KR101305816B1 - Method for controlling the operating characteristic of a hybrid electric vehicle - Google Patents

Abstract

According to the present invention, when the pedal pedal track changes little by little by continuously monitoring the accelerator pedal track, it is recognized that the driver is determined to drive at constant speed or slow acceleration. After down-shift, the engine output demand value is considered in consideration of the step ratio between the gear stages. The present invention relates to a method of controlling operating characteristics of a hybrid electric vehicle, in which a sudden acceleration situation is not generated by dropping).

Description

TECHNICAL FOR CONTROLLING THE OPERATING CHARACTERISTIC OF A HYBRID ELECTRIC VEHICLE}

The present invention relates to a method for controlling the operating characteristics of a hybrid electric vehicle, and more specifically, down-shift when it is recognized that the change of the pedal track is small and the driver's constant speed or slow acceleration is continued by continuously monitoring the accelerator pedal track. After is made, the method of controlling the operating characteristics of the hybrid electric vehicle to reduce the engine output demand (Demand Value) in consideration of the step ratio between each gear stage to prevent the sudden acceleration situation.

In general, the up / down shift RPM of Auto TM (hereinafter, ATM), which is widely applied to passenger cars, is determined using an Excel track and RPM.

In other words, on a slow hill road of 2 to 3%, a slow or constant speed operation is performed with 10 to 30% of excel orbit in a low speed range of 1300 to 2000 RPM, when the road slope suddenly changes to 5 to 6% or flat In the low speed range of 1300 ~ 2000RPM, the vehicle accelerates or accelerates at 10% level of the Excel track. When the road slope suddenly changes to 2 ~ 4%, the slope resistance increases due to the road slope. (Down-Shift).

As in the above situation, the driver wants to accelerate or drive at a constant speed, but if the downshift occurs due to a sudden increase in the gradient resistance, the sudden acceleration of the vehicle occurs due to the downshift. Inconvenience to reduce the acceleration will occur.

For example, assuming that the step ratio between the gear stages of the six-speed ATM is about 1.4, it can be seen that the driving force of the vehicle increases by 1.4 times even with a simple calculation. Of course, depending on the engine map along the accelerator pedal track, the increase in driving force will not be 1.4 times, but it is 1.4 times for understanding.

The graph of FIG. 1 arbitrarily displays the 4 & 5 drive force diagram of a 6-speed ATM vehicle.

Assume that the driving force position is "A" when the vehicle runs at 78KPH with a 30% Excell trajectory on a 3% gradient. At this time, there is almost no driving force, and it is almost constant speed.

Suddenly, when the road slope changes to 5%, the driving resistance is increased than the driving force, so the TCU (Transaxle Control Unit) issues a downshift command, and the downshift is performed from five to four stages.

As the graph shows, the driving force suddenly changes to 40 kgf at the level of 0 kgf. The driving force suddenly accelerates, and the driver is surprised by the sudden acceleration.

If the driver wants a 78KPH, he or she must release the accelerator pedal. If the vehicle is in close contact, there is a possibility of a contact accident.

Referring to FIG. 2, the speed change trend at the time when the downshift occurs is reduced when the road slope becomes middle while driving (A) at a desired speed, but the driver maintains the Excel track (B).

This increases downshift and revolution per minute (RPM) and accelerates rapidly. And suddenly shifted, the Excel pedal is maintained (C).

After that the downshift and RPM are increased, accelerated and suddenly shifted to maintain the Excel pedal. Then the driver feels a rapid acceleration and takes his foot off the accelerator pedal to lower the speed (D). There is no gear shift. The driver then achieves and maintains the desired speed, and the accelerator pedal also maintains this track (E).

That is, as shown in FIG. 3, when the driver travels to a specific stage (S100), the main controller continuously checks the RPM (S110) and checks the Excel orbit (S120).

In operation S110, it is determined whether the RPM is smaller than a predetermined set value, and if the RPM is smaller than the predetermined value, the down shift mode is executed (S140). If the RPM of the determination result of step S130 is greater than the predetermined value is repeated from the step S100.

Such a phenomenon is a situation that can occur and experience frequently during the actual operation, there is a problem that causes the risk of accidents and the merchandise deterioration due to the driver's surprise due to the fuel consumption and sudden acceleration due to the increase in RPM.

In addition, this phenomenon has a problem in that the gear stage is more frequent as the step ratio becomes smaller due to the application of high horsepower and multi-stage TM.

The present invention has been made to solve the problems of the prior art, the present invention is to continuously monitor the accelerator pedal track, the change in the pedal track is small, if it is recognized that the driver's willing to constant speed or slow acceleration after each shift is made It is an object of the present invention to provide a method of controlling operating characteristics of a hybrid electric vehicle in which a sudden acceleration situation is not generated by lowering an engine output demand value in consideration of a step ratio between gear stages.

Accordingly, the method for controlling operating characteristics of a hybrid electric vehicle according to an embodiment of the present invention includes (1) checking a current RPM when a driver travels in a specific stage (2) checking a current average value of an Excel track (3) Determining whether the checked RPM is less than a predetermined RPM value. (4) determining whether an excel track change is less than a predetermined reference value based on the checked Excel track average value and (5) the Excel. Executing the smart down-shift mode in the current mode when the trajectory change is less than the reference value.

Preferably, when performing the smart down-shift mode and then switching back to the down-shift mode, determining whether the change in the excel orbit is less than the reference value and the excel orbit And if the amount of change is less than the reference value, causing the current mode to switch back to the smart down shift mode.

Preferably, the method further comprises the step of controlling the vehicle to be driven to a specific stage set by the driver by releasing the smart down shift mode and returning the output when the amount of change in the orbit of the excel is greater than or equal to the reference value.

Preferably, the smart down shift may be implemented by changing the pattern of the fuel demand value (TCU) of the transaxle control unit (TCU).

Preferably, the smart down shift can be implemented by varying the output along the pedal trajectory.

Preferably, the smart down shift can be implemented by changing the Pedal-Fuel Map.

In the present invention, the road gradient and the driving resistance are increased, but the Smart Down-Shift function is applied so that the vehicle can be operated as it is without speed & RPM sudden increase and the change of the excel orbit, and the driver shows the intention to accelerate by pressing the accelerator pedal. The Smart Down Shift function is applied when the vehicle is restored and driven according to the current specification map and the change of the accelerator pedal track is small.However, when the driver steps on the Excel and the TCU recognizes the acceleration will, the driving effect is reduced based on the current specification map. have.

In addition, when the driver does not want to accelerate, the down-shift does not occur, and the RPM is prevented from increasing suddenly, the hill road can also be operated comfortably, and the fuel efficiency can be increased. .

1 is a graph showing a hill drive amount applied to a conventional hybrid electric vehicle.
2 is a chart for explaining a Down-Shift mode applied to a conventional hybrid electric vehicle.
3 is a flowchart illustrating a method of controlling operating characteristics of a conventional hybrid electric vehicle.
4 is a flowchart illustrating a method for controlling operating characteristics of a hybrid electric vehicle according to the present invention.
5 to 7 are views for explaining a method for implementing a Smart Down Shift mode applied to the present invention.
8 is a graph for explaining the difference between the Smart Down Shift mode and the driver acceleration.
9 is a graph for explaining an Excel orbit output.

Hereinafter, a method of controlling operating characteristics of a hybrid electric vehicle according to the present invention will be described.

As shown in FIGS. 4 to 9, the main controller (not shown) of the vehicle checks the current revolutions per minute (RPM) when the driver is traveling in a specific stage (S200), and then checks the current Excel track. After checking (S210), the average value of the Excel orbit is checked (S220).

The main controller first determines whether the checked RPM is less than the preset RPM value (S230), and then determines whether the change in the orbit of the Excel track is less than 0.1 V based on the checked average value of the Excel track (S240).

As a result of the determination in step S240, when the change in the orbit of the excel track is less than 0.1 V, the main controller executes the smart down-shift mode in the current mode so that the current hybrid electric vehicle is driven in the smart down shift mode ( S250).

When the smart down shift mode ends, the main controller switches the hybrid electric vehicle to run in the down-shift mode again (S260), and then again determines whether the change in the excel orbit is less than 0.1V (S270). .

If the result of the determination in step S270 is less than 0.1 V, the main controller changes the current mode from the down shift mode back to the smart down shift mode to maintain the hybrid electric vehicle in the smart down shift mode (S280).

As a result of the determination in step S270, when the change in the orbit of the excel track is 0.1 V or more, the main controller releases the smart down shift mode and returns the output (S290) to control the entire system to drive the vehicle to a specific stage set by the driver. At this time, the main controller determines whether the output is returned to 99% or more (S295), and if the output return is made to 99% or more, the step is repeatedly performed from step S200 to allow the hybrid electric vehicle to travel to a specific stage preset by the driver.

Referring to the graph of FIG. 8 while comparing the difference between the application of the smart downshift and when the driver accelerates, the speed and RPM is increased by applying the smart downshift function of the present invention even when the road gradient and driving resistance are increased. It is possible to operate as it is without any sudden increase of the orbit (A), while the driver releases the accelerator pedal, indicating the willingness to accelerate, and the output is returned to its original position and is driven according to the current map (MAP). That is, when the amount of change in the accelerator pedal track is small, the smart downshift function is applied, but when the driver steps on the accelerator and the TCU (Transaxle control unit) recognizes the acceleration, it is reduced and driven based on the current specification MAP.

At this time, the smart down shift mode implementation method implemented by the main controller has three methods shown through FIGS.

First, the smart down shift mode implementation method changes the pattern of the fuel demand value of the TCU as shown in FIG. 5 to step the existing fuel demand value from 100% to the gear stage. The ratio is changed to 71%, which is equivalent to 1.4. This value is then determined by tuning.

As shown in FIG. 6, the second smart down shift mode is implemented by varying the output according to the pedal track, and uniformly outputs the output value according to the existing pedal track by an amount corresponding to 1.4 of the gear stages. It is set to the value dropped by. At this time, the value of FIG. 6 is an arbitrary value of the value which the step ratio between gears dropped uniformly by the amount corresponding to 1.4. The voltage Volt is any number and can be any value representing the pedal trajectory.

The third smart down shift mode is implemented by changing the pedal-fuel map as shown in FIG. 7, and changing the amount of fuel in the pedal-fuel map. In this case, the fuel change amount of FIG. 7 is an arbitrary value of the step ratio between the gear stages uniformly dropped by an amount corresponding to 1.4, and the fuel injection amount is any number.

Referring to FIG. 9 for the Excel orbital output applied to the present invention, the difference between the voltage average value (Volt average 1) and the voltage check value (Volt CHK 1) at the time of measurement 1 second before and after 1 second is compared. At 1.1 seconds, Volt average 1) and Volt CHK 1.1 are compared and Volt 1 and Volt CHK 1 are deleted from memory. In this way, pedal trajectories are continuously compared to determine the amount of change in the accelerator track. At this time, the change rate of the Excel track is the absolute value of (check value-average value), and the driver's determination of acceleration / deceleration / constant speed determination. The value for judging the magnitude of change is small as an evaluation, and is set here as 0.1 Volt which is 5% of 2 Volt arbitrarily. Here, the average value is the average value of the accelerator pedal output for 1 second (arbitrary value), and it is used as a reference for judging the acceleration / deceleration and constant speed will of the driver immediately before the check (CHK). This value recognizes the pedal output, and the driver's will is determined by the difference from the average value.

In addition, briefly explaining the smart downshift mode applied to the present invention, ① recognizes that there is no driver's will to accelerate by constantly changing the change of the accelerator pedal track, ② the running resistance suddenly increased due to the gentle gradient resistance, etc. When the TCU issues a downshift command, ③ the engine output is controlled after the downshift by three ways on page 3 of the present invention, and ④ when the track of the accelerator pedal is maintained. This will continue to apply, but when the driver's determination of acceleration and deceleration is determined due to the change of the accelerator pedal orbit, this mode returns to the current specification TCU Map.

As mentioned above, although preferred embodiments of the present invention have been described in detail, those of ordinary skill in the art to which the present invention pertains should realize the present invention without departing from the spirit and scope of the present invention as defined in the appended claims. Although various modifications or changes may be made, these are included in the spirit and scope of the invention as included in the appended claims.

Claims (6)

(1) checking the current revolution per minute (RPM) when the driver is traveling in a specific stage;
(2) checking a current Excel orbit mean value;
(3) determining whether the checked RPM is less than a predetermined RPM value;
(5) determining whether the amount of change in the orbit of the excel is less than a preset reference value based on the checked average value of the excel orbit; And
And (6) executing a smart down-shift mode in a current mode when the excel orbit change amount is less than the reference value.
The method of claim 1,
Determining whether the amount of change in the orbit of the Excel is less than the reference value once the smart down shift mode is switched to the down-shift mode again; And
And re-switching the current mode to the smart down shift mode when the excel orbit change is less than the reference value.
3. The method of claim 2,
And if the amount of change in the orbit of the excel is greater than or equal to the reference value, releasing the smart down shift mode and returning the output so that the vehicle is driven to a specific stage set by the driver.
The method of claim 1,
The smart down shift mode is implemented by changing the pattern of the fuel demand value (Fuel Demand Value) of the TCU (Transaxle control unit) operating characteristics control method of a hybrid electric vehicle.
The method of claim 1,
The smart down shift mode is a method of controlling the operating characteristics of a hybrid electric vehicle, characterized in that implemented by changing the output according to the pedal (Pedal) track.
The method of claim 1,
The smart down shift mode is a method of controlling the operating characteristics of a hybrid electric vehicle, characterized in that implemented by changing the pedal (Pedal)-fuel map (Fuel Map).

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