release pressure PR.
By controlling R), the pump impeller (not shown) and the turbine runner (not shown) of the torque converter 10 are directly connected or opened.

When the apply pressure PA becomes lower than the release pressure PR, the lock-up clutch 10c releases the space between the pump impeller of the torque converter 10 and the turbine runner (converter state), and the apply pressure PA becomes lower than the release pressure PR. When high, the torque converter 10
Is directly connected (lock-up state) between the pump impeller and the turbine runner.

The differential pressure (= PA-PR) is controlled by switching a lock-up control valve 16 in a control valve (not shown). The spring 16S acts in the same direction, and from the other side, the release pressure PR and the spring force act in the same direction, and the signal pressure Ps from the lock-up solenoid 17 acts.

The signal pressure Ps from the lock-up solenoid 17 is determined by using the pump pressure
Is created in accordance with the drive duty D of.
The controller 100 receives a coast state signal I indicating that the vehicle is coasting, a signal RI from the impeller rotation sensor 20, a signal RT from the turbine rotation sensor 30, and a signal Ro from the vehicle speed sensor 1. Note that the impeller rotation sensor 20 can be replaced with a signal from an engine rotation sensor (not shown) that detects the number of rotations of the engine.

The input of these signals causes the controller 10
The rotational speed difference (slip rotation) between the pump impeller and the turbine runner is determined from the impeller rotational speed and the turbine rotational speed detected at 0. For example, during coasting, no relative rotation occurs between the pump impeller and the turbine runner. Control is performed to the smallest differential pressure between the front and rear (= PA-PR) to prevent engine stall (engine stall) due to a response delay when lockup is released at a predetermined deceleration. In addition,
The relationship between the signal pressure Ps by the duty control and the differential pressure (= PA-PR) based on the signal pressure Ps is as shown in FIG. 2. When the signal pressure Ps is small, the lockup is released and the signal pressure Ps is released. Lockup occurs when Ps increases.

FIG. 3 is a flowchart illustrating a first embodiment of the vehicle acceleration detecting device according to the present invention. This is a control routine for changing the detection amount of the pulse signal. Each time the pulse signal Ro is input to the controller 100, the processing is repeated periodically or irregularly at sufficiently short time intervals. FIG. 4 is a subroutine of the control routine of FIG.
Is interrupted.

The operation according to these flowcharts will be described below with reference to FIG. First, step 501 in FIG.
It is determined whether or not the vehicle is stopped. At this time, if the vehicle is in a stopped state, the process proceeds to step 502, and the vehicle state flag is set to “VCNT = 0”.
However, if the vehicle is not in a stopped state, the process directly proceeds from step 501 to step 503.

In step 503, it is determined whether or not the current vehicle speed V is in a vehicle speed region that does not exceed a predetermined vehicle speed Von. When the vehicle starts to start, the vehicle speed V is equal to the predetermined vehicle speed V.
Since it does not exceed on, steps 503 to 504
Then, the rotation speed input capture interrupt is permitted, and control is performed according to the flowchart of FIG. However, if it is determined in step 503 that the vehicle speed V is in a vehicle speed region exceeding the predetermined vehicle speed Von, the process proceeds from step 503 to step 50.
Then, the process proceeds to step 5, where the rotational speed input capture interrupt is prohibited, and the control according to the flowchart of FIG. 4 is not performed.

First, in step 503, when it is found that the vehicle speed V is in a vehicle speed region not exceeding the predetermined vehicle speed Von, a rotation speed input capture interrupt is made in step 504, and in step 511 in FIG. The time when the signal was input is stored as time data Ta, and it is determined whether or not the vehicle state flag is "VCNT = 1". Since the vehicle state flag is “VCNT = 0” in the state where the vehicle has started to start, the vehicle state flag is incremented to “VCNT = 1” in step 516.

Thereafter, the running vehicle state flag is set to "VCN".
Since “T = 1”, when a new pulse signal is input, in step 511, the time at which the pulse signal was input is stored as time data Tb. At this time, since the vehicle state flag is “VCNT = 1”, step 51
At 2, the previous time data Ta and the current time data T
b, a basic pulse time (or basic pulse period) P which is a time interval of a pulse signal generated corresponding to the vehicle speed.
Calculate ROD.

After calculating the pulse time PROD, it is determined in step 514 whether a predetermined deceleration state is detected in the basic pulse time PROD. Here, if the basic pulse time PROD is equal to or greater than a predetermined threshold value (hereinafter referred to as a deceleration determination threshold value) CLTPROD, a condition for detecting a predetermined deceleration state (in this embodiment, a condition regarded as rapid deceleration) is satisfied. Then, the process proceeds to step 515 to perform control for releasing the lockup. However, in step 514, the basic pulse time PROD is equal to the deceleration judgment threshold C.
If LTPROD is not satisfied, it is determined that the predetermined deceleration state is not detected, and the lockup release in step 515 is not performed.

In step 513, a new deceleration judgment threshold value CL for the next basic pulse time PROD is calculated.
Calculate TPROD. The deceleration determination threshold CLT
The method of calculating PROD will be described later in detail.

Next, at step 503 in FIG.
Is in the vehicle speed region exceeding the predetermined vehicle speed Von,
The process shifts from step 503 to step 505. At step 505, the rotational speed input capture interrupt is prohibited, and the control according to the flowchart of FIG. 4 is not performed. That is, when the vehicle speed V is in the vehicle speed region equal to or higher than the predetermined vehicle speed Von, the detection of the pulse signal is prohibited, and the calculation of the basic pulse time PROD and the deceleration determination threshold value CLTPROD shown in the flowchart of FIG. Is not performed.

That is, the acceleration state detection / reduction means in this embodiment corresponds to steps 503, 504, and 505.

FIG. 5 illustrates a method of calculating the deceleration determination threshold value CLTPROD described in step 513 of FIG. The deceleration determination threshold value CLPPROD determines the deceleration state for each basic pulse time PROD corresponding to the vehicle speed. FIG. 5A shows a deceleration determination threshold value C.
It is a characteristic curve X for obtaining LTPROD. In step 513 of FIG.
Basic pulse time PROD (PROD (N-1)
) Is determined. This threshold value CLPPROD becomes a deceleration determination threshold value to be used next time.

FIG. 5B shows a characteristic curve Y in which the deceleration Gc for judging the deceleration state is plotted for each vehicle speed.
It is. In the present embodiment, the upper region A of the curve Y is
This is an area in which lockup is released assuming rapid deceleration, and a lower area B of the curve Y is an area in which it is determined that rapid deceleration is not occurring. That is, the deceleration determination threshold C obtained in FIG.
Determining the deceleration state by comparing LTPROD with the latest basic pulse time PROD is achieved by comparing the deceleration actually calculated from the latest basic pulse time PROD with the deceleration Gc shown in FIG. It is the same as making a judgment.

FIG. 6 is an operation diagram for explaining the first embodiment. FIG. 7A is a characteristic curve α indicating the minimum engine speed Nemin corresponding to the predetermined switching vehicle speed Von. The minimum engine speed Nemin indicates the minimum engine speed when the vehicle is suddenly braked in the coasting state. The minimum engine speed N
When the engine speed falls below the allowable minimum engine speed No, the engine stalls. FIG. 6B shows a characteristic curve β indicating the pulse frequency fv corresponding to the vehicle speed V, and the allowable vehicle speed pulse frequency fvm.
ax is a limit frequency value at which the controller 100 can perform arithmetic processing.

As apparent from FIG. 6, the controller 1
The upper limit of the vehicle speed that can be calculated by 00 is the vehicle speed V at which the pulse frequency fv corresponding to the vehicle speed becomes the allowable vehicle speed pulse frequency fvmax.
onmax, and the lower limit of the vehicle speed at which engine stalling does not occur due to sudden braking during coasting is the vehicle speed Vonmin at which the engine rotation becomes the minimum permissible engine rotation No. Therefore, the switching vehicle speed Von is the vehicle speed corresponding to the minimum permissible engine rotation No. Von
min and the vehicle speed V corresponding to the allowable vehicle speed pulse frequency fvmax.
It is preferable to set it between onmax.

Here, the operation of the first embodiment will be described with reference to FIG. As shown in FIG. 3B, the deceleration state is detected for each basic pulse time PROD corresponding to the vehicle speed on the solid line β1 where the vehicle speed V does not exceed the predetermined vehicle speed Von. However, since the detection of the pulse signal is prohibited at the one-dot chain line β2 exceeding the predetermined vehicle speed Von, the calculation for detecting the deceleration state is not performed in the high vehicle speed region where the load on the controller 100 is high.
Therefore, in the first embodiment, since the algorithm is simpler, the CPU time and the program amount can be reduced.

FIG. 7 is a flowchart for explaining a second embodiment of the vehicle acceleration detecting device according to the present invention, together with FIG. FIG. 7 shows a control routine for changing the detection amount of the pulse signal Ro. The control routine is repeated periodically or irregularly at sufficiently short time intervals every time a pulse signal is input. FIG. 4 is a flowchart described in the first embodiment, which is interrupted in step 506 or step 507 in FIG.

The second embodiment is different from the first embodiment in that, when the vehicle speed becomes equal to or higher than the predetermined vehicle speed Von, a frequency divider for dividing the number of detections of the pulse signal is provided instead of prohibiting the detection of the pulse signal. This is to reduce the number of times a pulse signal is detected.

The operation according to these flowcharts will be described below with reference to FIG. First, the controller 100
When the pulse signal is input to the step 50 in FIG.
At 1, it is determined whether the vehicle is in a stopped state. At this time, if the vehicle is in a stopped state, the process proceeds to step 502, and the vehicle state flag is set to “VCNT = 0”. However, if the vehicle is not in a stopped state, the process proceeds directly from step 501 to step 503.

In step 503, it is determined whether or not the current vehicle speed V is in a vehicle speed region that does not exceed a predetermined vehicle speed Von. When the vehicle starts to start, the vehicle speed V is equal to the predetermined vehicle speed V.
Since the value does not exceed on, steps 503 to 506 are performed.
Then, the rotation speed input capture interrupt is permitted, and control is performed according to the flowchart of FIG.
However, if it is determined in step 503 that the vehicle speed V is in a vehicle speed region exceeding the predetermined vehicle speed Von, steps 503 to 5
In step 07, the number of times the pulse signal is detected is divided by N, and control is performed according to the flowchart of FIG. 4 based on the N-divided pulse signal.

The flowchart of FIG. 4 is the same as that of the first embodiment, and detailed description is omitted. However, the basic pulse time PROD and the deceleration determination threshold value CLPPRO
The calculation of D, that is, the calculation for detecting the deceleration state is performed.

Immediately after the number of times the pulse signal is detected in step 507 is divided by N, the depulse cycle data such as the time data T and the basic pulse time PROD become indefinite. Therefore, in step 508, it is determined whether or not the detection amount of the pulse signal has been changed.
If the frequency division is changed on, the vehicle state flag is cleared to "VCNT = 0" in step 502 'so that the programs in steps 512 and 513 in FIG. 4 cannot be executed until a predetermined condition is satisfied. . However, step 5
At 08, if there is no change in the frequency division, the flow exits without clearing the vehicle state flag.

That is, the acceleration state detection / reduction means in this embodiment corresponds to steps 503, 506, and 507.

FIG. 8 illustrates another method of calculating the deceleration determination threshold value CLTPROD described in step 513 of FIG. The deceleration judgment threshold value CLTP here
ROD determines a deceleration state for each basic pulse time PROD obtained from a pulse signal divided by N. FIG.
(A) is a characteristic curve x1, x2 for obtaining the deceleration determination threshold value CLPPROD. Since the frequency division is performed as described above at a predetermined vehicle speed Von or more, the characteristic curves x1, x2 are
Partially discontinuous at a predetermined vehicle speed Von. The method of calculating the deceleration determination threshold value CLPPROD used in the deceleration determination is the same as that described in the first embodiment. That is, the characteristic curve x1 in FIG.
, X2, a deceleration determination threshold value CLTPROD corresponding to the basic pulse time PROD (PROD (N-1)) by dividing by N determined in step 512 of FIG.
LTPROD is a deceleration determination threshold value to be used next time.

FIG. 8B shows a characteristic curve y in which the deceleration Gc for judging the deceleration state is plotted for each vehicle speed.
It is. In the present embodiment, the upper region A of the curve y is
This is an area in which lockup is released assuming rapid deceleration, and an area B below the curve y is an area in which it is determined that rapid deceleration is not occurring. That is, the deceleration determination threshold C obtained in FIG.
To determine the deceleration state by comparing LTPROD with the latest basic pulse time PROD is to compare the deceleration actually calculated from the latest basic pulse time PROD with the deceleration Gc shown in FIG. It is the same as making a judgment.

FIG. 9 is a circuit diagram showing an example of the frequency divider. This frequency divider has a through circuit 50 that directly outputs a pulse signal Ro corresponding to the vehicle speed to the controller 100, a frequency dividing circuit 60 composed of N D flip-flops 18a to 18n, and a switch 19. The pulse signal corresponding to the vehicle speed input from code (A) is
9, the through circuit 50 or the frequency dividing circuit 6
The signal is output from the code (C) to the controller 100 via 0. Note that a reset signal is input from the code (B), and the reset signal is used as a trigger to change the D flip-flop to be actually operated.

When the vehicle speed V does not exceed the predetermined vehicle speed Von, the frequency divider outputs a pulse signal corresponding to the vehicle speed V to the controller 100 by using the through circuit 50 by switching the switch 19, and When the vehicle speed exceeds the predetermined vehicle speed Von, the frequency of the pulse signal corresponding to the vehicle speed V is divided by N by using the frequency dividing circuit 60 by switching the switch 19 to reduce the number of times of output of the pulse signal.

FIG. 10 illustrates the operation of the frequency divider when a pulse signal corresponding to the vehicle speed V is input. First, when the vehicle speed V does not exceed the predetermined vehicle speed Von, the through circuit 50 outputs a pulse signal corresponding to the vehicle speed V in FIG. Next, when the vehicle speed V exceeds the predetermined vehicle speed Von, the frequency dividing circuit 60 divides the pulse signal corresponding to the vehicle speed V by N and outputs the pulse signal to the controller 100. For example, 1 by the D flip-flop 18a
In the frequency division, one cycle of the pulse signal is thinned out at equal intervals as shown in FIG.
In the frequency division, two periods of the pulse signal are thinned out at equal intervals as shown in FIG. The frequency divider of FIG. 9 can divide the pulse signal corresponding to the vehicle speed V from 1 frequency division to N frequency division.

In the second embodiment, as the vehicle speed V increases, more pulse signals are thinned out and detected, so that the acceleration state can be detected at a uniform rate.
Further, in the present embodiment, when the vehicle speed region is equal to or higher than a predetermined speed,
Since the number of times of detection of the pulse signal is divided at least once, the acceleration state can be detected with high accuracy in a vehicle speed region lower than the predetermined vehicle speed, and at least in a vehicle speed region higher than the predetermined vehicle speed. The acceleration state can be detected with the required accuracy. Further, since the pulse signals are thinned out at equal intervals, the detection algorithm is simplified.

FIG. 11 is an operation diagram for explaining the second embodiment. FIG. 7A is a characteristic curve α indicating the minimum engine speed Nemin corresponding to the predetermined switching vehicle speed Von. The minimum engine speed Nemin indicates the minimum engine speed when the vehicle is suddenly braked in the coasting state. If the minimum engine speed Nemin becomes equal to or lower than the allowable minimum engine speed No, an engine stall occurs. FIG. 6B shows a characteristic curve β indicating a pulse frequency fv corresponding to the vehicle speed V, and the allowable vehicle speed pulse frequency f
vmax is a limit frequency value at which the controller 100 can perform arithmetic processing.

A predetermined vehicle speed Von for judging the deceleration state
Are the vehicle speed Vonmin corresponding to the minimum allowable engine speed No and the allowable vehicle speed pulse frequency fvmax, as in the first embodiment.
Is preferably set between the vehicle speed Vonmax and the vehicle speed Vonmax.

Here, the operation of the second embodiment will be described with reference to FIG. As shown in FIG. 3B, on the solid line β1 where the vehicle speed V does not exceed the predetermined vehicle speed Von, the acceleration state is detected based on the basic pulse time PROD corresponding to the vehicle speed. However, at the dashed line β2 exceeding the predetermined vehicle speed Von, the number of times of detection of the pulse signal is reduced by frequency division.

Therefore, as the vehicle speed V increases, more pulse signals can be detected by thinning them out at equal intervals, and the acceleration state can be detected at a uniform rate. Further, the predetermined vehicle speed Von
In the above region, the frequency of detection of the pulse signal is divided at least once. In a low vehicle speed region below the predetermined vehicle speed Von, as shown by a solid line β1, based on the pulse frequency fv corresponding to the vehicle speed. The acceleration state can be detected with high accuracy, and the acceleration state can be detected with the minimum required accuracy in the high vehicle speed region equal to or higher than the predetermined vehicle speed Vo, as shown by the dashed line β2.

Incidentally, in the first and second embodiments,
Even in a high vehicle speed region equal to or higher than the predetermined vehicle speed Von, it may be necessary to determine the deceleration state with high accuracy. Therefore, when a vehicle speed Vm (for example, a vehicle speed between a predetermined vehicle speed Von and a vehicle speed Vonmax) exceeds a predetermined range, the calculation for detecting the deceleration state is performed at time intervals corresponding to the vehicle speed. According to this, in this region (region where the vehicle speed is equal to or higher than Vm), the acceleration state can be detected based on the pulse signal corresponding to the vehicle speed, as in the related art, so that it is not required to detect the deceleration state with high accuracy. This is effective when it is required to detect the deceleration state with high accuracy in the vehicle speed region.

The vehicle speed V obtained in the first and second embodiments is obtained based on the speed ratio of the transmission 10 and the input rotation of the transmission 10. In this case, it is effective even when the output shaft sensor cannot be used.

As is apparent from the above description, in the vehicle acceleration detecting apparatus according to the present invention, the higher the vehicle speed V, the smaller the amount of calculation performed to detect the deceleration state. It is possible to obtain information for judging the deceleration state with an accuracy required for vehicle control without increasing the cost of the controller 100 as it is.

[Brief description of the drawings]

FIG. 1 is a control system diagram showing a power train including a vehicle acceleration detection device according to the present invention.

FIG. 2 is a diagram illustrating a relationship between a differential pressure supplied to a lockup clutch and a signal pressure Ps.

FIG. 3 is a flowchart illustrating a first embodiment of the present invention.

FIG. 4 is a flowchart showing a subroutine in the embodiment.

FIG. 5A is a deceleration determination threshold CL used for deceleration determination.
It is a figure explaining the calculation method of TPROD. (B)
FIG. 8 is a diagram for explaining a method of determining a deceleration determination based on a deceleration Gc.

FIG. 6A is a diagram showing a minimum engine rotation Nemin corresponding to a predetermined vehicle speed Vo by a characteristic curve α. (B)
Is a diagram showing a pulse frequency fv corresponding to the vehicle speed V by a characteristic curve β.

FIG. 7 is a flowchart illustrating a second embodiment of the present invention.

FIG. 8A is a deceleration determination threshold CL used for deceleration determination.
It is a figure explaining the calculation method of TPROD. (B)
FIG. 8 is a diagram for explaining a method of determining a deceleration determination based on a deceleration Gc.

FIG. 9 is a circuit diagram illustrating a frequency divider used in the second embodiment.

FIG. 10 is a time chart for explaining the operation of the frequency divider shown in FIG. 9;

FIG. 11A is a diagram showing a minimum engine speed Nemin corresponding to a predetermined vehicle speed Vo by a characteristic curve α. (B)
Is a diagram showing a pulse frequency fv corresponding to the vehicle speed V by a characteristic curve β.

[Explanation of symbols]

 1 Vehicle speed sensor 10 Torque converter 10a Lock-up clutch 11 Transmission 12 Final reducer 13 Output shaft 14 Axle 15 Wheel 16 Lock-up control valve 17 Lock-up solenoid 18 D flip-flop 19 Changeover switch 100 Controller

Claims (5)

[Claims] 1. An acceleration detecting device for a vehicle, which determines an acceleration state of a vehicle based on a pulse signal generated at a time interval corresponding to a vehicle speed, reduces the amount of calculation performed to detect the acceleration state as the vehicle speed increases. An acceleration detecting device for a vehicle, comprising: an acceleration state detecting / reducing means for causing the acceleration to be detected. 2. The acceleration detecting device for a vehicle according to claim 1, wherein the acceleration state detection / reduction means thins out and detects more pulse signals as the vehicle speed increases. 3. The acceleration state detection / reduction means according to claim 2, wherein the acceleration state detection / reduction means is configured to output at least one of
A vehicle acceleration detecting device, wherein the number of times of detecting a pulse signal is divided. 4. The apparatus according to claim 1, wherein the acceleration state detection / reduction means prohibits the detection of the pulse signal in a vehicle speed region equal to or higher than a predetermined value and does not perform an operation for detecting the acceleration state. Vehicle acceleration detecting device. 5. The vehicle acceleration detecting apparatus according to claim 1, wherein the vehicle speed is obtained based on a gear ratio of a transmission and an input rotation of the transmission. .