Vehicle control device

Abstract

To provide a vehicle control device capable of suppressing an increase in shift shock during a failure of a barrel rotation angle sensor when a transmission undergoes an upshift.SOLUTION: When a barrel rotation angle sensor has a failure, a vehicle control device reduces an increase rate of power source torque in torque restoration control compared with the torque increase rate when the barrel rotation angle sensor is normal. Thus, in a case where the barrel rotation angle sensor has the failure, even if a cycle from a reduction to a restoration of drive force becomes close to a resonance period of sprung mass in a vehicle pitch direction, the vehicle control device suppresses an increase in amplitude of acceleration in a vehicle longitudinal direction. Therefore, the vehicle control device can suppress an increase in shift shock during the failure of the barrel rotation sensor when a transmission undergoes an upshift.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a control device for a vehicle equipped with a transmission that can change gears in response to rotation of a shift barrel. [Background technology]

[0002] A well-known control device for a vehicle includes a power source, a transmission that is provided in a power transmission path between the power source and drive wheels and that changes gears by switching the engagement and disengagement of a dog clutch in accordance with the rotation of a shift barrel, and a barrel rotation angle sensor that detects the rotation angle of the shift barrel. Patent Document 1 discloses an example of such a transmission. Patent Document 1 discloses a device that determines whether the dog clutch has malfunctioned, i.e., whether the gear of the transmission has shifted to a target gear after a gear change is completed, based on the rotation angle of the shift barrel detected by the barrel rotation angle sensor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-14868 Summary of the Invention [Problem to be solved by the invention]

[0004] During an upshift of a transmission, torque reduction control may be performed to temporarily reduce the torque of the power source to facilitate disengagement of the meshing teeth of the engaged dog clutch. In this case, once it is determined that the gear of the transmission has shifted to the target gear after the upshift is completed, the torque reduction control is terminated, and torque restoration control is performed to restore the torque of the power source. Whether the gear of the transmission has shifted to the target gear is determined based on the rotation angle of the shift barrel detected by a barrel rotation angle sensor. However, there are cases where the barrel rotation angle sensor is malfunctioning. In such cases, it is possible to determine whether the gear of the transmission has shifted to the target gear based on a predetermined method other than the method using the barrel rotation angle sensor, such as a gear estimation method that calculates a gear ratio using the input rotation speed and output rotation speed of the transmission. However, the time required to determine whether the gear of the transmission has shifted to the target gear may differ between the method using the barrel rotation angle sensor and the other predetermined method. In this case, the period from the start of the torque down control to the gear change determination, i.e., the period from the reduction in driving force to its return, becomes close to the sprung resonance period in the vehicle pitch direction, which may increase the amplitude of the vehicle longitudinal acceleration. Therefore, if torque recovery control is performed when gear change determination is made using a different predetermined method in the same way as torque recovery control when gear change determination is made using a barrel rotation angle sensor, there is a risk of increasing gear change shock.

[0005] The present invention has been made in light of the above circumstances, and its object is to provide a vehicle control device that can suppress an increase in shift shock when the barrel rotation angle sensor fails during an upshift of the transmission. [Means for solving the problem]

[0006] The gist of a first invention is a control device for a vehicle including: (a) a power source; a transmission provided in a power transmission path between the power source and drive wheels, the transmission being configured to change gears by switching between an engaged and disengaged state of a dog clutch in accordance with the rotation of a shift barrel; and a barrel rotation angle sensor that detects a rotation angle of the shift barrel; (b) when the barrel rotation angle sensor is normal, the control device determines whether the gear stage of the transmission has switched to a target gear stage after the completion of gear shifting based on the rotation angle of the shift barrel detected by the barrel rotation angle sensor; and when the barrel rotation angle sensor is faulty, the control device determines whether the gear stage of the transmission has switched to a target gear stage after the completion of gear shifting based on a predetermined method other than the method using the barrel rotation angle sensor. (c) a gear change determination unit that determines whether the gear stage of the transmission has changed to the target gear stage; and (c) a power source control unit that performs torque down control to temporarily reduce the torque of the power source when the transmission is upshifted, and if the gear change determination unit determines that the gear stage of the transmission has changed to the target gear stage, terminates the torque down control and performs torque return control to return the torque of the power source, and (d) if the barrel rotation angle sensor is faulty, the power source control unit reduces the rate of increase in the torque of the power source in the torque return control compared to when the barrel rotation angle sensor is normal. [Effects of the Invention]

[0007] According to the first aspect of the present invention, when the barrel rotation angle sensor is malfunctioning, the torque increase rate of the power source during torque recovery control is reduced compared to when the barrel rotation angle sensor is functioning normally. This prevents the amplitude of the vehicle longitudinal acceleration from increasing even if the cycle from the reduction in driving force to its recovery approaches the sprung resonance cycle in the vehicle pitch direction when the barrel rotation angle sensor is malfunctioning. This prevents an increase in gear shift shock when the transmission is upshifting due to a malfunction of the barrel rotation angle sensor. [Brief explanation of the drawings]

[0008] [Figure 1]1 is a diagram illustrating a schematic configuration of a vehicle to which the present invention is applied; [Figure 2] 3 is a flowchart illustrating a main part of the control operation of the electronic control device. [Figure 3] 3 is a diagram showing an example of a time chart when the control operation shown in the flowchart of FIG. 2 is executed. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. [Example]

[0010] Fig. 1 is a diagram illustrating the schematic configuration of a vehicle 10 to which the present invention is applied. In Fig. 1, the vehicle 10 includes an engine 12 that functions as a power source, drive wheels 14, and a power transmission device 16 that is provided in a power transmission path between the engine 12 and the drive wheels 14. Note that, for example, an electric motor may be used as the power source in addition to or instead of the engine 12.

[0011] The engine 12 is, for example, a known internal combustion engine, and an electronic control device 80 (described later) controls a fuel injection device, an ignition device, and the like provided on the vehicle 10, thereby controlling the engine torque Te of the engine 12.

[0012] The power transmission device 16 includes a K1 clutch 18, a transmission 20, etc. The power transmission device 16 also includes a propeller shaft 22 connected to an output shaft 20o, a differential gear 24 connected to the propeller shaft 22, and a pair of drive shafts 26 connected to the differential gear 24. The output shaft 20o is an output rotating member of the transmission 20.

[0013] The K1 clutch 18 is, for example, a hydraulic friction engagement device provided between the engine 12 and the input shaft 20i. The input shaft 20i is an input rotating member of the transmission 20. The control state (engaged state, disengaged state) of the K1 clutch 18 is switched by a K1 oil pressure PRk1 supplied from a hydraulic control circuit 28 provided in the vehicle 10.

[0014] The transmission 20 is a so-called parallel two-shaft transmission in which one of a plurality of gear stages (also synonymous with speed ratio) GS with different gear ratios (also synonymous with gear stages) γ (= input rotation speed Ni / output rotation speed No) is formed. The input rotation speed Ni is the rotation speed of the input shaft 20i, and the output rotation speed No is the rotation speed of the output shaft 20o.

[0015] The transmission 20 includes a plurality of gear pairs 30 that are constantly meshed. The gear pairs 30 include, in order from the engine 12 toward the drive wheels 14 in the direction of the rotation axis CL1, a second-speed gear pair 30a, a fifth-speed gear pair 30b, a third-speed gear pair 30c, a sixth-speed gear pair 30d, a first-speed gear pair 30e, and a fourth-speed gear pair 30f. The direction of the rotation axis CL1 is synonymous with the axial direction of the input shaft 20i.

[0016] The gear pair 30 includes a drive gear 32 (including 32a, 32b, 32c, 32d, 32e, and 32f) and a driven gear 34 (including 34a, 34b, 34c, 34d, 34e, and 34f) that is constantly meshed with the drive gear 32. The drive gear 32 is rotatable relative to the input shaft 20i. The driven gear 34 is fixed to the output shaft 20o so as not to be rotatable relative to the input shaft 20o.

[0017] The transmission 20 includes a switching mechanism 36 (including 36a, 36b, and 36c) disposed on the input shaft 20i. The first switching mechanism 36a is disposed adjacent to the second drive gear 32a and the fifth drive gear 32b in the direction of the rotation axis CL1. The same applies to the second switching mechanism 36b and the third switching mechanism 36c.

[0018] The switching mechanism 36 switches the power transmission state of the gear pair 30 between a power transmission enabled state and a power transmission disabled state. The switching mechanism 36 is a disconnecting device that can switch between a connected state in which one of the adjacent drive gears 32 is connected to the input shaft 20i so that they rotate integrally, and a disconnected state in which the other drive gear 32 is disconnected from the input shaft 20i so that they rotate relative to each other.

[0019] For example, when the second-speed drive gear 32a and the input shaft 20i are connected via the first switching mechanism 36a, the transmission 20 is switched to a power transmission enabled state via the second-speed gear pair 30a, and a second gear stage 2nd is formed in the transmission 20. The same applies to the fifth gear stage 5th, the third gear stage 3rd, the sixth gear stage 6th, the first gear stage 1st, and the fourth gear stage 4th.

[0020] The switching mechanism 36 has switching meshing teeth 38 (including 38a, 38b, 38c, 38d, 38e, and 38f) formed at a position facing the drive gear 32 in the direction of the rotation axis CL1. The drive gear 32 has gear-side meshing teeth 40 (including 40a, 40b, 40c, 40d, 40e, and 40f) that can mesh with the switching meshing teeth 38 formed at a position facing the switching mechanism 36 in the direction of the rotation axis CL1.

[0021] The transmission 20 is a dog transmission having dog clutches 50 (including 50a, 50b, 50c, 50d, 50e, and 50f). The dog clutch 50 is a dog clutch that is configured with a switching mechanism 36 having switching meshing teeth 38, gear-side meshing teeth 40, and the like. The switching meshing teeth 38 and the gear-side meshing teeth 40 are meshing teeth, i.e., dog teeth, that make up part of the dog clutch 50. The dog clutch 50 is in an engaged state when the dog teeth mesh with each other, and in a disengaged state when the meshing is released.

[0022] The transmission 20 includes a shift mechanism 60 for moving the switching mechanism 36 in the direction of the rotational axis CL1. The shift mechanism 60 includes a shift fork 62 (including 62a, 62b, 62c) that fits into the switching mechanism 36, a shift barrel 64, and a shift actuator 66. The shift barrel 64 is formed with a shift groove 68 (including 68a, 68b, 68c) that determines the movement position of the switching mechanism 36 in the direction of the rotational axis CL1 via the shift fork 62.

[0023] The shift grooves 68 are formed along the circumferential direction of the shift barrel 64, with a portion of the circumferential direction bent in the axial direction of the shift barrel 64. Therefore, when the shift barrel 64 is rotated, the shift forks 62 are moved in the axial direction of the shift barrel 64 along the groove shape of the shift grooves 68. Furthermore, when the shift forks 62 are moved in the axial direction of the shift barrel 64, the switching mechanism 36 is moved in conjunction with the shift forks 62 toward the rotation axis CL1. The shift grooves 68 each have a different shape relative to the position in the circumferential direction of the shift barrel 64. The shape of the shift grooves 68 is formed so that the transmission 20 sequentially shifts between first gear 1st and sixth gear 6th as the shift barrel 64 rotates.

[0024] The transmission 20 changes gears by switching the engagement / disengagement state of the dog clutch 50 as the switching mechanism 36 moves to specified positions in the direction of the rotation axis CL1 in accordance with the rotation of the shift barrel 64. The engagement / disengagement states of the dog clutch 50 include a connected state (synonymous with an engaged state) in which power transmission between the drive gear 32 and the input shaft 20i is possible, and a disconnected state (synonymous with a disengaged state) in which power transmission between the drive gear 32 and the input shaft 20i is disconnected.

[0025] The vehicle 10 further includes an electronic control device 80 as a controller including control devices of the vehicle 10 related to the control of the engine 12 and the transmission 20. The electronic control device 80 includes a so-called microcomputer equipped with, for example, a CPU, RAM, ROM, an input / output interface, etc.

[0026] The electronic control device 80 is supplied with various signals based on detection values ​​from various sensors provided in the vehicle 10. The various sensors include, for example, an engine rotation speed sensor 70, an input rotation speed sensor 72, an output rotation speed sensor 74, an accelerator opening sensor 76, and a barrel rotation angle sensor 78. The various signals include, for example, an engine rotation speed Ne, an input rotation speed Ni, an output rotation speed No, an accelerator opening θacc, and a barrel rotation angle θbrl. The output rotation speed No is a rotation speed corresponding to the vehicle speed V. The barrel rotation angle θbrl is a rotation angle of the shift barrel 64. The barrel rotation angle sensor 78 is a sensor that detects the barrel rotation angle θbrl.

[0027] The electronic control device 80 outputs various command signals to each device provided in the vehicle 10. These devices include, for example, the engine 12, the hydraulic control circuit 28, and the shift actuator 66. The various command signals include, for example, an engine control command signal Se, a K1 hydraulic control command signal Sk1, and a barrel control command signal Sbrl. The barrel control command signal Sbrl is a control command signal for driving the shift barrel 64 to rotate.

[0028] The electronic control unit 80 includes a power source control unit 82, a transmission control unit 84, a rotation angle sensor failure determination unit 86, and a gear shift determination unit 88 in order to realize various controls in the vehicle 10.

[0029] The power source control unit 82 calculates the required drive torque Trdem by, for example, applying the accelerator opening θacc and the vehicle speed V to a predetermined drive demand amount map. The power source control unit 82 takes into consideration the gear ratio γ of the transmission 20 and the like and outputs an engine control command signal Se to obtain the engine torque Te that realizes the required drive torque Trdem.

[0030] The transmission control unit 84 determines whether to shift gears in the transmission 20 using, for example, a predetermined shift map, and outputs a barrel control command signal Sbrl as needed to rotationally drive the shift barrel 64 and execute shift control of the transmission 20. Note that the transmission control unit 84 may also determine whether to shift gears based on an upshift request or a downshift request from the driver received, for example, via a paddle switch or the like.

[0031] The rotation angle sensor malfunction determination unit 86 determines whether or not the barrel rotation angle sensor 78 is malfunctioning, that is, whether or not there is an abnormality, based on, for example, a signal from the barrel rotation angle sensor 78.

[0032] When the rotation angle sensor failure determination unit 86 determines that the barrel rotation angle sensor 78 is normal, the gear switching determination unit 88 determines whether the gear position GS of the transmission 20 has switched to the target gear position GSt after the shift is completed, based on the barrel rotation angle θbrl detected by the barrel rotation angle sensor 78. On the other hand, when the rotation angle sensor failure determination unit 86 determines that the barrel rotation angle sensor 78 has failed, the gear switching determination unit 88 determines whether the gear position GS of the transmission 20 has switched to the target gear position GSt based on a predetermined method other than the method using the barrel rotation angle sensor 78. The other predetermined method is, for example, a method of calculating a gear ratio γ (=Ni / No) using the input rotation speed Ni and the output rotation speed No, and estimating the gear position GS from the calculated gear ratio γ.

[0033] The power source control unit 82 performs torque reduction control to temporarily reduce engine torque Te when the transmission 20 is upshifted. This torque reduction control is a control to facilitate disengagement of the dog teeth of the dog clutch 50, which is switched from an engaged state to a disengaged state when the transmission 20 is upshifted, for example. Furthermore, when the gear shift determination unit 88 determines that the gear position GS of the transmission 20 has been switched to the target gear position GSt, the power source control unit 82 terminates the torque reduction control and performs torque return control to return the engine torque Te to, for example, the engine torque Te that achieves the required drive torque Trdem. In the torque return control, the engine torque Te is increased at a predetermined torque return rate Rrt so that the engine torque Te can be quickly returned. The torque return rate Rrt is the rate of increase (= increasing gradient) of the engine torque Te during the torque return control.

[0034] Incidentally, when the barrel rotation angle sensor 78 fails, the determination of gear switching to the target gear position GSt is delayed compared to normal times (synonymous with normal times) using the barrel rotation angle sensor 78, and the timing of restoring the engine torque Te is delayed. As a result, the cycle from the decrease in driving force to its restoration becomes close to the sprung resonance cycle in the pitch direction of the vehicle 10, and if torque restoration control is performed at the same torque restoration rate Rrt as normal times, the amplitude of the vehicle longitudinal acceleration increases, which could result in a larger gear shift shock than normal times.

[0035] Therefore, in order to suppress an increase in gear shift shock when upshifting the transmission 20, the power source control unit 82 switches the torque recovery rate Rrt between when the barrel rotation angle sensor 78 has failed and when it is normal. For example, when the rotation angle sensor failure determination unit 86 determines that the barrel rotation angle sensor 78 has failed, the power source control unit 82 reduces the torque recovery rate Rrt compared to when the barrel rotation angle sensor 78 has not failed, i.e., is normal. Note that because the magnitude of the driving force differs depending on the gear ratio γ even when the engine torque Te is the same, the torque recovery rate Rrt when the barrel rotation angle sensor 78 has failed may be switched for each gear position GS.

[0036] FIG. 2 is a flowchart illustrating the main control operations of the electronic control device 80. This flowchart explains the control operations for suppressing an increase in shift shock when the barrel rotation angle sensor 78 fails during an upshift of the transmission 20, and is executed repeatedly, for example.

[0037] 2, first, in step S10 (hereinafter, "step" will be omitted) corresponding to the function of the transmission control unit 84, it is determined whether or not to perform an upshift of the transmission 20. If the determination in S10 is negative, the routine is terminated. If the determination in S10 is positive, in S20 corresponding to the function of the power source control unit 82, torque reduction control of the engine 12 is initiated to remove the dog teeth from the current gear GS during an upshift. When the engine torque Te is reduced, the force pressing the dog teeth is reduced, and the dog teeth are removed from the current gear GS. Next, in S30 corresponding to the function of the rotation angle sensor failure determination unit 86, it is determined whether or not the barrel rotation angle sensor 78 is abnormal. If the determination in S30 is positive, then in S40, which corresponds to the function of the gear switching determination unit 88, it is determined whether or not the gear has been switched to the target gear position GSt, based on the gear ratio γ calculated using the input rotation speed Ni (also synonymous with the engine rotation speed Ne) and the output rotation speed No (also synonymous with the vehicle speed V). If the determination in S40 is negative, then S40 is repeatedly executed. If the determination in S40 is positive, then in S50, which corresponds to the function of the power source control unit 82, a relatively low torque recovery rate Rrt is set, and torque recovery control in the event of a failure is initiated. On the other hand, if the determination in S30 is negative, then in S60, which corresponds to the function of the gear switching determination unit 88, it is determined whether or not the gear has been switched to the target gear position GSt, based on the barrel rotation angle θbrl detected by the barrel rotation angle sensor 78. If the determination in S60 is negative, then S60 is repeatedly executed. If the determination in S60 is positive, a relatively high torque recovery rate Rrt is set in S70, which corresponds to the function of the power source control unit 82, and normal torque recovery control is started. Following S50 or S70, in S80, which corresponds to the function of the power source control unit 82, the engine torque Te is recovered by torque recovery control.

[0038] FIG. 3 is a diagram showing an example of a time chart when the control operation shown in the flowchart of FIG. 2 is executed. In FIG. 3, time t1 indicates the time when torque reduction control of the engine 12 is initiated during an upshift when the barrel rotation angle sensor 78 fails. Time t2 indicates the timing of gear backlash jamming. Because the barrel rotation angle sensor 78 fails, a gear change to the target gear GSt is determined at a timing later than time t2 (see time t3). In the comparative example shown by the dashed line, torque return control is performed at the same torque return rate Rrt as in normal operation, resulting in increased gear shift shock. In contrast, in the present embodiment shown by the solid line, torque return control is performed at a torque return rate Rrt that is smaller than in normal operation. This reduces or avoids an increase in gear shift shock.

[0039] As described above, according to this embodiment, when the barrel rotation angle sensor 78 fails, even if the period from the reduction in driving force to its recovery approaches the sprung resonance period in the pitch direction of the vehicle 10, the amplitude of the vehicle longitudinal acceleration is prevented from increasing.

[0040] Although the embodiments of the present invention have been described in detail above with reference to the drawings, the present invention can be embodied in various forms with various modifications and improvements based on the knowledge of those skilled in the art. [Explanation of symbols]

[0041] 10: Vehicle 12: Engine (power source) 14: Drive wheels 20: Transmission 50: Dog clutch (meshing clutch) 64: Shift barrel 78: Barrel rotation angle sensor 80: Electronic control unit (control unit) 82: Power source control unit 88: Gear change determination unit

Claims

[Claim 1] A control device for a vehicle including: a power source; a transmission provided in a power transmission path between the power source and drive wheels, the transmission changing speed by switching the engagement and disengagement state of a mesh clutch in accordance with the rotation of a shift barrel; and a barrel rotation angle sensor detecting the rotation angle of the shift barrel, a gear change determination unit that, when the barrel rotation angle sensor is normal, determines whether the gear stage of the transmission has been switched to a target gear stage after the completion of the shift based on the rotation angle of the shift barrel detected by the barrel rotation angle sensor, and, when the barrel rotation angle sensor is faulty, determines whether the gear stage of the transmission has been switched to the target gear stage based on a predetermined method other than the method using the barrel rotation angle sensor; a power source control unit that performs torque reduction control to temporarily reduce the torque of the power source when the transmission is upshifted, and that terminates the torque reduction control and performs torque recovery control to restore the torque of the power source when the gear change determination unit determines that the gear stage of the transmission has been changed to the target gear stage; and a power source control unit that, when the barrel rotation angle sensor is faulty, reduces the rate of increase in the torque of the power source during the torque recovery control compared to when the barrel rotation angle sensor is normal.

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