JP5204029B2 - Reaction force device - Google Patents

Description

  The present invention relates to a reaction force device that applies a reaction force to an accelerator pedal or a brake pedal by an actuator.

  There are reaction force devices that assist the driving of a vehicle by applying a reaction force to an accelerator pedal or a brake pedal (Patent Documents 1 and 2). In patent document 1, the relationship between a vehicle speed and the drive signal of a rotary motor (2) is prescribed | regulated for every threshold speed, and reaction force is applied with respect to an accelerator pedal (1) from a rotary motor (2) according to a vehicle speed. (For example, refer to FIG. 2 of Patent Document 1).

  In Patent Document 2, in auto cruise control (ACC), a footrest device (24) that regulates the movement of the brake pedal (13) so that the brake pedal (13) is not depressed even if the foot is put on the brake pedal (13). (Patent Document 2 paragraph [0033]). In this footrest device (24), electromagnetic force is generated by energizing the coil (19), and the mover (18) is attracted to the stator (17), thereby restricting the movement of the brake pedal (13) ( The same paragraph). Further, the footrest force is adjusted according to the signals from the load sensor and the position sensor (paragraph [0046] of Patent Document 2).

JP 2003-260951 A JP 2001-322538 A

  In Patent Document 1, the relationship between the vehicle speed and the drive signal (that is, the reaction force) of the rotary motor (2) is changed according to the threshold speed, but the adjustment of the magnitude of the reaction force is mentioned. Absent. Moreover, in patent document 2, the structure which regulates the motion of a brake pedal (13) by attracting a needle | mover (18) to a stator (17), ie, so that a brake pedal (13) cannot be stepped on temporarily. The structure to be described is described.

  However, as part of driving assistance, it is preferable that the reaction force upper limit value can be adjusted in relation to the amount of depression of the accelerator pedal or the brake pedal. The same applies to the target value of the reaction force of the accelerator pedal and the brake pedal (reaction force target value) when the vehicle is traveling at a constant speed.

  The present invention has been made in consideration of such problems, and provides a reaction force device capable of adjusting a reaction force upper limit value and a reaction force target value in relation to the amount of depression of an accelerator pedal or a brake pedal. The purpose is to do.

  The reaction force device according to the present invention applies a reaction force to the vehicle pedal by an actuator, and the reaction force device includes a reaction force control unit that controls a reaction force generated by the actuator, and the vehicle. A pedaling force determining unit that determines the pedaling force of the vehicle pedal, and a pedaling speed determining unit that determines the pedaling speed of the vehicle pedal, wherein the reaction force control unit includes a reaction force upper limit value that is an upper limit value of the reaction force; A target value setting reference value that defines a difference between a reaction force target value that is a target value of the reaction force and a reaction force upper limit value when the vehicle is traveling at a constant speed, and a depression speed threshold that is a threshold of the depression speed And a deviation threshold value that is a threshold value of deviation between the pedal force and the reaction force target value, and the reaction force control unit further determines a difference between the reaction force upper limit value and the target value setting reference value. The reaction force target value is calculated, and the stepping speed is When the difference between the pedaling force and the reaction force target value exceeds the deviation threshold value, the sum of the pedaling force and the target value setting reference value is set as a new reaction force upper limit value. The target value setting reference value is decreased when the pedaling force exceeds the reaction force target value and falls below the reaction force upper limit for a predetermined time or longer.

  According to the present invention, when the driver does not intend to accelerate or decelerate, when the deviation between the pedal effort and the reaction force target value exceeds the deviation threshold (that is, the depression speed is equal to or less than the predetermined value) When the vehicle pedal is depressed beyond the depression amount corresponding to the target value), a value obtained by adding the reference value for target value setting to the depression force at that time is set as a new reaction force upper limit value. As a result, the new reaction force target value becomes equal to the pedal force at that time. For this reason, it becomes possible to set reaction force target value more appropriately. In addition, when the driver has an intention to accelerate or decelerate, but the pedal force does not reach the reaction force upper limit value because the driver's pedal force is insufficient, the target value setting reference value is decreased. As a result, the reaction force upper limit value is also decreased. For this reason, it becomes possible to adjust reaction force upper limit more appropriately.

  A reaction force device according to the present invention applies a reaction force to an accelerator pedal by an actuator, and the reaction force device includes a reaction force control unit that controls a reaction force generated by the actuator, and the accelerator pedal. A stepping force determining unit that determines the pedaling force of the vehicle, a stepping speed determining unit that determines the stepping speed of the accelerator pedal, a vehicle speed determining unit that determines the vehicle speed of the vehicle, and a vehicle speed target value setting unit that sets the vehicle speed target value of the vehicle The reaction force control unit includes a reaction force upper limit value that is an upper limit value of the reaction force, a reaction force target value that is a target value of the reaction force when the vehicle travels at a constant speed, and the reaction force upper limit value. A target value setting reference value that defines a difference between the stepping speed, a stepping speed threshold that is a threshold of the stepping speed, and a deviation threshold that is a threshold of deviation between the stepping force and the reaction force target value, The reaction force control unit The reaction force target value is calculated from the difference between the force upper limit value and the target value setting reference value, the stepping speed is less than the stepping speed threshold, and the deviation between the stepping force and the reaction force target value is the deviation. When the threshold value is exceeded, the sum of the pedal force and the target value setting reference value is set as a new reaction force upper limit value, the pedal force exceeds the reaction force target value, and the vehicle speed exceeds the vehicle speed target value When the state continues for a predetermined time or more, the target value setting reference value is increased.

  According to the present invention, even when the driver does not intend to accelerate, the pedaling force exceeds the pedaling force threshold for determining the driver intention (that is, the pedaling speed corresponding to the reaction force target value when the pedaling speed is equal to or less than a predetermined value). When the accelerator pedal is depressed beyond the amount), a value obtained by adding the reference value for target value setting to the pedaling force at that time is set as a new reaction force upper limit value. As a result, the new reaction force target value becomes equal to the pedal force at that time. For this reason, it becomes possible to set reaction force target value more appropriately. In addition, even if the driver does not intend to accelerate, when the accelerator pedal is depressed more than necessary because the reaction force is insufficient and the vehicle speed exceeds the vehicle speed target value, the target value setting reference value is set. increase. As a result, the reaction force upper limit value is also increased. For this reason, it becomes easy to prevent further acceleration. Therefore, the reaction force target value and the reaction force upper limit value can be adjusted more appropriately.

  The reaction force control unit determines whether or not a deviation between the pedal force and the reaction force target value exceeds a deviation threshold based on an average value of deviations between the pedal force and the reaction force target value. Also good.

  The reaction force control unit may set the new reaction force upper limit value using a moving average process. As a result, it is possible to avoid giving the driver a sense of incongruity by suddenly changing the reaction force upper limit value.

  The reaction force device further includes a road attribute determination unit that determines a road attribute that affects the acceleration / deceleration operation of the vehicle, and the reaction force control unit is provided for each road attribute determined by the road attribute determination unit. The new reaction force upper limit value may be stored. This makes it possible to set a new reaction force upper limit value according to the road attribute that affects the acceleration / deceleration operation of the vehicle.

  According to the present invention, when the driver does not intend to accelerate or decelerate, when the deviation between the pedal effort and the reaction force target value exceeds the deviation threshold (that is, the depression speed is equal to or less than the predetermined value) When the vehicle pedal is depressed beyond the depression amount corresponding to the target value), a value obtained by adding the reference value for target value setting to the depression force at that time is set as a new reaction force upper limit value. As a result, the new reaction force target value becomes equal to the pedal force at that time. For this reason, it becomes possible to set reaction force target value more appropriately. In addition, when the driver has an intention to accelerate or decelerate, but the pedal force does not reach the reaction force upper limit value because the driver's pedal force is insufficient, the target value setting reference value is decreased. As a result, the reaction force upper limit value is also decreased. For this reason, it becomes possible to adjust reaction force upper limit more appropriately.

1 is a block diagram of a vehicle equipped with a reaction force device according to an embodiment of the present invention. It is explanatory drawing which shows the relationship between the depression amount of an accelerator pedal, and the reaction force provided to an accelerator pedal. 5 is a flowchart for updating a reaction force upper limit value and a reference value for setting a target value. It is a flowchart which determines the possibility of learning of the said reaction force upper limit and the said reference value for target value setting. It is a flowchart which acquires the said reference value setting reference value and provisional reaction force upper limit. It is a flowchart which produces | generates a reaction force acquisition flag. It is a figure which shows the relationship between the reaction force of an accelerator pedal, and reaction force acquisition flag. It is a figure which shows the relationship between a pedal effort value and the production | generation of reaction force acquisition flag. It is a flowchart which calculates provisional reaction force upper limit. It is a figure which shows the relationship between a pedaling force value, the reference value for target value setting, and reaction force upper limit value at the time of flag acquisition. It is a flowchart which calculates a new reaction force upper limit. It is a flowchart which evaluates a new reaction force upper limit. It is a figure which shows the relationship between a pedal effort value and reaction force target value. It is a flowchart which evaluates the new reference value for target value setting. It is explanatory drawing which shows the state in which a driver | operator's treading force does not reach reaction force upper limit although a driver | operator has an intention of acceleration. It is a figure which shows the state in which a vehicle speed exceeds a vehicle speed target value, although a driver | operator does not have the intention of acceleration.

A. EMBODIMENT OF THE INVENTION Hereinafter, the vehicle carrying the reaction force apparatus which concerns on one Embodiment of this invention is demonstrated with reference to drawings.

1. Configuration of Vehicle 10 FIG. 1 is a block diagram of a vehicle 10 equipped with a reaction force device 12 according to this embodiment. The vehicle 10 is, for example, a four-wheeled vehicle. In addition to the reaction force device 12, the vehicle 10 includes an accelerator pedal 14 and a return spring 16 that applies a reaction force Fr_sp [N] to the accelerator pedal 14.

  The reaction force device 12 includes a depression amount sensor 18, a vehicle speed sensor 20, a reaction force application start switch 22, a navigation system 24 (recommended vehicle speed determination unit), an ECU (electric control unit) 26, an actuator 28, an electric current, And a sensor 30 (stepping force sensor).

  The depression amount sensor 18 detects the depression amount (depression amount θ) [degree] from the original position of the accelerator pedal 14 and outputs it to the ECU 26. The vehicle speed sensor 20 measures the vehicle speed V [km / hour] of the vehicle 10 and outputs it to the ECU 26.

  The reaction force application start switch 22 (hereinafter also referred to as “switch 22”) commands the ECU 26 to start the application of the reaction force Fr [N] from the actuator 28 to the accelerator pedal 14 by the operation of the driver. It is. That is, when the driver turns on the switch 22, a reaction force application start signal Ss instructing the start of reaction force application is transmitted from the switch 22 to the ECU 26. The ECU 26 starts to apply the reaction force Fr in response to the received reaction force application start signal Ss.

  The navigation system 24 can detect the position of the vehicle using GPS (Global Positioning System), and includes a memory 32 that stores information (road attribute information Ir) related to attributes of each road. The road attribute information Ir includes, for example, “general road”, “highway”, and “other roads”. Then, the navigation system 24 notifies the ECU 26 of road attribute information Ir corresponding to the detected position of the vehicle 10.

  The ECU 26 sets a characteristic for imparting a reaction force Fr (reaction force imparting characteristic Cfr) according to a vehicle speed target value Vtgt [km / hour] that is a target value of the vehicle speed V, and the reaction force imparting characteristic Cfr and the amount of depression. Using θ, a reaction force Fr [N] applied from the actuator 28 to the accelerator pedal 14 is calculated. Then, a control signal Sr indicating the calculated reaction force Fr is transmitted to the actuator 28. The reaction force imparting characteristic Cfr defines the relationship between the depression amount θ and the reaction force Fr for each vehicle speed target value Vtgt, and is stored in the memory 34 of the ECU 26. In the present embodiment, the upper limit value of the reaction force Fr (reaction force upper limit value Fmax) and the target value setting reference value α (hereinafter also referred to as “reference value α”) in the reaction force application characteristic Cfr are updated. The reaction force imparting characteristic Cfr can be adjusted (details will be described later).

  The actuator 28 includes a motor (not shown) connected to the accelerator pedal 14 and applies a reaction force Fr corresponding to the control signal Sr received from the ECU 26 to the accelerator pedal 14. Thereby, in addition to the reaction force Fr_sp by the return spring 16, the reaction force Fr from the actuator 28 is added to the accelerator pedal 14. The actuator 28 may be other driving force generation means (for example, a pneumatic actuator).

  The current sensor 30 detects the current (current consumption Ia) [A] consumed by the actuator 28 and notifies the ECU 26 of it. The current Ia changes according to the output of the actuator 28, and the ECU 26 can determine the reaction force Fr generated by the actuator 28 based on the current Ia.

2. Update of reaction force upper limit value Fmax and target value setting reference value α [reaction force imparting characteristic Cfr]
As described above, in the present embodiment, the reaction force application characteristic Cfr can be adjusted by updating the reaction force upper limit value Fmax and the reference value α.

  FIG. 2 shows the relationship between the depression amount θ of the accelerator pedal 14, the reaction force Fr_sp by the return spring 16, and the reaction force Fr by the actuator 28. As shown in FIG. 2, the reaction force Fr_sp by the return spring 16 increases as the stepping amount θ increases. The reaction force Fr by the actuator 28 is a lower limit value Fmin (zero in this embodiment) until the depression amount θ reaches θ1, and the reaction force Fr increases between the depression amount θ1 and the depression amount θ2. . Hereinafter, the region from the depression amount θ1 to the depression amount θ2 is referred to as a reaction force increase region Rfr. When the stepping amount θ becomes θ2, the reaction force Fr becomes the upper limit value (reaction force upper limit value Fmax). When the stepping amount θ exceeds θ2, the reaction force upper limit value Fmax is continuously maintained (or the reaction force Fr is reduced). It may be gradually reduced.)

  In the present embodiment, a target value of the reaction force Fr (reaction force target value Ftgt) [N] when the vehicle 10 is traveling at a constant speed is set. The reaction force target value Ftgt is, for example, the reaction force Fr that the driver feels can easily attach his / her foot, and is adjusted to coincide with the reaction force Fr when the vehicle 10 is traveling at a constant speed. In the present embodiment, the reaction force target value Ftgt can be adjusted during operation of the vehicle 10. Further, the pedal depression amount θ corresponding to the reaction force target value Ftgt is referred to as a pedal depression amount target value θtgt.

  In the present embodiment, the reaction force target value Ftgt is defined as the difference between the reaction force upper limit value Fmax and the reference value α (Ftgt = Fmax−α). Therefore, the reference value α is a value for setting the reaction force target value Ftgt. Further, as will be described later, the reaction force upper limit value Fmax and the reference value α are updated, and the reaction force target value Ftgt can also be updated by updating them. Therefore, it is possible to set an appropriate reaction force upper limit Fmax and reaction force target value Ftgt according to the driver.

[Outline of Update of Reaction Force Upper Limit Fmax and Reference Value α]
FIG. 3 shows a flowchart for updating the reaction force upper limit value Fmax and the reference value α in the present embodiment.

  In step S1, the ECU 26 determines whether or not the current process is the first process after the switch 22 is turned on. When the current process is the first process (S1: YES), in step S2, the ECU 26 sets various initial values and proceeds to step S3. The initial value here includes the initial value and evaluation of the reaction force upper limit value Fmax, and the initial value and evaluation of the reference value α. The evaluation of the reaction force upper limit value Fmax and the reference value α will be described later. If the current process is not the first process (S1: NO), the process proceeds to step S3.

  In step S <b> 3, the ECU 26 acquires a pedaling force value Fcrr [N] that is a force by which the driver depresses the accelerator pedal 14. That is, the ECU 26 receives the value of the consumption current Ia of the actuator 28 from the current sensor 30 and applies a low-pass filter to the value of the consumption current Ia. This consumption current Ia corresponds to the output of the actuator 28 (that is, the reaction force Fr generated by the actuator 28). Then, the ECU 26 calculates the pedaling force value Fcrr based on the reaction force Fr indicated by the consumption current Ia.

  In subsequent step S4, the ECU 26 determines a road attribute based on the road attribute information Ir notified from the navigation system 24. The road attributes in the present embodiment include “general road”, “highway”, and “other roads”.

  In step S5, the ECU 26 determines whether the vehicle 10 is traveling, that is, whether the vehicle 10 is traveling straight at a constant speed. Specifically, by determining whether or not the absolute value of the change amount (change amount ΔV) [V / sec] per unit time of the vehicle speed V is equal to or less than a threshold value THΔV for determining constant speed travel, It is determined whether or not the vehicle 10 is traveling at a constant speed. Further, it is determined whether or not the vehicle 10 is traveling straight by determining whether or not the absolute value of the steering angle θs [degree] of the steering (not shown) is equal to or less than a threshold value THθs for determining straight traveling. Alternatively, it may be determined based on position information from the navigation system 24 whether or not the vehicle is traveling at a constant speed.

  In step S6, the ECU 26 determines whether or not the accelerator pedal 14 is in a stopped state. Specifically, it is determined whether or not the absolute value of the change amount Δθ [degrees / sec] per unit time of the depression amount θ of the accelerator pedal 14 is equal to or less than a threshold value THΔ for determining the stop state of the accelerator pedal 14. By doing so, it is determined whether or not the accelerator pedal 14 is in a stopped state. Since only the determination of the constant speed straight traveling state in step S5 cannot exclude the case where steady straight traveling is being performed by operating the accelerator pedal 14 on a slope or the like, such a case can be excluded in step S6. it can.

  In step S7, the ECU 26 determines whether or not a learning process for updating the reaction force upper limit value Fmax and the reference value α is possible. In step S8, the ECU 26 calculates a provisional reaction force upper limit value Ftmax and a new reference value α as candidates for a new reaction force upper limit value Fmax. In step S9, the ECU 26 evaluates the reaction force upper limit value Fmax. In step S10, the ECU 26 evaluates the reference value α. Details of steps S7 to S10 will be described later.

  In step S11, the ECU 26 updates the reaction force upper limit value Fmax and the reference value α based on the evaluation results of steps S9 and S10. That is, if the reaction force upper limit value Fmax is not appropriate, the provisional reaction force upper limit value Ftmax is set as a new reaction force upper limit value Fmax. If the reaction force upper limit value Fmax is appropriate, the reaction force up to that point is set. The force upper limit value Fmax is used as it is as a new reaction force upper limit value Fmax.

[Details of Judgment of Whether to Learn (Step S7)]
FIG. 4 is a flowchart for determining whether or not learning for updating the reaction force upper limit value Fmax and the reference value α is possible. In step S21, the ECU 26 determines whether or not the accelerator pedal 14 is stopped. This determination is performed using the determination result of step S6. When the accelerator pedal 14 is stopped (S21: YES), in step S22, the ECU 26 determines whether or not the vehicle 10 is traveling straight at a constant speed. This determination is performed using the determination result of step S5. When the vehicle 10 is traveling straight at a constant speed (S22: YES), in step S23, the ECU 26 determines that learning is possible. If the accelerator pedal 14 is not stopped (S21: NO) or the vehicle 10 is not traveling straight at a constant speed (S22: NO), the ECU 26 determines in step S24 that learning is not possible.

[Details of Calculation of Temporary Reaction Force Upper Limit Ftmax and Reference Value α (Step S8)]
FIG. 5 is a flowchart for calculating a new provisional reaction force upper limit value Ftmax and a reference value α.

  In step S31, the ECU 26 calculates a new reference value α. FIG. 6 shows a flowchart for calculating a new reference value α. In step S41, the ECU 26 checks whether or not the evaluation (S10) of the reference value α (hereinafter also referred to as “reference value α (previous)”) in the previous process was “appropriate”. When the evaluation is “appropriate” (S41: YES), in step S42, the ECU 26 directly uses the reference value α (previous) as the reference value α in the current process (hereinafter also referred to as “reference value α (current)”). .

  If the evaluation is not “appropriate” in step S41 (S41: NO), in step S43, the ECU 26 determines whether or not the evaluation of the reference value α (previous) is “excessive”. When the evaluation is “excessive” (S42: YES), in step S44, the ECU 26 sets a value obtained by subtracting 0.5N from the reference value α (previous) as the reference value α (current). When the evaluation of the reference value α (previous) is not “over” (S43: NO), the evaluation is “under”. Therefore, in step S45, the ECU 26 sets a value obtained by adding 0.5N to the reference value α (previous) as the reference value α (current).

  Returning to FIG. 5, in step S <b> 32, the ECU 26 generates a reaction force acquisition flag Flg (hereinafter also referred to as “flag Flg”). FIG. 7 shows a flowchart for generating the reaction force acquisition flag Flg. In step S51, the ECU 26 determines whether learning for updating the reaction force upper limit value Fmax is possible. This determination is made based on the determination result of step S7. When the learning is possible (S51: YES), the process proceeds to step S52. If the learning is not possible (S51: NO), in step S56, the ECU 26 ends the current process without acquiring the reaction force acquisition flag Flg.

  In step S52, the ECU 26 reads the pedaling force value Fcrr acquired in step S3. In subsequent step S53, the ECU 26 determines whether or not the pedal effort value Fcrr is stable. In this determination, the absolute value of the difference between the previous pedaling force value Fcrr (hereinafter also referred to as “the pedaling force value Fcrr (previous)”) and the current pedaling force value Fcrr (hereinafter also referred to as “the pedaling force value Fcrr (currently)”), Judgment is made based on whether or not the state below the threshold THfcrr continues for a predetermined time THsbl. The threshold value THfcrr and the predetermined time THsbl here are a threshold value and a time for determining the stable state of the pedal effort value Fcrrr. Instead of the predetermined time THsbl, the number of times for determining the stable state of the pedaling force value Fcrr may be used.

  When the pedaling force value Fcrr is stable in step S53 (S53: YES), in step S54, the ECU 26 acquires a reaction force acquisition flag Flg (see FIG. 8). This flag Flg defines whether or not to obtain a reaction force upper limit calculation pedal force value Ft (hereinafter also referred to as “treading force value Ft”) for calculating the provisional reaction force upper limit value Ftmax. When the flag Flg is set, acquisition of the pedal force value Ft is permitted, and when the flag Flg is not set, acquisition of the pedal force value Ft is not permitted.

  When the pedal effort value Fcrr is not stable in step S53 (S53: NO), in step S55, the ECU 26 determines whether or not the pedal effort value Fcrrr is a maximum value. This determination is made based on whether or not the difference becomes equal to or less than the threshold THdcs after a state in which the difference between the pedal effort value Fcrr (previous) and the pedal effort value Fcrr (current) is equal to or greater than the threshold THics continues for a predetermined time THics. Here, the threshold THics and the predetermined time THics are a threshold and time for determining an increase in the pedal effort value Fcrrr, and the threshold THdcs is a threshold for determining a decrease in the pedal effort value Fcrrr. Instead of the predetermined time THics, the number of times of determining an increase in the pedaling force value Fcrr may be used.

  When the pedaling force value Fcrr is the maximum value in step S55 (S55: YES), in step S54, the ECU 26 acquires the reaction force acquisition flag Flg (see FIG. 8). If the pedaling force value Fcrr is not the maximum value (S55: NO), in step S56, the ECU 26 ends the current process without acquiring the reaction force acquisition flag Flg.

  Returning to FIG. 5, in step S33, the ECU 26 calculates a provisional reaction force upper limit value Ftmax. FIG. 9 shows a flowchart for calculating the provisional reaction force upper limit value Ftmax. In step S61, the ECU 26 reads the pedaling force value Fcrr acquired in step S3. In step S62, the ECU 26 reads out the new reference value α calculated in step S31.

  In step S63, the ECU 26 confirms whether or not the reaction force acquisition flag Flg has been acquired. When the flag Flg has been acquired (S63: YES), the process proceeds to step S64. When the flag Flg has not been acquired (S63: NO), in step S65, the ECU 26 sets the previous reaction force upper limit value Fmax as the current provisional reaction force upper limit value Ftmax.

  In step S64, the ECU 26 sets the sum of the pedal force value Fcrr at the time when the flag Flg is acquired and the reference value α as the reaction force upper limit calculation pedal force value Ft. For example, in FIG. 10, when the pedaling force value Fcrr reaches the maximum value at the time point t1, the sum of the pedaling force value Fcrr and the reference value α at that time point is acquired as the reaction force upper limit calculation pedaling force value Ft1. When the pedaling force value Fcrr becomes stable at time t2, the sum of the pedaling force value Fcrr and the reference value α at that time is acquired as the reaction force upper limit calculation pedaling force value Ft2. Similarly, when the pedaling force value Fcrr reaches the maximum value at time points t3 and t4, the sum of the pedaling force value Fcrr and the reference value α at that time point is acquired as the reaction force upper limit calculation pedaling force values Ft3 and Ft4.

  In subsequent step S66, the ECU 26 determines whether or not the road attribute in the current process is “general road”. When the road attribute is “general road” (S66: YES), in step S67, the ECU 26 stores the current pedaling force value in the general road database (hereinafter referred to as “general road DB”) configured in the memory 34. Save Ft. The general road DB is a first-in / first-out database and stores ten pedal force values Ft.

  In step S68, the ECU 26 calculates a pedaling force average value Fave that is an average value of the ten pedaling force values Ft stored in the general road DB. In subsequent step S69, the ECU 26 sets the pedal effort average value Fave calculated in step S68 to a new provisional reaction force upper limit value Ftmax.

  Returning to step S66, if the road attribute is not a general road (S66: NO), in step S70, the ECU 26 determines whether or not the road attribute is "highway". When the road attribute is “highway” (S70: YES), in step S71, the ECU 26 stores the current pedaling force value in the highway database (hereinafter referred to as “highway DB”) configured in the memory 34. Save Ft. The highway DB is a first-in / first-out database and stores ten pedal force values Ft.

  In step S72, the ECU 26 calculates a pedaling force average value Fave that is an average value of the ten pedaling force values Ft stored in the highway DB. In subsequent step S73, the ECU 26 sets the pedal effort average value Fave calculated in step S72 to a new provisional reaction force upper limit value Ftmax.

  Returning to step S70, when the road attribute is not “highway” (S70: NO), the road attribute is “other road”. Therefore, in step S74, the ECU 26 stores the current pedaling force value Ft in another road database (hereinafter referred to as "other road DB") configured in the memory 34. The other road DB is a first-in / first-out database and stores ten pedal force values Ft.

  In step S75, the ECU 26 calculates a pedal effort average value Fave that is an average value of the ten pedal effort values Ft stored in the other road DBs. In subsequent step S76, the ECU 26 sets the pedal effort average value Fave calculated in step S75 to a new provisional reaction force upper limit value Ftmax.

  Returning to FIG. 5, in step S <b> 34, the ECU 26 determines whether or not the provisional reaction force upper limit value Ftmax can be adopted. FIG. 11 shows a flowchart for determining whether or not the provisional reaction force upper limit value Ftmax can be adopted. In step S81, the ECU 26 reads the previous reaction force upper limit value Fmax (hereinafter referred to as “reaction force upper limit value Fmax (previous)”). In step S82, the ECU 26 reads the current provisional reaction force upper limit value Ftmax (hereinafter referred to as “provisional reaction force upper limit value Ftmax (current)”).

  In step S83, the ECU 26 determines whether or not the depression speed Vθ [degrees / sec] of the accelerator pedal 14 is high. The depression speed Vθ is obtained using the depression amount θ of the accelerator pedal 14. Further, the large stepping speed Vθ means the stepping speed Vθ when the driver intends to accelerate. When the stepping speed Vθ is not large (S83: NO), in step S84, the ECU 26 confirms whether or not the evaluation of the reaction force upper limit value Fmax (previous) is “appropriate”. This confirmation is performed based on the result of step S9 in the previous process. If the evaluation of the reaction force upper limit Fmax (previous) is not “appropriate” (S84: NO), in step S85, the ECU 26 sets the provisional reaction force upper limit Ftmax (current) as the reaction force upper limit Fmax (current). Set.

  If the stepping speed Vθ is large in step S83 (S83: YES) or if the evaluation of the reaction force upper limit Fmax (previous) is “appropriate” in step S84 (S84: YES), in step S86, the ECU 26 The force upper limit Fmax (previous) is used as it is as the reaction force upper limit Fmax (current).

[Details of Evaluation of Reaction Force Upper Limit Fmax (Step S9)]
FIG. 12 shows a flowchart for evaluating the reaction force upper limit value Fmax. In step S91, the ECU 26 reads the pedaling force value Fcrr (current time) acquired in step S3. In step S92, the ECU 26 reads the reaction force upper limit value Fmax (current) calculated in step S8. In step S93, the ECU 26 reads the current reference value α calculated in step S8 (hereinafter referred to as “reference value α (current)”).

  In step S94, the ECU 26 calculates a deviation (deviation Fd) [N] between the current reaction force target value Ftgt (hereinafter referred to as “reaction force target value Ftgt (current)”) and the pedaling force value Fcrr (current). As described above, the reaction force target value Ftgt is a value obtained by subtracting the reference value α from the reaction force upper limit value Fmax (Ftgt = Fmax−α). Therefore, the deviation Fd can be calculated as an absolute value of a value obtained by further subtracting the pedaling force value Fcrr (current) from the value obtained by subtracting the reference value α from the reaction force upper limit value Fmax (Fd = | (Fmax−α) − Fcrr |).

  In step S95, the ECU 26 determines whether or not the deviation Fd exceeds the threshold value of the deviation Fd (deviation threshold value THfd) for evaluating the reliability of the reaction force upper limit value Fmax in a relatively short period. For example, at time t11 in FIG. 13, the difference Fd between the immediately preceding reaction force upper limit Fmax and the reference value α (Fmax−α) and the pedaling force value Fcrr exceeds the deviation threshold THfd. On the other hand, at time t12, the difference Fd between the immediately preceding reaction force upper limit Fmax and the reference value α (Fmax−α) and the pedaling force value Fcrr exceeds the deviation threshold value THfd.

  When the deviation Fd exceeds the deviation threshold THfd (S95: YES), in step S96, the ECU 26 determines that the reaction force upper limit Fmax (current) is “inappropriate”. When the deviation Fd is equal to or smaller than the deviation threshold THfd (S95: NO), the process proceeds to step S97.

  In step S97, the ECU 26 calculates a deviation average value Fdave which is a moving average value of the deviation Fd. In subsequent step S98, the ECU 26 determines whether or not the deviation average value Fdave exceeds the threshold value of the deviation average value Fdave (deviation average threshold value THfdave) for evaluating the reliability of the reaction force upper limit value Fmax in a relatively long period. To do. For example, it is determined whether or not the deviation average value Tdave from time t12 to time t13 in FIG. 13 exceeds the deviation average threshold value THfdave.

  When deviation average value Fdave exceeds deviation average threshold value THfdave (S98: YES), in step S99, ECU 26 determines that reaction force upper limit value Fmax (current) is inappropriate. When the average deviation value Fdave is equal to or smaller than the average deviation threshold THfdave (S98: NO), in step S100, the ECU 26 determines that the reaction force upper limit value Fmax (current) is appropriate.

[Details of Evaluation of Reference Value α (Step S10)]
FIG. 14 shows a flowchart for evaluating a new reference value α. In step S101, the ECU 26 reads the vehicle speed target value Vtgt. In step S102, the ECU 26 reads the vehicle speed V. In step S103, the ECU 26 reads the maximum upper limit value Fmax (current time). In step S104, the ECU 26 reads the reference value α (current). In step S105, the ECU 26 reads the pedaling force value Fcrr (current time).

  In step S106, the ECU 26 obtains the depression speed Vθ [degree / sec] of the accelerator pedal 14 using the depression amount θ of the accelerator pedal 14. In step S107, the ECU 26 calculates a deviation (vehicle speed deviation Vd) between the vehicle speed V and the vehicle speed target value Vtgt (Vd = V−Vtgt).

  In step S108, the ECU 26 calculates a reaction force deviation Fdd. The reaction force deviation Fdd is an absolute value of the difference between the reaction force upper limit value Fmax and the pedaling force value Fcrr (Fdd = | Fmax−Fcrrr |).

  In step S109, the ECU 26 continues the state where the reaction force deviation Fdd is less than the deviation threshold value THfdd (for example, 1.5 N) for at least the depression force determination period THfl (for example, 3 seconds), and the depression speed Vθ is the depression speed threshold value THvθ. It is determined whether or not it exceeds. The pedal effort shortage determination period THfl is a period for judging a state in which the pedal effort value Fcrr does not reach the reaction force upper limit Fmax because the driver's pedal effort is insufficient even though the driver intends to accelerate. is there.

  For example, in FIG. 15, the deviation Fdd between the reaction force upper limit value Fmax and the pedaling force value Fcrr is greater than the deviation threshold value THfdd until time t21, but at time t21, the deviation Fdd becomes equal to the deviation threshold value THfdd. At time t22, the period in which the deviation Fdd is less than the deviation threshold value THfdd is equal to the pedal effort shortage determination period THfl, and the reaction force deviation Fdd is less than the deviation threshold value THfdd by more than the pedal effort shortage judgment period THfl in the condition of step S109. The condition is satisfied. Whether or not the depression speed Vθ exceeds the depression speed threshold THvθ may be satisfied when the deviation Fdd becomes equal to or less than the deviation threshold THfdd.

  When all the conditions of step S109 are satisfied (S109: YES), the driver has an intention to accelerate, but it is considered that the reaction force Fr is too large to reach the reaction force upper limit Fmax. Therefore, in step S110, the ECU 26 determines that the reference value α is excessive.

  If any of the conditions in step S109 is not satisfied (S109: NO), in step S111, the ECU 26 determines that the vehicle speed deviation Vd exceeds the vehicle speed deviation threshold THvd for a reaction force shortage determination period THrl (for example, 15 seconds) or more. It is determined whether or not the depression speed Vθ is lower than the depression speed threshold THvθ. In the reaction force shortage determination period THrl, the pedal force value Fcrr exceeds the reaction force target value Ftgt because the reaction force Fr is insufficient even though the driver does not intend to accelerate. As a result, the vehicle speed deviation Vd becomes the vehicle speed. This is a period for determining a state in which the deviation threshold THvd is exceeded.

  For example, in FIG. 16, the vehicle speed V was lower than the vehicle speed target value Vtgt until time t31. However, at time t31, the vehicle speed V becomes equal to the vehicle speed target value Vtgt. At time t32, the vehicle speed deviation Vd exceeds the vehicle speed deviation threshold THvd, and at time t33, the period during which the vehicle speed deviation Vd exceeds the vehicle speed deviation threshold THvd becomes equal to the reaction force deficiency determination period THrl. Of these, the condition that the vehicle speed deviation Vd exceeds the vehicle speed deviation threshold THvd by the reaction force shortage determination period THrl or more is satisfied. It should be noted that whether or not the stepping speed Vθ is lower than the stepping speed threshold THvθ always needs to be satisfied in the reaction force shortage determination period THrl, for example.

  When both conditions of step S111 are satisfied, the reaction force Fr is too small, so that the accelerator pedal 14 can easily exceed the vehicle speed target value. Therefore, when all the conditions in step S111 are satisfied (S111: YES), in step S112, the ECU 26 determines that the reference value α (current) is too small. When any of the conditions in step S111 is not satisfied (S111: NO), in step S113, the ECU 26 determines that the reference value α (current) is appropriate.

3. As described above, according to the present embodiment, when the reaction force acquisition flag Flg is acquired, that is, when the pedaling force value Fcrr is in a stable state or a maximum value, the pedaling force value Fcrr at that time is obtained. A value obtained by adding the reference value α is set as a new reaction force upper limit value Fmax. As a result, the new reaction force target value Ftgt becomes equal to the pedal effort value Fcrr at that time. For this reason, the reaction force target value Ftgt can be set more appropriately. When the stepping speed Vθ exceeds the stepping speed threshold THvθ and the driver intends to accelerate, the pedaling force value Fcrr does not reach the reaction force upper limit Fmax because the driver's stepping force is insufficient. Decrease the value α. As a result, the reaction force upper limit value Fmax is also decreased. For this reason, the reaction force upper limit value Fmax can be set more appropriately.

  In the present embodiment, the ECU 26 sets a new reaction force upper limit value Fmax using a moving average process using a general road DB, a highway DB, and other road DBs (see FIG. 9). As a result, the reaction force upper limit value Fmax is suddenly greatly changed, and it can be avoided that the driver feels uncomfortable.

  In the present embodiment, the ECU 26 stores a new reaction force upper limit calculation pedal force value Ft for each road attribute determined by the navigation system 24, and calculates the reaction force upper limit value Fmax using the pedal force value Ft. Thus, a new reaction force upper limit value Fmax can be set according to the road attribute that affects the acceleration / deceleration of the vehicle 10.

B. Modifications It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various configurations can be adopted based on the contents described in this specification. For example, the following configuration can be adopted.

  In the above embodiment, the accelerator pedal 14 is used as a target to which the reaction force Fr is applied, but a brake pedal may be used. For example, in the configuration of FIG. 1, the present invention may be applied to a configuration in which a reaction force is applied to the brake pedal by using a brake pedal instead of the accelerator pedal 14. For the purpose of applying a reaction force to the brake pedal, as described in Patent Document 2, it can be used for auto cruise control (ACC) or the like.

DESCRIPTION OF SYMBOLS 10 ... Vehicle 12 ... Reaction force apparatus 14 ... Accelerator pedal 16 ... Return spring 18 ... Depression amount sensor 20 ... Vehicle speed sensor 24 ... Navigation system 26 ... ECU (Reaction force control part, Depression speed determination part, Vehicle speed target value setting part)
28 ... Actuator 30 ... Current sensor (stepping force determination unit)
Fcrr ... pedaling force value Fmax ... reaction force upper limit value
Fr ... reaction force Ftgt ... reaction force target value THfl ... stepping force shortage determination period THvθ ... stepping speed threshold V ... vehicle speed Vtgt ... vehicle speed target value Vθ ... accelerator pedal depression speed α ... target value setting reference value θ ... accelerator pedal depression amount

Claims (5)

A reaction force device for applying a reaction force to a vehicle pedal by an actuator,
The reaction force device is
A reaction force control unit for controlling a reaction force generated by the actuator;
A pedaling force determination unit that determines the pedaling force of the vehicle pedal;
A stepping speed determining unit for determining a stepping speed of the vehicle pedal;
The reaction force control unit
A reaction force upper limit which is an upper limit of the reaction force;
A target value setting reference value that defines a difference between a reaction force target value, which is a target value of the reaction force when the vehicle is traveling at a constant speed, and the reaction force upper limit value;
A depression speed threshold which is a threshold of the depression speed;
Set a deviation threshold that is a threshold of deviation between the pedal force and the reaction force target value,
Furthermore, the reaction force control unit
Calculate the reaction force target value from the difference between the reaction force upper limit value and the target value setting reference value,
When the stepping speed is less than the stepping speed threshold and the deviation between the stepping force and the reaction force target value is greater than the deviation threshold, the sum of the stepping force and the reference value for setting the target value is set as a new reaction force. Set as the upper limit,
The reaction force device, wherein the target value setting reference value is decreased when the pedaling force exceeds the reaction force target value and falls below the reaction force upper limit value for a predetermined time or longer. A reaction force device that applies a reaction force to an accelerator pedal by an actuator,
The reaction force device is
A reaction force control unit for controlling a reaction force generated by the actuator;
A pedaling force determination unit that determines the pedaling force of the accelerator pedal;
A depressing speed determining unit for determining a depressing speed of the accelerator pedal;
A vehicle speed determination unit for determining the vehicle speed of the vehicle;
A vehicle speed target value setting unit for setting a vehicle speed target value of the vehicle,
The reaction force control unit
A reaction force upper limit which is an upper limit of the reaction force;
A target value setting reference value that defines a difference between a reaction force target value, which is a target value of the reaction force when the vehicle is traveling at a constant speed, and the reaction force upper limit value;
A depression speed threshold which is a threshold of the depression speed;
Set a deviation threshold that is a threshold of deviation between the pedal force and the reaction force target value,
Furthermore, the reaction force control unit
Calculate the reaction force target value from the difference between the reaction force upper limit value and the target value setting reference value,
When the stepping speed is less than the stepping speed threshold and the deviation between the stepping force and the reaction force target value is greater than the deviation threshold, the sum of the stepping force and the reference value for setting the target value is set as a new reaction force. Set as the upper limit,
The reaction force device, wherein the target value setting reference value is increased when the pedaling force exceeds the reaction force target value and the vehicle speed exceeds the vehicle speed target value for a predetermined time or longer. The reaction force device according to claim 1 or 2,
The reaction force control unit determines whether a deviation between the pedal force and the reaction force target value exceeds a deviation threshold based on an average value of deviations between the pedal force and the reaction force target value. A reaction force device characterized by. In the reaction force device according to any one of claims 1 to 3,
The reaction force control unit is configured to set the new reaction force upper limit value using a moving average process. The reaction force device according to claim 4, wherein
The reaction force device further includes a road attribute determination unit that determines a road attribute that affects an acceleration / deceleration operation of the vehicle.
The reaction force control unit stores the new reaction force upper limit value for each road attribute determined by the road attribute determination unit.

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