JP2013095212A - Running control device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle running control device that can suppress a sense of discomfort of a driver while reflecting the intent of the driver to accelerate.SOLUTION: When the vehicle travels on a curved road, the acceleration and deceleration of the vehicle is controlled so that it reaches a target vehicle velocity VO* calculated based on the curvature of the curved road. When an accelerator pedal operation by the driver is detected during the acceleration and deceleration control, the target velocity VO* is corrected based on the detected accelerator pedal operation amount (acceleration position AP) and the target velocity V* is restricted so that it does not exceed a permissible velocity Vupr which permits a lateral acceleration larger than the lateral acceleration αof the vehicle generated by the target velocity VO*. In case the permissible velocity Vupr increases while the target velocity V* is being restricted, a reaction force F of the accelerator pedal operation is generated and the acceleration of the vehicle while the acceleration and deceleration is controlled is restricted so that it becomes smaller than the acceleration αwhich realizes the permissible velocity Vupr until the accelerator pedal operation becomes undetected.

Description

  The present invention relates to an apparatus for controlling traveling of a vehicle.

  2. Description of the Related Art Conventionally, when a vehicle travels on a curved road, a vehicular travel control device that controls acceleration / deceleration of the vehicle so as to achieve a target vehicle speed calculated based on the curvature of the curved road is known. For example, in the device described in Patent Document 1, when the driver's accelerator pedal operation is detected during the acceleration / deceleration control operation, the driver's acceleration operation is corrected by correcting the target vehicle speed based on the detected accelerator pedal operation amount. The realization of appropriate acceleration / deceleration control that reflects the intention of the system.

Japanese Patent Laid-Open No. 2007-230440

  However, in the above-described conventional apparatus, depending on the contents of the driver's accelerator pedal operation, acceleration that is greater than intended by the driver is performed, which may cause the driver to feel uncomfortable.

  The present invention has been made paying attention to the above problem, and an object of the present invention is to provide a vehicle travel control device that can suppress a driver's uncomfortable feeling while reflecting the driver's acceleration intention.

  In order to achieve the above object, in the vehicle travel control device of the present invention, when the driver's accelerator pedal operation is detected during acceleration / deceleration control, the target vehicle speed is corrected based on the detected accelerator pedal operation amount, The vehicle speed is limited so as not to exceed the allowable vehicle speed, and when the accelerator pedal operation is performed even after the vehicle speed is limited, the vehicle acceleration is limited until the accelerator pedal operation is not performed.

  Therefore, by correcting the target vehicle speed based on the amount of accelerator pedal operation, the driver's intention to accelerate is reflected, and when the accelerator pedal operation is performed even after the vehicle speed is limited, the driver feels uncomfortable by limiting the vehicle acceleration. Can be suppressed.

1 illustrates a system configuration of a vehicle travel control apparatus according to a first embodiment. The structure of the control system of the vehicle travel control apparatus of Example 1 is represented. 4 is a flowchart illustrating a control process by the vehicle travel control apparatus according to the first embodiment. 6 is a time chart illustrating an action during curve traveling by the vehicle travel control device according to the first embodiment. 6 is a time chart illustrating an action during curve traveling by the vehicle travel control device according to the first embodiment.

[Example 1]
FIG. 1 shows a system configuration of a vehicle travel control apparatus according to a first embodiment. The vehicle travel control device is mounted on a vehicle including an engine as a driving force source. The vehicle travel control system includes an ambient environment recognition sensor 1, a vehicle speed sensor 2, an accelerator opening sensor 3, a navigation device 4, an engine controller 5, a brake controller 6, and an accelerator pedal reaction force controller 7. The vehicle controller 10 is provided.

  The ambient environment recognition sensor 1 detects an environment around the vehicle such as a front obstacle and a road width, and detects the degree of approach of the obstacle around the vehicle to the vehicle. The surrounding environment recognition sensor 1 has a front monitoring camera as a sensor for detecting the position (traveling position) of the host vehicle in the traveling lane. The front monitoring camera is a monocular camera composed of, for example, a CCD camera or the like, and is configured to be able to photograph a traveling road several meters to several tens of meters ahead of the host vehicle. The captured image of the front monitoring camera is output to the vehicle controller 10. The surrounding environment recognition sensor 1 is a sensor for detecting a three-dimensional object (obstacle) around the host vehicle and detecting the degree of proximity of the obstacle to the host vehicle (distance of the obstacle to the host vehicle). Have a laser radar. The detection signal of the laser radar is output to the vehicle controller 10. Note that not only the laser radar but also a stereo camera or the like may be used. The vehicle speed sensor 2 detects the speed of the vehicle (vehicle speed V) by detecting the rotational speed of the wheels and the rotational speed on the output side of the transmission. A detection signal from the vehicle speed sensor 2 is output to the vehicle controller 10. The accelerator opening sensor 3 detects an operation amount when the driver performs an accelerator pedal operation, that is, an accelerator opening AP. A detection signal from the accelerator opening sensor 3 is output to the vehicle controller 10.

  The engine controller 5 controls the output of the engine by controlling the throttle opening of a throttle valve (not shown) based on a command from the vehicle controller 10. The brake controller 6 controls the brake force of each wheel by controlling a brake actuator (not shown) based on an instruction from the vehicle controller 10. The accelerator pedal reaction force controller 7 generates an accelerator pedal reaction force by controlling an accelerator pedal reaction force actuator (not shown) based on a command from the vehicle controller 10. The accelerator pedal reaction force controller 7 is provided so as to generate an accelerator pedal reaction force based on the accelerator opening AP detected by the accelerator opening sensor 3 and the traveling state of the vehicle.

  The navigation device 4 includes a GPS unit 40 and a map database 41, and performs general processing of the car navigation device 4 such as calculation of a recommended route to the destination and display of a map near the current location of the vehicle. The GPS unit 40 receives a GPS signal transmitted from a GPS satellite and detects the current position of the host vehicle. The map database 41 stores map data of a plurality of scales (scale ratios). The map data includes road data that expresses a road map with nodes and links. In road data, nodes correspond to intersections, and line segments connecting the nodes, that is, road sections correspond to links.

  Based on each detection signal supplied, the vehicle controller 10 calculates a target vehicle speed V * when the vehicle travels on a curved road based on the road curvature, and the vehicle speed V detected by the vehicle speed sensor 1 is the target vehicle speed V. * Commands are output to the engine controller 5 and the brake controller 6 so as to perform the following acceleration / deceleration control of the vehicle. In addition, if the allowable vehicle speed Vupr that allows acceleration / deceleration and lateral acceleration greater than the acceleration / deceleration and lateral acceleration of the vehicle based on the target vehicle speed V * is calculated and the driver's accelerator pedal operation is detected during acceleration / deceleration control, the target vehicle speed The target vehicle speed V * is corrected based on the accelerator pedal operation amount while limiting V * to the allowable vehicle speed Vupr or less. In addition, if the accelerator pedal operation is detected when the target vehicle speed V * is limited to the allowable vehicle speed Vupr or lower, if the allowable vehicle speed Vupr starts to increase, the target vehicle speed V * based on the amount of accelerator pedal operation is prohibited from being corrected. This limits the acceleration of the vehicle. A method for correcting and limiting the target vehicle speed V * and a method for limiting the vehicle acceleration will be described later.

  FIG. 2 is a block diagram showing a schematic configuration of a control system provided in the vehicle controller 10. As shown in FIG. 2, the vehicle controller 10 includes a road curvature calculation unit 101, an ambient environment recognition unit 102, a vehicle speed detection unit 103, an accelerator pedal operation amount detection unit 104, a target vehicle speed calculation unit 105, an acceleration / deceleration unit A control unit 106, an allowable vehicle speed calculation unit 107, an accelerator pedal operation detection unit 108, a target vehicle speed correction unit 109, a target vehicle speed limit unit 110, a target vehicle speed return unit 111, and an accelerator pedal reaction force control unit 112. Have.

The road curvature calculation unit 101 calculates the curvature of the curved road ahead of the vehicle based on information from the navigation device 4 such as the current position of the vehicle. First, road data within a predetermined range in front of the vehicle position is read from the map database 41 based on the current position of the vehicle detected by the GPS unit 40. The road data to be read includes data such as latitude / longitude of each node, road type, road width, speed limit, and the like included in the road data. Next, an estimated route that the host vehicle is supposed to travel is specified. For example, when the user sets a destination for the navigation device 4 and calculates a recommended route to the destination, the calculated recommended route is set as the estimated route. If the user has not set a destination, the route priority and route priority are estimated based on data such as road type and road width, and the route with the highest priority is estimated. Set as a route. This estimated route includes n (n is an integer) nodes in front of the vehicle position. The radius (curvature radius) of the curved road is calculated for each node N _k (k = 1, 2,..., N) on the estimated route. The curvature can be calculated from the curve radius. For example, the node N curve radius R _k at the position of _k, the node N and _k, based on the position coordinates of the nodes N _k-1 and N _{k + 1} of the neighboring, nodes N _k-1, N _k, N k ₊ It can be calculated from the radius of a circle passing through three points of ₁ . Each node _{N k (k = 1,2, ...} , n) calculating the curve radius R _k as the target, together with the data of the distance L _k from vehicle position to each node _{N k, (N 1, L} 1, R ₁ ), (N ₂ , L ₂ , R ₂ ),..., (N _n , L _n , R _n ) are stored in a memory (storage device). Also, the shape of the curved road is specified. Here, a node serving as the entrance of the curve, a node serving as the exit, and a node having the smallest curve radius are obtained. The node that becomes the entrance of the curve is the node when the calculated curve radius R _k and the predetermined value R _in are compared in ascending order of R, and R _k becomes smaller than the predetermined value R _in. . For example, if the curve radii R ₁ and R ₂ are larger than the predetermined value R _in and the curve radius R ₃ is smaller than the predetermined value R _in , the node N ₃ is a node at the entrance of the curve. Further, the node serving as the exit of the curve, as the target node after the node serving as the entrance of the curve, and a curve radius R _k and a predetermined value R _out, compare them in order value of k is small, R _k is a predetermined Let it be the node when it becomes larger than the value _Rout .

  The ambient environment recognition unit 102 detects the degree of approach to the obstacles around the vehicle (the distance from the vehicle to the obstacles) based on the output of the ambient environment recognition sensor 1. The vehicle speed detector 103 detects the vehicle speed V based on the output of the vehicle speed sensor 2. The accelerator pedal operation amount detection unit 104 detects an operation amount (accelerator opening AP) when the driver performs an accelerator pedal operation based on the output of the accelerator opening sensor 3.

The target vehicle speed calculation unit 105 calculates a default value VO * of the target vehicle speed V * when the vehicle travels on a road including a curved road based on the curvature of the curved road calculated by the road curvature calculation unit 101. The target vehicle speed calculation unit 105 sets the target vehicle speed VO * so that the acceleration / deceleration and lateral acceleration of the vehicle generated when the vehicle travels according to the target vehicle speed VO * are within a predetermined range where the driver feels comfortable. To do.
First, a passable vehicle speed _Vck for traveling a curve ahead of the host vehicle at a preset lateral acceleration (turning acceleration) α _y (for example, α _y = 3.0 m / s ² ) or less is calculated. The passable vehicle speed _{Vck at the} node _Nk is obtained by the following equation.
V _ck = √ (α _y · R _k )
At the point where the curve radius _Rk is minimum, the passable vehicle speed _Vck is the smallest value. In the following, the distance from the vehicle position to the node at the curve entrance is L _cin , the distance from the vehicle position to the node having the smallest curve radius is L _cmin , and the distance from the vehicle position to the node at the curve exit is L _cout . Calculated passable vehicle speed V _ck, and are stored in the memory, based on the distance L _k from vehicle position to the node N _k, to calculate the vehicle speed limit V _cck at the current position of the vehicle. The limit vehicle speed V _cck is such that the vehicle speed at the node N _k becomes the passable vehicle speed V _ck when the vehicle is decelerated from the own vehicle position at a predetermined deceleration rate α _x (for example, α _x = 1.0 m / s ² ). It is the vehicle speed and is calculated by the following formula.
V _cck = √ (V _ck ² + 2 · α _x · L _k )

Next, a comfortable target vehicle speed VO * pattern that matches the road shape is calculated.
First, for each node on the estimated route, a node for which the calculated limit vehicle speed V _cck is the minimum value is specified. Here, it is assumed that the identified node is N _k ^* , the passing vehicle speed of the node N _k ^* is V _ck ^* , and the distance from the vehicle position to the node N _k ^* is L _k ^* . If the target deceleration from the vehicle position to the node N _k ^* is the predetermined value alpha _x as described above, the node N _k ^* among up, the target vehicle speed V at the position of the distance L from the vehicle position _ok * Is given by
V _ok ^* = √ (2 · α _x · (L ₀ ^* −L))
However, L ₀ ^* is a value represented by the following equation.
L ₀ ^* = (V _ck ^{* 2} + 2 · α _x · L _k ^* ) / (2 · α _x )
Further, the target vehicle speed V _{KK + 1 at} the position after the node N _k ^* is obtained by the following equation. V _{KK + 1} is a target vehicle speed at a position where the distance from the vehicle position is L between the node N _k and the node N _{k + 1} .
V _{KK + 1} = √ {2α _{KK + 1} (L ₀ −L)}
However,
L ₀ = (L _{K + 1} · V _ck ² −L _k · V _{ck + 1} ² ) / (V _ck ² −V _{ck + 1} ² )
α _{KK + 1} = 0.5 · (V _ck ² −V _{ck + 1} ² ) / (L _{K + 1} −L _K )
α _{KK + 1} is a target acceleration / deceleration between the node N _k and the node N _{k + 1} .
The data of the target vehicle speed V * (= V _ok ^* , V _{KK + 1} ) and target acceleration / deceleration α _x * (= α _x , α _{KK + 1} ) calculated based on the above equation are stored in the memory together with the distance L data. Remember me. For example, it is stored in the memory in the form of (L, V * (L), α _x * (L)) together with the distance L from the vehicle position. The target vehicle speed V * (L) and the target acceleration / deceleration α _x * (L) corresponding to the distance L are default values when there is no accelerator operation by the driver during acceleration / deceleration control.

  Further, when the surrounding environment recognition unit 102 detects an obstacle around the vehicle, the target vehicle speed calculation unit 105 corrects the default value VO * of the target vehicle speed V * based on the degree of approach of the obstacle to the vehicle. . Specifically, the target vehicle speed VO * is corrected to a value that allows any driver to stop in front of an obstacle with acceleration or deceleration that provides smooth (feeling comfortable) acceleration / deceleration. .

  The acceleration / deceleration control unit 106 outputs an acceleration / deceleration command to the engine controller 5 and the brake controller 6 so as to accelerate / decelerate the vehicle so that the vehicle speed V detected by the vehicle speed sensor 2 becomes the target vehicle speed V *. Specifically, a driving force command value corresponding to the target vehicle speed V * is calculated, and an engine torque command and a brake fluid pressure command for realizing the driving force command value are calculated.

The allowable vehicle speed calculation unit 107 calculates the allowable vehicle speed Vupr based on the curvature of the curved road calculated by the road curvature calculation unit 101. In order to reflect the driver's preferred vehicle speed, the allowable vehicle speed calculation unit 107 uses the same method as the pattern of the target vehicle speed VO * and the acceleration / deceleration α _x ′ larger than the pattern of the target vehicle speed VO *, and the allowable vehicle speed Vupr Calculate the pattern. That is, the allowable vehicle speed calculation unit 107, the lateral acceleration of the vehicle that occurs when the vehicle in accordance with the calculated target vehicle speed VO * by the target vehicle speed calculating section 105 has traveled alpha _y and acceleration alpha _x * large lateral acceleration alpha _y than The allowable vehicle speed Vupr is set to a value that allows '(> α _y ) and acceleration / deceleration α _x '(> α _x *) and ensures the stability of the vehicle behavior. Further, when the surrounding environment recognition unit 102 detects an obstacle around the vehicle, the allowable vehicle speed calculation unit 107 corrects the allowable vehicle speed Vupr based on the degree of approach of the obstacle to the vehicle. Specifically, when the driver depresses the accelerator pedal, he / she can approach the front of the obstacle with a large acceleration / deceleration (compared to the target vehicle speed V *) and secure the vehicle's behavior while ensuring safe vehicle behavior. The allowable vehicle speed Vupr is corrected to a value that can be stopped before this.

(1) For example, during deceleration traveling (when entering a curve) or acceleration traveling (when exiting a curve), that is, when acceleration / deceleration occurs, the allowable vehicle speed Vupr is set higher than the target vehicle speed VO *.
(2) While traveling at a constant vehicle speed, that is, when lateral acceleration occurs, the allowable vehicle speed Vupr is set higher than the target vehicle speed VO *.
(3) When traveling on a straight road (before and after the curve) at a constant vehicle speed, that is, when acceleration / deceleration and lateral acceleration do not occur, the allowable vehicle speed Vupr is set equal to the target vehicle speed VO *. However, when approaching an obstacle or when the driver avoids steering, the allowable vehicle speed Vupr is set higher than the target vehicle speed VO *, as in (1) and (2) above.

  The accelerator pedal operation detection unit 108 detects whether the driver has operated the accelerator pedal based on the output of the accelerator pedal operation amount detection unit 104 (accelerator opening AP detected by the accelerator opening sensor 3). Specifically, it is determined whether or not the detected accelerator opening AP exceeds a predetermined depression threshold AP_0, and if it exceeds, it is detected that the accelerator pedal is being operated.

  The target vehicle speed correction unit 109 detects that the accelerator pedal operation is detected by the accelerator pedal operation detection unit 108 and the vehicle speed V detected by the vehicle speed detection unit 103 is the target vehicle speed VO during acceleration / deceleration control by the acceleration / deceleration control unit 106. * If it is above, the target vehicle speed (default value) VO * calculated by the target vehicle speed calculation unit 105 is corrected based on the accelerator pedal operation amount (accelerator opening AP) detected by the accelerator pedal operation amount detection unit 104 V1 * (corrected value). Specifically, the greater the accelerator pedal operation amount during deceleration control, the smaller the deceleration rate becomes (the deceleration level decreases), and the greater acceleration pedal operation amount during acceleration control, the greater the acceleration rate. The target vehicle speed VO * is corrected to V1 * so that the acceleration increases. In either case, the corrected value V1 * is calculated to be higher than the default value VO *, and the corrected value V1 * is set as the target vehicle speed V *.

  The target vehicle speed limiting unit 110 limits the target vehicle speed V * so that the target vehicle speed V1 * corrected by the target vehicle speed correction unit 109 does not become higher than the allowable vehicle speed Vupr calculated by the allowable vehicle speed calculation unit 107. That is, if the corrected target vehicle speed V1 * is equal to or higher than the allowable vehicle speed Vupr, the target vehicle speed V * is set to Vupr.

  In the state where the target vehicle speed V * is limited by the target vehicle speed limiting unit 110 (the target vehicle speed V * is set to Vupr), the target vehicle speed return unit 111 sets the allowable vehicle speed Vupr calculated by the allowable vehicle speed calculation unit 107 ( When the accelerator pedal operation detection unit 108 detects that the accelerator pedal operation is detected by the accelerator pedal operation detection unit 108 until the accelerator pedal operation is no longer detected, the target vehicle speed correction unit 109 sets the target vehicle speed. Prohibit modification of VO *. Specifically, after the target vehicle speed V * (after the above correction) is limited to the allowable vehicle speed Vupr or less during deceleration control, the allowable vehicle speed Vupr increases (from a state where it is lowered or maintained) during acceleration control. However, if the accelerator pedal operation is detected, the correction of the target vehicle speed VO * is prohibited until the accelerator pedal operation is not detected. That is, the target vehicle speed V * is set to the default value V0 * (before the above correction) and is not corrected so as to increase the acceleration (acceleration magnitude increases) according to the accelerator pedal operation.

  The accelerator pedal reaction force control unit 112 performs the allowable vehicle speed Vupr calculated by the allowable vehicle speed calculation unit 107 in a state where the target vehicle speed V * is limited by the target vehicle speed limiting unit 110 (the target vehicle speed V * is set to Vupr). When the accelerator pedal operation is detected by the accelerator pedal operation detecting unit 108, the target value of the operation reaction force of the accelerator pedal is set and the accelerator pedal operation is not detected. A command is output to the accelerator pedal reaction force controller 7 according to the set target reaction force pattern to generate an operation reaction force of the accelerator pedal. As the reaction force generation pattern, for example, a predetermined constant value is generated according to the detected accelerator opening AP.

FIG. 3 is a flowchart showing the contents of control performed by the vehicle travel control apparatus of the first embodiment. When the vehicle is activated, the vehicle controller 10 repeatedly executes the process of FIG. 3 at a predetermined cycle.
In step S1, the road curvature calculation unit 101 calculates the curvature of a curved road existing ahead of the vehicle position on the vehicle traveling road. Thereafter, the process proceeds to step S2.
In step S2, the surrounding environment recognition unit 102 detects the degree of approach of the obstacle around the vehicle to the vehicle. Thereafter, the process proceeds to step S3.
In step S3, the target vehicle speed calculation unit 105 determines a pattern of the target vehicle speed VO *. Thereafter, the process proceeds to step S4.
In step S4, the allowable vehicle speed calculation unit 107 determines the pattern of the allowable vehicle speed Vupr. Thereafter, the process proceeds to step S5.
In step S5, the vehicle speed detection unit 103 detects the vehicle speed V, and the accelerator pedal operation amount detection unit 104 detects the accelerator pedal operation amount (accelerator opening AP). Thereafter, the process proceeds to step S6.

In steps S6 and S10, whether or not to shift from the normal mode in which the vehicle speed V is controlled to the default target vehicle speed V * to the override mode in which the vehicle speed V is controlled to the target vehicle speed V1 * that has been upwardly corrected according to the accelerator opening AP. Determine.
In step S6, the accelerator pedal operation detection unit 108 detects whether or not an accelerator pedal operation has been performed. If it is not detected that the accelerator pedal is operated, the process proceeds to step S7, and if it is detected that the accelerator pedal is operated, the process proceeds to step S9.
In step S7, an override prohibition flag indicating that the override prohibition mode prohibiting the override mode is in progress is cleared (set to 0). Thereafter, the process proceeds to step S8.
In step S8, the target vehicle speed V * is set to the default value VO *. Thereafter, the process proceeds to step S18.
In step S9, it is determined whether or not the override prohibition flag is 1. If the flag is 0, the process proceeds to step S10, and if the flag is 1, the process proceeds to step S16.
In step S10, it is determined whether or not the detected vehicle speed V is equal to or higher than the target vehicle speed (default value VO *). If the vehicle speed V has not reached the target vehicle speed VO *, the process proceeds to step S7. If the vehicle speed V has reached the target vehicle speed VO * (if it is equal to or higher than the target vehicle speed VO *), the process proceeds to step S11.
In step S11, the target vehicle speed correcting unit 109 corrects the target vehicle speed (default value) VO * according to the detected accelerator opening AP, and sets the target vehicle speed V * to the corrected value V1 *. Thereafter, the process proceeds to step S12.

  In step S12, it is determined whether or not to shift from the override mode to an override limit mode for controlling the vehicle speed V to the allowable vehicle speed Vupr. Specifically, it is determined whether or not the detected vehicle speed V is equal to or higher than the allowable vehicle speed Vupr. If the vehicle speed V has not reached the permissible vehicle speed Vupr, the process proceeds to step S18, and if the vehicle speed V has reached the permissible vehicle speed Vupr (if it is equal to or greater than the permissible vehicle speed Vupr), the process proceeds to step S13.

In step S13, it is determined whether or not to shift from the override limit mode to the override prohibit mode. Specifically, it is determined whether or not the allowable vehicle speed Vupr has started to rise from a state where it falls or is maintained in a set pattern. If the allowable vehicle speed Vupr does not turn up (if it is lowered or maintained), the process proceeds to step S14. If the allowable vehicle speed Vupr starts to increase, the process proceeds to step S15.
In step S14, the target vehicle speed limiting unit 110 sets the target vehicle speed V * to the allowable vehicle speed Vupr. Thereafter, the process proceeds to step S18.
In step S15, an override prohibition flag is set (set to 1). Thereafter, the process proceeds to step S16.
In step S16, the target vehicle speed return unit 111 sets the target vehicle speed V * to the default value VO *. Thereafter, the process proceeds to step S17.
In step S17, the accelerator pedal reaction force control unit 112 performs an operation reaction force control that generates an operation reaction force of the accelerator pedal. Thereafter, the process proceeds to step S18.

  In step S18, the acceleration / deceleration control unit 106 performs acceleration control or deceleration control of the vehicle. That is, the vehicle speed V is controlled so that the detected vehicle speed V becomes the set target vehicle speed V *. Thereafter, the current control cycle is terminated.

  Next, the effect | action by the vehicle travel control apparatus of Example 1 is demonstrated using FIG.4 and FIG.5. 4 and 5 are timing charts showing changes in the target vehicle speed V * and the accelerator pedal opening AP when the accelerator pedal operation is performed when traveling on a curved road. The default value V0 * of the target vehicle speed V * is indicated by a one-dot chain line, the corrected value V1 * is indicated by a broken line, the allowable vehicle speed Vupr is indicated by a two-dot chain line, and the final target vehicle speed V * is indicated by a solid line.

  First, the override mode and the override limit mode will be described with reference to FIG. It is assumed that the default value V0 * of the target vehicle speed V * and the allowable vehicle speed Vupr are set as shown in FIG. That is, V0 * and Vupr are set to constant values until time t1 (when traveling on a straight road before the curve). After time t1 (during traveling at the entrance of the curve), V0 * decreases at a predetermined deceleration and becomes a constant value at time t3. After time t2, which is later than time t1, Vupr decreases from the above constant value with a deceleration greater than V0 * and becomes a constant value greater than V0 * at time t3. From time t3 to time t4 (when traveling on the curve), V0 * and Vupr are maintained at the constant values. At time t4, V0 * and Vupr start to rise from the state where they are maintained at the constant values. After time t4 (when traveling on the curve exit), V0 * rises at a predetermined increase gradient (acceleration) and becomes a constant value at time t6. After time t4, Vupr rises with an increasing gradient (acceleration) greater than V0 *, and reaches a constant value at time t5 earlier than time t6. After time t6 (when traveling on a straight road after the curve), V0 * and Vupr are set to the above constant values. On the other hand, the accelerator opening AP is 0 until time t0, and increases after time t0. The threshold value AP_0 is exceeded at time t1, and becomes a constant value at time t31. Thereafter, the constant value is maintained until time t32. After time 32, the accelerator pedal opening AP decreases and becomes equal to or less than the threshold value AP_0 at time t34 (earlier than time t4 when the allowable vehicle speed Vupr starts to increase), and becomes 0 at time t35. Thereafter, it is 0 until time t51, and increases again after time t51. The threshold value AP_0 is again exceeded at time t52, becomes a constant value at time t54, and then maintained.

Until the time t1, the accelerator pedal opening AP is not more than the threshold value AP_0. Therefore, in the flowchart of FIG. (Normal mode: section A).
After time t1, since the accelerator opening AP exceeds the threshold value AP_0, (from the corrected target vehicle speed V1 * reaches the allowable vehicle speed Vupr at time t21), the process proceeds from step S1 to S6 to step S9 → S10 → S11 → S17. The target vehicle speed V * is corrected according to the accelerator opening AP (override mode: section B). Specifically, the target vehicle speed V * is corrected so that the degree of deceleration decreases as the accelerator opening AP increases.
At time t21, the corrected target vehicle speed V1 * reaches the allowable vehicle speed Vupr, and the allowable vehicle speed Vupr has not yet started to increase (decreases), so steps S1 to S6 to steps S9 → S10 → S11 → S12. The process proceeds from S13 to S14 to S17, and the target vehicle speed V * is set to the allowable vehicle speed Vupr (start of the override restriction mode).
From time t21 to time t33, the flow is similar, and the target vehicle speed V * is set to the allowable vehicle speed Vupr (override limit mode: section C).
After the time t33, the corrected target vehicle speed V1 * is lower than the allowable vehicle speed Vupr. Therefore, the flow proceeds from steps S1 to S6 to steps S9 → S10 → S11 → S12 → S18, and the target vehicle speed V * is set to the accelerator pedal opening AP. Correct accordingly (override mode: section B).
From time t34 to time t52, the accelerator pedal opening AP is equal to or less than the threshold value AP_0. Therefore, the flow proceeds from steps S1 to S6 to steps S7 → S8 → S18, and the target vehicle speed V * is set to the default value V0 * ( Normal mode: section A).
After time t52, the accelerator pedal opening AP again exceeds the threshold value AP_0, so that the flow proceeds from step S1 to step S6 to steps S9 → S10 → S11 → S12 → S18, and the target vehicle speed V0 * is corrected according to the accelerator pedal opening AP. (Override mode: B section). Specifically, the target vehicle speed V0 * is corrected so that the acceleration degree increases as the accelerator opening AP increases.
After time t53, the corrected target vehicle speed V1 * has reached the allowable vehicle speed Vupr and the allowable vehicle speed Vupr has not started to increase (is maintained at a constant value), so steps S1 to S6 to steps S9 → S10 → S11. → S12 → S13 → S14 → S18, and the target vehicle speed V * is set to the allowable vehicle speed Vupr (override limit mode: section C). Illustration of the target vehicle speed V1 * after time t53 is omitted.

  As described above, apart from the comfortable target vehicle speed VO * pattern according to the road shape, the allowable vehicle speed Vupr pattern calculated with acceleration / deceleration greater than the target vehicle speed VO * is set, and this allowable vehicle speed Vupr and accelerator The target vehicle speed V0 * is corrected using the opening AP. When the driver depresses the accelerator pedal during acceleration / deceleration control, the override mode is entered, and the target vehicle speed V * is corrected to increase to a correction value V1 * that is higher than the default value V0 *. At times t1 to t2), acceleration is increased during acceleration control (times t52 to t53). Therefore, the driver's favorite acceleration / deceleration can be reflected in the acceleration / deceleration control (vehicle speed control). Further, when the corrected target vehicle speed V1 * reaches the allowable vehicle speed Vupr, the override restriction mode is set, and the target vehicle speed V1 * is not increased beyond the allowable vehicle speed Vupr even if the accelerator pedal operation continues (time t21 to t33). Therefore, even if the acceleration / deceleration is changed in accordance with the driver's accelerator pedal operation, the vehicle behavior can be stabilized. Here, not only the map database information of the road, but also when the vehicle is approaching an obstacle around the road or the road is congested, the target vehicle speed V * and the allowable vehicle speed Vupr are determined according to the surrounding environment. Is optimally corrected. Therefore, acceleration / deceleration control more suitable for the driver's feeling can be realized.

  Next, the override prohibit mode will be described with reference to FIG. FIG. 5 also shows changes in the accelerator pedal operation reaction force F, and it is assumed that the default value V0 * of the target vehicle speed V * and the allowable vehicle speed Vupr are set in the same manner as in FIG. The accelerator opening AP is the same as in FIG. 4 until time t31. Thereafter, the constant value is maintained until time t51. After time 51, the accelerator pedal opening AP decreases and becomes equal to or less than the threshold value AP_0 at time t52 (later than time t4 when the allowable vehicle speed Vupr starts to increase). After that, it becomes 0 at time t53 and starts increasing again. The threshold value AP_0 is again exceeded at time t55, and is maintained after reaching a constant value at time t57.

The process up to time t31 is the same as in FIG. 4, and after time t31, the target vehicle speed V * is set to the allowable vehicle speed Vupr (override restriction mode: section C).
At time t4, the allowable vehicle speed Vupr starts to increase, but the accelerator pedal opening AP still exceeds the threshold value AP_0. Therefore, in the flowchart of FIG. 3, steps S1 to S6 to steps S9 → S10 → S11 → S12 → S13 → S15 → The flow proceeds from S16 to S17 to S18, and the target vehicle speed V * is set to the default value V0 * (start of the override prohibit mode). From time t4, until the time t52 when the accelerator opening AP becomes equal to or less than the threshold value AP_0, the flow proceeds from steps S1 to S6 to steps S9 → S16 → S17 → S18, and the target vehicle speed V * is set to the default value V0 * ( Override prohibition mode: D section). During this time, an accelerator pedal reaction force F is generated (S17). Specifically, after time t4, the accelerator pedal reaction force increases and becomes a constant value at time t41, and thereafter is maintained until time t52.
From time t52 to time t55, the accelerator pedal opening AP is equal to or less than the threshold value AP_0. Therefore, the flow proceeds from steps S1 to S6 to steps S7 → S8 → S18, and the target vehicle speed V * is set to the default value V0 * ( Normal mode: section A). Since the accelerator pedal reaction force control is terminated at time t52, the accelerator pedal reaction force F decreases after time 52 and becomes zero at time t54.
After time t55, it is the same as after time t52 in FIG.

  As described above, when the driver keeps stepping on the accelerator pedal when the vehicle speed V is limited by the allowable vehicle speed Vupr, the acceleration of the acceleration / deceleration control is limited by the override prohibition mode. Specifically, the allowable vehicle speed Vupr increases when traveling on a curve exit or exiting a curve and entering a straight road. At this time, if it is in the override limit mode and the accelerator pedal is depressed, the generation of acceleration according to the amount of depression of the driver's accelerator pedal is limited, and the default target vehicle speed V0 * is increased. Accelerated slowly. In other words, if the driver's accelerator pedal operation is blocked in the override limit mode and the vehicle speed is limited, even if the allowable vehicle speed Vupr subsequently increases, the driver finishes the accelerator pedal operation by switching to the override prohibit mode. Unless it was done, the acceleration limit was maintained and only weak acceleration was performed. Therefore, even if the driver accidentally continues the accelerator pedal operation while the vehicle speed is limited, it is possible to suppress the occurrence of strong acceleration due to this erroneous operation, and to suppress acceleration beyond the driver's intention (or sudden vehicle behavior). , The uncomfortable feeling given to the driver can be reduced. That is, even when the driver steps on the accelerator pedal and enters a road with a high permissible vehicle speed Vupr, acceleration control can be performed at an acceleration with a little uncomfortable feeling to the driver without generating a strong acceleration.

When shifting from the override restriction mode in which the target vehicle speed V * is set to the allowable vehicle speed Vupr to the override prohibit mode in which the target vehicle speed V * is set to the default value V0 *, the target vehicle speed V * is changed from the allowable vehicle speed Vupr to the default value V0. By gradually shifting toward *, it is possible to suppress a sudden change in the vehicle speed V, thereby suppressing the driver's uncomfortable feeling. Further, in the first embodiment, as a means for suppressing the acceleration beyond the driver's intention, the target vehicle speed V * is set to the default value V0 * in the override prohibit mode, thereby realizing the allowable vehicle speed Vupr. The acceleration is limited to be smaller than the acceleration α _y ', but the target vehicle speed V * is maintained at the default value V0 *. The vehicle speed V * may be returned toward the allowable vehicle speed Vupr.

  In addition, since the override prohibit mode is canceled when the accelerator pedal operation is completed, it is possible to shift to the override mode by a simple operation of depressing the accelerator pedal (time t52 to tt56), which matches the driver's feeling. Traveling is possible. In other words, the acceleration intention can be input to the travel control device with a simple operation of once depressing the accelerator pedal, and the acceleration / deceleration control can be corrected with the acceleration intended by the driver.

  Here, when the allowable vehicle speed Vupr increases again during the override limit mode, it is switched to the override prohibit mode, and the accelerator pedal operation reaction force F is generated to prompt the driver to re-operate the accelerator pedal. It is provided to encourage acceleration operations. Therefore, since the operation of stepping on the accelerator pedal is naturally guided by the generation of the reaction force F, it is possible to intuitively perform override acceleration (transition to the override mode again) without a sense of incongruity. Note that the time for generating the reaction force F is not limited to the time when the accelerator pedal operation is not detected, and may be the time before that time. Further, the pattern for generating the reaction force F (target value pattern) is not limited to a pattern that generates a predetermined constant value. For example, the magnitude of the reaction force F is changed or the reaction force F is generated intermittently. It is also possible to make it. In short, it is only necessary to prompt the driver to operate the accelerator pedal again.

As described above, the following effects can be obtained in the vehicle travel control apparatus of the first embodiment.
(1) When the vehicle travels on a curved road, in the vehicle travel control device for controlling the acceleration / deceleration of the vehicle so that the target vehicle speed V0 * is calculated based on the curvature of the curved road, When accelerator pedal operation is detected, the target vehicle speed V0 * is corrected based on the detected accelerator pedal operation amount (accelerator opening AP), and is larger than the lateral acceleration α _{y of the} vehicle generated by the target vehicle speed V0 *. When the target vehicle speed V * is limited so as not to be higher than the allowable vehicle speed Vupr that allows the lateral acceleration, and the allowable vehicle speed Vupr rises while the target vehicle speed V * is limited, an operation reaction force F of the accelerator pedal is generated, Until acceleration pedal operation is not detected, the acceleration of the vehicle in the acceleration / deceleration control is limited to be smaller than the acceleration α _y ′ that realizes the allowable vehicle speed Vupr.
Therefore, by correcting the target vehicle speed V0 * in a range that does not become higher than the allowable vehicle speed Vupr based on the accelerator pedal operation amount, the driver's intention to accelerate within the specified range can be achieved even during acceleration / deceleration control. Can be reflected freely. In addition, if the allowable vehicle speed Vupr rises while the target vehicle speed V * is limited by the allowable vehicle speed Vupr, limiting acceleration will suppress undesired acceleration caused by the driver's incorrect accelerator operation and reduce the sense of discomfort given to the driver. be able to. In addition, by generating the reaction force F, it is possible to prompt the driver to start the accelerator operation again, thereby promptly (more accurately) reflecting the acceleration intention of the driver in the accelerator operation.

(2) Specifically, the vehicle is curved based on the road curvature calculation means (road curvature calculation unit 101) for calculating the curvature of the curved road ahead of the vehicle and the curvature of the curved road calculated by the road curvature calculation means. Target vehicle speed calculation means (target vehicle speed calculation unit 105) for calculating a target vehicle speed V0 * when traveling on a road including the road, vehicle acceleration / deceleration α _x * based on the target vehicle speed V0 * calculated by the target vehicle speed calculation means, and the allowable vehicle speed calculating means for calculating an allowable vehicle speed Vupr to permit acceleration and the lateral acceleration is greater than the lateral acceleration alpha _y (allowable vehicle speed calculating section 107), acceleration and deceleration control means for the vehicle to acceleration or deceleration based on the target vehicle speed V * (Acceleration / deceleration control unit 106), accelerator pedal operation detection means (accelerator pedal operation detection unit 108) for detecting the driver's accelerator pedal operation, and the operation amount (accelerator when the driver performs the accelerator pedal operation) Accelerator pedal operation amount detection means (accelerator pedal operation amount detection unit 104) for detecting the opening degree AP) and acceleration / deceleration control by the acceleration / deceleration control means are detected by the accelerator pedal operation detection means. Then, target vehicle speed correcting means (target vehicle speed correcting section 109) for correcting the target vehicle speed V0 * based on the accelerator pedal operation amount detected by the accelerator pedal operation amount detecting means, and the target corrected by the target vehicle speed correcting means. The target vehicle speed limiting means (target vehicle speed limiting unit 110) for limiting the vehicle speed V * to the allowable vehicle speed Vupr or less and the corrected target vehicle speed V * are limited by the target vehicle speed limiting means, the allowable vehicle speed Vupr starts to increase. When the accelerator pedal operation detecting means detects the driver's accelerator pedal operation, the accelerator pedal operation detecting means detects the driver's accelerator pedal operation. The target vehicle speed return means (target vehicle speed return section 111) sets the target vehicle speed V * to the value before correction by the target vehicle speed correction means (default value VO *) and the target vehicle speed return means until the pedal operation is no longer detected. When the vehicle speed V * is set to the value before the above correction (default value VO *), the accelerator pedal reaction force control means (the accelerator pedal reaction force control unit 112, step of FIG. 3) that generates the operation reaction force F of the accelerator pedal is generated. S16 → S17).
Therefore, the same effect as the above (1) is obtained.

(3) The target vehicle speed correction means (target vehicle speed correction unit 109) decelerates as the accelerator pedal operation amount (accelerator opening AP) detected by the accelerator pedal operation amount detection means (accelerator pedal operation amount detection unit 104) increases. The target vehicle speed V * is corrected so that the deceleration rate during control is reduced or the acceleration rate during acceleration control is increased, and the target vehicle speed return means (target vehicle speed return unit 111) After the target vehicle speed V * after the above correction is limited by the target vehicle speed limiting means (target vehicle speed limiting unit 110), the accelerator pedal operation is detected by the accelerator pedal operation detecting means (accelerator pedal operation detecting unit 108) during acceleration control. Is detected, the target vehicle speed V * is set to the value before the above correction (default value VO *).
Therefore, by prohibiting the target vehicle speed V * from being corrected so as to increase the acceleration according to the amount of accelerator pedal operation, even if the driver performs an incorrect accelerator operation during acceleration control after deceleration control, The acceleration beyond the driver's intention can be suppressed, and the uncomfortable feeling given to the driver can be reduced.

(4) A surrounding environment recognizing unit (ambient environment recognizing unit 102) for detecting the degree of obstacle approach to the vehicle is provided, and the target vehicle speed calculating unit (target vehicle speed calculating unit 105) determines the approaching degree of the detected obstacle. Based on this, the target vehicle speed V * and the allowable vehicle speed Vupr are corrected.
Therefore, it is possible to realize acceleration / deceleration control that is more suitable for the driver's sense while ensuring the stability of the vehicle behavior.

The present invention has been described based on the embodiments. However, the present invention is not limited to the above-described embodiments, and other configurations are also included in the present invention.
For example, the vehicle travel control device of the present invention may be mounted on a hybrid vehicle or an electric vehicle provided with a motor in addition to an engine as a driving force source.
The calculation method of the target vehicle speed V * and the allowable vehicle speed Vupr is not limited to that of the embodiment. For example, the curvature of the curved road ahead of the vehicle may be calculated based on information from the front monitoring camera of the surrounding environment recognition sensor 1 (arrangement of left and right lane marking lines in the captured image).
The accelerator pedal operation amount used for correcting the target vehicle speed V * is not limited to the accelerator opening AP, and for example, a time integral value of the accelerator opening AP may be used.
The target vehicle speed V * may be corrected based on the accelerator pedal depression speed and return speed. Further, the target vehicle speed V * may be corrected based on the vehicle position detected when the accelerator pedal operation is performed.

101 Road curvature calculation unit (road curvature calculation means)
104 accelerator pedal operation amount detection unit (accelerator pedal operation amount detection means)
105 Target vehicle speed calculation unit (target vehicle speed calculation means)
106 Acceleration / deceleration control unit (acceleration / deceleration control means)
107 Allowable vehicle speed calculation unit (allowable vehicle speed calculation means)
108 Accelerator pedal operation detector (Accelerator pedal operation detector)
109 Target vehicle speed correction unit (target vehicle speed correction means)
110 Target vehicle speed limiting unit (Target vehicle speed limiting means)
111 Target vehicle speed return unit (target vehicle speed return means)
112 accelerator pedal reaction force control unit (accelerator pedal reaction force control means)

Claims (4)

Road curvature calculation means for calculating the curvature of a curved road ahead of the vehicle;
Target vehicle speed calculating means for calculating a target vehicle speed when the vehicle travels on a road including the curved road based on the curvature of the curved road calculated by the road curvature calculating means;
An allowable vehicle speed calculating means for calculating an allowable vehicle speed allowing an acceleration / deceleration and a lateral acceleration larger than the acceleration / deceleration and the lateral acceleration of the vehicle according to the target vehicle speed calculated by the target vehicle speed calculating means;
Acceleration / deceleration control means for accelerating / decelerating the vehicle based on the target vehicle speed;
An accelerator pedal operation detecting means for detecting the driver's accelerator pedal operation;
An accelerator pedal operation amount detection means for detecting an operation amount when the driver performs an accelerator pedal operation;
When an accelerator pedal operation of the driver is detected by the accelerator pedal operation detecting means during the operation of the acceleration / deceleration control by the acceleration / deceleration control means, based on the accelerator pedal operation amount detected by the accelerator pedal operation amount detecting means. Target vehicle speed correcting means for correcting the target vehicle speed;
Target vehicle speed limiting means for limiting the target vehicle speed corrected by the target vehicle speed correcting means to the allowable vehicle speed or less;
When the corrected target vehicle speed is limited by the target vehicle speed limiting means, the allowable vehicle speed starts to increase, and when the accelerator pedal operation of the driver is detected by the accelerator pedal operation detection means, the accelerator pedal operation Target vehicle speed return means for setting the target vehicle speed to a value before correction by the target vehicle speed correction means until the driver's accelerator pedal operation is not detected by the detection means;
An accelerator pedal reaction force control means for generating an operation reaction force of an accelerator pedal when the target vehicle speed is set to the value before the correction by the target vehicle speed return means;
A vehicle travel control device comprising: The vehicle travel control apparatus according to claim 1,
The target vehicle speed correction means is configured such that the greater the accelerator pedal operation amount detected by the accelerator pedal operation amount detection means, the smaller the deceleration rate during deceleration control or the greater acceleration rate during acceleration control. Next, correct the target vehicle speed,
The target vehicle speed return means detects the accelerator pedal operation of the driver by the accelerator pedal operation detection means during acceleration control after the corrected target vehicle speed is restricted by the target vehicle speed restriction means during deceleration control. The vehicle travel control apparatus, wherein the target vehicle speed is set to a value before the correction. In the vehicle travel control device according to claim 1 or 2,
Ambient environment recognition means for detecting the degree of obstacle approach to the vehicle,
The target vehicle speed calculating means corrects the target vehicle speed and the allowable vehicle speed based on the detected degree of approach of an obstacle, and the vehicle travel control device. When the vehicle travels on a curved road, in the vehicle travel control device for controlling acceleration / deceleration of the vehicle so that the target vehicle speed is calculated based on the curvature of the curved road,
If the driver's accelerator pedal operation is detected during the acceleration / deceleration control, the target vehicle speed is corrected based on the detected accelerator pedal operation amount, and the lateral acceleration greater than the lateral acceleration of the vehicle generated by the target vehicle speed The target vehicle speed is limited so as not to be higher than an allowable vehicle speed that allows
When the allowable vehicle speed increases while the target vehicle speed is limited, an accelerator pedal operation reaction force is generated, and the acceleration of the vehicle in the acceleration / deceleration control is realized until the accelerator pedal operation is not detected. The vehicle travel control apparatus is characterized in that it is limited to be smaller than the acceleration to be performed.

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