JPH09242862A - Presuming device for road surface slope and control device for automatic transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely presume a road surface slope during traveling, regardless of a speed change ratio. SOLUTION: A presuming device and control device have a road surface slope presuming section 41 for calculating a road surface slope during traveling and a gear setting up section for setting up a gear stage on a car speed, a throttle opening and the road surface slope during traveling. The road surface slope presuming section 41 has an accelerating torque calculating section 45 for calculating acceleration resistance torque using weight equivalent to a rotary part meeting the gear stage of AT. Thus the road surface slope presuming section 41 can precisely presume the road surface slope regardless of the gear stage. In addition, the gear setting up section can finely set up the gear stage according to the road surface slope during traveling.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a road surface gradient estimating device for estimating a road surface gradient during traveling, and a control device for an automatic transmission.

[0002]

2. Description of the Related Art Conventionally, a stepped automatic transmission (hereinafter referred to as A
As a control method of (T), the gear position corresponding to the vehicle speed and the throttle opening at the present time is detected from the shift diagram as shown in FIG. 7 so that the AT gear position matches the detected gear position. The method of controlling is used. However, in the above control method, since the road gradient is not taken into consideration when determining the gear position, the following problems occur.

Normally, the driver returns the accelerator pedal for the purpose of reducing the vehicle speed when the vehicle approaches a certain downhill. Therefore, the throttle opening moves in the closing direction. For this reason, as shown in FIG. 7, when the vehicle speed is not sufficiently reduced, the downshift is not performed, so that the engine braking cannot be effectively applied.

When the vehicle continues to climb uphill to some extent, the accelerator pedal must be increased to maintain the vehicle speed. If this is a steep climb, you have to take a considerable step. In this case, as shown in FIG. 7, the accelerator pedal is further depressed to shift down at the same time, but if the slope is steep, it is still impossible to obtain a sufficient driving force.

In order to solve such a problem, Japanese Unexamined Patent Publication (Kokai) No. Hei 6
-147304 gazette estimates road gradient while running,
Select a shift diagram according to the estimated road gradient from a plurality of shift diagrams prepared in advance, and use the shift diagram to select A
An apparatus for performing T shift control is disclosed. In the road gradient estimating device disclosed in the above publication, the vehicle driving torque for driving the driving wheels of the automobile is a flatland running resistance torque,
The gradient resistance torque is estimated by utilizing the balance with the acceleration resistance torque and the gradient resistance torque, and the road surface gradient is obtained from this.

[0006]

By the way, in the conventional road surface gradient estimating device described in the above publication, in order to accurately perform the gradient estimation, the vehicle driving torque, the level running resistance torque, and the acceleration resistance torque are calculated. Each must be calculated accurately. Where acceleration resistance torque is T
Assuming α, Tα is expressed by the following equation. Tα = (W + Wr) · α · Rt / g where W is the vehicle weight, Wr is the rotating part equivalent weight, α is the vehicle acceleration, Rt is the tire radius, and g is the gravitational acceleration.

In the above expression representing the acceleration resistance Tα, the rotating portion equivalent weight Wr changes depending on the gear ratio of the AT, and becomes larger at lower speed stages. However, in the conventional road surface gradient estimation device described in the above publication, the rotating portion equivalent weight Wr is fixed and used, and therefore the acceleration resistance torque Tα cannot be accurately obtained depending on the gear stage. Therefore, it is not possible to accurately estimate the road surface slope,
Therefore, there is a problem in that it is not possible to perform detailed shift control according to the road surface gradient during traveling.

The present invention has been made based on the above circumstances, and uses a road surface gradient estimating device capable of accurately estimating a road surface gradient during traveling regardless of a gear ratio, and using the road surface gradient estimating device. Therefore, it is an object of the present invention to provide a control device for an automatic transmission, which can finely perform shift control according to the road surface gradient during traveling.

[0009]

In order to solve the above-mentioned problems, an invention according to claim 1 is a road surface gradient estimating device for estimating a road surface gradient while a vehicle equipped with an automatic transmission is running, A vehicle speed detection unit that detects the vehicle speed of the automobile, a vehicle drive torque calculation unit that obtains a vehicle drive torque for driving the drive wheels of the automobile, and a flatland running resistance torque based on the vehicle speed detected by the vehicle speed detection unit. A running resistance torque calculating section for obtaining, an acceleration torque calculating section for obtaining an acceleration resistance torque of the automobile, a flat surface running resistance torque calculated by the running resistance torque calculating section from the vehicle driving torque calculated by the vehicle driving torque calculating section, and the A gradient calculating section for obtaining a gradient torque by subtracting the acceleration resistance torque calculated by the acceleration torque calculating section, and obtaining a road surface gradient during traveling based on the gradient torque, The speed torque calculating section includes an acceleration detecting means for detecting an acceleration of the automobile, a gear ratio detecting means for detecting a gear ratio of the automatic transmission, a predetermined gear ratio of the automatic transmission and a rotating portion of the automobile. Rotating portion equivalent weight detecting means for detecting the rotating portion equivalent weight corresponding to the gear ratio detected by the gear ratio detecting means based on the correspondence with the equivalent weight, acceleration detected by the acceleration detecting means and the rotating portion equivalent. Arithmetic means for calculating the acceleration resistance torque based on the weight equivalent to the rotating portion detected by the weight detecting means.

According to a second aspect of the present invention, there is provided an automatic transmission control device for controlling a gear ratio of an automatic transmission mounted on an automobile, the vehicle speed detecting section detecting a vehicle speed of the automobile.
Based on the vehicle speed detected by the vehicle speed detection section, a throttle opening detection section for detecting a throttle valve opening of the vehicle, a vehicle drive torque calculation section for obtaining a vehicle drive torque for driving the drive wheels of the vehicle. The running resistance torque calculating means for obtaining the flat running resistance torque, the acceleration torque calculating means for obtaining the acceleration resistance torque of the automobile, and the running resistance torque calculating means from the vehicle driving torque calculated by the vehicle driving torque calculating means A road surface gradient estimating unit having a flat surface running resistance torque and a gradient calculating means for obtaining a gradient torque by subtracting the acceleration resistance torque calculated by the acceleration torque calculating means, and a road surface gradient during traveling based on the gradient torque; Vehicle speed detected by the vehicle speed detector, throttle opening detected by the throttle opening detector, and estimated by the road surface slope estimator A target gear ratio setting unit that sets a target gear ratio based on the road gradient during traveling, and the automatic transmission is controlled so that the gear ratio becomes the target gear ratio set by the target gear ratio setting unit. The acceleration torque calculating means includes an acceleration detecting means for detecting an acceleration of the automobile, a gear ratio detecting means for detecting a gear ratio of the automatic transmission, and a preset automatic transmission of the automatic transmission. Based on the correspondence between the gear ratio and the rotating portion equivalent weight of the automobile, the rotating portion equivalent weight detecting means for detecting the rotating portion equivalent weight corresponding to the gear ratio detected by the gear ratio detecting means, and the acceleration detecting means. Arithmetic means for calculating an acceleration resistance torque based on the detected acceleration and the rotating portion equivalent weight detected by the rotating portion equivalent weight detecting means.

According to a third aspect of the present invention, in the second aspect of the present invention, the target gear ratio setting unit selects the vehicle speed from a gear shift schedule that shows a relationship between a vehicle speed, a throttle opening, and a gear ratio prepared in advance. A gear ratio extracting means for extracting a gear ratio corresponding to the vehicle speed detected by the detector and the throttle opening detected by the throttle opening detecting means, and a table showing a relationship between a road surface gradient prepared in advance and a minimum gear ratio. From, a minimum gear ratio extraction means for extracting a minimum gear ratio corresponding to the road gradient during traveling estimated by the road gradient estimating unit,
If the gear ratio extracted by the gear ratio extracting means is larger than the minimum gear ratio extracted by the minimum gear ratio extracting means, the gear ratio is set to the target gear ratio, and if not, the minimum gear ratio is set to the target gear ratio. And a determination unit for setting a ratio.

According to a fourth aspect of the present invention, in the second aspect of the present invention, the target gear ratio setting unit selects the vehicle speed based on a gear change schedule prepared in advance that indicates the relationship between the vehicle speed, the throttle opening, and the gear ratio. A gear ratio extracting means for extracting a gear ratio corresponding to the vehicle speed detected by the detector and the throttle opening detected by the throttle opening detecting means, and a relationship between a road surface gradient, a vehicle speed and a minimum gear ratio prepared in advance. From the table shown, the minimum speed ratio extraction means for extracting the minimum speed ratio corresponding to the running road surface slope estimated by the road surface slope estimation part and the vehicle speed detected by the vehicle speed detection part, and extracted by the speed ratio extraction means. If the gear ratio is greater than the minimum gear ratio extracted by the minimum gear ratio extraction means, the gear ratio is set to the target gear ratio, and if not, the minimum gear ratio is set to the target gear ratio. It is characterized in that it has a cross section, the.

According to a fifth aspect of the present invention, in the case of the third or fourth aspect of the invention, when the determination section determines that the throttle opening detected by the throttle opening detecting means is larger than a preset threshold value. Even if the gear ratio extracted by the gear ratio extracting means is not greater than the minimum gear ratio extracted by the minimum gear ratio extracting means, the gear ratio is set to the target gear ratio. is there.

The invention according to claim 6 is the invention according to claims 2, 3, and 4.
Alternatively, in the invention of claim 5, the automatic transmission is a stepped automatic transmission having a plurality of gear stages, and the target gear ratio setting unit sets a target gear stage as the target gear ratio, and The gear ratio detecting means has a switching timing detecting means for detecting a gear shifting timing of the automatic transmission, and when the switching timing detecting means detects the gear shifting timing, the gear ratio setting is performed. The target gear stage set by the section is detected as the gear ratio.

According to a seventh aspect of the present invention, in the invention according to the sixth aspect, the switching timing detecting means has an engine speed detecting means for detecting a speed of an engine mounted on the automobile. The change timing of the engine speed detected by the rotation speed detecting means is detected to detect the shift timing of the gear stage of the automatic transmission.

The invention according to claim 8 is the invention according to claim 2, 3,
In the invention described in 3, 4, 5, 6 or 7, the acceleration detecting means obtains the acceleration of the vehicle by differentiating the vehicle speed detected by the vehicle speed detecting unit with respect to time.

The invention according to claim 9 is the invention according to claim 2,
In the invention described in 4, 5, 6, 7, or 8, the driving force from an engine mounted on the automobile of the automatic transmission is input via a torque converter, and the vehicle driving torque calculation means is provided. An engine speed detecting means for detecting the engine speed, a turbine speed detecting means for detecting the turbine speed of the torque converter, a turbine speed detected by the turbine speed detecting means, and the engine. A slip ratio calculation means for calculating a ratio with the engine speed detected by the rotation speed detection means to obtain a slip ratio of the torque converter, a slip ratio of the torque converter prepared in advance, a pump torque and a turbine torque From the map showing the relationship with the torque ratio, the torque ratio according to the slip ratio detected by the slip ratio detecting means is calculated. And a pump capacity for obtaining a pump capacity coefficient corresponding to the slip ratio calculated by the slip ratio calculating means from a map showing the relationship between the slip ratio and the pump capacity coefficient of the torque converter prepared in advance. A coefficient calculation means, an engine speed detected by the engine speed detection means, a gear ratio calculated by the gear ratio calculation means, a torque ratio calculated by the torque ratio calculation means, and the pump capacity. The wheel drive torque is calculated based on the pump capacity coefficient obtained by the coefficient calculation means.

According to the present invention, since the acceleration torque calculating unit calculates the acceleration resistance torque by using the weight corresponding to the rotating portion corresponding to the gear ratio of the automatic transmission, the acceleration torque calculating unit calculates the acceleration resistance torque regardless of the gear ratio. The road surface gradient can be accurately obtained, and the road surface gradient estimation accuracy in the road surface gradient estimating unit is improved.

Further, according to the present invention, by using the road surface gradient estimating unit having the above-mentioned structure, it is possible to perform fine shift control according to the road surface gradient.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic block diagram showing a drive system of an automobile to which a control device for an automatic transmission according to an embodiment of the present invention is applied.

As shown in FIG. 1, an automobile drive system to which this embodiment is applied has an engine 1 and an engine 1 as shown in FIG.
AT2 connected to the output shaft of the drive wheel 8, a drive wheel 8, a drive shaft 7 that rotationally drives the drive wheel 8, and a differential gear 6 that transmits the drive force of the engine 1 extracted from the output side of the AT2 to the drive shaft 7. An intake pipe 11 for sending air to the engine 1, an exhaust pipe 14 for guiding exhaust gas from the engine 1 to the outside, an injector 15 for injecting fuel into a cylinder of the engine 1, and a fuel injected into the cylinder by the injector 15. And a spark plug 31 that ignites the spark plug 31 at a predetermined timing.
A distributor 32 for supplying electric power to the vehicle, a hydraulic circuit 17 for operating the AT2, a transmission control valve 18 for controlling the hydraulic circuit 17, and an engine control unit 30.
And an AT control unit 40.

The engine 1 is provided with a crank angle sensor 23 for detecting the rotational speed Ne of the crankshaft which is the output shaft of the engine 1.

The AT 2 has a torque converter 3 connected to the crankshaft of the engine 1 and a gear train 4 connected to the output shaft of the torque converter 3.

The torque converter 3 is provided between the pump 3a directly connected to the crankshaft of the engine 1, the turbine 3b directly connected to the input shaft of the gear train 4, and the oil between the pump 3a and the turbine 3b. And a stator 3c.

The gear train 4 has a planetary gear mechanism that creates a plurality of gear stages. In the gear train 4, the engagement state between the input shaft and the output shaft is changed by the hydraulic circuit 17.
This creates multiple gear stages. Further, the gear train 4 includes the input shaft of the gear train 4, that is, the turbine rotation sensor 29 that detects the turbine rotation speed Nt that is the rotation speed of the turbine 3b of the torque converter 3, and the rotation speed of the output shaft of the gear train 4. An output shaft rotation sensor 26 for detecting a certain output shaft rotation number No is provided. The output shaft speed No. is proportional to the vehicle speed.

An air cleaner 10 for cleaning air, an idle speed valve 13 for adjusting the amount of air passing through the intake pipe 11, and an intake pipe 11 are passed through the intake pipe 11 according to the movement of an accelerator pedal (not shown). A throttle valve 12 for adjusting the air amount, an air flow sensor 21 for detecting the air amount Qa passing through the intake pipe 11, and a throttle opening sensor 22 for detecting the valve opening Tvo of the throttle valve 12 are provided. . In this embodiment, the throttle valve 12 is provided so as to mechanically interlock with the accelerator pedal. The operation amount of the accelerator pedal and the throttle opening Tvo have a substantially one-to-one relationship, and the operation amount of the accelerator pedal is 0.
At this time, the throttle opening Tvo is also 0 (the throttle valve 12 is closed). Therefore, the throttle opening Tv
Detecting o indirectly detects the operation amount of the accelerator pedal. The intake pipe 11 is provided with a bypass pipe (not shown) so that the idling state can be maintained even when the throttle opening Tvo is 0.
Air is slightly supplied to the engine 1 via this bypass pipe.

The engine control unit 30 obtains an ignition timing suitable for the current operating condition based on the information from the air flow sensor 21, the throttle opening sensor 22, the crank angle sensor 23, and the AT control unit 40, and the distributor. Ignition timing control is performed by supplying an ignition signal to the ignition plug 31 via 32. Further, the engine control unit 30 obtains an optimum fuel injection amount, supplies a drive pulse to the injector 15, and performs fuel injection control. The engine control unit 30 of this embodiment is basically the same as an engine control unit that has been conventionally used.
The engine control unit 30 includes a CPU and R
The hardware includes the OM and the RAM.

The AT control unit 40, based on the information from the turbine rotation sensor 29, the output shaft rotation sensor 26, the vehicle weight sensor 27, the AT oil temperature sensor 28, and the engine control unit 30, the optimum gear position of the AT 2 and the like. To decide. Then, a signal such as a gear shift command is output to the transmission control valve 18 to control the operating hydraulic pressure of the hydraulic circuit 17 of the AT 2 to change the engagement state of the gear train 4 and create the determined gear position. AT
Like the engine control unit 30, the control unit 40 also includes a CPU, a ROM, a RAM, and the like, and is configured by hardware.

FIG. 2 is a schematic block diagram of the AT control unit 40. AT control unit 40
As shown in FIG. 2, is a road surface gradient estimating unit 41 that estimates the road surface gradient sin θ, a gear determining unit 47 that determines the gear position of the gear train 4, and a control that controls the transmission operation valve 18. And a section 50.

FIG. 3 is a schematic block diagram of the road surface slope estimating section 41. The road surface slope estimating unit 41, as shown in FIG.
A torque calculation unit 42 that calculates the drive shaft torque To transmitted to the drive shaft 7 that drives the drive wheels 8, a running resistance calculation unit 43 that calculates the flatland running resistance torque Tr, and an acceleration calculation unit that calculates the acceleration of the vehicle. 44, an acceleration torque calculation unit 45 that calculates the acceleration resistance torque Tα, and a gradient calculation unit 46.

The torque calculation unit 42 includes a turbine rotation speed Nt sent from the turbine rotation sensor 29, an engine rotation speed Ne delayed from the crank angle sensor 23, and a gear train sent from a control unit 50 described later. Based on the gear position GP of 4 and the current drive shaft torque T
o is calculated.

FIG. 4 is a schematic block diagram of the torque calculation unit 42. As shown in FIG. 4, the torque calculation unit 42 includes a gear ratio detection unit 56 that detects the gear ratio of the gear train 4, and a pump torque calculation unit 80 that calculates the pump torque Tp input to the pump 3 a of the torque converter 3. And a torque ratio calculation unit 52 that calculates a torque ratio t between the torque on the input (pump 3a) side and the torque on the output (turbine 3b) side of the torque converter 3, a multiplication unit 58, a multiplication unit 59, and a multiplication unit. And 83.

The gear ratio detector 56 uses a table showing the relationship between each gear position of the gear train 4 and the gear ratio, and the gear ratio r corresponding to the current gear position GP sent from the controller 50. To detect.

The pump torque calculation unit 80 includes a division unit 57.
And a pump capacity coefficient calculation unit 53 for calculating a pump capacity coefficient Cp of the torque converter 3, a multiplication unit 54, and a multiplication unit 55. The divider 57 divides the turbine speed Nt by the engine speed Ne to calculate the speed (slip) ratio e (= Nt / Ne) of the torque converter 3. The pump capacity coefficient calculation unit 53 uses a map showing the relationship between the speed ratio e of the torque converter 3 and the pump capacity coefficient Cp, as shown in FIG. 5, and uses the map corresponding to the speed ratio e calculated by the division unit 57. The capacity coefficient Cp is obtained. The multiplication unit 54 squares the engine speed Ne to calculate Ne2. The multiplier 55 multiplies the pump capacity coefficient Cp calculated by the pump capacity coefficient calculator 53 by Ne2 calculated by the multiplier 54. Thereby, the pump torque Tp (= Cp · Ne2) is calculated.

The torque ratio calculation unit 52 uses the map showing the relationship between the speed ratio e and the torque ratio t of the torque converter 3 as shown in FIG. 5, and calculates it by the division unit 57 of the pump torque calculation unit 80. A torque ratio t corresponding to the speed ratio e is calculated.

The multiplication unit 58 multiplies the pump torque Tp calculated by the pump torque calculation unit 80 by the torque ratio t calculated by the torque ratio calculation unit 52. Accordingly, the turbine torque Tt output from the turbine 3b of the torque converter 3
(= Tp · t) is calculated. This turbine torque Tt
Corresponds to the input torque of AT2.

The multiplying unit 59 adds the turbine torque Tt calculated by the multiplying unit 58 to the gear ratio r detected by the gear ratio detecting unit 56.
Multiply. Thus, the output torque of AT2 is calculated.

The multiplication unit 83 calculates the AT calculated by the multiplication unit 59.
The output torque of 2 is multiplied by the final gear ratio rf of AT2. As a result, the drive shaft torque To (= Tt · r · r
f) is obtained.

The running resistance calculating unit 43 uses the map showing the relationship between the vehicle speed V and the level running resistance torque Tr as shown in FIG. 6, and outputs the output shaft rotation number No sent from the output shaft rotation sensor 26. Vehicle speed V as specified by
The flatland running resistance torque Tr corresponding to is calculated. The flatland running resistance torque Tr is expressed by the following equation. Tr = (μr
* W + ka * V2) * Rt Here, μr is the rolling friction coefficient of the tire, W is the vehicle weight, ka is the air resistance coefficient, and Rt is the radius of movement of the tire. Here, as the vehicle weight W, the standard vehicle weight of the vehicle in which the present embodiment is mounted, for example, the vehicle weight for two passengers is used. A vehicle weight sensor may be provided in the suspension to detect the vehicle weight W. Further, the vehicle weight W may be estimated from the change between the vehicle speed V at a certain time and the vehicle speed V at another time, provided that the road gradient θ and the drive shaft torque To are not changed during traveling. Good.

The acceleration calculating section 44, as shown in FIG.
Vehicle speed difference unit 44a and low-pass filter (LPF) 44
b. The vehicle speed difference unit 44a uses the output shaft rotation speed No.
The acceleration α at the present time is obtained by differentiating the vehicle speed V determined by The LPF 44b has a vehicle speed difference unit 4
The noise component included in the signal specifying the acceleration α output from 4a is removed. The acceleration α may be directly obtained from an acceleration sensor provided in the vehicle body instead of providing the acceleration calculation unit 44.

As shown in FIG. 3, the acceleration torque calculating section 45 has a correction value determining section 45a and a calculating section 45b.
The correction value determination unit 45a uses the table showing the relationship between each gear position of the gear train 4 and the correction value ψ, and the current gear position GP sent from the control unit 50.
The correction value ψ (= Wk / W) corresponding to is detected. Here, Wk is the weight equivalent to the rotating portion (rotational inertia weight).
The rotating portion equivalent weight Wk varies depending on the gear ratio (gear ratio) and increases as the gear ratio shifts to the low side. Computing unit 45
b calculates the acceleration resistance torque Tα based on the correction value ψ detected by the correction value determination unit 45a and the acceleration α obtained by the acceleration calculation unit 44. The acceleration resistance torque Tα is expressed by the following equation. Tα = (1 + ψ) · W · α · Rt / g where Rt is the radius of the tire and g is the gravitational acceleration.

The gradient calculating section 46 has the drive shaft torque To calculated by the torque calculating section 42, the level ground running resistance torque Tr calculated by the running resistance calculating section 43, and the acceleration torque calculating section 45.
Based on the acceleration resistance torque Tα calculated in step 1, the road surface slope sin θ during running is calculated. The drive shaft torque To, the level running resistance torque Tr, the acceleration resistance torque Tα, and the road surface gradient torque Tθ have the relationship shown in the following equation. To = Tr + Tα + Tθ Therefore, in the gradient calculation unit 46 of the present embodiment, as shown in FIG. 3, the subtraction unit 46a subtracts the flatland traveling resistance torque Tr and the acceleration resistance torque Tα from the drive shaft torque To, thereby traveling. The inside road surface gradient torque Tθ is calculated, and thereafter, the LPF 46b removes the noise component contained in the signal that specifies the road surface gradient torque Tθ output from the subtraction unit 46a.

The road surface gradient torque Tθ is expressed by the following equation. Tθ = W · g · sin θ · Rt Therefore, in the gradient calculating unit 46 of the present embodiment, as shown in FIG. 3, in the dividing unit 46c, the road surface gradient torque Tθ calculated by the subtracting unit 46a is expressed by W · g · Rt. By dividing, the road surface gradient sin θ during traveling is calculated. If the calculated sin θ is positive, it means that the road surface on which the vehicle is running is an uphill slope, and if it is negative, it means a downhill slope.

The gear setting section 47 of the AT control unit 40, as shown in FIG.
A throttle state determination unit 47b and a map memory 47.
c, a target gear position determination unit 47d, and an acceleration determination unit 47e. The road surface state determination unit 47a divides the traveling road surface into a plurality of stages based on the road surface gradient sin θ calculated by the road surface gradient estimation unit 41. In the present embodiment, the road surface gradient sinnθ calculated by the road surface gradient estimating unit 41.
Is less than or equal to −30% gradient, −30% gradient to −20% gradient,
The case is divided into 7 stages of -20% gradient to -10% gradient, -10% gradient to 10% gradient, 10% gradient to 20% gradient, 20% gradient to 30% gradient, and 30% gradient or more.

The throttle state determination unit 47b is configured to detect the throttle opening Tv sent from the throttle opening sensor 22.
It is determined whether or not o is smaller than a preset determination value.
The acceleration determining unit 47e determines whether the absolute value of the vehicle acceleration α obtained by the acceleration calculating unit 44 of the road surface slope estimating unit 41 is larger than a preset determination value.

The map memory 47c stores a shift diagram showing the relationship among the throttle opening Tvo, the vehicle speed V and the gear position GP as shown in FIG. Here, three solid lines 1 → 2Up, 2 → 3Up, 3 → 4 in FIG.
Up means 1-> 2 speed shift up, 2-> 3 speed shift up, and 3-> 4 speed shift up, respectively. Similarly, three broken lines 2 → 1Down, 3 → 2Down, 4 → 3Down
Indicates 2 → 1st gear downshift, 3 → 2nd gearshiftdown, and 4 → 3rd gear downshift, respectively.

The target gear position deciding unit 47d determines the vehicle speed V at the present time which is specified by the throttle opening Tvo sent from the throttle opening sensor 22 and the output shaft rotation speed No sent from the output shaft rotation sensor 26. , The target gear position GPt is determined based on the results of the road surface condition determining unit 47a and the throttle condition determining unit 47b, using the shift diagram stored in the map memory 47c. A specific method for determining the target gear position GPt will be described later.

Control unit 5 of AT control unit 40
As shown in FIG. 2, 0 indicates the shift operation command output unit 50a.
And a GP information output unit 50b. The gear shift operation command output unit 50 a determines the operation amount of the gear ratio control valve 18 based on the target gear position GPt determined by the gear determination unit 47, and outputs the gear shift command to the gear ratio control valve 18. As a result, the gear ratio control valve 18 receives the gear shift command from the gear shift operation command output unit 50a and controls the gear train 4 to reach the target gear position GPt. Further, the gear shift operation command control unit 50a outputs a gear shift command to the gear ratio control valve 18, and at the same time, outputs information regarding the target gear position GPt to the GP information output unit 50b.

The GP information output unit 50b is used for the gear train 4
The current gear position GP is determined, and information regarding the determined gear position GP is output to the road surface gradient estimation unit 41 and the gear determination unit 47. Here, the processing in the GP information output unit will be described with reference to FIG. Figure 8 is GP
It is a flowchart for demonstrating a process in the information output part 50b.

First, in step 111, it is determined whether or not the gear train 4 is in the shifting operation. Here, the shift operation command output unit 50 determines whether or not the shift operation is in progress.
It is performed by determining whether or not a is within a predetermined period (a period considered to be necessary for the operation of the transmission control valve 18) after issuing a command to the transmission control valve 18. In step 111, if it is determined that the gear shifting operation is being performed, the process proceeds to step 112, and if it is determined that the gear shifting operation is not being performed, the process proceeds to step 113.

Next, at step 112, it is judged whether or not the gear train 4 is at the timing of actually switching the gear position (actual shift start timing). This determination method will be described later. In step 112,
When it is determined that it is time to switch the gear position, information about the gear position GP after the switching, that is, the shift operation command output unit 5 at the present time point.
The information about the gear position GP sent from 0a is output to the road surface slope estimating unit 41 and the gear determining unit 47 (step 114). On the other hand, when it is determined that it is not the timing to switch the gear position, the information about the gear position GP before the switching, that is, the information about the gear position GP currently sent from the shift operation command output unit 50a is sent. The information about the received gear position GP is output to the road surface slope estimating unit 41 and the gear determining unit 47 (step 11).
5).

In step 113, the information about the current gear position GP, that is, the information about the gear position GP currently sent from the gear shift operation command output unit 50a is used as the road slope estimating unit 41 and the gear determining unit 47.
Output to

The flow shown in FIG. 8 is repeated. Accordingly, the gear position GP of the gear train 4 can be detected quickly and accurately.

Next, the determination method in step 112 of FIG. 8 will be described with reference to FIGS. 9 and 10. FIG. 9 is a diagram for explaining a method (method 1 to method 5) of detecting gear switching timing when the gear position is switched to the top side (shifted up), and FIG. 10 is switched to the low side (step 1). It is a figure for demonstrating the detection method (method 6-10) of the gear change timing in the case of (shifting down). Both are timing charts of various information such as the engine speed Ne that specifies the state of the vehicle.

First, the method of detecting the gear change timing when shifting up will be described with reference to FIG.
Here, the start of the actual gear shifting operation is the gear switching timing.

In the method 1, the engine speed Ne sequentially sent from the crank angle sensor 23 is used. The change in the engine speed Ne is checked, and the engine speed Ne is higher than the maximum value Ne_max by a predetermined speed (ΔNe, for example, 100r.
pm), it is determined that the gear actually shifts up to the target gear position GPt. This is because when the gear actually shifts up, the input shaft rotation speed of the AT2 decreases once. Therefore, the timing at which the gear train 4 actually shifts up the gear position by checking the change in the engine speed Ne that changes similarly to the input shaft speed of the AT2 and detecting the maximum value of the engine speed Ne. Can be detected.
Normally, the vehicle speed does not suddenly change suddenly even if the gear shifts up. Therefore, the output shaft rotation speed No of the AT2 sent from the output shaft rotation sensor 26 does not change abruptly even if the gear shifts up, as shown in FIG.

In the method 2, the turbine rotation speed Nt successively sent from the turbine rotation sensor 29 is used. The change in the turbine rotation speed Nt is examined, and the timing at which the gear train 4 actually shifts up the gear position to the target gear position GPt is detected in the same manner as the method 1.
The turbine rotation speed Nt corresponds to the input shaft rotation speed of the AT2.

In method 3, the turbine speed Nt and AT2
Ratio of output shaft speed No.
Use o. When the gear ratio Gratio becomes equal to or lower than the slice level Sg_Gratio, it is determined that the gear actually shifts up to the target gear position GPt. The slice level Sg_Gratio is preferably set in consideration of the variation range of the gear ratio Gratio due to the detection error of the turbine rotation sensor 29 and the output shaft rotation sensor 26 or the like in order to prevent erroneous determination of the gear switching timing.

In the method 4, the engine speed Ne sent from the crank angle sensor 23 and the output shaft rotation sensor 2 are used.
6 and the target gear position G output from the gear shift operation command output unit 50a.
The ratio Ratio calculated by the following formula based on Pt and
Is used. Ratio = GPt · No / Ne The ratio Ratio calculated by the above formula is, as shown in FIG. 9, the target gear position GP output from the shift operation command output unit 50a at the start of output of the shift command.
By changing t to the gear position on the top side (G
p (a) → Gp (b)) changes stepwise and decreases. Then, the gear shift is actually started, and the engine speed N
It increases as e decreases. Therefore, the ratio Rat
The change of io is examined, and when the ratio Ratio becomes equal to or higher than the slice level Sr_Ratio, it is determined that the gear is actually shifted up to the target gear position GPt. It is preferable that the slice level Sr_Ratio is set in consideration of a variation range of the ratio Ratio due to detection errors of the crank rotation sensor 23 and the output shaft rotation sensor 26, etc., in order to prevent erroneous determination of the gear switching timing.

In the method 5, the turbine torque Tt calculated by the torque calculating section 42 of the road surface gradient estimating section 41 is used.
As shown in FIG. 9, when the gear is actually shifted up, the turbine speed Nt decreases first, and then the engine speed Ne decreases with a slight delay. Therefore, the speed (slip) ratio e of the torque converter 3 becomes small, and FIG.
As shown in, the pump capacity coefficient Cp and the torque ratio t increase. Therefore, the turbine torque Tt (= Cp · t ·
Ne2) increases although the engine speed Ne becomes smaller. Therefore, after the output of the shift command is started, that is, the target gear position GPt output from the shift operation command output unit 50a is the top gear position (Gp (a) →
After switching to Gp (b)), the turbine torque Tt after a lapse of a fixed time t is held (Tt_hld), and the turbine torque Tt held by the turbine torque Tt is held.
ld plus offset kk (Tt_hld + k
k) When it reaches the above value, it is determined that the gear actually shifts up to the target gear position GPt. The offset amount kk is preferably set in consideration of a variation amount of the turbine torque Tt due to a detection error or the like of the crank rotation sensor 23 and the turbine rotation sensor 29, in order to prevent erroneous determination of the gear switching timing. Further, the timing for holding the turbine torque Tt depends on the processing speed of the AT control unit 40 and the transmission control valve 18
In consideration of the operation speed of, the turbine torque Tt is set to be held before the actual shift is started.
In the present embodiment, the setting is made so that the hold is held 0.1 seconds after the output of the shift command is started.

Next, the method of detecting the gear change timing in the case of downshifting will be described with reference to FIG. In the case of downshifting, unlike the case of upshifting, the end of the actual shifting operation is the gear switching timing.

In method 6, the engine speed Ne used in method 1 of FIG. 9 is used. The change in the engine speed Ne is examined, and when the engine speed Ne reaches a predetermined threshold value Ne1, it is determined that the gear is actually downshifted to the target gear position GPt. This is because when the gear is actually downshifted, the input shaft rotation speed of AT2 increases. Therefore, the timing at which the gear train 4 actually shifts up the gear position can be detected by examining the change in the engine speed Ne that changes similarly to the speed of the input shaft of the AT2. In this embodiment, the threshold Ne1 is calculated by the following formula. Ne1 = k · (Gp (c) / Gp (d)) · Ne0 where Ne0 is the engine speed at the start of output of the gear shift command, Gp (c) is the gear position before gear change, and Gp (d) is This is the gear position after gear switching.
Further, k is a constant of 1 or less. In the present embodiment, in order to prevent erroneous determination of the gear switching timing, the engine speed N due to a detection error of the crank angle rotation sensor 23 or the like
In consideration of the variation range of e, k is set to 0.9.

In method 7, the turbine speed Nt used in method 2 of FIG. 9 is used. The change in turbine rotational speed Nt is examined, and in the same manner as in method 6, it is determined that the downshift has occurred when turbine rotational speed Nt reaches a predetermined threshold value Nt1. The threshold value Nt1 is calculated by the following formula. Ne1 = k (Gp (c) / Gp (d)) Nt0 where Nt0 is the engine speed at the start of output of the shift command. Otherwise, the threshold value Ne1 of Method 6
It is similar to the formula for calculation.

In method 8, the gear ratio Gratio used in method 3 of FIG. 9 is used. When the gear ratio Gratio becomes equal to or higher than the slice level Sg'_Gratio, it is determined that the gear is actually downshifted to the target gear position GPt. Slice level Sg'_Gr
In order to prevent erroneous determination of gear switching timing, it is preferable to set the atio in consideration of the variation range of the gear ratio Gratio due to detection errors of the turbine rotation sensor 29 and the output shaft rotation sensor 26.

In method 9, the ratio Ratio used in method 4 of FIG. 9 is used. As shown in FIG. 10, the ratio Ratio is the target gear position G output from the shift operation command output unit 50a at the start of output of the shift command.
By changing Pt to the low gear position (G
p (c) → Gp (d)) changes stepwise and increases. Then, the gear shift is actually started, and the engine speed N
It decreases as e increases. Therefore, the ratio Rat
The change in io is examined, and when the ratio Ratio becomes equal to or lower than the slice level Sr′_Ratio, it is determined that the gear is actually downshifted to the target gear position GPt. The slice level Sr'_Ratio is preferably set in consideration of the range of variation of the Ratio Ratio due to detection errors of the crank rotation sensor 23 and the output shaft rotation sensor 26, etc. in order to prevent erroneous determination of the gear switching timing.

In method 10, the turbine torque Tt used in the method of FIG. 9 is used. As shown in FIG. 10, when the gear is actually downshifted, the turbine speed Nt first increases, and then the engine speed Ne increases with a slight delay. Therefore, the speed (slip) ratio e of the torque converter 3 increases, and as shown in FIG. 5, the pump capacity coefficient Cp and the torque ratio t decrease. Therefore, the turbine torque Tt (= Cp · t · Ne2) decreases although the engine speed Ne increases. Therefore, after the output of the shift command is started, that is, after the target gear position GPt output from the shift operation command output unit 50a is switched to the low gear position (Gp (c) → Gp (d)), a fixed time t The turbine torque Tt after the lapse of time is held (Tt_hld ′), and the turbine torque Tt holds the turbine torque Tt_hld ′ by an offset amount k.
When it reaches a value (Tt_hld '+ kk') or more in which k'is added, it is determined that the gear is actually downshifted to the target gear position GPt. Offset amount kk '
Is preferably set in consideration of the fluctuation amount of the turbine torque Tt due to the detection error of the crank rotation sensor 23 and the turbine rotation sensor 29 or the like in order to prevent erroneous determination of the gear switching timing. Further, the timing for holding the turbine torque Tt is the AT control unit 40.
In consideration of the processing speed and the operation speed of the transmission control valve 18, the turbine torque Tt is set to be held immediately after the actual shift is started. In the present embodiment, the setting is made so that the hold is held 0.5 seconds after the output of the shift command is started.

In this embodiment, the crank angle sensor 2
The actual gear change timing is detected by the method 1 and the method 6 using the engine speed Ne sequentially sent from No. 3.

Next, the operation of the AT control unit 40 will be described with reference to FIGS. 11 to 13. FIG.
1 to 13 are flow charts for explaining the operation of the AT controller 40.

First, the road surface slope estimating section 41 obtains a road surface slope sin θ during traveling (step 151). Next, the road surface state determination unit 47a of the gear determination unit 47 determines whether or not the road surface gradient sin θ obtained in step 151 is an uphill gradient (step 152). In the present embodiment, when the road surface slope sin θ obtained in step 151 is larger than the 3% slope, it is determined that the road surface is an upslope.

If it is determined in step 152 that the road is not an uphill slope, the process proceeds to step 166, and the road surface state determination unit 47a determines whether or not the road surface gradient sin θ obtained in step 151 is a downhill slope. In the present embodiment, θ of sin θ obtained in step 151 is −3.
When it is smaller than the% gradient, it is determined that the gradient is a downhill gradient. Here, when it is determined that the vehicle is descending, the process proceeds to step 167. On the other hand, if it is determined that the road is not downhill, it is already determined in step 152 that the road is not uphill, and thus it is determined that the road surface on which the vehicle is traveling is flat. Therefore, the routine proceeds to step 154, where the target gear position determination unit 47d of the gear setting unit 47 uses the shift diagram shown in FIG. 7 stored in the map memory 47c to send the current time from the throttle opening sensor 22. The target gear position GPt is determined according to the throttle opening degree Tvo and the current vehicle speed V specified by the current output shaft rotation speed No sent from the output rotation shaft sensor 26. Next, the transmission operation command output unit 50a of the control unit 50 operates the transmission control valve 18 so that the gear position GP of the gear train 4 becomes the target gear position GPt determined in step 154,
Then, the process returns to step 151.

When it is determined in step 152 that the vehicle is uphill, the process proceeds to step 153, and the throttle state determination section 47b of the gear determination section 47 causes the throttle opening degree sensor 22 to send the current throttle opening degree. Tvo is a preset control determination throttle opening T
It is determined whether it is smaller than vo_Up. This is shown in Figure 7.
As can be seen from the gear shift diagram shown in, the throttle opening T
This is because when vo is small, the vehicle speed V is not downshifted unless the vehicle speed V is sufficiently reduced, so that it is not possible to obtain sufficient driving force for traveling uphill. When the throttle opening Tvo is smaller than the control determination throttle opening Tvo_Up,
The process moves to step 155 in FIG. On the other hand, when it is determined that the throttle opening Tvo is equal to or larger than the control determination throttle opening Tvo_Up, the process proceeds to step 154.

In step 155, the gear information output unit 50b of the control unit 50 detects the current gear position GP of the gear train 4. And the next block 1
56, 157, and 158, the road surface state estimating unit 47a
Thus, it is determined whether θ of the road surface slope sin θ calculated in step 151 is greater than θ_Up1, greater than θ_Up2, and greater than θ_Up3, and case classification is performed. In this embodiment, θ_Up1 is 3
0% slope, θ_Up2 is 20% slope, θ_Up3 is 10
% Gradient.

The road surface slope sin calculated in step 151
When θ of θ is 10% or less, the process proceeds to step 165, and the target gear position determination unit 47d uses the shift diagram shown in FIG. 7 stored in the map memory 47c to output the throttle opening Tvo and the output. A target gear position GPt corresponding to the current vehicle speed V specified by the shaft rotation number No is determined. Next, the shift operation command output unit 50
By the operation a, the transmission control valve 18 is operated so that the gear position GP of the gear train 4 becomes the target gear position GP determined in step 154 (step 192), and then the process returns to step 151.

When θ of the road surface slope sin θ calculated in step 151 exceeds the gradient of 10% and is less than the gradient of 20%, the process proceeds to step 163, and the target gear position determination unit 47d detects the gear detected in step 155. It is compared whether or not the position GP is higher than the third speed. If it is larger than the third speed, the target gear position GPt is determined to be the third speed (step 164) and then the process proceeds to step 192. As a result, the driving force can be secured by downshifting with an upward gradient. On the other hand, if it is the third speed or lower, the process proceeds to step 165.

When θ of the road surface slope sin θ calculated in step 151 exceeds 20% slope and is 30% slope or less, the process proceeds to step 161, and the target gear position determination unit 47d detects the gear detected in step 155. It is compared whether or not the position GP is higher than the second speed. If it is greater than the second speed, the target gear position GPt is determined to be the second speed (step 162), and then the process proceeds to step 192. As a result, the driving force can be secured by downshifting with an upward gradient. On the other hand, if it is the second speed or lower, the process proceeds to step 165.

When θ of the road surface slope sin θ calculated in step 151 exceeds 30%, step 1
59, and the target gear position determination unit 47d sets the gear position GP detected in step 155 to 1
Compare to see if it is faster or faster. If it is greater than the first speed, the target gear position GP is determined to be the first speed (step 160), and then the process proceeds to step 192. As a result, the driving force can be secured by downshifting with an upward gradient. On the other hand, in the case of the first speed, the shift down cannot be performed any more, and therefore the process proceeds to step 165.

When it is determined in step 166 that the vehicle is descending, the throttle state determination unit 47b determines the current throttle opening Tvo sent from the throttle opening sensor 22 as the control determination throttle opening Tvo_Dow.
It is determined whether it is smaller than n (step 167). As can be seen from the shift line diagram shown in FIG. 7, when the throttle opening Tvo is small, the vehicle speed V is not sufficiently reduced until the vehicle is downshifted, so that sufficient engine braking can be obtained to drive downhill. Because it will disappear. The throttle opening Tvo is the control determination throttle opening Tvo_D
If it is determined that it is smaller than own, step 168.
Move to. On the other hand, if it is determined that the throttle opening Tvo is equal to or larger than the control determination throttle opening Tvo_Down, the process proceeds to step 154.

At step 168, the throttle opening Tv
When it is determined that o is smaller than the control determination throttle opening Tvo_Down, the acceleration determination unit 47e of the gear setting unit 47 causes the acceleration calculation unit 44 of the road surface slope estimation unit 41.
The absolute value of the acceleration α of the vehicle obtained in step 3 is the determination value α_Down
It is determined whether it is greater than or equal to. This is because when the absolute value of the acceleration is large, it is considered that the driver frequently uses the foot brake to reduce the vehicle speed. If the absolute value of the vehicle acceleration α is larger than the determination value α_Down, the process proceeds to step 169 of FIG. 13, and if it is less than or equal to the determination value α_Down, the process proceeds to step 154.

At step 169, the current gear position GP of the gear train 4 is detected by the gear information output section 50b of the control section 50. And the next block 1
70, 171, 172, the road surface state determination unit 47a
Therefore, whether θ of the road surface slope sin θ calculated in step 151 is smaller than θ_Down1 or not, θ_Down
It is determined whether or not it is smaller than 2 and whether or not it is smaller than θ_Down3, and case classification is performed. In this embodiment, θ
_Down1 is -30% gradient, θt_Down2 is -2
The gradient is 0% and θ_Down3 is a gradient of −10%.

The road surface slope sin calculated in step 151
When θ of θ is -10% or more, the routine proceeds to step 179, where the target gear position determination unit 47d uses the shift diagram shown in FIG. 7 stored in the map memory 47c,
The target gear position GPt corresponding to the current vehicle speed V specified by the throttle opening Tvo and the output shaft speed No is determined. Next, the gear shift operation command output unit 50b operates the transmission control valve 18 so that the gear position GP of the gear train 4 becomes the target gear position GP determined in step 179 (step 193), and then to step 151. Return.

When θ of the road surface slope sin θ calculated in step 151 is smaller than −10% slope and is equal to or larger than −20% slope, the process proceeds to step 177, and the target gear position determination unit 47d detects it in step 169. The determined gear position GP is compared with the third gear. If it is greater than the third speed, the gear determination unit 47 determines the target gear position GPt to the third speed (step 17
8) Then, the process proceeds to step 193. As a result, the engine braking by downshifting can be applied with a downhill slope. On the other hand, if the third speed or lower,
When it is determined that there is no need for engine braking due to downshift, the process proceeds to step 179.

When θ of the road surface gradient sin θ calculated in step 151 is smaller than -20% and is -30% or more, the process proceeds to step 175, and the target gear position determination unit 47d detects the gear detected in step 169. It is compared whether or not the position GP is higher than the second speed. If it is greater than the second speed, the gear determination unit 47 determines the target gear position GPt to the second speed (step 176), and then proceeds to step 193. As a result, the engine braking by downshifting can be applied with a downhill slope. On the other hand, if it is the second speed or lower, it is determined that there is no need for engine braking due to downshifting, and the routine proceeds to step 179.

When θ of the road surface slope sin θ calculated in step 151 exceeds -30%, step 17
3, the target gear position determination unit 47d
It is compared whether or not the gear position GP detected in step 169 is greater than the first speed. If it is larger than the first speed, the target gear position GPt is determined to be the first speed (step 17
4) Then, the process proceeds to step 193. As a result, the engine braking by downshifting can be applied with a downhill slope. On the other hand, in the case of the first speed, it is not possible to shift down any further, so the routine proceeds to step 179.

In this embodiment, the acceleration torque calculating section 45 of the road surface slope estimating section 41 calculates the acceleration resistance torque α using the rotating partial weight Wr corresponding to the gear position GP. For this reason, the acceleration resistance torque Tα can be accurately obtained regardless of the gear position GP, so that the road surface gradient with less error than the actual road surface gradient can be calculated.

FIG. 14 is a diagram for explaining the accuracy improvement of the road surface gradient during traveling by the road surface gradient estimation according to the present embodiment, and the estimated road surface gradient during traveling and various items necessary for estimating the road surface gradient. It is a timing chart of information. FIG.
In, the solid line indicates the value obtained by the present embodiment, and the alternate long and short dash line indicates the value obtained by the conventional road surface gradient estimating device.

As described above, in the conventional road surface gradient estimating device, the rotating portion equivalent weight Wr has a uniform value irrespective of the gear ratio. Therefore, as shown in FIG. 14, the acceleration resistance torque Tα (= (W + Wr) ・ α ・ Rt /
There was an error in g). Therefore, the acceleration resistance torque T
Gradient resistance torque Tθ (= To-Tr + T
θ) also has an error, and the road surface gradient sin θ (= Tθ / W · g · Rt) obtained based on the gradient resistance torque Tθ also has an error.

On the other hand, in the road surface slope estimating unit 41 of this embodiment, the acceleration torque calculating unit 45 uses the correction coefficient ψ (= Wr / W) according to the gear ratio of the gear position GP to accelerate the acceleration resistance torque. Tα (= (1 + ψ) ・ W ・ α ・
Rt / g) is calculated. Therefore, according to the present embodiment, as shown in FIG. 14, it is possible to calculate the road surface gradient sin θ with less error than the actual road surface gradient.

Further, in the present embodiment, the gear position information output section 50a of the control section 50 detects the actual gear change timing when the AT2 is in the shifting operation, and based on the detected timing, the current gear change timing is detected. The information about the gear position GP of is output. Therefore,
The gear position GP of the gear train 2 during the shift operation period.
The acceleration resistance torque α can be accurately calculated even during the gear shift operation. As a result, even during the gear shifting operation, it is possible to calculate the road surface gradient with less error than the actual road surface gradient.

Further, in the present embodiment, the usable gear position is set according to the road surface gradient, and the usable gear position can be used when the gear position set by using the shift schedule is on the top side of the usable gear position. The gear position is set to the target gear position. Therefore, according to the present embodiment, it is possible to secure the driving force on the uphill slope and automatically apply the engine braking on the downhill grade without providing a different shift schedule for each magnitude of the road surface gradient.

The present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist thereof. For example, in the above embodiment, the gear setting unit 47
In the road surface state determination unit 47a, the case classification of the road surface state during traveling is determined by a predetermined determination value (θ_Up1, θ_down).
However, the determination value used for different cases may be changed according to the vehicle speed V. In this case, for example, when the vehicle speed V is extremely high, the target gear position GP
Overrev can be avoided by changing the determination value used for different cases so that t is not set to the first speed or the second speed.

In the above embodiment, the pump torque calculating section 80 of the torque calculating section 42 of the road surface slope estimating section 41 calculates the pump capacity coefficient Cp, and the calculated pump capacity coefficient Cp is used to calculate the pump torque Tp. Are seeking. However, the present invention is not limited to this.

FIG. 15 is a schematic block diagram of a modified example of the torque calculation unit used in this embodiment. In addition, in the torque calculation unit 42a shown in FIG. 15, the torque calculation unit 4a shown in FIG.
Those having the same function as 2 are given the same reference numerals, and detailed description thereof will be omitted.

The torque calculation unit 42a shown in FIG. 15 differs from the torque calculation unit 42 shown in FIG. 4 in that the pump torque calculation unit 80 is used in place of the pump torque calculation unit 80. The pump torque calculation unit 80a includes a divider 57
And the engine torque T, which is the output shaft torque of the engine 1.
an engine torque calculation unit 53a for calculating e, and a subtractor 5
3b is used to provide a pump torque calculation unit 80a.

The engine torque calculating section 53a detects the crank angle sensor 23 using a map showing the relationship between the engine speed Ne of the engine 1, the throttle opening Tvo and the engine torque Te as shown in FIG. An engine torque Te corresponding to the engine speed Ne and the throttle opening Tvo detected by the throttle opening sensor 22 is obtained. The subtractor 53b is the engine torque calculation unit 53a.
Subtract the auxiliary machine torque Tacc consumed by the air conditioner and lamps from the engine torque Te obtained in. Thus, the pump torque Tp is obtained.

The torque calculation unit includes a pump torque calculation unit 80 shown in FIG. 4 and a pump torque calculation unit 80 shown in FIG.
Both b may be provided, and which pump torque calculation unit to use may be selected depending on the magnitude of the speed ratio e calculated by the divider 57. For example, when the speed ratio e is 0.
When it is 8 or less, the pump torque calculation unit 80 is used and 0.8
When it is larger, the pump torque calculation unit 80a may be used.

Further, although the present embodiment has been described as applied to a stepped automatic transmission, the present invention is not limited to this and is applied to a continuously variable automatic transmission (CVT). May be

[0098]

As described above, according to the present invention,
The acceleration resistance torque is obtained using the rotating portion equivalent weight Wr according to the gear ratio, and the road surface gradient is estimated using the acceleration resistance torque, so that an error with respect to the actual road surface gradient can be obtained regardless of the gear ratio. It is possible to calculate a small road surface gradient. In addition, by recognizing the road shape using the road gradient obtained in this way and performing gear shift control corresponding to it, the driving force is ensured by suppressing the upshift on the uphill slope, and the downshift also shifts. By suppressing the increase, the engine brake can be automatically applied.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing a vehicle drive system to which a control device for an automatic transmission according to an embodiment of the present invention is applied.

FIG. 2 is a schematic block diagram of an AT control unit.

FIG. 3 is a schematic block diagram of a road gradient estimating unit.

FIG. 4 is a schematic block diagram of a torque calculation unit.

FIG. 5 is a diagram showing a relationship among a speed ratio e, a capacity coefficient Cp, and a torque ratio t.

FIG. 6 is a diagram showing a relationship between a vehicle speed V and a flatland running resistance torque Tr.

FIG. 7 is a shift diagram showing a general shift schedule of an AT.

FIG. 8 is a flowchart for explaining the operation of the GP information output unit.

FIG. 9 is a timing chart for explaining a method of determining the actual gear change timing at the time of upshifting.

FIG. 10 is a timing chart for explaining a method of determining the actual gear change timing at the time of downshifting.

FIG. 11 is a flowchart for explaining the operation of the AT control unit.

FIG. 12 is a flowchart for explaining the operation of the AT control unit.

FIG. 13 is a flowchart for explaining the operation of the AT control unit.

FIG. 14 is a timing diagram illustrating the accuracy of road surface gradient estimation according to an embodiment of the present invention.

FIG. 15 is a schematic block diagram of a modified example of a torque calculation unit.

FIG. 16 is an engine speed Ne and an engine torque Te.
FIG. 3 is a diagram showing the relationship between the throttle opening and the throttle opening Tvo.

[Explanation of symbols]

 1 Engine 2 AT 3 Torque Converter 4 Gear Train 6 Differential Gear 7 Drive Shaft 8 Drive Wheel 12 Throttle Valve 17 Hydraulic Circuit 18 Transmission Control Valve 21 Air Flow Sensor 22 Throttle Opening Sensor 23 Crank Angle Sensor 26 Output Shaft Rotation Sensor 29 Turbine Rotation Sensor 30 Engine control unit 40 AT control unit 41 Road surface gradient estimation unit 42 Torque calculation unit 43 Running resistance calculation unit 44 Acceleration calculation unit 45 Acceleration torque calculation unit 46 Gradient calculation unit 47 Gear setting unit 50 Control unit

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical display location F16H 59:66 59:68 (72) Inventor Masahiko Masamoto Motoi, Hitachi, Naka, Ibaraki 2520 Takaba Ceremony Company Hitachi Ltd. Automotive Equipment Division (72) Inventor Kazuhiko Sato 2520 Takaba, Hitachinaka City, Ibaraki Prefecture Stock Company Hitachi Ltd. Automotive Equipment Division (72) Inventor Junichi Noda 2520 Takaba, Hitachinaka City, Ibaraki Prefecture Ceremony Company Hitachi Ltd. Automotive Equipment Division (72) Inventor Yuichiro Nanao 2520 Takaba, Hitachinaka City, Ibaraki Prefecture Hitachi Ltd. Automotive Equipment Division

Claims (9)

[Claims] 1. A road surface slope estimating device for estimating a road surface slope of a vehicle equipped with an automatic transmission while the vehicle is running, the vehicle speed detecting section detecting a vehicle speed of the vehicle, and driving wheels of the vehicle. A vehicle drive torque calculating section for obtaining a vehicle drive torque for the vehicle, a running resistance torque calculating section for obtaining a flatland running resistance torque based on the vehicle speed detected by the vehicle speed detecting means, and an acceleration torque calculating section for obtaining an acceleration resistance torque of the vehicle. And, the gradient torque is obtained by subtracting the leveling resistance torque calculated by the running resistance torque calculating section and the acceleration resistance torque calculated by the acceleration torque calculating section from the vehicle driving torque calculated by the vehicle driving torque calculating section to obtain the gradient torque. A gradient calculation unit that obtains a road surface gradient during traveling based on torque, wherein the acceleration torque calculation unit is an acceleration detection unit that detects acceleration of the vehicle. A gear ratio detecting means for detecting a gear ratio of the automatic transmission; and a gear ratio detecting means for detecting the gear ratio based on a correspondence between a predetermined gear ratio of the automatic transmission and a weight of a rotating portion of the vehicle. The rotating portion equivalent weight detecting means for detecting the rotating portion equivalent weight corresponding to the gear ratio, and the acceleration resistance based on the acceleration detected by the acceleration detecting means and the rotating portion equivalent weight detected by the rotating portion equivalent weight detecting means. A road surface gradient estimating device comprising: a calculating unit that calculates a torque; 2. A control device for an automatic transmission, which controls a gear ratio of an automatic transmission mounted on an automobile, comprising: a vehicle speed detecting unit for detecting a vehicle speed of the automobile; and a throttle valve opening degree of the automobile. A throttle opening detection unit for detecting, a vehicle drive torque calculation unit for obtaining a vehicle drive torque for driving the drive wheels of the automobile, and a running resistance for obtaining a flatland running resistance torque based on the vehicle speed detected by the vehicle speed detection unit. Torque calculation means, acceleration torque calculation means for obtaining the acceleration resistance torque of the vehicle, and flat ground running resistance torque and acceleration torque calculation calculated by the running resistance torque calculation means from the vehicle driving torque calculated by the vehicle driving torque calculation means And a gradient calculating means for obtaining a gradient torque by subtracting the acceleration resistance torque calculated by the means, and obtaining a road surface gradient during traveling based on the gradient torque. Based on the road gradient estimation unit, the vehicle speed detected by the vehicle speed detection unit, the throttle opening detected by the throttle opening detection unit, and the road surface gradient during traveling estimated by the road surface gradient estimation unit, the target gear shift is performed. A target gear ratio setting unit that sets a ratio, and a control unit that controls the automatic transmission so that the gear ratio becomes the target gear ratio set by the target gear ratio setting unit, and the acceleration torque calculation unit An acceleration detecting means for detecting an acceleration of the vehicle; a gear ratio detecting means for detecting a gear ratio of the automatic transmission; a correspondence between a preset gear ratio of the automatic transmission and a weight of a rotating portion of the vehicle. Based on the above, the rotating portion equivalent weight detecting means for detecting the rotating portion equivalent weight corresponding to the gear ratio detected by the gear ratio detecting means, the acceleration detected by the acceleration detecting means and the rotating portion equivalent weight. Control apparatus for an automatic transmission, characterized in that it comprises calculating means for calculating an acceleration resistance torque based on the rotational portion corresponding weight detected by means exit, a. 3. The target speed ratio setting unit determines the vehicle speed detected by the vehicle speed detecting unit and the throttle opening detecting unit from a speed change schedule showing a relationship between a vehicle speed, a throttle opening and a speed ratio prepared in advance. From the gear ratio extraction means for extracting the gear ratio corresponding to the detected throttle opening and a table showing the relationship between the road gradient and the minimum gear ratio prepared in advance, the road surface in motion estimated by the road gradient estimating section is calculated. A minimum speed ratio extracting means for extracting a minimum speed ratio corresponding to the gradient; and if the speed ratio extracted by the speed ratio extracting means is higher than the minimum speed ratio extracted by the minimum speed ratio extracting means, the target speed ratio is set as a target. 3. The control device for an automatic transmission according to claim 2, further comprising: a determination unit that sets the gear ratio and, if not, sets the minimum gear ratio to the target gear ratio. 4. The target gear ratio setting unit determines the vehicle speed detected by the vehicle speed detecting unit and the throttle opening detecting unit from a shift schedule showing a relationship between a vehicle speed, a throttle opening and a gear ratio prepared in advance. From the gear ratio extraction means for extracting the gear ratio corresponding to the detected throttle opening, and the table showing the relationship between the road gradient, the vehicle speed and the minimum gear ratio prepared in advance, during the running estimated by the road gradient estimating section. And a minimum speed ratio extracted by the minimum speed ratio extraction means, and a minimum speed ratio extraction means for extracting a minimum speed ratio corresponding to the vehicle speed detected by the vehicle speed detector and the road speed gradient extracted by the minimum speed ratio extraction means. 3. If the ratio is greater than the ratio, the speed change ratio is set to the target speed change ratio, and if it is not high, the determining unit that sets the minimum speed change ratio to the target speed change ratio is included. The control device of the dynamic transmission. 5. The determining unit determines that the gear ratio extracted by the gear ratio extracting unit is the minimum gear ratio when the throttle opening detected by the throttle opening detecting unit is larger than a preset threshold value. 5. The automatic transmission control device according to claim 3, wherein the gear ratio is set to the target gear ratio even when it is not larger than the minimum gear ratio extracted by the extracting means. 6. The automatic transmission is a stepped automatic transmission having a plurality of gear stages, and the target gear ratio setting unit sets a target gear ratio as the target gear ratio, and The gear ratio detecting means has a change timing detecting means for detecting a gear change timing of the automatic transmission. When the change timing detecting means detects the gear change timing, the gear ratio is changed. The control device for an automatic transmission according to claim 2, 3, 4 or 5, wherein a target gear set by a setting unit is detected as the gear ratio. 7. The switching timing detection means has an engine rotation speed detection means for detecting the rotation speed of an engine mounted on the automobile, and detects a change in the engine rotation speed detected by the engine rotation speed detection means. The control device for the automatic transmission according to claim 6, wherein the switching timing of the gear stage of the automatic transmission is detected by performing the above. 8. The acceleration detecting means obtains the acceleration of the vehicle by differentiating the vehicle speed detected by the vehicle speed detecting section with respect to time.
6. A control device for an automatic transmission according to 6 or 7. 9. The automatic transmission is configured such that a driving force from an engine mounted on the automobile is input via a torque converter, and the vehicle driving torque calculation means detects a rotational speed of the engine. Engine rotation speed detection means, turbine rotation speed detection means for detecting the rotation speed of the turbine of the torque converter, turbine rotation speed detected by the turbine rotation speed detection means and engine rotation speed detected by the engine rotation speed detection means A slip ratio calculating means for calculating a slip ratio of the torque converter by calculating a ratio with a number; and a slip ratio of the torque converter prepared in advance,
From a map showing the relationship between the pump torque and the torque ratio of the turbine torque, a torque ratio calculating means for obtaining a torque ratio according to the slip ratio detected by the slip ratio detecting means, and a slip ratio of the torque converter prepared in advance. An engine detected by the engine speed detecting means, which has a pump capacity coefficient calculating means for obtaining a pump capacity coefficient corresponding to the slip ratio calculated by the slip ratio calculating means from a map showing a relationship with the pump capacity coefficient. Wheel drive torque is calculated based on the number of revolutions, the gear ratio obtained by the gear ratio calculation means, the torque ratio obtained by the torque ratio calculation means, and the pump capacity coefficient obtained by the pump capacity coefficient calculation means. Claims 2, 3, 4, 5,
A control device for an automatic transmission according to 6, 7, or 8.