JP2021059280A - Tire fall-off prevention system - Google Patents

Abstract

To provide a tire fall-off prevention system which, when predicted that a tire may fall off, causes a vehicle to retreat to a safe place, while avoiding application of a large load to that tire.SOLUTION: A vehicle 10 includes: front side tires 11, 12; rear side tires 13, 14; sensors 31, 32, 33, 34 for detecting a state of the tires 11, 12, 13, 14; a control part 40; a navigation device 41; and the like. If abnormality is predicted in any of the tires 11, 12, 13, 14, the control part 40 reduces output of an engine 50 of the vehicle 10 to lower the speed of the vehicle, and when causing the vehicle 10 to retreat to a safe place, the control part 40 displays a travel route for limiting turning of the vehicle 10 to a tire side where fall-off has been predicted, in a display unit 61.SELECTED DRAWING: Figure 1

Description

The present invention relates to a tire dropout prevention system that prevents a tire mounted on a vehicle such as an automobile from falling off during traveling.

As one means for preventing the wheels mounted on the vehicle (also referred to as tires with wheels or only tires in this specification) from falling off during traveling, for example, wheel dropout described in Patent Document 1 is described. A detector has been proposed. The wheel dropout detection device of Patent Document 1 detects the acceleration in the axle direction generated on the wheels during traveling, determines that the wheels may fall off when the acceleration is out of a predetermined range, and issues an alarm. This encourages the driver to stop the vehicle.

Assumed wheel dropout may occur when the tire comes off the axle together with the wheel, or when only the tire comes off the wheel with the wheel fixed to the axle. The term "tire dropout" as used in this specification includes the fact that the tire has fallen off completely, but in addition to that, the tire is significantly loosened and is about to fall off, or it comes off the vehicle. It also includes a state in which it can be said that the tire has actually dropped out.

As a result of investigating cases of tires falling off when a large vehicle such as a truck traveled on a road traveling on the left side, it was pointed out that most of the tires that fell off were the rear tires, and among them, the rear left tires were the most common. It was. One of the possible causes is that when the vehicle turns left on a road with left-hand traffic, the turning radius of the rear left tire located inside the turn is the minimum, and the rear left tire does not change direction. It was thought that this was because it was attached to the steering axle and therefore a large load was applied. On the other hand, when turning right, all the tires turn with a relatively large turning radius, so the load applied to the tires is smaller than when turning left.

Japanese Unexamined Patent Publication No. 2005-329907

Even if the driver is urged to stop by issuing an alarm when a tire dropout is predicted, as in the wheel dropout detection device described in Patent Document 1, it depends on the surrounding conditions of the running vehicle. It may not be best to stop the vehicle immediately. For example, when it is difficult to park or stop on a narrow road due to traffic conditions, or when the vehicle is stopped as when driving on a highway, it may be unsafe. In such situations, you should avoid forcibly stopping the vehicle and slow down to a safe place (for example, on general roads, parking lots and vacant lots of large stores, boulevards with shoulder belts where you can park and stop, highways. On the road, it may be desirable to guide the vehicle to parking, highway bus stops, etc.).

When a vehicle for which tires are predicted to fall off has to be driven to an evacuation site, it is desirable to drive the tires that are likely to fall off with as little load as possible. It is rare for the right tire and the left tire to fall off at the same time during normal driving, and only one of the left and right tires will fall off. Therefore, if one of the tires is predicted to fall off during driving, the position of the tire (right side or left side) so that the tire (called a dropout sign tire) is not overloaded while driving to a safe place. ) Is taken into consideration when driving.

Therefore, the present invention is to provide a tire dropout prevention system capable of moving a vehicle in which a tire abnormality is detected to a safe place.

One embodiment of the present invention is a tire dropout prevention system for a vehicle having a tire arranged on the right side of the vehicle body and a tire arranged on the left side, and a determination unit for determining the risk of each tire falling off. And, when there is a tire that may fall off, the vehicle is provided with a control unit that restricts the vehicle from turning to the tire that may fall off (falling sign tire).

The control unit may reduce the speed of the vehicle when the dropout sign tire is detected. Further, the control unit may control the steering mechanism of the vehicle so as to prevent the vehicle from making a sharp turn (turning with a small radius) toward the dropout sign tire side. For example, the steering angle may be limited or resistance may be given to the steering force when the steering wheel (steering) is operated toward the tire side that is a sign of falling off.

The control unit includes a navigation device that displays a travel route that guides the vehicle to the nearest parkingable space on a map, and the navigation device restricts the vehicle from turning toward the dropout sign tire side. The route may be displayed on the map. Further, the navigation device may display on the map the travel route having the shortest distance among the plurality of travel routes for guiding the vehicle from the current position to the plurality of parkable spaces.

As an example of the navigation device, when a part of the traveling route includes a turning angle that changes the course toward the dropout sign tire side, a coefficient of a value corresponding to the turning angle can be parked from the current location of the vehicle. The correction distance is obtained by multiplying the distance to the space, the priorities of a plurality of travel routes are ranked based on the correction distance, and the travel route having the highest priority is displayed on the map. Further, when the navigation device includes a corner where the course changes to the dropout sign tire side as a part of the traveling route, the larger the angle of the corner, the larger the coefficient can be parked from the current location of the vehicle. The correction distance may be obtained by multiplying the distance to.

According to the tire dropout prevention system according to the present invention, the vehicle is operated under the condition that a large load is suppressed on the tires according to the position of the tires predicted to fall off (whether the tires on the right side or the tires on the left side). Can be moved to a safe place.

A plan view schematically showing a vehicle provided with a tire dropout prevention system according to one embodiment. The block diagram which showed the component of the tire fall prevention system of the vehicle shown in FIG. A flowchart showing the processing flow of the dropout prevention system. The flowchart which shows an example of the processing of the navigation device which forms a part of the dropout prevention system. The figure which showed an example of the traveling route to the parkingable space searched by the dropout prevention system. The figure which showed the other example of the driving route to the parkingable space searched by the dropout prevention system.

Hereinafter, embodiments of a vehicle provided with a tire dropout prevention system according to the present invention will be described with reference to FIGS. 1 to 6. FIG. 1 is a plan view schematically showing a vehicle 10 provided with a tire dropout prevention system. The arrow F in FIG. 1 indicates the front side of the vehicle 10.

The vehicle 10 shown in FIG. 1 includes a tire 11 arranged on the front right side of the vehicle body 10a, a tire 12 arranged on the front left side of the vehicle body 10a, a tire 13 arranged on the rear right side, and a rear left side. It has a tire 14 arranged in. The rear tires 13 and 14 may be single tires or double tires, respectively.

The front tires 11 and 12 can be changed in direction by operating the steering wheel 23 arranged in the driver's cab 22, and the course of the vehicle 10 can be changed. The rear tires 13 and 14 are attached to both ends of the axle (rear axle) 25 via wheels, respectively.

The vehicle 10 includes a traveling drive system 28 that generates power for traveling, a steering mechanism 29 that functions when changing the course of the vehicle 10, a braking system that functions when braking the vehicle 10, and tires 11 and 12. , 13, 14 are sensors 31, 32, 33, 34 that detect the state of each tire when rotating, a control unit 40 that includes an electronic circuit using an in-vehicle computer, and a navigation device (navigation system for automobiles). ) 41 and a hazard lamp (warning light) 42 and the like. The hazard lamp 42 may also serve as a turn signal lamp (direction indicator lamp).

The traveling drive system 28 includes an engine 50, a transmission 51, a power transmission mechanism 52, and the like, and transmits torque of the engine 50 to drive wheels (for example, rear tires 13 and 14). As the engine 50, an electric motor may be used in addition to the internal combustion engine, or the internal combustion engine and the electric motor may be used in combination.

The steering mechanism 29 includes a steering 23 operated by the driver when changing the course of the vehicle 10, a power steering unit 56 that generates an assist force that changes the direction of the front tires 11 and 12 according to the steering angle of the steering 23, and the like. including.

FIG. 2 is a block diagram showing the components of the tire dropout prevention system of the vehicle 10. The sensors 31, 32, 33, 34 convert the rotating behavior of the tires 11, 12, 13, 14 such as an infrared sensor, an optical camera, or an acceleration sensor into an electric signal and output it to the determination unit 35.

By processing the signals input from the sensors 31, 32, 33, and 34, the determination unit 35, for example, when the amount of tire sway exceeds the permissible range, or the steering angle of the tire matches the steering angle of the steering 23. By detecting abnormal behavior that occurs when tires 11, 12, 13, and 14 are about to fall off, such as when the tires are not, the tires that may fall off (referred to as fall-off sign tires) are identified. ing. The determination unit 35 is not limited to the above configuration, for example, cracks in the axle 25 and the wheels of the tires 11, 12, 13, and 14, and slack in the bolts that fix the wheels of the tires 11, 12, 13, and 14 to the vehicle. May be detected by an infrared sensor, an optical camera, or the like.

The navigation device 41 identifies the current position of the receiver by using GPS (Global positioning system) in order to assist the driver in reaching the destination, and displays the distance and direction between the current position and the destination. (Display panel) It is configured to be displayed on the map screen of 61.

The control unit 40 includes an engine control unit that electronically controls the traveling drive system 28, a steering control unit that controls the power steering unit 56 and the like, a determination unit 35, a computer program that controls the display 61, and the like. There is.
As will be described below, when the dropout sign tire is detected, the control unit 40 makes a sharp turn in which a large load is applied to the dropout sign tire according to the position of the dropout sign tire (whether it is the right tire or the left tire). A computer program is incorporated to guide the vehicle 10 to a safe place while avoiding (turning with a small radius).

The term "sudden turning of a vehicle" as used herein means turning at a radius that causes a large load that encourages the tires inside the turning to fall off, and it depends on the vehicle or the load weight. It may be based on the data actually measured using it, or it may be obtained by simulation.

FIG. 3 is a flowchart showing a processing flow of the tire dropout prevention system. Hereinafter, the processing flow of the tire dropout prevention system of the present embodiment will be described with reference to FIG.
In step ST1 in FIG. 3, signals from sensors 31, 32, 33, 34 (shown in FIGS. 1 and 2) are input to the determination unit 35. The determination unit 35 constantly monitors whether or not the state of each tire is normal when the tires 11, 12, 13, and 14 are rotating, based on the signals of the sensors 31, 32, 33, and 34. There is.

If it is determined in step ST2 that at least one of the tires 11, 12, 13, and 14 is abnormal (a tire that is a sign of falling off) (“YES” in step ST2), the process proceeds to step ST3.

In step ST3, as an example of a means for warning the driver of the vehicle 10 and surrounding vehicles (particularly the following vehicle) that an abnormality has occurred in the tires of the vehicle 10, the hazard lamp 42 (in FIGS. 1 and 2). In addition to blinking (shown), the indicator 61 in the driver's cab 22 is displayed to notify the abnormality, and / or an alarm sound is emitted. At this time, it is advisable to notify the position of the tire that is a sign of falling off. Then, the process immediately proceeds to step ST4.

In step ST4, the engine control unit of the control unit 40 reduces the output of the engine 50 so as to limit the speed of the vehicle 10. For example, the speed is controlled so that the driver does not exceed a predetermined speed (for example, 20 km / h when traveling at a low speed) even if the driver depresses the accelerator pedal. At this time, the warning operation to the surroundings by the hazard lamp 42 or the like is continued, and the evacuation run to the parkable space is started. The predetermined speed may be set to a speed that does not give a large load to the tires, for example, from the speed during normal driving (for example, the speed limit on a general road) when there is no sign tire (normal state). Should also be set small.

In step ST5, as will be described in detail later, the vehicle 10 turns in the direction of the drop-predicted tire depending on whether the tire predicted to fall (fall-out sign tire) is the right tire or the left tire. Is restricted. As a result, it is possible to prevent a large load from being applied to the dropout prediction tire when turning a corner or the like.

In one example of step ST5, the steering mechanism 29 is controlled in order to prevent the vehicle from turning toward the tire side, which is a sign of falling off, and changing the course. For example, when the steering 23 is operated during the retracting run, the steering angle of the steering mechanism 29 is limited so as to prevent the vehicle 10 from making a sharp turn in the direction of the dropout prediction tire, or the steering 23 is largely operated. Even if the steering speed is increased, the power steering unit 56 is controlled so that the steering speed is reduced or the assist force is smaller (the steering becomes heavier) than in the normal state.

In step ST6, the vehicle 10 is stopped when the vehicle 10 has moved to the parking space, and the tires predicted to fall off are inspected, and all the tires are also inspected. For example, if the hub bolts and nuts are loose, they are tightened. If any problems are found in the tire or parts around the tire, repair it.

FIG. 4 is an example of the process performed by using the navigation device 41 in step ST5 in FIG. For example, in step ST10 of FIG. 4, a plurality of travel route candidates for evacuation to a safe place (parkable space) are searched according to the position of the tire that is a sign of falling off (whether the tire is on the right side or the tire on the left side). To. In step ST11, among the plurality of travel route candidates searched in step ST10, the candidate for the travel route having the highest priority is adopted as the travel route for evacuation and displayed on the map of the display 61. Guides the driver in the direction to the destination so that the vehicle can move to a safe place.

An example of searching a travel route for evacuating a vehicle to a safe place without applying a large load to the tire when a tire is predicted to fall off will be described below.
[Search example 1 of travel route]
FIG. 5 is an example of a map screen displayed on the display 61 of the navigation device 41, and shows the current location A of the vehicle 10 (shown in FIG. 1). It is assumed that when the vehicle 10 is traveling on a road traveling on the left side, an abnormality (possibility of falling off) is detected in the tire 14 on the left side of the rear part. At this time, on the map of the display 61, it is shown that there are two parking spaces P1 and P2 at positions relatively close to the current location A. Further, at a position farther than the parkable spaces P1 and P2, there is a road T1 having a sufficient road width for parking on the shoulder.

When the vehicle 10 turns left, it is expected that a large load will be applied to the rear left tire 14. Therefore, the navigation device 41 of the present embodiment has a large angle θ1 close to 90 °, for example, a turning angle C1 in order to limit the change of course to the left turn side when the tire 14 on the rear left side is predicted to fall off. Search for a driving route so as to avoid turning left at. On the other hand, when turning right, the load on the rear left tire 14 is not so large. Therefore, at the corner where the course changes to the right turn side, the traveling route is searched so as to allow turning regardless of the size of the angle.

The closest evacuation site on the map of FIG. 5 is the parking space P1 (for example, the parking lot of the large store 1). However, in order to reach the parkable space P1 from the current location A, there is an intersection C1 that turns left at a large angle θ1 in the middle of the traveling route. Therefore, from the viewpoint of protecting the tire 14 on the left side of the rear part, the traveling route to the parkingable space P1 is not adopted. There may be detours that can reach the parking space P1 simply by turning right at all intersections from the current location A, but such detours have extremely long mileage. You don't want to drive long distances with tires that are predicted to fall off.

The second closest evacuation site on the map of FIG. 5 is the parking space P2 (for example, the parking lot of a large store 2). If the parking space P2 is reached by turning right at the intersection C2 at an angle θ2 from the current location A, the parking space P2 can be reached only by turning right. Therefore, if the distance to the parkable space P2 is closer than the distance (distance) to reach the parkable space P1 by the detour and the parkable space P2 can be used, the control unit 40 may use the intersection. Turn right at C2 to display the travel route toward the parking space P2 on the display 61.

As another travel route when heading from the current location A to the parkingable space P2 on the map of FIG. 5, the travel route that passes through the intersection C1 to the right and then to the left at the angle θ3 is also relatively short. However, even if the angle θ3 is gentle, it is necessary to make a left turn, so avoid making a left turn at the corner C3. That is, a traveling path that turns the corner C3 to the left turn side is not adopted. At this time, if the angle θ3 is smaller than a predetermined angle (for example, 30 °), a traveling path that turns the turning angle C3 to the left turn side may be adopted.

The third closest evacuation site on the map of FIG. 5 is the shoulder belt of the main street T1. On the way from the current location A to the main street T1, there is a turning angle C4 that turns left at an angle θ4, but if the angle θ4 is smaller than a predetermined angle, it is judged that the left turn is not prohibited. Therefore, when it is difficult to use the parking space P2 closest to the second one (for example, when it is outside business hours or when it is detected by network communication that the parking lot is full), the travel route close to the third one. (The route from the current location A to the main street T1 via the corner C4) is displayed.

[Search example 2 of travel route]
FIG. 6 is another example of the map screen displayed on the display 61 of the navigation device 41, and shows the current location B of the vehicle 10 (shown in FIG. 1). It is assumed that when the vehicle 10 is traveling on a road traveling on the left side, an abnormality (possibility of falling off) is detected in the tire 14 on the left side of the rear part. At this time, on the map of the display 61, it is shown that there are two parking spaces P3 and P4 at positions relatively close to the current location B.

If a tire is predicted to fall off, the longer the distance traveled, the closer the tire will fall off, so even if you need to make a left turn, if the left turn angle is gentle, you can park on the closer side. Sometimes it is better to move to possible space. From this point of view, if there is a left turn in the middle of the travel route, multiple travels are based on the correction distance (distance longer than the actual distance) obtained by multiplying the actual distance by a predetermined coefficient. Prioritize routes. As a result, the vehicle is restricted from turning to the left turn side (the tire side that is a sign of falling off), and the movement to the parkable space is suppressed from being a long distance.

For example, when it is predicted that the tire 14 on the left side of the rear part will fall off and there is a left turn turn in the middle of the traveling path for evacuation, the larger the left turn angle, the larger the coefficient is multiplied by the actual distance. In other words, even if there is a parkable space nearby, if the angle of the left turn is large, it is considered that the distance to the parkable space is long, and the priority of the traveling route is lowered. On the other hand, even if the parking space is relatively far away, if the vehicle can be reached only by turning right, the priority of the traveling route is obtained based on the actual distance without multiplying by the coefficient. When the left turn angle is small, the correction distance is calculated by multiplying the actual distance by a coefficient of a relatively small value, and the priority is determined.

For example, on the map of FIG. 6, in the case of a candidate for a traveling route from the current location B to the main street T2, there is a left turn C5 with a relatively gentle angle θ5 on the way from the current location B to the main street T2. Since the angle θ5 of this turning angle C5 is 30 ° or less, it is permitted to turn to the left turn side, but since the load on the rear left tire is larger in the left turn than in the right turn, the load on the tire is taken into consideration. The value (L1 × 1.2) obtained by multiplying the actual distance L1 by 1.2, which is an example of the coefficient, is taken as the distance (correction distance) from the current location B to the main street T2.

When the actual distance on the map from the current location B to the main street T2 is 300 meters, the correction distance (360 meters) longer than the actual distance is obtained by multiplying by the coefficient (1.2). The coefficient used here is set to a larger value as the left turn angle is larger. For example, when the tire load passes through a relatively small left turn angle of 15 °, the coefficient is set to 1.1, and the coefficient is gradually reduced as the left turn angle becomes smaller.

On the other hand, the distance (actual distance on the map) from the current location B to the parkable space P3 via the right turn C6 is 380 meters. When reaching the parkingable space P3 from the current location B via the corner C6, the priority can be determined without multiplying the actual distance (380 meters on the map) by the coefficient because it can be reached only by turning right.

In this example, the distance (correction distance) 360 meters from the current location B to the main street T2 by turning left at the corner C5 is 380 meters from the current location B to the corner C6 turning right to the parking space P3. Shorter than. That is, since the priority is higher toward the main street T2, the travel route toward the main street T2 is displayed by turning left at the corner C5 from the current location B.

On the map of FIG. 6, there may be a candidate for a traveling route from the current location B to the parkingable space P4. For example, the distance of the traveling route from the current location B to the parkingable space P4 via the left turn C5 and the right turn intersections C7 and C8 is 400 meters. However, since it passes through the left turn angle C5 of θ5 = 30 °, the correction distance obtained by multiplying the actual distance of 400 meters by the coefficient 1.2 is 480 meters. If it is not possible to park or stop on the main street T2, the travel route to which the parking space P3 and the parking space P4 have a shorter distance (corrected distance if there is a left turn) is displayed. In this case, the distance to the parkable space P3 (actual distance) is 380 meters, and the distance to the parkable space P4 (correction distance) is 480 meters, so the travel route toward the parkable space P3 is displayed. ..

On the map of FIG. 6, the travel route from the current location B to the right at the turn C9, and further to the parking space P3 via the left turn C10 at θ6 = 60 ° is also short, but the left turn angle θ6 at the turn C10. Is as large as 60 °, so the travel route that turns left at the corner C10 is not adopted.

Needless to say, the tire dropout prevention system according to the present invention can be similarly applied not only to large vehicles but also to small or medium-sized passenger cars and the like. The tire dropout prevention system of the present invention can be applied to, for example, a vehicle having a two-axle front wheel side tire (steering tire), or a large vehicle having a two-axle rear wheel side tire (non-steering tire). May be applied. Especially in the case of large vehicles, a large load is applied to the rear tires inside the turn when turning, so by arranging sensors that detect tire abnormalities at least on the rear tires, emphasis is placed on the rear tires. You may predict the dropout.

The vehicle may be equipped with an automatic driving system that guides the vehicle to a parkable space by automatic driving when a tire is predicted to fall off. Further, a communication system may be provided that automatically notifies the road administrator or the like that a problem has occurred in the tire. In addition to parking lots such as stores and factories, as places to evacuate vehicles when tires are predicted to fall off, navigation map information such as road shoulder belts that can ensure safety, emergency shelters on downhill slopes, vacant lots, etc. A place that can be registered in is available.

10 ... Vehicle, 10a ... Body, 11, 12, 13, 14 ... Tire, 23 ... Steering, 28 ... Driving drive system, 29 ... Steering mechanism, 31, 32, 33, 34 ... Sensor, 35 ... Judgment unit, 40 ... Control unit, 41 ... Navigation device, 50 ... Engine, 51 ... Transmission, 61 ... Display.

Claims (8)

A tire dropout prevention system for a vehicle having a tire arranged on the right side of the vehicle body and a tire arranged on the left side.
A judgment unit that detects a sign of a dropout of each tire and determines whether or not there is a dropout sign tire that may fall off.
When the determination unit determines that there is a dropout sign tire, a control unit that restricts the vehicle from turning toward the dropout sign tire.
A tire dropout prevention system characterized by being equipped with. The first aspect of the present invention is characterized in that, when the determination unit determines that the dropout sign tire is present, the control unit limits the maximum speed of the vehicle to a lower speed side than when the dropout sign tire is absent. The described tire dropout prevention system. When the determination unit determines that the vehicle has the drop-out predictive tire, the control unit increases the maximum turning radius of the vehicle toward the drop-out sign tire so that the maximum turning radius of the vehicle becomes larger than that when the vehicle does not have the drop-out predictive tire. The tire dropout prevention system according to claim 1 or 2, wherein the steering mechanism of the tire is controlled. When the determination unit determines that there is a dropout sign tire, the control unit makes the steering operation of the vehicle toward the dropout sign tire side heavier than when the dropout sign tire is absent. The tire dropout prevention system according to any one of claims 1 to 3, wherein the steering mechanism is controlled. The control unit includes a navigation device that displays a travel route that guides the vehicle to the nearest parkingable space on a map, and the navigation device restricts the vehicle from turning toward the dropout sign tire side. The tire dropout prevention system according to any one of claims 1 to 4, wherein the route is displayed on the map. 5. The navigation device is characterized in that, among a plurality of travel routes for guiding the vehicle from a current position to a plurality of parkable spaces, the travel route having the shortest distance is displayed on the map. The described tire dropout prevention system. When a part of the traveling route includes a turning angle that changes the course toward the dropout sign tire side, the navigation device calculates a coefficient of a value according to the turning angle from the current position of the vehicle to the parkable space. The claim is characterized in that the correction distance is obtained by multiplying the distance of the above, the priorities of a plurality of travel routes are ranked based on the correction distance, and the travel route having the highest priority is displayed on the map. The tire dropout prevention system according to 6. When the navigation device includes a corner that changes course toward the dropout sign tire side as a part of the traveling route, the larger the angle of the corner, the larger the coefficient from the current location of the vehicle to the parkable space. The tire dropout prevention system according to claim 7, wherein the correction distance is obtained by multiplying the distance of the tire.

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