JP5343590B2 - Vehicle deceleration control device and vehicle deceleration control method - Google Patents

Description

  The present invention relates to a technique for performing regenerative braking when a vehicle is decelerated.

  Conventionally, a technique for performing regenerative braking when a vehicle is decelerated (see Patent Document 1). In this technique, if the regeneration amount by regenerative braking is increased during deceleration, the deceleration of the vehicle becomes too large. To prevent this, the regeneration amount is controlled within a predetermined allowable deceleration range.

Japanese Patent Laid-Open No. 2007-131093

  However, there is an individual difference in the allowable deceleration, so if the individual's allowable deceleration is lower than the predetermined allowable deceleration, the vehicle will decelerate more than the driver expects. You may make a very small stepping on. In this case, there is a problem that fuel consumption is deteriorated because the fuel cut is ended by a minimum depression.

The vehicle deceleration control device and the vehicle deceleration control method according to the present invention perform regenerative braking by the regenerative braking means within the allowable deceleration range when the vehicle is decelerating and the deceleration fuel cut is performed while the fuel supply is stopped. During regenerative braking, if it is detected that the accelerator pedal has been depressed by a predetermined amount of time or less, the allowable deceleration is reduced and the minimum depression is performed. The frequency is calculated, and the allowable deceleration is reduced as the calculated minimum depression frequency increases .

  According to the present invention, for a driver who thinks that the braking force due to regenerative braking is large, the braking force due to regenerative braking can be reduced by reducing the allowable deceleration, so that the minimum depression can be suppressed.

It is a system configuration figure of the deceleration control device for vehicles in one embodiment. It is a flowchart which shows the processing content performed by ECM. It is a figure which shows the conditions which judge that the minimum depression of the accelerator pedal was performed. It is a figure which shows an example of the driving | running | working scene of a vehicle containing the scene where the minimum depression resulting from regenerative braking is performed. 7 is a flowchart showing a processing procedure for calculating a target generated voltage of the alternator 2 based on an allowable deceleration G. It is a figure which shows an example of the relationship between minimum depressing frequency and deceleration adjustment coefficient Gx.

  FIG. 1 is a system configuration diagram of a vehicle deceleration control apparatus according to an embodiment. A transmission composed of a torque converter 3 with a lock-up mechanism (hereinafter referred to as torque converter 3) and a belt-type continuously variable transmission 4 is connected to the output side of the engine 1 which is a vehicle drive source. The driving force output from the engine 1 is shifted by the continuously variable transmission 4 and then transmitted to the left and right drive wheels 6 via the final drive 5.

  An alternator (generator) 2 that is an auxiliary machine generates power by the power of the engine 1 based on a command from the USM 20. The alternator 2 also performs regeneration (regenerative power generation) by the kinetic energy of the vehicle when the torque converter 3 is in the lock-up state, and when the vehicle is decelerating and when the fuel is cut off and the fuel is stopped. . When the alternator 2 is regenerated, so-called regenerative braking occurs, in which braking force is applied to the vehicle. The USM 20 controls the regeneration of the alternator 2 so that the deceleration during regenerative braking falls within a predetermined allowable deceleration range.

  The electric power generated by the alternator 2 is stored in the battery 7. The electrical load 9 is operated by electric power supplied from the battery 7. The current sensor 8 detects the charge / discharge current of the battery 7.

  The inter-vehicle distance detection device 11 detects the inter-vehicle distance to a preceding vehicle traveling in front of the host vehicle by a known method. The vehicle speed sensor 12 detects the speed of the host vehicle. The brake pedal sensor 13 detects the amount of depression of the brake pedal. The accelerator pedal sensor 14 detects the amount of depression of the accelerator pedal. Detection signals from the devices and sensors 11 to 14 are output to the ECM 10.

  The ECM 10 obtains a target power generation voltage of the alternator 2 in order to control regenerative braking during vehicle deceleration based on detection signals from the devices and the sensors 11 to 14. Specifically, the allowable deceleration G calculated by multiplying the basic value Gb of the allowable deceleration by a deceleration adjustment coefficient Gx, which will be described later, when the torque converter 3 is performing the deceleration fuel cut in the lock-up state. Based on the above, the target generated voltage of the alternator 2 is obtained. The basic value Gb of the allowable deceleration may be a predetermined fixed value, or may be a fluctuation value determined according to the vehicle speed at the start of the deceleration fuel cut or the accelerator pedal depression amount immediately before the deceleration fuel cut is started.

  The USM 20 controls the regeneration of the alternator 2 based on the target power generation voltage calculated by the ECM 10.

  FIG. 2 is a flowchart showing the contents of processing performed by the ECM 10. When the vehicle is activated, the ECM 10 starts the process of step S10. The processing from Step S10 to Step S50 is processing for determining whether or not the vehicle is in a state where the driver performs a minimum depression when the deceleration fuel is cut.

  In step S10, it is determined whether or not the vehicle is in a decelerating state and the fuel is being decelerated while the fuel supply is stopped. If it is determined that the vehicle is in the deceleration fuel cut, the process proceeds to step S20. If it is determined that the vehicle is not in the deceleration fuel cut, the process waits in step S10.

  In step S20, it is determined whether regeneration by the alternator 2 is being performed. When regeneration by the alternator 2 is not performed, even if the driver performs a minimal depression that depresses the accelerator pedal slightly, the minimal depression does not cause regenerative braking. Accordingly, when it is determined that regeneration is not performed, the process returns to step S10. On the other hand, if it determines with regeneration being performed, it will progress to step S30.

  In step S30, it is determined whether the inter-vehicle distance detected by the inter-vehicle distance detection device 11 is equal to or greater than a predetermined distance Da. When the inter-vehicle distance to the preceding vehicle is less than the predetermined distance Da, the driver may step on the accelerator pedal due to the influence of the preceding vehicle. Accordingly, when it is determined that the inter-vehicle distance to the preceding vehicle is less than the predetermined distance Da, the process returns to step S10. On the other hand, if it determines with the inter-vehicle distance to a preceding vehicle being more than predetermined distance Da, it will progress to step S40. The predetermined distance Da is set in advance by experimentally determining a distance for determining that the minimum depression of the accelerator pedal is caused by regenerative braking.

  In step S40, it is determined whether or not the vehicle speed detected by the vehicle speed sensor 12 is equal to or lower than a predetermined vehicle speed Va. In general, the minimum depression caused by regeneration of the alternator 2 is caused when the driver determines that the actual deceleration is too large than the deceleration expected by the driver and the vehicle does not reach the target stop position. To happen. That is, the minimum depression occurs under the condition where the vehicle speed is low. Therefore, when it is determined that the vehicle speed is higher than the predetermined vehicle speed Va, the process returns to step S10. On the other hand, if it is determined that the vehicle speed is equal to or lower than the predetermined vehicle speed Va, the process proceeds to step S50. The predetermined vehicle speed Va is set in advance by experimentally determining a vehicle speed for determining that the minimum depression of the accelerator pedal is caused by regenerative braking.

  In step S50, it is determined whether or not the time during which the brake is kept off is equal to or longer than a predetermined time BRKOFFt. The duration of brake off is calculated based on a signal input from the brake pedal sensor 13. When the duration of brake off is less than the predetermined time BRKOFFt, it cannot be determined whether the minimum depression is caused by excessive depression of the brake pedal or the regeneration of the alternator 2. Therefore, if it is determined that the brake-off duration is less than the predetermined time BRKOFFt, the process returns to step S10. On the other hand, if it is determined that the duration of brake off is equal to or longer than the predetermined time BRKOFFt, the process proceeds to step S60. Note that the predetermined time BRKOFFt is set in advance by experimentally determining a brake-off continuation time for determining that the minimum depression of the accelerator pedal is caused by regenerative braking.

  In step S60, it is determined whether or not it is the first time that the process proceeds to step S60 after starting the process starting from step S10 after the vehicle is started. If it is determined that the process has proceeded to step S60 for the first time, the process proceeds to step S70, the parameter GEN indicating the number of decelerations is increased by 1, and the process proceeds to step S80. The number of times of deceleration GEN is counted once when the deceleration condition that can cause the minimum depression is satisfied, and the initial value is zero. The calculated number of decelerations GEN is stored in a memory (not shown). On the other hand, if it is determined that the process has not proceeded to step S60 for the first time, the process proceeds to step S80.

  In step S80, based on the signal input from the accelerator pedal sensor 14, it is determined whether or not the accelerator pedal is depressed by the driver. If it is determined that the accelerator pedal is not depressed, the process returns to step S10. If it is determined that the accelerator pedal is depressed, the process proceeds to step S90.

  In step S90, a timer for measuring the time during which the accelerator pedal is depressed (accelerator on time) is started, and the process proceeds to step S100. Here, the measurement time of the timer is expressed as ACCTIM. In step S100, based on a signal input from the accelerator pedal sensor 14, it is determined whether or not the accelerator pedal is in an off state where the accelerator pedal is not depressed. If it is determined that the accelerator pedal is not turned off, the process proceeds to step S140, and the timer measurement time ACCTIM is counted up.

  In step S150 following step S140, it is determined whether or not the accelerator opening ACC indicating the amount of depression of the accelerator pedal is greater than the maximum accelerator opening ACCMAX. For example, while it is determined in step S80 that the accelerator pedal has been depressed, while the accelerator opening ACC is increasing, it is determined that the accelerator opening ACC is larger than the maximum accelerator opening ACCMAX. On the other hand, when the driver returns the accelerator pedal, it is determined that the accelerator opening ACC is equal to or less than the maximum value ACCMAX of the accelerator opening so far. If it is determined that the accelerator opening degree ACC is equal to or less than the maximum value ACCMAX of the accelerator opening so far, the process returns to step S100. If it is determined that the accelerator opening degree ACC is larger than the maximum value ACCMAX of the accelerator opening so far, the process proceeds to step S160. .

  In step S160, the accelerator opening ACC when it is determined that it is larger than the maximum value ACCMAX of the accelerator opening so far is set to the maximum value ACCMAX of the accelerator opening, and the process returns to step S100.

  If it is determined in step S100 that the accelerator pedal is off, the process proceeds to step S110. In step S110, it is determined whether or not the timer measurement time ACCTIM, that is, the time during which the accelerator pedal is depressed is longer than the predetermined time Ta. The predetermined time Ta is, for example, 1 second. If it is determined that the timer measurement time ACCTIM is longer than the predetermined time Ta, it is determined that it is not a minimum depression, the process returns to step S10, and if it is determined that it is less than the predetermined time Ta, the process proceeds to step S120.

  In step S120, it is determined whether or not the maximum value ACCMAX of the accelerator opening is larger than a predetermined accelerator opening ACMXa. The predetermined accelerator opening degree ACMXa is, for example, 5 degrees. If it is determined that the maximum value ACCMAX of the accelerator opening is larger than the predetermined accelerator opening ACMXa, it is determined that it is not a minimum depression, the process returns to step S10, and if it is determined that it is equal to or smaller than the predetermined accelerator opening ACMXa, move on.

  FIG. 3 is a diagram illustrating a condition for determining that the accelerator pedal has been minimally depressed. The hatched area shown in FIG. 3, that is, when the time ACCTIM during which the accelerator pedal is on is equal to or less than the predetermined time Ta and the maximum value ACCMAX of the accelerator opening is equal to or less than the predetermined accelerator opening ACMXa. , It is determined that the accelerator pedal has been pressed a minimum.

  In step S130, it is determined that the minimum depression due to the regenerative power generation of the alternator 2 has been performed, the minimum depression frequency GENACC is increased by 1, and the process returns to step S10. The minimum depression count GENACC is stored in a memory (not shown).

  FIG. 4 is a diagram illustrating an example of a traveling scene of the vehicle, and shows, from the top, the vehicle speed, the presence or absence of fuel cut, the accelerator opening, the accelerator on time, and the minimum depressing frequency GENACC. As described above, even when the accelerator pedal is depressed during deceleration fuel cut, if the accelerator on time ACCTIM is longer than the predetermined time Ta, it is determined that the depression is not minimal. That is, the scene 1 shown in FIG. Even if the accelerator on time ACCTIM is equal to or shorter than the predetermined time Ta, as shown in the scene 1, when the maximum value ACCMAX of the accelerator opening is larger than the predetermined accelerator opening ACMXa, it is not a minimum depression.

  On the other hand, in FIG. 4, the scene 2 where the accelerator pedal is stepped on is extremely small because the accelerator-on time ACCTIM is not more than the predetermined time Ta and the maximum value ACCMAX of the accelerator opening is not more than the predetermined accelerator opening ACMXa. Judge that it is a step. In this case, as described above, the minimum depressing number GENACC increases by one.

  FIG. 5 is a flowchart showing a processing procedure for calculating the target generated voltage of the alternator 2 based on the allowable deceleration G. The process starting from step S500 is performed by the ECM 10.

  In step S500, a deceleration adjustment coefficient Gx is calculated. The deceleration adjustment coefficient Gx is calculated based on the minimum depression frequency obtained by dividing the minimum depression number GENACC calculated in step S130 in the flowchart of FIG. 2 by the deceleration number GEN calculated in step S70.

  FIG. 6 is a diagram illustrating an example of the relationship between the minimum depression frequency and the deceleration adjustment coefficient Gx. When the minimum stepping frequency is equal to or lower than the predetermined frequency, the value of the deceleration adjustment coefficient Gx is set to 1, and when the minimum stepping frequency becomes higher than the predetermined frequency, the coefficient Gx decreases as the frequency increases. That is, when the minimum stepping-on frequency is equal to or lower than the predetermined frequency, the deceleration adjustment coefficient Gx is set to 1 because it is not necessary to change the allowable deceleration at the time of deceleration fuel cut. Further, when the minimum stepping-on frequency is higher than the predetermined frequency, the deceleration adjustment coefficient Gx is set to a value smaller than 1 in order to reduce the deceleration of the vehicle.

  In step S510 of FIG. 5, the allowable deceleration G is calculated by multiplying the basic value Gb of the allowable deceleration by the deceleration adjustment coefficient Gx. As described above, since the allowable deceleration G is reduced by decreasing the value of the deceleration adjustment coefficient Gx as the frequency of the minimum depression becomes higher, the minimum depression of the driver can be effectively suppressed.

  In step S520, the target generated voltage of the alternator 2 is obtained based on the allowable deceleration G calculated in step S510. The USM 20 controls the regeneration of the alternator 2 based on the target power generation voltage obtained by the ECM 10.

  According to the vehicle deceleration control device in the embodiment, in the device that performs regenerative braking by the regenerative braking means within the allowable deceleration range when the deceleration fuel is cut, during regenerative braking, the accelerator pedal having a predetermined opening or less is operated. When it is detected that the minimum stepping is performed for a predetermined time or less, the allowable deceleration is reduced. As a result, it is considered that the deceleration at the time of regenerative braking is large, so that the allowable deceleration can be reduced for the driver who performs the minimum depression, and the braking force at the time of regenerative braking can be reduced. In addition, a driver who does not consider the deceleration at the time of regenerative braking to be large and does not perform the minimum depression is not controlled to reduce the allowable deceleration, so that the normal braking force can be maintained.

  Further, the minimum depressing frequency is obtained, and the allowable deceleration is reduced as the obtained minimum depressing frequency increases, so that the braking force during regenerative braking can be controlled more effectively.

  Furthermore, according to the vehicle deceleration control apparatus in the embodiment, the inter-vehicle distance to the preceding vehicle is detected, and when the detected inter-vehicle distance is equal to or greater than the predetermined distance, the minimum depression is detected. As a result, it is possible to accurately detect the minimum depression caused by regenerative braking by excluding the situation where the inter-vehicle distance is less than the predetermined distance and the driver depresses the accelerator pedal due to the influence of the preceding vehicle.

  Further, since the minimum depression is detected when the vehicle speed is equal to or lower than the predetermined vehicle speed, the depression not caused by regenerative braking can be excluded.

  Furthermore, since the minimum depression is detected when the brake-off duration is equal to or longer than the predetermined time, it is possible to accurately detect the minimum depression caused by regenerative braking by excluding the depression caused by excessive depression of the brake pedal. .

  The present invention is not limited to the embodiment described above. For example, an example in which regenerative braking is performed by regenerating the alternator 2 when the deceleration fuel is cut has been described. However, the present invention can also be applied to a vehicle that performs regenerative braking by regenerating an electric motor, for example. Further, the present invention can also be applied to a vehicle that performs regenerative braking by regenerating an air conditioner compressor. That is, the regenerative braking means is not limited to the alternator 2.

  The relationship of the deceleration adjustment coefficient Gx to the minimum depression frequency is not limited to the relationship shown in FIG. Further, the deceleration adjustment coefficient Gx may be determined based on the number of detections of the minimum depression, not the minimum depression frequency.

  In the flowchart shown in FIG. 2, if it is the first time that the process proceeds to step S <b> 60 after starting the vehicle, 1 is added to the parameter GEN indicating the number of times of deceleration, and then the vehicle is decelerated until the vehicle engine is turned off. The number of times GEN does not change. However, when the deceleration fuel cut is completed, the vehicle speed becomes 0, and the subsequent travel proceeds to step S60 again, 1 may be added to the parameter GEN indicating the number of times of deceleration.

DESCRIPTION OF SYMBOLS 1 ... Engine 2 ... Alternator 3 ... Torque converter with lock-up mechanism 4 ... Belt type continuously variable transmission 6 ... Drive wheel 10 ... ECM
DESCRIPTION OF SYMBOLS 11 ... Distance detection apparatus 12 ... Vehicle speed sensor 13 ... Brake pedal sensor 14 ... Accelerator pedal sensor 20 ... USM
2. S80 to S120 in FIG. 2 ... Minimum depression detection means S500 to S510 in FIG. 5 ... Allowable deceleration changing means

Claims (5)

A vehicle deceleration control device that performs regenerative braking by regenerative braking means within a permissible deceleration range when the vehicle is decelerating and fuel is cut off while decelerating fuel.
During the regenerative braking, a minimum depression detecting means for detecting that a minimum depression in which an accelerator pedal having a predetermined opening or less is depressed for a predetermined time or less has been performed;
When a minimum depression is detected by the minimum depression detection means, an allowable deceleration changing means for reducing the allowable deceleration,
A minimum depression frequency calculating means for calculating a frequency at which the minimum depression is performed;
Equipped with a,
The vehicle deceleration control device, wherein the allowable deceleration changing means reduces the allowable deceleration as the minimum depression frequency calculated by the minimum depression frequency calculation means increases. Further comprising an inter-vehicle distance detecting means for detecting an inter-vehicle distance to a preceding vehicle traveling in front of the host vehicle;
2. The vehicle deceleration control device according to claim 1, wherein the minimum depression detection unit detects the minimum depression when an inter-vehicle distance detected by the inter-vehicle distance detection unit is equal to or greater than a predetermined distance. It further comprises vehicle speed detecting means for detecting the vehicle speed,
The minimum depression detecting means, wherein when the vehicle speed detected by the vehicle speed detecting means is equal to or less than the predetermined vehicle speed, vehicle deceleration control device according to claim 1 or claim 2, characterized in that detecting the minimum depression . Brake off duration detection means for detecting the brake off duration when the brake is off is further provided,
The vehicle deceleration control according to any one of claims 1 to 3 , wherein the minimum depression detection means detects the minimum depression when the brake-off duration is a predetermined time or more. apparatus. A vehicle deceleration control method for performing regenerative braking by regenerative braking means within a permissible deceleration range when the vehicle is decelerating and fuel is cut off while the fuel supply is stopped.
During the regenerative braking, it is detected that a minimum depression in which an accelerator pedal having a predetermined opening or less is depressed for a predetermined time or less is performed,
When the minimum depression is detected, the allowable deceleration is reduced.
With
Calculating the frequency at which the minimal depression is performed;
The allowable deceleration is reduced as the calculated minimum depression frequency increases.
A vehicle deceleration control method characterized by the above.

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