Vehicle tilt determination device and vehicle

Abstract

To satisfactorily determine various inclinations that may occur in a vehicle.SOLUTION: An inclination determination device 10 for a vehicle 1 includes: an inclination sensor 11 that detects a value of an inclination angle or an inclination angle velocity of the vehicle 1; a memory 15 that records information about a determination threshold for determining inclination of the vehicle 1; a determination control unit 16 that determines the inclination of the vehicle 1, on the basis of a detection value of the inclination sensor 11 and information about the determination threshold recorded in the memory 15; and a road surface detection unit 12 that detects a road surface in a traveling direction of the vehicle 1. The determination control unit 16 acquires from the memory 15 the information 20 about the determination threshold for determining the inclination, changes the information 20 about the determination threshold acquired from the memory 15, according to an inclination of the road surface in the traveling direction of the vehicle 1 detected by the road surface detection unit 12, thereby generating information about an adjustment threshold adjusted according to the inclination of the road surface, and compares information about the adjustment threshold adjusted according to the inclination of the road surface in the traveling direction of the vehicle 1 with the detection value of the inclination sensor 11, thereby determining the inclination of the vehicle 1.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a vehicle tilt determination device and a vehicle. [Background technology]

[0002] Vehicles such as automobiles may overturn due to external disturbances while traveling. For this reason, vehicles are sometimes provided with a device for determining whether the vehicle is tilting, such as when the vehicle is rolling over (Patent Documents 1 and 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-216747 [Patent Document 2] Japanese Patent Application Laid-Open No. 2001-171481 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the vehicle tilt determination in Patent Documents 1 and 2, tilt is determined by detecting a roll angle or the like that indicates the tilt of the vehicle body and comparing the detected value with a threshold value. In this way, when tilting is determined by comparing one detection value with one corresponding threshold value, it cannot necessarily be said that it is possible to accurately determine various types of tilting that may actually occur in the vehicle. For example, if it is possible that a situation occurs in which it is not possible to determine that the vehicle will tilt when it actually will tilt, this means that the determination of tilt is insufficient. In addition to this, for example, if it is possible that the vehicle is determined to be tilting in a situation where it is not actually tilting, this would result in excessive tilt determinations.

[0005] Thus, there is a demand for vehicles that can accurately determine various types of tilting that may occur in the vehicle. [Means for solving the problem]

[0006] A vehicle tilt determination device according to one aspect of the present invention includes a tilt sensor that detects a value related to a tilt angle or a tilt angular velocity of a vehicle, a memory that records information on a determination threshold for determining tilt of the vehicle, a determination control unit that determines tilt of the vehicle based on the detection value of the tilt sensor and the information on the determination threshold recorded in the memory, and a road surface detection unit that detects the inclination of the road surface from an image of a road surface in a traveling direction of the vehicle, wherein the determination control unit acquires the information on the determination threshold for determining tilt from the memory, changes the information on the determination threshold acquired from the memory in accordance with the inclination of the road surface in the traveling direction of the vehicle detected by the road surface detection unit, thereby generating information on an adjusted threshold adjusted in accordance with the inclination of the road surface in the traveling direction of the vehicle, and determines tilt of the vehicle by comparing the information on the adjusted threshold adjusted in accordance with the inclination of the road surface in the traveling direction of the vehicle with the detection value of the tilt sensor. the memory records, as the information on the determination thresholds, information on a first determination threshold for tilting the vehicle to the right and information on a second determination threshold for tilting the vehicle to the left, and the first determination threshold for tilting to the right and the second determination threshold for tilting to the left are each defined, in a graph with axes of roll angle and roll angular velocity, by a first line segment along which the absolute value of the roll angle is equal to or greater than a first roll angle threshold and the absolute value of the roll angular velocity is equal to a first roll angular velocity threshold, a second line segment along which the absolute value of the roll angle is smaller than the first roll angle threshold and the absolute value of the roll angular velocity is equal to or greater than a second roll angular velocity threshold that is larger than the first roll angular velocity threshold, and a third line segment connecting the first roll angle threshold and the first roll angular velocity threshold on the first line segment to the second roll angle threshold and the second roll angular velocity threshold on the second line segment, The judgment control unit generates information about the adjusted thresholds adjusted according to the inclination of the road surface by decreasing the absolute values ​​of all the judgment thresholds for the first line segment, the second line segment, and the third line segment regarding a rightward tilt acquired from the memory when the road surface detection unit detects that the road surface in the traveling direction of the vehicle slopes downward to the right, and by increasing the absolute values ​​of all the judgment thresholds for the first line segment, the second line segment, and the third line segment regarding a leftward tilt acquired from the memory when the road surface detection unit detects that the road surface in the traveling direction of the vehicle slopes downward to the left, and by increasing the absolute values ​​of all the judgment thresholds for the first line segment, the second line segment, and the third line segment regarding a rightward tilt acquired from the memory when the road surface detection unit detects that the road surface in the traveling direction of the vehicle slopes downward to the left, and by decreasing the absolute values ​​of all the judgment thresholds for the first line segment, the second line segment, and the third line segment regarding a leftward tilt acquired from the memory.

[0007] A vehicle according to one embodiment of the present invention has the vehicle tilt determination device described above and an on-board device including an occupant protection device that can be activated when the vehicle tilts, and the on-board device including the occupant protection device begins to operate when tilting is determined by the tilt determination device. [Effects of the Invention]

[0008] In the present invention, instead of directly comparing the judgment threshold information acquired from the memory with the detection value of the tilt sensor, the judgment threshold information is changed according to the inclination of the road surface in the vehicle's traveling direction detected by the road surface detection unit, and adjusted according to the inclination of the road surface is generated. Then, in the present invention, the adjusted threshold information generated by the adjustment is compared with the detection value of the tilt sensor. In the present invention, various inclinations that may occur on the road surface can be determined by comparing the detection value with the threshold. Furthermore, in the present invention, various inclinations that may occur on the road surface can be determined collectively, so that the determination can be made in a short time without repeating the comparison determination for each of the various inclinations that may occur on the road surface multiple times. As a result, the present invention can predictively determine vehicle tilt before, for example, a road surface detection unit detects a tilt angle at which the vehicle will actually overturn. Based on this predictive tilt determination, the vehicle can begin vehicle control before the vehicle actually tilts. By starting operation of an on-board device such as an occupant protection device based on such predictive tilt determination, the vehicle of the present invention can start operation of an on-board device such as an occupant protection device at an appropriate timing in a tilted vehicle. Furthermore, in the present invention, it is possible to perform comparative judgments for a plurality of road surface inclinations by simply storing information on the judgment threshold for one road surface inclination in the memory, and the judgment control unit simply performing a certain comparison judgment based on that information once. There is no need to store information on a plurality of judgment thresholds for each road surface inclination in the memory. Also, there is no need for the judgment control unit to perform case-specific judgment processing for each road surface inclination, for example. As a result, the present invention can perform a reliable determination that adequately responds to changes in the occurrence of tilting, which changes depending on the inclination of the road surface. For example, the present invention makes it less likely that an excessive determination of tilting occurs in a situation where tilting does not actually occur, or that an inaccurate determination of tilting occurs in a situation where tilting actually occurs. The present invention can effectively operate on-board devices such as passenger protection devices when operation is necessary, while suppressing excessive operation of the devices. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is an explanatory diagram of a driving state of an automobile to which an embodiment of the present invention is applied. [Figure 2] FIG. 2 is an explanatory diagram showing the state in which the automobile of FIG. 1 is traveling on a road surface that slopes downward to the right. [Figure 3] FIG. 3 is an explanatory diagram of a control system serving as a tilt determination device provided in the automobile of FIG. [Figure 4] FIG. 4 is an explanatory diagram of a plurality of sets of rollover determination thresholds including a roll angle determination threshold and a roll angular velocity determination threshold. [Figure 5] FIG. 5 is an explanatory diagram of a plurality of sets of rollover determination threshold information recorded in the memory of FIG. 3 and a determination procedure based on the same. [Figure 6] FIG. 6 is a flowchart showing the flow of control for determining whether an automobile has rolled over, performed by the ECU of FIG. [Figure 7] FIG. 7 is a diagram illustrating the adjustment process of threshold information in the case of a road surface sloping downward to the right. [Figure 8] FIG. 8 is a diagram illustrating the adjustment process of threshold information in the case of a road surface sloping downward to the left. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0011] 1 is an explanatory diagram of a traveling state of an automobile 1 to which an embodiment of the present invention is applied. The automobile 1 is an example of a vehicle. In Figure 1, a car 1 is shown as seen from behind, traveling on a horizontal road surface 2. On the road surface 2, there are curbs 3 on both the left and right sides of the car 1. Under these circumstances, if the direction of travel of the car 1 deviates to the right or left, it will hit the curb 3. For example, if the automobile 1 hits the curb 3 hard, the automobile 1 may roll over. In this way, the automobile 1 may roll over due to an external disturbance while traveling. The automobile 1 may roll over due to a rollover while traveling.

[0012] FIG. 2 is an explanatory diagram showing the state in which the automobile 1 of FIG. 1 is traveling on a road surface 2 that slopes downward to the right. In FIG. 2, the automobile 1 is shown as seen from behind, similar to FIG. 1, but unlike FIG. 1, it is traveling on a road surface 2 that slopes downward to the right in the left-right direction.

[0013] Even when traveling on a road surface 2 sloping downward to the right or downward to the left in this way, the automobile 1 may roll over due to a rollover or the like. However, as shown in Figures 1 and 2, the right rollover angle at which the automobile 1 rolls over to the right and the left rollover angle at which the automobile 1 rolls over to the left differ depending on the inclination of the road surface 2 on which the automobile 1 is traveling. The right rollover angle at which the automobile 1 rolls over to the right when traveling on a road surface 2 sloping downward to the right as shown in FIG. 2 is smaller than the right rollover angle when traveling on a flat road surface 2 as shown in FIG. Similarly, the right rollover angle at which the automobile 1 rolls over to the left when traveling on a road surface 2 sloping downward to the left is smaller than the left rollover angle when traveling on a flat road surface 2 as shown in FIG.

[0014] The situation in which the automobile 1 actually tilts in this way varies depending on various factors, such as the inclination in the left-right direction of the road surface 2 on which the automobile 1 is traveling. Furthermore, while the rollover angle at which automobile 1 actually tilts changes due to various factors, if the roll angle detected by the vehicle body is compared with a fixed judgment threshold to determine whether automobile 1 is tilting, it is not possible to accurately determine the tilt that may actually occur in automobile 1. For example, if the right roll angle in FIG. 1 is used as a determination threshold and compared with the detection value in FIG. 2, it will be impossible to determine whether the automobile 1 is actually leaning in a situation where the automobile 1 is actually leaning. In addition, for example, if the left roll angle in Figure 1 is used as a judgment threshold and compared with the detection value in Figure 2, it may be possible that the vehicle 1 is judged to be tilting in a situation where it is not actually tilting, and this would result in excessive judgment of tilting. In this way, it is required for the automobile 1 to be able to accurately determine various tilts that may occur in the automobile 1 without being excessive or insufficient.

[0015] FIG. 3 is an explanatory diagram of a control system 10 serving as a tilt determination device provided in the automobile 1 of FIG. The control system 10 of the automobile 1 in FIG. 3 includes an acceleration sensor 11, an exterior camera 12, an occupant protection device 13, an alarm device 14, a memory 15, and an ECU 16 to which these are connected.

[0016] The acceleration sensor 11 detects acceleration in three axial directions of the automobile 1, namely, acceleration in the front-rear direction, acceleration in the left-right direction, and acceleration in the up-down direction. The acceleration sensor 11 may generate the roll angular velocity, pitch angular velocity, and yaw angular velocity of the automobile 1 as detection values ​​based on the detected accelerations in the three axes. Furthermore, the acceleration sensor 11 may time-integrate the generated roll angular velocity to generate the roll angle of the automobile 1 as a detected value. The acceleration sensor 11 may time-integrate the generated pit angular velocity to generate the pit angle of the automobile 1 as a detected value. The acceleration sensor 11 may time-integrate the generated yaw angular velocity to generate the yaw angle of the automobile 1 as a detected value. Such an acceleration sensor 11 can function as a tilt sensor to detect a value relating to the current tilt angle or roll angular velocity of the automobile 1 .

[0017] The exterior camera 12 is installed facing outward, for example, in the cabin of the automobile 1. The automobile 1 may be equipped with a plurality of exterior cameras 12, for example, corresponding to the front, rear, left and right sides of the automobile 1. The automobile 1 may also be equipped with an exterior camera capable of capturing images of the surrounding area in 360 degrees. The outside camera 12 serves as a road surface detection unit and captures an image including a road surface 2 in the traveling direction of the automobile 1. Furthermore, the exterior camera 12 may function as a road surface detection unit and detect the inclination of the road surface 2 in the traveling direction of the automobile 1 based on feature points of the road surface 2 in the captured image. In this case, the inclination of the road surface 2 in the traveling direction of the automobile 1 may be the overall inclination of the road surface 2 or the inclination due to unevenness in the area of ​​the road surface 2 where the automobile 1 is traveling. The feature points of the road surface 2 used to detect the inclination of the road surface 2 include lane boundary lines painted on the road surface 2. In addition to the image captured by the exterior camera 12, information on the road surface 2 in the direction of travel of the automobile 1 also includes information on the shape and unevenness of the road surface 2 obtained by, for example, Lidar. Lidar, for example, outputs a high-frequency signal around the automobile 1 and detects the distance to a tangible object in the direction of the light based on the reflection of the signal. Lidar can detect the shape of the area outside the automobile, including the road surface 2, by switching the output direction of the high-frequency signal.

[0018] The occupant protection device 13 is a device for protecting occupants in the automobile 1. Examples of the occupant protection device 13 include a seat belt device and an airbag device. The seat belt device prevents the seat belt from being pulled out in response to an activation signal based on collision detection or the like. The body of an occupant seated in a seat of the automobile 1 is supported by the seat belt, making it difficult for the occupant to leave the seat. The airbag device deploys an airbag around the body of an occupant seated in a seat of the automobile 1 in response to an activation signal based on collision detection or the like. As a result, for example, the upper body of the occupant who begins to lean is supported by the deployed airbag. These occupant protection controls absorb and mitigate the impact acting on the occupant.

[0019] The warning device 14 outputs a warning to passengers and the like in the automobile 1. The warning device 14 may output the warning by sound, light, or the like. The warning lets passengers and the like know that an emergency has occurred or is about to occur. The warning device 14, together with the passenger protection device 13, is an in-vehicle device that can be activated when the automobile 1 tilts.

[0020] The memory 15 may be configured with, for example, a semiconductor memory such as an SSD or RAM, a HDD, etc. The memory 15 stores various information used for control based on the program as data, along with the program. In this example, the memory 15 stores information 20 on the rollover angle determination threshold.

[0021] The ECU 16 is a microcomputer that executes a program stored in the memory 15. This allows the ECU 16 to function as a determination control unit. The ECU 16 as a determination control unit may determine whether the automobile 1 has tilted, such as rolled over, based on the detection value of the acceleration sensor 11 and the determination threshold information 20 recorded in the memory 15. The ECU 16 as a determination control unit may output an activation signal to the passenger protection device 13 and the warning device 14 when determining that the automobile 1 is tilting, such as rolling over.

[0022] FIG. 4 is an explanatory diagram of a plurality of sets of rollover determination thresholds including a roll angle determination threshold and a roll angular velocity determination threshold. 4, the horizontal axis represents the roll angular velocity, and the vertical axis represents the roll angle. The origin indicates a state in which the automobile 1 is not rolling. Here, as shown in FIG. 1, the roll angle is detected with the upward direction of the automobile 1 as a reference, with the left direction being positive (+) and the right direction being negative (-). The upward direction of the automobile 1 can basically be considered to be along the normal direction perpendicular to the road surface 2.

[0023] 4, in this embodiment, the judgment threshold that can be used to judge whether the vehicle 1 has rolled over is set based on a judgment curve for the left side and a judgment curve for the right side. The judgment curve for the left side is made up of line segments in sections A, B, and C. The judgment curve for the right side is made up of line segments in sections D, E, and F. When a combination of roll angle and roll angular velocity that is above the judgment curve for the left side in the upper right of FIG. 4 is detected, the automobile 1 rolls over to the left. When a combination of roll angle and roll angular velocity that is below the judgment curve for the right side in the lower left of FIG. 4 is detected, the automobile 1 rolls over to the right. When a combination of roll angle and roll angular velocity in a range including the origin between the judgment curve for the left side and the judgment curve for the right side is detected, the automobile 1 does not roll over. In rollover judgment, it is required to judge whether or not the vehicle 1 will actually roll over properly without being too much or too little. The left-side judgment curve and the right-side judgment curve shown in Fig. 4 are symmetrical with respect to the origin. These judgment curves shown in Fig. 4 are for the case where the automobile 1 is traveling on a horizontal road surface 2, for example.

[0024] The threshold used for rollover determination can be a simple threshold line, such as the dashed line in the figure, which intersects the vertical axis of the roll angle and the horizontal axis of the roll angular velocity. If a rollover is determined using a threshold based on such a simple threshold line, even if the roll angular velocity of automobile 1 becomes 0 and the roll angle does not increase any further, it will be determined that automobile 1 is about to roll over based solely on the fact that the roll angle has exceeded the threshold. In addition, for example, if an excessive roll angular velocity is detected when the automobile 1 is not rolling at all (roll angle = 0), it will be determined that the automobile 1 is about to roll over based solely on the fact that the roll angular velocity has exceeded the threshold value. In this way, rollover determination using a threshold based on a simple threshold line has room for improvement so that it can better determine whether or not the automobile 1 will actually roll over.

[0025] For this reason, in this embodiment, a judgment threshold based on a judgment curve for the left side consisting of the line segments in section A, section B, and section C, and a judgment threshold based on a judgment curve for the right side consisting of the line segments in section D, section E, and section F are used. Here, the line segment in section A of the left-side judgment curve is a line segment that indicates a combination of a plurality of judgment thresholds where the roll angle is equal to or greater than D1 and the roll angular velocity is V1. The line segment in section B is a line segment that indicates a combination of a plurality of determination thresholds at which the roll angle is D2 and the roll angular velocity is equal to or greater than V2. The line segment in section C is a line segment that connects the line segment in section A with the line segment in section B. The line segment in section C overlaps with a part of the simple threshold line. The line segment in section C and the line segment in section A are connected at a roll angle D1 and a roll angular velocity V1. The line segment in section C and the line segment in section B are connected at a roll angle D2 and a roll angular velocity V2.

[0026] The line segment in section D of the right-side judgment curve is a line segment that indicates a combination of a plurality of judgment thresholds where the roll angle is equal to or greater than D3 and the roll angular velocity is V3. The line segment in section E is a line segment that indicates a combination of a plurality of determination thresholds where the roll angle is D4 and the roll angular velocity is equal to or greater than V4. The line segment in section F is a line segment that connects the line segment in section D with the line segment in section E. The line segment in section F overlaps with a part of the simple threshold line. The line segment in section F and the line segment in section D are connected at a roll angle D3 and a roll angular velocity V3. The line segment in section F and the line segment in section E are connected at a roll angle D4 and a roll angular velocity V4.

[0027] By making a judgment using a threshold based on such a judgment curve, it becomes difficult to make a judgment like the above-mentioned case where a threshold based on a simple threshold line is used. For example, when the roll angular velocity of automobile 1 reaches 0 and the roll angle does not increase any further, it is possible to determine that automobile 1 will not roll over even if the absolute value of the roll angle becomes larger than D1 or D3. In addition, even if an excessive roll angular velocity whose absolute value exceeds V2 or V4 is detected when the automobile 1 is not rolling at all (roll angle = 0), it is possible to determine that the automobile 1 will not roll over.

[0028] FIG. 5 is an explanatory diagram of a plurality of sets of rollover determination threshold information 20 recorded in the memory 15 of FIG. 3 and a determination procedure based on the information.

[0029] 5, multiple sets of rollover determination thresholds are recorded in memory 15. Here, a combination of roll angle determination threshold D1 and roll angular velocity determination threshold V1, and a combination of roll angle determination threshold D2 and roll angular velocity determination threshold V2 are recorded. Also, a combination of roll angle determination threshold D3 and roll angular velocity determination threshold V3, and a combination of roll angle determination threshold D4 and roll angular velocity determination threshold V4 are recorded. The memory 15 also stores a plurality of combinations of determination thresholds for the roll angle and the roll angular velocity on the inclined line segment in section C. The memory 15 also stores a plurality of combinations of determination thresholds for the roll angle and the roll angular velocity on the inclined line segment in section F.

[0030] In this way, the memory 15 records, as the determination threshold information 20, the determination threshold information 20 for the leaning of the automobile 1 to the right and the determination threshold information 20 for the leaning of the automobile 1 to the left. The memory 15 also stores, as the determination threshold information 20, a plurality of sets of determination threshold information 20 including combinations of a roll angle determination threshold and a roll angular velocity determination threshold that will cause the automobile 1 to roll over. The ECU 16 as a determination control unit uses information 20 of these multiple sets of determination thresholds stored in the memory 15 to determine whether the automobile 1 has rolled over, regardless of the inclination of the road surface 2.

[0031] 5 show the determination content and determination procedure for determining whether the vehicle 1 has rolled over when the vehicle 1 is rolling to the left. The determination procedure may be recorded as data in the memory 15 or may be written as a program process. When the automobile 1 is rolling to the left, the ECU 16 first executes the process in the first row of FIG. 5 to determine whether the detected value of the roll angle is equal to or greater than the determination threshold D1. If the detected value of the roll angle is equal to or greater than the determination threshold D1, the ECU 16 further determines whether the detected value of the roll angular velocity is equal to or greater than the determination threshold V1. If the detected value of the roll angular velocity is equal to or greater than the determination threshold V1, the ECU 16 determines that the automobile 1 will roll over to the left. In this way, the ECU 16 can determine whether the automobile 1 will roll over when the detected value of the roll angle is equal to or greater than the determination threshold D1. If it is not determined in the processing of the first line in Fig. 5 that the automobile 1 will roll over, the ECU 16 then executes the processing of the second line in Fig. 5 to determine whether the detected value of the roll angular velocity is equal to or greater than the determination threshold V2. If the detected value of the roll angular velocity is equal to or greater than the determination threshold V2, the ECU 16 further determines whether the detected value of the roll angle is equal to or greater than the determination threshold D2. If the detected value of the roll angle is equal to or greater than the determination threshold D2, the ECU 16 determines that the automobile 1 will roll over to the left. In this way, the ECU 16 can determine whether the automobile 1 will roll over when the detected value of the roll angular velocity is equal to or greater than the determination threshold V2. If the ECU 16 does not determine that the vehicle 1 will roll over in the processing of the second line in Fig. 5, then it executes the processing of the third line in Fig. 5. The ECU 16 determines whether or not the combination of the detected value of the roll angular velocity and the detected value of the roll angle is equal to or greater than the combination of the roll angular velocity and the roll angle on the threshold line of section C. If a combination equal to or greater than the threshold line of section C is detected, the ECU 16 determines that the vehicle 1 will roll over to the left. By performing the threshold determinations in the first to third lines in Fig. 5, the ECU 16 can determine whether or not the vehicle 1 will roll over to the left.

[0032] 5 show the determination content and determination procedure for determining whether the vehicle 1 has rolled over when the vehicle 1 is rolling to the right. The determination procedure may be recorded as data in the memory 15 or may be written as a program process. When the automobile 1 is rolling to the right, the ECU 16 first executes the processing in the fourth line of FIG. 5. The ECU 16 determines whether the absolute value of the detected value of the roll angle is equal to or greater than the determination threshold D3. If the absolute value of the detected value of the roll angle is equal to or greater than the determination threshold D3, the ECU 16 further determines whether the absolute value of the detected value of the roll angular velocity is equal to or greater than the determination threshold V3. If the absolute value of the detected value of the roll angular velocity is equal to or greater than the determination threshold V3, the ECU 16 determines that the automobile 1 will roll over to the right. In this way, the ECU 16 can determine whether the automobile 1 will roll over when the absolute value of the detected value of the roll angle is equal to or greater than the determination threshold D3. If it is not determined in the processing of the fourth line in Figure 5 that the automobile 1 will roll over, the ECU 16 then executes the processing of the fifth line in Figure 5. The ECU 16 determines whether the absolute value of the detected value of the roll angular velocity is equal to or greater than a determination threshold V4. If the absolute value of the detected value of the roll angular velocity is equal to or greater than the determination threshold V4, the ECU 16 further determines whether the absolute value of the detected value of the roll angle is equal to or greater than a determination threshold D4. If the absolute value of the detected value of the roll angle is equal to or greater than the determination threshold D4, the ECU 16 determines that the automobile 1 will roll over to the right. In this way, the ECU 16 can determine whether the automobile 1 will roll over when the absolute value of the detected value of the roll angular velocity is equal to or greater than the determination threshold V4. If the ECU 16 does not determine that the vehicle 1 will roll over in the processing of the fifth line in Fig. 5, the ECU 16 then executes the processing of the sixth line in Fig. 5. The ECU 16 determines whether or not the combination of the absolute value of the detected value of the roll angular velocity and the absolute value of the detected value of the roll angle is equal to or greater than the combination of the absolute value of the roll angular velocity and the absolute value of the roll angle on the threshold line in section F. If a combination equal to or greater than the threshold line in section F is detected, the ECU 16 determines that the vehicle 1 will roll over to the right. By performing the threshold determinations in the fourth to sixth lines in Fig. 5, the ECU 16 can determine whether or not the vehicle 1 will roll over to the right.

[0033] FIG. 6 is a flowchart showing the flow of control for determining whether the automobile 1 has rolled over, performed by the ECU 16 of FIG. The ECU 16 of the automobile 1 in FIG. 2 may repeatedly execute the rollover determination control in FIG. 6 as a determination control unit, for example, every time the automobile 1 travels.

[0034] In step ST1, the ECU 16 acquires the roll angular velocity and roll angle from the acceleration sensor 11 as detection values ​​regarding the roll of the automobile 1 in the left-right direction. It should be noted that, for example, when the acceleration sensor 11 detects only the roll angular velocity, the ECU 16 may integrate the roll angular velocity continuously acquired from the acceleration sensor 11 to acquire the roll angle. The automobile 1 leans to the right or left while traveling. If this left-right lean becomes too great, the automobile 1 will roll over.

[0035] In step ST2, the ECU 16 reads and acquires from the memory 15 multiple sets of determination threshold information 20, which are combinations of the roll angle determination threshold and the roll angular velocity determination threshold described in Fig. 5, in order to determine the tilting of the automobile 1. The multiple sets of determination threshold information 20 acquired here are, for example, multiple sets of determination threshold information 20 for when the road surface 2 is flat, as shown in Fig. 4.

[0036] In step ST3, the ECU 16 acquires information about the inclination of the road surface 2 in the traveling direction of the automobile 1 from the exterior camera 12. The road surface 2 on which the automobile 1 is traveling is not always flat, but may be inclined downward to the right or downward to the left. The exterior camera 12 detects the inclination of the road surface 2 in the traveling direction of the automobile 1 based on the captured image. Note that the ECU 16 may acquire information about the inclination of the road surface 2 in the traveling direction of the automobile 1 by acquiring the captured image from the exterior camera 12 and determining the inclination of the road surface 2 in the traveling direction of the automobile 1.

[0037] In step ST4, the ECU 16 generates an adjustment value for generating an adjustment threshold by changing the determination threshold in accordance with the acquired inclination of the road surface 2. Here, the ECU 16 generates a larger adjustment value as the inclination of the road surface 2 in the traveling direction of the automobile 1 detected by the exterior camera 12 increases. For example, the ECU 16 may use the inclination angle of the road surface 2 from the horizontal plane as the adjustment value. If the road surface 2 is inclined downward to the left, the ECU 16 may generate a negative adjustment value by adding a minus sign to the absolute value of the inclination angle. If the road surface 2 is inclined downward to the right, the ECU 16 may generate a positive adjustment value by adding a plus sign to the absolute value of the inclination angle.

[0038] In step ST5, the ECU 16 generates information on an adjusted threshold value to be used in an actual comparison and determination based on the information 20 on the determination threshold value acquired from the memory 15 and the adjustment value. For example, the ECU 16 may generate each adjustment threshold for the roll angle by adding an adjustment value generated in accordance with the inclination of the road surface 2 to each determination threshold for the roll angle obtained from the memory 15. In this case, the multiple adjustment thresholds corresponding to the multiple roll angles D1 to D4 in Fig. 5 are obtained by adding the adjustment value to each of the values ​​D1 to D4. Furthermore, the ECU 16 may generate each adjustment threshold value for the roll angular velocity by adding an adjustment value generated in accordance with the inclination of the road surface 2 to each determination threshold value for the roll angular velocity acquired from the memory 15. In this case, the multiple adjustment threshold values ​​corresponding to the multiple roll angular velocities V1 to V4 in Fig. 5 are obtained by adding the adjustment value to each of the values ​​V1 to V4. As a result, ECU 16 generates a plurality of roll angle adjustment thresholds corresponding to all of the plurality of roll angle determination thresholds acquired from memory 15. ECU 16 also generates a plurality of roll angular velocity adjustment thresholds corresponding to all of the plurality of roll angular velocity determination thresholds acquired from memory 15. ECU 16 can change determination threshold information 20 acquired from memory 15 in accordance with the inclination in the lateral direction of road surface 2 in the traveling direction of automobile 1 detected by exterior camera 12, and generate adjustment threshold information adjusted in accordance with the inclination of road surface 2.

[0039] In step ST6, the ECU 16 compares the current detected values ​​of the roll angle and roll angular velocity obtained from the acceleration sensor 11 with the generated adjustment thresholds for the roll angle and roll angular velocity. In this case, the ECU 16 may basically compare the detected values ​​of the roll angle and the roll angular velocity with each of multiple sets of adjusted threshold values ​​based on the combination of the roll angle and the roll angular velocity adjusted according to the inclination in the left-right direction of the road surface 2 in the direction of travel of the automobile 1. Additionally, for example, when the automobile 1 is rolling to the left, the ECU 16 may replace the determination threshold with an adjusted threshold in the processing of the first to third lines in Fig. 5 described above. Also, when the automobile 1 is rolling to the right, the ECU 16 may replace the determination threshold with an adjusted threshold in the processing of the fourth to sixth lines in Fig. 5 described above. In this way, the ECU 16 can determine whether the automobile 1 is rolling over to the left or right. Through this process, the ECU 16 can predictively determine the possibility of rollover if the automobile 1 continues to move forward on the road surface 2 in the traveling direction while maintaining the current inclination.

[0040] In step ST7, the ECU 16 determines whether or not any of the combinations of the detected roll angle and roll angular velocity exceeds the adjustment threshold value. If the combination of the detected values ​​exceeds any one of the combinations of the adjustment threshold values, the ECU 16 proceeds to step ST8. On the other hand, if the combination of detection values ​​does not exceed any of the combinations of the plurality of adjustment threshold values, the ECU 16 does not proceed to step ST8, but proceeds to step ST9.

[0041] In step ST8, the ECU 16 executes rollover control in the event that the automobile 1 rolls over. The ECU 16 outputs an activation signal to, for example, the passenger protection device 13 and the alarm device 14. When an activation signal based on a rollover prediction is input, the occupant protection device 13 starts control to protect the occupant. When an activation signal based on a rollover prediction is input, the warning device 14 outputs a warning to the occupants by sound or light.

[0042] In step ST9, the ECU 16 determines whether or not to end the rollover determination control of FIG. For example, when the automobile 1 is stopped and an engine start button (not shown) is operated, the ECU 16 may determine to end the rollover determination control. In this case, the ECU 16 ends the rollover determination control of FIG. If the ECU 16 does not determine that the rollover determination control should be terminated, the ECU 16 returns the process to step ST1. The ECU 16 repeats the processes from step ST1 to step ST9 until it determines that the rollover determination control should be terminated. As a result, the ECU 16 can always predictively determine whether or not a rollover will occur while the automobile 1 is traveling, and when it determines that a rollover has actually occurred, it can cause the in-vehicle device to execute an operation to deal with the rollover.

[0043] 7 is a diagram illustrating the adjustment process of threshold information in the case of a road surface 2 that slopes downward to the right. The vertical and horizontal axes in FIG. 7 are the same as those in FIG. In FIG. 7, the left-side judgment curve and the right-side judgment curve stored in the memory 15 shown in FIG. 4 are shown by dashed lines.

[0044] In the processing of steps ST3 to ST5 in FIG. 6, the ECU 16 adjusts these judgment curves with adjustment values ​​according to the inclination of the road surface 2 to generate adjustment curves shown by solid lines in the figure. FIG. 7 shows the generation process when the road surface 2 is inclined downward to the right. In this case, the ECU 16 shifts the judgment curve for the right side, which is located at the bottom left of the figure, toward the top right by the adjustment value, so that the absolute value of the adjustment threshold for rightward tilt becomes smaller than the absolute value of the judgment threshold. Furthermore, the ECU 16 shifts the judgment curve for the left side, which is located at the upper right of the figure, toward the upper right by the adjustment value, so that the absolute value of the adjustment threshold for leftward tilting becomes greater than the absolute value of the judgment threshold.

[0045] 8 is a diagram illustrating the adjustment process of threshold information in the case of a road surface 2 sloping downward to the left. The vertical and horizontal axes in FIG. 8 are the same as those in FIG. In FIG. 8, the left-side judgment curve and the right-side judgment curve stored in the memory 15 shown in FIG. 4 are shown by dashed lines.

[0046] In the processing of steps ST3 to ST5 in FIG. 6, the ECU 16 adjusts these judgment curves with adjustment values ​​according to the inclination of the road surface 2 to generate adjustment curves shown by solid lines in the figure. FIG. 8 shows the generation process when the road surface 2 is inclined downward to the left. In this case, the ECU 16 shifts the right-side judgment curve, which is located at the bottom left of the figure, downward and leftward by the adjustment value, so that the absolute value of the adjustment threshold for rightward tilting becomes larger than the absolute value of the judgment threshold. Furthermore, the ECU 16 shifts the judgment curve for the left side, which is located in the upper right corner of the figure, downward and to the left by the adjustment value, so that the absolute value of the adjustment threshold for the leftward tilt becomes smaller than the absolute value of the judgment threshold.

[0047] In this way, the memory 15 stores information 20 on the threshold value for determining whether the vehicle will roll over on the road surface 2 at a certain inclination, such as horizontal. Based on the determination threshold information 20 in the memory 15, the ECU 16 generates information on an adjustment threshold corresponding to the inclination of the road surface 2 in the traveling direction, and compares the generated information on the adjustment threshold with the detection value.

[0048] For example, as shown by the two-dot chain line in the upper right of Fig. 7, there are cases where the detected roll angle of the automobile 1 continues to tilt to the left on a road surface 2 that slopes downward to the right. In this case, the ECU 16 does not determine that the automobile 1 has rolled over to the left until the detected value becomes a combination of a roll angle and a roll angular velocity that is larger than when the road surface 2 is flat. The timing T4 at which it is determined that a rollover has occurred to the left on a road surface 2 that slopes downward to the right is later than the timing T3 at which a similar determination is made on a horizontal road surface 2. The roll angle to the left at this time also becomes larger.

[0049] 7, there are cases where the detected roll angle of the automobile 1 continues to tilt to the right on a road surface 2 that slopes downward to the right. In this case, the ECU 16 determines that the automobile 1 has rolled over to the right when the detected roll angle and roll angular velocity are smaller than those detected on a horizontal road surface 2. The timing T1 at which a rollover to the right is determined on a road surface 2 that slopes downward to the right is earlier than the timing T2 at which a similar determination is made on a horizontal road surface 2. The roll angle to the right at this time is also smaller.

[0050] As described above, in this embodiment, the judgment threshold information 20 acquired from the memory 15 is not directly compared with the detection value of the acceleration sensor 11. In this embodiment, the judgment threshold information is changed according to the lateral inclination of the road surface 2 in the traveling direction of the automobile 1, as detected by the exterior camera 12, to generate adjusted threshold information adjusted according to the inclination of the road surface 2. In this case, the adjustment threshold information is generated such that the judgment threshold information 20 acquired from the memory 15 is changed more significantly as the lateral inclination of the road surface 2 in the traveling direction of the automobile 1, as detected by the exterior camera 12, increases. In this embodiment, the adjustment threshold information generated by the adjustment is compared with the detection value of the acceleration sensor 11. In this embodiment, various inclinations that may occur on the road surface 2 can be determined by comparing the detection value with the threshold. Furthermore, in this embodiment, various inclinations that may occur on the road surface 2 can be determined collectively. In this embodiment, the judgment can be performed in a short time without repeating the comparison and determination for each of the various inclinations that may occur on the road surface 2 multiple times. As a result, in this embodiment, it is possible to predictively determine whether the vehicle 1 will tilt, for example, before the exterior camera 12 detects a tilt angle at which the vehicle 1 will actually overturn. Based on this predictive tilt determination, the vehicle 1 can begin controlling the vehicle 1 before it actually tilts. By starting operation of on-board devices such as the occupant protection device 13 based on such predictive tilt determination, the vehicle 1 of this embodiment can start operation of on-board devices such as occupant protection devices at an appropriate timing when the vehicle 1 tilts. In this embodiment, the memory 15 stores information 20 of the judgment threshold for one inclination of the road surface 2 (for example, horizontal). The ECU 16 as a judgment control unit can perform comparison judgments for a plurality of different inclinations of the road surface 2 simply by performing a certain comparison judgment based on the information. It is not necessary to store information 20 of a plurality of judgment thresholds for each inclination of the road surface 2 in the memory 15. The ECU 16 does not need to perform judgment processing that is divided into cases for each inclination of the road surface 2, for example. As a result, in this embodiment, it is possible to perform a reliable determination that satisfies changes in the occurrence of tilting, which changes according to the inclination of the road surface 2. In this embodiment, for example, it is less likely that an excessive determination of tilting occurs in a situation where tilting does not actually occur, or that a failure to determine tilting occurs in a situation where tilting actually occurs, etc. In this embodiment, excessive operation of in-vehicle devices such as the occupant protection device 13 can be suppressed, while the device can be operated satisfactorily when operation is necessary.

[0051] In this embodiment, the memory 15 stores, as the judgment threshold information 20, information 20 on the judgment threshold for tilting the automobile 1 to the right and information 20 on the judgment threshold for tilting the automobile 1 to the left. In the automobile 1, there may be a case where the road surface 2 in the traveling direction is detected as sloping downward to the right by the exterior camera 12. In this embodiment, the absolute value of the determination threshold for tilting to the right acquired from the memory 15 is decreased, and the absolute value of the determination threshold for tilting to the left is increased, thereby generating information on the adjusted thresholds adjusted according to the inclination of the road surface 2. Furthermore, in the automobile 1, the road surface 2 in the traveling direction may be detected as sloping downward to the left by the exterior camera 12. In this embodiment, the absolute value of the determination threshold for tilting to the right acquired from the memory 15 is increased, and the absolute value of the determination threshold for tilting to the left is decreased, thereby generating information on the adjusted thresholds adjusted according to the slope of the road surface 2. In this way, by dividing the tilt direction of the automobile 1 into left and right, preparing judgment thresholds for each of the left and right, and adjusting each separately, it is possible to generate information on adjustment thresholds for both the left and right using a certain processing procedure.

[0052] In this embodiment, multiple sets of judgment threshold information 20, including a judgment threshold for the roll angle and a judgment threshold for the roll angular velocity of the automobile 1, are recorded in memory 15 as judgment threshold information 20. In this embodiment, the roll angle judgment threshold and the roll angular velocity judgment threshold included in the multiple sets of judgment threshold information 20 acquired from memory 15 are changed depending on the inclination of the road surface 2 in the traveling direction of the automobile 1, which is detected by the exterior camera 12. Then, in this embodiment, multiple sets of adjustment threshold information, including an adjustment threshold for the roll angle and an adjustment threshold for the roll angular velocity adjusted depending on the inclination of the road surface 2, are generated and compared with the detection value of the acceleration sensor 11. Then, in this embodiment, if the detection value of the acceleration sensor 11 exceeds any set of adjustment threshold information, it can be predictively determined that the automobile 1 is leaning. As a result, in this embodiment, based on the relationship between the roll angle and roll angular velocity of the automobile 1, tilting can be determined not only in accordance with the inclination of the road surface 2 but also in accordance with the movement occurring in the automobile 1. In this embodiment, it is possible to perform a reliable determination that satisfies changes in the occurrence of these tilts.

[0053] The above-described embodiment is an example of a preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications and changes are possible within the scope of the gist of the invention.

[0054] In the above-described embodiment, the case where the automobile 1 rolls in the left and right direction and overturns has been described. In addition to this, for example, the present invention may be used to determine whether the automobile 1 is tilting in the pitch direction or whether the automobile 1 is tilting in the roll direction. [Explanation of symbols]

[0055] 1... automobile (vehicle), 2... road surface, 3... curb, 10... control system (tilt determination device), 11... acceleration sensor (tilt sensor), 12... outside vehicle camera (road surface detection unit), 13... occupant protection device (on-vehicle device), 14... alarm device (on-vehicle device), 15... memory, 16... ECU (determination control unit), 20... determination threshold information

Claims

1. a tilt sensor for detecting a value relating to a tilt angle or a tilt angular velocity of the vehicle; a memory for recording information on a determination threshold for determining whether the vehicle is tilting; a determination control unit that determines whether the vehicle is tilting based on the detection value of the tilt sensor and information on the determination threshold value recorded in the memory; a road surface detection unit that detects the inclination of the road surface from an image of the road surface in the traveling direction of the vehicle; and The determination control unit acquiring, from the memory, information on the determination threshold for determining tilt; changing the judgment threshold information acquired from the memory in accordance with the inclination of the road surface in the traveling direction of the vehicle detected by the road surface detection unit, and generating adjusted threshold information adjusted in accordance with the inclination of the road surface; and determining whether the vehicle is tilting by comparing information on the adjusted threshold value, which is adjusted according to the inclination of a road surface in the traveling direction of the vehicle, with the detection value of the tilt sensor; The memory stores the following as information about the determination threshold: Information on a first determination threshold for the rightward tilt of the vehicle; and recording information of a second determination threshold value for the vehicle tilting to the left; The first determination threshold for the rightward tilt and the second determination threshold for the leftward tilt are each set to: a first line segment along which the absolute value of the roll angle is equal to or greater than a first roll angle threshold and the absolute value of the roll angular velocity is equal to a first roll angular velocity threshold; a second line segment along which the absolute value of the roll angle is equal to or greater than a second roll angular velocity threshold that is smaller than the first roll angle threshold and the absolute value of the roll angular velocity is equal to or greater than a second roll angular velocity threshold that is larger than the first roll angular velocity threshold; and a third line segment connecting the first roll angle threshold and the first roll angular velocity threshold on the first line segment with the second roll angle threshold and the second roll angular velocity threshold on the second line segment, and not including a threshold that intersects with both the roll angle axis and the roll angular velocity axis, The determination control unit generates information about the adjusted threshold value adjusted according to the inclination of the road surface, When the road surface detection unit detects that the road surface in the traveling direction of the vehicle slopes downward to the right, the absolute values ​​of all the determination thresholds for the first line segment, the second line segment, and the third line segment regarding a rightward tilt acquired from the memory are decreased, and the absolute values ​​of all the determination thresholds for the first line segment, the second line segment, and the third line segment regarding a leftward tilt are increased; When the road surface detection unit detects that the road surface in the traveling direction of the vehicle is sloping downward to the left, the absolute values ​​of all the determination thresholds for the first line segment, the second line segment, and the third line segment regarding a rightward tilt acquired from the memory are increased, and the absolute values ​​of all the determination thresholds for the first line segment, the second line segment, and the third line segment regarding a leftward tilt are decreased. Vehicle tilt detection device.

2. the road surface detection unit is a camera that captures an image including the road surface, The determination control unit the larger the inclination of the road surface in the traveling direction of the vehicle detected by the road surface detection unit, the more the information on the determination threshold value acquired from the memory is changed to generate the information on the adjustment threshold value. The vehicle tilt determination device according to claim 1.

3. the memory records, as the information on the determination thresholds, information on a plurality of sets of determination thresholds including a determination threshold for a tilt angle of the vehicle and a determination threshold for a tilt angular velocity; The determination control unit acquiring information on a plurality of sets of determination thresholds from the memory; changing the judgment threshold value for the tilt angle and the judgment threshold value for the tilt angular velocity included in the plurality of sets of judgment threshold information in accordance with the inclination of the road surface in the traveling direction of the vehicle detected by the road surface detection unit, and generating a plurality of sets of adjustment threshold information including an adjustment threshold value for the tilt angle and an adjustment threshold value for the tilt angular velocity adjusted in accordance with the inclination of the road surface; comparing the detection value of the tilt sensor with information on a plurality of sets of adjusted threshold values ​​adjusted according to the inclination of the road surface in the traveling direction of the vehicle, and determining that the vehicle is tilted when the detection value of the tilt sensor exceeds information on any of the sets of adjusted threshold values; 3. The vehicle tilt determination device according to claim 1 or 2.

4. The determination control unit: an absolute value of the roll angle is equal to or greater than the first roll angle threshold and an absolute value of the roll angular velocity is equal to or greater than the first roll angular velocity threshold; an absolute value of the roll angular velocity is equal to or greater than the second roll angular velocity threshold and an absolute value of the roll angle is equal to or greater than a second roll angle threshold; when the absolute value of the roll angle is less than the first roll angle threshold, the absolute value of the roll angular velocity is less than the second roll angular velocity threshold, and the combination of the absolute value of the roll angle and the absolute value of the roll angular velocity is equal to or greater than the absolute value of a determination threshold on the third line segment, determining that the vehicle is tilting; The vehicle tilt determination device according to claim 1 .

5. The determination control unit When the road surface detection unit detects that the road surface in the traveling direction of the vehicle is sloping downward to the right, the absolute values ​​of all the determination thresholds for the first line segment, the second line segment, and the third line segment regarding a rightward tilt acquired from the memory are decreased by a first predetermined value, and the absolute values ​​of all the determination thresholds for the first line segment, the second line segment, and the third line segment regarding a leftward tilt are increased by the first predetermined value, When the road surface detection unit detects that the road surface in the traveling direction of the vehicle is sloping downward to the left, the absolute values ​​of all the determination thresholds for the first line segment, the second line segment, and the third line segment regarding a rightward tilt acquired from the memory are increased by a second predetermined value, and the absolute values ​​of all the determination thresholds for the first line segment, the second line segment, and the third line segment regarding a leftward tilt are decreased by the second predetermined value. The vehicle tilt determination device according to claim 1 .

6. A vehicle tilt determination device according to any one of claims 1 to 5, an in-vehicle device including an occupant protection device that can be activated when the vehicle tilts, The in-vehicle device including the occupant protection device is activated when the tilting determination device determines that the vehicle is tilting. vehicle.

Images