JP7333764B2 - Control device, control method and program - Google Patents

Description

The present invention relates to a control device, control method and program.

In recent years, technologies related to automatic driving have been proposed for automatically driving a vehicle without relying on driving operations (specifically, acceleration/deceleration operations and steering operations) by a driver. In automatic driving, control is performed to drive the vehicle along a target route. As a technology related to such automatic driving, for example, as disclosed in Patent Document 1, a tangent line along the current traveling direction of the vehicle at the current point passing through the target point and the current point on the target route of the vehicle There is a technique for controlling the steering angle (that is, the turning angle of the tires) so that the vehicle runs on an arc having

WO2017/208781

According to the steering angle control based on the arc disclosed in Patent Document 1, it is possible to suppress sudden changes in the steering angle. It is possible to stabilize the behavior of the vehicle before reaching the target point. However, the tangential direction of the arc at the target point on the target route does not necessarily match the tangential direction of the target route at the target point, and may deviate greatly. In this case, when the vehicle reaches the target point, the traveling direction of the vehicle tends to deviate from the tangential direction of the target route. Such divergence of the traveling direction of the vehicle from the tangential direction of the target route can be a factor of unstable behavior of the vehicle after reaching the target point.

Therefore, in view of such problems, it is an object of the present invention to provide a control device, a control method, and a program that enable the vehicle to travel along a target route while stabilizing the behavior of the vehicle. .

In order to solve the above-described problems, the control device of the present invention includes a determination unit that determines a target steering angle, and a control unit that controls the steering angle of the vehicle to the target steering angle. A first arc that passes through the reference target point and the current point on the route and has a tangent line along the tangential direction of the target route at the reference target point is specified, and is in front of the reference target point and based on the first arc A second arc that passes through the current position and the secondary target point set by , and has a tangent line along the current direction of travel of the vehicle at the current point is specified, and the steering angle when the vehicle is made to run on the second arc Based on this, the target steering angle is determined.

The determination unit sets the secondary target point inside the first arc when the center position of the first arc is located on the side of the current traveling direction of the vehicle with respect to the current position, and sets the secondary target point inside the first arc. If the point is located on the opposite side of the current traveling direction of the vehicle, the secondary target point may be set outside the first arc.

The determination unit determines that the greater the relative angle between the current traveling direction of the vehicle and the tangential direction of the first arc at the current point, the longer the distance between the first arc and the secondary target point. A secondary target point may be set.

Assuming that the first steering angle is the steering angle at which the vehicle travels on the second arc, the determining unit draws a tangent line along the current traveling direction of the vehicle at the current point, passing through the reference target point and the current point. The second steering angle may be determined as the steering angle when the vehicle travels on the third arc, and the target steering angle may be determined based on the first steering angle and the second steering angle.

The determination unit may determine a steering angle obtained by weighted averaging the first steering angle and the second steering angle as the target steering angle.

The determination unit weights each of the first steering angle and the second steering angle in determining the target steering angle based on the tangential direction of the target route at the reference target point and the tangential direction of the third arc at the reference target point. You may change according to the relative angle between.

In order to solve the above problems, the control method of the present invention includes the steps of determining a target steering angle, and controlling the steering angle of a vehicle to the target steering angle by a control device. In the step, specifying a first arc that passes through the reference target point and the current point on the target route of the vehicle and has a tangent line along the tangential direction of the target route at the reference target point; , passing through the current position and the secondary target point set based on the first arc, specifying a second arc having a tangent line along the current traveling direction of the vehicle at the current point, and driving the vehicle along the second arc. A target steering angle is determined based on the steering angle when the vehicle is to be turned on.

In order to solve the above-described problems, the program of the present invention is a program for causing a computer to function as a determination unit that determines a target steering angle and a control unit that controls the steering angle of a vehicle to the target steering angle. Then, the determination unit identifies a first arc passing through the reference target point and the current point on the target route of the vehicle and having a tangent line along the tangential direction of the target route at the reference target point. A second arc that passes through the current position and the secondary target point set based on the first arc and has a tangent line along the current traveling direction of the vehicle at the current point is specified, and the second arc is specified. A target steering angle is determined based on the steering angle when the vehicle is driven.

According to the present invention, it is possible to make the vehicle travel along the target route while stabilizing the behavior of the vehicle.

1 is a schematic diagram showing a schematic configuration of a vehicle in which a control device according to an embodiment of the invention is mounted; FIG. It is a block diagram showing an example of functional composition of a control device concerning an embodiment of the present invention. It is a figure for demonstrating the determination process of the target steering angle in a comparative example. FIG. 5 is a diagram for explaining target steering angle determination processing by a determining unit of the control device according to the embodiment of the present invention; It is a flow chart which shows the 1st example of the flow of processing about steering control in automatic operation mode which a control device concerning an embodiment of the present invention performs. FIG. 7 is a schematic diagram showing how a secondary target point is set inside a first arc in the secondary target point setting process according to the embodiment of the present invention. FIG. 7 is a schematic diagram showing how a secondary target point is set outside the first arc in the secondary target point setting process according to the embodiment of the present invention. It is a flowchart which shows the 2nd example of the flow of a process regarding the steering control in automatic driving mode which the control apparatus which concerns on embodiment of this invention performs.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in these embodiments are merely examples for facilitating understanding of the invention, and do not limit the invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are given the same reference numerals to omit redundant description, and elements that are not directly related to the present invention are omitted from the drawings. do.

<Vehicle configuration>
A configuration of a vehicle 1 equipped with a control device 100 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG.

Note that the vehicle 1 described below is merely an example of a vehicle in which the control device according to the present invention is mounted, and the vehicle in which the control device according to the present invention is mounted is particularly limited to the vehicle 1, as will be described later. not.

FIG. 1 is a schematic diagram showing a schematic configuration of a vehicle 1 in which a control device 100 is mounted. As shown in FIG. 1, the vehicle 1 includes a drive motor 21, an inverter 22, a battery 23, a braking device 31, a hydraulic pressure control unit 32, a master cylinder 33, an accelerator pedal 41, and a brake pedal. 42, a power transmission system 51, wheels 52, a steering wheel 53, an accelerator opening sensor 61, a brake sensor 62, a power steering mechanism 71, a navigation device 81, a vehicle speed sensor 91, and a vehicle position sensor 92. and a control device 100 .

The vehicle 1 is an electric vehicle that includes only a drive motor 21 as a drive source and runs using power output from the drive motor 21 .

The driving mode of the vehicle 1 can be switched between a manual driving mode and an automatic driving mode. The manual driving mode is a driving mode in which the acceleration/deceleration and steering angle of the vehicle 1 are controlled according to the driver's driving operation (that is, acceleration/deceleration operation and steering operation). The automatic driving mode is a driving mode in which the acceleration/deceleration and steering angle of the vehicle 1 are automatically controlled without depending on the driving operation of the driver.

The drive motor 21 is a motor that outputs power to be transmitted to the wheels 52 of the vehicle 1, and is, for example, a three-phase AC motor. The drive motor 21 is connected to a battery 23 via an inverter 22, and is driven using the power of the battery 23 to output power.

The drive motor 21 may be a motor generator that is regeneratively driven when the vehicle 1 decelerates and can generate electricity using the kinetic energy of the wheels 52 . In this case, electric power generated by drive motor 21 is supplied to battery 23 via inverter 22 . Thereby, the battery 23 is charged with electric power generated by the drive motor 21 .

An output shaft of the driving motor 21 is connected to wheels 52 via a power transmission system 51 , and power output from the driving motor 21 is transmitted to the wheels 52 via the power transmission system 51 .

In the vehicle 1, the driving wheels to which the power output from the driving motor 21 is transmitted may be the front wheels or the rear wheels. Moreover, the power output from the output side of the power transmission system 51 may be transmitted to both the front wheels and the rear wheels via a propeller shaft (not shown).

The inverter 22 is a power conversion device that performs bidirectional power conversion. For example, inverter 22 includes a three-phase bridge circuit. The inverter 22 can convert DC power supplied from the battery 23 into AC power and supply the drive motor 21 with the AC power. Further, the inverter 22 can convert AC power generated by the drive motor 21 into DC power and supply the DC power to the battery 23 .

The battery 23 is a battery that can charge and discharge electric power. As the battery 23, for example, a lithium ion battery, a lithium ion polymer battery, a nickel hydrogen battery, a nickel cadmium battery, or a lead acid battery is used, but batteries other than these may be used. The battery 23 stores electric power supplied to the driving motor 21 .

The master cylinder 33 is connected to the brake pedal 42 via a booster (not shown), and generates hydraulic pressure according to the brake operation amount, which is the operation amount of the brake pedal 42 . The master cylinder 33 is connected via a hydraulic control unit 32 to a brake device 31 provided for each wheel 52 . The hydraulic pressure generated by the master cylinder 33 is supplied to each brake device 31 via the hydraulic pressure control unit 32 .

The braking device 31 applies a braking force to the wheels 52 using hydraulic pressure. The total braking force applied to each wheel 52 by each braking device 31 is the braking force applied to the vehicle 1 .

The brake device 31 has, for example, a brake caliper (not shown) including brake pads and wheel cylinders. A pair of brake pads are provided, for example, on both side surfaces of a brake disc that rotates integrally with the wheel 52 so as to face each other. A wheel cylinder is formed in the brake caliper, and a piston is slidably provided in the wheel cylinder. The tip of the piston faces the brake pad, and the brake pad moves toward each side of the brake disc as the piston slides. Hydraulic pressure generated by the master cylinder 33 is supplied to the wheel cylinders of the brake device 31 . As a result, the piston in the brake caliper and the brake pads move, so that both side surfaces of the brake disc are sandwiched between the pair of brake pads, and braking force is applied to the wheels 52 .

The hydraulic pressure control unit 32 can adjust the hydraulic pressure supplied to each brake device 31 (that is, the brake hydraulic pressure of each brake device 31). Specifically, the hydraulic pressure control unit 32 has devices such as pumps and control valves, and the brake hydraulic pressure of each brake device 31 is controlled by controlling the operation of these devices. Thereby, the braking force applied to each wheel 52 is controlled. The hydraulic pressure control unit 32 may be able to individually adjust the hydraulic pressure supplied to each braking device 31 . Also, the number of brake systems may be two.

The accelerator pedal 41 receives an accelerator operation by the driver. Specifically, the accelerator operation is an operation of stepping on the accelerator pedal 41 .

The brake pedal 42 receives a brake operation by the driver. Specifically, the braking operation is an operation of depressing the brake pedal 42 .

The accelerator opening sensor 61 detects the accelerator opening, which is the amount of operation of the accelerator pedal 41 by the driver, and outputs the detection result to the control device 100 .

The brake sensor 62 detects the amount of brake operation, which is the amount of operation of the brake pedal 42 by the driver, and outputs the detection result to the control device 100 .

The power steering mechanism 71 assists the driver's steering operation using the steering wheel 53 . For example, the power steering mechanism 71 has an electric motor capable of outputting power for rotating the steering wheel 53 . In this case, the driver's steering operation is assisted by driving the electric motor. As will be described later, in the automatic driving mode, the power steering mechanism 71 is used to control the steering angle of the vehicle 1 .

The navigation device 81 is a device that guides a route from the current location of the vehicle 1 (that is, the location where the vehicle 1 is currently located) to a destination desired by the user in accordance with an input operation by the user. The navigation device 81 outputs to the control device 100 information indicating a travel route to be guided (that is, a route set by the user as a route from the current location of the vehicle 1 to the destination). In addition, the navigation device 81 has a function of visually displaying information, and includes various types of information related to route guidance (for example, the current location of the vehicle 1, the travel route to be guided, the position of the destination, the current location of the vehicle 1). distance on the driving route from the point to the destination, arrival time to the destination, etc.). The navigation device 81 can acquire the current location of the vehicle 1 using, for example, detection results from a vehicle position sensor 92, which will be described later.

Vehicle speed sensor 91 detects vehicle speed, which is the speed of vehicle 1 , and outputs the detection result to control device 100 .

Vehicle position sensor 92 detects the position of vehicle 1 and outputs the detection result to control device 100 . Specifically, the vehicle position sensor 92 can detect the current point, which is the point where the vehicle 1 is currently located. For example, the vehicle position sensor 92 can identify the position of the vehicle 1 by acquiring a GPS (Global Positioning System) signal or the like.

The control device 100 includes a CPU (Central Processing Unit) that is an arithmetic processing unit, a ROM (Read Only Memory) that is a storage element that stores programs used by the CPU, operation parameters, and the like, and parameters that change as appropriate during execution of the CPU. Random Access Memory (RAM), which is a storage element for temporarily storing data, etc., is included.

FIG. 2 is a block diagram showing an example of the functional configuration of the control device 100. As shown in FIG. For example, as shown in FIG. 2, the control device 100 has an acquisition unit 110, a control unit 120, and a determination unit .

Acquisition unit 110 acquires various types of information used in the processing performed by control unit 120 and determination unit 130 and outputs the information to control unit 120 and determination unit 130 . For example, the acquisition unit 110 acquires various information output from the accelerator opening sensor 61 , the brake sensor 62 , the navigation device 81 , the vehicle speed sensor 91 and the vehicle position sensor 92 .

Control unit 120 controls the operation of each device in vehicle 1 . For example, the controller 120 includes a motor controller 121 , a brake controller 122 and a steering controller 123 .

The motor control section 121 controls the operation of the drive motor 21 . Specifically, the motor control unit 121 controls the power supply between the battery 23 and the drive motor 21 by controlling the operation of the switching elements of the inverter 22 . Thereby, the motor control unit 121 can control the power generation and power generation by the drive motor 21 .

The brake control section 122 controls the operation of the brake device 31 . Specifically, the brake control section 122 controls the brake hydraulic pressure of each brake device 31 provided for each wheel 52 by controlling the operation of the hydraulic pressure control unit 32 . Thereby, the brake control unit 122 can control the braking force applied to the vehicle 1 .

The steering control section 123 controls the operation of the power steering mechanism 71 . Specifically, the steering control unit 123 can control the torque applied to the steering wheel 53 by the electric motor of the power steering mechanism 71 by controlling the output of the electric motor.

As described above, the driving mode of the vehicle 1 can be switched between the manual driving mode and the automatic driving mode. For example, the vehicle 1 is provided with an input device (for example, a switch or button) for selecting which of the manual driving mode and the automatic driving mode is to be executed, and the driver operates the input device. By doing so, manual operation mode or automatic operation mode can be selected. It should be noted that switching from the automatic operation mode to the manual operation mode may be performed when a specific operation such as a brake operation is performed by the driver during the automatic operation mode. The control unit 120 controls the acceleration/deceleration and the steering angle of the vehicle 1 according to the driving mode.

In the manual operation mode, the control unit 120 controls each device so that the acceleration/deceleration of the vehicle 1 corresponds to the acceleration/deceleration operation (that is, accelerator operation and brake operation) by the driver. Specifically, the control unit 120 controls the operation of the driving motor 21 so that the driving force applied to the vehicle 1 corresponds to the accelerator opening. Thereby, the acceleration of the vehicle 1 can be controlled according to the accelerator operation by the driver. Further, the control unit 120 controls the operation of the brake device 31 so that the braking force applied to the vehicle 1 becomes a braking force corresponding to the amount of brake operation. Thereby, the deceleration of the vehicle 1 can be controlled according to the brake operation by the driver. Further, the control unit 120 controls the operation of the power steering mechanism 71 so that torque is applied to the steering wheel 53 in the same direction as the turning direction of the steering wheel 53 when the steering operation is performed by the driver. . This assists the driver's steering operation.

In the automatic driving mode, the control unit 120 controls each device so that the vehicle 1 automatically travels along the target route. As the target route, for example, a travel route that is set in response to an input operation by the user in the navigation device 81 is used. Specifically, in the automatic driving mode, the control unit 120 controls the operation of the power steering mechanism 71 so that the steering angle of the vehicle 1 becomes the target steering angle θt determined by the determination unit 130 described later. Further, the control unit 120 controls the acceleration/deceleration of the vehicle 1, for example, so that the vehicle speed of the vehicle 1 is maintained at the set speed. Note that when there is a preceding vehicle traveling ahead of the vehicle 1, the control unit 120 can control the acceleration/deceleration of the vehicle 1 so that the inter-vehicle distance between the vehicle 1 and the preceding vehicle is maintained at the set distance. preferable.

The determination unit 130 determines the above-described target steering angle θt used in steering angle control (hereinafter also referred to as steering control) in the automatic driving mode, and outputs the target steering angle θt to the control unit 120 .

The control device 100 communicates with each device mounted on the vehicle 1 as described above. Communication between the control device 100 and each device is realized using, for example, CAN (Controller Area Network) communication.

Note that the functions of the control device 100 according to the present embodiment may be partially divided by a plurality of control devices, and a plurality of functions may be realized by one control device. When the functions of the control device 100 are partially divided by a plurality of control devices, the plurality of control devices may be connected to each other via a communication bus such as CAN.

Here, after describing the determination processing of the target steering angle θt in the comparative example with reference to FIG. 3, with reference to FIG. An outline of the decision processing will be described.

FIG. 3 is a diagram for explaining the process of determining the target steering angle θt in the comparative example. 3 and FIGS. 4, 6 and 7 to be referred to below, the current traveling direction of the vehicle 1 is the Y direction, and the direction orthogonal to the Y direction is the X direction.

In the comparative example, an arc 303 passing through the reference target point 203 on the target route 9 and the current point 201 and having a tangent line along the current traveling direction (that is, the Y direction) of the vehicle 1 at the current point 201 is specified, The steering angle at which the vehicle 1 is caused to travel on the arc 303 is determined as the target steering angle θt. Therefore, the vehicle 1 is controlled to run on the arc 303 in the automatic driving mode.

Here, if the reference target point 203 is too close to the current point 201 , the target steering angle θt tends to change according to changes in the curvature of the target route 9 . Therefore, for example, when there is a sharp curve on the target route 9, the target steering angle θt may suddenly change, and the behavior of the vehicle 1 may become unstable. Therefore, the reference target point 203 is set far from the current point 201 to the extent that a rapid change in the target steering angle θt is suppressed. By controlling the steering angle as described above using the reference target point 203 set in this way, it is possible to suppress the change in the target steering angle θt before the vehicle 1 reaches the reference target point 203. . Therefore, the behavior of the vehicle 1 before reaching the reference target point 203 can be stabilized.

However, when the tangential direction D2 of the arc 303 at the reference target point 203 deviates greatly from the tangential direction D1 of the target route 9 at the reference target point 203 (that is, the tangential direction D1 shown in FIG. There is a case where the relative angle φ1 with respect to the tangential direction D2 increases. In this case, when the vehicle 1 reaches the reference target point 203 , the traveling direction of the vehicle 1 tends to deviate from the tangential direction D<b>1 of the target route 9 . As a result, the behavior of the vehicle 1 after reaching the reference target point 203 tends to become unstable.

FIG. 4 is a diagram for explaining the determination processing of the target steering angle θt by determination unit 130 of control device 100. As shown in FIG.

In the control device 100 according to the present embodiment, the determination unit 130 determines the first arc 301 passing through the reference target point 203 and the current point 201 and having a tangent line along the tangential direction D1 of the target route 9 at the reference target point 203. Identify. Then, the determining unit 130 passes through the current point 201 and the secondary target point 205 that is set based on the first arc 301 on the near side of the reference target point 203 (that is, on the side closer to the vehicle 1), and reaches the current point. A second circular arc 302 having a tangent line along the current direction of travel of the vehicle 1 (that is, the Y direction) at the point 201 is identified. Then, the determination unit 130 determines the target steering angle θt based on the steering angle when the vehicle 1 is caused to run on the second arc 302 . For example, the determining unit 130 determines the steering angle when the vehicle 1 is caused to run on the second arc 302 as the target steering angle θt.

Note that the secondary target point 205 may be a point on the first arc 301 as in the example shown in FIG. 1 point in the vicinity of the arc 301).

In this embodiment, as described above, the vehicle 1 is driven on the second arc 302 passing through the current point 201 and the secondary target point 205 set based on the first arc 301, before the reference target point 203. A target steering angle θt is determined based on the steering angle for traveling. As a result, the travel route of the vehicle 1 can be brought closer to the first circular arc 301 having a tangent line along the tangential direction D<b>1 of the target route 9 at the reference target point 203 . Therefore, when the vehicle 1 reaches the reference target point 203 , it is possible to prevent the traveling direction of the vehicle 1 from deviating from the tangential direction D1 of the target route 9 . Therefore, it is possible to prevent the behavior of the vehicle 1 from becoming unstable after reaching the reference target point 203 due to the divergence of the traveling direction of the vehicle 1 from the tangential direction D1 of the target route 9 . Therefore, it is possible to make the vehicle 1 travel along the target route 9 while stabilizing the behavior of the vehicle 1 . The details of the processing related to the steering control performed by the control device 100 during the automatic driving mode (in particular, the target steering angle θt determination processing performed by the determination unit 130) will be described later.

<Control device operation>
Next, operations of the control device 100 according to the embodiment of the present invention will be described with reference to FIGS. 5 to 8. FIG. Specifically, a first example and a second example will be described in this order as an example of the flow of processing relating to steering control during the automatic driving mode.

[First example]
First, with reference to FIGS. 5 to 7, a first example of the flow of processing relating to steering control during the automatic driving mode performed by the control device 100 will be described. Specifically, the first example will be described below with appropriate reference to FIG. 4 referred to above.

FIG. 5 is a flowchart showing a first example of the flow of processing relating to steering control during the automatic driving mode performed by the control device 100 . Specifically, the control flow shown in FIG. 5 is repeatedly executed at preset time intervals while the operation mode is the automatic operation mode.

When the control flow shown in FIG. 5 is started, first, in step S501, the control device 100 determines whether or not the target route 9 exists in front of the vehicle 1. If it is determined that the target route 9 exists ahead of the vehicle 1 (step S501/YES), the process proceeds to step S502. On the other hand, if it is determined that the target route 9 does not exist ahead of the vehicle 1 (step S501/NO), the control flow shown in FIG. 5 ends.

If determined as YES in step S501, the determination unit 130 sets the reference target point 203 in step S502.

As described above, the target steering angle θt is determined based on the arc passing through the reference target point 203 and the current point 201 (specifically, the first arc 301). If the reference target point 203 is too close to the current point 201, the arc trajectory is likely to change rapidly, so the target steering angle θt will also tend to change rapidly. As a result, the behavior of the vehicle 1 tends to become unstable. Therefore, the determining unit 130 specifically sets the reference target point 203 at a position far from the current point 201 to the extent that a rapid change in the target steering angle θt is suppressed.

For example, when the determining unit 130 drives the target route 9 at the current vehicle speed from the closest point 209 (see FIG. 4) to the current point 201 on the target route 9 for a reference running time (for example, 1.5 seconds) is set as a reference target point 203 .

Next, in step S<b>503 , the determination unit 130 identifies the first arc 301 .

As described above, the first arc 301 is an arc that passes through the reference target point 203 and the current point 201 and has a tangent line along the tangential direction D1 of the target route 9 at the reference target point 203 .

Next, in step S<b>504 , the determination unit 130 sets the secondary target point 205 .

As described above, the secondary target point 205 is a point that is set based on the first circular arc 301 and that is closer to the vehicle 1 than the reference target point 203 . For example, the determining unit 130 sets the secondary target point 205 at a position on the first circular arc 301 in front of the reference target point 203, as shown in FIG.

Here, the distance between the reference target point 203 and the secondary target point 205 on the first arc 301 can be set as appropriate. For example, the determination unit 130 may use a preset distance as the distance between the two points, or may use the travel distance when the vehicle travels for a predetermined time at the current vehicle speed. Note that the shorter the distance from the current point 201 to the secondary target point 205, the closer the travel route of the vehicle 1 to the first arc 301 can be effectively. is preferably set as appropriate.

Next, in step S<b>505 , the determination unit 130 identifies the second arc 302 .

As described above, the second arc 302 passes through the secondary target point 205 and the current point 201, and extends along the current traveling direction of the vehicle 1 (for example, the Y direction in the example shown in FIG. 4) at the current point 201. A circular arc with a tangent line.

Next, in step S506, determination unit 130 determines a target steering angle θt.

Specifically, the determination unit 130 identifies the steering angle when the vehicle 1 is caused to travel on the second arc 302, and determines the identified steering angle as the target steering angle θt. More specifically, determination unit 130 determines the steering angle when vehicle 1 travels on second arc 302 based on the radius of second arc 302 and the vehicle speed. Here, as the steering angle when the vehicle 1 is caused to run on the second circular arc 302, it is preferable to determine a larger value as the vehicle speed increases.

Next, in step S507, the control unit 120 controls the steering angle of the vehicle 1 to the target steering angle θt, and the control flow shown in FIG. 5 ends.

Although the example in which the secondary target point 205 is set at a position on the first arc 301 has been described above, the determining unit 130 may set the secondary target point 205 at a position away from the first arc 301. . Here, from the viewpoint of stabilizing the behavior of the vehicle 1 more effectively, if the center position of the first arc 301 is located on the side of the current traveling direction of the vehicle 1 with respect to the current point 201, the determining unit 130 When the secondary target point 205 is set inside the first arc 301 and the center position of the first arc 301 is located on the opposite side of the current traveling direction side of the vehicle 1 with respect to the current point 201, the first arc 301 It is preferable to set the secondary target point 205 outside.

FIG. 6 is a schematic diagram showing how the secondary target point 205 is set inside the first arc 301 in the secondary target point 205 setting process.

FIG. 6 shows a first arc 301a passing through the reference target point 203a and the current point 201a on the target route 9a and having a tangent line along the tangential direction D1a of the target route 9a at the reference target point 203a. Here, in the example shown in FIG. 6, the center position 305a of the first circular arc 301a is located on the side of the current traveling direction of the vehicle 1 (that is, the Y direction side) with respect to the current point 201a. Therefore, the determining unit 130 sets the secondary target point 205a inside the first arc 301a (that is, on the side of the center position 305a with respect to the first arc 301a).

The determining unit 130 sets, for example, an arc 309a concentric with the first arc 301a having a smaller radius than the first arc 301a, and sets the secondary target point 205a at a position on the arc 309a. Specifically, as shown in FIG. 6, the determination unit 130 sets a point 207a closest to the reference target point 203a on the arc 309a, and places a sub-point 207a on the arc 309a in front of the point 207a. A target point 205a is set. Here, the distance between the point 207a and the secondary target point 205a on the arc 309a is the distance between the reference target point 203 and the secondary target point 205 on the first arc 301 in the example shown in FIG. can be set as appropriate in the same manner as the distance of .

As in the example shown in FIG. 6, when the center position of the first arc 301 is located on the side of the current traveling direction of the vehicle 1 with respect to the current point 201, the secondary target point 205 is positioned on the first arc 301. When set, the effect of bringing the travel route of the vehicle 1 closer to the first arc 301 is enhanced, while the vehicle 1 tends to travel across the first arc 301 from the inside to the outside. When the vehicle 1 crosses the first arc 301 in this way, the steering is controlled in the direction in which the vehicle 1 returns to the first arc 301 , so that the steering angle tends to change rapidly. The behavior of the vehicle 1 becomes unstable before reaching .

Here, as described with reference to FIG. 6, by setting the secondary target point 205 inside the first arc 301, the travel route of the vehicle 1 can be adjusted inside the first arc 301. . As a result, it is possible to prevent the vehicle 1 from traveling across the first circular arc 301 from the inside to the outside, so that the behavior of the vehicle 1 before reaching the reference target point 203 can be stabilized. can.

FIG. 7 is a schematic diagram showing how the secondary target point 205 is set outside the first arc 301 in the secondary target point 205 setting process.

FIG. 7 shows a first arc 301b passing through the reference target point 203b and the current point 201b on the target route 9b and having a tangent line along the tangential direction D1b of the target route 9b at the reference target point 203b. Here, in the example shown in FIG. 7, the center position 305b of the first circular arc 301b is located on the opposite side of the current traveling direction side of the vehicle 1 (that is, opposite to the Y direction side) with respect to the current point 201b. ing. Therefore, the determining unit 130 sets the secondary target point 205b outside the first arc 301b (that is, on the side opposite to the center position 305b with respect to the first arc 301b).

The determination unit 130 sets, for example, an arc 309b concentric with the first arc 301b having a larger radius than the first arc 301b, and sets the secondary target point 205b at a position on the arc 309b. Specifically, as shown in FIG. 7, the determination unit 130 sets a point 207b closest to the reference target point 203b on the arc 309b, and places a sub-point 207b on the arc 309b in front of the point 207b. A target point 205b is set. Here, the distance between the point 207b and the secondary target point 205b on the arc 309b is the distance between the reference target point 203 and the secondary target point 205 on the first arc 301 in the example shown in FIG. can be set as appropriate in the same manner as the distance of .

As in the example shown in FIG. 7 , if the center position of the first arc 301 is located on the opposite side of the current traveling direction of the vehicle 1 with respect to the current point 201 , the secondary target is positioned on the first arc 301 . When the point 205 is set, the effect of bringing the travel route of the vehicle 1 closer to the first arc 301 is enhanced, but the vehicle 1 tends to travel across the first arc 301 from the outside to the inside. As described above, when the vehicle 1 crosses the first arc 301, the steering is controlled in the direction in which the vehicle 1 returns to the first arc 301, so that the steering angle tends to change rapidly. The behavior of the vehicle 1 becomes unstable before reaching the point 203 .

Here, as described with reference to FIG. 7, by setting the secondary target point 205 outside the first arc 301, the travel route of the vehicle 1 can be adjusted outside the first arc 301. . As a result, it is possible to prevent the vehicle 1 from traveling across the first circular arc 301 from the outside to the inside, so that the behavior of the vehicle 1 before reaching the reference target point 203 can be stabilized. can.

As described above, when the secondary target point 205 is set at a position away from the first arc 301, from the viewpoint of more effectively stabilizing the behavior of the vehicle 1, the determination unit 130 determines the current progress of the vehicle 1 The secondary target point 205 is positioned such that the greater the relative angle between the direction and the tangential direction of the first circular arc 301 at the current point 201, the longer the distance between the first circular arc 301 and the secondary target point 205. It is preferable to set

For example, in the example shown in FIG. 6, the determining unit 130 determines the relative angle φ2a between the current traveling direction of the vehicle 1 (that is, the Y direction) and the tangential direction D3a of the first arc 301a at the current point 201a. is increased, the radius difference ΔRa between the first circular arc 301a and the circular arc 309a is increased. Thereby, the distance between the first circular arc 301a and the secondary target point 205a can be lengthened.

Also, for example, in the example shown in FIG. 7, the determining unit 130 determines the relative distance between the current traveling direction of the vehicle 1 (that is, the Y direction) and the tangential direction D3b of the first circular arc 301b at the current point 201b. The larger the angle φ2b, the larger the radius difference ΔRb between the first circular arc 301b and the circular arc 309b. Thereby, the distance between the first circular arc 301b and the secondary target point 205b can be lengthened.

The greater the relative angle between the current traveling direction of the vehicle 1 and the tangential direction of the first circular arc 301 at the current point 201 (for example, the relative angle φ2a in FIG. 6 or the relative angle φ2b in FIG. 7), the greater the first When the secondary target point 205 is set on the arc 301, the angle formed by the second arc 302 and the first arc 301 (specifically, the angle formed by both arcs at the secondary target point 205) becomes large. Therefore, a situation in which the vehicle 1 travels across the first circular arc 301 is more likely to occur. Therefore, the greater the relative angle between the current traveling direction of the vehicle 1 and the tangential direction of the first arc 301 at the current point 201, the longer the distance between the first arc 301 and the secondary target point 205. As a result, the situation in which the vehicle 1 travels across the first circular arc 301 can be more effectively suppressed. Note that the distance between the first arc 301 and the secondary target point 205 (for example, the radius difference ΔRa in FIG. 6 or the radius difference ΔRb in FIG. 7) may have an upper limit.

[Second example]
Next, with reference to FIG. 8, a second example of the flow of processing relating to steering control during the automatic driving mode performed by the control device 100 will be described.

FIG. 8 is a flowchart showing a second example of the flow of processing relating to steering control during the automatic driving mode performed by the control device 100 . Specifically, the control flow shown in FIG. 8 is repeatedly executed at preset time intervals while the operation mode is the automatic operation mode, similar to the control flow shown in FIG. 5 described above. .

In the control flow shown in FIG. 8, compared with the control flow shown in FIG. 5 described above, the processing for determining the target steering angle after the determination in step S501 is YES (specifically, the control flow shown in FIG. , steps S601 to S604) are different.

When the control flow shown in FIG. 8 is started and the determination in step S501 is YES, in step S601, determination unit 130 determines the first steering angle θ1.

The first steering angle θ1 is the steering angle (that is, the steering angle used as the target steering angle θt in the control flow shown in FIG. 5) when the vehicle 1 is caused to run on the second arc 302 described above. The determining unit 130 identifies the first circular arc 301 as described above, sets the secondary target point 205 based on the first circular arc 301, and identifies the second circular arc 302 based on the secondary target point 205. , the first steering angle θ1 can be determined.

Next, in step S602, determination unit 130 determines the second steering angle θ2.

The second steering angle θ2 is a steering angle when the vehicle 1 is caused to travel on a third arc passing through the reference target point 203 and the current point 201 and having a tangent line along the current traveling direction of the vehicle 1 at the current point 201. is. For example, arc 303 in the example shown in FIG. 3 corresponds to the third arc. That is, the steering angle determined as the target steering angle θt in the comparative example described above with reference to FIG. 3 is the second steering angle θ2. The arc 303 is hereinafter also referred to as the third arc 303 . Specifically, determination unit 130 determines second steering angle θ2 based on the radius of third arc 303 and the vehicle speed. Here, it is preferable to determine a larger value as the second steering angle θ2 as the vehicle speed increases.

Next, in step S603, the determining unit 130 determines the weight of each of the first steering angle θ1 and the second steering angle θ2 in determining the target steering angle θt.

As will be described later, in the control flow shown in FIG. 8, in determining the target steering angle θt, the determination unit 130 determines the target steering angle θt based on the first steering angle θ1 and the second steering angle θ2 (specifically, Specifically, it is determined by weighted averaging the first steering angle θ1 and the second steering angle θ2). The weight of each steering angle in determining the target steering angle θt corresponds to the extent to which each steering angle contributes to determination of the target steering angle θt. For example, when weighted averaging is performed in determining the target steering angle θt, the coefficient by which each steering angle is multiplied corresponds to the weight of each steering angle.

For example, the determination unit 130 assigns the weights of the first steering angle θ1 and the second steering angle θ2 in determining the target steering angle θt to the tangential direction D1 of the target route 9 at the reference target point 203 and and the tangential direction D2 of the third arc 303 at . Specifically, determination unit 130 increases the weight of first steering angle θ1 as relative angle φ1 increases. For example, when the relative angle φ1 is 1°, the determination unit 130 sets the ratio of the weights of the first steering angle θ1 and the second steering angle θ2 to 1:9, and when the relative angle φ1 is 8°, the first steering angle θ1 The weight ratio of the steering angle θ1 and the second steering angle θ2 is set to 8:2.

In determining the target steering angle θt, the greater the weight of the first steering angle θ1, the greater the extent to which the travel route of the vehicle 1 approaches the first circular arc 301 . Therefore, when the vehicle 1 reaches the reference target point 203 , it becomes easier to prevent the traveling direction of the vehicle 1 from deviating from the tangential direction D<b>1 of the target route 9 . Therefore, the effect of stabilizing the behavior of the vehicle 1 after reaching the reference target point 203 can be increased.

As described above, the heavier the weight of the first steering angle θ1 is, the greater the effect of stabilizing the behavior of the vehicle 1 after reaching the reference target point 203 is. The effect of stabilizing the behavior of On the other hand, as the weight of the second steering angle θ2 increases, the effect of stabilizing the behavior of the vehicle 1 before reaching the reference target point 203 increases. is less effective in stabilizing In other words, the effect of stabilizing the behavior of the vehicle 1 after reaching the reference target point 203 and the effect of stabilizing the behavior of the vehicle 1 before reaching the reference target point 203 are in a trade-off relationship. Also, the degree of these effects changes according to the weight of each of the first steering angle θ1 and the second steering angle θ2.

Therefore, by determining the target steering angle θt based on the first steering angle θ1 and the second steering angle θ2 as described above, it is possible to appropriately achieve both effects having the trade-off relationship. , the behavior of the vehicle 1 can be appropriately stabilized before and after reaching the reference target point 203 . Here, the relative angle φ1 between the tangential direction D1 of the target route 9 at the reference target point 203 and the tangential direction D2 of the third arc 303 at the reference target point 203 is such that the vehicle 1 reaches the reference target point 203. This is an index that indicates the extent to which the traveling direction of the vehicle 1 deviates from the tangential direction D1 of the target route 9 when the target route 9 is set. That is, the greater the relative angle φ1, the greater the need to suppress the divergence of the traveling direction of the vehicle 1 from the tangential direction D1 of the target route 9 and to stabilize the behavior of the vehicle 1 after reaching the reference target point 203. . Therefore, by changing the weight of each of the first steering angle θ1 and the second steering angle θ2 in accordance with the relative angle φ1 as described above, the behavior of the vehicle 1 can be changed before and after reaching the reference target point 203. It can be stabilized more appropriately.

Next, in step S604, determination unit 130 determines a target steering angle θt.

Here, the determining unit 130 determines the target steering angle θt based on the first steering angle θ1 and the second steering angle θ2, as described above. Specifically, determination unit 130 determines a steering angle obtained by weighting and averaging first steering angle θ1 and second steering angle θ2 as target steering angle θt.

Next, in step S507, control unit 120 controls the steering angle of vehicle 1 to target steering angle θt, and the control flow shown in FIG. 8 ends.

In the above description, the weight of each of the first steering angle θ1 and the second steering angle θ2 in determining the target steering angle θt is changed according to the relative angle φ1. The weighting ratio of the angle θ1 and the second steering angle θ2 may be set to a preset ratio.

Further, in the above description, an example in which the first steering angle θ1 and the second steering angle θ2 are weighted and averaged in determining the target steering angle θt has been described. may For example, the determining unit 130 may determine a steering angle obtained by simply averaging the first steering angle θ1 and the second steering angle θ2 as the target steering angle θt.

<Effect of control device>
Next, effects of the control device 100 according to the embodiment of the present invention will be described.

In the control device 100 according to the present embodiment, the determination unit 130 passes through the reference target point 203 and the current point 201 on the target route 9 of the vehicle 1, and moves along the tangential direction D1 of the target route 9 at the reference target point 203. Identify the first arc 301 that has a tangent line. Further, the determining unit 130 passes through the current point 201 and the secondary target point 205 which is set based on the first arc 301 and is on the near side of the reference target point 203 (that is, on the side closer to the vehicle 1). A second arc 302 with a tangent line along the current direction of travel of the vehicle 1 at the point 201 is identified. Further, the determining unit 130 determines the target steering angle θt based on the steering angle when the vehicle 1 is caused to run on the second arc 302 . Then, the control unit 120 controls the steering angle of the vehicle 1 to the target steering angle θt.

As a result, the travel route of the vehicle 1 can be brought closer to the first circular arc 301 having a tangent line along the tangential direction D<b>1 of the target route 9 at the reference target point 203 . Therefore, when the vehicle 1 reaches the reference target point 203 , it is possible to prevent the traveling direction of the vehicle 1 from deviating from the tangential direction D1 of the target route 9 . Therefore, it is possible to prevent the behavior of the vehicle 1 from becoming unstable after reaching the reference target point 203 due to the divergence of the traveling direction of the vehicle 1 from the tangential direction D1 of the target route 9 . Therefore, the vehicle 1 can travel along the target route 9 while stabilizing the behavior of the vehicle 1 .

Further, in the control device 100 according to the present embodiment, when the center position of the first arc 301 is located on the current traveling direction side of the vehicle 1 with respect to the current point 201, the determining unit 130 When the secondary target point 205 is set inside and the center position of the first arc 301 is located on the opposite side of the current traveling direction of the vehicle 1 with respect to the current point 201, the secondary target point is set outside the first arc 301. A point 205 is preferably set. As a result, it is possible to prevent the vehicle 1 from traveling across the first circular arc 301, so that the behavior of the vehicle 1 before reaching the reference target point 203 can be stabilized. Therefore, the behavior of the vehicle 1 can be stabilized more effectively.

In addition, in the control device 100 according to the present embodiment, the determination unit 130 determines the relative angle between the current traveling direction of the vehicle 1 and the tangential direction of the first arc 301 at the current point 201 (for example, It is preferable to set the secondary target point 205 such that the greater the relative angle φ2a or the relative angle φ2b in FIG. 7, the longer the distance between the first arc 301 and the secondary target point 205 . As a result, the situation in which the vehicle 1 travels across the first circular arc 301 can be more effectively suppressed. Therefore, the behavior of the vehicle 1 before reaching the reference target point 203 can be stabilized more effectively. Therefore, the behavior of the vehicle 1 can be stabilized more effectively.

In addition, in the control device 100 according to the present embodiment, the determination unit 130 passes through the reference target point 203 and the current point 201, and determines the third arc 303 having a tangent line along the current traveling direction of the vehicle 1 at the current point 201. The steering angle when the vehicle 1 is caused to run on the top is determined as the second steering angle θ2. It is preferable to determine the target steering angle θt based on θ2. As a result, the behavior of the vehicle 1 can be appropriately stabilized before and after reaching the reference target point 203 .

Further, in the control device 100 according to the present embodiment, the determination unit 130 preferably determines the steering angle obtained by weighted averaging the first steering angle θ1 and the second steering angle θ2 as the target steering angle θt. As a result, it is possible to appropriately stabilize the behavior of the vehicle 1 before and after reaching the reference target point 203 .

Further, in the control device 100 according to the present embodiment, the determination unit 130 sets the weight of each of the first steering angle θ1 and the second steering angle θ2 in determining the target steering angle θt to the target route 9 at the reference target point 203. and the tangential direction D2 of the third arc 303 at the reference target point 203 according to the relative angle φ1. Thereby, the weight of each of the first steering angle θ1 and the second steering angle θ2 can be changed according to the necessity of suppressing the divergence of the traveling direction of the vehicle 1 from the tangential direction D1 of the target route 9 . Therefore, the behavior of the vehicle 1 can be more appropriately stabilized before and after reaching the reference target point 203 .

Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is of course not limited to the above-described embodiments, and various modifications within the scope of the claims can be made. It goes without saying that modifications also fall within the technical scope of the present invention.

For example, although the configuration of the vehicle 1 has been described above with reference to FIG. 1, the configuration of the vehicle according to the present invention is not limited to such an example. A vehicle according to the present invention may be, for example, the vehicle 1 shown in FIG. 1 with some components removed, added, or changed. For example, the vehicle according to the present invention may be a vehicle in which each wheel is provided with a drive motor (that is, four drive motors are provided). Further, for example, the vehicle according to the present invention may be a hybrid vehicle that includes an engine in addition to a drive motor as a drive source. Further, for example, the vehicle according to the present invention may be an engine vehicle provided with only an engine without a drive motor as a drive source.

Also, for example, the processes described using flowcharts in this specification do not necessarily have to be executed in the order shown in the flowcharts. Also, additional processing steps may be employed, and some processing steps may be omitted.

INDUSTRIAL APPLICABILITY The present invention can be used for a control device, control method and program.

1 Vehicles 9, 9a, 9b Target path 21 Drive motor 22 Inverter 23 Battery 31 Brake device 32 Hydraulic pressure control unit 33 Master cylinder 41 Accelerator pedal 42 Brake pedal 51 Power transmission system 52 Wheel 53 Steering wheel 61 Accelerator opening sensor 62 Brake Sensor 71 Power steering mechanism 81 Navigation device 91 Vehicle speed sensor 92 Vehicle position sensor 100 Control device 110 Acquisition unit 120 Control unit 121 Motor control unit 122 Brake control unit 123 Steering control unit 130 Decision unit 201, 201a, 201b Current location 203, 203a, 203b Reference target points 205, 205a, 205b Sub-target points 301, 301a, 301b First circular arc 302 Second circular arc 303 Third circular arc

Claims (8)

a determination unit that determines a target steering angle;
a control unit that controls the steering angle of the vehicle to the target steering angle;
with
The decision unit
identifying a first arc that passes through a reference target point and a current point on the target route of the vehicle and has a tangent line along the tangential direction of the target route at the reference target point;
A second line that is in front of the reference target point and passes through the current point and the secondary target point that is set based on the first arc, and that has a tangent line along the current traveling direction of the vehicle at the current point. Identify two arcs,
determining a target steering angle based on a steering angle when the vehicle is caused to travel on the second arc;
Control device. The decision unit
setting the secondary target point inside the first arc when the center position of the first arc is located on the side of the current traveling direction of the vehicle with respect to the current point;
setting the secondary target point outside the first arc when the center position of the first arc is located on the side opposite to the current traveling direction side of the vehicle with respect to the current point;
A control device according to claim 1 . The determining unit determines the distance between the first arc and the secondary target point as the relative angle between the current traveling direction of the vehicle and the tangential direction of the first arc at the current point increases. setting the secondary target point such that
3. A control device according to claim 2. When the steering angle when the vehicle is caused to run on the second arc is the first steering angle,
The determination unit determines a steering angle when the vehicle is caused to travel on a third arc passing through the reference target point and the current point and having a tangent line along the current traveling direction of the vehicle at the current point. 2 steering angles, and determining the target steering angle based on the first steering angle and the second steering angle;
A control device according to any one of claims 1 to 3. The determination unit determines a steering angle obtained by weighted averaging the first steering angle and the second steering angle as the target steering angle.
5. A control device according to claim 4. The determination unit weights each of the first steering angle and the second steering angle in determination of the target steering angle, in a tangential direction of the target route at the reference target point and in a tangential direction of the target route at the reference target point. Varying according to the relative angle between the tangential direction of the third arc,
6. A control device according to claim 4 or 5. determining a target steering angle;
a step of controlling the steering angle of the vehicle to the target steering angle by a control device;
with
In the step of determining the target steering angle,
identifying a first arc passing through a reference target point and a current point on the target route of the vehicle and having a tangent line along the tangential direction of the target route at the reference target point;
A second line that is in front of the reference target point and passes through the current point and the secondary target point that is set based on the first arc, and that has a tangent line along the current traveling direction of the vehicle at the current point. Identify two arcs,
determining a target steering angle based on a steering angle when the vehicle is caused to travel on the second arc;
control method. the computer,
a determination unit that determines a target steering angle;
a control unit that controls the steering angle of the vehicle to the target steering angle;
A program for functioning as
The decision unit
identifying a first arc that passes through a reference target point and a current point on the target route of the vehicle and has a tangent line along the tangential direction of the target route at the reference target point;
A second line that is in front of the reference target point and passes through the current point and the secondary target point that is set based on the first arc, and that has a tangent line along the current traveling direction of the vehicle at the current point. Identify two arcs,
determining a target steering angle based on a steering angle when the vehicle is caused to travel on the second arc;
program.

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