JP2006008009A - Travel assist device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a traveling assist device capable of reducing a sense of incongruity of a driver to motion of a steering means while realizing suitable guiding of a vehicle. <P>SOLUTION: The traveling assist device 100 for the vehicle assists traveling of the vehicle so as to travel along a target movement track from an initial position to a target position. The device 100 is provided with a turning angle control pattern production means 12 for producing a control pattern for controlling a turning angle of a turning means 32 such that the vehicle travels along the target movement track; a steering angle control pattern production means 11 for producing a control pattern for controlling a steering angle of a steering means 22; and control means 20, 30 for controlling the turning means 32 based on the control pattern of the turning angle and controlling the steering means 22 based on the control pattern of the steering angle. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicular travel support apparatus that assists a vehicle to travel along a trajectory to a target position.

A travel support device that guides a vehicle to a target position by automatic steering is known. For example, the device described in Patent Document 1 is designed to guide the garage entry smoothly by operating the steering means (wheels) continuously at a constant speed in conjunction with the steering by the constant constant speed operation of the steering means (steering). It is said.
Japanese Patent Laid-Open No. 6-75629

  However, since the calculation for drawing a smooth movement trajectory is complicated and requires a large amount of calculation, in reality, there is a movement trajectory in which the rotation speed of the steering changes during steering or the rotation of the steering temporarily includes a stop. It was often generated. In addition, in order to avoid an obstacle or the like, there is a case where a movement trajectory is generated such that the steering is operated at a high rotational speed. As a result, the driver may feel uncomfortable with the movement of the steering wheel.

  The present invention has been made in view of the above circumstances, and provides a vehicular travel support apparatus capable of reducing a driver's uncomfortable feeling with respect to movement of a steering means while appropriately guiding the vehicle. With the goal.

  The vehicle travel support device according to the present invention assists the travel of the vehicle so as to travel along the target movement locus from the initial position to the target position. This apparatus includes (1) a turning angle control pattern generating means for generating a control pattern for controlling the turning angle of the turning means so that the vehicle travels along the target movement locus, and (2) a steering means. Steering angle control pattern generating means for generating a control pattern for controlling the steering angle of the vehicle, and (3) steering means based on the steering angle control pattern, and steering means based on the steering angle control pattern And a control means for controlling.

  According to this apparatus, the control pattern for controlling the turning angle of the turning means is generated by the turning angle control pattern generation means so that the vehicle travels along the target movement locus. On the other hand, a control pattern for controlling the steering angle is generated by the steering angle control pattern generating means. The steering means can be controlled based on the steering angle control pattern while the steering means can be controlled based on the steering angle control pattern. Therefore, even when the movement of the steering means is not smooth, the steering means can be controlled with a control pattern that smoothes the movement of the steering means. As a result, it is possible to reduce the driver's uncomfortable feeling with respect to the movement of the steering means while appropriately guiding the vehicle.

  The steering angle control pattern is preferably generated based on the turning angle control pattern. In this way, it is possible to easily generate a steering angle control pattern for smoothly controlling the steering means while approximating the steering angle control pattern.

  The control pattern of the steering angle preferably includes a section generated by changing the ratio of the change in the steering angle with respect to the change in the steering angle. Thus, by changing the ratio of the change in the steering angle with respect to the change in the turning angle, a steering angle control pattern for smoothly controlling the steering means is generated.

  It is preferable that the steering angle control pattern includes a section in which the steering angle is changed when the turning angle is not changed. The steering angle control pattern preferably includes a section in which the steering angle is not changed when the steering angle is changed. When the steering angle control pattern includes such a section, it becomes easy to realize smooth control of the steering means.

  The steering angle control pattern preferably includes a section in which the steering angle is changed at a rate smaller than the rate of change of the turning angle with respect to the travel distance in the turning angle control pattern. In this way, the change in the steering angle becomes gentler than the change in the turning angle, and the driver's uncomfortable feeling with respect to the movement of the steering means is reduced.

  The time point at which the angle change starts from the steering angle neutral in the steering angle control pattern is preferably the same as the time point at which the angle change starts from the turning angle neutral in the turning angle control pattern. If it does in this way, the cutting-out time of a steering means and the cutting-out time of a steering means can be made to correspond, and a driver's discomfort can be reduced further.

  The time point at which the angle change is started from the steering angle hold in the steering angle control pattern is preferably the same as the time point at which the angle change is started from the turning angle hold in the turning angle control pattern. Alternatively, the time point at which the steering angle change becomes an extreme value in the steering angle control pattern is preferably the same as the time point at which the turning angle change becomes an extreme value in the turning angle control pattern. If it does in this way, the turning-back time of a steering means and the turning-back time of a steering means can be made to correspond, and a driver's discomfort can be reduced further.

  The steering angle control pattern preferably includes a section generated by connecting a straight line between the maximum turning angle and the minimum turning angle in the turning angle control pattern. In this way, it is possible to easily generate a steering angle control pattern for smoothly controlling the steering means while approximating the steering angle control pattern.

  The steering angle control pattern and the turning angle control pattern are preferably generated when the target movement locus is generated. In this way, when the target movement locus is generated, the control pattern of the steering angle and the control pattern of the turning angle are respectively generated, and the steering means and the turning means are controlled by the control means based on them. The

  According to the vehicle travel support device of the present invention, it is possible to reduce the driver's uncomfortable feeling with respect to the movement of the steering means while appropriately guiding the vehicle. That is, the driver can recognize how the vehicle is moving by the movement of the steering means. Therefore, the steering means is controlled based on the steering angle control pattern so that the vehicle travels along the target movement locus, while the vehicle motion is shown to the driver based on the steering angle control pattern. By controlling the steering means by movement, it is possible to reduce the driver's uncomfortable feeling with respect to the movement of the steering means while appropriately guiding the vehicle.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.
(First embodiment)

  In the present embodiment, a parking assistance device will be described as an example of the driving assistance device. FIG. 1 is a block configuration diagram of a parking assistance device 100 according to the present embodiment. The parking assistance device 100 includes an automatic steering device 20 and an automatic steering device 30, and is controlled by a parking assistance ECU 1 that is a control device. The parking assist ECU 1 includes a CPU, a ROM, a RAM, an input signal circuit, an output signal circuit, a power circuit, and the like, and includes an image processing unit 10 that processes an image acquired by a rear camera 42 described later, and an automatic steering device 20. It has the steering control part 11 which performs control, and the steering control part 12 which controls the automatic turning apparatus 30. The image processing unit 10, the steering control unit 11, and the steering control unit 12 may be separated in hardware in the parking assistance ECU 1, but are divided in software using a common CPU, ROM, RAM, and the like. May be.

  A steering angle sensor 23 that detects a steering amount of the steering shaft 21 and a steering actuator 24 that applies a steering force are connected to the steering shaft 21 that is rotated by the movement of the steering wheel 22. The steering control unit 11 controls driving of the steering actuator 24 and receives an output signal of the steering angle sensor 23.

  In addition to the output of the steering angle sensor 23, the steering control unit 11 is also supplied with outputs of a wheel speed sensor 51 that is disposed on each wheel and detects the wheel speed, and an acceleration sensor 52 that detects vehicle acceleration. ing.

  A turning mechanism 31 that turns the wheels 32 is connected to a turning angle sensor 33 that detects a turning amount of the wheels 32 and a turning actuator 34 that applies a turning force. The turning control unit 12 controls the driving of the turning actuator 34 and receives an output signal from the turning angle sensor 33.

  In addition to the output of the steering angle sensor 33, the steering control unit 12 has outputs of a wheel speed sensor 51 that is disposed on each wheel and detects the wheel speed, and an acceleration sensor 52 that detects the acceleration of the vehicle. Have been entered.

  Thus, the parking assistance apparatus 100 of this embodiment controls the steering angle of the steering wheel 22 and the turning angle of the wheel 32 independently. Therefore, this parking assistance apparatus 100 is suitably used for a steer-by-wire (SBW) vehicle in which steering and turning are mechanically separated.

  The image processing unit 10 described above of the parking assistance ECU 1 receives an image signal that is an output signal of the rear camera 42 that is disposed at the rear of the vehicle and obtains a rear image, and also receives a driver's operation input for parking assistance. An input means 41 for accepting, a monitor 44 for displaying information by an image to the driver, and a speaker 43 for presenting information by voice are connected.

  Next, the support operation in the parking support apparatus 100 will be specifically described. In the parking assistance ECU 1 of the parking assistance device 100, a turning angle logic for generating a turning angle control pattern for controlling the turning angle of the wheel (steering means) 32, and a steering wheel (steering means). A steering angle logic for generating a steering angle control pattern for controlling the steering angle 22 is stored. Further, the turning angle logic includes a movement trajectory pattern generation logic for parallel parking and a movement trajectory pattern generation logic for garage parking. FIG. 2 shows a basic movement locus pattern for parallel parking, and FIG. 3 shows a basic movement locus pattern for garage parking.

In the parallel parking shown in FIG. 2, the host vehicle is placed in a parking space 215 between a vehicle 201 (hereinafter referred to as a front vehicle) parked beside the road 211 and a vehicle 202 (hereinafter referred to as a rear vehicle). 200 in those to reach the retraction, from the initial position 200a to the target position 200 g, arrives through a path P ₁ shown in FIG. In general, this P ₁ is to reverse while turning the steering to the left, reversely return the steering, and reverse to the right while turning to the right beyond the neutral position to reach the target position. When approaching the target position, the steering may be returned to neutral (in this case, the length of the parking space is required).

In the garage parking shown in FIG. 3, the host vehicle 200 is caused to reach the garage 220 provided facing the road 210 by reversing, and the route shown in the figure from the initial position 200 a to the target position 200 g. to reach through the P _2. In general, this P ₂ is to reverse while turning the steering to the right, reversely return the steering, return to the neutral position, and reach the target position.

  Here, the first half of the parallel parking route (the state until the steering is returned to neutral) is similar to the operation when entering the garage (the first half of the route P1 in FIG. 2 and the route P2 in FIG. 3 are reversed). State). Therefore, paying attention to this similarity, the parking assist device 100 uses a garage parking movement trajectory pattern (route setting logic) for the initial route setting in the parallel parking route setting.

  Hereinafter, this parallel parking route setting will be described in detail. In route setting, the driver operates the input means 41 to instruct the parking assistance ECU 1 to start parking assistance control until reaching the vicinity of the designated target parking position or once to the target parking position. Until it is determined that the vehicle cannot be reached by reversing, the parking assistance ECU 1 continues to execute unless the driver cancels the assistance operation from the input means 41.

  Specifically, the driver moves the vehicle 200 to an arbitrary parking assistance start position (front right side of the front vehicle 201), and the target in the rear image captured by the rear camera 42 displayed on the monitor 44. After confirming the parking space 215 as the position, the input means 41 is operated to start this parking support control. When the parking space 215 cannot be confirmed in the display image of the monitor 44, the vehicle is moved to a position where the parking space 215 can be confirmed, and support is started. Hereinafter, the reference point of the vehicle 200 at the parking assistance start position (in the following description, the center of the axle of the rear wheel of the vehicle will be described as a reference point. The front end or the rear end on one side may be used as a reference point.) Is point A, and the vehicle at this position is represented by 200a.

  When parking assistance is started, the driver operates the input means 41 while viewing the image captured by the rear camera 42 displayed on the monitor 44, thereby displaying the parking frame (see FIG. 2) displayed on the screen. The target parking position is set by moving it to the target parking position by moving the vehicle to the target parking position.

The parking assist ECU 1 obtains the vehicle position 200g at the target parking position, specifically, the position of the reference point G and the direction of the vehicle at that position by image recognition processing. What is necessary is just to obtain | require the position of this G point as a relative coordinate with respect to the reference point A in the present vehicle position, for example. Hereinafter, as shown in FIG. 4, a description will be given by a coordinate system in which the target position G point is the origin, the vehicle direction at the target position is the z-axis direction, and the direction orthogonal thereto is the x-axis. Hereinafter, an angle formed by the current vehicle direction and the z axis is referred to as a deflection angle θ, and an initial deflection angle is represented by θ ₀ . The position of point A is represented by coordinates (X ₀ , Z ₀ ).

  Next, the switching position is calculated using a two-circle model. FIG. 5 is a diagram for explaining the concept of the two-circle model. In order to use the garage entry logic, it is necessary to calculate a switching point between a route using the garage entry logic and a route using a logic peculiar to parallel parking. The actual path is set by combining an arc, a straight line, and a clothoid curve, but for the sake of simplicity, here, each path is modeled and handled as an arc.

That is, as shown in FIG. 5, the switching position M (X _M , Z ₀ ) is traced from the initial position A (X ₀ , Z ₀ ) to the arc of radius R _A centered on O ₁ (X _A , Z ₀ ). _M ) is reached, and from there, the target position G (0, 0) is reached by following an arc of radius R _min centered on O ₂ (X _B , 0). Here, from the switching position M, it moves with the minimum turning radius _Rmin which can be used in route setting. Thus, the coordinates of the switching position M and the deflection angle θmax at this position can be obtained using X ₀ , Z ₀ , X _A , and X _B.

Next, in order to use the garage entry logic, the route to the switching position M is geometrically transformed. As shown in FIG. 4, the coordinate system is converted into an X′Z ′ coordinate system in which the switching position M is the origin, the vehicle direction at this position is the Z ′ axis, and the horizontal direction perpendicular thereto is the X ′ axis. . By this coordinate system conversion, the initial position A (X ₀ , Z ₀ ) is converted to (X ₀ ′, Z ₀ ′), and the initial deflection angle θ ₀ can be expressed as θ ₀ ′. By setting a path in which the change amount of the deflection angle is θ ₀ ′, the deflection angle of the vehicle at the origin M of the X′Z ′ coordinate system can be matched.

Next, a moving route from the initial position A to the switching position M is generated using the garage entry logic. As shown in FIG. 6, the travel route is usually a section for increasing the steering angle (section S ₁ ), a section for maintaining the steering angle in an increased state (section S ₂ ), and a section for returning the steering angle to neutral. ₃ sections (section S ₃ ) are included, and in sections S ₁ and S ₃ , the amount of change in curvature of curvature (curvature gradient) with respect to the travel distance is constant. As a result, the travel trajectory set is an arc in which the section S ₂ has a predetermined radius (curvature). The section S ₁ and the section S ₃ are a clothoid curve having one end with the predetermined curvature and the other end with a curvature of zero. Become.

Further, a path from the switching position M point to the target position G point is generated using parallel parking logic. In this route, for example, the absolute value of the curvature is increased (curvature becomes negative) with a predetermined inclination with respect to the travel distance (the curvature gradient is set to −ωmax, for example), and the maximum curvature state is maintained. This is a route that reaches the target position G. As a result, the travel trajectory set is an arc in which the section S ₆ has a predetermined radius (curvature), and the section S ₅ is a clothoid curve having one end with the predetermined curvature and the other end with a curvature of zero.

Then, the route from the current position A to the target position G is set by combining the first half route generated by the garage entry logic and the second half route generated by the parallel parking logic. At this time, since the clothoid section is not considered in the two-circle model, in order to satisfy the insufficient movement distance in the X direction and the Z direction, the straight sections S ₀ , S ₄ before the section S ₁ and after the section S ₃ are satisfied. Is granted.

The steering control unit (steering angle control pattern generating unit) 12 generates a control pattern of the steering angle of the wheels 32 so as to guide the vehicle along the target movement locus thus generated. FIG. 7 is a diagram showing a control pattern of the turning angle generated in the turning control unit 12. Since this control pattern includes the straight section S ₄ , if the steering angle is controlled in accordance with the control pattern of the turning angle, the steering wheel 22 is temporarily stopped during steering, The driver may feel uncomfortable with the movement of the steering wheel 22.

  Therefore, in this embodiment, the steering angle control pattern is independently generated in the steering control unit (steering angle control pattern generation means) 11 by using the steering angle logic, and the steering angle is controlled independently.

In the generation of the steering angle control pattern using the steering angle logic, first, as shown in FIG. 8, the maximum curvature γmax and the maximum curvature gradient ωmax are taken to generate a basic trajectory that satisfies the maximum deflection angle θmax. Next, a part of the basic trajectory is subjected to similarity transformation to satisfy the moving distance in the X direction. Then, by adding a straight section in the initial stage, the insufficient movement distance in the Z direction is satisfied. FIG. 9 shows the segment structure of the parallel parking track generated in this way. Section S ₃ from the section S ₁ is a section that is generated by the similarity transformation. FIG. 10 shows a steering angle control pattern generated to satisfy this trajectory. As shown in FIG. 10, according to the steering angle control pattern generated using the similarity transformation, a straight section like the section S ₄ in FIG. 7 does not occur during the steering.

  After generating the turning angle control pattern and the steering angle control pattern in this way, the process proceeds to actual guidance control. Here, it is preferable that the parking assist ECU 1 instructs the drive system (not shown) to perform torque-up control of the engine when the shift lever is set to the reverse position. The torque-up control is to shift the engine to a high driving force state (torque-up state) by rotating the engine at a higher rotational speed than during normal idling. As a result, the vehicle speed range that can be adjusted only with the brake pedal without the driver performing the accelerator operation is expanded, and the controllability of the vehicle is improved. When the driver operates the brake pedal, the vehicle speed is adjusted by adjusting the braking force applied to each wheel according to the pedal opening. At this time, it is preferable to guard the upper limit vehicle speed by controlling the braking force applied to each wheel so that the vehicle speed detected by the wheel speed sensor 51 does not exceed the upper limit vehicle speed.

  In the guidance control, the turning angle of the wheel 32 is controlled by the automatic turning device (control means) 30 based on the turning angle control pattern generated as described above. Thereby, suitable guidance of vehicle 200 can be aimed at. On the other hand, the steering angle of the steering wheel 22 is controlled by the automatic steering device (control means) 20 based on the steering angle control pattern generated as described above. At this time, as shown in FIG. 10, the control pattern of the steering angle does not include a straight section during the steering. As a result, since the steering wheel 22 does not stop once during the steering operation, the possibility that the driver feels uncomfortable with respect to the movement of the steering wheel 22 can be reduced.

Here, as shown in FIG. 10, when E _W start and angle change from the steering angle neutral in the control pattern of the steering angle, as shown in FIG. 7, the angle changes from the steering angle neutral in the control pattern of the turning angle preferably is the same as the point E _T to begin. If it does in this way, the cutting time of the steering wheel 22 and the cutting time of the wheel 32 can be made to correspond, and a driver's discomfort can be reduced further.

Further, as shown in FIG. 10, the time point _FW at which the angle change starts from the steering angle holding in the steering angle control pattern is changed from the turning angle holding in the turning angle control pattern as shown in FIG. preferably is the same as the point F _T start. In this way, the turning-back time of the steering wheel 22 and the turning-back time of the wheel 32 can be matched, and the driver's uncomfortable feeling can be further reduced.

Point addition, as shown in FIG. 10, when V _W to start the final steering angle holding the control pattern of the steering angle, which as shown in FIG. 7, started the final turning angle held in the control pattern of the turning angle preferably is the same as V _T. In this way, the driver's uncomfortable feeling with respect to the movement of the steering wheel 22 can be further reduced.
(Second Embodiment)

  Next, a second embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the element same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  In the first embodiment, the turning control unit 12 of the parking assist ECU 1 generates a turning angle control pattern for controlling the turning angle using the turning angle logic, and the steering control unit 11 uses the steering angle logic. A steering angle control pattern for controlling the steering angle is generated using. On the other hand, in this embodiment, the turning control unit 12 generates a turning angle control pattern for controlling the turning angle by the turning angle logic, and the steering control unit 11 generates the turning angle control pattern. Is used to generate a steering angle control pattern.

As shown in FIG. 11A, in the same manner as in the first embodiment (see FIG. 7), the turning control unit 12 controls the turning angle by using the turning angle logic. Generate a pattern. The steering control unit 11 uses this turning angle control pattern to generate a steering angle control pattern shown in FIG. Specifically, the start point V _T of the section S ₆ of the turning angle control pattern is shifted forward, and the section T ₄ that holds the steering angle is lengthened as the start point V _W. Further, the section S ₀ , the section S ₁ , and the section S ₂ of the turning angle control pattern are directly used as the section T ₀ , the section T ₁ , and the section T ₂ . Then, tie the starting point _{V W} endpoint _{F W} and the interval _{T 4} of the section T ₂ by a straight line, and the interval T _3. In this way, the steering angle control pattern is generated using the turning angle control pattern. The end point _FW and the point V _{T of} the section T ₂ may be directly connected by a straight line to form the section T ₃ .

When generating a turning angle control pattern for controlling the turning angle using the turning angle logic, depending on the distance from the initial position A to the switching position M and the amount of change in the deflection angle, FIG. as shown, there may not linear path is applied after the sections S _3. In this case, as shown in FIG. 12B, the section S ₀ , the section S ₁ , the section S ₂ , and the section S ₅ of the turning angle control pattern are the sections T ₀ , T ₁ , T _{2 as they are.} , and utilized as a section T _4. Then, tie the starting point _{V W} endpoint _{F W} and the interval _{T 4} of the section T ₂ by a straight line, and the interval T _3. In this way, the steering angle control pattern is generated using the turning angle control pattern.

Furthermore, when generating a turning angle control pattern for controlling the turning angle using the turning angle logic, depending on the distance from the initial position A to the switching position M and the amount of change in the deflection angle, FIG. As shown in FIG. 4, there is a case where the steering angle holding section of the circular arc path is not provided between the section S ₁ and the section S ₂ . In this case, as shown in FIG. 13B, the section S ₀ , the section S ₁ , and the section S ₄ of the turning angle control pattern are used as they are as the section T ₀ , the section T ₁ , and the section T ₃ . . Then, the end point _FW of the section T ₁ and the start point V _W of the section T ₃ are connected by a straight line to obtain a section T ₂ . In this way, the steering angle control pattern is generated using the turning angle control pattern.

Although not shown, a control pattern of the turning angle, a section S _0, S _1, S ₂ of FIG. 13 (a), and a section S _4, S _5, S ₆ shown in FIG. 11 (a) Something like a merge can be generated. In this case, the sections S ₀ , S ₁ , and S ₆ of the steering angle control pattern are used as the sections T ₀ , T ₁ , and T ₃ as they are. Then, the end point _FW of the section T ₁ and the start point V _W of the section T ₃ are connected by a straight line to obtain a section T ₂ . In this manner, the steering angle control pattern may be generated using the turning angle control pattern.

  Next, the process proceeds to actual guidance control. In the guidance control, the turning angle of the wheel 32 is controlled by the automatic turning device 30 based on the turning angle control pattern generated as described above. Thereby, suitable guidance of vehicle 200 can be aimed at. On the other hand, based on the steering angle control pattern generated as described above, the steering angle of the steering wheel 22 is controlled by the automatic steering device 20. At this time, in the case shown in FIG. 11B, the steering angle control pattern does not include a straight section during the steering. As a result, since the steering wheel 22 does not stop once during the steering operation, the possibility that the driver feels uncomfortable with respect to the movement of the steering wheel 22 can be reduced. In the above-described control, the relationship between the steering angle and the steering angle temporarily changes, but a normal driver does not notice that the relationship has changed, so that the change in the relationship is uncomfortable. The fear is small.

Also, in the case shown in FIG. 12 (b), the control pattern of the steering angle is in the interval T ₃ of crosscut operation in the middle of the steering, the curvature gradient is constant. As a result, the rotational speed of the steering wheel 22 in the middle of performing steering in the section T ₃ is not able to change, it is possible to reduce the risk of the driver to the movement of the steering wheel 22 feels uncomfortable.

Furthermore, the case shown in FIG. 13 (b), the control pattern of the steering angle is in the interval T ₂ of the crosscut operation in the middle steering curvature gradient is constant. As a result, since the rotational speed of the steering wheel 22 does not change during the steering in the section T ₂ , the possibility that the driver feels uncomfortable with the movement of the steering wheel 22 can be reduced.

  As described above, in the present embodiment, the steering wheel control pattern is generated based on the turning angle control pattern, so that the steering wheel 22 is smoothly controlled while being approximated to the turning angle control pattern. A steering angle control pattern can be easily generated.

Here, FIG. 11, as shown in FIGS. 12 and 13, when E _W start and angle change from the steering angle neutral in the control pattern of the steering angle, the angle change from the steering angle neutral in the control pattern of the turning angle preferably is the same as the point E _T start. If it does in this way, the cutting time of the steering wheel 22 and the cutting time of the wheel 32 can be made to correspond, and a driver's discomfort can be reduced further.

Further, as shown in FIGS. 11 and 12, when F _W start and angle change from the steering angle maintained in the control pattern of the steering angle, when F _T start and angle change from the steering angle maintained in the control pattern of the turning angle Are preferably the same. In this way, the turning-back time of the steering wheel 22 and the turning-back time of the wheel 32 can be matched, and the driver's uncomfortable feeling can be further reduced.

Further, as shown in FIG. 13, when F _W to the steering angle change becomes an extreme value in the control pattern of the steering angle is the same as the time F _T of the steering angle change becomes an extreme value in the control pattern of the turning angle Preferably there is. In this way, the turning-back time of the steering wheel 22 and the turning-back time of the wheel 32 can be matched, and the driver's uncomfortable feeling can be further reduced.

Further, as shown in FIGS. 12 and 13, when V _W to start the final steering angle holding the control pattern of the steering angle is equal to the time V _T to start the final turning angle held in the control pattern of the turning angle Is preferable. In this way, the driver's uncomfortable feeling with respect to the movement of the steering wheel 22 can be further reduced.

  As shown in FIGS. 11, 12, and 13, the steering angle control pattern preferably includes a section generated by changing the ratio of the change in the steering angle with respect to the change in the steering angle. Thus, by changing the ratio of the change in the steering angle with respect to the change in the steering angle, a steering angle control pattern for smoothly controlling the steering wheel 22 is easily generated.

  Further, as shown in FIG. 11, the steering angle control pattern preferably includes a section in which the steering angle is changed when the turning angle is not changed. The steering angle control pattern preferably includes a section in which the steering angle is not changed when the steering angle is changed. When the control pattern of the steering angle includes such a section, smooth control of the steering wheel 22 is easily realized.

Further, as shown in FIGS. 11, 12, and 13, the steering angle control pattern changes the steering angle at a rate smaller than the rate of change of the turning angle with respect to the travel distance in the turning angle control pattern. It is preferable to include a section. In this way, the change in the steering angle becomes gentler than the change in the turning angle, and the driver's uncomfortable feeling with respect to the movement of the steering wheel 22 is reduced.
(Third embodiment)

  Next, a third embodiment of the present invention will be described. In addition, the same code | symbol is attached | subjected to the element same as 1st Embodiment, and the overlapping description is abbreviate | omitted.

  As shown in FIG. 14 (a), the movement trajectory of parallel parking is required to generate a trajectory in which the first turning circle is a loose circle from the viewpoint of vehicle behavior and the appearance of the steering wheel rotation. However, due to the positional relationship between the initial position A and the obstacle E and the geometrical positional relationship between the initial position A and the target position G, the first turning circle is made a steep circle and the beginning of the movement trajectory. In some cases, the movement trajectory may include a straight section inserted in the middle. FIG. 14B shows a movement trajectory when the first turning circle becomes a steep circle due to the positional relationship between the initial position A and the obstacle E. FIG.

FIG. 15A shows a turning angle control pattern generated by the turning control unit 12 of the parking assistance ECU 1 in order to control the turning angle so as to guide the vehicle along such a movement trajectory. ing. As shown in FIG. 15A, in this turning angle control pattern, a section S ₁ , a section S ₂ , and a section S ₃ corresponding to the first turning circle are provided between the straight sections S ₀ and S _4. Is provided. Since these sections S _{1 to} S ₃ have a steep trajectory, the maximum curvature and the curvature gradient become large. Therefore, if the steering angle is controlled according to this turning angle control pattern, the steering wheel 22 moves suddenly, and the driver may feel uncomfortable with the movement of the steering wheel 22.

  Therefore, in the present embodiment, as shown in FIG. 14 (a), it is assumed that there is no obstacle E, and the movement trajectory of the parallel parking is obtained separately. Based on this, the steering control unit 11 controls the steering angle control pattern. Are generated separately. The steering angle control pattern generated in this way is shown by a solid line in FIG. 15B (the broken line shows the control pattern of the turning angle). As shown in FIG. 15B, in this case, since the first turning circle is a gentle circle, the maximum curvature and the curvature gradient are smaller than the control pattern of the turning angle. Accordingly, the movement of the steering wheel 22 becomes gentle.

  In the guidance control, the turning angle of the wheel 32 is controlled by the automatic turning device 30 based on the turning angle control pattern generated as described above. Thereby, suitable guidance of vehicle 200 can be aimed at. On the other hand, based on the steering angle control pattern generated as described above, the steering angle of the steering wheel 22 is controlled by the automatic steering device 20. At this time, in the steering angle control pattern shown in FIG. 15B, the maximum curvature and the curvature gradient are smaller than the turning angle control pattern. Accordingly, the movement of the steering wheel 22 becomes gentle. As a result, it is possible to reduce the possibility that the driver will feel uncomfortable with the movement of the steering wheel 22.

Here, as shown in FIG. 15, when E _W start and angle change from the steering angle neutral in the control pattern of the steering angle is equal to the time E _T to start the angle change from the steering angle neutral in the control pattern of the turning angle Is preferable. If it does in this way, the cutting time of the steering wheel 22 and the cutting time of the wheel 32 can be made to correspond, and a driver's discomfort can be reduced further.

Further, as shown in FIG. 15, the time point V _W at which the final steering angle holding in the steering angle control pattern starts is the same as the time point V _T at which the final turning angle holding starts in the turning angle control pattern. preferable. In this way, the driver's uncomfortable feeling with respect to the movement of the steering wheel 22 can be further reduced.

The present invention is not limited to the above-described embodiment, and various modifications can be made. For example, although the parking assistance device 100 of the present embodiment has been described for a case where the steering and turning are applied to a steer-by-wire (SBW) vehicle in which steering and steering are mechanically separated, the present invention is directed to steering and turning. However, the present invention can also be applied to a vehicle mechanically connected via a gear ratio variable device (VGRS). In this case, as shown in FIG. 16, the automatic turning device 30 controls the turning angle of the wheel 32 based on the turning angle control pattern, while the automatic steering device 20 uses the gear ratio based on the steering angle control pattern. The steering angle of the steering wheel 22 is controlled by controlling the variable device. In other words, in the section T ₄ where the curvature gradient of the steering angle is gentler than the curvature gradient of the turning angle, the gear ratio is increased in order to make the steering wheel 22 steer gently.

  Thus, the vehicle 200 can be appropriately guided by controlling the turning angle of the wheel 32 based on the turning angle control pattern. On the other hand, the driver feels uncomfortable with the movement of the steering wheel 22 by controlling the gear angle variable device and controlling the steering angle of the steering wheel 22 based on the steering angle control pattern generated as described above. The fear can be reduced.

  The present invention can also be applied to a vehicle in which the relationship between steering and turning is changed by a toe control actuator mechanism. The present invention is also applicable to a vehicle equipped with a 4WS mechanism that changes the relationship between steering and a movement locus by rear wheel steering. If the vehicle is equipped with a 4WS mechanism, it is possible to move the vehicle along the target movement locus by rear wheel turning while performing the steering angle control according to the steering control pattern.

It is a block block diagram of the parking assistance apparatus as a vehicle travel assistance apparatus which concerns on embodiment. It is a figure which shows the basic movement locus | trajectory pattern of parallel parking. It is a figure which shows the basic movement trace pattern of garage parking. It is a figure for demonstrating coordinate transformation when using a garage insertion logic. It is a figure explaining the concept of a 2 circle model. It is a figure which shows the segment structure of the track | orbit of parallel parking in 1st Embodiment. It is a figure which shows the control pattern of turning angle in 1st Embodiment, and the change of a deflection angle. It is a figure for demonstrating the method of producing | generating the track of parallel parking using similarity conversion by the logic for steering angles. It is a figure which shows the segment structure of the track | orbit of parallel parking produced | generated using similarity transformation. It is a figure which shows the control pattern of the steering angle in 1st Embodiment. It is a figure which shows the control pattern of the steering angle in 2nd Embodiment, and the control pattern of a steering angle. It is a figure which shows the control pattern of the other steering angle in 2nd Embodiment, and the control pattern of a steering angle. It is a figure which shows the control pattern of the other steering angle in 2nd Embodiment, and the control pattern of a steering angle. FIG. 14A shows a parallel parking trajectory when there is no obstacle, and FIG. 14B shows a parallel parking trajectory when there is an obstacle. It is a figure which shows the control pattern of the steering angle in the 3rd Embodiment, and the control pattern of a steering angle. Steering angle control pattern, steering angle control pattern, and gear ratio variable when the parking assist device is applied to a vehicle in which steering and steering are mechanically connected via a gear ratio variable device (VGRS). It is a figure which shows the relationship with the gear ratio of an apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Parking assistance ECU, 10 ... Image processing part, 11 ... Steering control part, 12 ... Steering control part, 20 ... Automatic steering device, 21 ... Steering shaft, 22 ... Steering wheel, 23 ... Steering angle sensor, 24 ... Steering Actuator, 30 ... automatic steering device, 31 ... steering mechanism, 32 ... wheel, 33 ... steering angle sensor, 34 ... steering actuator, 41 ... input means, 42 ... rear camera, 43 ... speaker, 44 ... monitor, DESCRIPTION OF SYMBOLS 51 ... Wheel speed sensor, 52 ... Acceleration sensor, 100 ... Parking assistance apparatus, 200 ... Own vehicle, 201 ... Front vehicle, 202 ... Rear vehicle, 210, 211 ... Road, 215 ... Parking space, 220 ... Garage

Claims (11)

A travel support device for a vehicle that supports travel of a vehicle so as to travel along a target movement locus from an initial position to a target position,
A turning angle control pattern generating means for generating a control pattern for controlling the turning angle of the turning means so that the vehicle travels along the target movement locus;
Steering angle control pattern generating means for generating a control pattern for controlling the steering angle of the steering means;
Control means for controlling the steering means based on the control pattern of the steering angle, and for controlling the steering means based on the control pattern of the steering angle;
A vehicle travel support apparatus comprising:   The vehicle travel support apparatus according to claim 1, wherein the steering angle control pattern is generated based on the steering angle control pattern.   The vehicle travel support apparatus according to claim 2, wherein the steering angle control pattern includes a section generated by changing a ratio of the change in the steering angle with respect to the change in the steering angle.   4. The vehicle travel support apparatus according to claim 2, wherein the steering angle control pattern includes a section in which the steering angle is changed when the turning angle is not changed. 5.   The vehicle travel support apparatus according to any one of claims 2 to 4, wherein the steering angle control pattern includes a section in which the steering angle is not changed when the turning angle is changed.   6. The control pattern of the steering angle includes a section in which the steering angle is changed at a rate smaller than a rate of change of the turning angle with respect to a travel distance in the turning angle control pattern. The vehicle travel support apparatus according to any one of the above.   The time point at which an angle change starts from the steering angle neutral in the steering angle control pattern is the same as the time point at which the angle change starts from the turning angle neutral in the turning angle control pattern. The vehicle travel support device according to any one of the above.   The time point at which an angle change is started from holding the steering angle in the steering angle control pattern is the same as the time point from which the angle change is started from holding the turning angle in the turning angle control pattern. The vehicle travel support device according to any one of the above.   The time point at which the steering angle change becomes an extreme value in the steering angle control pattern is the same as the time point at which the turning angle change becomes an extreme value in the steering angle control pattern. The vehicle travel support device according to any one of the above.   10. The steering angle control pattern includes a section generated by connecting a straight line between a maximum turning angle and a minimum turning angle in the turning angle control pattern. The vehicle travel support apparatus according to any one of the above.   The vehicle travel support according to claim 1, wherein the steering angle control pattern and the steering angle control pattern are generated when the target movement locus is generated. apparatus.

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