KR102518232B1 - Shifting control method for hybrid vehicles - Google Patents

Abstract

The present invention relates to a technology for improving the shift feel through gear shift section learning for feedforward hydraulic control of friction elements along with feedback control of motor torque. a shift section dividing step of dividing a target gear shift preparation section and a target actual gear shift section based on the target transmission input shaft rotation speed profile; a motor control step of feedback-controlling motor torque so that a current transmission input shaft rotation speed profile follows a target transmission input shaft rotation speed profile by a controller when entering the target actual speed range; And when a difference between the transmission input shaft rotation speed profile and the target transmission input shaft rotation speed profile occurs in the motor control step of the previous shifting process, the controller selectively controls the hydraulic pressure applied to the engagement-side friction element and the release-side friction element according to the degree of the difference. A shift control method for a hybrid vehicle comprising: an actual gear shift hydraulic compensation step of compensating and learning with

Description

Shift control method for hybrid vehicles {SHIFTING CONTROL METHOD FOR HYBRID VEHICLES}

The present invention relates to a shift control method for a hybrid vehicle that improves a shift feel through shift section-specific learning of feed-forward hydraulic control of a friction element along with feedback control of motor torque.

In the shifting of the vehicle, an optimal shift stage for transmitting the driving force required for the vehicle to the wheels is determined according to the road or the driving condition of the vehicle, and the shift is performed at a time when a shift is required.

This is shifted according to the road environment where the vehicle is driven and the shift pattern reflected by the driver's will, and the hybrid vehicle is also shifted according to the same principle.

On the other hand, a brief look at the control method for shifting in a vehicle equipped with an existing AT (Automatic Transmission) / DCT (Dual Clutch Transmission), HEV (Hybrid Electric Vehicle) / PHEV (Plug -In Hybrid Electric Vehicle), in order to shift gears, the torque of the power source is controlled by feed forward, and the friction elements of the transmission and the hydraulic pressure of the actuator are developed by using both feed forward and feedback control. are doing

However, in the case of recent hybrid vehicles and plug-in hybrid vehicles, due to the development of motor control, it is possible to develop a shift feel by feedback-controlling motor torque and feedforward-controlling transmission friction elements and hydraulic pressures of actuators.

Therefore, when the shift feeling is developed by the feedforward control of the transmission friction element along with the feedback control of the motor torque, it is necessary to prevent the shift feeling from deteriorating through the development of a new hydraulic pressure learning method during shifting.

The matters described as the background art above are only for improving understanding of the background of the present invention, and should not be taken as an admission that they correspond to prior art already known to those skilled in the art.

KR 10-1996-0031846 A

An object of the present invention is to provide a shift control method for a hybrid vehicle that improves a shift feel through shift section-specific learning of feed-forward hydraulic control of a friction element along with feedback control of motor torque.

The configuration of the present invention for achieving the above object is a gear shift section in which a controller distinguishes a target shift preparation section and a target actual shift section based on a target transmission input shaft rotation speed profile in a vehicle shift process according to a shift command. step; a motor control step of feedback-controlling motor torque so that a current transmission input shaft rotation speed profile follows a target transmission input shaft rotation speed profile by a controller when entering the target actual speed range; And when a difference between the transmission input shaft rotation speed profile and the target transmission input shaft rotation speed profile occurs in the motor control step of the previous shifting process, the controller selectively controls the hydraulic pressure applied to the engagement-side friction element and the release-side friction element according to the degree of the difference. It may be characterized by comprising a; actual shift hydraulic pressure compensation step of compensating and learning.

In the actual shift hydraulic pressure compensation step, when an absolute value of a difference between the transmission input shaft rotation speed profile and the target transmission input shaft rotation speed profile is equal to or less than a set value, the hydraulic pressure applied to the friction element on the engagement side or the friction element on the release side may be compensated and controlled. there is.

In the actual shift hydraulic pressure compensation step, when the absolute value of the difference between the transmission input shaft rotation speed profile and the target transmission input shaft rotation speed profile exceeds a set value, the hydraulic pressure applied to the friction element on the engagement side and the friction element on the release side may be compensated and controlled together. there is.

In the actual shift hydraulic pressure compensating step, when the transmission input shaft rotation speed profile is higher than the target transmission input shaft rotation speed profile and exceeds a first set value, the hydraulic pressure of the friction element on the engaging side is compensated and controlled in a direction in which the hydraulic pressure is further increased and released. The hydraulic pressure may be compensated and controlled in a direction in which the hydraulic pressure of the side friction element decreases less.

In the actual shift hydraulic pressure compensation step, the hydraulic pressure of the friction element on the engagement side is synchronized with the transmission input torque, and the transmission input shaft rotation profile in the actual gear shift preparation section and actual gear shift section of the previous shift process is synchronized with the target transmission input shaft rotation speed profile. It is determined by the relationship between the time to the starting point and the difference value between the target shift preparation time; The hydraulic pressure of the friction element on the release side is determined by the transmission input torque, the time and target shift until the transmission input shaft speed profile is synchronized with the target transmission input shaft speed profile in the actual shift preparation section and actual shift section of the previous shift process. It may be determined as a relationship between the difference value from the preparation time and the motor feedback torque at the entry point of the actual speed change range in the current speed change process.

In the actual shift hydraulic pressure compensating step, when the transmission input shaft rotation speed profile is higher than the target transmission input shaft rotation speed profile and is equal to or less than the first set value, the hydraulic pressure of the friction element on the release side may be compensated and controlled in a direction in which the hydraulic pressure decreases less. .

In the actual shift hydraulic pressure compensation step, the hydraulic pressure of the release-side friction element is synchronized with the transmission input torque and the transmission input shaft speed profile in the actual shift preparation section and actual shift section of the previous shift process with the target transmission input shaft speed profile. It may be determined as a relationship between a difference value between the time up to the starting point and the target shift preparation time, and the motor feedback torque at the entry point of the actual speed change section in the current shift process.

In the actual shift hydraulic pressure compensation step, when the transmission input shaft rotation speed profile is lower than the target transmission input shaft rotation speed profile and exceeds the second set value, the hydraulic pressure of the friction element on the engagement side is compensated and controlled in a direction in which the hydraulic pressure increases less. can

In the actual shift hydraulic pressure compensation step, the hydraulic pressure of the friction element on the engagement side is synchronized with the transmission input torque, and the transmission input shaft rotation profile in the actual gear shift preparation section and actual gear shift section of the previous shift process is synchronized with the target transmission input shaft rotation speed profile. It may be determined as a relationship between a difference value between the time up to the starting point and the target shift preparation time, and the motor feedback torque at the entry point of the actual speed change section in the current shift process.

In the actual shift hydraulic pressure compensating step, when the transmission input shaft rotational speed profile is lower than the target transmission input shaft rotational speed profile and is equal to or less than the second set value, the hydraulic pressure of the friction element on the engagement side is compensated and controlled in a direction where the hydraulic pressure increases less. The hydraulic pressure may be compensated and controlled in a direction in which the hydraulic pressure of the side friction element further decreases.

In the actual shift hydraulic pressure compensation step, the hydraulic pressure of the friction element on the engagement side is synchronized with the transmission input torque, and the transmission input shaft rotation profile in the actual gear shift preparation section and actual gear shift section of the previous shift process is synchronized with the target transmission input shaft rotation speed profile. It is determined as a relationship between a difference value between the time to the starting point and the target gear shift preparation time and the motor feedback torque at the entry point of the actual gear shift section in the current gear shift process; The hydraulic pressure of the friction element on the release side is determined by the transmission input torque, the time and target shift until the transmission input shaft speed profile is synchronized with the target transmission input shaft speed profile in the actual shift preparation section and actual shift section of the previous shift process. It can be determined by the relationship between the difference value and the preparation time.

At the end of the actual shift section according to the actual shift hydraulic pressure compensation step, when the difference between the time to which the target gear shift preparation time and the target actual gear shift time are added and the time to which the actual gear shift preparation time and the actual gear shift time are added are out of a set range, and a hydraulic pressure compensation step at the end of a transmission for controlling the hydraulic pressure of the friction element on the engagement side by compensating for the hydraulic pressure applied to the friction element on the engagement side.

In the hydraulic pressure compensation step at the end of the shift, when the difference between the time obtained by adding the target gear shift preparation time and the target actual gear shift time and the time obtained by adding the actual gear shift preparation time and the actual gear shift time is less than a first reference value, the hydraulic pressure of the friction element on the engagement side compensating the hydraulic pressure in the direction in which it increases less; When the difference between the time to which the target shift preparation time and the target actual shift time are added and the time to which the actual shift preparation time and actual shift time are added exceeds the second reference value, the hydraulic pressure of the friction element on the engaging side is compensated in the direction in which the hydraulic pressure is further increased. You can control it.

In the hydraulic pressure compensation step at the end of the shift, the hydraulic pressure of the friction element on the engaging side is a difference between the transmission input torque, the time obtained by adding the target gearshift preparation time and the target actual gearshift time, and the time obtained by adding the actual gearshift preparation time and actual gearshift time. relationship can be determined.

In the target gear shift preparation section prior to the actual shift hydraulic pressure compensation step, when a difference between the transmission input shaft speed profile and the target transmission input shaft speed profile occurs, the controller applies the friction element on the engagement side or the friction element on the release side according to the degree of the difference. An initial hydraulic pressure compensation step for selectively compensating and learning the applied hydraulic pressure; may include.

In the shift initial hydraulic pressure compensating step, when the transmission input shaft rotation speed profile is lower than the target transmission input shaft rotation speed profile, the hydraulic pressure of the friction element on the disengagement side may be compensated and controlled in a direction in which the hydraulic pressure decreases less.

In the initial hydraulic pressure compensation step for shifting, the hydraulic pressure of the release-side friction element is a relationship between the difference between the transmission input shaft speed and the target transmission input shaft speed and the difference between the target shift preparation time and the actual shift preparation time in the previous shift process. can be determined by

In the shift initial hydraulic pressure compensating step, when the transmission input shaft rotation speed profile is higher than the target transmission input shaft rotation speed profile, the hydraulic pressure of the friction element on the engagement side may be compensated and controlled in a direction in which the hydraulic pressure of the friction element on the engagement side increases less.

In the initial hydraulic pressure compensation step for shifting, the hydraulic pressure of the friction element on the engaging side is a relationship between the difference value between the transmission input shaft rotation speed and the target transmission input shaft rotation speed and the difference value between the target shift preparation time and the actual shift preparation time of the previous shift process. can be determined by

Through the above-mentioned problem solving means, the present invention provides feedback control of motor torque in the shifting process of the vehicle, and feedback of motor torque through hydraulic learning control that compensates for the difference between the transmission input shaft rotation speed profile and the target transmission input shaft rotation speed profile. There is an effect of shortening the shift time according to the control.

In addition, the effect of improving the shift feeling by continuously learning about the hardware deviation of the transmission hardware and the hardware deviation according to the durability of the friction element, as well as the transmission that deteriorates during shifting by minimizing the compensation control by hydraulic pressure according to this continuous learning Efficiency is improved, and there is also an effect of improving fuel economy.

1 is a diagram schematically showing the configuration of a hybrid vehicle applicable to the present invention.
Figure 2 is a view showing the overall flow of the shift control process according to the present invention.
3 is a view for explaining the operating state of motor torque and hydraulic pressure control for each shifting section in a shift control process according to the present invention;
4 is a diagram illustrating the behavior of transmission input shaft revolutions in a shift preparation section and an actual shift section according to the present invention by dividing them.

A preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The present invention may be applicable to a TMED (Transmission Mounted Electric Device) type hybrid vehicle equipped with an AT transmission as shown in FIG. 1, but may also be applicable to a hybrid vehicle equipped with a DCT transmission.

Accordingly, the engagement-side friction element and the release-side friction element described later may be a clutch or brake that is connected to the rotation element of the planetary gear device in the case of an AT transmission and permits or restricts their relative rotation, and also in the case of a DCT transmission, two It may be a clutch that is individually connected to each of the input shafts and selectively transmits power.

At this time, the expression of the engagement side and the release side is only for the convenience of understanding the present invention, and as the friction elements forming the current gear shift and the friction elements for forming the target gear shift change, the engagement side and the release side are changed. Sides can also be interchanged.

Meanwhile, the shift control method for a hybrid vehicle of the present invention may include a shift section division step, a motor control step, and an actual shift hydraulic pressure compensation step.

Referring to FIGS. 2 and 3, looking at the present invention in detail, first, in the shift section division step, in the process of shifting the vehicle according to the shift command, the controller prepares the target shift based on the target transmission input shaft rotation speed profile (Ni_target). The section and the target actual speed range can be distinguished.

For example, when a shift command to a specific shift range is applied according to a shift pattern based on an output value (APS opening amount, vehicle speed) reflecting the driving state of the vehicle, based on the output value and the gear ratio of the current shift range and the target shift range, An ideal target transmission input shaft speed profile for the current shift process can be extracted.

Further, based on the target transmission input shaft rotation speed profile (Ni_target), the shift process can be divided into a target shift preparation section, a target actual shift section, and a target shift finishing section to be described later.

In the motor control step, when the corresponding shift enters the target actual shift range, the controller may feedback control the motor torque so that the current transmission input shaft rotation speed profile Ni follows the target transmission input shaft rotation speed profile Ni_target.

And, in the actual shift hydraulic compensation step, when a difference occurs between the transmission input shaft speed profile Ni and the target transmission input shaft speed profile Ni_target in the motor control step of the previous shift process, the controller performs coupling according to the degree of the difference. The hydraulic pressure applied to the side friction element and the release side friction element can be selectively compensated for learning.

For example, when a difference in these profiles occurs because the number of rotations of the transmission input shaft is greater than or less than the number of rotations of the target transmission input shaft within the actual shifting section in the previous shifting process, to secure the difference in the profile and compensate for the obtained difference value. The hydraulic pressure of the friction element on the engagement side and/or the friction element on the release side may be controlled in a feed forward manner.

At this time, according to the size of the profile difference, it may be controlled to compensate only one friction element of the engagement-side friction element and the release-side friction element, or to compensate for both the engagement-side friction element and the release-side friction element.

Specifically, when the absolute value of the difference between the transmission input shaft rotation speed profile (Ni) and the target transmission input shaft rotation speed profile (Ni_target) is equal to or less than a set value, the hydraulic pressure applied to the engagement-side friction element or the release-side friction element is compensated and controlled. can

On the other hand, when the absolute value of the difference between the transmission input shaft rotation speed profile (Ni) and the target transmission input shaft rotation speed profile (Ni_target) exceeds a set value, the hydraulic pressure applied to the engagement-side friction element and the release-side friction element can be compensated and controlled together. there is.

That is, according to the above configuration, the feedback control of the motor torque in the actual gear shifting section during the shifting process of the vehicle is performed so that the transmission input shaft rotational speed profile Ni follows the target transmission input shaft rotational speed profile Ni_target, but the previous shifting process The hydraulic pressure of the engagement-side friction element and/or the release-side friction element is compensated and controlled to compensate for the difference between the transmission input shaft rotation speed profile (Ni) learned in the above and the target transmission input shaft rotation speed profile (Ni_target). At this time, the hydraulic pressure is feed-forward controlled with a constant slope per unit time (differentiation of slope according to the required torque) in the actual shift section in order to maintain a constant shift feeling.

Therefore, the shift time according to the feedback control of the motor torque is shortened, and the shift feeling is improved by continuously learning about the hardware deviation of the transmission hardware and the hardware deviation according to the durability of the friction element, as well as the continuous learning. Accordingly, the compensation control by hydraulic pressure is minimized to improve transmission efficiency, which is deteriorated during gear shifting, thereby improving fuel efficiency.

On the other hand, with reference to FIGS. 2 to 4, when a difference between the transmission input shaft rotation speed profile (Ni) and the target transmission input shaft rotation speed profile (Ni_target) occurs in the previous shift process, the hydraulic control control learning method for each behavior of the transmission input shaft rotation speed is described. let's take a look

First, as shown in 'c' of FIG. 4, the transmission input shaft rotation speed profile (Ni) draws a rotation speed profile higher than the target transmission input shaft rotation speed profile (Ni_target) within the target actual speed range, and the transmission input shaft rotation speed profile When (Ni) is greater than the first set value, the hydraulic pressure of the friction element on the disengagement side may be compensated and controlled in a direction in which the hydraulic pressure of the friction element on the disengagement side decreases less while compensating the hydraulic pressure in the direction in which the hydraulic pressure of the friction element on the engagement side increases.

Here, the first set value is a value that can be set through testing, and is set to draw a profile of rotations higher than at least the target transmission input shaft rotation speed profile (Ni_target), which means that the transmission input shaft rotation speed profile (Ni) is the target transmission It may be a reference value for determining how large a profile is formed based on the input shaft rotation speed profile (Ni_target).

That is, when the transmission input shaft rotation speed profile (Ni) is greater than the first set value, the difference between the transmission input shaft rotation speed profile (Ni) and the target transmission input shaft rotation speed profile (Ni_target) is relatively large. All hydraulic pressures of the friction elements on the release side are compensated so that the transmission input shaft rotation speed profile Ni is quickly synchronized with the target transmission input shaft rotation speed profile Ni_target.

At this time, the hydraulic pressure of the friction element on the engaging side corresponds to the transmission input torque and the transmission input shaft revolution profile Ni in the actual gear shift preparation section and actual gear shift section of the previous shift process to the target transmission input shaft revolution profile Ni_target. It may be determined as a relationship between the time to synchronization and the difference value ΔTB2 between the target shift preparation time (TB/TGT).

ΔTB2 = (time until the transmission input shaft rotation speed profile in the previous shift process becomes the same as the target transmission input shaft rotation speed profile) - TB/TGT (target shift preparation time)

That is, the hydraulic compensation amount of the friction element on the engagement side can be determined by the two-dimensional map according to the transmission input torque and ΔTB2.

In addition, the hydraulic pressure of the release-side friction element is synchronized with the transmission input torque and the transmission input shaft revolution profile Ni in the actual shift preparation section and actual shift section of the previous shift process to the target transmission input shaft revolution profile Ni_target. It can be determined by the relationship between the difference value ΔTB2 between the time until the gear shift is completed and the target shift preparation time (TB/TGT), and the motor feedback torque (Abs) at the entry point of the actual gear shift section in the current gear shift process.

That is, the hydraulic compensation amount of the friction element on the disengagement side can be determined by the three-dimensional map according to the transmission input torque and ΔTB2 and the motor feedback torque at the time of actual transmission.

At this time, the actual speed range entry point is immediately after entering the target speed range, the current transmission input shaft rotation increases or decreases due to the gear ratio difference between the current gear and the target gear to reach a predetermined target value. may be a point in time.

Next, as shown in 'd' of FIG. 4, when the transmission input shaft rotation speed profile Ni is greater than the target transmission input shaft rotation speed and is less than or equal to the first set value, the hydraulic pressure of the friction element on the release side decreases less. The hydraulic pressure can be compensated and controlled.

That is, when the transmission input shaft rotation speed profile Ni is smaller than the first set value, the difference between the transmission input shaft rotation speed profile Ni and the target transmission input shaft rotation speed profile Ni_target is relatively small, so that the release side friction element Only the hydraulic pressure is compensated so that the transmission input shaft rotation speed profile Ni is synchronized with the target transmission input shaft rotation speed profile Ni_target.

At this time, the hydraulic pressure of the release-side friction element corresponds to the transmission input torque and the transmission input shaft revolution profile Ni in the actual shift preparation section and actual shift section of the previous shift process to the target transmission input shaft revolution profile Ni_target. It can be determined by the relationship between the difference value (ΔTB2) between the time until synchronization and the target shift preparation time (TB/TGT) and the motor feedback torque (Abs) at the entry point of the actual speed change range in the current shift process.

That is, the hydraulic compensation amount of the friction element on the disengagement side can be determined by the three-dimensional map according to the transmission input torque and ΔTB2 and the motor feedback torque at the time of actual transmission.

In addition, as shown in 'e' of FIG. 4, when the transmission input shaft rotation speed profile (Ni) is smaller than the target transmission input shaft rotation speed profile (Ni_target) and exceeds the second set value, the hydraulic pressure of the friction element on the engagement side is reduced. The hydraulic pressure can be compensated and controlled in an increasing direction.

Here, the second set value, like the first set value, is set to draw a profile of revolutions lower than at least the target transmission input shaft revolution profile (Ni_target) with a value that can be set through testing, which is the transmission input shaft revolution profile. (Ni) may be a reference value for determining how small a profile is formed based on the target transmission input shaft rotation speed profile (Ni_target).

That is, when the transmission input shaft rotation speed profile Ni is greater than the second set value, the difference between the transmission input shaft rotation speed profile Ni and the target transmission input shaft rotation speed profile Ni_target is relatively small. Only the hydraulic pressure is compensated so that the transmission input shaft rotation speed profile Ni is synchronized with the target transmission input shaft rotation speed profile Ni_target.

At this time, the hydraulic pressure of the friction element on the engaging side corresponds to the transmission input torque and the transmission input shaft revolution profile Ni in the actual gear shift preparation section and actual gear shift section of the previous shift process to the target transmission input shaft revolution profile Ni_target. It can be determined by the relationship between the difference value (ΔTB2) between the time until synchronization and the target shift preparation time (TB/TGT) and the motor feedback torque (Abs) at the entry point of the actual speed change range in the current shift process.

That is, the hydraulic compensation amount of the friction element on the engagement side can be determined by the three-dimensional map according to the transmission input torque and ΔTB2 and the motor feedback torque at the time of actual transmission.

In addition, as shown in 'f' of FIG. 4, when the transmission input shaft rotation speed profile Ni is smaller than the target transmission input shaft rotation speed profile Ni_target and is equal to or less than the second set value, the hydraulic pressure of the friction element on the engagement side increases less. It is possible to compensate and control the hydraulic pressure in a direction in which the hydraulic pressure of the release-side friction element further decreases while compensating and controlling the hydraulic pressure in the direction of the release.

That is, when the transmission input shaft rotation speed profile (Ni) is smaller than the second set value, the difference between the transmission input shaft rotation speed profile (Ni) and the target transmission input shaft rotation speed profile (Ni_target) is relatively large. All hydraulic pressures of the friction elements on the release side are compensated so that the transmission input shaft rotation speed profile Ni is quickly synchronized with the target transmission input shaft rotation speed profile Ni_target.

At this time, the hydraulic pressure of the friction element on the engaging side corresponds to the transmission input torque and the transmission input shaft revolution profile Ni in the actual gear shift preparation section and actual gear shift section of the previous shift process to the target transmission input shaft revolution profile Ni_target. It can be determined by the relationship between the difference value (ΔTB2) between the time until synchronization and the target shift preparation time (TB/TGT) and the motor feedback torque (Abs) at the entry point of the actual speed change range in the current shift process.

That is, the hydraulic compensation amount of the friction element on the engagement side can be determined by the three-dimensional map according to the transmission input torque and ΔTB2 and the motor feedback torque at the time of actual transmission.

In addition, the hydraulic pressure of the release-side friction element is synchronized with the transmission input torque and the transmission input shaft revolution profile Ni in the actual shift preparation section and actual shift section of the previous shift process to the target transmission input shaft revolution profile Ni_target. It may be determined as a relationship between the time to the point of time and the difference value ΔTB2 between the target shift preparation time (TB/TGT).

That is, the hydraulic pressure compensation amount of the release-side friction element can be determined by the two-dimensional map according to the transmission input torque and ΔTB2.

On the other hand, in the present invention, at the end of the actual shift section according to the actual shift hydraulic pressure compensation step, the target shift preparation time (TB/TGT) and the time (TS/TGT) to which the target actual shift time is added, the actual shift preparation time and the actual actual shift preparation time When the time difference value ΔTS to which the shift time is added is out of a set range, a shift end hydraulic pressure compensation step of controlling the hydraulic pressure of the engaging-side friction element by compensating for the hydraulic pressure applied to the engaging-side friction element may be further included.

ΔTS = TS/TGT (target shift preparation time + target actual shift time) - (actual shift preparation time + actual actual shift time)

For example, in the hydraulic pressure compensation step at the end of the shift, the difference between the time obtained by adding the target gear shift preparation time (TB/TGT) and the target actual gear shift time (TS/TGT) and the time obtained by adding the actual gear shift preparation time and actual gear shift time ( When ΔTS) is less than the first reference value, the hydraulic pressure may be compensated and controlled in a direction in which the hydraulic pressure of the friction element on the engagement side is less increased.

On the other hand, when the difference between the time to which the target shift preparation time (TB/TGT) and the actual gear shift time are added (TS/TGT) and the time to which the actual shift preparation time and actual gear shift time are added (ΔTS) exceeds the second reference value, The hydraulic pressure may be compensated and controlled in a direction in which the hydraulic pressure of the friction element on the engagement side is further increased.

That is, after the actual shift section, the hydraulic pressure of the friction element on the engaging side is controlled to increase in the shift finishing section. When ΔTS is less than the first reference value, the actual shift time is too fast than the target shift time, so the shift feeling may deteriorate. In the finishing section, the hydraulic pressure may be compensated and controlled in a direction that provides a relatively small increase in the hydraulic pressure of the friction element on the engagement side.

And, when ΔTS exceeds the second reference value, since the actual shift time is too slow than the target shift time and the transmission is delayed, the hydraulic pressure is applied in the direction of providing a relatively higher hydraulic pressure increase of the friction element on the engaging side in the shift finishing section. compensation can be controlled.

At this time, the hydraulic pressure of the friction element on the engaging side is the difference between the transmission input torque, the time obtained by adding the target gear shift preparation time (TB/TGT) and the target actual shift time, and the time obtained by adding the actual gear shift preparation time and actual gear shift time. It can be determined by the relationship of (ΔTS).

That is, the hydraulic compensation amount of the friction element on the engagement side can be determined by the two-dimensional map according to the transmission input torque and ΔTS.

Meanwhile, referring to FIGS. 2 and 4 , in the present invention, learning by hydraulic pressure compensation control may be performed even in a target shift preparation section prior to the actual shift hydraulic pressure compensation step.

Specifically, when a difference between the transmission input shaft rotation speed profile (Ni) and the target transmission input shaft rotation speed profile (Ni_target) occurs in the target shift preparation section, the controller operates an engagement-side friction element or a release-side friction element according to the degree of the difference. It may be configured to further include an initial shift hydraulic pressure compensation step of learning by selectively compensating for the hydraulic pressure applied to.

For example, as shown in 'a' of FIG. 4 , when the transmission input shaft rotation speed profile Ni is lower than the target transmission input shaft rotation speed profile Ni_target, the hydraulic pressure of the friction element on the release side is compensated in a direction in which the hydraulic pressure decreases less. You can control it.

That is, when the transmission input shaft rotation speed profile (Ni) draws a profile of rotations lower than the target transmission input shaft rotation speed profile (Ni_target), the hydraulic pressure of the friction element on the release side is compensated so that the transmission input shaft rotation speed profile (Ni) is the target It is controlled to be synchronized with the transmission input shaft rotation speed profile (Ni_target).

At this time, the hydraulic pressure of the friction element on the release side is the difference between the transmission input shaft rotation speed and the target transmission input shaft rotation speed (run-up amount), the target shift preparation time (TB/TGT) of the previous shift process, and the actual shift preparation time. It can be determined by the relationship of the difference value ΔTB1 of .

ΔTB1 = TB/TGT (target shift preparation time) - actual shift preparation time

That is, the hydraulic compensation amount of the release-side friction element may be determined by the runup amount and the two-dimensional map according to ΔTB1.

Next, as shown in 'b' of FIG. 4, when the transmission input shaft rotation speed profile Ni is higher than the target transmission input shaft rotation speed profile Ni_target, the hydraulic pressure of the friction element on the engagement side increases less. compensation can be controlled.

That is, when the transmission input shaft rotation speed profile (Ni) draws a profile of rotations higher than the target transmission input shaft rotation speed profile (Ni_target), the hydraulic pressure of the friction element on the engaging side is compensated so that the transmission input shaft rotation speed profile (Ni) is the target It is controlled to be synchronized with the transmission input shaft rotation speed profile (Ni_target).

At this time, the hydraulic pressure of the friction element on the engaging side is the difference between the transmission input shaft rotation speed and the target transmission input shaft rotation speed (rundown amount), the target shift preparation time (TB/TGT) of the previous shift process, and the actual shift preparation time. It can be determined by the relationship of the difference value ΔTB1 of .

That is, the hydraulic compensation amount of the friction element on the engagement side can be determined by the rundown amount and the two-dimensional map according to ΔTB1.

Hereinafter, a shift control flow for a hybrid vehicle according to the present invention will be described with reference to FIGS. 2 to 4 .

First, when a shift command is applied (S10), a target shift preparation section, a target actual shift section, and a target gear shift finalization are performed based on the output values reflecting the driving state of the vehicle and the gear ratios of the current shift range and the target shift range. It is divided into sections (S20).

Therefore, it is determined whether there is a difference between the transmission input shaft rotation speed and the target transmission input shaft rotation number in the target shift preparation section (S30), and if there is a difference as a result of step S30, the transmission input shaft rotation speed profile and the target transmission input shaft rotation speed profile are compared ( S40).

As a result of the comparison, when the transmission input shaft rotation speed profile is higher than the target transmission input shaft rotation speed profile, the hydraulic pressure of the release-side friction element is compensated and learned based on the runup amount and the two-dimensional map according to ΔTB1 (S50).

On the other hand, when the transmission input shaft rotation speed profile is lower than the target transmission input shaft rotation speed profile, the hydraulic pressure of the friction element on the engagement side is compensated and learned based on the rundown amount and the two-dimensional map according to ΔTB1 (S60).

Subsequently, it is determined whether the target actual speed change range has been entered (S70), and as a result of the determination in step S70, when the target actual speed change range is entered, the motor torque is feedback-controlled to control the transmission input shaft speed profile to follow the target transmission input shaft speed profile. (S80).

In addition, it is determined whether there is a difference between the transmission input shaft speed and the target transmission input shaft speed in the target actual speed range (S90), and if there is a difference as a result of the determination in step S90, the transmission input shaft speed profile and the target transmission input shaft speed profile are calculated. Compare (S100).

As a result of the comparison, if the transmission input shaft rotation speed profile is greater than the target transmission input shaft rotation speed profile, the transmission input shaft rotation speed profile is compared with the first set value (S110), and if the transmission input shaft rotation speed profile is greater than the first set value, The oil pressure of the friction element on the engaging side is compensated by the 2-dimensional map according to the transmission input torque and ΔTB2, and the hydraulic pressure of the friction element on the disengagement side is compensated by the 3-dimensional map according to the transmission input torque and ΔTB2 and the motor feedback torque at the time of actual transmission. The hydraulic pressure is compensated and learned (S120).

On the other hand, as a result of comparison in step S110, when the transmission input shaft rotation speed profile is smaller than the first set value, the hydraulic pressure of the friction element on the release side is determined by the three-dimensional map according to the transmission input torque and ΔTB2 and the motor feedback torque at the time of actual transmission. Compensation and learning (S130).

Meanwhile, as a result of the comparison in step S100, if the transmission input shaft rotation speed profile is smaller than the target transmission input shaft rotation speed profile, the transmission input shaft rotation speed profile is compared with a second set value (S140), and the transmission input shaft rotation speed profile is If it is greater than 2 set values, the hydraulic pressure of the friction element on the engaging side is compensated and learned by means of a three-dimensional map according to the transmission input torque and ΔTB2 and the motor feedback torque at the time of actual transmission (S150).

On the other hand, as a result of comparison in step S140, when the transmission input shaft rotation speed profile is lower than the second set value, the hydraulic pressure of the friction element on the engagement side is determined by the three-dimensional map according to the transmission input torque and ΔTB2 and the motor feedback torque at the time of actual transmission. In addition, the hydraulic pressure of the friction element on the disengagement side is compensated and learned by the two-dimensional map according to the transmission input torque and ΔTB2 (S160).

Through the motor feedback control according to the hydraulic feed forward compensation control, it is determined whether the transmission input shaft rotation speed profile is synchronized with the target transmission input shaft rotation speed profile at the end of the actual gear shift section (S170), and ΔTS is out of the predetermined setting range during synchronization. It is determined whether or not (S180).

For example, when ΔTS is less than the first reference value or exceeds the second reference value, the shift is completed while compensating and learning the hydraulic pressure of the friction element on the engagement side by the transmission input torque and the two-dimensional map according to ΔTS (S190).

As described above, the present invention controls the transmission input shaft rotation speed profile to follow the target transmission input shaft rotation speed profile by feedback-controlling the motor torque in the actual shift section during the shift process of the vehicle, but the transmission input shaft rotation learned in the previous shift process. The hydraulic pressure of the engagement-side friction element and/or the release-side friction element is compensated and controlled to compensate for a difference between the male profile and the target transmission input shaft rotation speed profile.

Therefore, the shift time according to the feedback control of the motor torque is shortened, and the shift feeling is improved by continuously learning about the hardware deviation of the transmission hardware and the hardware deviation according to the durability of the friction element, as well as the continuous learning. Accordingly, the compensation control by hydraulic pressure is minimized to improve transmission efficiency, which is deteriorated during gear shifting, thereby improving fuel efficiency.

On the other hand, although the present invention has been described in detail only for the specific examples described above, it is obvious to those skilled in the art that various changes and modifications are possible within the scope of the technical idea of the present invention, and it is natural that these changes and modifications fall within the scope of the appended claims. .

Claims (19)

a shift section division step in which a controller distinguishes between a target gear shift preparation section and a target actual gear shift section based on a target transmission input shaft rotation speed profile in a vehicle shift process according to a shift command;
a motor control step of feedback-controlling motor torque so that a current transmission input shaft rotation speed profile follows a target transmission input shaft rotation speed profile by a controller when entering the target actual speed range; and
When a difference between the transmission input shaft rotation speed profile and the target transmission input shaft rotation speed profile occurs in the motor control step of the previous shifting process, the controller selectively applies hydraulic pressure to the friction element on the engagement side and the friction element on the release side according to the degree of the difference. A shift control method for a hybrid vehicle comprising the steps of compensating and learning actual shift hydraulic pressure. The method of claim 1,
In the actual gear shift hydraulic compensation step,
When the absolute value of the difference between the transmission input shaft rotation speed profile and the target transmission input shaft rotation speed profile is less than a set value, the hydraulic pressure applied to the friction element on the engagement side or the friction element on the release side is compensated and controlled. . The method of claim 1,
In the actual gear shift hydraulic compensation step,
When the absolute value of the difference between the transmission input shaft rotation speed profile and the target transmission input shaft rotation speed profile exceeds a set value, the hydraulic pressure applied to the friction element on the engagement side and the friction element on the release side are compensated and controlled together. . The method of claim 1,
In the actual gear shift hydraulic compensation step,
When the transmission input shaft rotation speed profile is higher than the target transmission input shaft rotation speed profile and exceeds the first set value, the hydraulic pressure of the friction element on the disengaging side decreases less while compensating and controlling the hydraulic pressure in the direction in which the hydraulic pressure of the friction element on the engagement side increases. A shift control method for a hybrid vehicle, characterized in that the hydraulic pressure is compensated and controlled in the direction of The method of claim 4,
In the actual shift hydraulic pressure compensation step, the hydraulic pressure of the friction element on the engagement side is
The relationship between the transmission input torque, the actual shift preparation section of the previous shift process and the time from the actual actual shift section to the point at which the transmission input shaft speed profile is synchronized with the target transmission input shaft speed profile and the difference between the target shift preparation time determined;
The hydraulic pressure of the release-side friction element,
The difference between the transmission input torque, the time from the actual shift preparation section of the previous shift process and the actual actual shift section to the point at which the transmission input shaft speed profile is synchronized with the target transmission input shaft speed profile and the target shift preparation time, and the current A shift control method for a hybrid vehicle, characterized in that it is determined by the relationship of the motor feedback torque at the point of entry into the actual shift section in the shift process. The method of claim 1,
In the actual gear shift hydraulic compensation step,
When the transmission input shaft rotation speed profile is higher than the target transmission input shaft rotation speed profile and is less than or equal to the first set value, the hydraulic pressure is compensated and controlled in a direction in which the hydraulic pressure of the friction element on the release side decreases less. Shift control method for a hybrid vehicle. The method of claim 6,
In the actual shift hydraulic pressure compensation step, the hydraulic pressure of the friction element on the release side is
The difference between the transmission input torque, the time from the actual shift preparation section of the previous shift process and the actual actual shift section to the point at which the transmission input shaft speed profile is synchronized with the target transmission input shaft speed profile and the target shift preparation time, and the current A shift control method for a hybrid vehicle, characterized in that it is determined by the relationship of the motor feedback torque at the point of entry into the actual shift section in the shift process. The method of claim 1,
In the actual gear shift hydraulic compensation step,
When the transmission input shaft rotation speed profile is lower than the target transmission input shaft rotation speed profile and exceeds the second set value, the hydraulic pressure is compensated and controlled in a direction in which the hydraulic pressure of the friction element on the engagement side increases less. method. The method of claim 8,
In the actual shift hydraulic pressure compensation step, the hydraulic pressure of the friction element on the engagement side is
The difference between the transmission input torque, the time from the actual shift preparation section of the previous shift process and the actual actual shift section to the point at which the transmission input shaft speed profile is synchronized with the target transmission input shaft speed profile and the target shift preparation time, and the current A shift control method for a hybrid vehicle, characterized in that it is determined by the relationship of the motor feedback torque at the point of entry into the actual shift section in the shift process. The method of claim 1,
In the actual gear shift hydraulic compensation step,
When the transmission input shaft rotation speed profile is lower than the target transmission input shaft rotation speed profile and is equal to or less than the second set value, the hydraulic pressure of the friction element on the disengagement side further decreases while compensating and controlling the hydraulic pressure in a direction in which the hydraulic pressure of the friction element on the engagement side increases less. A shift control method for a hybrid vehicle, characterized in that the hydraulic pressure is compensated and controlled in the direction of The method of claim 10,
In the actual shift hydraulic pressure compensation step, the hydraulic pressure of the friction element on the engagement side is
The difference between the transmission input torque, the time from the actual shift preparation section of the previous shift process and the actual actual shift section to the point at which the transmission input shaft speed profile is synchronized with the target transmission input shaft speed profile and the target shift preparation time, and the current It is determined by the relationship of the motor feedback torque at the point of entering the actual speed change section in the speed change process;
The hydraulic pressure of the release-side friction element,
The relationship between the transmission input torque, the actual shift preparation section of the previous shift process and the time from the actual actual shift section to the point at which the transmission input shaft speed profile is synchronized with the target transmission input shaft speed profile and the difference between the target shift preparation time A shift control method for a hybrid vehicle, characterized in that the determination. The method of claim 1,
At the end of the actual shift section according to the actual shift hydraulic pressure compensation step,
When the difference between the time to which the target shift preparation time and the target actual shift time are added and the time to which the actual shift preparation time and actual shift time are added is out of the set range, the hydraulic pressure applied to the friction element on the engagement side is compensated for friction on the engagement side. A shift control method for a hybrid vehicle, comprising a step of compensating for oil pressure at the end of a shift by controlling the oil pressure of the elements. The method of claim 12,
In the hydraulic pressure compensation step at the end of the transmission,
When the difference between the time to which the target shift preparation time and the target actual shift time are added and the time to which the actual shift preparation time and actual shift time are added is less than the first reference value, the hydraulic pressure of the friction element on the engagement side increases less. compensation control;
When the difference between the time to which the target shift preparation time and the target actual shift time are added and the time to which the actual shift preparation time and actual shift time are added exceeds the second reference value, the hydraulic pressure of the friction element on the engaging side is compensated in the direction in which the hydraulic pressure is further increased. A shift control method for a hybrid vehicle, characterized in that for controlling. The method of claim 13,
In the hydraulic pressure compensation step at the end of the shift, the hydraulic pressure of the friction element on the engagement side is
A shift control method for a hybrid vehicle, characterized in that it is determined by a relationship between transmission input torque and a difference between a time obtained by adding a target gear shift preparation time and a target actual gear shift time and a time obtained by adding the actual gear shift preparation time and actual gear shift time. The method of claim 1,
In the target shift preparation section before the actual shift hydraulic pressure compensation step,
When a difference between the transmission input shaft rotational speed profile and the target transmission input shaft rotational speed profile occurs, the controller selectively compensates for the hydraulic pressure applied to the friction element on the engagement side or the friction element on the release side according to the degree of the difference, and the initial hydraulic pressure compensation for shifting to learn. A shift control method for a hybrid vehicle comprising the steps; The method of claim 15
In the shift initial hydraulic pressure compensation step,
The shift control method for a hybrid vehicle, characterized in that, when the transmission input shaft rotation speed profile is lower than the target transmission input shaft rotation speed profile, the hydraulic pressure is compensated and controlled in a direction in which the hydraulic pressure of the friction element on the release side decreases less. The method of claim 16
In the shift initial hydraulic pressure compensation step, the hydraulic pressure of the release-side friction element is
The shift control method for a hybrid vehicle, characterized in that the relationship between the difference between the transmission input shaft speed and the target transmission input shaft speed and the difference between the target shift preparation time and the actual shift preparation time of the previous shift process. The method of claim 15
In the shift initial hydraulic pressure compensation step,
The shift control method for a hybrid vehicle, characterized in that, when the transmission input shaft rotation speed profile is higher than the target transmission input shaft rotation speed profile, the hydraulic pressure is compensated and controlled in a direction in which the hydraulic pressure of the friction element on the engagement side increases less. The method of claim 18
In the shift initial hydraulic pressure compensation step, the hydraulic pressure of the friction element on the engagement side is
The shift control method for a hybrid vehicle, characterized in that the relationship between the difference between the transmission input shaft speed and the target transmission input shaft speed and the difference between the target shift preparation time and the actual shift preparation time of the previous shift process.

Images