Vehicle posture calculation device and headlight optical axis control device

Abstract

To inhibit a change in a road surface angle from being erroneously detected as a change in a pitch angle.SOLUTION: A vehicle attitude calculation device 10 calculates an attitude of a vehicle V by using an acceleration sensor 2. The vehicle attitude calculation device 10 calculates a sensor detection angle which is a rotation angle around an axis along a vehicle width direction of the vehicle V with respect to a horizontal plane, on the basis of a detection result of the acceleration sensor 2. If a position of the vehicle V changes during a period from ignition-off to ignition-on, the vehicle attitude calculation device 10 detects a change in the sensor detection angle during the period from ignition-off to ignition-on as a change in a road surface angle. If the position of the vehicle V does not change during the period from ignition-off to ignition-on, the vehicle attitude calculation device 10 detects a change in the sensor detection angle during the period from ignition-off to ignition-on as a change in a pitch angle of the vehicle V.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] One aspect of the present invention relates to a vehicle attitude calculation device and an optical axis control device for a headlight.

Background Art

[0002] There is known a vehicle attitude calculation device that calculates the attitude of a vehicle using an acceleration sensor. As this type of technology, for example, Patent Document 1 describes a device that calculates a rotation angle (hereinafter, also referred to as "sensor detection angle") around an axis along the vehicle width direction of the vehicle with respect to the horizontal plane based on the detection result of an acceleration sensor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described device, it is assumed that the road surface angle does not change during ignition off, and in some cases, a change in the sensor detection angle during ignition off is detected as a change in the pitch angle (rotation angle around an axis along the vehicle width direction of the vehicle with respect to the road surface). However, in this case, for example, if the vehicle is transported by a trailer or a ship during ignition off and the road surface angle changes, there is a possibility that the change in the road surface angle is misdetected as a change in the pitch angle.

[0005] Therefore, an object of one aspect of the present invention is to provide a vehicle attitude calculation device and an optical axis control device for a headlight that can suppress misdetection of a change in the road surface angle as a change in the pitch angle.

Means for Solving the Problems

[0006] A vehicle attitude calculation device according to one aspect of the present invention is a vehicle attitude calculation device that calculates the attitude of a vehicle using an acceleration sensor, and calculates a sensor detection angle, which is the rotation angle around an axis along the vehicle width direction with respect to the horizontal plane, based on the detection result of the acceleration sensor, and if the position of the vehicle changes between ignition off and ignition on, the change in the sensor detection angle between ignition off and ignition on is detected as a change in the road surface angle, and if the position of the vehicle does not change between ignition off and ignition on, the change in the sensor detection angle between ignition off and ignition on is detected as a change in the pitch angle of the vehicle.

[0007] A vehicle attitude calculation device according to one aspect of the present invention may determine whether or not the position of the vehicle has changed based on the vehicle's position information acquired using GPS, or on camera images acquired by a camera that captures images of the area around the vehicle.

[0008] A headlight optical axis control device according to one aspect of the present invention includes the above-mentioned vehicle attitude calculation device, and adjusts the optical axis of the vehicle's headlights in accordance with the change in the pitch angle of the vehicle detected by the vehicle attitude calculation device. [Effects of the Invention]

[0009] According to one aspect of the present invention, it is possible to provide a vehicle attitude calculation device and a headlight optical axis control device that can suppress the misdetection of changes in road surface angle as changes in pitch angle. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a block diagram showing the configuration of a vehicle attitude calculation device and a headlight optical axis control device according to an embodiment. [Figure 2] Figure 2 illustrates the sensor detection angle, pitch angle, and road surface angle. [Figure 3]Figure 3(a) is a flowchart showing the processing in the vehicle attitude calculation device shown in Figure 1 when the ignition is off. Figure 3(b) is a flowchart showing the processing in the vehicle attitude calculation device shown in Figure 1 when the ignition is on. [Figure 4] Figure 4(a) is a flowchart showing other processes in the vehicle attitude calculation device shown in Figure 1 when the ignition is off. Figure 4(b) is a flowchart showing other processes in the vehicle attitude calculation device shown in Figure 1 when the ignition is on. [Modes for carrying out the invention]

[0011] The embodiments will be described in detail below with reference to the attached drawings. In the description of the drawings, the same or equivalent elements will be denoted by the same reference numeral, and redundant descriptions will be omitted.

[0012] As shown in Figure 1, the headlight optical axis control device 1 according to this embodiment is a device that controls the optical axis of the headlights of a vehicle V. The vehicle V may be a passenger car or a cargo vehicle. The vehicle V can accommodate one or more occupants. The vehicle V may be an autonomous driving vehicle capable of automatic driving. The vehicle V may also be capable of manual driving by a driver. The headlights are lamps that illuminate the front of the vehicle V. The headlights are configured so that their optical axis (the direction of the light emitted by the headlights) can be adjusted. The headlights are not particularly limited, and various known headlights may be used.

[0013] The headlight optical axis control device 1 comprises a vehicle attitude calculation device 10 and a headlight actuator 20. The vehicle attitude calculation device 10 is a device that calculates the attitude of the vehicle V using an acceleration sensor 2. The vehicle attitude calculation device 10 here is capable of calculating the change in the pitch angle θv of the vehicle V, which will be described later. The vehicle attitude calculation device 10 comprises an acceleration sensor 2, an ignition switch 3, a GPS [Global Positioning System] 4, a camera 5, and an ECU [Electronic Control Unit] 6.

[0014] The acceleration sensor 2 detects longitudinal acceleration, which is the acceleration of the vehicle V in the longitudinal direction, and vertical acceleration, which is the acceleration of the vehicle V in the vertical direction. The acceleration sensor 2 is not particularly limited, and various known sensors may be used. The acceleration sensor 2 transmits the detected longitudinal acceleration and vertical acceleration information to the ECU 6.

[0015] The ignition switch 3 is a switch for starting and stopping the power source of the vehicle V. The ignition switch 3 is not particularly limited, and various known devices may be used. When the ignition switch 3 is turned on, information regarding the ignition on operation is transmitted to the ECU 6. Also, when the ignition switch 3 is turned off, information regarding the ignition off operation is transmitted to the ECU 6.

[0016] GPS4 measures the current location of vehicle V by receiving signals from three or more GPS satellites. The current location of vehicle V is the current position of vehicle V (where vehicle V is currently located), and is expressed, for example, by latitude and longitude. GPS4 transmits the measured current location information (position information) of vehicle V to ECU6. Camera 5 takes images of the area around vehicle V. Camera 5 is not particularly limited, and various known imaging devices may be used. Camera 5 transmits the acquired camera images to ECU6.

[0017] The ECU6 is an electronic control unit that includes a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), and other components. The ECU6 implements various functions, for example, by loading a program stored in ROM into RAM and then executing the program loaded into RAM using the CPU. Some of the ECU6's functions may be performed on a server capable of communicating with the vehicle V. The ECU6 may be composed of multiple electronic units.

[0018] As a functional configuration, the ECU 6 includes a sensor detection angle calculation unit 61, a storage unit 62, and a change detection unit 63. The sensor detection angle calculation unit 61 calculates a sensor detection angle θs based on the detection result of the acceleration sensor 2. As shown in FIG. 2, the sensor detection angle θs is a rotation angle around an axis along the vehicle width direction of the vehicle V with respect to the horizontal plane. As shown in the following formula (1), the sensor detection angle θs is composed of the sum (composite angle) of the pitch angle θv of the vehicle V and the road surface angle θr. The pitch angle θv is a rotation angle around an axis along the vehicle width direction of the vehicle V with respect to the road surface. The road surface angle θr is a rotation angle around an axis along the vehicle width direction of the road surface with respect to the horizontal plane. Sensor detection angle θs = Pitch angle θv + Road surface angle θr …(1)

[0019] <000…​​​​​​​​​​​​​​​​If the vehicle V's current position changes between ignition off and ignition on, the change detection unit 63 detects the change in the sensor-detected angle θs between ignition off and ignition on as a change in the road surface angle θr. If the vehicle V's position does not change between ignition off and ignition on, the change detection unit 63 detects the change in the sensor-detected angle θs between ignition off and ignition on as a change in the pitch angle θv.

[0023] The headlight actuator 20 is an actuator that adjusts the optical axis of the headlight. The headlight actuator 20 is not particularly limited, and various known actuators may be used. The headlight actuator 20 is controlled by the ECU 6 and adjusts the optical axis of the vehicle V's headlights in accordance with the change in pitch angle θv detected by the change detection unit 63. As an example, the headlight actuator 20 is controlled by the ECU 6 using a data table that associates the pitch angle θv with the drive amount of the headlight actuator 20, and adjusts the optical axis of the headlights in accordance with the change in pitch angle θv.

[0024] Next, the processing in the vehicle attitude calculation device 10 will be described.

[0025] Figure 3(a) is a flowchart showing the processing when the ignition is turned off. When the ignition is turned off, the vehicle attitude calculation device 10 performs the following processing. As shown in Figure 3(a), first, the sensor detection angle calculation unit 61 calculates the sensor detection angle θs based on the detection result of the acceleration sensor 2 (step S1). The GPS 4 is used to acquire current location information (step S2). The calculated sensor detection angle θs and the acquired current location information are stored in the storage unit 62 (step S3). After that, the processing when the ignition is turned off is terminated.

[0026] Figure 3(b) is a flowchart showing the process when the ignition is turned on. After the process for when the ignition is turned off shown in Figure 3(a) has been performed in the vehicle attitude calculation device 10, if the ignition is turned on, the following process is performed. As shown in Figure 3(b), first, the sensor detection angle calculation unit 61 calculates the sensor detection angle θs based on the detection result of the acceleration sensor 2 (step S11). The GPS 4 is used to acquire current location information (step S12).

[0027] The change detection unit 63 compares the current location information acquired in step S12 with the current location information stored in the storage unit 62 and determines whether they match (step S13). If the result in step S13 is YES, the change detection unit 63 determines that the current location is the same as when the ignition was turned off, that is, the current location of the vehicle V has not changed between turning the ignition off and turning the ignition on, and detects the change in the sensor-detected angle θs as a change in the pitch angle θv (step S14). Then, the headlight actuator 20 adjusts the optical axis of the headlights according to the change in the pitch angle θv (step S15). After that, the processing for when the ignition is turned on is terminated.

[0028] On the other hand, if the answer in step S13 is NO, it is assumed that the current location is different from when the ignition is turned off, that is, the current location of vehicle V has changed between turning the ignition off and turning the ignition on, and the change in the sensor-detected angle θs is detected as a change in the road surface angle θr (step S16). After that, the processing for when the ignition is turned on is terminated.

[0029] In summary, the vehicle attitude calculation device 10 can prevent the system from mistakenly detecting a change in the road surface angle θr as a change in the pitch angle θv when the road surface angle θr changes between ignition off and ignition on due to transportation by a trailer or ship, for example.

[0030] The vehicle attitude calculation device 10 determines whether the current location of vehicle V has changed based on the current location information of vehicle V acquired using GPS 4. In this case, complex calculations are not required, and processing can be simplified.

[0031] The headlight beam axis control device 1 is equipped with a vehicle attitude calculation device 10, and as described above, it can suppress the misdetection of changes in the road surface angle θr as changes in the pitch angle θv. This makes it possible to appropriately control the beam axis of the headlights.

[0032] In this embodiment, the change detection unit 63 determined whether the vehicle V's current location had changed based on current location information. However, instead of this, or in addition, the change detection unit 63 may determine whether the vehicle V's current location had changed based on camera images acquired by camera 5. Specifically, the change detection unit 63 may compare the camera image at the time of ignition on with the camera image stored in the storage unit 62. If the two match, it may determine that the vehicle V's current location has not changed between ignition off and ignition on. If the two do not match, it may determine that the vehicle V's current location has changed between ignition off and ignition on. When determining whether the vehicle V's current location has changed based on camera images, the vehicle attitude calculation device 10 performs, for example, the following process.

[0033] When the ignition is turned off, as shown in Figure 4(a), first, the sensor detection angle calculation unit 61 calculates the sensor detection angle θs based on the detection result of the acceleration sensor 2 (step S21). A camera image is acquired by the camera 5 (step S22). The calculated sensor detection angle θs and the acquired camera image are stored in the storage unit 62 (step S33). After that, the processing for when the ignition is turned off is terminated.

[0034] If the ignition is turned on after the ignition-off process shown in Figure 4(a) has been executed, then, as shown in Figure 4(b), first, the sensor detection angle calculation unit 61 calculates the sensor detection angle θs based on the detection result of the acceleration sensor 2 (step S31). A camera image is acquired by the camera 5 (step S32). The change detection unit 63 compares the camera image acquired in step S32 with the camera image stored in the storage unit 62 and determines whether the two match (step S33).

[0035] If the answer in step S33 is YES, the change detection unit 63 determines that the vehicle V's current location is the same as when the ignition was turned off, that is, the vehicle V's current location has not changed between turning the ignition off and turning the ignition on, and detects the change in the sensor-detected angle θs as a change in the pitch angle θv (step S34). Then, the headlight actuator 20 adjusts the optical axis of the headlights according to the change in the pitch angle θv (step S35). After that, the ignition-on process is terminated.

[0036] On the other hand, if the answer in step S33 is NO, it is assumed that the vehicle V's current location is different from when the ignition was turned off, meaning that the vehicle V's current location has changed between turning the ignition off and turning the ignition on. In this case, the change in the sensor-detected angle θs is detected as a change in the road surface angle θr (step S36). After that, the processing for when the ignition is turned on is terminated. In this way, determining whether or not the vehicle V's current location has changed based on the camera image does not require complex calculations, and the processing can be simplified.

[0037] Although embodiments have been described above, the present invention is not limited to the embodiments described above. One embodiment of the present invention can be implemented in various forms, starting with the embodiments described above, with various modifications and improvements based on the knowledge of those skilled in the art.

[0038] In the above embodiment, if it is determined whether the current location of vehicle V has changed based solely on current location information, the camera 5 (acquisition of camera images) and the processes shown in Figures 4(a) and 4(b) are unnecessary. In the above embodiment, if it is determined whether the current location of vehicle V has changed based solely on camera images, the GPS 4 and the processes shown in Figures 3(a) and 3(b) are unnecessary.

[0039] In the above embodiments and modifications, it was determined whether the current location of the vehicle V has changed. However, instead of this, or in addition to this, it may be determined whether the orientation (direction of travel) of the vehicle V has changed. Specifically, if the position and / or orientation of the vehicle V changes between ignition off and ignition on, the vehicle attitude calculation device 10 may detect the change in the sensor-detected angle θs between ignition off and ignition on as a change in the road surface angle θr. If the position and / or orientation of the vehicle V does not change between ignition off and ignition on, the change in the sensor-detected angle θs between ignition off and ignition on may be detected as a change in the pitch angle θv. This prevents the misdetection of a change in the road surface angle θr as a change in the pitch angle θv when the road surface angle θr changes due to a change in the orientation of the vehicle V between ignition off and ignition on.

[0040] In the above embodiments and modifications, when determining whether the current location and / or orientation of vehicle V has changed based on both the current location information and the camera image, the determination may be made as follows: For example, if it is determined that the current location and / or orientation of vehicle V has not changed based on the current location information, and it is also determined that the current location and / or orientation of vehicle V has not changed based on the camera image, then it may be ultimately determined that the current location and / or orientation of vehicle V has not changed. Alternatively, for example, if it is determined that the current location and / or orientation of vehicle V has changed based on the current location information, and it is also determined that the current location and / or orientation of vehicle V has changed based on the camera image, then it may be ultimately determined that the current location and / or orientation of vehicle V has changed.

[0041] For example, if it is determined that the orientation of vehicle V has not changed based on current location information, but that the orientation of vehicle V has changed based on camera images, then it may ultimately be determined that the orientation of vehicle V has changed. Also, for example, if it is determined that the current location of vehicle V has changed based on current location information, but that the current location of vehicle V has not changed based on camera images, then it may ultimately be determined that the current location of vehicle V has changed. [Explanation of symbols]

[0042] 1...Headlight beam control device, 2...Accelerometer, 3...Ignition switch, 4...GPS, 5...Camera, 10...Vehicle attitude calculation device, 20...Headlight actuator, V...Vehicle.

Claims

1. A vehicle attitude calculation device that calculates the attitude of a vehicle using GPS, a camera, and an acceleration sensor, Based on the detection results of the acceleration sensor, the sensor detection angle, which is the rotation angle around the axis along the vehicle width direction relative to the horizontal plane, is calculated. Based on the vehicle's location information obtained using the GPS and the camera images obtained by the camera that captures images of the area around the vehicle, it is determined whether or not the vehicle's position and / or orientation has changed. When it is determined that the position and / or orientation of the vehicle has not changed based on the position information, and when it is determined that the position and / or orientation of the vehicle has not changed based on the camera image, it is ultimately determined that the position and / or orientation of the vehicle has not changed. When it is determined that the position and / or orientation of the vehicle has changed based on the position information, and when it is determined that the position and / or orientation of the vehicle has changed based on the camera image, it is ultimately determined that the position and / or orientation of the vehicle has changed. Based on the position information, it is determined that the orientation of the vehicle has not changed, but based on the camera image, it is determined that the orientation of the vehicle has changed, and ultimately, it is determined that the orientation of the vehicle has changed. If, based on the aforementioned location information, it is determined that the vehicle's position has changed, but based on the camera image, it is not determined that the vehicle's position has changed, then it is ultimately determined that the vehicle's position has changed. If the vehicle's position and / or orientation changes between ignition off and ignition on, the change in the sensor detection angle between ignition off and ignition on is detected as a change in the road surface angle. A vehicle attitude calculation device that, if the position and / or orientation of the vehicle has not changed between ignition off and ignition on, detects the change in the sensor detection angle between ignition off and ignition on as a change in the pitch angle of the vehicle.

2. The vehicle attitude calculation device is provided as described in claim 1, A headlight optical axis control device that adjusts the optical axis of the vehicle's headlights in accordance with the change in the pitch angle of the vehicle detected by the vehicle attitude calculation device.

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