Collision avoidance device, collision avoidance method, and program

Abstract

To provide a collision avoidance device capable of avoiding a collision even when a plurality of passing vehicles exist.SOLUTION: A collision avoidance device includes: a passing interval estimation section for defining a passing vehicle whose relative distance from an own vehicle is temporally reduced among passing vehicles as an avoidance object, so as to estimate a passing interval between the own vehicle and the avoidance object based on a relative speed vector and relative position vector of the own vehicle with the avoidance object; and a speed vector determination section for determining a speed vector to allow the own vehicle to perform a collision avoidance behavior based on the passing interval.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a collision avoidance device, a collision avoidance method, and a program. [Background technology]

[0002] Collision avoidance technology is important for multiple unmanned aerial vehicles (unmanned aerial vehicles) to fly simultaneously. A common collision avoidance technology, for example, is a method in which a person constantly monitors the separation between unmanned aerial vehicles from the ground, and when the separation between certain unmanned aerial vehicles becomes abnormally small, the person commands at least one or more of the unmanned aerial vehicles from the ground to change their course or speed to avoid a collision. However, if wireless communication between the ground and the unmanned aerial vehicles fails, the method of commanding from the ground by a person does not work.

[0003] Another example of a common technology for collision avoidance is the Traffic Alert and Collision Avoidance System (TCAS) for piloted aircraft (manned air vehicles). TCAS monitors the aircraft's surroundings without relying on ground air traffic control systems, and if there is another aircraft that may cause a mid-air collision, it issues a collision warning and audible instructions to the pilot. However, TCAS is not effective for unmanned air vehicles that do not have pilots.

[0004] Therefore, there is a demand for a technology for automatically avoiding collisions of vehicles, including unmanned vehicles. For example, Patent Document 1 describes a technology for expressing an avoidance trajectory by lines and arcs for an air vehicle to avoid collision (loss of separation) with another air vehicle. Parameters required for determining the lines and arcs (for example, duration or angle value of a turn represented by an arc) must be determined by iterative calculations such as the Newton-Raphson method. In other words, the avoidance trajectory cannot be determined by a simple one-way function. Therefore, the calculation load is high. Furthermore, in the method for determining the avoidance trajectory, when a new object to be avoided appears during the avoidance, the number of lines and arcs representing the avoidance trajectory increases, and the calculation becomes even more enormous.

[0005] Furthermore, Patent Document 2 describes the use of an avoidance command that changes the {heading, climb rate, descent rate, speed}, etc., of the vehicle (aircraft) rather than determining the avoidance trajectory with a line segment or an arc. The avoidance command can be determined by a one-way function, so the calculation load can be reduced compared to Patent Document 1. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 5933244 [Patent Document 2] Patent No. 6272637 Summary of the Invention [Problem to be solved by the invention]

[0007] However, in the conventional technology exemplified by Patent Document 2, it may be difficult to avoid a collision when multiple vehicles are passing by.

[0008] A specific example will be described. In Patent Document 2, when a first aircraft, which is the subject vehicle, and a second aircraft, which is another vehicle, fly within a certain airspace, in order to manage the distance between the first aircraft and the second aircraft, an area in which both the first aircraft and the second aircraft must not be present at the same time is defined by a virtual boundary line (spacing boundary). In addition, a collision prevention module of the first aircraft predicts the closest point of approach between the first aircraft and the second aircraft, and if the range between the first aircraft and the second aircraft at the closest point of approach violates the spacing boundary, an avoidance command is issued to change the flight path of the first aircraft. The collision prevention system also determines the required level of spacing m required , safety level interval m safe , or the interval m between prescribed levels imposed Alternatively, three-dimensional separation perimeter layers may be defined.

[0009] The collision prevention system determines a collision prevention command component C- for each of the separation boundaries. If there are multiple aircraft passing other than the host aircraft, the collision prevention system determines an avoidance command for each of the aircraft other than the host aircraft. Therefore, if the number of separation boundaries is p and the number of passing aircraft is n, there will be n x p collision prevention command components. For simplicity, the explanation will be given assuming the number of separation boundaries to be 1. In this case, the collision prevention command components are {C- 1,1 ,C- 1,2 ,…,C- 1,n} and there are n collision prevention command components. Even if the number of aircraft passing through the avoidance command is n, there is only one each of {heading, climb rate, descent rate, speed} of the own aircraft, so it is not possible to control according to multiple collision prevention command components. One {heading, climb rate, descent rate, speed} of the own aircraft must be determined from multiple avoidance commands. In Patent Document 2, the collision prevention system uses a gain K p,n The collision avoidance command components are weighted and summed to obtain the avoidance command F- control When the number of interval boundaries p is 1, the avoidance command F- control Make a decision.

[0010]

number

[0011] However, the weighted sum is not necessarily appropriate for the purpose of collision prevention. For example, the situation shown in Fig. 12 can be considered. Fig. 12 shows an example in which the own aircraft 90 intersects with a passing aircraft 91 and a passing aircraft 92. The positions of the aircraft 90, 91, and 92 at time t0 are represented by solid triangles P900, P910, and P920. Also, if the aircraft 90, 91, and 92 maintain their original routes 900, 910, and 920, the positions of the aircraft 90, 91, and 92 at time t x The positions of aircraft 90, 91, and 92 are indicated by dashed triangles at position P90. x ,P91 x ,P92 x If the passing aircraft 91 and the passing aircraft 92 maintain their original routes 910 and 920, the collision prevention command component C- 1,1 In the case of the original course 900, the course change to the left on the paper (course 901 changed by θ1) is appropriate. On the changed course 901, at time t x Own aircraft 90 is at position P90 x_1 At this time, the distance between the own aircraft 90 and the passing aircraft 91 is d, and d is a value that does not violate the distance boundaries B90 and B91. Similarly, the collision prevention command component C- 1,2 It would be appropriate to change course to the right on the page (course 902, which is a change of θ2 from the original course 900).

[0012] At this time, the collision avoidance command component C- 1,1 and anti-collision command component C- 1,2 , Gain K 1,1 = 0.5 and gain K 1,2 If we set =0.5 and follow equation (1), the left course change and the right course change cancel each other out, and the original course 900 is maintained as the avoidance command F- controlThis makes it difficult to avoid violating the interval boundary.

[0013] In the example of FIG. 12, the distance d between the own aircraft 90 and the passing aircraft 91, 92 is roughly as shown in FIG. 13 with respect to the course change angle θ from the original course 900. 1,1 (Left turn θ1) and collision prevention command component C- 1,2 Even if the weighted sum of (right lane change θ2) as in equation (1) is used, the "invasion" cannot be avoided. In the situation in Figure 12, as shown in Figure 13, the distance d is not a convex function in the interval [θ1, θ2] for the lane change angle θ, so it is not easy to avoid the "invasion" using a numerical search method.

[0014] An object of the present disclosure is to provide a collision avoidance device, a collision avoidance method, and a program that can avoid a collision even when a plurality of passing vehicles are present. [Means for solving the problem]

[0015] According to one aspect of the present disclosure, a collision avoidance device is a collision avoidance device that avoids a collision between the host vehicle and another passing vehicle, and includes a passing interval estimation unit that specifies, as an avoidance target, a passing vehicle whose relative distance to the host vehicle decreases over time among the passing vehicles, and estimates a passing interval between the host vehicle and the target to be avoided based on a relative speed vector and a relative position vector between the host vehicle and the target to be avoided, and a speed vector determination unit that determines a speed vector that causes the host vehicle to take collision avoidance action based on the passing interval.

[0016] According to one aspect of the present disclosure, a collision avoidance method is a collision avoidance method for avoiding a collision between the own vehicle and another passing vehicle, and includes the steps of: determining, as an avoidance target, a passing vehicle whose relative distance to the own vehicle decreases over time among the passing vehicles; estimating a passing interval between the own vehicle and the target to be avoided based on a relative speed vector and a relative position vector between the own vehicle and the target to be avoided; and determining a speed vector that causes the own vehicle to take collision avoidance action based on the passing interval.

[0017] According to one aspect of the present disclosure, the program causes a collision avoidance device, which avoids a collision of the host vehicle with another passing vehicle, to perform the following steps: designate as an avoidance target a passing vehicle whose relative distance to the host vehicle decreases over time among the passing vehicles; estimate a passing interval between the host vehicle and the target to be avoided based on a relative speed vector and a relative position vector between the host vehicle and the target to be avoided; and determine a speed vector that causes the host vehicle to take collision avoidance action based on the passing interval. Effect of the Invention

[0018] According to the above aspect, collisions can be avoided even when a plurality of passing vehicles are present. [Brief description of the drawings]

[0019] [Figure 1] 1 is a block diagram showing an outline of a functional configuration of a vehicle according to a first embodiment. [Diagram 2] 1 is a block diagram showing a functional configuration of a collision avoidance device according to a first embodiment. [Diagram 3] FIG. 2 is a diagram for explaining a collision avoidance function according to the first embodiment. [Figure 4] FIG. 11 is a block diagram showing a functional configuration of a collision avoidance device according to a second embodiment. [Diagram 5] FIG. 11 is a block diagram showing a functional configuration of a collision avoidance device according to a third embodiment. [Figure 6]FIG. 11 is a first diagram for explaining a collision avoidance function according to the third embodiment. [Figure 7] FIG. 13 is a second diagram for explaining the collision avoidance function according to the third embodiment. [Figure 8] FIG. 13 is a block diagram showing a functional configuration of a collision avoidance device according to a modified example of the third embodiment. [Figure 9] FIG. 13 is a block diagram showing a functional configuration of a collision avoidance device according to a modified example of the fourth embodiment. [Figure 10] FIG. 13 is a diagram for explaining a collision avoidance function according to a fourth embodiment. [Figure 11] 1 is a schematic block diagram illustrating a hardware configuration of a collision avoidance device according to at least one embodiment. [Figure 12] FIG. 1 is a first diagram showing an example of collision prevention processing in the prior art. [Figure 13] FIG. 2 is a second diagram showing an example of collision prevention processing in the prior art. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] <First embodiment> The first embodiment will be described in detail below with reference to FIGS.

[0021] (Vehicle functional configuration) FIG. 1 is a block diagram showing an outline of the functional configuration of a vehicle according to the first embodiment. The vehicle V is, for example, an unmanned autonomous mobile body such as an unmanned underwater vehicle, an unmanned guided vehicle, or an unmanned aerial vehicle, or a manned mobile body such as a ship, an aircraft, or a vehicle. An underwater vehicle is also referred to as an underwater vehicle, a ship as a surface vehicle, a carrier vehicle (vehicle) as a ground vehicle, and an aircraft as an air vehicle. An unmanned mobile body is also referred to as an unmanned vehicle, and a manned mobile body as a manned vehicle.

[0022] In this embodiment, an example in which the vehicle V is an aerial vehicle will be mainly described. Since an aerial vehicle moves in a three-dimensional space, it is suitable for generalizing and explaining vehicle collision avoidance technology. In other embodiments, the technology described below may be applied to an underwater vehicle, or may be applied to a surface vehicle or a land vehicle by, for example, fixing the up and down movement of the vehicle to the ground or water surface.

[0023] As shown in FIG. 1, a vehicle V includes a collision avoidance device 2, a path following control device 3, and a motion control device 4.

[0024] The collision avoidance device 2 is a device for preventing the vehicle V from colliding with another vehicle (hereinafter, also referred to as a "passing vehicle"). The collision avoidance device will be described in detail later.

[0025] The path following control device 3 issues a course command to the motion control device 4 based on a predefined path of the vehicle V and the position of the vehicle V so that the vehicle V moves along the path.

[0026] The motion control device 4 is a control device including, for example, thrusters and a rudder, and adjusts the thrust and rudder of the vehicle V according to the course commanded by the path tracking control device 3.

[0027] (Regarding normal vehicle navigation control) First, the control of normal navigation of the vehicle V will be described. Note that normal navigation control is already known, so only an outline will be described. The vehicle V has a destination, for example, Haneda Airport, and a route to the destination. Even if the navigation of the vehicle V is something like a sightseeing trip to Mt. Fuji, there is a route. The main function of the path following control device 3 is to make the vehicle V follow the route. This function will be called path following control. As shown in Figure 1, the path following function is performed by the path control unit 31 calculating a course command value p· RThe vehicle V outputs the command value. The course is the velocity vector of the translational motion. The motion control device 4 of the vehicle V adjusts the thrust of the thrusters, the rudder, etc. to control the speed and attitude of the vehicle V, thereby making the course of the vehicle V match the course command value. Under normal circumstances, the vehicle V is controlled in this way.

[0028] (Functional configuration of collision avoidance device) The control of the collision avoidance device 2 is performed by determining a course command value for collision avoidance separately and having the motion control device 4 temporarily follow that command value. In other words, when collision avoidance is performed, the original course command value p· R The original route command value output by the path tracking control device 3 is set to the original route p· org When the collision avoidance maneuver begins, the vehicle V deviates from the original path p· org In principle, p· is maintained at the value before the collision avoidance maneuver began. However, for example, there are cases where the vehicle V passes a waypoint on the route during collision avoidance maneuver. When the waypoint is passed, a course change may be performed if the vehicle were traveling normally. Therefore, even during collision avoidance maneuver, when an event occurs that would normally require a course change (such as passing a waypoint), the original course p· is adjusted to the original course p· in response to this course change. org may be modified.

[0029] FIG. 2 is a block diagram showing a functional configuration of the collision avoidance device according to the first embodiment. As shown in FIG. 2, the collision avoidance device 2 includes an avoidance command candidate generating unit 201 , a passing interval estimating unit 202 , an original course storage unit 203 , and a speed vector determining unit 204 .

[0030] The avoidance command candidate generating unit 201 generates an avoidance command candidate group having as elements a plurality of command value candidates for a velocity vector for the vehicle. For example, the avoidance command candidate group is determined by setting a plurality of command value candidates as a table, and the avoidance command candidate generating unit 201 generates the avoidance command candidate group by referring to the table recorded in advance in a storage medium.

[0031] The passing interval estimation unit 202 estimates a passing interval between the own vehicle and the avoidance target based on the relative speed vector and the relative position vector between the own vehicle and the avoidance target when the own vehicle performs a collision avoidance maneuver based on the position vector and speed vector of the own vehicle at the current time, a group of relative position vectors between the own vehicle and the passing vehicles at the current time, and a group of relative speed vectors between the own vehicle and the passing vehicles that are determined depending on the avoidance command candidate group. Details will be described later.

[0032] The original path memory unit 203 stores the path command value p· R Alternatively, the velocity vector p· of the own vehicle is stored as the original velocity vector.

[0033] The speed vector determination unit 204 determines, based on the passing interval, a passing vehicle whose relative distance to the vehicle decreases over time as an avoidance target, and determines a speed vector that allows the vehicle to avoid collision with the avoidance target. Specifically, the speed vector determination unit 204 determines, from the avoidance command candidate group, an element that makes the passing interval larger than a specified value and that minimizes the norm of the error between the original speed vector and the speed vector command value candidate, as the best avoidance command for collision avoidance of the vehicle. The speed vector determination unit 204 determines the speed vector based on the determined best avoidance command.

[0034] The speed vector determination unit 204 outputs the determined speed vector as a speed command value to the motion control device 4. Furthermore, the motion control device 4 steers the vehicle based on the speed command, so that the vehicle automatically avoids passing vehicles. Note that in other embodiments, the driver may control the motion control device 4 while checking the speed command value output by the speed vector determination unit 204.

[0035] (About collision avoidance function) FIG. 3 is a diagram for explaining the collision avoidance function according to the first embodiment. The function for avoiding a collision between the vehicle V and a passing vehicle Vi will be described in detail with reference to FIG. 3. The current time is t=t0. In FIG. 3, at t=t0, the vehicle V is at a position p and a speed p·, and a passing vehicle Vi is at a position q i , speed q i represents the uniform motion of each vehicle. Position and velocity are vector quantities. The origin of position is O. The position and velocity of each vehicle are expressed in Cartesian coordinates. {e1,e2,e3} are the bases of the Cartesian coordinates. Note that e3 is taken to be vertically upwards.

[0036] In addition, the origin O of the position may be the current position p of the vehicle V. The position of the passing vehicle Vi is q relative to the vehicle V. i The position p and velocity vector p of the vehicle V can be measured by a sensor mounted on the vehicle V. The position q of a passing vehicle Vi i and the velocity vector q i For example, if the vehicle is an aircraft, the vehicle position information may be obtained from the passing vehicle Vi by a communication means such as Automatic Dependent Surveillance Broadcast (ADS-B). Also, the vehicle V may measure the relative position and relative speed of the passing vehicle Vi by a radar of the vehicle V.

[0037] The path T_Vi of a traveling vehicle Vi is the current position q of the traveling vehicle Vi. i and the velocity vector q iThe path T_V of the vehicle V can be predicted as a straight line determined by the current position p and velocity vector p· of the vehicle V. When the velocity vector of the vehicle V is p·, the passing interval d(p·,p,q· i ,q) is a one-way function as shown in equation (2). d is a non-negative real number. The relative position vector (q i -p) and the relative velocity vector (q· i -p·) are parallel, i.e. (q· i -p )×(q i -If p)=0, then d is 0.

[0038]

number

[0039] In equation (2), the symbol × is the cross product (vector product) operator. The symbol 〇 is used for the inner product (scalar product) operator to distinguish it from the time derivative ·. If the speed vector of the vehicle V is p·, then the vehicle V's course is determined according to p·, and the passing intervals for all passing vehicles Vi from 1 to n (i.e., a group of passing vehicles) can be calculated according to the vehicle V's course. From the perspective of collision avoidance, the minimum value among the n is important in determining whether the speed vector p· is good or bad. To be selected, the passing intervals for all passing vehicles Vi from 1 to n must be within the specified interval d imposed It has to be bigger.

[0040] Furthermore, the passing related to equation (2) will occur in the future (i.e., t x ≧t0) and those that have already passed each other (i.e. t xThe avoidance command should be determined from those for the former, distinguishing it from <t0). To determine whether the passing vehicle will overtake the host vehicle or has already overtaken it, check as follows. If the passing vehicle will overtake the host vehicle in the future, the host vehicle and the passing vehicle should be approaching, and for approaching objects, the sign of the inner product (scalar product) of the relative position vector and the relative velocity vector is negative. Using this, it is possible to select vehicles that will overtake (i.e., at t x ≥ t0) from the passing vehicle group.

[0041] The position, velocity values of the host vehicle and the passing vehicle are given and cannot be changed for the avoidance maneuvers to be performed hereafter. The only thing that can be changed is the velocity vector p· of the host vehicle. In this embodiment, the value of the velocity vector is selected from the group of avoidance command candidates {C j p·} (j = 1, 2, …, m) output by the avoidance command candidate generation unit 201. C j p· represents the value of the velocity vector obtained by changing the value of the current velocity vector p· of the host vehicle according to the j-th avoidance command C j .

[0042] FIG. B is a diagram showing an example of avoidance command candidates according to the first embodiment. The avoidance command candidates are determined, for example, in a table as shown in FIG. B. Let the number of avoidance commands be m. In the example of FIG. B, there are 45 candidates, so the value of m is 45. For example, based on the table in FIG. B, avoidance commands in the left-right direction may be generated. The route change angle of number 23 is 0 degrees. This indicates that the original route is maintained in the left-right direction. The candidates may be set to be denser closer to the original route and sparser farther from the original route. Also, this table may be applied in the up-down direction. If the same table is used for route changes in the up-down direction, the number of candidates increases to 45 × 45 = 2025. However, since the upper and lower angles are limited to about 20 degrees, the number of candidates may be reduced accordingly. The calculation in this embodiment is a one-way function, and since iterative calculations such as the Newton method are not required, even if the number of candidates is several thousand, it has little impact on the calculation load.

[0043] In equation (2), p· is C j Substituting p·, the jth avoidance command is C j The passing interval estimation unit 202 evaluates the passing intervals from the passing vehicle 1 to the passing vehicle n, and calculates the n passing intervals and a predetermined prescribed interval d imposed The minimum difference between the jth avoidance command C j This is expressed mathematically as formula (3).

[0044]

number

[0045] Using equations (3) and (4), the speed vector determination unit 204 determines the speed vector (t x ≧t0) Passing vehicles are avoided, and the passing interval and the specified interval d imposed The difference between the two is positive, and the velocity vector p· org The best avoidance command is selected as the one with the smallest difference between j and * is an index pointing to the best avoidance command.

[0046]

number

[0047] Then, the speed vector determination unit 204 calculates the speed vector according to the best avoidance command as shown in equation (5) by the command value p· ref Let us assume that.

[0048]

number

[0049] The collision avoidance device 2 periodically inputs the positions and velocities of the vehicle and passing vehicles, for example, several times per second, and calculates a command value p·ref The vehicle updates the velocity vector command value p· ref Since the speed vector p follows the command value p of the speed vector with a delay of several seconds, the instantaneous values ​​are compared. ref However, after a few seconds, p = p ref Based on the current position and speed, the command value p ref If we keep updating p·=p· ref At this point, the collision is avoided.

[0050] The speed vector determination unit 204 may perform the above calculation only when it recognizes the presence of a passing vehicle. If there is no passing vehicle and there is no need to avoid a collision, or if a collision has already been avoided by a collision avoidance maneuver, p·=p· ref Therefore, collision avoidance maneuvers do not affect the operation of the vehicle.

[0051] (Action, effect) As described above, the collision avoidance device 2 of this embodiment is equipped with a passing interval estimation unit 202 that treats as an avoidance target a passing vehicle whose relative distance to the own vehicle decreases over time, and estimates the passing interval between the own vehicle and the target to be avoided based on the relative speed vector and relative position vector between the own vehicle and the target to be avoided, and a speed vector determination unit 204 that determines a speed vector that allows the own vehicle to avoid collision with the target to be avoided based on the passing interval.

[0052] In this way, even when there are a plurality of passing vehicles, the collision avoidance device 2 can steer the vehicle so as to be able to avoid collision with all of the passing vehicles.

[0053] In addition, the passing interval estimation unit 202 estimates the passing interval with a target to be avoided by performing a cross product operation and an inner product operation represented by ((relative speed vector × (relative speed vector × relative position vector)) × relative position vector) ÷ | relative speed vector × (relative speed vector × relative position vector) |, where the operator of the cross product is ×, the operator of the inner product is 〇, and the operator of the norm is | |, and determines a passing vehicle to be avoided as a target if the sign of the inner product of the relative position vector and the relative speed vector is negative.

[0054] In this manner, the collision avoidance device 2 can set only a passing vehicle approaching the own vehicle as a target for avoidance among a plurality of passing vehicles.

[0055] The collision avoidance device 2 further includes an original course storage unit 203 that stores an original speed vector of the vehicle before collision avoidance is started. The passing interval estimation unit 202 estimates a passing interval group between the vehicle and a passing vehicle for each element based on the position vector and speed vector of the vehicle at the current time, a relative position vector group with a passing vehicle (avoidance target) at the current time, and a relative speed vector group with the passing vehicle determined depending on the avoidance command candidate group. The speed vector determination unit 204 has an avoidance command determination unit that determines an element that makes the passing interval larger than a specified value based on the passing interval group and that minimizes the norm of the error between the original speed vector and a command value candidate of the speed vector as the best avoidance command for the vehicle, and determines a speed vector for collision avoidance based on the determined best avoidance command.

[0056] In this way, the collision avoidance device 2 can avoid all avoidance targets and minimize deviation from the original course. In other words, it is possible to reduce the effects of increasing travel distance and travel time due to collision avoidance.

[0057] <Second embodiment> Next, a second embodiment will be described with reference to Fig. 4. Components common to the above-mentioned embodiment will be given the same reference numerals and detailed description will be omitted.

[0058] Aircraft routes are stripes with vertical separation of 1000 feet (approximately 300 m) and horizontal separation of 14 nautical miles (approximately 14.4 km). From the perspective of keeping aircraft on route, it is desirable to perform collision avoidance horizontally within the route.

[0059] Therefore, in this embodiment, if a passing vehicle is far away, the risk of collision is not imminent, so route maintenance is prioritized by limiting avoidance commands to a predefined first steering direction (e.g., horizontal direction), and when a passing vehicle approaches, a function is added to prioritize collision avoidance by allowing avoidance commands in a second steering direction (e.g., vertical direction) instead of or in addition to the first steering direction.

[0060] FIG. 4 is a block diagram showing a functional configuration of a collision avoidance device according to the second embodiment. 4, the collision avoidance device 2 has a first functional unit 20A that prioritizes course maintenance and a second functional unit 20B that prioritizes collision avoidance. The collision avoidance device 2 further includes a switching unit 205 that switches the command value to be output to the motion control device 4 between the command values ​​of the velocity vector for collision avoidance determined by the first functional unit 20A and the second functional unit 20B.

[0061] The first functional unit 20A has a first avoidance command candidate generating unit 201A, a first passing interval estimating unit 202A, and a first speed vector determining unit 204A. The first avoidance command candidate generating unit 201A generates a first avoidance command candidate group limited to only avoidance commands of a predefined first steering direction. In this embodiment, an example in which the first steering direction is the horizontal direction will be described. The functions of the first passing interval estimating unit 202A and the first speed vector determining unit 204A are the same as the functions of the passing interval estimating unit 202 and the speed vector determining unit 204 in the first embodiment.

[0062] The second functional unit 20B has a second avoidance command candidate generating unit 201B, a second passing interval estimating unit 202B, and a second speed vector determining unit 204B.

[0063] The second avoidance command candidate generating unit 201B generates a second avoidance command candidate group including an avoidance command in a second steering direction different from the first steering direction. In this embodiment, the second avoidance command candidate generating unit 201B generates m2 second avoidance command candidates that change the command value of the vehicle in the up-down direction (vertical direction), the left-right direction (horizontal direction), and the front-rear direction without limiting the steering direction. The second avoidance command candidates (j=1, 2, ..., m2) are referred to as the second avoidance command candidate group. Note that, in this embodiment, an example will be described in which the second avoidance command candidate group includes both an avoidance command in the first steering direction (e.g., horizontal direction) and an avoidance command in the second steering direction (e.g., vertical direction and front-rear direction), but is not limited to this. In other embodiments, the second avoidance command candidate group may include only an avoidance command in the second steering direction (e.g., vertical direction).

[0064] The second group of avoidance command candidates is used when the risk of collision with a passing vehicle is imminent (when emergency avoidance is necessary). For example, if the distance to a passing vehicle is d imposed If the vehicle is close to a passing vehicle, it may be determined that the risk of collision is imminent (urgent avoidance is necessary). In this case, the passing vehicle group Q2 that is in imminent risk of collision is expressed by the formula (6).

[0065]

number

[0066] The second passing interval estimation unit 202B calculates passing intervals for the group of passing vehicles Q2 that are at imminent risk of collision and the second group of avoidance command candidates (j=1, 2, . . . , m2) in the same manner as in the first embodiment.

[0067] The second speed vector determination unit 204B evaluates the formula (7) for the second group of avoidance commands and selects the best avoidance command (second avoidance command). The difference from the first embodiment is that the second avoidance command is used when a passing vehicle is already approaching, so the passing interval is set to the safe interval d safe (d safe <d imposed ) and, from the viewpoint of speed, the best option is the one that satisfies the safety interval and is closest to the current velocity vector of the vehicle itself.

[0068] The performance of the second avoidance command is calculated by the passing interval and the safe interval d safe It is measured by the difference between.

[0069]

number

[0070] The second velocity vector determination unit 204B selects the best avoidance command as the one with the smallest difference from the current velocity vector p·, in other words, the avoidance command that successfully avoids the obstacle with the smallest course change, as shown in equation (8). *2 is an index pointing to the best second avoidance command.

[0071]

number

[0072] Then, the second velocity vector determination unit 204B determines the command value p· ref2 is determined by equation (9).

[0073]

number

[0074] Second velocity vector command value p ref2is calculated for the group of passing vehicles Q2 that are at imminent risk of collision. Therefore, when there are no passing vehicles at imminent risk of collision, i.e., when Q2 is an empty set, the command value p· ref2 is not calculated.

[0075] Second velocity vector command value p ref2 When the calculation is completed, the switching unit 205 outputs the command value p· ref , the command value of the second velocity vector p· ref2 The second velocity vector command value p· ref2 If the velocity vector command value p· ref Then, the command value p· of the first velocity vector calculated by the first functional unit 20A is ref1 Select.

[0076] As described above, the collision avoidance device 2 according to this embodiment adopts, as a command value, a first speed vector that causes the host vehicle to perform an avoidance action in a predefined first steering direction when the risk of collision of the host vehicle is not imminent (emergency avoidance is not necessary), and preferentially adopts a second speed vector that allows an avoidance action in a second steering direction when the risk of collision of the host vehicle is imminent (emergency avoidance is necessary). In this way, the collision avoidance device 2 can cause the host vehicle to perform a collision avoidance operation while maintaining the original course as much as possible when, for example, a passing vehicle to be avoided is far away. On the other hand, the collision avoidance device 2 can cause the host vehicle to perform a collision avoidance operation quickly when a passing vehicle to be avoided is approaching.

[0077] <Third embodiment> Next, a third embodiment will be described with reference to Figures 5 to 7. Components common to the above-described embodiment will be given the same reference numerals and detailed description will be omitted.

[0078] Regarding the passage of ships, Japan's Maritime Collision Prevention Act stipulates that "a ship that sees another ship on its right side must keep out of the other ship's path." In this embodiment, for example, a collision avoidance function is added while following this provision. Here, "a ship that sees another ship on its right side" refers to a passing vehicle whose line of sight angle is to the right when the speed vector of the own vehicle is used as the reference, and the own vehicle must avoid this passing vehicle.

[0079] FIG. 5 is a block diagram showing a functional configuration of a collision avoidance device according to the third embodiment. As shown in FIG. 5, the collision avoidance device 2 according to this embodiment further includes a priority determining unit 206.

[0080] The priority determination unit 206 determines whether each passing vehicle Vi is a passing vehicle that the vehicle V should avoid (has priority over the vehicle V). Here, as in the above example, the passing vehicle Vi on the right side of the vehicle V is determined to be a passing vehicle that the vehicle V should avoid. Whether the passing vehicle Vi is on the right side of the vehicle V (TRUE or FALSE) is determined as P right,i Then, P right,i can be evaluated by equation (10). The calculation of the avoidance command is P right , i The target vehicle is a vehicle with a value of TRUE. In equation (10), sgn is a sign function, and the output is 1 when the input is positive, and -1 when the input is negative. Equation (10) is expressed as P by the product of two sign functions. right It stipulates:

[0081]

number

[0082] Next is "avoiding the path of other ships". To avoid the path of other vehicles, your vehicle V should give way to the passing vehicle Vi and pass behind the passing vehicle Vi. To do this, change your course so that the passing point with the passing vehicle Vi is in front of your vehicle V.

[0083] The passing interval between the own vehicle V and a passing vehicle Vi can be measured using formula (2). Formula (2) only measures the length of the passing interval, and cannot distinguish whether the passing occurs in front of or behind the own vehicle V. Therefore, an evaluation formula is added to distinguish between in front and behind. If the passing point between a passing vehicle Vi and the own vehicle V is in front of the own vehicle V, the following inequality (11) holds. e3 is the base of the Cartesian coordinate system, and the direction is vertically upward.

[0084]

number

[0085] Using this inequality, the signed passing distance d signed is defined as equation (12).

[0086]

number

[0087] FIG. 6 is a first diagram for explaining the collision avoidance function according to the third embodiment. Figure 6 shows a plane determined by the vertically upward base e3 and the velocity vector p· of the vehicle V. The vehicle V passes a passing vehicle Vi on a circle at a distance r, and its position is at an angle φ from the base e3.

[0088] FIG. 7 is a second diagram for explaining the collision avoidance function according to the third embodiment. FIG. 7 shows the signed passing distance d signed This shows the difference between d and d in equation (2). d in equation (2) does not depend on φ. The value of d is constant at r. On the other hand, the signed passing distance d in equation (12) signed has a value of +r if φ is in the open interval (0,π), and a value of -r if φ is in the open interval (-π,0). Therefore, the prescribed interval d imposed While ensuring "avoiding the path of other ships", the vehicle must move in the right direction to avoid the passing vehicle.signed -d imposed The velocity vector of the vehicle is selected so that is positive.

[0089] Common sense would dictate, for example, the prescribed interval d imposed If you cross the path of another vessel (in front of it) while keeping a distance of several times d, you are not obstructing the path of the other vessel. signed For example, the absolute value of the specified interval d imposed If the distance between the two vessels exceeds five times the maximum allowable passing distance, it may be reasonable to allow one vessel to pass ahead of the other. Taking this into account, the signed passing interval may be evaluated using the following equation (13):

[0090]

number

[0091] In addition, "prescribed interval d imposed 5 times (5d imposed ) is merely an example and may be changed as desired depending on the vehicle's dynamic performance, regulations, etc.

[0092] In this embodiment, the passing interval estimation unit 202 performs a passing interval estimation process that takes priority into consideration. In the passing interval estimation process that takes priority into consideration, a group of passing vehicles that have priority over the vehicle itself, i.e., P right For approaching vehicles with the value of TRUE, the signed passing distance d signed Evasion command C j Evaluate p's performance. P right When the value of is TRUE, approaching passing vehicles are evaluated using the following equation (14).

[0093]

number

[0094] Evasion Command C j The performance of p· is determined by the following equation (15).

[0095]

number

[0096] The subsequent processing, for example the processing by the velocity vector determination unit 204, is the same as in the first embodiment.

[0097] As described above, the collision avoidance device 2 according to this embodiment further includes a priority determination unit 206 that determines whether or not each passing vehicle has a route priority over the vehicle itself. The passing interval estimation unit 202 estimates the passing interval for each passing vehicle that is determined to have a priority, and targets the vehicle to be avoided. In this manner, when the route priority is determined by regulations or the like, the collision avoidance device 2 can avoid a collision between the vehicle itself and another vehicle while maneuvering in accordance with the regulations.

[0098] In this embodiment, the method of determining priority based on the line of sight angle has been described using the rule that "a ship that sees another ship on its right must avoid the path of the other ship" as an example. Note that "a ship that sees another ship on its right" is one example of a determination criterion by the priority determination unit 206. For example, even when an overtaking ship must avoid the path of the ship being overtaken, priority is determined based on the line of sight angle, so the priority determination unit 206 may use this as a determination criterion.

[0099] <Modification of the third embodiment> In the third embodiment, the collision avoidance device 2 is configured to detect whether the vehicle V is a vehicle that is passing through P right Avoid passing vehicles whose value is TRUE. On the other hand, right Vehicles with a value of FALSE will not be avoided. right If the value of is FALSE, the other vehicle will start avoiding the obstacle first, so the vehicle itself does not have to start avoiding the obstacle. However, if the other vehicle does not start avoiding the obstacle or if the other vehicle's avoidance is not sufficient, the vehicle itself must also start avoiding the obstacle.

[0100] FIG. 8 is a block diagram showing a functional configuration of a collision avoidance device according to a modified example of the third embodiment. In consideration of an unlikely event, the configuration of the priority determination unit 206 of the third embodiment may be added to the configuration of the second embodiment, for example, as shown in Fig. 8. In this case, when the passing vehicle to be avoided is far away, the determination result of the priority determination unit 206 is input to the first passing interval estimation unit 202A, and it is determined that the passing vehicle has priority over the own vehicle in the same way as in the third embodiment (P right Avoid passing vehicles (whose value is TRUE).

[0101] On the other hand, as mentioned above, it is not a target for avoidance (P right When the risk of collision is imminent as a result of insufficient avoidance of the passing vehicle (the value of FAIL) the collision avoidance device 2 may issue the second best avoidance command determined by the second speed vector determination unit 204B to the vehicle V to avoid the approaching vehicle. Even if the vehicle has the priority and does not need to take evasive action, if the other vehicle does not take sufficient evasive action, the vehicle can be operated to avoid a collision. In other words, it is possible to more reliably avoid a collision between the vehicle and another vehicle.

[0102] <Fourth embodiment> Next, a fourth embodiment will be described with reference to Fig. 9. Components common to the above-mentioned embodiments are given the same reference numerals and detailed description will be omitted.

[0103] It is common for long vehicles such as ships and trucks to pass each other on waterways and roads. For example, a lane on a road is generally shorter than the length of a truck, but as long as the truck stays within the lane, it can pass each other in the opposite direction. Passing in the opposite direction is an exceptional way of passing that assumes that the vehicle and the other vehicle maintain their speed vectors parallel to each other.

[0104] FIG. 9 is a block diagram showing a functional configuration of a collision avoidance device according to a modified example of the fourth embodiment. FIG. 10 is a diagram for explaining a collision avoidance function according to the fourth embodiment. For example, two-way traffic is possible if the passing interval setting value is made variable according to the angle between the speed vector of the vehicle and the speed vector of the passing vehicle as shown in Fig. 10. Specifically, for example, in the passing interval estimation unit 202 of the first embodiment, d imposed As shown in Fig. 10, the value of d is changed according to the angle ∠q·-∠p· between the speed vector p· of the own vehicle and the speed vector q· of the passing vehicle. Note that this is just one example, and other than the angle ∠q·-∠p· between the speed vector p· of the own vehicle and the speed vector q· of the passing vehicle, for example, the value of d can be changed based on the magnitude of the relative speed between the own vehicle and the passing vehicle. imposed A value of may be defined.

[0105] In this embodiment, the specified interval d imposed The value of is not uniform for all vehicles, but differs for each vehicle. The prescribed interval for a vehicle Vi is d imposed,i Then, the jth avoidance command C j The performance is expressed by equation (16). The inequality in equation (16) is imposed In other words, the inequality in (16) expresses the relationship between the relative distance between the passing vehicle Vi and the vehicle V and the specified interval d imposed This shows that the time change of the difference between the specified interval d imposed is the velocity vector q of the passing vehicle Vi. i Since it depends on the angle between the velocity vector p of the vehicle V and the vehicle imposed must be treated as time-varying.

[0106]

number

[0107] Passing intervals and prescribed intervals d imposed The difference between the two is positive, and the velocity vector p· orgThe best avoidance command is the one that minimizes the difference between the first and second approximations.

[0108] As described above, in the collision avoidance device 2 according to this embodiment, the specified distance d impsed is the velocity vector p· of the vehicle V and the velocity vector q· of the passing vehicle Vi. i The collision avoidance control device 2 controls the vehicle V to pass a passing vehicle in parallel while avoiding a collision with the passing vehicle V, without making the vehicle V change its course unnecessarily, in a place where the vehicles can pass each other in a two-way manner.

[0109] <Other embodiments> Although one embodiment has been described in detail above with reference to the drawings, the specific configuration is not limited to the above, and various design changes are possible. That is, in other embodiments, the order of the above-mentioned processes may be changed as appropriate. Also, some of the processes may be executed in parallel.

[0110] <Hardware configuration> FIG. 11 is a schematic block diagram showing a hardware configuration of the collision avoidance device.

[0111] The computer 800 comprises a processor 801 , a main memory device 802 , an auxiliary memory device 803 , and an interface 804 .

[0112] The above-mentioned collision avoidance device 2 is implemented in a computer 800. The operations of the above-mentioned processing units are stored in the auxiliary storage device 803 in the form of a program. The processor 801 reads the program from the auxiliary storage device 803, loads it in the main storage device 802, and executes the above-mentioned processing in accordance with the program. The processor 801 also secures storage areas in the main storage device 802 corresponding to the above-mentioned storage units in accordance with the program.

[0113] The program may be for realizing a part of the functions to be performed by the computer 800. For example, the program may be for realizing the functions by combining with other programs already stored in the auxiliary storage device 803 or by combining with other programs implemented in other devices. In another embodiment, the computer 800 may include a custom LSI (Large Scale Integrated Circuit) such as a PLD (Programmable Logic Device) in addition to or instead of the above configuration. Examples of PLDs include PAL (Programmable Array Logic), GAL (Generic Array Logic), CPLD (Complex Programmable Logic Device), and FPGA (Field Programmable Gate Array). In this case, some or all of the functions to be realized by the processor 801 may be realized by the integrated circuit.

[0114] Examples of the auxiliary storage device 803 include a hard disk drive (HDD), a solid state drive (SSD), a magnetic disk, a magneto-optical disk, a compact disc read only memory (CD-ROM), a digital versatile disc read only memory (DVD-ROM), and a semiconductor memory. The auxiliary storage device 803 may be an internal medium directly connected to the bus of the computer 800, or an external storage device 810 connected to the computer 800 via an interface 804 or a communication line. In addition, when the program is distributed to the computer 800 via a communication line, the computer 800 that has received the program may load the program into the main storage device 802 and execute the above-mentioned processing. In at least one embodiment, the auxiliary storage device 803 is a non-transitory tangible storage medium.

[0115] The program may be for realizing part of the above-mentioned functions. Furthermore, the program may be a so-called differential file (differential program) that realizes the above-mentioned functions in combination with other programs already stored in the auxiliary storage device 803.

[0116] <Additional Notes> The collision avoidance device, the collision avoidance method, and the program described in the above-described embodiments can be understood, for example, as follows.

[0117] (1) According to a first aspect, the collision avoidance device 2 is a collision avoidance device 2 that avoids a collision of the own vehicle with another passing vehicle, and is equipped with a passing interval estimation unit 202 that estimates a passing interval between the own vehicle and the target to be avoided based on a relative speed vector and a relative position vector between the own vehicle and the target to be avoided, and a speed vector determination unit 204 that determines a speed vector that causes the own vehicle to take collision avoidance action based on the passing interval.

[0118] In this way, even when there are a plurality of passing vehicles, the collision avoidance device 2 can steer the vehicle so as to be able to avoid collision with all of the passing vehicles.

[0119] (2) According to the second aspect, in the collision avoidance device 2 related to the first aspect, the passing interval estimation unit 202 estimates the passing interval with the object to be avoided by performing a cross product operation and an inner product operation represented by ((relative velocity vector × (relative velocity vector × relative position vector)) × relative position vector) ÷ |relative velocity vector × (relative velocity vector × relative position vector)|, where the operator of the cross product is ×, the operator of the inner product is 〇, and the operator of the norm is ||, and determines a passing vehicle as an object to be avoided if the sign of the inner product of the relative position vector and the relative velocity vector is negative.

[0120] In this manner, the collision avoidance device 2 can set only a passing vehicle approaching the own vehicle as an avoidance target among a plurality of passing vehicles.

[0121] (3) According to a third aspect, the collision avoidance device 2 relating to the first or second aspect further includes an original course memory unit 203 that stores the original speed vector of the host vehicle before collision avoidance is started, and an avoidance command candidate generation unit 201 that generates a group of avoidance command candidates whose elements are multiple command value candidates for the speed vector for the host vehicle, and the passing interval estimation unit 202 estimates a group of passing intervals between the host vehicle and the target to be avoided for each element based on the position vector and speed vector of the host vehicle at the current time, a group of relative position vectors with the target to be avoided at the current time, and a group of relative speed vectors with the target to be avoided determined depending on the group of avoidance command candidates, and the speed vector determination unit 204 determines, based on the group of passing intervals, an element that makes the passing interval larger than a specified interval and that has the smallest norm of the error between the original speed vector and the command value candidate for the speed vector as the best avoidance command for the host vehicle, and determines the speed vector based on the determined best avoidance command.

[0122] In this way, the collision avoidance device 2 can avoid all avoidance targets and minimize deviation from the original course. In other words, it is possible to reduce the effects of increasing travel distance and travel time due to collision avoidance.

[0123] (4) According to the fourth aspect, in the collision avoidance device 2 according to the third aspect, the avoidance command candidate generation unit 201 has a first avoidance command candidate generation unit 201A that generates a first avoidance command candidate group including only avoidance commands in a first steering direction predefined for the vehicle, and a second avoidance command candidate generation unit 201B that generates a second avoidance command candidate group including avoidance commands in a second steering direction different from the first steering direction, and the passing interval estimation unit 202 has a first passing interval estimation unit 202A that estimates a first passing interval group with an avoidance target based on the first avoidance command candidate group, and a second avoidance command candidate generation unit 201B that generates a second avoidance command candidate group including avoidance commands in a second steering direction different from the first steering direction. The collision avoidance device 2 has a second passing interval estimation unit 202B that estimates a second group of passing intervals with the avoidance target based on the first passing interval group, and the speed vector determination unit 204 has a first speed vector determination unit 204A that determines a first best avoidance command based on the first passing interval group and determines a first speed vector based on the determined first best avoidance command when emergency avoidance of the vehicle is not necessary, and a second speed vector determination unit 204B that determines a second best avoidance command based on the second passing interval group and determines a second speed vector based on the determined second best avoidance command when emergency avoidance of the vehicle is necessary. The collision avoidance device 2 further includes a switching unit 205 that prioritizes the second speed vector as a command value for the vehicle when emergency avoidance is necessary.

[0124] In this way, the collision avoidance device 2 can make the vehicle steer to avoid a collision while maintaining the original course as much as possible when the passing vehicle to be avoided is far away, for example. On the other hand, when the passing vehicle to be avoided approaches, the collision avoidance device 2 can make the vehicle steer quickly to avoid a collision.

[0125] (5) According to a fifth aspect, the collision avoidance device 2 according to any one of the first to fourth aspects further includes a priority determining unit 206 that determines whether each passing vehicle has a priority on the route relative to the vehicle itself. The passing interval estimating unit 202 estimates a passing interval for each passing vehicle that is determined to have a priority, as an avoidance target.

[0126] In this manner, when the priority of routes is determined by regulations or the like, the collision avoidance device 2 can avoid a collision between the vehicle and another vehicle while maneuvering in accordance with the regulations.

[0127] (6) According to a sixth aspect, in the collision avoidance device 2 according to the third aspect, the specified interval changes depending on the angle between the speed vector of the host vehicle and the speed vector of a passing vehicle, or the relative speed between the host vehicle and the passing vehicle.

[0128] In this way, in a place where vehicles can pass each other in the opposite direction, the collision avoidance device 2 can steer the vehicle so that it passes a passing vehicle in parallel while avoiding a collision with the passing vehicle, without making the vehicle make unnecessary lane changes.

[0129] (7) According to a seventh aspect, the collision avoidance method is a collision avoidance method for avoiding a collision between the own vehicle and another passing vehicle, and includes the steps of: determining, as an avoidance target, a passing vehicle whose relative distance to the own vehicle decreases over time among the passing vehicles; estimating a passing interval between the own vehicle and the target to be avoided based on a relative speed vector and a relative position vector between the own vehicle and the target to be avoided; and determining a speed vector that causes the own vehicle to take collision avoidance action based on the passing interval.

[0130] (8) According to the eighth aspect, the program causes a collision avoidance device 2, which prevents a collision of the host vehicle with another passing vehicle, to execute the following steps: determining, as an avoidance target, a passing vehicle whose relative distance to the host vehicle decreases over time among passing vehicles; estimating a passing interval between the host vehicle and the target to be avoided based on a relative speed vector and a relative position vector between the host vehicle and the target to be avoided; and determining a speed vector that causes the host vehicle to take collision avoidance action based on the passing interval. [Explanation of symbols]

[0131] 2 Collision avoidance device 20A First Function Section 20B 2nd functional section 201 Avoidance command candidate generation unit 201A First Evasion Command Candidate Generation Unit 201B Second avoidance command candidate generation unit 202 Interval estimation part 202A Interval estimation part 202B Interval estimation part 203 Original Course Memory Section 204 Velocity Vector Determination Unit 204A First velocity vector determination unit 204B Second velocity vector determination unit 205 Switching section 206 Priority Judgment Division 3. Path Following Control Device 31 Route Control Unit 4. Motion Control Device V Vehicle

Claims

1. A collision avoidance device for avoiding a collision between a vehicle and another vehicle, a passing interval estimation unit that estimates a passing interval between the host vehicle and the object to be avoided based on a relative speed vector and a relative position vector between the host vehicle and the object to be avoided, the passing interval estimation unit determining, as an object to be avoided, a passing vehicle whose relative distance to the host vehicle decreases over time among the passing vehicles, a speed vector determination unit that determines a speed vector that causes the host vehicle to perform a collision avoidance action based on the passing interval; A collision avoidance device comprising:

2. The passing interval estimation unit estimates a passing interval with an avoidance target by a cross product calculation and an inner product calculation expressed by ((relative speed vector x (relative speed vector x relative position vector)) x relative position vector) ÷ | relative speed vector x (relative speed vector x relative position vector) |, where an operator of a cross product is x, an operator of an inner product is o, and an operator of a norm is | |, and determines a passing vehicle with a negative sign of an inner product of a relative position vector and a relative speed vector as an avoidance target. The collision avoidance device according to claim 1 .

3. an original path storage unit that stores an original velocity vector of the host vehicle before collision avoidance is started; an avoidance command candidate generating unit that generates an avoidance command candidate group having a plurality of command value candidates of a velocity vector for the host vehicle as elements; Further equipped with the passing interval estimation unit estimates a group of passing intervals between the host vehicle and the object to be avoided for each of the elements based on a position vector and a speed vector of the host vehicle at a current time, a group of relative position vectors with respect to the object to be avoided at a current time, and a group of relative speed vectors with respect to the object to be avoided that are determined depending on the group of avoidance command candidates; the speed vector determination unit determines an element that makes the passing interval longer than a specified interval based on the group of passing intervals and that minimizes a norm of an error between the original speed vector and a command value candidate of the speed vector as a best avoidance command for the host vehicle, and determines the speed vector based on the determined best avoidance command. The collision avoidance device according to claim 1 .

4. the avoidance command candidate generating unit has a first avoidance command candidate generating unit that generates a first avoidance command candidate group including only avoidance commands in a first steering direction that is predefined for the host vehicle, and a second avoidance command candidate generating unit that generates a second avoidance command candidate group including avoidance commands in a second steering direction that is different from the first steering direction, the passing interval estimation unit includes a first passing interval estimation unit that estimates a first group of passing intervals with the avoidance target based on the first group of avoidance command candidates, and a second passing interval estimation unit that estimates a second group of passing intervals with the avoidance target based on the second group of avoidance command candidates, the speed vector determination unit has a first speed vector determination unit which, when emergency avoidance of the host vehicle is not required, determines a first best avoidance command based on the first group of passing intervals, and determines a first speed vector based on the determined first best avoidance command, and a second speed vector determination unit which, when emergency avoidance of the host vehicle is required, determines a second best avoidance command based on the second group of passing intervals, and determines a second speed vector based on the determined second best avoidance command, The collision avoidance device further includes a switching unit that prioritizes the second velocity vector as a command value for the host vehicle when the emergency avoidance is necessary. A collision avoidance device according to claim 3.

5. a priority determination unit that determines whether each of the traveling vehicles has a priority of a route relative to the vehicle itself; the passing interval estimation unit estimates the passing interval by regarding the traveling vehicle determined to have the priority as the avoidance target; A collision avoidance device according to any one of claims 1 to 4.

6. the specified interval varies depending on an angle between the speed vector of the host vehicle and the speed vector of the passing vehicle, or a relative speed between the host vehicle and the passing vehicle. A collision avoidance device according to claim 3.

7. A collision avoidance method for avoiding a collision between a vehicle and another vehicle, comprising: a step of determining, as an avoidance target, a passing vehicle whose relative distance to the own vehicle decreases over time among the passing vehicles, and estimating a passing interval between the own vehicle and the avoidance target based on a relative speed vector and a relative position vector between the own vehicle and the avoidance target; determining a velocity vector for causing the host vehicle to take action to avoid a collision based on the passing interval; A collision avoidance method comprising:

8. A collision avoidance device that prevents a vehicle from colliding with other vehicles on the road. a step of determining, as an avoidance target, a passing vehicle whose relative distance to the own vehicle decreases over time among the passing vehicles, and estimating a passing interval between the own vehicle and the avoidance target based on a relative speed vector and a relative position vector between the own vehicle and the avoidance target; determining a velocity vector for causing the host vehicle to take action to avoid a collision based on the passing interval; A program that executes the following.

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