阅读说明：本技术 信息处理装置、程序及信息处理方法 (Information processing device, program, and information processing method ) 是由 花田武彦 小林克希 石渡要介 于 2019-02-18 设计创作，主要内容包括：具备：制动时间计算部(102),其计算车辆的制动时间；反应时间检测部(103),其检测车辆的驾驶员的反应时间；预测时间确定部(105),其以将制动时间与反应时间相加得到的时间越长则预测时间越长的方式确定该预测时间,该预测时间是预测车辆与周边车辆在将来发生碰撞的时刻的范围；位置速度预测部(107),其在预测时间所包含的时刻,执行车辆的位置及速度和周边车辆的位置及速度的预测；以及碰撞预测部(108),其根据该预测的结果,预测车辆与周边车辆是否会发生碰撞。(The disclosed device is provided with: a braking time calculation unit (102) that calculates the braking time of the vehicle; a reaction time detection unit (103) that detects the reaction time of a driver of the vehicle; a predicted time determination unit (105) that determines the predicted time, which is a range within which the time at which a collision between the vehicle and the nearby vehicle is predicted in the future, is longer as the time obtained by adding the braking time and the reaction time is longer; a position/speed prediction unit (107) that predicts the position and speed of the vehicle and the position and speed of the nearby vehicle at a time included in the prediction time; and a collision prediction unit (108) that predicts whether or not the vehicle and the nearby vehicle will collide with each other, based on the result of the prediction.)

1. An information processing device mounted on a vehicle,

the information processing device is provided with:

a braking time calculation unit that calculates a braking time that is a time required for the vehicle to stop by braking;

a reaction time detection unit that detects a reaction time that is a time required for a driver of the vehicle to take a response to a change in the surrounding environment of the vehicle into consideration and to execute the response;

a predicted time determination unit that determines a predicted time that is a range within which a time at which a collision between the vehicle and a nearby vehicle that is a vehicle around the vehicle is predicted to occur in the future is longer as a time obtained by adding the braking time and the reaction time is longer;

a position/speed prediction unit that predicts a position and a speed of the vehicle and a position and a speed of the nearby vehicle at a time included in the prediction time; and

and a collision prediction unit that predicts whether or not the vehicle and the nearby vehicle collide with each other, based on a result of the prediction.

2. The information processing apparatus according to claim 1,

the predicted time determination unit determines the predicted time by adding the braking time, the reaction time, and a predetermined time.

3. The information processing apparatus according to claim 1 or 2,

the reaction time detection unit detects the reaction time based on a time from a stop of a traffic light to a start of travel until the driver operates an accelerator pedal of the vehicle.

4. The information processing apparatus according to claim 3,

the reaction time detection unit determines the time at which the traffic light changes from the stop to the travel, based on an image obtained from an imaging device mounted on the vehicle.

5. The information processing apparatus according to claim 3 or 4,

the reaction time detection unit acquires information indicating an operation of the accelerator pedal from an electronic control unit of the vehicle, and thereby determines a timing at which the accelerator pedal is operated.

6. The information processing apparatus according to any one of claims 1 to 4,

the braking time calculation unit calculates the braking time by dividing the speed of the vehicle by a value obtained by multiplying a friction coefficient for a road by a gravitational acceleration.

7. The information processing apparatus according to claim 6,

the braking time calculation unit acquires information indicating whether or not a raindrop is detected by a raindrop sensor mounted on the vehicle from an electronic control unit of the vehicle, and sets the friction coefficient to a smaller value when a raindrop is detected than when a raindrop is detected.

8. A program, characterized in that,

the program causes a computer mounted on a vehicle to function as a braking time calculation unit, a reaction time detection unit, a predicted time determination unit, a position and speed prediction unit, and a collision prediction unit,

the braking time calculation section calculates a braking time that is a time required for the vehicle to stop by braking,

the reaction time detection unit detects a reaction time that is a time required for a driver of the vehicle to take into account a response to a change in the surrounding environment of the vehicle and to execute the response,

the predicted time determination unit determines the predicted time as a time obtained by adding the braking time and the reaction time is longer, the predicted time being a range within which a time at which the vehicle collides with a nearby vehicle that is a vehicle in the vicinity of the vehicle is predicted to be longer in the future,

the position/speed prediction unit performs prediction of the position and speed of the vehicle and the position and speed of the nearby vehicle at a time included in the prediction time,

the collision prediction unit predicts whether or not the vehicle and the nearby vehicle collide with each other, based on a result of the prediction.

9. An information processing method characterized by comprising, in a first step,

the time required for the vehicle to stop by braking, i.e. the braking time is calculated,

detecting a reaction time which is a time required for a driver of the vehicle to take into account a countermeasure against a change in the surrounding environment of the vehicle and until the countermeasure is performed,

determining the predicted time as a predicted time that is a range of a time at which a collision between the vehicle and a vehicle in the vicinity of the vehicle, that is, a nearby vehicle is predicted to occur in the future, the longer the time obtained by adding the braking time and the reaction time is,

performing prediction of the position and speed of the vehicle and the position and speed of the nearby vehicle at a time included in the prediction time,

and predicting whether the vehicle and the nearby vehicle collide with each other according to the prediction result.

Technical Field

The invention relates to an information processing apparatus, a program, and an information processing method.

Background

Conventionally, in order to assist driving of an automobile, a device has been developed which detects a rear automobile and warns a driver.

For example, a left/right turn assist device described in patent document 1 detects a target vehicle traveling in the rear lateral direction by a radar provided on the rear lateral side of a vehicle driven by a driver, and specifies an intersection between an expected trajectory of the vehicle and an expected trajectory of the detected target vehicle. Then, if the estimated time at which the vehicle reaches the specified intersection is later than the estimated time at which the subject vehicle arrives, the right-left turn support device issues a danger signal, thereby notifying the driver of the danger of collision with the detected subject vehicle traveling in the rear-side direction when the vehicle makes a right-left turn or changes lanes.

Documents of the prior art

Patent document

Patent document 1: japanese patent No. 2870096

Disclosure of Invention

Problems to be solved by the invention

Since the conventional apparatus specifies the virtual trajectory of the vehicle and the detected target vehicle, it is possible to immediately determine the intersection point indicating the collision.

However, in reality, the vehicle and the detected trajectory that the target vehicle can take are not uniquely determined, and their speeds are not fixed, so that the collision is not limited to the point of intersection of the trajectories. Therefore, a warning cannot be given to a collision occurring at a point other than the intersection point.

In addition, when it is considered that the vehicle moves in all directions at all speeds in order to detect a collision occurring at a point other than the intersection point, the calculation cost becomes a problem. On the other hand, if the prediction range of the vehicle movement is inadvertently narrowed, a collision that needs to be warned cannot be predicted.

In view of the above, one or more aspects of the present invention are directed to predicting a collision that requires warning to a driver while controlling the actual computation cost.

Means for solving the problems

An information processing apparatus according to an aspect of the present invention includes: a braking time calculation unit that calculates a braking time that is a time required for the vehicle to stop by braking; a reaction time detection unit that detects a reaction time that is a time required for a driver of the vehicle to take a response to a change in the surrounding environment of the vehicle into consideration and to execute the response; a predicted time determination unit that determines a predicted time that is a range within which a time at which a collision between the vehicle and a nearby vehicle that is a vehicle around the vehicle is predicted to occur in the future is longer as a time obtained by adding the braking time and the reaction time is longer; a position/speed prediction unit that predicts a position and a speed of the vehicle and a position and a speed of the nearby vehicle at a time included in the prediction time; and a collision prediction unit that predicts whether or not the vehicle and the nearby vehicle collide with each other, based on a result of the prediction.

A program according to an aspect of the present invention is a program causing a computer mounted on a vehicle to function as a braking time calculation unit that calculates a braking time that is a time required for the vehicle to stop by braking, a reaction time detection unit that detects a reaction time that is a time required for a driver of the vehicle to take a response to a change in a surrounding environment of the vehicle and to execute the response, a predicted time determination unit that determines a predicted time that is a range of times at which a collision between the vehicle and a neighboring vehicle that is a vehicle in the vicinity of the vehicle is predicted in the future, the predicted time being longer as a time obtained by adding the braking time and the reaction time is longer, and a collision prediction unit that makes a computer mounted on the vehicle function as a braking time calculation unit, a reaction time determination unit, a position and speed prediction unit, and a collision prediction unit that make a time included in the predicted time, the collision prediction unit predicts whether or not the vehicle and the nearby vehicle collide with each other based on a result of the prediction.

An information processing method according to an aspect of the present invention is characterized in that a braking time that is a time required for a vehicle to stop by braking is calculated, a reaction time that is a time required for a driver of the vehicle to take a response to a change in a surrounding environment of the vehicle until the response is executed is detected, the prediction time is determined such that the longer the time obtained by adding the braking time and the reaction time is, the longer the prediction time is, the prediction time is within a range of times at which a collision between the vehicle and a neighboring vehicle that is a vehicle surrounding the vehicle will be predicted in the future, the prediction of a position and a speed of the vehicle and a position and a speed of the neighboring vehicle is executed at a time included in the prediction time, and whether or not the vehicle and the neighboring vehicle will collide with each other is predicted based on a result of the prediction.

ADVANTAGEOUS EFFECTS OF INVENTION

According to one or more aspects of the present invention, it is possible to predict a collision that requires a warning to the driver while suppressing the actual calculation cost.

Drawings

Fig. 1 is a block diagram schematically showing the configuration of a collision prediction device according to an embodiment.

Fig. 2 is a schematic diagram for explaining a device mounted on a vehicle.

Fig. 3 is a block diagram schematically showing a hardware configuration of the collision prediction apparatus according to the embodiment.

Fig. 4 is a flowchart illustrating an operation of the collision prediction apparatus according to the embodiment.

Detailed Description

Fig. 1 is a block diagram schematically showing the configuration of a collision prediction apparatus 100 as an information processing apparatus according to an embodiment.

The collision prediction apparatus 100 includes a braking acceleration setting storage unit 101, a braking time calculation unit 102, a reaction time detection unit 103, a reaction time setting storage unit 104, a predicted time determination unit 105, a nearby vehicle information storage unit 106, a position/velocity prediction unit 107, and a collision prediction unit 108.

As shown in fig. 2, for example, collision prediction apparatus 100 is mounted on vehicle 130.

Fig. 2 is a schematic diagram for explaining a device mounted on vehicle 130.

The vehicle 130 is provided with a periphery monitoring sensor 131, an image sensor 132 as an imaging device, and a warning device 133, in addition to the collision prediction device 100.

The periphery monitoring sensors 131 are provided in the front, rear, side, and roof of the vehicle 130. The periphery monitoring sensor 131 need not be provided at all of these positions, and may be provided at another position.

The periphery monitoring sensor 131 measures the relative position and relative speed between the peripheral vehicle and the vehicle 130 in order to detect the peripheral vehicle (not shown) that is a vehicle in the periphery of the vehicle 130. Then, the periphery monitoring sensor 131 sends the measured value to the collision prediction apparatus 100.

The image sensor 132 acquires an image in the traveling direction of the vehicle 130, and supplies image information representing the acquired image to the collision prediction apparatus 100.

The warning device 133 warns the driver of the vehicle 130.

The warning device 133 receives as an input the probability of collision, and warns the driver by displaying on a display (not shown) or reproducing sound from a speaker (not shown) when the probability exceeds a predetermined threshold.

The collision prediction apparatus 100 is connected to a CAN (controller Area Network) of the vehicle 130, and CAN acquire information indicating an operation of an accelerator pedal, a detection result of a raindrop sensor, and vehicle speed information from an Electronic Control Unit (ECU) connected to the CAN.

Returning to fig. 1, the braking acceleration setting storage unit 101 stores information required to calculate the braking time of the vehicle 130. For example, the braking acceleration setting storage unit 101 stores the vehicle speed of the vehicle 130, the detection result of the raindrop sensor, the friction coefficient of the road, and the gravitational acceleration.

Here, as the friction coefficient of the road, the friction coefficient of the wet asphalt and the friction coefficient of the dry asphalt are stored. The coefficient of friction of wet asphalt is usually 0.4 to 0.6, where the minimum value, i.e., 0.4, is stored. The dry asphalt has a coefficient of friction of 0.7 to 0.8, where the minimum value, namely 0.7, is stored.

The acceleration of gravity is about 9.8 m/s.

The braking time calculation unit 102 calculates a braking time, which is a time required for the vehicle 130 to stop by braking. The braking time is calculated from the friction coefficient of the virtual road surface and the current vehicle speed. For example, the braking time s is obtained by the following equation (1).

s＝v/(μ·g) (1)

Here, v is the speed of the vehicle 130, μ is the friction coefficient, and g is the gravitational acceleration. They are stored in the braking acceleration setting storage unit 101.

The braking time calculation unit 102 determines a friction coefficient to be used based on the detection result of the raindrop sensor. Specifically, the friction coefficient of wet asphalt is used when the detection result of the raindrop sensor indicates that raindrops are detected, in other words, that it is raining, and the friction coefficient of dry asphalt is used when the detection result of the raindrop sensor indicates that raindrops are not detected, in other words, that it is not raining.

The reaction time detection unit 103 detects a reaction time, which is a time required until the driver takes measures against a change in the environment around the vehicle 130 and executes the measures, and stores the detected reaction time in the reaction time setting storage unit 104.

For example, the reaction time detection unit 103 detects a traffic light from an image indicated by the image information from the image sensor 132, and specifies the timing at which the detected traffic light changes from a red traffic light indicating stop to a green traffic light indicating travel. Next, the reaction time detection unit 103 determines the timing at which the driver operates the accelerator pedal after the traffic light turns to green from the information indicating the operation of the accelerator pedal obtained from the ECU via the CAN. Then, the reaction time detection unit 103 sets a time difference between the time when the blinker is changed and the time when the accelerator pedal is operated as the reaction time.

The predicted time determination unit 105 determines the predicted time, which is the range of the time when the position/velocity prediction unit 107 and the collision prediction unit 108 at the subsequent stage perform the prediction processing. For example, the predicted time determination unit 105 determines the predicted time, which is a range of the time at which the vehicle 130 and the nearby vehicle are predicted to collide in the future, so that the longer the time obtained by adding the braking time and the reaction time, the longer the predicted time. Here, the predicted time is determined by adding the braking time, the reaction time, and a predetermined time.

Specifically, the predicted time determination unit 105 limits the range of the time step k + n (k and n are positive integers), which is the time at which the position/velocity prediction unit 107 and the collision prediction unit 108 perform the prediction process, to the ranges expressed by the following expressions (2) and (3).

M＝{n：0＜n≦m} (2)

m＝《(r+s+α)/Δt》 (3)

Here, M is a set of predicted time steps, and thus the time at which the position/velocity prediction unit 107 and the collision prediction unit 108 perform the prediction processing is determined to be within a range from the time step k to the time step k + M.

Δ t is the cycle in which the position/velocity prediction unit 107 and the collision prediction unit 108 operate, s is the braking time described above, and r is the reaction time described above.

Further, "a" is an integer obtained by rounding up the first decimal of the real number a. α is a set value of the delay time from the start of collision prediction to the time at which braking must be started in order to stop the vehicle 130 before collision with the nearby vehicle.

The nearby vehicle information storage unit 106 stores the position and speed of the nearby vehicle. For example, the position/velocity prediction unit 107 may calculate the absolute position and the absolute velocity of the nearby vehicle from the relative position and the relative velocity of the nearby vehicle detected by the surrounding monitoring sensor 131, and store the calculated absolute position and absolute velocity in the nearby vehicle information storage unit 106 as the position and velocity of the nearby vehicle.

Further, the nearby vehicle information storage unit 106 stores the estimated value of the state value predicted by the position/velocity prediction unit 107 and the error covariance. The state values include position and velocity.

The position/velocity prediction unit 107 performs prediction of the position and velocity of the vehicle 130 and the position and velocity of the nearby vehicle at the time included in the prediction time. For example, the position/velocity prediction unit 107 predicts the position and velocity of the nearby vehicle in the future as follows from the position and velocity of the nearby vehicle stored in the nearby vehicle information storage unit 106 using a kalman filter.

< estimation processing by the position/velocity prediction unit 107 >

First, description will be given of the limitation to 1 neighboring vehicle.

Here, the forward direction of vehicle 130 shown in fig. 1 is defined as the Y-axis, the right direction of vehicle 130 is defined as the X-axis, and the X-axis and the Y-axis are orthogonal to each other.

When the X-coordinate p of the position of the nearby vehicle in the time step k is to be determined_xkY coordinate p_ykX-axis component v of speed of peripheral vehicle_xkY-axis component v_ykThe state value of the peripheral vehicle is x_k＝[p_xk p_yk v_xk v_yk]^TThe equation of state representing the constant velocity motion is expressed by the following equation (4).

x_k＝F·x_k-1 (4)

F is a linear model based on the time transition of the isokinetic motion, and is expressed by the following equation (5).

F is a linear model of the motion that gives the state value a time Δ t. In a general kalman filter, a term of a control input to a system to be estimated and a term of process noise generated during the operation of the system are included in a state equation, but the control input and the process noise generated in a surrounding vehicle are not clear here, and therefore these terms are regarded as a zero vector and the control input and the process noise are ignored.

Next, the state value x of the nearby vehicle is assumed as follows_kObservation value z that can observe the nearby vehicle with the surrounding monitoring sensor 131_kThe relationship (2) of (c).

z_k＝H·x_k+v_k

H is a mapping from the state space to the observation space, but here, it is assumed that both the state space and the observation space are euclidean spaces of position and velocity, and H is set as an identity matrix.

v_kThis is the observation noise of the periphery monitoring sensor 131, and is assumed to be a gaussian distribution with N (0, R). The variance R is a 4 × 4 covariance matrix.

Then, x ^ is fixed_kIs set to x_kAnd will be P_kIs set to x ^_kUsing the estimated value x-of the previous moment step length k-1 for the error covariance of (2)_k-1And its error covariance P_k-1Observed value z of step k at current moment_kX ^ as shown in formulas (6) to (10)_kAnd P_k。

x＾_k＝x＾_k|k-1+K_k·(z_k-H·x＾_k|k-1) (6)

P_k＝(I-K_k·H)·P_k|k-1 (7)

K_k＝P_k|k-1·H^T(R+H·P_k|k-1·H^T)^-1 (8)

x＾_k|k-1＝F·x＾_k-1 (9)

P_k|k-1＝F·P_k-1·F^T (10)

Here, x ^_k|k-1Based on time stepsPredicted value of step k at the next time, P, predicted from an estimate of length k-1_k|k-1Is its error covariance. Here, "#" is a symbol indicating an estimated value.

The position/speed predicting section 107 reads the estimated value x ^ of the previous time step k-1 from the surrounding vehicle information storing section 106_k-1And error covariance P_k-1For the next moment step length, the estimated value x ^ based on the previous moment step length k-1_k-1And error covariance P_k-1The estimated value x ^ of the current time step length k estimated as described above_kAnd error covariance P_kIs recorded in the nearby vehicle information storage unit 106.

Since there are usually a plurality of nearby vehicles, the position/velocity prediction unit 107 records the state values including the position and velocity and the error covariance in the nearby vehicle information storage unit 106 for each of the plurality of nearby vehicles.

< prediction processing method by position/velocity prediction unit 107 >

Here, by using the state transition model F (t) as follows, it is possible to use the estimate x ^ in the current time step k_kAnd error covariance P_kThen, not only the estimated value of the next time step k +1 but also the estimated value of an arbitrary time step k + n is predicted as in the following expressions (11) to (13).

x＾_k+n|k＝F(n)·x＾_k (11)

P_k+n|k＝F(n)·P_k·F(n)^T (12)

Alternatively, the prediction can be performed by the following formulas (14) to (16).

x＾_k+n|k＝F·x＾_k+n-1|k (14)

P_k+n|k＝F·P_k+n-1|k·F^T (15)

Where n is an integer having the maximum prediction time step k + m as described above.

< correlation processing by the position/velocity prediction unit 107 >

Next, the correlation between the estimated value stored in the nearby vehicle information storage unit 106 and the newly obtained observation value when a plurality of nearby vehicles are traveling will be described.

In time step k, I observation values z to be observed in a case where I nearby vehicles travel in the periphery of vehicle 130 are required_i，k(I ═ 1, 2, ·, I: I is a positive integer) is associated with any of the estimated values of the J peripheral vehicles (J is a positive integer) whose positions and speeds have been predicted by the kalman filter.

As a rough guideline, an observed value closest to the distance between the predicted positions of the present time step of the nearby vehicle, which have been predicted in the previous time step, is taken as an observed value of the nearby vehicle, and the two are associated. However, even if the observed value closest to the predicted position exceeds the threshold value, the observed value is not adopted as the observed value of the nearby vehicle, and no correlation is established.

Of the J neighboring vehicles, the neighboring vehicle that is not associated with any observation value is considered to be absent, and the estimated value and the error covariance thereof are deleted from the neighboring vehicle information storage unit 106, and thereafter, are not processed by the position/velocity prediction unit 107.

On the other hand, the observation value not related to any nearby vehicle is regarded as the observation value of the newly found nearby vehicle, and the observation value is stored in the nearby vehicle information storage unit 106 as the estimated value of the time step. For the error covariance of the newly stored observation, the variance R of the observation noise is used or a zero matrix is used.

The distance for correlation is measured as follows.

First, for the periphery of the J-stageO ^ of vehicle_jWhen considering the position Y x ^ in the time step k to be predicted in the time step k-1_k|k-1Set as the mean and the error covariance Y.P_j，k|k-1·Y^TMultivariate Gaussian distribution g set as its variance_j，kWhen (X) is, g_j，k(X) denotes surrounding vehicle o ^_jProbability of being located at position X. In other words, g_j，k(Y·z_i，k) Indicating peripheral vehicles o ^_jAt the observed position Y.z_i，kThe probability of (c).

To reduce the distance to more reasonable observations, 1/g will be used_j，k(Y·z_i，k) Or 1-g_j，k(Y·z_i，k) Set to the distance measured for establishing the association. Wherein Y is for from position speed x ^_k|k-1The matrix of the following equation (17) is extracted only at the position.

The collision prediction section 108 predicts a collision of the vehicle 130 with the nearby vehicle from the result of the prediction in the position and speed prediction section 107. For example, as described below, the collision prediction unit 108 predicts the presence or absence of a collision based on the probability of the collision occurring at an arbitrary time step and position.

When considering the position Y x ^ in the moment step k + n to be based on the prediction in the moment step k_k+n|k-1Set as the mean and the error covariance Y.P_j，k+n|k-1·Y^TMultivariate Gaussian distribution g set as its variance_j，k，n(x) This means that the peripheral vehicle o ^ in the time step k + n_jThe probability of being located at the position x, i.e., the surrounding vehicle position probability.

Similarly, if the target vehicle position probability, which is the probability that the vehicle 130 is located at the position x in the time step k + n based on the prediction of the position and speed of the vehicle 130, is set to f_k，n(x) When the vehicle 130 is located at the same coordinate x, that is, the collision probability h, which is the probability of collision, with any nearby vehicle_k，n(x) This is shown by the following formula (18).

[ numerical formula 1]

Therefore, according to the collision probability h_k，n(x) Whether or not the threshold λ is exceeded is determined as shown in the following expression (19).

[ numerical formula 2]

The range X of the position is represented by the following expression (20), and is defined as the target vehicle position probability f_k，n(x) Beyond the threshold lambda.

X＝{x：f_k，n(x)＞λ} (20)

Fig. 3 is a block diagram schematically showing the hardware configuration of collision prediction apparatus 100 according to the embodiment.

The collision prediction apparatus 100 includes a memory 120, a processor 121, a periphery monitoring sensor interface (hereinafter referred to as I/F)122, a warning I/F123, and a vehicle information I/F124.

The functions of the collision prediction apparatus 100 are stored in the memory 120 as programs, and the processor 121 reads and executes the programs.

Collision prediction apparatus 100 includes a periphery monitoring sensor I/F122, and periphery monitoring sensor 111 for measuring the periphery of vehicle 130 is connected to periphery monitoring sensor I/F122. The program executed by the processor 121 is capable of accessing sensor data of the surroundings monitoring sensor 111, i.e. the relative position and relative speed of the other vehicle with respect to the own vehicle. As described later, the absolute speed of the nearby vehicle can be obtained based on the speed of the vehicle 130 and the relative speed with the nearby vehicle.

The collision prediction apparatus 100 includes a warning I/F123, and the warning device 133 is connected to the warning I/F123. The program executed by the processor 121 is capable of prompting a warning to the driver of the vehicle 130 through the warning device 133.

The collision prediction apparatus 100 includes a vehicle information I/F124, and the CAN of the vehicle 130 is connected to the vehicle information I/F124. The processor 121 executes a program that has access to information on the accelerator pedal, the brake pedal, the raindrop sensor, and vehicle speed information.

The program as described above may be provided via a network or may be recorded in a recording medium. That is, such a program may also be provided as a program product, for example. Therefore, the collision prediction apparatus 100 can be realized by a computer executing the above-described program.

Next, the operation will be described.

Fig. 4 is a flowchart illustrating an operation of the collision prediction apparatus 100 according to the embodiment.

The collision prediction apparatus 100 repeats the processing of S11 to S15 at a cycle Δ t as shown in steps S10 and S16 in fig. 4, during a period from when the power supply is turned on to when the operation is started to when the power supply is turned off or the like to end the operation.

In step S11, the braking time calculation unit 102 calculates a braking time S based on the vehicle speed v, the friction coefficient μ, and the gravitational acceleration g of the vehicle 130.

In step S12, the reaction time detection unit 103 measures the reaction time of the driver of the vehicle 130 and records the reaction time in the reaction time setting storage unit 104.

In step S13, the predicted time determination unit 105 calculates a set M of predicted time steps corresponding to the predicted time for predicting the collision, based on the braking time S and the reaction time r.

In step S14, the position/velocity prediction unit 107 obtains an estimated value of the state value in the current time step using the position and velocity of the nearby vehicle detected by the surrounding monitoring sensor 131 as an observed value, and predicts the position and velocity of the nearby vehicle in each time step within the range of the predicted time step set M based on the estimated value.

In step S15, the collision prediction unit 108 calculates the probability of the vehicle 130 colliding with any nearby vehicle based on the positions and velocities of the vehicle 130 and nearby vehicles in each time step of the range of the prediction time step set M, and outputs the probability to the warning device 133.

As described above, according to the present embodiment, the time range of the prediction processing is limited based on the reaction time of the driver, and therefore, the calculation cost can be reduced without lacking the prediction of the collision that requires a warning to the driver.

Description of the reference symbols

100 collision prediction means, 101 braking acceleration setting storage means, 102 braking time calculation means, 103 reaction time detection means, 104 reaction time setting storage means, 105 prediction time determination means, 106 peripheral vehicle information storage means, 107 position/speed prediction means, 108 collision prediction means, 130 vehicle, 131 peripheral monitoring sensor, 132 image sensor, 133 warning means.