KR20180124197A - Control method and system of changing regenerative braking torque - Google Patents

Abstract

Introduced are a regenerative braking torque variable control method including the steps of: sensing an entry of a regenerative braking mode of a vehicle; deriving target deceleration corresponding to a selected gear when the vehicle enters the regenerative braking mode; calculating current acceleration of the vehicle; and calculating the regenerative braking torque in the regenerative braking mode based on the derived target deceleration and current acceleration; and controlling a motor according to the calculated regenerative braking torque, and a system thereof. Accordingly, the present invention can improve fuel efficiency.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a regenerative braking torque variable control method and system,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerative braking torque variable control method and system for an automobile using an electric motor, and more particularly, to a control method and system for varying a regenerative braking torque in accordance with an operation of a paddle shift during running.

As global warming becomes more and more serious today, the use of environmentally friendly energy is becoming increasingly important. Exhaust gases from automobiles using fossil fuels are one of the major causes of air pollution, especially in large cities.

Environmentally friendly vehicles including hybrid vehicles, electric vehicles, and the like using electric motors have been developed and operated in order to solve problems related to exhaust gas and provide fuel economy improvement. Such a hybrid vehicle has power generated by an engine and a motor, and is driven by appropriately using each of the power generated from the combustion operation of the engine and the power generated from the rotation of the motor mediated by the electric energy stored in the battery.

In hybrid vehicles, regenerative braking is used to improve fuel economy. Regenerative braking technology uses part of the braking force for power generation at the time of braking of the vehicle, charges the electric energy to the battery, and uses a part of the kinetic energy due to the running speed of the vehicle as energy required for driving the generator. Hybrid vehicles using this regenerative braking technology can extend the mileage of the vehicle to improve fuel economy and reduce the emission of noxious gases.

Generally, when regenerative braking is controlled, a downshift is performed in accordance with a predetermined shift pattern. Such a shift pattern is usually determined by the speed of the vehicle, and if the vehicle speed is reduced, the speed change stage is changed to the lower speed.

On the other hand, in the conventional eco-friendly automobile, the regenerative braking torque map is defined as one, and by this regenerative braking torque map, constant regenerative braking energy is always obtained during the other running in the D (Drive) position.

However, the optimal regenerative braking energy is different depending on the characteristics of the road, and therefore, the optimum regenerative braking energy can not be obtained only by the existing D stage. For example, in a steep downhill road, more regenerative braking energy can be obtained than in a gentle downhill road, but when one regenerative braking torque map is used to obtain regenerative braking energy, it is not possible to reflect various road driving conditions there was.

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

KR 10-1664580 B

SUMMARY OF THE INVENTION The present invention has been made in order to solve such a problem, and it is an object of the present invention to provide a regenerative braking torque variable control device capable of further improving fuel economy by setting a target deceleration according to a paddle shift operation and varying a regenerative braking torque, Method and system.

According to another aspect of the present invention, there is provided a control method for a regenerative braking torque, including: sensing an entry of a regenerative braking mode of a vehicle; Deriving a target deceleration corresponding to the selected gear stage when the vehicle enters a regenerative braking mode; Deriving a current acceleration of the vehicle; Calculating a regenerative braking torque in the regenerative braking mode based on the derived target deceleration and the current acceleration; And controlling the drive motor according to the calculated regenerative braking torque.

The target deceleration is stored in advance in the memory of the vehicle for each gear stage. In deriving the target deceleration, the target deceleration corresponding to the gear stage of the vehicle or the selected gear stage at the time of entering the regenerative braking mode is stored in the memory .

The target deceleration corresponding to the speed change stage of the vehicle at the time of entering the regenerative braking mode or the selected speed change stage can be set to be larger as the number of shift stages is higher.

In the step of deriving the target deceleration, the selection of the speed change stage may be input from the paddle shift.

Deriving the current acceleration of the vehicle may calculate the current acceleration based on the amount of change in the vehicle speed.

And detecting the drive mode before the step of deriving the target deceleration. In the step of deriving the target deceleration, the target deceleration can be derived when the detected drive mode is the ECO mode.

The step of calculating the regenerative braking torque may calculate the regenerative braking torque by performing the feedback control so that the derived actual acceleration follows the derived target deceleration.

And calculating a final regenerative braking torque before the step of controlling the drive motor, wherein the step of controlling the drive motor can be controlled by the calculated final regenerative braking torque.

The step of calculating the final regenerative braking torque includes the steps of comparing the calculated regenerative braking torque with a preset regenerative braking torque limit value, and if the calculated regenerative braking torque is greater than the predetermined regenerative braking torque limit value, the calculated regenerative braking torque is limited to the regenerative braking torque limit value can do.

According to an aspect of the present invention, there is provided a regenerative braking torque variable control system including: a memory for storing a target deceleration in advance for each gear stage; The control unit detects the entry of the regenerative braking mode of the vehicle, derives the target deceleration corresponding to the selected gear stage from the memory, derives the current acceleration of the vehicle, and determines the regenerative braking torque in the regenerative braking mode based on the target deceleration and the current acceleration A main controller for calculating an output value; And a motor controller for controlling the drive motor in accordance with the regenerative braking torque calculated in the main controller.

According to the regenerative braking torque variable control method and system of the present invention, the regenerative braking energy can be further absorbed on the downhill road while reflecting the actual road driving situation, and the amount of regenerative braking energy absorption on the uphill road can be reduced to improve the running performance of the vehicle. It is possible to save energy and it is effective to improve fuel efficiency. In addition, there is also an effect of improving the driver's convenience by minimizing the operation of the driver's brakes or accelerators on the downhill or uphill road. Particularly, the present invention is applied only to the ECO mode, and can maintain the existing driving feeling and deceleration feeling in the Normal or Sports mode.

1 is a configuration diagram showing a regenerative braking torque variable control system according to an embodiment of the present invention.
2 is a flowchart showing a regenerative braking torque variable control method according to an embodiment of the present invention.

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

FIG. 1 is a configuration diagram showing a regenerative braking torque variable control system according to an embodiment of the present invention, and FIG. 2 is a flowchart illustrating a regenerative braking torque variable control method according to an embodiment of the present invention.

Referring to FIGS. 1 and 2, the regenerative braking torque variable control method according to an embodiment of the present invention includes the steps of detecting an entry of a regenerative braking mode of a vehicle (S100); Deriving a target deceleration corresponding to the selected gear stage when the vehicle enters the regenerative braking mode (S300); Deriving a current acceleration of the vehicle (not shown); Calculating a regenerative braking torque in the regenerative braking mode based on the derived target deceleration and the current acceleration (S400); And controlling the drive motor according to the calculated regenerative braking torque (not shown).

The step S100 of detecting the entry of the regenerative braking mode of the vehicle may detect the entry of the regenerative braking mode of the vehicle through the brake and the accelerator in the main controller 20 during the running of the vehicle. For example, it can detect the entry of the regenerative braking mode of the vehicle through the opening degree (APS) of the accelerator pedal or the opening degree (BPS) of the brake pedal.

In addition, the regenerative braking of the vehicle converts the regenerative braking torque generated from the driving motor into DC power by the MCU (Motor Control Unit) 30 and is sent to a BHDC (bidirectional DC / DC) converter through a high voltage junction box, Can be charged. Therefore, it is possible to judge whether the high voltage battery and the BHDC converter or the like are operating normally to enter the regenerative braking mode of the vehicle.

If it is determined in step S100 that the regenerative braking mode of the vehicle is not in the regenerative braking mode, or if it is determined that regenerative braking is not possible, the regenerative braking step may be set to 0 in step S700. When the regenerative braking phase is 0, the target deceleration can be set to 0 [m / s2]. Accordingly, the regenerative braking torque command transmitted from the main controller 20 to the motor controller 30 is set to 0 (S800), so that the regenerative braking can be substantially prevented from occurring.

(S200) of detecting the drive mode before the step S300 of deriving the target deceleration when the vehicle enters the regenerative braking mode. In step S200 of detecting the drive mode, the drive mode input unit 50 can detect the drive mode input from the driver. The drive mode input unit 50 can sense the drive mode selected by the driver from various drive modes such as the ECO mode, the Normal mode, and the Sports mode. In step S300 of deriving the target deceleration, the target deceleration can be derived when the sensed drive mode is the ECO mode.

When the drive mode is the ECO mode, the target deceleration corresponding to the selected gear stage can be derived (S300). In step S300 of deriving the target deceleration, the selection of the speed change stage may be input from the paddle shift. The paddle shift is a multi-gear shifting device that can manually adjust the number of gears in an automatic vehicle. It is located directly below the steering wheel and can control the speed of the automatic transmission by simple paddle operation. That is, when the vehicle enters the regenerative braking mode, the paddle shift input unit 40 senses the speed change stage whose speed change stage is adjusted through the paddle shift from the driver, and the target deceleration corresponding to the speed change stage is stored in the memory 10 ) Can be derived from.

The target deceleration can be stored in advance in the memory 10 of the vehicle for each gear stage. In step S300 of deriving the target deceleration, the target deceleration corresponding to the selected speed change stage can be derived from the memory 10. [ In particular, the selected speed change stage may be a speed change stage of the vehicle at the time of entry into the regenerative braking mode, or a shift speed selected from the driver by a paddle shift or the like.

The target deceleration corresponding to the speed change stage can be set to be larger as the number of shift stages is higher. As shown in FIG. 1, for example, the target deceleration for each step according to the speed change stage can be set. In step 0, the target deceleration is 0 [m / s2], and as the step is increased, the target deceleration becomes larger. Although the target deceleration can be set for each gear position, it is also possible to set a step by grouping a plurality of gear positions to set the target deceleration for each step. Also, in the lowest step 0, the target deceleration can be set to 0 [m / s2].

In the case where the drive mode sensed in the step of detecting the drive mode (S200) is a Sports mode or a Normal mode instead of the ECO mode, the control can be performed in a manner different from that of the present invention. It is noted that this is not the content of the present invention, but only briefly. In the Sports mode or the Normal mode, etc., the regenerative braking torque map according to the gear stage is previously set, and the regenerative braking torque can be determined accordingly. That is, the paddle shift input unit 40 senses the speed change stage of which the speed change stage is adjusted through the paddle shift from the driver and confirms the regenerative braking mapping step (S500). In the torque map according to the speed change stage, And calculates a regenerative braking torque command (S600).

In the step of deriving the current acceleration of the vehicle (not shown), the current acceleration calculation unit 60 may calculate the current acceleration based on the variation amount of the vehicle speed. The speed of the vehicle can be measured in various ways, such as by measuring it through a motor or by directly measuring the speed of an actual vehicle. The acceleration of the current vehicle can be calculated by differentiating the amount of change in the measured vehicle speed over time have. Alternatively, it is also possible to measure the current acceleration using an acceleration sensor or the like.

The step S400 of calculating the regenerative braking torque in the regenerative braking mode on the basis of the derived target deceleration and the current acceleration is based on the change in the target deceleration and the vehicle speed derived from the memory 10 by the main controller 20 It is possible to calculate the regenerative braking torque based on the current acceleration.

Specifically, the step S400 of calculating the regenerative braking torque may feedback-control the feedback control unit 70 so as to follow the derived target deceleration to calculate the regenerative braking torque. For example, when the actual acceleration of the vehicle is smaller than the target deceleration, the regenerative braking torque can be reduced. On the contrary, when the actual acceleration of the vehicle is greater than the target deceleration, Can be calculated.

That is, the feedback control is performed so that the actual acceleration follows the target deceleration, so that the regenerative braking torque suitable for the road driving situation can be calculated, thereby improving the fuel economy and increasing the driving convenience for the driver.

And a step (not shown) of calculating a final regenerative braking torque before a step of controlling regenerative braking (not shown). The step of calculating the final regenerative braking torque (not shown) can restrict the regenerative braking torque in the torque limiting section 80. [

Specifically, when the calculated regenerative braking torque is compared with a predetermined regenerative braking torque limit value, and the calculated regenerative braking torque is greater than the predetermined regenerative braking torque limit value, the calculated regenerative braking torque can be limited to the regenerative braking torque limit value.

That is, the regenerative braking torque may have a maximum or minimum limit value. This is to prevent the unintentional drop in the drivability beyond the allowable regenerative braking amount. The predetermined regenerative braking torque limit will vary depending on the actual vehicle, and it will be necessary to derive the optimal value through the vehicle test.

Further, when the regenerative braking torque command changes in real time, an effect which is disadvantageous to the driver ' s driving will occur, so that the amount of change of the regenerative braking torque command can be limited.

A step (not shown) for controlling the drive motor in accordance with the calculated regenerative braking torque is performed by a motor controller 30 that receives a regenerative braking torque command corresponding to the regenerative braking torque calculated by the main controller 20, The drive motor (not shown) can be controlled.

And calculating the final regenerative braking torque, the drive motor can be controlled by the final regenerative braking torque calculated in the step of controlling the drive motor.

The regenerative braking torque variable control system according to an embodiment of the present invention includes a memory 10 in which a target deceleration is stored in advance for each gear stage; The control unit 10 detects the entry of the regenerative braking mode of the vehicle and derives the target deceleration corresponding to the selected gear range from the memory 10, derives the current acceleration of the vehicle, calculates the target deceleration in the regenerative braking mode based on the target deceleration and the current acceleration A main controller (20) for calculating a regenerative braking torque; And a motor controller (30) for controlling the drive motor in accordance with the regenerative braking torque calculated in the main controller.

The memory 10 means a data storage device capable of storing data, and an inactive memory can be used.

The main controller 20 may be a VCU (Vehicle Control Unit) as an upper controller of the motor controller 30. [ The memory 10, the current acceleration calculator 60, the feedback controller 70, the torque limiter 80, and the like may be included in the main controller 20.

The motor controller 30 can be an MCU (Motor Control Unit) and can control the regenerative braking by controlling the drive motor (not shown) in accordance with the regenerative braking torque commanded from the VCU.

While the invention has been shown and described with respect to the 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.

10: memory 20: main controller
30: motor controller 40: paddle shift input section
50: drive mode input unit 60: current acceleration calculation unit
70: feedback control section 80: torque limiting section

Claims (10)

Sensing an entry of a regenerative braking mode of the vehicle;
Deriving a target deceleration corresponding to the selected gear stage when the vehicle enters a regenerative braking mode;
Deriving a current acceleration of the vehicle;
Calculating a regenerative braking torque in the regenerative braking mode based on the derived target deceleration and the current acceleration; And
And controlling the drive motor in accordance with the calculated regenerative braking torque. The method according to claim 1,
The target deceleration is stored in advance in the memory of the vehicle for each gear stage. In deriving the target deceleration, the target deceleration corresponding to the gear stage of the vehicle or the selected gear stage at the time of entering the regenerative braking mode is stored in the memory Wherein said control means is operable to control said variable braking torque control means. The method of claim 2,
Wherein the target deceleration corresponding to the speed change stage of the vehicle or the selected speed change stage at the time of entering the regenerative braking mode is set to be larger as the speed change stage is higher. The method according to claim 1,
Wherein the step of deriving the target deceleration includes the step of selecting the speed change stage from the paddle shift. The method according to claim 1,
Wherein the step of deriving the current acceleration of the vehicle calculates the current acceleration based on the amount of change of the vehicle speed. The method according to claim 1,
Wherein the step of deriving the target deceleration includes deriving a target deceleration when the detected drive mode is the ECO mode. Braking torque variable control method. The method according to claim 1,
Wherein the step of calculating the regenerative braking torque calculates a regenerative braking torque by feedback-controlling the derived actual acceleration so as to follow the derived target deceleration. The method according to claim 1,
Further comprising the step of calculating a final regenerative braking torque before the step of controlling the drive motor, wherein the step of controlling the drive motor is controlled by the calculated final regenerative braking torque. The method of claim 8,
The step of calculating the final regenerative braking torque includes the steps of comparing the calculated regenerative braking torque with a preset regenerative braking torque limit value, and if the calculated regenerative braking torque is greater than the predetermined regenerative braking torque limit value, the calculated regenerative braking torque is limited to the regenerative braking torque limit value And a control device for controlling the variable braking torque. A memory for storing a target deceleration in advance for each gear stage;
The control unit detects the entry of the regenerative braking mode of the vehicle, derives the target deceleration corresponding to the selected gear stage from the memory, derives the current acceleration of the vehicle, and determines the regenerative braking torque in the regenerative braking mode based on the target deceleration and the current acceleration A main controller for calculating an output value; And
And a motor controller for controlling the drive motor in accordance with the regenerative braking torque calculated by the main controller.

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