KR20060014185A - Method for controlling driving speed of a vehicle in a curve - Google Patents

Abstract

The present invention relates to a curve road driving speed control method of a vehicle having a system for maintaining a driving interval with a preceding vehicle by using a radar sensor, the first process of receiving vehicle speed and curve angle information detected by the radar sensor and; Calculating a torque deceleration amount of engine torque based on the vehicle speed and curve angle information; A third step of decelerating by performing torque reduction within an extent that engine stall is not performed with respect to the torque deceleration amount; A fourth step of decelerating by performing a gear shift according to the remaining torque deceleration amount after performing the torque reduction; And a fifth process of controlling an engine torque amount by the inter-vehicle travel interval maintenance system when the curve road passes based on the detection information of the radar sensor. As a result, when the vehicle enters a curve road, the road situation is recognized in advance, thereby performing an appropriate deceleration function, thereby preventing the driver's brake operation so that the inter-vehicle driving interval maintenance system is not released, and the driver can safely drive the curve road.

Curve, driving, control

Description

Method for controlling driving speed of a vehicle in a curve}

1 is a configuration diagram of a vehicle driving speed control system in a curve road according to the present invention,

2 is an engine torque deceleration determination graph used in the present invention,

3 is a flowchart of a vehicle driving speed control method in a curve road according to the present invention;

4 is an engine torque graph used in the present invention;

<Description of Symbols for Major Parts of Drawings>

 1: ACC Radar 3: ACC ECU

 4: Engine ECU 5: TCU

 6: ESP ECU 7: Engine Drive

 8: shift drive unit 9: brake drive unit

The present invention relates to a driving speed control method for a vehicle, and more particularly, to a driving speed control method for automatically decelerating a traveling speed of a vehicle on a curved road.

The Adaptive Cruise Control system calculates the appropriate acceleration / deceleration status of its own vehicle (hereinafter referred to as 'vehicle') from the distance and relative speed of the preceding vehicle measured by a sensor mounted in front of the vehicle. It refers to a system that maintains the proper distance by controlling the throttle valve, brake, and transmission.

In this adaptive cruise control system, when the driver travels on a road that can be driven at a constant speed such as a highway, when the switch of the cruise system of the car is turned on, the vehicle is driven at a constant speed without a pedal operation. When the driver presses the pedal, the cruise system is turned off.

By the way, the adaptive cruise control system is in operation to maintain the speed set by the driver when controlling the curve and follow the preceding vehicle. In this case, when the vehicle is tilted by the law of inertia, the driver may decelerate by depressing the brake pedal in advance in order to prevent this, and the adaptive cruise system is released. That is, the adaptive cruise control system does not perform its function while driving on a continuous curve road, and the driver has to drive manually.

Accordingly, the present invention has been made to solve the above problems, and when entering the curve road to recognize the road situation in advance to perform the appropriate deceleration function to prevent the driver's brake operation so that the inter-vehicle driving interval maintenance system is not released, An object of the present invention is to provide a method for controlling a curve road speed of a vehicle capable of safely driving a curve road.

The present invention for achieving the above object, in the curve road driving speed control method of a vehicle having a system for maintaining a running interval with the preceding vehicle using the radar sensor, the vehicle speed and curve detected by the radar sensor A first step of receiving angle information; Calculating a torque deceleration amount of engine torque based on the vehicle speed and curve angle information; A third step of decelerating by performing torque reduction within an extent that engine stall is not performed with respect to the torque deceleration amount; A fourth step of decelerating by performing a gear shift according to the remaining torque deceleration amount after performing the torque reduction; And a fifth process of controlling the amount of engine torque by the inter-vehicle travel interval maintenance system when the curve road passes based on the detection information of the radar sensor.

The third process may include requesting a torque reduction from the engine control unit by the torque reduction amount, and comparing the torque amount obtained by subtracting the torque reduction amount from the current engine torque amount by the engine control unit with a preset engine stall limit amount. It can further reduce the engine torque by including a process.

The fourth process may further include: requesting a shift down control unit for the remaining torque deceleration amount not performed at the torque deceleration amount; The shift control unit may further reduce the engine torque by further including a step of performing a gear shift with respect to the remaining torque reduction amount.

In addition, the fourth process includes the step of shifting is prohibited by the shift control unit when the remaining torque reduction amount is less than the shock generation reference amount; The engine torque may be reduced by further including a step of decelerating by controlling the brake driving unit.

The third and fourth processes of performing the torque deceleration may be performed before receiving the distance information with respect to the curve from the radar sensor and entering the curve.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a vehicle driving speed control system in a curve road according to the present invention. As shown in FIG. 1, a radar sensor 1, an adaptive cruise control electronic control unit (hereinafter referred to as an ACC ECU) 3 for receiving information detected by the radar sensor 1, An engine ECU (Electronic Control Unit) 4 which receives an engine torque deceleration request from the ACC ECU 3 and serves as an engine control function, and a TCU (Transmission Control) that receives a deceleration request from the ACC ECU 3 and performs a shift control function. Unit (5), an Electronic Stability Program (ESP) ECU 6 that receives a brake control request from the ACC ECU 3, an engine driver 7 operated under the control of the engine ECU 4, and a TCU. It consists of the shift drive part 8 operated by the control of (5), and the brake drive part 9 operated by the control of the ESP ECU 6. As shown in FIG.

The radar sensor 1 detects the curve angle and the distance to the curve road by the reflected wave change of the road center separator and the reflected wave of the structure installed at the corner.

The ACC ECU 3 calculates the curve radius using the curve angle detected by the radar sensor 1 and sets the torque reduction amount based on the graph of FIG. 2. The torque reduction amount corresponding to the speed detected by the speed sensor in the radar sensor 1 is set based on the graph of FIG. 2. The ACC ECU 3 sets an appropriate torque reduction amount by comparing the torque reduction amount according to the curve radius with the torque reduction amount according to the speed.

The ACC ECU 3 receives the vehicle speed, the curve angle, and the distance to the curve road entry from the radar sensor 1 through CAN (Controller Area Network) communication, and decelerates the engine torque based on the engine torque deceleration determination graph. After the amount is calculated, a request is made to reduce the torque amount to the engine control unit (Engine ECU) 4 side. Referring to the graph of FIG. 2 as an example, the torque deceleration amount is 25% when the curve radius is 500 m and the vehicle speed is 100 km / h. Accordingly, the ACC ECU 3 requests the engine ECU 4 to reduce approximately 25% of the current torque.

The engine ECU 4 performs the deceleration control by controlling the engine driver 7 to reduce the engine speed to reduce the engine torque. The engine ECU 4 performs 25% reduction control when the 25% reduction in current torque is greater than the engine stall prevention torque (15%). At this time, when it is determined that the torque obtained by subtracting 25% from the current torque is equal to or less than the engine stall limit amount (15%), that is, when the current engine torque amount is less than 40% (25% + 15%), the engine stall limit amount (15 Torque control is performed as long as it does not fall to%), and the ACC ECU 3 is notified of the remaining amount of torque not controlled. In response to this, the ACC ECU 3 requests a shift down to the TCU 5 side to perform a reduction for the remaining torque amount.

The TCU 5 functions as a shift control function to improve steering performance of the vehicle during turning acceleration during driving on a general road, and reduces the torque by shifting down by controlling the shift driver 8 at the request of the ACC ECU 3. Perform deceleration control by executing.

The TCU 5 shifts from 4 steps to 2 steps if the torque reduction request amount requested from the ACC ECU 3 is 10% or more and less than 20%. Shift to a step. The TCU 5 prohibits shifting when the torque reduction request amount is equal to or less than the shock generation reference amount (5%), and informs the ACC ECU 3 of the information that the shift is prohibited. Accordingly, the ACC ECU 3 requests the brake control to the ESP ECU 6 to perform the deceleration control.

3 is a flowchart illustrating a vehicle driving speed control method in a curve road according to the present invention. As shown in FIG. 3, in operation S1, the sensing information detected by the ACC radar sensor 1 is received. In step S2, the ACC ECU 3 calculates the torque reduction amount based on the detection information of the ACC radar sensor 1, the vehicle speed information of the RPM sensor 2, and the engine torque reduction amount determination graph of FIG. In step S3, the ACC ECU 3 requests the engine ECU 4 to reduce the engine torque. In step S4, the engine ECU 4 compares the calculation amount obtained by subtracting the engine torque reduction request amount (25%) from the current engine torque with the engine stall limit amount (15%). At this time, when the engine ECU 4 calculates the amount of the engine torque reduction request amount (25%) from the current engine torque amount larger than the engine stall limit amount (15%), the engine ECU 4 performs the engine driving unit 7 in step S6. By controlling the engine speed to reduce the engine torque is sufficiently performed.

However, when the determination result of step S5 indicates that the calculation amount obtained by subtracting the engine torque reduction request amount (25%) from the current engine torque amount is smaller than the engine stall limit amount (15%), the engine ECU 4 does not become an engine stall in step S7. Engine torque reduction, unless In step S8, the engine ECU 4 provides the ACC ECU 3 with remaining torque deceleration amount information that has not been performed. In step S9, the ACC ECU 3 requests a shift down from the TCU 5 for the remaining torque deceleration amount that has not been performed. In step S10, the TCU 5 shifts from 4 steps to 2 steps in step S11 when the reduction request amount is 10% or more and less than 20%. However, if the reduction request amount in step S10 is less than 5% and less than 10%, in step S12 the TCU (5) is shifted from the fourth stage to the third stage, and in step S17 the TCU (5) controls the shift drive unit (8). To perform deceleration control.

On the other hand, if the determination result of step S10 is less than 5% of the shock generation reference amount, the shift is prohibited and the ACC ECU 3 is notified of the shift prohibition information. In step S15, the ACC ECU 3 requests the brake control to the Electronic Stability Program (ESP) ECU 6. In step S17, the ESP ECU 6 controls the ESP brake driver 9 to perform deceleration control.

The vehicle performs deceleration in the above-described order and before the curve is finished, the ACC system performs distance maintenance and estimation control with the preceding vehicle after the speed increase according to the detection information of the ACC radar sensor 1 and the existing speed control condition. .

4 is an engine torque graph showing an engine stall limit and a current engine torque. Based on the engine torque graph of FIG. 4, the current engine torque amount is 60% and the engine stall limit amount is 15%. Therefore, when the engine torque reduction request amount is 25%, the torque can be sufficiently reduced by the engine ECU 4 to decelerate.

With this configuration, before entering the curve, the torque deceleration is calculated by the ACC radar sensor, and the torque deceleration is carried out within a range where the engine ECU is not stalled in the engine ECU. If the deceleration is performed by shifting by requesting a shift down and the shifting cannot be performed by the TCU, the operation of the ACC system is guaranteed by requesting the ESP ECU to control the deceleration by performing the deceleration to perform the deceleration. As a result, the operation of the ACC system is guaranteed, so that the driver can safely drive a certain distance from the preceding vehicle on the curve.

As described above, according to the present invention, since the road situation is recognized in advance when the curve is entered, an appropriate deceleration function is performed to prevent the driver's brake operation so that the inter-vehicle spacing maintenance system is not released, and the driver can safely drive the curve. It becomes possible.

Claims (5)

In the curved road driving speed control method of a vehicle having a system for maintaining a running interval with the preceding vehicle by using a radar sensor, A first step of receiving vehicle speed and curve angle information detected by the radar sensor; Calculating a torque deceleration amount of engine torque based on the vehicle speed and curve angle information; A third step of decelerating by performing torque reduction within an extent that engine stall is not performed with respect to the torque deceleration amount; A fourth step of decelerating by performing a gear shift according to the remaining torque deceleration amount after performing the torque reduction; And a fifth process of controlling an amount of engine torque by the inter-vehicle travel interval maintenance system when the curve road passes based on the detection information of the radar sensor. The method of claim 1, The third process, Requesting a reduction of torque by the amount of torque reduction from the engine controller; And comparing, by the engine control unit, a torque amount obtained by subtracting the torque deceleration amount from a current engine torque amount with a preset engine stall limit amount. The method of claim 1, The fourth process, Requesting a shift down to the shift control unit for the remaining torque deceleration amount not performed at the torque deceleration amount; The shift control unit further comprises the step of performing a gear shift for the remaining torque deceleration amount of the curve road driving speed control method. The method of claim 3, The fourth process, Shifting is prohibited by the shift control unit when the remaining torque reduction amount is less than the shock generation reference amount; Driving speed control method of the vehicle curve characterized in that it further comprises the step of controlling the brake drive to decelerate. The method of claim 1, Third and fourth processes for performing the torque deceleration, Curve road running speed control method for a vehicle characterized in that it is performed before entering the curve by receiving the distance information with the curve from the radar sensor.

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