JP3624331B2 - Transmission control device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a transmission control device, and more particularly, to a transmission control technique capable of achieving both fuel efficiency and power performance.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, transmission control devices have been disclosed in Japanese Patent Application Laid-Open Nos. 59-23150 and 59-226750.
The one disclosed in Japanese Patent Laid-Open No. 59-23150 is configured to change the output torque and rotational speed of the engine while maintaining the horsepower constant, and to control the speed ratio to minimize the fuel consumption rate. ing.
[0003]
Japanese Patent Laid-Open No. 59-226750 discloses a target engine speed at which the required horsepower of the engine is obtained based on the engine speed and boost, and the required horsepower can be obtained with a minimum fuel consumption rate. Thus, the transmission ratio is feedback-controlled.
[0004]
[Problems to be solved by the invention]
By the way, the one disclosed in Japanese Patent Laid-Open No. 59-23150 is configured to change gears only in a situation where the engine speed is changed and the fuel consumption is improved compared to before the change. However, for example, when the driver places importance on the power performance rather than the fuel consumption performance, there is a problem that the gear shifting that matches the driver's intention is not performed.
[0005]
Further, even in the one disclosed in Japanese Patent Laid-Open No. 59-226750, the required horsepower of the engine is set based on the engine operating conditions and does not reflect the driver's power performance requirements. The speed ratio is not always controlled optimally to the demand, and the best fuel efficiency performance cannot be obtained while satisfying the driver's demand for power performance. Further, the configuration in which the gear ratio is feedback-controlled so as to achieve the target engine rotation speed has problems such as poor convergence and delay in response of the shift.
[0006]
The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a transmission control device that can respond to different driving performance requirements depending on the driver .
It is another object of the present invention to provide a transmission control apparatus that can obtain the best fuel efficiency while responding to different power performance requirements depending on the driver .
[0007]
[Means for Solving the Problems]
Therefore, the invention described in claim 1 is configured as shown in FIG.
In FIG. 1, the engine load detecting means detects a value correlated with the load of the engine combined with the transmission.
The maximum horsepower setting means sets the maximum horsepower that can be output at the engine load detected by the engine load detection means.
[0008]
On the other hand, the power performance requirement level setting means sets the driver's power performance requirement level based on the accelerator operation speed .
Then, the target horsepower setting means sets a target horsepower based on the maximum horsepower and the degree of power performance requirement, and the shift control means controls the transmission gear ratio or gear stage so as to achieve the target horsepower.
[0009]
According to this configuration, the target horsepower is set based on the maximum horsepower obtained from the engine load and the driver's power performance requirement level set based on the accelerator operation speed, and the shift is controlled so as to achieve this target horsepower. Thus, a shift according to the driver's intention is performed for each engine load condition.
Here, in general, when the accelerator operation speed is low, the driver has a relatively strong tendency to focus on fuel efficiency, and when the accelerator operation speed is high, the driver emphasizes power performance as much as possible. Since it can be estimated, the driver's power performance level can be set with high accuracy.
[0010]
In the invention according to claim 2, the shift control means obtains the target horsepower set by the target horsepower setting means based on the relationship between the preset target horsepower and the fuel consumption rate, and the best The transmission gear ratio or gear stage is controlled so as to achieve the fuel consumption rate.
According to such a configuration, the best fuel economy performance for generating the horsepower is ensured while generating the horsepower according to the driver's request.
[0011]
According to a third aspect of the present invention, the shift control means sets a target engine rotation speed that provides the best fuel consumption rate based on the target horsepower, and a gear ratio or gear position based on the target engine rotation speed and the vehicle speed. It was set as the structure which determines.
According to such a configuration, a target horsepower can be obtained, and a target engine rotational speed at which the best fuel consumption rate is obtained is determined, and further, a gear ratio or a gear stage that becomes the target engine rotational speed at the current vehicle speed. Therefore, the target horsepower can be obtained with a good response, and a gear change that follows the driver's intention with good response can be achieved.
[0012]
According to a fourth aspect of the present invention, the target horsepower setting means sets the target horsepower with a minimum horsepower set in advance according to the vehicle speed as a lower limit.
According to such a configuration, a necessary minimum horsepower is ensured, so that it is possible to avoid a shift control that impairs drivability by setting the target horsepower unduly small.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
FIG. 2 is a system diagram of a continuously variable transmission (CVT) 1 as a vehicle transmission. In FIG. 2, a continuously variable transmission 1 includes a primary pulley 2 on the engine side, a secondary pulley 3 on the drive shaft (difference) side, and a belt made of rubber or metal wound between them, or a combination thereof. 4 and a pulley ratio (secondary pulley side belt) by adjusting the transmission pressure to the primary pulley side actuator (transmission control oil chamber) 2a and the line pressure to the secondary pulley side actuator (tension control oil chamber) 3a. The gear ratio can be changed steplessly by changing the winding effective diameter / primary pulley side belt winding effective diameter. Other CVTs such as a known toroidal type can also be used.
[0015]
The transmission pressure and the line pressure are obtained by switching the hydraulic pressure in each hydraulic path (for example, a broken line portion) provided in the hydraulic circuit 6 connected to the oil pump 5 through opening / closing of the solenoid valves 7 and 8 having a relief function. The drive control of the solenoid valves 7 and 8 is performed by the controller 50.
In other words, the controller 50 controls the transmission pressure and the line pressure via the solenoid valves 7 and 8 to control the transmission ratio to the target value so that the required transmission ratio can be achieved according to the driving conditions. It is like that. The solenoid valves 7 and 8 are each composed of a plurality of solenoid valves, and the target transmission pressure and line pressure can also be achieved by a combination of opening and closing the plurality of solenoid valves.
[0016]
A lock-up pressure for driving the torque converter 10 interposed between the continuously variable transmission (CVT) 1 and the engine directly from a viewpoint of reducing fuel consumption under a predetermined condition is also supplied from the controller 50. Control is performed by opening and closing the electromagnetic valve 9 based on the signal.
For control of the gear ratio, etc., the controller 50 includes a throttle opening signal from a throttle sensor 51 that detects the opening TVO of the throttle valve of the engine that opens and closes in conjunction with the accelerator operated by the driver, A primary pulley rotation speed signal, a secondary pulley rotation speed signal, a vehicle speed signal VSP, an engine rotation speed signal, and the like are input.
[0017]
By the way, a transmission hydraulic pressure sensor 11 for detecting the transmission pressure and a line pressure sensor 12 for detecting the line pressure are provided in each hydraulic passage. It should be noted that feedback control of each hydraulic pressure may be performed using the detection values of these hydraulic pressure sensors 11 and 12.
Next, the state of the gear ratio control by the controller 50 will be described based on the control block diagram of FIG.
[0018]
Based on the throttle opening TVO detected by the throttle sensor 51, the maximum horsepower setting unit (maximum horsepower setting means) 71 sets the maximum horsepower that can be generated at the opening TVO at that time. Here, the throttle opening TVO is a value correlated with the engine load, and the throttle sensor 51 corresponds to the engine load detecting means.
[0019]
In addition to the throttle opening, the accelerator operation amount, the boost, the intake air amount of the engine, and the like may be detected as a value correlated with the engine load.
The maximum horsepower set by the maximum horsepower setting unit 71 is input to a target horsepower setting unit (target horsepower setting means) 72, and the target horsepower setting unit 72 sets the driver's power performance as described later. A target horsepower is set based on the required degree and the maximum horsepower.
[0020]
The power performance requirement level is set within a range of 0 to 1.0, and the higher the numerical value, the higher the power performance requirement level is set. The target horsepower is expressed as “target horsepower = Calculated as "maximum horsepower x power performance requirement degree".
Accordingly, the target horsepower is set within the range of 0 to maximum horsepower, but the minimum horsepower corresponding to the vehicle speed VSP is set in advance as shown in FIG. 4, and the minimum at the vehicle speed VSP at that time is set. The target horsepower below the horsepower is not set.
[0021]
The target horsepower is output to the target engine rotation calculation unit 73, where the target engine rotation speed is set based on the target horsepower.
The target engine rotation calculation unit 73 obtains a rotation condition with the best fuel consumption rate among the rotation speed conditions for obtaining the target horsepower. That is, a table in which a rotation condition with the best fuel consumption rate is obtained in advance among rotation speed conditions for obtaining a target horsepower, and the engine rotation speed with the best fuel consumption corresponding to the target horsepower is stored based on the result (see FIG. 5). And the table is stored in the target engine rotation calculation unit 73. Then, the target engine speed calculation unit 73 refers to the table based on the target horsepower, and the engine speed of the best fuel consumption at which the set target horsepower is obtained is set as the target engine speed.
[0022]
The target engine speed is output to the target speed ratio calculation unit 74, and the target speed ratio is calculated as target speed ratio = target engine speed / vehicle speed VSP based on the target engine speed and the vehicle speed VSP.
The transmission control unit 75 changes the pulley ratio (secondary pulley side belt winding effective diameter / primary pulley side belt winding effective diameter) by hydraulic control so that the actual transmission ratio matches the target transmission ratio.
[0023]
The target engine rotation calculation unit 73, the target gear ratio calculation unit 74, and the shift control unit 75 correspond to a shift control unit.
The flowchart of FIG. 6 schematically shows the state of the control shown in the control block diagram of FIG. 3. In S1, the throttle opening TVO, the vehicle speed VSP, the power performance requirement degree DRL, etc. are read.
[0024]
In S2, the maximum horsepower is set based on the throttle opening TVO.
In S3, a target horsepower is set based on the maximum horsepower and the power performance requirement degree DRL.
In S4, the engine rotational speed at the best fuel consumption rate at which the target horsepower is obtained is set as the target engine rotational speed.
[0025]
In S5, a target gear ratio is set based on the target engine speed and the vehicle speed VSP.
In S6, the pulley ratio is controlled so as to be the target gear ratio.
Next, the state of setting control of the power performance requirement degree DRL (power performance requirement degree setting means) will be described based on the control block diagram of FIG.
[0026]
The throttle opening signal from the throttle sensor 51 is differentiated in the differential calculation unit 81 as a value correlated with the accelerator operation amount by the driver, and the throttle opening change rate, that is, the accelerator operation speed is obtained.
The accelerator operation speed is obtained as a positive value on the accelerator depression side (throttle opening side) and as a negative value on the accelerator return side (throttle closing side). Therefore, the accelerator return speed is also detected as a parameter indicating the degree of demand of the driver's power performance.
[0027]
The accelerator operation speed that can take a positive value and a negative value is converted into an absolute value by the conversion table 82, but the conversion characteristic of the positive operation speed is different from the conversion characteristic of the negative operation speed. Even if the absolute values before conversion are the same, the minus side operation speed is converted to a value smaller than the plus side operation speed. This is because the assisting force by the spring works on the return side, and it is possible to correctly determine the driver's power performance requirement when judged by discounting than the stepping side.
[0028]
The maximum value of the accelerator operation speed obtained as an absolute value is stored in the peak hold unit 83.
The peak hold unit 83 compares the stored maximum value up to the previous time with the latest detected accelerator operation speed, and if the latest operation speed exceeds the stored value, the latest operation speed Is stored as the maximum value, and when the stored maximum value is larger than the latest value, the stored value is held as it is.
[0029]
Here, the attenuation processing unit 84 reads the maximum value stored in the peak hold unit 83 and gradually attenuates the maximum value every unit time based on a predetermined attenuation amount. The maximum value after the attenuation process is output to the power performance requirement level setting unit 86, while the stored data of the maximum value in the peak hold unit 83 is updated based on the maximum value after the attenuation process. For this reason, the peak hold unit 83 updates the stored data of the maximum value by comparing the stored data of the maximum value gradually attenuated with the latest operation speed.
[0030]
Therefore, even if the accelerator operating speed increases momentarily, if the accelerator operating speed continues to be low thereafter, the maximum value will gradually decrease, and conversely, a large operating speed will be detected frequently. Then, the maximum value holds a large value. Further, when an accelerator operation speed exceeding the maximum value is detected during the attenuation, the maximum operation value is updated to the latest operation speed.
[0031]
The attenuation amount in the attenuation processing unit 84 is set in the attenuation amount setting unit 85 based on the accelerator operation amount (throttle opening).
A throttle opening signal from the throttle sensor 51 is input to the attenuation amount setting unit 85 as a value corresponding to the accelerator operation amount, and the attenuation corresponding to the throttle opening (accelerator operation amount) in advance. A table storing the amount is referred to, and an attenuation amount corresponding to the throttle opening at that time is set.
[0032]
The attenuation amount in the table is configured such that the attenuation amount becomes smaller as the throttle opening (accelerator operation amount) increases, and the attenuation amount is set to 0 above a predetermined throttle opening.
Therefore, when the accelerator operation is performed in a region where the opening is small, the maximum value is attenuated relatively quickly, but the attenuation rate decreases as the opening increases, and the opening is larger than a predetermined region. When the accelerator operation is being performed, the maximum value of the accelerator operation speed is not attenuated and is held.
[0033]
The maximum value of the accelerator operation speed that is attenuated as described above is output to the power performance requirement degree setting unit 86, where it is converted into a parameter DRL that indicates the degree of demand of the driver's power performance.
Here, when the maximum value of the accelerator operation speed is large, the driver is more demanding of the power performance, and the shift control emphasizing the power performance is required, and conversely, the maximum value of the accelerator operation speed is small. In this case, it is assumed that the driver has a strong tendency to focus on fuel efficiency rather than power performance, and shift control that emphasizes fuel efficiency is required. The parameter DRL is within a range of 0 to 1.0, and the degree of power performance required It is assumed that the higher the value is, the larger the value is set.
[0034]
Note that the maximum value of the accelerator operation speed is passed through a low-pass filter (for example, a pass frequency range of 0.005 Hz or less) and then input to the power performance requirement level setting unit 86 to avoid fluctuations in the power performance requirement level at high frequencies. It is good to do.
The parameter DRL indicating the required level of power performance output from the power performance request level setting unit 86 is output to the target horsepower setting unit 72 shown in FIG. 3, and based on the maximum horsepower and the parameter DRL, the target horsepower is output. Is set.
[0035]
The parameter DRL setting means is not limited to that shown in the block diagram of FIG.
For example, while setting the basic value of the parameter DRL based on the accelerator operation amount (throttle opening), the basic value is corrected based on the accelerator operation speed (throttle opening change rate), and the corrected parameter DRL and Comparing with the stored maximum value, the stored data of the maximum value is updated and set, and the stored data of the maximum value is attenuated according to the accelerator operation amount (throttle opening), and the maximum value The stored data may be finally output as a parameter DRL indicating the degree of power performance requirement.
[0036]
Further, simply, a configuration may be adopted in which the power performance requirement degree is set based on a comparison between a throttle opening change rate (accelerator operation speed) level and a reference value.
In the above description, the continuously variable transmission 1 will be described as an example, the target horsepower is set based on the parameter indicating the degree of demand for the driver's power performance, and the gear ratio in the continuously variable transmission is controlled based on the target horsepower. However, a shift stage may be determined based on the target horsepower in the shift control of the stepped transmission having the gear train.
[0037]
【The invention's effect】
As described above, the operation according to the first aspect of the invention, Rutotomoni obtains the maximum horsepower from the engine load, based on an accelerator manipulation speed by setting the power performance requirements degree of a driver's target horsepower and the maximum horsepower The driver's power performance requirement level is set based on the driver's power performance requirement level, so that the driver's power performance requirement level can be set accurately, and the power performance in line with the driver's intention can be demonstrated for each engine load condition. There is an effect that can be.
[0038]
According to the second aspect of the invention, there is an effect that the maximum fuel consumption performance can be obtained while satisfying the driver's power performance requirement.
According to the invention described in claim 3, there is an effect that the target horsepower can be obtained with good response and the gear shift can be performed with good response to the driver's intention.
According to the fourth aspect of the present invention, it is possible to avoid that the target horsepower is set to be unduly small, and thus it is possible to prevent deterioration in drivability.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a configuration of an invention according to claim 1;
FIG. 2 is a system configuration diagram of a continuously variable transmission.
FIG. 3 is a control block diagram showing a state of shift control.
FIG. 4 is a diagram showing a correlation between vehicle speed and minimum horsepower.
FIG. 5 is a diagram showing a correlation between a target horsepower and a target engine rotation speed.
FIG. 6 is a flowchart showing a state of shift control.
FIG. 7 is a control block diagram showing how the power performance request level is set.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Continuously variable transmission 2 Primary pulley 2a Primary pulley side actuator 3 Secondary pulley 3a Secondary pulley side actuator 7 Solenoid valve 8 Solenoid valve 50 Controller 51 Throttle sensor

Claims (4)

Engine load detecting means for detecting a value correlated with the load of the engine combined with the transmission;
Maximum horsepower setting means for setting the maximum horsepower that can be output at the engine load detected by the engine load detection means;
Power performance requirement level setting means for setting the driver's power performance requirement level based on the accelerator operation speed ;
Target horsepower setting means for setting a target horsepower based on the maximum horsepower and the degree of power performance requirement;
Shift control means for controlling the transmission gear ratio or shift speed of the transmission so as to achieve the target horsepower;
A control apparatus for a transmission, comprising: Based on the relationship between the preset target horsepower and the fuel consumption rate, the shift control means obtains the target horsepower set by the target horsepower setting means and obtains the best fuel consumption rate. 2. The transmission control apparatus according to claim 1, wherein the transmission gear ratio or gear position of the transmission is controlled. The shift control means sets a target engine speed that provides the best fuel consumption rate based on the target horsepower, and determines a gear ratio or a gear position based on the target engine speed and the vehicle speed. The transmission control device according to claim 2. The control apparatus for a transmission according to any one of claims 1 to 3, wherein the target horsepower setting means sets the target horsepower with a minimum horsepower preset according to the vehicle speed as a lower limit.

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