Vehicle speed limit control device

Abstract

To provide a vehicle speed limit control device that enables a driver to visually recognize a difference between an actual accelerator operation amount and a release accelerator operation amount at appropriate timing.SOLUTION: A vehicle speed limit control device is configured to release vehicle speed limit control for controlling target driving force in accordance with a limit vehicle speed defined by a driver when an actual accelerator operation amount exceeds a predetermined release accelerator operation amount. The vehicle speed limit control device includes: a display section for displaying the actual accelerator operation amount and the release accelerator operation amount; and a controller for controlling the display section. When the actual accelerator operation amount is equal to or larger than a display determination threshold value that is smaller than the release accelerator operation amount and a change speed of the actual accelerator operation amount is less than or equal to a predetermined specified change speed, the controller displays the actual accelerator operation amount and the release accelerator operation amount on the display section (Step S18).SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a vehicle speed limit control device configured to determine a target driving force by correcting a driving force based on an accelerator operation in accordance with a vehicle speed limit set by a driver. [Background technology]

[0002] Patent Document 1 describes a control device configured to release a vehicle speed limit control, which corrects a target driving force according to a vehicle speed limit set by a driver, by an accelerator operation. Specifically, the control device is configured to release the vehicle speed limit control when the actual accelerator operation amount by the driver exceeds a release accelerator operation amount determined based on the vehicle speed limit. This control device is configured to determine a release accelerator operation amount based on the vehicle speed limit, and to divide the operation range up to the release accelerator operation amount into three areas: a non-correction area in which a target driving force is determined based on the accelerator operation amount, a correction area in which the target driving force is corrected according to the accelerator operation amount, and a correction and warning area in which the target driving force is corrected and the driver is notified that the actual accelerator operation amount has approached the release accelerator operation amount. In addition, this control device is configured to display the actual accelerator operation amount and the release accelerator operation amount for releasing the vehicle speed limit control on an indicator so that the driver can recognize the accelerator operation amount required to release the vehicle speed limit control, and to change the color of the display according to the area to which the actual accelerator operation amount belongs. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2010-269684 A Summary of the Invention [Problem to be solved by the invention]

[0004] The control device described in Patent Document 1 constantly displays the actual accelerator operation amount and the release accelerator operation amount on an indicator so that the driver can recognize the accelerator operation amount required to release the vehicle speed limit control. Therefore, if the accelerator operation amount is relatively small and the difference between the release accelerator operation amount and the actual accelerator operation amount is large, the driver may feel annoyed if the display of the indicator changes. In addition, if the driver operates the accelerator to overtake a preceding vehicle, it is considered that the driver intends to release the vehicle speed limit control, and in such a case, if the display of the indicator changes as the accelerator operation increases, the driver may feel annoyed.

[0005] The present invention has been made with attention to the above-mentioned technical problems, and aims to provide a vehicle speed limit control device that allows the driver to visually check the difference between the actual accelerator operation amount and the released accelerator operation amount at an appropriate timing. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, the present invention provides a vehicle speed limit control device configured to release vehicle speed limit control, which controls a target driving force in accordance with a limit vehicle speed set by a driver, when an actual accelerator operation amount exceeds a predetermined release accelerator operation amount, and is equipped with a display unit that displays the actual accelerator operation amount and the release accelerator operation amount, and a controller that controls the display unit, and is characterized in that the controller displays the actual accelerator operation amount and the release accelerator operation amount on the display unit when the actual accelerator operation amount is equal to or greater than a display judgment threshold that is smaller than the release accelerator operation amount and the rate of change of the actual accelerator operation amount is equal to or less than a predetermined change rate. Effect of the Invention

[0007] According to the present invention, when the actual accelerator operation amount is equal to or greater than a display determination threshold value smaller than the release accelerator operation amount, and the change rate of the actual accelerator operation amount is equal to or less than a predetermined change rate, the actual accelerator operation amount and the release accelerator operation amount are displayed on the display unit. That is, the actual accelerator operation amount and the release accelerator operation amount are displayed on the display unit only when the actual accelerator operation amount increases relatively slowly and may exceed the release accelerator operation amount. Therefore, when the difference between the actual accelerator operation amount and the release accelerator operation amount is large and the operation amount is low, the actual accelerator operation amount and the release accelerator operation amount are displayed on the display unit, which may cause the driver to feel annoyed, and when the driver suddenly operates the accelerator assuming that the vehicle speed limit control will be released, the actual accelerator operation amount and the release accelerator operation amount are displayed on the display unit, which may cause the driver to feel annoyed. In other words, by displaying the actual accelerator operation amount and the release accelerator operation amount on the display unit at an appropriate timing when there is a concern that the vehicle speed limit control may be released without the driver's recognition, the driver can be notified that the vehicle speed limit control may be released. [Brief description of the drawings]

[0008] [Figure 1] 2 is a block diagram for explaining an example of an electronic control device for setting a vehicle speed limit and controlling a driving force source. FIG. [Diagram 2] FIG. 4 is a diagram showing an example of a release accelerator opening map for determining a release accelerator opening. [Diagram 3] FIG. 4 is a diagram showing an example of a display determination opening map for determining a display determination opening. [Figure 4] 5 is a flowchart for explaining an example of override determination control. [Diagram 5] 10 is a flowchart illustrating an example of a display determination control. [Figure 6] FIG. 1 is a schematic diagram showing an example in which an actual accelerator opening degree and a released accelerator opening degree are displayed in the same position as a speedometer on an instrument panel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The vehicle speed limit control device in the embodiment of the present invention is intended for various vehicles such as engine vehicles that run only on engine power, electric vehicles that run only on motor power, and hybrid vehicles that run on both engine and motor power, and is configured to determine a target driving force so that the vehicle speed will be equal to or less than the limit vehicle speed set by the driver when the accelerator is operated below a release accelerator operation amount (release accelerator opening) described below. Note that the output torque of a driving force source such as an engine or a motor may be determined based on the target driving force, and the output torque of the driving force source and the gear ratio of a power transmission device such as a gear change mechanism may be determined.

[0010] An electronic control unit (hereinafter referred to as ECU) 1 for setting the above-mentioned vehicle speed limit and controlling the driving force source is shown in Figure 1. Signals are input to the ECU 1 shown in Figure 1 from a speed limiter switch 2 operated by the driver, wheel speed sensors 3 provided on each wheel, and an accelerator pedal sensor 4 that detects the amount of depression of the accelerator pedal (accelerator opening).

[0011] The ECU 1 corresponds to a "controller" in the embodiment of the present invention, and includes a vehicle speed limit calculation unit 5, an override determination unit 6, a driving acceleration calculation unit 7, and a display determination unit 8 in the example shown in FIG. 1. The vehicle speed limit calculation unit 5 is configured to set a vehicle speed limit requested by the driver. Signals are input from a speed limiter switch 2 and a wheel speed sensor 3 to the vehicle speed limit calculation unit 5 shown in FIG. 1. The vehicle speed limit calculation unit 5 obtains the vehicle speed at the time when the speed limiter switch 2 is operated based on the signal input from the wheel speed sensor 3, and sets the obtained vehicle speed as the vehicle speed limit. The speed limiter switch 2 also includes a tumbler switch for changing the vehicle speed limit, and when the driver operates the tumbler switch, the signal is input to the vehicle speed limit calculation unit 5 to increase or decrease the vehicle speed limit.

[0012] The override determination unit 6 is configured to determine whether the driver has operated the accelerator to such an extent that the vehicle speed limit is cancelled. Signals are input to the override determination unit 6 shown in Fig. 1 from the wheel speed sensor 3, the accelerator pedal sensor 4, and the vehicle speed limit calculation unit 5. The override determination unit 6 also stores a release accelerator opening map for setting a release accelerator opening θcancel according to the vehicle speed limit.

[0013] An example of the release accelerator opening map is shown in Figure 2, with the horizontal axis representing the vehicle speed limit and the vertical axis representing the release accelerator opening. In the example shown in Figure 2, when the vehicle speed limit is equal to or lower than a predetermined vehicle speed V1, a first accelerator opening θ1 with a relatively small accelerator opening is set to the release accelerator opening θcancel, and when the vehicle speed limit is higher than the predetermined vehicle speed V1, a second accelerator opening θ2 with a relatively large accelerator opening is set to the release accelerator opening θcancel.

[0014] Then, the override determination unit 6 executes override determination control, which will be described later, to determine a release accelerator opening θcancel for releasing the vehicle speed limit control, based on the vehicle speed based on the signal input from the wheel speed sensor 3 and the vehicle speed limit input from the vehicle speed limit calculation unit 5, and determines that an override has occurred, in which the actual accelerator opening θact based on the signal input from the accelerator pedal sensor 4 exceeds the release accelerator opening θcancel.

[0015] The traveling acceleration calculation unit 7 is configured to calculate a target acceleration (target driving force). A signal of the vehicle speed limit is input to the traveling acceleration calculation unit 7 shown in Fig. 1 from the vehicle speed limit calculation unit 5, and signals of the occurrence or absence of override, the vehicle speed, and the accelerator opening are input from the override determination unit 6. When the vehicle speed limit is set and an override is not occurring, the traveling acceleration calculation unit 7 sets a target driving force by referring to a driving force map that sets a target driving force based on the vehicle speed and the accelerator opening, similar to a conventional means for determining a target driving force of a vehicle, when the accelerator opening is less than a predetermined opening, and sets a target driving force that does not cause the vehicle speed to exceed the vehicle speed limit by, for example, multiplying the driving force obtained from the driving force map by a predetermined correction coefficient when the accelerator opening is greater than the predetermined opening.

[0016] The display determination unit 8 is configured to determine whether to display the actual accelerator opening θact and the released accelerator opening θcancel on a display unit 9 such as an instrument panel or a head-up display. The display determination unit 8 shown in FIG. 1 receives a signal of the vehicle speed limit from the vehicle speed limit calculation unit 5, and receives signals of the occurrence or non-occurrence of override, the vehicle speed, and the accelerator opening from the override determination unit 6, in the same manner as the traveling acceleration calculation unit 7. The display determination unit 8 also stores a display determination opening map that sets a display determination opening θdisplay for determining whether or not to display the actual accelerator opening and the released accelerator opening on the display unit 9 according to the vehicle speed limit. The display determination opening θdisplay corresponds to the "display determination threshold" in the embodiment of the present invention.

[0017] Fig. 3 shows an example of a display judgment opening map, with the horizontal axis representing the vehicle speed limit and the vertical axis representing the display judgment opening. In the example shown in Fig. 3, when the vehicle speed limit is equal to or less than a predetermined vehicle speed V1, a third accelerator opening θ3, which is a relatively small accelerator opening, is set as the display judgment opening θdisplay, and when the vehicle speed limit is higher than the predetermined vehicle speed V1, a fourth accelerator opening θ4, which is a relatively large accelerator opening, is set as the display judgment opening θdisplay. Note that the third accelerator opening θ3 is set to a smaller opening than the first accelerator opening θ1 shown in Fig. 2, and the fourth accelerator opening θ4 is set to a smaller opening than the second accelerator opening θ2 shown in Fig. 2.

[0018] Then, the display determination unit 8 executes the display determination control described later to determine the display determination opening θdisplay based on the vehicle speed based on the signal input from the wheel speed sensor 3 and the vehicle speed limit input from the vehicle speed limit calculation unit 5, and determines to output a signal to the display unit 9 when the actual accelerator opening θact based on the signal input from the accelerator pedal sensor 4 exceeds the display determination opening θdisplay.

[0019] A flow chart for explaining an example of override determination control is shown in Fig. 4. In the example shown in Fig. 4, first, the vehicle speed limit calculation unit 5 calculates the vehicle speed limit (step S1). In this step S1, the vehicle speed limit set by the driver is calculated from the speed limiter switch 2 and the wheel speed sensor 3 as described above.

[0020] Next, the override determination unit 6 sets the release accelerator opening θcancel. Specifically, following step S1, it is determined whether the vehicle speed limit set in step S1 is lower than a predetermined vehicle speed (step S2). This step S2 is a step for determining whether the vehicle is traveling on a road such as a general road with a relatively low legal vehicle speed limit, or on a road such as a highway with a relatively high legal vehicle speed limit, and the predetermined vehicle speed can be set to a vehicle speed V1 at which the release accelerator opening θcancel is the boundary between the first accelerator opening θ1 and the second accelerator opening θ2 shown in FIG. 2.

[0021] If the vehicle speed limit is higher than the predetermined vehicle speed and the answer is NO in step S2, the second accelerator opening θ2 is set to the cancellation accelerator opening θcancel based on the cancellation accelerator opening map shown in FIG. 2 (step S3).

[0022] Normally, when a vehicle speed limit is set, the actual vehicle speed is maintained at or below the vehicle speed limit. Therefore, by setting the release accelerator opening based on the release accelerator opening map, when the driver intends to accelerate and depresses the accelerator opening further, the vehicle speed limit control can be released and the driving force requested by the driver can be generated.

[0023] On the other hand, when the vehicle speed limit is set to a high speed and the driver switches the vehicle speed limit to a low speed, the actual vehicle speed decreases after the system speed limit is set to a low speed. In other words, there is a transitional period during which the actual vehicle speed exceeds the vehicle speed limit.

[0024] During this transitional period, if there is a request for acceleration by, for example, increasing the accelerator opening, it is preferable that the driving force be increased in accordance with the actual accelerator opening. In other words, if the release accelerator opening is set in accordance with the limited vehicle speed set to a low vehicle speed, the target driving force will be corrected to the low driving force side even if the accelerator opening is increased, and it may not be possible to output the driving force requested by the driver.

[0025] Therefore, if the vehicle speed limit is lower than the predetermined vehicle speed and the answer is YES in step S2, it is determined whether the current vehicle speed is equal to or lower than the vehicle speed limit (step S4). If the current vehicle speed is equal to or lower than the vehicle speed limit and the answer is YES in step S4, the first accelerator opening θ1 in the release accelerator opening map shown in Fig. 2 is set to the release accelerator opening θcancel (step S5), and if the current vehicle speed is higher than the vehicle speed limit and the answer is NO in step S4, the second accelerator opening θ2 in the release accelerator opening map shown in Fig. 2 is set to the release accelerator opening θcancel (step S6).

[0026] Then, following steps S3, S5, and S6, it is determined whether the actual accelerator opening θact is equal to or greater than the release accelerator opening θcancel (step S7). If the actual accelerator opening θact is equal to or greater than the release accelerator opening θcancel and thus the determination in step S7 is affirmative, it is determined that the override determination is established (step S8) and this routine is temporarily terminated. That is, the vehicle speed limit control is released, and a signal corresponding to a target driving force determined from the accelerator opening is output to the driving force source 10. On the other hand, if the actual accelerator opening is less than the release accelerator opening and thus the determination in step S7 is negative, it is determined that the override determination is not established (step S9) and this routine is temporarily terminated. That is, the vehicle speed limit control is continued. That is, a signal based on a target driving force for traveling at a vehicle speed equal to or less than the vehicle speed limit is output to the driving force source 10.

[0027] Next, an example of the display determination control will be described with reference to the flowchart shown in Fig. 5. In the example shown in Fig. 5, first, the vehicle speed limit calculation unit 5 calculates the vehicle speed limit (step S11). In this step S11, the vehicle speed limit set by the driver is calculated from the speed limiter switch 2 and the wheel speed sensor 3 as described above.

[0028] Next, the display determination opening θdisplay is set by the display determination unit 8. Specifically, following step S11, it is determined whether the vehicle speed limit set in step S11 is lower than a predetermined vehicle speed (step S12). This step S12 is the same as step S2 described above, and is a step for determining whether the vehicle is traveling on a road with a relatively low legal vehicle speed limit such as a general road, or on a road with a relatively high legal vehicle speed limit such as an expressway. Therefore, the predetermined vehicle speed can be set to a vehicle speed V1 at which the display determination opening θdisplay is a boundary between the third accelerator opening θ3 and the fourth accelerator opening θ4 shown in FIG. 3. The predetermined vehicle speed in step S2 and the predetermined vehicle speed in step S12 may be set to the same vehicle speed.

[0029] If the result of step S12 is negative because the vehicle speed limit is higher than the predetermined vehicle speed, the fourth accelerator opening θ4 is set to the display determination opening θdisplay based on the display determination opening map shown in FIG. 3 (step S13).

[0030] In the above-mentioned override determination control, when the vehicle speed limit is a low vehicle speed and the current vehicle speed is equal to or lower than the vehicle speed limit, the first accelerator opening θ1 is set to the release accelerator opening θcancel, and when the vehicle speed limit is a low vehicle speed and the current vehicle speed is higher than the vehicle speed limit, or when the vehicle speed limit is a high vehicle speed, the second accelerator opening θ2 is set to the release accelerator opening θcancel. Thus, in accordance with the override determination control, the display determination opening θdisplay is configured to be set according to the vehicle speed limit and the current vehicle speed.

[0031] Specifically, if the vehicle speed limit is lower than the predetermined vehicle speed and thus the vehicle speed is determined to be YES in step S12, it is determined whether the current vehicle speed is equal to or lower than the vehicle speed limit (step S14). If the current vehicle speed is equal to or lower than the vehicle speed limit and thus the vehicle speed is determined to be YES in step S14, the third accelerator opening θ3 in the display determination opening map shown in Fig. 3 is set to the display determination opening θcancel (step S15), and if the current vehicle speed is higher than the vehicle speed limit and thus the vehicle speed is determined to be NO in step S14, the fourth accelerator opening θ4 in the display determination opening map shown in Fig. 3 is set to the display determination opening θcancel (step S16).

[0032] Then, following steps S13, S15, and S16, it is determined whether the actual accelerator opening θact is equal to or greater than the display determination opening θdisplay and the rate of change of the accelerator opening θact is equal to or less than a predetermined rate of change (step S17). This step S17 is a step for suppressing a display determination when the driver operates the accelerator with the intention of releasing the vehicle speed limit control. Therefore, the predetermined rate of change is the rate of change of the accelerator opening when the driver intends to suddenly increase the acceleration, such as when overtaking a preceding vehicle, and can be determined in advance by experiment or the like.

[0033] If the actual accelerator opening θact is equal to or larger than the display judgment opening θdisplay and the rate of change of the accelerator opening θact is equal to or smaller than a predetermined rate of change, the vehicle speed limit control may be released without the driver's knowledge. Therefore, if the result of step S17 is YES, a signal for displaying the actual accelerator opening θact and the release accelerator opening θcancel on the display unit 9 is output (step S18), and this routine is temporarily terminated.

[0034] Fig. 6 shows an example in which the actual accelerator opening θact and the release accelerator opening θcancel are displayed in the same position as the speedometer on the instrument panel. In the example shown in Fig. 6, the release accelerator opening θcancel is shown with a "▼" symbol at the position of the vehicle speed limit, and the actual accelerator opening θact is shown with a gauge that expands and contracts along the outer edge of the speedometer.

[0035] On the other hand, if the actual accelerator opening θact is less than the display judgment opening θcancel, or the rate of change of the accelerator opening θact is higher than the predetermined rate of change and therefore the result of step S17 is negative, a signal for displaying the actual accelerator opening θact and the released accelerator opening θcancel on the display unit 9 is not output (step S19), and this routine is temporarily terminated.

[0036] After the actual accelerator opening θact and the released accelerator opening θcancel are displayed on the display unit 9, if the accelerator opening θact becomes equal to or less than the display judgment opening θdisplay, or if the rate of change of the accelerator opening θact becomes equal to or greater than a predetermined rate of change and the accelerator opening θact becomes equal to or less than the display judgment opening θdisplay, the display unit 9 may stop displaying the actual accelerator opening θact and the released accelerator opening θcancel.

[0037] The above-mentioned vehicle speed limit control device is configured to change the release accelerator opening θcancel for canceling the vehicle speed limit control in accordance with the vehicle speed limit. Therefore, in a driving environment such as when driving on a general road, where the vehicle speed limit is set to a relatively low vehicle speed and there are relatively many opportunities to accelerate to a vehicle speed equal to or higher than the set vehicle speed limit in order to overtake a preceding vehicle, the vehicle speed limit control can be released without excessively increasing the accelerator opening, thereby improving acceleration responsiveness and operability during acceleration.

[0038] In addition, in driving environments where the vehicle speed limit is set to a relatively high vehicle speed and there are relatively few opportunities for sudden acceleration, such as when driving on a highway, the vehicle speed limit control can be maintained until the accelerator opening increases significantly, thereby suppressing an increase in the load on the driver's accelerator operation caused by being conscious of maintaining the vehicle speed limit control.

[0039] Furthermore, during the transitional period when the vehicle speed limit is changed from a high vehicle speed to a low vehicle speed and the actual vehicle speed decreases to the changed vehicle speed limit, the release accelerator opening θcancel is maintained at a high state. In other words, the vehicle speed limit is not changed until the actual vehicle speed becomes equal to or lower than the vehicle speed limit. That is, the target driving force (driving force characteristics) set based on the actual accelerator opening θact is maintained in the state before the driver operates to change the vehicle speed limit. As a result, if there is an acceleration request before the actual vehicle speed decreases to or lower than the changed vehicle speed limit, the target driving force is not corrected and reduced, and a driving force corresponding to the actual accelerator opening θact can be output, thereby preventing the driver from feeling insufficient acceleration.

[0040] Furthermore, when the actual accelerator opening θact is equal to or greater than the display determination opening θdisplay which is smaller than the release accelerator opening θcancel and the rate of change of the actual accelerator opening θact is equal to or less than a predetermined rate of change, the actual accelerator opening θact and the release accelerator opening θcancel are displayed on the display unit 9. In other words, the actual accelerator opening θact and the release accelerator opening θcancel are displayed on the display unit 9 only when there is a possibility that the actual accelerator opening θact increases relatively slowly and exceeds the release accelerator opening θcancel.

[0041] Therefore, when the difference between the actual accelerator opening θact and the release accelerator opening θcancel is large and the operation amount is low, it is possible to suppress the driver from feeling annoyed by the actual accelerator opening θact and the release accelerator opening θcancel being displayed on the display unit 9, and when the driver suddenly operates the accelerator assuming that the vehicle speed limit control will be released, it is possible to suppress the driver from feeling annoyed by the actual accelerator opening θact and the release accelerator opening θcancel being displayed on the display unit 9. In other words, by displaying the actual accelerator opening θact and the release accelerator opening θcancel on the display unit 9 at an appropriate timing when there is a concern that the vehicle speed limit control will be released without the driver realizing it, it is possible to notify the driver that there is a possibility that the vehicle speed limit control will be released. [Explanation of symbols]

[0042] 1. Electronic Control Unit (ECU) 2 Speed ​​limiter switch 3 Wheel Speed ​​Sensor 4 Accelerator pedal sensor 5. Vehicle speed limit calculation section 6 Override judgment section 7. Running acceleration calculation section 8 Display judgment section 9 Display section 10. Driving force source

Claims

[Claim 1] A vehicle speed limit control device configured to release a vehicle speed limit control that controls a target driving force according to a vehicle speed limit set by a driver when an actual accelerator operation amount exceeds a predetermined release accelerator operation amount, a display unit that displays the actual accelerator operation amount and the released accelerator operation amount; A controller for controlling the display unit, The controller: When the actual accelerator operation amount is equal to or greater than a display determination threshold value that is smaller than the release accelerator operation amount and the rate of change of the actual accelerator operation amount is equal to or less than a predetermined rate of change, the actual accelerator operation amount and the release accelerator operation amount are displayed on the display unit. A vehicle speed limiting control device.

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