JP5148368B2 - Vehicle travel control device and vehicle travel control method - Google Patents

Description

  The present invention relates to a vehicle travel control device and a vehicle travel control method for performing constant speed cruise control for matching a vehicle cruise speed with a vehicle speed.

  A constant speed cruise control is known in which the throttle valve opening is automatically controlled separately from the operation of the accelerator pedal by the driver so that the vehicle speed matches the target speed (Patent Document 1). When performing constant speed cruise control in Patent Document 1, the set speed for constant speed cruise travel (hereinafter also referred to as “cruise speed”) is adjusted by operating the accelerator pedal while using reaction force applied to the accelerator pedal. can do. That is, when driving at a constant speed, the reaction force against the accelerator pedal is suddenly increased to detect the area where the driver can naturally place his right foot on the accelerator pedal ("footrest area") and the driver's intention to accelerate Area ("Acceleration detection area") and an area for detecting the driver's intention to decelerate ("Deceleration detection area"), the accelerator pedal is stepped over the footrest area to the acceleration detection area. The vehicle speed is increased, and when the accelerator pedal is stepped over the footrest area to the deceleration detection area, the vehicle speed is decreased. When the accelerator pedal exits the acceleration detection area or the deceleration detection area, the vehicle speed at that time is set as a new cruise speed. After the new cruise speed is set, the accelerator pedal is returned to the footrest area (see paragraphs [0026] to [0037] of FIG. 2 and FIG. 3).

  The constant speed cruise traveling in Patent Document 1 is performed while the driver keeps his right foot on the accelerator pedal, but there is also a technology that can perform constant speed cruise traveling without placing his foot on the accelerator pedal. (Patent Documents 2 and 3). In Patent Document 2, constant speed cruise traveling is realized by controlling the depression position of the accelerator pedal by pedal reaction force applying means (see paragraph [0037] of Patent Document 2). In Patent Document 3, the vehicle is driven at a cruise speed in a state where the driver does not operate the accelerator pedal by feedback controlling the operation of the throttle actuator so that the vehicle speed detected by the speed sensor becomes the cruise speed. (See paragraph [0013] of Patent Document 3).

JP 2006-143120 A JP 2003-291682 A Japanese Patent Laid-Open No. 10-315801

  In Patent Document 1, during constant-speed cruise traveling, the accelerator pedal is used for setting the cruise speed, and the amount of operation of the accelerator pedal and the opening of the throttle valve are controlled independently, except when changing the cruise speed. The accelerator pedal is maintained in the footrest area (see paragraphs [0026] to [0037] of FIG. 2 and FIG. 3). Further, in Patent Document 2, the throttle valve opening and the amount of operation of the accelerator pedal at the time when the cruise control switch is turned on are maintained, and the amount of operation of the accelerator pedal does not automatically change during constant speed cruise traveling ( Patent Literature 2 paragraphs [0036] to [0038]). Furthermore, in Patent Document 3, although there is a description that the vehicle travels at a cruise speed in a state in which the driver does not operate the accelerator pedal (see paragraph [0013] of Patent Document 3), constant speed cruise travel is performed. The operation of the accelerator pedal at the time is not touched.

  Therefore, in any patent document, the position of the footrest area of the accelerator pedal (the amount of pedal operation generated by the footrest area) does not change during constant speed cruise traveling. For this reason, even when the throttle valve opening is significantly changed to maintain the vehicle speed at the cruise speed, such as when approaching a steep slope from a flat road, the amount of operation of the accelerator pedal (depression position) does not change. The driver may feel uncomfortable.

  The present invention has been made in consideration of such problems, and an object of the present invention is to provide a vehicle travel control device and a vehicle travel control method that do not make the driver feel uncomfortable during constant speed cruise travel.

A vehicle travel control device according to the present invention sets a vehicle speed detection unit that detects a vehicle speed, a pedal operation amount detection unit that detects a pedal operation amount of an accelerator pedal, a cruise speed of the vehicle, and the cruise speed and the vehicle speed The constant speed cruise control unit that performs constant speed cruise control that automatically adjusts the opening of the throttle valve independently of the pedal operation amount, and the pedal operation amount when the cruise speed is set. the be those comprising a reaction force applying unit for surge a reaction force against the accelerator pedal, a reaction force control unit for controlling said reactive force applying portion, wherein the reaction force control section, the power source before Symbol vehicle If the external load on the vehicle is changed during running, this said in accordance with the opening degree of the throttle valve required to maintain the cruise speed, changing the pedal operation amount to rapidly the reaction force The features.

According to the present invention, when the external load on the vehicle is changed when the power source of vehicles is operating, in accordance with the opening degree of the throttle valve required to maintain the cruise speed, the Change the pedal operation amount to increase the reaction force rapidly . As a result, since the external load on the vehicle has changed, such as when the vehicle has reached a slope, when the output of the power source is increased or decreased in order to maintain the cruise speed, the pedal operation amount is changed according to the external load. be able to. As a result, it is possible to prevent the driver from feeling uncomfortable due to the difference between the output of the power source and the pedal operation amount.

  In the above, when the target opening of the throttle valve for matching the cruise speed and the vehicle speed or the actual opening following the target opening changes more than a predetermined value, the reaction force control unit The pedal operation amount for rapidly increasing the reaction force may be changed.

  Thereby, the change of the pedal operation amount that rapidly increases the reaction force against the accelerator pedal is performed only when the target opening of the throttle valve or the actual opening following the target opening changes by a predetermined value or more. If it does not change any more, it is not performed. Therefore, it is possible to adjust the frequency at which the pedal operation amount for rapidly increasing the reaction force occurs by appropriately setting a predetermined value. As a result, it is possible to avoid constantly changing the pedal operation amount that rapidly increases the reaction force, and to eliminate the driver's uncomfortable feeling caused by the change when the change in the target opening or the actual opening is small. be able to.

The constant speed cruise control unit calculates a target opening of the throttle valve based on a difference between the vehicle speed and the cruise speed, and sets a reference throttle valve opening according to a target pedal operation amount based on the cruise speed. The pedal operation amount for rapidly increasing the reaction force may be changed according to the difference between the target opening of the throttle valve and the reference throttle valve opening.
The vehicle travel control device further includes a deceleration mechanism that decelerates the vehicle. When the vehicle accelerates due to a decrease in the external load, the deceleration mechanism may decelerate the vehicle automatically. Good. This makes it easy to maintain the cruise speed even when the vehicle starts to accelerate due to a decrease in the external load when the vehicle travels.

The vehicle travel control method according to the present invention performs constant speed cruise control for matching the vehicle cruise speed and the vehicle speed, and an external load applied to the vehicle when the power source of the vehicle is operating. when it changed in accordance with the opening degree of the throttle valve required to maintain the cruise speed, characterized in that to change the pedal operation amount to rapidly the reaction force applied variably relative to the accelerator pedal .

According to the present invention, when the external load on the vehicle is changed when the power source of vehicles is operating, in accordance with the opening degree of the throttle valve required to maintain the cruise speed, the Change the pedal operation amount to increase the reaction force rapidly . As a result, since the external load on the vehicle has changed, such as when the vehicle has reached a slope, when the output of the power source is increased or decreased in order to maintain the cruise speed, the pedal operation amount is changed according to the external load. be able to. As a result, it is possible to prevent the driver from feeling uncomfortable due to the difference between the output of the power source and the pedal operation amount.

A. Hereinafter, an embodiment of a vehicle travel control device according to the present invention will be described with reference to the drawings.

1. Configuration of Vehicle Travel Control Device 10 FIG. 1 is a block diagram of a vehicle travel control device 10 according to this embodiment. The vehicle travel control device 10 can be mounted on a vehicle such as a four-wheeled vehicle, and basically includes an accelerator pedal 12, an operation amount sensor 14 (pedal operation amount detection unit), a throttle valve 16, and an opening sensor. 18, a vehicle speed sensor 20 (vehicle speed detection unit), a cruise switch 22, an ECU (electric control unit) 24 (reaction force control unit, constant speed cruise control unit), and a reaction force application mechanism 26 (reaction force application unit). And a brake system 28 (deceleration mechanism).

  The operation amount sensor 14 detects an operation amount (pedal operation amount P) [degree] from the original position of the accelerator pedal 12 and outputs it to the ECU 24. The throttle valve 16 is provided inside an intake pipe 32 connected to the engine 30. When the vehicle is traveling normally, its opening (throttle valve opening θ) [in accordance with the pedal operation amount P by the ECU 24. Degree] is controlled. That is, in this embodiment, a so-called throttle-by-wire system is adopted, and the throttle valve opening θ of the throttle valve 16 is controlled by a control signal St from the ECU 24. The throttle valve opening θ is detected by the opening sensor 18 and output to the ECU 24. A method in which the accelerator pedal 12 and the throttle valve 16 are mechanically connected can also be adopted.

  The vehicle speed sensor 20 measures a vehicle speed V [km / h] of a vehicle (not shown) and outputs it to the ECU 24. The cruise switch 22 is used by the driver to input a determination start command for instructing the start of determination as to whether or not to start constant speed cruise control. That is, when the driver turns on the cruise switch 22, a cruise signal Sc that transmits the determination start command is transmitted from the cruise switch 22 to the ECU 24.

  The ECU 24 controls the operation of the throttle valve 16 and the reaction force applying mechanism 26 based on the pedal operation amount P, the vehicle speed V, and the cruise signal Sc. Details of the control method will be described later. The ECU 24 includes a memory 34.

  The reaction force applying mechanism 26 includes a motor (not shown) connected to the accelerator pedal 12 and variably applies a reaction force Fr corresponding to the control signal Sr from the ECU 24 to the accelerator pedal 12. As a result, a reaction force Fr from the reaction force applying mechanism 26 is added to the accelerator pedal 12 in addition to the original position return force (force to return to the original position) of the accelerator pedal 12 itself by a spring or the like.

2. Vehicle Travel Control Method FIG. 2 shows a flowchart of the vehicle travel control method in the present embodiment.

  In step S1, the ECU 24 determines whether or not this time is the first processing (whether or not this time is the first time when the flowchart of FIG. 2 is executed). This determination can be performed by using, for example, a determination flag FLG. That is, when the determination flag FLG is “0”, this indicates that this is the first process, and when the determination flag FLG is “1”, it indicates that the process is the second or later. The initial value of the determination flag FLG (the value when the cruise signal Sc is first received from the cruise switch 22) is “0”. Further, at the end of the flowchart of FIG. 2, the determination flag FLG is set to “1”. In this way, the above determination can be made.

  If this is the second and subsequent processing (S1: No), the process proceeds to step S6. When this is the first process (S1: Yes), in step S2, the ECU 24 sets the cruise speed Vcr [km / h]. The initial value of the cruise speed Vcr is read from the memory 34. In subsequent step S3, the ECU 24 sets a target pedal operation amount Pt [degree]. The target pedal operation amount Pt can be set, for example, based on the set cruise speed Vcr by previously storing the relationship between the cruise speed Vcr and the target pedal operation amount Pt in the memory 34. Alternatively, when the vehicle speed V when the cruise control is started is set to the cruise speed Vcr, the pedal operation amount P when the cruise control is started can be set as the target pedal operation amount Pt.

  In subsequent step S4, the ECU 24 sets a reference throttle valve opening θr [degree] in accordance with the target pedal operation amount Pt. The reference throttle valve opening θr is set, for example, by previously storing the relationship between the target pedal operation amount Pt and the reference throttle valve opening θr in the memory 34 and based on the set target pedal operation amount Pt. it can. Alternatively, the throttle valve opening degree θ when the cruise control is started can be set as the reference throttle valve opening degree θr.

  In step S5, the ECU 24 sets an additional reaction force Fr applied by the reaction force applying mechanism 26 in accordance with the target pedal operation amount Pt. The reaction force Fr can be set, for example, based on the set target pedal operation amount Pt by storing the relationship between the target pedal operation amount Pt and the reaction force Fr in the memory 34 in advance. Alternatively, the reaction force Fr can be increased rapidly with reference to the position of the pedal operation amount P when the cruise control is started.

  In step S6, the ECU 24 determines whether or not the cruise speed Vcr should be changed. This determination can be made, for example, based on whether or not the state where the difference between the actual pedal operation amount P and the target pedal operation amount Pt corresponding to the cruise speed Vcr is larger than a predetermined threshold continues for a predetermined time. When the cruise speed Vcr should be changed (S6: Yes), in step S7, the ECU 24 changes (updates) the cruise speed Vcr that can be maintained with the actual pedal operation amount P to the new cruise speed Vcr. . When the cruise speed Vcr should not be changed (S6: No), the process proceeds to step S8.

  In step S8, the ECU 24 determines whether or not the current vehicle speed V is equal to the cruise speed Vcr. If the current vehicle speed V is equal to the cruise speed Vcr (S8: Yes), the current process is terminated. When the current vehicle speed V and the cruise speed Vcr are different (S8: No), the process proceeds to step S9.

  In step S9, the ECU 24 calculates a target value (target throttle valve opening θt) [degree] of the throttle valve opening θ based on the difference between the current vehicle speed V and the cruise speed Vcr. In subsequent step S10, the ECU 24 determines whether or not the target throttle valve opening degree θt has increased. Since the initial value of the target throttle valve opening θt is zero, it is always determined that the target throttle valve opening θt is increasing in the first processing. When the target throttle valve opening θt is increasing (S10: Yes), the vehicle equipped with the vehicle travel control device 10 requires a higher output to keep the cruise speed Vcr constant (at the start of travel or uphill) This is considered to be during driving of the vehicle. On the other hand, when the target throttle valve opening degree θt is decreasing (S10: No), a vehicle equipped with the vehicle travel control device 10 needs a lower output to keep the cruise speed Vcr constant (during deceleration or descending) This is considered to be when driving on a slope. Therefore, when the target throttle valve opening degree θt is increasing (S10: Yes), in step S11, the ECU 24 executes high output request processing (details will be described later). When the target throttle valve opening degree θt is decreasing (S10: No), in step S12, the ECU 24 executes low output request processing (details will be described later). When the high output request process in step S11 or the low output request process in step S12 is executed, the current process is completed, and the process returns to step S1.

  FIG. 3 shows a flowchart of the high output request process in the present embodiment. In step S21, the ECU 24 determines whether or not the difference D1 (D1 = θt−θr) between the target throttle valve opening θt and the reference throttle valve opening θr is less than a first threshold THθup [degree] that is a positive value. Determine. The first threshold THθup is uncomfortable for the driver by determining the degree of deviation of the target throttle valve opening θt from the current reference throttle valve opening θr (corresponding to the target pedal operation amount Pt. S4 in FIG. 2). It is a threshold value for determining whether or not it has occurred. The value of the first threshold THθup can be determined by experiments or the like.

  When the difference D1 is less than the first threshold THθup (S21: Yes), in step S22, the ECU 24 continues the direct throttle valve control. The direct throttle valve control is control in which the ECU 24 automatically adjusts the throttle valve opening θ of the throttle valve 16 using the cruise speed Vcr as a control target value regardless of the operation of the accelerator pedal 12. That is, when the current vehicle speed V is lower than the cruise speed Vcr, the ECU 24 increases the throttle valve opening θ, and when the current vehicle speed V is higher than the cruise speed Vcr, the ECU 24 increases the throttle valve opening θ. Decrease. In direct throttle valve control, control techniques such as proportional / integral / derivative control (PID control) can be used.

  In step S21, when the difference D1 between the target throttle valve opening θt and the reference throttle valve opening θr is equal to or greater than the first threshold THθup (S21: No), in step S23, the ECU 24 applies the reaction force applying mechanism 26. The additional reaction force Fr is reduced. The reduction of the reaction force Fr will be described later.

  In subsequent step S24, the ECU 24 determines that the change amount [degree / s] of the throttle valve opening θ per unit time (hereinafter also referred to as “throttle valve opening change amount Δθ”) is a predetermined threshold value (second threshold value THΔθup). ) Or less. This determination may be performed based on the target throttle valve opening degree θt. Further, when the driver changes the pedal operation amount P according to the change in the reaction force Fr, the determination may be made based on the pedal operation amount P. The second threshold THΔθup is used to determine whether or not changes in the travel environment (road inclination, material, etc.) of the vehicle have converged to some extent. The throttle valve opening change amount Δθ is smaller than the second threshold THΔθup. In this case, it can be considered that the traveling environment of the vehicle is substantially constant. In step S24, if the throttle valve opening change amount Δθ is smaller than the threshold value THΔθup (S24: Yes), the process proceeds to step S25. In step S24, when the throttle valve opening change amount θ is equal to or greater than the second threshold THΔθup (S24: No), the process is terminated.

  In step S25, the ECU 24 sets a new target pedal operation amount Pt according to the current target throttle valve opening degree θt. This setting can be performed by storing the relationship between the target throttle valve opening θt and the target pedal operation amount Pt in the memory 34 in advance. Alternatively, the current pedal operation amount P may be set as a new target pedal operation amount Pt.

  In subsequent step S26, the ECU 24 sets the current target throttle valve opening θt as a new reference throttle valve opening θr (θr ← θt).

  FIG. 4 shows a flowchart of low output request processing in the present embodiment. In step S31, the ECU 24 determines whether or not the difference D2 (D2 = θr−θt) between the reference throttle valve opening θr and the target throttle valve opening θt is less than a positive third value THθdown [degrees]. Determine. This third threshold value THθdown, like the first threshold value THθup, determines the degree of deviation of the target throttle valve opening degree θt from the current reference throttle valve opening degree θr (corresponding to the target pedal operation amount Pt; S4 in FIG. 2). Thus, the threshold value for determining whether or not the driver feels uncomfortable. The value of the third threshold THθdown can be determined by experiments or the like.

  When the difference D2 is less than the third threshold value THθdown (S31: Yes), in step S32, the ECU 24 continues the direct throttle valve control described above. When the difference D2 is greater than or equal to the third threshold THθdown (S31: No), in step S33, the ECU 24 increases the additional reaction force Fr applied by the reaction force application mechanism 26. The increase in the reaction force Fr will be described later.

  In subsequent step S34, the ECU 24 determines whether or not the accelerator pedal 12 has been returned. Specifically, it is determined whether or not the change amount ΔP [θ / sec] per predetermined time of the pedal operation amount P detected by the operation amount sensor 14 is a negative value for a predetermined time. When the accelerator pedal 12 has been returned (S34: Yes), in step S35, the ECU 24 transmits a brake signal Sb to operate the brake system 28 and assists in deceleration of the vehicle. After step S35 or when the accelerator pedal 12 is not returned (S34: No), the process proceeds to step S36.

  In step S36, the ECU 24 determines whether or not the throttle valve opening change amount Δθ is smaller than a predetermined threshold value (fourth threshold value THΔθdown). This fourth threshold value THΔθdown is used to determine whether or not changes in the travel environment (road inclination, material, etc.) of the vehicle have converged to some extent, and the throttle valve opening change amount Δθ is greater than the fourth threshold value THΔθdown. When it is small, it can be considered that the traveling environment of the vehicle is substantially constant. In step S36, if the throttle valve opening change amount θ is smaller than the fourth threshold THΔθdown (S36: Yes), the process proceeds to step S37. Steps S37 and S38 are the same as steps S25 and S26 of FIG. In step S36, when the throttle valve opening change amount Δθ is equal to or greater than the fourth threshold THΔθdown (S36: No), the process is terminated.

  FIG. 5 shows an example of changes in the target throttle valve opening θt, the pedal operation amount P, and the reaction force Fr when the vehicle 100 equipped with the vehicle travel control device 10 of the present embodiment travels uphill. It is explanatory drawing.

  When the vehicle 100 has not yet reached an uphill and is traveling on a flat road (state (A) in FIG. 5), if traveling conditions such as road conditions are constant, the target throttle valve opening θt Is controlled to keep the current vehicle speed V equal to the cruise speed Vcr by continuing to take a substantially constant value (the target throttle valve opening θt1 in FIG. 5). At this time, the pedal operation amount P is constant at P1, and accordingly, the reaction force Fr characteristic (reaction force application characteristic C) applied to the accelerator pedal 12 is also constant {reaction force in the state of (A). The application characteristic C is referred to as “reaction force application characteristic C1”. }. In this case, the target throttle valve opening θt1 in FIG. 5 is larger than the difference between the current reference throttle valve opening θr (reference throttle valve opening θr1) and the third threshold THθdown, and the reference throttle valve opening θr1 And the first threshold value THθup is smaller than (θr1−THθdown <θ1 <θr1 + THθup).

  When the vehicle 100 moves uphill from a flat road {state (B) in FIG. 5}, the vehicle speed V decreases with respect to the cruise speed Vcr. Therefore, the ECU 24 controls the difference between the vehicle speed V and the cruise speed Vcr to be zero by increasing the target throttle valve opening θt.

  Specifically, when the target throttle valve opening degree θt becomes equal to or greater than the sum of the reference throttle valve opening degree θr1 and the first threshold value THθup at the time point t1 in FIG. 5 (S21: No in FIG. 3), the reaction force application characteristic C1. Instead, another reaction force application characteristic C (reaction force application characteristic C2) is used. This reaction force imparting characteristic C2 is a characteristic set so that the reaction force Fr decreases to the reference reaction force characteristic Cr as the pedal operation amount P increases with reference to the pedal operation amount P1 at time t1. The reference reaction force characteristic Cr is a characteristic in which the reaction force Fr is increased in a linear function as the pedal operation amount P increases. The reference reaction force characteristic Cr is set so as to always take a lower value than the footrest reference reaction force Fr_r [N] set as the reaction force Fr that balances the stepping force of the driver when the footrest is formed. Therefore, when the reaction force application characteristic C1 is switched to the reaction force application characteristic C2, the driver naturally depresses the accelerator pedal 12.

  Next, when the throttle valve opening change amount Δθ becomes equal to or smaller than the second threshold THΔθup at time t2 (S24: Yes), the pedal operation amount P (pedal operation amount P2) corresponding to the target throttle valve opening θt at time t2 is It is set as a reference pedal operation amount Pt (referred to herein as “reference pedal operation amount Pt2”) (step S25 in FIG. 3). Further, the target throttle valve opening degree θt (target throttle valve opening degree θt2) at the time point t2 is set as a new reference throttle valve opening degree θr (herein referred to as “reference throttle valve opening degree θr2”) ( Step S26 in FIG. Further, after passing through the transient reaction force application characteristic C3 with the reference pedal operation amount Pt2 as a reference, a reaction force application characteristic C4 is generated, and the reaction force Fr is applied based on the reaction force application characteristic C4.

  When the vehicle 100 finishes climbing uphill and returns to a flat road again (state (C) in FIG. 5), the vehicle speed V increases with respect to the cruise speed Vcr. Therefore, the ECU 24 controls the difference between the vehicle speed V and the cruise speed Vcr to be zero by decreasing the target throttle valve opening θt.

  Specifically, when the difference D2 between the reference throttle valve opening θr2 and the target throttle valve opening θt becomes equal to or greater than the third threshold THθdown at time t3 in FIG. 5 (S31: No in FIG. 4), reaction force is applied. Instead of the characteristic C4, another reaction force application characteristic C (reaction force application characteristic C5) is used. The reaction force imparting characteristic C5 is a characteristic that increases the reaction force Fr according to the difference between the pedal operation amount P2 and the current pedal operation amount Pcur. For this reason, when the reaction force application characteristic C4 is switched to the reaction force application characteristic C5, the driver is prompted to return the accelerator pedal 12.

  Further, after time t3, it is determined whether or not the accelerator pedal 12 has been returned (S34). When the accelerator pedal 12 is returned at time t4 (S34: Yes), the brake system 28 is operated, and the braking force Fb [N] is generated so that the difference between the vehicle speed V and the cruise speed Vcr is zero. (S35). Furthermore, when the throttle valve opening change amount Δθ becomes equal to or smaller than the fourth threshold THΔθdown at time t4 (S36: Yes), the pedal operation amount P (pedal operation amount P3) corresponding to the target throttle valve opening θt at time t5 is It is set as a target pedal operation amount Pt (here, referred to as “target pedal operation amount Pt3”) (step S37 in FIG. 4). Further, the target throttle valve opening degree θt at the time point t5 is set as a new reference throttle valve opening degree θr (herein referred to as “reference throttle valve opening degree θr3”) (step S38 in FIG. 4). Further, after passing through the transient reaction force application characteristic C6 with the target pedal operation amount Pt3 as a reference, a reaction force application characteristic C7 is generated, and the reaction force Fr is applied based on the reaction force application characteristic C7.

  FIG. 6 shows an example of changes in the target throttle valve opening θt, the pedal operation amount P, and the reaction force Fr when the vehicle 100 equipped with the vehicle travel control device 10 of the present embodiment travels on a downhill. It is explanatory drawing.

  Basically, the control in the state of FIG. 6A (when the vehicle 100 has not yet reached the downhill and is traveling on a flat road) is controlled in the state of FIG. The control is the same as when the vehicle is traveling on a flat road. The state of FIG. 6B (when moving from a flat road to a downhill) is the same as the control in the state of FIG. 5C (when returning from a flat road to a flat road). The state of FIG. 6C (when returning from a downhill to a flat road) is the same as the control in the state of FIG. 5B (when moving from a flat road to an uphill).

  More specifically, in FIG. 6, the target throttle valve opening θt11 and the reference throttle valve opening θr11 are the target throttle valve opening when the vehicle is traveling on a flat road in the state of FIG. θt and the reference throttle valve opening θr. The target throttle valve opening θt12 is the target throttle valve opening θt when the vehicle is going downhill in the state of FIG. 6B, and is equal to the new reference throttle valve opening θr12. The target throttle valve opening degree θt13 is the target throttle valve opening degree θt when returning from a downhill to a flat road in the state of FIG. 6C, and is equal to the new reference throttle valve opening degree θr13.

  The time point t11 is when the difference D2 between the reference throttle valve opening degree θr11 and the target throttle valve opening degree θt11 becomes equal to or greater than the third threshold value THθdown, and the time point t12 is a time when the accelerator pedal 12 is returned to the brake system. The time t13 is when the throttle valve opening change amount Δθ becomes equal to or less than the fourth threshold value THΔθdown. Time t14 is when the difference D1 between the reference throttle valve opening θ12 and the target throttle valve opening θt12 is greater than or equal to the first threshold THθup, and at time 15 the throttle valve opening change amount Δθ is the second threshold. This is when THΔθup or less.

  The reaction force application characteristic C11 is a reaction force application characteristic C when the target throttle valve opening θt is substantially constant at θt11, and the reaction force application characteristic C12 is a reaction force application characteristic C from time t11 to time t13. . The reaction force application characteristic C13 is a transient reaction force application characteristic C at time t13, and the reaction force application characteristic C14 is a reaction force application characteristic C from time t13 to time t14. The reaction force application characteristic C15 is a reaction force application characteristic C from time t14 to time t15, the reaction force application characteristic C16 is a transient reaction force application characteristic C at time t15, and the reaction force application characteristic C17 is This is the reaction force application characteristic C after time t15.

3. As described above, in the present embodiment, the pedal operation amount P that rapidly increases the reaction force Fr against the accelerator pedal 12 is set to the target throttle valve opening θt when the engine 30 of the vehicle 100 is operating. It changes according to the difference D1 and D2 with reference | standard throttle valve opening degree (theta) r. As a result, since the external load on the vehicle 100 has changed, such as when the vehicle 100 approaches a slope, when the output of the engine 30 is increased or decreased in order to maintain the cruise speed Vcr, the pedal operation amount depends on the external load. P can be varied. As a result, it is possible to prevent the driver from feeling uncomfortable due to the difference between the output of the engine 30 and the pedal operation amount P.

  In the present embodiment, the change in the pedal operation amount P that rapidly increases the reaction force Fr against the accelerator pedal 12 is such that the differences D1 and D2 between the target throttle valve opening θt and the reference throttle valve opening θr are the first threshold THθup, the third It is performed only when the threshold THθdown is exceeded, and is not performed when the threshold is not exceeded. Accordingly, the frequency at which the pedal operation amount P that causes the reaction force Fr to increase rapidly can be adjusted by appropriately setting the first threshold value THθup and the third threshold value THθdown. As a result, it is possible to avoid constantly changing the pedal operation amount P that rapidly increases the reaction force Fr, and to eliminate the driver's uncomfortable feeling caused by the change occurring when the change in the target throttle valve opening θt is small. it can.

  In the present embodiment, when the vehicle 100 accelerates due to a decrease in the external load on the vehicle 100 due to the vehicle 100 returning from the uphill to a flat road or approaching the downhill from the flat road, the brake system 28 is accelerated. Automatically decelerates the vehicle 100. This makes it easy to maintain the cruise speed Vcr even if the vehicle 100 starts to accelerate due to a decrease in the external load when the vehicle 100 travels.

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 case where the external load on the vehicle 100 changes due to the movement of the vehicle 100 from a flat road to a slope or the movement from a slope to a flat road has been described, but the present invention is not limited to this. For example, the external load on the vehicle 100 may change due to a change in road material (asphalt, gravel, etc.).

  In the above embodiment, the pedal operation amount P that rapidly increases the reaction force Fr depending on whether or not the difference D1, D2 between the target throttle valve opening θt and the reference throttle valve opening θr exceeds the first threshold THθup and the third threshold THθdown. However, it is not limited to this. For example, the difference may be changed depending on whether or not the difference between the throttle valve opening θ and the reference throttle valve opening θr exceeds the first threshold THθup and the third threshold THθdown.

  In the above embodiment, when the vehicle 100 returns from an uphill to a flat road or moves from a flat road to a downhill, the brake system 28 is automatically operable. A configuration may be used in which the vehicle 100 shifts down when returning from a flat road to a flat road or when moving from a flat road to a downhill.

  In the above embodiment, the ECU 24 determines whether the differences D1 and D2 between the target throttle valve opening θt and the reference throttle valve opening θr are within the range of the first threshold THθup and the third threshold THθdown or outside the range. Regardless, the direct throttle valve control can be continued, but when the difference D1, D2 exceeds the first threshold THθup and the third threshold THθdown, the pedal for rapidly increasing the reaction force Fr based on the target throttle valve opening θt. The throttle valve control may be stopped directly while changing the operation amount P. By doing so, it is possible to perform throttle valve control following the driver's pedal operation. Therefore, if the driver intends to maintain the vehicle speed V, the driver may operate the accelerator pedal 12 so as to follow the change in the pedal operation amount P that rapidly increases the reaction force Fr. It is possible to eliminate the uncomfortable feeling felt when the throttle valve opening θ is significantly changed without being operated.

  In the above embodiment, each step of FIG. 2 is performed by one ECU 24, but each step can be shared by a plurality of arithmetic devices.

1 is a block diagram of a vehicle travel control device according to an embodiment of the present invention. It is a flowchart of the vehicle travel control method in the vehicle travel control apparatus of FIG. It is a flowchart of the process at the time of a high output request in the embodiment. It is a flowchart of the process at the time of a low output request | requirement in the said embodiment. Explanatory drawing which shows an example of a change with the target throttle valve opening degree, pedal operation amount, and reaction force which a reaction force provision mechanism provides when the vehicle carrying the vehicle travel control apparatus of this embodiment drive | works an uphill. It is. Explanatory drawing which shows an example of a change with the target throttle valve opening degree, pedal operation amount, and reaction force which a reaction force provision mechanism provides when the vehicle carrying the vehicle travel control apparatus of this embodiment drive | works a downhill. It is.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Vehicle travel control apparatus 12 ... Accelerator pedal 14 ... Operation amount sensor (pedal operation amount detection part)
DESCRIPTION OF SYMBOLS 16 ... Throttle valve 18 ... Opening sensor 20 ... Vehicle speed sensor (vehicle speed detection part) 22 ... Cruise switch 24 ... ECU (Reaction force control part, constant speed cruise control part)
26 ... Reaction force application mechanism 28 ... Brake system (deceleration mechanism)
30 ... Engine (power source) 32 ... Intake pipe 34 ... Memory Fr ... Reaction force TH? Up ... First threshold TH ?? up ... Second threshold TH? Down ... Third threshold TH ?? down ... Fourth threshold V ... Vehicle speed Vcr ... Cruise speed P ... Pedal operation amount θ: Throttle valve solution θr: Reference throttle valve solution θt: Target throttle valve solution

Claims (5)

A vehicle speed detector for detecting the vehicle speed;
A pedal operation amount detector for detecting the pedal operation amount of the accelerator pedal;
A constant speed cruise control unit that sets a cruise speed of the vehicle and performs constant speed cruise control that automatically adjusts the opening of the throttle valve independently of the pedal operation amount so that the cruise speed and the vehicle speed coincide with each other. When,
A reaction force applying unit that rapidly increases a reaction force against the accelerator pedal by a pedal operation amount when the cruise speed is set;
A reaction force control unit for controlling the reaction force application unit;
A vehicle travel control device comprising:
The reaction force control unit, when external load on the vehicle is changed when the power source of the prior SL vehicle is operating, in accordance with the opening degree of the throttle valve required to maintain the cruise speed A vehicle travel control device characterized by changing a pedal operation amount for rapidly increasing the reaction force . The vehicle travel control device according to claim 1,
When the target opening of the throttle valve for making the cruise speed coincide with the vehicle speed or the actual opening following the target opening changes by a predetermined value or more, the reaction force control unit The vehicle travel control device, wherein the pedal operation amount to be rapidly increased is changed. In the vehicle travel control device according to claim 1 or 2,
The constant speed cruise control unit
Based on the difference between the vehicle speed and the cruise speed, the target opening of the throttle valve is calculated,
A reference throttle valve opening is set according to the target pedal operation amount based on the cruise speed,
The pedal operation amount for rapidly increasing the reaction force is changed according to the difference between the target opening of the throttle valve and the reference throttle valve opening.
The vehicle travel control apparatus characterized by the above-mentioned. In the vehicle travel control device according to any one of claims 1 to 3 ,
In addition, a deceleration mechanism for decelerating the vehicle is provided,
When the vehicle accelerates due to the decrease in the external load, the deceleration mechanism automatically decelerates the vehicle. A vehicle travel control method for performing constant speed cruise control that matches a vehicle cruise speed and a vehicle speed,
When an external load applied to the vehicle changes while the power source of the vehicle is operating, it is variable with respect to the accelerator pedal according to the opening degree of the throttle valve necessary for maintaining the cruise speed. vehicle travel control method for causing a change of the pedal operation amount to rapidly the reaction force to be applied to.

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