KR101327021B1 - High Speed Driving Stabilizing Method for Motor Driven Vehicle - Google Patents

Abstract

The fast driving stabilization method of the present invention restricts the maximum vehicle speed to the target speed in the event of an inhibitor signal (Fault or Error) and applies a derating factor (DF) that simplifies the motor torque. By performing the inhibitor abnormality response logic that slows the vehicle speed increase response, the driver's attempt to drive at high speed can be forcibly limited in the event of the abnormality of the inhibitor, so that the driving safety is greatly improved.

Description

High Speed Driving Stabilizing Method for Motor Driven Vehicle

The present invention relates to a motor-driven vehicle, and in particular, the driver's safety by limiting the speed constantly even in the unconscious driver's high-speed driving in the event of an error (Fault or Error) that generates signals of P, R, N, D It relates to a high-speed driving stabilization method of a motor drive vehicle that can provide.

In general, a hybrid vehicle obtains driving power using an engine and a motor, and an electric vehicle or fuel cell vehicle obtains driving power using a motor.

The driving vehicle needs to realize instant and rapid driving power change in response to the driver's continuous and various vehicle speed changes. For this purpose, it is important to obtain information for accurately understanding the state of the driving vehicle in the vehicle controller.

This information becomes more important in electric vehicles or fuel cell vehicles in which the driving power change is realized by the change in the output of the motor.

Therefore, all the vehicles comprise an inverter switch, a shift lever, and an electric circuit in the vehicle control period, which informs the shift state of the transmission of the driving vehicle, and thus the driver's demand is shifted to the gear shift stages P, R, N, D) can be recognized.

In particular, in a motor vehicle in which the vehicle control reflecting the driver's intention is implemented as the torque of the motor, the accuracy and reliability of the P, R, N, and D signals provided through the inhibitor switch are inevitably important.

Korean Patent Publication 10-2008-0054001 (2008.06.17).

The patent document discloses a power distribution controller in which a vehicle control unit (VCU), which is a vehicle controller in charge of overall control of a fuel cell vehicle (or fuel cell battery hybrid vehicle), commands a motor control unit (MCU). When providing information to the PCU (Power Control Unit), it reflects the driver's intention based on vehicle speed (calculated from motor revolutions), acceleration pedal angle and shift gear (P, R, N, D) signals of the shift gear. The example which calculates a motor torque value is shown.

As such, it can be seen that the motor output control is based on the shift stage (P, R, N, D) signal of the shift gear, which is provided from the inhibitor switch.

However, a driving vehicle may face mechanical or electrical abnormalities (Fault or Error) due to various factors, and especially when an abnormality (Fault or Error) of an inhibitor is lost, Alternatively, the redundancy may cause crosstalk in the motor torque calculation.

For this reason, the safety of the unexpected abnormality of the inhibitor can be enhanced by determining whether the abnormality of the inhibitor (Fault or Error) is determined by the combination of the inhibitor switch or the judgment condition check plus the driving vehicle speed.

However, the above countermeasures can enhance the safety of the vehicle operation at the level of the inhibitor enough to stop the operation of the vehicle, but the driver is not aware of the abnormality of the inhibitor that is not enough to stop the operation of the vehicle. Inevitably, we have no other reason than to compromise our safety.

As an example, attempting to drive at high speed by a driver who is not aware of an abnormality of an insignificant inhibitor results in an increase in torque output of the motor in response to this, thereby causing the vehicle to travel at high speed with an abnormality of the inhibitor. Entry can lead to unexpected risks.

Accordingly, the present invention in view of the above point is to limit the unconscious high-speed driving attempt of the driver in a fault (Fault or Error) state determined by the continuous check of the inhibitor generating the P, R, N, D signal The purpose of the present invention is to provide a high speed driving stabilization method for a motor-driven vehicle that can significantly increase driving safety since the driver's attempt to drive at high speed does not appear as an increase in torque of the motor when the driver's high speed driving attempt is performed. .

The high speed driving stabilization method of the motor-driven vehicle of the present invention for achieving the above object is a condition for executing a fault flag set (Fault Flag = SET) when the inhibitor signal (Fault or Error) checked in the running state of the vehicle Establishment stage;

A safety control preparation step of setting a target speed which is the maximum speed of the driving vehicle in preparation for the acceleration demand of the driver;

When calculating the motor torque output according to the driver's acceleration demand, the safety control performance step of delaying the vehicle speed increase response to the driver's acceleration request by applying a derating factor (DF) that reduces the motor torque output size. ;

A safety control achievement step in which a vehicle speed increase made according to an acceleration demand of a driver does not exceed the target speed;

A double safety control step in which the target signal is maintained and the reduction factor value is not immediately released when the inhibitor signal is normally recovered;

 A normal control return step of releasing the target speed and simultaneously setting the reduction factor value to a value independent of the motor torque output size after the inhibitor signal normal recovery is performed;

Inhibitor ideally carried out as characterized in that the logic is included.

The abnormality of the inhibitor signal in the condition establishment step is when the inputs of P, R, N, and D are simultaneously performed or none is input.

In the safety control preparation step, the target speed is 100 Kph.

In the safety control step, the reduction factor value is applied with DF <1.

The reduction factor value is determined by the vehicle speed of the vehicle being driven at the time when it is applied, the vehicle speed is divided into at least one.

The vehicle speed is divided into 40 Kph or less, 80 Kph or less, 100 Kph or less, 100 Kph or more, and the reduction factor values having different values are applied to the divided vehicle speeds. More is reflected in the motor torque calculation.

The reduction factor value is DF = 0.5 when the vehicle speed is 40 Kph or less, DF = 0.0 when the vehicle speed is 100Kph or more, and 0.0 <DF <0.5 when the vehicle speed is 80Kph or less and the vehicle speed is 100Kph or less.

The double safety control step is a fault flag set (Fault Flag = = SET) according to the return of the inhibitor signal to normal, and then determine whether the P set (P = = SET), which is a specific signal value of the inhibitor When the P set (P == SET) is not reached, the control unit proceeds to the safety control step.

The normal control return step includes a fault flag set (Fault Flag == SET) and a P set (P == SET) which is a specific signal value of the inhibitor according to an abnormal return of the inhibitor signal value in the failsafe control execution step. Is determined, the fault flag is reset (Fault Flag == RESET), and then the target speed is released and at the same time the reduction factor is set to a value which is completely independent of the motor torque output size.

The reduction factor value is applied to DF = 1.

In the normal control return step, the traction control (Traction Control) of the motor is performed according to the normal of the lower beater.

The present invention does not forcibly perform the driver's high-speed driving intentionally attempted in the fault (Fault or Error) state of the checked inhibitor, which can greatly improve the driving safety of the vehicle in the event of any abnormality of the inhibitor. It works.

In addition, the present invention is forcibly controlled so that the motor torque increase in the abnormal state of the checked inhibitor does not exceed the set safety vehicle speed, thereby ensuring the operability of the vehicle in the event of any abnormality of the inhibitor.

1 is a flowchart of a fast driving stabilization method of a motor drive vehicle according to the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, which illustrate exemplary embodiments of the present invention. The present invention is not limited to these embodiments.

1 shows a fast driving stabilization method of a motor drive vehicle according to the present embodiment.

When the vehicle driving mode entry is made as in step S10, the inhibitor abnormal response logic is executed together to check the condition of the inhibitor.

The inhibitor abnormal response logic is implemented as a safety mode driving logic to which a derating factor of DF <1 or less is applied, and a recovery mode driving logic to recover to DF = 1.

Here, the signal of the inhibitor is checked because the inhibitor provides the position of the shift lever and the current shift stage state of the transmission as P, R, N, and D signals, and this indicates the function of the normally applied inhibitor. it means.

If it is checked in step S20 that the signal value of the inhibitor is fault (Fault), then the flow proceeds to step S30 and if the fault flag set (Fault Flag = SET) of the inhibitor, the control mode driving logic to which the derating factor is applied is transferred. .

At this time, the fault signal value of the inhibitor (Fault) means that the P, R, N, D inputs come together at the same time or none of the inputs.

The main feature of the safety mode driving logic performed in the present embodiment is to force the driver's request to maintain the driving speed so as not to exceed the set target speed. Specifically, at least three steps are performed based on the vehicle speed of the driving vehicle. By dividing, it is possible to minimize the inconvenience of the driver and to improve the driver's safety from dangerous situations that may occur during high speed driving.

The target speed is set to 100 Kph, but is not limited thereto and may be set in various ways in consideration of a safety situation.

The safe mode driving applied from the step S40 can increase the vehicle speed up to 100 Kph when driving below 40 Kph, and the step S50 to increase the vehicle speed up to 100 Kph when driving below 80 Kph, and up to 100 Kph when driving below 100 Kph. It is divided into a step S60 for increasing the vehicle speed, and a step S70 for decelerating the vehicle speed to 100 Kph when the vehicle is traveling at 100 Kph or more.

Step S41 means that the derating factor applied when driving at 40 Kph or less is set to DF = 0.5, from which the normal acceleration logic to which DF = 1 is applied when increasing the vehicle speed at the driver's acceleration request. In contrast, vehicle acceleration can be achieved with a safety mode-based acceleration logic with DF = 0.5.

As such, the vehicle acceleration of 40 Kph to 100 Kph with DF = 0.5 is about 50% slower than when DF = 1, and this response delay causes the driver to draw attention to the abnormality of the lower beater, The driver's safety can be promoted from the dangerous situation that can occur during driving.

In addition, the step S51 means that the derating factor applied when driving at 80 Kph or less is set to DF = 0.4, from which the normal acceleration to which the DF = 1 is applied when increasing the vehicle speed when the driver requests acceleration. In contrast to the logic, vehicle acceleration can be achieved with safe mode-based acceleration logic with DF = 0.4.

As such, the vehicle acceleration from 80 Kph to 100 Kph with DF = 0.4 is inevitably slowed down by about 40% compared to when DF = 1, and the response delay allows the driver to bring more attention to ventilation due to the abnormal lower beater. The driver's safety can be promoted from the dangerous situation that may occur during high speed operation.

In addition, the step S61 means that the derating factor applied when driving at 100 Kph or less is set to DF = 0.3, from which the normal acceleration to which the DF = 1 is applied when increasing the vehicle speed when the driver requests acceleration. In contrast to the logic, vehicle acceleration can be achieved with safe mode-based acceleration logic with DF = 0.3.

As such, the vehicle acceleration up to 100 Kph with DF = 0.3 is inevitably slowed by about 30% compared to when DF = 1, and the response delay allows the driver to bring more attention to ventilation due to abnormality of the lower beater. The driver's safety can be promoted from the dangerous situation that can occur during driving.

On the other hand, step S70 is a process of decelerating the vehicle traveling at 100 Kph or more to 100 Kph. In this case, the derating factor is set to DF = 0.0.

As DF = 0.0 does not respond to the driver's acceleration demand at all, the vehicle speed is decelerated to 100 Kph even with the driver's continuous acceleration demand. In addition, the driver's safety can be improved from the dangerous situation that may occur in high speed operation exceeding 100 Kph.

On the other hand, if the abnormal condition of the inhibitor during the safe mode driving according to the above step S40 to step S70 is eliminated, the safe mode driving logic is stopped and the recovery mode driving logic is restored to DF = 1.

At this time, the signal value normal of the inhibitor means a case where the P, R, N, and D inputs are respectively input.

The main feature of the recovery mode driving logic performed in this embodiment is that even though the inhibitor is returned to normal, it is not immediately recovered to DF = 1 before the specific signal value of the inhibitor is detected, resulting in the recovery after the abnormality of the inhibitor. It also prevents unexpected risks that may arise.

Here, the specific signal value of the inhibitor is set to the P signal.

If the fault flag set (Fault Flag == SET) as the inhibitor signal value returns to the normal state as in step S100, the process proceeds to step S110, while if the fault flag set (Fault Flag == SET) is not required, the process goes to step S130. Passing

If the P signal, which is a specific signal value of the inhibitor in step S110, is not P set (P == SET), the signal transitions back to the safe mode driving logic, and steps S40 to S70 according to the safe mode driving logic are performed.

On the other hand, if the P signal, which is a specific signal value of the inhibitor in step S110, is P set (P == SET), the process proceeds to step S120 and fault flag reset (Fault Flag == RESET), and immediately in step S130, DF = 1 Restores

In this case, DF = 1 means that the vehicle speed is accelerated to match the driver's acceleration request.

By implementing the recovery mode driving logic according to step S100 to step S130 as described above, the control stability of the vehicle can be made dual with the safety mode of step S40 to step S70 according to the abnormality of the inhibitor.

On the other hand, if the vehicle is switched to the control logic implemented in the normal state after the recovery to DF = 1, the traction control (Traction Control) for the motor as shown in step S200 is completely out of the inhibitor abnormal response logic.

It can be seen that the motor torque according to the traction control is calculated by applying DF as in step S300. However, in this case, since DF = 1, the motor torque is not affected at all by the DF.

As described above, the fast driving stabilization method according to the present embodiment applies a derating factor (DF) to limit the maximum vehicle speed to the target speed and reduce the motor torque in the event of an inhibitor signal (Fault or Error). As a result of the inhibitor abnormality response logic that slows the driver's acceleration response to the driver's acceleration demand, the driver's high speed driving attempt may be forcibly limited in the event of the abnormality of the inhibitor, thereby greatly improving the high speed driving safety.

Claims (11)

Inhibitor signal that is continuously checked in the driving state of the vehicle, when any two or more signals of P, R, N, D signals are checked at the same time, or none of the P, R, N, D signals is checked A condition establishment step of determining that the signal is abnormal and executing a fault flag set (Fault Flag = SET);
A safety control preparation step of setting a target speed which is the maximum speed of the driving vehicle in preparation for the acceleration demand of the driver;
When calculating the motor torque output according to the driver's acceleration demand, the safety control performance step of delaying the vehicle speed increase response to the driver's acceleration request by applying a derating factor (DF) that reduces the motor torque output size. ;
A safety control achievement step in which a vehicle speed increase made according to an acceleration demand of a driver does not exceed the target speed;
After the safety control step, even if the inhibitor signal is checked with any one of the P, R, N, and D signals, the target only when the inhibitor signal is checked with P set (P == SET). A double safety control step of performing an immediate release of the speed maintenance and an immediate release switching of the reduction factor value application;
After the safety control achievement step, the inhibitor signal is checked by any one of P, R, N, and D signals, and then the target speed is released, and at the same time, the reduction factor value has nothing to do with the motor torque output size. A normal control return step of setting one value;
High speed driving stabilization method of the motor-driven vehicle, characterized in that it comprises an inhibitor abnormal response logic performed by.
delete The method of claim 1, wherein the target speed is 100 Kph in the safety control preparation step.
The method of claim 1, wherein in the safety control step, the reduction factor value is DF <1.
The motor of claim 4, wherein the reduction factor value is determined as a vehicle speed of the vehicle being driven at the time when it is applied, and the vehicle speed is divided into at least one so that the reduction factor value is applied according to the section of the vehicle speed. Fast driving stability method of driving vehicle.
The method of claim 5, wherein the vehicle speed is divided into 40Kph or less, more than 40Kph to 80Kph or less, more than 80Kph to 100Kph or less, more than 100Kph, the different reduction values of the different values are applied to the vehicle speed, the vehicle speed is The larger the value is, the more the influence of the reduction factor value is reflected in the motor torque calculation.
The method of claim 6, wherein the reduction factor value is DF = 0.5 when the vehicle speed is less than 40Kph, DF = 0.0 when the vehicle speed is greater than 100Kph, 0.0 <DF <0.5 when the vehicle speed is greater than the 80Kph and 100Kph or less High speed driving stabilization method of the motor drive vehicle, characterized in that applied in.
The method of claim 1, wherein the failsafe control step is performed as the inhibitor signal value is checked with any one of P, R, N, and D signals.
After determining whether the fault flag is set (Fault Flag == SET) and the signal value of the inhibitor is P set (P == SET),
If the signal value of the inhibitor is not P set (P = = SET), the high speed driving stabilization method of the motor drive vehicle, characterized in that the transition to the safety control execution step.
The method of claim 1, wherein the normal control returning step is performed as the inhibitor signal value is checked as one of P, R, N, and D signals in the double safety control step.
When the fault flag set (Fault Flag == SET) and the signal value of the inhibitor is P set (P == SET),
After fault flag reset (Fault Flag == RESET), the target speed is released and the reduction factor value is set to a value irrelevant to the motor torque output size. .
10. The method of claim 9, wherein the reduction factor value is DF = 1.
10. The method of claim 9, wherein the normal control return step comprises a traction control of the motor according to the normal of the inhibitor.

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