JPH06201523A - Torque etimating device for output shaft of automobile and weight calculating device for vehicle - Google Patents

Abstract

PURPOSE:To determine the torque of an output shaft, the weight of a vehicle, etc., with excellent precision without providing sensors afresh, by providing a means for estimating an output torque of a driving device by computation or from a table. CONSTITUTION:A torque converter torque calculating means 1 determines a torque Tp on the input side of a torque converter by computation from the revolving speed Nt of a turbine and the number Ne of revolutions of an engine. An engine torque calculating means 2 determines arm output torque Te of the engine by map retrieval from the number Ne of revolutions and a throttle opening theta. A speed ratio computing means 3 determines a speed ratio Nt/Ne. Besides, art in-transmission detecting means 4 outputs an in-transmission flag when there is a difference between the current gear ratio CURGP and a gear ratio NXTGP after transmission. A coast engine brake lock-up determining means 7 selects an optimum torque and it is converted into a final output shaft torque by a gear ratio table 10. Besides, the weight of a vehicle is calculated by using data on an air resistance coefficient, a total projected area, the radius of a tire, the weight corresponding to a rotary part, etc.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art Conventionally, as disclosed in Japanese Patent Laid-Open No. 3-24362, for example, a method is known in which an engine load torque is estimated and calculated from a throttle opening.

[0003]

However, in the above-mentioned 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 component consumed by the auxiliary machinery are not calculated. It is not taken into consideration and the final output shaft torque cannot be obtained. Therefore, there is a problem in that it is not possible to use the shift control of an automobile in a finely tuned manner.

Further, when controlling the automatic transmission, it is desirable to select a low gear to facilitate torque output when the vehicle body is heavy, 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 high. The present invention has been made in view of such a problem, and an object thereof is to provide an output that can accurately obtain output shaft torque, gradient, and vehicle weight without newly providing a special sensor. A shaft torque estimating device and a vehicle weight calculating device are provided.

[0005]

In order to achieve the above-mentioned object, an output shaft torque estimating apparatus for a vehicle according to the present invention comprises:
Basically, a vehicle provided with a drive means by an engine or a motor has a drive torque estimating means for estimating an output torque of a drive device from at least an output torque arithmetic expression of the drive means or a table, and the drive torque estimating means. Is characterized in that the final output shaft torque is calculated.

Further, the vehicle weight calculating device according to the present invention is basically a vehicle equipped with a means for detecting the acceleration of the vehicle and the output shaft torque estimating means, and at least the acceleration, the output shaft torque, and the vehicle speed are used to calculate the vehicle weight. The feature is that the weight of the car is calculated.

[0007]

The output torque of the engine is calculated from the engine characteristic formula or table. Further, the input torque of the torque converter is calculated by the characteristic formula or table of the torque converter. The two types of torque and the accessory torque learning means calculate the accessory torque of the air conditioner or the like. Also,
A coast, engine brake, and lock-up determination means are provided so that the optimum torque can be selected according to the driving condition of the automobile. After that, the final output shaft torque is converted by the gear ratio table.

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

[0009]

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

The speed ratio calculation means 3 determines the turbine speed Nt.
And the engine speed Ne are input to obtain the speed ratio Nt / Ne. In addition, the gear shift detection means 4 determines the current gear ratio CUR.
The GP and the gear ratio NXTGP after the shift are detected, and if there is a difference between them, a signal for determining that the shift is in progress is output. The auxiliary machine torque learning means 5 inputs each signal of 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 auxiliary machine torque TACC by calculation. . Between both the torque converter torque calculation means 1 and the engine torque calculation means 2 is set to Tp in a steady state.
= Te-TACC, engine output torque T
Engine torque Te is subtracted from the auxiliary machine torque TACC from e
Calculate ₁ . This auxiliary machine torque TACC is not learned and calculated during shifting and when the speed ratio e is within a certain range.

The coast / engine brake lockup (L / U) determining means 7 has a speed ratio e and a lockup L.
/ U, throttle opening θ, and torque converter torque signals are input to determine coast, engine brake, and lockup L / U, and state signals thereof are input to the torque switching means 8. The torque switching means 8 inputs the torque Tp on the input side of the torque converter and the engine torque Te ₁ . Further, since the torque is not 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 less than or equal to a certain value, Tp, and when the speed ratio e is not equal or lockup, T
e ₁ , Te ₂ when coasting, Te ₁ when engine braking
Is selected, the selected torque signal Tsel is output, and the search values from the speed ratio-torque map 9, the gear ratio table 10, and the final gear ratio 11 are multiplied to finally output the output shaft torque To.

[0012]

[Formula 1] To = Ne ² · τ (e) · t (e) · r (G
p) · r _f where τ (e) is the torque converter pump capacity coefficient, t
(E) is the torque ratio of the torque converter, r (Gp) is the gear ratio for each gear position, and 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.

In this way, when the speed ratio e of the torque converter is high, or during coasting, engine braking, and lockup, the output torque obtained from the torque characteristic of the engine is more accurate than the output torque obtained from the characteristic of the torque converter. Therefore, the torque estimation error can be reduced by switching the torque to be used depending on the speed ratio e, the lockup L / U, the throttle opening θ, the torque converter torque, and the like.

Next, each constituent block of the output shaft torque estimating device shown in FIG. 1 will be described in detail. First, FIG.
FIG. 3 is a block diagram of the engine torque calculation means 2. The output torque Te of the engine changes substantially depending only on the throttle opening θ and the engine speed Ne. Therefore, the relationship between the engine torque Te, the throttle opening θ, and the engine speed Ne is prepared as a table. 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, it is necessary to subtract the accessory torque TACC of the air conditioner or the like.

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

[0016]

## EQU00002 ## e = Nt / Ne The pump torque Tp on the input side of the torque converter is calculated by Equation 3
Shown in.

[0017]

[Equation 3] Tp = Ne ² · τ (e) where τ (e) is the pump capacity coefficient of the torque converter. Further, the turbine torque Tt on the output side is as shown in Formula 4.

[0018]

## EQU00004 ## Tt = t (e) .Tp where t (e) is the torque ratio of the torque converter. In FIG. 3, the turbine rotation speed Nt and the engine rotation speed Ne are input to the speed ratio calculation means 3 to obtain the speed ratio e. From this, the pump torque coefficient τ (e) is obtained from the pump torque map 12, and the pump torque coefficient τ (e) is obtained. The pump torque Tp can be obtained by multiplying τ (e) by the square of the engine speed. However, when the speed ratio e becomes close to 1, the pump torque coefficient τ (e) changes abruptly, so the calculation error of the speed ratio e is amplified and reflected, and the accuracy falls. 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 from the turbine sensor 13 is used to calculate the turbine speed 1
The cycle is measured at 6 and converted to the turbine speed Nt. The pulse signal of the engine rotation sensor 14 is periodically measured by the engine rotation speed calculation means 15 and converted into the engine rotation speed Ne. The calculated turbine rotation speed Nt and engine rotation speed Ne are input to the speed ratio calculation means 3 to calculate the speed ratio e.

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 periodically measuring the pulse signal from the vehicle speed sensor 16 by the vehicle speed converting means 17.
The turbine rotation speed conversion means 18 converts the input signal of the gear position retrieved from the above into a turbine rotation speed. The pulse signal of the engine rotation sensor 14 is periodically measured by the engine rotation speed calculation means 15 and converted into an engine rotation speed. Then, the turbine rotation speed Nt and the engine rotation speed Ne thus calculated are input to the speed ratio calculation 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 learn the auxiliary machine torque TACC during gear shifting, 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, and a holding process is performed by using the speed ratio e, the rate of change Δe of the speed ratio e, and a speed change flag as an input signal, and holds in an undesired state so that noise is not output. There is.

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

(1) The gear is not changing. (2) The speed ratio e is 1 or less and smaller than a predetermined value Xe close to 1. (3) The absolute value of the change rate Δe of the speed ratio e is smaller than the predetermined value XΔe. If the above three conditions are satisfied, the pump torque Tp is subtracted from the engine torque Te and substituted into the accessory torque TACC to update the learning. That is, it is determined in step 101 that the speed change is not in progress based on the in-shift flag used in the speed change control, and in step 102 it is determined that the speed ratio e is smaller than the predetermined value Xe. Further, when the absolute value of the change rate Δe of the speed ratio e calculated in the process 151 is smaller than XΔe, the process 104 calculates the auxiliary machine torque TACC.

Next, coast engine brake L /
The U detection means will be described in detail. Figure 8 shows the coast
6 is a processing flowchart of an engine brake / L / U detection means 7. In FIG. 8, first, in step 105, when the speed ratio e is larger than the predetermined value Xe, the torque Te ₁ obtained by subtracting the accessory torque TACC from the engine torque Te is selected, and when the speed ratio e is smaller, the pump torque Tp is selected. . This is to improve the calculation accuracy. If the coast is detected in the process 108, Te
Select ₂ and calculate that the torque is not transmitted. Further, when engine braking and lockup are detected by the processes 110 and 112, Te ₁ is selected and the output shaft torque is calculated based on the engine torque.

FIG. 9 shows the coast engine brake L
It is another embodiment of the / U detection means. In FIG. 9, if the speed ratio e is determined to be larger than the predetermined value Xe in the process 114 and the output shaft torque To is smaller than the running resistance torque T _RL in the process 115, the process 117 determines to be in the coast state and Te _On the contrary, if To is larger than T _RL in the processing 115, the processing 116 judges that the engine braking or the normal driving state is selected and selects Te ₁ . 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. If the lockup solenoid is in the on state in the process 119, the process 120 judges that the lockup is performed and selects Te ₁ .

FIG. 10 shows the coast engine brake L
Yet another embodiment of the / U detection means will be described. In FIG. 10, if the speed ratio e is determined to be larger than the predetermined value Xe in the process 121, and the one-way clutch input side rotational speed Nowci is not equal to the one-way clutch output side rotational speed Nowco in the process 122, the process 124 is the coast state. Then select Te ₂ and select Nowci and Nowc
When o is equal, the process 123 judges that the engine is in the braking state or the normal driving 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 lockup solenoid is in the on state in the process 126, the process 127 determines that the lockup is performed and Te ₁
Select.

Here, as is well known, the one-way clutch is a clutch having a structure in which torque for rotating the tire from the engine is transmitted, but torque for rotating the engine from the tire is not transmitted. Therefore, the coast state can be detected by monitoring the input / output rotation speed. Further, FIG. 11 shows another embodiment of the coast engine brake L / U detection means. In FIG. 11, when the throttle opening θ is smaller than the predetermined value Xθ in the process 128, there is a high possibility that the engine is in the brake state or the coast state. Therefore, when the speed ratio e is larger than 1 by the processing 129, the processing 1
If the speed ratio e is less than or equal to 1, the process 30 determines that the engine brake state is Te ₁ , and Te ₁ is selected.
Judges Te ₂ and selects Te ₂ . If the throttle opening θ is larger than the predetermined value Xθ, the process 128 judges that the driving state is normal, and if the speed ratio e is larger than the predetermined value Xe by the process 132, the process 13 is executed.
3 selects Te ₁ , and conversely, when e is smaller than or equal to the predetermined value Xe, the process 134 selects Tp to improve the calculation accuracy. If the lock-up solenoid is in the on state in the process 135, the process 136 judges that the lock-up is performed and Te1 is selected.

Next, 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. Figure 1
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. Then, 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 the one-way clutch 212 and the overrun clutch 206 provided by bypassing the one-way clutch 212. As described above, the one-way clutch is a mechanism that transmits torque to rotate the tire from the engine side but does not transmit torque to rotate the engine from the tire side. Further, the overrun clutch is a mechanism in which torque is transmitted when the clutch is engaged and torque is not transmitted when the clutch is not engaged. Therefore, the overrun clutch must be engaged when the engine brake is applied. The outputs of the one-way clutch 212 and the overrun clutch 206 are input to the differential gear 209. This shaft has a gear 211 and an electromagnetic pickup 2
A speed sensor consisting of 07 is attached. The output torque of the differential gear 209 is the tires 208, 2
It is transmitted to 10 and is output 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, the torque obtained from the accurate estimation of the drive torque in consideration of the engine speed and the torque characteristic of the torque converter. Since there is a fixed relationship among the converter torque, the engine output torque, and the auxiliary machine torque, the auxiliary machine torque is estimated and the final output shaft torque is calculated.

Next, an embodiment to which the above-described output shaft torque estimation is applied will be described in detail. FIG. 13 is a diagram showing a state in which the accelerator pedal is further increased while the vehicle is climbing a slope having a constant slope, and the throttle opening degree is changed from θ1 to θ2. In addition, FIG. 14 is an embodiment in which the vehicle weight is estimated using the value calculated by the output shaft torque estimation.

First, the concept of FIG. 14 will be described with reference to FIG. 13 and mathematical expressions. If the throttle opening changes from θ1 to θ2, the vehicle acceleration changes from α1 to α2, and the calculated output shaft torque changes from To1 to To2.
The vehicle weight is derived from these two state changes. First, in order to distinguish between these two states, the difference processing 306 and the LPF processing 3
07, the differential Δ of the throttle opening by the absolute value processing 308
When the absolute value of θ is smaller than the predetermined value XΔθ, it is determined to be in a stable state, and sampling processes 317, 302 and 310 sample the acceleration α, the output shaft torque To, and the square of the vehicle speed Vsp. After that, storage processing 303, 31
₁ and 318 store To1, Vsp ₁ ² , and α1.
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 Equation 5 below.
Equations 6, 7, and 8 show dynamic equations of rolling resistance F _r , air resistance F _A , and gradient resistance F _Z.

[0032]

[Formula 5] F _R = F _r + F _A + F _Z

[0033]

[Equation 6] F _r = μ _r · Wo · g

[0034]

[Formula 7] F _A = μ _l · A · Vsp ²

[0035]

F _Z = Wo · g · sinz where Wo is the total weight of the vehicle, Wr is the weight equivalent to the rotating means, μ _r is the rolling resistance coefficient, μ _l is the air resistance coefficient, and A is the entire projected area of the vehicle. And z indicate the angle of the gradient. Note that as shown in FIG. 23, F _r and F _A can be calculated in advance and stored in a data table to reduce the calculation load. Further, by interpolating between the data points using linear interpolation or the like, it is possible to realize highly accurate calculation with a small amount of data.

The above equations 5-8 can be used to transform into equation 9. Further, by interpolating between the data points using linear interpolation or the like, it is possible to realize highly accurate calculation with a small amount of data.

[0037]

[Formula 9] F _R = μ _r · Wo · g + μ _l · A · Vsp ² +
Wo · g · sinz Further, the acceleration resistance Fα required for acceleration is given by Formula 10.

[0038]

## EQU10 ## Fα = (Wo + Wr) α Therefore, the force F _{O of the} output shaft is given by Formula 11.

[0039]

[Formula 11] F _O = Fα + F _r + F _A + F _Z Here, if the whole is expressed in the form of torque, the formula 12 is obtained at the time t ₁ , and the formula 13 is obtained at the time t ₂ . Equation 14 shows the difference between these two equations. When this is modified, Equation 15 is obtained, and the vehicle weight Wo can be obtained.

[0040]

[Equation 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]

[Formula 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]

## EQU00004 ## To1-To2 = (Wo + Wr) R (.alpha.1
_{-Α2) + μ l · A ·} R (Vsp 1 2 -Vsp 2 2)

[0043]

[Equation 15]

Therefore, the terms depending on the square of Vsp are the air resistance coefficient (μ _l ) 312, the total projected area (A) 313,
It is calculated by multiplying the tire radius (R) 314. The term of 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 rotating part equivalent weight (Wr) 305.

Further, since the data of the throttle opening is returned more stably than when the throttle opening is increased and the foot is released from the throttle, the calculation accuracy can be improved.
Next, the vehicle weight estimation will be described with reference to a flowchart.
FIG. 15 is an example of a flowchart of vehicle weight estimation. In process 150, 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,
Further, 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 process 152, it is determined that the state has not changed yet. Then, the process 153 stores the throttle opening θ1, the acceleration α1, and the output shaft torque To1. On the contrary, if the difference between the calculated throttle opening θ2 and the stored throttle opening θ1 is larger than the predetermined value Xθ, it is determined that the state has changed, and the vehicle weight is calculated by the process 154.

In this way, 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 newly providing a sensor. Next, an example applied to gradient estimation will be shown. Figure 1
6 is an embodiment in which the gradient is estimated using the calculated value of the output shaft torque estimation. First, the concept of FIG. 16 will be described below using mathematical expressions.

The running resistance F _R when the car is running is
Similar to the above-described embodiment, it is composed of the sum of rolling resistance, air resistance, and gradient resistance as shown in Equation 5. Equation 6
The equations are shown in ~ 8. Further, the acceleration resistance Fα required for acceleration is given by the above mathematical expression 10. Here, when the gradient resistance is obtained, the equation 16 is obtained, when it is deformed, the equation 17 is obtained, and when it is expressed by the torque, the equation 18 is obtained and the gradient z ^* can be calculated.

[0048]

[Equation 16] 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 surface running torque (air resistance + rolling resistance) T _RL due to the flat surface running resistance is shown in Formula 19.

[0052]

[ _Mathematical formula-see original document] T _RL = R. (F _r + F _A ) The acceleration α of the vehicle is obtained from the differential (difference) of the vehicle speed. Therefore, from the output shaft torque T _O ^* obtained by the output shaft torque estimation unit 301, the running resistance obtained from the flatland running resistance storage unit 403, the difference unit 405, the LPF unit 406 for reducing noise, and the vehicle weight / gravity. 407 and tire radius 40
The gradient z ^{* is} obtained by subtracting the acceleration resistance obtained from No. 8 and dividing by the vehicle weight and the tire radius 404 using the dividing means 402 ^.
Can be obtained. The LPF means 401 and the LPF
The means 406 can also be inserted together before or after the dividing means 402.

However, the gradient estimation uses the tentative vehicle weight W, and an error in this determination causes an error. Therefore, it is necessary to correct the provisional vehicle weight W when there is a vehicle weight error. FIG. 18 shows a block diagram for calculating the vehicle weight error Werr. First, the concept of FIG. 18 will be described with reference to FIG. 17 and mathematical expressions. FIG. 17 shows that when the vehicle is climbing a slope with a constant gradient, the accelerator is released and the throttle opening is changed from θ1 to θ.
The state changed to 2. At this time, the acceleration of the automobile 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 slope z
When calculating ^* , the tentatively 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 differential Δθ of the throttle opening obtained by
When it is smaller than XΔθ, it is judged to be stable, and the sample
Calculated values of acceleration α and gradient by the connecting means 502 and 510
z^*Is sampled and stored by the storage means 503, 511.
Remember. After that, when the stable state is detected again,
The vehicle weight is derived from the previously stored values and the current values. As mentioned above
As described above, the running resistance F when the vehicle runs _RThis
Rolling resistance F_r, Air resistance F_A, Gradient resistance F_ZEach,
It is as shown in Formulas 5-8. In addition, the acceleration required
The fast resistance Fα is given by Equation 10. Furthermore, the force F of the output shaft_O
Becomes Equation 11. Where the whole is expressed in the form of torque
And time t₁When is, formula 12, time t₂In case of
Become. On the other hand, the calculated gradient z^*Is a predetermined
It can be calculated from Formula 18 using the constant vehicle weight W. Servant
Time t₁Calculated gradient z₁ ^*Is equation 20
,

[0055]

[Equation 20]

Substituting equation 12 into this equation yields equation 21.

[0057]

[Equation 21]

Further, the calculated gradient z ₂ ^{* at} the time t ₂ is given by the following equation 22:

[0059]

[Equation 22]

Substituting equation 13 into this equation yields equation 23.

[0061]

[Equation 23]

[Mathematical formula-see original document] Here, the difference between equations 21 and 23 is calculated,
Between time t ₁ and time t ₂ is very small, and the true slope sinz ₁ and
Assuming that sinz ₂ does not change, Equation 24 can be obtained, and this can be transformed into Equation 25.

[0063]

Z ₁ ^* −z ₂ ^* = (Wo−W) (α1−α2) /
W · g

[0064]

[Equation 25]

[0065]

[Expression 26] W = Wo + Werr Here, since the relationship between the provisional vehicle weight W, the true vehicle weight Wo, and the vehicle weight error Werr is Equation 26, the vehicle weight error Werr is
It can be calculated as 7.

[0066]

[Equation 27]

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

Next, a description will be given based on the flowchart.
FIG. 19 is an example of a flowchart for calculating the vehicle weight error.
19, the absolute value of the differential value Δθ of the throttle opening θ is smaller than the predetermined value XΔθ by processing 190, and
By processing 191, the absolute value of the difference between the current throttle opening θ2 and the stored throttle opening θ1 is a predetermined value Xθ.
When it is smaller, it is determined that the state has not changed yet, and processing 1
The throttle opening θ1, acceleration α1, and calculated gradient z ₁ ^* are stored by 92. Conversely, the calculated throttle opening θ
The difference between the throttle opening θ1 stored as 2 and the predetermined value X
If it is larger than θ, it is determined that the state has changed, and processing 19
The vehicle weight error Werr is calculated according to 3. 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 above, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the claims. It can be performed. For example, in the embodiment of FIG. 1, if the allowable range of the estimation error is wide, the output shaft torque To can be estimated only by the torque converter torque calculation means 1 and the engine torque calculation means 2.

Further, in the embodiment shown in FIG. 14, it is generally considered that the time t ₁ and the time t ₂ are minute, and the changes in the vehicle speed Vsp ₁ and the vehicle speed Vsp ₂ are also minute.
The term depending on P can be omitted. Further, if data storage means is provided and data is sampled at a time t ₃ earlier than time t ₁ , and a delay means is provided and vehicle weight is calculated at a time t ₄ later than time t ₂ , more stable data can be used. The accuracy of calculating the vehicle weight is improved. However, at time t ₃ ,
If the absolute value of Δθ is larger than the predetermined value XΔθ at time t ₄ , the vehicle weight should not be calculated.

In the correction of FIG. 19, in addition to the direct correction using the obtained vehicle weight error Werr, if the sign of the vehicle weight error is positive, a small vehicle weight ΔW is subtracted from the provisional vehicle weight W, and the vehicle weight error Werr is subtracted. If so, add a small vehicle weight ΔW to the provisional vehicle weight W,
Integral correction, in which the correction is made little by little, is possible. Further, in each of the above embodiments, the resistance torque during steering is omitted, but more accurate estimation can be performed by detecting the steering angle and considering the steering resistance torque. Although the engine is used in the description in particular, when the electric motor is used, the torque of the electric motor can be calculated from the current flowing into the electric motor 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 parameter of the vehicle, and the equivalent vehicle weight W + Wr including the inertia are obtained.
The calculation is done using. Therefore, when the vehicle weight W changes, the gradient estimation result shifts.

For example, assume 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 will be smaller than the actual value in the process of FIG. In this way, the vehicle weight can be detected from the deviation of the estimated gradient value immediately after acceleration or deceleration.
Shown in. Further, FIG. 19 shows a flowchart of vehicle weight error estimation. 20 shows a means 4001 for correcting the three vehicle weight-dependent positions shown in FIG. 16 by using the vehicle weight correction value Werr corrected by the block diagram shown in FIG. Its concrete structure is shown in FIG.

Werr is used to correct the temporary vehicle weight W of 404, the temporary vehicle weight W of W + Wr of 407, and the flatland running resistance of 403. Since the vehicle weight correction value is updated immediately after acceleration or deceleration, the values at three points are corrected thereafter. Of these, it is possible to use only 407, which has a high contribution to the gradient calculation, and it is also possible to select and use only the one having a high 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, the correction calculation immediately after acceleration / deceleration does not require extra correction within the required number of times.
Here, for example, the provisional vehicle weight W of the processing block 404 is updated by the following formula.

[0076]

[Equation 28] W _NEW = W _OLD -Werr As is clear from the above formula 28, the vehicle weight uses a rewritable memory, and Werr is subtracted from the vehicle weight W _OLD before updating to obtain a new W _NEW . The processing blocks 407 and 403 are similarly rewritten. Processing block 403 W in Expression 6 is rewritten. The contents of 403 include the second term and the third term of the mathematical expression 12, so the mathematical expression 6 is changed and rewritten. Of course, since a fixed number of additions are made, the additions may be performed sequentially.

In the embodiment shown in FIG. 22, the steering resistance torque is calculated from the steering angle S of the vehicle by the steering resistance calculation means 411.
The gradient value z ^* can be calculated with higher accuracy by performing the calculation and subtracting this torque as the resistance torque. If the steering resistance torque is calculated in advance and stored as table data and is obtained by searching the table data, the calculation load can be reduced.

[0078]

As can 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. In addition, even if the engine is braked on a downhill or the accelerator is depressed on an uphill, it is possible to avoid an unnatural shift and a feeling of insufficient torque, and to provide a stable responsive shift control device. Can also be applied.

[Brief description of drawings]

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

FIG. 2 is a block diagram showing an 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 a torque converter.

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

FIG. 6 is a block diagram of auxiliary machine torque learning means.

FIG. 7 is a flowchart of an accessory torque learning means.

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

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

FIG. 10 is a flowchart of coast / engine braking / L / U determination means using the number of rotations of a one-way clutch.

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

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

FIG. 13 is a diagram showing changes in internal data when estimating a vehicle weight.

FIG. 14 is a block diagram of vehicle weight estimation to which output shaft torque estimation is applied.

FIG. 15 is a flowchart of vehicle weight estimation.

FIG. 16 is a block diagram of gradient estimation to which output shaft torque estimation is applied.

FIG. 17 is a diagram showing changes 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 taking steering resistance into consideration.

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

[Explanation of symbols]

 1 ... torque converter torque calculation means 2 ... engine torque calculation means 5 ... auxiliary machine torque learning means

Continuation of front page (51) Int.Cl. ⁵ Identification code Office reference number FI Technical display location F16H 59/16 9240-3J G01G 19/12 7529-2F G01L 5/13 8505-2F (72) Inventor Jun Ishii City, Hitachi, Ibaraki Prefecture, 7-1, Omika-cho, Hitachi Ltd. Inside Hitachi Research Laboratory, Hitachi, Ltd.

Claims (28)

[Claims] 1. A vehicle provided with a drive means by an engine or a motor, having a drive torque estimating means for estimating an output torque of a drive device from at least an output torque arithmetic expression of the drive means or a table, and the drive torque estimating means. An output shaft torque estimating device for an automobile, wherein the final output shaft torque is calculated using 2. The output shaft torque estimating apparatus for a vehicle according to claim 1, wherein the input signal of the engine output torque arithmetic expression or the table is at least the engine speed. 3. The output shaft torque estimating apparatus for a vehicle according to claim 1, wherein the engine output torque calculation formula or the input signal to the table is at least the engine speed and the throttle opening. 4. The output shaft torque estimating apparatus for a vehicle according to claim 1, wherein the input signals of the engine output torque calculation formula or the table are the engine speed and the intake air flow rate. 5. The output shaft torque estimating apparatus for an automobile according to claim 1, wherein the output torque arithmetic expression of the motor or the input signal of the table is at least a current value flowing through the drive coil. 6. A vehicle provided with an automatic transmission using a torque converter, having torque converter torque estimation means for estimating an output torque of the torque converter from at least an input / output arithmetic expression of the torque converter or a table, and the torque. An output shaft torque estimation device for a vehicle, wherein the final output shaft torque is estimated by using converter torque estimation means. 7. The output shaft torque estimating apparatus for an automobile according to claim 6, wherein the input / output arithmetic expression of the torque converter or the input signal of the table is at least the input rotation speed and the output rotation speed of the torque converter. . 8. The output shaft torque estimating apparatus for an automobile according to claim 6, wherein the input / output arithmetic expression of the torque converter or the input signal of the table is at least an input rotational speed of the torque converter and a vehicle speed signal. 9. An output shaft torque estimating device for an automobile, comprising: the drive torque estimating means and the torque converter torque estimating means. 10. A torque switching means for switching the output of the two torque estimating means among the two outputs of the drive torque estimating means and the torque converter torque estimating means is provided. The output shaft torque estimating device for an automobile according to claim 9, 11. The output shaft torque estimation device for a vehicle according to claim 10, wherein the output shaft torque is set to zero when the running resistance torque is larger than the output shaft torque. 12. The output shaft torque estimating device for an automobile according to claim 10, wherein the output shaft torque is set to zero when the input speed and the output speed of the one-way clutch are not equal. 13. The motor output shaft torque according to claim 10, further comprising means for forcibly switching the switching of the torque switching means to the drive torque estimating means side when the lockup solenoid is in an operating state. Estimator. 14. The output shaft torque estimating device for an automobile according to claim 10, wherein the torque selecting means selects the drive torque estimating means side when the speed ratio of the torque converter is equal to or more than a predetermined value. 15. The output of the automobile according to claim 10, further comprising an auxiliary machine torque estimating means for estimating an auxiliary machine torque by using a torque obtained from the torque converter torque estimating means and the drive torque estimating means. Shaft torque estimation device. 16. By subtracting the output of the accessory torque estimating means from the estimation result of the drive torque estimating means,
The output shaft torque estimating device for a vehicle according to claim 10, wherein the output torque of the drive torque estimating means is corrected. 17. The output torque of the drive torque estimating means is corrected by subtracting a predetermined value according to the operating condition of the auxiliary machinery from the estimation result of the drive torque estimating means. An output shaft torque estimating device for a vehicle as described above. 18. The output shaft torque estimating apparatus for a vehicle according to claim 1, wherein low-pass filter processing is added to the output result of the drive torque estimating means. 19. The low-pass filter processing is added to the output result of the torque switching means.
A vehicle output shaft torque estimation device according to 0. 20. A vehicle equipped with a means for detecting the acceleration of the vehicle and the output shaft torque estimating means, wherein the vehicle weight of the vehicle is calculated from at least the acceleration, the output shaft torque and the vehicle speed. Vehicle weight calculator. 21. A means for detecting a change in throttle opening is provided, and means for detecting that the amount of change in the throttle opening is smaller than a predetermined value and calculating vehicle weight accordingly is provided. The vehicle weight calculation device for an automobile according to claim 20. 22. A means for detecting a change in the throttle opening, a means for detecting that the amount of change in the throttle opening is smaller than a predetermined value, and starting a vehicle weight calculation with a delay of a predetermined time from the detection amount. 21. The vehicle weight calculation device for an automobile according to claim 20, wherein 23. A means for detecting a change in throttle opening is provided, and a means for calculating a vehicle weight is provided when the amount of change in the throttle opening becomes negative.
The vehicle weight calculation device for an automobile described in 0. 24. An acceleration torque calculated from at least a differential signal of the vehicle speed from the output of the output shaft torque estimation means according to claim 1, 6 or 10, and a level running resistance torque calculated with the vehicle speed as an input are subtracted. An output shaft torque estimation device for a vehicle, which calculates a gradient standardized by gradient torque or vehicle weight. 25. A traveling resistance torque is calculated in advance from at least the shape of the vehicle and a vehicle weight, and the traveling resistance storage unit stores the traveling resistance torque as a data table. The traveling resistance torque is obtained by searching the stored value. 25. The output shaft torque estimating device for a vehicle according to claim 24, wherein the calculation load is reduced. 26. Steering angle detecting means for detecting a steering angle of a vehicle, and steering resistance torque calculating means for calculating a steering resistance torque from at least the steering angle signal, wherein the output signal of the steering resistance torque calculating means is output as the output signal. 25. The output shaft torque estimating apparatus for a vehicle according to claim 24, wherein the accuracy of calculating the gradient torque or the gradient by subtracting the output from the shaft torque estimating means is improved. 27. The output shaft torque of an automobile according to claim 24, further comprising the vehicle weight calculating device means, wherein the output value is used to set or correct a vehicle weight parameter to improve calculation accuracy. Estimator. 28. All of the output shaft torque estimating means according to claim 24, the differential signal of the vehicle speed and the leveling resistance torque,
Alternatively, an output shaft torque estimating device for a vehicle, wherein low-pass filter processing is added to the gradient output result of the gradient calculating means.