KR100836308B1 - Control method of hybrid electric vehicle in oil pump/can fail - Google Patents

Abstract

A control method for CAN(Controller Area Network) communication and electric oil pump fails of an HEV(Hybrid Electric Vehicle) is provided to supply the sufficient amount of working fluid to an engine clutch and a transmission if a CAN communication line or an electric oil pump is defective, by controlling the transmission, a driving motor, and the high-speed operation of the electric oil pump. A control method for CAN communication and electric oil pump fails of an HEV comprises the steps of: supplying working fluid by forcibly controlling a pump driving motor at high speed in two stages by a P-MCU(Motor Control Unit,16) detecting a CAN communication fail, if a CAN communication fail between controllers of the HEV is detected and the P-MCU determines that an electric oil pump(6) and the pump driving motor are normal; judging whether vehicle speed exists or not, from a signal of a vehicle speed sensor by an HCU(Hybrid Control Unit,11) receiving a motor fail from the P-MCU, if CAN communication is normal and the P-MCU determines that the pump driving motor is broken down; and forcibly changing the gear level of an automatic transmission(5) to an N-stage according to a command of the HCU by a TCU(Transmission Control Unit,17) if vehicle speed does not exist, rotating a vehicle driving motor(4) according to a command of the HCU by the MCU, and supplying working fluid by operating the mechanical oil pump of the automatic transmission by driving of the driving motor.

Description

Control method of hybrid electric vehicle in oil pump / CAN fail}

1 is a block diagram showing a control relationship between each controller and the oil pump in a hybrid electric vehicle,

2 is a system configuration diagram for performing a control process according to the present invention;

3 is a flowchart illustrating a control process according to the present invention.

<Explanation of symbols for the main parts of the drawings>

3: engine clutch 4: drive motor

5: automatic transmission 6: external electric oil pump

7: Mechanical oil pump 10: CAN communication line

11: HCU 15: MCU

16: P-MCU 17: TCU

18, 19, 21: communication wire

The present invention relates to a control method of a can communication and an electric oil pump failure of a hybrid electric vehicle, and more particularly, to control the transmission and the driving motor when the can communication line or the electric oil pump is broken, and to control the high speed operation of the electric oil pump. By allowing a sufficient amount of hydraulic oil to be supplied to the engine clutch and the transmission through the can, the communication of the can of the hybrid electric vehicle that can effectively prevent the occurrence of abnormal operation of the engine clutch and the transmission that may occur due to insufficient supply of the hydraulic oil. And it relates to a control method when the electric oil pump failure.

In general, a hybrid vehicle in a broad sense means to drive a vehicle by efficiently combining two or more different power sources, but in most cases, a driving force is driven by an electric motor driven by an engine and a battery power that use a fuel to obtain driving power. Means a vehicle to obtain, it is called a hybrid electric vehicle (HEV).

In response to the recent demand for improving fuel economy and developing more environmentally friendly products, research on hybrid electric vehicles is being actively conducted.

Hybrid electric vehicles can form a variety of structures using engines and electric motors as power sources. Most of the vehicles studied so far employ either parallel or in series.

Among them, the parallel type is used to charge the battery but directly drive the vehicle together with the electric motor. However, the parallel type has the disadvantage that the structure is relatively more complicated than the series type and the control logic is more complicated. Since the electric energy of the battery can be used at the same time, the energy can be efficiently used.

In particular, by using the optimum operating area of the engine and the electric motor can improve the fuel efficiency of the entire drive system, as well as recover energy from the electric motor during braking, it is possible to use the efficient energy.

In addition, the hybrid electric vehicle is equipped with a vehicle control unit (hybrid control unit) for controlling the overall vehicle, and also has a controller for each device constituting the system.

For example, an engine control unit (ECU) for controlling the overall operation of the engine, a motor control unit (MCU) for controlling the overall operation of the electric motor, a transmission control unit (TCU) for controlling the transmission In addition, a battery controller (Battery Management System (BMS)) for controlling the operation of the battery, an air conditioner controller (Full Auto Temperature Controller, FATC) for controlling the room temperature is provided.

These controllers are connected to the high-speed CAN communication line around the vehicle controller, which is the upper controller, so that the upper controller transmits commands to the lower controller while transmitting and receiving information between the controllers.

As described above, in the hybrid electric vehicle, a plurality of controllers including the HCU as the upper controller perform cooperative control with each other.

For example, the HCU exchanges information with each controller through CAN communication and also controls subordinate controllers. The HCU communicates with the engine ECU from the engine ECU with engine torque and engine speed information, start key information, throttle / coolant On information is received, and the HCU is further configured to transmit fuel injection command, engine stop command, fuel injection prohibition command, electric motor start information, idle stop information, and the like to the engine ECU.

In addition, the HCU substantially controls the driving of the electric motor through the MCU. At this time, the MCU maintains the driveability by controlling the driving torque and the driving speed of the electric motor as the driving source according to the control signal applied from the HCU which is the upper controller.

As described above, cooperative control between controllers is very important in a hybrid electric vehicle. Such cooperative control between the controllers is performed in all cases from the start until the user turns off the ignition key.

On the other hand, in a hybrid electric vehicle is provided with an external electric oil pump for supplying the necessary hydraulic fluid to the engine clutch and the transmission interposed between the engine and the drive electric motor (hereinafter referred to as drive motor), and also such electric oil pump In addition, the mechanical pump provided in the automatic transmission is linked to promote the supply of hydraulic fluid.

FIG. 1 is a diagram illustrating a control relationship between each controller and an oil pump in a hybrid electric vehicle. As shown in FIG. 1, an I-MCU (Motor Control Unit) 12, an ECU 13, and a clutch control (CCU) are illustrated. Unit (14), MCU (15), P-MCU (16), TCU (17) is connected to the HCU (11), the upper controller by the CAN communication line (10) to exchange information with each other, In this case, the I-MCU 12 is a controller for substantially controlling an electric motor in which a starting motor and a generator function are integrated, that is, an integrated starter & generator (ISG) 2, and the CCU 14 controls the engine clutch 3. The MCU (including inverter) 16 is a controller for controlling the motor of the external electric oil pump 6.

In the case of the electric oil pump 6, when the HCU 11 determines the target rotational speed according to the vehicle driving state and the driver operation state and transmits it to the P-MCU 16, the P-MCU 16 sends the HCU 11 The oil pump driving motor is controlled according to the target rotational speed calculated from), and the oil pump is operated by the motor controlled according to the target rotational speed, thereby supplying the necessary hydraulic oil to the engine clutch and the transmission.

Here, the HCU 11 and the P-MCU 16 through the CAN communication information such as the target rotation speed and the actual rotation speed of the oil pump, the rotation speed of the oil pump driving motor, the operating state of the pump, that is, normal or faulty state Send and receive and perform cooperative control.

In general, the target rotational speed of the oil pump is controlled in two stages of predetermined low speed and high speed in consideration of system efficiency and driving responsiveness according to the vehicle driving state and driver operation state.

However, the conventional hybrid electric vehicle does not have a control method for supplying hydraulic oil in the event of failure of the electric oil pump.

Therefore, the present invention has been invented to solve the above problems, the engine clutch and the transmission through the control of the transmission and drive motor, high-speed running control of the electric oil pump in the event of a can communication line or electric oil pump failure. Control method in case of can communication and electric oil pump failure of hybrid electric vehicle which can effectively prevent the occurrence of abnormal operation of engine clutch and transmission that can be caused by insufficient supply of hydraulic oil. The purpose is to provide.

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

In order to achieve the above object, the present invention, if the CAN communication failure between the controller is detected in the hybrid electric vehicle and the electric oil pump and the pump driving motor is determined by the P-MCU is normal, CAN communication failure Forcibly controlling the pump driving motor, which is selectively controlled during the low speed and the high speed, by the sensed P-MCU to perform hydraulic oil supply; If the CAN communication is normal but the pump driving motor is determined to be in a fault state by the P-MCU, determining whether the vehicle speed is received from the signal of the vehicle speed sensor by the HCU received the motor fault state from the P-MCU; Subsequently, when it is determined that there is no vehicle speed, the TCU forcibly shifts the shift stage of the automatic transmission to the N (neutral) stage according to the command of the HCU, and then the MCU rotates the vehicle drive motor according to the command of the HCU, and thus the automatic transmission The mechanical oil pump is operated by the drive of the drive motor to provide a supply of hydraulic fluid; provides a control method when the can communication and electric oil pump failure of a hybrid electric vehicle comprising a.

Preferably, if a CAN communication failure between controllers is detected and it is determined by the P-MCU that the pump driving motor is in a failure state, the HCU receiving the motor failure state through a communication wire separately connected from the P-MCU is the vehicle speed sensor. Determining the vehicle speed from the signal of the vehicle; Subsequently, if it is determined that there is no vehicle speed, the HCU commands the TCU through a separately connected communication wire to force the TCU to control the shift stage of the automatic transmission to N (neutral), and then through the separately connected communication wire. Instructing the MCU to cause the MCU to rotate the vehicle drive motor, and thus the mechanical oil pump in the automatic transmission is operated by the drive of the drive motor to supply the operating oil; characterized in that it further comprises.

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

2 is a diagram illustrating a system for performing a control process according to the present invention, and FIG. 3 is a flowchart illustrating the control process according to the present invention.

In the present invention, when the operating state of the system is normal (CAN communication normal and external electric oil pump normal), the P-MCU 16 controls the pump driving motor according to the target rotation speed determined by the HCU 11, the external electric type Although the oil pump operates normally (d) of FIG. 2, in the case of a fault state, control is performed by being divided into a CAN communication fault state and an electric oil pump fault state as shown in Tables 1 and 3 below.

First, if CAN communication failure between controllers is detected in the hybrid electric vehicle and the electric oil pump 6 and its driving motor are in a normal state, the low-speed (first stage of setting the oil pump driving motor in the P-MCU 16) is set. 2) and forced high speed control during high speed (two stages) so that the hydraulic oil can be supplied (state (a) in FIG. 2), and the CAN communication failure state is stored in the controller memory and the oil pump 6 is operated. Notify the driver of the condition.

Here, the P-MCU 16 detects and judges CAN communication failure by itself (the CAN (Vehicle CAN) communication failure is normally detected by each controller in the vehicle), and the oil pump driving motor is forcedly controlled in two stages. However, in the case of a CAN communication failure, communication between the HCU 11 and the P-MCU 16 is not possible, and thus, a normal motor control of the oil pump driving motor through communication with the HCU 11 is performed. Since the P-MCU 16 cannot perform control by cooperative control of the two controllers, low speed and high speed), the motor is forcibly driven in two stages (high speed) where sufficient hydraulic fluid can be supplied at all times. Let's do it.

Next, if CAN communication is normal but the oil pump driving motor (electric oil pump) is determined to be in a failure state, the P-MCU 16 that has determined the failure state transmits the motor failure state to the HCU 11, and the motor The HCU 11, which has received the fault condition, determines whether the vehicle speed is present from the signal of the vehicle speed sensor.

At this time, when it is determined that there is no vehicle speed, the TCU 17 forcibly shifts the shift stage of the automatic transmission to the N (neutral) stage according to the command of the HCU 11 that recognizes the failure state from the P-MCU 16. Then, the MCU 15 rotates the drive motor (vehicle drive motor) 4 according to the command of the HCU 11, and the mechanical oil pump 7 in the automatic transmission 5 causes the drive motor 4 to be rotated. It is to be operated by the drive of, and the hydraulic oil is supplied to the system such as the engine clutch 3 and the automatic transmission 5 by the mechanical oil pump (7 (b) state).

If there is a vehicle speed, since the mechanical oil pump 7 in the automatic transmission 5 is operated, there is no problem because a sufficient amount of hydraulic oil is supplied to the system such as the engine clutch 3 and the automatic transmission 5. (State (c) of Figure 2).

If there is a vehicle speed in this way, there is no problem because a sufficient amount of hydraulic oil is supplied while the mechanical oil pump 7 in the automatic transmission 5 is operated, but in the case of no vehicle speed, the oil by the mechanical oil pump 7 Since the supply may be insufficient, the shift stage of the automatic transmission 5 is shifted to the N stage, and the driving motor 4 is driven to operate the mechanical oil pump 7 by driving the driving motor 4. And, this is to ensure that a sufficient amount of working oil is supplied by the mechanical oil pump (7).

On the other hand, when CAN communication fails and the oil pump driving motor also fails, the HCU 11 disconnects the communication wire 18 connected from the P-MCU 16 separately from CAN communication in a state in which CAN communication failure is detected by itself. The motor fault condition is transmitted.

In addition, the HCU 11 that recognizes the CAN communication and the motor failure determines the vehicle speed from the vehicle speed sensor signal.

At this time, when it is determined that there is no vehicle speed, the HCU 11 is instructed to the TCU 17 through the communication wire 19 connected separately, and the TCU 17 causes the shift stage of the automatic transmission 5 to be N (neutral). After the forced shift control, the HCU 11 commands the MCU 15 through a separately connected communication wire 21 to cause the MCU 15 to rotate the driving motor (vehicle driving motor) 4. To do that.

The mechanical oil pump (7) in the automatic transmission (5) is operated by the drive of the drive motor (4), by the mechanical oil pump (7) to the system such as the engine clutch (3) and automatic transmission (5). Allow hydraulic oil to be supplied (state (b) of FIG. 2).

If there is a vehicle speed, since the mechanical oil pump 7 in the automatic transmission 5 is operated, there is no problem because a sufficient amount of hydraulic oil is supplied to the system such as the engine clutch 3 and the automatic transmission 5. (State (c) of Figure 2).

In the above control process, the in-vehicle CAN communication failure state is generally detected in each controller 11 to 17, and the failure state of the oil pump driving motor is determined by a specific controller, for example, the P-MCU 16. When the difference between the target rotational speed (6) and the actual rotational speed is out of a certain range, the pump failure state is determined.

Of course, as a method of determining a failure state of the oil pump driving motor, the actual discharge flow rate according to the rotation speed of the oil pump driving motor may be monitored or determined by detecting the line pressure of the transmission controller. Additional hardware components, eg flow sensors or pressure sensors, will be required.

In this way, according to the present invention, by providing a control scheme for coping with the failure of the CAN communication line and the electric oil pump, various problems that may occur due to insufficient supply of hydraulic oil, that is, the abnormal operation of the engine clutch and the transmission, etc. It can be effectively prevented.

As described above, according to the control method of the can communication and the electric oil pump failure of the hybrid electric vehicle according to the present invention, the control of the transmission and the driving motor at the time of the failure of the can communication line or the electric oil pump, the high speed of the electric oil pump By allowing a sufficient amount of hydraulic oil to be supplied to the engine clutch and the transmission through the driving control, etc., it is possible to effectively prevent the occurrence of abnormal operation of the engine clutch and the transmission that may occur due to insufficient supply of the hydraulic oil.

Claims (2)

If a CAN communication failure between controllers is detected in the hybrid electric vehicle and the P-MCU determines that the electric oil pump and the motor for driving the pump are in a normal state, the P-MCU which detects the CAN communication failure is selected and controlled during low and high speeds. Forcibly controlling the pump driving motor at high speed by performing two-stage operation to supply hydraulic oil; If the CAN communication is normal but the pump driving motor is determined to be in a fault state by the P-MCU, determining whether the vehicle speed is received from the signal of the vehicle speed sensor by the HCU received the motor fault state from the P-MCU; Subsequently, when it is determined that there is no vehicle speed, the TCU forcibly shifts the shift stage of the automatic transmission to the N (neutral) stage according to the command of the HCU, and then the MCU rotates the vehicle drive motor according to the command of the HCU, and thus the automatic transmission A mechanical oil pump is operated by the driving of the driving motor to allow the hydraulic oil to be supplied; Can communication and control of the electric oil pump failure of the hybrid electric vehicle comprising a. The method according to claim 1, If a CAN communication failure between the controllers is detected and the pump driving motor is determined to be in a fault state by the P-MCU, the HCU received the motor failure state through a communication wire separately connected from the P-MCU is driven by the vehicle speed sensor signal. Determining the presence or absence; Subsequently, if it is determined that there is no vehicle speed, the HCU commands the TCU through a separately connected communication wire to force the TCU to control the shift stage of the automatic transmission to N (neutral), and then through the separately connected communication wire. Instructing the MCU to rotate the vehicle driving motor so that the mechanical oil pump in the automatic transmission is operated by driving the driving motor to supply hydraulic oil; Can communication and electric oil pump failure control method of a hybrid electric vehicle further comprising a.

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