JP4006927B2 - Slope judgment device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for determining the presence or absence of a gradient of a travel path using a braking force in a vehicle.
[0002]
[Prior art]
A conventional apparatus for detecting the gradient of a traveling path using braking force in a vehicle is disclosed in Japanese Patent Application Laid-Open No. 9-207735, and includes driving force, acceleration resistance, rolling / air resistance, and control of the vehicle. The gradient of the travel path is detected from the motive power so that gear shifting control can be performed properly even during brake operation. In this case, however, multiple parameters and complicated calculations for each unit time are required. Therefore, there are problems such as an increase in cost and an overload on the electronic control unit.
[0003]
[Problems to be solved by the invention]
The present invention seeks to discriminate an ascending or descending slope of a travel path using a braking force in a vehicle.
[0004]
[Means for Solving the Problems]
For this reason, the slope judgment device according to claim 1 of the present invention includes a brake fluid pressure sensor, first means for calculating a temporal integrated value of the brake fluid pressure detected by the brake fluid pressure sensor, second means for storing the time integration value calculated by the first means between the first vehicle speed during deceleration of the vehicle by the operation of the up said first speed is less than a second vehicle speed, said second means Between the time integrated value stored in step 1 and the flat ground equivalent reference value which is the time integrated value of the brake fluid pressure calculated by the first means between the first vehicle speed and the second vehicle speed on a flat ground. And a third means for comparison.
[0005]
That is, when the vehicle is decelerated due to the operation of the brake, the time integrated value of the brake fluid pressure calculated by the first means and stored by the second means between the first vehicle speed and the second vehicle speed and the flat ground equivalent reference If the former is larger than the latter, it can be determined that the road is an uphill slope. Conversely, if the former is smaller than the latter, the road is It can be determined that the road is a downhill slope, and the time integrated value is between the first vehicle speed and the second vehicle speed, and is not an instantaneous measurement value as in the conventional device. Therefore, the calculated value can be easily and always accurate, and appropriate slope determination can be realized.
[0006]
According to a third aspect of the present invention, there is provided a control device comprising: a brake fluid pressure sensor; first means for calculating a temporal integrated value of the brake fluid pressure detected by the brake fluid pressure sensor; When the vehicle is decelerated by the second means, the second means for storing the temporal integrated value calculated by the first means between the first vehicle speed and the substantial stop of the vehicle, and the second means are stored . A third comparison is made between the time integrated value and the level corresponding to a flat ground equivalent reference value which is a time integrated value of the brake fluid pressure calculated by the first means between the first vehicle speed and the second vehicle speed on a flat ground. Means, a fourth means for discriminating the upward or downward slope of the road based on the comparison result of the third means, and prohibiting the operation of the automatic engine stop control device when the fourth means determines that the road is an upward slope. And a fifth means that.
[0007]
That is, when the fourth means determines the road slope based on the comparison result of the third means, the fifth means prohibits the operation of the engine automatic stop control device. When the engine is automatically started when the vehicle is restarted after the engine has been automatically stopped, anxiety such as the engine starting malfunctioning due to the slope of the slope or the vehicle moving backwards may occur. Can be eliminated in advance.
[0008]
Further, the control device according to claim 4 of the present invention includes a brake fluid pressure sensor, a first means for calculating a temporal integrated value of the brake fluid pressure detected by the brake fluid pressure sensor, and a brake operation. When the vehicle is decelerated by the second means, the second means for storing the temporal integrated value calculated by the first means between the first vehicle speed and the substantial stop of the vehicle, and the second means are stored . A third comparison is made between the time integrated value and the level corresponding to a flat ground equivalent reference value which is a time integrated value of the brake fluid pressure calculated by the first means between the first vehicle speed and the second vehicle speed on a flat ground. Means, a fourth means for discriminating the upward or downward slope of the road based on the comparison result of the third means, and an idle neutral for the automatic transmission when the fourth means determines that the road is an upward slope. And a sixth means for inhibiting the operation of Le controller.
[0009]
That is, when the fourth means determines the upward slope of the road based on the comparison result of the third means, the sixth means prohibits the operation of the idle neutral control device for the automatic transmission. Even when the vehicle is stopped due to the operation of the brake in the held state, the neutral control for the automatic transmission is stopped, so that the vehicle can always be restarted smoothly.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention shown in the drawings will be described.
In FIG. 1, a vehicle electronic control device 1 includes a vehicle speed sensor 2, an idle switch 3 that detects that the accelerator pedal is not depressed, a brake switch 4 that detects depression of the brake pedal, and a brake pedal that is depressed. While receiving the detection signals from the pressure sensor 5 for detecting the brake hydraulic pressure generated in the hydraulic pressure path and the selector position sensor 6 for the automatic transmission, the fuel supply device 7 for the engine (not shown) mounted on the vehicle is received. The electronic control device 1 includes an engine automatic stop control device 9 and a restart control device 10, and an idle neutral control device 11 for the automatic transmission of the vehicle. ing.
[0011]
On the other hand, as shown in FIG. 2 (a), when the vehicle is decelerated by the operation of the brake, the vehicle speed V is the minimum at which the first vehicle speed A (for example, 15 km / h) to the second vehicle speed B (for example, the vehicle speed can be substantially measured). Within the time T when the value is reduced to 2-3 km / h), as shown in FIG. 2B, the cumulative time of the brake fluid pressure detected by the pressure sensor 5, that is, the cumulative value of the brake fluid pressure over time. E (shaded portion) is represented as shown in FIG. 2C and is proportional to the braking energy required to reduce the vehicle from the first vehicle speed A to the second vehicle speed B.
[0012]
Accordingly, since the slope is affected by gravity according to the gradient, the braking energy required for the deceleration from the first vehicle speed A to the second vehicle speed B is increased from the first vehicle speed A to the second on the flat ground. On the other hand, on the downhill road, the braking energy required for deceleration from the first vehicle speed A to the second vehicle speed B is less than the first vehicle speed A on the flat ground. From the braking energy when decelerating to the second vehicle speed B.
[0013]
Next, a specific operation of the electronic control device 1 will be described based on the control flowchart of FIG.
When the electronic control unit 1 detects that the vehicle is decelerating due to the operation of the brake based on signals from the vehicle speed sensor 2 and the brake switch 4, in step S1, the vehicle speed V detected by the vehicle speed sensor 2 is the first vehicle speed. If the vehicle speed V has not decreased to the first vehicle speed A, it is checked whether or not the time integrated value E of the brake fluid pressure is 0 in step S2, and the process returns to step S1, but the vehicle speed V is the first vehicle speed. If it has decreased below A, the process proceeds to step S3.
[0014]
In step S3, it is checked whether or not the vehicle speed V is greater than the second vehicle speed B. If the vehicle speed V has not decreased to the second vehicle speed B, the process proceeds to step S4. In step S4, the brake fluid pressure is accumulated over time. The value E is replaced by [brake fluid pressure integrated value E0 until the previous sampling] + [brake fluid pressure at the current sampling], and the process returns to step S1. Since the sampling time is a minute fixed time, if the brake fluid pressure at each sampling is simply added, it will be equivalent to the time integrated value of the brake fluid pressure without considering the value of the sampling time. It can be obtained.
[0015]
If it is determined in step S3 that the vehicle speed V has decreased to the second vehicle speed B, the process proceeds to step S5. In step S5, it is checked whether the brake fluid pressure temporal integration value E is between the constant K1 and the constant K2. Is done.
[0016]
That is, as shown in FIG. 4, when the road is uphill with respect to the time integrated value E1 of the brake fluid pressure required for decelerating from the first vehicle speed A to the second vehicle speed B on flat ground, As shown by the line, the greater the rising slope of the road, the smaller the accumulated time value E of the brake fluid pressure required for decelerating from the first vehicle speed A to the second vehicle speed B, and when the road has a downward slope. As indicated by the Y line, the greater the downhill slope of the road, the greater the time integrated value E of the brake fluid pressure required to decelerate from the first vehicle speed A to the second vehicle speed B. In step S5, the brake fluid pressure time If the integrated value E is between the constant K1 and the constant K2, even if there is a slope on the road, it is very small and can be regarded as almost flat. Therefore, in the next step S6, the slope judgment is not established, and in step S7 Brake fluid pressure To terminate the flow of temporal integration value E 0.
[0017]
In this case, when the second vehicle speed B detected by the vehicle speed sensor 2 is substantially 0, as is well known, the idle switch 3 detects that the accelerator pedal is not depressed, and the brake pedal is depressed. If the condition such as the brake switch 4 is detected is satisfied, the automatic stop control device 9 stops the fuel supply operation to the engine by the fuel supply device 7 and automatically stops the operation of the engine. When the vehicle restarts, the restart control device 10 restarts the fuel supply operation to the engine by the fuel supply device 7 and operates the starter device 8 to automatically start the engine, thereby improving vehicle fuel efficiency and exhaust gas. Or, as is well known, it is determined that the vehicle is stopped based on the vehicle speed detected by the vehicle speed sensor 2, and the automatic transmission It is detected by the position sensor 6 that the di, is detected by the idle switch 3 that no accelerator pedal is depressed, and the operation of the brake assumes that it is detected by the brake switch 4, the idle neutral control The device 11 reduces the hydraulic pressure with respect to the hydraulic engagement mechanism of the shift stage in the automatic transmission, weakens the engagement force of the hydraulic engagement mechanism, and puts the automatic transmission into the neutral state in a pseudo manner (substantially). The engine fuel efficiency is improved by reducing the load on the engine as in idling.
[0018]
In addition, when the first vehicle speed A is set to be relatively small and at the same time the second vehicle speed B is set to a sufficiently small value such as substantially zero, the influence of the air resistance on the traveling vehicle becomes small. The accuracy of the measurement can be easily improved.
[0019]
In step S5, when the time integrated value E of the brake fluid pressure does not reach the constant K1 or exceeds the constant K2, the process proceeds to step S8, and in step S8, the roads are respectively ascending or descending. Determined.
[0020]
In this case, when the integrated value E of the brake fluid pressure does not reach the constant K1, the road is going up and the second vehicle speed B is substantially zero. 9, the automatic engine stop control device 9 automatically stops the engine when the vehicle stops, and then the engine is automatically restarted by the restart control device 10 when the vehicle restarts. When starting automatically, it is possible to eliminate in advance the occurrence of anxiety that the engine starts malfunctioning due to the slope of the slope or the vehicle is behind, or the automatic transmission by the idle neutral control device 11 The operation of the idle neutral control described above is prohibited, thereby ensuring a smooth restart of the vehicle.
[0021]
In the next step S10, it is checked whether the vehicle has restarted and the vehicle speed V has exceeded the third vehicle speed C, which is greater than the first vehicle speed A. If the vehicle speed V has not reached the third vehicle speed C, the process returns to step S8. However, if the vehicle speed V exceeds the third vehicle speed C, the process proceeds to step S11, where the temporal integrated value E of the brake fluid pressure is set to 0 and the flow is terminated.
[0022]
In the above apparatus, when the vehicle is decelerated by the operation of the brake, the electronic control unit 1 measures the time integrated value E of the brake fluid pressure required for decelerating from the first vehicle speed A to the second vehicle speed B, By comparing the magnitude with the reference value equivalent to the flat land, the electronic control device 1 can easily and always accurately detect whether the road is an uphill or a downhill. Therefore, it is possible to realize appropriate slope judgment. Therefore, when the vehicle stops on an uphill slope, the engine automatic stop control device 9 and the idle neutral control device 11 are inadvertently operated, and the engine is restarted when the vehicle restarts. Such a problem that the automatic start-up of the vehicle is unsatisfactory, anxiety that the vehicle moves backwards, or lack of smoothness in starting the vehicle can be surely solved.
[0023]
In addition, since the above apparatus makes a slope judgment at the time of deceleration of the vehicle based on the time integrated value E of the brake fluid pressure, it is not affected at all by the driver of the vehicle, and thus complicated learning control is required. It is always easy to perform slope judgment with few parameters, and even if there are many passengers and loads, the slope judgment is accurate regardless of the posture of the vehicle. Therefore, an increase in cost can be suppressed, and slope determination can be performed without imposing an excessive load on an electronic control device or the like based on complicated calculations.
[0024]
Further, as shown in FIG. 5 related to the uphill road and FIG. 6 related to the downhill road, when the vehicle is decelerated by the operation of the brake, the vehicle speed V is changed from the first vehicle speed A (for example, 15 km / h) to the second speed. Time T that decreases to vehicle speed B (for example, a minimum value of 2 to 3 km / h at which the vehicle speed can be actually measured), a temporal integrated value E of brake fluid pressure during that time T, and a slope value α of the slope If a correlation diagram with (%) is created in advance based on actual vehicle experimental values, the slope value α can be determined specifically and accurately even on slopes with a slope value α in an arbitrary range. If necessary, the slope value α can be easily displayed on a road meter installed on the instrument panel of the vehicle.
[0025]
In the above embodiment, the determination of “constant K1 <time integrated value of brake fluid pressure E <constant K2?” Is performed in step S5. Instead, “constant K1 <brake fluid pressure”. The time integrated value E <constant K2? Or the time T when the vehicle speed V decreases from the first vehicle speed A to the second vehicle speed B> constant K3? "Is determined. Is relatively small, the time accumulated value E of the brake fluid pressure is close to the value on a flat ground. It ’s good.
[0026]
In the case of a passenger car, since the influence of the load amount on the time integrated value E of the brake fluid pressure is relatively small, it is not necessary to change the values of the constant K1 and the constant K2 much even if the number of passengers and the load amount change. However, when the influence of the load amount on the time integrated value E of the brake fluid pressure is relatively large as in the case of a commercial vehicle, for example, the time integration of the brake fluid pressure on a flat ground with respect to some typical load amounts. The value E1 is calculated in advance, and the constant K1 and the constant K2 are set for each of them, and the brake fluid pressure is obtained as a result of the time integration of the actual brake fluid pressure E and the brake at a representative load close to the actual load. By comparing the constant K1 and the constant K2 with respect to the time integrated value E1 of the hydraulic pressure, the determination of the slope may be made.
[0027]
Furthermore, it goes without saying that the first vehicle speed A and the second vehicle speed B in each of the above embodiments may be set to arbitrary vehicle speeds as necessary.
[0028]
【The invention's effect】
In the slope judging device according to the first aspect of the present invention, when the vehicle is decelerated by the operation of the brake, it is calculated by the first means between the first vehicle speed and the second vehicle speed, and is calculated by the second means. It is possible to detect whether the road is a slope with a rising slope or a slope with a downward slope by comparing the stored cumulative time value of the brake fluid pressure with a reference value equivalent to a flat ground. In addition, since the temporal integrated value is between the first vehicle speed and the second vehicle speed, and is not an instantaneous measurement value as in the conventional device, the calculation is easy and accurate. There is a feature that can be performed and an appropriate slope determination can be easily realized.
[0029]
Further, in the control device according to claim 3 or claim 4 according to the present invention, when the fourth means determines the upward slope of the road based on the comparison result of the third means, the fifth means is the engine. The operation of the automatic stop control device is prohibited, or the sixth means prohibits the operation of the idle neutral control device with respect to the automatic transmission. It has the advantage of being able to eliminate or ensure a smooth restart of the vehicle.
[Brief description of the drawings]
FIG. 1 is a schematic layout diagram according to an embodiment of the present invention.
FIG. 2 is an operation explanatory diagram of the embodiment.
FIG. 3 is a control flowchart of the embodiment.
FIG. 4 is a diagram for explaining the operation of the embodiment.
FIG. 5 is an operation explanatory diagram of another embodiment of the present invention.
FIG. 6 is an operation explanatory diagram of another embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Electronic controller 2 Vehicle speed sensor 3 Idle switch 4 Brake switch 5 Pressure sensor 6 Position sensor 7 Fuel supply device 8 Start-up device 9 Automatic stop control device 10 Restart control device 11 Idle neutral control device A 1st vehicle speed B 2nd vehicle speed E Brake fluid pressure over time V Vehicle speed

Claims (4)

A brake fluid pressure sensor; a first means for calculating a temporal integrated value of the brake fluid pressure detected by the brake fluid pressure sensor; and a first vehicle speed smaller than the first vehicle speed when the vehicle is decelerated by the operation of the brake. second means for storing the time integration value calculated by the first means until the second vehicle speed, the first in time integrated value and plains stored by said second means from said first speed A slope judgment device having a third means for comparing the magnitude with a reference value corresponding to a flat ground, which is a temporally integrated value of the brake fluid pressure calculated by the first means up to two vehicle speeds . 2. The time measuring means required for the vehicle to decelerate from the first vehicle speed to the second vehicle speed according to claim 1, the time integrated value stored by the second means, and the requirements measured by the measuring means. A slope determination device having detection means for detecting a slope of a slope based on time. A brake fluid pressure sensor; a first means for calculating a temporal integrated value of the brake fluid pressure detected by the brake fluid pressure sensor; and a substantial stop of the vehicle from the first vehicle speed when the vehicle is decelerated by the operation of the brake. said second means for storing the time integration value calculated by the first means, the said from the first vehicle speed in the stored temporal integration value and a flat by the second means second speed until the time The third means for comparing the level of the brake fluid pressure calculated by the first means with the standard value corresponding to the level of the flat ground and the rise of the road based on the comparison result of the third means. A control device comprising: a fourth means for discriminating a slope or a downward slope; and a fifth means for prohibiting the operation of the engine automatic stop control device when the road is judged to be an upward slope by the fourth means. A brake fluid pressure sensor; a first means for calculating a temporal integrated value of the brake fluid pressure detected by the brake fluid pressure sensor; and a substantial stop of the vehicle from the first vehicle speed when the vehicle is decelerated by the operation of the brake. said second means for storing the time integration value calculated by the first means, the said from the first vehicle speed in the stored temporal integration value and a flat by the second means second speed until the time The third means for comparing the level of the brake fluid pressure calculated by the first means with the standard value corresponding to the level of the flat ground and the rise of the road based on the comparison result of the third means. And a fourth means for discriminating the gradient or the downward slope, and a sixth means for prohibiting the operation of the idle neutral control device for the automatic transmission when the fourth means determines that the road is ascending. Apparatus.

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