Driving assistance method and driving assistance device

Abstract

This driving assistance method involves determining whether there has been a change from a state of depressing an accelerator pedal to a state of re-depression of the accelerator pedal following momentary release (S6). The driving assistance method further involves executing a process of outputting an alert to a driver if it is determined that there has been a change to the state of re-depression of the accelerator pedal following momentary release (S7). Alternatively, the driving assistance method involves executing a process of suppressing vehicle acceleration based on the operation of depressing the accelerator pedal if it is determined that there has been a change to the state of re-depression of the accelerator pedal following momentary release (S17).

Description

Technical Field

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[0001] The present invention relates to a driving support method and a driving support device.

Background Art

[0002] When the depression angle of the accelerator pedal of the travel control device described in Patent Document 1 below increases, a warning device by reaction force operates. When the depression angle further increases, a warning device by sound, light, vibration, etc. operates. When the depression angle further increases, the engine is stopped.

Prior Art Document

Patent Document

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the case of a device that detects and warns a strong depression of the accelerator pedal, since the vehicle has already accelerated rapidly when the accelerator pedal is strongly depressed, the driver may be panicked by the unintended acceleration and may not be able to lift their foot from the accelerator pedal. An object of the present invention is to detect an accelerator operation that may be a misoperation at an early stage and notify the driver.

Means for Solving the Problems

[0005] According to one aspect of the present invention, a driver assistance method is provided that performs at least one of the following: a process of outputting a warning to the driver, or a process of suppressing the acceleration of the vehicle based on the operation of pressing the accelerator pedal. The driver assistance method determines whether the state has changed from pressing the accelerator pedal to pressing the accelerator pedal again after a momentary release of the accelerator pedal, and if it is determined that the state has changed from pressing the accelerator pedal again after the momentary release of the accelerator pedal, at least one of the above processes is executed. [Effects of the Invention]

[0006] According to the present invention, potentially erroneous accelerator operation can be detected early and the driver can be notified. The objectives and advantages of the present invention are embodied and achieved using the elements and combinations thereof set forth in the claims. Both the general description above and the detailed description below are merely illustrative and descriptive, and should be understood not to limit the invention in any way that would be limited by the claims. [Brief explanation of the drawing]

[0007] [Figure 1] This is a schematic diagram of an example of a vehicle equipped with an accelerator pedal operation warning device according to an embodiment. [Figure 2] This is a block diagram of an example of the functional configuration of the controller in the first embodiment. [Figure 3] (a) and (b) are explanatory diagrams illustrating the operation of the accelerator pedal operation warning device of the first embodiment. [Figure 4] This is a flowchart of an example of an accelerator pedal operation warning method according to the first embodiment. [Figure 5] This is a block diagram of an example of the functional configuration of the controller in the second embodiment. [Figure 6] This is an explanatory diagram illustrating the operation of the accelerator pedal operation warning device according to the second embodiment. [Figure 7] This is a flowchart of an example of an accelerator pedal operation warning method according to the second embodiment. [Modes for carrying out the invention]

[0008] (First Embodiment) (composition) Figure 1 is a schematic diagram of an example of a vehicle equipped with an accelerator pedal operation warning device according to an embodiment. The vehicle 1 includes an accelerator pedal 10, an accelerator sensor 11, a brake pedal 12, a brake sensor 13, a braking force controller 14, a power controller 15, a drive force source 16, a brake controller 17, a braking device 18, a vehicle speed sensor 20, a human-machine interface (HMI) 21, a pedal actuator 22, and a controller 23. The accelerator sensor 11, brake sensor 13, vehicle speed sensor 20, HMI 21, pedal actuator 22, and controller 23 constitute the accelerator pedal operation warning device of this embodiment.

[0009] The accelerator pedal 10 is a pedal that is pressed in response to the driver's request for driving force (the driver's intention to accelerate) or braking force (the driver's intention to decelerate). The accelerator sensor 11 detects the amount of accelerator stroke (the amount pressed) of the accelerator pedal 10 and outputs an information signal of the accelerator stroke amount to the braking force controller 14 and the controller 23. The brake pedal 12 is a pedal that the driver presses only in response to a braking force request, and is provided separately from the accelerator pedal 10. The brake sensor 13 detects the brake stroke amount, which is the amount of stroke (pressure) of the brake pedal 12, and outputs an information signal of the brake stroke amount to the braking force controller 14 and the controller 23.

[0010] The braking / driving force controller 14 is an electronic control unit (ECU) that controls the braking force and driving force generated in the vehicle 1 based on the accelerator stroke amount, and also controls the braking force generated in the vehicle 1 based on the brake stroke amount. The braking / driving force controller 14 includes a processor and peripheral components such as a memory device. The functions of the braking / driving force controller 14 described below are realized by the processor executing a computer program stored in the memory device. The braking / driving force controller 14 may be formed by dedicated hardware. For example, the braking / driving force controller 14 may include a functional logic circuit (e.g., FPGA or ASIC) set up in a general-purpose semiconductor integrated circuit.

[0011] The braking force controller 14 calculates a drive torque command value, which is a command value for the drive torque determined based on the accelerator stroke amount, and outputs it to the power controller 15. If the drive force source 16 includes an electric motor, the braking force controller 14 may also calculate a regenerative braking torque command value, which is a command value for the regenerative braking torque determined based on the accelerator stroke amount, and output it to the power controller 15. Furthermore, a friction braking torque command value, which is a command value of the friction braking torque determined based on the brake stroke amount, is calculated and output to the brake controller 17.

[0012] The power controller 15 is an electronic control unit that controls the drive torque generated by the drive source 16, which is an electric motor or engine, and includes a processor and peripheral components such as a memory device. The power controller 15 may be formed by dedicated hardware. The power controller 15 controls the drive torque generated by the drive source 16 based on the drive torque command value output from the braking force controller 14. If the drive source 16 includes an electric motor, the power controller 15 controls the regenerative braking torque generated by the drive source 16 based on the regenerative braking torque command value.

[0013] The brake controller 17 is an electronic control unit that controls the frictional braking torque generated in the braking device 18, and includes a processor and peripheral components such as a storage device. The brake controller 17 may be formed by dedicated hardware. The brake controller 17 controls the frictional torque to be generated in Braking device 18 based on the frictional braking torque command value output from the braking force controller 14. Note that the braking force controller 14, the power controller 15, the brake controller 17, and the controller 23 may each be separate controllers, or any one or all of these controllers may be integrated into the same controller.

[0014] The vehicle speed sensor 20 detects the vehicle speed V of the vehicle 1 from the rotational speed of the wheels of the vehicle 1 (wheel speed) or the rotational speed of the drive motor or engine, which is the driving force source 16. The vehicle speed sensor 20 outputs an information signal of the vehicle speed V to the controller 23. The HMI 21 is an interface device that exchanges information between the vehicle 1 and the occupant. The HMI 21 includes a display device visible to the occupant of the vehicle 1 (for example, a display panel provided near the meter, in the center console, etc., the meter itself, a head-up display, etc.), lamps such as warning lamps, speakers, buzzers, and operating elements (buttons, switches, levers, dials, touch panels, etc.). The pedal actuator 22 is an actuator that applies a physical force to the accelerator pedal 10. For example, the pedal actuator 22 may vibrate the accelerator pedal 10 based on a control signal from the controller 23, or may generate a pedal reaction force, which is a force in the direction of pushing back the accelerator pedal 10 that the driver is stepping on.

[0015] The controller 23 is an electronic control unit that performs control to suppress misoperation between the accelerator pedal 10 and the brake pedal 12. For example, it includes a computer including a processor 23a and peripheral components such as a storage device 23b. The processor 23a may be, for example, a CPU (Central Processing Unit) or a MPU (Micro-Processing Unit). The storage device 23b may be any one of a semiconductor storage device, a magnetic storage device, and an optical storage device. The storage device 23b may include memories such as a ROM (Read Only Memory) and a RAM (Random Access Memory) used as a main memory, registers, and cache memories. The functions of the controller 23 described below are realized, for example, when the processor 23a executes a computer program stored in the storage device 23b.

[0016] Note that the controller 23 may be formed by dedicated hardware for executing each information process described below. For example, the controller 23 may include a functional logic circuit set in a general-purpose semiconductor integrated circuit. For example, the controller 23 may have a programmable logic device (PLD) such as a field-programmable gate array (FPGA).

[0017] The controller 23 determines whether the accelerator pedal 10 has changed from being pressed to being pressed again after a momentary release of the accelerator. If the accelerator pedal 10 has changed again after a momentary release of the accelerator, the controller 23 determines that the driver's intention to accelerate is unclear. In this case, the controller 23 outputs a warning to the driver. This allows the controller to detect accelerator operation where the driver's intention to accelerate is unclear at an early stage and outputs a warning to the driver before the vehicle 1 accelerates rapidly, so that the driver can recover from mistakenly pressing the accelerator pedal 10 instead of the brake pedal 12 before pressing the accelerator pedal 10 too hard.

[0018] Figure 2 is a block diagram of an example of the functional configuration of the controller 23 of the first embodiment. The controller 23 includes an acceleration intention determination unit 30, a timer 31, and an alarm generation unit 32. The acceleration intention determination unit 30 determines whether the driver is pressing the accelerator pedal 10 (i.e., whether the accelerator pedal 10 is being pressed) based on the accelerator stroke amount detected by the accelerator sensor 11. For example, it may determine that the driver is pressing the accelerator pedal 10 if the accelerator stroke amount is greater than or equal to a predetermined value, and that the driver is not pressing the accelerator pedal 10 if the accelerator stroke amount is less than the predetermined value. Furthermore, the acceleration intention determination unit 30 calculates the operating speed at which the driver presses the accelerator pedal 10 based on the accelerator stroke amount detected by the accelerator sensor 11. For example, the acceleration intention determination unit 30 may calculate the operating speed as the accelerator stroke amount per unit time.

[0019] Furthermore, the acceleration intention determination unit 30 determines whether the driver is pressing the brake pedal 12 (i.e., whether the brake pedal 12 is being pressed) based on the brake stroke amount detected by the brake sensor 13. For example, it may determine that the driver is pressing the brake pedal 12 if the brake stroke amount is greater than or equal to a predetermined value, and that the driver is not pressing the brake pedal 12 if the brake stroke amount is less than the predetermined value. Furthermore, the acceleration intention determination unit 30 determines whether the vehicle speed V detected by the vehicle speed sensor 20 is less than or equal to a predetermined speed Vth.

[0020] The timer 31 measures the accelerator-off time Tc, which is the period during which the driver takes their foot off the accelerator pedal 10. For example, the start time t1 of the accelerator-off time Tc may be the point when the accelerator stroke amount decreases to below a threshold. For example, it may be the point when the accelerator stroke amount decreases to zero. Alternatively, the start time t1 may be the point when the accelerator stroke amount begins to decrease. For example, the end time t2 of the accelerator-off time Tc may be the point when the accelerator stroke amount increases and becomes greater than a threshold. For example, it may be the point when the accelerator stroke amount increases and becomes greater than 0. For example, the end time t2 may be the point when the accelerator stroke amount begins to increase.

[0021] For example, at the start time t1 when the acceleration intention determination unit 30 detects a change in state from the accelerator pedal 10 being pressed to the accelerator off state (for example, a change in state from the accelerator pedal 10 being pressed to the accelerator pedal 10 not being pressed), it causes the timer 31 to start timing the accelerator off time Tc. After the start time t1, the acceleration intention determination unit 30 determines when the accelerator pedal 10 is pressed again after the accelerator off state. To the state At the end time t2, when a state change (for example, a change from a state where the accelerator pedal 10 is not pressed to a state where the accelerator pedal 10 is pressed) is detected, the accelerator-off time Tc = t2 - t1 may be obtained by reading the timing result of the timer 31.

[0022] The acceleration intention determination unit 30 determines whether the accelerator pedal 10 changed from a pressed state to a pressed state again after a momentary release of the accelerator. For example, the acceleration intention determination unit 30 may determine whether the accelerator is released instantaneously or not based on the length of the accelerator-off time Tc. For example, the acceleration intention determination unit 30 may determine that the accelerator is released instantaneously if the length of the accelerator-off time Tc is within a predetermined time T1, and determine that the accelerator is not released instantaneously if the length of the accelerator-off time Tc is longer than the predetermined time T1. For example, the predetermined time T1 may be set based on the typical (or standard) time required to switch from the accelerator pedal 10 to the brake pedal 12. The predetermined time T1 may be, for example, 1 second.

[0023] The acceleration intention determination unit 30 determines, when it determines that the accelerator pedal 10 has been pressed again after a momentary release of the accelerator, that it is unclear whether the driver's pressing of the accelerator pedal 10 (i.e., accelerator operation) initiated at the end of the release of the accelerator (t2) was an operation performed with the driver's intention to accelerate. In other words, it determines that it is unclear whether the driver had an intention to accelerate. On the other hand, if it is determined that the accelerator pedal 10 was pressed again after a non-momentary release of the accelerator, it is determined that the pressing operation of the accelerator pedal 10 initiated at the end time t2 was an operation performed with the driver's intention to accelerate. In other words, it is determined that the driver had an intention to accelerate.

[0024] If the alarm generation unit 32 determines that it is unclear whether the driver intended to accelerate, it generates an alarm (hereinafter referred to as "pedal misapplication alarm") to inform the driver that there is a possibility that the accelerator pedal 10 and brake pedal 12 have been mistakenly pressed. The alarm generation unit 32 outputs the pedal misapplication alarm to the driver from the HMI 21 and / or pedal actuator 22. For example, the pedal misapplication alarm may be a visual message, an auditory message, an alarm sound, or the illumination of a warning lamp. Alternatively, the alarm generation unit 32 may drive the pedal actuator 22 to vibrate the accelerator pedal 10 or generate a pedal reaction force to push back the accelerator pedal 10 that the driver is pressing, as a pedal misapplication alarm.

[0025] Conversely, if the alarm generation unit 32 determines that the driver has an intention to accelerate, it will not generate a pedal misapplication warning. Furthermore, if the driver changes from pressing the brake pedal 12 to pressing the accelerator pedal 10, the driver's intention to accelerate can be inferred. Therefore, in this case, the warning generation unit 32 does not need to generate a pedal misapplication warning. For example, if the driver changes from pressing the brake pedal 12 to pressing the accelerator pedal 10 while the accelerator is off, the pedal misapplication warning does not need to be generated.

[0026] Furthermore, mistaking the accelerator pedal 10 for the brake pedal 12 is more likely to occur when the vehicle speed V is low, and less likely to occur when the vehicle speed V is high. For this reason, the warning generation unit 32 generates a pedal misapplication warning when the vehicle speed V is less than or equal to a predetermined speed Vth after the accelerator pedal 10 is pressed again following a momentary release of the accelerator, and does not need to generate a pedal misapplication warning if the vehicle speed V is higher than the predetermined speed Vth even after the accelerator pedal 10 is pressed again following a momentary release of the accelerator. For example, the predetermined speed Vth may be set based on the speed range in which mistaking the accelerator pedal 10 for the brake pedal 12 is common. The predetermined speed Vth may be 20 [km / h].

[0027] The timing t3 at which the warning generation unit 32 starts outputting a pedal misapplication warning when it is determined that the driver's intention to accelerate is unclear may be variably controlled. For example, the time interval Δt1 from the end of the accelerator release point t2 to the point t3 at which the warning generation unit 32 starts outputting a pedal misapplication warning may be variably controlled. For example, if the accelerator-off time Tc is short, the mis-pedal warning can be started earlier than if it were long (i.e., the time interval Δt1 can be shorter when the accelerator-off time Tc is short than when it is long). For example, the shorter the accelerator-off time Tc, the earlier the mis-pedal warning can be started (i.e., the shorter the accelerator-off time Tc, the shorter the time interval Δt1 can be).

[0028] Furthermore, for example, if it is determined that the driver's intention to accelerate is unclear, the mis-pedal warning may be output earlier if the operating speed of the accelerator pedal 10, which was started from the end of the accelerator-off time t2, is high compared to when the operating speed is low (the time interval Δt1 may be shorter when the operating speed is high compared to when it is low). For example, the higher the operating speed, the earlier the mis-pedal warning may be output (i.e., the higher the operating speed, the shorter the time interval Δt1 may be).

[0029] For example, the alarm generation unit 32 may variably control the intensity of the pedal misapplication warning. For example, the alarm generation unit 32 may change the intensity of the pedal misapplication warning by changing the size or strength of the stimulus without changing the type of stimulus (visual stimulus, auditory stimulus, tactile stimulus) output as the pedal misapplication warning. For example, the intensity of the pedal misapplication warning may be changed by changing the size, brightness, and saturation of the visual message displayed on the HMI21 display device. For example, the intensity of the pedal misapplication warning may be changed by changing the illuminance of the warning lamp.

[0030] Furthermore, the intensity of the pedal misapplication warning may be changed by altering the volume and pitch (frequency) of the auditory messages and warning sounds output from the speaker or buzzer of the HMI21. Alternatively, the intensity of the pedal misapplication warning may be changed by altering the magnitude of the vibration or pedal reaction force applied to the accelerator pedal 10 by the pedal actuator 22. Furthermore, the alarm generation unit 32 may change the intensity of the pedal misapplication warning by changing the type of stimulus output as the pedal misapplication warning. For example, the alarm generation unit 32 may change the intensity of the pedal misapplication warning by changing the type of stimulus output as the pedal misapplication warning between at least two of visual stimuli, auditory stimuli, and tactile stimuli.

[0031] For example, the alarm generation unit 32 may output a visual message or light up a warning lamp as a relatively weak pedal misapplication alarm, generate vibrations or pedal reaction force on the accelerator pedal 10 as a tactile stimulus as a relatively strong pedal misapplication alarm, or output an auditory message or alarm sound as an auditory stimulus as an intermediate level of pedal misapplication alarm.

[0032] For example, the alarm generation unit 32 may output a stronger pedal misapplication warning when the accelerator off time Tc is short than when it is long. For example, the shorter the accelerator off time Tc, the stronger the pedal misapplication warning may be output. For example, the shorter the accelerator off time Tc, the stronger the pedal misapplication warning may be output. Furthermore, for example, the alarm generation unit 32 may output a stronger pedal misapplication warning when the operating speed of the accelerator pedal 10 depressing operation, which started from the end of the accelerator-off time t2, is high compared to when it is low. For example, the higher the operating speed, the stronger the pedal misapplication warning may be output.

[0033] Alternatively, for example, the acceleration intention determination unit 30 may variably control a predetermined time T1, which is a threshold for determining whether or not the accelerator is released instantaneously. For example, a predetermined time T1 may be set according to the frequency with which it is determined that the driver's intention to accelerate is unclear (i.e., the frequency with which it is determined that the accelerator pedal 10 was pressed again after a momentary release of the accelerator). For example, the predetermined time T1 may be shortened when the frequency is high compared to when it is low. For example, the acceleration intention determination unit 30 may set the length of the predetermined time T1 shorter when the frequency is above a threshold compared to when the frequency is below a threshold.

[0034] As a result, if the frequency with which the system determines that the driver's intention to accelerate is unclear is high, the predetermined time T1 is set shorter, making it less likely that the system will determine that the driver's intention to accelerate is unclear. Consequently, the system is less likely to issue a pedal misapplication warning. As a result, it is possible to suppress the likelihood of pedal misapplication warnings being issued in cases where the driver frequently presses and releases the accelerator pedal 10 to adjust speed, or when driving in traffic jams. Alternatively, pedal misapplication warnings may be suppressed by switches or other controls also received by the HMI 21.

[0035] For example, the acceleration intention determination unit 30 may count the number of times it is determined that the driver's intention to accelerate is unclear (i.e., the number of times it is determined that the driver has changed from a momentary release of the accelerator to pressing the accelerator pedal 10 again). Furthermore, if the number of times it is determined that the driver's intention to accelerate is unclear during the period between the present time and a predetermined time 1 hour prior to the present time is equal to or greater than a threshold, the predetermined time T1 may be shortened. For example, the predetermined time T1 may be shortened to a time shorter than the initial value (fixed value). On the other hand, if the number of times it is determined that the driver's intention to accelerate is unclear during the period between the present time and a predetermined second time prior to the present time is less than a threshold, the predetermined time T1 may be extended. For example, the predetermined time T1 may be extended to an initial value (fixed value). The second time may be the same length as the first time, or it may be different from the first time (for example, the second time may be longer or shorter than the first time), thereby introducing a hysteresis characteristic between the conditions for shortening and extending the predetermined time T1.

[0036] For example, the acceleration intention determination unit 30 counts the number of times it is determined that the driver's intention to accelerate is unclear at any given timing or period, measures the driving time of the vehicle 1, and calculates the frequency of the driver's intention to accelerate being unclear by dividing the number of times it is determined that the driver's intention to accelerate is unclear by the driving time. If the calculated frequency is high, the predetermined time T1 may be shortened compared to when it is low.

[0037] Next, the operation of the accelerator pedal operation warning device of the first embodiment will be explained. Figure 3(a) is a schematic diagram of the warning timing of the conventional technology when pedal misapplication occurs, and Figure 3(b) is a schematic diagram of the operation of the accelerator pedal operation warning device of the first embodiment. As shown in Figure 3(a), the conventional technology outputs a warning at point tx when the accelerator pedal depression opening exceeds a predetermined opening A1. However, at this point, the vehicle speed has already increased, so the driver may panic due to the unintended acceleration and be unable to take their foot off the accelerator pedal 10. In addition, a warning may be mistakenly output when the accelerator pedal 10 is pressed hard on an uphill slope, etc.

[0038] In contrast, the accelerator pedal operation warning device of the embodiment, as shown in Figure 3(b), outputs a pedal misapplication warning (time t3) when the accelerator pedal 10 is pressed again after a short accelerator off time Tc≦T1.

[0039] Pedal misapplication is more likely to occur in a state of urgency. In such situations, attention resources are limited, and even though the pedal next to the foot is the accelerator pedal 10, one may mistakenly press the brake pedal 12. This is one of the causes of pedal misapplication, and it is more likely to occur in elderly people who have limited attention resources. Therefore, if the driver momentarily takes their foot off the accelerator pedal 10 and then attempts to press it again, the system assumes that the driver is hastily trying to switch from the accelerator pedal 10 to the brake pedal 12 and outputs a pedal misapplication warning. This allows the driver to realize their mistake before pressing the accelerator pedal 10 too hard and to switch to the brake pedal 12.

[0040] (operation) Figure 4 is a flowchart of an example of an accelerator pedal operation warning method according to the first embodiment. In step S1, the acceleration intention determination unit 30 determines whether the accelerator pedal 10 is pressed or not. If the accelerator pedal 10 is pressed (step S1:Y), the process proceeds to step S2. If the accelerator pedal 10 is not pressed (step S1:N), the process returns to step S1. In step S2, the acceleration intention determination unit 30 determines whether the accelerator pedal 10 is in the accelerator-off state. If the accelerator pedal 10 is in the accelerator-off state (step S2:Y), the process proceeds to step S3. If the accelerator pedal 10 is not in the accelerator-off state (step S2:N), the process returns to step S1.

[0041] In step S3, the acceleration intention determination unit 30 determines whether the vehicle speed V is less than or equal to a predetermined speed Vth. If the vehicle speed V is less than or equal to the predetermined speed Vth (step S3:Y), the process proceeds to step S4. If the vehicle speed V is not less than or equal to the predetermined speed Vth (step S3:N), the process returns to step S1. In step S4, the acceleration intention determination unit 30 causes the timer 31 to start timing the accelerator off time Tc. In step S5, it is determined whether the accelerator pedal 10 is depressed or not (whether the accelerator has been released or not). If the accelerator pedal 10 is depressed (step S5:Y), the process proceeds to step S6. If the accelerator pedal 10 is not depressed (step S5:N), the process proceeds to step S9.

[0042] In step S6, the acceleration intention determination unit 30 determines whether the accelerator off time Tc is less than or equal to a predetermined time T1. If the accelerator off time Tc is less than or equal to the predetermined time T1 (step S6:Y), the acceleration intention determination unit 30 determines that it is unclear whether the accelerator pedal 10 depressing operation detected in step S5 was an operation performed with the driver's intention to accelerate. Then, the process proceeds to step S7. If the accelerator-off time Tc is not less than or equal to a predetermined time T1 (step S6:N), the acceleration intention determination unit 30 determines that the accelerator pedal 10 depressing operation detected in step S5 is an operation performed by the driver with an intention to accelerate. Then, the process proceeds to step S8.

[0043] In step S7, the alarm generation unit 32 outputs a pedal misapplication warning to the driver. The process then proceeds to step S8. In step S8, the acceleration intention determination unit 30 stops the timer 31 from timing the accelerator off time Tc. The process then ends. If it is determined in step S5 that the accelerator pedal 10 is not pressed (step S5:N), then in step S9 the acceleration intention determination unit 30 determines whether or not the brake pedal 12 is pressed. If the brake pedal 12 is pressed (step S9:Y), the process proceeds to step S8. If the brake pedal 12 is not pressed (step S9:N), the process returns to step S5.

[0044] (Second Embodiment) In the second embodiment, the controller 23 determines that the driver's intention to accelerate is unclear when the accelerator pedal 10 is pressed again after a momentary release of the accelerator, and suppresses the acceleration of the vehicle based on the pressing operation of the accelerator pedal 10. As a result, the controller detects accelerator operation where the driver's intention to accelerate is unclear at an early stage and suppresses the acceleration of the vehicle 1, allowing the driver to recover from mistakenly pressing the accelerator pedal 10 instead of the brake pedal 12 before pressing the accelerator pedal 10 too hard. Figure 5 is a block diagram of an example of the functional configuration of the controller 23 of the second embodiment. The controller 23 of the second embodiment has a configuration similar to that of the controller 23 of the first embodiment, and identical or similar components are indicated by the same reference numerals. The controller 23 includes an acceleration suppression unit 33.

[0045] The acceleration suppression unit 33 prevents sudden starts and rapid acceleration of the vehicle 1 by suppressing the acceleration of the vehicle 1 caused by the pressing of the accelerator pedal 10, which started from the end of the accelerator-off period t2, when the accelerator pedal 10 is pressed again after a momentary release of the accelerator. In addition, when the accelerator pedal 10 is pressed again after a momentary release of the accelerator, the control that suppresses the acceleration of the vehicle 1 caused by the pressing of the accelerator pedal 10, which started from the end of the release of the accelerator t2, may be referred to as "acceleration suppression control" in the following explanation.

[0046] For example, the acceleration suppression unit 33 may output an acceleration prohibition signal to the braking force controller 14 that reduces or sets to "0" the driving torque generated by the driving force source 16. When the acceleration prohibition signal is received, the braking force controller 14 may reduce the driving torque command value output to the power controller 15 to a value smaller than the driving torque command value determined based on the accelerator stroke amount, or set it to "0".

[0047] Alternatively, the acceleration suppression unit 33 may output an automatic deceleration signal to the braking force controller 14 that generates or increases braking torque in the braking device 18. Upon receiving the automatic deceleration signal, the braking force controller 14 sets the friction braking torque command value output to the brake controller 17 and the regenerative braking torque command value output to the power controller 15 to a value greater than 0, or increases them to a value greater than the friction braking torque command value determined based on the brake stroke amount and the regenerative braking torque command value determined based on the accelerator stroke amount. Furthermore, the acceleration suppression unit 33 may be configured so that the implementation of acceleration suppression control can be suppressed by an operator such as a switch received by the HMI21.

[0048] Conversely, if the acceleration suppression unit 33 determines that the driver has an intention to accelerate, it does not perform the acceleration suppression control described above. In this case, the braking force controller 14 performs acceleration control based on the accelerator pedal depression operation. For example, the braking force controller 14 performs control to accelerate the vehicle 1 with a driving torque determined based on the accelerator stroke amount. If the driver changes from pressing the brake pedal 12 to pressing the accelerator pedal 10, the driver's intention to accelerate can be inferred. Therefore, in this case, acceleration suppression control does not need to be implemented. For example, if the driver changes from pressing the brake pedal 12 to pressing the accelerator pedal 10 while the accelerator is released, acceleration suppression control does not need to be implemented.

[0049] Furthermore, the acceleration suppression unit 33 performs acceleration suppression control when the vehicle speed V is less than or equal to a predetermined speed Vth after the accelerator pedal 10 is pressed again following a momentary release of the accelerator. However, if the vehicle speed V is higher than the predetermined speed Vth even after the accelerator pedal 10 is pressed again following a momentary release of the accelerator, acceleration suppression control does not need to be performed.

[0050] The timing t4 at which the acceleration suppression unit 33 starts acceleration suppression control when it is determined that the driver's intention to accelerate is unclear may be variably controlled. In other words, the time interval Δt2 from the end of accelerator off time t2 to the time t4 at which the acceleration suppression unit 33 starts acceleration suppression control may be variably controlled. For example, acceleration suppression control may be started earlier when the accelerator-off time Tc is short than when it is long (i.e., the time interval Δt2 may be shorter when the accelerator-off time Tc is short than when it is long). For example, the shorter the accelerator-off time Tc, the earlier acceleration suppression control may be started (i.e., the shorter the accelerator-off time Tc, the shorter the time interval Δt2 may be).

[0051] For example, if it is determined that the driver's intention to accelerate is unclear, acceleration suppression control may be initiated earlier when the operating speed of the accelerator pedal 10, which was started from the end of the accelerator-off time t2, is high compared to when it is low (i.e., the time interval Δt2 may be shorter when the operating speed is high compared to when it is low). For example, the higher the operating speed, the earlier acceleration suppression control can be started (i.e., the higher the operating speed, the shorter the time interval Δt2 can be).

[0052] Figure 6 is a schematic diagram of the operation of the accelerator pedal operation warning device of the second embodiment. In the accelerator pedal operation warning device of the second embodiment, acceleration suppression control is started when the accelerator pedal 10 is pressed again after a short accelerator off time Tc ≤ T1 (time t4). Pedal misapplication is most likely to occur in a state of urgency. In a state of urgency, attention resources are insufficient, and even though the pedal next to the foot is the accelerator pedal 10, the driver may mistakenly press it thinking it is the brake pedal 12. This is one of the causes of pedal misapplication and is more likely to occur in elderly people who have fewer attention resources. Therefore, if a situation occurs where the driver briefly takes their foot off the accelerator pedal 10 and then tries to press it again, the system assumes that the driver is hastily trying to switch from the accelerator pedal 10 to the brake pedal 12, and suppresses the acceleration of the vehicle based on the pressing operation of the accelerator pedal 10.

[0053] Figure 7 is a flowchart of an example of an accelerator pedal operation warning method according to the second embodiment. The processes in steps S11-S16, S19, and S20 are the same as those in steps S1-6, S8, and S9 in Figure 4. If the accelerator-off time Tc in step S16 is less than or equal to the predetermined time T1 (step S16:Y), the process proceeds to step S17. If the accelerator-off time Tc is not less than or equal to the predetermined time T1 (step S16:N), the process proceeds to step S18. In step S17, the acceleration suppression unit 33 performs acceleration suppression control. The process then proceeds to step S19. In step S18, the braking force controller 14 performs acceleration control based on the accelerator pedal depression operation. The process then proceeds to step S19.

[0054] Furthermore, the first and second embodiments may be combined. That is, if the acceleration intention determination unit 30 determines that the accelerator pedal 10 has been pressed again after a momentary release of the accelerator, the alarm generation unit 32 may output a pedal misapplication alarm, and the acceleration suppression unit 33 may perform acceleration suppression control.

[0055] (Effects of the embodiment) (1) The controller 23 determines whether the accelerator pedal 10 has changed from a pressed state to a pressed state after a momentary release of the accelerator. If the accelerator pedal 10 has changed to a pressed state after a momentary release of the accelerator, the controller 23 executes a process to output a pedal misapplication warning to the driver. Alternatively, if the accelerator pedal 10 has changed to a pressed state after a momentary release of the accelerator, the controller 23 executes a process to suppress the acceleration of the vehicle based on the pressing operation of the accelerator pedal 10. This allows the system to detect accelerator operation early, even if the driver's intention to accelerate is unclear, and to either issue a pedal misapplication warning to the driver or suppress the acceleration of vehicle 1 before vehicle 1 suddenly accelerates. As a result, the driver can recover from mistakenly pressing the accelerator pedal 10 instead of the brake pedal 12 before pressing the accelerator pedal 10 too hard. If it is determined that the accelerator pedal 10 has been pressed again after a momentary release of the accelerator, both a process to output a warning to the driver and a process to suppress the acceleration of the vehicle based on the accelerator pedal operation may be executed.

[0056] (2) The controller 23 may measure the length of the instantaneous accelerator-off period using the timer 31. This makes it possible to determine whether pressing the accelerator pedal 10 after releasing the accelerator is an operation intended to accelerate. (3) When the brake pedal 12 is pressed while the accelerator is off, the controller 23 does not need to perform a process to output a pedal misapplication warning or a process to suppress the vehicle's acceleration based on the pressing of the accelerator pedal 10. This prevents the controller from mistakenly outputting a pedal misapplication warning or suppressing acceleration.

[0057] (4) The controller 23 does not need to output a pedal misapplication warning or suppress the acceleration of the vehicle 1 based on the operation of pressing the accelerator pedal 10 if the accelerator pedal 10 is pressed again after a momentary release of the accelerator. This prevents the controller from mistakenly outputting a pedal misapplication warning or suppressing acceleration. (5) The controller 23 may output an earlier pedal misapplication warning or a stronger pedal misapplication warning when the period of momentary accelerator off is shorter than when it is longer. Furthermore, the controller 23 may suppress the acceleration of the vehicle 1 based on the pressing operation of the accelerator pedal 10 at an earlier point when the instantaneous period of accelerator off is shorter than when it is longer. This allows for the early activation of pedal misapplication warnings and acceleration suppression control in situations of high urgency, and enables the output of stronger pedal misapplication warnings.

[0058] (6) The controller 23 may output an earlier mis-pedal warning or a stronger mis-pedal warning when the operating speed at which the accelerator pedal 10 is pressed again after a momentary release of the accelerator is higher than when it is lower. The controller 23 may suppress the acceleration of the vehicle 1 based on the pressing operation of the accelerator pedal 10 when the operating speed at which the accelerator pedal 10 is pressed again after a momentary release of the accelerator is higher than when it is lower. This allows for the early activation of pedal misapplication warnings and acceleration suppression control in situations of high urgency, and enables the output of stronger pedal misapplication warnings.

[0059] (7) The controller 23 may determine that the accelerator pedal has been pressed again after a momentary accelerator-off if the accelerator-off time Tc from the start time t1 to the end time t2 is within a predetermined time T1. A shorter predetermined time T1 may be set if the time frequency in which it is determined that the accelerator pedal has been pressed again after a momentary accelerator-off is higher than the time frequency in which it is determined to be pressed again is lower. This makes it possible to suppress the likelihood of pedal misapplication warnings being issued or acceleration suppression control being implemented in cases where the driver frequently presses and releases the accelerator pedal 10 to adjust speed, or when driving in traffic jams.

[0060] All examples and conditional terms set forth herein are intended for educational purposes to help the reader understand the concepts given by the inventors for the advancement of the invention and the art, and should be interpreted without limitation to the examples and conditions specifically described herein, as well as the configuration of examples relating to demonstrating the superiority and inferiority of the invention. Although embodiments of the invention are described in detail, it should be understood that various changes, substitutions, and modifications are possible without departing from the spirit and scope of the invention. [Explanation of symbols]

[0061] 1...Vehicle, 10...Accelerator pedal, 11...Accelerator sensor, 12...Brake pedal, 13...Brake sensor, 14...Brake / driving force controller, 15...Power controller, 16...Drive source, 17...Brake controller, 18...Braking device, 20...Vehicle speed sensor, 21...Human-machine interface (HMI), 22...Pedal actuator, 23...Controller, 23a...Processor, 23b...Storage device, 30...Acceleration intention determination unit, 31...Timer, 32...Warning generation unit, 33...Acceleration suppression unit

Claims

1. A driver assistance method that performs warning output processing to output a warning to the driver, The controller The system determines whether the state changes from pressing the accelerator pedal to momentarily releasing the accelerator, and whether the state changes back to pressing the accelerator pedal after the momentary release. If it is determined that the accelerator pedal has been pressed again after the aforementioned momentary release of the accelerator, the alarm output process is executed. A driving assistance method characterized in that, in the alarm output processing, the shorter the period of instantaneous accelerator off, the shorter the time elapsed from the end of the instantaneous accelerator off, and the shorter the time elapsed from the end of the instantaneous accelerator off, or the stronger the alarm, is output.

2. A driving assistance method that performs acceleration suppression processing to suppress the acceleration of a vehicle based on the operation of pressing the accelerator pedal, The controller The system determines whether the state changes from pressing the accelerator pedal to momentarily releasing the accelerator, and whether the state changes back to pressing the accelerator pedal after the momentarily releasing the accelerator. If it is determined that the accelerator pedal has been pressed again after the aforementioned momentary release of the accelerator, the acceleration suppression process is executed. A driving assistance method characterized in that, in the acceleration suppression process, the shorter the period of instantaneous accelerator off, the shorter the time elapsed from the end of the instantaneous accelerator off when the acceleration of the vehicle based on the accelerator pedal depression operation is suppressed.

3. The driving assistance method according to claim 2, characterized in that when it is determined that the accelerator pedal has been pressed again after the momentary release of the accelerator, both the acceleration suppression process and the warning output process, which outputs a warning to the driver, are performed.

4. The driving assistance method according to claim 1 or 2, characterized in that the length of the instantaneous period of accelerator off is measured by a timer.

5. The driving assistance method according to Claim 1, characterized in that the state changes to pressing the accelerator pedal again after the momentary accelerator off, and the brake pedal is not pressed during the time the accelerator is off, and the alarm output processing is executed.

6. The driving assistance method according to claim 2, characterized in that the accelerator pedal is pressed again after the momentary accelerator off state, and the brake pedal is not pressed during the accelerator off state, and the acceleration suppression process is executed.

7. The driving assistance method according to claim 1, characterized in that the state changes to pressing the accelerator pedal again after the momentary release of the accelerator pedal, and the vehicle speed is 20 km / h or less, and the warning output processing is executed.

8. The driving assistance method according to claim 2, characterized in that the accelerator pedal is pressed again after the momentary release of the accelerator, and the acceleration suppression process is performed when the vehicle speed is 20 km / h or less.

9. The driving assistance method according to claim 1, characterized in that the faster the speed at which the accelerator pedal is pressed again after the momentary release of the accelerator, the earlier the warning is output or the stronger the warning is output.

10. The driving assistance method according to claim 2, characterized in that the faster the speed at which the accelerator pedal is pressed again after the momentary release of the accelerator, the earlier the acceleration of the vehicle based on the pressing operation of the accelerator pedal is suppressed.

11. If the period from the start to the end of the accelerator off is within a predetermined time, it is determined that the accelerator pedal was pressed again after the momentary accelerator off. The driving assistance method according to claim 1 or 2, characterized in that when the time frequency at which it is determined that the accelerator pedal has been pressed again after the momentary release of the accelerator pedal is greater than or equal to a threshold, the predetermined time is set to be shorter than when the time frequency is less than the threshold.

12. A driver assistance device that performs warning output processing to output a warning to the driver, A sensor that detects the operation of the accelerator pedal, A controller that determines whether the state changes from pressing the accelerator pedal to momentarily releasing the accelerator, and whether the state changes back to pressing the accelerator pedal after the momentary release, and if it is determined that the state changes back to pressing the accelerator pedal after the momentary release, executes the alarm output process, A driving assistance device comprising the controller, wherein in the alarm output processing, the shorter the period of instantaneous accelerator off, the shorter the time elapsed from the end of the instantaneous accelerator off, and the shorter the alarm output time from the end of the instantaneous accelerator off, or the stronger the alarm output.

13. The driving assistance method according to claim 1 or 2, characterized in that the aforementioned accelerator off is the operation in which the driver takes their foot off the accelerator pedal.

14. The driving assistance device according to claim 12, characterized in that the aforementioned accelerator off is the operation in which the driver takes their foot off the accelerator pedal.

15. A driver assistance device that performs acceleration suppression processing to suppress the acceleration of a vehicle based on the operation of pressing the accelerator pedal, A sensor that detects the operation of the accelerator pedal, A controller that determines whether the state changes from pressing the accelerator pedal to momentarily releasing the accelerator, and whether the state changes back to pressing the accelerator pedal after the momentary release, and if it is determined that the state changes back to pressing the accelerator pedal after the momentary release, executes the acceleration suppression process. A driver assistance device comprising the controller, wherein in the acceleration suppression process, the shorter the period of instantaneous accelerator off, the shorter the time elapsed from the end of the instantaneous accelerator off, thereby suppressing the acceleration of the vehicle based on the accelerator pedal depression operation.

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