JP2017172416A - Vehicle control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a brake negative pressure shortage state by suppressing engine load in shortage of a negative pressure by precisely determining whether the brake negative pressure shortage state exists or not with a simple and inexpensive constitution without disposing a sensor for detecting the brake negative pressure and the like.SOLUTION: A requested brake negative pressure according to a detected vehicle speed of a vehicle speed sensor 2 is derived by an engine ECU 8, an available brake negative pressure is estimated on the basis of a detected gear by gear detection means 4, an engine rotating speed, an engine water temperature by a water temperature sensor 3, an air conditioner load state, and an alternator load state, or on the basis of an engine intake manifold pressure by an intake manifold pressure sensor 5, and whether the estimated available brake negative pressure is short or not to the derived requested brake negative pressure, is determined, so that a sensor for detecting the brake negative pressure becomes unnecessary. Thus the brake negative pressure shortage state can be precisely determined with a simple and inexpensive constitution without specially loading a new sensor, and the brake negative pressure shortage state can be prevented by on/off control of an air conditioner.SELECTED DRAWING: Figure 1

Description

  The present invention relates to vehicle control for stopping and controlling engine loads such as an air conditioner and an alternator when a shortage of required brake negative pressure required for operating a brake booster occurs while driving an engine mounted on a vehicle. Relates to the device.

  Conventionally, in order to reduce the brake operating force by the driver, negative pressure (intake air) generated in the intake manifold of the engine is used, negative pressure is generated in a part of the brake booster, and the generated negative pressure is used. In this way, the pedaling force of the brake pedal is amplified.

  In such a configuration, if the brake negative pressure is insufficient, the brake performance will deteriorate. Therefore, a detection means (pressure sensor) for detecting the brake negative pressure is provided, and the air conditioner is turned off by detecting the state of the brake negative pressure insufficient by the detection means. By doing so, it is considered that the engine load is reduced, the shortage of the brake negative pressure is resolved, and the deterioration of the brake performance is suppressed (see Patent Document 1).

JP 2010-221894A (see paragraphs 0012 to 0046 and FIGS. 1 to 7)

  However, the configuration described in Patent Document 1 described above requires a detecting means such as a pressure sensor for detecting the brake negative pressure, and there is a problem that the cost increases due to an increase in the number of parts.

  The present invention accurately determines whether or not the brake negative pressure is insufficient without providing a sensor or the like for detecting the brake negative pressure, and reduces the engine load when the negative pressure is insufficient. It aims at making it possible to avoid a state of insufficient pressure.

  In order to achieve the above-described object, the vehicle control device of the present invention, when an insufficient state of the required brake negative pressure required to operate the brake booster occurs during driving of the engine mounted on the host vehicle. In the vehicle control apparatus for stopping and controlling the engine load such as an air conditioner and an alternator, a detecting means for detecting the vehicle speed of the own vehicle, a gear detecting means for detecting which gear of the traveling own vehicle is, and the detecting means Deriving means for deriving the required brake negative pressure according to the detected vehicle speed, the gear detected by the gear detecting means, the engine speed and the engine water temperature, the air conditioner load state, the alternator load state, or based on the engine intake manifold pressure, Estimating means for estimating the brake negative pressure that can be generated, and for the required brake negative pressure by the deriving means, the estimating means Judgment means for judging whether or not the brake negative pressure is in a state of insufficient brake negative pressure, and the brake negative pressure is insufficient when it is determined by the determination step that the brake negative pressure is in an insufficient state. Control means for performing on / off control of the engine load, which alternately repeats predetermined off time and on time, respectively, until the state is resolved, is provided.

  Further, the present invention derives a detecting means for detecting the vehicle speed of the own vehicle, a gear detecting means for detecting which gear of the traveling vehicle is in operation, and a required brake negative pressure corresponding to the detected vehicle speed by the detecting means. Deriving means for estimating the brake negative pressure that can be generated based on the gear detected by the gear detecting means, engine speed and engine water temperature, air conditioner load condition, alternator load condition, or based on engine intake manifold pressure; Determining means for determining whether or not the brake negative pressure that can be generated by the estimating means is insufficient with respect to the required brake negative pressure by the deriving means; When it is determined that the negative pressure is insufficient, it is determined that the deceleration of the host vehicle has occurred based on the vehicle speed detected by the detection means. To come, during the up brake negative shortage condition is removed, it may be provided with a control means for off-control of the engine load.

  According to the present invention, the required brake negative pressure corresponding to the vehicle speed detected by the detecting means is derived by the deriving means, and the detecting gear by the gear detecting means, the engine speed and the engine water temperature, the air conditioner load state, the alternator load by the estimating means The possible brake negative pressure is estimated based on the state or the engine intake manifold pressure, and the estimated negative brake pressure is insufficient with respect to the required brake negative pressure derived by the judging means. A determination is made as to whether the condition is present.

  At this time, the means for detecting the vehicle speed, the means for detecting the current gear, the means for detecting the engine speed, and the means for detecting the engine water temperature are normally mounted on the vehicle. Needless to say, there is no need for a sensor to detect negative pressure, and it is possible to determine whether the brake negative pressure is insufficient or not with a simple and inexpensive configuration by computer software processing without installing a new sensor. .

  Therefore, it is possible to accurately determine whether the brake negative pressure is insufficient with a simple and inexpensive configuration. If it is determined that the brake negative pressure is insufficient, the engine load such as an air conditioner or alternator is turned off. By performing control to reduce the brake negative pressure, it is possible to avoid an insufficient state of the brake negative pressure.

1 is a block diagram of a first embodiment of a vehicle control device according to the present invention. It is operation | movement explanatory drawing of 1st Embodiment. It is operation | movement explanatory drawing of 1st Embodiment. It is a flowchart for operation | movement description of 1st Embodiment. It is a flowchart for operation | movement description of 2nd Embodiment.

(First embodiment)
A vehicle control apparatus according to a first embodiment of the present invention will be described in detail with reference to FIGS. 1 to 4.

  As shown in FIG. 1, the vehicle control device 1 includes a vehicle speed sensor 2 that is detection means for detecting the vehicle speed of the host vehicle, a water temperature sensor 3 that detects a water temperature of an engine (not shown), and the host vehicle that is running. Gear detecting means 4 for detecting which gear of the engine, an intake manifold pressure sensor 5 for detecting the intake manifold pressure of the engine, an accelerator pedal switch 6 for detecting whether or not the accelerator pedal is operated, and a brake lamp by operating the brake pedal. A brake lamp switch 7 that is turned on when energized, and an engine ECU (computer ECU) that takes in signals from the vehicle speed sensor 2, the water temperature sensor 3, the gear detection means 4, the intake manifold pressure sensor 5, the accelerator pedal switch 6, and the brake lamp switch 7. (Electronic Control Unit) 7 and this engine ECU 8 Operation control of the air conditioner ECU 9 and the alternator 10 is performed.

  The engine ECU 8 functions as a derivation means for deriving the required brake negative pressure corresponding to the vehicle speed detected by the vehicle speed sensor 2, the gear detected by the gear detection means 4, the engine water temperature by the engine speed and water temperature sensor 3, the air conditioner Based on the load state, alternator load state, or based on the engine intake manifold pressure by the intake manifold pressure sensor 5, the function as an estimation means for estimating the possible brake negative pressure that can be generated, and the estimated required brake negative pressure are estimated. And a function as a determination means for determining whether or not the generated brake negative pressure is in a negative pressure deficient state exceeding a preset set amount.

  Here, the required brake negative pressure varies depending on the vehicle speed as shown in FIG. 2, and the relationship between the required brake negative pressure and the vehicle speed is previously examined and mapped for each vehicle type and stored in the internal memory of the engine ECU 8 or the like. The required brake negative pressure corresponding to the current vehicle speed may be extracted from the map and derived. In FIG. 2, the horizontal axis indicates the vehicle speed, and the vertical axis indicates the brake negative pressure, which is the negative pressure.

  By the way, the brake negative pressure with respect to the engine speed changes almost proportionally when the throttle opening is constant, and the brake negative pressure with respect to the throttle opening changes almost inversely when the engine speed is constant. There is. Further, in a state where the engine is not warmed and the engine water temperature is low, there is a characteristic that the engine load increases because the viscosity of the engine oil is high. In addition, the engine load increases when the load on the air conditioner and alternator is large.

  Therefore, as described above, it is desirable to estimate the brake negative pressure that can be generated based on the number of gear stages, engine speed, engine water temperature, air conditioner, and alternator load. Regarding possible brake negative pressure, the relationship between the number of gear stages of different car types, engine speed, engine water temperature, air conditioner, and alternable brake negative pressure with respect to the load of the alternator is examined and mapped in advance, and stored in the internal memory of the engine ECU 8, etc. Thus, the running gear detected by the gear detection means 4, the current engine speed, the current engine water temperature by the water temperature sensor 3, the air conditioner, and the brake negative pressure that can be generated corresponding to the load on the alternator are mapped. It may be extracted and estimated from. Alternatively, the brake negative pressure that can be generated may be estimated from the engine intake manifold pressure by the intake manifold pressure sensor 5.

  Then, the magnitude of the required brake negative pressure derived by the engine ECU 8 is compared with the estimated magnitude of the possible brake negative pressure, and the difference between the magnitude of the required brake negative pressure and the magnitude of the possible brake negative pressure is set in advance. It is determined whether or not the set amount Pt is exceeded, and if it exceeds, it is determined that the brake negative pressure is insufficient.

  As described above, when the engine ECU 8 determines that the negative pressure is insufficient, the engine ECU 8 determines the magnitude of the required brake negative pressure and the brake negative pressure that can be generated until the brake negative pressure insufficient state is resolved. As shown in FIG. 3, the air conditioner ECU 9 is controlled by the engine ECU 8 to reduce the load on the engine until the difference from the size becomes equal to or less than a preset set amount Pt, which will be described below. The air conditioner on / off control is executed.

  That is, when it is determined that the brake negative pressure is insufficient, as shown in FIG. 3, the operating air conditioner is turned off at time t1, and the air conditioner is turned on at time t2 after ΔT1 hours from time t1, and time t2 The air conditioner is turned off again at time t3 after ΔT2 hours, and thereafter the air conditioner is turned on at time t4, off at time t5, and turned on at time t6. Such air conditioner on / off control is caused by insufficient brake negative pressure. Repeat until it is determined that the condition has been resolved. Here, the horizontal axis in FIG. 3 represents time, and the vertical axis represents the brake negative pressure, which is a negative pressure.

  When the alternator 10 can be controlled to be turned off by the engine ECU 8, the engine ECU 8 may perform control to turn off the alternator 10 in addition to the air conditioner on / off control.

  By the way, FIG. 2 shows an example in which ΔT1 time, which is a period for turning off the air conditioner, and ΔT2 time, which is a period for turning on the air conditioner, is set to be longer than ΔT2. In FIG. It may be long or both may be the same. In addition, for the ΔT1 time and the ΔT2 time, an optimum length for each vehicle type is obtained in advance by experiments and set to a length corresponding to the vehicle type.

  Next, a control procedure by the engine ECU 7 will be described with reference to a flowchart of FIG.

  As shown in FIG. 4, the engine ECU 8 derives the required brake negative pressure corresponding to the current vehicle speed from the map based on the output of the vehicle speed sensor 2 as described above (step S1), and further the gear. The running gear detected by the detecting means 4, the current engine speed, the current engine water temperature by the water temperature sensor 3, the air conditioner load state, and the possible brake negative pressure corresponding to the alternator load state are extracted from the map and estimated. Or is estimated from the engine intake manifold pressure (step S2), and the brake negative pressure is insufficient depending on whether or not the difference between the required brake negative pressure and the generated brake negative pressure exceeds a preset amount Pt. It is determined whether or not (step S3).

  If the determination result in step S3 is YES, that is, if it is determined that the difference between the magnitude of the required brake negative pressure and the magnitude of the brake negative pressure that can be generated exceeds the set amount Pt, the brake negative pressure is insufficient. Based on the output of the accelerator pedal switch 6, it is determined whether the accelerator pedal is not operated and is in the off state (step S4). If the determination result is NO, the determination in step S4 is continued until the determination result is YES. Repeatedly, if it is determined that the accelerator pedal is off (YES in step S4), it is determined whether the brake lamp is turned on by operating the brake pedal based on the output of the brake lamp switch 7 (step S5). If the determination result is NO, the process returns to step S4, and if the determination result is YES, the process proceeds to the next step S6. Note that steps S4 and S5 are processes for reliably determining whether or not the brake operation has been performed, and the determination process of step S4 is not particularly necessary.

  In step S6, since it is already determined that the brake negative pressure is insufficient, the air conditioner ECU 8 is controlled by the engine ECU 8, and the air conditioner on / off control as shown in FIG. 3 is executed (step S6). After that, it is determined whether or not the difference between the magnitude of the required brake negative pressure and the magnitude of the brake negative pressure that can be generated is equal to or less than the set amount Pt and the insufficient brake negative pressure state is resolved (step S7). If a determination result is NO, it will return to step S6, and if a determination result is YES, it will return to a start with the case where the determination result of above-mentioned step S3 is NO.

  Therefore, according to the first embodiment described above, the engine ECU 8 derives the required brake negative pressure corresponding to the vehicle speed detected by the vehicle speed sensor 2, and the current gear, engine speed, and water temperature sensor 3 by the gear detection means 4. The brake negative pressure that can be generated is estimated based on the engine water temperature, air conditioner load condition, alternator load condition by the engine pressure, or the engine intake manifold pressure by the intake manifold pressure sensor 5, and the size of the derived required brake negative pressure is estimated In order to determine whether or not the brake negative pressure is in a state where the difference from the magnitude of the brake negative pressure exceeds the preset amount Pt, a pressure sensor, a negative pressure sensor, etc. for detecting the brake negative pressure are no longer necessary. Without the need to install a dedicated sensor, it is possible to accurately detect the shortage of brake negative pressure by computer software processing. It is possible to cross.

  If it is determined that the brake negative pressure is insufficient, the air conditioner ON / OFF control is executed until the brake negative pressure is resolved, and the engine load is reduced to avoid the brake negative pressure insufficient condition. .

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to the flowchart of FIG. The apparatus configuration in the present embodiment is the same as that in the first embodiment described above, that is, the same as that in FIG. 1, and therefore detailed description of the apparatus configuration is omitted, and differences from the first embodiment will be described.

  The second embodiment is different from the first embodiment in that when the engine ECU 8 determines that the brake negative pressure is insufficient, the brake operation is performed based on the output of the brake lamp switch 7, and the vehicle speed sensor As a result of the calculation of the acceleration / deceleration calculated from the detected vehicle speed according to 2, when it is determined that the deceleration of the host vehicle has occurred, the air conditioner OFF control is performed until the insufficient brake negative pressure state is resolved. The engine load is reduced. At this time, since the occurrence of deceleration differs for each vehicle type, it is desirable to experimentally verify in advance for each vehicle type, for example, at which timing it is determined that deceleration has occurred since the brake lamp is turned on.

  The control operation of the engine ECU 7 in the second embodiment will be described with reference to the flowchart of FIG.

  As shown in FIG. 5, the engine ECU 8 derives a required brake negative pressure corresponding to the current vehicle speed from the map based on the output of the vehicle speed sensor 2 as described above (step S11). The running gear detected by the detecting means 4, the current engine speed, the current engine water temperature by the water temperature sensor 3, the air conditioner load state, and the possible brake negative pressure corresponding to the alternator load state are extracted from the map and estimated. Or is estimated from the engine intake manifold pressure (step S12), depending on whether or not the difference between the magnitude of the required brake negative pressure and the magnitude of the brake negative pressure that can be generated exceeds a preset set amount Pt. It is determined whether or not (step S13).

  If the determination result in step S13 is YES, that is, if it is determined that the difference between the magnitude of the required brake negative pressure and the magnitude of the brake negative pressure that can be generated exceeds the set amount Pt, the brake negative pressure is insufficient. Based on the output of the brake lamp switch 7, it is determined whether or not the brake lamp is turned on by operating the brake pedal (step S14). If the determination result is NO, the determination in step S4 is performed until the determination result is YES. Is repeated and it is determined that the brake pedal is on (YES in step S14), it is determined whether or not the deceleration of the host vehicle has occurred due to the brake operation based on the vehicle speed detected by the vehicle speed sensor 2 (step S15). If the determination result is NO, the process returns to step S14, and if the determination result is YES, the next step S16 Migrate.

  In step S16, since it is determined that the brake negative pressure is already insufficient, the air conditioner ECU 9 is controlled by the engine ECU 8 to execute the forced off control of the air conditioner (step S16), and the engine load is reduced. Thereafter, it is determined whether or not the difference between the magnitude of the required brake negative pressure and the magnitude of the brake negative pressure that can be generated is equal to or less than the set amount Pt and the insufficient brake negative pressure state has been resolved (step S17). If NO, the process returns to step S16. If the determination result is YES, the air conditioner is turned back on again (step S18), and then the process returns to the start when the determination result in step S13 is NO.

  Therefore, according to the second embodiment described above, in addition to obtaining the same effect as the first embodiment, the brake negative pressure is insufficient compared to the control in which the air conditioner is repeatedly turned on and off as in the first embodiment. Since the air conditioner is turned off when the host vehicle starts decelerating in this state, the control for reducing the brake load is simple in order to eliminate the shortage of brake negative pressure.

  In the second embodiment, when the alternator 9 can be turned off by the engine ECU 8, the engine ECU 8 may perform the control to turn off the alternator 9 in addition to the air conditioner off control. The form is the same.

  The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention.

  For example, in the above-described embodiment, an air conditioner and an alternator are exemplified as engine loads to be controlled in order to avoid insufficient brake negative pressure, but the engine loads to be controlled are not limited to these air conditioners and alternators.

  In the above-described embodiment, the brake negative pressure that can be generated is estimated based on the current running gear detected by the gear detection means 4. This is particularly effective for shift vehicles. Further, even in an automatic shift vehicle, it is possible to obtain the same effect by applying the above-described apparatus without any problem. However, in the case of an automatic shift vehicle, the gear detection means 4 is not always necessary. Absent.

DESCRIPTION OF SYMBOLS 1 ... Vehicle control apparatus 2 ... Vehicle speed sensor (detection means)
4 ... gear detection means 8 ... engine ECU (derivation means, estimation means, judgment means, control means)

Claims (2)

In a vehicle control device for controlling stop of engine loads such as an air conditioner and an alternator when an insufficient state of required brake negative pressure required for operating a brake booster occurs while driving an engine mounted on the host vehicle.
Detection means for detecting the vehicle speed of the host vehicle;
Gear detection means for detecting which of the vehicle's own gear is running,
Derivation means for deriving a required brake negative pressure corresponding to a vehicle speed detected by the detection means;
An estimation means for estimating a brake negative pressure that can be generated based on a gear detected by the gear detection means, an engine speed and an engine water temperature, an air conditioner load state, an alternator load state, or an engine intake manifold pressure;
Judgment means for judging whether or not the brake negative pressure is in a state where the possible brake negative pressure by the estimation means is insufficient with respect to the required brake negative pressure by the deriving means;
When it is determined by the determination step that the brake negative pressure is insufficient, the engine repeatedly repeats a predetermined off time and on time alternately until the brake negative pressure insufficient state is resolved. A vehicle control device comprising control means for performing on / off control of a load. In a vehicle control device for controlling stop of engine loads such as an air conditioner and an alternator when an insufficient state of required brake negative pressure required for operating a brake booster occurs while driving an engine mounted on the host vehicle.
Detection means for detecting the vehicle speed of the host vehicle;
Gear detection means for detecting which of the vehicle's own gear is running,
Derivation means for deriving a required brake negative pressure corresponding to a vehicle speed detected by the detection means;
An estimation means for estimating a brake negative pressure that can be generated based on a gear detected by the gear detection means, an engine speed and an engine water temperature, an air conditioner load state, an alternator load state, or an engine intake manifold pressure;
Judgment means for judging whether or not the brake negative pressure is in a state where the possible brake negative pressure by the estimation means is insufficient with respect to the required brake negative pressure by the deriving means;
When it is determined by the determination step that the brake negative pressure is insufficient, and when it is determined that deceleration of the host vehicle has occurred based on the vehicle speed detected by the detection means, the brake negative pressure is insufficient. A vehicle control device comprising control means for performing off control of the engine load until the state is resolved.

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