KR101214266B1 - Device and method for controlling torque distribution for 4 wheel driving vehicle - Google Patents

Abstract

The present invention is to determine the rear torque distribution ratio by using the longitudinal acceleration and the rear wheel weight support ratio, so that the weight transfer effect amount from the front wheel side to the rear wheel side according to the vehicle acceleration during acceleration is reflected so as not to cause a loss of driving force. A torque distribution control device and method for a four-wheel drive vehicle,
Engine torque sensor for detecting engine torque, engine speed sensor for detecting engine speed, wheel speed sensor for detecting wheel speed of front and rear wheels, transmission gear ratio, gross vehicle weight in stationary vehicle, rear wheel weight in stationary vehicle, The vehicle's center of gravity, the memory that stores the data of the wheelbase full length, the longitudinal acceleration sensor for detecting the acceleration in the longitudinal direction (length) of the vehicle, and the average speed of the vehicle from the signal of the wheel speed sensor Calculates the transmission gear ratio from the vehicle average speed and the signal of the engine speed sensor and the transmission gear ratio information stored in the memory, calculates the maximum torque that can be driven from the signal of the engine torque sensor, and calculates the longitudinal direction. The longitudinal acceleration VEH_ACC is calculated from the average speed of the vehicle from the signal of the acceleration sensor, and the above-mentioned longitudinal acceleration VEH_ is calculated. A four-wheel drive controller for controlling the 4WD torque by calculating the rear wheel torque distribution ratio (TQCtrl_DIST_R) from the ACC), and a power transmission device for distributing and transmitting the driving force of the front and rear wheels in accordance with the control signal input from the four-wheel drive controller Is done.

Description

Device and method for controlling torque distribution for 4 wheel driving vehicle

The present invention relates to a torque distribution control device and method for a four-wheel drive vehicle, and more specifically, to determine the rear torque distribution ratio by using the longitudinal acceleration and the rear wheel support ratio by the rear wheel at the front wheel side according to the vehicle acceleration during acceleration The present invention relates to a torque distribution control device and method for a four-wheel drive vehicle, such that the weight transfer effect amount to the side is reflected so as not to cause a loss of driving force.

In general, a four-wheel drive vehicle (WWD) distributes the drive torque of the engine to the front and rear wheels according to the driving situation to drive the front and rear wheels simultaneously. In such a road that requires a large driving force, driving slippage and road surface are minimized to provide driving safety and escape.

The driver can control the driving force distribution of the front and rear wheels according to the driving conditions by operating the four-wheel drive mode changeover switch mounted on the driver's seat. When the 4WD mode switch is turned on, the 4WD controller of the 4WD vehicle receives a signal from an engine torque sensor, a throttle position sensor, an engine speed sensor, a speed sensor for each wheel, and calculates a torque distribution amount accordingly. By controlling the coupling to actuate the actuator, the drive torque is controlled by controlling the distribution of the drive torque.

The conventional four-wheel drive controller of a four-wheel drive vehicle controls the torque distribution ratio of the front and rear wheels to Wf / W: Wr / W or to a fixed value of 50:50, respectively. The torque distribution control value of the front and rear wheels is generally as follows.

Rear torque distribution control value = total vehicle torque × rear torque distribution ratio

Front wheel torque distribution control value = vehicle total torque × (1- rear wheel torque distribution ratio)

Rear torque distribution ratio = Rear wheel axle weight (Wr) at standstill / Total vehicle weight (W) at standstill

Front wheel torque distribution ratio = Front wheel axle weight at stop (Wf) / Total vehicle weight at stop (W)

The maximum torque that can be transmitted from each wheel is as follows.

Torque = (coefficient of friction between tire and ground) × (support weight of each wheel)

From the above equation, it can be seen that the torque distribution ratio of the ideal front and rear wheels that maximizes the driving force while suppressing the slip of the front and rear wheels coincides with the weight support ratio of the front and rear wheels.

However, the conventional four-wheel drive vehicle described above does not reflect the weight transfer effect amount from the front wheel side to the rear wheel according to the vehicle acceleration during acceleration, and thus the front wheel torque distribution ratio is different from the front wheel weight support ratio, which is an ideal value. This has a problem of causing a loss of driving force.

DISCLOSURE OF THE INVENTION An object of the present invention is to solve the conventional problems as described above, and to determine the rear torque distribution ratio by using the longitudinal acceleration and the rear wheel weight support ratio to move the weight from the front wheel side to the rear wheel side according to the vehicle acceleration during acceleration. It is to provide a torque distribution control apparatus and method for a four-wheel drive vehicle, such that the effective amount is reflected so as not to cause a loss of driving force.

As a means for achieving the above object, the first configuration of the present invention, the engine torque sensor for detecting the engine torque, the engine speed sensor for detecting the engine speed, the wheel speed for detecting the wheel speed of the front and rear wheels Sensor, transmission gear ratio, stationary vehicle gross weight, stationary vehicle rear wheel weight, vehicle center of gravity height, memory that stores the data of the wheelbase full length, and longitudinal direction for sensing the acceleration in the longitudinal direction of the vehicle. The vehicle average speed is calculated from the acceleration sensor and the wheel speed sensor signal, the transmission gear ratio is calculated from the signal of the vehicle average speed and engine speed sensor and the transmission gear ratio information stored in the memory, and the engine The maximum torque that can be driven is calculated from the signal of the torque sensor, and the longitudinal acceleration (VEH_AC) is calculated from the signal of the longitudinal acceleration sensor. C) and a four wheel drive controller for controlling 4WD torque by calculating the rear wheel torque distribution ratio TQCtrl_DIST_R from the longitudinal acceleration VEH_ACC, and the front and rear wheels according to the control signal input from the four wheel drive controller. It is preferable to include a power transmission device for distributing and transmitting the driving force.

In the first configuration of the present invention, the rear wheel torque distribution ratio TQCtrl_DIST_R is preferably calculated by the following equation.

Rear torque distribution ratio (TQCtrl_DIST_R) = WEIGHT_R / GVW

WEIGHT_R = WEIGHT_STA_R + GVW × VEH_ACC / GRAVITY_ACC × HEIGHT_MassCenter / WHEEL_TREAD

Here, the WEIGHT_R is the rear wheel support weight in consideration of the acceleration effect, WEIGHT_STA_R is the rear vehicle weight of the stationary vehicle, GVW is the gross vehicle weight of the stationary vehicle, VEH_ACC is the longitudinal acceleration, GRAVITY_ACC is the gravity acceleration (9.81 kPa), HEIGHT_MassCenter is the vehicle's center of gravity height and WHEEL_TREAD is the wheelbase overall length.

The first configuration of the present invention is preferably such that the power transmission device is made of an electronic coupling.

According to a second aspect of the present invention, when the operation is started, reading sensor signals input from the engine torque sensor, the engine speed sensor, and the wheel speed sensor, calculating a vehicle average speed from the signal of the wheel speed sensor, and Calculating a gear ratio based on the transmission gear ratio information stored in the memory and the signal of the vehicle average speed and engine speed sensor, calculating a maximum torque that can be driven from the signal of the engine torque sensor, and a longitudinal acceleration sensor Calculating the longitudinal acceleration (VEH_ACC) from the signal of, calculating the rear torque distribution ratio (TQCtrl_DIST_R) from the longitudinal acceleration (VEH_ACC), and calculating the 4WD rear wheel distribution torque to control the 4WD torque. It is preferable to include.

As for the 2nd structure of this invention, it is preferable that said rear-wheel torque distribution ratio TQCtrl_DIST_R is calculated by following Formula.

Rear torque distribution ratio (TQCtrl_DIST_R) = WEIGHT_R / GVW

WEIGHT_R = WEIGHT_STA_R + GVW × VEH_ACC / GRAVITY_ACC × HEIGHT_MassCenter / WHEEL_TREAD

Here, the WEIGHT_R is the rear wheel support weight in consideration of the acceleration effect, WEIGHT_STA_R is the rear vehicle weight of the stationary vehicle, GVW is the gross vehicle weight of the stationary vehicle, VEH_ACC is the longitudinal acceleration, GRAVITY_ACC is the gravity acceleration (9.81 kPa), HEIGHT_MassCenter is the vehicle's center of gravity height and WHEEL_TREAD is the wheelbase overall length.

According to a second aspect of the present invention, the step of calculating the shift gear ratio and calculating the maximum torque and the step of calculating the longitudinal acceleration VEH_ACC and the calculating of the rear wheel torque distribution ratio TQCtrl_DIST_R are preferably performed in parallel. Do.

The present invention is to determine the rear torque distribution ratio by using the longitudinal acceleration and the rear wheel weight support ratio, so that the weight transfer effect amount from the front wheel side to the rear wheel side according to the vehicle acceleration during acceleration is reflected so as not to cause a loss of driving force. Has an effect.

1 is a block diagram of a torque distribution control apparatus for a four-wheel drive vehicle according to an exemplary embodiment of the present invention.
2 is an operation flowchart of a torque distribution control method of a four-wheel drive vehicle according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings in order to describe in detail enough to enable those skilled in the art to easily carry out the present invention. . Other objects, features, and operational advantages, including the purpose, operation, and effect of the present invention will become more apparent from the description of the preferred embodiments.

For reference, the embodiments disclosed herein are only presented by selecting the most preferred embodiment in order to help those skilled in the art from the various possible examples, the technical spirit of the present invention is not necessarily limited or limited only by this embodiment Rather, various changes, additions, and changes are possible within the scope without departing from the spirit of the present invention, as well as other equivalent embodiments.

1 is a block diagram of a torque distribution control apparatus for a four-wheel drive vehicle according to an exemplary embodiment of the present invention.

As shown in Figure 1, the configuration of the torque distribution control device for a four-wheel drive vehicle according to an embodiment of the present invention, the engine torque sensor 10 for detecting the engine torque, and for detecting the engine speed Engine speed sensor 20, the wheel speed sensor 30 for detecting the wheel speed of the front and rear wheels, the transmission gear ratio, the stationary vehicle gross weight (GVW), the stationary vehicle rear wheel weight (WEIGHT_STA_R), the vehicle center of gravity height ( HEIGHT_MassCenter), a memory 40 in which data of the wheelbase total length (WHEEL_TREAD) are stored, a longitudinal acceleration sensor 50 for detecting acceleration in the longitudinal direction (length direction) of the vehicle, and the wheel speed sensor ( The average vehicle speed is calculated from the signal of 30), the transmission gear ratio is calculated from the vehicle average speed, the signal of the engine speed sensor 20, and the transmission gear ratio information stored in the memory 40, and the engine torque described above. Sensor (10) The maximum torque that can be driven from the signal is calculated, the longitudinal acceleration VEH_ACC is calculated from the signal of the longitudinal acceleration sensor 50, and the rear wheel torque distribution ratio TQCtrl_DIST_R is calculated from the longitudinal acceleration VEH_ACC. It includes a four-wheel drive controller 60 for controlling the 4WD torque, and a power transmission device 70 for distributing and transmitting the driving force of the front wheel and the rear wheel according to the control signal input from the four-wheel drive controller 60.

The power transmission device 70 is made of an electronic coupling.

2 is a flowchart illustrating an operation of a torque distribution control method of a four-wheel drive vehicle according to an exemplary embodiment of the present invention.

As shown in Figure 2, the configuration of the torque distribution control method for a four-wheel drive vehicle according to an embodiment of the present invention, the step of starting the operation, the engine torque sensor, the engine speed sensor and the wheel speed Reading the sensor signal input from the sensor (S20), calculating the average vehicle speed from the signal of the wheel speed sensor (S30), and storing the average vehicle speed and the engine speed sensor in the signal and memory Calculating the gear ratio from the transmission gear ratio information (S40), calculating the maximum torque that can be driven from the signal of the engine torque sensor (S50), and longitudinal acceleration (VEH_ACC) from the signal of the longitudinal acceleration sensor. Calculating (S60), calculating the rear wheel torque distribution ratio (TQCtrl_DIST_R) from the longitudinal acceleration (VEH_ACC) (S70), calculating the 4WD rear wheel distribution torque (S80), and controlling the 4WD torque. And a step (S100) of terminating the operation.

The operation of the torque distribution control device and method of the four-wheel drive vehicle according to the embodiment of the present invention by the above configuration is as follows.

When the operation is started (S10), the four-wheel drive controller 60 reads the sensor signal input from the engine torque sensor 10, the engine speed sensor 20 and the wheel speed sensor 30 (S20).

The 4WD controller 60 calculates an average vehicle speed from the signal of the wheel speed sensor 30 (S30).

Next, the 4WD controller 60 estimates and estimates the transmission gear ratio of the current vehicle from the above-described vehicle average speed, the signal of the engine speed sensor 20, and the transmission gear ratio information stored in the memory 40 (S40).

Subsequently, the 4WD controller 60 calculates the maximum torque that can be driven from the signal of the engine torque sensor 10 (S50).

At the same time, the 4WD controller 60 calculates the longitudinal acceleration VEH_ACC from the signal of the longitudinal acceleration sensor 50 (S60).

Next, the 4WD controller 60 inputs data of the stationary vehicle total weight GVW, the stationary vehicle rear wheel weight WEIGHT_STA_R, the vehicle center of gravity height HEIGHT_MassCenter, and the wheelbase total length WHEEL_TREAD. The rear wheel torque distribution ratio TQCtrl_DIST_R is calculated from the longitudinal acceleration VEH_ACC (S70). The rear wheel torque distribution ratio TQCtrl_DIST_R is calculated using the following equation.

Rear torque distribution ratio (TQCtrl_DIST_R) = WEIGHT_R / GVW

Here, the WEIGHT_R is the rear wheel support weight in consideration of the acceleration effect, and the GVW is the gross vehicle weight of the stationary vehicle.

The rear wheel support weight WEIGHT_R considering the acceleration effect is calculated using the following equation.

Rear wheel support weight considering acceleration effect (WEIGHT_R) = WEIGHT_STA_R + GVW × VEH_ACC / GRAVITY_ACC × HEIGHT_MassCenter / WHEEL_TREAD

Here, the WEIGHT_STA_R is a stationary vehicle rear wheel weight, the GVW is a stationary vehicle gross weight, the VEH_ACC is a longitudinal acceleration, the GRAVITY_ACC is a gravity acceleration (9.81 kPa), the HEIGHT_MassCenter is a vehicle It is the height of the center of gravity, and the above WHEEL_TREAD is the wheelbase full length.

In this way, the rear torque distribution ratio (TQCtrl_DIST_R) is determined by using the longitudinal acceleration and the rear wheel weight support ratio so that the weight transfer effect amount from the front wheel to the rear wheel according to the vehicle acceleration during acceleration is reflected so as not to cause a loss of driving force. There is a number.

Next, the 4WD torque distribution calculating unit of the 4WD controller 60 calculates the 4WD rear wheel distribution torque in accordance with the rear wheel torque distribution ratio TQCtrl_DIST_R (S80).

Subsequently, the power transmission device control signal unit of the 4WD controller 60 outputs a control signal to the power transmission device 70 to control the 4WD torque (S90), and then ends the operation (S100).

10: engine torque sensor 20: engine speed sensor
30: wheel speed sensor 40: memory
50: longitudinal acceleration sensor 60: 4 wheel drive controller
70: power train

Claims (6)

An engine torque sensor for detecting engine torque,
An engine speed sensor for detecting engine speed,
Wheel speed sensor for detecting the front wheels and rear wheels,
A memory that stores the transmission gear ratio, the gross vehicle weight of the stationary vehicle, the weight of the rear vehicle of the stationary vehicle, the center of gravity of the vehicle, the wheelbase length,
A longitudinal acceleration sensor for detecting acceleration in the longitudinal direction (lengthwise direction) of the vehicle,
The average vehicle speed is calculated from the signal of the wheel speed sensor, the transmission gear ratio is calculated from the transmission gear ratio information stored in the memory and the signal of the vehicle average speed and engine speed sensor, and the signal of the engine torque sensor is calculated. 4WD torque is controlled by calculating the maximum torque that can be driven from the motor, calculating the longitudinal acceleration VEH_ACC from the signal of the longitudinal acceleration sensor, and calculating the rear wheel torque distribution ratio TQCtrl_DIST_R from the longitudinal acceleration VEH_ACC. 4 wheel drive controller,
It includes a power transmission device for distributing and transmitting the driving force of the front wheel and the rear wheel according to the control signal input from the four-wheel drive controller,
The rear wheel torque distribution ratio (TQCtrl_DIST_R) is a torque distribution control device for a four-wheel drive vehicle, characterized in that calculated by the following equation.
Rear torque distribution ratio (TQCtrl_DIST_R) = WEIGHT_R / GVW
WEIGHT_R = WEIGHT_STA_R + GVW × VEH_ACC / GRAVITY_ACC × HEIGHT_MassCenter / WHEEL_TREAD
Here, the WEIGHT_R is the rear wheel support weight in consideration of the acceleration effect, WEIGHT_STA_R is the rear vehicle weight of the stationary vehicle, GVW is the gross vehicle weight of the stationary vehicle, VEH_ACC is the longitudinal acceleration, GRAVITY_ACC is the gravity acceleration (9.81 kPa), HEIGHT_MassCenter is the vehicle's center of gravity height and WHEEL_TREAD is the wheelbase overall length. delete The method of claim 1,
The power transmission device is a torque distribution control device for a four-wheel drive vehicle, characterized in that made of an electronic coupling. Reading the sensor signal input from the engine torque sensor, the engine speed sensor, and the wheel speed sensor when the operation is started;
Calculating the average vehicle speed from the signal of the wheel speed sensor;
Calculating a transmission gear ratio from the transmission gear ratio information stored in the signal and the memory of the vehicle average speed and engine speed sensor;
Calculating a maximum torque that can be driven from the signal of the engine torque sensor;
Calculating a longitudinal acceleration (VEH_ACC) from the signal of the longitudinal acceleration sensor,
Calculating a rear wheel torque distribution ratio TQCtrl_DIST_R from the longitudinal acceleration VEH_ACC;
Comprising a step of controlling the 4WD torque by calculating the 4WD rear wheel distribution torque,
The rear wheel torque distribution ratio (TQCtrl_DIST_R) is a torque distribution control method for a four-wheel drive vehicle, characterized in that calculated by the following equation.
Rear torque distribution ratio (TQCtrl_DIST_R) = WEIGHT_R / GVW
WEIGHT_R = WEIGHT_STA_R + GVW × VEH_ACC / GRAVITY_ACC × HEIGHT_MassCenter / WHEEL_TREAD
Here, the WEIGHT_R is the rear wheel support weight in consideration of the acceleration effect, WEIGHT_STA_R is the rear vehicle weight of the stationary vehicle, GVW is the gross vehicle weight of the stationary vehicle, VEH_ACC is the longitudinal acceleration, GRAVITY_ACC is the gravity acceleration (9.81 kPa), HEIGHT_MassCenter is the vehicle's center of gravity height and WHEEL_TREAD is the wheelbase overall length. delete 5. The method of claim 4,
Computing the gear ratio and calculating the maximum torque, and calculating the longitudinal acceleration (VEH_ACC) and calculating the rear wheel torque distribution ratio (TQCtrl_DIST_R) of the torque of the four-wheel drive vehicle, characterized in that in parallel Distribution control method.

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