Vehicle

Abstract

The present invention provides a vehicle that reduces the error in the change of the distance between a road surface measurement point and a tire and improves controllability. The vehicle (1) of the present invention includes: a vehicle body (1h); front wheels (2r, 2l) and rear wheels (3r, 3l) that move the vehicle body (1h); and a road surface state detection mechanism (5f) that detects the state of the road surface (R) in front of the front wheels (2r, 2l). The road surface state detection mechanism (5f) is located in front of the front wheels (2r, 2l), and the irradiation direction of the road surface state detection mechanism (5f) for detecting the measurement point (5s) on the road surface (R) is inclined toward the tangent direction (c1s) of the measurement point (5s) on an arc (c1) centered on the bump center (c) of the vehicle body (1h).

Description

Technical Field

[0001] The present invention relates to a vehicle. Background Art

[0002] Conventionally, in order to improve comfort in a vehicle, the road surface condition on which the wheels travel is detected and controlled.

[0003] As two methods for sensing the road surface as a sensor for detecting the road surface condition in the past, there are the following two.

[0004] The first method is to mount a sensor above the windshield to measure the front of the vehicle. The second method is to mount a sensor on the bumper to measure directly below the vehicle.

[0005] For example, Patent Document 1 discloses using a projection device 12 and a camera 18 provided near the front bumper to estimate the road surface condition in front of the vehicle 10. The projection device 12 uses a projection control unit 24 to control the projection / non-projection of a reference pattern and adjusts the irradiation intensity according to the surrounding conditions.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2013-205196 (FIGS. 1 to Figure 4 , paragraphs 0015, 0016, etc.) Summary of the Invention

[0009] However, in Patent Document 1, when the vehicle jolts, the measurement point on the road surface shifts back and forth. In this case, a change occurs in the distance between the measurement point and the tire, and there is a concern that an error may occur. For example, even when traveling at the same speed, since the distance from the time when the road surface unevenness is detected by the sensor to the time when the tire crosses the unevenness is different, a time difference occurs, which becomes a cause of error when controlling the electromagnetic shock absorber of the suspension. Therefore, it is necessary to correct the distance between the measurement point and the tire by control. That is, in order to correct this error, calculation processing is required.

[0010] On the other hand, in the case of mounting a sensor on the bumper to measure directly below the vehicle, when the vehicle jolts, although the variation in the distance from the tire to the road surface measurement position is smaller than that in Patent Document 1, an error also occurs in the same manner.

[0011] The present invention has been made in view of the above actual situation, and an object thereof is to provide a vehicle that reduces the error in the change in the distance between the road surface measurement point and the tire and improves controllability.

[0012] To solve the above problems, a vehicle according to a first aspect of the present invention includes: a vehicle body; front wheels and rear wheels that move the vehicle body; and a road surface state detection mechanism that detects the road surface state in front of the front wheels. The road surface state detection mechanism is located in front of the front wheels, and the irradiation direction of the road surface state detection mechanism for detecting a measurement point on the road surface is inclined toward the tangent direction of the measurement point on an arc. This arc is an arc passing through the measurement point centered on the pitching center of the vehicle body when the vehicle body is viewed from the side.

[0013] A vehicle according to a second aspect of the present invention includes: a vehicle body; front wheels and rear wheels that move the vehicle body; and a road surface state detection mechanism that detects the road surface state in front of the rear wheels. The road surface state detection mechanism is located in front of the rear wheels, and the irradiation direction of the road surface state detection mechanism for detecting a measurement point on the road surface is inclined toward the tangent direction of the measurement point on an arc. This arc is an arc passing through the measurement point centered on the pitching center of the vehicle body when the vehicle body is viewed from the side.

[0014] Advantages of the Invention

[0015] According to the present invention, it is possible to provide a vehicle that reduces the error in the distance change between the road surface measurement point and the tire and improves controllability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1A is a conceptual side view of a vehicle according to an embodiment of the present invention.

[0017] Figure 1B is a perspective view of the vehicle according to the embodiment.

[0018] Figure 2 is a conceptual side view showing the positional relationship among the pitching center, the front wheels, and the measurement point of the prediction sensor on the road surface of the vehicle according to the embodiment.

[0019] Figure 3A is a conceptual side view showing the relationship between the vehicle equipped with the prediction sensor of Comparative Example 1 and the measurement point detected by the road surface state detection sensor on the road surface.

[0020] Figure 3B is a conceptual side view showing the variation of the measurement point detected by the road surface state detection sensor on the road surface when the vehicle of Comparative Example 1 pitches.

[0021] Figure 4 is a conceptual side view showing the relationship between the vehicle equipped with the prediction sensor of Comparative Example 2 and the measurement point detected by the road surface state detection sensor on the road surface.

[0022] Figure 5AIt is a conceptual side view showing the variation of the measurement points detected by the prediction sensor on the road surface in the case of vehicle bumpiness in Comparative Example 2.

[0023] Figure 5B It represents Comparative Example 2 Figure 5A An enlarged side view of the positional relationship between the measurement point in and the front wheel.

[0024] Figure 6A It is a conceptual side view of the vehicle in the Embodiment bumping around the bump center.

[0025] Figure 6B It is a conceptual side view of the positional relationship between the bump center, the front wheel and the measurement point of the prediction sensor when the vehicle bumps.

[0026] Figure 7A It is a conceptual side view of the vehicle climbing on an uphill road surface.

[0027] Figure 7B It is a conceptual side view of the positional relationship between the bump center, the front wheel and the measurement point of the prediction sensor when the vehicle goes uphill.

[0028] Description of Reference Numerals

[0029] 1 Vehicle

[0030] 1h Body

[0031] 2l Left Front Wheel (Front Wheel)

[0032] 2r Right Front Wheel (Front Wheel)

[0033] 3l Left Rear Wheel (Rear Wheel)

[0034] 3r Right Rear Wheel (Rear Wheel)

[0035] 5f, 5r Prediction Sensor (Road Surface State Detection Mechanism)

[0036] 5s, 5sr Measurement Point

[0037] C Bump Center

[0038] c1, c2 Circular Arc

[0039] c1s, c2s Tangent

[0040] R, Rn Road Surface

[0041] Rb Laser Beam (Irradiation Direction) Detailed Embodiment

[0042] Hereinafter, embodiments of the present invention will be described in detail with appropriate reference to the drawings.

[0043] Figure 1AConceptual side view of the vehicle 1 showing an embodiment of the present invention, Figure 1B Perspective view of the vehicle 1 showing the embodiment.

[0044] The present invention relates to the sensing measurement directions of the prediction sensors 5f, 5r for measuring the road surface state of the vehicle 1. The prediction sensors 5f, 5r use lasers or the like for measurement.

[0045] The vehicle 1 of the embodiment has a right front wheel 2r and a left front wheel 2l as steering wheels for changing the traveling direction of the vehicle 1 in the front. In the rear of the vehicle 1, there are a right rear wheel 3r and a left rear wheel 3l as driven wheels or drive wheels.

[0046] An occupant rides in a vehicle body 1h supported by the wheels 2r, 2l, 3r, 3l of the vehicle 1.

[0047] The vehicle 1 is provided with a headlamp 3h that irradiates the front road surface R in the front, and a rear lamp 3a that irradiates the rear road surface R in the rear. In addition, a front bumper 4f and a rear bumper 4r that absorb the impact of collisions in the front and rear are respectively provided on the vehicle 1.

[0048] As shown in Figure 1B In the vehicle 1, a prediction sensor 5f is provided at a position that overlaps with the right front wheel 2r when viewed from the front. Similarly, in the vehicle 1, a prediction sensor 5f is provided at a position that overlaps with the left front wheel 2l when viewed from the front. The prediction sensors 5f are respectively arranged at overlapping positions that are not misaligned in the vehicle width direction with respect to the front wheels 2r, 2l when viewed from the front. Therefore, the road surface state passed by the front wheels 2r, 2l can be detected more accurately.

[0049] Similarly, in the vehicle 1, a prediction sensor 5r is provided at a position that overlaps with the right rear wheel 3r when viewed from the front. Similarly, in the vehicle 1, a prediction sensor 5r is provided at a position that overlaps with the left rear wheel 3l when viewed from the front. The prediction sensors 5r are respectively arranged at overlapping positions that are not misaligned in the vehicle width direction with respect to the rear wheels 3r, 3l when viewed from the front. Therefore, the road surface state passed by the rear wheels 3r, 3l can be detected more accurately.

[0050] The prediction sensors 5f, 5r use, for example, radar, cameras, laser sensors, and other sensors. The prediction sensors 5f, 5r can be arbitrarily selected as long as they are sensors capable of detecting the road surface state.

[0051] In the present embodiment, a sensor using a laser is taken as an example for the prediction sensors 5f, 5r for explanation.

[0052] The prediction sensors 5f, 5r irradiate laser light rays rb toward the road surface R side as follows in order to detect the state of the road surface R (refer toFigure 1A ) to detect the distance from the road surface (the state of the road surface).

[0053] In Figure 1A In the stationary state of the vehicle 1 shown, there is a bump center c on the vehicle 1 (the vehicle body 1h) relative to the road surface R.

[0054] Figure 2 It is a conceptual side view showing the positional relationship between the bump center c of the vehicle 1 according to the embodiment, the front wheels 2l, 2r, and the measurement points 5s, 5sr of the prediction sensors 5f, 5r on the road surface R.

[0055] With the bump center c of the vehicle 1 as the center, draw an arc c1 passing through the measurement point 5s on the road surface R illuminated by the laser beam rb of the prediction sensor 5f on the road surface R. And draw a tangent c1s passing through the measurement point 5s on the arc c1.

[0056] In this way, in the stationary state of the vehicle 1, set the irradiation direction of the laser beam rb to the direction of the tangent c1s of the measurement point 5s on the arc c1.

[0057] In other words, in Figure 1A In the stationary state of the vehicle 1 shown, make the irradiation direction of the laser beam rb of the prediction sensor 5f coincide with the direction of the tangent c1s of the measurement point 5s on the arc c1 passing through the measurement point 5s with respect to the bump center c of the vehicle 1.

[0058] That is to say, make the irradiation direction of the laser beam rb of the prediction sensor 5f tilt towards the tangent direction of the measurement point 5s on the arc c1 with the bump center c of the vehicle 1 as the center. In other words, the irradiation direction of the laser beam rb of the prediction sensor 5f coincides with the direction of the tangent c1s of the measurement point 5s on the arc c1 with the bump center c of the vehicle 1 as the center.

[0059] Thereby, the vehicle 1 sets the irradiation direction of the laser beam rb for detecting the state of the road surface R to the tangent direction of the measurement point 5s on the arc c1 with the bump center c as the center, to detect the state of the road surface R.

[0060] With the bump center c of the vehicle 1 as the center, draw an arc c2 passing through the measurement point 5sr on the road surface R illuminated by the laser beam rb of the prediction sensor 5r on the road surface R. And draw a tangent c2s passing through the measurement point 5sr on the arc c2.

[0061] In this way, in the stationary state of the vehicle 1, set the irradiation direction of the laser beam rb to the direction of the tangent c2s of the measurement point 5sr on the arc c2.

[0062] In other words, inFigure 1A In the stationary state of the vehicle 1 shown, the irradiation direction of the laser beam rb of the prediction sensor 5r is made to coincide with the direction of the tangent c2s of the measurement point 5sr on the circular arc c2 passing through the measurement point 5sr with respect to the bump center c of the vehicle 1.

[0063] That is, the irradiation direction of the laser beam rb of the prediction sensor 5r is inclined toward the tangent direction of the measurement point 5sr on the circular arc c2 centered on the bump center c of the vehicle 1. In other words, the irradiation direction of the laser beam rb of the prediction sensor 5r coincides with the direction of the tangent c2s of the measurement point 5sr on the circular arc c2 centered on the bump center c of the vehicle 1.

[0064] Thereby, the vehicle 1 sets the irradiation direction of the laser beam rb for detecting the state of the road surface R to the tangent direction of the measurement point 5sr on the circular arc c2 centered on the bump center c, and detects the state of the road surface R.

[0065] Here, the rear prediction sensor 5r is measured by the same method as the front prediction sensor 5f. Therefore, the following describes the prediction sensor 5f, and the description of the prediction sensor 5r is omitted.

[0066] Next, Comparative Examples 1 and 2 will be described.

[0067] <Conceptual side view showing the relationship between the vehicle 101 of Comparative Example 1 ( Figure 3A , Figure 3B ) and the measurement point up to the measurement position on the road surface from the front wheels during bumping>

[0068] Figure 3A is a conceptual side view showing the relationship between the vehicle 101 equipped with the road surface state detection sensor 105 of Comparative Example 1 and the measurement point r0 detected by the road surface state detection sensor 105 on the road surface R. Figure 3B is a conceptual side view showing the change of the measurement point r0 detected by the road surface state detection sensor 105 on the road surface R when the vehicle 101 of Comparative Example 1 bumps.

[0069] As Figure 3A shown, the vehicle 101 of Comparative Example 1 is equipped with the road surface state detection sensor 105 above the windshield 101a.

[0070] The vehicle 101 sets the measurement point r0 detected by the road surface state detection sensor 105 on the stationary road surface R. The road surface state detection sensor 105 measures the measurement point r0 on the road surface R in front of the vehicle 101 by the laser beam rb and detects the road surface state.

[0071] In this case, the distance from the front wheels 102r, 102l to the measurement point r0 of the road surface measurement position is s0.

[0072] As Figure 3B shown, since the vehicle 101 jolts around the jolting center 101c, the measurement point r0 detected by the road surface state detection sensor 105 on the road surface R varies between the measurement point r1 and the measurement point r2. Accordingly, the distance s1 from the front wheels 102r, 102l to the measurement point r1 of the road surface measurement position and the distance s2 to the measurement point r2 vary.

[0073] Therefore, in order to accurately control by detecting the road surface state, it is necessary to correct the difference between the distance s1 from the front wheels 102r, 102l to the measurement point r1 of the road surface measurement position and the distance s2 to the measurement point r2 with respect to the distance s0 at the measurement point r0.

[0074] <Vehicle 201 of Comparative Example 2 ( Figure 4 , Figure 5A , Figure 5B ) Variation in the distance from the front wheels to the measurement point of the road surface measurement position during jolting>

[0075] Figure 4 is a conceptual side view showing the relationship between the vehicle 201 equipped with the road surface state detection sensor 205 of Comparative Example 2 and the measurement point r10 on the road surface R detected by the road surface state detection sensor 205.

[0076] In the vehicle 201 of Comparative Example 2, the road surface state detection sensor 205 is mounted on the front bumper 204f and measures the road surface R directly below.

[0077] The road surface state detection sensor 205 is set to measure the measurement point r10 on the road surface R directly below the vehicle 201 by the laser beam rb.

[0078] Figure 5A is a conceptual side view showing the variation of the measurement point r10 detected by the road surface state detection sensor 205 on the road surface R when the vehicle 201 of Comparative Example 2 jolts, Figure 5B is a side view showing the Figure 5A positional relationship between the measurement points r11, r12 and the front wheels 202r, 202l in Comparative Example 2.

[0079] As Figure 5A shown, since the vehicle 201 of Comparative Example 2 jolts around the jolting center 201c, as Figure 5BAs shown, the measurement point r10 detected by the road surface state detection sensor 205 in the stationary state on the road surface R varies between the measurement points r11 and r12. Thus, the distance s10 from the front wheels 202r and 202l to the measurement point r10 of the road surface measurement position varies between the distance s11 from the measurement point r11 and the distance s12 from the measurement point r12.

[0080] Therefore, in order to accurately control the detection of the road surface state, it is necessary to correct the difference between the distance s11 from the front wheels 202r and 202l to the measurement point r11 of the road surface measurement position and the distance s12 from the measurement point r12 to the distance s10 at the measurement point r10.

[0081] <Change in distance from the front wheels 2r and 2l to the measurement point when the vehicle 1 in the embodiment jolts>

[0082] Compared with the above Comparative Examples 1 and 2, in the vehicle 1 of the embodiment, as Figure 2 shown, the irradiation direction of the laser beam rb when acquiring the state information of the road surface R from the prediction sensor 5f is made to coincide with the direction of the tangent c1s of the measurement point 5s on the circular arc c1 centered on the jolting center c of the vehicle 1 when observing the stationary vehicle 1 (body 1h) from the side. In other words, the irradiation direction of the laser beam rb of the prediction sensor 5f is perpendicular to the straight line connecting the measurement point 5s on the circular arc centered on the jolting center c of the vehicle 1 and the jolting center c ( Figure 2 the thick single-dot chain line).

[0083] As Figure 1A 、 Figure 1B shown, the prediction sensor 5f is installed in front of the front wheels 2r and 2l at a position where the vehicle 1 is observed from the front and overlaps with the front wheels 2r and 2l of the body 1h.

[0084] Figure 6A is a conceptual side view when the vehicle 1 of the embodiment jolts around the jolting center c, Figure 6B a conceptual side view showing the positional relationship between the jolting center c, the front wheels 2r and 2l, and the measurement point 5s of the prediction sensor 5f when the vehicle 1 jolts.

[0085] As Figure 6A shown, when the vehicle 1 jolts according to the state of the road surface R, the body 1h jolts around the jolting center c. The prediction sensor 5f installed on the body 1h also jolts around the jolting center c.

[0086] For example, as Figure 6BAs shown, when the road surface R changes to the road surface R1 with the front part lowered relative to the vehicle body 1h, the measurement point 5s changes to the position of the measurement point 5s1 on the road surface R1. At this time, the prediction sensor 5f rotates downward around the bump center c and moves toward the position of the prediction sensor 5a. At this time, since the front wheels 2r and 2l bump around the bump center c, the distances between the front wheels 2r and 2l and the bump center c do not change.

[0087] In this way, when the entire vehicle 1 bumps in a manner that lowers the front part around the bump center c, the change of the position of the measurement point 5s1 on the road surface R1 after the measurement point 5s of the road surface R moves due to the bump relative to the circular arc c1 centered on the bump center c is extremely small.

[0088] Similarly, when the road surface R changes to the road surface R2 with the front part rising relative to the vehicle body 1h, the measurement point 5s changes to the position of the measurement point 5s2 on the road surface R2. At this time, the prediction sensor 5f rotates upward around the bump center c and moves toward the position of the prediction sensor 5b. At this time, since the front wheels 2r and 2l bump in a manner that raises them around the bump center c, the distances between the front wheels 2r and 2l and the bump center c remain unchanged.

[0089] In this way, even when the entire vehicle 1 bumps in a manner that raises the front part around the bump center c, the change of the position of the measurement point 5s2 on the road surface R2 after the measurement point 5s of the road surface R moves due to the bump relative to the circular arc c1 centered on the bump center c is also extremely small.

[0090] Figure 7A is a conceptual side view of the state where the vehicle 1 climbs on the uphill road surface Rn, Figure 7B is a conceptual side view of the positional relationship among the bump center c, the front wheels 2r and 2l, and the measurement point 5s of the prediction sensor 5f when the vehicle 1 climbs on the uphill road surface Rn.

[0091] As Figure 7A shown, when the vehicle 1 climbs on the uphill road surface Rn, as Figure 7B shown, the prediction sensor 5f (refer to Figure 1A , Figure 1B ) installed on the vehicle body 1h on the flat road surface R changes to the position of the prediction sensor 5a. The measurement point according to the prediction sensor 5a on the uphill road surface Rn becomes 5s3 (refer to Figure 7B ). In the case of the uphill road surface Rn, the vehicle 1 has a tendency for the front part to rise.

[0092] In this case, as Figure 7BAs shown, for the measurement point 5s of the prediction sensor 5f on the flat road surface R and the measurement point 5s3 of the prediction sensor 5a on the uphill road surface Rn, the positional relationship between the bump center c of the vehicle body 1h and the front wheels (2r, 2l) hardly changes.

[0093] In the case of a downhill road surface, compared with Figure 7B Similarly, for the measurement point of the prediction sensor 5f on the downhill road surface and the measurement point 5s of the prediction sensor 5f on the flat road surface R, the positional relationship between the bump center c of the vehicle body 1h and the front wheels (2r, 2l) hardly changes.

[0094] When the vehicle 1 travels on an inclined road surface, although there is a forward rising or forward lowering of the vehicle 1, similar to the flat road, the positional relationship from the measurement point 5s3 of the forward rising road surface Rn to the front wheels 2r, 2l hardly changes.

[0095] Based on the above, compared with Figure 3B the comparative example 1 shown and Figure 5B the comparative example 2 shown, when the vehicle 1 of the embodiment bumps, the positional relationship between the measurement points 5s (5s1, 5s2) and the front wheels 2r, 2l hardly changes.

[0096] According to the above configuration, as shown in FIG. 1, Figure 2 the irradiation direction of the prediction sensor 5f conforms to the tangential direction of the measurement point 5s on the circular arc c1 centered on the bump center c of the vehicle 1.

[0097] Therefore, as Figure 7A , Figure 7B shown, when the vehicle 1 bumps and travels on a road surface Rn with a slope, the errors in the distance changes between the measurement points 5s1, 5s2, 5s3 of the road surfaces R, Rn and the front wheels 2r, 2l are small, and the controllability is improved.

[0098] In addition, since there is no need to correct the errors between the measurement points 5s1, 5s2, 5s3 of the road surfaces R, Rn and the front wheels 2r, 2l, the calculation burden is reduced.

[0099] In addition, as shown in FIG. 1, the irradiation direction of the prediction sensor 5r conforms to the tangential direction of the measurement point 5sr on the circular arc c2 centered on the bump center c of the vehicle 1.

[0100] Therefore, similar to Figure 7B the above, when the vehicle 1 bumps and travels on a road surface Rn with a slope, the errors in the distance changes between the measurement points of the road surfaces R, Rn and the rear wheels 3r, 3l are small, and the controllability is improved.

[0101] In addition, since there is no need to correct the error between the measurement points of the road surfaces R and Rn and the rear wheels 3r and 3l, the calculation burden is reduced.

[0102] <<Other Embodiments>>

[0103] 1. The present invention is not limited to the configurations of the above-described embodiments and modified examples, and various modification methods and specific methods can be implemented within the scope of the technical solution.

Claims

1. A vehicle, characterized in that, it has: a vehicle body; front wheels and rear wheels for moving the vehicle body; and a road surface state detection mechanism for detecting the road surface state in front of the front wheels, the road surface state detection mechanism is located in front compared with the front wheels, the irradiation direction of the road surface state detection mechanism for detecting a measurement point on the road surface coincides with the tangent direction of the measurement point on an arc, and the arc is an arc passing through the measurement point centered on the bump center of the vehicle body when observing the vehicle body from the side.

2. The vehicle according to claim 1, characterized in that, the road surface state detection mechanism is provided at a position overlapping with the front wheels when observing the vehicle from the front.

3. A vehicle, characterized in that, it has: a vehicle body; front wheels and rear wheels for moving the vehicle body; and a road surface state detection mechanism for detecting the road surface state in front of the rear wheels, the road surface state detection mechanism is located in front compared with the rear wheels, the irradiation direction of the road surface state detection mechanism for detecting a measurement point on the road surface coincides with the tangent direction of the measurement point on an arc, and the arc is an arc passing through the measurement point centered on the bump center of the vehicle body when observing the vehicle body from the side.

4. The vehicle according to claim 3, characterized in that, the road surface state detection mechanism is provided at a position overlapping with the rear wheels when observing the vehicle from the front.

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