JP2013252043A - Vehicular control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently collect regenerative power while controlling fluctuation of deceleration of a vehicle.SOLUTION: A vehicular control device (600) includes: a post-deceleration vehicle speed estimating means (640) that presumes vehicle speed of a vehicle after execution of deceleration for the predetermined time; deceleration for battery calculation means (650) to calculate the deceleration for the battery in deceleration in the predetermined time using the presumed vehicle speed; a capacitor charge amount calculation means (660) to calculate a regenerative charge amount of a capacitor by deceleration in the predetermined time using the deceleration for the battery; a target regeneration deceleration setting means (670) to set the prescribed time when the regenerative charge amount of the capacitor becomes allowable charge amount of the capacitor for the capacitor charging period, and set the deceleration for the battery in the deceleration in a capacitor regenerative charging period for the target regenerative deceleration of the regenerative braking means, and control means (680 and 690) that control a regenerative braking means and a hydraulic braking means to achieve the target regeneration deceleration.

Description

  The present invention relates to a technical field of a vehicle control device including hydraulic braking means that operates by hydraulic pressure to brake a wheel, and regenerative braking means that brakes a wheel by regenerative torque of a rotating electrical machine.

  When a vehicle equipped with a rotating electrical machine such as a hybrid vehicle or an electric vehicle is equipped with a regenerative braking device that transmits torque generated during regeneration of the rotating electrical machine to a wheel as a regenerative braking force in addition to a hydraulic braking device that operates by hydraulic pressure. There is.

  In a vehicle including a hydraulic braking device and a regenerative braking device, control is performed so that the total value of braking forces output from each of the hydraulic braking device and the regenerative braking device becomes a total braking force to be realized. That is, the total braking force to be realized is shared and output by the hydraulic braking device and the regenerative braking device.

  The electric power regenerated by the regenerative braking device is charged, for example, in a battery, a capacitor (that is, a large capacity capacitor), or the like. When the battery and the capacitor are used in combination, the regenerative electric power can be efficiently recovered by making the mutual charge distribution appropriate. For example, Patent Document 1 proposes a technique in which the battery is preferentially charged when the required braking force is relatively large, and the capacitor is preferentially charged when the required braking force is relatively small.

JP 2008-017681 A

  The capacitor can output a voltage higher than that of a normal battery, but has a smaller charge capacity than the battery. For this reason, the capacitor is in a state where it cannot be charged earlier than the battery, and thereafter, the regenerative power is charged only by the battery. In such a case, the regenerative braking means temporarily reduces the regenerative torque when the capacitor cannot be charged, and then increases the regenerative torque as the battery charge amount increases.

  Here, the fluctuation of the regenerative torque in the regenerative braking means is compensated by the hydraulic braking means. However, the hydraulic braking means has a large error in the actual braking force with respect to the command due to a change in μ of the brake pad, a winning state, or the like. For this reason, the hydraulic braking means cannot appropriately compensate for fluctuations in the regenerative torque in the regenerative braking means, and as a result, the deceleration of the vehicle fluctuates. Such a change in deceleration may cause a sense of discomfort to the driver of the vehicle.

  On the other hand, in the technique of Patent Document 1, the above-described change in vehicle deceleration is not taken into consideration. That is, the prior art including the above-described prior art documents has a technical problem that drivability may be deteriorated due to fluctuations in vehicle deceleration even if the recovery efficiency of regenerative power can be increased. Has a point.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a vehicle control device that can efficiently recover regenerative power while suppressing fluctuations in vehicle deceleration. .

  In order to solve the above problems, a vehicle control apparatus according to the present invention operates by hydraulic pressure to brake a wheel, regenerative braking means for braking the wheel by regenerative torque of the rotating electrical machine, and charging to the rotating electrical machine. A control device for a vehicle including a capacitor and a battery for discharging, wherein when the vehicle has a deceleration request, the vehicle speed of the vehicle is estimated after executing deceleration for a predetermined time based on the requested deceleration Vehicle speed estimation means, battery partial deceleration calculation means for calculating a battery partial deceleration corresponding to the regenerative charge of the battery during deceleration for the predetermined time using the estimated vehicle speed, and the battery partial deceleration And a capacitor charge amount calculating means for calculating a regenerative charge amount of the capacitor due to deceleration for the predetermined time, and the regenerative charge amount of the capacitor A target regenerative deceleration setting that sets the predetermined time, which is an allowable charge amount of the loader, in a capacitor charging period, and sets the battery deceleration in the deceleration during the capacitor charging period as a target regenerative deceleration of the regenerative braking means And control means for controlling the hydraulic braking means so as to realize a deceleration obtained by subtracting the target regenerative deceleration from the required deceleration while controlling the regenerative braking means so as to realize the target regenerative deceleration. With.

  The vehicle according to the present invention is a vehicle equipped with rotating electricity such as a hybrid vehicle or an electric vehicle, for example, and as a braking means for applying a braking force to wheels, braking is performed using hydraulic braking means that operates by hydraulic pressure and regenerative torque of the rotating electrical machine. Regenerative braking means is provided. According to the regenerative braking means, the regenerative torque in the rotating electrical machine can be used as a braking force, and the electric power obtained by the regeneration can be charged to the power storage means such as a battery and used for driving the vehicle. Therefore, it is possible to realize driving with higher energy efficiency as compared with the case where only the hydraulic braking means is provided.

  The electric power regenerated by the regenerative braking means is charged to a battery and a capacitor that are electrically connected to the rotating electrical machine. The battery is configured as a secondary battery such as a lithium ion battery, which is a main power source of the rotating electrical machine, and the capacitor is configured as a large-capacity capacitor. The capacitor has a characteristic that it can output a higher voltage than the battery, but has a small charge capacity.

  A vehicle control device of the present invention is a control device that controls the output of braking force by the above-described hydraulic braking means and regenerative braking means, and includes, for example, one or a plurality of CPUs (Central Processing Units), MPUs (Micro Processing Units). ), Various processors or various controllers, or further various storage means such as ROM (Read Only Memory), RAM (Random Access Memory), buffer memory or flash memory, etc. Various processing units such as Unit), various controllers, various computer systems such as a microcomputer device, and the like can be employed.

  According to the vehicle control device of the present invention, when the vehicle has a deceleration request (for example, when the driver operates the brake pedal), first, the vehicle speed estimation means after deceleration is the predetermined time based on the requested deceleration. The vehicle speed after the vehicle deceleration is executed is estimated. That is, the actual deceleration operation is not performed here, and the vehicle speed after deceleration is estimated on the assumption that the deceleration operation has been performed. The vehicle speed after deceleration is estimated using, for example, the vehicle speed at the time when a deceleration request is made, in addition to the requested deceleration and a predetermined time. Here, the “predetermined time” is a value for appropriately setting a capacitor charging period to be described later, and is set, for example, according to a period during which deceleration of the vehicle is estimated to be continued. The “predetermined time” is a fluctuation value that is counted up each time the process is repeated.

  When the vehicle speed after deceleration is estimated, the battery deceleration calculation means calculates the battery deceleration corresponding to the regenerative charge of the battery during deceleration for a predetermined time. Specifically, the battery deceleration is calculated as the maximum deceleration when charging the regenerative power by the regenerative braking means with the battery alone. The battery deceleration can be calculated as, for example, a value obtained by dividing the regenerative power by the amount of movement of the vehicle (that is, vehicle speed after deceleration x vehicle body mass).

  When the battery deceleration is calculated, the regenerative charge amount of the capacitor due to deceleration for a predetermined time is calculated by the capacitor charge amount calculation means. That is, assuming that deceleration for a predetermined time has been executed, the amount of charge that will be charged in the capacitor within a predetermined time by regenerative power is calculated. The regenerative charge amount of the capacitor can be calculated by, for example, time integration using a battery deceleration.

  The calculated regenerative charge amount of the capacitor is compared with the allowable charge amount of the capacitor at the time when the deceleration request is made by the target regenerative deceleration setting means, and a predetermined time during which the regenerative charge amount of the capacitor becomes the allowable charge amount of the capacitor. It is set during the capacitor charging period. Specifically, when the regenerative charge amount of the capacitor is smaller than the allowable charge amount of the capacitor, the target regenerative deceleration setting means calculates the regenerative charge amount of the capacitor again by slightly extending the predetermined time. By repeating such processing, the regenerative charge amount of the capacitor can be brought close to the allowable charge amount of the capacitor.

  If the capacitor charging period is set as described above, a period in which the capacitor is fully charged after deceleration is set as the capacitor charging period. However, the regenerative charge amount of the capacitor and the permissible charge amount of the capacitor here do not need to completely match, and a period in which a slight difference occurs between the regenerative charge amount of the capacitor and the permissible charge amount of the capacitor is the capacitor charge period. Even if it is set, the effects of the present invention to be described later can be exhibited accordingly.

  When the capacitor charging period is set, the target regeneration deceleration setting means sets the battery deceleration in deceleration during the capacitor charging period as the target regeneration deceleration of the regenerative braking means. That is, the target regeneration deceleration is set as a regeneration deceleration that can fully charge the capacitor. Since the target regeneration deceleration eventually becomes the target regeneration torque in actual control, it may be calculated as the target torque or the target braking force in consideration of, for example, the tire radius, the vehicle body mass, the gear ratio, and the like. .

  When the target regeneration deceleration is set, the vehicle is actually decelerated by the control means. Specifically, the regenerative braking means is controlled to achieve the target regenerative deceleration. On the other hand, the hydraulic braking means is controlled to realize a deceleration obtained by subtracting the target regeneration deceleration from the required deceleration. Thus, the required deceleration is realized by sharing the regenerative braking means and the hydraulic braking means.

  According to the above-described deceleration, a constant target regeneration deceleration is realized during the capacitor charging period, so that fluctuations in the deceleration can be suppressed. Specifically, for example, when the capacitor cannot be charged, the regenerative torque temporarily decreases, and thereafter, the fluctuation in the deceleration due to the increase in the regenerative torque accompanying the increase in the battery charge amount can be suppressed. The fluctuation of the regenerative deceleration can be compensated also by the hydraulic braking means, but the hydraulic braking means has a characteristic that an error of the actual deceleration with respect to the command value becomes large, and there is a possibility that appropriate compensation cannot be performed. Therefore, the effect of the present invention that can suppress fluctuations in regeneration deceleration is extremely beneficial.

  In the present invention, the capacitor can be fully charged by regeneration during the capacitor charging period. Therefore, the recovery efficiency of regenerative power by the capacitor can be maximized. That is, it is possible to prevent the charging of the capacitor from being restricted even though there is an allowance for the charging capacity of the capacitor.

  As described above, according to the vehicle control apparatus of the present invention, it is possible to efficiently recover regenerative power while suppressing fluctuations in vehicle deceleration.

  In one aspect of the vehicle control device of the present invention, when the capacitor charging period is equal to or greater than a predetermined upper limit value, the regenerative charge amount of the capacitor due to deceleration to the predetermined upper limit value is an allowable charge amount of the capacitor. The target regeneration deceleration correction means for increasing the target regeneration deceleration is provided.

  According to this aspect, the predetermined upper limit value is set during the capacitor charging period. The “predetermined upper limit value” corresponds to the maximum value at which the vehicle can be decelerated (for example, the maximum value during a period in which the driver continues to step on the brake pedal).

  In this aspect, when the capacitor charging period becomes equal to or longer than the predetermined upper limit value, the target regenerative deceleration correction means causes the regenerative charge amount of the capacitor due to the deceleration to the predetermined upper limit value to be the allowable charge amount of the capacitor. The target regeneration deceleration is increased. That is, if the capacitor cannot be fully charged even if the deceleration time is a predetermined upper limit value, the target regeneration speed is increased (in other words, the regenerative charge amount for the capacitor per unit time is increased). Electricity recovery efficiency can be increased.

  It should be noted that by increasing the target regenerative speed, it is only necessary to make the regenerative charge amount of the capacitor equal to the allowable charge amount of the capacitor. However, even if the target regenerative speed is the limit value on the system, the regenerative charge amount of the capacitor is equal to the allowable charge amount of the capacitor. It is possible that the amount will not be reached. However, even in such a case, the recovery efficiency of regenerative power can be increased by the amount that the regenerative charge amount of the capacitor approaches the allowable charge amount of the capacitor.

  In another aspect of the vehicle control apparatus of the present invention, when the target regeneration deceleration is different from the realized regeneration deceleration, the target regeneration deceleration setting means is controlled so as to reset the target regeneration deceleration. The target regeneration deceleration resetting means is provided.

  According to this aspect, for example, when the target regeneration deceleration (that is, the command value by the control means) and the realized regeneration deceleration (that is, the actual regeneration deceleration) are different due to, for example, the charging limit of the capacitor. Then, the target regeneration deceleration is reset by the target regeneration deceleration resetting means.

  When resetting the target regenerative deceleration, when it is determined that the target regenerative deceleration is different from the realized regenerative deceleration, the vehicle speed is estimated again by the post-deceleration vehicle speed estimation means, and the battery is reduced. The calculation of the battery deceleration by the speed calculation means, the calculation of the capacitor charge by the capacitor charge calculation means, the setting of the capacitor charging period and the setting of the target regeneration deceleration by the target regeneration deceleration setting means may be executed.

  When the target regeneration deceleration is reset, even if the target regeneration deceleration is not realized and the actual charge amount of the capacitor becomes low, the actual regeneration deceleration is found to be different. Thus, the target regeneration deceleration is set so that the capacitor can be fully charged again. Accordingly, regenerative charging of the capacitor can be performed more suitably.

  The effect | action and other gain of this invention are clarified from the form for implementing invention demonstrated below.

It is a schematic block diagram which shows the structure of the vehicle by which the control apparatus of the vehicle which concerns on embodiment is mounted. It is a schematic block diagram which shows the structure of the hydraulic brake provided in the vehicle. It is the elements on larger scale which show the inside of a brake caliper. It is a block diagram which shows the structure of ECU which concerns on embodiment. It is a time chart which shows the problem concerning the 1st comparative example. It is a flowchart which shows the flow of operation | movement of the control apparatus of the vehicle which concerns on embodiment. It is a time chart which shows each parameter at the time of control concerning an embodiment. It is a time chart which shows the problem concerning the 2nd comparative example. It is a flowchart which shows the flow of the correction control of the target deceleration which concerns on embodiment. It is a time chart which shows each parameter at the time of correction control of target deceleration concerning an embodiment. It is a time chart which shows the problem concerning the 3rd comparative example. It is a flowchart which shows the flow of update control of the target deceleration which concerns on embodiment. It is a time chart which shows each parameter at the time of update control of target deceleration concerning an embodiment.

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

<Device configuration>
First, the overall configuration of the vehicle according to the present embodiment will be described with reference to FIG. FIG. 1 is a schematic configuration diagram showing a configuration of a vehicle on which the vehicle control device according to the present embodiment is mounted.

  1, the vehicle according to the present embodiment includes a battery 100, an inverter 200, a motor generator 300, a capacitor 400, a system main relay 510 (SMR (1) 500, a limiting resistor 502, an SMR (2) 504, SMR (3) 506) and ECU 600. In the present embodiment, the vehicle is described as an electric vehicle that travels only by the driving force from the motor generator 300, but may be a hybrid vehicle, a fuel cell vehicle, or the like.

  The battery 100 is an assembled battery in which a plurality of modules in which a plurality of cells are connected in series are further connected in series. Capacitor 700 is provided in addition to battery 100, and both supply electric power to motor generator 300 according to the respective characteristics. The voltage of battery 100 is detected by voltage sensor 105 and output to ECU 600.

  Inverter 200 includes six IGBTs and six diodes connected in parallel to each IGBT so that a current flows from the emitter side to the collector side of the IGBT. Inverter 200 causes motor generator 300 to function as a motor or a generator based on a control signal from ECU 600.

  Inverter 200 converts DC power supplied from battery 100 or capacitor 700 into AC power and supplies it to motor generator 300 when motor generator 300 functions as a motor. Inverter 200 controls the electric power supplied to motor generator 300 by turning on / off (energizing / cutoff) the gate of each IGBT so that motor generator 300 is in an output state required by a control signal from ECU 600. To control.

  Inverter 200 converts AC power generated by motor generator 300 into DC power and charges battery 100 and capacitor 700 when motor generator 300 functions as a generator. The inverter 200 controls the electric power (regenerative electric power) generated by the motor generator 300 by turning on / off (energizing / interrupting) the gates of the respective IGBTs, so that the regenerative braking force (regenerative electric power) required by the control signal from the ECU 600 is obtained. Torque) is controlled to act on the vehicle.

  Motor generator 300 is an example of the “rotary electric machine” according to the present invention, and is a three-phase AC motor and a generator that generates electric power during regenerative braking of the vehicle. The rotation shaft of motor generator 300 is finally connected to a drive shaft (not shown) of the vehicle. The vehicle travels with the driving force from motor generator 300.

  The capacitor 400 is connected in parallel with the inverter 200. Capacitor 400 temporarily stores electric charge in order to smooth the power supplied from battery 100 or the power supplied from inverter 200. The smoothed power is supplied to the inverter 200 or the battery 100.

  The system main relay 510 includes SMR (1) 500 and SMR (2) 504 on the positive side and SMR (3) 506 on the negative side. SMR (1) 500, SMR (2) 504, and SMR (3) 506 are relays that close contacts that are turned on when an exciting current is applied to the coil.

  SMR (1) 500 and SMR (2) 504 are provided on the positive electrode side of battery 100.

  SMR (1) 500 and SMR (2) 504 are connected in parallel. A limiting resistor 502 is connected to the SMR (1) 500 in series. SMR (1) 500 is a precharge SMR that is connected before SMR (2) 504 is connected and prevents an inrush current from flowing through inverter 200.

  SMR (2) 504 is a positive SMR connected after SMR (1) 500 is connected and precharge is completed.

  S MR (3) 506 is a negative SMR provided on the negative electrode side of the battery 100. Each SMR is controlled by ECU 600.

  When the power is turned on (that is, when the ignition switch position is switched from the OFF position to the STA position), the ECU 600 first turns on SMR (3) 506 and then turns on SMR (1) 500 to perform precharging. Run. Since the limiting resistor 502 is connected to the SMR (1) 500, even when the SMR (1) 500 is turned on, the voltage applied to the inverter 200 rises gently, and the occurrence of an inrush current can be prevented. After the precharge is executed, ECU 600 turns on SMR (2) 504. When the power is off (when the position of the ignition switch is switched from the STA position to the OFF position), ECU 600 prevents SMR (1) 500, SMR (2) 504, and SMR (3) 506 to prevent leakage from battery 100 and the like. Turn off.

  The ECU 600 is an electronic control unit that includes a CPU, a ROM, a RAM, and the like, and is configured to be able to control the operation of each part of the vehicle, and is an example of the “vehicle control device” of the present invention. The ECU 100 is configured to be able to execute various controls in the vehicle according to a control program stored in a ROM or the like, for example. The specific configuration of ECU 600 will be described in detail later.

  In addition to the battery 100, the capacitor 700 is mounted on the vehicle as described above. Capacitor 700 is connected between the input side terminal of inverter 200 and capacitor 400. The voltage of capacitor 700 is detected by voltage sensor 705 and output to ECU 600.

  Capacitor 700 charges and discharges electric power to and from inverter 200 by ECU 600 controlling opening and closing of relays 702 and 704 that close contacts that are turned on when an exciting current is supplied to the coil. When the power is turned on, relays 702 and 704 are turned on. When the power is turned off, the relay 702 and the relay 704 are turned off to prevent leakage from the capacitor 700 and the like.

  The capacitor 700 has a higher rated charge / discharge power than the battery 100 and can handle instantaneous high input / output. Capacitor 700 has a smaller storage capacity than battery 100 and is fully charged in a short time when regenerative energy is charged.

  Further, this vehicle is provided with a boost converter 800 between battery 100 and inverter 200. When the vehicle is accelerated, boosted converter 800 boosts the rated voltage of battery 100 (about 200 V), for example, to about 500 V (rated voltage of motor generator 300) and supplies it to inverter 200. During regenerative braking of the vehicle, a regenerative voltage of about 500 V converted to a DC voltage by the inverter 200 is stepped down to the rated voltage of the battery 100 and supplied to the battery 100. Boost converter 800 includes two IGBTs and a reactor that reduces a current change.

  Further, this vehicle is provided with a brake pressure sensor 2100 and a vehicle speed sensor 2200 connected to the ECU 600. Brake pressure sensor 2100 detects a brake pressure corresponding to the depression force of a brake pedal (not shown) by the driver, and transmits a signal representing the brake pressure to ECU 600. The vehicle speed sensor 2200 detects the vehicle speed and transmits a signal representing the vehicle speed to the ECU.

  ECU 600 executes a program stored in ROM based on signals transmitted from an ignition switch (not shown), an accelerator pedal depression amount sensor (not shown), brake pressure sensor 2100, and the like. By this program, inverter 200, boost converter 800, each SMR, and the like are controlled, and the vehicle is controlled to travel in a desired state.

  In the present embodiment, charging / discharging of the battery 100 and the capacitor 700 is controlled by changing the output voltage (system voltage) of the boost converter 800, for example. Specifically, when power is supplied to motor generator 300, capacitor 700 is discharged preferentially when the output voltage of boost converter 800 is made lower than the voltage of capacitor 700. When the output voltage of boost converter 800 exceeds the voltage of capacitor 700, battery 100 is preferentially discharged.

  On the other hand, when the battery 100 or the capacitor 700 is charged with the electric power generated by the motor generator 300 during regenerative braking, the battery 100 is preferentially charged when the output voltage of the boost converter 800 is made equal to or lower than the voltage of the capacitor 700. When the output voltage of boost converter 800 is made higher than the voltage of capacitor 700, capacitor 700 is preferentially charged.

  Further, ECU 600 calculates a battery charge power limit value (maximum value of power charged in battery 100) WIN (B) based on the temperature, charge state, etc. of battery 100. Similarly, ECU 600 calculates a capacitor charging power limit value (maximum value of power charged in capacitor 700) WIN (C) based on the temperature and voltage of capacitor 700. Charging power limit value WIN (B) and charging power limit value WIN (C) are calculated so as not to exceed the respective rated charging power values.

  Next, a hydraulic brake as an example of the “hydraulic control means” of the present invention will be described with reference to FIGS. FIG. 2 is a schematic configuration diagram showing a configuration of a hydraulic brake provided in the vehicle. FIG. 3 is a partially enlarged view showing the inside of the brake caliper.

  As shown in FIG. 2, the vehicle 1 is provided with a hydraulic brake 40 that brakes the left and right front wheels 2F and the left and right rear wheels 2R. Hereinafter, when it is not necessary to distinguish between the front wheel 2F and the rear wheel 2R, they are simply referred to as wheels 2.

  The hydraulic brake 40 includes a brake disc 41 that rotates together with the wheel 2, and a brake caliper 42 that sandwiches the brake disc 41 and applies a braking force to the wheel 2. As shown in this figure, the brake disc 41 and the brake caliper 42 are provided on each wheel 2.

  As shown in an enlarged view in FIG. 3, the brake caliper 42 includes a brake pad 43 that is pressed against the brake disc 41 and a cylinder 44 that drives the brake pad 43. Each cylinder 44 is connected to a brake actuator 46 via a brake pipe 45.

  The brake actuator 46 has a hydraulic pump, an electromagnetic valve, and the like inside. The brake actuator 46 sends the brake oil in the master cylinder 47 operated by the brake pedal BP to each cylinder 44. Apply braking force. The brake actuator 46 can adjust the hydraulic pressure in each cylinder 44 by opening and closing an electromagnetic valve provided therein, and thereby can individually adjust the braking force applied to each wheel 2.

  Next, a specific configuration of ECU 600 will be described with reference to FIG. FIG. 4 is a block diagram showing the configuration of the ECU according to this embodiment. In FIG. 4, for convenience of explanation, among the parts that can be included in the ECU 600, only those deeply related to the present embodiment are shown, and the other parts are not shown.

  In FIG. 4, the ECU 600 includes a deceleration request determination unit 610, a capacitor allowable charge amount calculation unit 620, a deceleration time setting unit 630, a post-deceleration vehicle speed estimation unit 640, a battery deceleration calculation unit 650, and a capacitor charge amount. The calculation unit 660 includes a target regeneration deceleration setting unit 670, a target regeneration deceleration correction unit 671, a target regeneration deceleration update determination unit 672, a regeneration torque command unit 680, and a hydraulic pressure command unit 690. ing.

  The deceleration request determination unit 610 determines whether deceleration is requested for the vehicle based on the detection value of the brake pressure sensor 2100 or the like. The determination result of the deceleration request determination unit 610 can be output to the capacitor allowable charge amount calculation unit 620 and the deceleration time setting unit 630, respectively.

  Capacitor allowable charge amount calculation unit 620 calculates the allowable charge amount of capacitor 700 at the time when the vehicle is requested to decelerate based on OCV (Open Circuit Voltage) of capacitor 700 and the like. The calculation result of the capacitor allowable charge amount calculation unit 620 can be output to the target regeneration deceleration setting unit 670.

  The deceleration time setting unit 630 sets a deceleration time t that is an example of the “predetermined time” in the present invention in order to set a target regeneration deceleration that will be described later. In the deceleration time setting unit 630, an initial value of the deceleration time t is set in advance, and at the start of processing, this initial value is first set as the deceleration time t. The deceleration time t fluctuates in the target regeneration deceleration setting process.

  The post-deceleration vehicle speed estimation unit 640 is an example of the “post-deceleration vehicle speed estimation unit” of the present invention, and estimates the vehicle speed after the deceleration time t set by the deceleration time setting unit 630 has been reduced. The vehicle speed after deceleration estimated by the post-deceleration vehicle speed estimation unit 640 can be output to the battery deceleration calculation unit 650.

  The battery deceleration calculation unit 650 calculates a deceleration corresponding to the regenerative charge amount of the battery 100 using the vehicle speed after deceleration estimated by the vehicle speed estimation unit 640 after deceleration. The battery deceleration calculated by the battery unit deceleration calculation unit 650 can be output to the capacitor charge amount calculation unit 660.

  The capacitor charge amount calculation unit 660 is an example of the “capacitor charge amount calculation unit” of the present invention, and the capacitor 700 is generated by the deceleration of the deceleration time t using the battery deceleration calculated by the battery unit deceleration calculation unit 650. The amount of charge is calculated. The capacitor charge amount calculated by the capacitor charge amount calculation unit 660 can be output to the target regeneration deceleration setting unit 670.

  The target regeneration deceleration setting unit 670 is an example of the “target regeneration deceleration setting unit” of the present invention, and is calculated by the capacitor allowable charge amount calculated by the capacitor allowable charge amount calculation unit 620 and the capacitor charge amount calculation unit 660. The target regeneration deceleration (that is, the deceleration to be realized by the regeneration of the motor generator 300) is set by comparing with the charged amount of the capacitor.

  The target regeneration deceleration correction unit 671 is an example of the “target regeneration deceleration correction unit” of the present invention, and the target regeneration deceleration when the deceleration time t set in the deceleration time setting unit 630 is greater than a predetermined threshold. The target regeneration deceleration set in the setting unit 670 is corrected.

  The target regeneration deceleration update determination unit 672 is an example of the “target regeneration deceleration resetting unit” in the present invention, and compares the actual regeneration deceleration with the target regeneration deceleration set by the target regeneration deceleration setting unit 670. Then, it is determined whether or not the target regeneration deceleration should be updated according to the result. When it is determined that the target regeneration deceleration should be updated, the target regeneration deceleration update determination unit 672 outputs a command to the target regeneration deceleration setting unit 670 to set the target regeneration deceleration again.

  Regenerative torque command unit 680 controls the regenerative torque of motor generator 300 so as to realize the target regenerative deceleration. The hydraulic pressure command unit 690 controls the hydraulic pressure so as to realize a deceleration obtained by subtracting the target regeneration deceleration from the required braking force. That is, the regenerative torque command unit 680 and the hydraulic pressure command unit 690 here are examples of the “control unit” of the present invention.

  The ECU 600 is an integrated electronic control unit configured to include the above-described parts, and all the operations related to the parts are configured to be executed by the ECU 600. However, the physical, mechanical, and electrical configurations of the above-described parts according to the present invention are not limited thereto. For example, each of these parts includes various ECUs, various processing units, various controllers, microcomputer devices, and the like. It may be configured as a computer system or the like.

<Target regeneration deceleration setting control>
Next, a problem that may occur in a vehicle including the battery 100 and the capacitor 700 described above as a regenerative power charging unit will be described with reference to FIG. FIG. 5 is a time chart showing the problems according to the first comparative example. FIG. 5 is a chart showing changes in parameters after the vehicle is requested to decelerate. Assume that a decelerating request is made at time “0”.

In FIG. 5, it is assumed that the target deceleration for the operation of the brake pedal is −2 m / s ² . In this case, the target deceleration includes the hydraulic pressure by the hydraulic brake, the regenerative by the motor generator (more specifically, as shown in the figure, the battery corresponding to the amount of charge of regenerative power to the battery 100, and (Capacity equivalent to the amount of charge to the capacity 700).

  Here, if the deceleration is performed without optimizing the distribution between the battery and the capacity, the allowable charge amount of the capacitor 700 is smaller than the battery 100, so that the capacitor 700 is fully charged before the deceleration ends. . For this reason, as shown in the figure, the capacitor portion decreases after the time of 6 seconds has passed and approaches zero as much as possible. When such deceleration is performed, the regenerative torque temporarily decreases when the WIN of the capacitor 700 is limited, and then the regenerative torque also increases as the battery WIN increases. Therefore, the regeneration deceleration increases and decreases.

  Here, the fluctuation of the regeneration deceleration is compensated by the hydraulic brake. However, the hydraulic brake has a large error in the actual deceleration with respect to the command due to the change in μ of the brake pad, the hit state, and the like. For this reason, in the hydraulic brake, the fluctuation of the regenerative deceleration cannot be compensated appropriately, and as a result, the actual deceleration of the vehicle fluctuates as shown in the figure. Such a change in deceleration may cause a sense of discomfort to the driver of the vehicle.

  The vehicle control device according to the present embodiment aims to efficiently recover regenerative power while preventing the fluctuations in deceleration as described above. Below, the flow of operation | movement of the control apparatus of the vehicle which concerns on this embodiment is demonstrated with reference to FIG. FIG. 6 is a flowchart showing an operation flow of the vehicle control apparatus according to this embodiment. In FIG. 6, for convenience of explanation, among the various processes executed by the ECU 600, only the processes deeply related to the braking force control unique to the present embodiment are shown, and other general processes are omitted as appropriate. .

  In FIG. 6, when the vehicle control apparatus according to the present embodiment operates, first, it is determined in the deceleration request determination unit 610 whether or not a brake operation has been started (step S101). In addition, when the brake operation is not started (step S101: NO), the processes after step S102 are not started.

  When the brake operation is started (step S101: YES), the capacitor allowable charge amount calculation unit 620 calculates the capacitor allowable charge amount at the start of the brake operation (step S102). The capacitor allowable charge amount Ecap can be calculated using the following formula (1), where Ccap is the capacitance, Vc_max is the capacitor upper limit voltage, and Vc_ini is the capacitor OCV voltage at the start of the brake operation.

Ecap = 1/2 Ccap (Vc_max ² −Vc_ini ² ) (1)
Subsequently, the deceleration time t is set by the deceleration time setting unit 630 (step S103). Here, the deceleration time t (n) is set by adding the minute time dt to the immediately preceding deceleration time t (n−1) except when it is set as an initial value. That is, the deceleration time t is counted up for a minute time dt.

  It is determined whether the set deceleration time t (n) is shorter than a predetermined brake upper limit time Tmax (step S104). Here, when the deceleration time t (n) is equal to or greater than the brake upper limit time Tmax (step S104: NO), the target regeneration deceleration correction unit 671 performs target deceleration correction control, which will be described later (step S104). S105). The brake upper limit time Tmax is an example of the “predetermined upper limit value” in the present invention, and is the maximum value at which the vehicle can be decelerated (for example, the maximum value during a period in which the driver continues to step on the brake pedal). ) In advance.

  On the other hand, when the deceleration time t (n) is smaller than the brake upper limit time Tmax (step S104: YES), the vehicle speed after deceleration is estimated by the post-deceleration vehicle speed estimation unit 640, and the battery Win rate calculation unit 650 calculates the battery Win. Αbatt (t (n)), which is a considerable regeneration deceleration, is calculated (step S106). Here, the battery regenerative deceleration αbatt (t (n)) is expressed by the following formula (2), where the battery power is Winb, the vehicle speed at the start of the brake operation is Vel_ini, the required deceleration is αtg, and the vehicle body mass is Mv. Can be used to calculate.

αbatt (t (n)) = Winb / (Vel_ini−0.5 · αtg · t (n) ² · Mv) (2)
Note that “Vel_ini−0.5 · αtg · t (n) ² ” in Equation (2) corresponds to the vehicle speed after deceleration.

  It is determined whether or not the calculated battery-specific regeneration deceleration rate αbatt (t (n)) is greater than the regeneration lower limit deceleration rate αrg_lim on the system (step S107). When the battery-specific regeneration deceleration rate αbatt (t (n)) is equal to or less than the regeneration lower limit deceleration rate αrg_lim (step S107: NO), steps S108 and S109 described later are omitted.

  If the battery-specific regeneration deceleration rate αbatt (t (n)) is larger than the regeneration lower limit deceleration rate αrg_lim (step S107: YES), the capacitor charge amount Ecap_rg charged in the capacitor 700 by regeneration at the deceleration time t (n) is Calculated. The capacitor charge amount Ecap_rg can be calculated by using the following mathematical formula (3) including the battery regenerative deceleration αbatt (t (n)).

  Subsequently, in the target regeneration deceleration setting unit 670, the capacitor allowable charge amount Ecap calculated in the capacitor allowable charge amount calculation unit 620 and the capacitor charge amount Ecap_rg (n) calculated in the capacitor charge amount calculation unit 660 are mutually equal. It is determined whether or not they are equal (step S109). Here, when the capacitor allowable charge amount Ecap and the capacitor charge amount Ecap_rg (n) are not equal to each other (step S109: NO), the processing after step S103 is started again. That is, the processes after step S103 are repeated until the capacitor allowable charge amount Ecap and the capacitor charge amount Ecap_rg (n) become equal.

  In addition, if the process after step S103 is repeated, the deceleration time t will be gradually increased in step S103. Therefore, the battery regenerative deceleration rate αbatt (t (n)) calculated using the deceleration time t and the capacitor charge amount Ecap_rg also increase each time the process is repeated. Therefore, the capacitor charge amount Ecap_rg is gradually brought closer to the capacitor allowable charge amount Ecap.

  When the capacitor allowable charge amount Ecap and the capacitor charge amount Ecap_rg (n) are equal to each other (step S109: YES), the battery regenerative deceleration αbatt (t (n)) at that time is set as the target regenerative deceleration αrgt. (Step S110). That is, the target regeneration deceleration rate αrgt is set as a deceleration rate that fully charges the capacitor 700 by the deceleration of the deceleration time t (n).

  Hereinafter, parameter variations during deceleration when the above-described target regeneration deceleration rate αrgt is set will be described with reference to FIG. FIG. 7 is a time chart showing parameters at the time of control according to the present embodiment.

In FIG. 7, it is assumed that the deceleration time t is about 14 seconds and the target regeneration deceleration rate αrgt is set to −1 m / s ² . In this case, the capacitor 700 is fully charged at the time 14 seconds when the elapsed time from the start of the brake is the deceleration time t, and the regenerative power is recovered only by the battery 100 after the time 14 seconds. Note that the capacitor charge amount Ecap_rg (n) due to deceleration corresponds to the area of the shaded portion in the figure.

  If the target regeneration deceleration is set as described above, a constant target regeneration deceleration rate αrgt is realized in the deceleration time t (n), so that fluctuations in vehicle deceleration can be suppressed. That is, the fluctuation of the deceleration as shown in FIG. 5 can be suppressed. Note that fluctuations in the regenerative deceleration can be compensated also by the hydraulic brake, but due to the characteristics of the hydraulic brake, there is a possibility that the actual deceleration error with respect to the command value becomes large and appropriate compensation cannot be performed. Therefore, the effect of this embodiment which can suppress the fluctuation | variation of regeneration deceleration is very useful.

  In the present embodiment, the capacitor 700 can be fully charged by the regenerative power during deceleration. Therefore, the recovery efficiency of regenerative power by the capacitor 700 can be maximized. That is, it is possible to prevent the charging of the capacitor 700 from being restricted even though there is a margin in the capacitor allowable charge amount Ecap.

<Target regeneration deceleration correction control>
Next, the correction control of the target regeneration deceleration rate αrgt (that is, step S105 in FIG. 6) will be specifically described.

  First, problems that may occur when the correction control of the target regeneration deceleration rate αrgt is not performed will be described with reference to FIG. FIG. 8 is a time chart showing the problems according to the second comparative example.

  In FIG. 8, the deceleration of the vehicle can be interrupted, for example, when the driver releases the brake pedal halfway. Specifically, in the example shown in the figure, the amount of depression of the brake pedal begins to decrease around time 6 seconds, and deceleration is interrupted at time 8 seconds. In such a case, the deceleration time t (n) cannot be sufficiently long, and as a result, the amount of charge to the capacitor 700 may be insufficient. The purpose of the correction control of the target regeneration deceleration rate αrgt according to the present embodiment is to suppress a decrease in the regeneration efficiency of the regenerative energy even when the deceleration time t (n) is short.

  Next, the flow of the correction control for the target regeneration deceleration rate αrgt will be specifically described with reference to FIG. FIG. 9 is a flowchart showing the flow of target deceleration correction control according to this embodiment.

  In FIG. 9, when correction control is started (that is, when it is determined in step S104 shown in FIG. 6 that the deceleration time t (n) is equal to or greater than the brake upper limit time Tmax), the correction amount is determined. The correction reference value m is incremented unless it is set as an initial value (step S201).

  Subsequently, a corrected regeneration deceleration rate αrg_Tmax when the deceleration time t (n) is the brake upper limit time Tmax is calculated (step S202). The corrected regeneration deceleration rate αrg_Tmax can be calculated using the following formula (4), with a predetermined deceleration increase amount as Δα.

αrg_Tmax = αbatt (Tmax) + Δα · m (4)
As can be seen from Equation (4), the corrected regeneration deceleration rate αrg_Tmax is a value obtained by adding Δα · m to αbatt (Tmax) that can be set as the target regeneration deceleration rate in the normal setting control.

  Subsequently, the capacitor charge amount Ecap_rg (m) charged in the capacitor 700 when the corrected regeneration deceleration rate αrg_Tmax is realized is calculated (step S203). The capacitor charge amount Ecap_rg (m) can be calculated using the following mathematical formula (5) including the corrected regeneration deceleration rate αrg_Tmax.

  Subsequently, it is determined whether the capacitor allowable charge amount Ecap calculated by the capacitor allowable charge amount calculation unit 620 is equal to the capacitor charge amount Ecap_rg (m) when the corrected regeneration deceleration rate αrg_Tmax is realized. (Step S204). Here, when the capacitor allowable charge amount Ecap and the capacitor charge amount Ecap_rg (m) are not equal to each other (step S204: NO), the processing after step S201 is started again. That is, the processes after step S201 are repeated until the capacitor allowable charge amount Ecap and the capacitor charge amount Ecap_rg (m) become equal.

  In addition, when the process after step S201 is repeated, the correction reference value m is incremented by 1 in step S201. Therefore, the corrected regeneration deceleration rate αrg_Tmax and the capacitor charge amount Ecap_rg (m) calculated using the correction reference value m also increase each time the process is repeated. Therefore, the capacitor charge amount Ecap_rg (m) is gradually brought closer to the capacitor allowable charge amount Ecap.

  When the capacitor allowable charge amount Ecap and the capacitor charge amount Ecap_rg (m) are equal to each other (step S204: YES), the corrected regeneration deceleration rate αrg_Tmax after correction is set as the target regeneration deceleration rate αrgt (step S205). . That is, the target regeneration deceleration rate αrgt is set as a deceleration rate that fully charges the capacitor 700 even when the deceleration time is limited to Tmax.

  Hereinafter, parameter variation during deceleration when the above-described correction control of the target regeneration deceleration rate αrgt is executed will be described with reference to FIG. FIG. 10 is a time chart showing parameters at the time of target deceleration correction control according to the embodiment.

In FIG. 10, the target regeneration deceleration rate αrgt when the correction control is executed is slightly increased as compared with the case where the correction control is not executed. Specifically, while the target regeneration deceleration shown in FIG. 8 is −1 m / s ² , the target regeneration deceleration αrgt after the correction control is about −1.2 m / s ² . .

  By correcting the target regeneration deceleration rate αrgt to be larger in this way, even if the upper limit is set for the deceleration time t, the capacitor charge amount Ecap_rg (m) is increased, and as a result, after deceleration. The capacitor 700 can be fully charged.

  Even when the target regeneration deceleration rate αrgt is set as a system limit value, a case where the capacitor charge amount Ecap_rg (m) does not reach the capacitor allowable charge amount Ecap is also assumed. However, even in such a case, as the target regeneration deceleration rate αrgt increases, the capacitor charge amount Ecap_rg (m) reliably approaches the capacitor allowable charge amount Ecap. Can do.

<Target regeneration deceleration update control>
Next, update control of the target regeneration deceleration rate αrgt will be described.

  First, a problem that may occur when the target regeneration deceleration rate αrgt is not updated is described with reference to FIG. FIG. 11 is a time chart showing the problems according to the third comparative example.

  In FIG. 11, the deceleration for the capacitor in the regenerative deceleration may not be an appropriate value depending on the state of the capacitor 700. Specifically, the operation of the capacitor 700 is determined according to voltage, current, power, and the like. Therefore, if the deceleration required for the capacitor 700 exceeds the upper limit values such as voltage, current, and power, the actual deceleration for the capacitor is smaller than the required deceleration.

In the example shown in the figure, since the capacitor OCV at time 0 seconds is about 120 V, the capacitor current reaches the upper limit value of 200 A, and the target regeneration deceleration rate αrgt cannot be realized. Specifically, the target regenerative deceleration αrgt is approximately -1.2m / ^{s 2} to, at the time 0 second time point, not only the regenerative deceleration is obtained approximately -0.8m / ^{s 2} Absent. For this reason, the actual deceleration is not constant, and tends to decrease from time 0 seconds to 2 seconds. In the update control of the target regeneration deceleration rate αrgt according to the present embodiment, even when the difference between the target regeneration deceleration rate αrgt and the actual deceleration rate has occurred in this way, it is possible to realize suitable charge control. It is aimed.

  Next, the flow of update control of the target regeneration deceleration rate αrgt will be specifically described with reference to FIG. FIG. 12 is a flowchart showing a flow of target deceleration update control according to the present embodiment.

  In FIG. 12, when performing update control of the target regeneration deceleration αrgt, first, the target regeneration deceleration update determination unit 672 determines whether the target regeneration deceleration αrgt is equal to or less than the actual regeneration deceleration αrg_act. (Step S301). That is, it is determined whether or not there is a difference between the target regeneration deceleration rate αrgt and the actual regeneration deceleration rate αrg_act.

  Here, when the target regeneration deceleration rate αrgt is not less than or equal to the actual regeneration deceleration rate αrg_act (step S301: NO), the update control of the target regeneration deceleration rate αrgt is not executed. That is, when there is no difference between the target regeneration deceleration rate αrgt and the actual regeneration deceleration rate αrg_act, the update control of the target regeneration deceleration rate αrgt is not executed.

  On the other hand, when the target regeneration deceleration rate αrgt is equal to or less than the actual regeneration deceleration rate αrg_act (step S301: YES), update control of the target regeneration deceleration rate αrgt is executed. That is, when there is a difference between the target regeneration deceleration rate αrgt and the actual regeneration deceleration rate αrg_act, update control of the target regeneration deceleration rate αrgt is executed.

  When the update control of the target regeneration deceleration rate αrgt is started, the processes after step S102 shown in FIG. 6 are executed again. Thus, the target regeneration deceleration rate αrgt is reset in consideration of each parameter when it is determined that there is a difference between the target regeneration deceleration rate αrgt and the actual regeneration deceleration rate αrg_act. Therefore, even when there is a period in which the target regeneration deceleration rate αrgt is not realized, the capacitor 700 is fully charged after the deceleration time t has elapsed.

  Hereinafter, parameter variation during deceleration when the above-described update control of the target regeneration deceleration rate αrgt is executed will be described with reference to FIG. FIG. 13 is a time chart showing parameters in the target deceleration update control according to the embodiment.

  In FIG. 13, from time 0 seconds to 2 seconds, the regenerative deceleration does not reach the initial target regenerative deceleration αrgt due to the operation limitation of the capacitor 700. Therefore, even if the initial regeneration deceleration rate αrgt can be realized after 2 seconds from the time when the regeneration deceleration reaches the initial target regeneration deceleration rate αrgt, the capacitor charge amount Ecap_rg (m) due to the deceleration is set from the time 0 seconds. A difference from the capacitor allowable charge amount Ecap is generated by the shortage of 2 seconds.

  Therefore, in the present embodiment, the target regeneration deceleration rate αrgt is updated when it is determined that the regeneration deceleration rate has not reached the initial target regeneration deceleration rate αrgt. The target regeneration deceleration rate αrgt after the update is larger than the initial regeneration deceleration rate αrgt. For this reason, the shortage of 2 seconds from time 0 seconds can be compensated by charging after time 2 seconds. Therefore, the capacitor 700 after deceleration can be fully charged.

  In the example shown in the figure, the regenerative deceleration after the time of 4 seconds is always equal to the target regenerative deceleration αrgt, so that subsequent update control is not performed. However, even if the target regeneration deceleration rate αrgt is updated, if there is a difference between the regeneration deceleration rate and the target regeneration deceleration rate αrgt, the update control may be performed again.

  As described above, according to the vehicle control apparatus of the present embodiment, it is possible to efficiently recover regenerative power while suppressing fluctuations in vehicle deceleration.

  The present invention is not limited to the above-described embodiments, and can be appropriately changed without departing from the gist or concept of the invention that can be read from the claims and the entire specification, and control of the vehicle accompanying such changes. The apparatus is also included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 2 ... Wheel, 40 ... Hydraulic brake, 41 ... Brake disc, 42 ... Brake caliper, 43 ... Brake pad, 44 ... Cylinder, 45 ... Brake piping, 46 ... Brake actuator, 47 ... Master cylinder, 50 ... Vehicle control apparatus, 51 ... Vehicle speed sensor, 100 ... Battery, 200 ... Inverter, 300 ... Motor generator, 400 ... Capacitor, 510 ... System main relay, 600 ... ECU, 610 ... Deceleration request determination unit, 620 ... Capacitor allowable charge amount calculation unit, 630 ... Deceleration Time setting unit, 640 ... post-deceleration vehicle speed estimation unit, 650 ... battery deceleration calculation unit, 660 ... capacitor charge amount calculation unit, 670 ... target regeneration deceleration setting unit, 671 ... target regeneration deceleration correction unit, 672 ... target Regenerative deceleration update determination unit, 680 ... Regenerative torque command unit, 690 ... Hydraulic finger Department, 700 ... capacitor, 800 ... converter, 2100 ... brake pressure sensor, 2200 ... vehicle speed sensor.

Claims (3)

A vehicle control device comprising hydraulic braking means that operates by hydraulic pressure to brake a wheel, regenerative braking means that brakes the wheel by regenerative torque of a rotating electrical machine, and a capacitor and a battery that charge and discharge the rotating electrical machine,
When the vehicle has a deceleration request,
A post-deceleration vehicle speed estimation means for estimating a vehicle speed of the vehicle after performing deceleration for a predetermined time based on a required deceleration;
A battery decelerating speed calculating means for calculating a battery decelerating speed corresponding to the regenerative charge of the battery in the deceleration of the predetermined time using the estimated vehicle speed;
Capacitor charge amount calculation means for calculating the regenerative charge amount of the capacitor by deceleration for the predetermined time using the battery deceleration,
The predetermined time during which the regenerative charge amount of the capacitor becomes the allowable charge amount of the capacitor is set as a capacitor charge period, and the battery deceleration in deceleration during the capacitor charge period is set as the target regenerative deceleration of the regenerative braking means. Target regeneration deceleration setting means to be set as
Control means for controlling regenerative braking means so as to realize the target regenerative deceleration, and controlling the hydraulic brake means so as to realize deceleration obtained by subtracting the target regenerative deceleration from the required deceleration. A control apparatus for a vehicle.   When the capacitor charging period becomes equal to or greater than a predetermined upper limit value, the target regenerative deceleration is increased so that the regenerative charge amount of the capacitor due to deceleration to the predetermined upper limit value becomes an allowable charge amount of the capacitor. The vehicle control device according to claim 1, further comprising target regeneration deceleration correction means for causing the vehicle to regenerate.   A target regeneration deceleration resetting unit configured to control the target regeneration deceleration setting unit so as to reset the target regeneration deceleration when the target regeneration deceleration is different from the realized regeneration deceleration; The vehicle control device according to claim 1 or 2.

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