JP2016010235A - Electric-vehicular control apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric-vehicular control apparatus capable of suppressing occurrence of a failure in engaging an engagement element due to an insufficient lowering of motor torque when increasing a power generation volume associated with a down speed change.SOLUTION: A control apparatus is used for an electric vehicle that includes: a travelling-motor MG driven with power from a fuel cell 30 and a strong-electric battery 40; an automatic transmission 10 for switching between engagement and disengagement of a meshing clutch and a friction clutch during a speed-change; and a control unit 100 for controlling the fuel cell 30, travelling-motor MG and automatic transmission 10. During a shift-down speed change, the control unit 100 increases a power generation volume of the fuel cell 30; calculates absorption-possible spare power Wgen_batt on the basis of a state of the strong-electric battery 40; calculates motor lower-limit torque on the basis of the absorption-possible spare power Wgen_batt and power generation volume; and increases disengagement-side clutch transmission torque to the motor lower-limit torque or higher.

Description

  The present invention relates to a control device for an electric vehicle provided with power generation means such as a fuel cell in addition to power storage means such as a battery.

  2. Description of the Related Art Conventionally, in an electric vehicle equipped with power generation means, there is known one that performs control to change the output of the fuel cell in accordance with the operating state of the transmission and protect the power storage means from overheating (for example, Patent Document 1). reference).

JP 2005-19033 JP

According to the prior art as described above, it is preferable to increase the amount of power generated by the power generation means and reduce the power consumption of the power storage means during a downshift accompanying acceleration.
However, when the power generation amount is increased, the lower limit value of the torque that can be output by the motor increases due to an increase in power that can be supplied to the motor.
For this reason, at the end of the inertia phase, if the power generation amount does not sufficiently decrease from the increased state, the motor lower limit torque also remains increased, and the decrease in motor torque is limited to the motor lower limit torque and cannot be sufficiently decreased. There is a case.
In this case, at the end of the inertia phase, the motor torque cannot be reduced to the level corresponding to the clutch engagement torque, and as a result, the engagement element on the engagement side cannot be engaged smoothly, which may cause a problem in the transmission.

  The present invention has been made paying attention to the above-described problem, and provides an electric vehicle control device capable of suppressing the occurrence of clutch engagement failure due to insufficient decrease in motor torque when the amount of power generation associated with downshifting is increased. Objective.

In order to achieve the above object, the present invention provides:
A transmission that transmits the power of the rotating electrical machine driven by the electric power from the power generation means and the power storage means to the drive wheel side, and that engages and disengages the clutch at the time of shifting;
Control means for controlling the operation of the power generation means, the rotating electrical machine, and the transmission;
An electric vehicle control device comprising:
The control means increases the power generation amount of the power generation means during a downshift, and obtains an absorbable surplus power that is power that can be absorbed by the power storage means based on the state of the power storage means. A motor lower limit torque is calculated based on surplus power and the amount of power generated by the power generation means, and the clutch transmission torque on the disengagement side is increased to be equal to or greater than the motor lower limit torque. .

In the control apparatus for an electric vehicle according to the present invention, the motor lower limit torque is calculated based on the absorbable surplus power that is the power that can be absorbed by the power storage means and the power generation amount of the power generation means during the downshift. Is increased beyond the motor lower limit torque.
Therefore, even when the lowering of the motor torque is limited to the motor lower limit torque due to the increase of the motor lower limit torque accompanying the increase in the power generation amount, the motor torque can be reduced to the clutch transmission torque. Therefore, the fastening element on the fastening side can be fastened smoothly.

1 is an overall system diagram of an electric vehicle to which a control device for an electric vehicle according to a first embodiment is applied. FIG. 2 is a configuration diagram showing a configuration of an automatic transmission in the control device for an electric vehicle according to the first embodiment. It is a flowchart which shows the flow of the process regarding the downshift of the electric vehicle control apparatus of Embodiment 1, Comprising: The flow of the process implemented for every calculation period is shown. 3 is a flowchart showing a flow of processing related to a shift down shift of the control apparatus for an electric vehicle according to the first embodiment, and shows a flow of processing from the start of the shift down shift. FIG. 3 is a calculation block diagram showing a configuration for calculating a required output in the control device for an electric vehicle according to the first embodiment. FIG. 3 is a calculation block diagram showing a configuration for calculating an absorbable surplus power in the control device for an electric vehicle according to the first embodiment. FIG. 3 is a calculation block diagram showing a configuration for calculating outputable surplus power in the control apparatus for an electric vehicle according to the first embodiment. FIG. 3 is a calculation block diagram showing a configuration for calculating a motor lower limit torque in the control device for an electric vehicle according to the first embodiment. 6 is a time chart showing an example of changes in absorbable energy and holding energy with respect to the burnout limit of the friction clutch in the control apparatus for an electric vehicle according to the first embodiment. FIG. 3 is a calculation block diagram illustrating a configuration for calculating a motor upper limit torque in the control device for an electric vehicle according to the first embodiment. FIG. 3 is a safety factor characteristic diagram showing a setting characteristic of a safety factor according to the response estimation accuracy of a fuel cell as a power generation means in the control apparatus for an electric vehicle according to the first embodiment. FIG. 4 is a safety coefficient characteristic diagram showing a setting characteristic of a safety coefficient according to clutch transmission torque accuracy in the control apparatus for an electric vehicle according to the first embodiment. 5 is a time chart showing an example of an operation when a downshift is performed in a comparative example of the control apparatus for an electric vehicle according to the first embodiment. 3 is a time chart illustrating an example of an operation when the downshift of the control device for an electric vehicle according to the first embodiment is performed. It is a flowchart which shows the flow of the process regarding the shift down shift of the control apparatus of the electric vehicle of Embodiment 2, Comprising: The flow of the process after the shift down shift start is shown. FIG. 10 is a flowchart showing a process flow related to a downshift in the control apparatus for an electric vehicle according to a third embodiment, and shows a process flow from the start of the downshift. 10 is a time chart illustrating an example of an operation when a downshift of the control device for an electric vehicle according to the third embodiment is performed. FIG. 10 is a flowchart showing a process flow related to a shift down shift of the control apparatus for an electric vehicle according to a fourth embodiment, and shows a process flow from the start of the shift down shift. 10 is a time chart illustrating an example of an operation when a downshift of the control apparatus for an electric vehicle according to a fourth embodiment is performed. FIG. 10 is an overall system diagram of an electric vehicle to which a control device for an electric vehicle according to a third embodiment is applied.

Hereinafter, the best mode for realizing an electric vehicle control device of the present invention will be described based on the embodiments shown in the drawings.
(Embodiment 1)
First, the configuration of the control apparatus for an electric vehicle according to the first embodiment will be described separately in [Overall system configuration] [Configuration of automatic transmission] [Configuration of shift control system] [Shift down shift control processing configuration].

[Overall system configuration]
1 is an overall system diagram of a control device for an electric vehicle according to Embodiment 1. FIG.
As shown in FIG. 1, the drive system configuration of the electric vehicle includes a travel motor MG as a rotating electrical machine, an automatic transmission 10, and drive wheels W.

The travel motor MG is an electric motor that obtains a driving force for vehicle travel (performs power running), and can be constituted by, for example, a three-phase synchronous motor.
The travel motor MG is connected to the fuel cell 30 and the high-power battery 40 via the motor inverter 20. That is, at least one of the fuel cell 30 and the high-power battery 40 is used as a power source for the traveling motor MG, and the DC power is converted into a three-phase AC by the motor inverter 20 and supplied.
Further, when the vehicle is braked, etc., the traveling motor MG functions (regenerates) as a generator to generate three-phase AC power, and the three-phase AC is converted into DC by the motor inverter 20 and charged to the high-power battery 40. The

The power supply state among the motor inverter 20, the fuel cell 30, and the high-power battery 40 is switched by the distribution unit 50 based on the control of the control unit 100. That is, the distribution unit 50 supplies power to the traveling motor MG from either one or both of the fuel cell 30 and the high-power battery 40 based on various conditions.
As is well known, the fuel cell 30 is a power generator that can continuously extract electric power by reacting a negative electrode active material such as hydrogen with a positive electrode active material (oxygen in the air, etc.). The high-power battery 40 is a chargeable / dischargeable battery. Further, in the figure, illustrations of the vehicle, the auxiliary machines of the fuel cell 30, and the DC-DC converter are omitted.

[Configuration of automatic transmission]
Next, the configuration of the automatic transmission 10 will be described with reference to FIG.
The automatic transmission 10 is a constantly meshing stepped transmission that transmits power by one of two gear pairs having different gear ratios. The automatic transmission 10 is a second gear (high speed) having a small reduction ratio and a gear 1 having a large reduction ratio. A two-speed transmission mechanism having a high speed (low speed) is used.

  This automatic transmission 10 is provided between a transmission input shaft 11 and a transmission output shaft 12 that are arranged in parallel, and implements a first-speed transmission mechanism 13 that realizes the first gear and a second gear. A second-speed transmission mechanism 14 is provided.

  The first speed side transmission mechanism 13 is configured so that the gear 131 is engaged with the transmission output shaft 12 so that the low speed gear pair 130 (gear 131, gear 132) is drivingly coupled between the transmission input / output shafts 11 and 12. A meshing clutch 133 for releasing is provided. Here, the low-speed gear pair 130 includes a gear 131 rotatably supported on the transmission output shaft 12 and a gear 132 that meshes with the gear 131 and rotates together with the transmission input shaft 11.

The second speed side transmission mechanism 14 is configured to frictionally engage the gear 141 with respect to the transmission input shaft 11 so that the high speed gear pair 140 (gear 141, gear 142) is drivingly coupled between the transmission input / output shafts 11 and 12. A friction clutch 143 that performs the release is provided. As the friction clutch 143, in the first embodiment, a dry friction clutch is used.
The high-speed gear pair 140 includes a gear 141 that is rotatably supported on the transmission input shaft 11 and a gear 142 that meshes with the gear 141 and rotates together with the transmission output shaft 12.

  The transmission output shaft 12 is drivably coupled to a differential gear device 16 via a final drive gear set 15. The final drive gear set 15 includes a gear 15 a fixed to the transmission output shaft 12, and a gear 15 b that meshes with the gear 15 a and rotates to the differential gear device 16.

Next, the meshing clutch 133 and the friction clutch 143 will be described.
The meshing clutch 133 is a clutch by synchro meshing engagement, and includes a clutch gear 134 provided on the gear 131, a clutch hub 135 coupled to the transmission output shaft 12, and a coupling sleeve 136. Then, the coupling sleeve 136 is stroke driven by the electric actuator 121 to engage / disengage the mesh.

  The friction clutch 143 includes a driven plate 144 that rotates together with the gear 141 and a drive plate 145 that rotates together with the transmission input shaft 11. Then, the electric actuator 122 applies or removes the pressing force to both the plates 144 and 145 to engage / release the friction. The actuator for frictionally engaging / releasing the clutches 133 and 143 is not limited to an electric one, and other actuators such as an actuator driven by fluid pressure may be used.

[Configuration of shift control system]
As shown in FIG. 1, the control system configuration of the electric vehicle includes a control unit 100 and sensors including an accelerator opening sensor 111, a vehicle speed sensor 112, an input rotation sensor 113, and an output rotation sensor 114. .
The control unit 100 receives a signal indicating the clutch position (gear ratio) from the automatic transmission 10 and receives a signal indicating the motor rotational speed Nmo and the motor torque from the motor inverter 20. Further, the control unit 100 receives SOC, voltage, current, input power and output power from the high voltage battery 40.

The control unit 100 releases the engagement clutch 133 and releases the friction clutch 143 when shifting up to the second speed in the state where the first speed is selected in which the engagement clutch 133 is engaged and the friction clutch 143 is released. Performs switching control by frictional engagement.
Further, when shifting down to the first speed in the state where the second speed stage in which the engagement clutch 133 is released and the friction clutch 143 is frictionally engaged is selected, the change is made by the engagement of the engagement clutch 133 and the release of the friction clutch 143. Carry out control.
Note that, as is well known, for example, the shift-down shift is executed when the motion point determined by the accelerator opening and the vehicle speed crosses a shift line set in advance on the map from the second speed side to the first speed side. Judge as a request. Further, it may be executed by selecting the first gear by a manual shift operation (not shown).

[Shift-down shift control processing configuration]
Next, the control when shifting down from the second gear to the first gear when accelerating in the accelerator depression state, which is a feature of the control unit 100 of the first embodiment, will be described.
In performing this downshift control, in the first embodiment, a calculation process that is always executed regardless of whether or not the downshift is performed, and a shift process that is performed after a shiftdown shift execution request is made, Exists.

(Always operation processing)
Therefore, first, the calculation process that is always executed will be described in order based on the flowchart of FIG.
The process of FIG. 3 is always executed at a predetermined calculation cycle (for example, 30 msec) during traveling, and the required output Wreq is calculated in the first step S101.
This required output Wreq is obtained by the configuration shown in FIG.
That is, the accelerator opening and the vehicle speed are read from the accelerator opening sensor 111 and the vehicle speed sensor 112, and the target driving force is obtained based on a map set in advance in the map unit 501. Then, the target driving force is divided by the current gear ratio in the division unit 502, and the divided value is converted into an output in the output conversion unit 503 to obtain the required output Wreq.

Returning to FIG. 3, in step S102 following step S101, the kinetic energy E _IP that changes with the downshift is calculated using the following equation (1).
E _IP = (I / 2) × (Nmo) ² × (1− (1 / α ² )) (1)
Here, I is the inertia around the shaft that changes in rotation at the time of shifting, Nmo is the number of rotations of the motor at the start of shifting, and α is the gear ratio of the automatic transmission (second gear ratio / first gear ratio).

In step S103 following step S102, the absorbable surplus power Wgen_batt is calculated. This surplus absorbable power Wgen_batt is power that can be charged in the high-power battery 40 at present, and is calculated by the configuration shown in FIG.
That is, the adding unit 601 adds the battery-inputtable power, which is the power that can be charged to the current high-power battery 40, and the power consumption of the in-vehicle auxiliary equipment not shown. These values are positive for the output from the high-power battery 40 and negative for the input. Therefore, when the high-power battery 40 can be sufficiently charged, the added value is a negative value.
The comparison unit 602 compares the addition value obtained by the addition unit 601 with the power that can be passed to the high-power battery 40 in the distribution unit 50, and sets the larger value as the absorbable surplus power Wgen_batt. The electric power that can pass to the high-power battery 40 side is a negative value because it is in the battery input direction.

Returning to FIG. 3, in step S <b> 104 following step S <b> 103, the output possible surplus power Wdrive_batt is calculated. This output surplus power Wdrive_batt is power that can be output from the high-power battery 40 to the traveling motor MG, and is calculated by the configuration shown in FIG.
That is, the subtracting unit 701 calculates the power that can be output from the high-power battery 40 to the current traveling motor MG by subtracting the auxiliary machine power consumption from the battery-outputtable power that is the power that can be output from the current high-power battery 40. To do.
The comparison unit 702 compares the power that can be output to the current traveling motor MG with the power that can be passed through the distribution unit 50 from the high-power battery 40 to the traveling motor MG, and can output the lower value as surplus power. Wdrive_batt.

Returning to FIG. 3, in step S105 following step S104, the motor lower limit torque Tmotor_Lolim is calculated. This motor lower limit torque Tmotor_Lolim is a lower limit value determined based on the surplus absorbable power Wgen_batt, the current power generation amount of the fuel cell 30, and the traveling motor rotational speed Nmo, and is calculated by the configuration shown in FIG.
That is, the addition / subtraction unit 801 subtracts the absorbable surplus power Wgen_batt from the current power generation amount of the fuel cell 30. Then, the output conversion unit 802 performs torque conversion with the remaining power obtained by subtracting this absorbable power, and calculates a motor lower limit torque Tmotor_Lolim corresponding to the traveling motor rotational speed Nmo.

Returning to FIG. 3, in step S106 following step S105, the motor upper limit torque Tmotor_Hilim [Nm] is calculated. This motor upper limit torque Tmotor_Hilim is an upper limit value set based on the current power generation amount of the fuel cell 30, the output surplus power Wdrive_batt, and the traveling motor rotational speed Nmo, and is calculated by the configuration shown in FIG.
That is, the adding unit 901 adds the current power generation amount of the fuel cell 30 and the output surplus power Wdrive_batt. Then, the output conversion unit 902 converts the electric power added in the adding unit 901 into a motor torque based on the traveling motor rotational speed, and sets this as a motor upper limit torque Tmotor_Hilim.

Returning to FIG. 3, in step S107 following step S106, it is determined whether or not the shift control is being performed. If the shift control is being performed, the process proceeds to step S108, and if the shift control is not being performed, the process proceeds to step S109.
In step S108 which proceeds during the shift control, the absorbed energy Eclutch_sft [kJ] absorbed by the friction clutch 143 by the shift until the current control cycle is calculated by the following equation (2).
Eclutch_sft (this time)
= Tclutch (current) x ΔNclutch (current) x ST + Eclutch_sft (previous) (2)
Tclutch is the clutch transmission torque, ΔNclutch is the clutch differential rotation, and ST is the calculation cycle. At the time of non-shifting, the previous value is used as the absorbed energy Eclutch_sft.
The clutch transmission torque Tclutch uses an estimated value. This clutch transmission torque Tclutch can be estimated from the driving amount of the electric actuator 122 that drives the friction clutch 143 or its command value. Alternatively, it can be estimated from the motor torque when the friction clutch 143 is engaged, and can be estimated from the required drive torque based on the accelerator opening and the vehicle speed when the slip is engaged.

In the following step S109, the absorbable energy Eclutch_max of the friction clutch 143 is calculated.
The absorbable energy Eclutch_max [kJ] in the friction clutch 143 is based on the retained energy (KJ) held by the friction clutch 143 from the burnout limit value (KJ) of the friction clutch 143 as shown in the following equation (3). The value is obtained by subtracting.
Eclutch_max = burnout limit value-clutch holding energy (3)

  That is, as shown in FIG. 9, the burnout limit of the friction clutch 143 is set in advance based on the material and the like. On the other hand, the energy held by the friction clutch 143 changes from moment to moment when shifting is performed. The difference between the two becomes the energy that can be absorbed by the friction clutch 143.

Here, the clutch holding energy is a value that constantly changes every time the control period is calculated, and is calculated by the following equation (4).
Holding energy (current) = max (0, holding energy (previous value)-heat dissipation characteristics (KJ / sec) x calculation period (sec) + energy absorbed by friction clutch [KJ]) through gear shifting) (4)

(Shift-down shift control)
Next, based on the flowchart of FIG. 4, control when a downshift request is generated and downshift control is started will be described. Note that this downshift request is determined by, for example, the accelerator opening degree and the vehicle speed crossing the 2nd speed → 1st speed shift line as described above.

In FIG. 4, in step S201, it is determined whether or not a shift-down shift is possible. When the permission is determined, the shift-down shift is started and the process proceeds to step S202. When the shift-down stop is determined, the process proceeds to step S208.
This downshift possibility determination is performed by comparing the energy Eclutch_DW that the friction clutch 143 converts into heat at the time of downshift obtained based on the output surplus power Wdrive_batt and the power generation amount WFC1 and the absorbable energy Eclutch_max of the friction clutch 143. .
That is, if the estimated energy value Eclutch_DW converted to heat is smaller than the absorbable energy Eclutch_max, the downshift is permitted, and if the estimated energy value Eclutch_DW converted to heat is larger than the absorbable energy Eclutch_max, the shift is prohibited.

  Here, first, a method for estimating the energy estimated value Eclutch_DW that the friction clutch 143 converts into heat during the downshift will be described. In this estimation, first, the inertia phase time timeIP_DW at the time of downshift is estimated from the following equation (5) based on the surplus output possible power Wdrive_batt and the power generation amount WFC1. Then, from the shift time based on the inertia phase time timeIP_DW, an estimated energy value Eclutch_DW that the friction clutch 143 converts into heat when downshifting is obtained based on the following equation (8).

timeIP_DW = EIP / (-WinfoG + WFC1 + Wdrive_batt) (5)
EIP is the kinetic energy that changes with the shift obtained in step S102. WinfoG is a motor output necessary for generating information G. WFC1 is the command value of the power generation amount of the fuel cell at the start of shifting, and Wdrive_batt is the surplus power that can be output obtained in step S104.
The information G is an acceleration that generates a very slight acceleration 0.00a (a is a single digit value) set in advance as an initial response acceleration with respect to the accelerator depressing operation, and is converted into a motor output by the following equation (6). .
WinfoG
= 0.00a motor torque conversion value [Nm] x vehicle speed motor rotation number conversion value [rad / sec] (6)
Moreover, the motor torque conversion value of 0.00a is calculated | required by following formula (7).
Motor torque conversion value = 0.00a [G] x 9.8 x weight [kg] x tire radius [m] x gear ratio passing through transmission (7)

Further, the equation (8) for obtaining the above-described energy estimated value Eclutch_DW is as follows.
Eclutch_DW
= WinfoG × (1- (1 / α)) × (timeIP_DW + timeTP) ÷ 2 × γFC × γclutch (8)
In the above equation (8), WinfoG is the motor output necessary to obtain the information G obtained by the above equation (6), α is the step ratio, and timeIP_DW is the inertia phase time obtained by the above equation (5). Further, timeTP is a target torque phase time determined by the shift control at the start of the shift.

In equation (8), γFC is a safety factor when the responsiveness estimation accuracy of the fuel cell 30 is degraded, and γclutch is a safety factor when the clutch transmission torque estimation accuracy is degraded.
These safety factors γFC and γclutch are set so that the energy estimation value Eclutch_DW increases in response to the power generation amount and the friction clutch 143 accuracy deterioration, that is, the shift down prohibition determination tendency becomes strong in step S201. Yes.

The setting characteristics of the safety factors γFC and γclutch are shown in FIGS.
FIG. 11 shows the characteristic of the safety coefficient γFC when the responsiveness estimation accuracy of the fuel cell 30 deteriorates corresponding to the coolant temperature of the fuel cell 30. That is, when the coolant temperature is in a region where the responsiveness estimation accuracy of the fuel cell 30 is high, the safety coefficient γFC is set to 1.0. Therefore, the correction to the safe side by the safety coefficient γFC is not performed on the energy estimated value Eclutch_DW obtained by WinfoG, α, timeIP_DW, and timeTP. On the other hand, when the cooling water temperature shifts from the high accuracy region to the low temperature side and the high temperature side, the value obtained from the energy estimated value Eclutch_DW obtained from WinfoG, α, timeIP_DW, and timeTP is corrected to the increasing side. In the figure, the value a is a value after the decimal point, and the safety coefficient γFC is set to a value that is about 20 to 30% higher than when the water temperature is in the high accuracy region.
That is, in the first embodiment, when the estimation accuracy is low according to the estimation accuracy of the responsiveness of the fuel cell 30 as the power generation means when calculating the energy estimation value Eclutch_DW that the friction clutch 143 converts into heat during the downshift, The energy estimated value Eclutch_DW is increased as compared with the case where the estimation accuracy is high.

FIG. 12 shows the characteristic of the safety coefficient γ clutch when the clutch transmission torque estimation accuracy deteriorates. The safety coefficient γ clutch when the clutch transmission torque estimation accuracy deteriorates uses at least one of oil temperature, clutch command transmission torque, and clutch differential rotation as a change factor.
The safety coefficient γclutch is set to 1.0 when the oil temperature, the clutch transmission torque command, and the clutch differential rotation are in the high-accuracy region on the lower side. Therefore, the correction to the safe side by the safety coefficient γFC is not performed on the energy estimated value Eclutch_DW obtained by WinfoG, α, timeIP_DW, and timeTP.
On the other hand, when each factor of oil temperature, clutch transmission torque command, and clutch differential rotation becomes a value higher than this high accuracy region, the safety coefficient γclutch is set to a value larger than 1.0. In the figure, the value of b is a value after the decimal point, and the safety coefficient γclutch is set so that it is a maximum of about 20 to 30% higher than when each factor is in the high accuracy region. Therefore, the energy estimated value Eclutch_DW obtained by WinfoG, α, timeIP_DW, and timeTP is corrected to the increasing side.

  That is, in the first embodiment, when calculating the estimated energy value Eclutch_DW that the friction clutch 143 converts into heat during downshifting, the estimation accuracy of the transmission torque command, the estimation accuracy of the oil temperature, and the estimation accuracy of the clutch differential rotation are calculated. Accordingly, when each estimation accuracy is low, the estimated energy value Eclutch_DW is increased as compared with a case where each estimation accuracy is high.

  In step S202 that proceeds when the downshift is executed, it is determined whether or not the inertia phase has been started. The determination in step S202 is repeated until the inertia phase is started, and the process proceeds to step S203 in which the inertia phase is started.

  In step S203, which proceeds by the start of the inertia phase, it is determined whether or not the clutch transmission torque Tclutch is smaller than the motor lower limit torque Tmotor_Lolim. If the clutch transmission torque Tclutch is smaller, the process proceeds to step S204. If the clutch transmission torque Tclutch is larger, the process proceeds to step S206.

In step S204 that proceeds when the clutch transmission torque Tclutch is smaller than the motor lower limit torque Tmotor_Lolim, it is determined whether the clutch differential rotation is equal to or less than a threshold value. If the clutch differential rotation is equal to or smaller than the threshold value, the process proceeds to step S205. If the clutch differential rotation is larger than the threshold value, the determination in step S204 is repeated.
The comparison with the threshold value of the clutch differential rotation is for determining that the inertia phase is nearing the end, and that it is an appropriate timing to start increasing the clutch transmission torque Tclutch in step S205. Therefore, the threshold value is set to a value that can properly end the increase of the clutch transmission torque Tclutch in step S205 by the end of the inertia phase.

In step S205, the clutch transmission torque Tclutch is increased at the calculated rate of change (increasing gradient). Here, the increasing gradient that is the rate of change will be described.
In the first embodiment, the increasing gradient of the clutch transmission torque Tclutch is calculated by the following equation (9).
Increasing slope = [(Tmotor_Lolim−Tclutch) / (timeIP_target−timeIP)] × calculation cycle (9)
In the above equation (9), Tmotor_Lolim is the motor lower limit torque, Tclutch is the estimated clutch transmission torque of the engagement-side friction clutch 143, timeIP_target is the target inertia phase time, and timeIP is the inertia phase when it is determined that the clutch transmission torque has increased. The elapsed time from the start.

  The target inertia phase time timeIP_target is a time set in advance so as not to give the driver a sense of incongruity. By setting the target inertia phase time timeIP_target, it is possible to suppress an increase in the shift time caused by the heat absorption time by the friction clutch 143 becoming too long.

  Therefore, the increase gradient is set such that there is no difference between the clutch transmission torque Tclutch and the motor lower limit torque Tmotor_Lolim from the time when the increase of the clutch transmission torque is determined until the target inertia phase time timeIP_target ends.

  In step S206, which proceeds after the increase of the clutch transmission torque Tclutch is started in step S205, it is determined again whether or not the clutch transmission torque Tclutch is smaller than the motor lower limit torque Tmotor_Lolim. When the clutch transmission torque Tclutch is smaller than the motor lower limit torque Tmotor_Lolim, the processing from step S203 is repeated. When the clutch transmission torque Tclutch becomes larger than the motor lower limit torque Tmotor_Lolim, the routine proceeds to step S207 and shift down shift control is performed. Execute.

That is, when the clutch transmission torque Tclutch is smaller than the motor lower limit torque Tmotor_Lolim, the downshift is not permitted.
At the time of downshift control, the friction clutch 143 is released and the clutch for engaging the meshing clutch 133 is switched.

(Operation of Embodiment 1)
Next, the operation of the first embodiment will be described based on the time charts of FIGS.
(Comparative example)
First, before explaining the operation of the first embodiment, a problem to be solved by the present invention will be described by the operation of the comparative example based on the time chart of FIG.

FIG. 13 shows an operation example in which a shift-down shift is performed in response to an acceleration operation by depressing the accelerator from a state where the accelerator is released at the second gear. That is, there is a shift down shift start request at the time t0 with respect to the acceleration operation, and from the time t1, the rotational speed control is performed to make the input / output rotational speeds of the meshing clutch 133 coincide with each other, and the motor rotational speed is increased. As a result, an inertia phase is started in which the transmission input / output rotation speed ratio changes from the gear ratio of the second gear before the gear shift to the gear ratio of the first gear after the gear shift.
Therefore, the friction clutch 143 is in the slip engagement state and transmits a torque corresponding to the driver's requested drive torque while forming a rotational speed difference.
For this reason, the motor torque is increased from the time t1, and the power generation amount (FC output) and the battery output are increased according to the torque increase.

As the power generation amount of the fuel cell 30 increases, the motor lower limit torque Tmotor_Lolim also increases from the time t1 (FIG. 8).
However, when the motor lower limit torque Tmotor_Lolim increases in this way, the motor torque may not be reduced to the transmission torque of the friction clutch 143 at the end of the inertia phase. In this case, as shown in the figure, the motor rotational speed is higher than the target rotational speed after shifting, that is, the rotational speed becomes inappropriate for engaging the clutch on the engagement side, and the shift can be completed. There was a risk of being unable to do so. In particular, when the meshing clutch 133 is used as the clutch on the fastening side as in the first embodiment, this problem becomes significant.

(Embodiment 1)
The first embodiment suppresses the occurrence of a shift failure due to the increase in the motor lower limit torque Tmotor_Lolim in the comparative example described above, and the operation example of the first embodiment will be described below based on FIG. To do.
The time chart of FIG. 14 is also an example of operation in the case of performing a downshift by performing the same acceleration operation as the time chart of FIG. 13, and will be described below in order.
In this operation example, at time t0, a shift down shift request from the second gear to the first gear is determined according to the driver's acceleration operation, and the motor torque is increased. Then, the rotational speed control on the input side of the automatic transmission 10 is performed from time t1 to time t2 (inertia phase). Further, at time t2 to t3, a synchronization operation is performed to synchronize the input / output rotation of the meshing clutch 133, and at time t3 to t4, the friction clutch 143 is released and the meshing clutch 133 is engaged to change gears. Is finished (torque phase).

The above operations will be described in order.
If a downshift request is made across the shift line at time t0, first, it is determined whether or not a downshift is possible (S201). That is, the heat generation amount (energy estimated value Eclutch_DW) in the friction clutch 143 is predicted based on the surplus power Wdrive_batt that can be output from the high-power battery 40 and the power generation amount WFC of the fuel cell 30. When the estimated energy value Eclutch_DW can be predicted to complete the inertia phase within the range of the absorbable energy Eclutch_max of the friction clutch 143, the shift down shift is permitted. On the other hand, when the energy estimated value Eclutch_DW exceeds the absorbable energy Eclutch_max of the friction clutch 143 by the end of the inertia phase, the shift down shift is prohibited (S208).

When the downshift is permitted, the rotational speed control is performed so as to make the input / output rotational speeds of the meshing clutch 133 coincide from the time point t1, and the motor rotational speed is increased (inertia phase start). During this inertia phase, the friction clutch 143 is in a slip engagement state, and transmits a torque corresponding to the driver's requested drive torque while forming a difference in input / output rotational speed of the friction clutch 143.
Further, during the inertia phase, the power generation amount (FC output) and the battery output are increased as the motor torque increases. As the power generation amount of the fuel cell 30 increases, the motor lower limit torque Tmotor_Lolim also increases from the time t1 (FIG. 8).

  Therefore, in the first embodiment, the motor lower limit torque Tmotor_Lolim has exceeded the clutch transmission torque Tclutch of the friction clutch 143 after the start of the inertia phase at time t1 (YES determination in step S203).

  Thereafter, the clutch transmission torque Tclutch is calculated at the calculated rate of change at the time t1a when the input differential rotation of the engagement-side mesh clutch 133 becomes equal to or less than the threshold value (ie, near the end of the inertia phase) due to the increase in the motor rotation speed. Increase (step S205).

  Therefore, the clutch transmission torque Tclutch is kept constant from the time point t1 to the time point t1a and the friction clutch 143 is slip-engaged. However, as shown in the figure, the clutch transmission torque Tclutch is increased from the time point t1a with a large gradient.

  In the first embodiment, the increase gradient of the clutch transmission torque Tclutch is a gradient that eliminates the difference from the motor lower limit torque Tmotor_Lolim until the target inertia phase time timeIP_target ends based on the arithmetic expression of (9) described above. And

  Then, at the end of the inertia phase where the input / output rotation difference of the engagement-side meshing clutch 133 is almost eliminated, the increase in the motor rotation speed is stopped and the motor torque is decreased. At this time, since the clutch transmission torque Tclutch is increased to the motor lower limit torque Tmotor_Lolim, even if the decrease in the motor torque is limited to the motor lower limit torque Tmotor_Lolim, the motor rotation speed increases as if the friction clutch 143 slips. There is nothing.

Therefore, after the meshing clutch 133 is synchro-engaged from the time t2 to the time t3, the engagement and release of the clutches 133 and 143 are switched between the time t3 and the time t4 (torque phase), and the time t4 To finish shifting.
As described above, the clutch transmission torque Tclutch is increased to the motor lower limit torque Tmotor_Lolim even if the motor lower limit torque Tmotor_Lolim is higher than the clutch transmission torque Tclutch by increasing the power generation amount and the battery output during the inertia phase. Therefore, the shift can be completed.

(Effect of Embodiment 1)
The effects of the control apparatus for the electric vehicle according to the first embodiment are listed below together with the actions.
1) A control device for an electric vehicle according to Embodiment 1
A fuel cell 30 as a power generation means mounted on a vehicle and a high-power battery 40 as a power storage means;
A traveling motor MG as a rotating electrical machine driven by electric power from the fuel cell 30 and the high-power battery 40;
An automatic transmission 10 that transmits the power of the traveling motor MG to the driving wheel W side and that engages and disengages the mesh clutch 133 and the friction clutch 143 at the time of shifting;
A control unit 100 as a control means for controlling the operation of the fuel cell 30, the traveling motor MG, and the automatic transmission 10;
An electric vehicle control device comprising:
The control unit 100 increases the power generation amount of the fuel cell 30 during the downshift and changes the absorbable surplus power Wgen_batt that is the power that can be absorbed by the high-power battery 40 based on the state of the high-power battery 40. The motor lower limit torque Tmotor_Lolim is calculated based on the surplus absorbable power Wgen_batt and the power generation amount of the fuel cell 30, and the clutch transmission torque Tclutch on the disengagement side is increased beyond the motor lower limit torque Tmotor_Lolim. To do.
At the time of downshift, the motor lower limit torque Tmotor_Lolim increases by increasing the power generation amount as the motor torque is increased, and when the motor torque is decreased, the decrease may be limited to the motor lower limit torque. . In this case, since the disengagement side clutch transmission torque Tclutch is increased to the motor lower limit torque Tmotor_Lolim or more, the motor torque can be reduced to the clutch transmission torque Tclutch. Therefore, the input rotation speed of the engagement clutch 133 can be reduced, and the engagement can be performed smoothly.
In addition, since the motor lower limit torque Tmotor_Lolim is calculated based on the absorbable surplus power Wgen_batt and the power generation amount of the fuel cell 30, the motor torque reduction margin can be accurately reduced rather than simply calculated based on the power generation amount. Can be set. As a result, it is possible to secure a margin of reduction in the motor rotation speed at the end of the inertia phase, and to reduce the rotation speed on the input side of the meshing clutch 133 that is the engagement side clutch, and to increase the clutch transmission torque Tclutch. Can be suppressed. For this reason, it is excellent in controllability.
In particular, in the first embodiment, when the meshing clutch 133 is used as the clutch on the fastening side, it is necessary to synchronize the rotational speeds on the input side and the output side, and the rotational speed on the input side is synchronized as described above. The above control becomes more effective when the rotational speed is reduced to a necessary level.

2) In the control device for an electric vehicle according to the first embodiment,
In the inertia phase, the control unit 100 increases the clutch transmission torque Tclutch when the clutch transmission torque Tclutch of the disengagement friction clutch 143 is smaller than the motor lower limit torque Tmotor_Lolim.
Therefore, even when the clutch transmission torque Tclutch is smaller than the motor lower limit torque Tmotor_Lolim during the inertia phase, the meshing clutch 133 that is the clutch on the engagement side can be securely engaged smoothly at the end of the inertia phase.

3) The control device for the electric vehicle according to the first embodiment is
The control unit 100 increases the clutch transmission torque Tclutch at a constant rate of change.
Therefore, it is possible to suppress the uncomfortable feeling given to the driver by minimizing the change in the driving force associated with the increase in the clutch transmission torque Tclutch of the disengagement friction clutch 143.

4) The control device for the electric vehicle according to the first embodiment is
The control unit 100 is characterized in that the change rate is a change rate at which the clutch transmission torque Tclutch coincides with the motor lower limit torque Tmotor_Lolim at the end of the inertia phase.
Therefore, when the clutch transmission torque Tclutch is increased, the increase amount and the increase gradient (change rate) can be minimized. Thereby, in obtaining the effects 1) to 3), it is possible to minimize the change in the driving torque and further suppress the uncomfortable feeling given to the driver.

5) The control device for the electric vehicle according to the first embodiment is
The control unit 100 is characterized in that the clutch transmission torque Tclutch is started when it is determined that the end time of the inertia phase is approaching.
Accordingly, during the inertia phase, the increase of the inertia phase time can be prevented by not increasing the clutch transmission torque Tclutch of the disengagement friction clutch 143 until the end of the inertia phase is approached. In addition, after approaching the end of the inertia phase, the effects 1) to 4) can be obtained by increasing the clutch transmission torque Tclutch.

6) The control device for the electric vehicle according to the first embodiment is:
The control unit 100 determines that the end time of the inertia phase is approaching when the input / output differential rotation of the engagement clutch 133 on the engagement side has fallen below a set value.
Therefore, it is possible to reliably determine that the end phase of the inertia phase is approaching, and to increase the clutch transmission torque Tclutch of the disengagement friction clutch 143 at an appropriate timing even at different vehicle speeds.

7) The control device for the electric vehicle according to the first embodiment is
When the clutch on the engagement side at the time of the downshift is the meshing clutch 133, the control unit 100 determines that the clutch clutch 133 has a clutch transmission torque Tclutch of the disengagement friction clutch 143 smaller than the motor lower limit torque Tmotor_Lolim. The control apparatus of the electric vehicle characterized by not commanding the fastening of.
That is, when the disengagement-side friction clutch 143 clutch transmission torque Tclutch is smaller than the motor lower limit torque Tmotor_Lolim, the input-side rotation speed of the meshing clutch 133 may not be controlled to a desired rotation speed. Therefore, it is possible to prevent the meshing clutch 133 from being fastened in a state where the rotational speed control is not properly performed, and to damage the meshing clutch 133 by fastening at such an inappropriate speed.

(Other embodiments)
Next, a transmission device for a hybrid vehicle according to another embodiment will be described.
In the description of the other embodiments, the same reference numerals as those in the first embodiment are assigned to the same components as those in the first embodiment, and the description thereof is omitted. Only the differences from the first embodiment will be described. .

(Embodiment 2)
Next, the control device for the electric vehicle according to the second embodiment will be described.
FIG. 15 is a flowchart showing a flow of processing related to a downshift in the control apparatus for an electric vehicle according to the second embodiment, and shows a flow of processing after the start of the downshift.
That is, the processing in step S304 following step S203 is different from that in the first embodiment. This step S304 is an example in which it is determined that the inertia phase end time is approaching because the inertia phase time, which is the elapsed time from the start of the inertia phase, has exceeded the set value time_start.

Therefore, in the second embodiment, the time from t1 to t1a in FIG. 14 is the set value time_start.
Since other functions and effects are the same as those of the first embodiment, description thereof is omitted.

Therefore, Embodiment 2 has the following effects in addition to the effects 1) to 5) and 7).
2-1) The control device for the electric vehicle according to the first embodiment is:
The control unit 100 determines that the end time of the inertia phase is approaching when an inertia phase time that is an elapsed time from the start of the inertia phase exceeds a set value time_start.
Therefore, it is possible to reliably determine that the end phase of the inertia phase is approaching, and to increase the clutch transmission torque Tclutch of the disengagement friction clutch 143 at an appropriate timing even at different vehicle speeds.

(Embodiment 3)
Next, an electric vehicle control apparatus according to Embodiment 3 will be described.
FIG. 16 is a flowchart showing a flow of processing related to a downshift in the control apparatus for an electric vehicle according to the third embodiment, and shows a flow of processing after the start of the downshift.

  In the third embodiment, when the clutch transmission torque Tclutch is smaller than the motor lower limit torque Tmotor_Lolim in step S203, the process proceeds to step S405, and after increasing the clutch transmission torque Tclutch at the calculated rate of change, the process proceeds to step S206. .

In step S405, the rate of change (increase in gradient) is different from that in the first embodiment, and is calculated using the following equation (10).
Increasing slope = [(Tmotor_Lolim−Tclutch) / timeIP_target] × operation period [Nm / sec] (10)
In equation (10), Tmotor_Lolim is the motor lower limit torque, Tclutch is the clutch transmission torque (estimated value) of the friction clutch 143, and timeIP_target is the target inertia phase time described above. Each torque is an estimated value at the end of the inertia phase.

  Therefore, in the third embodiment, the motor lower limit torque Tmotor_Lolim and the clutch transmission torque Tclutch are set to increase gradients that coincide with each other during the target inertia phase time timeIP_target.

Next, an operation example of the third embodiment will be described with reference to the time chart of FIG.
In the operation description of the third embodiment, only differences from the first embodiment will be described.
In the third embodiment, during the inertia phase, the clutch transmission torque Tclutch is increased at a constant rate from the time t1 when the clutch transmission torque Tclutch of the friction clutch 143 becomes smaller than the motor lower limit torque Tmotor_Lolim. In the third embodiment, the clutch transmission torque Tclutch is increased at a rate of change (increasing gradient) at which the clutch transmission torque Tclutch matches the motor lower limit torque Tmotor_Lolim at time t2 when the target inertia phase ends. .

Therefore, even in the third embodiment, even if the motor lower limit torque Tmotor_Lolim is higher than the clutch transmission torque Tclutch during the inertia phase, the clutch transmission torque Tclutch is increased to the motor lower limit torque Tmotor_Lolim at the end of the inertia phase. Thus, the shift can be completed.
Therefore, even in the third embodiment, the effects 1) to 5) and 7) described above are achieved.

(Embodiment 4)
Next, an electric vehicle control apparatus according to Embodiment 4 will be described.
FIG. 18 is a flowchart showing a flow of processing related to a downshift in the control apparatus for an electric vehicle according to the third embodiment, and shows a flow of processing after the start of the downshift.
That is, the process of step S603 that proceeds at the start of the inertia phase in step S202 is different from that of the first embodiment. In step S603, it is determined whether or not the motor lower limit torque Tmotor_Lolim and the actual output torque of the traveling motor MG match during the inertia phase. If they match, the process proceeds to step S205. Proceed to

An operation example of the fourth embodiment is shown in FIG.
As shown in this figure, after the time t1 when the inertia phase is started, when the input / output rotational difference of the meshing clutch 133 becomes relatively small by the rotational speed control, the motor torque is reduced. At this time, at time t1b when the motor torque coincides with the increased motor lower limit torque Tmotor_Lolim and further decrease is restricted, the clutch transmission torque Tclutch of the friction clutch 143 on the disengagement side from the motor lower limit torque Tmotor_Lolim is The clutch transmission torque Tclutch of the friction clutch 143 is increased assuming that the friction clutch 143 is small.
Note that the increasing gradient of the clutch transmission torque Tclutch at this time is the same as in the first embodiment.

  Therefore, even in the fourth embodiment, even if the motor lower limit torque Tmotor_Lolim is higher than the clutch transmission torque Tclutch during the inertia phase, the clutch transmission torque Tclutch is increased to the motor lower limit torque Tmotor_Lolim at the end of the inertia phase. Thus, the shift can be completed.

Therefore, Embodiment 4 has the following effects in addition to the effects 1) to 4) and 7).
4-1) The control device for the electric vehicle in the third embodiment is
The control unit 100 increases the clutch transmission torque Tclutch when the motor lower limit torque Tmotor_Lolim and the actual output torque of the traveling motor MG coincide with each other during the inertia phase (at time t1b). It is assumed that the disengagement side friction clutch 143 clutch transmission torque Tclutch is smaller than the lower limit torque Tmotor_Lolim, and starts.
Thus, since the increase timing of the clutch transmission torque Tclutch is performed based on the motor lower limit torque Tmotor_Lolim and the actual output torque of the traveling motor MG, it is determined regardless of the estimated accuracy of the clutch transmission torque Tclutch of the disengagement side friction clutch 143. it can.
Therefore, even when the estimation accuracy of the clutch transmission torque Tclutch of the disengagement friction clutch 143 is poor, the clutch transmission torque Tclutch can be appropriately increased.

(Embodiment 5)
Next, an electric vehicle control apparatus according to Embodiment 5 shown in FIG. 20 will be described.
In the fifth embodiment, a power generator 402 that is driven by an engine 401 to generate power is used as the power generation means 400. Other configurations are the same as those in the first embodiment, and thus description thereof is omitted.
As described above, the power generation means 400 driven by the engine 401 can be used instead of the fuel cell 30. As the power generation means, other power generation means can be used.

  As mentioned above, although the control apparatus of the electric vehicle of this invention was demonstrated based on embodiment, about a specific structure, it is not restricted to this embodiment, 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.

  In the first embodiment, the automatic transmission as the transmission has a structure in which the friction clutch is released and the meshing clutch is engaged during the downshift. However, this transmission is not limited to the engagement clutch for the clutch on the engagement side during the downshift, and a friction clutch can also be used on the engagement side. Further, the number of shift stages is not limited to the two-stage stage shown in the embodiment.

Further, in the embodiment, an example is shown in which, when increasing the transmission torque of the clutch on the disengagement side beyond the motor lower limit torque, the clutch transmission torque is larger than the motor lower limit torque. It may be increased until Alternatively, the clutch transmission torque may be increased more than the motor lower limit torque at a time before the end of the inertia phase.
Further, in the embodiment, the rate of change when the clutch transmission torque is increased is shown to match the clutch transmission torque to the motor lower limit torque at the end of the inertia phase, but the rate of change is not limited to this. If the clutch transmission torque can be surely increased beyond the motor lower limit torque, the clutch transmission torque may be reduced at a preset rate of change. Alternatively, the change rate may be a curvilinear change rate.

10 Automatic transmission 30 Fuel cell (power generation means)
40 High-power battery (power storage means)
100 Control unit (control means)
133 meshing clutch (clutch on the fastening side)
143 Friction clutch (release side clutch)
400 Power generation means Tclutch Clutch transmission torque Tmotor_Lolim Motor lower limit torque Wgen_batt Absorbable surplus power WFC1 Power generation amount (at the start of shifting)

Claims (9)

Power generation means and power storage means mounted on the vehicle;
A rotating electrical machine driven by electric power from the power generation means and the power storage means;
A transmission that transmits the power of the rotating electrical machine to the drive wheel side, and that engages and disengages the clutch at the time of shifting;
Control means for controlling the operation of the power generation means, the rotating electrical machine, and the transmission;
An electric vehicle control device comprising:
The control means increases the power generation amount of the power generation means during a downshift, and obtains an absorbable surplus power that is power that can be absorbed by the power storage means based on the state of the power storage means. A control apparatus for an electric vehicle, wherein a motor lower limit torque is calculated based on surplus power and the amount of power generated by the power generation means, and a transmission torque of the clutch on the disengagement side is increased to be equal to or greater than the motor lower limit torque. In the control apparatus of the electric vehicle according to claim 1,
The control device for an electric vehicle, wherein the control means increases the transmission torque when the transmission torque of the clutch on the disengagement side is smaller than the motor lower limit torque during the inertia phase. In the control apparatus of the electric vehicle according to claim 2,
The control device for an electric vehicle characterized in that the control means increases the transmission torque at a constant rate of change. In the control apparatus of the electric vehicle according to claim 3,
The control means of the electric vehicle characterized in that the control means sets the change rate so that the transmission torque matches the motor lower limit torque at the end of the inertia phase. In the control apparatus of the electric vehicle according to any one of claims 2 to 4,
The control device for an electric vehicle, wherein the control means starts increasing the transmission torque when it is determined that the end time of the inertia phase is approaching. In the control apparatus of the electric vehicle according to claim 5,
The control device for an electric vehicle, wherein the control means determines that the end time of the inertia phase is approaching, because an input / output differential rotation of the clutch on the engagement side falls below a set value. In the control apparatus of the electric vehicle according to claim 5,
The control device for an electric vehicle, wherein the control means determines that the end time of the inertia phase is approaching when an elapsed time from the start of the inertia phase exceeds a set value. In the control apparatus of the electric vehicle according to claim 2 or claim 3,
The control means increases the transmission torque when the motor lower limit torque and the actual output torque of the rotating electrical machine coincide with each other during the inertia phase. The control apparatus for an electric vehicle is characterized in that it is started as if the vehicle is small. In the control device of the electric vehicle according to any one of claims 1 to 8,
The control means does not command the engagement of the meshing clutch when the clutch on the engagement side during the downshift is a meshing clutch and the transmission torque of the release-side clutch is smaller than the motor lower limit torque. A control device for an electric vehicle.