JPH05263904A - Automobile, method and device for controlling motive power thereof - Google Patents

Abstract

PURPOSE:To remove differential torque taking place across a process of shifting gears while realizing optional torque in torque control of the driving shaft of an automobile. CONSTITUTION:The torque of a driving shaft becomes a target from the view of speed of an automobile and the opening of an acceleration pedal is computed from a map 1. A target engine torque and engine speed therefor for all gear ratios available to an automatic transmission for the purpose of realizing such a torque are computed by a torque converter characteristics 3. Throttle openings for giving the target engine torque in each gear ratio and the engine speed are computed from a map 4. Then, a condition judging unit 5 having a fuel consumption map selects the throttle opening which is best in fuel consumption characteristics and controls the automatic transmission to the gear ratio in correspondence with the throttle opening while controlling a throttle valve to that throttle opening.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle equipped with a power transmission mechanism for shifting the driving force of an engine by an automatic transmission and transmitting it to wheels, a power control method and apparatus therefor, and more particularly, an electronic throttle throttle opening. TECHNICAL FIELD The present invention relates to a power control method and a device thereof, which are suitable for improving fuel economy characteristics and accelerator operability when controlling a vehicle and suppressing a shift shock.

[0002]

2. Description of the Related Art In a vehicle equipped with a mechanism for transmitting a driving force of an engine by an automatic transmission to wheels, when determining a gear ratio of the automatic transmission, an automatic transmission previously held by a control device is conventionally used. The gear ratio is selected according to the gear shift map. This gear shift map stores gear ratio data for transmitting the engine torque to the drive shaft with high efficiency, and as a result, the engine torque is efficiently transmitted to the drive wheels.

Incidentally, as a device related to a control device for an automatic transmission, for example, JP-A-61-94831 and JP-A-6-9431.
2-110535, JP-A-63-74734, and JP-A-63-222943.

[0004]

In the above-mentioned prior art, only efficient transmission of engine torque to the drive shaft is taken into consideration. Therefore, if the gear ratio of the automatic transmission changes when accelerating with the accelerator pedal held constant in a vehicle equipped with an electronic throttle, there will be a step difference in the torque of the drive shaft before and after the gear shift, which causes a shift shock. There is a problem of giving offensiveness to members. Further, since transmitting the engine torque to the drive shaft with high efficiency is not the same as improving the fuel consumption, the conventional technique has a problem that the fuel consumption may be sacrificed depending on the driving condition. Further, the conventional technique has a problem that the accelerator work is complicated and delicate, and only a skilled person can smoothly start the vehicle.

An object of the present invention is to reduce shift shock,
An object of the present invention is to provide a vehicle with good fuel consumption in all driving areas and a simple accelerator work, a power control method thereof, and a device thereof.

[0006]

SUMMARY OF THE INVENTION The above-mentioned object is to provide an electronic throttle which takes in an accelerator opening signal to control the opening of a throttle valve, a means for detecting a vehicle speed, an engine power transmission by an automatic transmission and a wheel. In a vehicle equipped with a power transmission mechanism that transmits the target drive shaft torque from the vehicle speed and accelerator opening, the target drive shaft torque and all possible gear ratios of the transmission are set as targets for each gear ratio. The throttle opening value at each gear ratio is calculated from the target engine torque and engine speed, and the largest opening value among the calculated throttle opening values for each gear ratio. Alternatively, select an opening value that gives the best fuel consumption characteristics, control the throttle valve to achieve this opening value, and change the gear ratio corresponding to the opening value. By controlling the speed change ratio of the serial automatic transmission is achieved.

The above object is also to obtain a target drive shaft torque from the vehicle speed and the accelerator opening, and to obtain a target engine torque and an engine speed for the target drive shaft torque and the gear ratio that the transmission can take. The throttle opening value is calculated from this target engine torque and engine speed, and the throttle valve is controlled to reach the calculated throttle opening value, and the drive shaft torque is set to the target value calculated by the vehicle speed and accelerator opening. In the case of control, Te: engine torque TT: turbine torque ne: engine speed nT: turbine speed η: efficiency (η = (TT × nT) / (Te × ne)) CP: output capacity coefficient (CP = TT) / (Ne · ne)) t: torque ratio (t = TT / Te) e: rotation ratio (e = nT / ne), the coefficient CP ′ = TT / (nT × nT) is defined,
It can also be achieved by calculating the target engine torque and engine speed from the relationship between the coefficient CP 'and the rotation ratio e.

[0008]

In order to control the drive shaft torque on the output side of the automatic transmission to a target value, the engine torque and the engine speed that give this target drive shaft torque are obtained, and a gear that gives the engine torque and the engine speed is obtained. By calculating the ratio and throttle opening, and controlling the gear ratio and throttle opening to obtain the desired gear ratio and throttle opening, the drive shaft torque required for the vehicle can be obtained, and the torque step disappears even when gear shifting is performed, resulting in good driving performance. And the complicated accelerator work is unnecessary. At this time, the gear ratio and the throttle opening that give the target drive shaft torque are calculated for each gear ratio of the automatic transmission. Among the calculated gear ratio and throttle opening, the one with the best fuel consumption characteristic (most In this case, the fuel economy improves as the throttle opening increases.)

The target engine torque and rotational speed are calculated from the above-mentioned coefficient CP ', so that the CPU
Since these can be calculated without performing infinite convergence calculation, the load on the CPU can be reduced and these can be calculated at high speed and with high accuracy.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a functional configuration diagram of a power control device according to an embodiment of the present invention. In this embodiment, first, as shown in FIG. 10, the actual vehicle speed is detected (step 27). The vehicle speed may be calculated by a microcomputer that performs power control by obtaining it with a vehicle speed detection device, or the detected value of wheel rotation speed obtained by the brake control device may be sent to the microcomputer that performs power control by communication. You may. Next, the accelerator opening is detected (step 2
8). The accelerator opening is calculated by the microcomputer from the detection value of the opening sensor mounted on the accelerator.

Reference numeral 1 in FIG. 1 is a three-dimensional map in which the relationship between the target drive shaft torque of the automatic transmission output side, the vehicle speed, and the accelerator opening is predetermined. This three-dimensional map 1 is composed of a plurality of maps according to the operating state of the engine, etc., and one of them is selected based on the operating state at that time (step 29 in FIG. 10) to detect the vehicle speed and open the accelerator. This three-dimensional map 1 is searched by the degree detection value,
The value of the target drive shaft torque is obtained (step 30). If there is no corresponding data in the map, the target drive shaft torque is calculated using linear interpolation from the values before and after that.

FIG. 2 is a detailed view of an example of this three-dimensional map. This map is created with reference to the driving torque characteristics of the automobile. The vehicle speed is plotted on the horizontal axis, and the torque characteristic curve corresponding to the accelerator pedal depression angle is arbitrarily set within the range of the maximum torque as shown by the wavy line in the figure. By making this map, it is possible to achieve an acceleration that matches the accelerator pedal depression angle and to change the acceleration feeling as desired.

FIG. 3 is a schematic diagram of a shift map for a 4-speed automatic transmission. When the value of the target drive shaft torque is obtained in step 30 of FIG. 10, the target drive torque limits the speed ratio that the transmission can take. For example, in FIG. 3, a large torque is required when the accelerator opening is fully open at low speed immediately after starting. Therefore, it is necessary to select only the 1st and 2nd speeds and not to adopt the 3rd and 4th speeds. Therefore, in the present embodiment, a gear shift prohibition flag is set at a gear position where gear shift is prohibited. As a result, the condition determination unit 5 (FIG. 1) described later can control the automatic transmission so as not to enter the shift stage in which the shift inhibition flag is set. Even if the target drive shaft torque is calculated in step 30 of FIG. 10, it may be necessary to correct the calculated torque value depending on the state of the vehicle at that time. For example, a larger torque is required when climbing a slope, and conversely, a smaller torque than the torque value calculated from the map is required when descending a slope. Therefore, as shown in FIG. 4, the inclination of the vehicle at that time, that is, the inclination of the road is calculated (step 21), and in the next step 22, the value of the target drive shaft torque is set to the target drive shaft torque calculated from the map. Correction is performed by adding “gradient” × K (K: correction coefficient). At this time, if it is an uphill slope, it is a positive "gradient", and if it is a downhill slope, it is a negative "gradient". The target drive shaft torque is calculated as described above.

FIG. 11 is a throttle opening prediction flowchart. In this embodiment, for example, when the number of gears is 5, the throttle opening degree prediction process is performed for each gear,
In step 31 of 1, the speed i is first set to the first speed. Then, in step 32, it is determined whether or not the following processing has been performed at all the shift speeds, and if all the processing has not been completed, the process proceeds to the next step 33 to obtain the gear ratio corresponding to the shift speed i. Then, the target turbine torque is calculated from the target drive shaft torque obtained as described above (step 34).
The target turbine torque is obtained by dividing the target drive shaft torque by the product of the gear ratio of the automatic transmission and the final reduction ratio, that is, the gear ratio (Equation 1). Target turbine torque = target drive shaft torque / (gear ratio × final reduction ratio) (1) When the automatic transmission is the fifth speed, there are five “gear ratios” in Formula 1, so the formula for each gear ratio is The target turbine torque is calculated from 1 (steps 37 and 32).

Then, in step 35, the following processing is performed. First, the target turbine rotation speed corresponding to each gear ratio can be calculated from the vehicle speed and each gear ratio that the automatic transmission can take, using the following equation 2. Target turbine speed = vehicle speed / gear ratio × final gear ratio / (2 × π × tire radius) (2) From this target turbine speed and the target turbine torque obtained from the above equation 1, the target engine speed and target Calculate the engine torque. In this embodiment, this calculation is performed using the torque converter characteristic map 3 shown in FIG.

FIG. 6 is a detailed characteristic diagram of the torque converter. Where, Te: engine torque TT: turbine torque ne: engine speed nT: turbine speed η: efficiency CP: output capacity coefficient t: torque ratio, output capacity coefficient CP is CP = TT / (ne · ne ) (3) and the efficiency η is expressed by η = (TT × nT) / (Te × ne) (4). The torque ratio t is represented by t = TT / Te (5).

One of the features of this embodiment is that the coefficient CP 'is defined as CP' = TT / (nT * nT) (6). This coefficient CP '
From equations 3, 4 and 5, CP '= CP x t / (η x η) (7). Here, since the rotation ratio e is defined as e = nT / ne (8), η = t · e from Equation 4, and from this and Equation 7, the Cp′-e curve shown in FIG. 6 is determined. ..

When calculating the target engine speed from the target turbine speed, the target turbine speed can be calculated by dividing the target turbine speed by the rotation ratio e according to the equation (8). Rotation ratio e at this time
Is calculated by dividing the target turbine torque by the square of the target turbine speed (Equation 6), and the rotation ratio e is calculated from the CP'-e curve.

On the other hand, in order to calculate the target engine torque from the target turbine torque, first, the torque ratio t is calculated from the et curve, and then from equation 5, the target turbine torque is divided by the torque ratio t. , Calculate the target engine torque. The above is the processing in step 35 of FIG.

In the next step 36, the target throttle opening is calculated from the target engine torque and the target engine speed by linear interpolation using the torque characteristic map 4 (FIG. 1) of the engine. The details of the torque characteristic map of the engine are shown in FIG. Since this step 36 is performed for each shift speed i, if the fifth speed is set, five throttle opening values for each shift speed can be obtained.

As described above, in this embodiment, the target value of the drive shaft torque required by the vehicle at that time is calculated from the vehicle speed and the accelerator opening degree, and then the engine torque and the engine speed that give the target drive shaft torque are calculated. Each target value of the number is calculated,
Next, the throttle opening that gives the target engine torque and the target engine speed is calculated. Since this throttle opening is obtained for each shift stage of the automatic transmission,
If the speed is high, it is necessary to select which of the five throttle opening values and which gear stage to correspond to. This selection is performed by the condition determination unit 5 in FIG.

The condition determination unit 5 in the present embodiment selects the throttle opening value which shows the maximum value from the target throttle opening values calculated for the shift speeds, and becomes the gear ratio corresponding to the throttle opening value. Thus, a command is given to the control device 6 of the automatic transmission to control the automatic transmission. Then, a command is given to the throttle control device 7 so that the selected throttle opening degree is obtained, and the opening degree of the throttle valve is controlled. As a result, the drive shaft torque becomes the target value calculated from the vehicle speed and the accelerator opening.

The algorithm described above is shown in FIG. Figure 7
Then, in step 12, the throttle opening value θ0 is initialized and the gear position GP corresponding to the gear ratio one to one is initialized. After that, if the above-mentioned shift prohibition flag is not set for all the shiftable gears,
The target throttle opening value θi corresponding to the gear i is compared with the throttle opening value θ0. If θ0 <θi, the target throttle opening value θi is substituted into the throttle opening value θ0. By repeating the above processing for each gear, the maximum target throttle opening value θi and the gear position GP at that time are calculated within the range where gear shifting is possible.

In the above embodiment, the accelerator opening is 0 (zero).
Only run if greater than. FIG. 9 is a flowchart showing the processing procedure. In step 23, the accelerator opening is determined, and if the accelerator opening is greater than 0, the above-described embodiment is executed (step 24) to control the shift speed and the throttle opening to control the drive shaft torque to the target value. .. When the accelerator opening ≦ 0, the routine proceeds to step 25, where a conventionally known control (control for searching a map by the vehicle speed and the accelerator opening value to shift gears) is instructed to the control device of the automatic transmission to open the throttle opening. Is set to 0 (step 26), and this processing ends. In this way, since the drive shaft torque control according to the above-described embodiment is not performed when the accelerator opening is 0 or less, it is possible to utilize the engine brake in such a case.

FIG. 8 is a functional block diagram of the power control system according to the second embodiment of the present invention. In this embodiment, the throttle opening value output to the throttle control device 7 is calculated by a method different from that of the first embodiment. The algorithm will be described according to the flowchart of FIG. First, in step 38, the condition determination unit 5 (FIG. 8) selects the most suitable gear that can achieve the target drive shaft torque from all the gear ratios that the automatic transmission can take, and the automatic transmission control device 6 is instructed. Order. This condition determination may be made by the gear ratio corresponding to the maximum throttle opening value as in the first embodiment, or by the method shown in FIG. In FIG. 14, in step 47, after calculating the target engine speed and the target engine torque, each gear ratio is calculated using the optimum fuel consumption calculation map (FIG. 13) stored in advance in the storage device in the microcomputer. The fuel economy in
8) Then, a gear ratio that achieves a value that minimizes fuel consumption is selected as an optimum gear ratio (step 49). The curve for calculating the optimum fuel consumption of the map shown in FIG. 13 can be generally created from what is called the total performance curve of the engine.

In step 39 of FIG. 12, the condition determination unit 5
The turbine torque is calculated by dividing the target drive shaft torque (obtained from map 1 of FIG. 8 from the vehicle speed and the accelerator opening) by the gear ratio corresponding to the gear position calculated in. In step 40, the turbine speed is taken in and step 41
The engine speed is taken in and the turbine speed is divided by the engine speed in step 42 to calculate the rotation ratio e. In step 43, the torque ratio t corresponding to this rotation ratio e is calculated by linear interpolation with reference to the torque ratio characteristic map 11 of the torque converter of FIG.

In the next step 44, this torque ratio t
Is divided by the turbine torque obtained in step 39 to calculate the engine torque. In step 45, using the torque characteristic map 4 (FIG. 8) of the engine,
The target throttle opening value is calculated by linear interpolation, and in step 46, this target throttle opening value is output to the throttle opening control device 7. As a result, the gear ratio is selected and the throttle opening is controlled so that the drive shaft torque reaches the target value with the minimum fuel consumption.

According to the second embodiment, since the actual turbine speed and engine speed are used, more accurate throttle opening can be calculated.

According to the above-described embodiment, it is possible to predict the throttle opening such that an arbitrary drive shaft torque is obtained, and it is possible to travel at the throttle opening that provides the best fuel economy or drivability. ..

Further, since the throttle opening which becomes the maximum value among the predicted throttle opening is controlled and the automatic transmission is controlled so that the gear ratio becomes the maximum value among the calculated throttle opening, the pumping is performed. Loss is reduced and fuel efficiency is improved.

Further, when the accelerator opening is 0, the automatic transmission is controlled according to the shift map which the automatic transmission has in advance, so that engine braking can be utilized.

Further, since the turbine speed and the engine speed of the automatic transmission are fed back, the responsiveness at the time of switching the gear ratio is improved.

Further, the output capacity coefficient C of the torque converter
P, efficiency characteristic η, and torque ratio t characteristic are used to obtain a coefficient CP ′
Since the target engine speed and engine output torque at each gear ratio are calculated from this coefficient CP ′, it is possible to calculate at high speed and high accuracy without performing infinite convergence calculation, and the load on the CPU is reduced. Get smaller.

Further, since the target drive shaft torque magnitude limits the gear ratio at which the automatic transmission can shift, it is possible to shift within a range that does not impair the transient responsiveness during shifting. , Responsiveness is improved.

Furthermore, when traveling uphill or downhill, the target drive shaft torque is corrected according to the slope of the slope, so that drivability independent of the slope can be obtained.

Further, since the gear ratio and throttle opening of the automatic transmission are controlled using the fuel consumption map, fuel consumption is improved.

In the above-described embodiment, the throttle opening for achieving the target drive shaft torque is calculated for each gear, using a stepped automatic transmission such as 4th and 5th gears as an example. Needless to say, when applied to a stepped automatic transmission, this may be treated as an arbitrary stepped automatic transmission, for example, 10 steps or 20 steps, and the above calculation may be performed for each step.

[0038]

According to the present invention, since an arbitrary drive shaft torque can be obtained, the step in torque is eliminated, the riding comfort is improved, and the complicated accelerator work is released to improve the drivability. effective.

[Brief description of drawings]

FIG. 1 is a functional configuration diagram of a power control device according to a first embodiment of the present invention.

FIG. 2 is a driving torque characteristic graph of an automobile.

FIG. 3 is a configuration diagram of a target drive shaft torque calculation map.

FIG. 4 is a flowchart showing a slope gradient correction algorithm.

FIG. 5 is a torque characteristic graph of the engine.

FIG. 6 is a characteristic graph of a torque converter.

FIG. 7 is a flowchart showing an algorithm for calculating a throttle opening and a gear ratio.

FIG. 8 is a functional configuration diagram of a power control device according to a second embodiment of the present invention.

FIG. 9 is a flowchart showing a control procedure when the accelerator opening is 0.

FIG. 10 is a flowchart for calculating a target drive shaft torque.

FIG. 11 is a flowchart showing a procedure for predicting a throttle opening degree from a target drive shaft torque.

FIG. 12 is a flowchart for calculating a throttle opening according to the second embodiment.

FIG. 13 is a curve graph for calculating optimum fuel efficiency.

FIG. 14 is an optimum gear ratio determination flowchart.

[Explanation of symbols]

1 ... Target drive shaft torque calculation map, 2 ... Gear ratio capable of shifting, 3 ... Torque converter characteristic map, 4 ... Target throttle opening calculation map, 5 ... Condition determination unit, 6 ... Automatic transmission control device, 7 ... Throttle Control device, 8 ... Electronic throttle, 9 ... Automatic transmission, 10 ... Engine, 11 ... Torque ratio characteristic map of torque converter.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Michimasa Horiuchi 2520 Takaba, Takata, Katsuta-shi, Ibaraki Hitachi Ltd. Automotive Equipment Division (72) Inventor Toshimichi Minowa 4026 Kujicho, Hitachi City, Ibaraki Japan Co., Ltd. Tachi Works Hitachi Research Laboratory

Claims (16)

[Claims] 1. In a vehicle equipped with an engine, an automatic transmission, and a device for controlling a throttle opening by a microcomputer, a target for each gear ratio is obtained from a target drive shaft torque and all possible gear ratios of the automatic transmission. Means for calculating engine torque and engine speed
A means for calculating a throttle opening value in each gear ratio from the engine torque and the engine speed, and a maximum opening value among the calculated throttle opening values for each gear ratio is selected to be the opening value. And a means for controlling the throttle valve. 2. In a vehicle equipped with an engine, an automatic transmission, and a device for controlling a throttle opening by a microcomputer, a target is set for each gear ratio from a target drive shaft torque and all possible gear ratios of the transmission. The means for calculating the engine torque and the engine speed, the means for calculating the throttle opening value in each gear ratio from the engine torque and the engine speed, and the most calculated throttle opening value for each gear ratio. A vehicle comprising: a means for selecting an opening value that improves fuel efficiency and controlling a throttle valve so that the opening value becomes the opening value. 3. The vehicle according to claim 1, further comprising means for automatically selecting a gear ratio of the transmission to a gear ratio corresponding to a selected opening value. 4. The automobile according to claim 3, wherein the transmission is a stepped automatic transmission or an unauthorized automatic transmission. 5. The vehicle according to claim 1 or 2, further comprising means for not controlling the drive shaft torque to a target value when the accelerator opening is 0. 6. In a vehicle equipped with an engine, an automatic transmission, and a device for controlling a throttle opening by a microcomputer, a target is set for each gear ratio from a target drive shaft torque and all possible gear ratios of the transmission. Means for calculating the engine torque and the engine speed
A second means for calculating a throttle opening value at each gear ratio from the engine torque and the engine speed, and one of the calculated throttle opening value for each gear ratio are selected so as to obtain this opening value. And a third means for controlling the throttle valve, wherein the first means is: Te: engine torque TT: turbine torque ne: engine speed nT: turbine speed η: efficiency (η = (TT × nT) / (Te × ne)) CP: Output capacity coefficient (CP = TT / (ne · ne)) t: Torque ratio (t = TT / Te) e: Coefficient CP when rotation ratio (e = nT / ne) '= TT / (nT × nT) is defined,
An automobile characterized in that target engine torque and engine speed are calculated from the relationship between the coefficient CP 'and the rotation ratio e. 7. The device according to claim 3 or 4, further comprising: a means for setting a gear ratio which is prohibited from being taken according to a target drive shaft torque, and a means for not selecting the prohibited gear ratio. A car characterized by that. 8. The method according to claim 1, further comprising means for correcting the value of the target drive shaft torque when traveling on an uphill or a downhill according to the slope of the slope. Characteristic automobile. 9. An electronic throttle for taking in an accelerator opening signal to control the opening of a throttle valve, means for detecting a vehicle speed, and a power transmission mechanism for transmitting the power of an engine by an automatic transmission to wheels. In a vehicle power control method, a target drive shaft torque is obtained from the vehicle speed and the accelerator opening, and a target drive shaft torque and a target engine torque for each gear ratio are calculated from all possible gear ratios of the transmission. Obtain the engine speed, find the throttle opening value for each gear ratio from the target engine torque and engine speed, and select the largest or best throttle opening value for each calculated gear ratio. An opening value that gives fuel consumption characteristics is selected, the throttle valve is controlled so that this opening value is obtained, and the automatic transmission is set to a gear ratio corresponding to the opening value. The power control method is characterized in that the drive shaft torque is controlled to a target value obtained from the vehicle speed and the accelerator opening. 10. An electronic throttle for taking in an accelerator opening signal to control the opening of a throttle valve, means for detecting a vehicle speed, and a power transmission mechanism for transmitting the power of an engine by an automatic transmission to wheels. In a vehicle power control method, a target drive shaft torque is calculated from the vehicle speed and the accelerator opening, and an impossible gear ratio is determined according to the target drive shaft torque. The target engine torque and engine speed for each gear ratio are obtained from all possible gear ratios of the machine, and the throttle opening value at each gear ratio is calculated from the target engine torque and engine speed. Of the throttle opening values for each gear ratio other than the gear ratio, select the largest opening value or the opening value that gives the best fuel economy characteristics. The throttle valve is controlled so that the value becomes a value, and the gear ratio of the automatic transmission is controlled to a gear ratio corresponding to the opening value to set the drive shaft torque to a target value obtained by the vehicle speed and the accelerator opening. A characteristic power control method. 11. An electronic throttle for taking in an accelerator opening signal to control the opening of a throttle valve, means for detecting a vehicle speed, and a power transmission mechanism for transmitting the power of an engine by an automatic transmission to wheels. In a vehicle power control method, a target drive shaft torque is obtained from the vehicle speed and the accelerator opening, and a target drive shaft torque and a target engine torque for each gear ratio are calculated from all possible gear ratios of the transmission. Obtain the engine speed, find the throttle opening value for each gear ratio from the target engine torque and engine speed, and select the largest or best throttle opening value for each calculated gear ratio. Select the opening value that gives the fuel consumption characteristic, control the throttle valve to achieve this opening value, and change the automatic gear ratio to the gear ratio corresponding to the opening value. A power control method comprising controlling a gear ratio of a machine, and activating an engine brake without performing the control when the accelerator opening is 0. 12. A target drive shaft torque is obtained from a vehicle speed and an accelerator opening, and target engine torque and engine speed are obtained for the target drive shaft torque and a gear ratio that a transmission can have. Power to control the throttle opening value from the engine torque and engine speed to control the throttle valve so that the calculated throttle opening value is reached, and to control the drive shaft torque to the target value obtained from the vehicle speed and accelerator opening. In the control method, Te: engine torque TT: turbine torque ne: engine speed nT: turbine speed η: efficiency (η = (TT × nT) / (Te × ne)) CP: output capacity coefficient (CP = TT / (Ne · ne)) t: torque ratio (t = TT / Te) e: rotation ratio (e = nT / ne), the coefficient CP ′ = TT / (nT × nT) is defined,
A power control method characterized in that target engine torque and engine speed are calculated from the relationship between the coefficient CP 'and the rotation ratio e. 13. An electronic throttle that takes in an accelerator opening signal to control the opening of a throttle valve, a means for detecting a vehicle speed, and a power transmission mechanism that shifts the power of an engine by an automatic transmission and transmits the power to wheels. In a vehicle power control device, a means for obtaining a target drive shaft torque from a vehicle speed and an accelerator opening, and a target engine for each gear ratio from the target drive shaft torque and all possible gear ratios of a transmission Means for obtaining torque and engine speed, means for obtaining a throttle opening value at each gear ratio from the target engine torque and engine speed,
A means for selecting the largest opening value among the calculated throttle opening values for each gear ratio or the opening value that gives the best fuel consumption characteristics, and controlling the throttle valve so that this opening value is obtained. A power control apparatus comprising: a unit for controlling a gear ratio of the automatic transmission to a gear ratio corresponding to an opening value. 14. An electronic throttle for taking in an accelerator opening signal to control the opening of a throttle valve, means for detecting a vehicle speed, and a power transmission mechanism for transmitting the power of an engine by an automatic transmission to wheels. In a vehicle power control device, a means for obtaining a target drive shaft torque from a vehicle speed and an accelerator opening, a means for determining an prohibited gear ratio that cannot be obtained depending on the target drive shaft torque, and a target drive A means for obtaining the target engine torque and engine speed for each gear ratio from the shaft torque and all possible gear ratios of the transmission, and the throttle opening value at each gear ratio from the target engine torque and engine speed. Of the throttle opening value for each gear ratio other than the prohibited gear ratio or the best fuel efficiency characteristic Means for selecting an opening value that gives
A power control device comprising: a means for controlling the throttle valve to have this opening value and controlling the gear ratio of the automatic transmission to a gear ratio corresponding to the opening value. 15. An electronic throttle for taking in an accelerator opening signal to control the opening of a throttle valve, a means for detecting a vehicle speed, and a power transmission mechanism for transmitting the power of an engine by an automatic transmission to wheels. In a vehicle power control device, a means for obtaining a target drive shaft torque from a vehicle speed and an accelerator opening, and a target engine for each gear ratio from the target drive shaft torque and all possible gear ratios of a transmission Means for obtaining torque and engine speed, means for obtaining a throttle opening value at each gear ratio from the target engine torque and engine speed,
A means for selecting the largest opening value among the calculated throttle opening values for each gear ratio or the opening value that gives the best fuel consumption characteristics, and controlling the throttle valve so that this opening value is obtained. Power comprising means for controlling the gear ratio of the automatic transmission to a gear ratio corresponding to the opening value, and means for operating the engine brake without performing the control when the accelerator opening is 0 Control device. 16. A target drive shaft torque is obtained from a vehicle speed and an accelerator opening, and a target engine torque and an engine speed are obtained for a target drive shaft torque and a gear ratio that a transmission can have. Power to control the throttle opening value from the engine torque and engine speed to control the throttle valve so that the calculated throttle opening value is reached, and to control the drive shaft torque to the target value obtained from the vehicle speed and accelerator opening. In the control device, Te: engine torque TT: turbine torque ne: engine speed nT: turbine speed η: efficiency (η = (TT × nT) / (Te × ne)) CP: output capacity coefficient (CP = TT / (Ne · ne)) t: torque ratio (t = TT / Te) e: rotation ratio (e = nT / ne), the coefficient CP ′ = TT / (nT × nT) is defined,
A power control device comprising means for calculating target engine torque and engine speed from the relationship between the coefficient CP 'and the rotation ratio e.