JP7443977B2 - Vehicle control device - Google Patents

Description

The present disclosure relates to a vehicle control device.

A power transmission system of an electric vehicle has a configuration in which power from a motor is transmitted to drive wheels via a reduction gear. Therefore, when a vehicle accelerates from a decelerated state or decelerates from an accelerated state, the motor torque may pass through a dead zone region where it is not transmitted to the drive shaft due to the backlash of the gears that are the components of the reducer. . If the angular velocity of the motor increases in the dead zone region when the vehicle is accelerating or decelerating, there is a concern that noise, vibration, etc. may be generated at the timing when adjacent gears mesh with each other. As a vehicle control device capable of suppressing noise, vibration, etc. caused by crossing such a dead zone region of a power transmission system, there is, for example, a control device described in Patent Document 1.

The control device described in Patent Document 1 includes a calculation section, a control section, an estimation section, and a restriction section. The calculation unit calculates a torque command value that suppresses vibration components of the drive shaft by feedback controlling the torsion angular velocity of the drive shaft with respect to a target torque that determines the power of the motor. The control unit controls the operation of the motor based on the torque command value. The estimation unit estimates a dead zone region in which the torque of the motor in the vehicle is not transmitted to the drive shaft based on the target torque. The limiter limits the torque command value when the power transmission system is in a dead zone region. According to this configuration, since the output torque of the motor is limited when the power transmission system straddles the dead zone region, it is possible to suppress noise, vibration, etc.

Patent No. 6614357

In the components of the power transmission system that transmits the power of the motor to the wheels, there is a possibility that actual dimensions and design values may differ due to variations due to individual differences or deterioration over time. Additionally, errors may occur when controlling the operation of the motor. Such control errors and dimensional errors become factors that reduce the estimation accuracy of the dead zone area.

In this regard, if a method of simply estimating the dead zone area from the target torque is used, as in the control device described in Patent Document 1 mentioned above, errors in control, dimensional errors, etc. are not reflected, so the dead zone area is estimated. There is concern that the accuracy is low. In order to avoid this, for example, the area in which the output torque of the motor is limited may be expanded so that control errors, dimensional errors, etc. can be absorbed. However, when such a method is adopted, the responsiveness of the motor torque control decreases by the extent that the motor output torque limit area is expanded, so the responsiveness of the vehicle to the driver's accelerator operation decreases. descend. As a result, the driver may feel a sense of stagnation.

The present disclosure has been made in view of these circumstances, and an object of the present disclosure is to provide a vehicle control device that can more appropriately detect a dead zone region of a power transmission system.

A vehicle control device (60) that solves the above problem transmits torque output from a motor (20) from a drive shaft (24) to drive wheels (11, 12) via a power transmission system (23). It is installed in the vehicle (10) and controls the motor. The control device includes a rotational state detection section (61) and a dead zone region estimation section (62). The rotational state detection section detects the torque of the drive shaft based on an output signal of a sensor that outputs a signal corresponding to the torque applied to the drive shaft . The dead zone estimating section estimates the start time of a dead zone region of the power transmission system due to backlash of gears provided in the power transmission system, based on the rotational state of the drive shaft.

When a dead zone region is formed in the power transmission system due to backlash of gears provided in the power transmission system, a change occurs in the rotational state of the drive shaft. Therefore, according to the above configuration, it is possible to estimate the dead zone area. Furthermore, even if a shift occurs in the dead zone region of the power transmission system due to control errors, dimensional errors, etc., the influence of the shift in the dead zone region appears as a change in the rotational state of the drive shaft. Therefore, by estimating the dead zone area based on the rotational state of the drive shaft as in the above configuration, it is possible to detect the dead zone area that reflects the influence of control errors and dimensional errors, so that the power transmission system can be more appropriately adjusted. It becomes possible to detect the dead zone area.

Note that the above-mentioned means and the reference numerals in parentheses described in the claims are examples showing correspondences with specific means described in the embodiments to be described later.

According to the vehicle control device of the present disclosure, it is possible to more appropriately detect the dead zone region of the power transmission system.

FIG. 1 is a diagram schematically showing a schematic configuration of a vehicle according to a first embodiment. FIG. 2 is a block diagram showing the electrical configuration of the vehicle according to the first embodiment. FIG. 3 is a flowchart showing the procedure of processing executed by the integrated ECU of the first embodiment. FIG. 4 is a graph showing changes in relative angular velocity, which is the difference between the angular velocity of the motor generator and the angular velocity of the drive shaft in the vehicle of the first embodiment. FIGS. 5A to 5D are graphs showing changes in the basic torque target value Tb, drive shaft torque Td, motor generator torque Tm, and motor generator rotational speed ωm in the vehicle of the first embodiment. . FIG. 6 is a graph showing changes in the phase difference Δθ, which is the difference between the rotation angle of the motor generator and the rotation angle of the drive shaft in the vehicle of the second modification of the first embodiment. FIG. 7 is a graph showing changes in the torque Td of the drive shaft in the vehicle of the third modification of the first embodiment. FIG. 8 is a graph showing changes in the relative angular velocity Δω, which is the difference between the angular velocity of the motor generator and the angular velocity of the drive shaft in the vehicle of the fourth modification of the fourth embodiment. FIGS. 9A to 9D are graphs showing changes in the basic torque target value Tb, drive shaft torque Td, motor generator torque Tm, and motor generator rotational speed ωm in the vehicle of the second embodiment. .

Hereinafter, one embodiment of a vehicle control device will be described with reference to the drawings. In order to facilitate understanding of the description, the same components in each drawing are denoted by the same reference numerals as much as possible, and redundant description will be omitted.
<First embodiment>
First, a vehicle control device according to a first embodiment will be described. First, a schematic configuration of a vehicle in which the control device of this embodiment is mounted will be described.

As shown in FIG. 1, the vehicle 10 of this embodiment includes a motor generator 20, an inverter device 21, a battery 22, and a differential device 23. Vehicle 10 is a so-called electric vehicle that travels based on the power of motor generator 20.
Inverter device 21 converts DC power stored in battery 22 into three-phase AC power, and supplies the converted three-phase AC power to motor generator 20 .

Motor generator 20 operates as an electric motor and a generator. When operating as an electric motor, motor generator 20 is driven based on three-phase AC power supplied from inverter device 21 . The driving force of the motor generator 20 is transmitted to the front right wheel 11 and the front left wheel 12 of the vehicle 10 via the differential device 23 and the drive shaft 24, so that these wheels 11 and 12 rotate and the vehicle 10 runs. do. In the vehicle 10, the right front wheel 11 and the left front wheel 12 function as driving wheels, and the right rear wheel 13 and the left rear wheel 14 function as driven wheels. Hereinafter, for convenience, the front right wheel 11 and the front left wheel 12 will also be collectively referred to as drive wheels 11 and 12.

The motor generator 20 performs regenerative power generation when the vehicle is decelerated. When motor generator 20 performs regenerative power generation, braking force is applied to drive wheels 11 and 12, and vehicle 10 can be decelerated. Three-phase AC power generated by motor generator 20 is converted into DC power by inverter device 21 and charged into battery 22 .

The differential device 23 is configured by a combination of a plurality of gears, and when a difference occurs between the angular velocities of the right front wheel 11 and the left front wheel 12, the differential device 23 absorbs the angular speed difference and moves the motor generator 20. The driving force transmitted from the front right wheel 11 and the left front wheel 12 is divided and transmitted. In this embodiment, the differential gear 23 also corresponds to a reduction gear.

The wheels 11 to 14 of the vehicle 10 are provided with friction brake devices 31 to 34, respectively. The friction brake devices 31 to 34 are devices that apply braking force to each wheel 11 to 14 by applying friction force to a rotating body that rotates together with each wheel 11 to 14.
Next, the electrical configuration of the vehicle 10 will be explained.

As shown in FIG. 2, the vehicle 10 includes wheel speed sensors 41 to 44, torque sensors 51 and 52, and an integrated ECU (Electronic Control Unit) 60.
As shown in FIG. 1, wheel speed sensors 41-44 are provided on wheels 11-14, respectively. The wheel speed sensors 41 to 44 detect wheel speeds ωw11 to ωw14, which are the angular velocities of the wheels 11 to 14, respectively, and output signals corresponding to the detected wheel speeds ωw11 to ωw14 to the integrated ECU 60.

As shown in FIG. 1, the torque sensor 51 is provided at a portion of the drive shaft 24 that is connected to the right front wheel 11. The torque sensor 52 is provided at a portion of the drive shaft 24 that is connected to the left front wheel 12 . The torque sensors 51 and 52 each detect the torque of the drive shaft 24 at the installed portion, and output a signal corresponding to the detected torque to the integrated ECU 60.

As shown in FIG. 2, motor generator 20 is provided with a rotation sensor 200 that detects its rotation angle. Rotation sensor 200 outputs a signal according to the rotation angle of motor generator 20 to integrated ECU 60 .
The integrated ECU 60 is mainly composed of a microcomputer including a CPU, ROM, RAM, and the like. In this embodiment, the integrated ECU 60 corresponds to a control device. Integrated ECU 60 is a part that centrally controls the operation of motor generator 20 by executing a program stored in advance in ROM.

Specifically, the integrated ECU 60 is communicably connected to a host ECU 70 mounted on the vehicle 10. The host ECU 70 detects the accelerator position, traveling speed, shift position, etc. of the vehicle 10 using various sensors mounted on the vehicle 10, and also calculates the basic torque target value Tb based on the detected information using a calculation formula, a map, etc. Calculate. Basic torque target value Tb is a target value of torque to be output from motor generator 20. For example, when it is necessary to accelerate the vehicle 10, the basic torque target value Tb is set to a positive value. Further, when it is necessary to decelerate the vehicle 10, the basic torque target value Tb is set to a negative value. When the integrated ECU 60 receives the basic torque target value Tb transmitted from the host ECU 70, it calculates an energization control value according to the basic torque target value Tb, and controls the inverter device 21 based on the calculated energization control value. . Thereby, three-phase AC power according to the energization control value is supplied from the inverter device 21 to the motor generator 20, and a torque according to the basic torque target value Tb is output from the motor generator 20.

By the way, in such a vehicle 10, when there is a transition from an acceleration state to a deceleration state, in other words, when the output torque of the motor generator 20 changes from a positive value to a negative value, the differential gear 23 When backlash occurs in the provided gears, a dead zone may be formed in the power transmission system from motor generator 20 to drive shaft 24. If a dead zone region is formed in the power transmission system, there is a concern that noise, vibration, etc. may be generated at the timing when adjacent gears subsequently mesh with each other.

Therefore, the integrated ECU 60 of this embodiment determines whether a dead zone region is formed in the power transmission system based on the torque of the drive shaft 24 detected by the torque sensors 51 and 52. When integrated ECU 60 determines that a dead zone region is formed in the power transmission system, it controls the torque of motor generator 20 so that noise, vibration, etc. are not generated.

Next, the configuration of integrated ECU 60 for controlling motor generator 20 will be specifically described.
As shown in FIG. 2, the integrated ECU 60 includes a rotation state detection section 61, a dead zone region determination section 62, a target torque calculation section 63, and a motor control section 64. Each of these elements repeatedly executes the process shown in FIG. 3 at a predetermined calculation cycle.

As shown in FIG. 3, the target torque calculation unit 63 first obtains the basic torque target value Tb from the host ECU 70 as a process in step S10. Further, as the process of step S11, the motor control unit 64 sets the torque target value T* of the motor generator 20 to the basic torque target value Tb, and then controls the output torque Tm of the motor generator 20 to the torque target value T*. Executes torque feedback control. Specifically, the motor control unit 64 calculates the actual output torque Tm of the motor generator 20 using at least one of the torques detected by the torque sensors 51 and 52, based on a calculation formula, a map, etc. The output torque Tm of the motor generator 20 is feedback-controlled so that the calculated actual output torque Tm of the motor generator 20 follows the torque target value T*.

Note that in the process of step S11, the motor control unit 64 may perform torque feedback control by estimating the output torque Tm of the motor generator 20 based on the value of the current supplied to the motor generator 20, for example. . Furthermore, in the process of step S11, the motor control unit 64 may perform feedforward control of the output torque Tm of the motor generator 20 based on the torque target value T*.

The dead zone region determination unit 62 determines whether or not the start time of the dead zone region of the power transmission system is detected as processing in step S12 following step S11. Specifically, the rotation state detection unit 61 calculates the torque Td of the drive shaft 24 based on the torque detected by the torque sensors 51 and 52. Note that the rotation state detection unit 61 may use the average value of the torques detected by the torque sensors 51 and 52 as the torque Td of the drive shaft 24, or may use one of these torques as the torque of the drive shaft 24. It may also be used as Td. In the process of step S12, the dead zone region determination section 62 determines whether the torque Td of the drive shaft 24 detected by the rotational state detection section 61 is zero (=0 [Nm]). If the dead zone region determination unit 62 determines that the torque Td of the drive shaft 24 is not zero, it makes a negative determination in the process of step S12, and temporarily ends the process shown in FIG. 3.

On the other hand, when backlash occurs in the gears provided in the differential device 23, a dead zone region is formed in which the output torque Tm of the motor generator 20 is not transmitted to the drive shaft 24, so that the torque Td of the drive shaft 24 temporarily becomes zero. become. In this case, the dead zone area determination unit 62 makes a positive determination in the process of step S12. As a result, the target torque calculation unit 63 calculates the basic torque target value as the process of step S13 in order to reduce gear collision sounds, vibrations, etc. that occur due to the formation of a dead zone region in the power transmission system. A dead zone torque target value Th different from Tb is set. The specific procedure of the process in step S13 is as follows.

If a dead zone region is not formed in the power transmission system, the output torque Tm of the motor generator 20 is directly transmitted to the drive shaft 24, so there is a difference between the angular velocity of the output shaft of the motor generator 20 and the angular velocity of the drive shaft 24. A correlation is established.
On the other hand, if a dead zone region is formed in the power transmission system due to gear backlash, no load is applied to the output shaft of motor generator 20, so the angular velocity of motor generator 20 temporarily decreases. To increase. Therefore, there is no correlation between the angular velocity of motor generator 20 and the angular velocity of drive shaft 24. Thereafter, when the dead zone region of the power transmission system is eliminated by the contact of the gears, the correlation between the angular velocity of the motor generator 20 and the angular velocity of the drive shaft 24 is established again.

Utilizing this, in the integrated ECU 60 of this embodiment, when the speed obtained by subtracting the angular velocity ωd of the drive shaft 24 from the angular velocity ωm of the motor generator 20 is the relative angular velocity Δω (=ωm−ωd), the power transmission system has a dead band region. An angular velocity profile that is an ideal transition of the relative angular velocity Δω so as not to generate sound, vibration, etc. when the angular velocity is formed is determined in advance through experiments or the like and stored in the ROM. The angular velocity profile consists of a map showing the temporal transition of the relative angular velocity Δω. The angular velocity profile is created as a map in which the relative angular velocity Δω is increased and then decreased, for example, when the output torque of the motor generator 20 changes from a negative value to a positive value. Further, the angular velocity profile is created as a map in which the relative angular velocity Δω is decreased and then increased when the output torque of the motor generator 20 changes from a positive value to a negative value. Alternatively, the angular velocity profile is created as a map that maintains the relative angular velocity Δω at a constant velocity.

When a map in which the relative angular velocity Δω is increased and then decreased is used as the angular velocity profile, the relative angular velocity Δω changes as shown, for example, by a solid line or a dashed-dotted line in FIG. 4. That is, when the relative angular velocities at the start time t10 of the dead zone region are set to predetermined values Δωa and Δωb, the relative angular velocities Δω increase from the predetermined values Δωa and Δωb and then decrease. This angular velocity profile is set in advance through experiments or the like so that the end time of the dead zone region is a time t11 when the relative angular velocity Δω becomes the predetermined values Δωa and Δωb again after the start time t10 of the dead zone region. By using such an angular velocity profile, when gears that have once caused backlash come into contact with each other again, their relative angular velocity returns to the relative angular velocity at the start of the dead zone region, thereby suppressing noise and vibration. becomes possible.

On the other hand, when a map that maintains the angular velocity of the motor generator 20 at a constant velocity is used as the angular velocity profile, the relative angular velocity Δω changes as shown by the two-dot chain line in FIG. 4, for example. That is, the relative angular velocity Δω is maintained at a constant speed during the period from the start time t10 to the end time t11 of the dead zone region. Note that in this angular velocity profile, the end time t11 is set at the time when a predetermined time T10 has elapsed from the start time t10.

Note that, for convenience's sake, hereinafter, a case where a profile shown by a solid line or a dashed-dotted line in FIG. 4 is used as an angular velocity profile will be described as an example.
In the process of step S13 shown in FIG. 3, the rotation state detection unit 61 detects the respective wheel speeds ωw11 and ωw12 of the driving wheels 11 and 12 based on the output signals of the wheel speed sensors 41 and 42, and also detects the detected wheel speeds ωw11 and ωw12. The angular velocity ωd of the drive shaft 24 is calculated based on the wheel speeds ωw11 and ωw12. Note that the rotation state detection unit 61 may calculate the angular velocity ωd of the drive shaft 24 from the average value of the wheel speeds ωw11 and ωw12, or may calculate the angular velocity ωd of the drive shaft 24 from either one of the wheel speeds ωw11 and ωw12. Good too. Further, rotation state detection section 61 detects the actual angular velocity of motor generator 20 based on the output signal of rotation sensor 200.

Target torque calculation unit 63 calculates a target angular velocity of motor generator 20 from the angular velocity ωd of drive shaft 24 detected by rotation state detection unit 61 and the angular velocity profile of relative angular velocity Δω. In order to cause the actual angular velocity of the motor generator 20 detected by the rotation state detection unit 61 to follow the target angular velocity, the target torque calculation unit 63 calculates the target value of the output torque of the motor generator 20 based on the deviation. A certain dead zone torque target value Th is calculated using an arithmetic expression, a map, etc.

The motor control unit 64 executes dead zone torque control as processing in step S14 following step S13. Specifically, the motor control unit 64 sets the torque target value T* of the motor generator 20 to the dead zone torque target value Th, and then sets the actual output torque Tm of the motor generator 20 to the torque target value T*. The motor generator 20 is controlled as follows. Note that this torque control may be either feedback control or feedforward control.

The dead zone determination unit 62 determines whether the vehicle has passed through a dead zone, as a process in step S15 following step S14. Specifically, the dead zone region determination unit 62 determines whether the relative angular velocity Δω has decreased to the value of the start time t10 of the dead zone region, that is, the predetermined values Δωa and Δωb shown in FIG. 4. In this embodiment, the process of determining whether the relative angular velocity Δω has decreased to the predetermined values Δωa, Δωb corresponds to the process of estimating the end time of the dead zone region. If the relative angular velocity Δω has not decreased to the predetermined values Δωa and Δωb, a negative determination is made in the process of step S15. In this case, the target torque calculation section 63 and the motor control section 64 estimate that the dead zone has not been passed, in other words, it is not the end time of the dead zone, and repeat the processes of steps S13 and S14. As a result, the relative angular velocity Δω between the angular velocity ωm of the motor generator 20 and the angular velocity ωd of the drive shaft 24 is shown in FIG. It changes according to either a solid line or a dashed-dotted line.

Thereafter, when the relative angular velocity Δω decreases to predetermined values Δωa and Δωb at the start time t10 of the dead zone region, the dead zone region determination unit 62 estimates that the dead zone region has been passed, in other words, it is the end time of the dead zone region, An affirmative determination is made in the process of step S15. At this point, the backlash of the gears in the power transmission system has been eliminated, and the gears are back in mesh with each other. In this case, the process shown in FIG. 3 is temporarily ended.

Next, with reference to FIG. 5, an example of the operation of the vehicle 10 of this embodiment will be described.
In order to transition the vehicle 10 from a deceleration state to an acceleration state, as shown in FIG. Suppose that it changes towards the value of . At this time, if the torque target value T* of the motor generator 20 is set to the basic torque target value Tb, the torque Td of the drive shaft 24 and the motor generator 20 The output torque Tm changes with a positive correlation with the basic torque target value Tb.

If backlash is formed in the gears of the power transmission system at time t22 while the basic torque target value Tb is changing in this way, and a dead zone region occurs, the output torque Tm of the motor generator 20 is applied to the drive shaft 24. It will no longer be transmitted. Therefore, as shown in FIG. 5(B), the torque of the drive shaft 24 becomes zero at time t22. At this time, if the basic torque target value Tb shown in FIG. 5(A) is used as is as the torque target value T* of the motor generator 20, the motor The output torque Tm of the generator 20 will continue to increase. Then, when the dead zone region ends at time t23, that is, when the gears contact each other again, the torque of the drive shaft 24 oscillates as shown by the dashed line in FIG. 5(B) due to the impact at that time, and As shown by the dashed line in D), the angular velocity ωm of the motor generator 20 also oscillates. This becomes a factor that causes the vehicle 10 to generate abnormal noises and vibrations.

On the other hand, when using a method of estimating the dead zone region based on the torque target value and limiting the output torque of the motor generator 20 during the period of the dead zone region, as in the conventional control device described in Patent Document 1, Since it is not possible to directly detect whether or not a dead zone has occurred, it is necessary to increase the region in which the output torque of the motor generator 20 is limited relative to the actual dead zone. Furthermore, there is a possibility that deviations may occur between the actual dimensions and design values of parts such as gears that make up the power transmission system due to individual differences or deterioration over time. It is necessary to further enlarge the area in which the output torque is limited. As a result, as shown by the two-dot chain line in FIG. 5(C), the output torque of the motor generator 20 is started to be limited at time t21, which is earlier than time t22, which is the actual start time of the dead zone region. It is necessary to release the restriction on the output torque of the motor at time t25, which is after time t24, which is the actual end time of the dead zone region. In this case, the period during which the output torque of motor generator 20 is limited becomes longer, so the responsiveness of control of motor generator 20 decreases.

Note that the two-dot chain lines shown in FIGS. 5(B) and (D) indicate that the dead zone region is estimated based on the torque target value like the conventional control device described in Patent Document 1, and the dead zone region is estimated during the period of the dead zone region. 4 shows the changes in the torque Td of the drive shaft 24 and the changes in the angular velocity ωm of the motor generator 20 when a method of limiting the output torque of the motor generator 20 is used.

On the other hand, when the integrated ECU 60 of the present embodiment detects that the torque Td of the drive shaft 24 has become zero at time t22 based on the torque detected by the torque sensors 51 and 52, the integrated ECU 60 moves to the dead zone region at time t22. It is determined that it is time to start. Thereafter, when the relative angular velocity Δω at the start time t22 is set to a predetermined value Δωa, and the relative angular velocity Δω decreases to the predetermined value Δωa at time t24, the integrated ECU 60 determines that it is the end time of the dead zone region at that time. Integrated ECU 60 calculates a target angular velocity of motor generator 20 based on angular velocity ωd of drive shaft 24 and a predetermined angular velocity profile of relative angular velocity Δω during a period from time t22 to time t24. Then, the integrated ECU 60 sets a dead zone torque target value Th that allows the actual angular velocity ωm of the motor generator 20 to follow the target angular velocity, and converts the set dead zone torque target value Th into the torque of the motor generator 20. Used as target value T*. As a result, the output torque of the motor generator 20 increases and then decreases as shown by the solid line in FIG. 5(C). As a result, as shown by the solid line in FIG. 5(D), if the angular velocity of the motor generator 20 at time t22 is "ωma", the angular velocity ωm of the motor generator 20 decreases after increasing from the predetermined speed ωma, At time t24, the speed changes again to the predetermined speed ωma. By reducing the output torque Tm of the motor generator 20, it becomes difficult to generate an impact when the backlash is eliminated at time t23, that is, when the gears come into contact with each other. As a result, as shown by the solid line in FIG. 5(B), the torque Td of the drive shaft 24 changes without vibration, so that noise, vibration, etc. can be reduced.

Further, after time t24, integrated ECU 60 gradually changes torque target value T* of motor generator 20 from dead zone torque target value Th toward basic torque target value Tb. Therefore, as shown by the solid line in FIG. 5(C), the output torque Tm of the motor generator 20 changes toward the basic torque target value Tb. Thereby, as shown by the solid line in FIG. 5(B), the torque of the drive shaft 24 can be increased without vibration occurring in the drive shaft 24 after time t24.

According to the integrated ECU 60 of this embodiment described above, the functions and effects shown in (1) to (7) below can be obtained.
(1) The rotation state detection unit 61 detects the torque Td of the drive shaft 24 as the rotation state of the drive shaft 24. Based on the torque Td of the drive shaft 24, the dead zone region determination unit 62 determines a dead zone region of the power transmission system caused by backlash of gears provided in the power transmission system from the motor generator 20 to the drive shaft 24. According to this configuration, when a dead zone region is formed in the power transmission system due to backlash of gears provided in the power transmission system, a change occurs in the torque Td of the drive shaft 24. can detect the occurrence of dead zone regions. On the other hand, even if a shift occurs in the dead zone region of the power transmission system due to control errors, dimensional errors, etc., the influence of the shift in the dead zone region appears as a change in the torque Td of the drive shaft 24. Therefore, if the dead zone area of the power transmission system is determined based on the torque Td of the drive shaft 24, it is possible to detect the dead zone area that reflects the effects of control errors, dimensional errors, etc. It becomes possible to detect the dead zone area of the transmission system.

(2) Target torque calculation section 63 calculates torque target value T* of motor generator 20 based on the dead zone region determined by dead zone region determination section 62. Motor control unit 64 controls motor generator 20 based on torque target value T*. According to this configuration, the relative angular velocity Δω, which is the speed obtained by subtracting the angular velocity ωw of the drive wheels 11 and 12 from the angular velocity ωm of the motor generator 20, can be changed as shown by the solid line and the dashed-dotted line in FIG. It is possible to suppress noise and vibration when gears come into contact with each other after backlash occurs.

(3) The dead zone determination section 62 detects the start time of the dead zone based on the torque Td of the drive shaft 24. According to this configuration, the start time of the dead zone region can be detected with higher accuracy.
(4) The rotation state detection unit 61 detects the angular velocity ωd of the drive shaft 24 as the rotation state of the drive shaft 24. The dead zone region determination unit 62 uses the angular velocity ωm of the motor generator 20 as the rotational state of the motor generator 20, and determines the dead zone based on the relative angular velocity Δω, which is the difference between the angular velocity ωd of the drive shaft 24 and the angular velocity ωm of the motor generator 20. Estimate when the region will end. In this embodiment, the relative angular velocity Δω corresponds to the relative difference between the rotational state of the drive shaft 24 and the rotational state of the motor generator 20. The target torque calculation unit 63 calculates a torque target value Th for the dead zone based on the relative angular velocity Δω during a period from the start time to the end time of the dead zone region, and also sets the torque target value T* of the motor generator 20 to the torque target value for the dead zone. Set to the value Th. According to this configuration, the relative angular velocity Δω can be more appropriately controlled in the dead zone region, so the generation of sound and vibration can be further suppressed.

(5) The target torque calculation unit 63 sets the dead zone torque target value Th based on the angular velocity profile which is a map of the relative angular velocity Δω set in advance. According to this configuration, the dead zone torque target value Th can be easily set.
(6) The target torque calculation unit 63 temporarily changes the dead zone torque target value Th during the period from the start time to the end time of the dead zone region. As a result, as shown in FIG. 5C, the output torque Tm of the motor generator 20 can be changed to increase and then decrease during the period from the start time t22 to the end time t24 of the dead zone region. Therefore, the generation of noise and vibration can be suppressed.

(7) The rotation state detection unit 61 detects the angular velocity ωd of the drive shaft 24 based on the wheel speeds ωw11 and ωw12 of the drive wheels 11 and 12 detected by the wheel speed sensors 41 and 42. According to this configuration, the angular velocity ωd of the drive shaft 24 can be easily detected.

(First modification)
Next, a first modification of the integrated ECU 60 of the first embodiment will be described.
Instead of using the method of detecting the start timing of the dead zone region using the torque Td of the drive shaft 24, the dead zone region determination unit 62 of this modification uses the difference between the angular velocity ωm of the motor generator 20 and the angular velocity ωd of the drive shaft 24. The start time of the dead zone region is detected using a certain relative angular velocity Δω. Specifically, the dead zone region determination unit 62 determines the dead zone region based on the fact that |d(Δω)/dt|, which is the absolute value of the time differential value of the relative angular velocity Δω, is equal to or greater than a predetermined determination value α. Detect when the start of. Even with such a configuration, it is possible to detect the start time of the dead zone area.

Note that when using the configuration of this modification, it is not necessary to detect the torque of the drive shaft 24. Therefore, the configuration of this modification is also applicable to vehicles in which the torque sensors 51 and 52 are not provided.
(Second modification)
Next, a second modification of the integrated ECU 60 of the first embodiment will be described.

In place of the method of estimating the end timing of the dead zone region based on the relative angular velocity Δω, which is the difference between the angular velocity ωm of the motor generator 20 and the angular velocity ωd of the drive shaft 24, the dead zone region determination unit 62 of this modification The end time of the dead zone region is estimated based on the phase difference Δθ, which is the angle obtained by subtracting the rotation angle θd of the drive shaft 24 from the rotation angle θm of the generator 20.

Specifically, when a dead zone region occurs in the power transmission system, the phase difference Δθ monotonically increases as shown in FIG. 6, for example. At this time, if the start time of the dead zone region is detected at time t30, for example, the dead zone region determination unit 62 determines the time after a predetermined time T20 has elapsed from the start time t30 as the end time t31. Note that the predetermined time T20 may be set in advance through experiments or the like, or a learned value obtained by learning the passing time of the dead zone region may be used. Note that the process of learning the passing time of the dead zone area may be executed, for example, when an affirmative determination is made in the process of step S15 shown in FIG.

In this modification, rotation state detection section 61 detects rotation angle θm of motor generator 20 based on the output signal of rotation sensor 200. Further, the rotation state detection unit 61 detects the drive speed by using the wheel speeds ωw11 and ωw12 of the drive wheels 11 and 12 detected by the wheel speed sensors 41 and 42, or by using the rotation sensor provided on the drive shaft 24. The rotation angle θd of the shaft 24 is detected. The dead zone region determination section 62 calculates a phase difference Δθ from the rotation angle θm of the motor generator 20 and the rotation angle θd of the drive shaft 24 detected by the rotation state detection unit 61. The dead zone region determination unit 62 determines the relative angle value "Δθb" after a predetermined time T20 has elapsed from the start time t30, based on the relative angle value "Δθa" at the start time t30 and the amount of change over time. presume. Then, the dead zone region determination unit 62 uses "Δθb" as a determination value and determines that it is the end time of the dead zone region when the phase difference Δθ reaches the determination value Δθb. Even with such a configuration, it is possible to detect the end time of the dead zone area.

In addition, by learning the dead zone area, the dead zone area determination unit 62 can detect the dead zone area more accurately, so it is possible to perform motor control with high precision to avoid noise and vibration. becomes.
(Third modification)
Next, a third modification of the integrated ECU 60 of the first embodiment will be described.

The dead zone region determination unit 62 of this modification detects the end time of the dead zone region based on the torque Td of the drive shaft 24 detected by the torque sensors 51 and 52. For example, if a dead zone region is formed when the torque Td of the drive shaft 24 shows an increasing tendency as shown in FIG. 7, the torque Td of the drive shaft 24 becomes zero at the start time t40 of the dead zone region. After that, an increasing tendency is shown again from the end time t41 of the dead zone region. Utilizing this, the dead zone region determination unit 62 of this modification detects the end time of the dead zone region based on the change in the torque Td of the drive shaft 24 from zero. Even with such a configuration, it is possible to detect the end time of the dead zone area.

(Fourth modification)
Next, a fourth modification of the integrated ECU 60 of the first embodiment will be described.
The dead zone determination unit 62 of this modification uses the angular velocity ωm of the motor generator 20 to detect the end time of the dead zone. For example, when a dead zone region is formed, the angular velocity ωm of the motor generator 20 changes as shown in FIG. 8. That is, the angular velocity ωm of the motor generator 20 shows an increasing tendency at the start time t50 of the dead zone region, but when the dead zone region ends at the subsequent time t51, the angular velocity ωm of the motor generator 20 shows a decreasing tendency after the time t51. show. Therefore, the tendency of change in the angular velocity ωm of the motor generator 20 is different before and after the end of the dead zone region. Utilizing this, the dead zone region determination unit 62 of the present modification determines whether the relative angular velocity Δω changes from an increasing tendency to a decreasing tendency, or based on the relative angular velocity Δω changing from a decreasing tendency to an increasing tendency. Detect the end of the dead zone area. Even with such a configuration, it is possible to detect the end time of the dead zone area.

Note that by using the relative angular velocity Δω, which is the difference between the angular velocity ωm of the motor generator 20 and the angular velocity ωd of the drive shaft 24, instead of the angular velocity ωm of the motor generator 20, the end timing of the dead zone region can be similarly detected. It is possible.
<Second embodiment>
Next, a second embodiment of the integrated ECU 60 will be described. Hereinafter, differences from the integrated ECU 60 of the first embodiment will be mainly explained.

The target torque calculation unit 63 of this embodiment sets the dead zone torque target value Th to zero (=0 [Nm]) in the process of step S13 shown in FIG. Further, as a process in step S14 following step S13, the motor control unit 64 sets the torque target value T* of the motor generator 20 to the dead band torque target value Th, that is, sets the torque target value T* to zero. Then, the motor generator 20 is controlled so that the actual output torque Tm of the motor generator 20 becomes the torque target value T*.

Next, with reference to FIG. 9, an example of the operation of the vehicle 10 of this embodiment will be described.
As shown in FIG. 9, when the integrated ECU 60 of this embodiment detects that the torque Td of the drive shaft 24 becomes zero at time t60, it determines that time t60 is the start time of the dead zone region. As a result, the integrated ECU 60 sets the torque target value T* of the motor generator 20 to zero during the period from the start time t60 to the end time t61 of the dead zone region, as shown by the solid line in FIG. 9(C). The output torque of motor generator 20 is zero during the period from time t60 to time t61. This reduces the impact when the gears come into contact with each other when the dead zone ends, so that the torque Td of the drive shaft 24 changes without vibration, as shown by the solid line in FIG. 9(B). Therefore, noise and vibration can be reduced.

Note that the solid lines shown in FIGS. 9A and 9D show the transition of the basic torque target value Tb and the transition of the angular velocity ωm of the motor generator 20 in the vehicle 10 of this embodiment. Furthermore, the dashed-dotted lines shown in FIGS. 9(B) to 9(D) indicate the transition of the torque Td of the drive shaft 24 when the torque of the motor generator 20 is not specially controlled when a dead zone region occurs, and the transition of the torque Td of the motor generator 20. The transition of the output torque and the transition of the angular velocity ωm of the motor generator 20 are shown for reference. Furthermore, the two-dot chain lines shown in FIGS. 9(B) to (D) indicate that the dead zone region is estimated based on the torque target value like the conventional control device described in Patent Document 1, and the dead zone region is estimated during the period of the dead zone region. For reference, the changes in the torque Td of the drive shaft 24, the changes in the output torque of the motor generator 20, and the changes in the angular velocity ωm of the motor generator 20 in the case of using a method of limiting the output torque of the motor generator 20 are shown. It is something.

According to the integrated ECU 60 of the present embodiment described above, the following operation and effect (8) can be obtained as an alternative operation and effect to (6) above.
(8) The target torque calculation unit 63 maintains the dead zone torque target value Th at zero during the period from the start time to the end time of the dead zone region. According to this configuration, it becomes difficult to generate an impact when the gears come into contact with each other again after the dead zone region has occurred, so that it is possible to reduce noise and vibration.

<Other embodiments>
Note that each embodiment can also be implemented in the following forms.
- The target torque calculation unit 63 of the first embodiment sets the torque target value T* of the motor generator 20 based on the relative angular velocity Δω during the period from the start time to the end time of the dead zone region. Torque target value T* of motor generator 20 may be set based on a parameter that has a correlation with angular velocity Δω. Further, the target torque calculation unit 63 calculates the speed of the motor generator 20 based on a phase difference Δθ, which is the difference between the rotation angle θm of the motor generator 20 and the rotation angle θd of the drive shaft 24, or a parameter correlated with the phase difference Δθ. A torque target value T* may be set. Note that, as a parameter that has a correlation with the relative angular velocity Δω, for example, the rotation angle and angular velocity of a hub or wheel that rotates integrally with the drive shaft 24 can be used. Furthermore, as a parameter that has a correlation with the phase difference Δθ, for example, the difference between the rotation angle θm of the motor generator 20 and the rotation angle of a hub or wheel that rotates integrally with the drive shaft 24 can be used.

- The configurations of the first to fourth modifications of the first embodiment can be applied to the integrated ECU 60 of the second embodiment.
- The integrated ECU 60 of each embodiment may be configured as a plurality of ECUs for each function.
- The vehicle 10 of each embodiment may be provided with only one of the torque sensors 51 and 52.

- The vehicle 10 of each embodiment is not limited to a two-wheel drive configuration, but may be a four-wheel drive configuration. In addition, when the vehicle 10 has a four-wheel drive configuration, by providing a torque sensor on each of the drive shafts corresponding to the front two wheels and the drive shafts corresponding to the rear two wheels, the control processing of each embodiment can be performed on each drive shaft. You can also go to

- Instead of the torque of the drive shaft 24 detected by the torque sensors 51 and 52, the rotation state detection unit 61 may detect the amount of twist, angular velocity, angular acceleration, etc. of the drive shaft 24 using a sensor. Further, the dead zone determining section 62 may determine the dead zone region of the power transmission system based on the amount of twist, angular velocity, angular acceleration, etc. of the drive shaft 24.

- The motor generator 20, the inverter device 21, the differential device 23, and the integrated ECU 60 may be configured as one module.
- The integrated ECU 60 and its control method described in the present disclosure are provided by configuring a processor and memory that are programmed to execute one or more functions embodied by a computer program. It may be realized by a dedicated computer. The integrated ECU 60 and its control method described in this disclosure may be implemented by a dedicated computer provided by configuring a processor that includes one or more dedicated hardware logic circuits. The integrated ECU 60 and its control method described in the present disclosure are configured by a combination of a processor and memory programmed to execute one or more functions and a processor including one or more hardware logic circuits. It may be implemented by one or more special purpose computers. A computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible storage medium. Dedicated hardware logic circuits and hardware logic circuits may be implemented by digital circuits that include multiple logic circuits, or by analog circuits.

- The present disclosure is not limited to the above specific examples. Design changes made by those skilled in the art to the specific examples described above are also included within the scope of the present disclosure as long as they have the characteristics of the present disclosure. The elements included in each of the specific examples described above, as well as their arrangement, conditions, shapes, etc., are not limited to those illustrated, and can be changed as appropriate. The elements included in each of the specific examples described above can be appropriately combined as long as no technical contradiction occurs.

10: Vehicles 11, 12: Drive wheels 20: Motor generator 23: Differential device (power transmission system)
24: Drive shaft 41-44: Wheel speed sensor 60: Integrated ECU (control device)
61: Rotation state detection section 62: Dead band region determination section 63: Target torque calculation section 64: Motor control section 200: Rotation sensor

Claims (11)

A control provided in the vehicle (10) in which torque output from the motor (20) is transmitted from the drive shaft (24) to the drive wheels (11, 12) via the power transmission system (23), and controls the motor. A device (60),
a rotation state detection unit (61) that detects the torque of the drive shaft based on an output signal of a sensor that outputs a signal corresponding to the torque applied to the drive shaft ;
a dead zone region determination unit (62) that determines, based on the torque of the drive shaft, a start timing of a dead zone region of the power transmission system caused by backlash of gears provided in the power transmission system.Vehicle control Device. The rotational state detection unit further detects the rotational state of the motor,
The vehicle control device according to claim 1, wherein the dead zone region determination unit determines the dead zone region based on a relative difference between a rotational state of the drive shaft and a rotational state of the motor. a target torque calculation unit (63) that calculates a torque target value of the motor based on the dead band area determined by the dead band area determination unit;
The vehicle control device according to claim 2, further comprising: a motor control unit (64) that controls the motor based on the torque target value. The rotational state detection unit detects the angular velocity of the drive shaft as the rotational state of the drive shaft, and detects the angular velocity of the motor as the rotational state of the motor,
The dead zone region determination unit estimates an end time of the dead zone region based on the angular velocity of the drive shaft and the angular velocity of the motor,
The target torque calculation unit is configured to calculate a period from a start time to an end time of the dead zone region based on a relative angular velocity that is a difference between the angular velocity of the motor and the angular velocity of the drive shaft, or a parameter that has a correlation with the relative angular velocity. The vehicle control device according to claim 3 , wherein the torque target value is set by The target torque calculation unit sets the relative angular velocity in a period from a start time to an end time of the dead zone region based on a preset map showing temporal changes in the relative angular velocity. vehicle control device. The rotational state detection unit detects a rotational angle of the drive shaft as the rotational state of the drive shaft, and detects a rotational angle of the motor as the rotational state of the motor,
The dead zone region determination unit detects the end timing of the dead zone region based on the rotation angle of the drive shaft and the rotation angle of the motor,
The target torque calculation unit calculates a phase difference that is a difference between a rotation angle of the drive shaft and a rotation angle of the motor during a period from a start time to an end time of the dead zone region, or a parameter that has a correlation with the phase difference. The vehicle control device according to claim 3 , wherein the torque target value is set based on. The vehicle control device according to any one of claims 4 to 6 , wherein the target torque calculation unit temporarily changes the torque target value during a period from a start time to an end time of the dead zone region. The vehicle control device according to any one of claims 4 to 6 , wherein the target torque calculation unit sets the torque target value to zero during a period from a start time to an end time of the dead zone region. The motor is provided with a rotation sensor (200) that detects its rotation angle,
The vehicle control device according to any one of claims 1 to 8 , wherein the rotation state detection section uses a rotation angle of the motor detected by the rotation sensor as the rotation state of the motor. Further comprising a wheel speed sensor (41, 42) that detects the angular velocity of the drive wheel,
The rotation state detection unit detects the angular velocity of the drive shaft as the rotation state of the drive shaft based on the angular velocity of the drive wheel detected by the wheel speed sensor. Control device for the vehicle described. The vehicle control device according to any one of claims 1 to 10 , wherein the dead zone area determining section learns the dead zone area.

Images