Radar system, radar control method, and program

Abstract

To provide a radar device, a radar control method, and a program with which it is possible to reduce notifications based on unnecessary alarms, even when a variation occurs in a speed or a position of a target that is detected.SOLUTION: A radar device 2 comprises: a detection processing unit 21 that detects an object to be detected that moves in a direction that crosses a front-back direction Y; a course prediction unit 23 that sets, on the basis of a position and a speed of a target 150, a reference predicted trajectory 50 in which a movement of the target 150 is predicted; an auxiliary trajectory setting unit 24 that sets a first predicted trajectory and a second predicted trajectory 51, 52, adding an assumed value to the position and / or the speed of the target 150 taking a variation into account; and a collision determination processing unit 22 that sets a TTC line as a collision determination trajectory that indicates the predicted position of a vehicle 100, determines a possibility of collision on the basis of whether the reference predicted trajectory 50 and the auxiliary predicted trajectory intersect the TTC line, and outputs the result of this determination.SELECTED DRAWING: Figure 8

Description

Technical Field

[0004] , , , , , , , ,

[0003] , ,

[0001] The present invention relates to a radar device mounted on a moving body, a radar control method, and a program.

Background Art

[0002] Conventionally, technologies related to an alarm system that is mounted on a moving body such as a vehicle and notifies a user boarding the vehicle of the risk of collision are known. For example, Patent Document 1 and Patent Document 2 describe this type of technology. Patent Document 1 relates to a technology for improving the determination accuracy of an alarm target in an alarm device that issues an alarm when a vehicle approaches. Patent Document 2 relates to a pedestrian detection device for a vehicle that can accurately detect pedestrians at positions that are out of sight.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] Incidentally, the risk of collision is determined based on whether or not the predicted path of the moving object equipped with the radar device intersects with the predicted path of other moving objects detected by the radar device. However, if there are errors in estimating the speed and position of these other moving objects, then there will also be variations in the predicted paths of these other moving objects. As a result, even when there is actually no risk, the system may determine that there is a risk of collision due to these variations, and unnecessary warnings may be issued to the user. In this respect, the technology described in Patent Document 1 cannot be said to adequately consider the error in the estimated speed of the target object being detected. Furthermore, the technology described in Patent Document 2 calculates the relative speed from the estimated relative distance to the pedestrian, but since it estimates the speed in the radial direction centered on the vehicle, there is a risk of estimation errors in the angular direction. The conventional technology had room for improvement in terms of further improving the accuracy of collision risk determination.

[0005] The present invention aims to provide a radar device, a radar control method, and a program that can reduce unnecessary alarm notifications even when there are variations in the speed and position of detected targets. [Means for solving the problem]

[0006] The present invention relates to a radar device mounted on a moving body, comprising a transmitting antenna for transmitting signals and a receiving antenna for receiving signals that are reflected by a detection target and that are transmitted by the transmitting antenna, and further comprising: a detection processing unit for detecting a detection target moving in a direction intersecting the direction of travel, backward movement, left turn, or right turn of the moving body based on the signal received by the receiving antenna; a path prediction unit for setting a reference predicted trajectory that predicts the movement of the target based on the position and velocity of the target detected by the detection processing unit; an auxiliary trajectory setting unit for setting an auxiliary predicted trajectory by adding an assumed value that takes variability into account for at least one of the position and velocity of the target that formed the basis for the prediction of the reference predicted trajectory; and a collision determination processing unit for setting a collision determination trajectory that indicates the predicted position of the moving body, determining the risk of collision based on whether or not the reference predicted trajectory and the auxiliary predicted trajectory intersect the collision determination trajectory, and outputting the determination result.

[0007] The auxiliary trajectory setting unit may set a forward prediction trajectory that passes in front of the reference prediction trajectory and a backward prediction trajectory that passes behind the reference prediction trajectory as the auxiliary prediction trajectory, and the collision determination processing unit may determine that there is a risk of collision when the reference prediction trajectory, the forward prediction trajectory and the backward prediction trajectory all intersect with the collision determination trajectory that extends in the longitudinal direction of the moving body.

[0008] The assumed values ​​may also be assumed speed values ​​for the components of the moving body's velocity in the direction of forward movement, backward movement, left turn, or right turn.

[0009] The assumed values ​​may also be assumed positional values ​​relative to the position of the target in the direction of the moving body's movement, the direction of its backward movement, the direction of its left turn, or the direction of its right turn.

[0010] The collision determination processing unit may determine that there is a risk of collision if the target is located on the side of the moving body than the reference position based on the moving body, and the reference predicted trajectory intersects the collision determination trajectory.

[0011] The present invention also relates to a control method for a radar device mounted on a moving body, comprising a transmitting antenna for transmitting signals and a receiving antenna for receiving signals that are reflected by a detection target, the method comprising: a detection processing step for detecting a detection target moving in a direction intersecting the direction of travel, backward movement, left turn, or right turn of the moving body based on a signal received by the receiving antenna; a path prediction step for setting a reference predicted trajectory that predicts the movement of the target based on the position and velocity of the target detected in the detection processing step; an auxiliary trajectory setting step for setting an auxiliary predicted trajectory by adding an assumed value that takes variability into account for at least one of the position and velocity of the target that formed the basis for the prediction of the reference predicted trajectory; and a collision determination processing step for setting a collision determination trajectory that indicates the predicted position of the moving body, determining the risk of collision based on whether or not the reference predicted trajectory and the auxiliary predicted trajectory intersect the collision determination trajectory, and outputting the determination result.

[0012] The present invention also relates to a program that causes a computer in a radar device mounted on a moving body to execute the following functions: a detection processing function that detects a target moving in a direction intersecting the direction of travel, backward movement, left turn, or right turn of the moving body based on the signal received by the receiving antenna; a path prediction function that sets a reference predicted trajectory that predicts the movement of the target based on the position and velocity of the target detected by the detection processing function; an auxiliary trajectory setting function that sets an auxiliary predicted trajectory by adding an assumed value that takes variability into account for at least one of the position and velocity of the target that formed the basis for the prediction of the reference predicted trajectory; and a collision determination processing function that sets a collision determination trajectory that indicates the predicted position of the moving body, determines the risk of collision based on whether or not the reference predicted trajectory and the auxiliary predicted trajectory intersect the collision determination trajectory, and outputs the determination result. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a radar device, a radar control method, and a program that can reduce unnecessary alarm notifications even when there are variations in the speed and position of the detected target. [Brief explanation of the drawing]

[0014] [Figure 1] This is a schematic diagram of an alarm system including a radar device according to one embodiment of the present invention. [Figure 2] This is a block diagram showing an example of the hardware configuration of the radar device according to this embodiment. [Figure 3] This is a block diagram showing an example of the functional configuration related to collision detection in the radar device of this embodiment. [Figure 4] This is a schematic plan view showing the forward detection range of the radar device of this embodiment when the vehicle is moving. [Figure 5] This is a schematic plan view showing the detection range behind the vehicle when the radar device of this embodiment is stopped. [Figure 6] This is a schematic plan view illustrating the collision detection method of the radar system in this embodiment, which takes into account the variation in the longitudinal velocity of the target. [Figure 7] This is a schematic plan view illustrating the collision detection method of the radar system in this embodiment, which takes into account the variation in the front-to-back position of the target. [Figure 8] This is a schematic plan view illustrating the collision detection method of the radar system in this embodiment, which takes into account variations in both the longitudinal velocity and position of the target. [Figure 9] This flowchart shows an example of the collision detection process using the radar device of this embodiment. [Modes for carrying out the invention]

[0015] Embodiments of the present invention will be described below with reference to the drawings.

[0016] FIG. 1 is a schematic view of an alarm system 1 including a radar device 2 according to an embodiment of the present invention. The alarm system 1 shown in FIG. 1 is mounted on a vehicle 100 as a moving object, and is a device that notifies a user of the possibility of a collision. In the present embodiment, the “target” refers to an object whose position and speed are estimated based on a received signal from a detection target by a radar.

[0017] The alarm system 1 includes front, rear, left, and right radar devices 2-1 to 2-4, an ECU (Electric Control Unit) 3 that receives detection information from the radar devices 2-1 to 2-4, and a notification device 4 that notifies a user of danger.

[0018] The radar devices 2-1 to 2-4 are target detection devices that detect detection targets other than the vehicle 100 on which the alarm system 1 is mounted. For example, the radar device 2-1 is disposed in the bumper on the left front side of the vehicle 100, and the radar device 2-2 is disposed in the bumper on the right front side of the vehicle. Further, the radar device 2-3 is disposed in the bumper on the left rear side of the vehicle, and the radar device 2-4 is disposed in the bumper on the right rear side of the vehicle. The radar devices 2-1 to 2-4 transmit electromagnetic waves and receive reflected waves reflected by the detection target. Based on the received signal, a target whose distance, speed, azimuth angle, etc. related to the detection target are estimated is detected. The radar devices 2-1 to 2-4 detect the position of the target based on the detected distance and azimuth angle, vehicle information such as the length and width of the vehicle, and information related to the mounting position and angle of the radar device itself in the vehicle. In the following description, when the radar device 2 is mentioned, it means any one or a combination of the radar devices 2-1 to 2-4.

[0019] The ECU 3 is a computer that controls various electronic components of the vehicle 100. When the ECU 3 receives detection information indicating the risk of collision from the radar devices 2-1 to 2-4, it performs control to operate the notification device 4 according to the type thereof. Note that electronic devices other than the radar devices 2-1 to 2-4 and the notification device 4 may be connected to the ECU 3. The alarm system 1 can be said to be one of the systems realized by the ECU 3.

[0020] The notification device 4 is a device that notifies the user of the risk of collision by light, sound, video, or a combination thereof. The notification device 4 is composed of, for example, an indicator light that illuminates, a speaker that generates sound, a display that shows video, etc.

[0021] Next, we will describe the hardware configuration of radar device 2. Note that the hardware configuration of radar device 2 described below with reference to Figure 2 is merely an example and is not the only possible configuration.

[0022] Figure 2 is a block diagram showing an example of the hardware configuration of the radar device 2 in this embodiment. In the example shown in Figure 2, the radar device 2 comprises an antenna unit 5 that transmits and receives electromagnetic waves, and a radar control unit 10 that performs various controls on the radar device 2, such as processing the detection signal from the antenna unit 5.

[0023] The antenna unit 5 comprises a transmitting antenna 6 that transmits signals such as electromagnetic waves, and a receiving antenna 7 that receives the reflected signals when the signals transmitted by the transmitting antenna 6 are reflected by the detection target. The transmitting antenna 6 and the receiving antenna 7 are each composed of multiple antenna elements. The antenna unit 5 processes the received signals from the receiving antenna 7 and transmits them to the radar control unit 10.

[0024] The radar control unit 10 is a computer comprising a processor 11, ROM (read-only memory) 12, RAM (random-access memory) 13, auxiliary storage device 14, and communication I / F (interface) 15, with each part connected by a bus or the like.

[0025] The processor 11 is the central part of the computer that performs calculations and control processes necessary for the operation of the radar device 2, and performs various calculations and processes. The processor 11 is, for example, a CPU (central processing unit), MPU (micro processing unit), SoC (system on a chip), DSP (digital signal processor), GPU (graphics processing unit), ASIC (application specific integrated circuit), PLD (programmable logic device), or FPGA (field-programmable gate array). Alternatively, the processor 11 is a combination of several of these. Furthermore, the processor 11 may also be a combination of these with hardware accelerators, etc.

[0026] The processor 11 controls various parts of the radar device 2 to realize various functions based on programs such as firmware, system software, and application software stored in the ROM 12 or auxiliary storage device 14. The processor 11 also executes the processes described later based on the said programs. Some or all of the said programs may be incorporated into the circuitry of the processor 11.

[0027] ROM12 and RAM13 are the main memory of the computer, with the processor 11 at its core. ROM12 is a non-volatile memory used exclusively for reading data. ROM12 stores programs such as firmware. ROM12 also stores data used by the processor 11 in various processes. RAM13 is memory used for reading and writing data. RAM13 is used as a work area to store data temporarily used by the processor 11 in various processes. RAM13 is typically a volatile memory.

[0028] The auxiliary storage device 14 is, for example, an EEPROM (electric erasable programmable read-only memory), an HDD (hard disk drive), or flash memory. The auxiliary storage device 14 stores, for example, system software and application software from the above-mentioned programs. The auxiliary storage device 14 also stores data used by the processor 11 in performing various processes, data generated by processing by the processor 11, and various setting values.

[0029] Communication I / F15 is an interface for communicating with ECU3. The detection results from the radar control unit 10 are transmitted to ECU3 via communication I / F15.

[0030] Next, the functions of the radar device 2 implemented by the processor 11 will be described. Figure 3 is a block diagram showing an example of the functional configuration of the radar device 2 in this embodiment related to collision detection.

[0031] As shown in Figure 3, the radar control unit 10 of the radar device 2 includes a detection processing unit 21, a collision determination processing unit 22, a trajectory prediction unit 23, and an auxiliary trajectory setting unit 24, as functional units executed by the processor 11.

[0032] The detection processing unit 21 performs a process to detect a target based on the signal received by the receiving antenna 9 of the antenna unit 5. The detection processing unit 21 detects other vehicles and other targets that enter the illumination range as objects 150. The detection processing unit 21 also acquires information about the objects 150 (position, relative speed, and azimuth angle, etc.).

[0033] Furthermore, the detection processing unit 21 sets a detection range as a criterion for initiating the determination of whether or not there is a risk of collision. The detection range is set based on the direction and state of movement of the vehicle 100, etc.

[0034] The detection ranges 101FL and 101FR when the vehicle 100 is moving will be explained with reference to Figure 4. Figure 4 is a schematic plan view showing the forward detection ranges 101FL and 101FR of the radar device 2 of this embodiment when the vehicle 100 is moving. Figure 4 shows the illumination range of radar device 2-1 at the field of view angle θ and the illumination range of radar device 2-2 at the field of view angle θ. Also shown are a left-side reference line 100L extended from the left end of the vehicle 100 in the direction of travel or reversal of the vehicle 100 (hereinafter referred to as the front-rear direction) Y, a right-side reference line 100R extended from the right end of the vehicle 100 in the front-rear direction Y, and a front-end reference line 100F extended from the front end of the vehicle in the left-right direction X that intersects the front-rear direction Y. In this specification, the direction in which the vehicle 100 is traveling is referred to as the front direction Y1, and the direction in which the vehicle 100 is reversing is referred to as the rear direction Y2.

[0035] When the vehicle 100 is moving at a predetermined speed Vs (for example, 10 km / h) or less, the detection processing unit 21 sets the detection range 101FL and the detection range 101FR based on a hypothetical vehicle 110 which is set to a hypothetical position ahead of the actual vehicle 100. The detection range 101FL is set inside the illumination range of radar device 2-1, and the detection range 101FR is set inside the illumination range of radar device 2-2.

[0036] The detection range 101FL is a rectangular area set to the left of the assumed vehicle 110. Taking into account the movement of vehicle 100, the detection range 101FL is set to include the area in front of the assumed vehicle 110's front end reference line 110F, which corresponds to the front end reference line 100F of vehicle 100. The detection range 101FR is a rectangular area set to the right of the assumed vehicle 110. The detection range 101FR is set to include the area in front of the front end reference line 110F.

[0037] The detection ranges 101RL and 101RR when the vehicle 100 is stopped will be explained with reference to Figure 5. Figure 5 is a schematic plan view showing the rear detection ranges 101RL and 101RR of the radar device 2 of this embodiment when the vehicle 100 is stopped. Figure 5 shows a left-side reference line 100L extended in the longitudinal direction Y from the left end of the vehicle 100, a right-side reference line 100R extended in the longitudinal direction Y from the right end of the vehicle 100, and a rear-end reference line 100B extended in the left-right direction X from the rear end of the vehicle 100.

[0038] When vehicle 100 comes to a stop, the detection processing unit 21 sets a detection range 101RL to the left rear of vehicle 100 and a detection range 101RR to the right rear of vehicle 100. Detection range 101RL is set inside the illumination range of radar device 2-3, and detection range 101RR is set inside the illumination range of radar device 2-4.

[0039] The detection range 101RL is a rectangular area set to the left of the left-side reference line 100L at the rear of the vehicle 100. The detection range 101RR is a rectangular area set to the right of the right-side reference line 100R at the rear of the vehicle 100.

[0040] Next, the collision detection processing unit 22 will be described. In order to perform collision detection, the collision detection processing unit 22 sets TTC (Time to collision) lines as collision detection trajectories corresponding to the detection ranges 101FL, 101FR, 101RL, and 101RR.

[0041] Returning to Figure 4, let's describe the TTC line set in front of vehicle 100 when it is moving. The TTC line corresponding to the detection range 101FL is denoted as TTC line 1L. TTC line 1L is set as a straight line extending in the longitudinal direction Y, offset to the left of the left-side reference line 100L, which passes through the left edge of vehicle 100. The longitudinal direction Y position of TTC line 1L is set to include the area in front of the front-end reference line 110F of the assumed vehicle 110, from the rear end of the assumed vehicle 110. The length of TTC line 1L corresponds to the longitudinal direction Y range of the detection range 101FL. Similarly, if the TTC line corresponding to the detection range 101FR is denoted as TTC line 1R, TTC line 1R is set as a straight line extending in the longitudinal direction Y, offset to the right of the right-side reference line 100R, which passes through the right edge of vehicle 100. The longitudinal direction Y position and length of the straight line of TTC line 1R are the same as those of TTC line 1L, and correspond to the longitudinal direction Y range of the detection range 101RL.

[0042] Returning to Figure 5, let's explain the TTC line set behind vehicle 100 when it is stopped. The TTC line corresponding to detection range 101RL is denoted as TTC line 2L. TTC line 2L is set as a straight line extending along the left-side reference line 100L, which passes through the left edge of vehicle 100. The front end position of TTC line 2L in the longitudinal direction Y is set to an offset position below the rear end reference line 100B, and the rear end position is set appropriately based on the length of vehicle 100, etc. The length of the straight line of TTC line 2L also corresponds to the longitudinal direction Y range of detection range 121L. Similarly, if the TTC line corresponding to detection range 101RR is denoted as TTC line 2R, TTC line 2L is set as a straight line extending along the right-side reference line 100R, which passes through the right edge of vehicle 100. The longitudinal position and length of TTC line 2R are the same as TTC line 2R and correspond to the longitudinal direction Y range of detection range 121R.

[0043] The above is an example of the detection range. In the following explanation, anything common to detection ranges 101FL, 101FR, 101RL, and 101RR will be referred to as detection range 101. Similarly, anything common to TTC line 1L, TTC line 1R, TTC line 2L, and TTC line 2R will be referred to as TTC line.

[0044] The collision determination processing unit 22 determines the risk of collision based on whether the predicted trajectory of the target 150, which has entered the detection range 101, intersects with the TTC line. The predicted trajectory of the target 150 is estimated by the trajectory prediction unit 23 and the auxiliary trajectory setting unit 24. Referring to Figure 6, the setting of the reference predicted trajectory 50 by the trajectory prediction unit 23 and the setting of the first predicted trajectory 51a and the second predicted trajectory 52a as auxiliary predicted trajectories by the auxiliary trajectory setting unit 24 will be explained.

[0045] Figure 6 is a schematic plan view illustrating the collision detection of the radar device 2 in this embodiment, taking into account the variation in the velocity of the target 150 in the longitudinal direction Y. Note that the detection range 101 is not shown in Figure 6.

[0046] The path prediction unit 23 performs a process to predict the movement of the target 150 based on the position of the target 150 and its change over time, which is acquired by the detection processing unit 21. For example, the path prediction unit 23 estimates a reference predicted trajectory 50 for several seconds from the time of detection of the target 150 based on the position and relative velocity of the target 150, using a position difference method. The reference predicted trajectory 50 is a vector, and in Figure 6, the reference predicted trajectory 50 is shown as a straight line indicating the direction of movement with the direction of the arrow.

[0047] The path prediction unit 23 changes the criteria for determining a collision based on the position of the target 150, and determines whether the position of the target 150 satisfies the auxiliary trajectory determination conditions. If these auxiliary trajectory determination conditions are met, the auxiliary predicted trajectories (first predicted trajectory 51a and second predicted trajectory 52a), described later, are used to determine whether there is a risk of collision. In this embodiment, a proximity line 130 is set at the reference position, indicating that it is a predetermined distance (for example, 2m) from the tip reference line 131 indicating the tip of the TTC line toward the vehicle 100. If the rear end position of the target 150 (the front right end position as seen from the target 150) is further forward (farther away) than the proximity line 130, it is determined that the auxiliary trajectory determination conditions are met. If the rear end position of the target 150 as seen from the vehicle 100 is further toward the vehicle 100 than the proximity line 130, the risk of collision is determined based on whether the TTC line intersects only the reference predicted trajectory 50.

[0048] The auxiliary trajectory setting unit 24 sets the first predicted trajectory 51a and the second predicted trajectory 52a by considering the variation in velocity in the forward / backward direction Y of the velocity component of the movement direction of the target 150 used by the trajectory prediction unit 23 when estimating the reference predicted trajectory 50. In Figure 6, the first predicted trajectory 51a is shown as a straight line obtained by tilting the reference predicted trajectory 50 at a predetermined angle θv in the forward direction Y1. That is, the first predicted trajectory 51a is a trajectory generated based on the reference predicted trajectory 50 so as to be tilted at an angle θv in the forward direction Y1. Similarly, the second predicted trajectory 52a is shown as a straight line obtained by tilting the reference predicted trajectory 50 at an angle θv in the backward direction Y2. That is, the second predicted trajectory 52a is a trajectory generated based on the reference predicted trajectory 50 so as to be tilted at an angle θv in the backward direction Y2.

[0049] The first predicted trajectory 51a is calculated by adding the assumed velocity value ΔV (e.g., 0.5 m / s) to the longitudinal Y velocity Vfb of the target 150's initial parameters. The second predicted trajectory 52a is calculated by subtracting the assumed velocity value ΔV (e.g., 0.5 m / s) to the longitudinal Y velocity Vfb of the target 150's initial parameters. The assumed velocity value can be calculated empirically or theoretically. For example, setting the assumed velocity value based on the detection accuracy of the radar device 2 can further improve collision detection. In this example, no addition or subtraction of the assumed value is performed for the lateral X velocity Vfl. The assumed velocity value ΔV may also be changed dynamically.

[0050] The collision determination processing unit 22 determines the possibility of collision with the target 150 based on whether the reference predicted trajectory 50, the first predicted trajectory 51a, and the second predicted trajectory 52a intersect the TTC line. In this embodiment, if the auxiliary trajectory determination conditions are met, it is determined that there is a risk of collision if the TTC line intersects all of the reference predicted trajectory 50, the first predicted trajectory 51a, and the second predicted trajectory 52a.

[0051] Referring to Figure 6, an example was described in which the first predicted trajectory 51 and the second predicted trajectory 52 are set considering the variation in the velocity of the target 150 in the longitudinal direction Y. However, the setting of auxiliary trajectories is not limited to this method. Below, a description of setting auxiliary predicted trajectories different from the example in Figure 6 will be given. Note that components common to or similar to the above-described components may be given the same reference numerals and their descriptions may be omitted.

[0052] Figure 7 is a schematic plan view illustrating the collision determination of the radar device 2 in this embodiment, taking into account the variation in the position of the target 150 in the longitudinal direction Y. In the example shown in Figure 7, the auxiliary trajectory setting unit 24 sets the first predicted trajectory 51b and the second predicted trajectory 52b, taking into account the variation in the position of the target 150 in the longitudinal direction Y, which was used by the trajectory prediction unit 23 when estimating the reference predicted trajectory 50.

[0053] In Figure 7, the first predicted trajectory 51b is shown as a straight line parallel to the reference predicted trajectory 50, separated by a predetermined distance d in the forward direction Y1 from the reference predicted trajectory 50. That is, the first predicted trajectory 51b is a trajectory generated at a distance d in the forward direction Y1 based on the reference predicted trajectory 50. Similarly, the second predicted trajectory 52b is shown as a straight line parallel to the reference predicted trajectory 50, separated by a distance d in the backward direction Y2 from the reference predicted trajectory 50. That is, the second predicted trajectory 52a is a trajectory generated at a distance d in the backward direction Y2 based on the reference predicted trajectory 50.

[0054] The first predicted trajectory 51b is calculated by adding an assumed position value ΔP (e.g., 0.5m) to the initial position Pfb in the longitudinal Y direction of the target 150. The second predicted trajectory 52b is calculated by subtracting an assumed position value ΔP (e.g., 0.5m) to the initial position Pfb in the longitudinal Y direction of the target 150. The assumed position value can be calculated empirically or theoretically. For example, by setting the assumed position value based on the detection accuracy of the radar device 2, collision determination can be further improved. In this example, no addition or subtraction of the assumed value is performed for the position Plr in the lateral X direction. The assumed position value ΔP may also be changed dynamically.

[0055] The collision determination processing unit 22 determines the possibility of collision with the target 150 based on whether the reference predicted trajectory 50, the first predicted trajectory 51b, and the second predicted trajectory 52b intersect the TTC line. In this embodiment, a collision risk is determined if the TTC line intersects all of the reference predicted trajectory 50, the first predicted trajectory 51b, and the second predicted trajectory 52b. In this example as well, the collision determination processing unit 22 changes the criteria for determining a collision depending on the position of the target 150. If the rear end position of the target 150 as seen from the vehicle 100 is closer to the vehicle 100 than the proximity line 130, the collision risk is determined based on whether the TTC line intersects only the reference predicted trajectory 50.

[0056] Figure 8 is a schematic plan view illustrating the collision determination of the radar device 2 of this embodiment, which takes into account variations in both the velocity and position in the longitudinal direction Y of the target 150. In the example shown in Figure 8, the auxiliary trajectory setting unit 24 sets the first predicted trajectory 51c and the second predicted trajectory 52c, taking into account variations in both the velocity and position in the longitudinal direction Y of the target 150, which were used by the trajectory prediction unit 23 when estimating the reference predicted trajectory 50.

[0057] In Figure 8, the first predicted trajectory 51c is shown as a straight line obtained by offsetting the base end of the reference predicted trajectory 50 on the target 150 side in the forward direction Y1 and then tilting it at an angle θv in the forward direction Y1. That is, the first predicted trajectory 51c is a trajectory generated based on the reference predicted trajectory 50, with the base end of the reference predicted trajectory 50 separated by a distance d in the forward direction Y1 and tilted at an angle θv in the forward direction Y1. Similarly, the second predicted trajectory 52c is shown as a straight line obtained by offsetting the base end of the reference predicted trajectory 50 on the target 150 side in the backward direction Y2 and then tilting it at an angle θv in the backward direction Y2. That is, the second predicted trajectory 52c is a trajectory generated based on the reference predicted trajectory 50, with the base end of the reference predicted trajectory 50 separated by a distance d in the backward direction Y2 and tilted at an angle θv in the backward direction Y2.

[0058] The first predicted trajectory 51c is calculated by adding an assumed position value ΔP (e.g., 0.5m) to the initial position Pfb of the target 150 in the longitudinal direction Y, and adding an assumed velocity value ΔV (e.g., 0.5m / s) to the initial velocity Vfb of the target 150 in the longitudinal direction Y. The second predicted trajectory 52c is calculated by subtracting an assumed position value ΔP (e.g., 0.5m) to the initial position Pfb of the target 150 in the longitudinal direction Y, and subtracting an assumed velocity value ΔV (e.g., 0.5m / s) to the initial velocity Vfb of the target 150 in the longitudinal direction Y. The assumed position values ​​and velocity values ​​can be calculated empirically or theoretically. For example, by setting the assumed values ​​based on the detection accuracy of the radar device 2, collision determination can be further improved. Furthermore, the combinations of assumed speed and position values ​​are not limited to those described above; adjustments to these values ​​can be made as appropriate. Additionally, the assumed speed value ΔV and position value ΔP may be dynamically changed.

[0059] The collision determination processing unit 22 determines the possibility of collision with the target 150 based on whether the reference predicted trajectory 50, the first predicted trajectory 51c, and the second predicted trajectory 52c intersect the TTC line. In this embodiment, a collision risk is determined if the TTC line intersects all of the reference predicted trajectory 50, the first predicted trajectory 51c, and the second predicted trajectory 52c. In this example as well, the collision determination processing unit 22 changes the criteria for determining a collision depending on the position of the target 150. If the rear end position of the target 150 as seen from the vehicle 100 is closer to the vehicle 100 than the proximity line 130 which is the reference position, the collision risk is determined based on whether the TTC line intersects only the reference predicted trajectory 50.

[0060] If the collision detection processing unit 22 determines that there is a risk of collision with the target 150, it sends a signal to the ECU3, for example via the communication I / F 15, indicating that there is a risk of collision.

[0061] The above describes an example of collision detection. Next, the overall flow of the collision detection process will be explained with reference to Figure 9. Figure 9 is a flowchart showing an example of the collision detection process flow by the radar device 2 of this embodiment.

[0062] First, the detection processing unit 21 detects a target within the illumination range of the radar device 2 (step S101). Next, if the detected target 150 is not located within the detection range 101, the detection processing unit 21 terminates this cycle (step S102; No). If the detected target 150 is located within the detection range 101, the process proceeds to step S103 to proceed with collision determination (step S102; Yes).

[0063] In step S103, the path prediction unit 23 sets a reference predicted trajectory 50 (step S103). Next, the path prediction unit 23 determines whether the position of the target 150 satisfies the above-mentioned auxiliary trajectory determination conditions (step S104). For example, if the rear end position of the target 150 as seen from the vehicle 100 is ahead of the proximity line 130, it is determined that the auxiliary trajectory determination conditions are met and the process moves to step S105 (step S104; Yes). On the other hand, if the rear end position of the target 150 as seen from the vehicle 100 is behind (vehicle 100) the proximity line 130, the process in step S105 is skipped and the process moves to step S106 (step S104; No).

[0064] In step S105, the auxiliary trajectory setting unit 24 sets the first predicted trajectory 51 and the second predicted trajectory 52 (step S106). For example, the first predicted trajectory 51 is one of the first predicted trajectory 51a, first predicted trajectory 51b, and first predicted trajectory 51c described above, and the second predicted trajectory 52 is one of the corresponding second predicted trajectory 52a, second predicted trajectory 52b, and second predicted trajectory 52c.

[0065] In step S106, the collision determination processing unit 22 determines the risk of collision between the vehicle 100 and the target 150 based on the previously set predicted trajectories (step S106). If the first predicted trajectory 51 and the second predicted trajectory 52 were set in step S105, the collision determination processing unit 22 determines that there is a risk of collision if the TTC line intersects all of the reference predicted trajectory 50, the first predicted trajectory 51, and the second predicted trajectory 52. ​​If step S105 is skipped and the first predicted trajectory 51 and the second predicted trajectory 52 are not set, the collision determination processing unit 22 determines that there is a risk of collision if the TTC line intersects the reference predicted trajectory 50.

[0066] The collision detection processing unit 22 terminates processing if it determines that there is no risk of collision (step S106; No). If the collision detection processing unit 22 determines that there is a risk of collision, it proceeds to step S107 (step S106; Yes).

[0067] In step S107, the collision determination processing unit 22 performs a notification process to send a notification to the ECU 3 indicating that there is a risk of collision, and then terminates the process (step S107). When the ECU 3 receives information from the radar device 2 indicating that there is a risk of collision, it activates the notification device 4 to notify the user of the risk of collision.

[0068] As described above, the radar device 2 of this embodiment includes a transmitting antenna 6 that transmits signals and a receiving antenna 7 that receives the reflected signals when the signals transmitted by the transmitting antenna 6 are reflected by the object to be detected, and is mounted on a vehicle 100 as a mobile device. The radar device 2 includes a detection processing unit 21 that detects a target moving in a direction intersecting the longitudinal direction Y based on a signal received by the receiving antenna 7; a path prediction unit 23 that sets a reference predicted trajectory 50 that predicts the movement of the target 150 based on the position and speed of the target 150 detected by the detection processing unit 21; an auxiliary trajectory setting unit 24 that sets an auxiliary predicted trajectory (first predicted trajectory 51, second predicted trajectory 52) by adding an assumed value that takes variability into account for at least one of the position and speed of the target 150 that formed the basis for the prediction of the reference predicted trajectory 50; and a collision determination processing unit 22 that sets a TTC line as a collision determination trajectory indicating the predicted position of the vehicle 100, determines the risk of collision based on whether or not the reference predicted trajectory 50 and the auxiliary predicted trajectory intersect the TTC line, and outputs the determination result.

[0069] As a result, even if there are variations in the position and speed of the target 150 that serves as the basis for estimating the predicted path due to estimation errors of the radar device 2, the collision risk can be accurately determined using the auxiliary predicted trajectory that takes these variations into account, along with the reference predicted trajectory 50, and the determination result can be output. Therefore, it is possible to avoid situations where a collision risk is judged to exist even though there is actually no risk of collision, and the occurrence of false alarms can be effectively suppressed.

[0070] Furthermore, the auxiliary trajectory setting unit 24 of this embodiment sets a first predicted trajectory 51 and a second predicted trajectory 52, which are generated based on the reference predicted trajectory 50, as auxiliary predicted trajectories. The collision determination processing unit 22 determines that there is a risk of collision if all three of the reference predicted trajectory 50, the first predicted trajectory 51, and the second predicted trajectory 52 intersect with the TTC line extending in the longitudinal direction Y of the vehicle 100.

[0071] As a result, a collision risk is determined only when the TTC line intersects all three of the reference prediction trajectories 50, the first prediction trajectory 51, and the second prediction trajectory 52, which are important factors in determining collision risk and are aligned in the longitudinal direction. This allows for a more precise determination of collision risk.

[0072] Furthermore, the assumed values ​​in this embodiment are assumed velocity values ​​for the component of the velocity in the longitudinal direction Y of the moving speed of the target 150.

[0073] This makes it possible to more reliably prevent misjudgments of collision risk caused by variations in the velocity of the longitudinal Y component of the target 150's movement speed.

[0074] Furthermore, the assumed values ​​in this embodiment are assumed positional values ​​with respect to the front-to-back position of the target 150.

[0075] This makes it possible to more reliably prevent misjudgments of collision risk caused by variations in the position of the target 150 in the longitudinal direction Y.

[0076] Furthermore, in this embodiment, the collision determination processing unit 22 determines that there is a risk of collision if the target 150 is located on the side of the vehicle 100 that is closer to the vehicle 100 than the proximity line 130 which is a reference position based on the position of the vehicle 100, and the reference predicted trajectory 50 intersects with the TTC line.

[0077] As a result, when the target 150 is located close to the vehicle 100 and the probability of collision is high, the risk of collision can be reliably detected even when the TTC line does not intersect the first predicted trajectory 51a, by requiring only that the TTC line intersect the reference predicted trajectory 50.

[0078] Furthermore, the control method for the radar device 2 of this embodiment includes: a detection processing step of detecting a target moving in a direction intersecting the longitudinal direction Y of the vehicle 100 based on a signal received by the receiving antenna 7; a path prediction step of setting a reference predicted trajectory 50 that predicts the movement of the target 150 based on the position and speed of the target 150 detected in the detection processing step; an auxiliary trajectory setting step of setting an auxiliary predicted trajectory (first predicted trajectory 51, second predicted trajectory 52) by adding an assumed value that takes into account the variation in at least one of the position and speed of the target 150 that formed the basis for the prediction of the reference predicted trajectory 50; and a collision determination step of setting a TTC line that indicates the predicted position of the vehicle 100, determining the risk of collision based on whether or not the reference predicted trajectory 50 and the auxiliary predicted trajectory intersect the TTC line, and outputting the determination result.

[0079] As a result, even if there are variations in the position and speed of the target 150 that serves as the basis for estimating the predicted path due to estimation errors of the radar device 2, the collision risk can be accurately determined using the auxiliary predicted trajectory that takes these variations into account, along with the reference predicted trajectory 50, and the determination result can be output. Therefore, it is possible to avoid situations where a collision risk is judged to exist even though there is actually no risk of collision, and the occurrence of false alarms can be effectively suppressed.

[0080] Furthermore, the program of this embodiment causes the computer of the radar device 2 to execute a detection processing function that detects a target moving in a direction intersecting the longitudinal direction Y of the vehicle 100 based on the signal received by the receiving antenna 7; a path prediction function that sets a reference predicted trajectory 50 that predicts the movement of the target 150 based on the position and speed of the target 150 detected by the detection processing function; an auxiliary trajectory setting function that sets an auxiliary predicted trajectory (first predicted trajectory 51, second predicted trajectory 52) by adding an assumed value that takes variability into account for at least one of the position and speed of the target 150 that formed the basis of the prediction of the reference predicted trajectory 50; and a collision determination function that sets a TTC line indicating the predicted position of the vehicle 100, determines the risk of collision based on whether or not the reference predicted trajectory 50 and the auxiliary predicted trajectory intersect the TTC line, and outputs the determination result.

[0081] As a result, even if there are variations in the position and speed of the target 150 that serves as the basis for estimating the predicted path due to estimation errors of the radar device 2, the collision risk can be accurately determined using the auxiliary predicted trajectory that takes these variations into account, along with the reference predicted trajectory 50, and the determination result can be output. Therefore, it is possible to avoid situations where a collision risk is judged to exist even though there is actually no risk of collision, and the occurrence of false alarms can be effectively suppressed.

[0082] Although embodiments and modifications of the present invention have been described above, the present invention is not limited to the embodiments described above and can be modified as appropriate. For example, in the above embodiments, the TTC line was a straight line, but it is not limited thereto. The trajectory showing the predicted path may be a curve or a region having a certain range.

[0083] In the above embodiment, the assumed values ​​for the radar device 2 were assumed velocity values ​​in the longitudinal direction Y and assumed position values ​​in the longitudinal direction Y, but are not limited to these. For example, the configuration may be such that the auxiliary predicted trajectory is set by adding or subtracting assumed position values ​​and assumed velocity values ​​in the lateral direction X.

[0084] Alternatively, for example, the detection processing unit 21 may detect a target moving in a direction that intersects the left or right turn direction (left-right direction X) of the vehicle 100, and the path prediction unit 23 may set a reference predicted trajectory 50 that predicts the movement of the target 150 based on the position and speed of the detected target 150. Alternatively, for example, the collision determination processing unit 22 may determine that there is a risk of collision if all of the first predicted trajectory 51 and the second predicted trajectory 52 intersect with the TTC line extending in the left-right direction X.

[0085] In the above embodiment, the radar control unit 10 is configured to perform collision detection processing, but the configuration is not limited to this. For example, the radar control unit 10 may be incorporated into an external device such as the ECU 3, which is an external device to the radar devices 2-1 to 2-4.

[0086] Furthermore, the series of processes in the above-described embodiments and modifications can be executed by hardware or by software. When the series of processes are executed by software, the programs constituting the software are installed on a computer or the like from a network or recording medium. The computer may be a computer built into dedicated hardware. Alternatively, the computer may be a computer capable of performing various functions by installing various programs, such as a general-purpose personal computer. [Explanation of symbols]

[0087] 2. Radar equipment 6 Receiving antenna 7 Transmitting antenna 21 Detection Processing Unit 22 Collision detection processing unit 23 Career Guidance Prediction Department 24 Auxiliary trajectory setting section

Claims

1. A radar device mounted on a moving object, comprising a transmitting antenna that transmits a signal and a receiving antenna that receives the signal that is reflected by the object being detected after the signal transmitted by the transmitting antenna has been transmitted, A detection processing unit detects a detection target moving in a direction that intersects the direction of the moving body's forward movement, backward movement, left turn, or right turn, based on the signal received by the receiving antenna. A path prediction unit sets a reference predicted trajectory that predicts the movement of an object based on the position and velocity of the object detected by the detection processing unit, An auxiliary trajectory setting unit sets an auxiliary predicted trajectory by adding an assumed value that takes into account the variation in at least one of the position and velocity of the target that formed the basis for the prediction of the aforementioned reference predicted trajectory, A collision determination processing unit sets a collision determination trajectory indicating the predicted position of the moving object, determines the risk of collision based on whether both the reference prediction trajectory and the auxiliary prediction trajectory intersect with the collision determination trajectory, and outputs the determination result. A radar device equipped with [a specific feature / feature].

2. The auxiliary trajectory setting unit is, As the auxiliary prediction trajectories, a first prediction trajectory and a second prediction trajectory are set, which are generated based on the reference prediction trajectory. The collision determination processing unit, The radar device according to claim 1, which determines that there is a risk of collision when the reference prediction trajectory, the first prediction trajectory and the second prediction trajectory all intersect with the collision determination trajectory that extends in the direction of travel, backward movement, left turn, or right turn of the moving body.

3. The radar device according to claim 2, wherein the assumed value is a speed assumption value for the component of the moving body's velocity in the direction of travel, the direction of reversal, the direction of left turn, or the direction of right turn in relation to the moving speed of the target.

4. The radar device according to claim 2, wherein the assumed value is a positional value relative to the position of the target in the direction of the moving body's movement, the direction of its backward movement, the direction of its left turn, or the direction of its right turn.

5. The collision determination processing unit, The radar device according to any one of claims 1 to 4, wherein if the target is located on the side of the moving body than the reference position based on the moving body, a collision risk is determined when the reference predicted trajectory intersects the collision determination trajectory.

6. A control method for a radar device mounted on a moving object, comprising a transmitting antenna that transmits a signal and a receiving antenna that receives the signal that is reflected by a detection target after the signal transmitted by the transmitting antenna has been reflected, A detection process step in which the receiving antenna detects a target moving in a direction that intersects the direction of the moving body's forward movement, backward movement, left turn, or right turn, based on the signal received by the receiving antenna, A path prediction step in which a reference predicted trajectory is set by predicting the movement of the target based on the position and velocity of the target detected in the detection processing step, A supplementary trajectory setting step, which sets an auxiliary prediction trajectory by adding an assumed value that takes into account the variation in at least one of the position and velocity of the target that formed the basis for the prediction of the aforementioned reference prediction trajectory, A collision determination processing step includes setting a collision determination trajectory that indicates the predicted position of the moving object, determining the risk of collision based on whether both the reference prediction trajectory and the auxiliary prediction trajectory intersect with the collision determination trajectory, and outputting the determination result. A method for controlling a radar device, including [a specific component].

7. The radar system, which is mounted on a mobile object, includes a transmitting antenna that transmits a signal and a receiving antenna that receives the reflected signal when the signal transmitted by the transmitting antenna is reflected by the object being detected, and the computer of the radar system is configured to transmit a signal to a mobile object. A detection processing function that detects a target moving in a direction intersecting the direction of the moving body's forward or backward movement, or in a left turn or right turn direction, based on the signal received by the receiving antenna. A path prediction function sets a reference predicted trajectory that predicts the movement of an object based on the position and velocity of the object detected by the detection processing function, An auxiliary trajectory setting function that sets an auxiliary prediction trajectory by adding an assumed value that takes into account the variation in at least one of the position and velocity of the target that formed the basis for the prediction of the aforementioned reference prediction trajectory, A collision determination processing function sets a collision determination trajectory indicating the predicted position of the moving object, determines the risk of collision based on whether both the reference prediction trajectory and the auxiliary prediction trajectory intersect with the collision determination trajectory, and outputs the determination result. A program that executes the command.

Images