KR20150069929A - Shift control system for plug in hybrid vehicle and method thereof - Google Patents

Abstract

The present invention discloses a method to control the shifting of a plug-in hybrid vehicle, capable of capable of providing shifting control pursuing the maximum efficiency of the output of an operating motor in response to demanded power of a driver in electric vehicle (EV) mode driving in which a battery is controlled in a charge depleting mode (CD mode). The method includes a step of detecting RPM of the operating motor and the demanded power in the driving of the EV mode in which the battery is controlled in a CD mode; a step of driving the output of the operating motor to the maximum power area by shifting down a gear step when the operating motor is driven in a lower area than the rating RPM; a step of driving the output of the operating motor to the maximum power area by shifting up the gear step when the operating motor is driven in a higher area than the maximum rating RPM; a step of starting an engine when the demanded power exceeds the output power of the operating motor; a step of shifting up the gear step when the maximum power, determined by the sum of the engine and the operating motor, exceeds the demanded power; a step of shifting down the gear step when the maximum power, determined by the sum of the engine and the operating motor, is smaller than the demanded power; and a step of holding the gear step when the maximum power is similar to or the same as the demanded power.

Description

TECHNICAL FIELD [0001] The present invention relates to a shift control system for a plug-in hybrid vehicle,

The present invention relates to a plug-in hybrid vehicle, and more particularly, to a plug-in hybrid vehicle in which an output of a drive motor is maximized with respect to a driver's required power in an EV (Electric Vehicle) mode in which a battery is controlled in a charge- Speed hybrid vehicle, which is capable of improving responsiveness and fuel economy by providing a shift control that follows efficiency, and to a shift control apparatus and method of a plug-in hybrid vehicle.

The demand for environmentally friendly automobiles is increasing due to the demand for constant fuel efficiency improvement for vehicles and the strengthening of exhaust gas regulations of each country, and a plug-in hybrid vehicle is provided as a practical alternative to this.

The plug-in hybrid vehicle can be divided into a discharge-oriented mode (CD mode) and a charge-oriented mode (CS mode) according to the state of charge (SOC) of the battery.

The discharge-oriented mode (CD mode) means an interval of an EV mode in which the battery runs only by a drive motor using battery power charged with an external power source.

The charge-oriented mode (CS mode) refers to a period in which electric power charged in the battery is used up to a certain amount and then traveled in an appropriate combination of the driving force of the engine and the driving motor in the same manner as in the HEV (Hybrid Electric Vehicle) mode.

In a plug-in hybrid vehicle, the engine is proportional to the RPM and the output is constant regardless of the RPM, so the engine requires a shift to accommodate the required power and the motor does not need a shift.

The plug-in hybrid vehicle has one or two clutches, and can be applied in a TMED (Transmission Mounted Electric Device) type in which a drive motor is mounted on the input shaft of the transmission and a multi-speed transmission is applied.

In addition, the plug-in hybrid vehicle is designed so that the power of the driving motor does not satisfy the driver's required power, and when the driver's requested power exceeds the power of the driving motor, the engine is started to meet the requirement of the driver. ).

The plug-in hybrid vehicle may be equipped with a transmission, and when the hybrid vehicle is of the hybrid type, the engine may be started. Therefore, the shift must be controlled at an appropriate time when the battery is driven in an EV mode controlled in a discharge-oriented mode (CD mode).

5 is a diagram showing output characteristics of a drive motor applied to a general plug-in hybrid vehicle.

Referring to FIG. 5, since the drive motor has the same maximum torque up to the rated RPM (Rated RPM), the output gradually increases and the torque gradually decreases to the maximum rated RPM (Max RPM) (Max Rated RPM), the torque and power drops sharply.

A conventional plug-in hybrid vehicle has a rated RPM (Rated RPM) when the gear stage is determined in the EV mode in which the battery is controlled in a discharge-oriented mode (CD mode) by applying the same shift map as a general automatic transmission. Or below the maximum rated RPM (Max Rated RPM).

5, even if the required power A of the driver is smaller than the rated power (output and torque) of the drive motor, the power (output and torque) of the drive motor that can be output at the corresponding speed change stage, If it is smaller than the power (A), a downshift (D / Shift) must be performed to satisfy the required power.

If the downshift is not executed, the engine must be turned on to satisfy the required power of the driver. If the engine is started, the response and the fuel economy may be deteriorated.

SUMMARY OF THE INVENTION The present invention has been developed in order to solve such a problem, and an object of the present invention is to provide a driving method and a driving method for a vehicle in which an electric motor is driven in an EV mode in which a battery is controlled in a discharge- When the RPM of the driving motor is decreased and the rated RPM is reached, the control of down / shift is performed to control the output of the driving motor with maximum efficiency. We want to provide the shift control of the plug-in hybrid vehicle that we are interested in.

According to an embodiment of the present invention, an engine and a drive motor, which are power sources, are provided. A battery manager for managing a state of charge of the battery; An operation demand detector for detecting a demanded power of the driver; (CD mode) or a charge-oriented mode (CS mode) according to a state of charge of the battery, and the hybrid controller includes a hybrid controller for controlling the battery to be driven in a discharge-oriented mode There is provided a shift control device for a plug-in hybrid vehicle in which the drive motor is operated in the optimum range by up / down-controlling the speed change stage in accordance with the driver's required power and RPM of the drive motor in mode operation.

The hybrid controller can operate the drive motor to the maximum power range by downshifting the speed change stage when the drive motor is operated in a range of rated RPM (Rated RPM) or less.

The hybrid controller can operate the drive motor to the maximum power range by upshifting the speed change stage when the drive motor is operated in the region of the maximum rated RPM (Max Rated RPM) or more.

The hybrid controller may start the engine if the required power is greater than the output power of the drive motor and to downshift the speed change stage if the maximum power determined by the sum of the engine and the drive motor is less than the driver's required power.

The hybrid controller can start up the engine if the required power is greater than the output power of the drive motor and upshift control the speed change stage if the maximum power determined by the sum of the engine and the drive motor is greater than the required power.

The hybrid controller may start the engine if the required power is greater than the output power of the driving motor, and perform the shift hold control when the maximum power and the required power determined by the sum of the engine and the driving motor are within a certain range.

The hybrid controller can prevent frequent shift control by applying hysteresis to the up / down control of the speed change stage according to the required power and RPM of the drive motor.

According to another aspect of the present invention, there is also provided a method of driving a hybrid vehicle, the method comprising: detecting RPM of a driving motor and a required power in a driving of an EV mode in which a battery is controlled in a discharge-oriented mode (CD mode); Shifting the speed change stage to operate the output of the drive motor to the maximum power range when the drive motor is operated in an area below the rated RPM; Shifting the speed change stage to operate the output of the drive motor to the maximum power range when the drive motor is operated in the region of the maximum rated RPM or more; Starting the engine when the required power exceeds the output power of the drive motor; A step of upshifting the speed change stage when the maximum power determined by the sum of the engine and the drive motor exceeds the required power; A step of downshifting the speed change stage when the maximum power determined by the sum of the engine and the drive motor is smaller than the required power; And a step of performing shift-hold control of the speed change stage when the maximum power determined by the sum of the engine and the drive motor and the required power are equal to or similar to each other.

When the output voltage of the drive motor to which the voltage of the HSG is applied and the output voltage of the drive motor to which the voltage of the battery is applied is greater than the required power, the shift stage is controlled to be a shift hold and the drive of the serial mode using the HSG generation voltage can be provided have.

As described above, according to the embodiment of the present invention, the maximum power of the driving motor can always be used in the EV mode running in which the battery is controlled in the discharge-oriented mode (CD mode) in the plug-in hybrid vehicle, So that a quick response can be provided.

In addition, according to the embodiment of the present invention, unnecessary shift control is not generated in the EV running in the discharge-oriented mode of the plug-in hybrid vehicle, so that safety and reliability can be provided without generation of a shock due to shift control or loss of hydraulic pressure .

Further, according to the embodiment of the present invention, an appropriate speed change stage can be selected at the time of starting the engine, so that the engine noise is reduced and the fuel economy can be improved by selecting the appropriate speed change ratio.

1 is a view schematically showing a shift control device of a plug-in hybrid vehicle according to an embodiment of the present invention.
2 is a flowchart schematically showing a shift control procedure of a plug-in hybrid vehicle according to an embodiment of the present invention.
3 is a view showing shift hold in shift control of a plug-in hybrid vehicle according to an embodiment of the present invention.
4 is a view showing an upshift in shift control of a plug-in hybrid vehicle according to an embodiment of the present invention.
5 is a diagram showing output characteristics of a drive motor applied to a general plug-in hybrid vehicle.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention.

The present invention may be embodied in many different forms and is not limited to the embodiments described herein.

In order to clearly illustrate the present invention, parts not related to the description are omitted, and the same or similar components are given the same reference numerals throughout the specification.

In addition, since the components shown in the drawings are arbitrarily shown for convenience of explanation, the present invention is not necessarily limited to those shown in the drawings.

1 is a view schematically showing a shift control device of a plug-in hybrid vehicle according to an embodiment of the present invention.

The present invention is a technology for controlling the shift during driving of the EV mode in which the battery is controlled in the discharge-oriented mode (CD) in the plug-in hybrid vehicle.

1, an embodiment of the present invention includes an operation request detector 101, a hybrid controller 102, a motor controller 103, a battery 104, a battery manager 105, an engine controller 106, An engine 107, an engine 108, a hybrid starter and generator (HSG) 109, a drive motor 110, an engine clutch 111 and a transmission 112.

The operation request detector 101 detects the power demanded by the driver input by the operation of the accelerator pedal and provides the electric signal to the hybrid controller 102.

The hybrid controller 102 is a top-level controller, and integrally controls controllers connected to the network.

The hybrid controller 102 analyzes the state of charge (SOC) of the battery 104 provided in the battery manager 105 and determines whether the battery 104 is driven in the driving mode of the EV mode in which the battery 104 is controlled in the discharge- 110 to perform the shift control through the shift controller 107 according to the RPM of the driver and the driver's required power so as to provide the drive in which the drive motor 110 is driven in the operating region having the highest efficiency.

The hybrid controller 102 analyzes the RPM of the drive motor 110 to determine whether or not a shift is necessary. If the shift is necessary, the hybrid controller 102 executes the shift control according to the RPM.

The hybrid controller 102 determines whether the RPM of the drive motor 110 is operating in an area below a rated RPM or in an area of a maximum rated RPM or more.

The hybrid controller 102 controls the speed change stage of the transmission 112 to be downshifted when the RPM of the drive motor 110 is operating in the range below the rated RPM so that the drive motor 110 So that it can be operated in an area where maximum power can be exerted.

The hybrid controller 102 controls the speed change stage of the transmission 112 to be shifted up or shifted in a state where the RPM of the drive motor 110 is operating in the region of the maximum rated RPM or more So that the motor 110 can be operated in an area where maximum power can be output.

As described above, the hybrid controller 102 controls the upshift or downshift of the speed change stage according to the RPM of the drive motor 110 to drive the output of the drive motor 110 in the region where the maximum efficiency and the maximum power are always output And the hydraulic pressure loss can be prevented by minimizing the number of shifts.

Further, the hybrid controller 102 analyzes the driver's requested power, and if the driver's requested power is greater than the motor power, the hybrid controller 102 operates the HSG 109 as an electric motor to turn the engine 108 on.

If the required power of the driver is greater than the maximum power determined by the sum of the engine 108 and the drive motor 110 at the current speed change stage, the hybrid controller 102 downshifts the speed change stage to satisfy the driver's required power .

At this time, it is possible to perform downshift control of the various stages at a time by comparing the required power of the driver with the maximum output of each of the shift stages capable of downshifting.

When the maximum power of the current speed change stage is smaller than or equal to the driver's required power and the shift hold standard, the hybrid controller 102 controls the shift operation since the current speed change stage is appropriately combined with the driver required power Do not.

As shown in FIG. 3, the reference of the shift hold means a value that is larger than the maximum output of the one-step upshift control of the speed change stage and slightly smaller than the maximum output of the current speed change stage.

The reason why the reference of the shift hold is greater than the maximum output of the one-step upshift control of the speed change stage is to satisfy the driver's requested torque.

If the maximum power of a certain gear position is higher than the driver's required power, the hybrid controller 102 is in a state where the RPM of the present driving motor 110 is operating in an area where the RPM of the current driving motor 110 is too high. .

As can be seen from Fig. 4, the maximum output of each gear position is compared with the driver's required power, and the lowest gear position among the gear positions larger than the driver's required power is selected.

If the output power of the drive motor 110 to which the power generation power of the battery 104 and the HGS 109 is applied is greater than the required power of the driver, the hybrid controller 102 controls the HSG 109, The control unit 108 starts up the engine 108 and then drives the HSG 109 without connecting the engine clutch 111 to drive the vehicle in series.

The hybrid controller 102 may apply hysteresis to the references of the shift control to prevent the frequent shift control from being executed.

The motor controller 103 controls the output torque of the driving motor 110 according to a control signal applied from the hybrid controller 102 so that the motor can be driven at a rated RPM having the maximum efficiency.

The motor controller 103 includes an inverter composed of a plurality of power switching elements, and the power switching element constituting the inverter is composed of one of IGBT (Insulated Gate Bipolar Transistor), MOSFET, FET, transistor TR and relay .

The motor controller 103 monitors the flow of the power source and distributes or cuts off power when an overvoltage or an overcurrent flows into the power source due to various reasons such as collision, And stably protects the occupant from high pressure.

The battery 104 is composed of a plurality of unit cells, and a high voltage for providing a voltage to the driving motor 110 is stored.

The battery manager 105 manages the state of charge (SOC) by detecting the current, voltage, temperature, etc. of each cell within the operating range of the battery 104, manages the charge / discharge limit value of the battery 104, Overflowing to the maximum limit value or overflowing to shorten the lifetime.

The engine controller 106 controls the operating point of the engine 108 in accordance with the control signal applied through the network from the hybrid controller 102 so that the optimum torque can be output.

The transmission controller 107 controls the speed change coupling of the transmission 112 according to a control signal applied through the network in the hybrid controller 102 so that the outputs of the engine 108 and the drive motor 110 are maximized So that the driving can be provided at the operating point having the driving force.

The engine 108 is applied to any one of a diesel engine, a gasoline engine, an LPG engine, and an LNG engine. The engine 108 outputs a torque to an operating point corresponding to a control signal applied from the engine controller 106, So as to properly maintain the combination of the driving forces.

The HSG 109 serves as an electric motor and a generator and is operated as an electric motor in accordance with a control signal applied from the motor controller 103 to start up the engine 108. In the state in which the engine 108 is kept on, And provides the generated voltage to the battery 104 as a charging voltage.

The drive motor 110 is operated by the three-phase alternating-current voltage applied from the motor controller 103 to generate torque, and operates as a generator in another run to supply the regenerative energy to the battery 104. [

The engine clutch 111 is mounted between the engine 108 and the drive motor 110 so as to interrupt power transmission so that the operation of the EV mode and the HEV mode can be provided.

The transmission 112 is applied as an automatic transmission or a continuously variable transmission, and the engagement element and the release element are operated by the operation of hydraulic pressure under the control of the shift controller 107 to engage any gear position.

1 illustrates the structure of a hybrid vehicle of TEMD (Transmission Mounted Electric Device). However, the present invention is not limited to this and can be applied to a hybrid type TMED (hybridized TMED) hybrid vehicle.

The operation of the present invention including the above-described functions is as follows.

2 is a flowchart illustrating a shift control procedure of a plug-in hybrid vehicle according to an embodiment of the present invention.

The operation of the shift control to the HEV mode in which the battery 104 is controlled in the charge-oriented mode (CS mode) in the plug-in hybrid vehicle to which the present invention is applied is the same as or similar to the ordinary operation, and a detailed description thereof will be omitted.

When the plug-in hybrid vehicle to which the present invention is applied is operated, the hybrid controller 102 determines the operation mode based on the state of charge (SOC) of the battery 104 provided in the battery manager 105 (S101) Is operated in the discharge-oriented mode (CD mode) (S102).

The hybrid controller 102 performs the normal shift control if the battery 104 is in the HEV mode in which the battery 104 is controlled in the charge-oriented mode (CS mode) in step S102, and a detailed description thereof will be omitted (S103).

The hybrid controller 102 sets the speed RPM of the driving motor 110 controlled by the motor controller 103 as the driving speed of the EV mode in which the battery 104 is controlled in the discharge-oriented mode (CD mode) (S104) and determines whether or not the state of the gear position of the transmission 112 is required (S105).

The hybrid controller 102 operates in a state where the RPM of the driving motor 110 is less than the rated RPM or greater than the maximum rated RPM in step S105 so that the speed change stage control of the transmission 112 If it is determined that the driving motor 110 is in a required state, it is determined whether the driving motor 110 is operating in an area less than the rated RPM (S106).

If the RPM of the drive motor 110 is operating in the range below the rated RPM (Rated RPM) in step S106, the hybrid controller 102 controls the speed ratio of the transmission 112 (Down / Shift) so that the driving motor 110 is operated in an area where the maximum power can be output (S107).

The hybrid controller 102 determines whether the speed ratio of the transmission 112 is higher than the rated RPM of the drive motor 110 through the transmission controller 107 connected to the network if the RPM of the drive motor 110 is operating in the range exceeding the maximum rated RPM (Down / Shift) so that the driving motor 110 is operated in the region where the maximum power can be output (S108).

The hybrid controller 102 controls the upshift or downshift of the speed change stage according to the RPM of the drive motor 110 to drive the output of the drive motor 110 to the maximum power having the highest efficiency at all times, The number of times can be minimized to prevent hydraulic pressure loss.

The hybrid controller 102 analyzes the driver's required power provided by the operation request detector 101 (S109) and determines whether the driver's requested power is greater than the output power of the drive motor 110 (S110).

The hybrid controller 102 operates the HSG 109 as an electric motor to assist the output power of the drive motor 110 when the driver's requested power is greater than the output power of the drive motor 110, The start-up is turned on (S111).

Then, the hybrid controller 102 determines whether the maximum power or shift-hold reference determined by the sum of the engine 108 and the drive motor 110 at the current gear stage is less than or equal to the driver's requested power S112).

The hybrid controller 102 determines in S112 whether the maximum power determined by the sum of the engine 108 and the drive motor 110 at the current speed change stage is less than or equal to the driver's required power, (S113), the current shift position is determined to be properly combined with the driver's requested power, and the shift hold is maintained without performing the shift control.

As shown in FIG. 3, the reference of the shift hold means a value that is larger than the maximum output of the one-step upshift control of the speed change stage and slightly smaller than the maximum output of the current speed change stage.

The reason why the reference of the shift hold is greater than the maximum output of the one-step upshift control of the speed change stage is to satisfy the driver's requested torque.

If the hybrid controller 102 determines that the maximum power determined by the sum of the engine 108 and the drive motor 110 is less than the driver's required power at the current gear stage (S114), the hybrid controller 102 determines that the RPM Is shifted to the speed change stage through the speed change controller 107 (S115).

If the hybrid controller 102 determines that the maximum power determined by the sum of the engine 108 and the drive motor 110 at the current gear stage is greater than the driver's requested power (S114), the hybrid controller 102 determines that the RPM Is controlled to an upshift to the speed change stage through the speed change controller 107 (S116).

As can be seen from Fig. 4, the maximum output of each gear position is compared with the driver's required power, and the lowest gear position among the gear positions larger than the driver's required power is selected.

If the output power of the drive motor 110 to which the power generation power of the battery 104 and the HGS 109 is applied is greater than the required power of the driver, the hybrid controller 102 controls the HSG 109, The control unit 108 starts up the engine 108 and then drives the HSG 109 without connecting the engine clutch 111 to drive the vehicle in series.

The hybrid controller 102 may apply hysteresis to the references of the shift control to prevent the frequent shift control from being executed.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood that various modifications and changes may be made without departing from the scope of the appended claims.

101: Operation request detector 102: Hybrid controller
103: motor controller 104: battery
105: battery manager 106: engine controller
107: Transmission controller 108: Engine
109: HSG 110: drive motor
111: engine clutch 112: transmission

Claims (9)

An engine and a drive motor which are power sources;
A battery manager for managing a state of charge of the battery;
An operation demand detector for detecting a demanded power of the driver;
A hybrid controller for controlling the running of the discharge-oriented mode (CD mode) or the charge-oriented mode (CS mode) according to the charged state of the battery;
/ RTI >
The hybrid controller includes a plug-in hybrid that drives the drive motor to an optimum region by up / down-controlling the gear stage in accordance with RPM of the drive motor and the required power of the driver in an EV mode operation in which the battery is controlled in a discharge- A shift control device for an automobile. The method according to claim 1,
Wherein the hybrid controller operates the drive motor to the maximum power range by downshifting the speed change stage when the drive motor is operated in an area below the rated RPM (rated RPM). The method according to claim 1,
Wherein the hybrid controller operates the drive motor to the maximum power range by upshifting the speed change stage when the drive motor is operated in a region of maximum rated RPM (Max Rated RPM) or more. The method according to claim 1,
Wherein the hybrid controller starts up the engine if the required power is greater than the output power of the drive motor and controls the downshift of the gear stage when the maximum power determined by the sum of the engine and the drive motor is less than the driver's required power Shift control device. The method according to claim 1,
Wherein the hybrid controller starts up the engine if the required power is greater than the output power of the drive motor and controls the upshift of the speed change stage when the maximum power determined by the sum of the engine and the drive motor is greater than the required power, . The method according to claim 1,
Wherein the hybrid controller performs a shift-and-hold control when the required power is greater than the output power of the driving motor and when the maximum power and the required power determined by the sum of the engine and the driving motor are within a predetermined range, Device. The method according to claim 1,
Wherein the hybrid controller interrupts the occurrence of frequent shift control by applying hysteresis to the up / down control of the shift stage in accordance with the required power and RPM of the drive motor. Detecting the RPM of the driving motor and the required power in the EV mode in which the battery is controlled in the discharge-oriented mode (CD mode);
Shifting the speed change stage to operate the output of the drive motor to the maximum power range when the drive motor is operated in an area below the rated RPM;
Shifting the speed change stage to operate the output of the drive motor to the maximum power range when the drive motor is operated in the region of the maximum rated RPM or more;
Starting the engine when the required power exceeds the output power of the drive motor;
A step of upshifting the speed change stage when the maximum power determined by the sum of the engine and the drive motor exceeds the required power;
A step of downshifting the speed change stage when the maximum power determined by the sum of the engine and the drive motor is smaller than the required power;
When the maximum power determined by the sum of the engine and the drive motor and the required power are the same or similar, shift-hold control of the speed change stage;
Wherein the hybrid vehicle is a hybrid vehicle. 9. The method of claim 8,
Wherein the control unit controls the speed change stage to a shift hold when the output voltage of the drive motor to which the voltage of the HSG generator is applied and the output voltage of the drive motor to which the voltage of the battery is applied is greater than the required power, A method of controlling a shift of a hybrid vehicle.

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