JP2022039224A - On-vehicle device and steering angle adjustment method - Google Patents

Abstract

To provide a device which accurately obtains a steering angle of a tire of a vehicle.SOLUTION: An on-vehicle device mounted on a vehicle comprises: an image acquisition unit which acquires an image by a camera photographing the front side or rear side of the vehicle; a steering angle acquisition unit which acquires a steering angle by a steering angle sensor for detecting the steering angle of a steering wheel of the vehicle; a storage unit which stores correspondence data indicating a correspondence between the steering angle and the steering angle of the tire of the vehicle and the maximum steering angle being the steering angle at which the steering angle of the tire becomes the maximum; and a control unit which acquires the steering angle of the tire of the vehicle with respect to the steering angle on the basis of the steering angle and the correspondence data when the steering angle acquired by the steering angle acquisition unit is less than the maximum steering angle, acquires the steering angle of the tire of the vehicle with respect to the maximum steering angle when the steering angle acquired by the steering angle acquisition unit is equal to or greater than the maximum steering angle, and outputs to a display unit a combined image in which a prediction image indicating a route of the vehicle according to the calculated steering angle of the tire is superimposed on the image of the front side or rear side captured by the camera.SELECTED DRAWING: Figure 1

Description

The present invention relates to an in-vehicle device and a steering angle adjusting method.

In recent years, in vehicles such as passenger cars and trucks, there is a technology to display an image of the rear of the vehicle taken by a camera installed at the rear of the vehicle on the display of an in-vehicle device installed in the vehicle when the vehicle moves backward. .. The driver of the vehicle can see the rear of the vehicle on the display and safely retreat the vehicle. Further, in the in-vehicle device, the rotation angle (steering angle) of the steering wheel of the vehicle is acquired, the steering angle (direction of the tire) of the tire is calculated from the rotation angle, and the image of the tire of the vehicle is displayed on the rear image of the vehicle. There is a technique to superimpose and display the predicted progress line indicating the course. The driver of the vehicle can confirm the position where the vehicle travels by confirming the predicted traveling line of the tire of the vehicle displayed on the display.

International Publication No. 2012/032809

When the course of the tire is superimposed on the image behind the vehicle, the in-vehicle device calculates the steering angle of the tire based on the steering angle detected by the steering angle sensor that detects the steering angle, and determines the steering angle of the tire. Based on this, the predicted progress line of the tire is calculated and displayed. The in-vehicle device calculates the steering angle of the tire with respect to the steering angle based on the correspondence between the steering angle and the steering angle of the tire.

Depending on the vehicle, the steering angle of the tire is limited to a predetermined angle (stopper angle), and when the steering angle of the steering wheel exceeds the predetermined angle, the steering angle of the tire may not change even if the steering wheel is rotated. However, since the steering angle sensor detects the steering angle of the steering wheel, there may be a difference between the steering angle of the tire calculated based on the detected steering angle and the actual steering angle of the tire. When a difference in the steering angle of the tire occurs, the predicted progress line of the tire displayed by the in-vehicle device and the actual trajectory of the tire will deviate from each other.

An object of the present invention is to provide a device for accurately determining the steering angle of a vehicle tire.

In order to solve the above problems, the following means will be adopted.
That is, the first aspect is
It is an in-vehicle device mounted on a vehicle.
An image acquisition unit that acquires an image from a camera that captures the front or rear of the vehicle,
A steering angle acquisition unit that acquires the steering angle of the steering wheel from a steering angle sensor that detects the steering angle of the steering wheel of the vehicle, and a steering angle acquisition unit.
Correspondence relationship data showing the correspondence relationship between the steering angle and the steering angle of the tire of the vehicle changed by the steering wheel and the maximum steering angle which is the steering angle at which the steering angle of the tire is maximized are stored. With the memory
When the steering angle acquired by the steering angle acquisition unit is less than the maximum steering angle, the steering angle of the tire of the vehicle with respect to the steering angle is acquired based on the steering angle and the corresponding relationship data. When the steering angle acquired by the steering angle acquisition unit is equal to or greater than the maximum steering angle, the steering angle of the tire of the vehicle with respect to the maximum steering angle is acquired, and the steering angle of the tire is calculated. A control unit that outputs a composite image of a predicted image showing the course of the vehicle superimposed on the front or rear image taken by the camera to the display unit.
It is an in-vehicle device equipped with.

Aspects of disclosure may be realized by the program being executed by an information processing device. That is, the configuration of the disclosure can be specified as a program for causing the information processing apparatus to execute the process executed by each means in the above-described embodiment, or as a computer-readable recording medium on which the program is recorded. Further, the configuration of the disclosure may be specified by a method in which the information processing apparatus executes the processing executed by each of the above-mentioned means. The configuration of the disclosure may be specified as a system including an information processing apparatus that performs processing executed by each of the above-mentioned means.

According to the present invention, it is possible to provide a device for accurately determining the steering angle of a vehicle tire.

FIG. 1 is a diagram showing a configuration example of the system of the embodiment. FIG. 2 is a diagram illustrating an example of an operation flow of displaying a predicted image of a vehicle course of an in-vehicle device. FIG. 3 is a diagram showing the relationship between the vehicle 100 and the rotation center O when the steering angle of the tire is φ. FIG. 4 is a diagram showing an example of a composite image displayed on the display unit. FIG. 5 is a diagram showing an example of an operation flow for acquiring the maximum steering angle.

Hereinafter, embodiments will be described with reference to the drawings. The configuration of the embodiment is an example, and the configuration of the invention is not limited to the specific configuration of the disclosed embodiment. In carrying out the invention, a specific configuration according to the embodiment may be appropriately adopted.

[Embodiment]
(Configuration example)
FIG. 1 is a diagram showing a configuration example of the system of the present embodiment. The system of this embodiment has a vehicle 100 for adjusting a steering angle, an upper camera 400 installed above the vehicle 100 for photographing the vehicle 100, and a rotation angle for measuring the rotation angle of a turntable on which the front wheels of the vehicle 100 are mounted. It has a sensor 500. The vehicle 100 includes an in-vehicle device 200, a camera 310, a steering angle sensor 320, a shift position sensor 330, a steering angle sensor 340, a speed sensor 350, and an angular velocity sensor 360. The vehicle 100 is a vehicle such as a passenger car or a truck. It is assumed that the direction of the front wheels of the vehicle 100 is changed by operating the steering wheel.

The in-vehicle device 200 includes a control unit 210, a storage unit 220, a communication unit 230, a display unit 240, an input unit 250, an image acquisition unit 261 and a steering angle acquisition unit 262, a shift position acquisition unit 263, a steering angle acquisition unit 264, and a speed acquisition unit. It has a unit 265 and an angular velocity acquisition unit 266.

The system of the present embodiment converts the steering angle into the steering angle of the tire based on the correspondence data showing the correspondence relationship between the steering angle of the steering wheel and the steering angle of the tire, and predicts the course of the vehicle 100. Further, the system of the present embodiment stores the steering angle of the steering wheel as the maximum steering angle when the steering angle of the tire does not change even if the steering wheel is rotated. The system of the present embodiment uses the maximum steering angle to adjust the steering angle of the steering wheel and the steering angle of the tire when predicting the course of the vehicle 100.

The control unit 210 controls the in-vehicle device 200. The control unit 210 controls the in-vehicle device 200. Based on various information acquired by the image acquisition unit 261 and the steering angle acquisition unit 262, the control unit 210 has a maximum steering angle, which is the steering angle at which the tire steering angle is maximum, and a course (vehicle locus, vehicle trajectory) of the vehicle 100. Find the track of the tire, etc.). Further, the control unit 210 generates an image to be displayed by the display unit 240. The control unit 210 is, for example, a CPU (Central Processing Unit) or a D.
SP (Data Signal Processor).

The storage unit 220 includes correspondence data indicating the correspondence between the steering angle and the steering angle of the tire of the vehicle 100 changed by the steering wheel, the maximum steering angle which is the steering angle at which the steering angle of the tire is maximized, and the image acquisition unit. Information such as image data of the image acquired in 261 is stored. The storage unit 220 stores vehicle shape information indicating the shape of the vehicle such as the vehicle body length, the vehicle width, the wheelbase, and the tire diameter. Further, the storage unit 220 stores data, programs, information acquired from an external device, etc. used in the in-vehicle device 200. The correspondence data and the maximum steering angle are stored in the storage unit 220 at the time of factory shipment of the vehicle 100 or by the operation of the user of the vehicle 100. The acquisition of the maximum steering angle will be described later. When the steering angle of the staying wheel is equal to or greater than the maximum steering angle, the steering angle of the tire does not change even if the steering wheel is rotated.

Here, when the tire is not cut to the right or left and the direction of the tire is straight, the steering angle of the tire is set to 0 degrees, and when the tire is turned to the right, the steering angle of the tire is set to a positive angle to the left. The steering angle of the tire when it is turned is a negative angle. In addition, the rotation angle (steering angle) of the steering wheel when the tire is not cut to the right or left and is straight is set to 0 degrees, and the steering angle when the steering wheel is rotated clockwise from 0 degrees is positive. The steering angle when the angle is rotated counterclockwise from 0 degrees is defined as a negative angle.

The correspondence data showing the correspondence between the steering angle and the steering angle of the tire of the vehicle 100 changed by the steering wheel is a relational expression showing the relationship between the steering angle and the steering angle of the tire (the steering angle is a function of the steering angle). It can be expressed) or by a corresponding table that associates the steering angle with the steering angle of the tire. The relational expression may be linear or non-linear. From the correspondence data, the steering angle of the tire with respect to the steering angle of the steering wheel can be known.

The maximum steering angle includes the maximum steering angle on the right and the maximum steering angle on the left. The maximum steering angle on the right is when the steering angle of the tire becomes maximum when the steering wheel is gradually rotated from 0 degrees to the right (when the stopper angle of the steering angle of the tire (right stopper angle) is reached). The steering angle of the steering wheel. The maximum steering angle on the left is when the absolute value of the steering angle of the tire becomes maximum when the steering wheel is gradually rotated from 0 degrees to the left (stopper angle of the steering angle of the tire (stopper angle on the left)). It is the steering angle of the steering wheel. The absolute value of the maximum steering angle on the right and the absolute value of the maximum steering angle on the left may differ. The right stopper angle and the left stopper angle may be stored in the storage unit 220. The stopper angle may be obtained in advance as a specification from, for example, a manufacturer of a part or a vehicle.

The stopper angle may not be taken into account in the correspondence data. Therefore, when the absolute value of the steering angle of the steering wheel is larger than the absolute value of the maximum steering angle, the actual steering angle of the tire may differ from the steering angle of the tire based on the steering angle and the correspondence data. .. At this time, if the course of the vehicle 100 is calculated based on the steering angle and the steering angle of the tire based on the corresponding relationship data, a deviation from the actual course of the vehicle 100 will occur. Correspondence-related data may be obtained in advance as specifications from, for example, manufacturers of parts and vehicles.

The storage unit 220 is, for example, a RAM (Random Access Memory) or a ROM (Read Only Memory). Further, the storage unit 220 is, for example, an EPROM (Erasable Programmable ROM).
), Hard Disk Drive (HDD, Hard Disk Drive) Removable media, that is, portable recording media. The removable medium is, for example, a USB (Universal Serial Bus) memory or a disc recording medium such as a CD (Compact Disk) or a DVD (Digital Versatile Disk).

The communication unit 230 is a communication interface that communicates with other information processing devices and the like via a communication network and the like. The communication unit 230 acquires images, rotation angle information, and the like from an external upper camera 400, a rotation angle sensor 500, and the like. The communication unit 230 is an example of an upper image acquisition unit and a rotation angle acquisition unit.

The display unit 240 is a display that displays images, character information, and the like generated by the control unit 210. The display unit 240 is, for example, a display device such as an LCD (Liquid Crystal Display), an EL (Electroluminescence) panel, a CRT (Cathode Ray Tube) display, or a PDP (Plasma Display Panel).

The input unit 250 is an input device that receives information input by the user of the vehicle-mounted device 200. The input unit 250 is an input device such as a button, a toggle switch, a touch panel, a pointing device, and a keyboard. Further, the input unit 250 may be a voice input device such as a microphone.

The image acquisition unit 261 acquires an image (image data) taken by the camera 310 installed in the vehicle 100. Further, the image acquisition unit 261 controls the camera 310.

The steering angle acquisition unit 262 acquires information (steering angle information) indicating the steering angle of the steering wheel (steering wheel) of the vehicle 100 from the steering angle sensor 320.

The shift position acquisition unit 263 acquires information on the position of the shift lever of the vehicle 100 from the shift position sensor 330.

The steering angle acquisition unit 264 acquires information on the steering angle (angle of the direction of the tire) of the tire of the vehicle 100 from the steering angle sensor 340.

The speed acquisition unit 265 acquires information on the speed of the vehicle 100 from the speed sensor 350. The speed acquisition unit 265 may acquire the acceleration of the vehicle 100 by an acceleration sensor that detects the acceleration of the vehicle 100, and may calculate the speed of the vehicle 100 by integrating the acceleration of the vehicle 100 over time. Further, the speed acquisition unit 265 acquires the rotation speed of the tire of the vehicle 100 per unit time and the diameter of the tire, and obtains the speed of the vehicle 100 by the product of the rotation speed of the vehicle 100 per unit time and the diameter of the tire. It may be calculated. The speed of the vehicle 100 may be calculated by the control unit 210.

The angular velocity acquisition unit 266 acquires information on the angular velocity of the vehicle 100 from the angular velocity sensor 360.

The steering angle acquisition unit 262, the shift position acquisition unit 263, the steering angle acquisition unit 264, the speed acquisition unit 265, and the angular velocity acquisition unit 266 can be determined from the vehicle control system or the like by the vehicle CAN (Control Area Network) or the like. Information such as position, speed, and angular velocity may be acquired.

The in-vehicle device 200 can be realized by using a dedicated or general-purpose computer such as a PC, a workstation (WS, Work Station), a PDA (Personal Digital Assistant), or an electronic device equipped with the computer. Further, the in-vehicle device 200 can be realized by using a dedicated or general-purpose computer such as a car navigation device, or an electronic device equipped with the computer. A computer, i.e., an information processing device, includes a processor, a main storage device, and an interface device with a secondary storage device and a peripheral device such as a communication interface device. The main storage device and the secondary storage device are computer-readable recording media. A computer loads a program stored in a recording medium into a work area of a main memory and executes it, and peripheral devices are controlled through the execution of the program to realize a function that meets a predetermined purpose. Can be done.

The camera 310 is installed at the rear of the vehicle 100. The camera 310 can photograph the external space behind the vehicle 100. The camera 310 is, for example, a still camera or a video camera. The installation position and installation angle (lens orientation, etc.) of the camera 310 are set to predetermined values in advance. The installation position and installation angle of the camera 310 may be variable. The direction of the lens of the camera 310 is, for example, diagonally downward to the rear of the vehicle 100.

The steering angle sensor 320 is a sensor that detects the rotation angle (steering angle) of the steering wheel of the vehicle 100. The shift position sensor 330 is a sensor that detects the position of the shift lever of the vehicle 100. The steering angle sensor 340 is a sensor that detects the steering angle of the tire (front wheel) of the vehicle 100. The speed sensor 350 is a sensor that detects the speed of the vehicle 100. The angular velocity sensor 360 is a sensor that detects the angular velocity of the vehicle 100. The angular velocity sensor 360 is installed, for example, at the midpoint of a line segment connecting the center of the left rear wheel and the center of the right rear wheel.

The upper camera 400 is a camera installed above the vehicle 100 and taking a picture of the vehicle 100. The upper camera 400 is, for example, a still camera or a video camera.

The rotation angle sensor 500 is a sensor that detects the rotation angle of the turntable on which the front wheel of the vehicle 100 is mounted. The front wheel of the vehicle 100 is placed at the center of rotation of the turntable, and when the steering angle of the tire changes with the change of the steering angle of the steering wheel, the turntable rotates. The rotation angle sensor 500 detects the rotation angle of the turntable. The rotation angle sensor 500 is, for example, a rotary encoder.

(Operation example)
<Course prediction image display>
FIG. 2 is a diagram illustrating an example of an operation flow of displaying a predicted image of a vehicle course of an in-vehicle device. The in-vehicle device 200 predicts the course of the vehicle 100 based on the steering angle, the maximum steering angle, and the like of the steering wheel, and displays the predicted image of the course of the vehicle. The operation flow of FIG. 2 is started when the shift position acquisition unit 263 of the in-vehicle device 200 detects that the shift lever is in the reverse (reverse) position.

When the shift lever is moved to the reverse position by the operation of the user (driver) of the vehicle 100, the shift position sensor 330 detects that the shift lever is in the reverse position. The shift position acquisition unit 263 of the in-vehicle device 200 acquires information from the shift position sensor 330 that the shift lever is in the reverse position. The control unit 210 acquires information on the position of the shift lever (which is the reverse position) from the control unit 210 via the shift position acquisition unit 263.

In S101, the control unit 210 of the in-vehicle device 200 has the correspondence data indicating the correspondence relationship between the steering angle and the steering angle of the tire of the vehicle 100 changed by the steering wheel from the storage unit 220, and the steering angle of the tire is the maximum. The maximum steering angle, which is the steering angle, and the vehicle shape information indicating the shape of the vehicle 100 are extracted.

In S102, the control unit 210 acquires steering angle information indicating the steering angle of the steering wheel via the steering angle acquisition unit 262. The control unit 210 stores the acquired steering angle information in the storage unit 220. The steering angle acquisition unit 262 acquires the steering angle of the steering wheel by the steering angle sensor 320.

In S103, the control unit 210 acquires the image behind the vehicle 100 taken by the camera 310 via the image acquisition unit 261. The control unit 210 stores the acquired image in the storage unit 220.

In S104, the control unit 210 calculates the course of the vehicle 100 based on the correspondence data, the maximum steering angle, the steering angle of the steering wheel, and the like. The course of the vehicle 100 is, for example, a vehicle locus and a tire locus. The vehicle locus is an area through which the vehicle 100 passes when the vehicle 100 retracts at the steering angle of the tires of the current vehicle 100. The tire locus is a region through which the tire of the vehicle 100 passes when the vehicle retracts at the steering angle of the tire of the current vehicle 100. The locus of the tire is a position through which the tire of the vehicle 100 passes when the vehicle retracts at the steering angle of the tire of the current vehicle 100. Next, an example of calculating the tire locus as the course of the vehicle 100 will be described, but the vehicle locus can also be calculated in the same manner. The tire locus and the vehicle locus may be calculated by other well-known methods.

The control unit 210 obtains the steering angle φ of the tire with respect to the steering angle based on the steering angle of the steering wheel and the correspondence data. When the steering angle is less than the maximum steering angle, the control unit 210 obtains the steering angle φ of the tire based on the steering angle and the correspondence data. On the other hand, when the steering angle is equal to or greater than the maximum steering angle, the control unit 210 replaces the steering angle with the maximum steering angle and obtains the steering angle φ of the tire based on the maximum steering angle and the corresponding relationship data. Further, when the steering angle is equal to or larger than the maximum steering angle, the control unit 210 may acquire the stopper angle stored in the storage unit 220 as the steering angle φ of the tire. Here, when the steering angle is a positive value, the maximum steering angle on the right is used as the maximum steering angle. Further, when the steering angle is a negative value, the left maximum steering angle is used as the maximum steering angle. Further, when the absolute value of the steering angle is less than the absolute value of the maximum steering angle, the steering angle φ of the tire is obtained based on the steering angle and the corresponding relational data, and the absolute value of the steering angle is equal to or larger than the absolute value of the maximum steering angle. If, the steering angle is replaced with the maximum steering angle on the left, and the steering angle φ of the tire is obtained based on the maximum steering angle on the left and the correspondence data.

Further, the control unit 210 calculates the position of the rotation center O with respect to the steering angle φ of the tire of the vehicle 100. When the steering angle φ of the tire is not 0 degrees, the vehicle 100 rotates about the rotation center O. The position of the center of rotation O depends on the steering angle φ of the tire and the wheelbase W. The wheelbase W is the distance between the axles of the front wheels and the axles of the rear wheels of the vehicle 100. The wheelbase W may be stored in advance in the storage unit 220 as vehicle shape information. When the steering angle φ of the tire is 0 degrees, the rotation center O is not calculated. However, when the steering angle φ of the tire is 0 degrees, the rotation center O may be regarded as a position at infinity from the vehicle 100 on the axle of the rear wheel.

FIG. 3 is a diagram showing the relationship between the vehicle 100 and the rotation center O when the steering angle of the tire is φ. FIG. 3 is a view of the vehicle 100 as viewed from above. The rotation center O of the vehicle 100 is an intersection of the extension line of the axle of the front wheel on the outer wheel side of the vehicle 100 and the extension line of the axle of the rear wheel. Here, when the front wheel of the vehicle 100 is tilted to the right with respect to the traveling direction, the tire on the right side of the vehicle 100 is on the inner ring side, and the tire on the left side is on the outer ring side. Here, the distance between the center of the front wheel on the outer ring side and the center of rotation O is defined as the turning radius r of the vehicle 100 at the steering angle φ. The turning radius r is obtained as r = W / sinφ.

Further, the control unit 210 calculates the locus of the tire drawn by the tire of the rear wheel of the vehicle 100. The control unit 210 obtains the locus of the tire drawn by the tire when the vehicle 100 retreats from the current position of the vehicle 100 by a predetermined distance. Each tire of the rear wheel of the vehicle 100 draws an arc of the radius of gyration of each tire in the direction in which the vehicle retracts from the current position of the vehicle 100 with the center of rotation O as the center. Further, when the center of rotation O does not exist, the locus of the tire drawn by the tire of the rear wheel of the vehicle 100 becomes the locus of the tire drawn by the tire when the tire recedes straight from the current position of the vehicle 100 by a predetermined distance. The control unit 210 calculates the coordinates of the calculated tire locus. The coordinates of the locus of the tire are calculated as the coordinates relative to the vehicle 100.

Returning to FIG. 2, in S105, the control unit 210 matches the coordinates of the rear image of the vehicle 100 acquired from the image acquisition unit 261 from the course (coordinates) of the vehicle 100 calculated in step S104. Generates a predicted image showing the course of. Here, it is assumed that the plane formed by the bottom surface of the tire of the vehicle 100 and the periphery of the vehicle 100 are the same plane. The angle of view of the lens of the camera 310, the installation position of the camera 310, the direction of the lens of the camera 310, and the like are known. Therefore, it is possible to easily calculate which position each pixel of the image captured by the camera 310 corresponds to on the coordinates. Therefore, the control unit 210 can generate a predicted image that matches the coordinates of the image behind the vehicle 100 from the coordinates of the course of the vehicle. The predicted image may include one or both of the tire locus and the vehicle locus as the course of the vehicle. Further, the predicted image may include a vehicle path other than the tire locus and the vehicle locus.

Further, the control unit 210 generates a composite image in which the image behind the vehicle 100 is superimposed on the predicted image showing the course of the generated vehicle 100. The control unit 210 can color the area of the vehicle path of the predicted image in a translucent color so that the image behind the vehicle 100 is not completely hidden. The control unit 210 displays the generated composite image on the display unit 240.

FIG. 4 is a diagram showing an example of a composite image displayed on the display unit. FIG. 4 is a diagram showing an example of a case where the vehicle 100 rotates to the parking frame and retreats (when the steering angle φ of the tire is not 0 degrees). The course (vehicle locus and tire locus) of the vehicle 100 is superimposed on the image behind the vehicle 100 taken by the camera 310. In addition, other vehicles are parked on both sides of the parking frame. The driver of the vehicle 100 can advance the vehicle 100 while confirming the actual image including the parking frame displayed on the display unit 240 and the course of the vehicle 100 superimposed on the image.

Returning to FIG. 2, in S106, the control unit 210 confirms whether or not the shift lever is in the reverse position via the shift position acquisition unit 263. The shift position acquisition unit 263 acquires the position of the shift lever of the vehicle 100 by the shift position sensor 330. When the shift lever is in the reverse position (S106; YES), the vehicle-mounted device 200 repeats the processes after step S102. If the shift lever is not in the reverse position (S106; NO), the vehicle-mounted device 200 ends the process.

According to the operation flow of FIG. 2, when the shift lever is in the reverse position, the display unit 240 of the in-vehicle device 200 shows the image of the rear of the vehicle 100 taken by the camera 310 and the course of the vehicle 100 according to the steering angle of the tire. However, they are displayed in an overlapping manner. When the steering angle of the steering wheel is equal to or greater than the maximum steering angle, the steering angle of the tire is obtained as a value with respect to the maximum steering angle. As a result, the vehicle-mounted device 200 can accurately display the course of the vehicle 100 even when the steering angle is equal to or larger than the maximum steering angle.

(Modified example of course prediction image display)
In the above example, the camera 310 is installed at the rear of the vehicle to display the course of the vehicle 100 traveling backward, but the camera 310 is installed at the front of the vehicle and forward in the same manner as in the above case. It is also possible to display the course of the vehicle 100 traveling forward when traveling to the front.

<Acquisition of maximum steering angle>
FIG. 5 is a diagram showing an example of an operation flow for acquiring the maximum steering angle. The maximum steering angle is acquired, for example, before the vehicle 100 is shipped from the factory, and is stored in the storage unit 220. The maximum steering angle may be acquired by the operation of the user of the vehicle 100 after the vehicle 100 is shipped from the factory. Since the maximum steering angle may vary from vehicle to vehicle 100, it is desirable to set the maximum steering angle for each vehicle 100. The operation flow of FIG. 5 is started by selecting the maximum steering angle acquisition mode or the like by, for example, operating the vehicle-mounted device 200.

In S201, the control unit 210 of the in-vehicle device 200 displays on the display unit 240 a display requesting input such as pressing down a button when the steering wheel is turned to the right and the tire does not move (when the tire cannot be cut). .. The user of the vehicle-mounted device 200 who sees the display turns the steering wheel to the right, and when the tire does not move (the direction of the tire does not change), inputs such as pressing down the button of the input unit 250. When the input unit 250 receives an input such as pressing down a button indicating that the tire has stopped moving, the control unit 210 acquires the steering angle of the steering wheel via the steering angle acquisition unit 262. The input such as pressing down the button is an example of inputting information indicating that the steering angle of the tire does not change even if the steering wheel of the vehicle 100 is rotated. The control unit 210 sets the acquired steering angle as the maximum steering angle on the right. Similarly, the control unit 210 also acquires the steering angle when the steering wheel is turned counterclockwise, and sets it as the maximum steering angle on the left.

In S202, the control unit 210 stores the maximum steering angle on the right and the maximum steering angle on the left acquired in S201 in the storage unit 220. The stored maximum steering angle is used together with the correspondence data when determining the steering angle of the tire of the vehicle 100. The in-vehicle device 200 can acquire the maximum steering angle by the user's operation without using a sensor or the like for detecting the steering angle of the tire.

(Modification example 1 of acquisition of maximum steering angle)
Here, the maximum steering angle is acquired by acquiring the steering angle of the tire of the vehicle 100 by the steering angle sensor 340 that detects the steering angle of the tire.

At this time, the control unit 210 displays on the display unit 240 to urge the steering wheel to be turned to the right. The user of the vehicle-mounted device 200 who sees the display turns the steering wheel to the right. While the steering wheel is turned to the right, the control unit 210 repeatedly acquires the steering angle of the tire by the steering angle acquisition unit 264, and acquires the steering angle of the steering wheel by the steering angle acquisition unit 262. When the steering angle of the tire acquired last is the same as the steering angle of the tire acquired immediately before, the control unit 210 sets the steering angle of the steering wheel acquired immediately before as the maximum steering angle on the right. Similarly, the control unit 210 also acquires the steering angle when the steering wheel is turned counterclockwise, and sets it as the maximum steering angle on the left. According to the first modification, the maximum steering angle can be acquired from the steering angle of the tire acquired by the steering angle sensor 340.

(Modification example 2 for acquiring maximum steering angle)
In the first modification, the steering angle of the tire of the vehicle 100 is acquired by the steering angle sensor 340 that detects the steering angle of the tire, but here, the steering angle of the tire is determined by the rotation angle of the turntable on which the front wheel of the vehicle 100 is mounted. Get the corner. At this time, the ground contact portion of the front wheel of the vehicle 100 is placed at the center of rotation of the turntable. When the direction of the front wheels of the vehicle 100 changes, the turntable rotates. Since the front wheel of the vehicle 100 is placed at the center of rotation of the turntable, the rotation angle of the turntable corresponds to the steering angle of the tire. The rotation angle sensor 500 detects the rotation angle of the turntable and outputs it to the in-vehicle device 200. Here, the control unit 210 acquires the rotation angle of the turntable from the rotation angle sensor 500 via the communication unit 230. The control unit 210 regards the rotation angle of the turntable as the steering angle of the tire, and acquires the maximum steering angle in the same manner as in the first modification. According to the second modification, the maximum steering angle can be acquired even when the vehicle 100 does not have the steering angle sensor 340 for detecting the steering angle of the tire.

(Modification example 3 for acquiring maximum steering angle)
In the first modification and the second modification, the steering angle of the steering wheel is gradually increased, and the steering angle when the steering angle of the tire does not change is set as the maximum steering angle. Here, the steering angle is gradually reduced from the state where the steering wheel is fully turned (the state where the steering angle of the steering wheel is maximized), and the steering angle when the steering angle of the tire changes is set as the maximum steering angle. ..

At this time, the control unit 210 displays on the display unit 240 to urge the steering wheel to be turned to the right to the limit. The user of the vehicle-mounted device 200 who sees the display turns the steering wheel to the right to the limit (until the steering angle of the steering wheel is maximized). Next, the control unit 210 displays on the display unit 240 to urge the steering wheel to be turned to the left. While the steering wheel is turned counterclockwise, the control unit 210 repeatedly acquires the steering angle of the tire as in the modification 1 or the modification 2, and the steering angle acquisition unit 262 obtains the steering angle of the steering wheel. To get. When the steering angle of the tire acquired last is different from the steering angle of the tire acquired immediately before, the control unit 210 sets the steering angle of the steering wheel acquired immediately before as the maximum steering angle on the right. Similarly, the control unit 210 also acquires the steering angle when the steering wheel is turned counterclockwise, and sets it as the maximum steering angle on the left. According to the third modification, the maximum steering angle can be obtained in a shorter time by detecting the steering angle and the steering angle of the tire by gradually reducing the steering angle from the state where the steering wheel is fully turned. ..

(Modification example 4 for acquiring maximum steering angle)
In the modified example 1, the modified example 2, and the modified example 3, the steering angle of the steering wheel was acquired by the steering angle acquisition unit 262, but here, the steering of the steering wheel is steered based on the steering angle of the tire and the corresponding relationship data. Calculate the angle. For example, in the first modification, when the steering angle of the tire acquired last is the same as the steering angle of the tire acquired immediately before, the control unit 210 uses the steering angle of the tire and the corresponding relationship data to obtain the tire. The steering angle of the steering wheel with respect to the steering angle is calculated, and the steering angle is set as the maximum steering angle. Further, in the modification 3, the control unit 210 acquires the steering angle of the tire when the steering wheel is turned to the limit, and steers the steering angle of the tire based on the steering angle of the tire and the correspondence data. The steering angle of the wheel is calculated, and the steering angle is set as the maximum steering angle. According to the modification 4, the maximum steering angle can be acquired without acquiring the steering angle of the steering wheel by the steering angle acquisition unit 262.

(Variation example 5 for acquiring maximum steering angle)
Here, the user is made to input the minimum turning radius of the vehicle 100, the steering angle of the tire when the steering wheel is fully turned is obtained from the minimum turning radius, and the maximum steering angle is acquired. The minimum turning radius is the turning radius of the front wheel on the outer wheel side when the steering wheel is fully turned. As described above, the turning radius r can be obtained as r = W / sinφ by using the wheelbase W and the steering angle φ of the tire.

At this time, the control unit 210 displays on the display unit 240 to prompt the input of the minimum turning radius of the vehicle 100. The user of the vehicle-mounted device 200 who sees the display inputs the minimum turning radius of the vehicle 100 by the input unit. When the control unit 210 receives the input of the minimum turning radius of the vehicle 100 by the input unit 250, the control unit 210 calculates the steering angle of the tire with respect to the minimum turning radius. Further, the control unit 210 calculates the steering angle of the steering wheel with respect to the steering angle of the tire based on the steering angle of the tire and the correspondence data, and sets the steering angle as the maximum steering angle. According to the modification 5, the maximum steering angle can be obtained from the minimum turning radius of the vehicle 100.

(Variation example 6 for acquiring maximum steering angle)
Here, the upper camera 400 installed above the vehicle 100 photographs the vehicle 100 traveling with the steering wheel turned to the limit, and the minimum turning radius is based on the locus of the front wheels on the outer ring side of the vehicle 100. To obtain the maximum steering angle.

At this time, the control unit 210 displays on the display unit 240 to turn the steering wheel to the right to the limit and urge the vehicle to travel. The user of the vehicle-mounted device 200 who sees the display turns the steering wheel to the right to the limit and drives the vehicle 100. When the vehicle 100 is traveling, the control unit 210 causes the upper camera 400 to photograph the traveling vehicle 100 via the communication unit 230, and acquires the photographed image. The control unit 210 obtains the locus of the front wheel (front wheel on the left side) on the outer ring side of the vehicle 100 based on the acquired image by a well-known image recognition technique or the like, and determines the radius of the circle when the locus is an arc. The minimum turning radius. Using the minimum turning radius, the maximum steering angle can be obtained in the same manner as in the modified example 5. Similarly, the control unit 210 also acquires the steering angle when the steering wheel is turned counterclockwise, and sets it as the maximum steering angle on the left. According to the modification 6, the maximum steering angle can be obtained even when the minimum turning radius of the vehicle 100 is unknown.

(Modification example 7 for acquiring maximum steering angle)
Here, the camera 310 installed in the vehicle 100 captures the outside from the vehicle 100 traveling with the steering wheel turned to the limit, obtains the minimum turning radius of the vehicle 100 by image recognition processing, and performs maximum steering. Get the corner.

At this time, the control unit 210 displays on the display unit 240 to turn the steering wheel to the right to the limit and urge the vehicle to travel. The user of the vehicle-mounted device 200 who sees the display turns the steering wheel to the right to the limit and drives the vehicle 100. When the vehicle 100 is traveling, the control unit 210 causes the camera 310 to photograph the outside of the traveling vehicle 100 via the image acquisition unit 261 and acquires the photographed image. The control unit 210 obtains the locus of the front wheel on the outer ring side (front wheel on the left side) based on the movement locus of a specific object outside the vehicle 100 included in the image by a well-known image recognition technique or the like, and obtains the locus. The radius of the circle when it is an arc is defined as the minimum turning radius. Using the minimum turning radius, the maximum steering angle can be obtained in the same manner as in the modified example 5. Similarly, the control unit 210 also acquires the steering angle when the steering wheel is turned counterclockwise, and sets it as the maximum steering angle on the left. According to the modification 7, the maximum steering angle can be obtained by using the camera 310 installed in the vehicle 100.

(Modification 8 for acquiring maximum steering angle)
Here, the speed and angular velocity of the vehicle 100 are acquired by the speed sensor 350 and the angular velocity sensor 360 installed in the vehicle 100, the minimum turning radius is obtained from the speed and the angular velocity, and the maximum steering angle is acquired.

At this time, the control unit 210 displays on the display unit 240 to turn the steering wheel to the right to the limit and urge the vehicle to travel. The user of the vehicle-mounted device 200 who sees the display turns the steering wheel to the right to the limit and drives the vehicle 100. When the vehicle 100 is traveling, the control unit 210 acquires the speed v and the angular velocity ω of the vehicle 100 detected by the speed sensor 350 and the angular velocity sensor 360 via the speed acquisition unit 265 and the angular velocity acquisition unit 266. do. The control unit 210 calculates the minimum turning radius r as r = v / ω. Using the minimum turning radius, the maximum steering angle can be obtained in the same manner as in the modified example 5. Similarly, the control unit 210 also acquires the steering angle when the steering wheel is turned counterclockwise, and sets it as the maximum steering angle on the left. Here, when the position where the speed sensor 350 and the angular velocity sensor 360 are installed is significantly different from the position of the front wheel on the outer ring side, the control unit 210 relates to the position of the front wheel on the outer ring side, the position of each sensor, the center of rotation, and the like. The minimum turning radius r may be adjusted based on the above. According to the modification 8, the maximum steering angle can be obtained even when the minimum turning radius of the vehicle 100 is unknown.

(Action and effect of the embodiment)
The in-vehicle device 200 includes correspondence data showing the correspondence between the steering angle of the steering wheel and the steering angle of the vehicle tire changed by the steering wheel, and the maximum steering angle of the steering wheel at which the steering angle of the tire is maximized. The steering angle is stored in the storage unit 220. The in-vehicle device 200 acquires the steering angle of the steering wheel, and when the steering angle is equal to or larger than the maximum steering angle, the in-vehicle device 200 assumes that the steering angle is the maximum steering angle and determines the steering angle of the tire of the vehicle 100 based on the correspondence data. Ask. By using the maximum steering angle, the in-vehicle device 200 can appropriately calculate the steering angle of the tire from the steering angle of the steering wheel even when the steering angle of the tire of the vehicle 100 has a stopper angle. .. The in-vehicle device 200 calculates the course of the vehicle 100 based on the obtained steering angle of the tire, and outputs an image obtained by superimposing the image taken by the camera 310 and the predicted image of the course of the vehicle 100 on the display unit 240. do. According to the in-vehicle device 200, when the steering angle is equal to or larger than the maximum steering angle, the deviation between the course of the vehicle 100 based on the predicted image and the course of the actual vehicle 100 can be reduced.

<Computer readable recording medium>
A program that realizes any of the above functions in a computer or other machine or device (hereinafter referred to as a computer or the like) can be recorded on a recording medium that can be read by a computer or the like. Then, by having a computer or the like read and execute the program of this recording medium, the function can be provided.

Here, a recording medium that can be read by a computer or the like is a recording medium that can store information such as data and programs by electrical, magnetic, optical, mechanical, or chemical action and can be read from a computer or the like. To say. In such a recording medium, elements constituting a computer such as a CPU and a memory may be provided, and the CPU may execute a program.

Further, among such recording media, those that can be removed from a computer or the like include, for example, a flexible disk, a magneto-optical disk, a CD-ROM, a CD-R / W, a DVD, a DAT, an 8 mm tape, a memory card, and the like.

In addition, there are hard disks, ROMs, and the like as recording media fixed to computers and the like.

(others)
Although the embodiments of the present invention have been described above, these are merely examples, and the present invention is not limited thereto, and as long as the gist of the claims is not deviated, combinations of each configuration and the like may be used. Various changes can be made based on the knowledge of those skilled in the art.

100 Vehicle 200 In-vehicle device 210 Control unit 220 Storage unit 230 Communication unit 240 Display unit 250 Input unit 261 Image acquisition unit 262 Steering angle acquisition unit 263 Shift position acquisition unit 264 Steering angle acquisition unit 265 Speed acquisition unit 266 Angular velocity acquisition unit 310 Camera 320 Steering angle sensor 330 Shift position sensor 340 Steering angle sensor 350 Speed sensor 360 Angular velocity sensor

Claims (11)

It is an in-vehicle device mounted on a vehicle.
An image acquisition unit that acquires an image from a camera that captures the front or rear of the vehicle,
A steering angle acquisition unit that acquires the steering angle of the steering wheel from a steering angle sensor that detects the steering angle of the steering wheel of the vehicle, and a steering angle acquisition unit.
Correspondence relationship data showing the correspondence relationship between the steering angle and the steering angle of the tire of the vehicle changed by the steering wheel and the maximum steering angle which is the steering angle at which the steering angle of the tire is maximized are stored. With the memory
When the steering angle acquired by the steering angle acquisition unit is less than the maximum steering angle, the steering angle of the tire of the vehicle with respect to the steering angle is acquired based on the steering angle and the corresponding relationship data. When the steering angle acquired by the steering angle acquisition unit is equal to or greater than the maximum steering angle, the steering angle of the tire of the vehicle with respect to the maximum steering angle is acquired, and the steering angle of the tire is calculated. A control unit that outputs a composite image of a predicted image showing the course of the vehicle superimposed on the front or rear image taken by the camera to the display unit.
In-vehicle device equipped with. Equipped with an input unit that accepts input by users
When information indicating that the steering angle of the tire does not change even if the steering wheel of the vehicle is rotated is input to the input unit, the control unit acquires the steering angle by the steering angle acquisition unit and obtains the steering angle. The steering angle is stored in the storage unit as the maximum steering angle.
The in-vehicle device according to claim 1. It is provided with a steering angle acquisition unit that acquires the steering angle of the tire from the steering angle sensor that detects the steering angle of the tire.
The control unit acquires the steering angle of the tire by the steering angle acquisition unit when the vehicle is traveling with the steering angle of the steering wheel maximized, and the steering angle of the tire and the correspondence data. The steering angle with respect to the steering angle of the tire is calculated based on the above, and the calculated steering angle is stored in the storage unit as the maximum steering angle.
The in-vehicle device according to claim 1. It is provided with a steering angle acquisition unit that acquires the steering angle of the tire from the steering angle sensor that detects the steering angle of the tire.
When the steering angle of the steering wheel is being increased, the control unit repeatedly acquires the steering angle of the tire by the steering angle acquisition unit, and repeatedly acquires the steering angle by the steering angle acquisition unit. When the steering angle of the tire acquired last is the same as the steering angle of the tire acquired immediately before, the steering angle acquired immediately before is stored in the storage unit as the maximum steering angle.
The in-vehicle device according to claim 1. A rotation angle acquisition unit for detecting the rotation angle from the rotation angle sensor for detecting the rotation angle of the turntable on which the tire of the vehicle is placed is provided.
The control unit determines that (1) when the steering angle of the steering wheel reaches the maximum range, or (2) the rotation angle of the turntable does not follow the increase in the steering angle of the steering wheel. When this is done, the rotation angle is acquired by the rotation angle acquisition unit, the steering angle of the tire corresponding to the rotation angle is calculated, and the steering angle of the tire and the corresponding relationship data of the tire are used. The steering angle with respect to the steering angle is calculated, and the calculated steering angle is stored in the storage unit as the maximum steering angle.
The in-vehicle device according to claim 1. A rotation angle acquisition unit for detecting the rotation angle from the rotation angle sensor for detecting the rotation angle of the turntable on which the tire of the vehicle is placed is provided.
When the steering angle of the steering wheel is being increased, the control unit repeatedly acquires the rotation angle by the rotation angle acquisition unit, and repeatedly acquires the steering angle by the steering angle acquisition unit, and finally. When the acquired rotation angle is the same as the rotation angle acquired immediately before, the steering angle acquired immediately before is stored as the maximum steering angle in the storage unit.
The in-vehicle device according to claim 1. It is equipped with an input unit that accepts the input of the minimum turning radius of the vehicle by the user.
When the minimum turning radius of the vehicle is input to the input unit, the control unit calculates the steering angle of the tire corresponding to the minimum turning radius, and is based on the steering angle of the tire and the correspondence data. The steering angle with respect to the steering angle of the tire is calculated, and the calculated steering angle is stored in the storage unit as the maximum steering angle.
The in-vehicle device according to claim 1. It is provided with an upper image acquisition unit that acquires an image from an upper camera that photographs the vehicle from above the vehicle.
When the vehicle is traveling with the steering angle of the steering wheel maximized, the control unit repeatedly acquires an image by the upper image acquisition unit, and based on the movement locus of the vehicle included in the image. The turning radius of the vehicle is calculated, the steering angle of the tire corresponding to the turning radius is calculated, and the steering angle with respect to the steering angle of the tire is calculated based on the steering angle of the tire and the corresponding relationship data. , The calculated steering angle is stored in the storage unit as the maximum steering angle.
The in-vehicle device according to claim 1. The control unit repeatedly acquires an image by the image acquisition unit when the vehicle is traveling with the steering angle of the steering wheel maximized, and based on the movement locus of a specific object included in the image. The turning radius of the vehicle is calculated, the steering angle of the tire corresponding to the turning radius is calculated, and the steering angle with respect to the steering angle of the tire is calculated based on the steering angle of the tire and the corresponding relationship data. , The calculated steering angle is stored in the storage unit as the maximum steering angle.
The in-vehicle device according to claim 1. A speed acquisition unit that acquires the speed of the vehicle, and
It is provided with an angular velocity acquisition unit for acquiring the angular velocity of the vehicle.
When the vehicle is traveling with the steering angle of the steering wheel maximized, the control unit acquires the speed of the vehicle by the speed acquisition unit and acquires the angular speed of the vehicle by the angular speed acquisition unit. , The turning radius of the vehicle is obtained from the acquired speed and the angular speed, the steering angle of the tire corresponding to the turning radius is calculated, and the steering angle of the tire is relative to the steering angle of the tire based on the steering angle of the tire and the corresponding relational data. The steering angle is calculated, and the calculated steering angle is stored in the storage unit as the maximum steering angle.
The in-vehicle device according to claim 1. The computer
Acquire an image from a camera that shoots the front or back of the vehicle,
The steering angle is acquired from the steering angle sensor that detects the steering angle of the steering wheel of the vehicle, and the steering angle is acquired.
Correspondence relationship data showing the correspondence relationship between the steering angle and the steering angle of the tire of the vehicle changed by the steering wheel and the maximum steering angle which is the steering angle at which the steering angle of the tire is maximized are stored. ,
When the acquired steering angle is less than the maximum steering angle, the steering angle of the tire of the vehicle with respect to the steering angle is acquired based on the steering angle and the corresponding relationship data, and the acquired steering angle is the steering angle. When the steering angle is equal to or greater than the maximum steering angle, the steering angle of the tire of the vehicle with respect to the maximum steering angle is acquired, and a predicted image showing the course of the tire of the vehicle according to the calculated steering angle of the tire is obtained. A composite image superimposed on the front or rear image taken by the camera is output to the display unit.
How to adjust the rudder angle to do that.

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