Road projection control device

Abstract

The purpose of the present disclosure is to provide a road projection control device capable of warning both parties for whom there is a possibility of collision. A road projection control device according to the present disclosure comprises: a reception unit that receives a signal from a traffic participant detection unit capable of detecting a first traffic participant and a second traffic participant; a predicted collision location calculation unit that calculates a degree of risk that the first traffic participant and the second traffic participant will collide and a predicted collision location where it is predicted that the first traffic participant and the second traffic participant will collide; a collision possibility determination unit that determines that there is a possibility of collision if the degree of risk is greater than or equal to a predetermined value; and a road projection unit that, when the collision possibility determination unit determines that there is a possibility of collision, gives instructions to project, on the road surface in a location including the predicted collision location, a road projection pattern warning of the collision.

Description

Road surface drawing control device

[0005]

[0001] The present disclosure relates to a road surface drawing control device that controls road surface drawing to notify traffic participants around the host vehicle of the possibility of a collision.

[0002] Conventionally, when the host vehicle approaches an intersection and detects other vehicles waiting for a right turn in the oncoming lane and also detects a following vehicle traveling behind the host vehicle, a technique has been disclosed that uses light irradiation to notify the other vehicle turning right that there is a following vehicle behind the host vehicle (see, for example, Patent Document 1).

[0003] Also, a technique has been disclosed that irradiates an obstacle with light to notify a moving object when it is determined that the moving object has not detected the obstacle (see, for example, Patent Document 2).

[0004] Japanese Patent Application Laid-Open No. 2005-182309 International Publication No. 2016 / 013040

[0005] In Patent Documents 1 and 2, the presence of one party in a blind spot relationship is notified to the other party by light irradiation. However, Patent Documents 1 and 2 do not mention alerting both parties that may collide regardless of the presence or absence of a blind spot relationship, and there is room for improvement.

[0006] The present disclosure has been made to solve such problems, and an object thereof is to provide a road surface drawing control device capable of alerting both parties that may collide.

[0007] To solve the above problems, a road surface drawing control device according to the present disclosure includes a receiving unit that receives a signal from a traffic participant detection unit capable of detecting a first traffic participant and a second traffic participant, a risk degree of collision between the first traffic participant and the second traffic participant, and a collision prediction position calculation unit that calculates a collision prediction position where it is predicted that the first traffic participant and the second traffic participant will collide, a collision possibility determination unit that determines that there is a possibility of collision when the risk degree is equal to or greater than a predetermined value, and a road surface drawing unit that, when the collision possibility determination unit determines that there is a possibility of collision, instructs to draw a road surface drawing pattern that alerts to a collision at a position including the collision prediction position.

[0008] This disclosure makes it possible to draw attention to both parties who may be in conflict.

[0009] The purposes, features, aspects, and advantages of this disclosure will become more apparent from the following detailed description and accompanying drawings.

[0010] This is a block diagram showing an example of the configuration of a road surface drawing control device according to Embodiment 1. This is a flowchart showing an example of the operation of a road surface drawing control device according to Embodiment 1. This is a diagram for explaining the collision prediction position and risk level according to Embodiment 1. This is a diagram showing an example of the risk level evaluation function according to Embodiment 1. This is a diagram showing an example of road surface drawing according to Embodiment 1. This is a diagram showing an example of road surface drawing according to Embodiment 1. This is a flowchart showing an example of the operation of a road surface drawing control device according to Modification 4 of Embodiment 1. This is a diagram for explaining the operation of a road surface drawing control device according to Modification 5 of Embodiment 1. This is a diagram for explaining the operation of a road surface drawing control device according to Modification 5 of Embodiment 1. This is a flowchart showing an example of the operation of a road surface drawing control device according to Embodiment 2. This is a diagram showing an example of road surface drawing according to Embodiment 2. This is a diagram showing an example of a road surface drawing pattern according to Modification 1 of Embodiment 2. This is a diagram showing an example of a road surface drawing pattern according to Modification 1 of Embodiment 2. This is a diagram showing an example of a road surface drawing pattern according to Modification 1 of Embodiment 2. This is a diagram showing an example of a road surface drawing pattern according to Modification 1 of Embodiment 2. This is a diagram showing an example of a road surface drawing pattern according to Modification 1 of Embodiment 2. This is a diagram showing an example of a road surface drawing pattern according to Modification 1 of Embodiment 2. This is a diagram showing an example of a road surface drawing pattern according to Modification 1 of Embodiment 2. This is a diagram showing an example of a road surface drawing pattern according to Modification 1 of Embodiment 2. This is a diagram showing an example of a road surface drawing pattern according to Modification 1 of Embodiment 2. This is a diagram showing an example of a road surface drawing pattern according to Modification 1 of Embodiment 2. This is a diagram showing an example of a road surface drawing pattern according to Modification 1 of Embodiment 2. This is a diagram showing an example of a road surface drawing pattern according to Modification 1 of Embodiment 2. This is a diagram showing an example of a road surface drawing according to Modification 3 of Embodiment 2. This is a diagram showing an example of a road surface drawing according to Modification 4 of Embodiment 2. This is a diagram showing an example of a road surface drawing according to Modification 5 of Embodiment 2. This is a flowchart showing an example of the operation of the road surface drawing control device according to Embodiment 3. This is a diagram showing an example of a road surface drawing according to Embodiment 3. This is a diagram showing an example of the hardware configuration of the road surface drawing control device according to Embodiments 1 to 3. This is a diagram showing an example of the hardware configuration of the road surface drawing control device according to Embodiments 1 to 3.

[0011] <Embodiment 1> <Configuration> Figure 1 is a block diagram showing an example of the configuration of a road surface drawing control device 1 according to Embodiment 1. The road surface drawing control device 1 comprises a receiving unit 2, a collision prediction position calculation unit 3, a collision possibility determination unit 4, and a road surface drawing unit 5. The road surface drawing control device 1 is also connected to a lighting device 6, a traffic participant detection unit 7, and a vehicle information acquisition unit 8 in a communicative manner. The road surface drawing control device 1 may also be constructed as a system by appropriately combining a PND (Portable Navigation Device) that can be mounted on a vehicle, and a server provided outside the vehicle. In this case, each function or component of the road surface drawing control device 1 is distributed and arranged to each function that makes up the system.

[0012] The traffic participant detection unit 7 detects traffic participant information regarding traffic participants present around the vehicle. This traffic participant information includes, for example, the type of traffic participant, the relative distance, relative position, and relative speed of the traffic participant relative to the vehicle, and the direction of movement of the traffic participant (including the direction indicated by the turn signal). Examples of traffic participant types include four-wheeled vehicles, two-wheeled vehicles, bicycles, and pedestrians.

[0013] The traffic participant detection unit 7 consists of all or some of the cameras, radar, Lidar (Light detection and ranging), ToF (Time of Flight) cameras, and sonar included in the ADAS (Advanced Driver Assistance System) sensors mounted on the vehicle. The cameras, radar, and sonar are located on the front, rear, and sides of the vehicle, respectively. The Lidar is located on the front and rear of the vehicle, respectively.

[0014] The vehicle information acquisition unit 8 acquires vehicle information about the vehicle from the in-vehicle LAN (Local Area Network) or in-vehicle equipment. Examples of vehicle information include driving control information, body system information, location information, and road maps. Driving control information includes information about the vehicle's speed, acceleration, steering, and brakes. Body system information includes turn signal information. Location information includes location information acquired by the positioning device (GNSS: Global Navigation Satellite System).

[0015] The receiving unit 2 receives information about traffic participants from the traffic participant detection unit 7. The receiving unit 2 also receives vehicle information from the vehicle information acquisition unit 8. The receiving unit 2 only needs to receive vehicle information from the vehicle information acquisition unit 8 as needed. In other words, vehicle information is not essential and is used, for example, to supplement traffic participant information.

[0016] The collision prediction position calculation unit 3 extracts two traffic participants around the vehicle based on the traffic participant information received by the receiving unit 2. The collision prediction position calculation unit 3 then calculates the predicted collision position where the predicted travel paths of each traffic participant intersect, and the degree of risk of the two traffic participants colliding, based on the relative distance, relative position, relative speed, and direction of each traffic participant relative to the vehicle. The degree of risk is calculated based on the time difference (collision allowance) until each of the two traffic participants reaches the predicted collision position.

[0017] The collision possibility determination unit 4 determines whether the risk level is above a predetermined value. If the risk level is above a predetermined value, the collision possibility determination unit 4 determines that there is a possibility of collision and outputs an instruction to the road surface drawing unit 5 to draw the road surface.

[0018] If the collision possibility determination unit 4 determines that there is a possibility of collision, the road surface drawing unit 5 instructs the light fixture 6 to draw a road surface drawing pattern that warns of the possibility of collision at the location including the predicted collision position.

[0019] The light fixture 6 is a light fixture with a road surface drawing function and is built into or individually installed in the vehicle's front and rear lights. The light fixture 6 operates according to the instructions (lighting timing, extinguishing timing, lighting pattern) of the road surface drawing unit 5.

[0020] <Operation> Figure 2 is a flowchart showing an example of the operation of the road surface drawing control device 1 according to Embodiment 1.

[0021] In step S11, the receiving unit 2 acquires traffic participant information (relative position and relative speed of traffic participants relative to the vehicle, and direction of movement of traffic participants) from the traffic participant detection unit 7 regarding multiple traffic participants present around the vehicle. The receiving unit 2 also acquires road shape information around the vehicle. Note that the road shape information may be road map information included in the vehicle information acquired from the vehicle information acquisition unit 8, or it may be information included in the traffic participant information acquired from the traffic participant detection unit 7 (for example, information obtained by image processing of images taken by a camera).

[0022] In step S12, the collision prediction position calculation unit 3 calculates the collision prediction position Pc based on the expected travel path of each traffic participant. Then, the collision prediction position calculation unit 3 calculates the degree of risk of collision between the two based on the travel time until each traffic participant reaches the collision prediction position Pc.

[0023] The following explains how to calculate the predicted collision position Pc and the risk level Rc using Figure 3. Figure 3 shows a case where a right-turning vehicle 12 (first traffic participant) is flashing its turn signal and attempting to turn right at an intersection, and a motorcycle 10 (second traffic participant) is attempting to go straight through the intersection without flashing its turn signal. At time t0, the position of the right-turning vehicle 12 is P2 (t0) and its speed is V2, and the position of the motorcycle 10 is P1 (t0) and its speed is V1.

[0024] First, the collision prediction position calculation unit 3 calculates the predicted travel path 13 that the right-turning vehicle 12 is expected to travel and the predicted travel path 11 that the motorcycle 10 is expected to travel. Then, the collision prediction position calculation unit 3 calculates the point (position) where the predicted travel path 13 and the predicted travel path 11 intersect as the collision prediction position Pc.

[0025] Next, the collision prediction position calculation unit 3 calculates the time it takes for each of the right-turning vehicle 12 and the motorcycle 10 to reach the collision prediction position Pc. For the sake of simplicity, we will assume that the speeds of both vehicles remain constant, but various assumptions or models of speed changes may be applied.

[0026] If Tc1, Tc2, L1, and L2 are defined as follows, then Tc1 = L1 / V1 and Tc2 = L2 / V2.

[0027] Tc1: Estimated time required for motorcycle 10 to reach Pc from P1(t0) Tc2: Estimated time required for right-turning vehicle 12 to reach Pc from P2(t0) L1: Path length from P1(t0) to Pc L2: Path length from P2(t0) to Pc

[0028] Here, the collision margin time is defined as Tallow = |Tc1 - Tc2|. The collision prediction position calculation unit 3 calculates the risk level Rc = 1 (maximum) when Tallow < Tth1 (first threshold) and the risk level Rc = 0 (minimum) when Tallow ≥ Tth2 (second threshold). Furthermore, when Tth1 ≤ Tallow < Tth2, the collision prediction position calculation unit 3 calculates by setting "Rc = evaluation function f(Tallow)" such that the risk level Rc increases as Tallow decreases.

[0029] Figure 4 shows an example of an evaluation function for the risk level Rc. In Figure 4, the first threshold Tth1 is 2 seconds and the second threshold Tth2 is 6 seconds. For simplicity of explanation, the collision allowance Tallow was calculated based on the time it takes for the leading edge of the right-turning vehicle 12 and motorcycle 10 to reach the predicted collision position Pc. However, to be precise, the time it takes for the rear of the vehicle to escape from the predicted collision position Pc should also be considered, so the second threshold Tth2 may be changed according to the length of the traffic participant. The length of the traffic participant can be detected by the traffic participant detection unit 7 as traffic participant information. For example, the second threshold Tth2 will be longer for traffic participants with longer vehicle lengths, such as trucks, than for traffic participants with shorter lengths. Alternatively, the collision allowance Tallow may be calculated taking into account the time it takes for the rear of the vehicle to escape from the predicted collision position Pc.

[0030] The evaluation function described above is merely an example, and functions can be used that are tailored to differences in the speed or type of each traffic participant. For example, since the risk of collision increases with speed, the first threshold Tth1 and the second threshold Tth2 may be made longer in proportion to the speed. Also, since the risk of collision is higher when a vehicle collides with a motorcycle or a vehicle collides with a pedestrian than when two vehicles collide, the first threshold Tth1 and the second threshold Tth2 may be made longer. Furthermore, in the case where Tth1 ≤ Tallow < Tth2, the evaluation function for the risk degree Rc is not limited to a straight line, but may use any characteristics such as a monotonically decreasing function or a step-like function.

[0031] Furthermore, the threshold Rth may be varied depending on the speed or type of each traffic participant. For example, the threshold Rth may be set lower the higher the risk of collision.

[0032] Returning to the explanation of Figure 2, in step S13, the collision possibility determination unit 4 determines that there is a "possibility of collision" if the collision risk level Rc is equal to or greater than a predetermined threshold Rth. On the other hand, the collision possibility determination unit 4 determines that there is "no possibility of collision" if the collision risk level Rc is less than a predetermined threshold Rth. Here, the threshold Rth is 0.5 (see Figure 4). In the example in Figure 4, the collision possibility determination unit 4 determines that there is a "possibility of collision" if the collision allowance time Tallow is 4 seconds or less.

[0033] In step S14, the road surface drawing unit 5 determines the road surface drawing position and road surface drawing pattern based on the collision prediction position Pc, with the position of the vehicle as the reference point. Here, the road surface drawing position is assumed to be the collision prediction position Pc.

[0034] In step S15, the road surface drawing unit 5 instructs the light fixture 6 to draw a star mark road surface drawing pattern at the road surface drawing position.

[0035] Figures 5 and 6 show examples of road surface drawing. Figure 5 shows an example of road surface drawing when a vehicle 20 approaches an intersection with its turn signal flashing, intending to turn right, and there is a possibility of collision between a vehicle 21 (first traffic participant) that is also turning right at the intersection and a pedestrian 22 (second traffic participant) that is crossing a crosswalk. The vehicle 20 draws a road surface drawing pattern 23 at the predicted collision position Pc, alerting both the right-turning vehicle 21 and the pedestrian 22. At this time, although the right-turning vehicle 21 and the pedestrian 22 are not in a blind spot relationship, they can drive or walk safely because they are alerted to the possibility of collision.

[0036] Figure 6 shows an example of road surface rendering in a scenario where, as vehicle 20 approaches an intersection with its turn signal flashing to make a right turn, there is a possibility of collision between a vehicle 21 (first traffic participant) also making a right turn at the intersection and a motorcycle 24 (second traffic participant) passing behind and to the side of vehicle 20 and proceeding straight through the intersection. Vehicle 20 renders a road surface rendering pattern 23 at the predicted collision position Pc, alerting both the right-turning vehicle 21 and the motorcycle 24. At this time, the right-turning vehicle 21 and the motorcycle 24 are in a blind spot relationship, and the warning of the possibility of collision allows them to drive safely.

[0037] Thus, in Embodiment 1, the same warning road surface pattern is drawn on the road surface regardless of whether the first traffic participant and the second traffic participant are in a blind spot relationship or not.

[0038] In step S16, the road surface drawing unit 5 instructs the light fixture 6 to finish drawing the road surface.

[0039] In step S17, the road surface drawing control device 1 determines whether at least one of the traffic participants has passed the predicted collision location. If neither of the traffic participants has passed the predicted collision location, the process returns to step S11. On the other hand, if at least one of the traffic participants has passed the predicted collision location, the operation shown in Figure 2 is terminated. At this time, if the lighting device 6 is drawing a road surface drawing pattern, the road surface drawing is terminated.

[0040] <Effects> According to Embodiment 1, regardless of the presence or absence of blind spots, if the risk of collision between the first traffic participant and the second traffic participant is determined to be above a predetermined threshold and therefore "possible to collide," a road surface pattern is drawn on the road surface so that both the first and second traffic participants can see the location where they should pay the most attention (predicted collision location). This makes it possible to draw the attention of both parties who are at risk of collision and to concentrate their attention on them.

[0041] <Modification 1> Although Embodiment 1 does not mention the correspondence between the degree of risk and the form of the road surface drawing pattern, the form of the road surface drawing pattern may be changed according to the degree of risk.

[0042] For example, as the degree of risk increases, a road surface drawing pattern aspect, color tone, size, or animation such as blinking with higher saliency may be adopted.

[0043] <Modification Example 2> In Embodiment 1, a road surface drawing pattern is drawn on the collision prediction position Pc regardless of whether the first traffic participant and the second traffic participant are in a blind spot relationship. In Modification Example 2, in step S12 of FIG. 2, the collision prediction position calculation unit 3 determines whether the first traffic participant and the second traffic participant are in a blind spot relationship. Then, in step S13, when the collision possibility determination unit 4 determines that the first traffic participant and the second traffic participant are in a blind spot relationship and there is a possibility of collision, in step S14, the road surface drawing unit 5 instructs the lamp 6 to perform road surface drawing.

[0044] In Embodiment 1, the road surface drawing pattern is drawn on the road surface in both situations of FIGS. 5 and 6. In Modification Example 2, the road surface drawing pattern is drawn only in the situation of FIG. 6 where the first traffic participant and the second traffic participant are in a blind spot relationship (the road surface drawing pattern is not drawn in the situation of FIG. 5).

[0045] According to Modification Example 2, when the first traffic participant and the second traffic participant are not in a blind spot relationship, there is no annoyance because road surface drawing is not performed, and attention can be called only when they are in a blind spot relationship that truly requires attention.

[0046] Note that whether to perform road surface drawing regardless of the presence or absence of a blind spot relationship as in Embodiment 1, or to perform road surface drawing only when there is a blind spot relationship as in Modification Example 2, may be a configuration that can be arbitrarily set by the user.

[0047] <Modification Example 3> In Modification Example 2, road surface drawing is performed only when the first traffic participant and the second traffic participant are in a blind spot relationship. In Modification Example 3, the road surface drawing pattern is made different when the first traffic participant and the second traffic participant are in a blind spot relationship and when they are not in a blind spot relationship. For example, when they are in a blind spot relationship, a road surface drawing pattern with higher saliency may be drawn on the road surface than when they are not in a blind spot relationship.

[0048] When there is no blind spot relationship, a road surface drawing pattern without an animation effect may be adopted. When there is a blind spot relationship, a road surface drawing pattern such as a blinking animation, a pulsating animation of enlargement and reduction, or a color cycle deformation animation may be adopted. When there is a blind spot relationship that truly requires attention, a road surface drawing pattern with high saliency may be drawn on the road surface to attract attention, and even when there is no blind spot relationship, a certain degree of attention can be drawn.

[0049] The threshold value Rth (see Figure 4) used when judging the possibility of collision may be made different between the case of having a blind spot relationship and the case of not having a blind spot relationship. Specifically, the threshold value Rth in the case of having a blind spot relationship may be made smaller than the threshold value Rth in the case of not having a blind spot relationship. Or, when the threshold value Rth is the same as that in the case of not having a blind spot relationship in the case of having a blind spot relationship, a function with the relationship between the collision margin time and the risk degree shifted to the right so that a longer collision margin time is determined as a risk may be adopted.

[0050] <Modification Example 4> In Embodiment 1, in the situations shown in FIGS. 5 and 6, when there is a possibility of collision between the first traffic participant and the second traffic participant when the host vehicle 20 turns right at an intersection, a road surface drawing pattern is drawn on the road surface. When the host vehicle 20 travels straight through the intersection at a speed approximately equal to the restricted speed in the situations shown in FIGS. 5 and 6, the right-turning vehicle 21 does not start a right-turning operation. However, when the host vehicle 20 decelerates with the intention of yielding the right of way, etc., the right-turning vehicle 21 may start a right-turning operation and thus may collide with the second traffic participants (pedestrian 22, motorcycle 24).

[0051] In Modification Example 4, when the speed of the host vehicle drops below a predetermined speed, the possibility of collision between the first traffic participant and the second traffic participant is judged in the same manner as in Embodiment 1, and when there is a possibility of collision, a road surface drawing pattern is drawn on the road surface. The situation for drawing the road surface is the same as in FIGS. 5 and 6.

[0052] Figure 7 is a flowchart showing an example of the operation of the road surface drawing control device according to Modification 4. Steps S21 and S23 to S28 in Figure 7 are the same as steps S11 to S17 in Figure 2, so a detailed explanation is omitted here. Step S22 will be described below.

[0053] In step S22, the collision prediction position calculation unit 3 determines whether the vehicle's speed has decreased. The determination of whether the vehicle's speed has decreased can be based on any criteria, but for example, if the vehicle's speed falls to 1 / 3 or less, or if the vehicle's speed falls to 20 km / h or less, it is determined that the vehicle's speed has decreased.

[0054] Furthermore, if a vehicle slows down to allow another vehicle with no priority to pass, even though it has priority, the road surface drawing pattern may be drawn on the road surface. For example, in Figure 6, when vehicle 20 is going straight (vehicle 20 is not flashing its turn signal), the system may determine that the vehicle should slow down if it detects a gesture from the driver of vehicle 20 to yield to another vehicle, regardless of whether the vehicle has priority or not. In addition to gestures from the driver of vehicle 20, the system may also determine that the vehicle should slow down if it detects light communication from the vehicle (flashing its headlights or using its lights to indicate its intention to yield).

[0055] According to Modification 4, it becomes possible to prevent accidents that could occur if the vehicle yields the right of way.

[0056] <Modification 5> In Embodiment 1, the road surface pattern is drawn on the road surface when the vehicle can simultaneously detect both the first and second traffic participants and there is a possibility of a collision between them. In Modification 5, once the vehicle has detected both the first and second traffic participants and determined that there is a possibility of a collision between them, the road surface pattern is drawn on the road surface when it is possible to detect one of them.

[0057] Figures 8 and 9 illustrate the operation of the road surface drawing control device 1 according to Modification 5. As shown in Figures 8 and 9, the vehicle 20 is traveling straight along the main road 26, with a narrow alley 27 on the left, and a following vehicle 25 is traveling behind the vehicle 20. The vehicle 20 is equipped with the road surface drawing control device 1 according to Modification 5.

[0058] In the situation shown in Figure 8, the road surface drawing control device 1 of the vehicle 20 detects a pedestrian 22 entering the main road 26 from the alley 27, and a following vehicle 25. When the road surface drawing control device 1 of the vehicle 20 determines that there is a possibility of collision between the pedestrian 22 and the following vehicle 25, it instructs the light fixture 6 to draw the road surface drawing pattern 23 at the predicted collision position Pc (on the alley 27 side of the main road 26) between the pedestrian 22 and the following vehicle 25 in the situation shown in Figure 9 (a situation where only the following vehicle 25 is detected). The light fixture 6 draws the road surface drawing pattern 23 at the predicted collision position Pc according to the instructions of the road surface drawing control device 1. In this way, the road surface drawing pattern may be drawn even in situations where both the first and second traffic participants are not detected simultaneously. In Figure 9, if the pedestrian mark road surface drawing pattern 29, which will be described in Embodiment 2 later, is used, the following vehicle 25 can recognize that a pedestrian 22 is entering the main road 26 from the alley 27, making it more effective.

[0059] Furthermore, if the road surface drawing control device 1 of the vehicle 20 detects a pedestrian 22 at the same time that a following vehicle 25 is traveling down an alley 28 toward the main road 26, and then the road surface drawing control device 1 of the vehicle 20 detects that the following vehicle 25 has entered the main road 26 as shown in Figure 9, and determines that there is a possibility of a collision between the pedestrian 22 and the following vehicle 25, the road surface drawing pattern 23 may be drawn on the road surface. In other words, the detection timing of the first traffic participant and the detection timing of the second traffic participant do not have to be simultaneous.

[0060] <Embodiment 2> In Embodiment 1, a star mark road surface drawing pattern 23 was drawn on the road surface, but the road surface drawing pattern may be selected depending on the situation. The road surface drawing control device according to Embodiment 2 is the same as the road surface drawing control device 1 according to Embodiment 1.

[0061] Figure 10 is a flowchart illustrating an example of the operation of the road surface drawing control device 1 according to Embodiment 2. Steps S33 and S35 to S37 in Figure 10 are the same as steps S13 and S15 to S17 in Figure 2, so a detailed explanation is omitted here. Steps S31, S32, and S34 will be described below.

[0062] In step S31, the receiving unit 2 acquires traffic participant information and road shape information, similar to the first embodiment. The receiving unit 2 also acquires traffic rule information around its own vehicle. The traffic rule information is used to determine the priority of driving for multiple traffic participants, and may be road signs or road markings detected by the traffic participant detection unit 7 through image recognition, or it may be information about traffic rules included in the road map around the own vehicle acquired by the vehicle information acquisition unit 8.

[0063] In step S32, the collision prediction position calculation unit 3 calculates the collision prediction position Pc and the risk level Rc, similar to the first embodiment. The collision prediction position calculation unit 3 also refers to the traffic rules on the expected route of the first traffic participant and the traffic rules on the expected route of the second traffic participant to determine the priority order indicating which expected route has priority.

[0064] In step S34, the road surface drawing unit 5 determines a road surface drawing position and a road surface drawing pattern based on the collision prediction position Pc, with the position of the vehicle as the reference point. The road surface drawing pattern determined at this time indicates that a higher priority indicates priority driving.

[0065] Figure 11 shows an example of road surface drawing. In Figure 11, when vehicle 20 approaches an intersection with its turn signal flashing to turn right, there is a possibility of collision between a vehicle turning right at the intersection 21 (first traffic participant) and a pedestrian 22 (second traffic participant) crossing a crosswalk. As shown in Figure 11, since the pedestrian 22 has a higher priority than the vehicle turning right 21, vehicle 20 draws a pedestrian mark road surface drawing pattern 29 at the predicted collision position Pc. At this time, the road surface drawing pattern 29 is drawn in a direction that is easily visible to the lower-priority vehicle turning right 21. As a result, the vehicle turning right 21 can understand the presence of the pedestrian 22 and the direction of the pedestrian 22's movement (that the pedestrian 22 is walking towards the crosswalk), and can drive while paying attention to the pedestrian 22. In addition, the pedestrian 22 can pay attention to the vehicle turning right 21, even though their own walking has priority, and it is possible to prevent an accident from occurring.

[0066] <Effects> According to Embodiment 2, in addition to the effects of Embodiment 1, it is possible to inform which of the traffic participants that may collide has priority, thereby making it possible to draw more attention to the non-priority traffic participant.

[0067] <Modification 1> The road surface drawing pattern may be any drawing method, such as shapes (circles, polygons, star marks, warning marks, arrows), letters, or icons (icons indicating the type or direction of traffic participants). Figures 12 to 22 show examples of road surface drawing patterns.

[0068] Figure 12 shows a road surface drawing pattern 23 with star marks. The road surface drawing pattern 23 is a non-directional figure that indicates the predicted collision position Pc and can be seen equally from any direction.

[0069] Figure 13 shows a road surface drawing pattern 30 with two intersecting arrows. The arrows represent the respective directions of movement of the two traffic participants, and the point where the two arrows intersect represents the predicted collision position Pc.

[0070] Figure 14, like Figure 13, shows a road surface drawing pattern 31 in which two arrows intersect. The thick upward-pointing arrows in the figure represent the direction of movement of traffic participants with higher priority.

[0071] Figures 15 and 16 show road surface drawing patterns 32 and 33, which are arrows that gradually widen towards the end. Road surface drawing patterns 32 and 33 represent the direction of movement of traffic participants. Typically, road surface drawing patterns 32 and 33 are configured in such a way that traffic participants with lower priority can distinguish the direction of movement of traffic participants with higher priority.

[0072] Figure 17 shows a road surface drawing pattern 34 for a motorcycle, Figure 18 shows a road surface drawing pattern 35 for an automobile, and Figure 19 shows a road surface drawing pattern 29 for a pedestrian. The road surface drawing pattern 34 is not limited to motorcycles, but can be any two-wheeled vehicle such as a motorbike or bicycle. The road surface drawing pattern 35 is not limited to automobiles, but can be any four-wheeled vehicle such as a light vehicle, regular automobile, or heavy automobile. The road surface drawing patterns 34, 35, and 29 indicate the type of traffic participant. Typically, the road surface drawing patterns 34, 35, and 29 indicate the higher priority of the other party by drawing their type on the road surface for traffic participants with lower priority. For example, in the situation shown in Figure 6, since the motorcycle 24 has high priority, the two-wheeled vehicle road surface drawing pattern 34 may be drawn on the road surface instead of the star pattern road surface drawing pattern 23. In addition, the road surface drawing patterns 34, 35, and 29 may be made by recognizing the color tone or pattern of the traffic participant and assigning a similar color tone or pattern.

[0073] Figure 20 shows a road marking pattern 36 consisting of a stop line and text to prompt one type of traffic participant to stop. It is desirable that the road marking pattern 36 be oriented so that it is visible to the traffic participant who requires attention. Typically, the road marking pattern 36 is drawn for traffic participants with lower priority.

[0074] Figure 21 shows a road surface drawing pattern 37 consisting of a combination of symbols and letters to alert road users.

[0075] Figure 22 shows a road surface drawing pattern 38 in which, for two traffic participants, the one with higher priority is shown a combination of symbols and letters to draw attention, and the one with lower priority is shown a combination of a stop line and letters to encourage stopping, in an easily visible manner.

[0076] <Modification 2> The road surface drawing patterns, including road surface drawing patterns 23, 29, 30-38 shown in Figures 12-22, may be selected to be the most optimal pattern depending on various conditions, and animation effects may be added.

[0077] For example, animations (movement, flashing, color changes, shape changes) may be added depending on the level of risk or urgency. Additionally, the color (green, yellow, and red in that order), flashing frequency (high, low, and normal in that order), and display area may be changed as the level of risk increases.

[0078] <Modification 3> Figure 23 shows an example of road surface drawing according to Modification 3 of Embodiment 2. The vehicle 20 detects a straight-going vehicle 39 and a merging vehicle 40 that is about to merge into the lane in which the straight-going vehicle 39 is traveling. The straight-going vehicle 39 and the merging vehicle 40 are in a blind spot relationship. At the collision prediction position, the vehicle 20 draws an arrow road surface drawing pattern 33 on the road surface to match the direction of travel of the straight-going vehicle 39, which has a higher priority. The driver of the merging vehicle 40 can recognize from which direction the straight-going vehicle 39 is approaching by looking at the road surface drawing pattern 33.

[0079] Figure 24 shows a situation where a merging vehicle 41 is attempting to merge into a lane where a straight-going vehicle 42 is traveling. In this case, since the straight-going vehicle 42 has a higher priority than the merging vehicle 41, the vehicle 20 draws a four-wheel road surface drawing pattern 35 at the collision prediction position so as to match the direction of travel of the straight-going vehicle 42. Alternatively, the vehicle 20 may draw a road surface drawing pattern 33 as shown in Figure 23.

[0080] <Modification 4> Figure 25 shows an example of road surface drawing according to Modification 4 of Embodiment 2. As shown in Figure 25, a pedestrian 22 is about to cross a crosswalk. The vehicle 20 is stopped before the crosswalk and draws a road surface drawing pattern 38 at the predicted collision position between the pedestrian 22 and the vehicle 39 going straight. The vehicle 39 going straight can recognize that the word "STOP" and its shape are drawn on the road surface in a position directly in front of it, and that this is a warning directed at it. The pedestrian 22 can recognize that the word "Caution" and its symbol are drawn on the road surface in a position directly in front of it, and that this is a warning directed at it. In this way, by drawing words and other symbols on the road surface in a way that is easily visible to each traffic participant, it is possible to make it easier to recognize which traffic participant the warning is directed at.

[0081] In the example shown in Figure 25, since pedestrians 22 have a higher priority than vehicles 39 traveling straight, a pedestrian marking pattern 29 may be drawn on the road surface. In this case, the orientation of the road surface drawing pattern 29 should be such that it is easily visible to vehicles 39 traveling straight, which have a lower priority.

[0082] In the example shown in Figure 25, a pedestrian 22 and a vehicle 39 traveling straight are in a blind spot. However, if the vehicle 39 is traveling in the opposite lane of the vehicle 20 towards the pedestrian crossing, the road surface drawing pattern 38 is drawn on the road surface at the predicted collision position between the vehicle 39 and the pedestrian 22. In this case, the orientation of the "STOP" characters and shapes in the road surface drawing pattern 38 should be such that they are easily visible to the vehicle 39 traveling straight.

[0083] In the example shown in Figure 25, if a motorcycle is passing on the left side of the vehicle 20, a road surface drawing pattern 38 is drawn on the road surface at the predicted collision location between the pedestrian 22 and the motorcycle. In this case, the orientation of the "STOP" characters and shapes in the road surface drawing pattern 38 should be such that they are easily visible to the motorcycle.

[0084] <Modification 5> The above explanation has described the case where there are two traffic participants who are likely to collide. However, the road surface drawing pattern may also be drawn when there are three or more traffic participants who are likely to collide (when it is determined that there is a possibility of collision for multiple groups). In this case, the road surface drawing pattern with the highest prominence may be drawn at the collision prediction location with the highest urgency, or the road surface drawing pattern may be drawn only at the collision prediction location with the highest urgency.

[0085] Figure 26 shows an example of road surface drawing according to modification 5 of Embodiment 2. Figure 26 shows an example in which the road surface drawing pattern is drawn only at the collision prediction position with the highest urgency. The vehicle 20 is approaching an intersection with its turn signal flashing, intending to turn right. At this time, there is a possibility of collision between the right-turning vehicle 21, which is also attempting to turn right at the intersection, and the motorcycle 24, which is passing the vehicle 20 from behind and to the side and attempting to go straight through the intersection, at collision prediction position Pc1. Also, there is a possibility of collision between the right-turning vehicle 21 and the pedestrian 22, which is attempting to cross the road, at collision prediction position Pc2. In the example in Figure 26, there is a possibility of collision at collision prediction position Pc1 at an earlier timing than at collision prediction position Pc2. Therefore, the vehicle 20 draws the road surface drawing pattern 34 for a two-wheeled vehicle at collision prediction position Pc1, but does not draw the road surface drawing pattern at collision prediction position Pc2.

[0086] According to variation 5, it becomes possible to direct each traffic participant's attention to the location and situation with the highest level of urgency.

[0087] <Embodiment 3> Embodiments 1 and 2 described a case in which a road surface drawing pattern is drawn on the collision prediction position Pc, assuming that the collision prediction position Pc can be seen by both the first and second traffic participants. Embodiment 3 describes a case in which the position of road surface drawing is shifted when the collision prediction position Pc is not visible to at least one of the first and second traffic participants. The road surface drawing control device according to Embodiment 3 is the same as the road surface drawing control device 1 according to Embodiment 1.

[0088] <Operation> Figure 27 is a flowchart showing an example of the operation of the road surface drawing control device 1 according to Embodiment 3. Steps S41 to S43 in Figure 27 are the same as steps S11 to S13 in Figure 2, step S45 in Figure 27 is the same as step S14 in Figure 2, and steps S47 to S49 in Figure 27 are the same as steps S15 to S17 in Figure 2, so a detailed explanation is omitted here. Steps S44 and S46 will be described below.

[0089] In step S44, the road surface drawing unit 5 determines whether each traffic participant can see the predicted collision location Pc. This determination can be made using image recognition processing. If each traffic participant can see the predicted collision location Pc, the process proceeds to step S45. On the other hand, if each traffic participant cannot see the predicted collision location Pc, the process proceeds to step S46.

[0090] In step S46, the road surface drawing unit 5 determines a shift position Ps that is visible to each traffic participant based on predetermined rules. The road surface drawing unit 5 also determines a road surface drawing pattern to be drawn on the road surface at the shift position Ps. For example, the predetermined rules include setting the shift position Ps to a position on the line connecting the traffic participant's position and the predicted collision position Pc that is visible to the traffic participant and is closest to the predicted collision position Pc.

[0091] Figure 28 shows an example of road surface drawing. In Figure 28, the vehicle 20 is proceeding straight through an intersection. A pedestrian 22 is crossing the road. A motorcycle 24 is passing the vehicle 20 from behind and to the side, attempting to turn left at the intersection. The vehicle 20 determines that there is a possibility of collision between the pedestrian 22 and the motorcycle 24 at the predicted collision position Pc, but the driver of the motorcycle 24 cannot see the predicted collision position Pc because of the obstruction 43. Therefore, the vehicle 20 calculates a shift position Ps that is visible to the motorcycle 24 and draws the road surface drawing pattern 29 at that shift position Ps.

[0092] Ideally, the shift position Ps should be visible to both pedestrians 22 and motorcyclists 24, but if there is no position visible to both, it should be at least visible to the party that should yield (the traffic participant with lower priority).

[0093] In the example shown in Figure 28, the shift position Ps is visible to the pedestrian 22, so no road surface pattern is drawn at the predicted collision position Pc. However, a warning mark road surface pattern 37 may be drawn at the predicted collision position Pc for the pedestrian 22.

[0094] The appearance of the road surface drawing pattern may differ depending on whether the road surface drawing pattern is drawn at the predicted collision position Pc or at the shift position Ps. For example, the road surface drawing pattern drawn at the shift position Ps may be made more noticeable by using a flashing animation.

[0095] <Effects> According to Embodiment 3, even when the predicted collision location cannot be seen by both traffic participants, safety can be contributed to by effectively marking the road surface.

[0096] <Modification 1> Embodiment 3 described a case where the collision prediction position Pc is shifted to the shift position Ps when each traffic participant cannot visually perceive the collision prediction position Pc, but it is not limited to this.

[0097] For example, drawing a road surface pattern on a pedestrian crossing or road markings would result in poor visibility. Therefore, it would be better to avoid such locations and draw the road surface pattern at a shifted position Ps, which is shifted from the predicted collision position Pc towards the traffic participants.

[0098] <Hardware Configuration> In the road surface drawing control device 1 described in Embodiment 1, the functions of the receiving unit 2, collision prediction position calculation unit 3, collision possibility determination unit 4, and road surface drawing unit 5 are realized by processing circuits. Specifically, the road surface drawing control device 1 receives signals from a traffic participant detection unit capable of detecting a first traffic participant and a second traffic participant, calculates the degree of risk of a collision between the first traffic participant and the second traffic participant, and the predicted collision position where the first traffic participant and the second traffic participant are predicted to collide, determines that there is a possibility of a collision if the degree of risk is greater than or equal to a predetermined value, and if it is determined that there is a possibility of a collision, it includes a processing circuit to instruct the road surface to draw a road surface drawing pattern that warns of a collision at the position including the predicted collision position. The processing circuit may be dedicated hardware, or it may be a processor (also called a CPU, central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, or DSP (Digital Signal Processor)) that executes a program stored in memory.

[0099] When the processing circuit is dedicated hardware, as shown in Figure 29, the processing circuit 50 may be, for example, a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or a combination thereof. The functions of the receiving unit 2, the collision prediction position calculation unit 3, the collision possibility determination unit 4, and the road surface drawing unit 5 may each be implemented by a processing circuit 50, or all functions may be implemented together by a single processing circuit 50.

[0100] When the processing circuit 50 is the processor 60 shown in Figure 30, the functions of the receiving unit 2, the collision prediction position calculation unit 3, the collision possibility determination unit 4, and the road surface drawing unit 5 are realized by software, firmware, or a combination of software and firmware. The software or firmware is written as a program and stored in the memory 61. The processor 60 realizes each function by reading and executing the program recorded in the memory 61. That is, the road surface drawing control device 1 includes a memory 61 for storing a program that will ultimately execute the following steps: receiving a signal from a traffic participant detection unit capable of detecting a first traffic participant and a second traffic participant; calculating the degree of risk of a collision between the first traffic participant and the second traffic participant, and the predicted collision position where the first traffic participant and the second traffic participant are predicted to collide; determining that there is a possibility of a collision if the degree of risk is greater than or equal to a predetermined value; and, if it is determined that there is a possibility of a collision, instructing the road surface to draw a road surface drawing pattern that warns of a collision at the position including the predicted collision position. Furthermore, these programs can be said to cause the computer to execute the procedures or methods of the receiving unit 2, the collision prediction position calculation unit 3, the collision possibility determination unit 4, and the road surface drawing unit 5. Here, memory may be, for example, non-volatile or volatile semiconductor memory such as RAM (Random Access Memory), ROM (Read Only Memory), flash memory, EPROM (Erasable Programmable Read Only Memory), EEPROM (Electrically Erasable Programmable Read Only Memory), magnetic disks, flexible disks, optical disks, compact disks, DVDs (Digital Versatile Discs), or any storage medium that may be used in the future.

[0101] Furthermore, some functions of the receiving unit 2, collision prediction position calculation unit 3, collision possibility determination unit 4, and road surface drawing unit 5 may be implemented using dedicated hardware, while other functions are implemented using software or firmware.

[0102] Thus, the processing circuit can realize each of the above-mentioned functions through hardware, software, firmware, or a combination thereof.

[0103] Within the scope of this disclosure, it is possible to freely combine the embodiments, or to modify or omit the embodiments as appropriate.

[0104] Although this disclosure has been described in detail, the above description is illustrative and not limiting in all aspects. It is understood that countless variations not illustrated are possible.

[0105] 1 Road surface drawing control device, 2 Receiving unit, 3 Collision prediction position calculation unit, 4 Collision possibility judgment unit, 5 Road surface drawing unit, 6 Lighting device, 7 Traffic participant detection unit, 8 Vehicle information acquisition unit, 10 Motorcycle, 11 Driving prediction route, 12 Right-turning vehicle, 13 Driving prediction route, 20 Own vehicle, 21 Right-turning vehicle, 22 Pedestrian, 23 Road surface drawing pattern, 24 Motorcycle, 25 Following vehicle, 26 Main road, 27 Alley, 28 Alley, 29 Road surface drawing pattern, 30 Road surface drawing pattern, 31 Road surface drawing pattern, 32 Road surface drawing pattern, 33 Road surface drawing pattern, 34 Road surface drawing pattern, 35 Road surface drawing pattern, 36 Road surface drawing pattern, 37 Road surface drawing pattern, 38 Road surface drawing pattern, 39 Straight-going vehicle, 40 Merging vehicle, 41 Merging vehicle, 42 43. Straight-moving vehicle, 43. Obstacle, 50. Processing circuit, 60. Processor, 61. Memory.

Claims

1. A road surface drawing control device comprising: a receiving unit that receives signals from a traffic participant detection unit capable of detecting a first traffic participant and a second traffic participant; a collision prediction position calculation unit that calculates the degree of risk of collision between the first traffic participant and the second traffic participant, and the predicted collision position where the first traffic participant and the second traffic participant are predicted to collide; a collision possibility determination unit that determines that there is a possibility of collision when the degree of risk is greater than or equal to a predetermined value; and a road surface drawing unit that, when the collision possibility determination unit determines that there is a possibility of collision, instructs the road surface drawing unit to draw a road surface drawing pattern that warns of the collision at a position including the predicted collision position.

2. The road surface drawing control device according to claim 1, wherein the collision prediction position calculation unit determines that the first traffic participant and the second traffic participant are in a blind spot relationship, and the collision possibility determination unit permits the road surface drawing unit to draw the road surface when the blind spot relationship exists.

3. When the predicted path of the vehicle itself intersects with the predicted path of the first traffic participant or the second traffic participant, and the speed of the vehicle itself falls below a predetermined speed, the collision possibility determination unit determines the possibility of a collision, as described in claim 1.

4. The road surface drawing control device according to claim 1, wherein the road surface drawing unit is instructed to draw the road surface drawing pattern indicating which of the first traffic participant or the second traffic participant has a higher priority for driving.

5. The road surface drawing control device according to claim 4, wherein the road surface drawing unit is instructed to draw the road surface drawing pattern indicating the direction of travel of the one with higher priority among the first traffic participant and the second traffic participant.

6. The road surface drawing control device according to claim 4, wherein the road surface drawing unit is instructed to draw the road surface drawing pattern indicating the type of the first traffic participant and the second traffic participant with higher priority.

7. The road surface drawing control device according to claim 1, wherein the road surface drawing unit shifts the position at which it draws the road surface drawing pattern if at least one of the first traffic participant and the second traffic participant cannot see the collision prediction position.

8. The road surface drawing control device according to claim 7, wherein the road surface drawing unit shifts the position in which the road surface drawing pattern is drawn on the road surface to a position visible to the first traffic participant and the second traffic participant, whichever has lower priority.

9. The road surface drawing control device according to claim 1, wherein the collision possibility determination unit determines that there is a possibility of collision for multiple pairs of traffic participants, including the first traffic participant and the second traffic participant, and instructs the road surface drawing unit to draw the road surface drawing pattern on the road surface at a position including the predicted collision position for the pair that was determined to have a possibility of collision earliest.

Images