KR20180066755A - Transmission Controlling Method of Automatic Transmission vehicle - Google Patents

Abstract

Disclosed is a transmission control method of an automatic multi-speed transmission vehicle, for implementing optimum shift and fuel efficiency. The method includes: receiving information necessary for determining a target speed for each gear from transmission control unit and sensors, and determining a target speed (RPM_target) as a reference for shifting to the next gear by utilizing the received information (S100); selecting fuel efficiency reference speed (RPM_efficiency), which serves as an optimum fuel efficiency reference point, matched with an engine output due to an accelerator pedal by utilizing a fuel efficiency map, and determining a target gear by comparing the target speed (RPM_target) with the fuel efficiency reference speed (RPM_efficiency) (S200); collecting information necessary for figuring out an accelerating will during driving the vehicle directed to the target gear, and determining the accelerating will of a driver based on the collected information (S300); determining a kick-down target gear on the basis of information about the kick-down allowable number and accelerator pedal operation for each gear, when determined that a current operation state of the vehicle indicates the accelerating will of the driver based on the collected information (S400); and shifting to the gear determined in step S400 (S500).

Description

TECHNICAL FIELD [0001] The present invention relates to a transmission control method for a multi-stage automatic transmission,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control method for an automatic transmission, and more particularly, to a shift control method for a multi-stage automatic transmission vehicle capable of realizing an optimum fuel economy while meeting a driving situation of a vehicle and a driver.

Acceleration by the driver and manipulation of the braking pedal are elements reflecting the driver's will and appear as output through the dynamometer. Generally, the engine power, that is, the output [kW] can be expressed by a product of the engine torque [Nm] and the engine speed [RPM], and the torque and the speed are appropriately controlled, Can be obtained.

In the case of a vehicle equipped with an automatic transmission, an appropriate shift according to the driving situation is executed by the internal shift logic of the TCU (Transmission Control Unit) controller in the shift strategy. Although there is a slight difference in each manufacturer, basically, it adopts a method of determining an appropriate gear stage according to the situation by using a standardized shifting map expressed by a relationship between the manipulated variable of the accelerator pedal by the driver and the vehicle speed.

In the shift control of the automatic transmission, the driver's acceleration is affected by the operation of the accelerator pedal. The driver's request (acceleration will) is satisfied in accordance with the changing running situation by varying the shift stage decision according to the change pattern of the accelerator pedal. Basically, the determination of acceleration is determined from the degree of manipulation (amount of displacement) of the accelerator pedal, and the rate of change of the accelerator pedal (angular velocity) is also a determining factor.

For example, if a change in the operating state is detected within 1-2 seconds of 90% of the running while the accelerator pedal is operated at 20%, it can be determined that the driver is willing to pass or accelerate rapidly, It can be satisfied by down-level guidance or output increase. In the former case, it is judged whether or not the target speed change stage for the current speed change stage should be taken from the running situation (speed, gradient, etc.) to satisfy the acceleration will.

However, in the case of the shift control using the standardized shift map as in the prior art, it is difficult to select an appropriate gear position for the situation in response to a large number of running situations, resulting in a decrease in ride comfort and fuel economy due to frequent shifts. Also, there is a disadvantage in that the complexity of the control logic to be considered increases as the speed change stage is increased according to the automatic transmission multi-shoe.

Japanese Patent Application Laid-Open No. 2000-343983 (published December 12, 2000)

SUMMARY OF THE INVENTION It is an object of the present invention to provide a shift control method for a multi-stage automatic transmission vehicle capable of realizing an optimum shift and fuel economy corresponding to a driving situation of a vehicle and a driver's demand.

According to an embodiment of the present invention as a solution to the problem,

(a) receives information necessary for determining the target speed for each gear position from the shift control unit and sensors, and uses the received information to calculate a target speed ( RPM_target ) as a reference for shifting to the next gear position ( S100 );

(b) a comparison of the advantage of the fuel consumption map (Map) by selecting the fuel consumption based on speed (RPM_efficiency) optimal fuel consumption reference point is matched to the engine output by the accelerator pedal, and the target speed (RPM_target) and fuel reference speed (RPM_efficiency) A step S200 of determining a target speed change stage through the step S100 ;

(c) collecting information necessary for grasping acceleration intention during operation with the target shift stage determined based on the target speed ( RPM_target ) and the fuel consumption reference speed ( RPM_efficiency ), and determining the driver's will to be accelerated based on the collected information S300 );

(d) determining a kick down target shift stage based on the number of kick down possible stages per shift position and the accelerator pedal operation information if the current operating state of the vehicle recognized from the collected information is determined to be the driver's acceleration intention ( S400) ; And

(e) a step S500 of shifting to a speed change stage determined in the step S400 of determining a kick down target speed change stage ( S500 ).

In step S400 , the kick down target shift stage corresponding to the current accelerator pedal operation amount is determined from the accelerator pedal operation amount corresponding to the shift speed difference from the current gear stage to the maximum gear stage capable of kicking down. by a specific offset (offset) performance reference speed is determined as a value obtained by adding a value (RPM_performance) to fuel the reference speed (RPM_efficiency) is matched to the output compared to the target speed (RPM_target) of said kick-down target shift speed final kick-down target speed change Can be determined.

At this time, the predetermined offset (Offset) value may be calculated from the proportional relationship between the accelerator pedal operation amount according to the current shift stage and the maximum possible shift speed kick down each of the target speed and the car driver's acceleration operation.

In addition, in order to maintain the engine speed at a performance reference speed ( RPM_performance ) for a period of time during which the accelerator pedal is maintained in a state where the accelerator pedal is moved to a desired acceleration position, It is preferable that the shifting to the end is performed.

In addition, in step S100, the information required to determine the target speed for each gear position may include the axle speed (output shaft speed) and the gear ratio information per gear step.

The fuel consumption map includes information on the relationship between the accelerator pedal and the output. If the engine output is determined according to the accelerator pedal operation, an algorithm for selecting a fuel consumption reference speed ( RPM_efficiency ) matching the output may be applied have.

The information necessary for grasping the acceleration in step S300 may be an acceleration pedal operation amount obtained through the acceleration pedal detection sensor and an acceleration pedal change rate expressed by a change amount of the acceleration pedal with respect to time.

Here, it can be determined that there is an acceleration will if the set value is equal to or greater than the set value corresponding to each of the accelerator pedal operation amount and the accelerator pedal change rate.

According to the shift control method of the present invention, by predicting the driver's will to change in real time according to various driving situations and finding the optimum gear stage corresponding thereto, it is possible to obtain a frequent map as in the rule based shifting There is an advantage that the sense of heterogeneity due to the conversion can be reduced, and the load imposed on the controller can be reduced.

Further, based on the fuel consumption data, it is possible to find the fuel efficiency reference speed that can optimize the fuel efficiency according to the engine output, select the target shift stage based on the fuel efficiency, By controlling the shift based on the reference speed plus a specific option value, the fuel efficiency can be efficiently managed even in an accelerating situation where the driver's acceleration will be fully reflected, while the fuel consumption is high.

Brief Description of the Drawings Fig. 1 is a flow chart for a shift control for fuel economy driving according to an embodiment of the present invention. Fig.
FIG. 2 is a flowchart illustrating a process of determining a kick down target shift range in accordance with a driver's acceleration.
3 is an exemplary diagram for explaining an output state change and a shift according to a change in an amount of operation of an accelerator pedal in a kick down shift state;

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. It is to be understood that the terms "comprises", "having", and the like in the specification are intended to specify the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, parts, or combinations thereof.

Also, the terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

In addition, the terms " part, "" unit," " module, "and the like, which are described in the specification, refer to a unit for processing at least one function or operation, which may be implemented by hardware or software or a combination of hardware and software .

In the following description with reference to the accompanying drawings, the same reference numerals are given to the same constituent elements, and a duplicate description thereof will be omitted. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

FIG. 1 is a flowchart illustrating a shift control for fuel economy driving according to an embodiment of the present invention.

Referring to FIG. 1, the shift control method according to the embodiment of the present invention is divided into five steps. Preferably, a step S100 of determining a target speed RPM_target , a step S200 of determining a target speed change stage, a step S300 of determining an acceleration will of the driver, a determination of a kick down target speed change stage ( S400 ) of determining the target speed change stage And a step S500 of shifting is performed.

In step S100 of determining the target speed RPM_target , information necessary for determining the target speed for each gear position is received from the speed change control unit and the sensors provided in the vehicle. Then, using the received information, the target speed is determined as a reference for shifting to the next stage of the shift stage. At this time, the information required for determining the target speed may include the axle speed and the gear ratio information per gear ratio.

That is, the target speed RPM_target can be derived from the current axle speed and the gear ratio information of each gear range. Specifically, the input shaft speed corresponding to the current axle speed (output shaft speed) is calculated for each gear stage through the reduction ratio for each gear ratio stored in the gear ratio map, Is determined as a target speed ( RPM_target ) serving as a reference for shifting to the target speed ( RPM_target ).

More specifically, the target speed can be calculated by a simple calculation of " axle speed * gear ratio = input shaft speed ". For example, if the current gear ratio is in a five-speed running state where the gear ratio is 1: 1 and the axle speed calculated from the vehicle speed is 2300RPM, the input shaft speed, i.e., the target speed, will be 2300RPM, The next step is a shift to the sixth step.

In step S200 of determining the target speed change stage, the fuel efficiency map RPM_efficiency , which is an optimal fuel consumption reference point matched with the engine output by the accelerator pedal, is selected by using the fuel consumption map Map. Then, the target speed RPM_target and the fuel efficiency reference speed RPM_efficiency are compared with each other to determine a shift state and a target shift stage at the time of shifting.

For example, according to the current engine output, If the selected fuel-economy reference speed ( RPM_efficiency ) is equal to or greater than the target speed of the third speed-change stage among the target speeds ( RPM_target ) of the speed-change stage determined by the current vehicle speed and gear ratio, the four- . Conversely, if the target speed of the 3-speed range is less than the target speed, the 3-speed range is determined as the target speed range.

The fuel mileage map contains information about the relationship between the accelerator pedal and the output. Specifically, when the engine output (demand output) is determined in accordance with the operation of the accelerator pedal, the fuel efficiency data is stored for each engine output according to the number of revolutions of the engine. The engine speed at the lowest fuel consumption rate among the revolutions is selected as the fuel consumption reference speed ( RPM_efficiency ).

For reference, the engine output can be determined through an engine output map storing data of the required output (kW) per vehicle speed (corresponding to the transmission output shaft speed) in accordance with the accelerator pedal operation amount (or throttle opening amount or load amount). In other words, the engine output map is a data matrix of the required output required to produce a certain vehicle speed in terms of two factors of the accelerator pedal operation amount and the vehicle speed.

In step S300 of determining the driver's will to accelerate, the target speed change stage determined through the mutual comparison of the target speed RPM_target and the fuel consumption reference speed RPM_efficiency based on the fuel consumption map, And collects necessary information to grasp Based on the collected information, the driver's acceleration will is determined.

In step S300 , the information required for grasping the acceleration may be an acceleration pedal manipulated variable obtained through the accelerator pedal detection sensor and an accelerator pedal change rate expressed by a change amount of the accelerator pedal with respect to time. Preferably, when the set value is equal to or greater than a set value corresponding to each of the accelerator pedal operation amount and the accelerator pedal change rate, it can be determined that there is an acceleration will.

For example, if a change in operating state is detected within 1-2 seconds of 90% of the running while the accelerator pedal is operated at 20%, it can be determined that the driver is willing to overtake or accelerate rapidly. Of course, the amount of operation of the accelerator pedal and the rate of change of the accelerator pedal are not limited to specific values, because they can be applied differently depending on the vehicle in consideration of the output performance of the engine, the specifications,

If the current operation state of the vehicle is identified from the information collected in step S300 a determination is made that the acceleration intention of the driver, that is, if the set value or more set in correspondence to each of the accelerator pedal operation amount and accelerator pedal change rate, through the S400 step A process of determining a kick down target shift range is performed based on the kick down possible number of gear positions per gear position and the accelerator pedal operation information.

FIG. 2 is a flowchart illustrating a process of determining a kick down target shift range in accordance with an acceleration of the driver.

Referring to FIG. 2, in operation S400, a step S410 of determining a kick-down target shift stage corresponding to an accelerator pedal operation in which the driver's acceleration intention is reflected ( S410 ) ( Step S420 ) of determining a final kick down target speed range from a rotational speed (a performance reference speed to be described later) obtained by adding a specific value to the fuel economy reference speed RPM_efficiency .

In step S410 , the kick down target shift stage corresponding to the current accelerator pedal operation amount is determined from the accelerator pedal operation amount and the gear stage difference from the current gear stage to the maximum gear stage capable of kicking down. At this time, the number of kickdown possible gears per gear position is determined by the shift map, and the gear shift map stores the maximum gear ratio that can be kicked down in each step within a range that can suppress the physical damage of the power transmission system during kick down transmission.

That is, the maximum number of kick down possible gear ratios for each stage stored in the shift map is the maximum shiftable value within a range capable of preventing the damage of the power transmission system from the sudden change in the number of rotations due to the gear ratio difference during the kick down shift, Number, stress of the power system, and stiffness of the power system, etc., and the shift map can be formed by converting the obtained results into a matrix form.

In the case of an 8-speed transmission, the shift map generally stores the maximum number of kick down shift stages in 8 stages, and the maximum kick down shift stages in the 7th stage is stored in two stages. In other words, if the accelerator pedal is operated at the maximum (100%) within the set time during the 7th step, the second step is determined as the kick down target speed change stage. As the target speed change stage.

In step S420 , an engine output corresponding to the rapid acceleration operation is determined (using an engine output map), and a fuel consumption reference speed ( RPM_efficiency ) matched with the determined engine output is found using the fuel consumption map. And by comparing the specific offset (Offset) plus the number of rotation based on the performance rates (RPM_performance) to a selected speed and fuel economy based on the target speed (RPM_target) of said kick-down target speed change stage determines the final target shift speed kick down.

The specific offset value is an additional number of revolutions added to the fuel consumption-based engine speed (fuel consumption reference speed) in order to satisfy the acceleration feeling in the acceleration operation. The offset value is a target speed derived from the current gear ratio of the current axle speed and the speed change stage, Can be determined from the proportional relationship between the difference between the current axle speed of the possible speed change stage and the target speed derived from the gear ratio and the amount of operation of the accelerator pedal by the driver rapid acceleration operation.

For example, if the target speed of the shift stage (when the accelerator pedal is fully stepped on) that is capable of kicking down at a maximum compared to the target speed of the current gear stage is about 100 RPM, and the manipulated amount of the accelerator pedal is 100, , The x value (50 RPM) obtained from a simple proportional formula, ie, 100: 50 = 100: x ', is added to the fuel economy reference speed ( RPM_efficiency ) determined as the offset value and matched to the engine output.

On the other hand, during the acceleration operation, the accelerator pedal operation information, preferably the engine output, is controlled based on the performance reference speed during a period of time during which the accelerator pedal is maintained in the state of being moved to the desired acceleration position by the driver, The shift control is performed so that the shift to the final kick-down target speed change stage is performed ( S500 ). Then, when the shifting is completed, it is switched back to the fuel economy reference speed driving.

For example, as shown in Fig. 3 for explaining the change of the operating state and the shifting according to the change of the accelerator pedal operation amount in the kick down shift state, when the kick down shift is performed in four stages in the seventh stage , The engine output is controlled at the fuel consumption reference speed up to a specific point in the section where the change of the accelerator pedal operation amount rapidly changes, and then the engine output control based on the performance reference speed is switched.

The speed change stage is shifted from the seventh stage to the fourth stage at a certain time (the shifting point of time in Fig. 3) during the time when the accelerator pedal is maintained in the state where the accelerator pedal is moved to the desired acceleration position, The driver is switched back to the fuel economy reference speed operation at the time point when the driver's acceleration will end, that is, when the driver releases the accelerator pedal to the output reduction side.

According to the shift control method of the present invention, it is possible to predict the driver's will to change in real time according to various driving situations and to find the optimum gear stage corresponding thereto. As a result, There is an advantage that the sense of heterogeneity due to the map conversion can be reduced, and the load imposed on the controller can be reduced.

Further, based on the fuel consumption data, it is possible to find the fuel efficiency reference speed that can optimize the fuel efficiency according to the engine output, select the target shift stage based on the fuel efficiency, By controlling the shift based on the reference speed plus a specific option value, the fuel efficiency can be efficiently managed even in an accelerating situation where the driver's acceleration will be fully reflected, while the fuel consumption is high.

In the foregoing detailed description of the present invention, only specific embodiments thereof have been described. It is to be understood, however, that the invention is not to be limited to the specific forms thereof, which are to be considered as being limited to the specific embodiments, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims. .

Claims (8)

(a) receives information necessary for determining the target speed for each gear position from the shift control unit and sensors, and uses the received information to calculate a target speed ( RPM_target ) as a reference for shifting to the next gear position ( S100 );
(b) a comparison of the advantage of the fuel consumption map (Map) by selecting the fuel consumption based on speed (RPM_efficiency) optimal fuel consumption reference point is matched to the engine output by the accelerator pedal, and the target speed (RPM_target) and fuel reference velocity (RPM_efficiency) A step S200 of determining a target speed change stage through the step S100 ;
(c) collecting information necessary for grasping acceleration intention during operation with the target shift stage determined based on the target speed ( RPM_target ) and the fuel consumption reference speed ( RPM_efficiency ), and determining the driver's will to be accelerated based on the collected information S300 );
(d) determining a kick down target shift stage based on the number of kick down possible stages per shift position and the accelerator pedal operation information if the current operating state of the vehicle recognized from the collected information is determined to be the driver's acceleration intention ( S400) ; And
( S500 ) of shifting to a speed change stage determined in the step ( S400 ) of determining a kick down target speed change stage ( S500 ).
The method according to claim 1,
In step S400 ,
Determining ( S410 ) a kick down target shift stage corresponding to a current accelerator pedal operation amount from an accelerator pedal operation amount for a shift speed difference from a current gear stage to a maximum gear stage capable of being kicked down; And
A specific offset (Offset) performance reference speed is determined as a value obtained by adding a value (RPM_performance) to fuel the reference speed (RPM_efficiency) matched to the current engine output target speed of the kick-down target gear position according to the accelerator pedal operation (RPM_target) And determining a final kick-down target speed change stage ( S420 ).
3. The method of claim 2,
Wherein the specific offset value is calculated from a proportional relationship between a target speed difference of each of the current speed change stage and the maximum speed changeable speed range capable of being kicked down and an accelerator pedal operation amount by the driver rapid acceleration operation. .
3. The method of claim 2,
The engine speed is maintained at a performance reference speed ( RPM_performance ) for a period of time during which the accelerator pedal is maintained in a state where the accelerator pedal is moved to a desired acceleration position,
So as to cause the shifting to the final kick-down target speed change stage to be performed in a section in which the engine rotation speed is maintained at the performance reference speed.
The method according to claim 1,
Wherein the information required for determining the target speed for each of the gear positions includes the gear ratio information for the axle speed and the gear ratio in step S100.
The method according to claim 1,
The fuel consumption map includes information on the relationship between the accelerator pedal and the output, and when the engine output is determined according to the accelerator pedal operation, an algorithm for selecting a fuel consumption reference speed ( RPM_efficiency ) matching the output is applied Speed automatic transmission.
The method according to claim 1,
Wherein the information necessary for grasping the acceleration intention in the step S300 is an accelerator pedal operation amount obtained through the accelerator pedal detection sensor and an accelerator pedal change rate expressed by a change amount of the accelerator pedal with respect to time. Way.
8. The method of claim 7,
And determines that there is an acceleration if the set value is equal to or greater than a set value corresponding to each of the accelerator pedal operation amount and the accelerator pedal change rate.

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