JP2021000881A - Control device, control method, and control program - Google Patents

Abstract

To effectively prevent deterioration in gear change feeling by suppressing acceleration unintended by a driver.SOLUTION: A control device 100 of a vehicle 1 that transmits an output torque of a driving force source 10 as a driving force to driving wheels 17 and 18 through a transmission 20 includes a torque limit control part 120 that executes torque limit of limiting the output torque of the driving force source 10 to a predetermined torque upper limit value or lower so that a driving force after a gear change is equal to or lower than a driving force before the gear change over a predetermined period from the start of the gear change, when the gear change of shifting-up the transmission 20 is started.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a control device, a control method, and a control program, and in particular, a vehicle control device, a control method, and a control program in which an output torque of a driving force source is transmitted as a driving force to a driving wheel via a transmission. Regarding.

Generally, in a stepped automatic transmission mounted on a vehicle, the transmission is automatically set to a desired shift stage based on the vehicle speed of the vehicle and the accelerator opening according to the amount of operation of the accelerator pedal by the driver. Shift control for shifting up or down is appropriately performed (see, for example, Patent Documents 1 and 2).

JP-A-2017-207122 Japanese Unexamined Patent Publication No. 2016-223547

In the above shift control, it is common to shift up the current gear to the next gear before the so-called cross point where the driving force of the current gear becomes equal to the driving force of the next gear. .. However, for various purposes such as preventing torque loss due to shifting and improving exhaust emission performance, the current gear may be maintained up to the cross point and shifted up to the next gear after the cross point.

In this way, when the transmission is shifted up after the cross point, even if the acceleration required by the driver (accelerator opening) is substantially constant, the driving force increases after the shift, and the vehicle accelerates unintentionally by the driver. There is a possibility that the shift feeling and the running feeling may be deteriorated by causing the above.

The technique of the present disclosure has been made in view of the above circumstances, and an object of the present invention is to effectively prevent deterioration of shift feeling and driving feeling by suppressing unintended acceleration by the driver.

The device of the present disclosure is a vehicle control device in which the output torque of the driving force source is transmitted as a driving force to the driving wheels via the transmission, and when the shift for shifting up the transmission is started, A torque limit is implemented to limit the output torque of the driving force source to a predetermined torque upper limit or less so that the driving force after the shifting becomes equal to or less than the driving force before the shifting for a predetermined period from the start of the shifting. It is characterized by including a torque limiting control unit.

Further, the torque limit control unit multiplies the output torque of the driving force source immediately before the start of shifting by the ratio of the gear ratio of the gear stage before shifting and the gear ratio of the gear stage after shifting to the torque upper limit value. It is preferable to set.

Further, it is preferable to further include a torque limit release unit that releases the torque limit when the vehicle is accelerated during the torque limit by the torque limit control unit.

The method of the present disclosure is a vehicle control method in which the output torque of the driving force source is transmitted to the driving wheels as a driving force via the transmission, and when the shift for shifting up the transmission is started, A torque limit is implemented to limit the output torque of the driving force source to a predetermined torque upper limit or less so that the driving force after the shifting is equal to or less than the driving force before the shifting for a predetermined period from the start of the shifting. It is characterized by doing.

The program of the present disclosure starts the shift when the shift of the vehicle computer in which the output torque of the drive force source is transmitted to the drive wheels via the transmission as a drive force is started to shift up the transmission. Torque limit that limits the output torque of the driving force source to a predetermined torque upper limit or less so that the driving force after shifting is equal to or less than the driving force before shifting for a predetermined period from It is characterized by functioning as a control unit.

According to the technique of the present disclosure, it is possible to effectively prevent deterioration of shift feeling and driving feeling by suppressing unintended acceleration by the driver.

It is a schematic overall block diagram which shows the power transmission system of the vehicle which concerns on this embodiment. It is a schematic functional block diagram which shows the control device which concerns on this embodiment, and the related peripheral configuration. It is a schematic diagram explaining the operation by torque limitation control which concerns on this Embodiment. It is a flowchart explaining the process of torque limitation control which concerns on this Embodiment.

Hereinafter, the control device and the control method according to the present embodiment will be described with reference to the accompanying drawings. The same parts have the same reference numerals, and their names and functions are also the same. Therefore, detailed explanations about them will not be repeated.

[overall structure]
FIG. 1 is a schematic overall configuration diagram showing a power transmission system of the vehicle 1 according to the present embodiment.

The engine 10 is mounted on the vehicle 1 as an example of a driving force source. The crankshaft 11 of the engine 10 is connected to the input shaft 21 of the transmission 20 via the clutch device 12. The output shaft 22 of the transmission 20 is connected to the left and right drive wheels 17 and 18 via the propeller shaft 13, the differential gear device 14, and the left and right drive shafts 15 and 16, respectively.

That is, after the output torque Te of the engine 10 is transmitted from the clutch device 12 to the transmission 20 to decelerate or accelerate at a desired gear ratio, the propeller shaft 13, the differential gear device 14, and the left and right drive shafts 15, The driving force F is transmitted to the left and right driving wheels 17 and 18 via 16. The driving force source of the vehicle 1 is not limited to the engine 10, and a traveling motor or a combination thereof may be used. Further, the vehicle 1 may be rear-wheel drive, front-wheel drive, or four-wheel drive.

The engine 10 is provided with a plurality of injectors I that inject fuel into a combustion chamber (not shown) of the engine 10. The fuel injection amount and injection timing of the injector I are controlled in response to a command from the control device 100. The engine 10 is not limited to the direct injection engine, and may be a premixed engine. Further, the number of injectors I is not limited to the plurality of the illustrated examples, and may be one if the engine 10 has a single cylinder.

The clutch device 12 connects and disconnects the transmission of power from the crankshaft 11 to the input shaft 21. Specifically, the clutch device 12 receives power from a "contact state" in which power is transmitted by operating an actuator (not shown) in response to a command from the control device 100 during shift control by the control device 100 described later. It is switched to the "disengaged state" in which the transmission is cut off, and when the power transmission path of the next gear stage of the transmission 20 is established, it is switched to the "contact state" again.

The clutch device 12 is not limited to the dry single-plate clutch shown in the illustrated example, and may be a wet multi-plate clutch, a dual clutch, or the like. Further, when the transmission 20 is a manual transmission, the clutch device 12 may be a manual clutch device that operates in response to depression of a clutch pedal (not shown).

The transmission 20 is an automatic transmission that automatically shifts up or down in response to a command from the control device 100, and is provided in parallel with the input shaft 21, the output shaft 22, and each of these shafts 21 and 22. The counter shaft 23 is provided.

The input shaft 21 is provided with an input main gear 24. The output shaft 22 is provided with a plurality of output main gears 25. The counter shaft 23 is provided with an input counter gear 26 that meshes with the input main gear 24, and a plurality of output counter gears 27 that mesh with each output main gear 25.

Further, in the transmission 20, among the gears 24 to 27, a freewheeling gear that can rotate relative to the shaft (in the illustrated example, an output main gear 25 that can rotate relative to the output shaft 22) is synchronized with the shaft 22. A plurality of synchronization devices 30 to be combined are provided. The transmission 20 is not limited to the input reduction type shown in the illustrated example, and may be an output reduction type.

The synchronization device 30 includes a hub 31 rotatably provided on the output shaft 22, a sleeve 32 having inner peripheral teeth that mesh with the outer peripheral teeth of the hub 31, and a dog gear 33 rotatably provided on the output main gear 25. And a synchronizer ring 34 provided between the hub 31 and the dog gear 33. A shift fork 35 fixed to the shift rod 36 is integrally movably engaged with the sleeve 32. The shift rod 36 is connected to the shift actuator 39 via a shift block 37, a shift lever 38, a link mechanism (not shown), and the like.

In the synchronization device 30, when the shift actuator 39 is operated by the shift control of the control device 100, the sleeve 32 shifts due to the shift thrust transmitted via the link mechanism, the shift block 37, the shift rod 36, and the shift fork 35. When the synchronizer ring 34 is pressed with the shift movement of the sleeve 32, a synchronous load is generated between the synchronizer ring 34 and the tapered cone portion of the dog gear 33. When the sleeve 32 and the dog gear 33 rotate and synchronize due to the synchronous load, the sleeve 32 further shifts and completely meshes with the dog gear 33 so that the output main gear 25 is selectively synchronously coupled (gear-in) with the output shaft 22. It is configured.

In the following description, when the operation signal is transmitted from the control device 100 to the clutch device 12 and / or the synchronization device 30 with the start of the shift control, or the sleeve 32 shifts toward the dog gear 33. The time when the transmission starts is simply called "shift start", and when the sleeve 32 is completely engaged (detented) with the dog gear 33, or the ratio of the input / output rotation speeds of the transmission 20 is substantially the same as the gear ratio of the next gear stage. When this happens, it is simply called "shift completion".

The engine speed sensor 90 acquires the engine speed Ne from the crankshaft 11 (or flywheel). The transmission output rotation speed sensor 91 acquires the transmission output rotation speed Nt _Out from the propeller shaft 13 or the output shaft 22. The accelerator opening sensor 92 acquires an accelerator opening Q (fuel injection instruction value of the engine 10) according to the amount of depression of the accelerator pedal 80 by the driver. The brake sensor 93 acquires the driver's depression of the brake pedal 81 (presence or absence of brake operation). The sensor values of each of these sensors 90 to 93 are transmitted to the electrically connected control device 100.

[Control device]
FIG. 2 is a schematic functional block diagram showing the control device 100 according to the present embodiment and related peripheral configurations.

The control device 100 is, for example, a device that performs calculations such as a computer, and is a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), an input port, and an output port connected to each other by a bus or the like. Etc., and execute the program.

Further, the control device 100 functions as a device including a shift control unit 110, a torque limit control unit 120, and a torque limit release unit 130 by executing a program. Each of these functional elements will be described as being included in the control device 100, which is integrated hardware in the present embodiment, but any part of these may be provided in separate hardware.

The shift control unit 110 executes shift control for automatically shifting up or down the transmission 20 according to the traveling state of the vehicle 1. Specifically, a plurality of shift maps M1 and M2 referred to based on the vehicle speed V and the accelerator opening degree Q are stored in the memory of the control device 100. In the following, upshifting will be described as an example of shift control, and downshifting will be omitted.

Here, as the plurality of shift maps M1 and M2, the current gear stage is before the cross point (the point at which the driving force F of the current gear stage becomes equal to the driving force F of the next gear stage) and the next gear stage. For the shift map M1 for the normal running mode in which the shift-up line L1 for shifting up to is set, and for the predetermined running mode in which the shift-up line L2 for shifting up the current gear to the next gear after the cross point is set. At least two types of maps of the shift map M2 (for example, torque loss prevention mode, exhaust emission improvement mode, etc.) are stored.

The shift control unit 110 obtains the shift maps M1 and M2 corresponding to the running state of the vehicle 1 or the mode selected by the driver, the accelerator opening Q acquired by the accelerator opening sensor 92, and the transmission output. With reference to the vehicle speed V obtained from the transmission output speed Nt _Out acquired by the speed sensor 91, the accelerator opening Q and the vehicle speed V refer to the shift up lines L1 and L2 on the shift maps M1 and M2. When it exceeds (for example, when moving from the area on the left side in the figure to the area on the right side in the figure with respect to the lines L1 and L2), the transmission 20 is automatically operated by transmitting an operation signal to the clutch device 12 and the synchronization device 30. Execute shift control to shift up to. The number of shift maps M1 and M2 is not limited to two, and may be three or more. Further, each of the maps M1 and M2 does not need to be stored as a graph in the memory of the control device 100, and may be stored as numerical data.

When the shift control by the shift control unit 110 is started, the torque limit control unit 120 waits until the driver performs an additional operation (such as stepping on the accelerator pedal 80) between the start of the shift and the completion of the shift. Torque limit control for limiting the output torque Te of the engine 10 is performed so that the driving force F after the shift is equal to or less than the driving force F before the shift.

Specifically, in the torque limit control unit 120, after the shift control is started, the amount of change in the accelerator opening Q acquired by the accelerator opening sensor 92 per predetermined time is a predetermined lower limit threshold value (for example, the driver accelerates the accelerator). While it is about 5% or less of the degree to which the foot is placed on the pedal 80), the output torque Te _{_n + 1} of the engine 10 is equal to or less than the torque upper limit value Te _{_Lim} obtained by the formula (1). The fuel injection amount of the injector I is limited.

Te _{_Lim} = Te _{_n} x (Gr _{_n} / Gr _{_n + 1} ) ... (1)
In the formula (1), Te _{_n} is the output torque of the engine 10 immediately before the shift control is started, and the engine speed Ne acquired by the engine speed sensor 90 and the accelerator immediately before the start of the shift control. It may be obtained by referring to a map or the like based on the accelerator opening Q obtained by the opening sensor 92. Further, Gr _{_n} is the gear ratio of the gear stage before the shift up, and Gr _{_n + 1} is the gear ratio of the gear stage after the shift up, and these are the gear ratio data of each gear stage stored in the memory of the control device 100 in advance. You can read from. Incidentally, the pre-shift gear ratio Gr _{_n} just before the start of the shift control may be calculated from the ratio between the engine speed Ne to the clutch device 12 is obtained by contacting condition and the transmission output rotational speed Nt _Out.

In this way, when torque limit control is performed to limit the output torque Te _{_n + 1} of the engine 10 to the torque upper limit value Te _{_Lim} or less in consideration of the ratio of the gear ratios before and after shifting, for example, as shown in FIG. 3, the gear stage also shift control to shift up the G _n to 1 stage high gear G _{n + 1} is started at the cross point X after the X1, so an increase in the X2 of the driving force F after the shift can be suppressed. As a result, even when the transmission 20 is upshifted after the cross point X, the driver's unintended acceleration is effectively suppressed, and deterioration of the shift feeling and the running feeling can be prevented. Can be done.

When any of the following release conditions (1) and (2) is satisfied during the torque limit by the torque limit control unit 120, the torque limit release unit 130 releases the limit to release the torque limit.
(1) When the driver's acceleration request is detected because the amount of change in the accelerator opening Q acquired by the accelerator opening sensor 92 per predetermined time exceeds a predetermined lower limit threshold value.
(2) When the elapsed time measured from the start of torque limit control reaches a predetermined upper limit time.

In this way, by appropriately canceling the torque limit control according to the acceleration request by the driver and the upper limit time, deterioration of the acceleration response due to the torque limit control can be effectively prevented. The release condition may include a brake operation by the driver. The driver's brake operation may be acquired by the brake sensor 93.

When either the release condition (1) or (2) is satisfied, the torque limit release unit 130 _{gradually sets} the torque upper limit value _{Te_Lim} to the output torque Te of the engine 10 according to the amount of depression of the accelerator pedal 80 by the driver. Performs ramp processing back to. The ramp processing may be performed by reading the ramp coefficient from the coefficient map 131 referenced based on the engine speed Ne and the accelerator opening Q, and adding this ramp coefficient to the torque upper limit value _{Te_Lim} . By performing the lamp processing that gradually returns the torque upper limit value _{Te_Lim} in this way, it is possible to effectively prevent the driving force F of the vehicle 1 from being suddenly returned.

Next, the processing flow of the torque limit control according to the present embodiment will be described with reference to FIG. It should be noted that this control preferably starts at the same time as the vehicle 1 travels.

In step S100, it is determined whether or not the shift control by the shift control unit 110 has been started. Whether or not the shift control has been started may be determined based on, for example, whether or not an operation signal has been transmitted from the control device 100 to the clutch device 12 or the synchronization device 30. Alternatively, when a shift stroke sensor (not shown) is provided, the determination may be made based on the detection value of the sensor. When the shift control is started (Yes), the control proceeds to the process of step S110, and when the shift control is not started (No), the control repeats the determination process of step S100.

In step S110, it is determined whether or not the shift control by the shift control unit 110 is a shift up. In the case of upshifting (Yes), this control proceeds to the process of step S120. On the other hand, if it is not upshifting (No), that is, if the shift control is downshifting, this control is returned.

In step S120, the torque according to the above formula (1) is obtained by multiplying the output torque Te _{_n} of the engine 10 immediately before the shift control is started by the ratio of the gear ratio Gr _{_n} before the shift up and the gear ratio Gr _{_n + 1} after the shift up. Set the upper limit value _{Te_Lim} . Next, in step S130, torque limiting control is performed to limit the output torque Te _{_n + 1} of the engine 10 so as to be equal to or less than the torque upper limit value Te _{_Lim} .

In step S140, it is determined whether or not the amount of change in the accelerator opening Q acquired by the accelerator opening sensor 92 per predetermined time exceeds a predetermined lower limit threshold value. When the amount of change in the accelerator opening Q exceeds the lower limit threshold value (Yes), this control proceeds to the process of step S160. On the other hand, when the amount of change in the accelerator opening Q does not exceed the lower limit threshold value (No), this control proceeds to the process of step S150.

In step S150, it is determined whether or not the elapsed time measured from the start of the torque limit control has reached a predetermined upper limit time. When the elapsed time reaches the upper limit time (Yes), this control proceeds to the process of step S160. On the other hand, when the elapsed time has not reached the upper limit time (No), this control is returned to the process of step S130 in order to continue the torque limiting control.

In step S160, the upper limit torque value _{Te_Lim} is gradually returned to the output torque Te of the engine 10 according to the amount of depression of the accelerator pedal 80 of the driver, and the limit release for releasing the torque limit is executed. This control is returned.

According to the present embodiment described above, until the acceleration operation by the driver from the start of speed change control is performed, the output torque Te _n _{+ 1} of the engine 10, the ratio of the gear ratios before and after shifting the shift immediately before the output torque Te _{_n} It is configured to implement a torque limit that limits the torque to a torque upper limit value Te _{_Lim} or less multiplied by (Gr _{_n} / Gr _{_n + 1} ). As a result, even when the shift control is started after the cross point X, the driving force F after the shift can be made equal to the drive force F before the shift, and the shift feeling due to the acceleration unintentional by the driver can be achieved. And deterioration of driving feeling can be effectively prevented.

[Other]
It should be noted that the present disclosure is not limited to the above-described embodiment, and can be appropriately modified and implemented without departing from the spirit of the present disclosure.

For example, the shift control unit 110 and the torque limit control unit 120 do not need to function in the same control device 100, and the engine control device and the transmission control device are provided as separate hardware capable of intercommunication. The control device may be configured to provide a shift control unit 110 and a torque limit control unit 120 as functional elements.

In the above embodiment, the transmission 20 has been described by taking an automatic transmission as an example, but the transmission 20 may be a manual transmission that shifts according to the operation of the transmission operating device. Further, as the coupling device for coupling the gear 25 and the shaft 22, the synchronization device 30 having the synchronizer phosphorus 34 has been described as an example, but a non-synchronous type coupling device having no synchronizer ring may be used.

Further, although the torque limitation of the engine 10 has been described as being performed by limiting the fuel injection amount of the injector I, the load of the engine 10 is limited by auxiliary machinery (for example, an alternator) driven by the power of the engine 10. It may be done by increasing.

1 vehicle 10 engine (driving force source)
12 Clutch device 14 Differential gear device 17, 18 Drive wheels 20 Transmission 90 Engine rotation speed sensor 91 Transmission output rotation speed sensor 92 Accelerator opening sensor 100 Control device (computer)
110 Shift control unit 120 Torque limit control unit 130 Torque limit release unit

Claims (5)

It is a vehicle control device in which the output torque of the driving force source is transmitted to the driving wheels as driving force via the transmission.
When the shift to shift up the transmission is started, the output torque of the drive force source is set so that the drive force after the shift is equal to or less than the drive force before the shift for a predetermined period from the start of the shift. A control device including a torque limit control unit that limits torque to a predetermined torque upper limit or less. The torque limit control unit sets the torque upper limit value by multiplying the output torque of the driving force source immediately before the start of shifting by the ratio of the gear ratio of the gear stage before shifting and the gear ratio of the gear stage after shifting. The control device according to claim 1. The control device according to claim 1 or 2, further comprising a torque limit release unit that releases the torque limit when an acceleration operation of the vehicle is performed during the torque limit by the torque limit control unit. It is a vehicle control method in which the output torque of the driving force source is transmitted to the driving wheels as driving force via the transmission.
When the shift to shift up the transmission is started, the output torque of the drive force source is set so that the drive force after the shift is equal to or less than the drive force before the shift for a predetermined period from the start of the shift. A control method characterized in that a torque limit is applied to limit the torque to a predetermined torque upper limit or less. A vehicle computer in which the output torque of the driving force source is transmitted as driving force to the driving wheels via the transmission.
When the shift to shift up the transmission is started, the output torque of the drive force source is set so that the drive force after the shift is equal to or less than the drive force before the shift for a predetermined period from the start of the shift. A control program characterized in that it functions as a torque limit control unit that implements torque limit that limits the torque to a predetermined torque upper limit or less.

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