Vehicle control device

Abstract

To more quickly and accurately correct a driving force transmitted to a start clutch according to fluctuation of clutch torque of the start clutch.SOLUTION: A vehicle control device includes an engine, a battery, a motor driven by power supplied from the battery, and a start clutch, and controls a motor torque of the motor without receiving constraints on a battery of the motor when clutch torque of the start clutch fluctuates, and thereby previously increases or decreases the engine torque of the engine so as to correct driving force transmitted to the start clutch.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a vehicle control device. [Background technology]

[0002] The following Patent Document 1 discloses a technology for reducing the torque capacity of a starting clutch provided between a motor and an automatic transmission in a hybrid vehicle when the motor torque cannot be increased, in order to counteract torque fluctuations that occur when the starting clutch is engaged, the engine is started, etc. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-070138 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the conventional technology, when the torque capacity of the starting clutch is reduced, the driving torque transmitted to the driving wheels is also reduced, so that the driver of the vehicle may feel a lack of driving force of the vehicle.

[0005] Incidentally, when torque fluctuations occur in the starting clutch, it is preferable to control the driving force transmitted to the starting clutch to be equal to the clutch torque of the starting clutch so that the rotation speed does not fluctuate. This control is preferably achieved by changing the driving force transmitted to the starting clutch (i.e., the engine torque and the motor torque) rather than changing the clutch torque of the starting clutch. Furthermore, since the motor torque has a higher responsiveness to increases and decreases than the engine torque, it is preferable to change the motor torque without changing the engine torque.

[0006] However, there are cases where the upper and lower limits of the motor torque are restricted due to battery restrictions, and in this case, it is not possible to control the driving force transmitted to the starting clutch to be equal to the clutch torque of the starting clutch simply by changing the motor torque within the restricted range, and it is necessary to change the engine torque. In this case, since the response of the increase and decrease in the engine torque is low, there is a risk that the driving force transmitted to the starting clutch cannot be corrected quickly and accurately in response to the fluctuation in the clutch torque of the starting clutch. [Means for solving the problem]

[0007] In order to solve the above-mentioned problems, one embodiment of a vehicle control device is a control device for a vehicle that includes an engine, a battery, a motor driven by power supplied from the battery, and a starting clutch, and when a fluctuation occurs in the clutch torque of the starting clutch, the engine torque of the engine is increased or decreased in advance so that the driving force transmitted to the starting clutch can be corrected by controlling the motor torque of the motor without the motor being restricted by the battery. Effect of the Invention

[0008] According to the vehicle control device of one embodiment, the driving force transmitted to the starting clutch can be corrected more quickly and with higher accuracy in accordance with fluctuations in the clutch torque of the starting clutch. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a diagram showing a configuration of a drive train system for a vehicle according to an embodiment; [Diagram 2] A flowchart showing an example of a process performed by a control device according to an embodiment. [Diagram 3] 11 is a flowchart showing another example of processing by the control device according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] (Configuration of the drive transmission system of the vehicle 10) Fig. 1 is a diagram showing the configuration of a drive train of a vehicle 10 according to one embodiment. The drive train of the vehicle 10 shown in Fig. 1 is a so-called hybrid vehicle that includes an engine 12 and a motor 14 as power sources.

[0012] As shown in FIG. 1, the drive train of a vehicle 10 includes an engine 12, a motor 14, a first clutch 16, a second clutch 18, an automatic transmission 20, a differential gear 22, drive wheels 24, a control device 30, and a battery 32.

[0013] The engine 12 is a first power source of the vehicle 10. The engine 12 operates as an internal combustion engine by receiving fuel from a fuel supply system (not shown), thereby generating a driving torque for running the vehicle 10. The driving torque output from the engine 12 (hereinafter referred to as "engine torque") is transmitted to driving wheels 24 via a first clutch 16, a motor 14, a second clutch 18, an automatic transmission 20, and a differential gear 22.

[0014] The motor 14 is a second power source of the vehicle 10. The motor 14 is supplied with power from the battery 32 via an inverter (not shown) and thereby rotates to generate a driving torque for driving the vehicle 10. The driving torque output from the motor 14 (hereinafter referred to as "motor torque") is transmitted to the driving wheels 24 via the second clutch 18, the automatic transmission 20, and the differential gear 22. In addition, the motor 14 can regenerate energy to generate electricity when the vehicle 10 decelerates, thereby charging the battery 32.

[0015] The first clutch 16 is provided in a drive transmission path 41 between the engine 12 and the motor 14. The first clutch 16 can switch between an engaged state and a released state, thereby switching the drive transmission path 41 between a disconnected state and a connected state. The first clutch 16 is, for example, a dry-type multi-plate hydraulic friction engagement device, and is configured to include a plurality of friction plates stacked on top of each other. The operation of the first clutch 16 is controlled by a first hydraulic control system (not shown) provided in the vehicle 10. The first hydraulic control system is configured to include an oil pump, a hydraulic actuator, a solenoid valve, and the like.

[0016] The second clutch 18 is a so-called "starting clutch" and is provided in a drive transmission path 42 between the motor 14 and the automatic transmission 20. The second clutch 18 can switch between an engaged state and a released state, thereby switching the drive transmission path 42 between a disconnected state and a connected state. The second clutch 18 is, for example, a wet-type multi-plate hydraulic friction engagement device, and is configured with a plurality of friction plates stacked on top of each other. The operation of the second clutch 18 is controlled by a second hydraulic control system (not shown) provided in the vehicle 10. The second hydraulic control system is configured to include an oil pump, a hydraulic actuator, a solenoid valve, and the like.

[0017] The control device 30 controls the operations of the engine 12, the motor 14, the first clutch 16, the second clutch 18, the automatic transmission 20, and the battery 32. For example, the control device 30 performs engine torque control of the engine 12, drive control of the motor 14, control of the switching operation of the first clutch 16, control of the switching operation of the second clutch 18, shift control of the automatic transmission 20, charge / discharge control of the battery 32, etc.

[0018] The control device 30 is configured to include a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), etc. Each function of the control device 30 described above is realized, for example, by the CPU executing a program stored in the ROM in the control device 30. In reality, the control device 30 is realized by a plurality of ECUs (Electronic Control Units) provided for each function.

[0019] Note that, in order to prevent the rotation speed from revving up, the control device 30 issues commands to each of the engine 12, the motor 14, and the second clutch 18 so that the resultant force of the engine torque and the motor torque (i.e., the driving torque transmitted to the second clutch 18) becomes equal to the clutch torque of the second clutch 18. For example, when the required driving force is 100, the control device 30 issues commands to each of the engine 12, the motor 14, and the second clutch 18 so that the clutch torque of the second clutch 18 becomes 100 and the resultant force of the engine torque and the motor torque becomes 100.

[0020] In addition, since the clutch torque of the second clutch 18 is controlled by hydraulic pressure and requires frictional transmission, it is easy for unintended increases and decreases to occur with respect to the target clutch torque (i.e., the torque realization accuracy is relatively low). Therefore, when the clutch torque of the second clutch 18 increases or decreases unintendedly, the control device 30 maintains the rotation speed by issuing a command to the engine 12 or the motor 14 to increase or decrease the engine torque or the motor torque through feedback control (i.e., maintaining a state in which the resultant force of the engine torque and the motor torque is equal to the second clutch torque). When the second clutch torque decreases unintendedly from 100 to 80, a command is issued to the engine 12 or the motor 14 to increase or decrease the engine torque or the motor torque so that the resultant force of the engine torque and the motor torque becomes 80.

[0021] However, in this case, in this embodiment, the control device 30 gives priority to issuing a command to the motor 14 to increase or decrease the motor torque. This is because the motor torque is less likely to fluctuate than the engine torque, and the torque realization accuracy is relatively high.

[0022] However, for the motor 14, the upper limit motor torque and the lower limit motor torque are limited by the constraints of the chargeable power Win and the dischargeable power Wout of the battery 32. For this reason, the control device 30 cannot change the motor torque outside the range between the upper limit motor torque and the lower limit motor torque. The chargeable power Win specifies the limit on the input power of the battery 32. The dischargeable power Wout specifies the limit on the output power of the battery 32. The chargeable power Win and the dischargeable power Wout are controlled according to the temperature of the battery 32, the SOC (State Of Charge) of the battery 32, etc.

[0023] (An example of processing by the control device 30) Fig. 2 is a flowchart showing an example of processing by the control device 30 according to an embodiment of the present invention, in which the motor lower limit torque is limited due to a constraint on the chargeable power Win of the battery 32.

[0024] First, the control device 30 determines whether or not a fluctuation in the clutch torque of the second clutch 18 is predicted (step S201).

[0025] In step S201, when it is determined that a fluctuation in the clutch torque of second clutch 18 is not predicted (step S201: No), control device 30 ends the series of processes shown in FIG.

[0026] On the other hand, in step S201, if it is determined that a fluctuation in the clutch torque of second clutch 18 is predicted (step S201: Yes), control device 30 calculates the increase or decrease due to the fluctuation in the clutch torque of second clutch 18 as the feedback requirement amount (step S202).

[0027] Next, the control device 30 determines whether or not the engine torque is predicted to become greater than the clutch torque of the second clutch 18 (step S203).

[0028] If it is determined in step S203 that the engine torque is predicted to be smaller than the clutch torque of second clutch 18 (step S203: No), control device 30 ends the series of processes shown in FIG.

[0029] On the other hand, in step S203, if it is determined that the engine torque is predicted to be greater than the clutch torque of the second clutch 18 (step S203: Yes), the control device 30 calculates the offset torque based on the motor lower limit torque and the feedback requirement calculated in step S202 (step S204).

[0030] Then, the control device 30 issues a command to decrease the engine torque and increase the motor torque by the amount of the offset torque calculated in step S204 (step S205). After that, the control device 30 ends the series of processes shown in FIG.

[0031] For example, if the engine torque is set to "100", the motor torque is set to "0", and the clutch torque of second clutch 18 is set to "100", and it is predicted that the clutch torque of second clutch 18 will change from "100" to "80", then in step S202, the control device 30 calculates "-20" as the feedback requirement.

[0032] Then, when the motor lower limit torque is "-10" and the feedback requirement is "-20", the control device 30 calculates the offset torque to be "10" or more in step S204. Furthermore, when the control device 30 calculates the offset torque to be "20" in step S204, the control device 30 reduces the engine torque from "100" to "80" and increases the motor torque from "0" to "20" in step S205.

[0033] As a result, when the clutch torque of second clutch 18 actually changes from "100" to "80", the control device 30 changes the resultant force of the engine torque and the motor torque from "100" to "80", but this change can be realized by changing the motor torque from "20" to "0" without changing the engine torque. At this time, because the motor lower limit torque is "-10" due to the restriction of the chargeable power Win of the battery 32, the change in the motor torque is not restricted by the motor lower limit torque.

[0034] Furthermore, when the clutch torque of second clutch 18 actually changes from "100" to "120", control device 30 changes the resultant force of engine torque and motor torque from "100" to "120", but this change can be achieved by changing motor torque from "20" to "40" without changing engine torque. At this time, there is no restriction on dischargeable power Wout of battery 32, and since the motor upper limit torque is "200", the change in motor torque is not restricted by the motor upper limit torque.

[0035] (Another example of processing by the control device 30) Fig. 3 is a flowchart showing another example of processing by the control device 30 according to an embodiment. Fig. 3 shows an example of processing by the control device 30 when the motor lower limit torque and the motor upper limit torque are limited by a constraint on the chargeable power Win of the battery 32 and a constraint on the dischargeable power Wout of the battery 32.

[0036] First, the control device 30 determines whether or not a fluctuation in the clutch torque of the second clutch 18 is predicted (step S301).

[0037] In step S301, if it is determined that a fluctuation in the clutch torque of second clutch 18 is not predicted (step S301: No), control device 30 ends the series of processes shown in FIG.

[0038] On the other hand, in step S301, if it is determined that a fluctuation in the clutch torque of second clutch 18 is predicted (step S301: Yes), control device 30 calculates the increase or decrease due to the fluctuation in the clutch torque of second clutch 18 as the feedback requirement amount (step S302).

[0039] Next, the control device 30 determines whether or not the engine torque is predicted to become greater than the clutch torque of the second clutch 18 (step S303).

[0040] In step S303, if it is determined that the engine torque is predicted to be greater than the clutch torque of the second clutch 18 (step S303: Yes), the control device 30 calculates the offset torque based on the motor lower limit torque and the feedback requirement calculated in step S302 (step S304).

[0041] Then, the control device 30 issues a command to decrease the engine torque and increase the motor torque by the amount of the offset torque calculated in step S304 (step S305). After that, the control device 30 ends the series of processes shown in FIG.

[0042] On the other hand, if it is determined in step S303 that the engine torque is predicted to be smaller than the clutch torque of the second clutch 18 (step S303: No), the control device 30 calculates the offset torque based on the motor upper limit torque and the feedback requirement calculated in step S302 (step S306).

[0043] Then, the control device 30 issues a command to increase the engine torque and decrease the motor torque by the amount of the offset torque calculated in step S306 (step S307). After that, the control device 30 ends the series of processes shown in FIG.

[0044] For example, if the engine torque is set to "100", the motor torque is set to "0", and the clutch torque of second clutch 18 is set to "100", and it is predicted that the clutch torque of second clutch 18 will change from "100" to "80", then in step S302, the control device 30 calculates "-20" as the feedback requirement.

[0045] Then, when the motor lower limit torque is "-10" and the required feedback amount is "-20", the control device 30 calculates the offset torque to be "10" or more in step S304. Furthermore, when the control device 30 calculates the offset torque to be "20" in step S304, the control device 30 decreases the engine torque from "100" to "80" and increases the motor torque from "0" to "20" in step S305.

[0046] As a result, when the clutch torque of second clutch 18 actually changes from "100" to "80", the control device 30 changes the resultant force of the engine torque and the motor torque from "100" to "80", but this change can be realized by changing the motor torque from "20" to "0" without changing the engine torque. At this time, since the motor lower limit torque is "-10", the change of the motor torque to "0" is not restricted by the motor lower limit torque.

[0047] However, when the clutch torque of second clutch 18 actually changes from "100" to "120", contrary to expectations, control device 30 changes the resultant force of engine torque and motor torque from "100" to "120". However, this change cannot be achieved by changing motor torque from "20" to "40" without changing engine torque. This is because in this case, since the motor upper limit torque is "10", the change of motor torque to "40" is restricted by the motor upper limit torque.

[0048] Also, for example, when the engine torque is set to "100", the motor torque is set to "0", and the clutch torque of second clutch 18 is set to "100", if it is expected that the clutch torque of second clutch 18 will change from "100" to "120", in step S302, the control device 30 calculates "+20" as the feedback requirement.

[0049] Then, when the motor lower limit torque is "10" and the required feedback amount is "+20", the control device 30 calculates the offset torque to be "10" or more in step S306. Furthermore, when the control device 30 calculates the offset torque to be "20" in step S306, the control device 30 increases the engine torque from "100" to "120" and decreases the motor torque from "0" to "-20" in step S305.

[0050] As a result, when the clutch torque of second clutch 18 actually changes from "100" to "120", control device 30 changes the resultant force of engine torque and motor torque from "100" to "120", but this change can be achieved by changing motor torque from "-20" to "0" without changing engine torque. At this time, because the motor upper limit torque is "10", the change of motor torque to "0" is not restricted by the motor upper limit torque.

[0051] However, when the clutch torque of second clutch 18 actually changes from "100" to "80", contrary to expectations, control device 30 changes the resultant force of engine torque and motor torque from "100" to "80". However, this change cannot be achieved by changing motor torque from "-20" to "-40" without changing engine torque. In this case, because the motor lower limit torque is "-10", the change of motor torque to "-40" is restricted by the motor lower limit torque.

[0052] 3, if the clutch torque of second clutch 18 fluctuates in the opposite direction to the predicted fluctuating direction (increasing or decreasing direction), there are cases where the resultant force of the engine torque and the motor torque cannot be made equal to the clutch torque of second clutch 18 by only controlling the motor torque due to the constraints of the motor upper limit torque or the motor lower limit torque. Therefore, it is preferable that control device 30 predicts with high accuracy the fluctuating direction of the clutch torque of second clutch 18 based on the initial characteristic value of the clutch torque of second clutch 18, on-board learning, etc., so that the clutch torque of second clutch 18 does not fluctuate in the opposite direction to the predicted direction.

[0053] As described above, the control device 30 in one embodiment is a control device 30 for a vehicle 10 that has an engine 12, a battery 32, a motor 14 driven by power supplied from the battery 32, and a second clutch 18, and when a fluctuation in the clutch torque of the second clutch 18 occurs, the control device 30 increases or decreases the engine torque of the engine 12 in advance so that the driving force transmitted to the second clutch 18 can be corrected by controlling the motor torque of the motor 14 without the motor 14 being restricted by the battery 32.

[0054] As a result, when a fluctuation occurs in the clutch torque of the second clutch 18, the control device 30 in one embodiment can correct the driving force transmitted to the second clutch 18 by controlling the motor torque of the motor 14 without the motor 14 being restricted by the battery 32 and without controlling the engine torque of the engine 12.

[0055] As a result, according to the control device 30 of one embodiment, the driving force transmitted to second clutch 18 can be corrected more quickly and with higher accuracy in response to fluctuations in the clutch torque of second clutch 18.

[0056] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to these embodiments, and various modifications and changes are possible within the scope of the gist of the present invention described in the claims. [Explanation of symbols]

[0057] 10 Vehicles 12 Engine 14 Motor 16 First clutch 18 Second clutch 20 Automatic transmission 22 Differential gear 24 Drive wheels 30 Control device 32 Battery 41,42 Driveline

Claims

[Claim 1] An engine that generates engine torque, which is a drive torque for running a vehicle; A battery; a motor that is driven by the electric power supplied from the battery to generate a motor torque that is a drive torque for running the vehicle; a starting clutch to which a resultant force of the engine torque and the motor torque is transmitted; A control device for a vehicle comprising: determining whether a change in clutch torque of the starting clutch is predicted; When it is determined that the clutch torque fluctuation is predicted, an increase or decrease due to the clutch torque fluctuation is calculated as a feedback required amount; Calculating an offset torque based on an upper limit torque or a lower limit torque of the motor and the required feedback amount; The engine torque of the engine is increased or decreased by the offset torque. A vehicle control device comprising:

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