JP3260190B2 - Vehicle output shaft torque estimation device and vehicle weight calculation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output shaft torque calculating device for a running automobile, and more particularly to an output shaft torque estimating device and a vehicle weight calculating device capable of obtaining an output shaft torque, a gradient and a vehicle weight. It is.

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Application Laid-Open No. 3-24362, for example, an engine load torque obtained by estimating an engine load torque from a throttle opening is known.

[0003]

However, in the prior art, since the engine load torque is estimated from the throttle opening, the torque difference due to the difference in engine speed and the torque consumed by accessories are reduced. It is not taken into account and the final output shaft torque cannot be obtained. For this reason, there has been a problem in that it is not possible to use the vehicle in a finely-tuned manner, such as in a vehicle speed change control.

When controlling an automatic transmission, it is desirable to select a low gear when the vehicle body is heavy to make it easier to output torque, and to select a high gear when the vehicle body is light to reduce fuel consumption. There is a problem that the cost of the sensor for detecting the vehicle weight is expensive. The present invention has been made in view of such a problem, and an object of the present invention is to provide an output that can accurately determine an output shaft torque, a gradient, and a vehicle weight without newly providing a special sensor. An object of the present invention is to provide a shaft torque estimating device and a vehicle weight calculating device.

[0005]

In order to achieve the above object, an apparatus for estimating the output shaft torque of an automobile according to the present invention comprises:
Basically, the engine, automatic with torque converter
Transmission with at least one microcomputer
A control device for controlling the engine and the automatic transmission
An output shaft torque estimating device for an automobile included in
The torque estimating device calculates a torque of an output shaft of the automatic transmission.
A driving torque calculating means for estimating the driving torque;
The means uses a prestored engine torque characteristic.
First drive torque calculating means for estimating the drive torque;
Drive torque using the characteristics of the torque converter
Second drive torque calculating means for estimating torque,
In the area where the converter slip is large, the second drive torque
Using the torque calculation means, the slip of the torque converter is small.
In the region, the first drive torque calculating means is used.
And torque switching means for switching.
From the second drive torque calculating means by the switching means
Two-wheel drive immediately before switching to the first drive torque calculating means
The torque deviation of the dynamic torque calculation means is used as an auxiliary for the engine.
Auxiliary torque learning hand that learns and stores as the load torque of
And a step .

[0006] The output shaft torque of the vehicle according to the present invention.
A specific aspect of the estimating device is that the torque estimating device is
From the second drive torque calculating means, the first drive torque operation is performed.
After switching to the first driving torque calculating means.
The auxiliary torque is stored in the auxiliary torque learning means from the estimated torque of the gear.
The auxiliary equipment torque is subtracted from the pump torque of the automatic transmission.
Correcting, the torque estimating device, the estimated
To estimate the weight of the vehicle based on the torque of the output shaft
Having a step, wherein the torque estimating device
For estimating the road gradient based on the output shaft torque
Having a step, or the torque estimating device,
In estimating the gradient, the automatic
It is characterized by comprising means for correcting the weight of the moving vehicle .

[0007]

The output torque of the engine is calculated from the characteristic equation of the engine or the table. Further, the input torque of the torque converter is calculated using a characteristic formula or a table of the torque converter. The accessory torque of the air conditioner or the like is calculated by the two types of torque and the accessory torque learning means. Also,
A coast, engine brake and lock-up determination means are provided to select an optimum torque according to the driving state of the vehicle. After that, it is converted into the final output shaft torque by the gear ratio table.

When estimating the vehicle weight, a means for detecting a change in the throttle opening is used to detect a change in the throttle opening.
The two states are determined. Further, two states are stored by the data storage means. After that, the vehicle weight is calculated using the data of the air resistance coefficient, the entire projected area, the tire radius, and the weight equivalent to the rotating portion together with the stored data.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a block diagram according to an embodiment of the output shaft torque estimating device of the present invention. In FIG. 1, a torque converter torque calculating means 1 receives a turbine speed Nt and an engine speed Ne, performs a map search, and calculates (multiplies the pump capacity coefficient by the square of the engine speed) a torque on the input side of the torque converter. Find Tp. The engine torque calculating means 2 receives the engine speed Ne and the throttle opening degree θ, and obtains the engine output torque Te by searching a map.

The speed ratio calculating means 3 calculates the turbine speed Nt.
And the engine speed Ne are input to determine the speed ratio Nt / Ne. The shift detecting means 4 detects the current gear ratio CUR.
GP and the gear ratio NXTGP after the shift are detected, and if there is a difference therebetween, a signal for determining that the gear is being shifted is output. The accessory torque learning means 5 receives the torque Tp on the input side of the torque converter, the shifting flag, the throttle opening, the speed ratio e, and the engine output torque Te, and outputs the accessory torque TACC by calculation. . Tp between the torque converter torque calculating means 1 and the engine torque calculating means 2 in a steady state.
= Te-TACC, and the engine output torque T
engine torque Te by subtracting accessory torque TACC from e
Calculate ₁ . This auxiliary machine torque TACC is not learned and calculated during gear shifting and when the speed ratio e is within a certain range.

The coast engine brake lock-up (L / U) determining means 7 includes a speed ratio e, a lock-up L
/ U, the throttle opening θ, and the torque of the torque converter are input, the coast, engine brake, and lockup L / U are determined, and the state signal is input to the torque switching means 8. Torque switching means 8 inputs the input side of the torque Tp of the torque converter, the engine torque Te _1. Since no torque is output during the coast, the torque is forcibly set to 0, and Te ₂ is input to the torque switching means 8. In the torque switching means 8, when the speed ratio e is lower than a certain value, Tp is set.
e ₁ , Te ₂ during coasting, Te ₁ during engine braking
Is selected, the selected torque signal Tsel is output, and a search value from the speed ratio-torque map 9, the gear ratio table 10, and the final gear ratio 11 is multiplied to finally output the output shaft torque To.

[0012]

## EQU00001 ## To = Ne ² .tau. (E) .t (e) .r (G
p) · rf _where τ (e) is the torque capacity coefficient of the torque converter, t
(E) the torque ratio of the torque converter, r (Gp) is the gear ratio of each gear position, r _f is the final gear ratio. Although not shown, a low-pass filter is provided to remove To noise. The switching conditions of the torque switching means 8 will be described later.

As described above, when the speed ratio e of the torque converter is high, or during coasting, engine braking, or lock-up, the output torque obtained from the torque characteristics of the engine is more accurate than the output torque obtained from the characteristics of the torque converter. Therefore, it is possible to reduce the torque estimation error by switching the torque to be used depending on the state of the speed ratio e, the lock-up L / U, the throttle opening θ, the torque converter torque, and the like.

Next, each component block of the output shaft torque estimating apparatus shown in FIG. 1 will be described in detail. First, FIG.
FIG. 3 is a block diagram of an engine torque calculating means 2. Since the output torque Te of the engine changes substantially depending only on the throttle opening θ and the engine speed Ne, a relationship between the engine torque Te, the throttle opening θ, and the engine speed Ne is prepared as a table, and the throttle opening degree is determined. The engine torque Te is searched by inputting θ and the engine speed Ne. In order to obtain the final output shaft torque using this, the auxiliary equipment torque TACC of the air conditioner or the like must be subtracted.

Next, details of the torque converter torque calculating means 1 will be described. FIG. 3 is a block diagram of the torque converter torque calculating means 1. The details will be described using Expressions 2, 3, and 4. The input / output rotation speed ratio e of the torque converter is as shown in Expression 2 below.

[0016]

E = Nt / Ne The pump torque Tp on the input side of the torque converter is expressed by Equation 3.
Shown in

[0017]

Tp = Ne ² · τ (e) where τ (e) is a pump displacement coefficient of the torque converter. Further, the output side turbine torque Tt is as shown in Expression 4.

[0018]

Tt = t (e) · Tp where t (e) is the torque ratio of the torque converter. In FIG. 3, the turbine speed Nt and the engine speed Ne are input to the speed ratio calculating means 3 to obtain a speed ratio e, from which a pump torque coefficient τ (e) is obtained from a pump torque map 12, and this pump torque coefficient The pump torque Tp can be obtained by multiplying τ (e) by the square of the engine speed. However, when the speed ratio e is close to 1, the pump torque coefficient τ (e) changes abruptly, so that the calculation error of the speed ratio e is amplified and reflected, and the accuracy is reduced. Therefore, in this case, it is desirable to use the engine torque Te.

Next, the calculation of the speed ratio e will be described in detail. FIG. 4 shows a block diagram for obtaining the speed ratio e. The pulse signal of the turbine sensor 13 is used to calculate the turbine speed
At 6, the cycle is measured and converted into the turbine speed Nt. The pulse signal of the engine rotation sensor 14 is cycle-measured by the engine speed calculating means 15 and is converted into the engine speed Ne. The calculated turbine speed Nt and engine speed Ne are input to the speed ratio calculating means 3, and the speed ratio e is calculated.

FIG. 5 is a block diagram of another embodiment for obtaining the speed ratio e. In FIG. 5, the vehicle speed and the gear ratio table 10 obtained by measuring the cycle of the pulse signal from the vehicle speed sensor 16 by the vehicle speed converting means 17 are shown.
From the input signal of the gear position retrieved from, the turbine speed conversion means 18 converts the input signal to the turbine speed. The pulse signal of the engine rotation sensor 14 is cycle-measured by the engine speed calculating means 15 and is converted into the engine speed. Then, the turbine speed Nt and the engine speed Ne calculated in this way are input to the speed ratio calculating means 3 to obtain the speed ratio e.

Next, the accessory torque learning means 5 will be described in detail. FIG. 6 is a block diagram of the accessory torque learning means 5. The accessory torque TACC can be obtained from the difference between the engine torque Te and the pump torque Tp. However, it is desirable not to perform the learning of the accessory torque TACC during a gear shift, when the speed ratio e is close to 1, or when the speed ratio e changes greatly. For this purpose, a holding means 19 is provided to perform a hold process by using the speed ratio e, the change rate Δe of the speed ratio e, and the shifting flag as input signals, and hold in an undesirable state so as not to output noise. I have.

FIG. 7 shows a processing flowchart of the accessory torque learning means 5. The learning of the accessory torque TACC is permitted, for example, when all of the following three conditions are satisfied, as shown in FIG.

(1) The gear is not being shifted. (2) The speed ratio e is equal to or less than 1 and smaller than a predetermined value Xe close to 1. (3) The absolute value of the rate of change Δe of the speed ratio e is smaller than a predetermined value XΔe. If the above three conditions are satisfied, the learning is updated by subtracting the pump torque Tp from the engine torque Te and assigning it to the accessory torque TACC. That is, it is determined in step 101 that the gear is not being shifted from the shifting flag used in the shift control, and it is determined in step 102 that the speed ratio e is smaller than the predetermined value Xe. Further, when the absolute value of the rate of change Δe of the speed ratio e calculated in the processing 151 is smaller than XΔe, the calculation of the accessory torque TACC is executed in the processing 104.

Next, coast engine brake L /
The U detecting means will be described in detail. Figure 8 shows the coast
5 is a processing flowchart of an engine brake / L / U detection unit 7; 8, the first process 105, if the speed ratio e is greater than the predetermined value Xe is selected torque Te ₁ minus the accessory torque TACC from the engine torque Te, conversely, smaller selects the pump torque Tp . This is performed to improve the calculation accuracy. If the coast is detected by the process 108, Te
Select ₂ and calculate as torque is not being transmitted. The processing 110, when detecting the engine brake and the lock-up in the process 112, calculates the output shaft torque select Te ₁ based on the engine torque.

FIG. 9 shows a coast, engine brake, L
This is another embodiment of the / U detection means. In FIG. 9, if it is determined in step 114 that the speed ratio e is larger than the predetermined value Xe, and if the output shaft torque To is smaller than the running resistance torque _{TRL in step} 115, step 117 is determined to be in the coast state and Te is determined. ₂ select, conversely, to in the process 115 is greater than T _RL, the process 116 selects a Te ₁ determines that the engine brake or normal driving conditions. If the speed ratio e is smaller than the predetermined value Xe, the process 118 selects the pump torque Tp to improve the calculation accuracy. The lock-up solenoid by the processing 119 if the on state, the process 120 selects a Te ₁ determines that the lock-up.

FIG. 10 shows a coast engine brake L
Another embodiment of the / U detection means will be described. In FIG. 10, when the speed ratio e is determined to be larger than the predetermined value Xe by the process 121, and the one-way clutch input side rotation speed Nowci and the one-way clutch output side rotation speed Nowco are not equal in the process 122, the process 124 is in the coast state. it is determined that selecting the Te _2, Nowci and Nowc
If o is equal, the process 123 determines that the engine is in the brake state or the normal drive state, and selects Te ₁ . Also,
If the speed ratio e is smaller than the predetermined value Xe, the process 125 selects the pump torque Tp to improve the calculation accuracy. If the lock-up solenoid is ON in step 126, step 127 is determined to be lock-up and Te ₁
Select

Here, as is well known, the one-way clutch is a clutch having a structure that transmits torque for rotating the tire from the engine but does not transmit torque for rotating the engine from the tire. Therefore, the coast state can be detected by monitoring the input / output rotation speed. FIG. 11 shows another embodiment of the coast / engine brake / L / U detecting means. In FIG. 11, when the throttle opening θ is smaller than the predetermined value Xθ by the process 128, there is a high possibility that the vehicle is in the engine brake or coast state. Therefore, when the speed ratio e is larger than 1 by the process 129, the process 1
At step 30, when the engine braking state is determined, Te ₁ is selected, and when the speed ratio e is smaller than or equal to 1, processing 131 is executed.
Determines that the vehicle is in the coast state and selects Te ₂ . If the throttle opening θ is larger than the predetermined value Xθ, the process 128 is determined to be in a normal driving state, and if the speed ratio e is larger than the predetermined value Xe in the process 132, the process 13 is executed.
3 Select Te _1, when e is equal predetermined value Xe smaller than the contrary, the process 134 is to improve the calculation accuracy by selecting Tp. If the lock-up solenoid is in the ON state in step 135, step 136 determines that lock-up has occurred and selects Te1.

Next, the details of the torque transmission mechanism from the engine to the tire will be described. FIG. 12 shows an embodiment of a torque transmission mechanism from the engine to the tire. FIG.
At 2, the output of the engine 201 enters the input shaft of the torque converter 203. A speed sensor including a gear 214 and an electromagnetic pickup 202 is attached to this shaft. The output from the torque converter 203 enters the input shaft of the gear 205. A speed sensor including a gear 213 and an electromagnetic pickup 204 is attached to this shaft. Further, the output of the gear 205 is input to a one-way clutch 212 and an overrun clutch 206 provided in a bypass manner. As described above, the one-way clutch has a mechanism that transmits torque for rotating the tire from the engine side, but does not transmit torque for rotating the engine from the tire side. The overrun clutch is a mechanism that transmits torque when the clutch is engaged and does not transmit torque when the clutch is not engaged. Therefore, when the engine brake is applied, the overrun clutch must be engaged. The outputs of the one-way clutch 212 and the overrun clutch 206 are input to a differential gear 209. This shaft has a gear 211 and an electromagnetic pickup 2
07 is attached. The output torque of the differential gear 209 is
And transmitted as drive torque.

As described above, since the output torque of the engine can be estimated in advance from the throttle opening and the engine speed, it is possible to accurately estimate the driving torque in consideration of the engine speed and to obtain the torque obtained from the torque characteristics of the torque converter. Since there is a certain relationship between the converter torque, the engine output torque, and the accessory torque, the accessory torque is estimated, and the torque of the final output shaft is calculated.

Next, an embodiment to which the aforementioned output shaft torque estimation is applied will be described in detail. FIG. 13 is a diagram showing a state in which the accelerator is further depressed while the vehicle is climbing a slope having a constant gradient, and the throttle opening is changed from θ1 to θ2. FIG. 14 shows an embodiment in which vehicle weight estimation is performed using a value calculated by the output shaft torque estimation.

First, the concept of FIG. 14 will be described with reference to FIG. 13 and equations. Assuming that the throttle opening changes from θ1 to θ2, the acceleration of the vehicle changes from α1 to α2, and the calculated value of the output shaft torque changes from To1 to To2.
The vehicle weight is derived from these two state changes. First, in order to distinguish these two states, the difference processing 306 and the LPF processing 3
07, derivative Δ of throttle opening by absolute value processing 308
When the absolute value of θ is smaller than the predetermined value XΔθ, it is determined that the state is stable, and the sampling of the acceleration α, the output shaft torque To, and the square of the vehicle speed Vsp is performed by the sampling processes 317, 302, and 310. Thereafter, storage processing 303, 31
1,318 by To1, Vsp ₁ ^2, and stores the [alpha] 1.
Then, when the stable state is detected again, the vehicle weight is derived from the previously stored values and the current values. The running resistance F _R when the vehicle runs is composed of the sum of the rolling resistance F _r , the air resistance F _A , and the gradient resistance F _Z as shown in Expression 5 below.
Equations 6, 7, and 8 show dynamic equations of the rolling resistance F _r , the air resistance F _A , and the gradient resistance F _Z.

[0032]

## EQU5 ## F _R = F _r + F _A + F _Z

[0033]

[6] _{F r = μ r · Wo ·} g

[0034]

[Equation 7] _{F A = μ l · A ·} Vsp 2

[0035]

Equation 8] F Z ₌ Wo · g · sinz here, Wo is the total weight automobiles, Wr is rotating means equivalent weight, mu _r is rolling resistance coefficient, mu _l is an air resistance coefficient, A is entirely projected area of the motor vehicle, And z indicate the angle of the gradient. As shown in FIG. 23, the calculation load can be reduced by calculating _Fr and F _A in advance and storing them in a data table. In addition, by performing interpolation between data points using linear interpolation or the like, highly accurate calculations can be realized with a small amount of data.

Equations 9 can be transformed using Equations 5 to 8 above. In addition, by performing interpolation between data points using linear interpolation or the like, highly accurate calculations can be realized with a small amount of data.

[0037]

[Equation 9] _{F R = μ r · Wo ·} g + μ l · A · Vsp 2 +
Wo · g · sinz Also, the acceleration resistance Fα required for acceleration is given by Expression 10.

[0038]

Fα = (Wo + Wr) · α Accordingly, the force F _{O of the} output shaft is represented by Expression 11.

[0039]

F _o = Fα + F _r + F _A + F _Z Here, when the whole is expressed in the form of torque, Expression 12 is obtained at time t ₁ and Expression 13 is obtained at time t ₂ . Equation 14 shows the difference between the two equations. By transforming this, equation 15 is obtained, and the vehicle weight Wo can be obtained.

[0040]

[Expression 12] To1 = (Wo + Wr) · R · α1 + μ _r
· Wo · R · g + μ l · A · R · Vsp 1 2 + sinz 1 · W
o ・ R ・ g

[0041]

[Expression 13] To2 = (Wo + Wr) · R · α2 + μ _r
· Wo · R · g + μ l · A · R · Vsp 2 2 + sinz 2 · W
o ・ R ・ g

[0042]

## EQU14 ## To1-To2 = (Wo + Wr) R (α1
_{-Α2) + μ l · A ·} R (Vsp 1 2 -Vsp 2 2)

[0043]

(Equation 15)

[0044] Thus, term air resistance coefficient which depends on the square of Vsp (μ _l) 312, the entire surface projected area (A) 313,
It is obtained by multiplying the tire radius (R) 314. The term of the acceleration α is obtained by multiplying the tire radius (R) 319.
Finally, the vehicle weight Wo can be obtained by dividing by the dividing means 304 and subtracting the weight (Wr) 305 corresponding to the rotating part.

The calculation accuracy can be improved since the data is more stably changed in the direction in which the throttle opening is returned from the direction in which the pedal is stepped up and the foot is released from the throttle, and the data is more stably changed thereafter.
Next, the vehicle weight estimation will be described with reference to a flowchart.
FIG. 15 is an example of a flowchart of the vehicle weight estimation. In step 150, the throttle opening θ2, acceleration α2, and output shaft torque To2 are fetched. By the processing 115, the absolute value of the differential value Δθ of the throttle opening θ is smaller than the predetermined value XΔθ,
When the absolute value of the difference between the current throttle opening θ2 and the stored throttle opening θ1 is smaller than the predetermined value Xθ by the processing 152, it is determined that the state has not changed yet. Then, the throttle opening θ1, the acceleration α1, and the output shaft torque To1 are stored by the process 153. Conversely, if the difference between the calculated throttle opening degree θ2 and the stored throttle opening degree θ1 is larger than the predetermined value Xθ, it is determined that the state has changed, and the vehicle weight is calculated through processing 154.

As described above, under the condition that the gradient is constant, there is a constant relationship between the vehicle weight, the output shaft torque, the vehicle speed, and the acceleration in two states with different throttle openings.
The vehicle weight can be obtained by calculation without providing a new sensor. Next, an example applied to gradient estimation will be described. FIG.
FIG. 6 shows an embodiment in which the gradient is estimated using the value calculated by the output shaft torque estimation. First, the concept of FIG. 16 will be described below using equations.

The running resistance F _R when the car runs is
As in the case of the above-described embodiment, as shown in Expression 5, it is composed of the sum of the rolling resistance, the air resistance, and the gradient resistance. Equation 6
The formulas are shown in FIGS. Further, the acceleration resistance Fα required for acceleration is represented by Expression 10 above. Here, when the gradient resistance is obtained, Equation 16 is obtained. When the resistance is transformed, Equation 17 is obtained. When the resistance is expressed by torque, Equation 18 is obtained, and the slope z ^* can be calculated.

[0048]

Wo · g · sinz = F _O − (F _r + F _A ) −F
α

[0049]

[Equation 17]

[0050]

(Equation 18)

Here, the driving force transmitted from the engine, the torque converter and the gear train is F _O. Further, the flat ground running torque (air resistance + rolling resistance) T _RL based on the flat road running resistance is shown in Expression 19.

[0052]

T _RL = R · (F _r + F _A ) The acceleration α of the vehicle is obtained from the differential (difference) of the vehicle speed. Therefore, the output shaft from the torque estimation unit 301 in the resulting output shaft torque T _O ^*, a running resistance obtained from the flat running resistance storage unit 403, LPF unit 406 and the vehicle weight / gravity to reduce the difference means 405 and the noise 407 and tire radius 40
8 is subtracted from the acceleration resistance obtained from Eq. 8 and divided by the vehicle weight and the tire radius 404 using the dividing means 402 to obtain a gradient z ^*.
Can be obtained. Note that the LPF unit 401 and the LPF
The means 406 can be combined and inserted before or after the dividing means 402.

However, the gradient estimation uses the provisional vehicle weight W, and an error in this determination results in an error. Therefore, when there is a vehicle weight error, it is necessary to correct the provisional vehicle weight W. FIG. 18 shows a calculation block diagram of the error Werr of the vehicle weight. First, the concept of FIG. 18 will be described with reference to FIG. 17 and mathematical expressions. FIG. 17 shows that the accelerator is released when the vehicle is climbing a slope with a constant gradient, and the throttle opening is changed from θ1 to θ.
The state changed to 2 is shown. At this time, the acceleration of the vehicle changes from α1 to α2, and the calculated value of the gradient changes from z ₁ ^* to z ₂ ^* . The vehicle weight is derived from these two state changes. Note that the gradient z
^In calculating ^* , a provisionally determined vehicle weight W is used.

First, in order to distinguish these two states,
Difference means 505, LPF means 506, absolute value means 507
The absolute value of the derivative Δθ of the throttle opening obtained by
When it is smaller than XΔθ, it is determined that the state is stable.
Calculation values of acceleration α and gradient by
z^*Are sampled and stored by the storage means 503 and 511.
Remember. Then, when a stable state is detected again,
The vehicle weight is derived from the previously stored values and the current values. Mentioned earlier
As shown in FIG. _RHako
Rolling resistance F_r, Air resistance F_A, Gradient resistance F_ZRespectively,
It is as shown in Formulas 5-8. The acceleration required for acceleration is also
The fast resistance Fα is represented by Expression 10. Further, the output shaft force F_O
Is represented by Expression 11. Here, the whole is expressed in the form of torque
And time t₁In the case of, Equation 12, time t_TwoAt the time of
Become. On the other hand, the calculated gradient z^*Is a predetermined time
It can be obtained from Expression 18 using the constant vehicle weight W. Obedience
The time t₁The calculated gradient z when₁ ^*Is the formula 20
And

[0055]

(Equation 20)

By substituting equation (12) into this equation, equation (21) is obtained.

[0057]

(Equation 21)

The calculated gradient z ₂ ^{* at} the time t ₂ is given by the following equation (22).

[0059]

(Equation 22)

By substituting equation (13) into this equation, equation (23) is obtained.

[0061]

(Equation 23)

Here, the difference between Equation 21 and Equation 23 is taken, and
The interval between time t ₁ and time t ₂ is very small, and the true gradient sinz ₁
If sinz ₂ does not change, Equation 24 is obtained, which can be transformed into Equation 25.

[0063]

Z ₁ ^* −z ₂ ^* = (Wo−W) (α 1 −α 2) /
W ・ g

[0064]

(Equation 25)

[0065]

W = Wo + Werr Since the relationship between the provisional vehicle weight W, the true vehicle weight Wo, and the vehicle weight error Werr is represented by Equation 26, the vehicle weight error Werr is represented by Equation 2.
7 can be obtained.

[0066]

[Equation 27]

The above will be described with reference to a block diagram.
The terms of the gradient z ^* obtained by the gradient estimating means 501, the sampling means 502, and the storage means 503 are the provisional vehicle weight and the gravity 50.
Multiplying by 4 gives the term of the numerator of the division in Equation 27. Also, the acceleration α is calculated by the difference means 508 and the LPF means 509.
Is calculated, and the term of the denominator of Expression 27 can be obtained using the sampling unit 510 and the storage unit 511. Therefore, this divisor becomes the vehicle weight error Werr.

Next, a description will be given based on a flowchart.
FIG. 19 is an example of a flowchart for calculating the vehicle weight error.
In FIG. 19, the absolute value of the differential value Δθ of the throttle opening θ is smaller than a predetermined value XΔθ by the processing 190, and
The absolute value of the difference between the current throttle opening θ2 and the stored throttle opening θ1 by the process 191 is equal to a predetermined value Xθ.
If it is smaller, it is determined that there is no change in the state and processing 1
At 92, the throttle opening θ1, the acceleration α1, and the calculated gradient z ₁ ^* are stored. Conversely, the calculated throttle opening θ
2 and the difference between the stored throttle opening θ1 and the predetermined value X
If it is larger than θ, it is determined that the state has changed, and processing 19
3, the vehicle weight error Werr is calculated. The vehicle weight error Werr thus obtained can be used for correcting the provisional vehicle weight W.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It can be performed. For example, in the embodiment of FIG. 1, if the permissible range of the estimation error is wide, it is possible to estimate the output shaft torque To only by the torque converter torque calculating means 1 or only the engine torque calculating means 2.

In the embodiment shown in FIG. 14, the time between time t ₁ and time t ₂ is generally very small, and the change in vehicle speed Vsp ₁ and vehicle speed Vsp ₂ is also considered to be very small.
The term depending on P can be omitted. Furthermore, by sampling the data at an earlier time t ₃ from the time t ₁ is provided a storage unit of the data, by calculating the vehicle weight at the time later than the provided time t ₂ the delay means t _4, is to use a more stable data The calculation accuracy of the completed vehicle weight is improved. However, at time t ₃ ,
The absolute value of Δθ at time t ₄ should not be performed calculation of the vehicle weight greater than the predetermined value Xderutashita.

In the correction of FIG. 19, in addition to directly correcting the obtained vehicle weight error Werr, if the sign of the vehicle weight error is plus, the minute vehicle weight ΔW is subtracted from the provisional vehicle weight W, and the result is subtracted. If there is, add a small vehicle weight ΔW to the provisional vehicle weight W,
It is also possible to perform integral correction in which correction is performed little by little. Further, in each of the above embodiments, the resistance torque at the time of steering is omitted, but more accurate estimation is possible by detecting the steering angle and considering the steering resistance torque. Although the engine is used in the description, the torque of the motor can be calculated from the current flowing into the motor even when the motor is used, and can be used for estimating the output shaft torque, the gradient, and the vehicle weight.

Further, in the embodiment of FIG. 20, FIG.
The vehicle weight error estimating means 4002 shown in FIG. 16 is used to correct the vehicle weight parameter used in the vehicle weight estimating means 4001 shown in FIG. 16, and a more accurate gradient value z ^* can be calculated. This will be described in more detail. As shown in FIG. 16, the gradient z ^* is obtained by processing the torque estimation result. Therefore, the vehicle weight W, which is a vehicle parameter, and the equivalent vehicle weight W including inertia W + Wr
Is calculated using. Therefore, when the vehicle weight W changes, the gradient estimation result shifts.

For example, it is assumed that the vehicle is accelerated from a constant speed operation state. If the vehicle weight deviates from the initially set W due to an increase in the number of passengers, the acceleration torque in the process of FIG. 16 becomes smaller than the actual value. As described above, the vehicle weight can be detected based on the deviation of the estimated gradient value immediately after acceleration or deceleration.
Shown in FIG. 19 shows a flowchart of the vehicle weight error estimation. FIG. 20 shows a means 4001 for correcting the three vehicle-weight dependent points shown in FIG. 16 using the vehicle weight correction value Werr corrected by the block diagram shown in FIG. FIG. 21 shows a specific configuration thereof.

The Werr is used for correcting the provisional vehicle weight W of 404, the provisional vehicle weight W of 407 and the provisional vehicle weight W of 403, and the flat ground running resistance of 403. Since the vehicle weight correction value is updated immediately after acceleration or deceleration, the three values are corrected thereafter. Among them, it is also possible to select only 407 having a high degree of contribution to the gradient calculation, or to select and use only one having a high degree of influence among the three.

Since the change in vehicle weight is mainly determined by the number of passengers, the load of luggage, and the weight of gasoline, it is not necessary to perform extra correction within the required number of times for the correction operation immediately after acceleration / deceleration.
Here, for example, the provisional vehicle weight W of the processing block 404 is updated by the following equation.

[0076]

W _NEW = W _OLD −Werr As is apparent from the above Expression 28, the vehicle weight is determined by using a rewritable memory and subtracting Werr from the vehicle weight W _OLD before updating to obtain a new W _NEW . Rewriting is similarly performed in processing blocks 407 and 403. Rewrite W in Equation 6 in processing block 403. Since the contents of 403 include the second and third terms of Expression 12, the contents of 403 are rewritten by changing Expression 6. Of course, since a certain number of additions are performed, they may be sequentially obtained.

In the embodiment shown in FIG. 22, the steering resistance torque is calculated from the steering angle S based on the steering angle S of the vehicle.
Thus, the gradient value z ^* can be calculated with higher accuracy by subtracting this torque as the resistance torque. If the steering resistance torque is calculated in advance, stored as table data, and obtained by retrieving the table data, the calculation load can be reduced.

[0078]

As will be understood from the above description, according to the present invention, the output shaft torque, the gradient, and the vehicle weight can be obtained without newly providing a special sensor. Also, even if the engine brake is applied on a downhill or the accelerator is depressed on an uphill, an unnatural shift and a feeling of insufficient torque can be avoided, and a stable shift control device with good responsiveness can be achieved. Can also be applied.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of an output shaft torque estimation device.

FIG. 2 is a block diagram showing engine torque calculation means.

FIG. 3 is a block diagram showing a torque converter (torque converter) torque calculating means.

FIG. 4 is a block diagram of a means for calculating a speed ratio e of the torque converter;

FIG. 5 is a block diagram of another example of a means for calculating the speed ratio e of the torque converter.

FIG. 6 is a block diagram of an accessory torque learning means.

FIG. 7 is a flowchart of an auxiliary machine torque learning means.

FIG. 8 is a flowchart of a coast / engine brake / L / U determination unit.

FIG. 9 is a flowchart of coast / engine brake / L / U determination means using running resistance torque.

FIG. 10 is a flowchart of a coast / engine brake / L / U determination unit using the rotation speed of the one-way clutch.

FIG. 11 is a flowchart of a coast / engine brake / L / U determination unit using the speed ratio e of the torque converter.

FIG. 12 shows an example of a torque transmission mechanism from an engine to a tire.

FIG. 13 is a diagram showing changes in internal data at the time of vehicle weight estimation.

FIG. 14 is a block diagram of vehicle weight estimation applying output shaft torque estimation.

FIG. 15 is a flowchart of vehicle weight estimation.

FIG. 16 is a block diagram of gradient estimation applying output shaft torque estimation.

FIG. 17 is a diagram showing a change in internal data when estimating a vehicle weight error.

FIG. 18 is a block diagram of vehicle weight error estimation using gradient estimation.

FIG. 19 is a flowchart of vehicle weight error estimation.

FIG. 20 is a schematic diagram of vehicle weight parameter correction for gradient estimation.

FIG. 21 is a block diagram of vehicle weight parameter correction for gradient estimation.

FIG. 22 is a block diagram of gradient estimation in consideration of steering resistance.

FIG. 23 is a data table of flatland running resistance torque.

[Explanation of symbols]

 1 Torque converter torque calculating means 2 Engine torque calculating means 5 Auxiliary torque learning means

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Jun Ishii 7-1-1, Omika-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. (56) References JP-A-4-121232 (JP, A) JP-A-4-191132 (JP, A) JP-A-4-94432 (JP, A) JP-A-4-36030 (JP, A) JP-A-5-149184 (JP, A) JP-A-5-209677 (JP, A) Japanese Utility Model Application Hei 4-52540 (JP, U) Japanese Utility Model Application Hei 3-42042 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01L 5/00 F02D 45 / 00

Claims (5)

(57) [Claims] 1. An engine having an engine and a torque converter.
Dynamic transmission with at least one microcomputer
A control device for controlling the engine and the automatic transmission;
An output shaft torque estimating device for an automobile, wherein the torque estimating device includes a torque of an output shaft of the automatic transmission.
A drive torque calculating means for estimating a said driving torque calculating means prestored engine torque
The first drive torque that estimates the drive torque using the torque characteristics
Torque calculation means and the characteristics of the torque converter stored in advance.
Second drive torque calculation that estimates drive torque using
Means in the region where the torque converter slips greatly.
Using the second drive torque calculating means, the torque converter
In the region where the motor slip is small, the first drive torque calculation
Torque switching means for switching to use a gear stage.
And the second drive torque calculating means by the switching means.
Immediately before switching to the first drive torque calculating means.
The torque deviation of the drive torque calculation means is supplemented by the engine.
Auxiliary machine torque learning that learns and stores the load torque of the machine
Means for an output shaft of a motor vehicle.
Luc estimation device. 2. The method according to claim 2, wherein the torque estimating device includes the second drive.
Switch from the torque calculating means to the first driving torque calculating means.
After the replacement, the estimated torque of the first drive torque calculating means is changed.
From the accessory torque stored in the accessory torque learning means.
To correct the pump torque of the automatic transmission by subtracting
2. The output shaft torque of an automobile according to claim 1, wherein:
Estimation device. 3. The torque estimation device according to claim 2 , wherein
Means for estimating vehicle weight based on output shaft torque
3. The self-diagnosis device according to claim 1 or 2,
An output shaft torque estimating device for a moving vehicle. 4. The torque estimation device according to claim 1 , wherein
A means is provided for estimating the road gradient based on the torque of the output shaft.
4. The method according to claim 1, wherein
An output shaft torque estimating device for an automobile according to the above section. 5. The torque estimating device estimates the gradient.
The weight of the car based on the throttle opening
請 Motomeko 4, wherein further comprising means for correcting the
Output shaft torque estimation device for automobiles.