JP5193290B2 - Vehicle travel control device - Google Patents

Description

The present invention relates to a vehicle travel control equipment comprises a reaction force applying unit for applying a reaction force to the accelerator pedal. More specifically, it relates to the suitably controllable vehicle travel control equipment the operation amount of the accelerator pedal to increase the reaction force.

  A cruise traveling technique is widely known in which the throttle opening is automatically controlled separately from the operation of the accelerator pedal by the driver, and the vehicle speed or the distance between the preceding vehicle and the vehicle is constant. Some vehicles using this cruise traveling technology control the reaction force of an accelerator pedal (Japanese Patent Laid-Open No. 2006-143120). In Japanese Patent Application Laid-Open No. 2006-143120, a set speed (hereinafter also referred to as “cruise speed”) when performing cruise traveling can be adjusted by operating an accelerator pedal. In other words, the area where the driver can naturally place his right foot on the accelerator pedal ("footrest area") and the area for detecting the driver's intention to accelerate during cruise driving ("Acceleration detection area") is provided, and the vehicle speed is increased when the accelerator pedal is stepped over the footrest area to the acceleration detection area. When the accelerator pedal exits the acceleration 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 region (see paragraphs [0026] to [0033] of Japanese Patent Laid-Open No. 2006-143120, FIGS. 2 and 3).

  There is also a technique for applying a reaction force to an accelerator pedal other than during cruise driving (Japanese Patent Laid-Open No. 2003-260951). In JP-A-2003-260951, a vehicle speed threshold value is set according to vehicle speed and road condition information detected using a vehicle speed sensor, a steering angle sensor, a gradient sensor, and a vibration sensor, and when the vehicle speed reaches the threshold value, By applying a reaction force to the accelerator pedal, the driver is allowed to recognize that the speed is excessive (see the summary of Japanese Patent Laid-Open No. 2003-260951).

  As described above, Japanese Patent Laid-Open No. 2006-143120 is designed so that the position of the accelerator pedal is returned to the footrest area after setting a new cruise speed. That is, even if the cruise speed is changed, the footrest area is not changed and remains as it is. However, it is normal to adjust the amount of operation of the accelerator pedal in order to change the vehicle speed except during cruise driving. For this reason, the driver may feel uncomfortable because the footrest area is not changed even though the actual vehicle speed is changed in accordance with the change of the cruise speed. In other words, in Japanese Patent Application Laid-Open No. 2006-143120, the throttle opening cannot be directly controlled by operating the accelerator pedal in the footrest region during cruise traveling, and the throttle can be opened without operating the accelerator pedal. Since the degree is adjusted, the driver may feel uncomfortable.

  Japanese Patent Laying-Open No. 2003-260951 does not disclose a configuration that allows the driver to adjust the amount of operation of the accelerator pedal that increases the reaction force.

The present invention has been made in consideration of such problems, and an object thereof is to provide a vehicle travel control equipment which can be suitably controlled application of reaction force to the accelerator pedal.

  A vehicle travel control device according to the present invention sets a reaction force applying unit that applies a reaction force to an accelerator pedal, a vehicle speed detecting unit that detects a vehicle speed, a target speed of the vehicle, and the vehicle speed exceeds the target speed A reaction force control unit that increases the reaction force applied by the reaction force application unit; a target speed change command input unit that inputs a change command of the target speed to the reaction force control unit by a driver's operation; The reaction force control unit changes the operation amount of the accelerator pedal that increases the reaction force by changing the target speed according to the change command input from the target speed change command input unit. It is characterized by making it.

  In the present invention, the operation speed of the accelerator pedal for increasing the reaction force is changed by changing the target speed as a guideline for increasing the reaction force by the operation of the driver. Thereby, the operation amount of the accelerator pedal which gives reaction force also changes with the change of the target speed by a driver | operator's operation. Therefore, the driver does not feel uncomfortable with the operation amount of the accelerator pedal that increases the reaction force, and can suitably control the application of the reaction force to the accelerator pedal.

  The vehicle travel control device includes an operation amount detection unit that detects an operation amount of the accelerator pedal, the target speed change command input unit is the accelerator pedal, and the reaction force control unit operates the accelerator pedal. It is preferable to change the target speed according to the amount. Thereby, the target speed is changed in accordance with the operation of the accelerator pedal by the driver. Since the operation of the accelerator pedal faithfully reflects the driver's intention of acceleration / deceleration, it is possible to prevent the driver from feeling uncomfortable between the change of the target speed and the movement of the accelerator pedal.

  The reaction force control unit is configured such that a vehicle speed when the accelerator pedal is held for a certain time with the same operation amount, a vehicle speed when the accelerator pedal depressing speed or a returning speed is decreased, and the accelerator pedal is released from the depressed state. Or the vehicle speed when the accelerator pedal is depressed from the return state can be used as the new target speed.

  When the accelerator pedal is held at the same operating amount for a certain period of time, when the accelerator pedal depressing speed or return speed decreases, when the accelerator pedal is released from the depressed state, and when the accelerator pedal is depressed from the returned state In either case, it is highly possible that the speed change desired by the driver has been achieved. Therefore, the target speed desired by the driver can be accurately and naturally set by using the vehicle speed when these conditions are satisfied as the target speed.

  The vehicle travel control device further includes a travel environment determination unit that determines a travel environment of a vehicle on which the vehicle travel control device is mounted and a travel environment response speed corresponding to the travel environment, and the reaction force control unit The target speed may be set according to the traveling environment-compatible speed and the change command. As a result, the target speed is updated both when the driving environment response speed changes and when there is a change command, so even if the driving speed changes due to the driver's intention, the driving environment changes. In this case, by setting the target speed according to the new speed corresponding to the travel environment, it is possible to apply the reaction force according to the travel environment. Furthermore, since the target speed can be updated again according to the driver's intention, the target speed can be set according to the driver's intention after the driver recognizes the change in the driving environment.

  The reaction force control unit compares the traveling environment correspondence speed before the update with the updated traveling environment correspondence speed when the traveling environment correspondence speed is updated, and compares the updated traveling environment correspondence speed. When it is determined that the vehicle speed is small, it is preferable that the updated travel environment response speed is set as the target speed. If the updated travel environment response speed is smaller than the previous travel environment support speed, it can be said that the vehicle has changed to a travel environment in which the vehicle should be decelerated. In this case, regardless of the driver's intention, the updated driving environment response speed is set as the target speed, and when the vehicle speed exceeds the new target speed, the reaction force is increased to prompt the driver to decelerate. be able to.

The vehicle travel control device further includes a deceleration mechanism that decelerates the vehicle, and after the traveling environment-compatible speed is updated, a predetermined deceleration operation from the driver for the deceleration mechanism or a predetermined amount of the accelerator pedal or more. When the return or the return of the accelerator pedal at a predetermined speed or higher is performed, the reaction force control unit may set the updated speed corresponding to the traveling environment as the target speed. When the driver decelerates or the accelerator pedal is returned, it is highly likely that the driving environment has changed.By setting the updated driving environment speed as the target speed, the target speed corresponding to the driving environment Therefore, the driver can travel according to the traveling environment after deceleration.

1 is a block diagram of a vehicle travel control device according to an embodiment of the present invention. 2 is a flowchart for determining a target speed limit and reaction force in the vehicle travel control apparatus of FIG. 1. FIG. 3A is a diagram illustrating an example of a reaction force application characteristic used when the vehicle travel control device is activated, and FIG. 3B is a diagram illustrating an example of a reaction force application characteristic when the target speed limit is changed. FIG. 3C is a diagram illustrating an example of a reaction force imparting characteristic when the recommended speed from the navigation system decreases. It is a flowchart for setting reaction force based on the current vehicle speed, the target speed limit, and the timer value of the timer. It is a time chart which shows an example of the relationship between a recommended speed and a target speed limit. It is a block diagram of the vehicle travel control apparatus which concerns on the modification of this invention. 7 is a flowchart for determining a target speed limit and a reaction force in the vehicle travel control apparatus of FIG. 6.

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. Basically, an accelerator pedal 12, an operation amount sensor 14, a vehicle speed sensor 16, a navigation system 18 (a travel environment determination unit), , An ECU (electric control unit) 20, a reaction force applying mechanism 22, and a brake system 24. The operation amount sensor 14 detects an operation amount (pedal operation amount θ) [degree] from the original position of the accelerator pedal 12 and outputs it to the ECU 20. The vehicle speed sensor 16 measures a vehicle speed V [km / hour] of a vehicle (not shown) and outputs it to the ECU 20. The navigation system 18 includes a memory 26 that can detect the position of the vehicle using GPS (Global Positioning System) and stores information on the recommended speed Vrec [km / hour] (traveling environment-compatible speed) of each road. ing. The recommended speed Vrec indicates, for example, a speed at which fuel consumption can be optimized or a speed limit depending on the situation of each road. The speed at which the fuel consumption can be optimized can be set in advance depending on the fuel consumption performance characteristics of the vehicle, the road gradient, the road type (asphalt, gravel road, etc.), the presence or absence of a curve, and the like. Then, the navigation system 18 notifies the ECU 20 of the recommended speed Vrec corresponding to the detected vehicle position.

  When the brake system 24 performs a predetermined deceleration operation, the brake system 24 transmits to the ECU 20 a deceleration operation notification signal Sb for notifying that the deceleration operation has been performed. As the predetermined deceleration operation, for example, the fact that a brake pedal (not shown) constituting the brake system 24 has been depressed more than a predetermined value, and that the depression speed of the brake pedal has become a predetermined value or more is used. Can be used. The ECU 20 can also determine the predetermined deceleration operation using the vehicle speed V or the return of the accelerator pedal 12 instead of determining the predetermined deceleration operation using the deceleration operation notification signal Sb.

  The ECU 20 calculates the target upper limit speed Vtar [km / hour] using the recommended speed Vrec, the vehicle speed V, the pedal operation amount θ, and the deceleration operation notification signal Sb, and based on the relationship between the calculated target upper limit speed Vtar and the vehicle speed V. To calculate the reaction force Fr [N]. The target upper limit speed Vtar indicates an upper limit speed that is provisionally set and can be changed. Then, a control signal Sr corresponding to the calculated reaction force Fr is generated and transmitted to the reaction force applying mechanism 22. Details of the method for determining the reaction force Fr will be described later. The ECU 20 includes a timer 28.

  The reaction force applying mechanism 22 includes a motor (not shown) connected to the accelerator pedal 12 and applies a reaction force Fr corresponding to the control signal Sr received from the ECU 20 to the accelerator pedal 12. As a result, in addition to the original position return force of the accelerator pedal 12 itself (force to return to the original position), the reaction force Fr from the reaction force applying mechanism 22 is added to the accelerator pedal 12.

2. Setting Method for Determining Target Upper Limit Speed Vtar and Reaction Force Fr FIG. 2 shows a flowchart for determining the target upper limit speed Vtar and the reaction force Fr.

  In step S <b> 1, the ECU 20 acquires the current recommended speed Vrec {recommended speed Vrec (current)} from the navigation system 18. In subsequent step S2, it is determined whether or not the current process (the process in the flowchart of FIG. 2) is the first time. This determination can be performed using, for example, the determination flag FLG. That is, the initial value of the determination flag FLG {the value when the flowchart of FIG. 2 is started (for example, when the ignition switch is turned on)} is set to “0”. In step S10 described later, the determination flag FLG is changed from “0” to “1” to indicate that the current process is the second or later as long as the flowchart of FIG. 2 is repeated.

  If the current process is the first time in step S2 (S2: Yes), in step S3, the ECU 20 sets the recommended speed Vrec (current) as the target upper limit speed Vtar {Vtar ← Vrec (current)}. After step S3, the process proceeds to step S7.

  If the current process is not the first time in step S2 (S2: No), in step S4, the ECU 20 determines whether the recommended speed Vrec (current) is less than the previous recommended speed Vrec {recommended speed Vrec (previous)}. To do. Thereby, it can be determined whether there has been a change in the traveling environment of the vehicle. When the recommended speed Vrec (current) is less than the recommended speed Vrec (previous) (S4: Yes), in step S5, the ECU 20 sets a predetermined timer value TMR [seconds] (for example, 3 seconds) in the timer 28. . When the timer value TMR is not yet zero and the process returns to step S5, the timer value TMR is set again to the initial value (for example, 3 seconds).

  After step S5, the process proceeds to step S3, where the recommended speed Vrec (current) is set as the target upper limit speed Vtar. When there is a change in the traveling environment of the vehicle in step S4 and subsequent step S3, the change of the target upper limit speed Vtar by the driver is reset and the target upper limit speed Vtar corresponding to the new traveling environment is set. be able to.

  When the recommended speed Vrec (current) is equal to or higher than the recommended speed Vrec (previous) in step S4 (S4: No), the process proceeds to step S6. In step S6, the ECU 20 determines whether or not the brake system 24 has performed a predetermined deceleration operation using the deceleration operation notification signal Sb from the brake system 24. When the brake system 24 performs a predetermined deceleration operation (S6: Yes), the process proceeds to step S3. When the brake system 24 is not performing the predetermined deceleration operation (S6: No), the process proceeds to step S7. Note that the deceleration operation in step S6 may be determined by the return amount or return speed of the accelerator pedal 12. That is, it can be determined that the deceleration operation has been performed when the return amount or the return speed of the accelerator pedal 12 exceeds a predetermined value. The deceleration operation may be a downshift.

  In step S7, the ECU 20 determines the reaction force Fr based on the current vehicle speed V, the current target upper limit speed Vtar {target upper limit speed Vtar (current)}, and the timer value TMR.

  FIG. 3A shows a reaction force application characteristic C1 (relationship between the vehicle speed V and the reaction force Fr) when the process shown in the flowchart of FIG. 2 is performed for the first time. In FIG. 3A, the reaction force Fr changes between the target upper limit speed Vtar and a speed slower than the target upper limit speed Vtar by a predetermined speed (reaction force application lower limit speed V1). That is, the reaction force Fr increases steeply from the reaction force application lower limit speed V1 toward the target upper limit speed Vtar. Further, the reaction force Fr is kept constant at the maximum value Fr_max between the target upper limit speed Vtar and a speed (reaction force application upper limit speed V2) that is a predetermined speed higher than the target upper limit speed Vtar. When the vehicle speed V falls below the reaction force application lower limit speed V1, or when the vehicle speed V exceeds the reaction force application upper limit speed V2, the reaction force Fr is set to zero. In other words, the reaction force application characteristic C1 in the present embodiment starts from the reaction force application lower limit speed V1 and increases the reaction force Fr as the vehicle speed V increases, and when the vehicle speed V reaches the target upper limit speed Vtar, the reaction force The reaction force Fr is maintained at the maximum value Fr_max until the application upper limit speed V2 is exceeded. When the vehicle speed V exceeds the reaction force application upper limit speed V2, the reaction force Fr is set to zero. As described above, the original position returning force is applied to the accelerator pedal 12 itself. For this reason, even if the reaction force Fr from the reaction force application mechanism 22 becomes zero, the accelerator pedal 12 is applied with a force to return to the original position.

  Further, the reaction force imparting characteristic C1 of the present embodiment includes the relationship between the vehicle speed V and the target upper limit speed Vtar (operation of the accelerator pedal 12 by the driver) and the timer value TMR of the timer 28 (recommended speed Vrec acquired from the navigation system 18). It changes according to. Details of these will be described later with reference to FIGS. 3B, 3C, and 4.

  In subsequent step S8, the ECU 20 determines whether or not the pedal operation amount θ is constant for a predetermined time (for example, 5 seconds). This determination can be performed as follows, for example. That is, it is determined whether or not the previous pedal operation amount θ matches the current pedal operation amount θ. If they match, the count value of a counter (not shown) is increased, and if they do not match, the count value of the counter is set to zero. . When the count value reaches a predetermined value, it is determined that the pedal operation amount θ is constant for a predetermined time.

  When the pedal operation amount θ is not constant for a predetermined time in step S8 (S8: No), the process proceeds to step S10. When the pedal operation amount θ is constant for a predetermined time in step S8 (S8: Yes), in step S9, the step ECU 20 sets the current vehicle speed V as the target upper limit speed Vtar (Vtar ← V). Thereby, the reaction force application characteristic C1 changes to, for example, the reaction force application characteristic C2 illustrated in FIG. 3B. That is, when the driver depresses the accelerator pedal 12 and the vehicle speed V exceeds the target upper limit speed Vtar for a predetermined time (for example, 5 seconds), the vehicle speed V (> Vtar) becomes the new target upper limit speed Vtar. Set as Accordingly, the range of the vehicle speed V in which the reaction force Fr is generated shifts to the right side in FIG. 3B, and the reaction force Fr is generated (increased) at a higher vehicle speed V. As a result, the reaction force Fr becomes the maximum value Fr_max at the pedal operation amount θ of the accelerator pedal 12 that maintains the current vehicle speed V, that is, the current pedal operation amount θ. In other words, the pedal operation amount θ at which the reaction force Fr increases is reset.

  In step S10, the ECU 20 sets the determination flag FLG to “1”. Then, the current process (the process shown in the flowchart of FIG. 2) is terminated, and the next process is started (return to step S1).

  FIG. 4 shows a flowchart (details of step S7 in FIG. 2) for determining the reaction force Fr. In step S71, the ECU 20 calculates a reaction force application lower limit speed V1 and a reaction force application upper limit speed V2 according to the target upper limit speed Vtar obtained in steps S3 and S9 of FIG. The reaction force application lower limit speed V1 is set to a speed that is a predetermined speed slower than the target upper limit speed Vtar, and the reaction force application lower limit speed V2 is set to a speed that is higher than the target upper limit speed Vtar by a predetermined speed.

  In step S72, the ECU 20 determines whether or not the current vehicle speed V is equal to or lower than the reaction force application lower limit speed V1. If the current vehicle speed V is equal to or lower than the reaction force application lower limit speed V1 (S72: Yes), the ECU 20 sets the reaction force Fr against the accelerator pedal 12 to zero in step S73. If the current vehicle speed V is greater than the reaction force application lower limit speed V1 (S72: No), the process proceeds to step S74.

  In step S74, the ECU 20 determines whether or not the current vehicle speed V is less than the target upper limit speed Vtar. When the current vehicle speed V is less than the target upper limit speed Vtar (S74: Yes), in step S75, the ECU 20 determines the reaction force Fr using the function formula f (V). The function formula f (V) is a function formula that defines a reaction force Fr that increases with an increase in the vehicle speed V, like the reaction force application characteristic C1 in FIG. 3A. When the current vehicle speed V is equal to or higher than the target upper limit speed Vtar (S74: No), the process proceeds to step S76.

  In step S76, the ECU 20 determines whether the timer value TMR of the timer 28 is greater than zero. When the timer value TMR is greater than zero (S76: Yes), in step S77, the ECU 20 sets the reaction force Fr to the maximum value Fr_max. When the timer value TMR is zero (S76: No), the process proceeds to step S78.

  In step S78, the ECU 20 determines whether or not the current vehicle speed V is equal to or lower than the reaction force application upper limit speed V2. When the current vehicle speed V is equal to or less than the reaction force application upper limit speed V2 (S78: Yes), the process proceeds to step S77, and the reaction force Fr is set to the maximum value Fr_max as described above. When the current vehicle speed V is greater than the reaction force application upper limit speed V2 (S78: No), in step S79, the ECU 20 sets the reaction force Fr to zero.

  FIG. 3C shows a state where the reaction force imparting characteristics C1 and C2 of FIG. 3A or 3B are used, the recommended speed Vrec (current) is less than the recommended speed Vrec (previous), and the recommended speed Vrec (current) is a new target. An example of the reaction force application characteristic C3 used when the timer value TMR of the timer 28 is not zero after being set to the upper limit speed Vtar is shown. In other words, the reaction force characteristic is shown when the timer value TMR is greater than zero in step S76 of FIG. In the reaction force application characteristic C3 of FIG. 3C, the reaction force Fr is always set to the maximum value Fr_max if the vehicle speed V is equal to or higher than the target upper limit speed Vtar. Therefore, the pedal operation amount θ of the accelerator pedal 12 is induced to a value corresponding to the target upper limit speed Vtar. In this case, the reaction force Fr may be greater than or equal to the maximum value Fr_max.

  FIG. 5 shows an example of the relationship between the recommended speed Vrec output from the navigation system 18 and the target upper limit speed Vtar set by the ECU 20. When the vehicle travel control device 10 starts the process shown in FIG. 2, first, the recommended speed Vrec (speed Va in FIG. 5) is set as the target upper limit speed Vtar (S1 to S3 in FIG. 2). Then, until the recommended speed Vrec is changed (S4: Yes → S5 → S3) or until the target upper limit speed Vtar is changed by the operation of the accelerator pedal 12 by the driver (S8: Yes → S9), the recommended speed Vrec is changed. It continues to be used as the target upper limit speed Vtar.

  At time t1, the target upper limit speed Vtar is changed by operating the accelerator pedal 12 (S8: Yes → S9), so the target upper limit speed Vtar increases, and at time t2, the speed becomes Vb in FIG. Next, at time t3, the recommended speed Vrec is reduced to the speed Vc in FIG. 5, and the target upper limit speed Vtar is also reduced to the new recommended speed Vrec (S4: Yes → S5 → S3). At time t4, the target upper limit speed Vtar is changed again by operating the accelerator pedal 12 (S8: Yes → S9), so that the target upper limit speed Vtar increases and is set to the speed Vd in FIG. 5 at time t5. .

3. As described above, in the present embodiment, the target upper limit speed Vtar as a guideline for increasing the reaction force Fr is changed by operating the driver, that is, by operating the accelerator pedal 12. The pedal operation amount θ that increases the force Fr is changed. Accordingly, the pedal operation amount θ of the accelerator pedal 12 that increases the reaction force Fr also changes with the change of the target upper limit speed Vtar by the driver's operation. Therefore, the driver does not feel uncomfortable with the pedal operation amount θ of the accelerator pedal 12 that increases the reaction force Fr, and can suitably control the application of the reaction force Fr to the accelerator pedal 12.

  In the present embodiment, the target upper limit speed Vtar is changed with the operation of the accelerator pedal 12 by the driver. Since the operation of the accelerator pedal 12 faithfully reflects the driver's intention of acceleration / deceleration, avoiding the driver feeling uncomfortable between the change of the target upper limit speed Vtar and the movement of the accelerator pedal 12. Can do.

  In the present embodiment, the ECU 20 uses the vehicle speed V when the accelerator pedal 12 is held for a certain time (for example, 5 seconds) as the new target upper limit speed Vtar (S8 in FIG. 2: Yes → S9). When the accelerator pedal 12 is held for a certain period of time, there is a high possibility that the speed change desired by the driver has been achieved. Therefore, by using the vehicle speed V when this condition is satisfied as the target upper limit speed Vtar, the target upper limit speed Vtar desired by the driver can be set accurately and naturally.

  In the present embodiment, the target upper limit speed Vtar is set according to the recommended speed Vrec from the navigation system 18 and the pedal operation amount θ of the accelerator pedal 12 (S3 and S9 in FIG. 2). That is, since the target upper limit speed Vtar is updated both when the recommended speed Vrec changes and when the pedal operation amount θ is constant for a predetermined time, it is assumed that the target upper limit speed Vtar has changed due to the driver's intention. However, when the traveling environment changes, the reaction force Fr according to the traveling environment can be applied by setting the target upper limit speed Vtar according to the new recommended speed Vrec. Furthermore, since the target upper limit speed Vtar can be updated again according to the driver's intention, it is possible to set the target speed Vtar according to the driver's intention after the driver recognizes the change in the driving environment. It becomes.

  In the present embodiment, after the recommended speed Vrec is updated, the recommended speed Vrec before update (previous) and the recommended speed Vrec after update (current) are compared, and the recommended speed Vrec after update (current) is smaller. Is determined, the updated recommended speed Vrec (current) is set as the target upper limit speed Vtar (S4 in FIG. 2: Yes → S3). If the recommended speed Vrec after updating (current) is smaller than the recommended speed Vrec before updating (previous), it can be said that the vehicle has changed to a traveling environment in which the vehicle should be decelerated. In this case, regardless of the driver's intention, the updated recommended speed Vrec (current) is set as the target upper limit speed Vtar, and the reaction force Fr is increased when the vehicle speed V exceeds the new target upper limit speed Vtar. Thus, the driver can be prompted to slow down.

  In the present embodiment, the vehicle travel control apparatus 10 includes the brake system 24, and after the recommended speed Vrec is updated, when the brake system 24 performs a predetermined deceleration operation by the driver's operation, the ECU 20 Is set as the target upper limit speed Vtar (S6 in FIG. 2: Yes → S3). When the driver decelerates, there is a high possibility that the driving environment has changed. By setting the target upper limit speed Vtar to the recommended speed Vrec after updating, the target upper limit speed Vtar corresponding to the driving environment is set. Therefore, the driver can travel in accordance with the traveling environment after deceleration.

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 said embodiment, although the recommended speed Vrec was acquired from the navigation system 18, it is not restricted to this. For example, it can also be obtained from outside the vehicle using wireless communication. In the embodiment described above, the recommended speed Vrec is acquired from the navigation system 18, but a configuration in which the ECU 20 calculates the recommended speed Vrec is also possible.

  In the above embodiment, the recommended speed Vrec is exemplified by the speed and the speed limit that can optimize the fuel consumption according to the situation of each road. However, the recommended speed Vrec can be determined from other matters. For example, the cruise speed (the set speed when performing cruise travel) can be used instead of the recommended speed Vrec. Alternatively, the recommended speed Vrec can be determined using distance information with the preceding vehicle, weather information (including information on the operation status of the wiper, raindrop sensor information, etc.), traffic jam information, past accident history, and the like.

  FIG. 6 shows a configuration using the initial value Vcr of the cruise speed as the recommended speed Vrec, that is, a vehicle travel control apparatus 10a as a modified example in which the present invention is applied to cruise control. In the vehicle travel control device 10a of FIG. 6, the same reference numerals are given to the same configurations as those of the vehicle travel control device 10 of FIG. The vehicle travel control device 10a does not have the navigation system 18 of FIG. 1, but has a cruise control start switch 30 that instructs the driver to start cruise control. When the cruise control start switch 30 is pushed by the driver, the cruise control start switch 30 transmits a cruise control start signal Sc to the ECU 20 to instruct the start of cruise control. The ECU 20 includes a memory 32 that stores an initial value Vcr of the cruise speed. The vehicle travel control apparatus 10a controls the reaction force Fr against the accelerator pedal 12 using a target cruise speed Vtar2 that is set based on the initial value Vcr and can be changed by the driver's operation.

  FIG. 7 shows a flowchart for determining the target cruise speed Vtar2 and the reaction force Fr. In step S21, it is determined whether or not the current process (the process of the flowchart of FIG. 7) is the first time. The process of step S21 can be performed similarly to step S2 of FIG. When this process is the first time (S21: Yes), in step S22, the ECU 20 reads the initial value Vcr of the cruise speed from the memory 32, and sets the initial value Vcr as the target cruise speed Vtar2 in step S23. After step S23, the process proceeds to step S25.

  If the current process is not the first time in step S21 (S21: No), in step S24, the ECU 20 determines whether or not the brake system 24 has performed a predetermined deceleration operation. The process of step S24 can be performed similarly to step S6 of FIG. When the brake system 24 is not performing the predetermined deceleration operation (S24: No), the process proceeds to step S25. When the brake system 24 is performing a predetermined deceleration operation (S24: Yes), the process proceeds to step S22 described above.

  In step S25, the ECU 20 determines the reaction force Fr based on the current vehicle speed V and the current target cruise speed Vtar2. The process in step S25 is the same as that in step S7 in FIG. 2 except that the timer value TMR is not used. As shown in FIGS. 3A to 3C, the selected reaction force imparting characteristics and the vehicle speed V are used. The reaction force Fr is determined. In other words, the accelerator pedal 12 during cruise traveling can directly control the throttle opening of a throttle valve (not shown) as well as changing the target cruise speed Vtar2, so that the driver does not feel uncomfortable.

  Subsequent steps S26, S27, and S28 are the same as steps S8, S9, and S10 of FIG.

  In the above embodiment, the trigger (condition) for setting the current vehicle speed V as the target speed limit Vtar is that the pedal operation amount θ is constant for a predetermined time (step S8: Yes in FIG. 2). I can't. For example, when the accelerator pedal 12 depressing speed or the returning speed is decreased, when the accelerator pedal 12 is released from the depressed state, or when the accelerator pedal 12 is depressed from the returned state, the vehicle speed V is set as a new target speed limit. It may be used as Vtar. Even in these cases, there is a high possibility that the speed change desired by the driver has been achieved. Therefore, by using the vehicle speed V when these conditions are satisfied as the target speed limit Vtar, the target speed limit Vtar desired by the driver can be set accurately and naturally.

  In the above embodiment, when the vehicle speed V is lower than the reaction force application lower limit speed V1, or when the vehicle speed V exceeds the reaction force application upper limit speed V2 when the reaction force application characteristics C1 and C2 are selected, the reaction force Fr is set. Although it is set to zero, it is not necessarily required to be zero.

  In the above embodiment, the target speed limit Vtar can be changed by operating the accelerator pedal 12 by the driver. However, the present invention is not limited to this. For example, a button for changing the target speed limit Vtar is provided. The target speed limit Vtar may be changed.

  In the above embodiment, the reaction force Fr is increased by inclining from the reaction force application lower limit speed V1 to the target upper limit speed Vtar. However, the reaction force Fr is set to zero from the reaction force application lower limit speed V1 to the target upper limit speed Vtar, and the target The maximum value Fr_max may be discontinuously (pulse-like) at the upper limit speed Vtar.

Claims (1)

A reaction force applying section (22) for applying a reaction force to the accelerator pedal (12);
A vehicle speed detector (16) for detecting the vehicle speed;
A reaction force control unit (20) for setting a target speed of the vehicle and increasing the reaction force applied by the reaction force application unit (22) when the vehicle speed exceeds the target speed;
A target speed change command input unit (12) for inputting a target speed change command to the reaction force control unit (20) by a driver's operation;
A traveling environment determination unit (18) for determining a traveling environment of the vehicle and a traveling environment-compatible speed according to the traveling environment;
A deceleration mechanism (24) for decelerating the vehicle,
The reaction force control unit (20)
By changing the target speed according to the change command input from the target speed change command input unit (12), the operation amount of the accelerator pedal (12) that increases the reaction force is changed,
When the travel environment correspondence speed has been updated, when the travel environment correspondence speed before the update and the updated travel environment correspondence speed are compared, and it is determined that the updated travel environment correspondence speed is smaller, When the updated driving environment response speed is set as a new target speed, and the updated driving environment response speed is determined to be greater, the target speed is maintained,
Even when towards the running environment corresponding rate after update is determined to be larger, the return of more than a predetermined amount of predetermined deceleration operation or the accelerator pedal from the driver with respect to the reduction mechanism (24) (12) or The vehicle travel control device (10), wherein when the accelerator pedal (12) is returned at a speed equal to or higher than a predetermined speed, the updated speed corresponding to the travel environment is set as a new target speed.

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