KR101156133B1 - Controlling method for regeneratative breaking of vehicles under the bus-off condition - Google Patents

Abstract

PURPOSE: A controlling method for regenerative breaking of a vehicle in the malfunction of communication is provided to prevent the reduction of a regenerative breaking amount by selectively determining a routine of regenerative braking through a controller. CONSTITUTION: It is determined whether regenerative braking enters(S101). Communication failure between each controller is determined(S102). A routine of the regenerative braking is determined by using a speed increase amount in vehicle driving and apply time for an accelerating pedal before braking(S103). A controller performs a regenerative braking maximization routine or a regenerative braking optimization routine(S104). The regenerative braking maximization routine is performed(S105). A communication state between controllers is monitored(S106). The regenerative braking optimization routine is performed(S107). Each controller performs a general operation such as braking or acceleration(S109).

Description

Control method of regenerative braking of vehicle in case of communication error {CONTROLLING METHOD FOR REGENERATATIVE BREAKING OF VEHICLES UNDER THE BUS-OFF CONDITION}

The present invention relates to a regenerative braking control method of a vehicle, and more particularly, to a regenerative braking control method of a vehicle implemented to perform regenerative braking with a corrected regenerative braking control amount when a regenerative control error due to a communication error of a second period provided in a vehicle is performed. It is about.

In response to environmental protection demands, the demand for electric vehicles has surged. Such an electric vehicle has almost no exhaust gas and has a very small noise because a secondary battery (cell) capable of charging and discharging uses a battery formed as a pack as a main power source.

In general, electric vehicles use a part of braking force for braking power for braking, and generate electric energy for charging batteries. Currently, electric vehicles use pure electric vehicles only as a power source. And a power source generated by the engine of the internal combustion engine is divided into a hybrid electric vehicle (HEV) used for charging a battery and / or driving a vehicle.

As a braking method of an electric vehicle, braking which simultaneously reduces the kinetic energy (ie, decreases the running speed) and generates electric energy by using a part of kinetic energy proportional to the traveling speed as the energy required to drive the generator. Method can be used. This method of braking is called regenerative braking.

For example, a hybrid electric vehicle (HEV) receives an output by an electric motor powered by a battery when starting or driving at a low speed, and a driving wheel rotates. In a normal driving, a combination of an internal combustion engine and an electric motor is performed according to the vehicle speed. Operation is made. In particular, during high speed operation, power is supplied to the electric motor to assist the power of the internal combustion engine so that the power of the internal combustion engine and the electric motor rotates the driving wheel (W). And when deceleration or regenerative braking, the electric motor is used as a generator to recharge the battery to recover energy, and when stopped, it automatically stops to reduce unnecessary fuel consumption and exhaust gas.

In the regenerative braking braking method, the generation of electric energy may be performed by using a separate generator or by reverse driving a provided motor. By using the regenerative braking control when braking the electric vehicle, not only the mileage of the electric vehicle can be improved, but also in the case of a hybrid electric vehicle, it is possible to further reduce the emission of harmful exhaust gas while improving fuel economy.

 On the other hand, a hydraulic brake system for generating a braking force by hydraulic pressure is also provided in an electric vehicle. This is because the regenerative braking force alone does not provide sufficient braking effect, and such regenerative braking force is generated only in the driving wheels connected to the motor.Because the braking of the driving wheels alone does not provide desirable vehicle dynamics control, the hydraulic braking system This is necessary. In this regard, referring to FIG. 1, FIG. 1 shows a ratio of hydraulic braking control ratio and regenerative braking control in general regenerative braking. As shown, the braking force in the regenerative braking of the vehicle is the sum of the hydraulic braking torque and the regenerative braking torque.

 In the steady state, the braking force (brake pedal operation) desired by the driver during regenerative braking is the sum of the hydraulic braking torque and the regenerative braking torque. When the hydraulic braking force that generates heat energy due to the friction between the disk and the pad does not achieve the desired regenerative braking force due to the limitations of the motor and the battery, the braking force fills the difference, and the regenerative braking force reduces the driving motor for driving. At the same time, it generates a braking force by operating as a generator and at the same time, the generated power is stored in the battery.

 In general, the motor of an electric vehicle acts as a generator and generates braking force for the entire vehicle. If the braking force is not controlled in conjunction with a general brake (eg, a conventional hydraulic brake) device, the driver may use a regenerative braking system when braking. Not only will you feel the deceleration as much as the braking force, you will not get the desired braking feeling, but you will always feel the braking when the motor develops.

 In order to prevent this, a braking force cooperative control is required between the regenerative braking torque controller responsible for regenerative braking of the motor and the hydraulic braking torque controller of the brake device. However, in the steady state, when an error occurs in the data communication between the regenerative braking torque controller and the hydraulic braking torque controller (eg, error, short circuit, etc.), the hydraulic braking torque increases rapidly and at the same time, the regenerative braking The torque drops sharply close to '0', which greatly reduces the sense of braking.

In view of this, U.S. Patent 6,086,166 discloses a braking torque control system having a regenerative braking torque controller and a friction braking torque controller, and the braking torque control system is a hydraulic braking torque control period for performing friction braking with the regenerative braking torque controller. If an abnormality occurs in the data communication, the total braking torque is controlled, but the control is performed to reduce the target regenerative braking torque. That is, US Pat. No. 6,086,166 discloses the effect of reducing the braking force or preventing the change of braking feeling in case of failure (error, short circuit, etc.) due to an error in data can communication between the regenerative braking torque controller and the hydraulic braking torque controller performing friction braking. To this end, a braking control technique is disclosed in which the regenerative braking torque generated by the motor is gradually reduced until the end of braking, and the hydraulic braking torque is gradually increased until the end of the braking. However, when the can communication fails, as the regenerative braking torque is reduced in this way, the energy recovery rate due to motor generation is reduced, and in reality, it is very difficult to control the hydraulic pressure accurately matching the reduction or increase of the regenerative braking torque with the hydraulic braking torque. In conclusion, there is a problem that the variation of braking feeling occurs according to the variation of regenerative braking torque and hydraulic braking torque.

 On the other hand, as a technique related to normal regenerative braking, Japanese Patent Laid-Open No. 11-004503 discloses a structure for reducing the regenerative braking torque of the regenerative braking device when an error occurs in information exchange between the regenerative braking device and the friction braking device. .

 In addition, Korean Patent Publication No. 2002-0091799 discloses a braking force control device that reduces the target regenerative braking force and increases the target friction braking force when anti-skid control is started during braking operation, and sets the target regenerative braking force to zero when anti skid control is started. Initiate. In other words, instead of abruptly reducing the regenerative braking force to zero at the stage where anti skid control is initiated, the anti skid control is gradually reduced by gradually reducing the regenerative braking force and gradually increasing the friction braking force at the stage where anti skid control may be initiated. It is disclosed to prevent a sudden change in the vehicle deceleration at the start.

In addition, Japanese Laid-Open Patent Publication No. 07-149209 discloses an apparatus for warning an abnormality of a regenerative apparatus by intermittently regulating the clutch connecting the regenerative apparatus and the drive system when an abnormality occurs in the regenerative apparatus.

In addition, Japanese Laid-Open Patent Publication No. 2000-156901 calculates the regenerative amount periodically according to the remaining capacity of the battery and the operation state of the motor, and sets the regenerative torque of the motor from the brake torque and the regenerative amount during brake operation to control the brake and the motor. Initiate the structure.

Furthermore, Korean Patent Laid-Open Publication No. 2010-0820489 discloses a method designed to recover more braking force by reducing the amount by reflecting the depth and duration of a brake stroke during braking operation.

However, in the above-described improvement methods, when the can communication fails or a failure in which regenerative control is difficult, the regenerative braking amount decreases, so that the battery charge amount is limited accordingly.

Thus, according to the embodiment of the present invention, when a regenerative braking of an electric vehicle is generated, each controller provided in the vehicle regenerates based on the regenerative control amount of the controllers provided in the vehicle and the driving state of each controller before the regenerative braking. The present invention provides a regenerative braking control method implemented to selectively perform a braking routine.

In addition, the embodiment of the present invention, when the failure of the regenerative braking of the electric vehicle is restored, immediately after the failure is restored by restoring the regenerative braking state of each controller provided in the vehicle to a predetermined previous regenerative braking state instead of the initialization state. Another object of the present invention is to provide a regenerative braking control method implemented to enable normal operation of each controller.

A regenerative braking control method for a vehicle according to an exemplary embodiment of the present invention includes determining whether regenerative braking is entered; Calculating and storing the regenerative braking control amount of the traveling controller HCU, the regenerative braking control amount of the electronic brake system EBS, and the regenerative braking control amount of the driving motor controller when the regenerative braking is entered; When a communication failure occurs, each controller includes determining a regenerative braking routine to be performed based on the regenerative braking control amount stored before the operation failure immediately before the regenerative braking and the communication failure.

In an embodiment, the regenerative braking routine is one of a gradual regenerative braking reduction routine, a regenerative braking maximizing routine, and a regenerative braking optimization routine.

In an embodiment, the regenerative braking maximizing routine is performed according to the output curve during motor regenerative braking, and the regenerative braking optimization routine is performed according to the regenerative braking control amount predicted using an extrapolation function.

The method may further include restoring a state of the controller to a predetermined state of the previous regenerative braking when the communication failure is recovered during the execution of the regenerative braking maximization routine or the regenerative braking optimization routine.

The method may further include initializing the regenerative braking state of the controller to '0' when the communication failure is recovered during the execution of the gradual regenerative braking reduction routine.

In addition, the regenerative braking control method of the vehicle according to an embodiment of the present invention, the step of determining whether or not to enter the regenerative braking; Storing the regenerative braking control amount of the travel controller HCU, the regenerative braking control amount of the electronic brake system EBS, and the regenerative braking control amount of the drive motor controller MCU when the regenerative braking is entered; Determining a regenerative braking routine to be performed by each controller based on an operating state before entering regenerative braking and a motor regenerative braking state before a failure occurs when a failure occurs; Performing regenerative braking of each controller according to the determined routine; Upon failure recovery, restoring the operation state of each controller to a predetermined operation state before the occurrence of a predetermined failure.

In an embodiment, the regenerative braking routine is one of a gradual regenerative braking reduction routine, a regenerative braking maximizing routine, and a regenerative braking optimization routine.

In an embodiment, the performing may further include storing a history of the corrected regenerative braking control amount as a result of performing the determined routine.

In addition, the regenerative braking control method of the vehicle according to the present invention, when the communication failure between the controller after the entry of the regenerative braking of the vehicle, the driving state of the vehicle pre-stored before entering the regenerative braking and each controller previously stored before the communication failure occurs Based on the regenerative braking control amount of, the regenerative braking of each controller is independently performed.

In addition, the regenerative braking control method of the vehicle according to the present invention comprises the steps of: storing the history of the driving data; Determining whether to enter regenerative braking based on the history of the operation data; Storing the regenerative braking control amount of the travel controller HCU, the regenerative braking control amount of the electronic brake system EBS, and the regenerative braking control amount of the drive motor controller MCU when the regenerative braking is entered; Determining whether a failure occurs based on an operation state of each controller; Upon determining a fault, each controller selectively selects one of a gradual regenerative braking reduction routine, a regenerative braking maximizing routine, and a regenerative braking optimization routine based on an operating state before regenerative braking and a motor regenerative braking state before a failure occurs. It comprises a step of performing.

In an embodiment, the driving data may include an increase in speed while driving the vehicle and an application time of the accelerator pedal before braking.

In an embodiment, the performing of the controller may include: performing the regenerative braking maximization routine or the regenerative braking optimization routine when the speed increase while driving the vehicle and the accelerator pedal application time before braking are within a normal range when the obstacle is determined. It is characterized by the steps.

In an embodiment, the performing may include: performing the regenerative braking maximization routine along an output curve if the motor regenerative braking state is within the maximum regenerative braking control amount curve, and performing an extrapolation function if the motor regenerative braking state is within the isooutput curve. And performing the regenerative braking optimization routine for predicting the braking force by using

In an embodiment, the performing of the step may include: when the failure is determined, if the speed increase during driving of the vehicle or the accelerator pedal application time before braking exceeds the normal range, the regenerative braking control ratio is decreased and the hydraulic control ratio is increased. Characterized in that the step of performing a regenerative braking reduction routine.

Embodiments of the present invention, when the regenerative braking failure, the controller selectively determines the regenerative braking routine based on the regenerative control amount of the controller EBS, HCU, and MCU and the operating state before regenerative braking. As a result, the reduction of the regenerative braking amount can be more reliably prevented and the regenerative braking control amount can be optimized according to the driving state of the vehicle.

In addition, embodiments of the present invention, by recovering the regenerative braking state of the controller EBS, HCU, and MCU provided to a predetermined previous regenerative braking state when the recovery of the regenerative braking failure, it is possible to immediately operate the vehicle, It is advantageous to charge the battery and improve the fuel economy of the vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram showing a ratio of a hydraulic braking control ratio and a regenerative braking control in general regenerative braking.
2 is a flowchart showing an example of a regenerative braking control method of a vehicle according to an embodiment of the present invention;
3 is a diagram illustrating a process of performing a regenerative braking maximization routine in the regenerative braking control method according to an embodiment of the present invention;
4 is a diagram illustrating a process of performing a regenerative braking optimization routine in the regenerative braking control method according to an exemplary embodiment of the present invention.

Hereinafter, the regenerative braking control method for a vehicle according to the present invention will be described in detail with reference to the accompanying drawings.

First, FIG. 2 shows an example of a regenerative braking control method of a vehicle in case of communication error, according to an embodiment of the present invention.

The present invention relates to a regenerative braking control method of a vehicle. When determining whether regenerative braking is entered and determining that regenerative braking is entered, each controller provided in the vehicle, that is, a traveling controller (HCU) and an electronic brake system ( EBS) and each regenerative braking control amount of the drive motor controller (MCU) are calculated and stored, respectively. Then, when a communication failure occurs in each of the control periods, each controller determines a routine of regenerative braking to be performed based on the regenerative braking control amount stored before the occurrence of the communication failure and the stored braking control amount before the occurrence of the communication failure.

At this time, the regenerative braking routine to be performed by each controller includes a gradual regenerative braking reduction routine, a regenerative braking maximizing routine, and a regenerative braking optimization routine, and each controller stores the regenerative stored state immediately before the regenerative braking entry and the communication failure. Based on the braking control amount, one of the above-described routines is selectively performed. The progressive regenerative braking reduction routine, the regenerative braking maximizing routine, and the regenerative braking optimization routine will be described in more detail below with reference to FIGS. 2 and 3.

As described above, according to the regenerative braking control method of the vehicle, in case of a regenerative braking control failure caused by a failure such as communication between the controllers, the controller EBS, the HCU, and the MCU can independently control the regenerative braking. The control routine of the regenerative braking to be performed may be determined according to a situation immediately before the regenerative braking control failure (bus off) and an operation situation before entering the regenerative braking. In addition, by regulating the regenerative braking control amount so that each controller can be restored to its previous state in case of failure recovery, it is possible to maximize the regenerative braking control amount of the vehicle in case of communication failure, and also contribute to the fuel efficiency of the vehicle due to the battery charging strategy. In addition, stability can be pursued at the same time.

Hereinafter, the regenerative braking control method of the vehicle will be described in more detail with reference to the flowchart of FIG. 2.

In the preferred embodiment of the present invention, the regenerative braking control method, as shown in the drawing, first determines whether to enter the regenerative braking. The determination of whether to enter the regenerative braking is performed based on previously stored vehicle driving data. In this case, the vehicle driving data, in particular, indicates information including the speed increase during the other traveling time and the acceleration pedal application time before braking (S101). If it is determined that regenerative braking has not been entered, the regenerative braking control amount is regarded as '0' and the vehicle continues to operate normally.

When it is determined in step S101 that the regenerative braking has been entered, the driving controller (hereinafter referred to as HCU), the electronic brake system (hereinafter referred to as EBS), and the driving motor controller (hereinafter referred to as MCU) that executes the regenerative braking, respectively The regenerative braking control amount is stored, and the operation state of each controller is monitored to determine whether communication between the controllers HCU, EBS, and MCU is in a failure state (bus off) during the execution of the regenerative braking (S102).

If a failure occurs in the bus off during the regenerative braking, that is, the communication between the controllers, the regenerative braking routine to be executed by the controller is selected based on driving data of the vehicle stored before the regenerative braking. That is, it determines the routine to be executed during gradual regenerative braking reduction / regenerative braking maximization / regenerative braking optimization routine according to the motor regenerative braking condition in the operation state before the regenerative braking and the fault (bus off) condition. In operation S103, the regenerative braking routine to be performed is determined using the accelerator pedal application time before braking.

Here, the type of bus off or failure associated with the regenerative braking may include a HCU can failure, an EBS can failure, an ABS failure, and the like. The failure or failure may be detected by, for example, an EBS controller. More specifically, the EBS detects this as a communication failure or failure when the regenerative braking control amount signal is not received for a predetermined time through can communication.

In an embodiment, when the speed increase while driving the vehicle or the accelerator pedal application time before braking exceeds the normal range, for example, when the speed increase application while driving the vehicle is 1 or less, or when the acceleration pedal application time before braking is 1 or less, regenerative braking control Decreases the ratio and increases the ratio of hydraulic control. This regenerative braking control routine corresponds to a gradual regenerative braking reduction routine (gradual hydraulic braking increasing routine), and is shown in step S106. Here, the value 1 corresponds to a reference value for which the speed increase or the pre-braking accelerator pedal application time requires continuous execution of regenerative braking control.

As a result of monitoring the communication state between the controllers, the above step S106 is repeated until the communication abnormal state between the controllers is released. If the bus-off state is canceled as a result of the monitoring, the regenerative braking control amount is initialized to "0" and the regenerative braking is terminated.

On the other hand, when the regenerative braking is entered, but the bus off does not occur as a result of the determination in step S102, each controller does not need to selectively perform the regenerative braking control routine, and performs the normal regenerative braking as in the prior art. Just do it.

In another embodiment, the controller (eg, HCU, EBS, or MCU) is configured to either the regenerative braking maximization routine or the regenerative braking optimization routine, provided that the acceleration pedal application time prior to braking and the acceleration increase before braking are within the normal range. Do one.

More specifically, in one embodiment, if the motor regenerative braking state was on the maximum regenerative braking control amount curve, the "regenerative braking maximizing routine" is performed along the output curve after the communication error. If the motor regenerative braking state is within the constant output curve, the regenerative braking optimization routine for predicting the braking force of the vehicle using the extrapolation function is performed.

As such, when a communication error occurs between the controllers during the regenerative braking of the vehicle, one of the following regenerative braking routines is performed according to a predetermined criterion. First, ① If the regenerative braking state of the motor is on the maximum regenerative braking control amount curve regardless of the driving condition of the vehicle, the regenerative braking of the vehicle is controlled along the output curve (regenerative braking maximization routine), and ② the driving strategy of the vehicle is normal. Extrapolation is maintained when the speed of change (e.g. speed increase during braking, just before braking> 1, acceleration pedal before braking / preset threshold> 1) and the regenerative braking state of the motor is within the constant output curve. The trend of the braking force is maintained by an extrapolation function (regenerative braking optimization routine). In addition, if the driving condition of the vehicle frequently decelerates or runs in a natural deceleration section such as a slope, the vehicle driving stability is improved by increasing the hydraulic control ratio and reducing the regenerative braking ratio according to the conventional method. (Gradual regenerative braking reduction routine).

3 and 4 show the performance of the regenerative braking maximization routine and the regenerative braking optimization routine.

First, a process of performing the regenerative braking maximization routine will be described in detail with reference to FIG. 3. For at least one of the controllers (eg, HCU, EBS, or MCU) provided in the vehicle, if the regenerative braking state of the motor exists on the maximum regenerative braking control amount curve, the regenerative braking of the controller is performed along the output curve (S110). ). Such regenerative braking is repeated until the vehicle stops running. If the vehicle is stopped while regenerative braking is being performed, the regenerative braking maximizing routine is terminated.

Furthermore, the process of performing the regenerative braking optimization routine will be described in detail with reference to FIG. 4. As the condition of the regenerative braking optimization routine, the driving state of the vehicle is maintained within a normal speed change range, and the regenerative braking state of the motor is equally output for at least one of the controllers (eg, HCU, EBS, or MCU) provided in the vehicle. When present in the curve, the extrapolation function is applied to calculate the regenerative braking control amount to optimize the regenerative braking.

Here, the extrapolation function calculates the value of the function using data outside the range of given basic values, and generally aims to obtain an approximation function when the data value is not known correctly. In the regenerative braking control method according to the present invention, for example, by applying a least mean square (LMS) algorithm, it is possible to predict the braking force of the vehicle required by using the following first equation (S111).

Y = a + bX

Here, the b value is b = (n∑XY-∑X∑Y) / (n∑X ^ 2- (∑X) ^ 2), and the a-value is a = (∑Y / n) -b ( ΣX / n).

Based on the estimated braking force calculated using such extrapolation function, regenerative braking of the vehicle is performed with the corrected regenerative braking control amount. Such regenerative braking is repeated until the vehicle stops running. On the other hand, if the vehicle stops while the regenerative braking is performed, the regenerative braking optimization routine ends.

Referring to FIG. 2 again, as described above, the regenerative braking control method according to the present invention includes a regenerative braking routine to be performed by the controller based on driving data of a vehicle stored before the regenerative braking before a bus off occurs during regenerative braking of the vehicle. Select. That is, the regenerative braking routine to be performed by each controller is determined during the gradual regenerative braking reduction / regenerative braking maximization / regenerative braking optimization routine according to the motor regenerative braking in the operation state before the regenerative braking and the failure (bus off) condition. At this time, the regenerative braking routine is determined using driving data values such as the speed increase during the driving time and the acceleration pedal application time before braking (S103). For example, the acceleration increase before the vehicle or the acceleration pedal before braking is applied. If the time is within the normal range (the value where the speed increase and the pre-braking accelerator pedal application time exceed a preset threshold value 1), the flow advances to step S104. That is, in the embodiment of the present invention, if the speed increase while the vehicle is running and the accelerator pedal application time before braking are within the normal range, the corresponding controller performs the regenerative braking maximization routine or the regenerative braking optimization routine.

At this time, if the motor is performing the maximum regenerative braking, the process moves to step S105 to perform the regenerative braking maximization routine. That is, in the embodiment according to the present invention, if the motor regenerative braking state is on the maximum regenerative braking control amount curve, the regenerative braking maximizing routine is performed along the output curve. Since the detailed procedure of performing the maximum regenerative maximization routine has been described in detail with reference to FIG. 3, the description thereof will be omitted. The execution of this regenerative braking maximization routine is performed until the communication failure of the controller, i.e., the bus off is released. When the bus is released, the controller senses this and each controller (HCU, EBS, or MCU) performs a general driving operation at a predetermined regenerative braking control amount or regenerative braking control position. That is, when recovering from a communication failure, each controller recovers together with the regenerative braking control amount in the state of predicting the same value individually and then performs a general driving operation such as acceleration after braking or stopping (S109).

On the other hand, if the motor is not at the maximum regenerative stage in step S104, the flow advances to step S107 to perform the regenerative braking optimization routine. In an embodiment according to the present invention, if the motor regenerative braking state is within the constant output curve, a regenerative braking optimization routine for predicting braking force is performed using an extrapolation function. In other words, when the motor is performing the normal regenerative braking according to the power generation characteristic curve, but the normal regenerative braking is performed, the regenerative braking control amount is estimated by extrapolating the interpolation function by reflecting the existing trend as shown. Perform the regenerative braking (S107). Similarly, since the detailed execution process of the regenerative braking optimization routine has been described in detail with reference to FIG. 4, a description thereof will be omitted.

The execution of the regenerative braking maximization routine is performed until the communication failure of the controller, that is, until the bus off is released, and when the bus off is released, the controller senses this and each controller (HCU, EBS, or MCU) is determined in advance. Perform general driving operations in the regenerative braking control amount or regenerative braking control position. That is, when recovering from a communication failure, each controller recovers together with the regenerative braking control amount in the state of predicting the same value individually and then performs a general driving operation such as acceleration after braking or stopping (S109).

Therefore, according to the regenerative braking control method of the vehicle according to the present invention, more accurate regenerative braking control is possible, which is advantageous for charging the battery of the vehicle and also improving vehicle fuel economy. In addition, when a disturbance (bus-off) occurs due to a communication error between controllers during regenerative braking of the vehicle, it is possible to improve the limitation of the battery charge amount of the vehicle due to the reduction of the conventional regenerative braking amount. When the communication is restored, the regenerative braking control amount is not always restored to the initial value but instead is restored to the regenerative braking control amount in a predetermined state, thereby contributing to the stability of the vehicle.

A first embodiment of a regenerative braking control method for a vehicle according to the present invention is as follows. First, it is determined whether regenerative braking is entered. For example, if it is determined based on the driving data of the vehicle, and it is determined that the regenerative braking is entered, the regenerative braking control amount of the travel controller HCU, the regenerative braking control amount of the electronic brake system EBS, and the regenerative driving motor controller MCU are determined. Calculate the braking control amount and store each. At this time, when a failure occurs in communication between the controllers, each controller (HCU, EBS, and MCU) performs a routine of regenerative braking to be performed based on the operation state immediately before the regenerative braking entry and each regenerative braking control amount stored before the communication failure occurs. Determine each one.

Here, the type of bus-off associated with the regenerative braking may include a HCU can failure, an EBS can failure, an ABS failure, and the like, or the failure may be detected by the EBS controller, for example. More specifically, the EBS may detect the communication failure or failure if it does not receive the regenerative braking control amount signal for a predetermined time through the can communication.

Here, the possible regenerative braking routine to be performed by the controller is as follows. First, there is a gradual regenerative braking reduction routine. The gradual regenerative braking reduction routine may be performed when the speed increase during vehicle driving or the acceleration pedal application time before braking exceeds the normal range, for example, when the speed increase during vehicle driving is 1 or less, or the acceleration pedal application time before braking is 1 or less. In other words, the regenerative braking routine refers to a method of reducing the rate of regenerative braking control and further increasing the rate of hydraulic control.

When the acceleration pedal application time before braking "and" braking is within the normal range, each controller (e.g., HCU, EBS, or MCU) performs either the regenerative braking maximization routine or the regenerative braking optimization routine.

More specifically, the second routine is a regenerative braking maximizing routine, which refers to the regenerative braking routine in which the regenerative braking is performed along the output curve even after a communication failure occurs if the motor regenerative braking state is on the maximum regenerative braking control amount curve. Furthermore, the third routine includes a regenerative braking optimization routine, which is a case where the motor regenerative braking state is in the constant output curve, and uses the extrapolation function for the approximation function prediction to estimate the braking force of the vehicle. Point.

When communication between the controllers occurs after the regenerative braking is started, each controller determines one of the above-described first routine, second routine, and third routine based on the previous operation state and the calculated regenerative braking control amount. .

Further, if the communication failure between the controllers is restored during the execution of the regenerative braking maximization routine or the regenerative braking optimization routine, the state of the controller can be restored to a predetermined state of the previous regenerative braking. In this way, when the failure recovery of the controller after entering the regenerative braking, the regenerative braking state of the controller is restored to the previously determined regenerative braking state when the failure is not the initial state, thereby contributing to the stability of the vehicle.

On the other hand, when the communication failure between the controllers is restored during the execution of the gradual regenerative braking reduction routine, the regenerative braking state of the controller is initialized to '0' and then general operation is performed, which is the same as the conventional regenerative braking control method.

A second embodiment of the regenerative braking control method according to the present invention is as follows. First, it is determined whether regenerative braking is entered. When it is determined that the regenerative braking is entered, the regenerative braking control amount of the travel controller HCU, the regenerative braking control amount of the electronic brake system EBS, and the regenerative braking control amount of the driving motor controller MCU are calculated and stored, respectively. At this time, when the regenerative braking fault occurs, the regenerative braking routine to be performed by each controller is determined based on the operation state before the regenerative braking entry and the motor regenerative braking state before the regenerative braking fault occurs. The controller of performs regenerative braking. Then, when the failure of the regenerative braking is restored, the operation state of each controller is restored to the operation state before the occurrence of the predetermined failure.

Here, the regenerative braking routine may be determined as one of a gradual regenerative braking reduction routine, a regenerative braking maximizing routine, and a regenerative braking optimization routine. The execution of each routine is described in detail above.

In addition, each controller may store a history of the regenerative braking control amount corrected according to the determined execution result of the routine, or may update and store a memory (not shown) having the most recently corrected regenerative braking control amount. The stored regenerative braking control amount may be used as the regenerative braking state value or the regenerative braking position value in the failure recovery of the controller.

A third embodiment of the regenerative braking control method according to the present invention is as follows. First, a history of operation data of each controller is stored. In an embodiment according to the present invention, the driving data may be driving data values including speed increase during driving of the vehicle and acceleration pedal application time before braking. Then, it is determined whether to enter regenerative braking based on the history of the operation data. When it is determined that the regenerative braking is entered, the regenerative braking control amount of the travel controller HCU, the regenerative braking control amount of the electronic brake system EBS, and the regenerative braking control amount of the driving motor controller MCU are calculated and stored, respectively. Each controller determines whether a failure occurs, for example, a communication failure or error, based on its operation state. If it is determined that a fault has occurred, each controller may determine one of a gradual regenerative braking reduction routine, a regenerative braking maximizing routine, and a regenerative braking optimization routine based on the operating state before the regenerative braking entry and the motor regenerative braking state before the failure. Optionally.

In the routine selection of each controller when a failure occurs, each controller performs a regenerative braking maximization routine or a regenerative braking optimization routine if the speed increase during vehicle driving and the accelerator pedal application time before braking are within a normal range.

In case of failure, when selecting the routine of each controller, if the motor regenerative braking state exists on the maximum regenerative braking control amount curve, the regenerative braking maximization routine following the output curve is performed. When the motor regenerative braking state exists within the iso output curve, Perform extra regenerative braking optimization routine to estimate braking force using extrapolation function.

On the other hand, in selecting a routine of each controller when a failure occurs, if the speed increase during vehicle driving or the acceleration pedal application time before braking exceeds the normal range, the regenerative braking reduction routine decreases the regenerative braking control ratio and increases the hydraulic control ratio. In this way, by allowing each controller to individually select and execute a routine in the event of a failure, it is possible to more reliably prevent the reduction of the existing regenerative braking amount and to optimize the regenerative braking control amount according to the driving state of the vehicle.

As described above, according to the regenerative braking control method of the vehicle according to an embodiment of the present invention, when the regenerative braking of the vehicle is disturbed, each regenerative control amount and the regenerative braking before the controller EBS, HCU, and MCU provided in the vehicle By allowing each controller to selectively determine and perform the regenerative braking routine based on the operating state of the controller, regenerative braking is performed by the regenerative braking control amount of optimization, and the regenerative braking amount is reduced when a failure occurs in each control period. It can prevent more reliably. In addition, when the regenerative braking failure is restored, the regenerative braking state of the EBS, HCU, and MCU is restored to a predetermined previous regenerative braking state so that each controller can immediately perform normal operation, which is advantageous for charging the battery of the vehicle. The vehicle's fuel economy is also improved.

Claims (14)

Determining whether to enter regenerative braking;
Calculating and storing the regenerative braking amount of the electronic brake system EBS and the regenerative braking amount of the driving motor controller when the regenerative braking is entered; And
In the event of a communication failure, the EBS and the MCU may respectively determine a routine of regenerative braking to be performed based on the speed increase and acceleration pedal application time while driving the vehicle immediately before the regenerative braking is entered and the regenerative braking amount stored before the communication failure occurs. Characterized by
Regenerative braking control method of vehicle. The method according to claim 1,
The regenerative braking routine is any one of a gradual regenerative braking reduction routine, a regenerative braking maximizing routine, and a regenerative braking optimization routine.
Regenerative braking control method of vehicle. The method of claim 2,
The regenerative braking maximization routine is performed along the output curve during motor regenerative braking, and the regenerative braking optimization routine is performed within a range of an output curve predicted from the history of the previous regenerative braking amount.
Regenerative braking control method of vehicle. The method of claim 2,
When the communication failure is restored during the execution of the regenerative braking maximization routine or the regenerative braking optimization routine, further comprising restoring the states of the EBS and the MCU to a predetermined state of the regenerative braking.
Regenerative braking control method of vehicle. The method of claim 2,
If the communication failure is recovered during the execution of the gradual regenerative braking reduction routine, further comprising the step of initializing the regenerative braking amount to '0',
Regenerative braking control method of vehicle. Determining whether to enter regenerative braking;
Calculating and storing the regenerative braking amount of the electronic brake system EBS and the regenerative braking amount of the driving motor controller when the regenerative braking is entered;
Determining a regenerative braking routine to be performed by the EBS and the MCU based on the speed increase and acceleration pedal application time while driving the vehicle before entering the regenerative braking and the motor regenerative braking state prior to the occurrence of the failure;
Performing regenerative braking by the EBS and the MCU according to the determined routine; And
And recovering the state of the EBS and the MCU to a state of regenerative braking before a predetermined fault occurs during the fault recovery.
Regenerative braking control method of vehicle. The method of claim 6,
The regenerative braking routine is any one of a gradual regenerative braking reduction routine, a regenerative braking maximizing routine, and a regenerative braking optimization routine.
Regenerative braking control method of vehicle. The method of claim 6,
The step of performing,
And storing a history of the corrected regenerative braking amount as a result of performing the determined routine.
Regenerative braking control method of vehicle. When a communication failure occurs between the electronic brake system (EBS) and the driving motor controller (MCU) after the regenerative braking of the vehicle, before the regenerative braking, the speed increase and acceleration pedal application time stored before driving the vehicle and before the occurrence of the communication failure On the basis of the regenerative braking amount of the EBS and MCU stored in advance, characterized in that to perform the regenerative braking of the EBS and MCU independently,
Regenerative braking control method of vehicle. Storing a history of driving data;
Determining whether to enter regenerative braking based on the history of the operation data;
Storing the regenerative braking amount of the electronic brake system EBS and the regenerative braking amount of the drive motor controller MCU when the regenerative braking is entered;
Determining whether failure of the EBS and MCU occurs;
In determining the fault, the EBS and MCU are based on the speed increase and acceleration pedal application time before driving the regenerative braking and the motor regenerative braking state prior to the occurrence of the fault, and the progressive regenerative braking reduction routine, the regenerative braking maximizing routine, and the regenerative braking. Selectively performing any one of the braking optimization routines,
Regenerative braking control method of vehicle. The method of claim 10,
The driving data may include an increase in speed while driving the vehicle and an accelerator pedal application time before braking.
Regenerative braking control method of vehicle. The method according to claim 10 or 11, wherein
The step of performing,
In determining the obstacle, if the speed increase while driving the vehicle and the acceleration pedal application time before braking are within the normal range, the EBS and MCU perform the regenerative braking maximization routine or the regenerative braking optimization routine.
Regenerative braking control method of vehicle. delete The method according to claim 10 or 11, wherein
The step of performing,
In determining the obstacle, if the speed increase during driving of the vehicle or the acceleration pedal application time before braking exceeds the normal range, the gradual regenerative braking reduction routine of reducing the regenerative braking control ratio and increasing the hydraulic control ratio is performed. ,
Regenerative braking control method of vehicle.

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