JP2016061414A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a cost increase, and to improve reliability when learning and correcting characteristics of the clutch torque of a friction clutch which is switchable between engagement and release by a movement of a piston by rotation of a motor.SOLUTION: In a vehicle control device, by comparing relationships (motor MAPa-i) between a motor rotation angle Am and a motor current Im in an actual motor MAPa-i and a base MAPa-i, characteristics of the clutch torque Tclt of each individual clutch 30 can be captured, or a temporal change of the characteristics of the clutch torque Tclt can be captured. Thereby, the characteristics (torque MAPm-c) of the clutch torque Tclt of the clutch 30 with respect to the motor rotation angle Am can be suitably corrected without adding a rotation speed sensor for detecting a rotation speed of a rotating member which is changed due to the engagement of the clutch 30. Therefore, when correcting the torque MAPm-c by learning, a cost increase is suppressed, and reliability can be improved.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a vehicle control device including a friction clutch of a type in which a piston is moved by rotation of a motor to be switched between engagement and release.

  The characteristics of the clutch torque, which is the relationship between the indicated value in the friction clutch for the vehicle (or the movement of the actuator that operates the friction clutch) and the clutch torque, are corrected by learning to reduce the effects of individual differences and changes over time. Vehicle control devices are well known. For example, the driving state control device for a vehicle described in Patent Document 1 is that. This patent document 1 describes a part of a transfer in a four-wheel drive vehicle based on a front engine rear wheel drive (FR) on condition that the front wheel side propeller shaft stops rotating when the two-wheel drive (2WD) mode is selected. The current applied to the actuator of the multi-plate clutch mechanism constituting the motor is gradually increased from zero, and the current value at the time when the rotation of the front wheel side propeller shaft starts is distributed to the front wheel side when the four-wheel drive (4WD) mode is selected. Is disclosed that updates the relationship between the current supplied to the actuator of the multi-plate clutch mechanism and the distribution torque adjusted by the clutch so that the distribution torque transmission start current value when the value is increased from zero. .

JP 2013-95213 A

  By the way, as in the technique of Patent Document 1, when trying to capture the engagement mode of the friction clutch using the rotational speed change of the rotating member that changes with the engagement, in order to correct the torque characteristics, A rotation speed sensor that detects the rotation speed of the rotating member is required. Therefore, there is a possibility that the cost is increased by the rotation speed sensor, or the reliability is lowered due to a sensor failure. Depending on the hardware configuration to which the friction clutch is applied, a plurality of rotational speed sensors may be required to correct the torque characteristics. Since there are many rotation speed sensors, it becomes easy to cause a cost increase and a reliability fall. The above-described problem is not known.

  The present invention has been made against the background of the above circumstances, and the object of the present invention is to provide a clutch torque of a friction clutch of a type in which a piston is moved by rotation of a motor to be switched between engagement and release. An object of the present invention is to provide a vehicle control apparatus that can suppress an increase in cost and improve reliability when correcting characteristics by learning.

  The subject matter of the first invention for achieving the above object is: (a) Control of a vehicle provided with a friction clutch of a type in which a piston is moved by rotation of a motor to be switched between engagement and release. (B) the rotational position of the motor and the driving current of the motor are detected, and (c) the relationship between the rotational position of the motor and the driving current of the motor is the detected value. And (d) correcting the characteristics of the clutch torque of the friction clutch with respect to the rotational position of the motor based on the comparison result.

  In this way, by comparing the relationship between the rotational position of the motor and the driving current of the motor with a relationship based on the detected value and a predetermined relationship, the clutch torque for each individual friction clutch is compared. Characteristics can be captured, or changes in clutch torque characteristics over time can be captured. Thereby, the characteristic of the clutch torque of the friction clutch with respect to the rotational position of the motor is appropriately corrected without adding a rotation speed sensor that detects the rotation speed of the rotating member that changes as the friction clutch is engaged. Therefore, when the characteristics of the clutch torque of the friction clutch are corrected by learning, an increase in cost can be suppressed and reliability can be improved.

  Here, according to a second aspect, in the vehicle control device according to the first aspect, when the motor is rotated, a change in the drive current of the motor with respect to a change in the rotational position of the motor is within a predetermined value. The clutch torque characteristic is corrected using the motor drive current detected in the current stable region. In this way, using the current value in the packed region where the clutch torque is not generated, which is the current value in the current stable region, means that the rotational position of the motor and the motor drive in the region where the clutch torque is generated. Since this leads to an improvement in the correlation (proportional relationship) with the current, the accuracy of correction by learning can be improved.

  According to a third aspect of the present invention, in the vehicle control apparatus according to the second aspect of the present invention, the motor based on the detected value so that the drive current of the motor detected in the current stable region is zero. The relationship between the rotational position of the motor and the driving current of the motor is corrected, and the corrected relationship and the predetermined relationship in which the driving current of the motor in the current stable region is zero. The characteristic of the clutch torque is to be corrected based on the rotational position difference at the same drive current value of the motor when compared. In this way, individual variations in the current value in the current stable region can be suppressed, and the proportional relationship between the rotational position of the motor and the motor drive current in the region where the clutch torque is generated is improved, and learning is performed. The accuracy of correction by means of is improved.

  According to a fourth aspect of the present invention, there is provided the vehicle control apparatus according to any one of the first to third aspects, wherein the friction clutch pack is based on the corrected characteristic of the clutch torque. Determining the driving current value of the motor until packing, the driving current value of the motor after packing of the friction clutch, and the timing to start increasing the driving current value of the motor after packing of the friction clutch; The clutch torque is controlled. In this way, the control accuracy of the clutch torque can be improved.

  According to a fifth aspect of the present invention, in the vehicle control device according to any one of the first to fourth aspects, the vehicle includes a torque distribution device that distributes torque to left and right wheels. The friction clutch is a clutch involved in the torque distribution to the left and right wheels by the torque distribution device, and the clutch torque is controlled by controlling the clutch torque based on the corrected characteristic of the clutch torque. The purpose is to control the distribution of torque to the left and right wheels. In this way, the control accuracy of torque distribution to the left and right wheels can be improved.

It is a figure explaining the schematic structure of the torque distribution apparatus with which the vehicle to which this invention was applied is provided, and is a figure explaining the principal part of the control function and various control systems for various control in a torque distribution apparatus. It is a figure which overlaps and shows an example of the change of a motor rotation angle, and the change of a motor current in the same time series, Comprising: It is a figure for demonstrating a current stable area | region. It is a figure for demonstrating the outline | summary of the learning logic of the characteristic of a clutch torque, Comprising: It is a figure which shows an example of the relationship between an actual motor rotation angle and an actual motor current. It is a figure for demonstrating the outline | summary of the learning logic of the characteristic of a clutch torque, Comprising: It is a figure which shows an example of the relationship between the corrected motor rotation angle and motor current. It is a figure for demonstrating the outline | summary of the learning logic of the characteristic of a clutch torque, Comprising: It is a figure which shows an example which compared the corrected relationship and the predetermined relationship between a motor rotation angle and a motor electric current. . It is a figure for demonstrating the outline | summary of the learning logic of the characteristic of a clutch torque, Comprising: It is a figure which shows an example of the learning result of the characteristic of a clutch torque. It is a figure which shows an example of the motor control command signal in the case of using a motor current as a controlled variable. 7 is a flowchart for explaining a control operation for suppressing an increase in cost and improving reliability when correcting a principal part of the control operation of the electronic control unit, that is, the characteristics of the clutch torque of the clutch by learning.

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

  FIG. 1 is a diagram for explaining a schematic configuration of a torque distribution device 12 provided in a vehicle 10 to which the present invention is applied, and shows control functions for various controls in the torque distribution device 12 and main parts of a control system. It is a figure explaining. In FIG. 1, a vehicle 10 is, for example, an FR vehicle. The vehicle 10 includes a driving force source 14 such as an engine. In the vehicle 10, power from the driving force source 14 (synonymous with torque and force unless otherwise specified) is sequentially transmitted through the propeller shaft 16, the torque distribution device 12, and the like to the left and right rear wheels 18L, 18R (hereinafter referred to as rear wheel 18 unless otherwise specified).

  The torque distribution device 12 includes a rear wheel differential gear device 20 (hereinafter referred to as a differential gear device 20), left and right rear wheel axles 22L and 22R (hereinafter referred to as an axle 22 unless otherwise specified), and the like. Yes. The torque distribution device 12 distributes torque to the left and right rear wheels 18. For example, the torque distribution device 12 distributes the power from the driving force source 14 transmitted to the propeller shaft 16 from the differential gear device 20 to the left and right rear wheels 18 via the left and right axles 22. Thus, the torque distribution device 12 functions as a left / right driving force distribution device that distributes the power from the driving force source 14 to the rear wheels 18 as left / right driving wheels. The torque distribution by the torque distribution device 12 includes the movement of the torque between the left and right rear wheels 18L, 18R.

  The differential gear device 20 includes a differential case 20c and a differential mechanism 20d composed of a bevel gear, and a known bevel gear type differential gear that transmits rotation while appropriately applying differential rotation to the left and right axles 22. Mechanism. The differential case 20 c is provided with a ring gear 20 r that meshes with a drive pinion 16 d provided at the tip of the propeller shaft 16. Accordingly, the power from the driving force source 14 transmitted to the propeller shaft 16 is transmitted from the drive pinion 16d to the differential case 20c via the ring gear 20r.

  The torque distribution device 12 further includes left and right speed increasing devices 24L and 24R (hereinafter referred to as the speed increasing device 24 unless otherwise specified) between the differential case 20c and the left and right axles 22, respectively. Since the speed increasing devices 24L and 24R are symmetrically configured, the same members are denoted by the same reference numerals for the members included in the speed increasing devices 24L and 24R, respectively.

  The left and right speed increasing devices 24 include left and right first planetary gear devices 26, left and right second planetary gear devices 28, left and right clutches 30L and 30R (hereinafter referred to as clutch 30 unless otherwise specified), The motor M is provided. The first planetary gear device 26 and the second planetary gear device 28 are arranged around the axis of the axle 22 in the axial direction. The first planetary gear unit 26 is disposed on the differential gear unit 20 side, and the second planetary gear unit 28 is disposed on the rear wheel 18 side. The clutch 30 is a multi-plate clutch disposed around the axle of the axle 22. The clutch 30 includes a piston 30p that is moved along the axial direction of the axle 22 as the motor M rotates, and the engagement force is changed by being pressed by the piston 30p. The rotation of the motor M is decelerated via a gear mechanism 32 having a plurality of reduction gears and transmitted to the cam 34. The rotational movement of the cam 34 is linear movement in the axial direction of the axle 22 by the cam 34 and the ball 36. And is transmitted to the piston 30p. That is, the clutch 30 is a friction clutch of a type in which the piston 30p is moved by the rotation of the motor M to be switched between engagement and release, and the rotation angle Am of the motor M (hereinafter referred to as the motor rotation angle Am), Alternatively, the engagement force (the clutch torque Tclt is also agreed) is changed by the drive torque Tm of the motor M (hereinafter referred to as the motor torque Tm) or the drive current Im of the motor M (hereinafter referred to as the motor current Im).

  The first planetary gear device 26 includes a sun gear 26s and a plurality of planetary gears 26p that mesh with the sun gear 26s. The second planetary gear device 28 includes a sun gear 28s and a plurality of planetary gears 28p that mesh with the sun gear 28s. In addition, the first planetary gear device 26 and the second planetary gear device 28 include a common carrier 26c that supports the planetary gear 26p and the planetary gear 28p so as to rotate and revolve, respectively.

  In the first planetary gear device 26 and the second planetary gear device 28, the sun gear 26s is connected to the differential case 20c and rotates integrally with the differential case 20c. The sun gear 28 s is connected to the axle 22 and rotates integrally with the axle 22. The planetary gear 26p and the planetary gear 28p are integrally provided. The carrier 26c is selectively coupled to the housing 38, which is a non-rotating member, via the clutch 30. As an example, the number of teeth ZS1 of the sun gear 26s is larger than the number of teeth ZS2 of the sun gear 28s, and the number of teeth ZP2 of the planetary gear 28p is set to be larger than the number of teeth ZP1 of the planetary gear 26p.

  In the torque distribution device 12 configured as described above, when both the left and right clutches 30 are released, torque is distributed to the left and right rear wheels 18 only through the differential gear device 20. Further, when the clutch 30 is engaged (especially slip control here), the torque of the differential case 20c is increased to the axle 22 and further to the rear via the speed increasing device 24 on the side where the clutch 30 is controlled. It is transmitted to the wheel 18. That is, as the rotation of the carrier 26c on the side on which the clutch 30 is controlled to be engaged is restricted, a torque for increasing the rotation speed of the rear wheel 18 on the side on which the engagement is controlled is generated. The torque of the rear wheel 18 on the controlled side is increased, and the torque of the rear wheel 18 on the side where the clutch 30 is not relatively controlled is decreased in accordance with the increase of the torque. For example, when the engagement of the right clutch 30R is controlled with a predetermined engagement torque in order to increase the torque of the right rear wheel 18R, it is transmitted to the differential case 20c as shown by a broken line arrow A in FIG. Part of the torque is transmitted to the right rear wheel 18R via the right speed increasing device 24R, and the remaining portion is distributed to the left and right rear wheels 18L, 18R by the differential gear device 20. Thus, the clutch 30 is a clutch involved in the torque distribution to the left and right rear wheels 18 by the torque distribution device 12.

  The vehicle 10 further includes, for example, an electronic control unit (ECU) 70 that includes a control device for the vehicle 10 that controls the torque distribution to the left and right rear wheels 18 by the torque distribution device 12 (that is, executes the left / right torque distribution control). Prepare. The electronic control unit 70 includes, for example, a so-called microcomputer having a CPU, a RAM, a ROM, an input / output interface, and the like. The CPU uses a temporary storage function of the RAM and follows a program stored in the ROM in advance. Various controls of the vehicle 10 are executed by performing signal processing. For example, the electronic control unit 70 controls the engagement of only one of the left and right clutches 30 with a predetermined engagement torque, thereby increasing the torque of the rear wheel 18 on the side to be engaged and controlling the engagement. The left and right torque distribution control by the torque distribution device 12 is executed by relatively reducing the torque of the rear wheel 18 that is not controlled. The electronic control unit 70 performs output control of the driving force source 14, left-right torque distribution control by the torque distribution device 12, and the like, and is used for driving force source control, left-right torque distribution control, and the like as necessary. It is configured separately.

  The electronic control device 70 includes various sensors (for example, a motor rotation angle sensor 50, a motor drive current sensor 52, a wheel speed sensor 54, a temperature sensor 56, a battery voltage sensor 58, a yaw rate sensor 60, a steering sensor 62, an accelerator provided in the vehicle 10. Various actual values (for example, motor rotation angle Am corresponding to the rotation position of the motor M, motor current Im, left and right front wheels (not shown), and left and right rear wheels 18) Nfl, Nfr, Nrl, Nrr, a temperature THclt of the clutch 30 (hereinafter referred to as a clutch temperature THclt), a battery for supplying electric power to the electronic controller 70, a motor drive circuit 66 for driving the motor M, a vehicle auxiliary machine (not shown), etc. 68 voltage Vbat (hereinafter referred to as battery voltage Vbat), yaw rate Ryaw which is the rotational angular velocity around the vertical axis of the vehicle 10, Steering angle θsw and steering direction Dsw the tearing wheel, an accelerator opening theta] acc) are supplied. The electronic control unit 70 outputs a motor control command signal Sm as a control command value for controlling the motor M to the motor drive circuit 66 and the like. The electronic control unit 70 calculates the speed V of the vehicle 10 (hereinafter referred to as the vehicle speed V) as various actual values, for example, based on the average wheel speed Nf of the wheel speeds Nfl and Nfr of the left and right front wheels.

  The electronic control unit 70 includes left and right torque distribution control means, that is, a left and right torque distribution control unit 72. The left / right torque distribution control unit 72 executes left / right torque distribution control by the torque distribution device 12. As an example of the left / right torque distribution control, the left / right torque distribution control unit 72 controls the yaw moment so that, for example, an appropriate turning performance can be obtained during turning.

  Specifically, the left-right torque distribution control unit 72 determines the vehicle speed V, the steering from the relationship (for example, an arithmetic expression or a data map) obtained and stored experimentally or in advance (ie, predetermined). A target yaw rate Ryawtgt is calculated based on the angle θsw, the accelerator opening θacc, and the like. The left-right torque distribution control unit 72 calculates a necessary yaw moment amount (required yaw moment amount) based on the target yaw rate Ryawtgt and the actual yaw rate Ryaw from a predetermined relationship. The left / right torque distribution control unit 72 calculates a target left / right torque difference (in other words, target left / right torque distribution) necessary to obtain the necessary yaw moment amount from a predetermined relationship. The left / right torque distribution control unit 72 calculates the amount of torque movement from one of the left and right rear wheels 18 to the other, based on the torque input to the differential gear device 20, to obtain the target left / right torque distribution. The left and right torque distribution control unit 72 calculates the clutch torque Tclt of the clutch 30 of the speed increasing device 24 on the torque increasing side from which a torque movement amount can be obtained from a predetermined relationship. The left-right torque distribution control unit 72 obtains the clutch torque Tclt of the clutch 30 on the torque increase side from a predetermined relationship (predetermined torque MAPm-c) between the motor rotation angle Am and the clutch torque Tclt of the clutch 30. The target motor rotation angle Amtgt is calculated, and a motor control command signal Sm for setting the actual motor rotation angle Am to the target motor rotation angle Amtgt is output to the motor drive circuit 66.

  Here, when the clutch 30 is operated, the motor rotation angle Am at which the clutch torque Tclt rises (that is, the motor rotation angle Am at which the gaps between the plurality of clutch plates of the clutch 30 are clogged (packing of the clutch 30 is completed)) is grasped. It is important to. On the other hand, the motor rotation angle Am at which the clutch torque Tclt rises may not be a uniform value due to individual differences of the clutch 30 (for example, variations in gaps). Therefore, for example, the motor rotation angle Am at which the clutch torque Tclt rises is measured at the time of product shipment, and the characteristics of the clutch torque Tclt with respect to the motor rotation angle Am (that is, the motor rotation angle Am and the clutch torque Tclt are measured using an information recording code). (Torque MAPm-c)) may be written and stored in the electronic control unit 70. However, this method requires various facilities such as a facility for measuring the characteristics of the clutch torque Tclt and a facility for writing information to the electronic control unit 70, which may increase the cost. In addition, this method can cope with initial individual differences, but cannot cope with temporal changes such as wear of the clutch 30.

  Alternatively, as a method different from the above method, the clutch 30 is gradually operated, and the motor rotation angle Am when the rotating member that changes with the slip engagement of the clutch 30 changes is learned, and the predetermined torque MAPm− It is conceivable to correct c. However, this method requires a rotation speed sensor for detecting the rotation change of the rotating member for learning, which increases the cost or cannot be learned due to a failure of the rotation speed sensor, and the controllability of the clutch 30 is deteriorated. There is a risk of it. In particular, the torque distribution device 12 does not have a structure in which the rotation of one rotation target rotation member is simply changed by the slip engagement of the clutch 30, so that the rotation speed of a plurality of rotation members (for example, one of the rear wheels 18 A plurality of rotational speed sensors for detecting the rotational speed, the rotational speed of the other rear wheel 18 or the propeller shaft 16, and the rotational speed of the clutch 30 (in other words, the rotational speed of the carrier 26c) are required, which may increase the cost. There is. In addition, if there are many rotation speed sensors, the error will be larger and the probability that any one of the rotation speed sensors will break down is higher than when there is only one rotation speed sensor. There is a fear. Furthermore, it is necessary to actually perform the left / right torque distribution control while the vehicle is running and learn, and if the learning is not completed, the controllability of the clutch 30 may be deteriorated.

  Therefore, in this embodiment, paying attention to the fact that the force for pressing the clutch 30 (in other words, the clutch torque Tclt and the motor torque Tm) increases in proportion to the motor current Im, the information recording code and the rotational speed described above are used. A learning control is proposed that corrects the characteristic (torque MAPm-c) of the clutch torque Tclt using the motor rotation angle Am and the motor current Im without using a sensor. That is, the electronic control unit 70 detects the relationship between the motor rotation angle Am and the motor current Im (motor MAPa-i), which is a value detected by the motor rotation angle sensor 50 and the motor drive current sensor 52. The relationship based on the angle Am and the actual motor current Im (actual motor MAPa-i) is compared with a predetermined relationship (base MAPa-i), and the torque MAPm-c is corrected based on the comparison result. .

  By the way, when the clutch 30 is pressed, sliding resistance is generated in the internal parts involved in the pressing of the clutch 30, so that the force pressing the clutch 30 is not necessarily proportional to the motor current Im. In addition, this sliding resistance has individual differences. In this case, even if an attempt is made to read the motor rotation angle Am when a certain motor current Im is generated and use this motor rotation angle Am for learning correction, the accuracy of the correction may deteriorate. Therefore, in this embodiment, the current stable region is set in order to improve the correction accuracy when using the motor current Im. The electronic control unit 70 corrects the torque MAPm-c using the motor current Im detected in the current stable region.

  FIG. 2 is a diagram showing, for example, a change in the motor rotation angle Am and a change in the motor current Im when the motor M is rotated, in the same time series, for explaining the current stable region. is there. As shown in FIG. 2, the current stable region is a region where when the motor M is rotated, the change in the motor current Im with respect to the change in the motor rotation angle Am is within a predetermined value. Specifically, the current stable region is a region where the motor current Im becomes substantially constant when the motor rotation angle Am is gradually increased.

  Since the load increases when the clutch 30 is grasped, the motor current Im increases. On the other hand, the current stable region is a region where the clutch 30 is not grasped. However, the motor current Im in this current stable region is not 0 [A] but is stable with a certain value. The value of the motor current Im depends on the sliding resistance of internal components (for example, the gear mechanism 32 and the cam 34) until the clutch 30 is moved, and varies depending on the individual. By using this stable value of the motor current Im for correction, it is possible to suppress variations in individual machine parts and to maintain a proportional relationship between the pressing force of the clutch 30 and the motor current Im. Therefore, learning accuracy can be improved. The electronic control unit 70 corrects the actual motor MAPa-i so that the motor current Im detected in the current stable region becomes zero, the corrected motor MAPa-i, and the motor current Im in the current stable region. The torque MAPm-c is corrected based on the difference of the motor rotation angle Am at the same motor current Im value when compared with the base MAPa-i in which is set to zero.

  3 to 6 are diagrams for explaining the outline of the learning logic of the torque MAPm-c executed by the electronic control unit 70. FIG. FIG. 3 is a diagram illustrating an example of the actual motor MAPa-i. FIG. 4 is a diagram illustrating an example of the motor MAPa-i corrected using the value of the motor current Im in the current stable region. FIG. 5 is a diagram illustrating an example in which the corrected motor MAPa-i and the base MAPa-i are compared. FIG. 6 is a diagram illustrating an example of a learning result of the torque MAPm-c. 3 to 6 show an embodiment with three different individuals A, B, and C.

  In the actual motor MAPa-i in FIG. 3, the motor rotation angle Am when the motor current Im rises is different for each of the individuals A, B, and C. , B and C are different. Further, when looking at the current stable region (see the box surrounded by a broken line in the figure), the value of the motor current Im varies for each of the individuals A, B, and C. This is because the sliding resistance until the clutch 30 is grasped is different for each of the individuals A, B, and C. In the learning logic, the actual motor MAPa-i is stored.

  In FIG. 4, the motor current Im in the current stable region in the actual motor MAPa-i in FIG. 3 is corrected. That is, the value of the motor current Im of the actual motor MAPa-i in FIG. 3 is offset so that the average value of the motor current Im in the current stable region is 0 [A]. That is, in the learning logic, the value of the motor current Im of the entire actual motor MAPa-i is subtracted by the average value of the motor current Im in the current stable region, and the actual motor MAPa-i is converted into the corrected motor MAPa-i. Is done. By doing so, variation in sliding resistance (that is, variation in current load due to sliding resistance) can be suppressed, and the correlation between the motor current Im and the force pressing the clutch 30 can be improved.

  In FIG. 5, a base MAPa-i indicated by a thick solid line is a relational expression serving as a reference for the motor MAPa-i in which the motor current Im in the current stable region is zero. The difference between the base MAPa-i serving as the reference and the corrected motor MAPa-i in FIG. 4 is calculated. This difference is used as a correction amount. That is, in the learning logic, the difference (angle difference value) of the motor rotation angle Am at the same motor current Im value between the corrected motor MAPa-i and the reference base MAPa-i is calculated as a learning correction value. Is done. The base MAPa-i is moved by the angle difference value (that is, the motor rotation angle Am is shifted by the angle difference value in the base MAPa-i) to be the corrected base MAPa-i. As the angle difference value, for example, an angle difference value at the time of one predetermined motor current Im may be used, or an average value of each angle difference value at a plurality of values of the predetermined motor current Im is used. Alternatively, an angle difference value calculated using the motor current Im as a variable may be used.

  In FIG. 6, each bold line represents a final learning result obtained by converting the motor current Im in the corrected base MAPa-i into the clutch torque Tclt. That is, in the learning logic, the motor current Im in the corrected base MAPa-i is converted into the clutch torque Tclt, and the corrected torque MAPm-c is calculated as a learning value. Since the base MAPa-i can be regarded as a relationship in which the clutch torque Tclt at the predetermined torque MAPm-c is converted to the motor current Im, the predetermined torque MAPm-c is converted into the corrected torque MAPm by the series of learning control described above. It is corrected to -c. The left-right torque distribution control unit 72 controls the clutch torque Tclt so that the actual motor rotation angle Am becomes the target motor rotation angle Amtgt from which the desired clutch torque Tclt is obtained based on the corrected torque MAPm-c. Each thin line that controls the distribution of torque to the left and right rear wheels 18 is an actual measurement value when the clutch torque Tclt is controlled using the corrected torque MAPm-c, and the actual measurement value and the learning value are substantially equal. You can see that you are doing it.

  The control amount when the actual motor rotation angle Am is set as the target motor rotation angle Amtgt includes, for example, the motor rotation angle Am, the motor torque Tm, or the motor current Im. When the motor rotation angle Am or the motor torque Tm is used as a control amount, the motor control command signal Sm serving as an instruction value to the motor M is the target motor rotation angle Amtgt or the target motor torque Tmtgt that provides the target motor rotation angle Amtgt. This is the target value.

  On the other hand, when the motor current Im is used as the control amount, the motor control command signal Sm becomes an output instruction value such as the motor current Im output from the motor drive circuit 66 so as to be the target motor rotation angle Amtgt. In this case, the left / right torque distribution control unit 72 determines the value of the motor current Im until the clutch 30 is packed, the value of the motor current Im after the clutch 30 is packed, and the clutch based on the corrected torque MAPm-c. The timing for starting to increase the value of the motor current Im after 30 packs is determined to control the clutch torque Tclt.

  FIG. 7 is a diagram illustrating an example of a motor control command signal Sm when the motor current Im is used as a control amount. In FIG. 7, the corrected torque MAPm-c is reflected in the values A, B, and C of the motor current Im. The corrected torque MAPm-c is reflected in the torque control start timing t3. From the time t1 to the time t3 is a period in which the clutch 30 packs are performed within the range of the motor rotation angle Am immediately before the clutch torque Tclt is generated. Since the clutch torque Tclt is not generated regardless of the value of the motor current Im during packing, the value of the motor current Im corresponding to the sliding resistance is larger than the value B of the motor current Im corresponding to the sliding resistance until the time t2 after a predetermined timer Time1 has elapsed from the start time t1. The motor M is driven by the motor current Im having a high value A. This shortens the time required for packing. From time t2 to time t3 before the packing is completed, the motor M is driven by the motor current Im having a value B corresponding to the sliding resistance. At the time point t2 and the time point t3, the value of the motor rotation angle Am until the clutch torque Tclt rises at the corrected torque MAPm-c is reflected. After the time t3 when the packing is completed, the motor current Im reflects the value of the motor rotation angle Am after the rising of the clutch torque Tclt at the corrected torque MAPm-c so that the desired clutch torque Tclt is obtained. M is driven.

  More specifically, returning to FIG. 1, the electronic control unit 70 further includes a vehicle state determination unit, that is, a vehicle state determination unit 74, a learning start condition determination unit, that is, a learning start condition determination unit 76, and a learning control unit, that is, learning control. A portion 78 is provided.

  The vehicle state determination unit 74 determines, for example, whether or not the vehicle state is an ignition-off (IG-OFF) state in which the driving force source 14 cannot be operated. In the learning control of the torque MAPm-c according to the present embodiment, the generation of the clutch torque Tclt is not detected, and the rotation change of the rotating member is not detected. it can. That is, learning control can be performed without actually performing left-right torque distribution control. Therefore, the learning control of this embodiment is performed in the ignition off state. Therefore, it is determined whether or not the ignition is off.

  For example, when the vehicle state determination unit 74 determines that the vehicle state is the ignition off state, the learning start condition determination unit 76 determines whether or not the learning start condition is satisfied. The learning start conditions are, for example, that the vehicle 10 is stopped, the battery voltage Vbat is normal, and that there is no abnormality in the torque distribution device 12. The learning start condition determination unit 76 determines whether or not the vehicle 10 is stopped based on whether or not the vehicle speed V is a predetermined vehicle speed zero determination value. This is because the learning control is performed when the vehicle is stopped with the ignition off. The learning start condition determination unit 76 determines whether or not the battery voltage Vbat is normal based on whether or not the battery voltage Vbat is equal to or higher than a predetermined learnable voltage threshold. This is because the learning control is performed in the ignition-off state where the battery 68 is not charged.

  Further, the learning start condition determination unit 76 determines whether or not the torque distribution device 12 has an abnormality based on whether or not an abnormality related to the left and right torque distribution control by the torque distribution device 12 has occurred. The abnormality relating to the left / right torque distribution control includes, for example, an abnormality of the motor control command signal Sm itself, an abnormality of components (motor M, gear mechanism 32, etc.) related to the pressing of the clutch 30, and the like. The learning start condition determination unit 76 functionally includes a diagnosis device (diagnosis) that detects an abnormality in the motor control command signal Sm itself, and based on the diagnosis result by the diagnosis device, the motor control command signal Sm itself. It is determined whether or not an abnormality has occurred. Abnormalities of components related to the pressing of the clutch 30 can be determined, for example, by using the motor current Im in the current stable region for internal failure diagnosis. In the current stable region, the motor current Im is stable if normal, but the motor current Im becomes unstable when a foreign object is caught (for example, the change in the motor current Im has a predetermined value). Exceeded). When the motor M is driven, the learning start condition determination unit 76 monitors the motor current Im in a region where the predetermined clutch 30 is not grasped in consideration of component variations, and changes in the motor current Im Is determined to be within a predetermined value, it is determined whether or not an abnormality of a component related to the pressing of the clutch 30 has occurred.

  For example, when the learning start condition determining unit 76 determines that the learning start condition is satisfied, the learning control unit 78 performs learning control for correcting the torque MAPm-c. Specifically, the learning control unit 78 operates the motor M as a learning preparation. Then, the learning control unit 78 determines whether or not the motor current Im is stable based on whether or not the change in the motor current Im is within a predetermined value (that is, whether the operating state of the motor M is in the current stable region). Or not). When the learning control unit 78 determines that the current is in the current stable region, the learning control unit 78 calculates a correction amount (learning correction value) from the motor MAPa-i using the motor current Im in the current stable region. The learning control unit 78 corrects the base MAPa-i using the learning correction value, converts the corrected motor current Im in the base MAPa-i into the clutch torque Tclt, and corrects the corrected torque MAPm as a learning value. -c is calculated. The learning control unit 78 writes (stores) the corrected torque MAPm-c in a rewritable memory provided in the electronic control unit 70.

  Here, the gap between the clutch plates in the clutch 30 may change depending on the clutch temperature THclt. As a learning value, it is desirable to unify the value at a certain temperature. Therefore, the learning control unit 78 performs temperature correction on the learning value so as to obtain a unified value at a certain temperature according to the clutch temperature THclt at the time of learning control. Here, the clutch temperature THclt is exemplified as the temperature used for the temperature correction. However, the temperature is not limited to this, and any temperature that affects the clutch 30 may be used. For example, the temperature in the housing 38 that houses the clutch 30 or the temperature of the lubricating oil in the housing 38 may be used.

  The learning control by the learning control unit 78 is executed, for example, when the ignition is turned off after the first ignition is turned on (IG-ON). Further, this learning control may be executed, for example, every time the ignition is turned off, every elapse of a predetermined time, or every predetermined distance traveling. As a result, it is possible to cope with a change with time, and it is possible to maintain the performance of the torque distribution device 12 or suppress the deterioration of the performance. If it is possible to determine that the clutch 30 has changed over time (for example, the gap has changed due to wear of the clutch 30), learning control may be executed at the time of the change over time. When the learning control is repeatedly executed, the predetermined torque MAPm-c is always corrected to the corrected torque MAPm-c, or the base MAPa-i may be used as the corrected base MAPa-i. -c or corrected base MAPa-i may be handled as a predetermined torque MAPm-c or base MAPa-i, and the corrected value may be further subjected to learning control. In addition, the learning control by the learning control unit 78 has a cost merit because the measurement of the characteristics of the clutch 30, the setting of the information recording code, and the rotation speed sensor are unnecessary.

  FIG. 8 illustrates the control operation for suppressing the increase in cost and improving the reliability when the main part of the control operation of the electronic control unit 70, that is, the characteristic of the clutch torque Tclt of the clutch 30 is corrected by learning. This is a flowchart, and is repeatedly executed with an extremely short cycle time of, for example, about several milliseconds to several tens of milliseconds.

  In FIG. 8, first, in step (hereinafter, step is omitted) S10 corresponding to the vehicle state determination unit 74, for example, it is determined whether or not the vehicle state is an ignition-off (IG-OFF) state. If the ignition-on (IG-ON) state is continued and the determination in S10 is negative, this S10 is repeatedly executed. If the determination in S10 is affirmative, for example, in S20 corresponding to the learning start condition determination unit 76, is the learning start condition (vehicle stop, battery voltage Vbat normal (OK), torque distribution device 12 no abnormality) established? It is determined whether or not. If the determination in S20 is negative, this routine is terminated. If the determination in S20 is affirmative, in S30 corresponding to the learning control unit 78, the motor M is operated as a learning preparation. Next, in S40 corresponding to the learning control unit 78, it is determined whether or not the motor current Im is stable (that is, whether or not the operating state of the motor M is in the current stable region). If the determination at S40 is negative, this routine is terminated. If the determination in S40 is affirmative, in S50 corresponding to the learning control unit 78, the correction amount (learning correction value) is calculated from the motor MAPa-i using the motor current Im in the current stable region. Next, in S60 corresponding to the learning control unit 78, the learning correction value is written in a rewritable memory. The torque MAPm-c is corrected using this learning correction value.

  As described above, according to the present embodiment, the relationship (motor MAPa-i) between the motor rotation angle Am and the motor current Im is compared between the actual motor MAPa-i and the base MAPa-i. A characteristic of the clutch torque Tclt for each individual clutch 30 is captured, or a change with time in the characteristic of the clutch torque Tclt is captured. As a result, the characteristic (torque MAPm-c) of the clutch torque Tclt of the clutch 30 with respect to the motor rotation angle Am can be obtained without adding a rotation speed sensor that detects the rotation speed of the rotating member that changes as the clutch 30 is engaged. Corrected appropriately. Therefore, when the torque MAPm-c is corrected by learning, an increase in cost can be suppressed and reliability can be improved.

  Further, according to the present embodiment, the torque MAPm-c is corrected using the motor current Im detected in the current stable region, so that the motor rotation angle Am and the motor current Im in the region where the clutch torque Tclt is generated. This leads to an improvement in the correlation (proportional relationship), and the correction accuracy by learning is improved.

  Further, according to this embodiment, the actual motor MAPa-i is corrected so that the motor current Im detected in the current stable region is zero, and the corrected actual motor MAPa-i and base MAPa-i are Since the torque MAPm-c is corrected based on the angle difference value at the same motor current Im value when compared, the individual variation of the motor current Im value in the current stable region can be suppressed, and the clutch torque Tclt is The proportional relationship between the motor rotation angle Am and the motor current Im in the generated region is improved, and the accuracy of correction by learning is improved.

  Further, according to the present embodiment, based on the corrected torque MAPm-c, the value of the motor current Im until the clutch 30 is packed, the value of the motor current Im after the clutch 30 is packed, and the clutch 30 Since the timing to start increasing the value of the motor current Im after packing is determined and the clutch torque Tclt is controlled, the control accuracy of the clutch torque Tclt is improved.

  Further, according to the present embodiment, the torque distribution to the left and right rear wheels 18 is controlled by controlling the clutch torque Tclt based on the corrected torque MAPm-c. Can be improved.

  As mentioned above, although the Example of this invention was described in detail based on drawing, this invention is applied also in another aspect.

  For example, in the above-described embodiment, the clutch 30 involved in the torque distribution to the left and right rear wheels 18 by the torque distribution device 12 is illustrated as the friction clutch to which the invention is applied, but is not limited to this mode. In short, the present invention can be applied to any single-plate or multi-plate friction clutch of the type in which the piston 30p is moved by the rotation of the motor M to be switched between engagement and release.

  In the above-described embodiment, the motor rotation angle Am is exemplified as a value corresponding to the rotation position of the motor M. However, the present invention is not limited to this mode. For example, the rotational speed of the motor M may be used as a value corresponding to the rotational position of the motor M. In this case, 36 [deg], 90 [deg], 180 [deg], etc. of the motor rotation angle Am are 1/10 [number of rotations], 1/4 [number of rotations], 1/2 [number of rotations] of the motor M. ] Etc.

  In the above-described embodiment, the vehicle 10 is an FR vehicle including the torque distribution device 12 and the driving force source 14, but is not limited thereto. For example, the vehicle 10 may be a four-wheel drive vehicle, an FF vehicle, or an RR vehicle. Moreover, although the torque distribution apparatus 12 was provided with the speed increasing apparatus 24, it is not restricted to this. For example, the torque distribution device 12 is a torque distribution device of a type that transmits the power transmitted to the intermediate shaft of the axle to the left and right wheels via the left and right axles via the left and right clutches connected to the intermediate shaft, respectively. There may be. The driving force source 14 is a gasoline engine such as an internal combustion engine or a diesel engine, but other prime movers such as an electric motor can be used alone or in combination with the engine.

  The above description is only an embodiment, and the present invention can be implemented in variously modified and improved forms based on the knowledge of those skilled in the art.

10: Vehicle 12: Torque distribution device 18 (18L, 18R): Rear wheel (wheel)
30 (30L, 30R): Clutch (friction clutch)
30p: Piston 70: Electronic control device (control device)
M: Motor

Claims (5)

A control device for a vehicle having a friction clutch of a type in which a piston is moved by rotation of a motor to be switched between engagement and release,
Detecting the rotational position of the motor and the drive current of the motor;
Comparing the relationship between the rotational position of the motor and the driving current of the motor with a relationship based on the detected value and a predetermined relationship;
A vehicle control device that corrects a characteristic of a clutch torque of the friction clutch with respect to a rotational position of the motor based on the comparison result.   The characteristics of the clutch torque using the motor driving current detected in the current stable region where the change of the driving current of the motor with respect to the change of the rotational position of the motor is within a predetermined value when the motor is rotated. The vehicle control device according to claim 1, wherein: Correcting the relationship between the rotational position of the motor and the driving current of the motor based on the detected value so that the driving current of the motor detected in the current stable region is zero;
Based on the rotational position difference at the same driving current value of the motor when the corrected relationship is compared with the predetermined relationship in which the driving current of the motor in the current stable region is zero. The vehicle control device according to claim 2, wherein the clutch torque characteristic is corrected.   Based on the corrected characteristics of the clutch torque, the motor drive current value until the friction clutch is packed, the motor drive current value after the friction clutch is packed, and the friction clutch pack. 4. The vehicle control device according to claim 1, wherein the clutch torque is controlled by determining when to start increasing the drive current value of the motor later. 5. The vehicle includes a torque distribution device that distributes torque to left and right wheels,
The friction clutch is a clutch involved in the distribution of torque to the left and right wheels by the torque distribution device,
5. The distribution of torque to the left and right wheels is controlled by controlling the clutch torque based on the corrected characteristic of the clutch torque. 6. Vehicle control device.

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