JP2016142160A - Control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device for a vehicle which can suppress that a shift range is erroneously inputted into a direction which is reverse to an uphill direction, and a vehicle abruptly starts to a direction which is reverse to an intended direction of a driver.SOLUTION: It is determined whether or not a vehicle exists on a slope (step S1). When the vehicle 3 exists on the slope, it is further determined whether or not a vehicle speed of the vehicle is not higher than a prescribed vehicle speed (step S1). When the vehicle exists on the slope, and the vehicle speed is not higher than a precast speed (YES in step S1), it is determined whether or not a gradient of a road face is a down-gradient to a start direction or an advance direction of the vehicle (step S2). Then, when the gradient of the road face is the down-gradient to the start direction or the advance direction of the vehicle (YES in step S2), a throttle opening is limited (step S3).SELECTED DRAWING: Figure 2

Description

  The present invention relates to a control device used for a vehicle such as an automobile.

  In a vehicle such as an automobile, forward / reverse is switched by a shift operation, and torque output from a drive source such as an engine is adjusted by an accelerator operation.

  For example, in a vehicle equipped with an automatic transmission, when starting in the forward direction, the shift range is changed from the P range (parking range) to the N range (neutral range) to the D range (forward range) by operating the shift lever. ), The accelerator pedal is depressed. On the other hand, when starting in the reverse direction, the accelerator pedal is depressed after the shift range is switched from the P range or the N range to the R range by operating the shift lever. As the amount of depression of the accelerator pedal increases, a larger torque is output from the drive source, and the vehicle starts (suddenly starts) at a large acceleration on a flat road or a slope (gradient road) having a downward slope in the start direction of the vehicle.

JP-A-8-145154

  On a slope having a downward slope in the starting direction of the vehicle, the starting acceleration of the vehicle with respect to the depression amount of the accelerator pedal is greater than on a flat road. Therefore, while the driver intends to start the vehicle in the uphill direction on the slope, the shift range is erroneously entered into the travel range (D range or R range) in which the vehicle travels in the direction opposite to the uphill direction, and the accelerator pedal If the vehicle is stepped on greatly, the vehicle will suddenly start in the direction opposite to the driver's intention.

  The objective of this invention is providing the control apparatus for vehicles which can suppress that a vehicle accelerates suddenly (sudden start) in the downward direction of a slope.

  In order to achieve the above object, a vehicle control device according to the present invention is a control device used for a vehicle that travels by a driving force transmitted to a drive wheel, the vehicle is located on a slope, and the vehicle Determining means for determining whether or not the starting direction is a downward direction on a slope, and a driving force limit that limits the driving force transmitted to the driving wheel when the determining means determines that the starting direction is a downward direction Means.

  According to this configuration, when the vehicle is located on a slope, that is, a road surface having a gradient, and the starting direction of the vehicle is a downward direction (downhill direction), the driving force transmitted to the drive wheels is limited. The Thereby, it is possible to suppress the vehicle from suddenly starting and rapidly accelerating in the downward direction of the slope.

  The vehicle control device according to the present invention can be used for a vehicle equipped with a manual transmission, but can be suitably used for a vehicle equipped with an automatic transmission.

  In a vehicle equipped with an automatic transmission, when the brake pedal is switched to the accelerator pedal, the vehicle starts immediately. Further, in a vehicle equipped with an automatic transmission, the shift range may be mistaken for the forward range and the reverse range. If the driver intends to start the vehicle in an uphill direction on a slope and the shift range is wrong, the driving force will be limited even if the accelerator operating member such as the accelerator pedal is operated greatly. Can be prevented from suddenly starting in a direction unintended by the driver.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that a vehicle accelerates rapidly (sudden start) to the downhill direction of a slope.

It is a block diagram which shows the structure of the principal part of the vehicle by which the vehicle control apparatus which concerns on one Embodiment of this invention is mounted. It is a flowchart which shows the flow of a driving force limitation process. It is a figure which shows the content of the map which defined the relationship between a vehicle speed and a throttle upper limit guard.

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

<Vehicle configuration>

  FIG. 1 is a block diagram showing a configuration of a main part of a vehicle 3 equipped with a vehicle control device according to an embodiment of the present invention.

  The vehicle control device is mounted as an ECU (electronic control unit) 1 on a vehicle 3 that uses, for example, an engine 2 as a drive source. The ECU 1 includes a CPU, a ROM, a RAM, and the like.

  The vehicle 3 is equipped with an automatic transmission, and a shift position sensor 4 is connected to the ECU 1. The shift position sensor 4 inputs a signal corresponding to the position of the shift lever (select lever) to the ECU 1. As positions of the shift lever, for example, a P position, an R position, an N position, and a D position are provided. The P position, the R position, the N position, and the D position correspond to the P range (parking range), R range (reverse range), N range (neutral range), and D range (forward range), respectively. The shift lever can be shifted between the P position, the R position, the N position, and the D position, and the shift range can be switched by the shift operation.

  A vehicle speed sensor 5 is connected to the ECU 1. The vehicle speed sensor 5 includes, for example, a rotor made of a magnetic body that rotates as the vehicle 3 travels, and an electromagnetic pickup that is provided in non-contact with the rotor. Each time the rotor rotates by a certain angle, a pulse signal is output from the electromagnetic pickup, and the pulse signal is input to the ECU 1.

  Further, a G sensor (acceleration sensor) 6 is connected to the ECU 1. The G sensor 6 inputs a detection signal corresponding to the acceleration generated in the G sensor 6 to the ECU 1.

  The ECU 1 is connected with an electronic throttle valve 7 for adjusting the amount of intake air into the combustion chamber of the engine 2 as a control target.

<Function processing part>

  The ECU 1 substantially includes a downhill determination unit 11 and a driving force limiting unit 12 as function processing units realized by software through program processing. Some functions of the downhill determination unit 11 and the driving force limiting unit 12 may be realized by hardware such as a logic circuit.

  The downhill determination unit 11 calculates the gradient of the road surface where the vehicle 3 is located from the detection signal of the G sensor 6. In a state where the vehicle 3 is stopped, the downhill determination unit 11 calculates the gravitational acceleration from the detection signal of the G sensor 6, and calculates the slope of the road surface from the gravitational acceleration. In a state where the vehicle 3 is traveling, the downhill determination unit 11 calculates acceleration from the detection signal of the G sensor 6. Moreover, the downhill determination part 11 calculates the acceleration by converting the frequency of the pulse signal output from the vehicle speed sensor 5 into the vehicle speed and differentiating the vehicle speed. And the downhill determination part 11 acquires the acceleration component by the gradient of a road surface by calculating | requiring the difference of the acceleration calculated from the detection signal of G sensor 6, and the differential value of a vehicle speed, and calculates a gradient from the acceleration component. .

  Further, the downhill determination unit 11 determines whether the shift position is the P position, the R position, the N position, or the D position based on the signal input from the shift position sensor 4. When the shift position is the D position, it is determined that the starting direction or the traveling direction of the vehicle 3 is the forward direction. When the shift position is the R position, the starting direction or the traveling direction of the vehicle 3 is the reverse direction. Judge.

  The downhill determination unit 11 determines whether the vehicle 3 is located on the slope based on the slope of the road surface where the vehicle 3 is located and the current shift range, and whether the starting direction or the traveling direction of the vehicle 3 is the downward direction of the slope. Determine whether. If the slope of the road surface where the vehicle 3 is located is greater than or equal to a predetermined value, it is determined that the vehicle 3 is located on the slope, and if the slope is less than the predetermined value, it is determined that the vehicle 3 is not located on the slope. The When it is determined that the vehicle 3 is located on a slope, if the slope of the road surface is a downward slope in the starting direction or the traveling direction of the vehicle 3, the starting direction or the traveling direction of the vehicle 3 is a downward slope. The direction is determined.

  The driving force limiting unit 12 executes a driving force limiting process described below.

<Driving force limiting process>

  FIG. 2 is a flowchart showing the flow of the driving force limiting process. FIG. 3 is a diagram showing the contents of a map that defines the relationship between the vehicle speed and the throttle upper limit guard.

  In the driving force limiting process, it is determined whether or not the vehicle 3 is located on the slope (step S1). The determination result by the downhill determination unit 11 is used to determine whether or not the vehicle 3 is located on the slope.

  When the vehicle 3 is located on the slope, it is further determined whether or not the vehicle speed of the vehicle 3 is equal to or lower than a predetermined speed (step S1). The predetermined speed is set according to the gradient of the road surface on which the vehicle 3 is located in accordance with the contents of the map shown in FIG. That is, as shown in FIG. 3, the throttle upper limit guard that restricts the opening degree of the electronic throttle valve 7 (throttle opening degree) is released at a higher vehicle speed when the road surface gradient is larger (higher gradient) (the throttle opening degree is smaller). 100%) and the throttle upper limit guard is set to increase (the limit becomes loose) as the vehicle speed increases. The predetermined speed is set to a speed at which the throttle upper limit guard is released according to the road surface gradient.

  When the vehicle 3 is located on a slope and the vehicle speed is equal to or lower than a predetermined speed (YES in step S1), it is determined whether or not the road gradient is a downward gradient in the starting direction or the traveling direction of the vehicle 3 ( Step S2). The determination result by the downhill determination unit 11 is used for this determination.

  If the road surface slope is a downward slope in the starting direction or the traveling direction of the vehicle 3 (YES in step S2), a throttle upper limit guard corresponding to the vehicle speed is set according to the contents of the map shown in FIG. The throttle opening is limited to the throttle upper limit guard or less (step S3), and the driving force limiting process is terminated. By limiting the throttle opening, the engine torque is limited, and the driving force transmitted to the drive wheels 8 of the vehicle 3 is limited.

  If the vehicle 3 is not located on a slope, that is, if the vehicle 3 is located on a flat road (NO in step S1), the restriction of the driving force due to the restriction of the throttle opening is released (step S4). Then, the driving force limiting process is terminated. Also, when the vehicle speed of the vehicle 3 exceeds the predetermined speed (NO in step S1), the driving force limitation due to the throttle opening limitation is released (step S4), and the driving force limitation process is ended. . Further, when the road surface gradient is not a downward gradient in the starting direction or the traveling direction of the vehicle 3, that is, when the road surface gradient is an upward gradient in the starting direction or the traveling direction of the vehicle 3 (NO in step S2), the throttle The drive force restriction due to the opening restriction is released (step S4), and the drive force restriction process is terminated.

<Effect>

  When the vehicle 3 is located on a slope, that is, on a road surface having a gradient, and the starting direction or traveling direction of the vehicle 3 is a downward direction (downhill direction), the driving force transmitted to the drive wheels 8 is limited. The Thereby, it can suppress that the vehicle 3 starts suddenly and accelerates rapidly in the downward direction of a slope.

  In addition, when the driver intends to start the vehicle 3 in the uphill direction on the slope, the driving force transmitted to the drive wheels 8 is limited even if the accelerator pedal is operated greatly when the shift range is wrongly set. Thus, the vehicle 3 can be prevented from suddenly starting in a direction not intended by the driver.

<Modification>

  As mentioned above, although one Embodiment of this invention was described, this invention can also be implemented with another form.

  In the above-described embodiment, as a method of limiting the driving force transmitted to the drive wheels 8, the method of limiting the throttle opening is taken as an example. The driving force applied may be limited.

  For example, the driving force transmitted to the drive wheels 8 is limited by controlling the hydraulic pressure supplied to the clutch so that the clutch provided on the driving force transmission path of the automatic transmission slips. Also good.

  When the automatic transmission is a stepped automatic transmission (AT), the speed of the automatic transmission is set to the second speed when the vehicle 3 starts, and the vehicle 3 is started at the so-called second speed. Thereby, the driving force transmitted to the driving wheel 8 may be limited.

  The automatic transmission mounted on the vehicle 3 is an automatic transmission having a continuously variable transmission mechanism such as a CVT (Continuously Variable Transmission), a CVT with a sub-transmission, a power split type continuously variable transmission, or the like. Also good. The power-dividing continuously variable transmission is a belt-type continuously variable transmission mechanism that shifts the power steplessly by changing the gear ratio, and a constant gear shift that shifts the power at a constant gear ratio. The transmission includes a mechanism and an output gear mechanism that outputs the power from the continuously variable transmission mechanism and the power from the constant transmission mechanism, and can transmit the power of the drive source divided into two systems.

  When an automatic transmission having a continuously variable transmission mechanism is employed, when the vehicle 3 starts, the transmission gear ratio is set to a transmission gear ratio smaller than the maximum transmission gear ratio (lowest gear ratio). The driving force transmitted may be limited.

  In that case, the gear ratio may be set to a gear ratio smaller than the maximum gear ratio by changing the pulley ratio. When the CVT with a sub-transmission is adopted, not only the pulley ratio is changed, but the sub-transmission is set to a low speed gear, so that the transmission ratio is set to a transmission ratio smaller than the maximum transmission ratio. Also good.

  The transmission mounted on the vehicle 3 may be a manual transmission.

  When the vehicle 3 starts in the downward direction of the slope, the acceleration of the vehicle 3 increases as the total weight including the vehicle weight and the load amount of the vehicle 3 increases. Therefore, the total weight of the vehicle 3 is estimated, The driving force transmitted to the driving wheel 8 may be greatly limited as the weight increases. The total weight of the vehicle 3 can be calculated from the output of the engine 2 corresponding to the engine speed, the vehicle speed and the acceleration of the vehicle 3, for example.

  In a vehicle equipped with a motor as a driving source, when the vehicle is located on a slope and the starting direction of the vehicle is a downward direction, the driving force transmitted to the driving wheel is reduced by suppressing the motor torque. You may be restricted.

  In addition, although the example in which the vehicle control device is configured by a single ECU 1 has been described, the vehicle control device may be configured by a plurality of ECUs that are communicably connected to each other.

  In addition, various design changes can be made to the above-described configuration within the scope of the matters described in the claims.

1 ECU (vehicle control device)
8 Drive wheel 11 Downhill judgment part (determination means)
12 Driving force limiting part (driving force limiting means)

Claims (1)

A control device used for a vehicle that travels by a driving force transmitted to a driving wheel,
Determining means for determining whether the vehicle is located on a slope and whether the starting direction of the vehicle is a downward direction of the slope;
And a driving force limiting unit that limits a driving force transmitted to the driving wheel when the determination unit determines that the starting direction is the downward direction.

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