JP2002081989A - Apparatus for estimating weight of vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately estimate the weight of a vehicle. SOLUTION: The apparatus for estimating the weight of the vehicle is equipped with a high-pass filter B8 for removing the low frequency component of the acceleration in the before and behind direction of the vehicle, a high-pass filter B5 for removing the low frequency component of the drive force of the vehicle due to a prime mover, and a vehicle weight estimation means B2 for estimating the weight of the vehicle on the basis of the acceleration and drive force after filtering processing. Further, this apparatus is equipped with an estimation permitting means 3B for judging whether or not conditions are worked out such that the vehicle is set to a state state, large in acceleration, not in a variable speed state and a brake operation state are formed and a drive source is not reversely driven. Only when these estimation permitting conditions are formed, the weight of the vehicle is estimated.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle weight estimating apparatus for estimating a vehicle weight (vehicle weight) used for determining a gear position of an automatic transmission.

[0002]

2. Description of the Related Art Conventionally, a shift control device of an automatic transmission determines a shift speed to be achieved based on an accelerator pedal operation amount (a throttle opening) and a vehicle speed. Further, in such a shift control, a vehicle weight that fluctuates depending on the number of passengers, a load capacity, and the like is estimated, and the estimated vehicle weight is used for determining the shift speed, and the like, so that the engine brake during traveling on a downhill road is reduced. It is also known to exert the effect effectively and to improve the acceleration performance when traveling uphill.

An apparatus for estimating the weight of a vehicle is disclosed, for example, in Japanese Patent Application Laid-Open No. 2000-213981. In view of the fact that the influence of the road gradient appears as a low-frequency component on the driving force and acceleration of the vehicle, the disclosed device filters the detected driving force and acceleration with a high-pass filter, and outputs the filtered driving force and acceleration. The vehicle weight is estimated based on the acceleration and the equation of motion.

[0004]

However, the apparatus disclosed in the above publication does not consider under what driving conditions the vehicle weight should be estimated, so that the estimation accuracy of the vehicle weight may not be good.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to address the above-described problems, and is characterized by acceleration acquisition means for acquiring the longitudinal acceleration of the vehicle, and a motor provided by the motor mounted on the vehicle. Driving force acquiring means for acquiring the driving force of the above, acceleration processing means for acquiring the post-processing acceleration by removing the low frequency component of the acquired acceleration, and removing the low frequency component of the acquired driving force. A vehicle weight estimating apparatus comprising: a driving force processing unit that obtains a post-processing driving force; and a vehicle weight estimation unit that estimates a weight of the vehicle based on the post-processing acceleration and the post-processing driving force. A starting state determining means for determining whether the vehicle is in a starting state, and permitting the vehicle weight estimating means to estimate the vehicle weight only when it is determined that the vehicle is in a starting state. In that a constant allowing means.

According to this, the vehicle weight is estimated based on the post-processing acceleration and the post-processing driving force from which the influence of the road gradient has been removed by the acceleration processing unit and the driving force processing unit. In this case, when the acceleration and the driving force are small, the influence of the noise component included in these is also large in the post-processing acceleration and the post-processing driving force, and as a result, the estimation accuracy of the vehicle weight is reduced. On the other hand, in the above configuration, the estimation of the vehicle weight is allowed only at the time of the start of the vehicle in which a relatively large acceleration and a relatively large driving force are generated. The vehicle weight can be obtained.

In the apparatus, it is preferable that the estimation permitting means is configured to prohibit the estimation of the vehicle weight when the obtained acceleration is smaller than a predetermined acceleration.

[0010] According to this, for example, when the acceleration is small even at the time of starting such as when starting on an uphill road, the estimation of the vehicle weight is prohibited, so that a more accurate vehicle weight can be obtained. It becomes possible.

Another feature of the present invention is that acceleration obtaining means for obtaining an acceleration in the longitudinal direction of the vehicle, driving force obtaining means for obtaining a driving force of the vehicle by a motor mounted on the vehicle, Acceleration processing means for obtaining a post-processing acceleration by removing a low frequency component of the acceleration,
A driving force processing unit that obtains a post-processing driving force by removing a low-frequency component of the obtained driving force, and a vehicle weight that estimates a weight of the vehicle based on the post-processing acceleration and the post-processing driving force. In the vehicle weight estimating apparatus provided with the estimating means, there is provided an estimation permitting means for permitting the estimation of the vehicle weight only when the acquired acceleration is larger than a predetermined acceleration.

According to this, the vehicle weight is estimated based on the post-processing acceleration and the post-processing driving force from which the influence of the road gradient has been removed by the acceleration processing means and the driving force processing means. In this case, if the acceleration is at least small, the effect of the noise component included in the acceleration is also large in the post-processing acceleration, and as a result, the estimation accuracy of the vehicle weight is reduced. On the other hand, in the above configuration, the estimation of the vehicle weight is allowed only when the acceleration is greater than the predetermined acceleration. Therefore, a decrease in the estimation accuracy due to the noise component is suppressed, and a more accurate vehicle weight can be obtained.

In this case, the estimation permitting means includes:
It is preferable that the estimation of the vehicle weight is prohibited when the acquired driving force is smaller than a predetermined driving force.

According to this, the estimation of the vehicle weight is prohibited when the driving force is small even if the acceleration is large, for example, when the vehicle is traveling on a downhill, so that a more accurate vehicle weight is obtained. It becomes possible.

Further, the vehicle weight estimating apparatus having any of the above features includes a shift determining means for determining whether or not the transmission of the vehicle is shifting.
It is preferable that the estimation permitting means is configured to prohibit the estimation of the vehicle weight when it is determined that the transmission is shifting.

Since it is difficult to accurately determine the driving force during a gear shift, it is difficult to accurately determine the vehicle weight. However, according to the above configuration, the estimation of the vehicle weight is prohibited during the gear shift. , More accurate vehicle weight can be obtained.

Further, in the vehicle weight estimating apparatus having any one of the above-mentioned features, the vehicle weight estimating apparatus further includes a braking state determining means for determining whether or not braking is being performed by the braking device of the vehicle, and the estimation permitting means includes: It is preferable that the estimation of the vehicle weight is prohibited when it is determined that the braking is being performed.

When the braking is performed by a braking device such as a service brake or a parking brake, it is difficult to accurately determine the influence of the braking on the driving force. Although it is difficult, according to the above configuration, the estimation of the vehicle weight is prohibited during braking, so that a more accurate vehicle weight can be obtained.

Further, in the vehicle weight estimating apparatus having any one of the above features, a reverse drive state determining means for determining whether or not the prime mover is in a reverse drive state is provided, and the estimation permitting means is provided with the reverse drive. It is preferable to be configured to prohibit the estimation of the vehicle weight when it is determined that the vehicle is in the state.

In a so-called reverse driving state in which the prime mover is driven from the driving wheel side, it is difficult to accurately determine the driving force. Therefore, it is difficult to accurately determine the vehicle weight. Since the estimation of the vehicle weight is prohibited in the reverse driving state, more accurate vehicle weight can be obtained.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a vehicle weight estimating device according to the present invention will be described below with reference to the drawings.
FIG. 1 schematically shows an example in which a shift control device including the vehicle weight estimation device is mounted on a vehicle. This vehicle has a multi-stage (here, four forward stages, one reverse stage) including an engine 10 as a prime mover, a torque converter 20 with a lock-up clutch, and two or three sets of planetary gear units.
Stage), a hydraulic control circuit 40 for controlling the hydraulic pressure supplied to the torque converter 20 and the automatic transmission 30, and an electric control device 50 for providing a control instruction signal to the hydraulic control circuit 40. In addition, the drive torque of the engine 10 that is increased or decreased by the operation of an accelerator pedal (not shown) is transmitted to the drive wheels via a torque converter with lock-up 20, the automatic transmission 30, a differential gear device (not shown), and the like. Has become.

The torque converter 20 with lock-up is
A hydraulic transmission mechanism 21 that transmits the power generated by the engine 10 to the automatic transmission 30 via a fluid (hydraulic oil), and a lock-up clutch mechanism 22 connected in parallel to the hydraulic transmission mechanism 21 Has become. The hydraulic transmission mechanism 21 is provided by a pump impeller 21 a connected to a torque converter input shaft 12 that rotates integrally with a crankshaft of the engine 10 (not shown) and a flow of hydraulic oil generated by the pump impeller 21 a. Turbine impeller 21b rotated and connected to input shaft 31 of automatic transmission 30
And a stator impeller (not shown). The lock-up clutch mechanism 22 includes a lock-up clutch, and is connected to a hydraulic control circuit 40.
Supply and discharge of hydraulic oil by the torque converter input shaft 1
2 and the input shaft 31 of the automatic transmission 30 are mechanically connected by the same lock-up clutch to rotate them integrally, and the mechanical connection by the lock-up clutch is released and the engine 10 is released. And a non-engagement state in which the drive torque of the first transmission is not transmitted to the automatic transmission 30.

The automatic transmission 30 has an input shaft 31 and an output shaft 32 connected to driving wheels of a vehicle (not shown) via a differential gear device or the like. One of a plurality of forward gears (forward gears) and a reverse gear is selectively established according to a combination of a plurality of hydraulic friction engagement devices operated by supply and discharge of hydraulic oil by It is configured as a well-known stepped planetary gear device that integrally rotates the input shaft 31 and the output shaft 32 via the selected gear. This automatic transmission 30
A reverse driving state (engine braking state) in which the engine 10 is driven from the driving wheel side is achieved in gears other than the first and second speeds (third and fourth speeds). Meanwhile, 1
In the first and second speeds, the reverse drive state is not achieved by the operation of a one-way clutch (not shown), and the reverse drive is performed by engaging a friction engagement member (not shown) to deactivate the function of the one-way clutch. The state can be controlled to be achieved.

The hydraulic control circuit 40 includes a plurality of solenoid valves (not shown) that are turned on and off by a signal from the electric control unit 50, and a lock-up clutch mechanism based on a combination of operations of the solenoid valves. Supply and discharge of hydraulic oil to and from the automatic transmission 22 and the automatic transmission 30 are performed.

The electric control device 50 is a microcomputer including a CPU, a memory, an interface, and the like, all of which are omitted from the drawings.
1. Connected to an engine speed sensor 62, a turbine speed sensor 63, an output shaft speed sensor 64, a brake switch 65, a parking brake switch 66, and input signals generated by these sensors and switches. ing.

The throttle opening sensor 61 is connected to the engine 1
The opening degree of the throttle valve 11 provided in the intake passage of No. 0 and opened and closed in response to operation of an accelerator pedal (not shown) is detected, and a signal representing the throttle opening degree thr is generated. The engine rotation speed sensor 62 detects the rotation speed of the engine 10 and generates a signal indicating the engine rotation speed ne. The turbine rotation speed sensor 63 detects the rotation speed of the input shaft 31 of the automatic transmission, and generates a signal indicating the turbine rotation speed nt. The output shaft rotation speed sensor 64 detects the rotation speed of the output shaft 32 of the automatic transmission, and generates a signal representing the output shaft rotation speed (ie, the vehicle speed) no. The brake switch 65 outputs a brake operation signal STOP that changes to a high-level (“1”) signal and a low-level signal (“0”) according to the operation / non-operation of the brake pedal 70 for the service brake. It has become. The parking brake switch 66 is operated according to the operation / non-operation of the parking brake lever 80.
A parking brake signal that changes to a high level ("1") signal and a low level signal ("0")
Outputs PKB.

Hereinafter, the operation of the control device for the automatic transmission will be described. The electric control device 50 includes an output shaft rotation speed (vehicle speed) no and a throttle opening thr.
The shift map shown in (A) is stored in the memory,
When the detected output shaft rotation speed (vehicle speed) no and the detected throttle opening thr cross the shift line shown in the shift map, a shift request signal shift is generated to achieve a shift based on the shift line. Then, the electromagnetic valve of the hydraulic control circuit 40 is controlled based on this. Similarly, the electric control device 5
0 stores the lock-up clutch operation map shown in FIG. 3 composed of the output shaft rotation speed no and the throttle opening thr in the memory, and detects the detected output shaft rotation speed no and the detected throttle When the opening degree thr is in the lock-up area of the lock-up clutch operation map, the electromagnetic valve of the hydraulic control circuit 40 is controlled, and the lock-up clutch mechanism 22 is brought into the engaged state. Further, the electric control device 50 estimates a vehicle weight M that changes in accordance with the number of passengers and the actual load of luggage. When the vehicle weight M is equal to or greater than a predetermined value M0, the shift map is displayed as shown in FIG.
The low speed range achieved by switching from the one shown in FIG. 2A to the one shown in FIG. 2B is expanded, and the one-way clutches in the first and second speeds are deactivated to exert the engine braking effect.

Next, a method of estimating the vehicle weight M executed by the electric control device 50 will be described. The equation of motion of the vehicle is given by Equation 1 where M is the vehicle mass, α is the acceleration, F is the force acting on the vehicle excluding the road gradient force, 勾 配 is the road gradient, and g is the gravitational acceleration. It becomes street.

[0027]

## EQU1 ## Mα = F−MgsinΘ

The force F in the above equation (1) is obtained by subtracting the running resistance F2 from the driving force F1 by the prime mover (engine 10). Hereinafter, this is referred to as a substantial driving force F.

When the lock-up clutch is engaged, the driving force F1 of the prime mover is determined by the throttle opening thr of the engine 10 (or the engine load represented by the accelerator operation amount, the intake air amount, etc.) and the engine rotation speed. The output torque T of the engine 10 is estimated from the engine speed ne and is multiplied by a parameter such as the total gear ratio.
In this case, if the engine 10 is operated in a static state (steady state), the output torque T of the engine 10 can be obtained with a certain degree of accuracy from the throttle opening thr and the engine rotation speed ne. However, since the engine 10 is mostly operated in a transient state, it is generally difficult to accurately obtain the output torque T of the engine 10 during operation. On the other hand, when the lock-up clutch is in the disengaged state, that is, when the hydraulic transmission mechanism 21 is transmitting torque, the output torque T of the engine 10 can be obtained based on the following equation (2). Since the following equation 2 is satisfied even in a transient operation state, the output torque T of the engine 10 can be accurately obtained by using the same equation 2. In the following equation 2, Cp is a capacity coefficient of the fluid transmission mechanism 21 and an example is shown in FIG. 4, and λ is a torque amplification factor of the fluid transmission mechanism 21 and an example is shown in FIG. I have.

[0030]

## EQU2 ## T = Cp × λ × ne ²

On the other hand, the running resistance F2 is the sum of a friction resistance R1 such as a rolling resistance and an air resistance R2. Since the frictional resistance R1 such as the rolling resistance is a constant value specific to the vehicle, it can be determined in advance by measurement. The air resistance R2 is a value that changes substantially in proportion to the square of the vehicle speed.
If the relationship between the vehicle speed and the air resistance R2 for a certain vehicle is determined in advance by measurement and the actual vehicle speed is detected, the actual air resistance R2 can be determined.

Since the acceleration α of the vehicle is a differential value of the vehicle speed, it can be calculated by differentiating (time differential) the output shaft rotation speed no representing the vehicle speed. Note that the vehicle acceleration α
Can also be obtained from the output of the acceleration sensor mounted on the vehicle.

The vehicle weight M in the above equation (1) can be regarded as a value that changes with respect to the initial mass m of the vehicle in consideration of changes in the number of passengers, the load of luggage and the like.
Therefore, if the vehicle mass variation parameter is θ, the vehicle weight M is represented by the following equation (3), and the following equation (4) is obtained from the equations (2) and (3).

[0034]

## EQU3 ## M = θ × m

[0035]

Α = F / (θ × m) −g sinΘ

Since Θ is constant if the vehicle is traveling on a road with a constant road gradient, the term (−g sin Θ) relating to the road gradient in the above equation 4 is constant. That is, the influence of the road gradient should appear as its DC component at the acceleration α. Therefore, if the DC component is removed from the signal representing the acceleration α, a motion equation excluding the influence of the road gradient can be obtained.

In practice, the road gradient Θ changes relatively slowly, and the effect of the road gradient 現 れ る appears as a low-frequency component (1-2 Hz or less) at the acceleration α. Therefore, the acceleration α
If a signal having a frequency equal to or lower than a predetermined frequency is removed from the signal representing the substantial driving force F, the DC component is also removed at the same time, and the equation of motion shown in the following Equation 5 excluding the influence of the road gradient can be obtained. In equation (5), a signal obtained by removing a signal having a frequency equal to or lower than a predetermined frequency from the signal representing the acceleration α is α0, and the actual driving force F
Is a signal obtained by removing the predetermined frequency from F0.

[0038]

## EQU5 ## α0 = F0 / (θ × m) + error

In the above equation (5), error is a value caused by a gradient resistance that could not be completely removed or a measurement error of the acceleration α and the substantial driving force F. When an error is included in the expression as described above, a true value can be obtained by, for example, a sequential least squares method. Now, assuming that k is the number of samplings, Equation 5 can be rewritten as Equation 6 below.

[0040]

Α0 (k) = F0 (k) / (θ × m) + error (k)

Here, if the input u used for estimation is set as in the following equation 7, the estimated gain Kn can be expressed as in the following equation 8.

[0042]

## EQU7 ## u = F0 / m

[0043]

## EQU8 ## Kn (k + 1) = Pn (k) u (k + 1) / ｛λ + u (k + 1) P
n (k) u (k + 1)｝

Here, Pn is an estimated gain parameter, and its initial value is selected to be a sufficiently large value (for example, 1000), and is sequentially updated by the following equation (9).

[0045]

Pn (k + 1) = {1-Kn (k + 1) u (k + 1)} Pn (k)
/ Λ

In Equation 9, λ is a forgetting factor, for example, 0.99. From the above, the vehicle mass variation parameter θ can be expressed as in the following Expression 10. In the following equation 10, y (k + 1) = α0 (k).

[0047]

(10) θ (k + 1) = θ (k) + Kn (k + 1) + 1y (k + 1) −u (k
+1) θ (k)｝

The vehicle mass variation parameter θ is obtained using the equation (10), and the vehicle weight M (= θ × m) is estimated.

Next, the operation of the electric control device 50 for estimating the vehicle weight M based on the above principle will be described.
FIG. 6 is a functional block diagram illustrating a program for estimating the vehicle weight M executed by the CPU of the electric control device 50. The CPU includes a program related to a block B1 for estimating the gear position and the driving force, a program related to a block B2 for estimating the vehicle weight M, and a permission signal enable that permits the estimation of the vehicle weight M (and prohibits the estimation). , And mainly executes a program related to a block B3 to be supplied to the block B2. The block B2 constitutes a vehicle weight estimating unit, and the block B3 constitutes an estimation permitting unit.

In block B1, the CPU inputs the signals from the above-described sensors and the above-described shift request signal shift generated by executing a shift control program (not shown), estimates the actual shift speed, and sets the engine speed.
Is estimated. More specifically, the CPU
Is the currently recognized shift speed and the shift request signal sh
The newly achieved shift stage sh is estimated from ift. For example, if the currently recognized shift speed is the third speed and the shift request signal shift is an upshift request from the third speed to the fourth speed, the CPU estimates that the shift speed will be the fourth speed and performs the recognition. Change the current gear to 4th. This estimated gear position
sh is supplied to the permission signal generation block B3.

In estimating the driving force F, first, the current turbine rotational speed nt and the engine rotational speed ne are inputted to calculate a speed ratio (nt / ne), and the calculated speed ratio (nt / ne) is calculated. The capacity coefficient Cp and the torque amplification factor λ of the fluid transmission mechanism 21 are obtained from the maps shown in FIGS. And the current engine speed ne
The output torque T of the engine 10 is obtained based on the above equation (2). Thereafter, the CPU obtains the total gear ratio from the recognized gear position, and calculates the driving force F by multiplying the engine output torque T by the total gear ratio. If the running resistance F2 cannot be neglected, the sum of the frictional resistance R1 that is not affected by the vehicle speed such as the rolling resistance and the air resistance R2 obtained from the output shaft rotation speed no is subtracted from the driving force F. The calculated value may be used as the driving force F.

Next, the CPU removes high-frequency components (high-frequency noise) from the driving force F by low-pass filter processing in block B4, and removes low-frequency components by high-pass filter processing in block B5 to reduce the influence of the road gradient Θ. The removed real driving force F0 (the post-processing driving force) is calculated.

At the same time, the CPU removes a high-frequency component (high-frequency noise) from the detected output shaft rotational speed n0 by a low-pass filter process in a block B6, and performs time differentiation in a block B7 to obtain an acceleration α. Then, CP
U calculates the acceleration α0 (processed acceleration) by removing the low-frequency component from the obtained α and removing the influence of the road gradient に よ り in block B8.

The actual driving force F0 and the acceleration α0 are updated each time a predetermined time elapses.
Estimates the vehicle weight M using the successive least squares method shown in the above equation (10).

Next, the operation of the permission signal generation shown in block B3 will be described. The enable signal enable is established when all of the following conditions (1) to (7) are satisfied,
By setting the value to “1”, the estimation of the vehicle weight M by the block B2 is permitted. In other words, the following (1)-
When any of the conditions of (7) is not satisfied, the enable signal enable
Is set to "0", the estimation of the vehicle weight M by the block B2 is prohibited. It is to be noted that the estimation of the vehicle weight M is prohibited in that the estimation calculation operation of the vehicle weight M itself is prohibited by the CPU and the estimation calculation operation of the vehicle weight M is performed, but the result is not adopted as the vehicle weight M. It is also included. Further, when the estimation of the vehicle weight M is changed from the permitted state to the prohibited state, the block B2 becomes:
The value of the vehicle weight M estimated at that time is used for subsequent shift control (until a newly estimated vehicle weight M is obtained).

(1) The vehicle is starting. Specifically, the stop time (the output shaft rotation speed no that indicates the vehicle speed no = “0”)
After a predetermined time (for example, 2 seconds) for more than a predetermined time (for example, 2 seconds), the acceleration (or the vehicle speed) is no longer “0”. As described above, the vehicle weight M is equal to the driving force F.
If the driving force F and the acceleration α are not sufficiently large, the influence of noise contained in the driving force F and the acceleration α is large, and the estimation accuracy is not good. On the other hand, when the vehicle starts, a larger driving force F and acceleration α are obtained than when the vehicle is running. Therefore, the vehicle weight M is estimated only when the vehicle starts moving. According to the above equation 2, the output torque T of the engine 10 can be obtained with high accuracy. In this case, the lock-up clutch must be disengaged. However, since the vehicle speed (output shaft rotation speed no) is low when the vehicle starts, the lock-up clutch is disengaged as is apparent from FIG. . In this sense as well, estimating the vehicle weight M at the time of starting is advantageous for improving the accuracy of the estimation.

(2) The gear is not being shifted. This is because the vehicle weight M cannot be accurately estimated because the driving force F fluctuates during gear shifting.

(3) The output shaft rotation speed no is larger than 0 (that is, the vehicle speed is not 0) and the throttle opening thr is larger than a predetermined reference throttle opening thr0. Since the principle of estimating the vehicle weight M is based on the equation of motion of the vehicle in the front-rear direction of the above equation (4), the acceleration α and the driving force F
Is theoretically required (preferably) that the phases of the acceleration α and the driving force F coincide with each other. However, in practice, the driving force F obtained from the above-described engine torque characteristics or torque converter characteristics and the acceleration α obtained from the time derivative of the output shaft rotation speed no (a change amount with respect to a predetermined time, that is, a difference) are included in the power transmission system. There is a phase difference due to delay or the like.

More specifically, since the output shaft rotational speed sensor 64 for detecting the output shaft rotational speed no has a resolution, even if the vehicle actually starts, the vehicle cannot detect the start (at extremely low vehicle speeds). Output does not appear), and the accuracy of detecting the acceleration α decreases. On the other hand, the driving force F is not “0” from before the start because the stall torque is present even when the vehicle is stopped, and the driving force F is the output shaft 32 of the automatic transmission 30.
(The output shaft rotation speed sensor 64 is to detect the rotation speed).
Changes when the rotation speed ne changes. From the above, the driving force F is a signal whose phase is earlier than the acceleration α.

Accordingly, by adding the condition that the output shaft rotation speed no is greater than 0, the phase difference between the driving force F and the acceleration α is large (when the accelerator pedal is operated and the throttle opening thr becomes “0”). When the output shaft rotational speed n0 is “0” after the value is no longer “0”, the estimation of the vehicle weight M is avoided, and a decrease in the estimation accuracy of the vehicle weight M is avoided.

In order to estimate the vehicle weight M by the successive least squares method, a signal used for the estimation must have a certain power. The power is the magnitude of the change in the signal, and in this case, the acceleration α and the driving force F
Is the magnitude of the change. Generally, acceleration α and driving force F
Is small when the throttle opening thr is small.

Therefore, by adding the condition that the throttle opening thr is larger than the predetermined reference throttle opening thr0, the estimation of the vehicle weight M is performed when the change in the acceleration α and the driving force F is small. To avoid lowering the estimation accuracy of the vehicle weight M.

From the above conditions (1) and (2), the time during which the vehicle weight M can be estimated is limited to the period during which the first shift is performed after the vehicle starts moving. In order to calculate the vehicle weight M with high accuracy by the estimation method, a certain amount of time (a large number of samples) is required. Therefore, when it is necessary to start estimating the vehicle weight as early as possible after the vehicle starts, if the output shaft rotation speed no is greater than 0 or the throttle opening th
When r is larger than a predetermined reference throttle opening thr0, the vehicle weight M can be estimated.

(4) The first gear or the second gear.
This is because the vehicle weight M can be estimated even when the vehicle is started from the second speed.

(5) The brake is not operating. The brake includes a service brake based on the operation of the brake pedal 70 and a parking brake based on the operation of the parking brake lever 80. This is because when the service brake or the parking brake is actuated to bring the brake state, it is difficult to estimate the braking force, and as a result, it is difficult to estimate the driving force F.

(6) The acceleration α is larger than a predetermined reference acceleration A. This is because, when the acceleration α is small, the influence of noise on the acceleration α is large, and the estimation accuracy of the vehicle weight M is reduced. The reason why the condition (6) is added in addition to the condition (1) is that the acceleration α may be small even at the time of starting, such as when starting up a hill.

(7) The engine 10 is not in the reverse drive state. When the engine 10 is reversely driven from the driving wheel side, the flow of the hydraulic oil in the hydraulic transmission mechanism 21 of the torque converter 20 is disturbed, so that it becomes difficult to accurately estimate the driving force F. is there.

Hereinafter, the operation of the block B3 for determining whether or not the conditions (1) to (7) are satisfied will be described.
A description will be given with reference to a program executed by the CPU shown in FIGS. 7 and 8 every time a predetermined time elapses.

At a predetermined timing, the CPU
The processing is started from step 700 shown in FIG.
In step 05, it is determined whether or not the output shaft rotation speed no is greater than “0”. If “Yes” is determined, the process proceeds to step 710. If “No” is determined, the process proceeds to step 715. Then, it is determined whether or not the throttle opening is larger than a predetermined reference throttle opening thr0. If “Yes” is determined in step 715, the process proceeds to step 710. If “No” is determined, the process proceeds to step 720 to set the value of the enable signal enable to “0” and set the vehicle weight M After prohibiting the estimation, the routine is temporarily ended in step 795. Thus, step 705,
Step 715 is a step for judging whether or not the condition described in the note of (3) is satisfied.

When the CPU proceeds to step 710, the CPU determines whether or not the currently recognized gear, that is, the gear sh formed by the block B1 shown in FIG. 6 is the first gear. If it is determined to be “Yes”, step 725
To (No)
In step 730, it is determined whether or not the currently recognized shift speed is the second speed. And step 730
If the determination is "Yes", the process proceeds to step 725. If the determination is "No" (if not the second speed), the above-described step 720 is executed to prohibit the estimation of the vehicle weight M. In step 795, the present routine ends.
As described above, steps 710 and 730 are steps for determining whether or not the condition (4) is satisfied.

When the CPU proceeds to step 725, the CPU determines whether or not the gear is currently being shifted based on the change in the gear stage sh. If there is, the above step 720 is executed to prohibit the estimation of the vehicle weight M, and the routine is ended once in step 795. Thus, step 725 includes:
This is a step of determining whether or not the condition (2) is satisfied.

When the CPU proceeds to step 735, the CPU determines whether or not the vehicle is currently braking based on the brake operation signal STOP from the brake switch 65 and the parking brake signal PKB from the parking brake switch 66. Step 7 if not currently braking
Proceeding to step 40, if the brake is currently being applied, step 72
0 to prohibit the estimation of the vehicle weight M, and step 79
At 5, the routine is temporarily terminated. As described above, step 735 is a step of determining whether or not the condition (5) is satisfied.

When the CPU proceeds to step 740, the CPU determines whether or not the current acceleration α obtained in block B7 of FIG. Step 745 if the acceleration is larger than A
If the acceleration α is smaller than the predetermined reference acceleration A, the above-described step 720 is executed to prohibit the estimation of the vehicle weight M, and the routine is ended once in step 795. As described above, step 740 is a step for determining whether or not the condition (6) is satisfied.

When the CPU proceeds to step 745, the CPU determines whether or not the engine 10 is reversely driven from the driving wheel side. Specifically, if the one-way clutch in the automatic transmission 30 is actuated, it can be determined that the vehicle is in the reverse drive state. Therefore, the CPU recognizes the gear ratio determined from the turbine rotational speed nt and the output shaft rotational speed no at present. The reverse drive state is determined when the gear ratio is out of the range of ± 5% (out of the range of 0.95 to 1.05) of the gear ratio of the current gear. If it is determined in step 745 that the vehicle is not in the reverse drive state, the process proceeds to step 750. If it is determined that the vehicle is in the reverse drive state, step 720 is executed to prohibit the estimation of the vehicle weight M. Terminates this routine once. As described above, step 745 is a step of determining whether or not the condition (7) is satisfied.

When proceeding to step 750, the CPU determines whether or not the value of flag F is "1". The value of the flag F is a value operated by a program shown in FIG. 8 described later, and is set to “0” when the value of the enable signal “enable” changes from “1” to “0”. It is set to “1” when the vehicle has been stopped for a predetermined time (for example, 2 seconds) or longer.

Assuming that the stop state has continued for a predetermined time or more after the value of the permission signal enable has been set to "0", the value of the flag F is "1". In this case, the CPU proceeds to step 755 to set the value of the enable signal enable to “1”, and proceeds to step 795 to temporarily end the present routine. That is, reaching the step 750 is a case where “Yes” is determined in the previous step 740, and “Yes” is determined in at least one of the steps 705 and 715. Accordingly, it can be determined that the vehicle is in the starting state, and the estimation of the vehicle weight M is permitted by setting the value of the permission signal enable to "1".

On the other hand, if the value of the flag F is not “1” at the stage when the process proceeds to step 750, the CPU determines “No” at the step 750 and proceeds to step 720.
In step 720, the value of the enable signal enable is set to “0” to prohibit the estimation of the vehicle weight M, and then the process proceeds to step 795. As described above, step 750 is a step for determining whether or not the above condition (8) is satisfied.

Next, the operation of the flag F will be described. The value of the flag F is set to "1" when an unillustrated initial routine is executed when an unillustrated ignition switch of the vehicle is changed from an off state to an on state. Therefore, when the conditions (2) to (7) permitting the estimation of the vehicle weight are satisfied, the CPU proceeds to step 750, determines “Yes” in step 750, and proceeds to step 755 to permit. The value of the signal enable is set to “1”, and the estimation of the vehicle weight M is executed.

On the other hand, the CPU starts the processing of the program shown in FIG.
In step 805, it is determined whether the value of the enable signal enable has been changed from "1" to "0". If the above conditions (2) to (7) are continuously satisfied after the ignition switch is changed from the off state to the on state, the value of the enable signal enable is maintained at "1". , C
The PU determines “No” in step 805, and increases the value of the timer T by “1” when the output shaft rotation speed no (vehicle speed) is “0” in steps 810 and 815, that is, while the vehicle is stopped. . Next, in steps 820 and 825, the value of the timer T is guarded by the same maximum value TMAX so as not to become larger than the maximum value TMAX.
At 30, it is determined whether or not the value of the timer T is greater than a predetermined reference value TK corresponding to a predetermined time (2 seconds). And
When the CPU determines that the value of the timer T is larger than the predetermined reference value TK, it sets the value of the flag F to "1" in step 835 and temporarily ends the routine in step 895. On the other hand, when the CPU determines in step 830 that the value of the timer T is smaller than a predetermined reference value TK corresponding to a predetermined time,
Proceeding directly to step 895 to temporarily end this routine. Therefore, in this case, the value of the flag F is maintained at "1" regardless of the value of the timer T.

In this state, if any of the above conditions (2) to (7) is not satisfied, the CPU proceeds to step 72.
Execute 0 to set the value of the enable signal enable to “0”.
As a result, when the CPU executes step 805 in FIG. 8, it determines “Yes” in step 805 and proceeds to step 840, and clears the value of the timer T to “0” in step 840. Next, the CPU proceeds to step 845.
To set the value of the flag F to "0". As a result, until the value of the flag F is next changed to "1", even if all of the conditions (2) to (7) for permitting the estimation of the vehicle weight are satisfied, the step of FIG. At 750, “No” is determined and step 720 is executed, and the estimation of vehicle weight M is prohibited.

Thereafter, the value of the enable signal enable is maintained at "0", so that the CPU determines "No" at step 805 and proceeds to step 810 and thereafter. Therefore, the vehicle is stopped (the output shaft rotation speed n0 =
When it becomes "0"), step 815 is executed and the timer T
Gradually increases, and when the stop state continues for a predetermined time or more, the value of the timer T becomes larger than a predetermined reference value TK.
As a result, the CPU executes step 83 at a predetermined timing.
When the process proceeds to 0, "Yes" is determined in step 830, and the process proceeds to step 835, where the value of the flag F is set to "1".

When all the conditions (2) to (7) for permitting the estimation of the vehicle weight are satisfied,
The PU determines “Yes” in step 750 of FIG. 7 and proceeds to step 755 to set the value of the estimation permission signal enable to “1” and permit the estimation of the vehicle weight M. Thereafter, the above operation is repeated, and if any one of the above conditions (2) to (7) is not satisfied, the value of the estimation permission signal enable is set to “0”, and accordingly, the timer T and the flag F are reset. The value is set to "0". When the stop state continues for a predetermined time or more, the value of the flag F is set to “1” again, and
In this state, if all of the above conditions (2) to (7) are satisfied, the value of the estimation permission signal enable is set to "1".

As described above, according to the present embodiment, the vehicle weight M is estimated from the driving force F0 and the acceleration α0 from which the influence of the road surface gradient has been removed by the high-pass filter processing. At this time, it is determined that the vehicle weight M is estimated by excluding the situation where accurate estimation cannot be performed under the above conditions (1) to (7). As a result, the vehicle weight M can be more accurately estimated.

Note that the present invention is not limited to the above embodiment, and various modifications can be adopted within the scope of the present invention. For example, in the above-described embodiment, the configuration is such that the estimation of the vehicle weight M is permitted only when all the conditions (1) to (7) for permitting the estimation of the vehicle weight are satisfied. The vehicle weight M may be estimated only when at least one of the above (1) to (7) or any combination is established.

Further, instead of the above condition (1) or in addition to the condition (1), “the driving force F and the acceleration α are respectively equal to or more than the corresponding predetermined values” or “the driving force F and the acceleration α That the lock-up clutch is in the disengaged state, respectively, is equal to or more than the corresponding predetermined value "as one of the conditions for permitting the estimation of the vehicle weight M. Furthermore,
When the lockup clutch is in the engaged state, the engine output torque T may be obtained from the throttle opening thr and the engine speed ne to estimate the driving force F.

In the above embodiment, the drive source is the engine 10, but this engine may be any of a gasoline engine or a diesel engine, and may be an electric motor, or a combination of an electric motor and a gasoline engine. And so on.

Further, in the above embodiment, the vehicle weight M
The vehicle weight M obtained when the estimation of the vehicle is changed from the permitted state to the prohibited state is stored in a plurality of memories (non-volatile memory), and the average (weighted average) of the obtained values is used for the shift control. It can also be configured to be used for vehicle control such as.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram when a shift control device including a vehicle weight estimation device according to the present invention is mounted on a vehicle.

2 (A) and 2 (B) are shift diagrams used by the electric control device shown in FIG. 1 for shift control.

FIG. 3 is a map used by the electric control device shown in FIG. 1 to control a lock-up mechanism.

FIG. 4 is a capacity coefficient map of the fluid transmission mechanism shown in FIG.

FIG. 5 is a map of a torque amplification factor of the fluid transmission mechanism shown in FIG.

FIG. 6 is a diagram showing a vehicle weight estimation program executed by the electric control device shown in FIG. 1 for each functional block.

FIG. 7 is a flowchart showing a program for achieving the permission signal generation function block shown in FIG. 6;

FIG. 8 is a flowchart showing a program for achieving the permission signal generation function block shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Engine, 11 ... Throttle valve, 12 ... Torque converter input shaft, 20 ... Torque converter with lock-up clutch, 21 ... Fluid transmission mechanism, 22 ... Lock-up clutch mechanism, 30 ... Automatic transmission, 31 ... Automatic transmission Input shaft, 32: automatic transmission output shaft, 40: hydraulic control circuit, 50: electric control device, 61: throttle opening sensor, 62: engine speed sensor, 63: turbine speed sensor, 64: output shaft speed Sensor, 65: brake switch, 66: parking brake switch,
70 ... Brake pedal (for service brake), 80 ...
Parking brake lever.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroaki Kato 2-1-1 Asahi-cho, Kariya-shi, Aichi Prefecture Inside Aisin Seiki Co., Ltd. (72) Inventor Kisaburo Hayakawa 41-Yokomichi, Okumachi, Nagakute-cho, Aichi-gun, Aichi Prefecture No. 1 Toyota Central Research Laboratory Co., Ltd. (72) Inventor Masataka Osawa 41-cho, Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture F term (reference) 3J552 MA02 MA12 NA01 NB01 PA32 PA33 RB03 SB02 SB22 VA32Z VA37Z VA74Z VB04W VB20W VC01Z VC03Z VD11Z VE04Z

Claims (7)

[Claims] An acceleration acquisition unit for acquiring a longitudinal acceleration of the vehicle; a driving force acquisition unit for acquiring a driving force of the vehicle by a motor mounted on the vehicle; a low frequency component of the acquired acceleration. Acceleration processing means for obtaining a post-processing acceleration by removing, and driving force processing means for obtaining a post-processing driving force by removing a low frequency component of the obtained driving force, A vehicle weight estimating device comprising: vehicle weight estimating means for estimating the weight of the vehicle based on the post-processing driving force; a starting state determining means for determining whether the vehicle is in a starting state; A vehicle weight estimating device comprising: an estimation permitting unit that permits the vehicle weight estimating unit to estimate the vehicle weight only when it is determined that the vehicle is in the starting state. 2. The vehicle weight estimating device according to claim 1, wherein the estimation permitting means is configured to prohibit the estimation of the vehicle weight when the acquired acceleration is smaller than a predetermined acceleration. Characteristic vehicle weight estimation device. 3. An acceleration obtaining means for obtaining an acceleration in a longitudinal direction of the vehicle, a driving force obtaining means for obtaining a driving force of the vehicle by a motor mounted on the vehicle, and a low frequency component of the obtained acceleration. Acceleration processing means for obtaining a post-processing acceleration by removing the following, driving force processing means for obtaining a post-processing driving force by removing a low frequency component of the obtained driving force, A vehicle weight estimating device comprising: vehicle weight estimating means for estimating the weight of the vehicle based on the post-processing driving force, wherein the estimation that permits the estimation of the vehicle weight only when the obtained acceleration is greater than a predetermined acceleration A vehicle weight estimating device comprising a permitting means. 4. The vehicle weight estimating device according to claim 3, wherein the estimation permitting unit is configured to prohibit the estimation of the vehicle weight when the obtained driving force is smaller than a predetermined driving force. A vehicle weight estimating device characterized by the above-mentioned. 5. The vehicle weight estimating device according to claim 1, further comprising: a shift determining unit configured to determine whether a shift of a transmission of the vehicle is being performed. The vehicle weight estimating device, wherein the estimation permitting means is configured to prohibit the estimation of the vehicle weight when it is determined that the transmission is shifting. 6. The vehicle weight estimating apparatus according to claim 1, further comprising: a braking state determining unit configured to determine whether braking is performed by a braking device of the vehicle. The vehicle weight estimating device, wherein the estimation permitting unit is configured to prohibit the estimation of the vehicle weight when it is determined that the braking is being performed. 7. The vehicle weight estimating apparatus according to claim 1, further comprising: a reverse drive state determining unit configured to determine whether the prime mover is in a reverse drive state. The vehicle weight estimating device, wherein the estimation permitting means is configured to prohibit the estimation of the vehicle weight when it is determined that the vehicle is in the reverse driving state.