JP2005282741A - Control device for hybrid automobile - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device in which no interference occurs between synchronization of rotational frequency of a transmission and synchronization of rotational frequency by rotational frequency control to an electric motor. <P>SOLUTION: At the time of speed change, when rotational difference between the rotational frequency of an input shaft 9 and the target rotational frequency of the electric motor 7 is more than a lower limit value a with which no interference occurs between synchronization of rotational frequency of the transmission 9 and synchronization by rotational frequency control to the electric motor 7, the synchronization of rotational frequency of the transmission 9 and the synchronization of rotational frequency of the electric motor 7 are both used. When it is less than a, the rotation number synchronism of the transmission 9 only is used, while the electric motor 7 is controlled to generate similar output torque to rotational resistance of the electric motor 7 and rotational resistance of the transmission 9 to offset the torque. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an apparatus for controlling the rotational speed of a motor during shifting of a hybrid vehicle equipped with a mechanical automatic transmission.

In recent years, hybrid vehicles (HEV, Hybrid Electric Vehicle) have been developed for the purpose of coping with environmental problems and improving fuel efficiency.
A hybrid vehicle includes an electric motor as a power source in addition to a gasoline engine, a diesel engine, or the like. There are two types of hybrid vehicles: a series type that uses only an electric motor to drive the engine, and a parallel type that runs only with an electric motor, and a parallel type that runs with both the engine and the electric motor. The parallel type, which can improve fuel efficiency and suppress exhaust gas, has become the mainstream.

In recent years, a vehicle equipped with a mechanical automatic transmission has been developed in order to reduce the burden on the driver of a large truck or the like, and the hybrid vehicle may be equipped with a mechanical automatic transmission.

  In a parallel hybrid vehicle equipped with such a mechanical automatic transmission, when performing a shift, in addition to the rotational resistance of the transmission, the rotational resistance of the electric motor is generated. Compared with the automatic transmission, there is a drawback that it takes time to synchronize and the shift time becomes longer.

As an improvement measure, there is a method of performing synchronization by controlling the number of revolutions of the electric motor as well as using a transmission number synchronization device.
JP 2001-2131181 A

However, in such a method, when there is an error in vehicle speed information for controlling the target rotational speed of the electric motor or in the control accuracy of the rotational speed control, the speed of the transmission is synchronized with the rotational speed control of the electric motor. Interference occurs with the synchronization, causing problems such as an increase in the load on the synchronization device of the transmission and ringing of gears due to loss of synchronization.
More specifically, when controlling the rotational speed of the electric motor for synchronizing the rotational speed of the transmission, although the motor is actually already synchronized, the electric speed is detected due to an error in the detected vehicle speed or an error in the rotational speed control. The motor speed control may not end.
As a result, in addition to the inertia of the transmission gear, the rotational force of the electric motor becomes a load, increasing the load on the synchronization device of the transmission, causing a gear ringing due to a loss of synchronization.

The present invention has been made in view of such problems, and an object of the present invention is to provide a control device that shortens the synchronization time.

  In order to solve the above-described problems, the present invention includes an engine, a mechanical automatic transmission including a synchronization device, and an electric motor interposed between the engine and the mechanical automatic transmission. The hybrid vehicle provided has a combined synchronization function for performing synchronization at the time of gear shifting by both synchronization by the synchronization device and rotation control of the electric motor, and the input shaft rotation speed of the synchronization device and the target of the electric motor When the difference with the rotational speed is larger than a certain value, the synchronization by the combined synchronization function is performed, and when smaller than the certain value, only the synchronization by the synchronization device is continuously performed, and the rotational resistance of the electric motor and the A control apparatus for a hybrid vehicle, wherein the electric motor is controlled to generate an output torque equivalent to a rotational resistance of a mechanical automatic transmission.

  In the present invention, there are two synchronizations of the rotational speed of the mechanical transmission and the rotational speed synchronization of the electric motor, and at the time of shifting, the rotational difference between the input shaft rotational speed and the target rotational speed of the electric motor is a constant value. When it is large, two synchronizations are used together. When the difference in rotation is smaller than a certain value, the electric motor is controlled to generate an output torque equivalent to the rotational resistance of the electric motor and the rotational resistance of the mechanical automatic transmission. And offset these resistances.

By implementing the present invention, the rotational resistance of the electric motor and the rotational resistance of the mechanical automatic transmission at the time of shifting are offset, and the burden on the transmission is reduced, so that the shift time can be shortened.

DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail based on the drawings.
FIG. 1 is a schematic diagram of a hybrid vehicle 1 including a mechanical automatic transmission.
A clutch 5 is provided on the output side of the engine 3, an electric motor 7 is provided on the clutch 5, and a transmission 9 is provided on the electric motor 7.

The clutch 5 is connected / disconnected by an electric CCU (Clutch Control Unit) 11 that is an actuator, and the transmission 9 is operated to be shifted by an electric GSU (Gear Shift Unit) 13 that is an actuator. ing.
The engine 3 is controlled by an engine ECU (Electric Control Unit) 15, and the electric CCU 11 and the electric GSU 13 are controlled by the transmission ECU 17 through electric signals.

The transmission ECU 17 includes a CPU (Central Processing Unit), a memory, and the like. The transmission ECU 17 includes a change lever unit 19, a parking brake switch 23 that detects the operation of the parking brake 21, and a stop lamp that detects the operation of the brake pedal 25. The switch 27, the engine ECU 15 and the like are connected, and signals from the engine ECU 15, the change lever unit 19, the parking brake switch 23, the stop lamp switch 27 and the like are input.
Based on these input signals, the transmission ECU 17 determines whether or not to perform a shift, and when performing a shift, transmits a CCU drive signal for connecting and disconnecting the clutch 5 to the electric CCU 11, or shifts. A GSU drive signal for change is transmitted to the electric GSU 13.

The engine ECU 15 includes a CPU (Central Processing Unit), a memory, and the like. The engine ECU 15 includes an accelerator depression amount sensor 31 that detects the depression amount of the accelerator pedal 29, an exhaust brake main valve 33, an exhaust brake switch 35, a transmission ECU 17, and the like. Signals from the accelerator depression sensor 31, the exhaust brake switch 35, and the like are input.
The engine ECU 15 determines whether or not to change the rotational speed of the engine 3 based on these input signals, and sends an engine drive signal to the engine 3 when changing the rotational speed of the engine 3. Further, the engine ECU 15 determines whether or not to operate the exhaust brake based on the input signal, and when operating, sends an exhaust brake drive signal to the exhaust brake main valve 33.

  The motor ECU 37 includes a CPU (central processing unit), a memory, and the like, and an inverter 39 and a junction box 41 are connected to the motor ECU 37 so that a signal from the inverter 39 is input. A signal for operating the electric motor 7 is output to the inverter 39.

  The battery ECU 43 includes a CPU (Central Processing Unit), a memory, and the like. A junction box 41 and a battery 45 are connected to the battery ECU 43, and signals from the junction box 41 and the battery 45 are input. The remaining amount of the battery 45 is monitored based on the signal.

 Further, the engine ECU 15, the transmission ECU 17, the motor ECU 37, and the battery ECU 43 are connected through a CAN (Controller Area Network) communication 47 and can exchange information with each other.

Next, the transmission 9 and its peripheral devices will be described. FIG. 2 is a schematic diagram showing the transmission 9 and its peripheral device 47.
A clutch 5 is provided on the output side of the engine 3, an electric motor 7 is provided on the clutch 5, and a transmission 9 is provided on the electric motor 7.

  In the transmission 9, a drive gear 51 is provided on an input shaft 49 connected to the electric motor 7. The drive gear 51 meshes with a counter gear 55 provided on the counter shaft 53, and power from the input shaft 49 is always transmitted to the counter shaft 53.

Counter gears 57 and 59 provided on the countershaft 53 mesh with a first speed gear 63 and a second speed gear 65 provided on the output shaft 61, respectively. Normally, a plurality of gears such as the third speed, the fourth speed, etc. are provided, but the gears after the third speed are omitted. The output shaft 61 is provided with a hub 67 and synchronizer rings 69 and 71, and the hub 67 is provided with a sleeve 73. The sleeve 73 is provided with a selector 75, and the selector 75 can move in the A direction and the B direction integrally with the sleeve 73 by the electric GSU 13 at the time of shifting.

  A final gear 77 is provided at one end of the output shaft 61, and a wheel 79 is provided in the final gear 77, and the power from the output shaft 61 is finally adjusted by the final gear 77 to the wheel 79. Reportedly.

  2 shows a state where the gear is in a neutral state, and the first speed gear 63 and the second speed gear 65 are not connected to the output shaft 61, and the power of the engine 3 and the electric motor 7 is transmitted to the output shaft 61. Not.

  Therefore, it is necessary to perform a so-called speed change operation in which either the first speed gear 63 or the second speed gear 65 is connected to the output shaft 61. For example, when shifting to the first speed, the electric GSU 13 first moves the selector 75 in the B direction. Since the selector 75 is provided on the sleeve 73, the sleeve 73 moves together with the selector 75, and the synchronizer ring 71 is brought into contact with the first speed gear 63 to start synchronization. After the synchronization is completed, the sleeve 73 further moves, meshes with a gear (not shown) of the first speed gear 63, so-called gearing is performed, and the speed change operation is completed.

Next, the control method at the time of shifting according to the present embodiment will be described by taking as an example a case where the gear is shifted down from the second speed to the first speed.
FIG. 3 is a flowchart at the time of shifting according to the present embodiment.
Since the transmission ECU 17 shifts when the vehicle speed signal reaches a certain value, it transmits a CCU motor drive signal to the electric CCU 11 to issue a command to turn off the clutch 5, and the electric CCU 11 turns off the clutch 5 and shifts the clutch stroke signal. It transmits to machine ECU17 (step 101).
The transmission ECU 17 that has received the clutch stroke signal determines whether or not the clutch has been disengaged. If it is determined that the clutch has been disengaged, the process proceeds to the next step (step 102).

  Next, the transmission ECU 17 sends a GSU motor drive signal to the electric GSU 13 to issue a gear release command. The electric GSU 13 that has received the signal moves the selector 75 in the B direction, separates the sleeve 73 from the gear of the second speed gear 65 (gear release), and transmits a shift stroke signal to the transmission ECU 17. (Step 103).

The transmission ECU 17 that has received the shift stroke signal determines whether or not the gear removal has been completed, and proceeds to the next step if it has been completed (step 104).
The motor ECU rotates the electric motor 7 via the inverter 39 so as to reach the target rotational speed, and performs synchronization (step 105).

  The transmission ECU 17 sends a GSU motor drive signal to the electric GSU 13 to issue a gear engagement command. Receiving the signal, the electric GSU 13 moves the selector in the A direction to bring the synchronizer ring 71 into contact with the first speed gear via the sleeve 73 to perform synchronization (step 106).

  The motor ECU 37 obtains the difference between the rotational speed of the input shaft 49 and the target rotational speed of the electric motor 7, and determines whether this value is equal to or smaller than a certain value “a”. If it is equal to or smaller than “a”, the process proceeds to the next step ( Step 107). The target rotational speed of the electric motor 7 is a value obtained by multiplying the rotational speed of the output shaft 61 by the speed ratio after shifting. The rotational difference “a” is a lower limit value at which the synchronization action of the transmission 9 and the synchronization action of the electric motor 7 do not cause interference, and is a value obtained in advance through experiments or the like, for example, 60 rpm.

The motor ECU 37 stops the rotational speed control of the electric motor 7 via the inverter 39 and finishes the synchronization (step 108).
The motor ECU 37 controls the electric motor 7 via the inverter 39 so as to generate output torque equivalent to the rotational resistance of the electric motor 7 and the rotational resistance of the transmission 9. (Step 109)
The electric GSU 13 continues to move the selector 75 in the A direction to bring the synchronizer ring 71 into contact with the first speed gear 63 via the sleeve 73, thereby completing the synchronization (step 110).
The electric GSU 13 continues to move the selector 75 in the A direction, meshes the sleeve 73 with a gear (not shown) of the first speed gear 63, and gears (step 111).

  FIG. 4 is a diagram showing changes in time, the number of rotations of the input shaft 49, and changes in time and shift stroke. The shift stroke is the position of the selector 75, the position of FIG. 2 is the neutral position, the position of the selector 75 with the sleeve 73 meshing with the first speed gear 63 is the position of the second speed, and the sleeve The position of the selector 75 in a state where 73 is engaged with the second speed gear 65 is the second speed position.

  When shifting down, it is necessary to increase the rotational speed of the input shaft 49, but when the clutch 5 is disengaged and the shift is set to neutral, the rotational speed of the input shaft 49 decreases. Therefore, while the shift is neutral, synchronization is performed by controlling the rotational speed of the electric motor 7, and the rotational speed of the input shaft 49 is increased (electric motor 7 single-unit synchronization section 201, FIG. 3, steps 101 to 105).

  Next, when synchronization by the transmission 9 is started, synchronization is performed by both the electric motor 7 and the transmission 9, and the rotational speed of the input shaft 49 is further increased (the electric motor 7, the transmission 9 synchronization section 203, FIG. Steps 106-107)

  When the rotational difference between the rotational speed of the input shaft 49 and the target rotational speed of the electric motor 7 becomes a certain value “a” or less, the synchronization by the rotational speed control of the electric motor 7 is stopped, and thereafter the synchronization of the transmission 9 alone is synchronized. At the same time, the electric motor 7 is controlled to generate an output torque equivalent to the rotational resistance of the electric motor 7 and the rotational resistance of the transmission 9. (Transmission 9 single synchronization section and torque control section of electric motor 7, 205, FIG. 3, steps 108 to 111)

FIG. 5 is a diagram showing changes in time and rotational speed, and time and shift stroke.
Since it is necessary to reduce the rotational speed of the input shaft 49 when shifting up, synchronization is performed by controlling the rotational speed of the electric motor 7 while the shift is neutral, and the rotational speed of the input shaft 49 is decreased (electric motor 7 Single synchronization section 207, FIG. 3, steps 101-105).

  Next, when synchronization by the transmission 9 is started, synchronization is performed by both the electric motor 7 and the transmission 9, and the rotational speed of the input shaft 49 is further reduced (the electric motor 7, the transmission 9 synchronization section 209, FIG. Steps 106-107)

  When the rotational difference between the rotational speed of the input shaft 49 and the target rotational speed of the electric motor 7 becomes equal to or less than a predetermined value “a”, the synchronization by the rotational speed control of the electric motor 7 is stopped, and thereafter the transmission 9 alone is synchronized. At the same time, the electric motor 7 is controlled to generate an output torque equivalent to the rotational resistance of the electric motor 7 and the rotational resistance of the transmission 9. (Transmission 9 single synchronization section and torque control section of electric motor 7, 205, FIG. 3, steps 108 to 111)

  Therefore, when the difference between the rotational speed of the input shaft 49 and the rotational speed of the electric motor 7 becomes “a” or less, the electric motor 7 outputs torque equivalent to the rotational resistance of the electric motor 7 and the rotational resistance of the transmission 9. Therefore, the rotational resistance of the electric motor 7 and the rotational resistance of the transmission 9 are offset, and the required synchronization time and the shift time can be shortened.

As described above, according to the present embodiment, when the rotation difference is equal to or greater than the lower limit value at which the synchronization action of the transmission 9 and the synchronization action of the electric motor 7 do not cause interference, the rotation speed control and the speed change of the electric motor 7 are performed. Since the synchronization is performed by both the rotation speed control of the machine 9 and when it is below the lower limit value, the synchronization is performed only by the rotation speed control of the transmission. Therefore, the vehicle speed information for controlling the target rotation speed of the electric motor and the rotation speed Even when an error occurs in the control accuracy of the control, synchronization interference can be prevented. Moreover, the electric motor 7 is controlled to generate an output torque equivalent to the rotational resistance of the electric motor 7 and the rotational resistance of the transmission 9, and these torques are offset, so the burden on the transmission 9 can be reduced. And the shift time can be shortened.

  As mentioned above, although embodiment of this invention was described referring an accompanying drawing, it does not depend on embodiment mentioned above. It is obvious for those skilled in the art that various modifications or modifications can be conceived within the scope of the technical idea described in the claims, and these are naturally within the technical scope of the present invention. It is understood that it belongs.

  For example, in this embodiment, a mechanical automatic transmission is used, and the electric GSU 13 performs gear engagement and gear release operations under the control of the transmission ECU 17, but a manual transmission is used and a driver directly uses a shift knob. A method of performing gear engagement and gear release operations may be employed.

  In the present embodiment, the synchronizer rings 69 and 71 and the sleeve 73 are used as the synchronization device of the transmission 9, but a dog clutch or the like may be used.

Schematic diagram of hybrid vehicle system Hybrid vehicle power and transmission schematic diagram Flow chart during shifting Relationship between time and input shaft speed, time and shift stroke Relationship between time and input shaft speed, time and shift stroke

Explanation of symbols

1 ………… Hybrid vehicle 3 ………… Engine 5 ………… Clutch 7 ………… Electric motor 9 ………… Transmission 11 ……… Electric CCU
13 ... Electric GSU
15 ... Engine ECU
17 ......... Transmission ECU
37 ……… Motor ECU
39 ......... Inverter 41 ...... Junction box 43 ...... Battery ECU
45 ......... Battery 47 ......... Power and transmission 49 ......... Input shaft 51 ......... Drive gear 53 ......... Counter shaft 55 ......... Counter gear 57 ......... Counter gear 59 ......... Counter gear 61 ......... Output shaft 63 ......... First speed gear 65 ......... Second speed gear 67 ......... Hub 69 ......... Synchronizer ring 71 ......... Synchronizer ring 73 ......... Sleeve 75 ......... Selector

Claims (1)

A mechanical automatic transmission with an engine and a synchronization device;
An electric motor interposed between the engine and the mechanical automatic transmission;
In a hybrid vehicle equipped with
While having a synchronous function at the time of shifting by both the synchronization by the synchronization device and the rotation control of the electric motor,
When the difference between the input shaft rotation speed of the synchronization device and the target rotation speed of the electric motor is larger than a certain value, synchronization by the combined synchronization function is performed, and when smaller than the certain value, only synchronization by the synchronization device is performed. And controlling the electric motor to generate an output torque equivalent to the rotational resistance of the electric motor and the rotational resistance of the mechanical automatic transmission.

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