JP3379225B2 - Powertrain controls - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an output shaft torque calculation device for a traveling automobile, and the peculiar machine difference of each output shaft torque estimation device that occurs during mass production or the output shaft torque estimation device becomes abnormal. The present invention relates to a power train control device capable of highly accurate torque estimation even when a change with time occurs.

[0002]

2. Description of the Related Art Conventionally, it is known that output torque (drive shaft torque) is estimated and obtained from the engine rotation and turbine rotation using the characteristics of a torque converter (hereinafter referred to as torque converter).

[0003]

The data table or the function formula of the torque converter characteristics used for control in the above-mentioned prior art has characteristics obtained by a test for a small number of torque converters at the time of development. However, it is conceivable that individual torque converters may have individual differences, such as machine differences, such as a slight difference in the blade angle inside the mass production process, or the fluid inside the torque converter may change due to deterioration over time. Especially in the former, there are variations in individual torque converters,
Due to the machine difference, the torque converter characteristics greatly change. These are not taken into consideration, and if there is a machine difference, the estimated torque value will be calculated from the beginning by deviating by the machine difference.
After the change with time, the accuracy is further deteriorated and an accurate output torque (drive shaft torque) cannot be obtained. For this reason, there has been a problem that fine control cannot be performed in the shift control and driving force control of the automobile.

The present invention has been made in view of this problem, and an object of the present invention is to control a power train capable of estimating a highly accurate output shaft torque in consideration of a machine difference of the power train and a change over time. It is to provide a device.

[0005]

In order to achieve the above object, a powertrain control device according to the present invention is a powertrain control device for a vehicle having a powertrain including an internal combustion engine or a motor and a transmission. , Initial value storage means for storing initial values for judging machine differences and changes over time, initial value setting means for setting the initial values, and main estimated torque calculation for calculating estimated output shaft torque used for control It is characterized in that it comprises means for comparing the estimated torque value and the initial value to judge a machine difference and a change over time, and an estimated torque correction means for correcting the estimated torque.

[0006]

According to the present invention configured as described above, by comparing the estimated torque calculated by the main estimated torque calculating means and the reference torque of the initial value stored in advance with the absolute value and the relative value, the machine difference can be obtained. , The true output shaft torque considering the change over time is known, and the output shaft torque can be estimated with high accuracy by correcting the absolute value and the relative value, enabling finer control of driving force, speed change, etc. become.

[0007]

An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an outline of the torque correction device. Figure 1
The engine 1 includes a cylinder injection system, a lean burn engine, and a system driven by a motor. Engine 1 described above
In a vehicle 32 having the automatic transmission 2 and the automatic transmission 2, the accuracy of the estimated torque decreases due to the inherent machine difference that already exists from the time of completion of the engine and the torque converter that make up the vehicle and the change over time that occurs after completion of the torque estimation. With respect to the torque correction for preventing the above, an initial value serving as a reference is stored in the vehicle control unit 3 to determine the difference between the actual output shaft torque and the estimated output shaft torque due to the influence of machine differences and changes over time. An initial value storage means 40 is provided. The initial value storage means 40 stores in advance initial values for judging and correcting machine differences. Further, an initial value setting means 41 for setting the initial value is provided to set an initial value for judging a change with time, and the initial value of the above-mentioned initial value storage means 40 can be updated. Further, a main estimated torque calculating means 42 for performing torque estimation and calculating an estimated output shaft torque, and a torque comparing means 43 for comparing the estimated torque value with the above-mentioned initial value to judge a machine difference and a change over time are further provided. An estimated torque correction unit 44 that corrects the estimated torque according to the result of the comparison unit 43 is provided to configure the torque correction device. Here, as a concrete method of the main estimated torque calculating means 42, there are an engine characteristic method obtained from the throttle opening and the engine speed, a method obtained from the torque characteristic of the torque converter 10, and a method combining the characteristics of the engine and the torque converter. can give.

In order to obtain the information from the vehicle for this torque correction, the steering wheel steering angle detecting means 9 for detecting the operation amount of the steering wheel 7 from the steering angle sensor 8 mounted on the shaft, the output shaft of the engine 1 and the torque converter 10. Engine rotation detection means 13 for detecting the number of revolutions by a speed sensor including a gear 11 and an electromagnetic pickup 12 mounted between the input shafts of the torque converter 10 and a transmission 14, and a gear 15 and an electromagnetic pickup 16 mounted between the shafts of the torque converter 10 and the transmission 14. Turbine rotation detecting means 17 for detecting the output shaft speed (hereinafter referred to as turbine speed) of the torque converter by a speed sensor, a gear 18 mounted between the output shaft of the transmission 14 and the differential gear 20, or a drive wheel 21 and an electromagnetic wave. Vehicle speed detecting means 22 for detecting the vehicle speed of a vehicle by a speed sensor including a pickup Output torque detection means 23 by a torque sensor for detecting the output torque of the output torque from the distortion or phase difference of the output shaft, a fluid temperature detection means 24 for detecting the temperature of the fluid inside the torque converter 10, and an acceleration sensor 25 for detecting the acceleration of the vehicle. There are provided acceleration detection means 26, vehicle weight detection means 28 due to displacement of a vehicle height sensor 27 mounted on the vehicle, and road surface detection means 31 based on signals from damping of shock absorber 29 and expansion and contraction of suspension 30. The values from all of these detecting means may be used for torque correction, or the detecting means for supplying the minimum required parameters may be combined and taken into the vehicle control unit 3. In the control unit 3, the estimated output shaft torque is calculated from these values, the initial values are set, the two are compared, and the effects of machine differences and changes over time are corrected, thereby making it possible to accurately estimate the output shaft torque. Can be realized.

Further, the turbine rotation detecting means may estimate the turbine rotation Nt from the vehicle speed obtained by the vehicle speed detecting means by using the mathematical formula 1 instead of the detection method in which the rotation sensor shown in FIG. 1 is added. In Formula 1, Vsp is the vehicle speed, Gr is the gear ratio, and G is
f represents the final gear ratio, and Rw represents the drive wheel radius.

Nt = (VspGrGf1000) / (2πRw60) Equation 1 FIG. 2 shows a block diagram of acceleration detection, and the acceleration detection means 26 of FIG. 1 is realized without a sensor. An example for doing so will be described. The vehicle speed detecting means 22 estimates the acceleration of the vehicle speed obtained by measuring (converting) the speed sensor signal by using the difference means 202 and the noise reduction filter 203, and sets it as the longitudinal acceleration.

Next, taking the case where the output shaft torque is calculated by using the characteristics of the torque converter in the main estimated torque calculating means 42 of FIG. 1 as an example, the torque compensator determines the inherent machine difference of the torque converter. An embodiment for correcting the torque converter characteristics and improving the accuracy of the estimated output shaft torque will be described below. Basically, the torque correction considering the machine difference is performed when the vehicle first runs for the first time.

FIG. 3 shows a flow chart for correcting the output shaft torque of the machine difference, and the flow will be described. First, after the engine is started, when the vehicle starts running, the longitudinal acceleration αa of the vehicle is taken in, and then the estimated torque Ta is calculated by the main estimated torque calculation means 42 from the torque converter characteristics that it has in advance. The torque Ta is compared with the reference torque Tb (αa) at the acceleration αa of the initial value data stored in the initial value storage means 40, and the machine difference is estimated from the torque difference between the torque Ta and the torque Ta.
The characteristics such as the capacity coefficient C of the torque converter and the torque ratio t are corrected so that becomes the torque Tb of the initial value data, and the characteristics are replaced as the initial characteristics of the torque converter.

As the main estimated torque calculating means 42, a block diagram for calculating the estimated output shaft torque Ta using the characteristics of the torque converter 10 of the automatic transmission 2 is shown in FIG. 4 and will be described in detail. First, the speed ratio e is calculated from the engine speed Ne and the turbine speed Nt obtained by the engine speed detection means 13 and the turbine speed detection means 17 shown in FIG.

E = Nt / Ne (2) Further, from the speed ratio e, the torque converter characteristic data table 12 is obtained.
The capacity coefficient c (e) and the torque ratio t (e) are calculated from 2,123. When these are multiplied by the square of the engine rotation Ne, the torque on the output side of the torque converter (hereinafter referred to as turbine torque) T
t is calculated. Finally, the estimated torque Ta is obtained by multiplying the turbine torque Tt by the gear ratio r determined by the gear ratio r conversion 124 determined by the current gear position GP and the final gear ratio rf.
Is required. This relationship is shown in Equation 3.

Ta = Ne2t (e) c (e) rrf Equation 3 Next, an initial value stored in advance in the initial storage means 40 to be compared with the estimated torque Ta of the main estimated torque calculation means 42. Describe the data. First, FIG. 5 shows the relationship between the acceleration and the output shaft torque during traveling on a flat surface. Between the acceleration α and the output shaft torque T, there is a proportional characteristic that can be expressed by a functional expression f (x) as shown in the figure when the vehicle weight is constant and the vehicle travels straight. K in the functional expression f (x) in the figure represents a variable that takes into consideration the running of the vehicle, rolling resistance, and vehicle weight. As described above, since the torque difference of the machine difference is corrected at the first running of the new vehicle, the characteristics obtained by the functional expression f (x) are assumed to be initially running on a flat ground, but even if the initial running is a slope, f (x ) Is used instead of the variable k considering the gradient, and the characteristics of the acceleration and the output torque are set so as to correspond to the state in which the vehicle first runs.
The initial value storage means 42 is provided in advance with a data table for the absolute value of the output shaft torque due to this acceleration or a functional expression f (x) for obtaining the absolute value of the output shaft torque from the acceleration.

FIG. 6 shows a method of detecting the machine difference torque by the comparison means 43. When the estimated torque Ta estimated at the acceleration αa is input to the data table of the output shaft torque T held in the initial value storage means 40, the characteristic of the estimated torque indicated by the dotted line due to the acceleration is determined. The solid line shows the characteristic of the output shaft torque T of the initial value including the reference torque Tb at the acceleration αa.
It is determined that the shaded portion between these two lines is the machine difference torque in which the estimated torque deviates from the actual output shaft torque, and Ta = T in consideration of the machine difference torque in the estimated torque correction means 44.
b, that is, the capacity coefficient C and the torque ratio t of the torque converter are corrected so that the dotted line overlaps the slope of the characteristic of the solid line.

FIG. 7 shows a flowchart for correcting the torque converter characteristics in consideration of the machine difference, which is an embodiment of the estimated torque correction means 44. First, the torque difference D between the estimated torque Ta and the reference torque Tb compared by the comparison means 43 is obtained. Further, the estimated machine difference due to D and the acceleration αa is stored as a data table, and the machine difference value J is calculated from the table.
Then, based on the value of J, the correction coefficients k are k1 and k2, respectively.
Then, each characteristic of the torque converter is multiplied by k to create a new characteristic curve considering the machine difference. Although each torque converter has its own characteristics due to machine differences, the upper and lower limits are set for this machine difference that occurs due to variations in production, so the correction coefficient k is estimated and calculated in consideration of this range. Data or functional expression for the difference.

FIG. 8 shows a data table of the correction coefficient k. The correction coefficient k may be used to uniformly correct the entire area by k times, but the value of the capacity coefficient with respect to the speed ratio e is abruptly 0 in the coupling range after passing the clutch point.
And the torque ratio becomes almost 1. Therefore, as shown in the figure, there is a table in which the correction coefficient k is set in consideration of the above-mentioned characteristics by the J value and the speed ratio e, and the correction coefficient k corresponding to the speed ratio e is calculated uniformly instead of the same rate k times. You may make a correction. Further, instead of performing correction based on each characteristic of the torque converter stored in advance, each characteristic data considering the machine difference is also stored in advance, and each characteristic data corresponding to the value of the machine difference value J is stored. May be selected to replace the new property.

The above-mentioned machine difference is taken into account for correction when the new vehicle is first running, the fluid temperature is low, and the torque converter characteristics that it has in advance are the characteristics at low temperatures. Therefore, some torque converter characteristics having different temperatures (0 to 20 ° C.) at low temperatures are stored from the beginning, and the fluid temperature detecting means 24 selects the torque converter characteristics corresponding to the temperature during traveling to calculate the main estimated torque. Based on the estimated torque Ta calculated by the means 42,
In addition, the torque converter characteristics to be corrected are set considering the machine difference.
The correction coefficient k also uses a data table or a functional expression corresponding to the temperature of the torque converter characteristic to be corrected in consideration of the above temperature.

Next, the correction of the torque converter characteristic when the fluid temperature is high in the estimated torque correction means 44 will be described. Since each characteristic of the torque converter changes greatly with the rise of the internal fluid temperature, in order to improve the torque estimation accuracy, the torque converter characteristics corresponding to the temperature from low temperature to high temperature should be stored as a data table, or at a certain temperature. It is preferable to store a functional expression for calculating the torque converter characteristics of different temperatures by calculation from the torque converter characteristics of. In any case, the correction of the characteristics of the machine difference is necessary at all temperatures. An embodiment will be described in which the torque converter characteristics at different temperatures are also corrected by using the new torque converter characteristics obtained by correcting the characteristics at the low temperature during the first running described above in consideration of the machine difference. FIG. 9 shows a flowchart of the torque converter characteristic correction at high temperature. It is determined whether the correction of the machine difference when the vehicle is first running is completed. After the correction is completed, the fluid temperature corresponding to the new torque converter characteristic at the time of the low temperature to which the above-mentioned correction is added is set as the correction characteristic temperature. Next, fluid temperature (at high temperature)
A data table or functional equation of the temperature-dependent correction coefficient k ′ obtained from X and the correction characteristic temperature (at low temperature) is set in advance by calculation and calculation, and the temperature-based correction coefficient k ′ (X) is corrected using the data table. It is calculated from the fluid temperature X of the torque converter characteristic to be performed and the corrected characteristic temperature. k ′ (x) is calculated for each torque converter characteristic corresponding to a high temperature, and the corrected torque converter characteristics C ′, t ′ are multiplied by k ′ (X) to obtain the capacity coefficient C ″ and The torque ratio t ″ is newly calculated and the torque converter characteristic corresponding to the high temperature is corrected.

FIG. 10 shows an example of the corrected torque converter characteristics in consideration of the machine difference. The dotted line in the figure shows the characteristics of the capacity coefficient C and the torque ratio t at a low temperature which are previously held, and the capacity coefficient C ′ and the torque ratio t ′ shown by the solid line are corrected by the correction coefficient in consideration of the machine difference. It is the obtained new torque converter characteristics. The high temperature characteristic is also corrected by the above method and used as the initial characteristic of the torque converter at each fluid temperature for torque estimation. As a result, the true torque can be obtained in consideration of different machine differences for each torque converter, and it becomes possible to accurately estimate the actual output (drive) shaft torque. The high-precision actual output shaft torque estimated by correcting this machine difference is used for torque feed bag control, speed change / hydraulic control, gradient estimation control,
It can be used for all output shaft torques such as mapless shift control, engine torque control, lean burn control, overload prevention control, creep force control during warm-up, etc., and enables finer control. Also, after the vehicle has first run, the machine difference is judged, the torque converter characteristics are corrected in consideration of it, and all the above controls are not performed until the correction of the torque converter characteristics for each fluid temperature is completed. I will.

Next, taking the case of estimating the output shaft torque using the characteristics of the torque converter in the main estimated torque calculating means 42 of FIG. 1 as an example, the torque correction device determines the characteristics of the torque converter by determining the change with time of the torque converter. The diagnosis for correcting the estimated output shaft torque to improve the accuracy and for determining the abnormality of the torque converter will be described.

First, each detecting means in FIG. 1 used for the above correction and diagnosis will be described in detail. FIG. 11 shows a block diagram of steering wheel steering angle detection, and steering angle sensor 8 shown in FIG.
An example of the steering wheel steering angle detecting means when the steering wheel is not used will be described.

In the case of an automobile having rear wheels as driving wheels, wheel speed sensors (rotation sensors) 301 and 302 mounted near the left and right driving wheels are obtained by performing speed measurement (conversion) 303 by measuring cycle and frequency, respectively. Based on Vr and Vl, a steering angle determination means 304 generates a pseudo steering angle signal, which is used as steering wheel steering angle detection means.

FIG. 12 shows a flowchart for determining the rudder angle, and the rudder angle determination means 304 will be described. Since the outer wheels rotate fast and the inner wheels rotate slowly due to the differential device in the driving wheels of a turning automobile, the speed difference D between the rotational speeds Vr and Vl of the left and right driving wheels acquired in the process 401 is obtained and processed 40.
2, 403 is compared with the set value A or B, and processing 404,
At 405, the steering angle β corresponding to the speed difference D is determined. When the speed difference D in the process 406 is substantially equal to 0, the steering angle β = 0 in the process 407, and it is determined that the vehicle is traveling straight.

Further, as another steering wheel steering angle detecting means,
One example is detecting the rotational angular velocity (yaw rate) in the vertical axis direction of the automobile. It is possible to determine the steering angle of the steering wheel by replacing the degree of the detected value at the time of turning left and right with a value corresponding to the speed difference D of the processing 401 of FIG. 12, and using the set value similarly to the speed difference D and comparing. .

FIG. 13 shows an embodiment of a block diagram of the vehicle weight detecting means 28. Vehicle height sensor 50 mounted on the vehicle body
1 is used as a reference for the vehicle height based only on the vehicle weight, and the displacement of the vehicle body, the suspension, and the shock absorber in the downward distance when the vehicle weight changes, and the float signal 502 in the fuel tank to determine the remaining fuel amount. The vehicle weight is detected, the fuel equivalent value is calculated, and the value is taken into the vehicle weight calculation means 503 to detect the vehicle weight.

FIG. 14 shows a flowchart for calculating the vehicle weight. As shown in process 601, the vehicle weight is calculated when the vehicle speed is 0 Km after the engine is started, that is, when the vehicle is stopped and the vehicle weight FLAG indicating that the vehicle weight has been calculated is 0. If the condition is satisfied, the displacement X of the vehicle height in process 602 is detected. If the displacement X is larger than the set value A (for example, the displacement of the vehicle height when five people are on board) in the process 603, the vehicle weight M is temporarily set to the vehicle weight m + 300 kg as in the process 604. On the contrary, if it is smaller, the processing 605 compares it with the set value B. Then, process 606 or process 6
The vehicle weight corresponding to the displacement X is calculated through 07 and 608. If the displacement X as in processing 609 is smaller than the set value D (nearly zero), vehicle weight M = vehicle weight m. In this state, the engine is started, but it is determined that the inside of the vehicle is unmanned. Next, in process 612, the remaining fuel amount is detected, and in process 613, the weight equivalent to the fuel is added to obtain the vehicle weight M. Finally, as a process 614, 1 is set to the vehicle weight FLAG for which the vehicle weight has been calculated, and the process ends.

FIG. 15 shows RESE for clearing the vehicle weight FLAG.
An example of T processing is shown. Here, the door or trunk may be opened or closed while the engine is running, or the vehicle weight may have changed when the engine was restarted. Therefore, the RESET process is started when any of the above conditions is met. Then, the vehicle weight FLAG is set to 0, and the vehicle weight shown in FIG. 14 is calculated again when the vehicle is stopped.

FIG. 16 shows a flow chart of one embodiment of the road surface state detecting means, and the road surface state detecting means 31 shown in FIG. 1 will be described. If the running (rolling) resistance of the road surface is inconsistent with the value of the data table stored in the storage device in the control unit, that is, when the road surface is wet or there are severe irregularities, the estimated torque is corrected with time and the torque converter abnormality occurs. It is desirable not to make a diagnosis. When the wiper is operating in process 801, it is determined that the road surface is wet, and the flat road flag indicating whether the correction in process 802 can be performed is set to 0. If the wiper is not operating and the signal of the sensor for detecting the unevenness of the road surface in step 803 is equal to or lower than the set level, it is determined that the vehicle is traveling on level ground, and the level road flag is set to 1 in step 804.

FIG. 17 shows the signal of the road surface unevenness detection sensor and the state of the flat road flag. Examples of the sensor include a pressure sensor signal and an acceleration sensor signal built in the shock absorber. When the detected value of the sensor exceeds the setting Level indicated by the broken line in the figure, set the flat road flag to 0,
Otherwise, set to 1. As shown in the figure, the road surface condition changes every moment, so the correction of the estimated torque and the diagnosis of the torque converter abnormality due to the change over time should be performed when the road surface is stable (flat road flag = 1) (level running).

An embodiment will be described below which realizes the correction of the torque converter characteristic for the change with time and the diagnosis for judging the abnormality of the torque converter. In the torque correction device inside the control unit 3, the main estimated torque calculation means 42 uses the estimated torque calculation method using the torque converter characteristics described above. Further, in the initial value setting means 41, in order to calculate a reference torque Tb which is a reference for comparison with the estimated torque Ta, a method using a parameter which is difficult to change with time and which is not used in the main estimated torque calculating means 42 is used. To have.

FIG. 18 shows the basic concept of torque converter characteristic correction and diagnosis. This time change and torque converter abnormality judgment,
It shall be performed after the completion of the correction of the torque converter characteristics in consideration of the machine difference at each fluid temperature described above.

First, the reference torque Tb and the main estimated torque calculating means 42 obtained by the initial value setting means 41 at an arbitrary time ta when the vehicle is traveling and stored in the initial value storage means 40.
Based on the estimated torque Ta obtained in step 1, the comparing means 43 stores and compares the two and calculates the difference Da. After that, learning is repeated, and when the reference torque Tb calculated by the initial value setting means 41 becomes equal to Tb obtained at the time ta already stored in the comparing means 43, at the time tb in the figure, the main estimation is performed again. The estimated torque Ta is calculated by the torque calculation means 42, and the difference D from Tb is obtained as at the time ta.
Find b. Then, the difference Da at the time ta and the difference Db at the time tb are compared, and when Dc which is Db-Da exceeds a preset set value, it is determined from the degree of Dc whether the time-dependent change or the torque converter abnormality. Judgment, correction of the time-dependent torque converter characteristics for each time, warning of abnormality in the torque converter are given to each, and high-precision estimation for control that requires the above-mentioned actual output (drive) shaft torque calculated by the main estimated torque calculation means 42. It is possible to supply the estimated output shaft torque. At this time, the reference torque Tb serving as a reference for comparison does not have to match the actual output shaft torque, but it must always calculate the same value under the same conditions. By comparing the reference torque Tb with the main estimated torque Ta, the change over time of the torque converter and the foreign fluid (oil misplaced) can be determined from the relative values.
It is possible to estimate the true estimated torque by judging and considering the abnormality of the torque converter due to the damage of the impeller inside the torque converter and diagnose the torque converter. The above can be similarly determined by using the relative value when the engine torque characteristic is used in the main estimated torque calculating means 42 to determine the change over time and the engine abnormality. Further, instead of calculating the reference torque by the initial value setting means 41 at an arbitrary time, the calculation condition is stored in advance in the initial value storage means 40, and the reference torque calculated by the initial value setting means 41 is the condition. When the above condition is satisfied, the estimated torque of the main estimated torque calculation means 42 and the reference torque may be compared (stored) by the comparison means 43, and correction and diagnosis may be performed based on the relative value with respect to the reference torque.

Next, an embodiment using the basic concept of the relative value comparison described above will be described in detail. First, FIG. 19 shows a block diagram of calculation of the reference torque Tb serving as the initial value setting means 41 shown in FIG. This is a method for calculating the output shaft torque from the sum of the acceleration torque, the gradient torque, and the level running torque. The acceleration torque calculation 111 multiplies the sum of the total vehicle weight Wo (kg) and the rotating means equivalent weight Wr (kg) by the longitudinal acceleration ΔVsp and the driving wheel radius Rw (m) as shown in Formula 4, so that the vehicle weight is detected. Vehicle weight M (k
g) corresponds to the total vehicle weight Wo, and ΔVsp can be obtained by using the differential (difference) value of the vehicle speed obtained by the vehicle speed detecting means as the longitudinal acceleration.

Tα = (Wo + Wr) ΔVspRw (Equation 4) The gradient torque calculation 112 can be obtained by Equation 5, using the vehicle weight M (kg) and the acceleration G obtained by the acceleration detecting means 26, and sin θ Equation 6 is used in the θ conversion 113 to obtain

Tθ = Wo · g · sin θ · Rw (Equation 5) sin θ = (G−ΔVsp) / g (Equation 6) In the flat surface traveling torque calculation 114, the driving wheel radius is calculated as the sum of the traveling resistance Fa and the rolling resistance Fr in Equation 7. It is calculated by the formula multiplied by Rw. μa is the air resistance coefficient, A is the front projected area of the vehicle,
μr is a rolling resistance coefficient.

Tc = (Fa + Fr) Rw = μaA ・ Vsp2 + μrWog) Rw ... Equation 7 Here, the rolling resistance Fr can be generally regarded as a linear expression of the total vehicle weight Wo, The running resistance Fa is also the vehicle speed Vs.
Since it largely depends on p and can be set to a constant value for others, the flatland running torque Tc to be obtained from these can be obtained by table search by vehicle speed or the like using a data table created by actual values obtained by simulation or test. Good.

The above acceleration torque Tα and gradient torque Tθ
And the reference torque Tb based on the sum of the flatland traveling torque Tc.
To calculate. Further, instead of the total sum, even under a certain condition, for example, even when there is no gradient torque or no acceleration torque, only the flatland traveling torque Tc is used as the reference torque Tb and is calculated as the output of the initial value setting means 41.

In FIG. 20, the comparison means 43 using the estimated torque Ta and the reference torque Tb calculated in FIGS. 4 and 19 described above.
FIG. This program
It should be started at a timing with an arbitrary time and cycle. First, it is necessary to detect the traveling state in process 131. The method adopted by the initial value setting means 41 is valid when the vehicle is traveling straight, and during the turn, a new torque component is added, and the accuracy deteriorates in the calculation based on the acceleration. Therefore, basically, the reference torque Tb is calculated while the vehicle is traveling straight ahead.
In order to detect this traveling state, when the steering wheel steering angle β obtained by the steering wheel steering angle detecting means 9 shown in FIGS. 1, 11, and 12 is 0 °, the straight traveling flag indicating that the vehicle is traveling straight ahead is set to 1. Perform such processing. Then, the flag is determined in the process 132, the program ends if the vehicle is turning (straight ahead flag = 0), and the process proceeds to step 133 if the car is traveling straight. Process 13
In 3134, as in the case of the processing 131, the accuracy deteriorates even in the road surface condition, so the flat road flag obtained by the road surface condition detecting means 31 shown in FIGS. 1 and 16 is detected. If it is determined to be stable, the next process 1
35. In process 135, the torque converter characteristics change depending on the internal fluid temperature, so it is necessary to estimate the torque using the torque converter characteristics corresponding to each temperature. Here, the oil temperature TO is read as the fluid temperature, and the oil temperature X,
The torque converter characteristic data corresponding to each of Y and Z is selected. Further, a main flag indicating that the base reference torque Tb has already been calculated and a capacity flag described later are set, and the comparison program 137 is started.

FIG. 21 shows the comparison program 13 shown in FIG.
7 shows an example of the flowchart of FIG. The reference torque Tb that is the basis here is not one, but the reference torque Tb calculated at an arbitrary timing is stored in the memory in a set number. First, in process 141, the main flag indicating that the basic reference torque Tb has already been calculated is determined. If the flag is 0, the base Tb has not been calculated, so in steps 142 and 143, Tb and Ta are calculated by each calculation method. There is a process 145 for determining the memory address ADD for each oil temperature based on the value, and a process 145 for determining the capacity flag that becomes 1 when the reference torque Tb stored in the memory reaches the set number. The torque Tb and the estimated torque Ta are assigned to the addresses ADD and A.
The data is stored in DD + 1 as a pair of comparison reference data, and the program ends.

When the main flag is 1, it means that at least one pair of comparison reference data is stored, and Ta and Tb to be compared are calculated in the processing 142 and 143.
In process 147, the storage area of the comparison reference data is searched and the final address LAD of the data is determined. In process 148, first, the LAD data is compared with Tb, and all the stored data are compared with Tb. If all the data and Tb do not match, the process branches to process 144, and if the capacity flag is 0, Ta and Tb are newly stored as a pair of comparison reference data.

When the comparison reference data in the address LAD and Tb match in the process 148, the absolute difference between the two torque values stored as a pair as the comparison reference data in the process 149 and the Tb and Ta calculated this time. The absolute difference is calculated, and the relative displacement D is calculated from the difference between the two. If the calculated D exceeds the set values S1 and S2, the torque converter characteristic of the process 140 is corrected. Since there are set values S1 and S2, it is not possible to predict whether the relative displacement D of the torque converter over time or the abnormality will be positive or negative. Therefore, S1 and S2 must be set on both the positive and negative sides and exceed either set value. If so, correct it. Further, when the correction is performed once, the comparison reference data stored for the corresponding oil temperature is cleared to improve the accuracy, and after the correction, the comparison reference data is newly stored.

FIG. 22 shows a flow chart for determining the memory address ADD for each oil temperature, and the processing 144 shown in FIG.
A method of determining the memory address ADD for each oil temperature will be described.
In this case, the set number of comparison reference data is stored T
There are 100 pairs of a and Tb. First, the oil temperature T
The memory area is selected by O. Here, the explanation will be given taking the oil temperature X as an example. Xcoun that is an address counter
If t is judged to be 0, the start address T of the memory is added to ADD.
OP is substituted, and at the same time, the X flag reflected in the main flag indicating the presence or absence of the comparison reference data is set to 1. See also Xcoun
When t is not 0, the sum of TOP and Xcount is substituted into ADD. After determining the ADD in each, Xcoun
When 2 is added to t and Xcount becomes 198, the set number of stored data is 100 sets, so the X1 flag reflected in the capacity flag is set to 1 and the process is terminated. The operation is the same at other oil temperatures.

FIG. 23 shows an embodiment of a storage form of the comparison reference data in the memory. By using a non-volatile, electrically rewritable Flash memory or a backup RAM as the memory, correction can always be continued even when the vehicle is not continuously running, for example, when the engine is stopped. When the oil temperature is X, the memory start address ADD is set in order from TOP when the reference torque and the estimated torque data are paired.
When the oil temperature is Y, data is stored in order from the address TOP + 200. Further, counters such as Xcount, X flag, and X1 flag are also stored in this memory.

FIG. 24 shows the final address LAD of the stored data.
21 is a flowchart showing a flowchart for retrieving
47 will be described. According to the oil temperature TO, the head address of the area in which the corresponding comparison reference data for each oil temperature is stored is assigned to ADD. Here, since the corresponding X, Y, Zcounts, which are the counters of the memory, are values indicating the storage address of the next comparison reference data, 2 is subtracted before AD.
Add to D to obtain final data address LAD.

FIG. 25 shows a flowchart of an embodiment of the method for correcting the torque converter characteristic. Based on the relative displacement D calculated in the processing 149 of the comparison program of FIG. 21, it is determined whether the set value S1 is positive or negative. Next, the difference J between D and the set value is calculated for each, and that J is the reference value JP that represents the degree of correction.
1, JP2 or JM1, JM2 is determined, and the torque converter characteristic data TCC corresponding to the degree is corrected. As an example of the correction, as shown in the figure, TCC is uniformly multiplied by a constant such as a correction coefficient of 0.8, 0.5 or 1.5, 1.2, or addition and subtraction are performed.

FIG. 26 shows a partial correction diagram of characteristic data.
The torque ratio t and the capacity coefficient c of the torque converter characteristic are not uniformly corrected, but the amount of change in the torque converter characteristic greatly varies depending on the speed ratio as described above. Therefore, the speed ratio e calculated by the main estimated torque calculating means 42 is used. , Characteristic data t (e) of only the point e, or only the range of n points (hatched portion) near e,
You may correct c (e).

FIG. 27 shows a simple flowchart of partial correction. First, the speed ratio e is calculated to determine whether the relative displacement D is positive or negative, and the partial correction value k for each is calculated from the speed ratio e and the relative displacement D. Using this partial correction value k, the torque ratio and the torque converter characteristic data of the capacity coefficient are each multiplied by k for correction. The partial correction coefficient k is stored in advance as a data table or a functional formula in order to correct the estimated torque deviation due to the change with time.

FIG. 28 shows a flowchart for clearing the comparison reference data for each oil temperature. If you correct the corresponding oil temperature, for example, to clear the data at X, use Xcoun
If the t, X, X1 flags are set to 0, the existing data can be overwritten from the next time and the data can be updated. Further, this process is performed not only when the correction is performed, but also when the comparison reference data and the calculated reference torque Tb do not match even though the correction program has been started 1000 times, for example.

If an abnormality in the torque converter occurs due to a wrong oil supply or damage to the impeller inside the torque converter, the torque converter characteristics change drastically at once, so the torque converter characteristics are frequently corrected as described above. Here, the torque converter characteristics are not frequently corrected due to changes over time such as oil deterioration, and the limit of changes over time can be inferred.Therefore, the number of corrections and the degree of correction at the same oil temperature should be diagnosed before continuing. When the correction is performed more than the set number of times or exceeds the correction limit, it is determined that some abnormality has occurred in the torque converter in addition to the correction for the change over time, and a torque converter abnormality alarm or the like is output.

FIG. 29 shows a simple flow chart of the diagnosis when the torque converter is abnormal. In order to diagnose the number of times of correction, the number of times of clearing the comparison reference data, which is cleared at each correction, is counted for each oil temperature. Further, the correction coefficient at the time of correction is integrated for each oil temperature in order to diagnose the limit of correction. If the count value exceeds the set number of times n or (and) the integrated value exceeds the limit correction value m that does not correct the change over time, it is determined that an abnormality has occurred in the torque converter. Output an alarm etc.

Next, a method of correcting the change with time only while the automobile is continuously running will be described.

FIG. 30 shows a flow chart of an embodiment of correction performed only during continuous running. The basic concept of correction is the same as above. In process 230, the correction flag indicating whether or not the comparison reference data exists is judged, and if it is 0, processes 142, 231
At, the respective torques Tb and Ta (x) are calculated.
Here, in process 231, the torque is calculated for each of the torque converter characteristic data at several oil temperatures. Then, the calculated Tb is substituted for Tbold which becomes the comparison reference data in the process 232. Further, Ta (x) is also substituted into Taold (x) in processing 233. Since the comparison reference data has been secured, the correction flag is set to 1 in step 234. And the correction flag is 1 while the car is running continuously.
(Hereinafter described), the torque Tb,
If Ta is calculated and Tbold and Tb are compared in process 235 and they match, Taold (x) corresponding to the oil temperature when Ta is calculated in process 143 is substituted for Taold in process 236. Then, the relative displacement D is calculated as in step 237, the set values S1, S2 and D are compared and determined in step 238, and the correction of step 140 is performed if necessary.

As described above, the torque initially calculated when the correction flag becomes 0 is used as a reference, and during continuous running, the correction judgment is performed only when the torque that matches the torque is generated. Further, even if the vehicle weight cannot be detected in this method, since the correction is performed only during continuous traveling, the vehicle weight can be regarded as constant during that time, and the correction can be performed without being affected by the change in the vehicle weight.

FIG. 31 shows a flowchart for clearing the correction flag. When the vehicle weight may change, clear the flag basically.

(A) is for clearing the flag inside the RESET processing when the engine is stopped or restarted. In (b), the engine is in operation, but if the door or trunk is opened or the vehicle stops at a vehicle speed of 0 km, the change in vehicle weight is expected, so the flag is cleared. Accordingly, when the correction flag is 1, it can be determined that the vehicle is continuously traveling.

FIG. 32 shows a straight-ahead flag determination flow chart without the steering angle detection means, and a simple embodiment for obtaining a straight-ahead flag for determining a running state without using a signal from the steering angle detection means will be described. Throttle opening TV
If O is constant, the engine speed is constant, and the vehicle speed is increasing, it can be determined that there is no slope and the vehicle is traveling straight on a flat ground. In this case, in order to calculate the reference torque Ta,
The sum of the acceleration torque Tα and the level running torque Tc may be used.

[0060]

By comparing the estimated torque calculated by the main estimated torque calculating means and the reference torque of the initial value stored in advance with the absolute value and the relative value, the true difference in consideration of the machine difference and the change with time can be obtained. By knowing the output shaft torque and correcting it with the absolute value and the relative value, it is possible to estimate the output shaft torque with high accuracy, and it is possible to perform more detailed control of the driving force, gear shifting, and the like.

[Brief description of drawings]

FIG. 1 is a schematic diagram of an estimated torque correction system.

FIG. 2 is a block diagram of acceleration detection.

FIG. 3 is a flowchart of output shaft torque correction based on machine difference.

FIG. 4 is a block diagram for calculating an estimated torque Ta.

FIG. 5 is a diagram showing the relationship between acceleration and output shaft torque during flatland traveling.

FIG. 6 is an explanatory view showing a method of detecting machine difference torque by a comparison means.

FIG. 7 is a flowchart showing correction by an estimated torque correction means.

FIG. 8 is a schematic diagram showing an example of a data table of a correction coefficient K.

FIG. 9 is a flowchart of a high temperature torque converter characteristic correction.

FIG. 10 is a relationship diagram showing an example of a corrected torque converter characteristic in consideration of machine difference.

FIG. 11 is a block diagram of steering wheel steering angle detection.

FIG. 12 is a flowchart for determining a steering angle.

FIG. 13 is a block diagram showing a configuration of vehicle weight detection means.

FIG. 14 is a flowchart of vehicle weight calculation.

FIG. 15 is a flowchart showing an example of RESET processing for clearing the vehicle weight FLAG.

FIG. 16 is a flowchart of an embodiment of a road surface state detecting means.

FIG. 17 is a time chart diagram showing a signal of a road surface unevenness detection sensor and a state of a flat road flag.

FIG. 18 is a time chart showing the basic concept of correction and diagnosis of torque converter characteristics.

FIG. 19 is a block diagram of calculating a reference torque Tb.

FIG. 20 is a simple flowchart of comparison means.

FIG. 21 is a flowchart of a comparison program.

FIG. 22 is a flow chart for determining a memory address ADD for each oil temperature.

FIG. 23 is a diagram showing a storage form of comparison reference data in a memory.

FIG. 24 is a flowchart for searching the final address LAD of stored data.

FIG. 25 is a flowchart of an embodiment of a torque converter characteristic correcting method.

FIG. 26 is a partial correction diagram of characteristic data.

FIG. 27 is a simplified flowchart of partial correction.

FIG. 28 is a flowchart for clearing comparison reference data for each oil temperature.

FIG. 29 is a flowchart of a diagnosis when a torque converter is abnormal.

FIG. 30 is a flowchart of an example of learning correction performed only during continuous traveling.

FIG. 31 is a flowchart for clearing a correction flag.

FIG. 32 is a flowchart of a straight-ahead flag determination without a steering angle detection means.

[Explanation of symbols]

40 ... Initial value storage means, 41 ... Initial value setting means, 42 ...
Main estimated torque calculating means 43 ... Torque comparing means 44 ...
Estimated torque correction means.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiko Hashimoto 2520 Takaba, Takata, Ibaraki Pref., Hitachi Automotive Systems Division (72) Inventor Mitsuyasu Masuda 2520 Takata, Katsuta, Ibaraki (56) References JP 62-3137 (JP, A) JP 6-201523 (JP, A) JP 2-144231 (JP, A) JP JP 2-212663 (JP, A) JP-A-3-361 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B60K 41/00-41/28 F02D 29/00-29 / 06 F16H 59/00-63/50

Claims (7)

(57) [Claims] 1. A controller for a powertrain of a vehicle including a powertrain including an internal combustion engine or an electric motor and an automatic transmission, and an acceleration detecting means for detecting or calculating acceleration of the vehicle, and an output shaft of the powertrain. Torque of the automatic transmission
A torque calculation unit that calculates using the characteristics of the torque converter, an initial value storage unit that stores the relationship between the acceleration of the vehicle and the output shaft torque of the power train as an initial value, and the acceleration obtained from the acceleration detection unit. Corresponding to the first torque obtained by the initial value storage means and the second torque obtained by the torque calculation means and the torque comparison means for comparing, based on the result compared by the torque comparison means speed of the torque converter with the absolute value or relative value was collected using
Ratio of torque to speed ratio and speed ratio of the torque converter
A power train control device having a correction means for correcting the capacity coefficient of the power train. 2. The powertrain control device according to claim 1, further comprising an initial value setting means for updating the initial value stored in the initial value storage means, that is, for setting the initial value again. Using the relationship between the acceleration and the torque updated by the initial value setting means, the torque converter characteristic is corrected and
A controller for a power train, wherein the second torque is estimated when the power train changes with time by using a corrected torque converter characteristic . 3. The powertrain control device according to claim 2 , wherein the characteristic of the torque converter is a characteristic at least when the oil temperature is different. 4. The powertrain control device according to claim 1, wherein the characteristic of the torque converter is corrected by using a result of comparison by the torque comparison means. 5. The power train control device according to claim 4, wherein the torque difference when the oil temperature is different is a machine difference characteristic of a torque converter that is corrected by taking into consideration a machine difference which is an individual difference of the power train. A power train control device characterized by correcting characteristics of a converter. 6. The powertrain control device according to claim 1, wherein a correction completion detecting means for detecting completion of the correction of the second torque, and the output shaft torque when the completion of the correction is not detected.
And a means for prohibiting the application of the second torque to the control in which is a control parameter . 7. The powertrain control device according to claim 1, wherein the initial value storage means stores in advance an initial value for determining and correcting a machine difference, that is, the vehicle starts to run. The initial value is stored in advance, and the comparison between the first torque and the second torque is performed only when the vehicle is traveling for the first time. Control device.