Accelerator Pedal System

Abstract

To provide an accelerator pedal system that can properly release a lock state of a pedal.SOLUTION: A control part 60 of an accelerator pedal system 1 has an operation detecting part 61, a characteristics learning part 62 and an actuator control part 65. The operation detecting part 61 detects operation of pedal by a driver. The characteristic learning part 62 learns tread-force characteristics from the operation of the pedal by the driver. The actuator control part 65 controls driving of the actuator 40. The actuator control part 65 controls the driving of the actuator 40 so that a lock state of a pedal lever 20 is released, when it is determined that the driver actively steps on a pedal lever 20 on the basis of tread force F applied in a locked state of the pedal lever 20 and jerk dF that is a temporal differential value of the tread force. Determination thresholds Fth and dFth concerning the tread force F and jerk dF that are used in determining whether the locked state is released are set in accordance with the learnt tread force characteristics.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to an accelerator pedal system.

Background Art

[0002] Conventionally, it is known to use an accelerator pedal as a footrest during constant-speed driving. For example, in Patent Document 1, by turning a solenoid on and off, a holding pin is slid to hold the accelerator pedal at the footrest position or release the hold.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In Patent Document 1, when using the accelerator pedal as a footrest, when the driver wants to operate the accelerator pedal according to their intention, it is possible to perform an acceleration operation by stepping on the accelerator pedal strongly and quickly, or stepping on the accelerator pedal multiple times. However, Patent Document 1 does not consider variations due to individual differences in stepping force or the influence of disturbances.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide an accelerator pedal system capable of appropriately releasing the locked state of the pedal.

Means for Solving the Problems

[0006] The accelerator pedal system of the present invention includes a pedal lever (20), a lock mechanism (50), an actuator (40), and a control unit (60). The pedal lever operates in response to a depression operation. The lock mechanism can restrict the operation of the pedal lever. The actuator switches between a locked state in which the operation of the pedal lever is restricted by the lock mechanism and an unlocked state in which the operation is not restricted.

[0007] The control unit has an operation detection unit (61), a characteristic learning unit (62), and an actuator control unit (65). The operation detection unit detects a pedal operation by the driver. The characteristic learning unit learns the stepping force characteristics from the driver's pedal operation. The actuator control unit controls the driving of the actuator.

[0008] When it is determined that the driver has actively depressed the pedal lever based on the stepping force applied in the state where the pedal lever is locked and the time differential value of the stepping force, the actuator control unit controls the driving of the actuator to release the locked state of the pedal lever. The determination threshold values related to the stepping force and the time differential value of the stepping force used for the unlocking determination are set according to the learned stepping force characteristics. Thereby, the locked state of the pedal lever can be appropriately released.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Mode for Carrying Out the Invention

[0010] (First Embodiment) Hereinafter, an accelerator pedal system according to the present invention will be described with reference to the drawings. Hereinafter, in a plurality of embodiments, substantially the same configurations are denoted by the same reference numerals and description thereof is omitted. The first embodiment is shown in FIGS. 1 to 8. As shown in FIG. 1, the accelerator pedal system 1 includes a pedal lever 20, an actuator 40, a lock mechanism 50, a control unit 60, and the like.

[0011] The pedal lever 20 has a pad 21, an arm 31, and a pedal 35, and is integrally driven by a driver's stepping operation or the like. The pad 21 is provided so as to be operable to be stepped on by the driver. The pad 21 is rotatably supported by a fulcrum member 23 provided in the housing H. In FIG. 1, a so-called floor-mounted type (organ type) in which the pad 21 extends along one surface of the housing H is shown, but a suspended type (pendent type) may also be used. In the present embodiment, a housing portion that is not driven by driving of the actuator 40, such as a pedal housing or a motor housing, and stepping operation of the pedal lever 20 is collectively referred to as "housing H".

[0012] The arm 31 connects the pad 21 and the pedal 35. One end of the pedal 35 is rotatably supported by the housing H, and the other end is connected to the arm 31. Thus, when the driver operates the pad 21, the pad 21, the arm 31, and the pedal 35 are driven integrally. A pedal sensor 39 for detecting the pedal opening θ is provided on one end side of the pedal 35.

[0013] The pedal biasing member 37 is a compression coil spring. One end is fixed to the pedal 35, and the other end is fixed to the housing H, biasing the pedal 35 in the accelerator closing direction. In FIGS. 1 and 2, the position of the pedal 35 at full throttle is shown by a broken line.

[0014] The actuator 40 is composed of a motor, a speed reduction mechanism, a power transmission member 45, etc., and its driving is controlled by the control unit 60. One end of the power transmission member 45 is connected to a gear constituting the speed reduction mechanism, and the other end abuts on the pedal lever 20. Thus, the driving force of the motor as the driving source is transmitted to the pedal lever 20 via the speed reduction mechanism and the power transmission member 45. In FIG. 1, the other end of the power transmission member 45 abuts on the pad 21, but it may be configured to abut on the arm 31 or the pedal 35.

[0015] A position sensor 49 for detecting the rotational position is provided on the actuator 40. Hereinafter, the rotational direction when the actuator 40 is rotated counterclockwise in the paper plane is defined as positive, and the rotational direction when it is rotated clockwise is defined as negative. By rotating the actuator 40 in the positive direction in a state where the power transmission member 45 and the pedal lever 20 are in contact, a reaction force in the return direction can be applied to the pedal lever 20.

[0016] By actively applying a reaction force in the return direction to the pedal lever 20 by the actuator 40, for example, based on the driving situation, a reaction force is applied at the fuel consumption deterioration point to create a wall feeling and suppress the driver from stepping on the pad 21. As a result, the fuel consumption can be improved. Also, for example, by applying a pulsed reaction force to the pedal lever 20, it can be utilized for information transmission such as a switching notification from automatic driving to manual driving.

[0017] The locking mechanism 50 includes a locking member 51, a locked portion 52, an elastic member 55, etc. The locking member 51 is provided so as to be able to contact the locked portion 52 with a tapered surface formed on one end side. The other end side of the locking member 51 is housed in a housing chamber 56 formed in the housing H and is provided so as to be reciprocally movable in the axial direction. The locked portion 52 is provided on a member (for example, a gear) constituting the actuator 40. The locked portion 52 is formed so as to be able to contact the locking member 51 with a tapered surface.

[0018] The elastic member 55 is housed in a housing chamber 56 provided in the housing H. One end of the elastic member 55 contacts the locking member 51, and the other end is locked to the housing H, biasing the locking member 51 toward the locked portion 52.

[0019] FIG. 1 shows the start state of the locking process. When the actuator 40 is rotated in the positive direction with the locked portion 52 and the locking member 51 in contact, the elastic member 55 is compressed by the locked portion 52 pushing the locking member 51 in.

[0020] As shown in Fig. 2, when the actuator 40 is further rotated in the positive direction and the locked portion 52 overrides the locking member 51 and turns into the upper side of the paper surface, the locking member 51 returns to the initial position due to the biasing force of the elastic member 55. In the locked state, the rotation of the actuator 40 is restricted by the locking member 51 locking the locked portion 52 due to the biasing force of the elastic member 55. Further, since the power transmission member 45 functions as a lock transmission portion, the operation of the pedal lever 20 is restricted. Thereby, the operation of the pedal lever 20 can be restricted in a non-energized state where the power supply to the actuator 40 is turned off.

[0021] Hereinafter, restricting the operation of the pedal lever 20 is simply referred to as "locking". For example, during automatic driving or the like, by locking the pedal lever 20 and converting the pad 21 into a footrest, comfort can be ensured. In the present embodiment, the pedal lever 20 will be described as being locked at the fully closed position.

[0022] When the actuator 40 is rotated in the negative direction from the locked state shown in Fig. 2, the elastic member 55 is compressed by the locked portion 52 pushing the locking member 51. When the locked portion 52 overrides the locking member 51 and turns into the lower side of the paper surface, the locked state is released, and the locking member 51 returns to the initial position due to the biasing force of the elastic member 55. Similarly, the locked state can be released when a pedal force equal to or greater than a predetermined value is applied to the pedal lever 20. Note that in Fig. 2, the description of the control unit 60 and the like is omitted.

[0023] When the pedal lever 20 is not locked, it is desirable to retract the locking member 51 and the locked portion 52 so that they do not come into contact by rotating the actuator 40 counterclockwise from the state shown in Fig. 1.

[0024] The control unit 60 is mainly composed of a microcomputer or the like, and internally includes a CPU, a ROM, a RAM, an I / O, and bus lines for connecting these components, which are not shown in the figure. Each process in the control unit 60 may be software processing by executing a program pre-stored in a physical memory device such as a ROM (i.e., a readable non-transitory tangible recording medium) by the CPU, or may be hardware processing by a dedicated electronic circuit.

[0025] The control unit 60 includes, as functional blocks, an operation detection unit 61, a characteristic learning unit 62, a disturbance determination unit 63, an actuator control unit 65, and the like. The operation detection unit 61 detects the pedal opening θ and the pedaling force applied to the pedal lever 20 based on the detection value of the pedal sensor 39. Also, information regarding the pedaling force applied to the brake pedal 75 is acquired from the brake ECU 70. The characteristic learning unit 62 learns the driver's pedaling force characteristics based on the pedaling force applied to the pedal lever 20 or the brake pedal 75. Details of the learning of the pedaling force characteristics will be described later.

[0026] As shown in FIG. 3, the disturbance determination unit 63 determines a disturbance that causes a change in the pedaling force based on various sensor information, pedaling force information, and the like. Specifically, the vibration determination unit 631 performs a vibration determination based on information from an up-down G sensor, a suspension behavior detection device, and the like, such as when crossing a road surface step. Also, when it is estimated that there is a road surface step at the current position of the vehicle based on the map data in which the road surface state is stored and the current position information of the vehicle such as GPS, the vehicle vibration may be regarded as existing.

[0027] The deceleration determination unit 632 performs deceleration determination based on information from a vehicle speed sensor, a vehicle G sensor, etc. The turning determination unit 633 performs turning determination of the vehicle based on information from left and right G sensors, a steering sensor, a gyro sensor, etc. The repositioning determination unit 634 determines whether the driver has repositioned their foot on the pedal 21 based on information from a footwell camera, a seat surface pressure sensor, etc. The disturbance determination unit 63 determines that there is a disturbance and maintains the pedal lock state when vehicle vibration, deceleration or turning of the vehicle, or repositioning of the foot is detected. Note that determination may be made using information from sensors, communication, etc. other than those illustrated in FIG. 3. Disturbance determination based on stepping force information will be described later.

[0028] The actuator control unit 65 controls the driving of the actuator 40 to control the application of a reaction force to the pedal lever 20 and the switching of the locked state of the pedal lever 20.

[0029] The lock release process of this embodiment will be described based on the flowchart of FIG. 4. This process is a process executed by the control unit 60 at a predetermined cycle. Hereinafter, the "step" such as step S101 is omitted and simply denoted by the symbol "S".

[0030] In S101, the characteristic learning unit 62 performs individual difference learning processing related to the stepping force characteristics, and sets a stepping force determination threshold value Fth and a jerk determination threshold value dFth which is the time differential value of the stepping force value. If the stepping force determination threshold value Fth and the jerk determination threshold value dFth have been set, this step may be skipped. Note that when the shift range is switched to the P range, since the driver may be replaced in the next driving, re-learning is performed.

[0031] In S102, the control unit 60 determines whether or not the vehicle is running with the pedal lever 20 locked (hereinafter referred to as the pedal lock running state). If it is determined that the vehicle is not in the pedal lock running state (S102: NO), the processing after S103 is skipped. If it is determined that the vehicle is in the pedal lock running state (S102: YES), the process proceeds to S103.

[0032] In S103, the control unit 60 determines whether the depression force F applied to the pedal lever 20 is greater than the learned depression force determination threshold value Fth. When it is determined that the depression force F is less than or equal to the depression force determination threshold value Fth (S103: NO), the pedal lock state is continued. When it is determined that the depression force F is greater than the depression force determination threshold value Fth (S103: YES), the process proceeds to S104.

[0033] In S104, the control unit 60 determines whether a state where the jerk dF, which is the time differential value of the depression force F applied to the pedal lever 20, is greater than the learned jerk determination threshold value dFth has continued for the determination time Xs. When it is determined that the jerk dF is less than or equal to the jerk determination threshold value dFth, or the duration of the state where the jerk dF is greater than the jerk determination threshold value dFth has not reached the determination time Xs (S104: NO), the pedal lock state is continued. When it is determined that the state where the jerk dF is greater than the jerk determination threshold value dFth has continued for the determination time Xs (S104: YES), the process proceeds to S105. Note that the determination processes in S103 and S104 can be regarded as determining whether the driver's way of stepping is intentional.

[0034] In S105, the disturbance determination unit 63 determines whether there is a disturbance related to the change in the depression force. When it is determined that there is a disturbance (S105: YES), the pedal lock state is continued. When it is determined that there is no disturbance (S105: NO), the process proceeds to S106. In S106, the actuator control unit 65 releases the lock state of the pedal lever 20 by driving the actuator 40.

[0035] In this embodiment, when a pedaling force equal to or greater than a determination threshold is detected on the pedal lever 20 while the pedal lever 20 is locked and converted into a footrest, the actuator 40 is driven to release the lock of the pedal lever 20. Here, if the threshold value related to the lock release determination is set to a preset value, when the determination threshold value is relatively large and the driver's pedaling force is small, even if the driver actively depresses the pedal lever 20, the determination threshold value is not exceeded, and for example, a separate operation such as depressing the pedal lever twice is required for unlocking, and the locked state cannot be quickly released. On the other hand, if the determination threshold value is relatively small and the driver's pedaling force is large, there is a risk of unintentional unlocking. Therefore, it is desirable that the determination threshold value be set according to the driver's pedaling force.

[0036] Here, the inventors have found that there is a correlation between the jump dF when operating the brake pedal 75 when switching the shift range from the P range, for example, and the jump dF when operating the accelerator pedal when releasing the footrest. Therefore, in this embodiment, the driver's pedaling force characteristics are learned based on the braking force when switching from the P range to a range other than the P range, and the pedaling force determination threshold value Fth and the jump determination threshold value dFth related to the unlocking of the pedal lever 20 are set. Thereby, it is possible to perform individual difference learning before driving. Hereinafter, the case of switching from the P range to the D range after starting the vehicle will be described as an example.

[0037] The pedaling force characteristics will be described with reference to FIG. 5. In FIG. 5, the time axis is the horizontal axis, the pedaling force F [N] is shown in the upper row, and the jump dF [N / s] is shown in the lower row. When the shift operation starts at time x1 and ends at time x3, the pedaling force F increases from time x1, and after time x2, the maximum pedaling force Fmax continues. Also, the period from time x1 to time x2 is set as the learning period, the pedaling force F is differentiated with respect to time, and the jump dF is calculated. The jump dF has a bell shape as shown in the figure. Individual differences appear in the maximum pedaling force Fmax and the maximum jump dFmax.

[0038] In this embodiment, at S101 in FIG. 4, the characteristic learning unit 62 learns the maximum stepping force Fmax and the maximum jerk value dFmax. Further, the characteristic learning unit 62 sets a stepping force determination threshold value Fth based on the maximum stepping force Fmax, and sets a jerk determination threshold value dFth based on the maximum jerk value dFmax.

[0039] The learning process of the stepping force characteristics is shown in FIG. 6. At S201, the control unit 60 determines whether or not a brake depression during a shift operation from the P range to another range (the D range in this example) is detected. If it is determined that no brake depression during the P→D shift operation is detected (S201: NO), the process of S202 is skipped. If it is determined that a brake depression during the P→D shift operation is detected (S201: YES), the process proceeds to S202. At S202, the characteristic learning unit 62 learns the stepping force characteristics.

[0040] When the inventors conducted a sensory evaluation to verify the effect of learning, when it was configured to release the pedal lock when the stepping force F exceeded a fixed threshold value, the most responses were that the unlocking was too heavy. On the other hand, when the determination threshold values Fth and dFth were learned and the unlocking determination was made based on the stepping force F and the jerk dF, the most responses were that it was neither too heavy nor too light, but just right, and an improvement in the sensory function was confirmed.

[0041] By the way, in a state where the pedal lever 20 is locked and converted into a footrest, an unintended stepping force application may be detected due to disturbances such as crossing a step or vehicle deceleration. Therefore, in this embodiment, based on the stepping force F and the jerk dF, it is determined whether or not the driver intends to increase the stepping force.

[0042] The determination of the driver's intentional stepping force increase will be described based on the time chart in FIG. 7. In FIG. 7, the time axis is the horizontal axis, the stepping force F applied to the pedal lever 20 in the footrest state is shown in the upper row, the jerk dF is shown in the lower row, the waveform during the driver's intentional stepping force increase is shown by a solid line, and the waveform during the stepping force application due to disturbance is shown by a dashed-dotted line. Also, let the driver's stepping force value in the footrest state be FR.

[0043] When the pedal lever 20 with a depression intention is depressed, from the start time x10 of the depression to the completion time x13 of the increased depression, the depression force F rises relatively gently, and the jerk dF generally has a bell shape. On the other hand, in the case of disturbance, the depression force F and the jerk dF vibrate, and the jerk dF changes between positive and negative in a relatively short period. Therefore, the state where the jerk dF is greater than the jerk determination threshold dFth does not continue.

[0044] Therefore, in the present embodiment, when the state where the depression force F is greater than the depression force determination threshold Fth and the jerk dF is greater than the jerk determination threshold dFth continues for the determination time Xs, it is determined that the driver has an intention to increase the depression.

[0045] The depression force characteristic distribution according to the situation is shown in FIG. 8. In FIG. 8, the horizontal axis is the jerk dF and the vertical axis is the depression force F, and the disturbance region is indicated by hatching. The data of the depression force applied to the pedal lever 20 when the disturbance is the vehicle deceleration G, the vehicle lateral G due to turning, and the road surface step are distributed in the region where the jerk dF is less than the jerk determination threshold dFth. Also, the data of the depression force applied when the driver repositions the foot on the pedal lever 20 are distributed in the region where the depression force F is less than the depression force determination threshold Fth.

[0046] On the other hand, the data of the depression force applied by the driver's intentional increased depression are distributed in the region where the depression force F is greater than the depression force determination threshold Fth and the jerk dF is greater than the jerk determination threshold dFth. Thereby, based on the depression force F and the jerk dF, it is possible to appropriately discriminate whether it is the driver's intentional increased depression or the depression force application due to disturbance.

[0047] As described above, the accelerator pedal system 1 includes a pedal lever 20, a lock mechanism 50, an actuator 40, and a control unit 60. The pedal lever 20 operates in response to a depression operation. The lock mechanism 50 can restrict the operation of the pedal lever 20. Here, the phrase "can restrict the operation of the pedal lever" is a concept that includes not only making the movement amount zero by completely fixing the pedal lever 20, but also making the movement amount smaller than when it is not locked. The actuator 40 switches between a locked state in which the operation of the pedal lever 20 is restricted by the lock mechanism 50 and an unlocked state in which it is not restricted.

[0048] The control unit 60 includes an operation detection unit 61, a characteristic learning unit 62, and an actuator control unit 65. The operation detection unit 61 detects a pedal operation by the driver. The characteristic learning unit 62 learns the stepping force characteristics from the driver's pedal operation. The actuator control unit 65 controls the driving of the actuator 40.

[0049] When it is determined that the driver has actively depressed the pedal lever 20 based on the stepping force F applied in the state where the pedal lever 20 is locked and the jerk dF which is the time differential value of the stepping force, the actuator control unit 65 controls the driving of the actuator 40 to release the locked state of the pedal lever 20. The determination threshold values Fth and dFth for the stepping force F and the jerk dF used for the unlocking determination are set according to the learned stepping force characteristics.

[0050] By learning the individual differences in the driver's stepping force characteristics and setting the stepping force determination threshold value Fth and the jerk determination threshold value dFth, the locked state of the pedal lever 20 can be appropriately released in accordance with the driver's intention, and the vehicle can be accelerated.

[0051] The characteristic learning unit 62 learns the driver's pedaling force characteristics from the pedal operation of the brake pedal 75 before the start of vehicle travel. In the present embodiment, the pedaling force characteristics are learned from the brake operation during the shift operation from the P range to a range other than the P range. Thereby, it becomes possible to perform unlocking control according to the driver's pedaling force characteristics from the start of travel.

[0052] The control unit 60 includes a disturbance determination unit 63 that determines a disturbance related to the fluctuation of the pedaling force applied to the locked pedal lever 20. When it is determined that there is a disturbance, the control unit 60 maintains the locked state of the pedal lever 20. Thereby, it is possible to prevent unintentional unlocking due to a disturbance.

[0053] The disturbance determination unit 63 determines a disturbance based on the pedaling force applied to the pedal lever 20 and the time differential value of the pedaling force. When vehicle vibration is detected, the disturbance determination unit 63 determines that there is a disturbance. When vehicle deceleration is detected, the disturbance determination unit 63 determines that there is a disturbance. When vehicle turning is detected, the disturbance determination unit 63 determines that there is a disturbance. Further, when the driver's foot repositioning is detected, the disturbance determination unit 63 determines that there is a disturbance. Thereby, it is possible to appropriately determine a disturbance and prevent unintentional unlocking by the driver.

[0054] The locking mechanism 50 can maintain the locked state with the power supply to the actuator 40 turned off. Thereby, even when the pedal lever 20 is locked without power supply, it is possible to perform unlocking according to the driver's intention.

[0055] (Second and Third Embodiments) The second embodiment is shown in FIG. 9, and the third embodiment is shown in FIG. 10. Since the learning process of the pedaling force characteristics in the second to fifth embodiments is different from that in the above embodiment, this point will be mainly described. The learning process of the second embodiment will be described based on the flowchart of FIG. 9.

[0056] In S211, the control unit 60 determines whether or not a brake depression during the ON operation of a vehicle start switch such as an ignition switch (hereinafter, "IG") is detected. If it is determined that the brake depression during the IG ON operation is not detected (S211: NO), the process of S211 is skipped. If it is determined that the brake depression during the IG ON operation is detected (S211: YES), the process proceeds to S212.

[0057] In S212, the characteristic learning unit 62 learns the stepping force characteristics. That is, in the second embodiment, the driver's stepping force characteristics are learned from the brake operation during the start switch operation for switching the vehicle start switch from OFF to ON.

[0058] The learning process of the third embodiment will be described based on the flowchart of FIG. 10. The learning process of the third embodiment is a combination of the first embodiment and the second embodiment. The processes of S221 and S222 are the same as the processes of S211 and S212 in FIG. 9, and the driver's stepping force characteristics are learned from the brake operation during the IG ON operation.

[0059] Also, when a negative determination is made in S221, the process proceeds to S223. The processes of S223 and S224 are the same as S201 and S202 in FIG. 6, and the driver's stepping force characteristics are learned from the brake operation during the shift operation from P to D. Even with this configuration, the driver's stepping force characteristics can be learned before the start of vehicle travel. Also, the same effects as the above-described embodiments are achieved.

[0060] (Fourth Embodiment) The learning process of the fourth embodiment will be described based on the flowchart of FIG. 11. In this embodiment, in response to a stepping force characteristic learning instruction, a lock release operation of the pedal lever 20 is performed before the vehicle travels, and the driver's stepping force characteristics are learned based on the stepping force at the actual lock release operation.

[0061] In S231, the control unit 60 switches to the pedal force characteristic learning mode. In S232, the actuator control unit 65 drives the actuator 40 to lock the pedal lever 20, thereby converting the pedal lever 20 into a footrest.

[0062] In S233, the control unit 60 determines whether the depression of the pedal lever 20 has been detected. If it is determined that the pedal lever 20 has not been depressed (S233: NO), this determination process is repeated. If it is determined that the pedal lever 20 has been depressed (S233: YES), the process proceeds to S234, and the characteristic learning unit 62 learns the pedal force characteristics.

[0063] In the present embodiment, the characteristic learning unit 62 learns the driver's pedal force characteristics from the pedal operation when the lock of the pedal lever 20 is released in response to the pedal force characteristic learning instruction before the start of vehicle travel. Thereby, the determination thresholds Fth and dFth can be set based on the pedal force characteristics learned by the actual unlocking operation. Also, the same effects as those of the above embodiment are achieved.

[0064] (Fifth Embodiment) The learning process of the fifth embodiment will be described based on the flowchart of FIG. 12. In the present embodiment, the pedal force characteristics are sequentially learned based on the pedal force applied to the pedal lever 20 during starting and acceleration while the vehicle is running, and the pedal force applied to the brake pedal 75 during stopping and deceleration.

[0065] In S241, the control unit 60 determines whether the depression of the pedal lever 20 or the brake pedal 75 has been detected. If it is determined that the depression has not been detected (S241: NO), this determination process is repeated. If it is determined that the depression has been detected (S241: YES), the process proceeds to S242, and the characteristic learning unit 62 learns the pedal force characteristics.

[0066] In S243, the control unit 60 determines whether or not the vehicle travel has ended. Note that, for example, a state in which the vehicle is temporarily stopped due to a signal stop or the like is regarded as "traveling". If it is determined that the vehicle is traveling (S243: NO), the process returns to S241. If it is determined that the vehicle travel has ended (S243: YES), this process ends.

[0067] In the present embodiment, the characteristic learning unit 62 learns the driver's stepping force characteristics from at least one of the pedal operations of the pedal lever 20 and the brake pedal during vehicle travel. Thereby, the stepping force characteristics can be sequentially learned during vehicle travel. Further, the same effects as those of the above embodiment are achieved.

[0068] In the embodiment, the jerk dF corresponds to the "time differential value of the stepping force", and the stepping force determination threshold Fth and the jerk determination threshold dFth correspond to the "determination threshold".

[0069] (Other embodiments) In the above embodiment, the locking member 51 is provided on the fixed side and the locked portion 52 is provided on the movable side. In other embodiments, the locking member may be provided on the movable side and the locked portion may be provided on the fixed side. In the above embodiment, the locked portion is constituted by a convex portion. In other embodiments, the locked portion may be constituted by a concave portion.

[0070] In the above embodiment, the locking member is provided so as to be movable in a linear direction along the axial direction of the elastic member which is a compression coil spring. In other embodiments, the locking member may be configured such that the locked state and the unlocked state are switched by the rotation of the locking member. By switching the locked state by the rotation of the locking member, uneven wear of the contact portion can be suppressed. Further, in other embodiments, the elastic member is not limited to a compression coil spring, and may be, for example, a torsion spring. Furthermore, the locking member itself may be formed of an elastic member such as rubber and configured such that the locked state is switched by elastic deformation. In addition, the actuator, the power transmission mechanism, and the locking mechanism may be different from those in the above embodiment. Also, the shapes of the locking member and the unlocking member may be different from those in the above embodiment according to the component arrangement and the like.

[0071] In the above embodiment, the locking mechanism can hold the locked state in a non-energized state where the power supply to the motor is turned off. In other embodiments, the locking mechanism may be configured to hold the locked state by continuously supplying power to the motor.

[0072] In the above embodiment, the pedal lever is locked at the fully closed position by the locking mechanism. In other embodiments, the locking position of the pedal lever may be the fully open position, or may be an intermediate position between the fully closed position and the fully open position. Further, it may be configured to be lockable in multiple stages.

[0073] The features of the present invention may be as follows, for example. "The accelerator pedal system according to any one of claims 1 to 10, wherein the locking mechanism can hold the locked state in a state where the power supply to the actuator is turned off."

[0074] The control unit and its method described in the present disclosure may be realized by a dedicated computer provided by configuring a processor and a memory programmed to execute one or more functions embodied by a computer program. Alternatively, the control unit and its method described in the present disclosure may be realized by a dedicated computer provided by configuring a processor with one or more dedicated hardware logic circuits. Or, the control unit and its method described in the present disclosure may be realized by one or more dedicated computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured by one or more hardware logic circuits. Further, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by a computer. As described above, the present invention is not limited to the above embodiments, and can be implemented in various forms without departing from the spirit of the invention.

Explanation of Reference Numerals

[0075] 1 ··· Accelerator pedal system 20 ··· Pedal lever 40 ··· Actuator 50 ··· Lock mechanism 60 ··· Control unit 61 ··· Operation detection unit 62 ··· Characteristic learning unit 65 ··· Actuator control unit

Claims

1. A pedal lever (20) that operates in response to a stepping operation, a lock mechanism (50) capable of restricting the operation of the pedal lever, an actuator (40) that switches between a locked state in which the operation of the pedal lever is restricted by the lock mechanism and an unlocked state in which it is not restricted, a control unit (60) having an operation detection unit (61) that detects a pedal operation by the driver, a characteristic learning unit (62) that learns a stepping force characteristic from the driver's pedal operation, and an actuator control unit (65) that controls the driving of the actuator, comprising: When it is determined that the driver has actively depressed the pedal lever based on the stepping force applied and the time differential value of the stepping force in a state where the pedal lever is locked, the actuator control unit controls the driving of the actuator to release the locked state of the pedal lever. An accelerator pedal system in which determination threshold values related to the stepping force and the time differential value of the stepping force used for unlocking determination are set according to the learned stepping force characteristics.

2. The accelerator pedal system according to claim 1, wherein the characteristic learning unit learns the driver's stepping force characteristic from a pedal operation of a brake pedal (75) before the start of vehicle travel.

3. The accelerator pedal system according to claim 1, wherein the characteristic learning unit learns the driver's stepping force characteristic from a pedal operation at the time of releasing the lock of the pedal lever, which is performed in response to an instruction for learning the stepping force characteristic before the start of vehicle travel.

4. The accelerator pedal system according to claim 1, wherein the characteristic learning unit learns the driver's stepping force characteristic from a pedal operation of at least one of the pedal lever and the brake pedal (75) during vehicle travel.

5. The control unit has a disturbance determination unit (63) that determines a disturbance related to a variation in the stepping force applied to the pedal lever in the locked state, and when it is determined that there is a disturbance, the accelerator pedal system according to any one of claims 1 to 4 maintains the locked state of the pedal lever.

6. The accelerator pedal system according to claim 5, wherein the disturbance determination unit determines a disturbance based on the stepping force applied to the pedal lever and the time differential value of the stepping force.

7. The accelerator pedal system according to claim 5, wherein the disturbance determination unit determines that there is a disturbance when vehicle vibration is detected.

8. The accelerator pedal system according to claim 5, wherein the disturbance determination unit determines that there is a disturbance when vehicle deceleration is detected. **Claim 9** The accelerator pedal system according to claim 5, wherein the disturbance determination unit determines that there is a disturbance when vehicle turning is detected. **Claim 10** The accelerator pedal system according to claim 5, wherein the disturbance determination unit determines that there is a disturbance when a repositioning of the driver's foot is detected. **Claim 11** The accelerator pedal system according to claim 1, wherein the locking mechanism can maintain the locked state with the power supply to the actuator turned off.

Images