JPH09133699A - Device for detecting forward-backward acceleration of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the backward-forward acceleration of a vehicle with accuracy by eliminating the influence of the surface gradient of a road from the detected results of a forward-backward G sensor which detects the forward- backward acceleration of the vehicle. SOLUTION: A device for detecting forward-backward acceleration of vehicle not only reads the detected results of a forward and backward G sensor 12, but also those of a gradient sensor 13. The device calculates the component of the gravitational acceleration of its own vehicle in the forward-backward direction of the vehicle based on a gradient value θ detected by means of the sensor 13 and uses the component as a correction value Δα. Then the device corrects the detected results of the sensor 12 by removing the influence of the surface gradient of a road by subtracting the correction value Δα from the detected results of the sensor 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle front-rear acceleration detecting device, and more particularly to a technique for detecting a vehicle front-rear acceleration by an acceleration sensor.

[0002]

2. Description of the Related Art Conventionally, a device for detecting a longitudinal acceleration (forward / backward G) of a vehicle and performing a shift control based on the detection result is disclosed in, for example, Japanese Patent Laid-Open No. 1-229143 or Japanese Utility Model Laid-Open No. 2-2.
-48437 gazette. JP-A 1-22
The one disclosed in Japanese Patent No. 9143 is configured to perform a downshift based on an idle switch, a brake switch, and a deceleration, and the one disclosed in Japanese Utility Model Laid-Open No. 2-48437 discloses a method in which a brake switch is turned on. The downshift timing is changed according to the deceleration.

[0003]

When the information on the acceleration (deceleration) is used for the shift control as described above, the acceleration sensor for detecting the acceleration detects, for example, the displacement of the steel ball due to the acceleration by the change of the magnetic field. When a system type sensor is used to detect the longitudinal acceleration of the vehicle, the sensor is fixed to the vehicle body so that the moving direction of the steel ball is the longitudinal direction of the vehicle.

However, such an acceleration sensor changes its output in response to the longitudinal component of the vehicle as well as the acceleration component in the longitudinal direction of the vehicle and the gravitational acceleration generated by the inclination of the vehicle. When traveling on a sloped road surface such as a slope, the acceleration (deceleration) is erroneously detected based on the detection value of the acceleration sensor affected by the road surface slope.

Therefore, when the downshift is performed based on the deceleration, the downshift is performed even though the actual deceleration is not in a state in which the driver requests the downshift, and the driver feels uncomfortable. There was a fear. For example, figure
As shown in FIGS. 16 and 17, the actual deceleration ΔV2 is a level at which the downshift from the third speed to the second speed is not performed, but when the deceleration ΔV1 larger than the actual value is detected by the gradient, Although the downshift from 3rd speed to 2nd speed will be performed, the deceleration felt by the driver is the same,
There was a fear that the driver would feel uncomfortable because the downshift was performed or not performed depending on the gradient.

The present invention has been made in view of the above problems, and the actual acceleration (deceleration) can be detected even if the detected value of the acceleration sensor for detecting the longitudinal acceleration of the vehicle is influenced by the gradient. The purpose is to do so.

[0007]

Therefore, the longitudinal acceleration detecting device for a vehicle according to the invention of claim 1 is constructed as shown in FIG. In FIG. 1, an acceleration sensor detects an acceleration in the front-rear direction of the vehicle. The gradient component detecting means detects the component in the vehicle longitudinal direction of the gravitational acceleration due to the road gradient.

Then, the acceleration correction means corrects the detection result of the acceleration sensor based on the component in the vehicle longitudinal direction of the gravitational acceleration detected by the gradient component detection means. According to such a configuration, even if the detection result of the acceleration sensor is affected by the gradient, the component in the vehicle front-rear direction of the gravitational acceleration due to the road surface gradient is separately detected, and correction is performed to eliminate the gradient effect from the detection result of the acceleration sensor. Therefore, for example, the shift can be controlled based on the actual acceleration in the vehicle front-rear direction.

According to a second aspect of the present invention, the gradient component detecting means includes a gradient sensor that detects a road surface gradient, and the gravitational acceleration in the vehicle longitudinal direction is based on the road surface gradient detected by the gradient sensor. It is configured to detect the components.
According to such a configuration, by detecting the inclination of the vehicle due to the road surface gradient with the gradient sensor, the component in the vehicle longitudinal direction of the gravitational acceleration generated by the inclination can be detected, and thus the influence of the inclination from the detection result of the acceleration sensor can be detected. Correction that eliminates can be done.

According to the third aspect of the present invention, the gradient component detecting means detects the output value of the acceleration sensor when the vehicle speed is constant as a vehicle longitudinal component of the gravitational acceleration. With this configuration, when the vehicle speed is constant, it can be considered that the actual acceleration is substantially zero. Therefore, the acceleration detected at this time is a value detected under the influence of the road gradient. Can be Therefore, if the subsequent detection result of the acceleration sensor is corrected based on the output of the acceleration sensor when the vehicle speed is constant, the acceleration without the influence of the gradient can be detected.

According to a fourth aspect of the present invention, the gradient component detecting means calculates the gradient resistance based on the acceleration resistance based on the acceleration detected as the rate of change of the vehicle speed, the driving force and the rolling, and the air resistance. Based on the calculated gradient resistance, the vehicle longitudinal component is detected. According to such a configuration, by calculating the gradient resistance using the equation of motion of the vehicle composed of various running resistances and driving forces,
The vehicle longitudinal component can be detected without using a gradient sensor.

According to the present invention, the unit time for obtaining the rate of change of the vehicle speed is longer than the sampling period of the detection signal of the acceleration sensor. With this configuration, the component of the gravitational acceleration in the vehicle front-rear direction for correcting the detection result of the acceleration sensor is relatively stable, and the corrected detection result of the acceleration sensor can be stabilized.

[0013]

Embodiments of the present invention will be described below. FIG. 2 is a system configuration diagram of a shift control device for an automatic transmission. In FIG. 2, an automatic transmission 2 is provided on the output side of an engine 1 mounted on a vehicle (not shown). The automatic transmission 2 includes a fluid type torque converter 3 interposed on the output side of the engine 1, a gear type transmission 4 connected to the engine 1 via the fluid type torque converter 3, and a gear type transmission 4 of the gear type transmission 4. And a hydraulic actuator 5 for connecting / disconnecting various transmission elements therein.

The operating hydraulic pressure for the hydraulic actuator 5 is controlled through various electromagnetic valves (not shown), and the automatic transmission control unit 6 shifts gears to a target shift speed by turning on and off the various electromagnetic valves. . Signals from various sensors are input to the automatic transmission control unit 6. As the various sensors, there is provided a throttle sensor 8 for detecting an opening TVO of a throttle valve 7 which is interposed in an intake system of the engine 1 and opens and closes in conjunction with an accelerator pedal (not shown).

Further, the rotational speed N of the output shaft of the automatic transmission 2
A vehicle speed sensor 9 for detecting the vehicle speed VSP by detecting o is provided. Further, a brake switch 10 indicating the operation / non-operation of the brake, a lateral G sensor 11 for detecting a lateral acceleration of the vehicle (hereinafter also referred to as lateral G), and an acceleration in the longitudinal direction of the vehicle (hereinafter also referred to as longitudinal G). A front and rear G sensor 12 (acceleration sensor) for detecting the.

As the lateral G sensor 11 and the front-rear G sensor 12, both sensors having the structure shown in FIG. 3 are used. FIG.
2, 21 is a steel ball, 22 is a detection coil, and 23 is a magnet. The detection coil 22 detects a change in the magnetic field due to the displacement of the steel ball 21 in accordance with the acceleration in the detection direction in FIG. In the case of the lateral G sensor 11 which detects the lateral G, the lateral G is detected by fixing the lateral direction of the vehicle to the lateral direction of the vehicle, and the lateral G sensor 12 detects the lateral direction. The front-rear G is detected by fixing the front-rear direction of the vehicle to the vehicle body.

Further, a gradient sensor 13 for detecting the inclination of the vehicle body
Is provided. As shown in FIG. 4, the gradient sensor 13 has a weight 31 hung through a strain gauge 32 in a housing 31 fixed along the vertical direction of the vehicle body, and the housing 31 tilts according to the inclination of the road surface. Bending strain corresponding to the inclination θ is generated in the strain gauge 32 by the weight 33 that holds the vertical direction, and the inclination θ is detected as an output of the strain gauge 32. In addition, in the housing 31,
Silicone oil 34 having a high kinematic viscosity is filled, and braking the weight 33 with this silicone oil 34 is influenced by the longitudinal acceleration (front-rear direction G) of the vehicle, and the inclination θ is erroneously detected. It is possible to suppress that.

Then, the automatic transmission control unit 6 determines a target shift speed based on signals from the various sensors and outputs a shift signal for turning on / off the electromagnetic valve according to the target shift speed. , Control the shift operation in the automatic transmission 2. Next, shift control using the detection results of the front and rear G sensors by the automatic transmission control unit 6 will be described with reference to the flowcharts of FIGS.

First, in step 1 (denoted as S1 in the drawing; the same applies hereinafter), various input processes including calculation of the throttle operation speed ΔTVO and detection of front and rear G are performed. The processing contents of step 1 are shown in the flowchart of FIG. The automatic transmission control unit 6 is
The functions of the gradient component detecting means and the acceleration correcting means are provided by software as shown in the flowchart of FIG.

The flowchart of FIG. 12 shows a routine executed every 10 ms. First, at step 61, the throttle valve opening TVO detected at the previous execution of this routine is detected.
As the difference between the current detection value and the throttle operation speed ΔTV
O is calculated. In step 62, the longitudinal G (acceleration in the vehicle longitudinal direction) detected by the longitudinal G sensor 12 is read.

In step 63, the gradient value θ (%) detected by the gradient sensor 13 is read. In step 64, a correction value Δα for correcting the detection result of the front and rear G is calculated based on the read gradient value θ (%) according to the following formula. Δα = g × θ / (1 ² + θ ² ) ^1/2 (g is gravitational acceleration) The correction value Δα is a component of the gravitational acceleration in the vehicle front-rear direction, and is a negative value when the vehicle is descending (minus gradient). It is calculated, and is calculated as a positive value on the ascending slope (plus slope).

At the next step 65, the value obtained by subtracting the correction value Δα from the front-rear G read at the step 62 is set as the final front-rear G (acceleration ΔVSP in the vehicle front-rear direction). ΔVSP = front-rear G-Δα For example, when the vehicle is descending, a large deceleration (negative acceleration) is detected by the front-rear G sensor 12 as the descending gradient is large even if the actual acceleration is 0. By subtracting the correction value Δα (the vehicle front-rear direction component of the gravitational acceleration) calculated as a negative value from the detection result of the front-rear G sensor 12, as a result, the deceleration is detected to be larger than the actual value in the down slope. The deceleration can be corrected to a smaller value, and the acceleration that is detected as a smaller value than the actual value when the vehicle is accelerating can be corrected to a large value. As a result of correction, the actual acceleration (deceleration) excluding the effect of the gradient can be detected.

In the control shown in the flow chart of FIG. 12, the detection result of the front and rear G sensor 12 is corrected on the basis of the detection result of the gradient sensor 13 so that the gradient influence is obtained from the detection result of the front and rear G sensor 12 which is affected by the gradient. However, as described above, the detection result of the front-rear G sensor 12 when the actual acceleration (front-rear G) is 0 is nothing but the influence of the gradient. Therefore, the flowchart of FIG. As shown in, the correction for eliminating the influence of the gradient can be performed based on the detection result of the front and rear G sensor 12 without using the gradient sensor 13.

Steps in the flowchart of FIG.
At 71, the throttle operation speed ΔTVO is calculated. In step 72, it is determined whether or not the vehicle speed VSP is constant (including a stopped state), that is, whether or not the acceleration is substantially zero. If the vehicle speed VSP is substantially constant, the routine proceeds to step 73, where the detection output of the front and rear G sensor 12 at that time is stored as the correction value Δα.

Then, in step 74, the detection result of the front and rear G sensor 12 is read regardless of the vehicle speed VSP, and in the next step 75, when the vehicle speed VSP is constant from the detection result of the front and rear G sensor 12 read in step 74. The correction value Δα set as the sensor output is subtracted, and the correction result is set as the final front-rear G (acceleration ΔVSP in the vehicle front-rear direction).

.DELTA.VSP = front-rear G-.DELTA..alpha. The flowchart of FIG. 14 shows a routine executed every 10 ms. First, at step 81, the throttle operation speed ΔTV
Calculate O.

In step 82, the detection result of the front and rear G sensor 12 is read. In step 83, the correction value Δα is calculated according to the flowchart shown in FIG. In step 84,
A correction value Δα set according to the flowchart shown in FIG. 15 is subtracted from the read detection result of the front-rear G sensor 12, and the correction result is set as a final front-rear G (acceleration ΔVSP in the vehicle front-rear direction).

.DELTA.VSP = before-and-after G-.DELTA..alpha. The flowchart of FIG. 15 shows a routine executed every 400 ms, which is longer than the execution cycle of the routine shown in the flowchart of FIG. In the flowchart of FIG. 15, in step 91, the turbine torque Tt is obtained based on the turbine rotation speed Nt of the torque converter 3 and the throttle valve opening TVO.

In step 92, rolling and air resistance R _L are obtained based on the vehicle speed VSP. In step 93, the driving force F is calculated by the following equation using the turbine torque Tt, the gear ratio Gr, the differential gear ratio Gdef, and the tire effective radius R. F = Tt × Gr × Gdef / R In step 94, the detection result of the vehicle speed VSP is read.

In step 95, the previously read vehicle speed VS
The difference between P ₋₁ and the current value VSP is calculated as the vehicle longitudinal acceleration a based on the vehicle speed VSP. In step 96, the vehicle speed VSP read this time is set to the previous value VSP _-1 . In step 97, the correction value Δα is calculated according to the following equation. Note that m is the mass weight of the vehicle.

Δα = {F- (R _L + m · a)} / m The above-mentioned equation for the correction value Δα is a motion showing the correlation between the running resistance consisting of acceleration resistance, rolling, air resistance, and gradient resistance and the driving force. It is based on an equation, and calculates the vehicle longitudinal component of gravitational acceleration based on the acceleration resistance, rolling resistance, air resistance, and gradient resistance obtained from the driving force.
It is assumed to be α.

Here, the rate of change a of the vehicle speed used for calculating the correction value Δα is calculated as a rate of change per unit time longer than the period (10 ms) for sampling the output of the front-rear G sensor 12. As a result, the correction value Δα can be stabilized, and the detection result of the front-rear G sensor 12 can be accurately corrected. As described above, from the detection result of the front-rear G sensor 12 whose output is changed due to the influence of the gradient, a correction for eliminating the influence of the gradient is performed. Therefore, the corrected front-rear G (vehicle longitudinal acceleration) If the shift is controlled using ΔVSP) as described later, the acceleration (deceleration)
It is possible to properly execute the gear shift control corresponding to.

Here, the explanation will be continued by returning to the routines shown in the flow charts of FIGS. In the following, the acceleration Δ
As described above, VSP is a value obtained by eliminating the influence of the gradient from the front and rear G detected by the front and rear G sensor 12. In step 1, as described above, the throttle operation speed ΔTVO,
When the acceleration ΔVSP is calculated, in steps 2 to 23, the throttle operation speed ΔTVO (throttle opening TV
The time change rate of O), the vehicle acceleration ΔVSP (acceleration detected by the front-rear G sensor 12) and the vehicle speed VSP are set.

It is to be noted that the above ΔTVO and ΔVSP both show an increasing direction with a plus and a decreasing direction with a minus. In step 2, as will be described later, the deceleration request flag F ₁ is set to 1 in the vehicle deceleration request state.
When the flag F ₁ is φ, the routine proceeds to step 3 to step 8, where the curve control throttle operation speed ΔTVO1, the continuous curve control throttle operation speed ΔTVO2, the curve control vehicle longitudinal acceleration ΔVSP.
1, vehicle longitudinal acceleration ΔVSP for continuous curve control, vehicle speed VSP for curve control 1, vehicle speed VSP2 for continuous curve control
The latest throttle operation speed ΔTVO, acceleration ΔVSP, and vehicle speed VSP are set for each.

On the other hand, when the flag F ₁ is 1, the routine proceeds to step 9, where the curve traveling flag F ₂ which is set to 1 while the vehicle is traveling on a curve is discriminated as will be described later. When the deceleration request flag F ₁ is 1 and the curve running flag F ₂ is φ, the process proceeds to step 10 and the previous curve running flag F ₂ is determined.

When it is determined at step 10 that the flag F ₂ was 0 at the previous time as well, it is during deceleration, but it is in a state where the vehicle has not yet moved to the curve running. In this case, the process proceeds to step 11 and thereafter. In step 11, the smaller of the previously set curve control throttle operation speed ΔTVO1 and the latest calculated operation speed ΔTVO is set as the current operation speed ΔTVO1.

[0037] The operating speed ΔTVO1 the operating speed of 1 is set to the deceleration request flag F ₁ to the present time Δ
Since the operation speed ΔTVO is set as the minimum value of TVO and the closing operation direction is shown as a negative value, for example, when the throttle is suddenly closed and then held fully closed, Operation speed ΔTVO when closed suddenly
However, it will be held continuously thereafter.

Therefore, even in the state of being fully closed after the rapid closing operation, the rapid closing operation in which a shift request to a lower speed is strong is set as the shift speed set based on the throttle operation speed ΔTVO1. The corresponding low speed can be held, and the engine braking effect by the downshift can be reliably obtained even when the throttle operation is instantaneously performed.

At step 12, the latest ΔTVO is set to the continuous curve control throttle operation speed ΔTVO2. In step 13, similarly to the curve control throttle operation speed DerutaTVO1, sets the minimum value of the acceleration ΔVSP for curve control vehicle longitudinal acceleration DerutaVSP1, from the deceleration request flag F ₁ 1 is set to the current time process I do. Since the acceleration ΔVSP represents deceleration as a negative value, as described above, even if the deceleration becomes small immediately after the sudden deceleration, the required gear stage at the time of the sudden deceleration can be continuously maintained, and the engine braking by the downshift can be performed. The effect is surely obtained.

In step 14, the latest ΔVSP is set to the vehicle longitudinal acceleration ΔVSP2 for continuous curve control. In step 15, the maximum value of the vehicle speed VSP from when the deceleration request flag F ₁ is set to 1 to the present time is set to the curve control vehicle speed VSP1. As a result, during deceleration from a high vehicle speed, the gear set for deceleration control is held at the relatively high speed side, and it is possible to prevent excessive engine braking.

At step 16, the latest vehicle speed VSP is set to the continuous curve control vehicle speed VSP2. On the other hand, when it is determined in step 10 that the flag F ₂ was 1 last time, it is when the vehicle exits the curve, and in that case, the curve control is performed in steps 17 to 19 in preparation for the entry into the subsequent curve. For the throttle operation speed ΔTVO1, vehicle longitudinal acceleration ΔVSP1, vehicle speed VSP1 set for continuous curve control ΔTVO2, ΔVSP2, VSP
Set 2 respectively.

If it is determined in step 9 that the flag F ₂ is 1, it means that the vehicle is traveling on a curve, and the process proceeds to step 20 where the continuous curve flag F ₄ is 1.
It is determined whether or not the vehicle is traveling on a continuous curve. When the continuous curve flag F ₄ is 0, the routine proceeds to step 3 to step 8 and the throttle operation speeds ΔTVO1, ΔTVO.
2, vehicle longitudinal acceleration ΔVSP1, ΔVSP2, vehicle speed VS
The latest values are set in P1 and VSP2, respectively.

When the continuous curve flag F ₄ is 1, in step 21, the smaller one of the previously set continuous curve control throttle operating speed ΔTVO2 and the latest calculated operating speed ΔTVO is set. A process for setting the operation speed ΔTVO2 is performed. In step 22, the previously set vehicle longitudinal acceleration ΔVSP2 for continuous curve control is set.
The smaller one of the calculated operation speed ΔVSP and the latest operation speed ΔVSP is set as the current acceleration ΔVSP2.

In step 23, the previously set vehicle speed VSP is set.
The larger one of 2 and the latest calculated vehicle speed VSP is set as the current vehicle speed VSP2. In step 24, it is determined whether or not the shift position by the select lever (not shown) is in the D range in which the automatic shift control is performed for all the shift speeds (for example, 1st speed to 4th speed).

If it is in the D range, the routine proceeds to step 25, where the road load (Road) set according to the vehicle speed VSP is set.
Load) Throttle opening TVO equivalent to the latest detected throttle opening TVO is compared. When the throttle opening TVO is less than the road load (Road Load), the routine proceeds to step 26, where it is judged whether or not the throttle operation speed ΔTVO1 is equal to or smaller than a predetermined value 1 (negative value) (deceleration judgment). ).

As described above, the throttle operation speed ΔTVO (time change rate of the throttle opening TVO) is calculated with the change in the opening direction of the throttle being positive and the change in the closing direction being negative. . The predetermined value compared with the throttle operation speed ΔTVO1 is the throttle operation speed ΔTVO1 and the vehicle speed VSP, as will be described later.
It is preferable that the characteristic is changed according to the vehicle speed VSP1 in accordance with the characteristic of the second required shift speed set on the basis of 1. For example, in the present embodiment, the second shift speed request 4 → 3
The shift line is set to a predetermined value, which makes it possible to accurately detect a deceleration state that requires downshifting according to the operating state of the vehicle.

The throttle opening TVO is the road load (Ro
ad Load) and the throttle operation speed ΔTVO1 is less than or equal to the predetermined value 1, it is determined that the deceleration request is being issued due to the closing operation of the throttle, and step 29
Then, the flow advances to and the flag F ₁ indicating whether or not the deceleration request state is set to 1 corresponding to the deceleration request state. On the other hand, if it is not determined that the deceleration is required by the determination in steps 25 and 26, the process proceeds to step 27, it is determined whether the brake switch 10 is ON or OFF, the brake switch 10 is ON, and the driver operates the brake. If so, go to step 28.

In step 28, the vehicle acceleration ΔVSP1
It is determined whether or not (a value obtained by eliminating the influence of the gradient from the detection result of the front-rear G sensor 12) is less than or equal to a predetermined value 2 (negative value). As described above, the acceleration ΔVSP is calculated as a positive value when the vehicle is accelerated and a negative value when the vehicle is decelerated. Therefore, the determination in step 28 (determination of deceleration) is to determine whether or not the deceleration of the vehicle is equal to or higher than a predetermined value.

The predetermined value compared with the acceleration ΔVSP1 is the acceleration ΔVSP1 and the vehicle speed VSP, as will be described later.
It is preferable that the characteristic is changed according to the vehicle speed VSP1 in correspondence with the characteristic of the third required shift speed set on the basis of 1. For example, in the present embodiment, the third shift speed request 4 → 3
The shift line is set to a predetermined value, which makes it possible to accurately detect a deceleration state that requires downshifting according to the operating state of the vehicle.

When it is determined in step 28 that the acceleration ΔVSP1 is less than or equal to the predetermined value 2, the vehicle is decelerating due to the braking operation. At this time, the process proceeds to step 29, and the deceleration request flag F is set. It is set to 1 indicating a deceleration request state _1. That is, the deceleration request flag F
₁ indicates that the deceleration request is determined based on the throttle operation (the driver's intention to decelerate) and / or the deceleration request is determined based on at least one of the time when the vehicle is decelerated with the brake operation. Will be set.

In step 30, the deceleration request flag F ₁
When the deceleration request flag F ₁ is set to ₁ , the process proceeds to step 31, and the curve traveling flag F ₂ indicating whether or not the vehicle is traveling in a curve is determined. When the curve running flag F ₂ is set to φ indicating the non-curve running state, the routine proceeds to step 32, where it is determined whether the lateral G (lateral acceleration) detected by the lateral G sensor 11 is a predetermined value 4 or more. To determine.

Here, when the lateral G is equal to or larger than the predetermined value,
When it is determined that the vehicle is traveling on a curve, the curve traveling flag F ₂ is set to 1 in step 33, which indicates a traveling state on a curve. On the other hand, when φ indicating the non-curve traveling state is set in the curve traveling flag F ₂ and it is determined that the lateral G is less than the predetermined value, the process proceeds to step 34 and the timer T ₁ is set to the predetermined value 3 It is determined whether or not the value exceeds.

If the timer T ₁ is less than the predetermined value, the process proceeds to step 35, and the timer T ₁ is incremented by 1. If the timer T ₁ exceeds the specified value,
That is, when the deceleration request state is detected and the elapsed time after the deceleration request flag F ₁ is set to 1 exceeds the predetermined time, the process proceeds to step 38 and thereafter, whereby various flags F ₁ , F ₂ , F ₃ And reset each to zero,
The timer T ₁ is reset to zero.

Such timer T₁Reduced by
Shift control that responds to high speed demand is continued more than necessary and shift
Prevents delay in startup control. That is, the flag
F ₁When 1 is set to, as described later
Shift control to apply the engine brake to
However, such shift control is continued for a predetermined time or longer.
Then, based on the normal engine load and throttle opening,
Return to normal gear shift control, and shift up is possible after deceleration is complete.
It is possible to prevent the driver from feeling uncomfortable without doing so easily.
Stop.

On the other hand, if it is determined in step 31 that the flag F ₂ is set to 1, the step
Proceeding to 36, the end of the curve traveling is determined by determining whether the lateral G is smaller than the predetermined value 5.
It should be noted that the level of a predetermined value that is compared with the actual lateral G for discriminating the approach to the curve and the level of the predetermined value that is compared with the actual lateral G for the discrimination of the end of the curve may be different from each other.

Here, when it is determined that the lateral G is larger than the predetermined value and the curve traveling is continued, the routine proceeds to step 43, where the throttle opening TVO is set to a predetermined value (Road Load) during the curve traveling. ) Corresponding opening degree) It is determined whether or not the flag F ₃ indicating whether or not it has become greater than or equal to. When the flag F ₃ is φ, that is, when it is determined that the throttle opening TVO has not reached the predetermined value or more during the current curve traveling, the routine proceeds to step 44, and the vehicle speed at that time is determined. Road Load
The corresponding opening R / LTVO is compared with the latest opening detection value TVO.

Here, the opening TVO is the predetermined value R / LTVO.
If it is above, the process proceeds to step 45, and the flag F is set.
Set 1 to ₃ . In this way, when the throttle is opened to the extent that the driver's willingness to accelerate is set while the vehicle is traveling on a curve and the flag F ₃ is set to 1, in the subsequent traveling on a curve, the routine proceeds from step 43 to step 46. move on.

In steps 46 to 49, the deceleration request state is determined in the same manner as in steps 25 to 28. If a deceleration request during curve running is determined, step 50 is executed.
Then, 1 is set to the continuous curve flag (hereinafter, also referred to as a curve deceleration request flag) F ₄ . That is, if a deceleration request is made after the throttle is opened while the vehicle is traveling on a curve, the flag F ₄ is set to 1.

When the end of the curve running is determined by the determination of the lateral G in step 36, the process proceeds to step 37, and the flag F ₄ is determined. When the flag F ₄ is 0, the process proceeds to steps 38, 40 to 42 to reset the various flags F ₁ , F ₂ and F ₃ to zero and the timer T ₁ to zero.

Further, the flag F_FourIs set to 1
If so, in step 39 flag F_FourReset to zero
On the other hand, proceed to step 40 to step 42 to
F _Two, F_ThreeReset to zero and
Timer T₁To zero. Therefore, at this time
Flag F₁Remains 1. In step 51, the
Speed request flag F₁Of the flag F₁1 is set
If it is turned on, go to step 52 and turn the curve.
Running flag F_TwoIs determined.

The deceleration request flag F ₁ is 1, and
If the curve traveling flag F ₂ is φ, that is, if there is a deceleration request and the vehicle is not traveling on a curve, step 53.
Go to, throttle operation speed ΔTVO1 and vehicle speed VSP1
The second required shift speed is calculated based on and (see FIG. 10). Here, the characteristic is such that the lower speed stage is selected as the throttle operation speed ΔTVO increases to the negative side (the higher the throttle closing operation speed is), and further, the low vehicle speed side and the high vehicle speed side have a comparatively large characteristic. The gear on the high speed side is selected. On the high vehicle speed side, a relatively high speed is selected to avoid excessive engine braking due to downshifting and overrev, and on the low vehicle speed side, engine braking due to downshifting is effective. A relatively high speed stage is selected in order to avoid overshooting and to allow a smooth stop.

In the next step 54, the vehicle acceleration ΔVS
The third required shift speed is calculated based on P1 and the vehicle speed VSP1. The calculation of the shift speed in step 54 is performed with reference to a map as shown in FIG. 11 in which the shift speed is stored in advance according to the vehicle acceleration ΔVSP1 and the vehicle speed VSP1. Here, there is a characteristic that a lower speed stage is selected as the acceleration increases toward the negative side (the vehicle deceleration increases). Further, similarly to the characteristic in step 53, the low vehicle speed side and the high vehicle speed side are selected. Then, the shift stage on the relatively high speed side is selected.

Further, in step 57, the first required shift speed corresponding to the normal shift speed is calculated based on the vehicle speed VSP and the throttle opening TVO (engine load). The calculation of the required shift speed in step 57 is performed in advance by calculating the vehicle speed VS.
This is performed by referring to a map that stores the shift speed according to P and the throttle opening VSP. The shift map shows the vehicle speed V
If SP is the same, throttle opening (engine load)
Is set so that the smaller the value is, the higher the shift tends to be.

Then, in step 58, the first, second, and third required shift speeds are compared, and the shift speed which is the lowest speed among these is set as the final target shift speed,
The engine braking is activated by shifting to the target shift speed. In step 59, a shift signal is output to the electromagnetic valve to match the actual shift position with the set target shift speed.

On the other hand, when it is judged at step 51 that the deceleration request flag F ₁ is φ, the routine proceeds to step 55,
The fourth required speed is set as the second required speed,
In the next step 56, the fourth highest speed, which is also the highest speed, is set as the third required speed. By setting the highest speed, it is possible to prevent the target speed from being set at least to the speed lower than the first required speed when the process proceeds to step 58, and the speed reduction request flag F is substantially set. _{When 1} is φ, shift control is performed based on the first required shift speed.

In step 52, the curve running flag F ₂
When it is determined that 1 is set to 1, the step 53 to the step 58 are jumped to the step 59 so that the target shift speed is not updated. That is, even if the deceleration request flag F ₁ is set to ₁ , if the curve running flag F ₂ is set to 1, the gear position up to that point is held and the gear shift is performed during the curve running. As a result, it is possible to prevent the driving force from changing, and it is possible to secure traveling stability when traveling on a curve.

In the above description, the correction is performed to eliminate the influence of the gradient from the detection result of the front and rear G sensor 12, and the shift control is performed based on the corrected front and rear G (acceleration ΔVSP). The configuration may be used as other control information, such as controlling the active suspension using the front-rear G (acceleration ΔVSP). The gradient sensor 13 is not limited to the sensor having the configuration shown in FIG. 4 as long as it is not easily affected by the acceleration in the front-rear direction.

[0068]

As described above, according to the first aspect of the invention, even if the detection result of the acceleration sensor is affected by the gradient, the correction is performed to eliminate the influence of the gradient. Acceleration can be detected, and when gear shift control is performed based on, for example, longitudinal acceleration, gear shift can be controlled appropriately.

According to the second aspect of the present invention, the gradient sensor can accurately detect the vehicle longitudinal component of the gravitational acceleration, and thus the correction for eliminating the influence of the tilt from the detection result of the acceleration sensor can be accurately performed. effective. According to the invention described in claim 3, based on the output of the acceleration sensor when the vehicle speed is constant, the component of the gravitational acceleration in the vehicle longitudinal direction is simply detected without using the gradient sensor, and the acceleration sensor is detected. There is an effect that the correction for eliminating the influence of the inclination can be easily performed from the result.

According to the fourth aspect of the present invention, the gradient resistance is calculated by using the equation of motion of the vehicle composed of various running resistances and driving forces, so that the component of the gravitational acceleration in the vehicle longitudinal direction is not used by the gradient sensor. Therefore, there is an effect that the correction for simply removing the influence of the tilt from the detection result of the acceleration sensor can be easily performed. According to the invention described in claim 5,
The stability of the component of the gravitational acceleration in the vehicle front-rear direction for correcting the detection result of the acceleration sensor can be ensured, and thus the corrected detection result of the acceleration sensor can be stabilized.

[Brief description of the drawings]

FIG. 1 is a basic configuration block diagram of the invention according to claim 1;

FIG. 2 is a system configuration diagram of an automatic transmission.

FIG. 3 is a cross-sectional view showing configurations of a front and rear G sensor and a lateral G sensor.

FIG. 4 is a sectional view showing the configuration of a gradient sensor.

FIG. 5 is a flowchart showing an example of shift control using front and rear G.

FIG. 6 is a flowchart showing an example of shift control using front and rear G.

FIG. 7 is a flowchart showing an example of shift control using front and rear G.

FIG. 8 is a flowchart showing an example of shift control using front and rear G.

FIG. 9 is a flowchart showing an example of shift control using front and rear G.

FIG. 10 is a diagram showing a characteristic of a shift speed setting based on a throttle operation speed.

FIG. 11 is a diagram showing a characteristic of gear position setting based on vehicle longitudinal acceleration.

FIG. 12 is a flowchart showing a first form of front-back G correction control.

FIG. 13 is a flowchart showing a second form of front-rear G correction control.

FIG. 14 is a flowchart showing a third mode of front-rear G correction control.

FIG. 15 is a flowchart showing a third mode of front-rear G correction control.

FIG. 16 is a diagram showing how shift control is changed due to erroneous detection of acceleration.

FIG. 17 is a diagram showing a situation in which erroneous detection of acceleration occurs.

[Explanation of symbols]

 1 Engine 2 Automatic Transmission 3 Fluid Torque Converter 4 Gear Transmission 5 Hydraulic Actuator 6 Automatic Transmission Control Unit 7 Throttle Valve 8 Throttle Sensor 9 Vehicle Speed Sensor 10 Brake Switch 11 Lateral G Sensor 12 Front / Back G Sensor 13 Gradient Sensor

Claims (5)

[Claims] 1. An acceleration sensor for detecting a longitudinal acceleration of a vehicle, a gradient component detecting means for detecting a vehicle longitudinal component of a gravitational acceleration due to a road gradient, and a detection result of the acceleration sensor for the gradient component detecting means. A longitudinal acceleration detecting device for a vehicle, comprising: an acceleration correcting unit that corrects based on a component of the gravitational acceleration detected in the vehicle longitudinal direction. 2. The gradient component detecting means includes a gradient sensor for detecting a road surface gradient, and detects a component of a gravitational acceleration in a vehicle longitudinal direction based on the road surface gradient detected by the gradient sensor. The longitudinal acceleration detecting device for a vehicle according to claim 1, wherein 3. The front and rear of the vehicle according to claim 1, wherein the gradient component detecting means detects an output value of the acceleration sensor when the vehicle speed is constant as a component of the gravitational acceleration in the longitudinal direction of the vehicle. Directional acceleration detection device. 4. The gradient component detecting means calculates an acceleration resistance based on acceleration detected as a rate of change in vehicle speed, a driving force, and rolling, and calculates a gradient resistance based on air resistance. The vehicle longitudinal acceleration detection device according to claim 1, wherein the vehicle longitudinal component is detected based on the gravitational acceleration. 5. The longitudinal acceleration detecting device for a vehicle according to claim 4, wherein a unit time for obtaining the rate of change of the vehicle speed is longer than a sampling cycle of the detection signal of the acceleration sensor.