JP2018090064A - Travel control device, vehicle, control method for travel control device, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a sense of discomfort during vehicle stop control.SOLUTION: A travel control device includes braking force control means for controlling a braking force of a vehicle, driving force control means for controlling a driving force of the vehicle, and stop control means for performing control for stopping the vehicle, by controlling the braking force control means and the driving force control means. The stop control means increases the braking force to a second value, which enables the vehicle to be stopped, when the driving force reaches a predetermined first value after the vehicle is stopped, by using the braking force and the driving force.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vehicle travel control technique.

  A technique for realizing smooth driving by controlling a braking force and a driving force of a vehicle to control start, travel, and stop of the vehicle has been studied. Patent Document 1 describes a control technique for reducing the uncomfortable feeling when starting a gradient by releasing the braking force after increasing the driving force to a value corresponding to the gradient when the vehicle starts from a position with a gradient. Has been.

JP 2010-269671 A

  In patent document 1, although the control at the time of starting was examined, there existed the subject that the control at the time of a stop was not examined.

  The present invention has been made in view of the above problems, and an object thereof is to reduce a sense of incongruity during stop control of a vehicle.

  According to the present invention, the braking force control means for controlling the braking force of the vehicle, the driving force control means for controlling the driving force of the vehicle, the braking force control means, and the driving force control means are controlled to Stop control means for controlling to stop the vehicle, and the stop control means stops the vehicle using the braking force and the driving force, and then the driving force is a predetermined first value. A travel control device is provided, wherein the braking force is increased to a second value at which the vehicle can be stopped.

  In addition, according to the present invention, there is provided a control method for a travel control device, comprising: a braking force control unit that controls a braking force of a vehicle; and a driving force control unit that controls the driving force of the vehicle, wherein the braking force The braking force is increased to a second value at which the vehicle can stop when the driving force reaches a predetermined first value after controlling the driving force and the driving force. There is provided a control method characterized by comprising steps.

  Further, according to the present invention, the braking force control means for controlling the braking force of the vehicle and the driving force control means for controlling the driving force of the vehicle are provided in a computer provided in a travel control device. The braking force is increased to a second value at which the vehicle can stop when the driving force reaches a predetermined first value after controlling the driving force and the driving force. A program is provided.

  According to the present invention, it is possible to reduce a sense of incongruity during vehicle stop control.

The block diagram explaining the structure of a vehicle. The figure which shows the example of the relationship between the vehicle speed when not performing stop control of embodiment, and braking / driving force. The figure which shows the 1st example of the relationship between the vehicle speed and braking / driving force in the case of performing stop control of embodiment. The figure which shows the 2nd example of the relationship between the vehicle speed and braking / driving force in the case of performing stop control of embodiment. The figure which shows the 3rd example of the relationship between the vehicle speed and braking / driving force in the case of performing stop control of embodiment. The figure which shows the example of the relationship between the vehicle speed when not performing deceleration control of embodiment, and braking / driving force. The figure which shows the 1st example of the relationship between the vehicle speed and braking / driving force in the case of performing deceleration control of embodiment. The figure which shows the 2nd example of the relationship between the vehicle speed and braking / driving force in the case of performing deceleration control of embodiment. The figure which shows the 3rd example of the relationship between the vehicle speed and braking / driving force in the case of performing deceleration control of embodiment. The flowchart which shows the flow of the process which a traveling control part performs.

  Embodiments of the present invention will be described below with reference to the accompanying drawings. Throughout the various embodiments, similar elements are given the same reference numerals, and redundant descriptions are omitted. In addition, each embodiment can be appropriately changed and combined.

<Vehicle configuration>
FIG. 1 is a block diagram illustrating the configuration of a vehicle 100 according to at least some embodiments of the present invention. The vehicle 100 may be any of a two-wheeled vehicle, a three-wheeled vehicle, a four-wheeled vehicle, and the like. The vehicle 100 may be any of a gasoline vehicle, a hybrid vehicle, an electric vehicle, and the like.

  The vehicle 100 includes a travel control device 101 for controlling the travel of the vehicle 100. The travel control device 101 can be realized by an electronic control unit (ECU) that is a computer. The travel control device 101 includes a processor 102 configured with a central processing unit (CPU) and the like, and a memory 103 configured with a combination of ROM, RAM, and the like. The functional blocks such as the traveling control unit 104 included in the traveling control device 101 may be realized by a program stored in the memory 103. In this case, the processor 102 executes the program to thereby execute the function of each functional block. Is executed. Instead, the functional block of the travel control device 101 may be realized by a dedicated circuit such as an ASIC (Application Specific Integrated Circuit). Furthermore, the traveling control apparatus 101 may be realized by one ECU, or may be realized by a plurality of ECUs that can communicate through a network such as a CAN (controller area network). When the traveling control device 101 is realized by a plurality of ECUs, each ECU has a processor 102 and a memory 103 and one or more functional blocks included in the traveling control device 101.

  The requested braking / driving force determination unit 105 receives a signal from the accelerator sensor 112 that detects the stroke amount of the access pedal 111 and a signal from the brake sensor 114 that detects the stroke amount of the brake pedal 113. The requested braking / driving force determination unit 105 determines the braking / driving force (at least one of braking force and driving force) requested by the driver of the vehicle 100 with respect to the vehicle 100 based on these signals.

  The inter-vehicle distance measurement unit 106 receives the inter-vehicle distance from the preceding vehicle measured by the inter-vehicle distance measurement unit 106 using the data obtained by the front sensor 115. The front sensor 115 is a sensor that detects the front of the vehicle 100, and may be, for example, a millimeter wave radar, an optical camera sensor, a stereo camera, an infrared sensor radar, or the like. When the front sensor 115 is a camera sensor, the inter-vehicle distance measuring unit 106 measures the inter-vehicle distance from the preceding vehicle by analyzing an image obtained by the camera sensor.

  The vehicle 100 provides the driver with ACC (adaptive cruise control). ACC is a function of following a preceding vehicle and traveling at a constant speed while maintaining a distance between the vehicles. The ACC braking / driving force determination unit 107 starts the operation when the driver turns on the ACC using the ACC changeover switch 116, and ends the operation when the ACC is turned off. The ACC changeover switch 116 may be physically realized by a button, a lever, or the like, or may be realized by a virtual button displayed on the touch panel. The ACC braking / driving force determining unit 107 determines the braking / driving force for following the preceding vehicle based on the inter-vehicle distance measured with the inter-vehicle distance measuring unit 106.

  The gradient acquisition unit 110 acquires the gradient of the travel path on which the vehicle 100 is traveling. The gradient acquisition unit 110 may acquire a gradient using data from the gradient sensor 117 such as a gyro sensor or an acceleration sensor. Instead of or together with this, the gradient acquisition unit 110 may acquire the geographical position of the vehicle 100 by the positioning device 118 such as GPS, and may acquire the gradient from the map data or the like based on the geographical position. Furthermore, the gradient acquisition unit 110 may acquire the gradient of the travel path based on the output torque, the braking force of the brake, and the like.

  The traveling control unit 104 is based on information such as the braking / driving force determined by the requested braking / driving force determining unit 105, the braking / driving force determined by the ACC braking / driving force determining unit 107, and the gradient acquired by the gradient acquiring unit 110. Thus, the traveling of the vehicle 100 is controlled. The travel of the vehicle 100 includes start, acceleration, constant speed travel, deceleration, and stop. Therefore, the travel control unit 104 also functions as a start control unit, a travel control unit, a deceleration control unit, a stop control unit, and the like.

  The traveling control unit 104 controls the driving force and braking force of the vehicle 100 in order to control traveling. Specifically, the traveling control unit 104 controls the driving actuator 119 through the driving force control unit 108 so as to obtain a desired driving force, and controls the braking actuator 120 through the braking force control unit 109 so as to obtain a desired braking force. To do. The drive actuator 119 is an actuator that controls a mechanical element that applies a driving force to the vehicle 100. Any mechanical element that applies a driving force to the vehicle 100 may be used. For example, a throttle valve or an intake valve that controls the amount of intake air to the engine may be used. By adjusting the opening degree of the throttle valve and adjusting the lift amount of the intake valve, the intake air amount changes and the driving force changes. In the case of a vehicle that is driven not only by an engine but also using a motor, such as a hybrid vehicle, the mechanical element may be a motor. The driving force can be controlled through the control of the motor. The braking actuator 120 is an actuator that controls a mechanical element that applies a braking force to the vehicle 100. Any mechanical element that applies a braking force to the vehicle 100 may be used. For example, a hydraulic brake device or an electric parking brake may be used.

(Vehicle stop control)
Next, an overview of vehicle stop control executed by the travel control device 101 will be described. The vehicle stop control is executed by the driving control unit 104 controlling the driving force control unit 108 and the braking force control unit 109. When the vehicle is stopped, the traveling control unit 104 gradually decelerates and stops the vehicle by decreasing the driving force and increasing the braking force.

  For example, the traveling control unit 104 controls the driving force control unit 108 so that the driving force becomes a predetermined value such as a value corresponding to the creep torque on a flat road, so that the braking force exceeds the predetermined value. The vehicle can be stopped by controlling the braking force control unit 109. Here, the predetermined value can be, for example, a driving force when the vehicle is stopped on a flat road. That is, the predetermined value may be a value indicating the creep torque, but may be a value smaller than the creep torque, for example, when the driving force by the motor can be zero in an electric vehicle. Here, the creep torque is, for example, the driving force applied to the vehicle due to the structure of the driving actuator 119 or the like when the driving force control unit 108 controls the driving actuator 119 so as not to apply the driving force to the vehicle. Point to.

  On downhill roads, a force is applied to the vehicle in the forward direction with respect to the traveling direction due to gravitational acceleration. Therefore, by using a small driving force / a large braking force compared to a flat road, the vehicle decelerates and finally Will actually stop. For example, by maintaining a state where (driving force) + (the magnitude of the force due to the gradient acting in the forward direction with respect to the traveling direction of the vehicle) <(braking force), the vehicle continues to decelerate and stops Will be.

  On the uphill road, a force is applied to the vehicle in the direction opposite to the traveling direction due to the gravitational acceleration. Therefore, the vehicle decelerates with a large driving force / small braking force compared to the flat road, and finally Will stop. For example, by maintaining the state of (driving force) <(braking force) + (the magnitude of the force due to the gradient acting in the opposite direction to the traveling direction of the vehicle), the vehicle continues to decelerate and proceed Stop moving in the direction. On the uphill road, on the other hand, when (braking force) + (driving force) <(magnitude of force acting in the opposite direction to the traveling direction of the vehicle), the vehicle shifts in the direction opposite to the traveling direction. It can go down. Therefore, in a state where the braking force is greater than | (driving force) − (the magnitude of the force due to the gradient acting in the opposite direction to the traveling direction of the vehicle) |, the vehicle does not advance in the traveling direction or in the opposite direction. Will stop. Note that | x | represents the absolute value of the value x.

  On the uphill road, although the driving force is reduced only to a value larger than the above-mentioned predetermined value (for example, creep torque), it can be balanced with the sum of the braking force and the magnitude of the force due to the gradient. When the vehicle stops at a value greater than a predetermined value as described above, the travel control unit 104 can execute control to reduce the drive force to the predetermined value, for example, in order to improve fuel efficiency. Here, the braking force at the time when the vehicle stops is (braking force) ≧ (driving force) − (magnitude of a force acting in a direction opposite to the traveling direction of the vehicle) and (braking force) ≧ ( The magnitude of force due to the gradient acting in the opposite direction to the traveling direction of the vehicle) − (driving force). At this time, if the positive driving force becomes the above-mentioned predetermined value smaller than that, (braking force) ≧ (magnitude of force acting in the opposite direction to the traveling direction of the vehicle) − (driving force) is established. There are times when it stops. That is, even when (braking force) ≧ (magnitude of force due to a gradient acting in the opposite direction to the traveling direction of the vehicle) − (driving force) holds, (braking force) <(vehicle traveling direction) , The magnitude of the force due to the gradient acting in the opposite direction)-(predetermined value). In this case, when the driving force decreases to a predetermined value, the vehicle slides down, or suddenly increases the braking force to avoid such sliding down, which may give the passenger a sense of incongruity. .

  For this reason, the travel control unit 104 according to the present embodiment does not reduce the driving force when the vehicle is stopped, but first maintains the stopped state when the driving force is reduced to a predetermined value. Increase the braking force so that As a result, it is possible to prevent the vehicle from sliding down or suddenly braking to prevent it from occurring even after the driving force has decreased to a predetermined value, and to prevent the vehicle occupant from feeling uncomfortable. At this time, the traveling control unit 104 maintains the driving force at the time of stopping until the increase of the braking force to the target value is completed, and after the increase of the braking force to the target value is completed, for example, a flat road such as a creep torque. It is possible to reduce the driving force to a predetermined value corresponding to the driving force at the time of stopping at. The traveling control unit 104 may gradually reduce the driving force within a range in which the stop state can be maintained before the increase of the braking force to the target value is completed. As a result, it is possible to more reliably prevent the vehicle from sliding down or causing sudden braking to prevent the braking force from reaching the target value.

  In addition, as described above, the traveling control unit 104 determines, for example, the gradient angle by using the gradient sensor 117 such as a gyro sensor or an acceleration sensor, or the prior information obtained from the vehicle position and map data using the positioning device 118. Can know by. The traveling control unit 104 can determine a target value of the braking force according to the gradient angle. For example, the traveling control unit 104 estimates “the magnitude of the force due to the gradient acting in the direction opposite to the vehicle traveling direction” from the angle of the gradient, and uses the estimated value (with respect to the vehicle traveling direction). The target braking force can be calculated from (the magnitude of the force due to the gradient acting in the reverse direction)-(predetermined value). Then, the traveling control unit 104 changes the braking force according to the target braking force when the vehicle is stopped. However, for example, when there is an error in the positioning of the sensor or the vehicle or the weight of the load in the vehicle, the calculated target braking force may be insufficient to keep the vehicle stopped on the gradient road. Situation can occur. This can occur in the same way not only on an uphill road but also on a downhill road. In other words, when the braking force is set according to the estimated value of the angle of the gradient, if the braking force is insufficient, the vehicle will slide down in the direction opposite to the traveling direction in the upward gradient, while The slope can cause the vehicle to slide down in the direction of travel. Therefore, the traveling control unit 104 can add a predetermined margin to the target braking force calculated as described above in order to cope with such a situation. As a result, even if there is an error in the estimated value of the gradient angle, the vehicle can be surely stopped with sufficient braking force. When such a margin is used, the driving force generally decreases to a predetermined value such as a creep torque when the vehicle stops on a flat road, a down slope road, or an up slope road with a relatively gentle angle. Therefore, the traveling control unit 104 increases the braking force by the margin. That is, in such a case, since the driving force does not further decrease from the stop point, processing such as an increase in braking force corresponding to the decrease in driving force may not be performed.

Here, the process of the above-mentioned traveling control part 104 is demonstrated using FIGS. 2 and 3 show, for example, driving force and control when stopping from a state where an uphill road with a relatively steep angle is traveling at a constant speed (for example, low speed) while maintaining a constant distance from the preceding vehicle. The relationship between the magnitude of power and the vehicle speed is shown. 2 shows an example when the stop control according to the present embodiment is not executed, and FIG. 3 shows an example when the stop control according to the present embodiment is executed. 2 and 3, the vehicle starts to decelerate at time t _1, to reduce the driving force with increasing brake force. Then, the vehicle reaches a stop state at time t _{2 when} the vehicle speed reaches zero. This state is a state in which the sum of the force due to the gradient applied in the direction opposite to the traveling direction of the vehicle and the braking force that prevents the traveling in the traveling direction is greater than the driving force applied in the traveling direction. In this state, the sum of the driving force applied in the traveling direction of the vehicle and the braking force that prevents the traveling in the reverse direction of the traveling direction is greater than the force due to the gradient applied in the reverse direction of the traveling direction. But there is. In the following description, it is assumed that the predetermined value of the driving force is a value corresponding to the creep torque, but is not limited to this. For example, when the motor in the electric vehicle is turned off, the predetermined value may be any value such as 0. Can be a value.

If the driving force is not reduced to a predetermined value when the vehicle is stopped, the vehicle can reduce the driving force to the predetermined value after stopping. In FIG. 2, the driving force is reduced to the creep torque from time t ₂ to time t ₃ . At this time, when the stop control according to the present embodiment is not executed, the braking force that prevents the vehicle from traveling in the reverse direction of the traveling direction can be smaller than the force due to the gradient applied in the reverse direction of the traveling direction of the vehicle. . As a result, the vehicle speed becomes a negative value, and the vehicle can return the vehicle speed to 0, for example, at time t ₄ by increasing the braking force. However, even if it is a short period, the vehicle slips down, and a strong braking force is temporarily generated in order to return the vehicle speed to 0, which makes the vehicle occupant feel uncomfortable.

On the other hand, the traveling control unit 104 according to the present embodiment does not immediately decrease the driving force to the creep torque, but performs control to maintain the driving force at the stop point until the braking force is sufficiently increased. That is, as shown in FIG. 3, the travel control unit 104 according to the present embodiment performs a braking force until time t ₄ at which a braking force that does not cause the vehicle to slide down is achieved even if the driving force decreases to the creep torque. During this time, the driving force is maintained without lowering. Then, the traveling control unit 104 reduces the driving force to the creep torque in response to the sufficient braking force being achieved at time t ₄ (time t ₅ ). Here, the sufficient braking force may be a value including a margin as described above, for example. Thereby, as shown in FIG. 3, the negative vehicle speed does not occur and the vehicle does not slide down. In the example of FIG. 3, an example is shown in which the driving force is maintained from time t ₂ to time t _4, but the present invention is not limited to this. For example, the traveling control unit 104 increases the braking force. Along with this, the driving force may be gradually reduced. That is, the traveling control unit 104 may gradually decrease the driving force within a range where the decreasing speed of the driving force does not exceed the increasing speed of the braking force.

  FIG. 4 shows, for example, the magnitudes of the driving force and the braking force and the vehicle speed when stopping from a state where the vehicle travels at a low speed on an uphill road having a relatively gentle angle while keeping the distance from the preceding vehicle constant. Showing the relationship. Further, FIG. 5 shows the magnitudes of driving force and braking force when stopping from a state where the vehicle is traveling at a constant speed (for example, low speed) while keeping the distance from the preceding vehicle constant, for example, Shows the relationship. 4 and 5 show a state in which the vehicle is traveling at a low speed with creep torque. In this case, the driving force does not further decrease from the time when the vehicle is stopped. For this reason, after the vehicle is stopped, the travel control unit 104 does not need to increase the braking force for the decrease in the driving force, and increases the driving force by the margin described above. Thereby, it becomes possible to reliably maintain the stop state of the vehicle regardless of the error of the sensor or the like and the weight of the load. Note that FIG. 5 shows a state where, compared with FIG. 4, a large amount of braking force is required to maintain the speed when traveling at a low speed, and more braking force is required even at the time of stopping. ing.

  In this way, the traveling control unit 104 can reliably maintain the stop state of the vehicle on the slope road without causing the passenger to feel uncomfortable.

  The traveling control unit 104 can generate a negative driving force by, for example, engine braking by stopping the fuel supply to the engine when the vehicle speed is reduced. Thus, the traveling control unit 104 can decelerate the vehicle smoothly while suppressing fuel consumption. On the other hand, the traveling control unit 104 resumes the fuel supply to the engine when the traveling speed of the vehicle decreases to a certain value, cancels such negative driving force, and accordingly positive driving force (for example, creep) Torque). However, since the force applied in the reverse direction of the traveling direction of the vehicle by the negative driving force is applied in the forward direction, the vehicle speed does not decrease or the vehicle speed increases even during deceleration. It can give the passenger a sense of incongruity. Note that if the driving force increases due to other factors during the deceleration control, similar discomfort may occur.

  For this reason, when the driving force increases during deceleration due to the start of fuel supply or the like, the traveling control unit 104 according to the present embodiment increases the braking force accordingly. That is, the traveling control unit 104 performs control to cancel the increase in driving force by increasing the braking force. As a result, it is possible to prevent the vehicle speed from being reduced or the vehicle speed from being increased during deceleration of the vehicle, and to prevent the passenger of the vehicle from feeling uncomfortable.

  Here, the control of the traveling control unit 104 when the driving force changes from negative to positive will be described with reference to FIGS. 6 and 7 show, for example, the magnitudes of driving force and braking force when the vehicle is decelerated from a predetermined speed or higher on an uphill road with a relatively steep angle while keeping the distance from the preceding vehicle constant. And the vehicle speed. 6 shows an example when the stop control according to the present embodiment is not executed, and FIG. 7 shows an example when the stop control according to the present embodiment is executed. When the vehicle decelerates while traveling at a relatively high speed, the fuel supply to the engine can be stopped. In this case, as shown in FIGS. 6 and 7, for example, a negative driving force is generated by an engine brake, and the driving force can be in a direction opposite to the traveling direction of the vehicle. At this time, the vehicle gradually reduces the vehicle speed by simultaneously applying a braking force.

Thereafter, when the vehicle speed decreases to a constant speed at time t ₆ , the vehicle resumes fuel supply, thereby generating a positive driving force. At this time, when the stop control according to this embodiment is not executed, as shown in the state at time t ₇ from the time t ₆ in FIG. 6, in response to the driving force is increased, the vehicle speed despite the decelerating It will rise and give a sense of discomfort to the vehicle occupants. In addition, in order to stop the vehicle at the target position, it is necessary to decelerate a lot as a result of accelerating while decelerating, so the vehicle speed must be drastically reduced. Power is applied, and this can also make the passengers feel uncomfortable.

In contrast, the travel control unit 104 according to the present embodiment, as shown in the state at time t ₇ from the time t ₆ in FIG. 7, in accordance with the increase of the driving force, increasing the braking force. As a result, the vehicle speed will not increase during deceleration, and the passenger will not feel uncomfortable. In addition, if the traveling control unit 104 maintains the braking force increased in accordance with the increase in driving force as it is, it is assumed that the vehicle stops before the planned position. The vehicle speed is gradually reduced while gradually reducing the braking force so as not to give the vehicle. The traveling control unit 104 stops the vehicle in a state in which the sum of the braking force and the creep torque is balanced with the force due to the gradient (time t ₈ ), and then further increases the braking force by the margin described above. The control for maintaining the stop state is performed (time t ₉ ). FIG. 8 and FIG. 9 show the relationship between the magnitudes of the driving force and braking force and the vehicle speed, respectively, on an uphill road and a downhill road with relatively gentle angles. The control in this case is different in the magnitude of the braking force, but the overall control flow is the same as in the case of FIG. That is, when the driving force increases during deceleration, the traveling control unit 104 increases the driving force accordingly, and then stops the vehicle while gradually decreasing the braking force. Thereafter, the traveling control unit 104 performs control for increasing the braking force and maintaining the vehicle in a stopped state.

  To summarize the above, the traveling control unit 104 executes a process as shown in FIG. This process can be realized, for example, by a processor in the ECU reading and executing a program stored in a memory in the ECU. This process is started, for example, when the time (TTC, Time To Collision) until the vehicle collides with the preceding vehicle when the vehicle proceeds as it is becomes a predetermined value or less. Further, this process can be executed to stop at a predetermined position such as a destination or an intersection.

  When this process is started, the traveling control unit 104 first executes a deceleration process (S1001). In the deceleration control, the traveling control unit 104 generates a negative driving force by, for example, reducing the driving force within a positive value range or stopping the fuel supply, and instead of or in addition to the braking force, Decrease the vehicle speed by increasing.

  The traveling control unit 104 determines whether or not the driving force increases during the deceleration control (S1002). If the driving force increases (YES in S1002), the process proceeds to S1003, and the driving force does not increase ( If NO in S1002, the process proceeds to S1005. For example, the traveling control unit 104 can determine that the driving force increases when the traveling control unit 104 determines that it performs control for restarting fuel supply. That is, the traveling control unit 104 advances the process to S1003 when the fuel supply is resumed during the deceleration control, and advances the process to S1005 when the fuel supply is not stopped or maintained, for example. it can. In S1003, the traveling control unit 104 increases the braking force according to the increase in the driving force. Thereafter, the traveling control unit 104 gradually decreases the braking force toward the target value of the braking force so that the braking force does not become excessive (S1004). Note that the processing in S1003 and S1004 is the processing described with reference to FIGS. Thereafter, the process proceeds to S1005. Note that the processing of S1002 to S1004 may be omitted depending on circumstances, or only the processing of S1002 to S1004 may be executed alone without executing the processing after S1005 during deceleration control other than during stop control. Good.

  In S1005, the traveling control unit 104 determines whether or not the vehicle is in a stopped state. If the vehicle is in a stopped state (YES in S1005), the process proceeds to S1006, and if the vehicle is not in a stopped state (in S1005). If NO, the process returns to S1002. In S1006, the traveling control unit 104 determines whether the driving force has decreased to a predetermined value such as creep torque in the stopped state.

If the driving force has not decreased to the predetermined value (NO in S1006), the traveling control unit 104 increases the braking force so that the stop state can be maintained even if the current driving force decreases to the predetermined value. (S1007). In S1007, for example, the sum of the driving force and the braking force of the predetermined value described above is equal to or larger than a value obtained by adding a margin in consideration of sensor error, weight of load, etc. to the force due to the gradient at the stop position. The braking force is increased. Note that in S1007, the target braking force may be determined so that the vehicle can be stopped only by the braking force. That is, assuming that the driving force is 0, the target value of the braking force may be calculated. Thereafter, the traveling control unit 104 reduces the driving force to a predetermined value such as a creep torque in response to the increase of the braking force to the target value (S1008), and ends the process. The processing of S1007 and S1008 are shown in FIG. 3, it corresponds to the operation at time t ₂ ~ time t _5. With this control, it is possible to prevent the vehicle from sliding down due to the force of the gradient and sudden braking to prevent such sliding down, and the vehicle can be maintained in a stopped state.

On the other hand, when the driving force has decreased to a predetermined value (YES in S1006), the traveling control unit 104 has a braking force that is equal to or greater than a value including a margin that takes into account, for example, sensor error and weight of the load. The process is terminated (S1009). This process corresponds to the operation from time t ₂ to time t ₄ in FIGS. As a result, the braking force can be set to a sufficient value, and the state in which the vehicle is stopped can be more reliably maintained.

  As described above, the travel control unit 104 according to the present embodiment executes the braking force control for preventing the sliding after the stop state and the braking force control when the driving force increases during deceleration. By doing so, the vehicle can be smoothly decelerated and stopped. As a result, it is possible to prevent the vehicle occupant from feeling uncomfortable.

<Other embodiments>
The travel control apparatus 101 according to the present embodiment, for example, in a vehicle that is not configured to execute the above-described control but has an automatic travel control function, updates the program (firmware) related to the automatic travel control function. Can be achieved. In this update, for example, a device that stores a program for realizing the present invention is connected to a storage device in a control device that realizes an automatic travel control function via a cable or the like, and the program in the storage device is updated. It can be realized by rewriting. The apparatus for storing the program according to the present invention described above may be arranged on a network, and the update described above may be performed using a program downloaded via the network. It is also possible to update the program by other methods such as replacing the storage device itself. Thus, the present invention may be embodied in the form of a program for causing one or more processors mounted on a vehicle to execute the above-described processing or a storage medium storing such a program.

<Summary of Embodiment>
1. The travel control apparatus 101 (for example, 101) of the above embodiment is
Braking force control means (eg 109) for controlling the braking force of the vehicle;
Driving force control means (eg 108) for controlling the driving force of the vehicle;
Stop control means (for example, 104) for controlling the braking force control means and the driving force control means to stop the vehicle;
Have
The stop control means controls the braking force and the driving force to stop the vehicle and then stops the vehicle when the driving force reaches a predetermined first value. Increasing the braking force to a value (eg S1007),
It is characterized by that.

  According to this embodiment, after the vehicle stops, it is possible to reliably maintain the stopped state by the braking force, and to prevent the vehicle from moving due to factors such as a gradient.

2. The travel control apparatus 101 (for example, 101) of the above embodiment is
The stop control means maintains the magnitude of the driving force when the vehicle is stopped until the braking force reaches the second value (for example, S1007, S1008),
It is characterized by that.

  According to this embodiment, after the vehicle reaches a stop state, the vehicle is caused to slide down before reaching an appropriate braking force, or an uncomfortable feeling occurs due to sudden braking for preventing the sliding down. Can be prevented.

3. The travel control apparatus 101 (for example, 101) of the above embodiment is
The stop control means determines the second value based on the gradient of the position where the vehicle stops and the first value (for example, S1007),
According to this embodiment, after the vehicle stops on the gradient road, the stopped state can be reliably maintained by the braking force, and the vehicle can be prevented from sliding down.

4). The travel control apparatus 101 (for example, 101) of the above embodiment is
The stop control means stops the vehicle in a state where the magnitude of the driving force is greater than 0 when the gradient of the position where the vehicle is stopped is an upward gradient.
It is characterized by that.

  According to this embodiment, when the driving force contributes to stopping the vehicle, the stopped state can be reliably maintained regardless of the driving force, and the occurrence of the sliding can be prevented.

5. The travel control apparatus 101 (for example, 101) of the above embodiment is
The stop control means stops the vehicle in a state where the magnitude of the driving force is greater than the first value;
It is characterized by that.

  According to this embodiment, when the vehicle stops with a sufficiently large driving force, the stopping state is reliably maintained by sufficiently increasing the braking force, and the vehicle moves unintentionally from the stopping state. Can be prevented.

6). The travel control apparatus 101 (for example, 101) of the above embodiment is
The stop control means changes the driving force to the first value after the braking force reaches the second value (for example, S1008),
It is characterized by that.

  According to this embodiment, when the vehicle stops with a large driving force, the driving force can be prevented from being unnecessarily maintained.

7). The travel control apparatus 101 (for example, 101) of the above embodiment is
The first value is a value corresponding to a creep torque;
It is characterized by that.

  According to this embodiment, even when the driving force becomes sufficiently small, it is possible to set a braking force that can maintain the vehicle in a stopped state.

8). The travel control apparatus 101 (for example, 101) of the above embodiment is
When the driving force increases during deceleration, the stop control unit increases the driving force according to the amount of increase in the driving force (for example, S1003).
It is characterized by that.

  According to this embodiment, it is possible to prevent the vehicle from unintentionally accelerating despite the deceleration control.

  9. The vehicle (for example, 100) of the above embodiment includes a travel control device 101 (for example, 101).

  According to this embodiment, after stopping, the vehicle is reliably maintained in a stopped state by a braking force, and does not move due to a factor such as a gradient, or at least such a vehicle has a sufficiently low probability of moving. be able to.

10. The control method of the travel control apparatus 101 (for example, 101) of the above embodiment is as follows:
A control method for a travel control device 101 having braking force control means for controlling braking force of a vehicle and driving force control means for controlling the driving force of the vehicle,
After stopping the vehicle by controlling the braking force and the driving force, the braking force is increased to a second value at which the vehicle can stop when the driving force reaches a predetermined first value. Having a step of increasing
It is characterized by that.

  According to this embodiment, after the vehicle stops, it is possible to reliably maintain the stopped state by the braking force, and to prevent the vehicle from moving due to factors such as a gradient.

11. The program of the above embodiment is
A computer provided in a travel control device 101 having braking force control means for controlling the braking force of the vehicle and driving force control means for controlling the driving force of the vehicle controls the braking force and the driving force. Then, after the vehicle is stopped, the braking force is increased to a second value at which the vehicle can be stopped when the driving force reaches a predetermined first value.

  According to this embodiment, after the vehicle is stopped, the vehicle can be controlled to prevent the vehicle from moving due to a factor such as a gradient while reliably maintaining the stopped state by the braking force.

  101: traveling control device 101, 104: traveling control unit, 108: driving force control unit, 109: braking force control unit

Claims (11)

Braking force control means for controlling the braking force of the vehicle;
Driving force control means for controlling the driving force of the vehicle;
Stop control means for controlling the braking force control means and the driving force control means to stop the vehicle;
Have
The stop control means controls the braking force and the driving force to stop the vehicle and then stops the vehicle when the driving force reaches a predetermined first value. Increasing the braking force to a value,
A travel control device characterized by that. The stop control means maintains the magnitude of the driving force when the vehicle is stopped until the braking force reaches the second value.
The travel control apparatus according to claim 1. The stop control means determines the second value based on a gradient of the position where the vehicle stops and the first value;
The travel control device according to claim 1 or 2, wherein The stop control means stops the vehicle in a state where the magnitude of the driving force is greater than 0 when the gradient of the position where the vehicle is stopped is an upward gradient.
The travel control device according to any one of claims 1 to 3, wherein The stop control means stops the vehicle in a state where the magnitude of the driving force is greater than the first value;
The travel control apparatus according to claim 4, wherein The stop control means changes the driving force to the first value after the braking force reaches the second value.
The travel control apparatus according to any one of claims 1 to 5, wherein The first value is a value corresponding to a creep torque;
The travel control device according to any one of claims 1 to 6, wherein The stop control means increases the driving force in accordance with an increase amount of the driving force when the driving force increases during deceleration.
The travel control device according to any one of claims 1 to 7, wherein   A vehicle comprising the travel control device according to any one of claims 1 to 8. A control method for a travel control device comprising: braking force control means for controlling the braking force of a vehicle; and driving force control means for controlling the driving force of the vehicle,
After stopping the vehicle by controlling the braking force and the driving force, the braking force is increased to a second value at which the vehicle can stop when the driving force reaches a predetermined first value. Having a step of increasing
A control method characterized by that.   A computer provided in a travel control device having braking force control means for controlling the braking force of the vehicle and driving force control means for controlling the driving force of the vehicle controls the braking force and the driving force. A program for increasing the braking force to a second value at which the vehicle can be stopped when the driving force becomes a predetermined first value after the vehicle is stopped.

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