KR101490943B1 - Shift control system for plug in hybrid vehicle and method thereof - Google Patents

Abstract

Disclosed is a shift control method for a plug-in hybrid vehicle in which a battery is improved in fuel economy by restricting a shift to a vehicle speed or an operator's torque demand in EV mode running in a discharge-oriented mode (CD mode).
The method includes determining a driving mode based on a charged state of a battery; When the battery is in the EV mode controlled by the discharge-oriented mode (CD mode), the first gear stage is engaged by entering the shift limiting control; A step of shifting to a second gear stage to follow the required torque when the output torque does not follow the required torque in the state of running on the first gear stage; And releasing the shift limiting control when the engine is required to be started in response to a rapid acceleration demand in a state of running on the first gear stage or the second gear stage.

Description

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

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plug-in hybrid vehicle, and more particularly to a plug-in hybrid vehicle in which a shift is limited to a vehicle speed or an operator's torque demand in an electric vehicle (EV) mode in which a battery is controlled in a charge- And more particularly, to a shift control apparatus and method for a plug-in hybrid vehicle in which efficiency loss due to shifting is minimized to thereby improve fuel economy.

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 the discharge-oriented mode (CD mode), since the amount of charge of the usable battery is large, in most cases, driving is performed by the power of only the driving motor unless it is a special situation.

In the charge-oriented mode (CS mode), since the amount of available battery is relatively small, the vehicle is provided with a control to keep the state of charge (SOC) of the battery at an appropriate level in order to improve fuel economy.

The plug-in hybrid vehicle may be a TMED (Transmission Mounted Electric Device) type powertrain having one or two clutches, a drive motor mounted at the input of the transmission, and a multi-speed transmission.

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. TMED) power train can be applied.

As described above, the plug-in hybrid vehicle in which the TMED or Blended Type TMED powertrain is mounted is switched to the HEV mode in the EV mode in which the battery is controlled in the discharge-oriented mode (CD mode) A shift is made to keep the engine operating point at a low RPM.

If the vehicle speed is increased, the RPM of the driving motor continues to increase. If the engine and the driving motor are synchronized, the engine can be synchronized at 6000 RPM or more. A shock may be generated, and the sudden increase in RPM of the engine may deteriorate the fuel economy.

However, when shifting in accordance with the vehicle speed or the driver's demand torque in the EV mode running, energy loss occurs due to the hydraulic pressure control coupling the target speed change stage to shorten the travel distance in the discharge-oriented mode (CD mode) The fuel consumption may be lowered.

SUMMARY OF THE INVENTION The present invention has been developed in order to solve such a problem, and it is an object of the present invention to limit a shift in response to a vehicle speed or a driver's torque demand in an EV mode running in which a battery is controlled in a discharge-oriented mode (CD mode) To improve fuel efficiency.

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 A shift control device of a plug-in hybrid vehicle which enters a shift limiting control in a mode operation and which engages either the first gear stage or the second gear stage in accordance with the driver's requested power and vehicle speed is provided.

If the output torque does not satisfy the required torque, the hybrid controller shifts to the second gear stage to induce a downward RPM of the drive motor. When the RPM of the drive motor is lowered, .

The hybrid controller is capable of releasing the shift restriction control when a rapid acceleration is required in a state of running on the first gear stage or the second gear stage and the engine is required to start, have.

The hybrid controller may engage the first gear in the vehicle speed at which the regenerative braking is maximized when deceleration due to the driver's request is detected during running of the second gear.

The hybrid controller may set the first gear stage to an overdrive or a gear stage having a 1: 1 gear ratio to a three-stage fixed transmission, and the second gear stage to an underdrive gear stage to set a six-stage transmission.

According to another aspect of the present invention, there is provided a method of operating a battery pack, the method comprising: determining an operation mode based on a charged state of the battery; A step of entering the shift limiting control when the battery is in the EV mode controlled by the discharge-oriented mode (CD mode), and combining the first gear stage to provide the running; A step of shifting to a second gear stage to follow the required torque when the output torque does not follow the required torque in the state of running on the first gear stage; And releasing the shift restriction control if the engine is required to be started in response to a rapid acceleration demand in a state of traveling to the first gear stage or the second gear stage.

When deceleration is detected in the state of traveling to the second gear stage, the vehicle speed is shifted to the first gear stage and the vehicle speed at which regenerative braking is maximized can be provided.

When the mode is switched from the discharge-oriented mode (CD mode) to the charge-oriented mode (CS mode) in which the vehicle travels to the first gear stage or the second gear stage, the shift limiting control is canceled to synchronize the engine and the drive motor have.

As described above, according to the embodiment of the present invention, even if the vehicle speed or the driver's required torque satisfies the shift condition in the EV mode running in which the battery is controlled in the discharge-oriented mode (CD mode) in the plug-in hybrid vehicle, Thereby improving the fuel efficiency.

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 a shift limiting device of a plug-in hybrid vehicle according to an embodiment of the present invention.

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.

Referring to FIG. 1, an embodiment of the present invention includes an operation information detecting unit 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 information detector 101 detects the operation information including the demanded torque, the acceleration demand, the vehicle speed, etc. of the driver inputted by the operation of the accelerator pedal, and provides it 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 by the battery manager 105 and determines whether the battery 104 is in the EV mode in which the battery 104 is controlled in the discharge-oriented mode (CD mode) And the first gear stage or the second gear stage is engaged in accordance with the vehicle speed or the driver's required torque.

Thus, the efficiency loss that can be caused by the hydraulic operation is minimized, thereby providing fuel economy improvement.

The first gear stage means an overdrive or a gear stage having a 1: 1 gear ratio, and the second gear stage means an under drive gear stage, which means that the transmission is fixed at six stages. , Which may vary depending on the design of the transmission.

The hybrid controller 102 combines the first gear stage in the EV mode operation in which the battery 104 is controlled in the discharge-oriented mode (CD mode) to execute the travel from 0 KPH to approximately 100 KPH, The RPM of the drive motor 110 is downshifted to the second gear stage when the required torque of the driver can not be satisfied due to the output torque that can be reduced as the RPM of the drive motor 110 increases.

Thus, the output torque of the drive motor 110 is increased so as to provide an output power with an optimum efficiency.

When the vehicle speed is required to be a constant vehicle speed, for example, 100 KPH or more in a state in which the hybrid controller 102 travels to the first gear stage in the EV mode in which the battery 104 is controlled in the discharge-oriented mode (CD mode) And shifts to the second gear stage to prevent noise generation.

When the driver's sudden acceleration demand is input in the state where the hybrid controller 102 travels to the first gear stage or the second gear stage and the engine is required to be started, the hybrid controller 102 cancels the shift restriction control, And then the engine and the motor are synchronized to provide the running.

The hybrid controller 102 shifts to the first gear position or the second gear position in consideration of the vehicle speed if the EV mode can be traveled after satisfying the driver's acceleration demand and provides the travel.

When the vehicle speed is decelerated by a driver's request including braking or tip-off of the accelerator pedal in a state of traveling to the second gear position, the hybrid controller 102 controls the hybrid- Thereby controlling the shift.

When the hybrid controller 102 transitions from the discharge-oriented mode (CD mode) to the charge-oriented mode (CS mode), the hybrid controller 102 starts the engine 108 via the HSG 109, The shift limiting control is released.

The motor controller 103 controls the output torque of the driving motor 110 according to a control signal applied from the hybrid controller 102 through a network so that the motor can be driven to a region 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 according to a control signal applied from the hybrid controller 102 through a network so that an optimum torque can be output.

The transmission controller 107 controls the transmission 112 to the first gear position or the second gear position according to the control signal applied from the hybrid controller 102 through the network to perform the EV mode operation in the discharge direction mode (CD mode) So that fuel economy improvement can be provided.

The engine 108 can be applied to any one of a diesel engine, a gasoline engine, an LPG engine, and an LNG engine. The engine 108 outputs torque to an operating point according to a control signal applied from the engine controller 106, ) Of the driving force.

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.

The above-described configuration is an example of the configuration of a hybrid vehicle in which a TEMP (Transmission Mounted Electric Device) powertrain of FIG. 1 is mounted. However, the present invention is not limited thereto and may be applied to a hybrid vehicle equipped with a hybrid type TMED (Blended Type TMED) It can be applied to automobiles.

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 enters the shift limiting control in the EV mode in which the battery 104 is controlled in the discharge-oriented mode (CD mode) in step S102 (S103) and engages the first gear stage (S104).

The first gear stage means an overdrive or a gear stage having a 1: 1 gear ratio, which means that the transmission is three-stage fixed.

The hybrid controller 102 enters the shift restriction control in the EV mode in which the battery 104 is controlled in the discharge-oriented mode (CD), and executes the travel from 0 KPH to approximately 100 KPH with the first gear stage engaged.

The hybrid controller 102 detects the output torque of the drive motor 110, the vehicle speed, and the driver's requested torque in a state of traveling to the first gear position (S105), and determines whether the output torque is smaller than the required torque S106).

If the required torque of the driver can not be satisfied due to the output torque that can be reduced as the RPM of the drive motor 110 increases in step S106, the hybrid controller 102, as shown in FIG. 3A, And the RPM of the drive motor 110 is guided downward (S108).

Thus, the output torque of the drive motor 110 is increased so as to provide an output power with an optimum efficiency.

The hybrid controller 102 determines whether the vehicle speed is equal to or greater than a reference vehicle speed AKPH, for example, 100 KPH in a state of traveling to the first gear position (S107). If the vehicle speed is equal to or greater than the reference vehicle speed AKPH , As shown in FIG. 3 (b), the transmission is shifted to the second gear to prevent noise from occurring (S108).

In step S109, the hybrid controller 102 determines whether a sudden acceleration request of the driver is inputted and the engine 108 is in a start-up state in a state where the hybrid controller 102 travels to the first gear stage or the second gear stage.

The hybrid controller 102 cancels the shift restriction control (S110) and shifts to the gear stage that can satisfy the driver's demand by applying the general shift pattern, And the motor 110 (S111).

If the EV mode satisfies the driver's acceleration demand, the hybrid controller 102 shifts to the first gear stage or the raised stage in consideration of the vehicle speed and then restricts the shift to provide the drive.

In step S108, the hybrid controller 102 determines whether deceleration of the vehicle speed is detected in response to a driver's request including braking or tip-off of the accelerator pedal in a state where the hybrid controller 102 travels to the second gear position (S112).

The hybrid controller 102 controls the shift from the vehicle speed to the first gear to maximize the regenerative braking if the deceleration is determined by the driver's request (S113).

The hybrid controller 102 turns on the engine 108 via the HSG 109 when the battery 104 transitions from the discharge-oriented mode (CD mode) to the charge-oriented mode (CS mode) The shift restriction is canceled at the time of synchronizing with the shift limit.

Although the present invention has been described by way of example with reference to FIG. 1 as an example of a transmission limitation control of a hybrid automobile of a TEMD (Transmission Mounted Electric Device) type, the present invention is not limited to this and is applicable to hybrid vehicles of the hybrid type TMED Method can be applied.

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 information 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 enters a shift limiting control in an EV mode operation in which the battery is controlled in a discharge-oriented mode (CD mode), and controls the gear position of either the first gear position or the second gear position according to the driver's required power and vehicle speed A plug-in hybrid control device for a hybrid vehicle. The method according to claim 1,
If the output torque does not satisfy the required torque, the hybrid controller shifts to the second gear stage to induce a downward RPM of the drive motor. When the RPM of the drive motor is lowered, To control the shift of the plug-in hybrid vehicle. The method according to claim 1,
The hybrid controller is a plug-in device that, when a rapid acceleration is required in a state of running on a first gear stage or a second gear stage and the engine is required to be started, the shift restriction control is released and the engine is started up to provide a synchronized running of the engine and the motor A shift control device of a hybrid vehicle. The method according to claim 1,
Wherein the hybrid controller engages a first gear stage at a vehicle speed at which regenerative braking is maximized when deceleration due to a driver's request is detected during running of the second gear stage. 5. The method according to any one of claims 1 to 4,
The hybrid controller sets the first gear stage to an overdrive or a gear stage having a 1: 1 gear ratio to a three-stage transmission,
And the second gear stage is set to a six-stage fixed transmission by an underdrive gear stage. Determining a driving mode based on a charged state of the battery;
When the battery is in the EV mode controlled by the discharge-oriented mode (CD mode), the first gear stage is engaged by entering the shift limiting control;
A step of shifting to a second gear stage to follow the required torque when the output torque does not follow the required torque in the state of running on the first gear stage;
Releasing the shift limiting control when the engine is required to start in accordance with a rapid acceleration demand in a state of traveling to the first gear stage or the second gear stage;
Wherein the hybrid vehicle is a hybrid vehicle. The method according to claim 6,
And when the deceleration is detected in the state of traveling to the second gear stage, the transmission is shifted to the first gear stage to provide a vehicle speed at which regenerative braking is maximized. The method according to claim 6,
(CS mode) in a discharge-oriented mode (CD mode) in which the vehicle travels to the first gear stage or the second gear stage and releases the shift restriction control, and synchronizes the engine and the drive motor to provide a running A method of controlling a shift of a hybrid vehicle. An engine and a drive motor which are power sources;
A battery manager for managing a state of charge of the battery;
A hybrid controller for controlling the running of the discharge-oriented mode (CD mode) or the charge-oriented mode (CS mode) according to the state of charge of the battery;
/ RTI >
The hybrid controller is operated in accordance with a set program to enter the shift limiting control in the EV mode of the discharge-oriented mode (CD mode) by the method of any one of the sixth to eighth aspects, The shift control device of the plug-in hybrid vehicle.

Images