KR20140079104A - System of total control for electric 4 wheel drive system and method thereof - Google Patents

Abstract

Disclosed is an integrated control method of an E-4WD system capable of providing driving comfort without sense of difference by distributing a driving torque control section, a steering torque control section, and a combined section according to the driving conditions of a vehicle when a lane keep assist system (LKAS) is performed. The present invention includes: a process of detecting driving conditions includes left/right lane images, steering angle, steering torque, yaw rate, and speed during driving; a process of determining the position of a vehicle in a lane by analyzing the left/right lane images and analyzing the progress direction of the vehicle and determining if possibility of the vehicle leaving the lane exists by analyzing the steering angle and the yaw rate which is the rotating angular speed; a process of performing an integrated mode to calculate a steering torque and a driving torque to maintain the lane and determining a target steering torque and a target driving torque by combining the proportions of the calculated steering torque and driving torque; and a process of executing the LKAS by driving the MDPS with the target steering torque and adjusting the driving power of the left/right wheels with the target driving torque.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an E-4WD system,

The present invention relates to an e-4WD system, and more particularly, to an e-4WD system that distributes a driving torque control section, a steering torque control section, and a hybrid section according to a driving condition of a vehicle when a lane keeping assist system (LKAS) And to provide an E-4WD system integrated control method capable of providing driving performance in which no sense of heterogeneity is generated.

The 4WD system applied to the vehicle has different driving modes according to the driving situation in order to improve the fuel efficiency.

For example, when a slip occurs due to operation of rash, slippery road, sandy terrain, steep hill, muddy road, etc., and a large driving force is required, the vehicle is driven in 4WD mode.

When the vehicle is driven in the 4WD mode, the fuel economy of the vehicle is lower than that of the 2WD mode in terms of the posture control, the maneuverability, the backing performance, and the escape route.

When the vehicle is driven in the 2WD mode, the running torque is small and the stability of the running stability is good. However, the friction coefficient of the road surface is reduced in the case of the rain, snow, and freezing sections. .

A hybrid electric vehicle including an electric vehicle driven by a motor, a fuel cell vehicle, and a hybrid electric vehicle is being provided in accordance with the seriousness of environmental problems due to the use of fossil fuels and the depletion of limited resources.

Hybrid electric vehicles are equipped with various types of e-4WD system to control left and right wheels of front and rear wheels to control lane keeping (LKAS) function, steering assist function and yaw generation, So that a stable behavior can be provided.

In-wheel e-WD system that actively controls the front / left / right wheels according to the driving situation by individually mounting motors in each wheel of each wheel with e-4WD system, connecting output of internal combustion engine to front or rear axle An in-line e-WD system in which the output of the motor is connected to the left and right wheels by applying a motor to the other shaft and an independent drive system connected to the output of the internal combustion engine is applied to the front or rear axle, And an e-4WD system to which an in-wheel motor driven independently of each wheel of the e-4WD system is applied.

Generally, in the course of running of the vehicle, there is a tendency to deviate toward one direction when the vehicle runs straightly due to the gradient condition of the road surface, the asymmetric structure of the vehicle, and the difference in characteristics of the left and right tires. This is a chronic problem that always occurs in exponential evaluation.

When the driver is leaning toward one side during the running of the vehicle, the driver directly recognizes this and operates the steering wheel so that straight running can be provided.

The lane keeping function applied to the e-4WD system enables active control of only the steering angle and the steering torque in the case where leaning that deviates to one side occurs in the straight running state, so that the driving following the lane can be maintained.

However, in this case, the adjustment of the steering torque for the lane-following may be transmitted to the steering wheel and may be provided to the driver as a sense of heterogeneity.

In addition, when a leaning shift occurs in one direction in the straight running state, the driving torque of the left and right wheels is controlled so that the running following the lane can be maintained.

However, in this case, a sense of heterogeneity of the steering torque applied to the steering wheel is not generated, but it may cause a problem that the vehicle is recognized as an abnormal behavior of the vehicle irrespective of the driver's will.

Published Patent Publication No. 10-2012-0081771 (July 20, 2012)

SUMMARY OF THE INVENTION The present invention has been developed to solve such a problem, and an object of the present invention is to provide a steering control apparatus and a steering control apparatus that divides a driving torque control section, a steering torque control section, and a hybrid control section according to a driving condition of a vehicle, So as to provide a driving property in which no sense of heterogeneity is generated.

According to an embodiment of the present invention, an image detection unit detects an image of left and right lanes as an image; A steering angle detection unit for detecting a change in the steering angle; A steering torque detector for detecting a change in torque of the steering wheel; A vehicle speed detector for detecting a running vehicle speed; When the lane departure possibility is determined by analyzing the vehicle position, the steering angle and the yaw rate in the lane, the steering torque and the drive torque for maintaining the lane are calculated, and the MDPS and e-4WD are controlled by the control signal combining the steering torque and the drive torque An integrated control device of an e-4WD system that provides a lane keeping function is provided.

The control unit controls the steering angle and the steering torque by controlling the MDPS, and can assist the steering force by controlling the left and right driving torques of the e-4WD.

According to another embodiment of the present invention, there is provided a driving method of a vehicle, comprising: detecting driving information including left and right lane images, a steering angle, a steering torque, a yaw rate, and a vehicle speed in a running state; Analyzing the left and right lane images to determine the position of the vehicle in the lane, analyzing the information of the steering angle and the yaw rate which is the rotational angular velocity, analyzing the traveling direction of the vehicle, and determining the possibility of lane departure; Calculating a steering torque and a drive torque for maintaining the lane by executing the integrated mode when the lane departure possibility is determined, and determining the steering target torque and the drive target torque by combining the calculated ratio of the steering torque and the drive torque; There is provided an integrated control method of an e-4WD system including the steps of operating the MDPS with the steering target torque and adjusting the driving force of the left and right wheels with the driving target torque to execute the lane keeping function.

If the lane departure possibility is determined, if the steering torque exceeds the set reference torque, the lane keeping function may not be executed by determining the driver's intention to steer.

As described above, according to the present invention, the control period is classified according to the driving condition of the vehicle, and the driving torque and the steering torque are distributed and controlled according to the divided control period, so that the lane keeping control in which no sense of heterogeneity is generated can be stably provided.

1 is a view schematically showing an integrated controller of an e-WD system according to an embodiment of the present invention.
2 is a flowchart illustrating an integrated control procedure of an e-4WD system according to an embodiment of the present invention.
3 is a diagram illustrating a torque variable diagram of an integrated control section in an e-4WD system according to an embodiment of the present invention.
4 is a diagram showing an integrated control relationship of the e-4WD system according to the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

The present invention can be embodied in various different forms, and thus the present invention is not limited to the embodiments described herein.

1 is a schematic view of an integrated controller of an e-4WD system according to an embodiment of the present invention.

1, the present invention includes an image detecting unit 101, a steering angle detecting unit 102, a steering torque detecting unit 103, a vehicle speed detecting unit 104, a control unit 201, an MDPS 301 and an e-4WD 401, .

The image detecting unit 101 inputs the surroundings and left and right lane information of the driving vehicle as images and provides the images to the control unit 201.

The image detecting unit 101 may be a camera having a wide viewing angle, and may be mounted on at least one or more of the front and side of the vehicle.

The steering angle detection unit 102 detects a change in the steering angle, which is the traveling direction of the front wheel, and provides information about the steering angle to the control unit 201 as an electrical signal.

The steering torque detector 102 detects the torque change of the steering wheel operated by the driver and provides information about the torque change to the controller 201 as an electrical signal.

The vehicle speed detector 104 detects the speed of each wheel and provides information about the detected speed to the controller 201 as an electrical signal.

The control unit 201 analyzes the left and right lane information provided by the image detecting unit 101 to determine the position of the vehicle in the lane and analyzes the yaw rate which is the steering angle information and the rotational angular velocity to analyze the traveling direction of the vehicle, It is determined whether or not it is possible to depart.

If the possibility of the lane departure is determined, the control unit 201 analyzes the steering torque, and if it exceeds the set reference torque, the control unit 201 determines that the steering wheel is operated according to the steering intention of the driver and does not execute the lane assistance function.

If the lane departure is possible but the steering torque does not exceed the set reference torque, the control unit 201 executes the integrated mode for maintaining the lane according to the required steering angle to calculate the steering torque and the drive torque for lane keeping do.

The integrated mode for maintaining the lane can be determined by a combination of the drive torque and the steering torque.

The control unit 201 determines the control period by analyzing the steering torque and the driving torque calculated for the lane keeping and combines the ratio of the steering torque and the driving torque calculated according to the determined control period to obtain the final steering target torque And the drive target torque.

As can be seen from Fig. 3, the ratios of the drive torque and the steering torque are determined in combination according to the required steering angle required for lane keeping.

The controller 201 corrects the steering torque as shown in the following equation in consideration of the road curvature and the vehicle speed when the required steering angle that follows the road curvature is large in determining the final target steering torque.

F _TV2 = K _k f (k, V)

Here, _FTV2 is the driving force distribution amount of torque vectoring by the road curvature,

K denotes the road curvature detected through the camera,

V means the running speed of the vehicle.

Further, when a steering angle of a small degree of leaning is required when determining the final driving target torque, the control unit 201 determines the driving force distribution amount of e-4WD according to the following equation.

Here, _FTV1 is a driving force distribution amount of torque vectoring by the amount of deviation,

K _p is a proportional constant,

t denotes a tread which is the distance between the centers of the left and right wheels.

When the final steering target torque and the driving target torque are determined, the control unit 201 controls the steering angle and the steering torque through the MDPS (Motor Driven Power Steer) and assists the steering force by adjusting the left and right driving torques of the e-4WD, So that a driving following the vehicle can be provided.

 The MDPS 301 adjusts the steering angle and the steering torque according to the control signal applied from the control unit 201 so that driving following the lane can be provided.

The e-4WD 401 adjusts driving torques of the front, rear, left and right wheels according to a control signal applied from the control unit 201 so that driving following the lane can be provided.

The operation of the present invention including the functions as described above is executed as follows.

The control unit 201 detects an image of left and right lane information from the image detecting unit 101, detects a change in the steering angle from the steering angle detecting unit 102, The torque detecting unit 102 detects a change in the torque of the steering wheel, and detects the speed of each wheel from the vehicle speed detecting unit 104 (S102).

The control unit 201 analyzes the left and right lane information provided by the image detecting unit 101 to determine the position of the vehicle in the lane (S103), analyzes the steering angle information and the yaw rate, which is the rotational angular velocity, And determines whether or not the lane departure is possible (S104).

The control unit 201 analyzes the steering torque provided by the steering torque detecting unit 103 and determines whether the reference torque is exceeded (S105).

When the steering torque exceeds the set reference torque at S105, the control unit 201 determines that the steering wheel is operated according to the steering intention of the driver and does not execute the lane keeping function (S106).

However, if the steering torque is less than the reference torque set in S105, the control unit 201 enters the integrated mode of the lane keeping function (S107), and then calculates the required steering torque and driving torque for lane keeping (S108) .

The control unit 201 calculates the final target steering torque and the target driving torque according to the ratio between the steering torque and the driving torque by combining the calculated driving torque and the steering torque for lane keeping (S110).

As can be seen from Fig. 3, the ratios of the drive torque and the steering torque are determined in combination according to the required steering angle required for lane keeping.

The controller 201 corrects the steering torque as shown in the following equation in consideration of the road curvature and the vehicle speed when the required steering angle that follows the road curvature is large in determining the final target steering torque.

F _TV2 = K _k f (k, V)

Here, _FTV2 is the driving force distribution amount of torque vectoring by the road curvature,

K denotes the road curvature detected through the camera,

V means the running speed of the vehicle.

Further, when a steering angle of a small degree of leaning is required when determining the final driving target torque, the control unit 201 determines the driving force distribution amount of e-4WD according to the following equation.

Here, _FTV1 is a driving force distribution amount of torque vectoring by the amount of deviation,

K _p is a proportional constant,

t denotes a tread which is the distance between the centers of the left and right wheels.

When the final target steering torque and the target driving torque are determined in step S111, the control unit 201 controls the steering angle and the steering torque through MDPS (Motor Driven Power Steer), adjusts the left and right driving torques of the e-4WD, (S112) so that a running following the lane can be provided (S113).

As can be seen from Fig. 4, when the lane departure is expected in the lane A1, the torque vectoring is activated so that the steering is made rightward through the MDPS 301, and at the same time, So that the lane departure can be prevented from occurring.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood that various modifications and changes may be made without departing from the scope of the appended claims.

101: image detecting unit 102: steering angle detecting unit
103: Steering torque detecting unit 104:
201: control unit 301: MDPS
401: e-4WD

Claims (7)

An image detector for detecting left and right lanes as an image;
A vehicle state detector for detecting a steering angle and a yaw rate;
A steering torque detector for detecting a change in torque of the steering wheel;
A steering angle and a yaw rate are analyzed through a vehicle state detector to calculate a steering torque and a driving torque for maintaining a lane when the lane departure possibility is determined, and a combination of a steering torque and a drive torque Integrated control system of e-4WD system that provides lane keeping function by controlling MDPS and e-4WD with one control signal. The method according to claim 1,
Further comprising a vehicle speed detecting section for detecting a running vehicle speed,
Wherein the controller determines the steering torque in consideration of the curvature of the road detected by the image detector and the vehicle speed provided by the vehicle speed detector. The method according to claim 1,
The control unit controls the steering angle and the steering torque by controlling the MDPS, and assists the steering force by controlling the left and right driving torques of the e-4WD. The method according to claim 1,
Wherein the controller determines the steering torque by applying the following equation.
F _TV2 = K _k f (k, V)
Here, _FTV2 is the driving force distribution amount of the torque vectoring by the road curvature,
K denotes the road curvature detected through the camera,
V means the running speed of the vehicle. The method according to claim 1,
Wherein the controller determines the driving force distribution amount of the e-4WD by applying the following equation.

Here, _FTV1 is a driving force distribution amount of torque vectoring by the amount of deviation,
K _p is a proportional constant,
t denotes a tread which is the distance between the centers of the left and right wheels. Detecting driving information including left and right lane images, a steering angle, a steering torque, a yaw rate, and a vehicle speed in a running state;
Analyzing the left and right lane images to determine the position of the vehicle in the lane, analyzing the information of the steering angle and the yaw rate which is the rotational angular velocity, analyzing the traveling direction of the vehicle, and determining the possibility of lane departure;
Calculating a steering torque and a drive torque for maintaining the lane by executing the integrated mode when the lane departure possibility is determined, and determining the steering target torque and the drive target torque by combining the calculated ratio of the steering torque and the drive torque;
A step of operating the MDPS with the steering target torque and adjusting the driving force of the left and right wheels with the driving target torque to execute the lane keeping function;
Gt; e-4WD < / RTI > The method according to claim 6,
And the lane-keeping function is not executed when the steering torque exceeds the set reference torque in the state where the possibility of lane departure is determined, the lane keeping function is not executed.

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