JP2012091548A - Electric vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric vehicle control device that can suppress generation of torque vibration during cooperative regeneration.SOLUTION: The control device includes: a motor generator MG which performs regeneration by input from driving wheels (RL, RR); a brake unit BU which mechanically generates braking force according to the braking operation of a driver; a vehicle speed sensor 17 which detects vehicle speed VSP; and an integrated controller 10 and a brake controller 9 which performs at braking time, cooperative regenerative braking which performs braking by adjusting regeneration force by the motor generator MG and braking force by the brake unit BU, and ends the cooperative regenerative braking if the vehicle speed becomes below the cooperative regeneration end determination threshold and brakes only by mechanical braking force only by the brake unit BU. The integrated controller 10 forms the vehicle speed for cooperative regeneration reference by giving hysteresis to only increase side of a vehicle speed signal used for end determination of the cooperative regenerative braking and performs end determination of the cooperation regenerative braking by comparing this vehicle speed for cooperative regeneration reference with cooperation regeneration end determination threshold.

Description

  The present invention relates to a control device for an electric vehicle that performs cooperative regenerative braking control.

Conventionally, in a vehicle equipped with a motor generator in a driving system such as an electric vehicle or a hybrid vehicle, so-called cooperative regenerative braking control is performed in which the motor generator is regenerated during braking and braking is performed using the braking force generated by the regeneration and the braking force generated by the mechanical brake. Is known (for example, see Patent Document 1).
In such a conventional technique, from the viewpoint of brake feeling, when the vehicle speed is reduced to a set vehicle speed or less before the vehicle is stopped, the cooperative regenerative braking is terminated and the vehicle is stopped only by the mechanical brake.

JP 2001-16703 A

  By the way, there is a case where the fluctuation of the vehicle speed signal becomes large when the road surface is bad. When such a vibration occurs in the vehicle speed signal, the vehicle speed may increase or decrease the cooperative regeneration end determination threshold for determining whether to shift from cooperative regenerative braking to mechanical braking, and control hunting may occur, which may cause torque vibration. .

  The present invention has been made paying attention to the above problem, and an object of the present invention is to provide an electric vehicle control device that can suppress the occurrence of torque vibration during cooperative regeneration.

  In order to achieve the above object, the control device for an electric vehicle according to the present invention performs coordinated regenerative braking in which braking is performed by adjusting the regenerative force by the motor generator and the braking force by the brake device during braking, and the vehicle speed ends cooperative regeneration. A brake control unit is provided that terminates cooperative regenerative braking and brakes only with the mechanical braking force of only the brake device when the value is lower than the determination threshold, and this brake control unit includes an increase side in the vehicle speed signal used to determine the end of cooperative regenerative braking. Only the regenerative reference vehicle speed provided with hysteresis is formed, and the cooperative regenerative reference vehicle speed is compared with the cooperative regeneration end determination threshold value to determine the end of cooperative regenerative braking.

  In the present invention, since the end of cooperative regeneration is determined using the cooperative regeneration reference vehicle speed to which hysteresis is applied only on the increasing side of the vehicle speed signal, the amplitude on the increasing side is suppressed during vibration of the vehicle speed signal. Therefore, when the vehicle speed signal vibrates, compared to the case where no hysteresis is given to the increase side, hunting is prevented from occurring between cooperative braking and braking of only the mechanical brake unit near the cooperative end vehicle speed. The occurrence of torque vibration can be suppressed.

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 a flowchart which shows the flow of the vehicle speed signal process in the integrated controller 10 of the control apparatus of Example 1, and a cooperative regenerative braking control. It is a circuit diagram which shows the structure of the part which performs the vehicle speed signal process and cooperative regenerative braking control in the integrated controller 10 of the control apparatus of Example 1. FIG. It is a time chart which shows the vehicle speed signal Vsp3 which shows an example of the change of the vehicle speed VK for cooperative regeneration reference at the time of braking of the control apparatus of Example 1, and the vehicle speed signals Vsp1 and Vsp2 for the comparison.

  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 travel modes, an electric vehicle travel mode (hereinafter referred to as “EV mode”), a hybrid vehicle travel mode (hereinafter referred to as “HEV mode”), and a drive torque control travel mode. (Hereinafter referred to as “WSC mode”. WSC 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 controls the hydraulic pressure in the brake unit BU as a mechanical brake that applies a braking force to each wheel, and controls the braking force of each wheel. The wheel speed sensor 19 detects the wheel speed of each of the four wheels. Then, the sensor information from the brake pedal force sensor 20, the cooperative regeneration control command from the integrated controller 10, and other necessary information are input. For example, when the brake pedal is depressed by the driver, if the regenerative braking force is insufficient with respect to the required braking force obtained from the brake stroke BS, the shortage is reduced by the mechanical braking force (hydraulic braking force or motor braking force). Coordinated regenerative brake control is performed to compensate.

  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 Output cooperative regeneration control command.

  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 EV → HEV switching line are set with a hysteresis amount (H1 and H2 to be described later) as a threshold for dividing the EV region and the HEV region. 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).

  Next, signal processing of the vehicle speed VSP at the time of cooperative regenerative braking control in the integrated controller 10 will be described.

  The integrated controller 10 performs cooperative regenerative braking control at a vehicle speed VSP or higher that is set in advance when the driver performs a braking operation or performs automatic braking in auto cruise control or the like. This cooperative regenerative braking control is well known, and it is necessary to adjust the mechanical brake torque by the brake unit BU while obtaining the regenerative braking torque within the range of the maximum regenerative torque of the motor generator MG during braking. Control is performed so as to obtain a braking force.

In the first embodiment, in the cooperative regenerative braking control, the cooperative regeneration reference vehicle speed VK with hysteresis added to the increase side is formed without using the vehicle speed VSP as it is, and the cooperative regeneration control is performed based on the cooperative regeneration reference vehicle speed VK. And the end determination is performed.
The flow of vehicle speed signal processing and cooperative regenerative braking control in the integrated controller 10 will be described with reference to the flowchart of FIG.

In step S1, the vehicle speed VSP read at the current processing timing (this value V (n)) is used as the cooperative regeneration reference vehicle speed VK formed at the previous processing timing (this is the previous value VK (n). −1)) or less. If the previous value VK (n−1) or less (YES), the process proceeds to step S2. If the previous value VK (n−1) is greater (NO), the process proceeds to step S2. Proceed to step S3.
In step S2, a process of setting the current value V (n) of the vehicle speed VSP to the current value VK (n) of the cooperative regeneration reference vehicle speed VK is performed, and the process proceeds to step S6.

  In step S3, which proceeds when the current value V (n) of the vehicle speed VSP is larger than the previous value VK (n-1) of the cooperative regeneration reference vehicle speed VK, a preset increase from the current value V (n) of the vehicle speed VSP is performed. It is determined whether or not the value obtained by subtracting the side hysteresis Vh (hysteresis imparted vehicle speed) is greater than the previous value VK (n−1) of the cooperative regeneration reference vehicle speed VK. If greater (YES), the process proceeds to step S4. A value (hysteresis-applied vehicle speed) obtained by subtracting the increase-side hysteresis Vh from the current value V (n) of the vehicle speed VSP is set as the current value VK (n) of the cooperative regeneration reference vehicle speed VK. That is, VK (n) = V (n) −V (h).

  On the other hand, in step S3, when the current value V (n) of the vehicle speed VSP is equal to or less than the previous value VK (n-1) of the cooperative regeneration reference vehicle speed VK, in step S5, the previous value VK of the cooperative regeneration reference vehicle speed VK. Let (n-1) be the current value VK (n).

In other words, in steps S1 to S5, when the vehicle speed VSP is decreasing and the current value V (n) is equal to or less than the previous value VK (n-1) of the cooperative regeneration reference vehicle speed VK, the current value V ( n) is used as the current value VK (n) of the cooperative regeneration reference vehicle speed VK as it is.
On the other hand, when the vehicle speed VSP is increasing, this value is higher than the previous value VK (n−1) based on a value obtained by subtracting the increasing hysteresis Vh from the current value V (n) of the vehicle speed VSP. In this case, a value obtained by subtracting the increase-side hysteresis Vh from the current value V (n) of the vehicle speed VSP is set as the current value VK (n) of the cooperative regeneration reference vehicle speed VK. If the increasing speed from the previous value VK (n−1) is equal to or less than the increasing hysteresis Vh, the previous value VK (n−1) of the cooperative regeneration reference vehicle speed VK is set as the current value VK (n). Thus, when the vehicle speed VSP is increasing, the current value VK (n) of the cooperative regeneration reference vehicle speed VK is obtained by subtracting the increase-side hysteresis Vh from the current value V (n) of the vehicle speed VSP, and the previous value. The rise is suppressed as either the value VK (n−1).

  The increase-side hysteresis Vh is set to a value larger than the assumed maximum value of vibration of the preset vehicle speed VSP. In the first embodiment, the value of 1.5 to 3 km / h is set in order to reliably eliminate the influence of vehicle speed fluctuations of about 1 km / h.

In step S6, which proceeds after determining the current value VK (n) of the cooperative regeneration reference vehicle speed VK by any one of steps S2, S4, and S5 described above, based on the cooperative regeneration reference vehicle speed VK, the cooperative regeneration maximum torque MGTmax. The cooperative regenerative vehicle speed restriction gain GK for calculating is determined, and the process proceeds to step S7.
In step S7, the cooperative regenerative maximum torque MGTmax is multiplied by the cooperative regenerative vehicle speed restriction gain GK to calculate the current cooperative regenerative maximum torque MGTmax (n), and the process proceeds to step S8. Note that a constant is used as the cooperative regenerative maximum torque MGTmax, and the upper limit value is set by the maximum value (for example, about 0.1 to 0.2 G) of cooperative regenerative braking.
In step S8, the target cooperative regenerative torque MKT (n) is obtained from the lower value of the requested cooperative regenerative torque WKT sent from the brake controller 9 and the cooperative regenerative maximum torque MGTmax (n). The requested cooperative regenerative torque WKT takes into account, for example, the requested cooperative regenerative torque after considering the friction / regenerative brake torque distribution and the maximum regenerative torque CMTmax that can be output by the motor generator MG. Use the value obtained. The process flow shown in steps S6 to S8 shows an example of setting the target cooperative regenerative torque MKT (n). The setting of the target cooperative regenerative torque MKT (n) is not a specific matter of the present application, and is determined according to the current value VK (n) of the cooperative regenerative reference vehicle speed VK as shown in the first embodiment. It may be set using a different method.

  The cooperative regenerative braking described above ends when the cooperative regenerative reference vehicle speed VK is equal to or lower than a preset cooperative regeneration end determination threshold Ve. The vehicle speed VSP at the start of cooperative regenerative braking may use the cooperative regeneration end determination threshold value Ve as it is, or based on a cooperative start determination threshold value set with hysteresis with respect to this value. You may make it determine.

  FIG. 7 is a circuit diagram showing a configuration of a part that executes the above processing in the integrated controller 10.

  The comparator 10a outputs the current value V (n) to the switch unit 10e when the current value V (n) of the vehicle speed VSP is equal to or lower than the previous value VK (n-1) of the cooperative regeneration reference vehicle speed VK. That is, this is the part that performs the processing of steps S1 → S2.

The subtractor 10b outputs a value (hysteresis-applied vehicle speed) obtained by subtracting the increase-side hysteresis Vh from the current value V (n) of the vehicle speed VSP to the comparator 10c and the switch unit 10d.
When the value obtained by subtracting the increase-side hysteresis Vh from the current value V (n) of the vehicle speed VSP (hysteresis imparted vehicle speed) is less than the previous value VK (n−1) of the cooperative regeneration reference vehicle speed VK, the comparator 10c The previous value VK (n-1) is output.
When there is an input of either the value obtained by subtracting the increase side hysteresis Vh from the current value V (n) of the vehicle speed VSP (hysteresis applied vehicle speed) or the previous value VK (n−1), the switch unit 10d Is output.
That is, the subtractor 10b, the comparator 10c, and the switch unit 10d perform the processes of steps S3 to S5, and when the vehicle speed VSP increases, add the increasing-side hysteresis Vh to the current value V (n) of the vehicle speed VSP, This is a part for selecting whether to use the previous value VK (n−1) of the cooperative regeneration reference vehicle speed VK.

  When there is an input from either the comparator 10a or the switch unit 10d, the switch unit 10e uses the current value VK (n) of the cooperative regeneration reference vehicle speed VK as a cooperative regeneration vehicle speed throttle gain GK calculation unit 10f. Output to. That is, the switch unit 10e and the cooperative regenerative vehicle speed restriction gain GK calculation unit 10f cooperate with the current value VK (n) of the cooperative regenerative reference vehicle speed VK determined by performing any one of steps S2, S4, and S5. This is a part for calculating the regenerative vehicle speed restriction gain GK.

  The accumulator 10g integrates the cooperative regeneration maximum torque MGTmax with the cooperative regeneration vehicle speed restriction gain GK, and calculates the current cooperative regeneration maximum torque MGTmax (n). That is, the process of step S7 is performed.

The comparator 10h compares the required braking force of the driver with the requested cooperative regenerative torque WKT after considering the friction / regenerative brake torque distribution and the maximum regenerative torque CMTmax that can be output by the motor generator MG, and the smaller This value is output to the comparator 10j as the requested cooperative regenerative torque WKT.
The comparator 10j outputs the smaller value of the requested cooperative regenerative torque WKT that is the output of the comparator 10h and the current cooperative regenerative maximum torque MGTmax (n) as the target cooperative regenerative torque MKT. That is, the comparators 10h and 10j are portions that perform the process of step S8.

Next, the operation will be described.
First, “the problem of the comparative example” will be described. Then, the effect | action in the control apparatus of the hybrid vehicle of Example 1 is demonstrated.

[About the problem of the comparative example]
(First comparative example)
FIG. 8 shows an example of a change in the vehicle speed VSP during braking.
A vehicle speed signal Vsp1 indicated by a solid line is an example of a vehicle speed signal in which the road surface condition is bad during braking and the signal is vibrated. Such a vibration of the vehicle speed signal Vsp1 is likely to occur significantly due to the overlap of the vibration of the drive system, particularly in a traveling state where braking is performed at a downward slope and a constant vehicle speed is maintained.

  When the cooperative regeneration end determination threshold Ve for switching between cooperative regenerative braking and braking of only the mechanical brake unit BU during the vibration of the vehicle speed signal Vsp1 is a value Ve (a) indicated by a dotted line in the drawing, The vehicle speed signal Vsp1 repeatedly crosses the value Ve (a) (cooperative regeneration end determination threshold) up and down. In such a case, control hunting between cooperative regenerative braking and braking only by the brake unit BU occurs, which may cause vehicle vibration.

(Second comparative example)
As means for deciding the above problem, it is conceivable to filter the vehicle speed VSP to suppress the amplitude, and this is a second comparative example.
In FIG. 8, an alternate long and short dash line vehicle speed signal Vsp2 shows an example of a signal subjected to filter processing. Since the vehicle speed signal Vsp2 subjected to this filtering process can suppress the amplitude of the signal, compared with the vehicle speed signal Vsp1, it is difficult to cross the value Ve (a) (cooperative regeneration end determination threshold), as described above. Generation of control hunting can be suppressed.

However, the vehicle speed signal Vsp2 has a lower amplitude than the vehicle speed signal Vsp1 indicated by the solid line, and thus the lower value shifts higher.
As a result, when the cooperative regeneration end determination threshold Ve is a value Ve (b) indicated by a dotted line in the figure, the vehicle speed signal Vsp2 crosses the value Ve (b) (cooperative regeneration end determination threshold) downward and performs cooperative regenerative braking. There is a delay in the timing to end the process, and a problem arises in terms of control response.

(Operation of Example 1)
Next, the operation of the first embodiment will be described.
In FIG. 8, a signal Vsp3 indicated by a dotted line indicates the cooperative regeneration reference vehicle speed VK in which the increase-side hysteresis Vh described in the flowchart of FIG. 6 is added to the signal (Vsp1) of the vehicle speed VSP.
The cooperative regeneration reference vehicle speed VK (Vsp3) to which this increase-side hysteresis Vh is given varies along the vehicle speed signal Vsp1 when the vehicle speed signal Vsp1 decreases, but at the time of acceleration, a value obtained by subtracting the increase-side hysteresis Vh ( Therefore, the inclination is very gentle compared to the vehicle speed signal Vsp1, and the amplitude on the increase side is suppressed.

  For this reason, for example, when the cooperative regeneration end determination threshold value is the value Ve (a), the frequency at which the vehicle speed signal Vsp3 crosses the value Ve (a) up and down can be suppressed, and the occurrence of the control hunting can be suppressed. The occurrence of vehicle vibration caused by this control hunting can also be suppressed.

  In addition, compared with the filtered vehicle speed signal Vsp2, at the time of braking, it decreases at an earlier timing, and high control responsiveness can be obtained. Specifically, when the relationship with the cooperative regeneration end determination threshold is the value Ve (b), the cooperative regeneration reference vehicle speed VK (Vsp3) is set to the cooperative regeneration at the timing t1. The braking will end. On the other hand, when the vehicle speed signal Vsp2 is used, the cooperative regenerative braking is terminated at the timing t2, and a control response delay occurs.

(Effect of Example 1)
Next, the effect of Example 1 will be described.
In the hybrid vehicle control device of the first embodiment, the following effects can be obtained.
(1) The hybrid vehicle control device of the first embodiment is
A motor generator MG that is provided in a drive system of drive wheels (left and right rear wheels RL, RR), drives the drive wheels by power running, and generates power by regeneration;
A brake unit BU that mechanically generates a braking force in response to a driver's braking operation;
A vehicle speed sensor 17 for detecting the vehicle speed of the vehicle;
During braking, coordinated regenerative braking is performed by adjusting the regenerative force by the motor generator MG and the braking force by the brake unit BU, and the regenerative braking is terminated when the vehicle speed VSP is equal to or less than the coordinated regeneration end determination threshold Ve. An integrated controller 10 and a brake controller 9 for braking only with a mechanical braking force of only BU;
With
The integrated controller 10 forms a cooperative regeneration reference vehicle speed VK in which an increase-side hysteresis Vh is added only to the increase side to the vehicle speed signal used for determining the end of cooperative regenerative braking, and this cooperative regeneration reference vehicle speed VK is used as a cooperative regeneration end determination threshold value. Comparing with Ve, the end determination of cooperative regenerative braking is performed.
Therefore, the cooperative regeneration reference vehicle speed VK (Vsp3) given the increase-side hysteresis Vh changes along the vehicle speed signal Vsp1 when the vehicle speed signal Vsp1 decreases, but is a value obtained by subtracting the increase-side hysteresis Vh when increasing the speed. Therefore, the inclination is very gentle compared to the vehicle speed signal Vsp1, and the amplitude on the increase side is suppressed.

For this reason, the frequency at which the vehicle speed signal Vsp3 crosses up and down with respect to the cooperative regeneration end determination threshold value Ve can be suppressed, generation of control hunting can be suppressed, and generation of vehicle vibration caused by the control hunting can also be suppressed. it can.
Further, the cooperative regeneration reference vehicle speed VK (Vsp3) decreases on the lower side in the same manner as the vehicle speed signal Vsp1, and therefore decreases at an earlier timing during braking as compared to the vehicle speed signal Vsp2 subjected to the filtering process. As for the end determination of the cooperative regenerative braking, it is possible to obtain a high control accuracy without a control delay.

(2) The increase-side hysteresis Vh set in the integrated controller 10 is set to a value larger than the assumed maximum vibration value of the preset vehicle speed VSP.
Therefore, it is possible to reliably suppress the vibration of the vehicle speed VSP and to suppress the occurrence of the vehicle vibration. Moreover, the area | region which performs cooperative regenerative braking can be expanded, and the regeneration amount can be ensured.

(3) In forming the cooperative regeneration reference vehicle speed VK, the integrated controller 10 provides the previous value VK (n−1) of the cooperative regeneration reference vehicle speed VK to which the increase-side hysteresis Vh is applied and the current value V ( n), and if the current value V (n) of the vehicle speed VSP is less than or equal to the previous value VK (n-1) of the vehicle speed VK for cooperative regeneration reference, the current value V (n) of the vehicle speed VSP is referenced for cooperative regeneration. If the current value VK (n) of the vehicle speed VK is greater than the previous value VK (n-1) of the cooperative regeneration reference vehicle speed VK, the current value V (n) of the vehicle speed VSP. ) Is compared with the hysteresis applied vehicle speed (V (n) −Vh) obtained by subtracting the preset increase side hysteresis Vh from the previous value VK (n−1) of the cooperative regeneration reference vehicle speed VK, and the hysteresis applied vehicle speed (V (N) -Vh) is larger In this case, the hysteresis applied vehicle speed (V (n) −Vh) is the current value VK (n) of the cooperative regeneration reference vehicle speed VK, and the previous value VK (n−1) of the cooperative regeneration reference vehicle speed VK is greater. The previous value VK (n-1) of the cooperative regeneration reference vehicle speed VK is set to the current value VK (n) of the cooperative regeneration reference vehicle speed VK.
Therefore, the vibration on the increasing side of the vehicle speed VSP can be reliably suppressed.

(4) In the first embodiment, the electric vehicle is a hybrid vehicle including an engine Eng that provides driving force to the driving wheels (left and right rear wheels RL, RR) in series with the motor generator MG.
Therefore, a hybrid vehicle having the effects (1) to (3) can be provided.

  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 present invention, the method described in claim 3 is used in forming the cooperative regeneration reference vehicle speed. However, hysteresis is applied only to the increase side of the vehicle speed signal to form the cooperative regeneration reference vehicle speed. If it is a thing, it will not be limited to this. Further, the specific magnitude of the increase side hysteresis is not limited to the value shown in the first embodiment.

  In the first embodiment, an example in which the present invention is applied to a hybrid vehicle including an engine Eng in series with the motor generator MG is shown as an electric vehicle. However, the present invention is not limited to this, and the electric vehicle includes only a motor generator as a driving unit. You may apply to. Further, when applied to a hybrid vehicle, the motor generator may be provided in parallel with the engine as long as the motor generator can be regenerated. In addition, although a motor generator capable of powering to drive the drive wheels has been shown, it can also be applied to a motor generator that performs only regeneration.

  In the first embodiment, the second clutch CL2 is provided between the motor generator MG and the transmission input shaft separately from the stepped automatic transmission AT. The position to be provided is not limited to this, and may be provided between the transmission output shaft and the drive wheel. Alternatively, one of the friction elements built in the stepped automatic transmission AT may be selected and used.

  In the first embodiment, the example in which the first clutch CL1 is used as the mode switching means for switching between the HEV mode and the EV mode has been described. 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. However, the present invention can also be applied to the case where the front wheel is the drive wheel.

9 Brake controller (brake control device)
10 Integrated controller (brake control device)
17 Vehicle speed sensor (vehicle speed detector)
19 Wheel speed sensor 20 Brake pedal force sensor BU Brake unit Eng Engine MG Motor generator RL Left rear wheel (drive wheel)
RR Right rear wheel (drive wheel)

Claims (4)

A motor generator that regenerates by input from the drive wheels;
A brake device that mechanically generates a braking force in response to a driver's braking operation;
A vehicle speed detector for detecting the vehicle speed of the vehicle;
During braking, cooperative regenerative braking is performed in which braking is performed by adjusting the regenerative force by the motor generator and the braking force by the brake device, and the cooperative regenerative braking is terminated when the vehicle speed falls below a cooperative regenerative end determination threshold. A brake control unit for braking only by a mechanical braking force of only the brake device;
With
The brake control unit forms a cooperative regenerative reference vehicle speed with hysteresis added only to the increase side in a vehicle speed signal used for the end of cooperative regenerative braking, and compares the cooperative regenerative reference vehicle speed with the cooperative regenerative end determination threshold value. Then, an end determination of the cooperative regenerative braking is performed. In the control device of the electric vehicle according to claim 1,
The control device for an electric vehicle, wherein the hysteresis set in the brake control unit is set to a value larger than a preset maximum value of an assumed vibration at a vehicle speed. In the control apparatus for the electric vehicle according to claim 1 or 2,
The brake control unit
The previous value of the cooperative regeneration reference vehicle speed to which the hysteresis is applied is compared with the current value of the vehicle speed.If the current value of the vehicle speed is equal to or less than the previous value of the cooperative regeneration reference vehicle speed, the current value of the vehicle speed is The current value of the vehicle speed for reference for cooperative regeneration is as follows:
If the current value of the vehicle speed exceeds the previous value of the cooperative regeneration reference vehicle speed, a hysteresis applied vehicle speed obtained by subtracting a preset hysteresis setting value from the current value of the vehicle speed, and the previous value of the cooperative regeneration reference vehicle speed; If the vehicle speed with hysteresis applied is larger, the vehicle speed with hysteresis applied is the current value of the vehicle speed for reference for cooperative regeneration, and if the previous value of vehicle speed for reference for cooperative regeneration is greater, An apparatus for controlling an electric vehicle, wherein a previous value of a reference vehicle speed is set to a current value of the cooperative regeneration reference vehicle speed. In the control device of the electric vehicle according to any one of claims 1 to 3,
The electric vehicle control apparatus according to claim 1, wherein the electric vehicle is a hybrid vehicle including an engine that applies driving force to the drive wheels in series or in parallel with the motor generator.