JP2011143765A - Road gradient detector for vehicle, and engine controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a road gradient detector for a vehicle for detecting a road gradient without adding a special constitution. <P>SOLUTION: The road gradient detector for a vehicle detects the road gradient without adding the special constitution by using the existing constitution such as a brake hydraulic sensor 54 for detecting brake hydraulic pressure corresponding to brake depressing force F<SB>B</SB>since the detector detects that the gradient of a road where the vehicle runs is larger as the brake depressing force F<SB>B</SB>is larger based on the brake depressing force F<SB>B</SB>during stop of the vehicle from a predetermined relationship. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a vehicle road surface gradient detection device and an engine control device, and more particularly to an improvement for detecting a road surface gradient without providing a special configuration.

  In a vehicle having a manual transmission (manual transmission) that selectively establishes a plurality of shift stages by manual operation of a shift lever or the like, a clutch is provided between the manual transmission and the engine, and the clutch Transmission of driving force from the engine to the manual transmission is controlled according to the combined state. In such a vehicle, there is a problem that an engine stall is likely to occur when starting when the road surface on which the vehicle travels is an uphill, that is, when starting uphill, and a technique for solving such a problem has been proposed. For example, this is the vehicle travel control apparatus described in Patent Document 1. According to this technology, by controlling the engine output so that the engine speed at the time of starting uphill is larger than the idle speed at the normal time, it is possible to suitably suppress the occurrence of engine stall at the time of starting uphill. Can do.

JP-A-6-146945 Japanese Patent Laid-Open No. 6-8808

  However, in the conventional technology as described above, it is necessary to provide a device such as a front-rear G sensor as a sensor for detecting the tilt angle in the front-rear direction of the vehicle, and there is an adverse effect that the manufacturing cost increases. For this reason, development of the vehicle road surface gradient detection apparatus and engine control apparatus which detect a road surface gradient without providing a special structure was calculated | required.

  The present invention has been made in the background of the above circumstances, and its object is to provide a vehicle road surface gradient detection device and an engine control device that detect road surface gradients without providing a special configuration. There is to do.

  In order to achieve such an object, the gist of the first invention is a road surface gradient detecting device for a vehicle that detects the gradient of the road surface on which the vehicle travels, and is based on a predetermined relationship, and the vehicle is stopped. It is characterized in that, based on the brake pedal force, it is detected that the greater the brake pedal force, the greater the gradient of the road surface on which the vehicle travels.

  In order to achieve the above object, the gist of the second invention is a control device for a vehicle engine connected to a manual transmission that selectively establishes a plurality of shift stages by manual operation. When the vehicle starts while the road surface on which the vehicle travels is detected as being uphill by the vehicle road surface gradient detecting device according to the first aspect of the invention, the output of the engine is higher than in other cases. Is increased.

  As described above, according to the first aspect of the present invention, there is provided a vehicle road surface gradient detection device that detects the gradient of the road surface on which the vehicle travels, and based on the brake pedal force when the vehicle is stopped based on a predetermined relationship, Since it is characterized by detecting that the gradient of the road surface on which the vehicle travels is larger as the brake pedal force is larger, a special configuration can be obtained by using an existing configuration such as a sensor that detects the brake pedal force. It is possible to provide a vehicular road surface gradient detecting device that detects a road surface gradient without providing a vehicle.

  Here, in the first invention, preferably, when the vehicle deceleration with respect to the brake pedal force is greater than a predetermined threshold based on the brake pedal force and the vehicle deceleration before the vehicle stops, the vehicle is While it is detected that the road surface to be stopped is an uphill, when it is smaller than the threshold value, it is detected that the road surface on which the vehicle stops is a downhill. In this way, it is possible to detect whether the road surface on which the vehicle travels is uphill or downhill without providing a special configuration.

  According to the second aspect of the present invention, there is provided a control device for a vehicle engine connected to a manual transmission that selectively establishes a plurality of shift speeds by manual operation, wherein the vehicle road surface gradient detection according to the first aspect of the present invention is provided. When the vehicle is started in a state where it is detected that the road surface on which the vehicle travels is an uphill by the device, the output of the engine is increased more than in other cases. Therefore, by using an existing configuration such as a sensor for detecting the brake pedal force, a vehicle road surface gradient detection device that detects the road surface gradient without providing a special configuration, the engine stall at the time of starting uphill is started. A control device for a vehicle engine that can be suitably suppressed can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram schematically showing a vehicle drive device to which the present invention is preferably applied and a part of a control system thereof. It is a functional block diagram explaining the principal part of the control function with which the control apparatus of FIG. 1 was equipped. It is a figure which shows an example of the relationship used for determination whether the driving | running | working road surface of a vehicle is an uphill or a downhill by the control apparatus of FIG. It is a figure which shows the state in which unnecessary control may be performed by stopping at the place where the vehicle has gone up the uphill road, and determining the uphill. It is a flowchart explaining the principal part of the uphill start control by the control apparatus of FIG.

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

  FIG. 1 is a diagram schematically showing a part of a vehicle drive device 10 and its control system to which the present invention is preferably applied. The drive device 10 shown in FIG. 1 is mounted on a front engine front wheel drive (front engine front drive) type vehicle, and includes an engine 12 as a driving force source and a pair of left and right front wheels 14l as drive wheels. 14r (hereinafter, simply referred to as the front wheel 14 unless otherwise specified) includes a clutch 16, which is a power interrupting device, a manual transmission 18, a differential device 20, and the like. In other words, the output of the engine 12 is input to the input shaft 24 of the manual transmission 18 via the crankshaft 22 and the clutch 16 of the engine 12, and the driving force shifted by the manual transmission 18 is the difference. A pair of left and right front wheel axles 26l and 26r corresponding to the left and right front wheels 14 (hereinafter simply referred to as the front wheel axle 26 unless otherwise specified) is arranged via the moving device 20.

  The engine 12 is, for example, an internal combustion engine such as a gasoline engine or a diesel engine that generates driving force by combustion of fuel injected in a cylinder. Further, the clutch 16 is normally engaged, but is brought into a slip state or an open state by a depression operation of the clutch pedal 36, and the power output from the engine 12 is transmitted to the manual transmission 18. It is a power interrupting device that interrupts. The manual transmission 18 selectively reduces or increases the rotation input from the engine 12 at a predetermined gear ratio γ by selectively establishing a plurality of shift stages by manual operation of the shift lever 38 by the driver. It is a mechanical stepped transmission mechanism (manual transmission) that outputs at high speed, for example, among five forward shift stages from the first speed “1st” to the fifth speed “5th”, the reverse shift stage, and the neutral Any one of them is selectively established, and a speed conversion corresponding to each gear ratio γ is performed. The differential unit 20 transmits a driving force input from the manual transmission 18 to the left and right front wheel axles 26 while allowing relative rotation of the pair of left and right front wheel axles 26 (differential gear unit). Device).

  Further, the driving device 10 is provided with a foot brake pedal 34 that corresponds to each of the left and right front wheels 14 and a pair of left and right rear wheels 28l and 28r (hereinafter simply referred to as rear wheels 28 unless otherwise specified). Brakes 30fl, 30fr, 30rl, and 30rr (hereinafter simply referred to as brake 30 unless otherwise specified) are provided to generate a braking force according to the above. The brake 30 is a wheel brake such as a hydraulic disc brake or a drum brake that generates a braking force according to the hydraulic pressure, for example. In the driving device 10 of the present embodiment, preferably, the hydraulic pressure supplied from the hydraulic circuit 42 to each brake 30 is individually controlled according to control by an ABS (Anti-lock Brake System) or the like. The braking force corresponding to each brake 30, that is, each wheel can be individually controlled.

  The drive device 10 is provided with a control device 40 for performing various controls relating to the drive device 10. The control device 40 is, for example, a so-called microcomputer provided with a CPU, RAM, ROM, input interface, and the like, and performs signal processing according to a program stored in the ROM in advance using the temporary storage function of the RAM. Accordingly, various controls including the output control of the engine 12 and the braking control of the brake 30 via the hydraulic circuit 42 are executed. The control device 40 is configured as an individual control device for each control, such as for output control of the engine 12 or braking control of the brake 30 as necessary.

In addition, as shown in FIG. 1, signals indicating respective detection values are supplied to the control device 40 from various sensors and switches provided in the vehicle. That is, the operation amount of the accelerator pedal 32, known as so-called accelerator opening away from the accelerator operation amount sensor 44 signals representative of (accelerator opening) Acc, whether F _B of the operation of the foot brake pedal 34 is service brake from the brake switch 46 representing signal, signals representative of the vehicle speed V corresponding the vehicle speed sensor 48 to the output speed N _OUT of the manual transmission 18, the lever position of the shift lever 38 from a shift position sensor 50 as a shift operation member (operation position) S _P each signal from the clutch position sensor (clutch on-off switch) 52 from engaged state of the clutch 16 based on the depression amount of the clutch pedal 36 signal representative of the C _P (on-off of the clutch) and the brake hydraulic pressure sensor 54, which represents Shin representing the hydraulic pressure (hydraulic ABS) P _B supplied to the brake 30 There are respectively to be supplied to the control device 40. In the present embodiment, the hydraulic pressure supplied to each brake 30 is exemplified by the hydraulic circuit 42 in response to a command from the control device 40. The hydraulic pressure generated mechanically in response to the stepping on 34 may be supplied to the brake 30 corresponding to each wheel. In this case, the brake hydraulic pressure sensor 54 preferably detects the hydraulic pressure of the brake master cylinder that changes in accordance with the depression amount of the foot brake pedal 34.

  The control device 40 is configured to output a signal for controlling the operation of various devices provided in the vehicle. That is, as an engine output control command signal for controlling the output of the engine 12, for example, a signal for driving the throttle actuator 56 for controlling the opening / closing of the electronic throttle valve in accordance with the accelerator opening Acc, the injection from the fuel injection device 58 An injection signal for controlling the amount of fuel to be generated, an ignition timing signal for controlling the ignition timing of the engine 12 by the ignition device 60, and the like are output. Further, as a signal for controlling the braking force of each brake 30, for example, a signal for driving various solenoid valve devices provided in the hydraulic circuit 42 is output.

FIG. 2 is a functional block diagram for explaining the main part of the control function provided in the control device 40. The deceleration pedaling force determining means 64 shown in FIG. 2 determines the amount of brake operation for determining the pedaling force of the foot brake pedal 34, that is, the braking force of the brake 30, during vehicle deceleration. For example, when the vehicle decelerates, that is, when the time change dV / dt of the vehicle speed V detected by the vehicle speed sensor 48 is a negative value, the brake hydraulic pressure P detected by the brake hydraulic sensor 54 from a predetermined relationship. Based on _B , the depression force (depression amount) of the foot brake pedal 34 is calculated. Further, based on the time change of the brake oil pressure P _B detected by the brake oil pressure sensor 54, the change speed dF _B / dt of the depression force of the foot brake pedal 34 is detected.

Storage unit 62 is a storage medium RAM or a flash ROM or the like provided in the control unit 40, in association with the brake pedal force F _B and the vehicle deceleration dV / dt before the vehicle stops. That is, when the vehicle decelerates, that is, when the time change dV / dt of the vehicle speed V detected by the vehicle speed sensor 48 is a negative value, the brake that is determined (calculated) by the deceleration pedaling force determination means 64 every predetermined time. a depression force F _B, to the vehicle deceleration (acceleration) in association with dV / dt stored during the determination.

The stop pedaling force determination means 66 detects the gradient of the road surface on which the vehicle travels based on the brake pedaling force F _B when the vehicle is stopped from a predetermined relationship. Relationship used for this detection, it gradient of a road surface on which the vehicle smaller so that (a brake pressing force F _B to detect that the gradient of a road surface on which the vehicle the larger the brake pressing force F _B is traveling is large travel is small And is stored in the storage unit 62 or the like. The stop pedaling force determination means 66 calculates the pedal effort (depression amount) F _B of the foot brake pedal 34 based on the brake hydraulic pressure P _B detected by the brake hydraulic sensor 54 from the relationship stored in advance. To do.

Further, the stopping pedaling force determining means 66 is preferably configured such that the vehicle deceleration dV / dt relative to the brake pedaling force F _B based on the brake pedaling force F _B and the vehicle deceleration dV / dt stored in the storage unit 62. Is greater than a predetermined threshold value, it is detected that the road surface on which the vehicle travels is an uphill (uphill road), while when the road surface is smaller than the threshold value, the road surface on which the vehicle travels is a downhill (downhill road). Is detected. FIG. 3 is a diagram illustrating an example of a relationship for determining a threshold value used for such determination. In the example shown in FIG. 3, the brake pressing force F _B and the threshold value of the vehicle deceleration dV / dt is defined as a value proportional to the brake pedal force in the road surface without a flat road ie gradient F _B and the vehicle deceleration dV / dt This relationship corresponds to this threshold value. Then, the stopping pedaling force determining means 66 determines that the vehicle deceleration dV / dt relative to the brake pedaling force F _B is based on the brake pedaling force F _B and the vehicle deceleration dV / dt stored in the storage unit 62 as shown in FIG. When it is equal to or greater than the threshold value shown, it is detected that the road surface on which the vehicle travels is an uphill, while when it is smaller than the threshold value shown in FIG. 3, it is detected that the road surface on which the vehicle travels is a downhill.

The start preparation determination means 68 shown in FIG. 2 determines whether or not the vehicle is in a start preparation state. For example, the shift lever 38 lever position S _P detected by the shift position sensor 50 is a first speed "1st", the clutch 16 and by the clutch position sensor 52 is switched from the engaged state to the cutoff state Is detected, it is determined that the vehicle is in a start preparation state.

The uphill starting control means 70 performs output control of the engine 12 when the vehicle starts in a state where the road surface on which the vehicle travels is detected to be uphill by the stopping time pedaling force determination means 66. . That is, when it is determined by the start preparation determination means 68 that the vehicle is in a start preparation state, and when the stopping treading force determination means 66 detects that the road surface on which the vehicle travels is an uphill. In other cases, for example, the driving of the throttle actuator 56, the fuel injection device 58, the ignition device 60, and the like is controlled so that the output of the engine 12 is increased as compared with when starting on a flat road or a downhill. Preferably, the idle rotational speed N _IDLE of the engine 12 is increased by controlling the opening of the electronic throttle valve by the throttle actuator 56.

Here, the climbing start control means 70 preferably has a predetermined value (in a normal braking operation), the time change dF _B / dt of the brake pedal force F _B detected by the deceleration pedaling force determination means 64 is determined. If it is greater than or equal to a very large value that is not possible, it is determined that an emergency braking operation has been performed, and control for increasing the output of the engine 12 is not executed. That is, the output control of the engine 12 when starting uphill is not performed. Preferably, after the vehicle has stopped in a state in which it is detected that the road surface on which the vehicle travels is an uphill by the stop-time pedaling force determination unit 66, the stop-time pedaling force determination unit 66 determines when the vehicle is stopped. It is determined whether or not the brake pedal force is greater than a value corresponding to a flat road, and control for increasing the output of the engine 12 is executed only when the determination is affirmative. For example, as shown in FIG. 4, when the vehicle 72 is stopped immediately after fully up the uphill road 74, determined based on the stored brake pedal force F _B and the vehicle deceleration dV / dt in the storage unit 62 uphill Even so, it can be considered that the road is actually a flat road as shown in FIG. In such a case, it is possible to suitably suppress the generation of an unnecessarily large starting torque by determining the road surface gradient based on the brake depression force F _B when the vehicle is stopped.

  FIG. 5 is a flowchart for explaining a main part of the uphill starting control by the control device 40, which is repeatedly executed at a predetermined cycle.

First, in step (hereinafter, step is omitted) S1, the foot brake pedal is determined based on the brake hydraulic pressure P _B detected by the brake hydraulic sensor 54 from a predetermined relationship when vehicle deceleration is determined. 34 depression force F _B is determined (calculated). Further, the vehicle deceleration dV / dt at the time the brake pedal force F _B which is determined in this S1 is stored in the storage unit 62 in association with each other. Next, in S2, whether the vehicle deceleration dV / dt with respect to the brake depression force F _B is greater than a predetermined threshold based on the brake depression force F _B and the vehicle deceleration dV / dt stored in the storage unit 62. It is determined whether or not. If the determination in S2 is negative, it is determined that the road surface on which the vehicle travels is a flat road or a downhill, and the processing of S10 and subsequent steps is executed. However, if the determination in S2 is positive, After it is determined that the road surface on which the vehicle travels is an uphill, it is determined in S3 whether or not the vehicle has stopped, that is, whether or not the vehicle speed V detected by the vehicle speed sensor 48 has become zero. If the determination in S3 is negative, the processing after S1 is executed again. If the determination in S3 is affirmative, in S4 corresponding to the operation of the stopping force determination means 66 in advance, Based on the brake hydraulic pressure P _B detected by the brake hydraulic pressure sensor 52 from the determined relationship, the depression force F _B of the foot brake pedal 34 is determined (calculated).

Next, in S5, it is determined whether or not the change speed dF _B / dt of the brake pedal force F _B determined in S4 is equal to or greater than a predetermined very large predetermined value. If the determination in S5 is affirmative, it is determined that an emergency brake operation has been performed, and the processing from S10 is executed. If the determination in S5 is negative, the determination in S6 is performed in S4. and brake depression force F _B is whether greater than a predetermined prescribed value (a value corresponding to a flat road) is determined. If the determination in S6 is negative, it is determined that the vehicle has stopped at a point where it has climbed uphill 74 as shown in FIG. 4, and the processing in S10 and subsequent steps is executed, but the determination in S6 is affirmed. in this case, in step S7 corresponding to the operation of the start preparation determining means 68, wherein the shift lever 38 lever position S _P detected by the shift position sensor 50 is a first speed "1st", and the clutch position sensor It is determined at 52 whether or not it has been detected that the clutch 16 has been switched from the engaged state to the disconnected state. While the determination in S7 is denied, the determination is repeated to wait. If the determination in S7 is affirmative, the vehicle start mode is set to the uphill start mode in S8.

Next, in step S9, after the idling speed N _IDLE of the engine 12 is increased by controlling the opening of the electronic throttle valve by the throttle actuator 56, this routine is terminated. On the other hand, in S10, the vehicle start mode is set to the normal start mode, that is, the non-hill-start start mode. Then, in S11, after the control for changing the _idle speed N _IDLE of the engine 12 by the control of the electronic throttle valve or the like is not executed, this routine is terminated. In the above control, S1 and S2 correspond to the operation of the deceleration pedaling force determination means 64, and S8 and S9 correspond to the operation of the uphill start control means 70, respectively.

Thus, according to the present embodiment, based on the predetermined relationship, based on the brake pedal force F _B when the vehicle is stopped, the greater the brake pedal force F _B , the greater the gradient of the road surface on which the vehicle travels. Since it is characterized by detection, the road surface gradient can be detected without providing a special configuration by using an existing configuration such as a sensor that detects the brake hydraulic pressure corresponding to the brake depression force F _B. The control apparatus 40 as a vehicle road surface gradient detection apparatus can be provided. Further, in the sensor that detects the tilt angle in the front-rear direction of the vehicle, there is a risk of misidentifying that it is in an uphill state when luggage is loaded on the rear of the vehicle and the vehicle is tilted. The occurrence of such adverse effects can also be suppressed.

Further, based on the brake depression force F _B and provided with a storage unit 62 for storing the vehicle deceleration dV / dt, brake pedal force stored in the storage unit 62 F _B and the vehicle deceleration dV / dt before the vehicle stops When the vehicle deceleration dV / dt with respect to the brake depression force F _B is larger than a predetermined threshold value, it is detected that the road surface on which the vehicle stops is an uphill road. Since it detects that the road surface to be stopped is a downhill, it is possible to detect whether the road surface on which the vehicle travels is uphill or downhill without providing a special configuration.

In addition, according to the present embodiment, the control device 40 of the vehicle engine 12 connected to the manual transmission 18 that selectively establishes a plurality of shift speeds by manual operation, wherein the pedaling force determination means 66 when stopped is used. When the vehicle is started in a state in which it is detected that the road surface on which the vehicle travels is an uphill, the output of the engine 12 is increased more than in other cases. Thus, by using an existing configuration such as a sensor that detects a brake hydraulic pressure corresponding to the brake pedaling force F _B , a vehicle road surface gradient detection device that detects a road surface gradient without providing a special configuration, It is possible to provide the control device 40 for the vehicle engine 12 that suitably suppresses the engine stall at the time of starting.

  The preferred embodiments of the present invention have been described in detail with reference to the drawings. However, the present invention is not limited to these embodiments, and may be implemented in other modes.

  For example, in the above-described embodiment, the traveling road surface gradient is determined based on the brake hydraulic pressure detected by the brake hydraulic sensor 54, but the present invention is not limited to this. The determination of the stepping force or the various controls may be performed based on the depression amount of the foot brake pedal 34 detected by the brake stroke sensor.

In the illustrated embodiment, the brake pressing force F _B and the vehicle deceleration dV / dt is stored in the storage unit 62, a brake pedal force stored in the storage unit 62 after the vehicle is stopped before the vehicle stops It reads the F _B and the vehicle deceleration dV / dt, while road surface of the vehicle was to determine whether or downhill is uphill, is detected when the vehicle is performing deceleration that based on the brake depression force F _B and the vehicle deceleration dV / dt, the road surface the vehicle is traveling at that time may be one that is, whether or judgment is or downhill is uphill during vehicle travel .

  Further, the pedaling force determining means 66 at the time of stopping determines whether the traveling road surface of the vehicle is an uphill or a downhill based on the relationship shown in FIG. This is merely an example of a suitable relationship, and an optimum relationship is appropriately adopted according to the design and used for the determination.

  In addition, although not illustrated one by one, the present invention is implemented with various modifications within a range not departing from the gist thereof.

12: Engine 18: Manual transmission 30: Brake 40: Control device 62: Storage unit

Claims (3)

A vehicle road surface gradient detection device for detecting a gradient of a road surface on which a vehicle travels,
Based on a predetermined relationship, based on a brake pedal force when the vehicle is stopped, the vehicle road surface gradient detection is characterized in that the greater the brake pedal force, the greater the gradient of the road surface on which the vehicle travels. apparatus.   Based on the brake pedal force and vehicle deceleration before the vehicle stops, when the vehicle deceleration with respect to the brake pedal force is greater than a predetermined threshold, it is detected that the road surface on which the vehicle stops is an uphill road The road surface gradient detecting device for a vehicle according to claim 1, wherein when it is smaller than the threshold value, it is detected that the road surface on which the vehicle stops is a downhill. A control device for a vehicle engine connected to a manual transmission that selectively establishes a plurality of shift speeds by manual operation,
When the vehicle is started in a state in which the road surface on which the vehicle travels is detected as being uphill by the vehicle road surface gradient detection device according to claim 1 or 2, the engine is more than in other cases. The vehicle engine control apparatus is characterized in that the output of the vehicle is increased.

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