KR101704287B1

KR101704287B1 - Clutch control method for vehiclel

Info

Publication number: KR101704287B1
Application number: KR1020150161465A
Authority: KR
Inventors: 김진성; 남주현
Original assignee: 현대자동차주식회사
Priority date: 2015-11-18
Filing date: 2015-11-18
Publication date: 2017-02-08

Abstract

The present invention relates to a method for controlling a clutch of a vehicle, capable of preventing deterioration of driving performance of a vehicle by preventing vibration of a vehicle motor by rapidly controlling a clutch in case an excessive slip occurs in the clutch. According to the present invention, the method for controlling a clutch of a vehicle includes: a slip rate calculating step of calculating a slip rate of the clutch as a controller receives a rotation number of a power source and the rotation number of an input shaft; a target change rate determining step of determining a target slip change rate corresponding to the slip rate calculated in the slip rate calculating step by the controller; a feedforward calculating step of calculating a feedforward control rate using the target slip change rate by the controller; a feedback calculating step of calculating a feedback control rate in accordance with the slip rate calculated in the slip rate calculating step by the controller; and a clutch control step of controlling the clutch using a final control rate calculated as the feedforward control rate and the feedback control rate are added, by the controller.

Description

CLUTCH CONTROL METHOD FOR VEHICLEL "

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a clutch control method for a vehicle, and more particularly to a technique for controlling the dry clutch in a vehicle equipped with an AMT or DCT equipped with a dry clutch.

In a vehicle equipped with a transmission such as an AMT (Automated Manual Transmission) or a DCT (Dual Clutch Transmission) configured using a dry clutch, in the case of a vehicle oscillation or a shift, the slip of the dry clutch is controlled, .

The above-described dry clutch (hereinafter, referred to as "clutch") has a simple structure and high power transmission efficiency as compared with a torque converter, but has a disadvantage in that the transmission torque characteristic changes in real time depending on temperature, slip amount, and the like.

Conventionally, in a vehicle equipped with an AMT or a DCT as described above, a method of continuously performing feedback control while comparing the slip amount of the clutch with the target slip amount in the case of oscillation or shifting of the vehicle is used. Similarly, when instantaneous excessive slip occurs in the clutch due to the change of the transmission torque characteristic of the clutch in real time, it is difficult to quickly respond only by the feedback control, and vibration of the vehicle driv- ing system is caused and the drivability of the vehicle tends to deteriorate.

It is to be understood that the foregoing description of the inventive concept is merely for the purpose of promoting an understanding of the background of the present invention and should not be construed as an admission that it is a prior art already known to those skilled in the art. Will be.

KR 10-2006-0049944

SUMMARY OF THE INVENTION The present invention is conceived to solve the problems described above, and it is an object of the present invention to provide a vehicle equipped with a transmission equipped with a dry clutch, in which, when excessive slip occurs in the clutch, And it is an object of the present invention to provide a clutch control method for a vehicle that can prevent deterioration in driving performance.

According to an aspect of the present invention,

A slip amount calculating step of calculating a slip amount of the clutch by receiving the power source rotational speed and the input shaft rotational speed from the controller;

A target change rate determining step of the controller determining a target slip change rate corresponding to the slip amount calculated in the slip amount calculating step;

A feedforward calculating step of the controller calculating a feedforward control amount using the target slip change rate;

A feedback calculating step of the controller calculating a feedback control amount in accordance with the slip amount calculated in the slip amount calculating step;

And a clutch control step of controlling the clutch to a final control amount obtained by adding the feedforward control amount and the feedback control amount to the controller.

The target change rate determination step may determine a target slip change rate corresponding to the slip amount calculated in the slip amount calculation step from a map of the target slip change rate with respect to the slip amount of the clutch.

And the feedforward calculating step may calculate the feedforward control amount by multiplying the target slip change rate by the rotational moment of inertia of the vehicle drive system.

The feedback calculation step may be configured to calculate the PI control by calculating and adding the proportional control component and the integral control component using the slip amount and the target slip amount calculated in the slip amount calculating step.

Wherein the feedback calculation step calculates a differential control component by using a value obtained by differentiating the slip amount calculated in the slip amount calculation step and the target slip change rate and adding the calculated slip amount to the proportional control component and the integral control component, .

In the clutch control step, the final control amount may be treated as a rate limiter to prevent the final control amount from excessively changing rapidly.

The present invention can prevent the vehicle drivability from being deteriorated by preventing the vehicle driv- ing system from being vibrated by a quick control when an excessive slip occurs in the clutch, in a vehicle equipped with a transmission equipped with a dry clutch.

1 is a schematic diagram of a vehicle to which the present invention can be applied,
2 is a flowchart showing an embodiment of a control method according to the present invention,
3 is a block diagram illustrating a control method of the present invention,
4 is a block diagram showing in more detail an embodiment according to the control method of the present invention,
5 is a comparative graph for explaining the effect of the present invention.

1, the power of the engine E is configured to be provided to the drive wheels W through a DCT (DUAL CLUTCH TRANSMISSION), and the two clutches 1 constituting the DCT are each configured to be coupled to the clutch actuator 3 And the transmission gears constituting the respective speed change stages are shifted by a shift actuator 4 that selects and drives the synchronizing devices and the clutch actuator 3 and the shift actuator 4 are controlled by the controller 5 And the controller is configured to receive an ACCELERATOR POSITION SENSOR (APS) signal to receive an accelerator pedal operation amount.

Of course, the controller 5 is also provided with information such as engine torque and engine speed.

Here, the "controller" is a transmission controller that controls a transmission such as a DCT, unless otherwise specified, and a controller that controls the engine is referred to as an "engine controller"

Referring to FIG. 2, an embodiment of a method of controlling a clutch of a vehicle according to the present invention includes: a slip amount calculating step (S10) of calculating a slip amount of a clutch by receiving a power source rotational speed Ne and an input shaft rotational speed Ni; A target change rate determination step (S20) of determining, by the controller, a target slip change rate corresponding to the slip amount calculated in the slip amount calculation step; A feed forward calculation step (S30) in which the controller calculates a feed forward control amount using the target slip change rate; A feedback calculation step (S40) of the controller calculating a feedback control amount in accordance with the slip amount calculated in the slip amount calculating step; And a clutch control step (S50) of controlling the clutch to a final control amount obtained by adding the feedforward control amount and the feedback control amount to the controller.

That is, as shown in FIG. 3, the feedback control amount according to the slip amount as well as the feed forward control amount are additionally calculated, and the clutch is controlled to the final control amount obtained by adding the feedback control amount and the feedforward control amount, So that the vehicle drivability can be prevented from being lowered, thereby preventing deterioration of the driving performance of the vehicle and ultimately improving the commerciality of the vehicle.

Here, the power source corresponds to the engine of FIG. 1, but the present invention is not limited thereto, and may be a driving motor such as a hybrid vehicle or an electric car.

The target change rate determination step (S20) is configured to determine a target slip change rate corresponding to the slip amount calculated in the slip amount calculation step from a map of the target slip change rate with respect to the slip amount of the clutch.

That is, the map of the target slip change rate with respect to the slip amount of the clutch is constructed by carrying out a number of experiments and analyzes on the vehicle in advance and storing it in advance, and the controller immediately refers to the map, The target slip change rate corresponding to the target slip is calculated or calculated.

Of course, it is desirable that the map is appropriately constructed so as to quickly resolve an excessive slip of the clutch while not causing abrupt movement change of the vehicle according to the purpose of the present invention.

The feedforward calculation step S30 calculates the feedforward control amount by multiplying the target slip change rate by the rotational inertia moment of the vehicle drive system.

Here, the rotational moment of inertia of the vehicle driveline will be the rotational moment of inertia of all the rotating parts on the power transmission path from the clutch 1 to the drive wheel W when viewed from the example of Fig.

The feedback calculation step S40 can constitute the PI control by calculating and adding the proportional control component and the integral control component using the slip amount and the target slip amount calculated in the slip amount calculating step, , The differential control component is calculated using the differentiated value of the slip amount calculated in the slip amount calculating step and the target slip change rate and added to the proportional control component and the integral control component so as to perform PID control In particular, in the case of seeking a quick response as in the present invention, it is more preferable to configure it by PID control.

Here, the target slip amount is a value determined by the controller in accordance with the APS signal or the like, and can be obtained by obtaining a target slip amount corresponding to the current slip amount from the map of the target slip amount according to the slip amount .

In the present embodiment, the clutch control step S50 processes the final control amount by a rate limiter to prevent the final control amount from excessively changing rapidly.

The rate limiter can be driven by a method of continuously using the immediately preceding final control amount and controlling the clutch with a new final control amount only when the final control amount is changed at a predetermined ratio or more will be.

For reference, the process of calculating the feedforward control amount and the feedback control amount calculation above can be expressed by the following equations.

here,

T _C _{_FF} ; Feedforward control amount,

J _e ; Vehicle drive system rotational moment of inertia

T _C _{_} _FB ; Feedback control amount

K _p ; Proportional control gain

K _i ; Integral regulator

K _d ; Differentiator

; Slip amount = Ne-Ni

; Target slip amount

; Target slip change rate

Fig. 5 shows the effect of using the control method of the present invention as described above compared with the conventional case.

In the conventional diagram on the left side, the engine speed at the point A becomes higher than the clutch speed (transmission input shaft speed), which indicates an excessive increase of the slip amount. On the contrary, the conventional simple slip amount and feedback control by the target slip amount , The clutch torque is gradually increased in order to reduce the slip amount. When the time elapses in this state, the clutch torque is maximized at the point B. At this time, the slip amount has already been greatly reduced by the increased clutch torque, resulting in a state in which the engine speed is lower than the clutch speed and then increased again. So that vibrations are generated in the driving system, which adversely affects the driving performance of the vehicle.

In the diagram to which the present invention is applied, when the slip occurs at the point C, the feedback control amount and the feedforward control amount corresponding to the slip amount are provided together to control the clutch torque. Thus, The clutch torque that is the control amount reaches almost the maximum, and the slip amount can be appropriately reduced quickly, so that the vibration of the acceleration does not occur. This means that the driving performance of the vehicle is improved by preventing the vibration of the vehicle driveline.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the following claims It will be apparent to those of ordinary skill in the art.

One; clutch
3; Clutch actuator
4; Shift actuator
5; controller
7; APS
S10; Slip amount calculating step
S20; Target change rate determination step
S30; Feed forward calculation step
S40; Feedback calculation step
S50; Clutch control step

Claims

A slip amount calculating step of calculating a slip amount of the clutch by receiving the power source rotational speed and the input shaft rotational speed from the controller;
A target change rate determining step of the controller determining a target slip change rate corresponding to the slip amount calculated in the slip amount calculating step;
A feedforward calculating step of the controller calculating a feedforward control amount using the target slip change rate;
A feedback calculating step of the controller calculating a feedback control amount in accordance with the slip amount calculated in the slip amount calculating step;
A clutch control step of the controller controlling the clutch with a final control amount obtained by adding the feedforward control amount and the feedback control amount;
And a control unit for controlling the clutch of the vehicle.

The method according to claim 1,
The target change rate determination step determines a target slip change rate corresponding to the slip amount calculated in the slip amount calculating step from a map of the target slip change rate with respect to the slip amount of the clutch
And a clutch control means for controlling the clutch.

The method according to claim 1,
The feedforward calculating step may include calculating the feedforward control amount by multiplying the target slip change rate by the rotational inertia moment of the vehicle drive system
And a clutch control means for controlling the clutch.

The method according to claim 1,
The feedback calculation step may include constructing the PI control by calculating and adding the proportional control component and the integral control component using the slip amount and the target slip amount calculated in the slip amount calculating step
And a clutch control means for controlling the clutch.

The method of claim 4,
Wherein the feedback calculation step calculates a differential control component by using a value obtained by differentiating the slip amount calculated in the slip amount calculation step and the target slip change rate and adding the calculated slip amount to the proportional control component and the integral control component, To do
And a clutch control means for controlling the clutch.

The method of claim 5,
In the clutch control step, the final control amount is treated as a rate limiter to prevent the final control amount from excessively changing rapidly
And a clutch control means for controlling the clutch.