JP5760378B2 - Control device for electric vehicle - Google Patents

Description

  The present invention switches a fastening element provided between a drive wheel and a motor generator between a completely fastened lockup state and a slip fastening state in which driving force is transmitted while slipping based on a lockup determination threshold. The present invention relates to a control device for an electric vehicle that performs fastening control.

  2. Description of the Related Art Conventionally, there is known a control device for an electric vehicle that performs fastening control to switch between a completely fastened lockup state and a slip fastening state in which driving force is transmitted while slipping based on a lockup determination threshold (for example, a patent) Reference 1).

  In this prior art, a first fastening element is provided between the engine and the motor generator of the drive system, and a second fastening element is provided between the motor generator and the drive wheel, while releasing the first fastening element. The mode transition is described in the EV mode (electric vehicle mode) in which the second fastening element is fastened and the HEV mode (hybrid vehicle mode) in which both fastening elements are fastened.

In such a prior art, the second fastening element is moved from the slip fastening state to the lock-up state or when the engine is started, or when the vehicle is stopped, started, or decelerated in the HEV mode selected state. On the contrary, shifting from the lock-up state to the slip engagement state is performed.
Usually, such switching between slip engagement and lockup of the second engagement element is executed based on the vehicle speed, and this vehicle speed includes the drive wheels or the output shaft of the motor generator connected to the drive wheels. Rotational speed is used.

JP 2007-69790 A

However, in the above-described prior art, the problem described below occurs when a drive wheel slip occurs on a low μ road or the like and when TCS control is executed accordingly. TCS control means that if the drive wheel is rotating in the acceleration direction, such as when starting or accelerating, the drive force is reduced or braked when a drive wheel slip occurs. This control is to suppress this drive wheel slip.

  The second fastening element is in a slip-engaged state at a low speed range, such as when starting, and is brought into a lock-up state when the driving wheel speed is increased to some extent. In such a transition process of the engagement state, when driving wheel slip occurs on a low μ road or the like and TCS control is executed, the lockup and slip engagement state are repeated in the second engagement element.

That is, at the time of starting or the like, the vehicle speed is equal to or lower than the lock-up determination threshold value, so the second engagement element is in the slip engagement state. Therefore, when drive wheel slip occurs, the vehicle speed (drive wheel speed) increases and exceeds the lockup determination threshold value, and the second fastening element enters the lockup state. Further, when the drive wheel slip is suppressed by performing the TCS control, the vehicle speed (drive wheel speed) falls below the lockup determination threshold value, and the second engagement element enters the slip engagement state. Thereafter, when the vehicle speed is increased by acceleration after starting and exceeds the lockup determination threshold, the second fastening element is switched to the lockup state again.
As described above, when the driving wheel slip occurs, the slip fastening and the lock-up of the second fastening element may be repeated.

  The present invention has been made paying attention to the above problem, and provides an electric vehicle control device capable of suppressing the occurrence of hunting between slip fastening and lock-up of a fastening element provided between a motor generator and a drive wheel. The purpose is to do.

  In order to achieve the above object, the control device for an electric vehicle according to the present invention, when the vehicle body speed exceeds the lockup determination threshold, sets the fastening element to a fully locked-up state, and the vehicle speed is below the lockup determination threshold. A fastening element control unit configured to put the element into a slip fastening state in which the driving force is transmitted while slipping, and the lockup determination threshold value is relative to the actual vehicle speed in a region where the actual vehicle speed is relatively low. Therefore, it was set higher than the high-speed area.

  In the present invention, the lockup determination threshold value is set higher in the region where the actual vehicle speed is relatively low than in the region where the actual vehicle speed is relatively high. For this reason, in a low speed range such as when starting, when the driving wheel slip occurs and the driving wheel speed increases and decreases, the fastening element is less likely to shift from the slip fastening state to the lock-up state. Hunting that repeats is difficult to occur.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall system diagram illustrating a rear-wheel drive FR hybrid vehicle to which a control device according to a first embodiment is applied. FIG. 3 is a control block diagram illustrating arithmetic processing performed by the integrated controller 10 according to the first embodiment. It is a figure showing the torque map set to the target drive torque calculating part 100 of the integrated controller 10 of Example 1, (a) shows an example of the target drive force map by vehicle speed VSP and accelerator opening APO, (b) ) Shows an example of a target driving force (creep driving force) map based on the brake depression force. It is a figure which shows an example of the EV-HEV selection map set to the mode selection part 200 of the integrated controller 10 of Example 1. FIG. It is a figure which shows an example of the driving | running | working electric power generation request output map set to the target electric power generation output calculating part 300 of the integrated controller 10 of Example 1. FIG. It is characteristic explanatory drawing of the HEV-> WSC switching line (lockup determination threshold value) for D ranges used with the control apparatus of Example 1. FIG. It is explanatory drawing of the 1st switching line L1tcs at the time of TCS used with the control apparatus of Example 1. FIG. FIG. 3 is a circuit diagram illustrating a part for setting a lockup permission threshold in the integrated controller of the first embodiment. 6 is a flowchart illustrating a flow of processing for determining whether TCS control is performed or not performed in the VDC controller 101 according to the first embodiment. It is a flowchart which shows the determination process of the lockup permission of the 2nd clutch CL2 performed by the integrated controller 10 of Example 1, and disapproval. 3 is a time chart illustrating an example of operation of the first embodiment. Explanatory drawing of the 1st switching line for D ranges (lock-up determination threshold value: 1st determination value) L1 and the 2nd switching line for D ranges (lock-up determination threshold value: 2nd determination value) L2 in the other Example of this invention. It is.

  Hereinafter, the form which implement | achieves the control apparatus of the electric vehicle of this invention is demonstrated based on Example 1 shown on drawing.

First, the configuration will be described.
FIG. 1 is an overall system diagram showing an FR hybrid vehicle (an example of a hybrid vehicle) by rear wheel drive to which the control device for an electric vehicle according to the first embodiment is applied.

  As shown in FIG. 1, the drive system of the FR hybrid vehicle in the first embodiment includes an engine Eng, a flywheel FW, a first clutch CL1 (mode switching fastening element), a motor generator MG, and a mechanical oil pump M-. O / P, second clutch CL2 (engagement element), automatic transmission AT, transmission input shaft IN, propeller shaft PS, differential DF, left drive shaft DSL, right drive shaft DSR, left It has a rear wheel RL (drive wheel) and a right rear wheel RR (drive wheel). Note that FL is a left front wheel (driven wheel), and FR is a right front wheel (driven wheel).

  The engine Eng is a gasoline engine or a diesel engine. Based on an engine control command from the engine controller 1, engine start control, engine stop control, throttle valve opening control, fuel cut control, and the like are performed. The engine output shaft is provided with a flywheel FW.

  The first clutch CL1 is a clutch interposed between the engine Eng and the motor generator MG. The first clutch CL1 is a first clutch produced by the first clutch hydraulic unit 6 based on a first clutch control command from the first clutch controller 5. The clutch control hydraulic pressure controls the engaged / semi-engaged state / release. As the first clutch CL1, for example, a normally closed dry type in which complete engagement is maintained by an urging force of a diaphragm spring, and control from slip engagement to complete release is controlled by stroke control using a hydraulic actuator 14 having a piston 14a. A single plate clutch is used.

  The motor generator MG is a synchronous motor generator in which a permanent magnet is embedded in a rotor and a stator coil is wound around a stator, and a three-phase alternating current generated by an inverter 3 is applied based on a control command from the motor controller 2. It is controlled by doing. The motor generator MG can operate as an electric motor that is driven to rotate by receiving electric power supplied from the battery 4 (“power running”), and when the rotor receives rotational energy from the engine Eng or driving wheels, the stator It functions as a generator that generates electromotive force at both ends of the coil, and can also charge the battery 4 ("regeneration").

  The mechanical oil pump MO / P is provided on the motor shaft MS of the motor generator MG and is driven by the motor generator MG. This mechanical oil pump MO / P is used as a hydraulic pressure source for the hydraulic control valve unit CVU attached to the automatic transmission AT, and the first clutch hydraulic unit 6 and the second clutch hydraulic unit 8 incorporated therein. The An electric oil pump driven by an electric motor may be provided when the discharge pressure from the mechanical oil pump M-O / P cannot be expected or is insufficient.

  The second clutch CL2 is a clutch interposed between the motor generator MG and the left and right rear wheels RL, RR between the motor shaft MS and the transmission input shaft IN. The second clutch CL <b> 2 is controlled to be engaged / slip engaged / released by the control hydraulic pressure generated by the second clutch hydraulic unit 8 based on the second clutch control command from the AT controller 7. As the second clutch CL2, for example, a normally open wet multi-plate clutch capable of continuously controlling the oil flow rate and hydraulic pressure with a proportional solenoid is used.

  The automatic transmission AT is disposed at a downstream position of the second clutch CL2, and is a stepped transmission that automatically switches a stepped gear according to a vehicle speed, an accelerator opening, or the like, or a stepless gear ratio. A belt-type or toroidal-type continuously variable transmission that automatically changes according to the accelerator opening or the like is used.

  A propeller shaft PS is connected to the transmission output shaft of the automatic transmission AT. The propeller shaft PS is connected to the left and right rear wheels RL and RR via a differential DF, a left drive shaft DSL, and a right drive shaft DSR.

  The FR hybrid vehicle has, as basic driving modes, an electric vehicle mode (hereinafter referred to as “EV mode”), a hybrid vehicle mode (hereinafter referred to as “HEV mode”), and a drive torque control mode (hereinafter referred to as “EV mode”). The WSC mode is an abbreviation of “Wet Start Clutch”.

  The “EV mode” is a mode in which the first clutch CL1 is disengaged and the motor generator MG is used as a drive source, and has a motor travel mode and a regenerative travel mode, and travels in either mode. This “EV mode” is selected in a travel region where the required driving force is low and the battery SOC is secured.

  The “HEV mode” is a mode in which the first clutch CL1 is engaged and travels using the engine Eng and the motor generator MG as drive sources, and includes a motor assist travel mode, a power generation travel mode, and an engine travel mode. Drive in the mode. This “HEV mode” is selected when the required driving force is high or the battery SOC is insufficient.

  In the “WSC mode”, the second clutch CL2 is maintained in the slip engagement state by the rotational speed control and the clutch hydraulic pressure control of the motor generator MG, and the clutch transmission torque passing through the second clutch CL2 is applied to the vehicle state and the driver operation. In this mode, the vehicle travels while controlling the clutch torque capacity so that the required driving torque is determined accordingly. The “WSC mode” is selected in a travel region where the engine speed is lower than the idle speed, such as when starting with the “HEV mode” selected or when decelerating to a stop.

Next, the control system of the FR hybrid vehicle will be described.
As shown in FIG. 1, the control system of the FR hybrid vehicle in the first embodiment includes an engine controller 1, a motor controller 2, an inverter 3, a battery 4, a first clutch controller 5, and a first clutch hydraulic unit 6. And an AT controller 7, a second clutch hydraulic unit 8, a brake controller 9, and an integrated controller 10. The controllers 1, 2, 5, 7, and 9 and the integrated controller 10 are connected via a CAN communication line 11 that can exchange information with each other.

  The engine controller 1 inputs engine speed information from the engine speed sensor 12, a target engine torque command from the integrated controller 10, and other necessary information. Then, a command for controlling the engine operating point (Ne, Te) is output to the throttle valve actuator or the like of the engine Eng.

  The motor controller 2 inputs information from the resolver 13 that detects the rotor rotational position of the motor generator MG, a target MG torque command and a target MG rotational speed command from the integrated controller 10, and other necessary information. Then, a command for controlling the motor operating point (Nm, Tm) of motor generator MG is output to inverter 3. The motor controller 2 uses a motor torque as a target torque and a torque control that follows the rotation speed of the drive system as a basic control. However, during the slip control of the second clutch CL2, the motor rotation speed is set as a target rotation. The number of revolutions is controlled so that the torque follows the driving system load. The motor controller 2 monitors the battery SOC representing the charge capacity of the battery 4 and supplies the battery SOC information to the integrated controller 10 via the CAN communication line 11 (battery charge capacity detection means).

  The first clutch controller 5 inputs sensor information from the first clutch stroke sensor 15 that detects the stroke position of the piston 14a of the hydraulic actuator 14, a target CL1 torque command from the integrated controller 10, and other necessary information. . Then, a command for controlling engagement / semi-engagement / release of the first clutch CL1 is output to the first clutch hydraulic unit 6 in the hydraulic control valve unit CVU.

The AT controller 7 inputs information from an accelerator opening sensor 16, a vehicle speed sensor 17, and other sensors 18 and the like. Then, when driving with the D range selected, the optimum shift speed and gear ratio are searched according to the position where the driving point determined by the accelerator opening APO and the vehicle speed VSP exists on the shift map, and the searched shift speed and A control command for obtaining a gear ratio is output to the hydraulic control valve unit CVU.
In addition to this shift control, when a target CL2 torque command is input from the integrated controller 10, a command for controlling the clutch hydraulic pressure to the second clutch CL2 is output to the second clutch hydraulic unit 8 in the hydraulic control valve unit CVU. 2-clutch control is performed.
Further, when a shift control command is output from the integrated controller 10 in engine start control or the like, the shift control according to the shift control command is performed in preference to the normal shift control.

  The brake controller 9 inputs a wheel speed sensor 19 for detecting the wheel speeds of the four wheels, sensor information from the brake pedal force sensor 20, a regenerative cooperative control command from the integrated controller 10, and other necessary information. And, for example, at the time of brake depression, if the regenerative braking force is insufficient for the required braking force obtained from the brake stroke BS, the shortage is compensated by the mechanical braking force (hydraulic braking force or motor braking force) Regenerative cooperative brake control is performed.

  The integrated controller 10 manages the energy consumption of the entire vehicle and has a function for running the vehicle with the highest efficiency. The integrated controller 10 detects a motor rotation speed Nm as a detection unit that detects a running state. 21, a first clutch temperature sensor 22 that detects the temperature of the first clutch CL1, a second clutch temperature sensor 23 (second engagement element temperature detection means) that detects the temperature of the second clutch CL2, and a gradient of the traveling road surface Necessary information from the road surface gradient sensor 24 and other sensors and switches 25 and information are input via the CAN communication line 11. Then, the target engine torque command to the engine controller 1, the target MG torque command and the target MG rotational speed command to the motor controller 2, the target CL1 torque command to the first clutch controller 5, the target CL2 torque command to the AT controller 7, and the brake controller 9 Regenerative cooperative control command is output.

  FIG. 2 is a control block diagram illustrating arithmetic processing performed by the integrated controller 10 according to the first embodiment. 3 to 5 are diagrams illustrating examples of maps set in the target drive torque calculation unit 100, the mode selection unit 200, and the target power generation output calculation unit 300 of the integrated controller 10, respectively. Hereinafter, the arithmetic processing performed by the integrated controller 10 will be described with reference to FIGS.

  As shown in FIG. 2, the integrated controller 10 includes a target drive torque calculation unit 100, a mode selection unit 200, a target power generation output calculation unit 300, an operating point command unit 400, and a shift control unit 500. ing.

  The target driving torque calculation unit 100 uses the target driving force map based on the vehicle speed VSP and the accelerator opening APO shown in FIG. 3A and the target driving force map based on the brake pedal force shown in FIG. The force (= required driving force) is calculated.

  The mode selection unit 200 calculates a target travel mode (HEV mode, EV mode, WSC mode) from the accelerator opening APO and the vehicle speed VSP using the EV-HEV selection map shown in FIG. Further, the engagement and release of the first clutch CL1 and the second clutch CL2 are switched in accordance with the transition of these modes, which corresponds to an engagement element control unit.

  In the EV-HEV selection map, when the operating point (APO, VSP) existing in the EV region crosses, the EV⇒HEV switching line for switching to the “HEV mode” and the operating point (APO, VSP) existing in the HEV region are displayed. HEV⇒EV switching line that switches to “EV mode” when crossing, HEV → WSC switching line that switches to “WSC mode” when the operating point (APO, VSP) enters the WSC region when “HEV mode” is selected, Is set. The HEV → EV switching line and the HEV → EV switching line are set with a hysteresis amount (H1 and H2 to be described later) as threshold values for dividing the EV area and the HEV area. The HEV => WSC switching line is set along the vehicle speed at which the engine Eng maintains the idling speed when the automatic transmission AT is at the first gear and the minimum gear ratio. However, while the “EV mode” is selected, if the battery SOC falls below a predetermined value, the “HEV mode” is forcibly set as the target travel mode.

  The target power generation output calculation unit 300 calculates a target power generation output from the battery SOC using the traveling power generation request output map shown in FIG. Also, it calculates the output required to increase the engine torque from the current engine operating point (rotation speed, torque) to the best fuel consumption line, and adds it to the engine output as a required output compared to the target power generation output. To do.

  The operating point command unit 400 uses the accelerator opening APO, the target driving force, the target traveling mode, the vehicle speed VSP, and the required power generation output as the operating point reaching target, and the transient target engine torque, target MG torque, and target. CL2 torque capacity, target gear ratio (target AT shift) and CL1 solenoid current command are calculated.

  The shift control unit 500 calculates an AT solenoid current command for driving and controlling the solenoid valve in the automatic transmission AT so as to achieve these from the target CL2 torque capacity and the target gear ratio (target AT shift).

Further, in the first embodiment, the mode selection unit 200 executes control for changing the HEV → WSC switching line shown in FIG. 4 according to the traveling state, and the details thereof will be described below.
The HEV => WSC switching line is a lockup determination threshold value that is a reference for determining whether or not to engage the second clutch CL2, and when the vehicle speed VSP exceeds this threshold value, the second clutch CL2 is locked up, When the mode is switched to the HEV mode and the vehicle speed VSP becomes less than the threshold value, the second clutch CL2 is slipped to enter the WSC mode. The vehicle speed VSP used in the control of FIG. 4 is the speed on the output shaft side of the automatic transmission AT, that is, the driving wheel speed (Vr).

  FIG. 6 is an explanatory diagram of the characteristics of the HEV to WSC switching line (lockup determination threshold value) for the D range. As shown in FIG. 6, the D range first switching line L1 (first determination threshold), the D range second switching line L2 (second determination threshold), and the TCS first switching line L1tcs (first determination threshold). ), The TCS second switching line L2tcs (second determination threshold) is set.

The D range first switching line L1 and the D range second switching line L2 are HEV to WSC switching lines that are used when the shift position is the D range during normal operation (during non-TCS control).
The D range first switching line L1 indicates a threshold value used when shifting from the WSC mode to the HEV mode. When the vehicle speed VSP crosses the threshold value in the speed increasing direction, the second clutch CL2 slips. Switch from the fastening state to the lock-up state.
The D range second switching line L2 is a threshold value used when shifting from the HEV mode to the WSC mode. When the vehicle speed VSP crosses in the deceleration direction with respect to this threshold value, the second clutch CL2 is released from the lock-up state. Switch to the slip engagement state.
Further, as shown in the drawing, a D range hysteresis H1 for preventing hunting is set between the first D range switching line L1 and the second D range switching line L2.

On the other hand, the first switching line L1tcs during TCS and the second switching line L2tcs during TCS are switching lines used during TCS control (when the driving wheel slip determination condition is satisfied) executed when driving wheel slip occurs. These switching lines L1tcs and L2tcs are set to relatively high values as compared with the D range first switching line L1 and the D range second switching line L2 that are used during normal time during non-TCS control, respectively. Yes. Therefore, at the time of TCS control, the second clutch CL2 is set to be less likely to shift from the slip engagement state to the lock-up state as compared to the normal time.
A TCS hysteresis H2 is also set between the TCS first switching line L1tcs and the TCS second switching line L2tcs. The width of the TCS hysteresis H2 is set wider than the D range hysteresis H1 between the normal D range first switching line L1 and the D range second switching line L2.
These switching lines L1, L2, L1tcs, L2tcs and hysteresis H1, H2 as lockup determination thresholds are for the R range and other ranges in addition to those for the D range. It is stored in the form of a table.

Furthermore, the first switching line L1tcs time TCS, in response to vehicle speed, the vehicle speed is low regions, are set to a value higher than the relatively vehicle speed is high region, which will be described with reference to FIG. 7 . The vehicle speed shown in this figure is the actual vehicle speed, and this actual vehicle speed is calculated based on the driven wheel speed Vf, for example.
FIG. 7 is an explanatory diagram of the first switching line L1tcs at the time of TCS. The first switching line L1tcs at the time of TCS is set to the first lockup vehicle speed threshold value VL1 when the vehicle body speed is equal to or lower than the first set vehicle speed Vset1 set in advance. Has been. For example, when the second clutch CL2 is locked up in the first forward speed range, the first set vehicle speed Vset1 is set near the upper limit of the vehicle speed at which the engine speed may fall below the idle speed. Further, the first lockup vehicle speed threshold VL1 is set to a high value that is difficult to exceed even when drive wheel slip occurs on a low μ road, based on experiments and simulations with an actual vehicle. The value is in the range of about h, and is set to 18 km / h in the first embodiment.

  On the other hand, the TCS first switching line L1tcs is set to the second lockup vehicle speed threshold VL2 lower than the first lockup vehicle speed threshold VL1 at the second set vehicle speed Vset2 or higher that is higher than the first set vehicle speed Vset1. Yes. The second set vehicle speed Vset2 is set to a value that does not cause the engine speed to fall below the idle speed even when the second clutch CL2 is locked up. Further, the second lock-up vehicle speed threshold VL2 is about the lower limit of a range in which the engine Eng can maintain the number of revolutions necessary for generating torque even when the second clutch CL2 is locked up, based on experiments and simulations with an actual vehicle. Specifically, it is a value within a range of about 10 to 15 km / h, and is set to 13 km / h in the first embodiment.

  Further, the TCS first switching line L1tcs is set to an inclination connecting the first lock-up vehicle speed threshold VL1 and the second lock-up vehicle speed threshold VL2 between the first set vehicle speed Vset1 and the second set vehicle speed Vset2. Yes. In other words, within this range, the higher the vehicle speed, the faster the vehicle can be accelerated to a vehicle speed at which the engine speed does not fall below the idle speed even when the second clutch CL2 is locked up. ing. The threshold having this inclination is referred to as a third lockup vehicle speed threshold VL3.

FIG. 8 is a circuit diagram showing a part for setting the above-described lock-up permission threshold value in the integrated controller 10. The VDC controller 101 that executes TCS control includes the wheel speeds of the wheels FR, FL, RR, and RL. The accelerator opening APO is input. The TCS control operation determination unit 102 of the VDC controller 101 calculates the slip amount of the drive wheels RL and RR based on the difference between the vehicle speed obtained based on the driven wheel speed Vf and the drive wheel speed Vr. When the amount exceeds a preset TCS control intervention threshold (Vtcs), TCS control is performed to suppress slipping of the drive wheels RL and RR.

  In addition, the lockup determination threshold setting unit 103 of the integrated controller 10 inputs a signal indicating the TCS control desire from the TCS control operation determination unit 102 and a signal indicating the current shift range from the AT controller 7, and inputs them. Based on this, a lockup determination threshold (table) is set. The lockup determination threshold value (table) set by the lockup determination threshold value setting unit 103 is output to the second clutch lockup permission determination unit 104.

In the second clutch lock-up permission determination unit 104, based on and it sets the lock-up decision threshold lockup determination threshold setting unit 103 table and vehicle speed and the driving wheel speed V r, the lock-up of the second clutch CL2 Perform permission / denial determination. Further, a lockup determination threshold value is set based on the selected table and the vehicle body speed .

A flow of processing for determining whether the second clutch CL2 is permitted to be locked up or not in the VDC controller 101 and the integrated controller 10 shown in FIG. 8 will be described based on the flowcharts of FIGS.
The flowchart of FIG. 9 shows the flow of processing for determining whether or not TCS control is performed in the VDC controller 101.
In this TCS control determination process, first, in S1, it is determined whether or not the slip amount of the drive wheels RL and RR has exceeded a preset TCS control intervention threshold (Vtcs). If not, the process proceeds to step S3.

In step S2, after performing the TCS control, one flow is finished. In step S3, the TCS control is not performed, and one flow is finished.
As described above, when the slip amount of the drive wheels RL and RR exceeds the TCS control intervention threshold (Vtcs), the TCS control is performed, the target drive torque is reduced, and the slip of the drive wheels RL and RR is suppressed. .

Next, a process for determining whether the second clutch CL2 is permitted to be locked up or not will be described with reference to the flowchart of FIG.
First, in step S11, it is determined whether or not the current shift range is the D range. If it is the D range, the process proceeds to step S12, and if it is not the D range, the process proceeds to step S15.

  In step S12, which proceeds in the case of the D range in step S11, it is determined whether or not the TCS control is currently being performed. If the TCS control is being performed, the process proceeds to step S13. If not, the process proceeds to step S14.

In step S13, which proceeds when TCS control is being performed in step S12, the TCS time table is used as the lockup determination threshold, and the TCS time hysteresis H2 is used as the hysteresis. That is, as the HEV → WSC switching line, the first switching line L1tcs at TCS and the second switching line L2tcs at TCS shown in FIG. 6 are used. In this case, on the first switching line L1tcs at TCS, the first lockup vehicle speed threshold VL1 and the second set vehicle speed Vset2 or more are exceeded in the low vehicle speed range below the first set vehicle speed Vset1 according to the vehicle body speed (driven wheel speed Vf). The second lockup vehicle speed threshold VL2 is used in the high vehicle speed range, and the third lockup vehicle speed threshold VL3 is used in the speed range between the two set vehicle speeds Vset1, Vset2.

  In step S14 which proceeds during non-TCS control in step S12, the D range table is used as the lockup determination threshold, and the D range hysteresis H1 is used as the lockup determination threshold hysteresis. In other words, the D range first switching line L1 and the D range second switching line L2 shown in FIG. 6 are used as the lockup permission switching lines.

  On the other hand, in step S15, which is advanced in cases other than the D range in step S11, it is determined whether or not the current shift range is the R range that shifts to the reverse speed (R), and in the case of the R range (YES), step S16. If it is other than the R range (NO), the process proceeds to step S17.

  In step S16, which proceeds to the R range in step S15, the lockup determination threshold value is set to the R range table, and the lockup determination threshold hysteresis is set to the R range hysteresis Hr. Here, the lock-up determination threshold for the R range and the hysteresis for the R range Hr are not shown, but, similar to the D range, the first determination for determining the lock-up permission from the slip engagement state when the vehicle speed increases. A threshold value and a second determination threshold value that is lower than the first determination threshold value and that allows a transition from the lockup state to the slip engagement state during deceleration are set. In addition, an R range hysteresis Hr is set between the first determination threshold and the second determination threshold.

  Further, in step S17, which proceeds when the shift range is other than the R range in step S15, the lockup determination threshold value is set in the outside expected value table, and the lockup determination threshold value is set in the outside expected value hysteresis.

  Next, in step S18 that proceeds after performing any of the processes of steps S13, S14, S16, and S17, it is determined whether or not the previous value of the lockup determination threshold value is lockup disapproval, and the previous value is locked up. If it is not permitted (YES), the process proceeds to step S19, and if the previous value is lockup permitted (NO), the process proceeds to step S22.

In step S19, it is determined whether or not the current vehicle speed VSP (drive wheel speed) is equal to or higher than the lockup permission threshold value. The process proceeds to step S21.

  In step S20, after permitting the lockup of the second clutch CL2, the flow of one process is terminated, and in step S21, the lockup of the second clutch CL2 is not permitted and the process of one process is terminated. .

  On the other hand, in step S22 which proceeds when the previous value of the lockup determination is permitted in step S18, the vehicle speed VSP is equal to or greater than the value obtained by subtracting the lockup permission vehicle speed hysteresis from the lockup determination threshold (that is, the second determination threshold). If it is greater than or equal to this value (YES), the process proceeds to step S23, and if less than this value (NO), the process proceeds to step S24.

  In step S23, lock-up of the second clutch CL2 is permitted (maintaining the lock-up permission state), and one flow is ended. In step S24, lock-up of the second clutch CL2 is not permitted and one process is performed. End the flow.

(Description of the operation of the first embodiment)
Next, the effect | action of Example 1 is demonstrated based on the time chart which shows an example of an action | operation of FIG.
This time chart shows a change in the wheel speed when the vehicle starts on a low μ road and a drive wheel slip occurs on the drive wheels (RL, RR), and Vf is the driven wheel speed, which is the speed of the left and right front wheels FL, FR. (= vehicle body speed) indicates, Vr indicates the driving wheel speed is the speed of the left and right rear wheels RL, RR.

  That is, the start is started from time t0, driving wheel slip occurs at time t1, and the driving wheel speed Vr increases. Then, at the time t2 when the driving wheel speed Vr exceeds the TCS control intervention threshold (Vtcs), the execution of the TCS control is started (based on the processing from step S1 to S2). As a result of the execution of the TCS control, the driving wheel speed Vr is reduced, and at the time t6, the driving wheel speed Vr approaches the driven wheel speed Vf and increases together with the driven wheel speed Vf. In this case, since it is at the time of starting acceleration, the drive wheel speed Vr increases at a speed slightly higher than the driven wheel speed Vf.

(Description of operation of comparative example)
First, as an operation of a comparative example with the first embodiment when a change in the driving wheel speed Vr as shown in FIG. 11 occurs, an operation example in which the lockup determination threshold is only the D range first switching line L1. Will be explained.

In this case, when the driving wheel speed Vr exceeds the first D-range switching line L1, the second clutch CL2 is allowed to be locked up. At time t4 when the driving wheel speed Vr is lower than the first switching line L1 for the D range by TCS control, the lockup is not permitted and the second clutch CL2 is shifted to the slip engagement state. Thereafter, the drive wheel slip is settled, and at time t7 when the drive wheel speed Vr again exceeds the D range first switching line L1, the lockup is permitted again, and the second clutch CL2 shifts to the lockup state.
As described above, hunting occurs in which the engagement state of the second clutch CL2 is switched between the slip engagement state and the lockup state, which adversely affects the drivability.

  The second comparative example is a case where the D range second switching line L2 having the D range hysteresis H1 with respect to the D range first switching line L1 is set. Even in this case, the lockup is not permitted at the time t5 when the driving wheel speed Vr is lower than the second switching line L2 for D range, and hunting similar to the above occurs.

(Operation of Example 1)
Compared with the above-described operation, in the first embodiment, the HEV → WSC switching line as the lock-up determination threshold is switched to the TCS time table and the TCS time hysteresis H2 at the time t2 when the TCS control is started. It is set (based on the processing of steps S12 → S13). For this reason, as the lock-up determination threshold, the switching lines L1 and L2 are switched to the first switching line L1tcs at TCS and the second switching line L2tcs at TCS set to a higher value than these. Therefore, even if the driving wheel speed Vr subsequently increases, the first switching line L1tcs at TCS is not exceeded until the time t8, and the second clutch CL2 is maintained in the slip engagement state until the time t8.

  Therefore, the second clutch CL2 is not hunted in the slip engagement state and the lock-up state, and accordingly, the operability is hardly adversely affected.

Next, the effect will be described.
In the hybrid vehicle control device of the first embodiment, the following effects can be obtained.
(1) In the first embodiment, a motor generator MG that is provided in a drive system of drive wheels (RL, RR), drives the drive wheels by powering, and generates power by regeneration;
A second clutch CL2 provided between the motor generator MG and the drive wheels (RL, RR);
Each sensor (15-25) for detecting the running state including the vehicle speed,
When the vehicle body speed exceeds the lockup determination threshold (L1, L2, L1tcs, L2tcs) based on the lockup determination threshold (L1, L2, L1tcs, L2tcs) corresponding to the vehicle speed, the second clutch CL2 is completely engaged. The integrated controller 10 in which the vehicle body speed is equal to or lower than the lockup determination threshold value (L1, L2, L1tcs, L2tcs) and the second clutch CL2 is in the slip engagement state in which the driving force is transmitted while slipping,
With
The lockup determination threshold (first switching line L1tcs at TCS) is set higher in a region where the vehicle speed (actual vehicle speed) is relatively low than in a region where the vehicle speed (actual vehicle speed) is relatively high. did.
Therefore, even if the drive wheel slip occurs and the drive wheel speed Vr increases, the lockup permission determination is difficult to be made in the region where the actual vehicle speed is low, and the second clutch CL2 is in the slip engagement state and the lockup state. It is possible to suppress the occurrence of hunting that switches to. Thus, the deterioration of luck rolling resistance shall be the cause of this hunting can be suppressed.

(2) The integrated controller 10 increases the lockup determination threshold value from L1 to L1tcs when the drive wheel slip determination condition is satisfied (when TCS control is executed).
Therefore, when the driving wheel slip occurs or is likely to occur, the second clutch CL2 shifts from the slip engagement state to the lock-up state as compared with the case where the driving wheel slip does not occur or is less likely to occur. It becomes difficult.
Therefore, even if drive wheel slip occurs, hunting in which the second clutch CL2 switches between the slip engagement state and the lock-up state is less likely to occur as described in (1) above.

(3) The integrated controller 10 increases the lockup determination threshold by setting the execution of the TCS control to satisfy the drive wheel slip determination condition.
Therefore, even if drive wheel slip occurs and the drive wheel speed decreases due to TCS control, the above-described control hunting is less likely to occur, and deterioration in drivability can be suppressed.

(4) The integrated controller 10 sets the lockup determination threshold value to a relatively low value relative to the first determination threshold value (L1, L1tcs) used when the vehicle body speed is increased and the first determination threshold value (L1, L1tcs). The second determination threshold value (L2, L2tcs) used when the vehicle body speed is lowered with the hysteresis (H1, H2) is provided, and when the drive wheel slip determination condition is satisfied, compared to when it is not satisfied The hysteresis was widened (H1 <H2).
Therefore, when the drive wheel slip determination condition is satisfied, the switching between the slip engagement state and the lock-up state is less likely to occur than when the drive wheel slip determination condition is not satisfied, and the control hunting can be further suppressed.

(5) In the first embodiment, the motor generator MG is interposed in the middle of the drive system from the engine Eng to the drive wheels (RL, RR),
A first clutch CL1 is provided between the engine Eng and the motor generator MG,
An integrated controller 10 that performs mode transition between the EV mode in which the first clutch CL1 is released and the second clutch CL2 is engaged and the HEV mode in which both the clutches CL1 and CL2 are engaged is provided.
Therefore, the control hunting is less likely to occur when shifting from the EV mode to the HEV mode.
As described above, at the time of transition from the EV mode to the HEV mode, the first clutch CL1 is engaged to start the engine Eng. If drive wheel slip occurs at the start of the engine, the following problems may occur. . That is, although the actual vehicle speed (driven wheel speed Vf) is low, the drive wheel slip occurs, the drive wheel speed Vr rises and the second clutch CL2 is locked up, and then the drive wheel speed Vr becomes TCS in this lock-up state. When it falls by control, there exists a possibility that the rotation speed of engine Eng may fall too much.
In the first embodiment, as described in the above (1) to (4), since the second clutch CL2 is difficult to lock up, the above-described decrease in the engine speed can be suppressed.

(6) In the first embodiment, the first set vehicle speed Vset1 of the first switching line L1tcs at the time of TCS is set near the upper limit of the vehicle speed at which the engine speed may fall below the idle speed when the second clutch CL2 is locked up. In the low speed region below the first set vehicle speed Vset1, the TCS first switching line L1tcs is set to a high value (first lockup vehicle speed threshold VL1).
Therefore, in the low speed region, the second clutch CL2 is difficult to lock up, and it is possible to more reliably prevent the engine speed from excessively decreasing as in the above (3).

(7) In the first embodiment, the second set vehicle speed Vset2 of the first switching line L1tcs at TCS is set to a value that does not cause the engine speed to fall below the idle speed even if the second clutch CL2 is locked up. Above the second set vehicle speed Vset2, the TCS second switching line L2tcs is set to a relatively low value (second lockup vehicle speed threshold VL2).
Therefore, in the high speed region, even if the second clutch CL2 is locked up, the engine speed does not decrease excessively, and the effect (3) can be obtained more reliably.

(8) In the first embodiment, the third lockup vehicle speed threshold VL3 used in the speed region between the first set vehicle speed Vset1 and the second set vehicle speed Vset2 of the first switching line L1tcs at TCS is set to the first lockup vehicle speed. The inclination is set so that the threshold value VL1 and the second lockup vehicle speed threshold value VL2 are linearly connected.
In this speed region, as the vehicle speed increases, it can be expected that the vehicle is accelerated to a vehicle speed at which the engine speed does not fall below the idle speed even when the second clutch CL2 is locked up. It can suppress more reliably that an engine speed falls too much. In addition, by providing an inclination to the first switching line L1tcs at the time of TCS, for example, compared with a switch between the first lockup vehicle speed threshold VL1 and the second lockup vehicle speed threshold VL2 at the second set vehicle speed Vset2, It is easy to lock up and is advantageous for fuel economy.

  As mentioned above, although the control apparatus of the electric vehicle of this invention has been demonstrated based on Example 1, it is not restricted to this Example 1 about a concrete structure, The invention which concerns on each claim of a claim Design changes and additions are permitted without departing from the gist of the present invention.

For example, in the first embodiment, the lockup determination threshold value is made different between TCS control and non-TCS control. However, the present invention is not limited to this, and the lock-up determination threshold value uses the D range first switching line L1 regardless of the time of TCS control, and this D range first switching line L1 is as shown in FIG. May be set. Further, the first switch line L1 for the D range shown in FIG. 12, it may be used as the use time of non-TCS control in Embodiment 1.

  In the first embodiment, the occurrence of the drive wheel slip or the establishment of the drive wheel slip determination condition indicating the possibility thereof is determined by the ON / OFF of the TCS control. However, the present invention is not limited to this. That is, the driving wheel slip determination condition may be determined based on the driving wheel slip amount obtained from the difference between the driving wheel speed and the driven wheel speed. Alternatively, based on the road surface μ, the drive wheel slip determination condition may be satisfied when the value is low μ. In this case, the road surface μ may be actually detected, or may be determined as low μ when the automatic transmission is in the snow mode. Further, when snow or rain is detected, it may be determined as low μ. The road surface μ can be detected based on, for example, the difference between the driving wheel speed and the driven wheel speed, or the wheel acceleration during braking or acceleration.

  Moreover, although the example newly added as a 2nd clutch CL2 as an exclusive clutch independent of automatic transmission AT was shown, among the several friction elements fastened in each gear stage of automatic transmission AT, predetermined | prescribed The second clutch CL2 may be selected by selecting a friction element (clutch or brake) that meets the above conditions. Alternatively, the second clutch CL2 may be provided separately from the automatic transmission AT between the transmission output shaft and the drive wheels.

  In Example 1, the example which uses 1st clutch CL1 as a mode switching fastening element which switches HEV mode and EV mode was shown. However, as the mode switching means for switching between the HEV mode and the EV mode, for example, a differential device or a power split device that exhibits a clutch function without using a clutch, such as a planetary gear, may be used.

  In the first embodiment, the rear wheel is shown as the drive wheel, but the present invention can also be applied to the case where the front wheel is the drive wheel.

DESCRIPTION OF SYMBOLS 1 Engine controller 2 Motor controller 3 Inverter 4 Battery 5 1st clutch controller 6 1st clutch hydraulic unit 7 AT controller 8 2nd clutch hydraulic unit 9 Brake controller 10 Integrated controller (engagement element control part, driving wheel slip determination means)
12 Engine speed sensor (detector)
15 First clutch stroke sensor (detector)
16 Accelerator opening sensor (detector)
17 Vehicle speed sensor (detection unit)
18 Other sensors (detection unit)
19 Wheel speed sensor (detection unit)
20 Brake pedal force sensor (detector)
21 Motor rotation speed sensor (detector)
22 1st clutch temperature sensor (detection part)
23 Second clutch temperature sensor (detector)
24 Road surface gradient sensor (detection unit)
25 Other sensors and switches (detection unit)
AT automatic transmission CL1 first clutch (mode switching engagement element)
CL2 Second clutch (engagement element)
Eng Engine FL Left front wheel (driven wheel)
FR Front right wheel (driven wheel)
H1 Hysteresis for D range H2 Hysteresis at TCS L1 First switching line for D range (lockup judgment threshold: first judgment value)
L1tcs TCS first switching line (lock-up determination threshold: first determination value)
L2 D range second switching line (lock-up determination threshold: second determination value)
L2tcs TCS second switching line (lock-up determination threshold: second determination value)
MG Motor generator RL Left rear wheel (drive wheel)
RR Right rear wheel (drive wheel)

Claims (5)

A motor generator that is provided in a drive system of the drive wheels, drives the drive wheels by power running, and generates power by regeneration;
A fastening element provided between the motor generator and the drive wheel;
A detection unit for detecting a traveling state including a driving wheel speed and a driven wheel speed ;
Based on the lockup determination threshold corresponding to the vehicle speed based on the driven wheel speed, when the drive wheel speed exceeds the lockup determination threshold, the fastening element is brought into a fully engaged lockup state, and the drive wheel speed is A fastening element control unit that sets the fastening element to a slip fastening state in which the driving force is transmitted while slipping below the lock-up determination threshold,
VDC controller driving Wath lip exceeds the set value calculates the slip amount of the drive wheels on the basis of said driving wheel speed and the driven wheel speed is when occurs, executes the TCS control for controlling to suppress the driving wheel slip When,
With
The control device for an electric vehicle, wherein the lockup determination threshold is set higher in a region where the vehicle body speed is relatively low than in a region where the vehicle body speed is relatively high. In the control apparatus of the electric vehicle according to claim 1,
Drive wheel slip determination means included in the detection unit for determining whether or not a drive wheel slip determination condition indicating occurrence or possibility of drive wheel slip is satisfied;
The said engagement element control part raises the said lockup determination threshold value when the said driving wheel slip determination conditions are satisfied, The control apparatus of the electric vehicle characterized by the above-mentioned. In the control apparatus of the electric vehicle according to claim 2,
The drive wheel slip determination means is configured to satisfy a condition when TCS control is executed to reduce drive wheel torque when the slip occurs. In the control apparatus of the electric vehicle according to claim 2 or claim 3,
The fastening element control unit is provided with a first determination threshold used when the driving wheel speed is increased and a hysteresis set to a relatively low value with respect to the first determination threshold as the lockup determination threshold. And a second determination threshold value used when the driving wheel speed is lowered, and the hysteresis is increased when the driving wheel slip determination condition is satisfied compared to when the driving wheel slip determination condition is satisfied. . In the control device of the electric vehicle according to any one of claims 1 to 4,
The motor generator is interposed in the middle of the drive system from the engine to the drive wheel,
A mode switching fastening element is provided between the engine and the motor generator,
Characterized in that it comprises mode control means for performing mode transition between an electric vehicle mode in which the drive transmission fastening element is fastened while releasing the mode switching fastening element and a hybrid vehicle mode in which both fastening elements are fastened. A control device for an electric vehicle.