Object detection system
The object detection system addresses interference from stopped vehicles by adjusting waiting times and steering angles to minimize ultrasonic interference, enhancing detection accuracy and reducing false alarms.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- AISIN CORP
- Filing Date
- 2022-10-05
- Publication Date
- 2026-06-30
Smart Images
Figure 0007882079000001 
Figure 0007882079000002 
Figure 0007882079000003
Abstract
Description
Technical Field
[0006] ,
[0001] Embodiments of the present invention relate to an object detection system.
Background Art
[0002] In a system that detects an object existing around a vehicle by transmitting and receiving ultrasonic waves, a technique for suppressing interference by ultrasonic waves transmitted from other vehicles is used. For example, a technique is disclosed in which a waiting time from the end of a detection time, which is the time for transmitting and receiving ultrasonic waves once, until the start of the next detection time is changed according to the steering angle.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0004] When the vehicle is stopped, the steering wheel is often at a substantially central position (the steering angle is substantially zero degrees), so depending on the prior art, interference by ultrasonic waves from other vehicles during stopping may not be sufficiently suppressed.
[0005] Therefore, one of the problems to be solved by the embodiments of the present invention is to provide an object detection system capable of suppressing interference by ultrasonic waves from other vehicles during stopping.
Means for Solving the Problems
[0006] One embodiment of the present invention is an object detection system for detecting objects present around a vehicle, comprising: a calculation unit that calculates the distance from a sensor to an object by transmitting and receiving ultrasonic waves from a sensor installed on the side of the vehicle body; a waiting time control unit that changes the waiting time from the end of a predetermined detection time, which is the time it takes for the sensor to transmit and receive ultrasonic waves once, until the start of the next detection time; an interference determination unit that determines whether or not the vehicle is in a stopped interference state where it may be subjected to interference from ultrasonic waves transmitted from other vehicles when the vehicle is stopped, based on vehicle information indicating the driving state of the vehicle and distance information indicating the distance calculated by the calculation unit; and a steering state setting unit that, if the vehicle is in a stopped interference state, sets the steering angle of the vehicle to a predetermined reference steering angle, regardless of the actual steering angle of the vehicle, wherein the interference determination unit determines an interference state indicating whether or not there is interference from ultrasonic sensors from other vehicles to sensors located on the inside of the vehicle's turning direction and sensors located on the outside of the turning direction based on the steering angle set by the steering state setting unit, and the waiting time control unit sets a random time for the waiting time of sensors located on the inside of the turning direction and sensors located on the outside of the turning direction based on the reference steering angle and the interference state.
[0007] According to the above configuration, when a vehicle enters a stopped interference state, the steering angle is set to a predetermined reference steering angle regardless of the actual steering angle. Then, based on the ultrasonic interference state from other vehicles on the inside and outside of the turning direction based on the reference steering angle, a random time is set to be included in the waiting time for the sensor's ultrasonic transmission and reception. In other words, when a stopped interference state occurs, the sensor's waiting time automatically changes according to the interference state on both sides of the vehicle. As a result, even if another vehicle equipped with an object detection system with the same specifications as the vehicle is stopped on the side of the vehicle, interference from the other vehicle's sensor's ultrasonic waves can be suppressed, thereby suppressing the occurrence of false detections, etc.
[0008] Furthermore, in the above configuration, the waiting time control unit may set the waiting time to a random time selected from a predetermined set of random times, based on the interference state of the sensor located on the inside of the rotation direction and the interference state of the sensor located on the outside of the rotation direction.
[0009] With the above configuration, the waiting time can be changed by selecting one random time from a predetermined set of random times, thereby reducing the computational load.
[0010] Furthermore, in the above configuration, the multiple random times include a base random time and an additional time, and the multiple random times may be generated by adopting either a first additional time, a second additional time longer than the first additional time, or a third additional time longer than the second additional time as the additional time.
[0011] With the above configuration, multiple random time points can be generated without generating multiple random numbers.
[0012] Furthermore, in the above configuration, at least one sensor may be installed on each of the following locations: the front of the left side of the vehicle, the front of the right side, the rear of the left side, and the rear of the right side.
[0013] With the above configuration, the waiting time can be controlled with greater precision by taking into account the distance to other vehicles at the front and rear of the vehicle's side.
[0014] Furthermore, in the above configuration, the waiting time control unit sets the following conditions: the first condition is when the distance calculated by the calculation unit is less than the first distance; the second condition is when the absolute value of the difference between the current distance and the past distance is greater than the second distance which is greater than the first distance; if other vehicles are present only on the outside of the turning direction, and the distance calculated by the sensor located on the inside of the turning direction does not satisfy the first and second conditions, the random time is set to include the base random time and the first additional time; if other vehicles are present only on the inside of the turning direction, and the distance calculated by the sensor located on the inside of the turning direction satisfies at least one of the first and second conditions, and on the outside of the turning direction If the distance calculated by the sensor located in the first position does not satisfy the second condition, the random time may be set to include a second additional time that is longer than the base random time and the first additional time. If other vehicles are present on the outside and inside of the turning direction, and the distance calculated by the sensor located on the inside of the turning direction satisfies at least one of the first and second conditions, and at least one of the two object distances calculated by two sensors located on the outside of the turning direction, which are installed on the front and rear of the vehicle respectively, satisfies the second condition, the random time may be set to include a third additional time that is longer than the base random time and the second additional time.
[0015] According to the above configuration, the random time can be appropriately varied based on conditions related to the distance from the vehicle (sensor) to other vehicles, and the interference state on the inside and outside of the turning direction. [Brief explanation of the drawing]
[0016] [Figure 1] Figure 1 is a top view showing an example of the configuration of a vehicle equipped with the object detection system of the embodiment. [Figure 2] Figure 2 is a top view illustrating an example of a situation in which an object detection system mounted on a vehicle according to the embodiment may be interfered with by ultrasonic waves transmitted from other vehicles. [Figure 3] Figure 3 shows an example of the functional configuration of the object detection system according to the embodiment. [Figure 4]FIG. 4 is a diagram showing an example of reflected wave information and distance information according to an embodiment. [Figure 5] FIG. 5 is a diagram showing an example of the relationship between the detection time and the waiting time according to an embodiment. [Figure 6] FIG. 6 is a diagram showing an example of the relationship between the turning direction of a vehicle and the position of a side sensor according to an embodiment. [Figure 7] FIG. 7 is a diagram showing an example of the configuration of the waiting time according to an embodiment. [Figure 8] FIG. 8 is a flowchart showing an example of a process for setting the waiting time of a side sensor in an object detection system according to an embodiment. MODE FOR CARRYING OUT THE INVENTION
[0017] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The configurations of the embodiments described below, as well as the actions and effects brought about by these configurations, are examples, and the present invention is not limited to the description below.
[0018] FIG. 1 is a top view showing an example of the configuration of a vehicle 1 equipped with an object detection system S according to an embodiment. The object detection system S is a system for detecting objects (obstacles such as other vehicles, pedestrians, and road structures) existing around the vehicle 1.
[0019] The object detection system S of the present embodiment includes four front sensors 11F installed at the front end of the vehicle body 2, four rear sensors 11R installed at the rear end of the vehicle body 2, four side sensors 11S (an example of sensors) installed on the side surface of the vehicle body 4, and an ECU (Electronic Control Unit) 15. Hereinafter, when it is not necessary to distinguish between the front sensors 11F, the rear sensors 11R, and the side sensors 11S, they may be referred to as sensors 11.
[0020] Each of the multiple sensors 11 transmits ultrasonic waves and receives reflected waves generated when the transmitted ultrasonic waves are reflected by an object. Based on information such as TOF (Time of Flight) and Doppler shift obtained through this transmission and reception of ultrasonic waves, information regarding the distance to objects around the vehicle 1, the position of the objects, and the movement of the objects can be generated.
[0021] In this embodiment, the side sensors 11S include a left front side sensor 11SLF installed on the front of the left side of the vehicle body 2, a left rear side sensor 11SLR installed on the rear of the left side of the vehicle body 2, a right front side sensor 11SRF installed on the front of the right side of the vehicle body 2, and a right rear side sensor 11SRR installed on the rear of the right side of the vehicle body 2. When it is not necessary to distinguish between the left front side sensor 11SLF, the left rear side sensor 11SLR, the right front side sensor 11SRF, and the right rear side sensor 11SRR, they may be referred to as side sensors 11S.
[0022] Figure 2 is a top view illustrating an example of a situation in which an object detection system S mounted on vehicle 1 of the embodiment may be interfered with by ultrasonic waves Wta transmitted from another vehicle 1A. In Figure 2, a situation is illustrated in which vehicle 1, equipped with an object detection system S having similar specifications, and another vehicle 1A are parked facing each other with a distance D between their right sides. Such a situation can occur, for example, when waiting at a traffic light on a multi-lane road or when parked in a parking lot.
[0023] In the situation described above, if the distance D is below a predetermined value, the right front side sensor 11SRF of vehicle 1 may receive not only the reflected ultrasonic wave Wr of the ultrasonic wave Wt it transmits, but also the ultrasonic wave Wta transmitted by the left front side sensor 11SLF of the other vehicle 1A. In such a case, the object detection system S of vehicle 1 may be affected by interference from the ultrasonic wave Wta from the other vehicle 1A, potentially leading to false object detection, a decrease in detection accuracy, etc. Similar phenomena may occur with the other side sensors 11S as well.
[0024] The object detection system S of this embodiment has a function to suppress ultrasonic interference from other vehicles 1A as described above.
[0025] Figure 3 shows an example of the functional configuration of the object detection system S of the embodiment. Here, we will describe the configuration related to the suppression of interference from ultrasonic Wta from other vehicles 1A as described above.
[0026] Each side sensor 11S includes a transmitting unit 51 and a receiving unit 52. The transmitting unit 51 is the part that generates ultrasonic waves and may be configured using, for example, a transducer such as a piezoelectric element, a DA converter, an amplifier, a control circuit that performs calculation processing and control processing, etc. The receiving unit 52 is the part that receives reflected waves generated when ultrasonic waves transmitted from the transmitting unit 51 are reflected by an object and outputs a signal (reflected wave information) indicating the intensity of the reflected waves and may be configured using, for example, a transducer, an AD converter, an amplifier, a control circuit, etc. The transmitting unit 51 and the receiving unit 52 may be configured as an integrated unit or as separate units.
[0027] The ECU15 is a computing unit that performs various information processing and can be configured using components such as a CPU (Central Processing Unit), memory, ASIC (Application Specific Integrated Circuit), FPGA (Field Programmable Gate Array), etc. The ECU15 is connected to each side sensor 11S via a network such as LIN (Local Interconnect Network), receives detection signals output from each side sensor 11S, and outputs control signals for controlling each side sensor 11S.
[0028] Furthermore, the ECU 15 connects to the drive mechanism 21, braking mechanism 22, output device 23, etc., provided in the vehicle 1 via a network such as CAN (Controller Area Network) to send and receive various information. The drive mechanism 21 is a mechanism that generates the driving force to move the vehicle 1, and can be configured using, for example, an internal combustion engine, an electric motor, a hybrid system, etc. The braking mechanism 22 is a mechanism that generates the braking force to decelerate the vehicle 1, and can be configured using, for example, a brake disc, a brake pad, a hydraulic mechanism, an actuator, a regenerative braking system, etc. The output device 23 is a device that outputs information to the occupants of the vehicle 1, and can be configured using, for example, a speaker, a display, etc.
[0029] Furthermore, the ECU15 may be connected to sensors 11 other than the side sensor 11S (front sensor 11F and rear sensor 11R) via LIN or the like, or it may be connected to other mechanisms (e.g., transmission mechanism, steering mechanism, communication device, etc.) via CAN or the like.
[0030] The ECU 15 of this embodiment includes a calculation unit 101, a notification control unit 102, a braking control unit 103, a vehicle information acquisition unit 104, an interference determination unit 105, and a waiting time control unit 106. These functional units 101 to 106 can be configured through the cooperation of the hardware and software constituting the ECU 15. Furthermore, at least a portion of the functional units 101 to 106 may be configured by dedicated hardware (circuits, etc.).
[0031] The calculation unit 101 generates distance information indicating the distance from each side sensor 11S to an object based on the reflected wave information obtained by the transmission and reception of ultrasonic waves at the side sensors 11S. The reflected wave information may be, for example, information indicating the time-series change in the intensity of the reflected wave.
[0032] Figure 4 shows an example of reflected wave information and distance information in an embodiment. The reflected wave information illustrated here is represented as an envelope L showing the time-series change in the amplitude value of the transducer built into the side sensor 11S. Here, the envelope L is illustrated when the transmitting unit 51 and the receiving unit 52 of the side sensor 11S share the same transducer. In the graph of Figure 4, the horizontal axis corresponds to the elapsed time since the start of ultrasonic transmission, and the vertical axis corresponds to the amplitude value of the transducer of the side sensor 11S, i.e., the intensity of the ultrasonic waves.
[0033] Figure 4 shows the transmission time Ttr, reception time Tre, and detection time Td. The transmission time Ttr is the time it takes to vibrate the transducer to generate the ultrasonic waves transmitted from the side sensor 11S. As shown by the envelope L in Figure 4, the amplitude value of the transducer attenuates after the end of the transmission time Ttr. The reception time Tre is the time to wait for the reception of the reflected waves that result from the ultrasonic waves generated during the transmission time Ttr being reflected by an object. The detection time Td is the time required to send and receive ultrasonic waves once, and includes one transmission time Ttr and one reception time Tre.
[0034] If an object to be detected (e.g., another vehicle, pedestrian, road structure, or other obstacle) is present within the detection range of the side sensor 11S, a peak PK1 with an amplitude value exceeding the threshold Th will appear within the reception time Tre (after the amplitude value has decayed after the transmission time Ttr), as shown in Figure 4. The threshold Th is an amplitude value set to distinguish whether the object that reflects the reflected wave is the object to be detected or an object other than the object to be detected (e.g., the road surface). The elapsed time (TOF) corresponding to such a peak PK1 is distance information indicating the distance from the side sensor 11S to the object to be detected. Note that the form of distance information is not limited to the above.
[0035] As described above, if the object detection system S of vehicle 1 is interfered with by ultrasonic waves from another vehicle 1A (for example, as shown in Figure 2), a peak PK2 caused by ultrasonic waves Wta from the other vehicle 1A may appear, regardless of the position of the object to be detected, as shown in Figure 4. Such a peak PK2 can cause false detection of objects, a decrease in detection accuracy, and other problems.
[0036] Returning to Figure 3, the notification control unit 102 performs processing to notify the occupants of obstacles approaching the vehicle 1, etc., based on the distance information generated by the calculation unit 101. For example, the notification control unit 102 controls the output device 23 installed inside the vehicle so that a predetermined sound or display is output when the distance between the vehicle 1 and the obstacle falls below a threshold.
[0037] The braking control unit 103 performs processing to avoid contact between the vehicle 1 and an obstacle based on the distance information generated by the calculation unit 101. For example, if the braking control unit 103 determines that there is a high probability of contact between the vehicle 1 and an obstacle, it controls the braking mechanism 22 to automatically decelerate the vehicle 1.
[0038] The vehicle information acquisition unit 104 acquires vehicle information, including information regarding the driving state of the vehicle 1 on which the object detection system S is installed. The vehicle information includes the speed and steering angle of the vehicle 1.
[0039] The interference determination unit 105 determines whether vehicle 1 is in a stopped interference state based on distance information generated by the calculation unit 101, the speed of vehicle 1 acquired by the vehicle information acquisition unit 104, etc. A stopped interference state is a state in which, when vehicle 1 is stopped, the object detection system S may be subjected to interference from ultrasonic waves transmitted from another vehicle 1A. The method for determining whether or not a vehicle is in a stopped interference state is not particularly limited, but for example, if vehicle 1 is in a stopped state (e.g., vehicle speed is 0 or approximately 0), and an object (other vehicle 1A) is within a predetermined distance from the side sensor 11S of vehicle 1, and the distance from vehicle 1 (side sensor 11S) to the object (other vehicle 1A) does not change or approximately change for a predetermined time or longer, then it can be determined that a vehicle is in a stopped interference state. When the interference determination unit 105 determines that a vehicle is in a stopped interference state, it outputs a stopped interference state occurrence signal. Furthermore, the interference determination unit 105 determines whether or not there is ultrasonic interference from another vehicle 1A to the side sensors 11S located on the inside of the vehicle 1's turning direction (for example, the left front side sensor 11SLF and the left rear side sensor 11SLR when turning left), and whether or not there is ultrasonic interference from another vehicle 1A to the side sensors 11S located on the outside of the vehicle 1's turning direction (for example, the right front side sensor 11SRF and the right rear side sensor 11SRR when turning left).
[0040] The waiting time control unit 106 changes the waiting time for each side sensor 11S from the end of one detection time Td until the start of the next detection time Td.
[0041] Figure 5 shows an example of the relationship between the detection time Td and the waiting time Tw in the embodiment. As shown in Figure 5, a waiting time Tw is interposed between each of the multiple detection times Td. That is, a waiting time Tw exists between the end of the first detection time Td1 and the start of the second detection time Td2.
[0042] Returning to Figure 3, the waiting time control unit 106 of this embodiment includes a random time generation unit 111, a steering state setting unit 112, and a waiting time modification unit 113.
[0043] The random time generation unit 111 generates a reference random time based on a predetermined random number. The method for generating the reference random time is not particularly limited, but for example, random numbers can be generated based on a predetermined random number table or algorithm stored in memory, and the reference random time can be generated based on these random numbers.
[0044] The steering state setting unit 112 sets the steering angle of vehicle 1 to a predetermined reference steering angle, regardless of the actual steering angle of vehicle 1, when vehicle 1 is in a stopped interference state. The reference steering angle is the steering angle when the steering wheel of vehicle 1 is turned in a predetermined direction (for example, to the left) by a predetermined angle (for example, an angle of 90 degrees or more).
[0045] When vehicle 1 is in a stopped interference state, the waiting time modification unit 113 randomly changes the waiting time Tw of the side sensors 11S located on the inside of the turning direction of vehicle 1 and the side sensors 11S located on the outside of the turning direction, based on the reference steering angle and the interference state. The waiting time modification unit 113 may also change the waiting time while vehicle 1 is in motion.
[0046] Figure 6 shows an example of the relationship between the turning direction Dt of the vehicle 1 in the embodiment and the position of the side sensors 11S. As shown in Figure 6, when the vehicle 1 is turning to the left, the left front side sensor 11SLF and the left rear side sensor 11SLR, which are installed on the left side of the vehicle body 2, are located on the inside, and the right front side sensor 11SRF and the right rear side sensor 11SRR, which are installed on the right side of the vehicle body 2, are located on the outside. For example, in a stopped interference state, if the reference steering angle is set to the steering angle when the steering wheel is rotated by a predetermined angle to the left, then, as shown in Figure 6, regardless of the actual steering angle, the side sensors 11S located on the inside of the turning direction will be the left front side sensor 11SLF and the left rear side sensor 11SLR, and the side sensors 11S located on the outside of the turning direction will be the right front side sensor 11SRF and the right rear side sensor 11SRR.
[0047] The waiting time modification unit 113 modifies the random waiting time Tw of the side sensor 11S based on the reference rudder angle and interference state. The waiting time modification unit 113 sets the waiting time Tw to a random time selected from a predetermined set of random times, based on, for example, the interference state of the side sensor 11S located on the inside in the turning direction and the interference state of the side sensor 11S located on the outside in the turning direction. This random time may include, for example, a reference random time generated by the random time generation unit 111 and a predetermined additional time.
[0048] Figure 7 shows an example of the configuration of the waiting time Tw in the embodiment. As shown in Figure 7, the random time Tr set in the waiting time Tw includes a reference random time Tr1 and an additional time Ta. The reference random time Tr1 is a value that fluctuates periodically based on a predetermined random number table or algorithm. The additional time Ta is a different value depending on predetermined conditions, and in this embodiment, it is set to either a first additional time Ta1, a second additional time Ta2 that is greater than the first additional time Ta1, or a third additional time Ta3 that is greater than the second additional time Ta2.
[0049] The waiting time modification unit 113 may set an additional time Ta based on whether the distance from vehicle 1 (side sensor 11S) to other vehicle 1A (hereinafter also referred to as object distance) meets predetermined conditions. These conditions may include, for example, a first condition in which the object distance is less than a predetermined first distance, and a second condition in which the absolute value of the difference between the current object distance and the past object distance from the present time back a predetermined time is greater than a second distance which is greater than the first distance.
[0050] When vehicle 1 is in a stopped interference state, if another vehicle 1A is present only outside the turning direction Dt, and the object distance calculated by the side sensors 11S located inside the turning direction Dt (for example, the left front side sensor 11SLF and the left rear side sensor 11SLR) does not satisfy the first and second conditions, the waiting time changing unit 113 sets the random time Tr to include the reference random time Tr1 and the first additional time Ta1.
[0051] Furthermore, when vehicle 1 is in a stopped interference state, if another vehicle 1A exists only on the inside of the turning direction Dt, and the object distance calculated by the side sensor 11S located on the inside of the turning direction Dt satisfies at least one of the first and second conditions, and the object distance calculated by the side sensor 11S located on the outside of the turning direction Dt (for example, the right front side sensor 11SRF and the right rear side sensor 11SRR) does not satisfy the second condition, the waiting time changing unit 113 sets the random time Tr to include the reference random time Tr1 and the second additional time Ta2.
[0052] Furthermore, when vehicle 1 is in a stopped interference state, if other vehicles 1A are present on the outside and inside of the turning direction Dt, and the object distance calculated by the side sensor 11S located on the inside of the turning direction Dt satisfies at least one of the first and second conditions, and at least one of the two object distances calculated by the two side sensors 11S located on the outside of the turning direction Dt and installed on the front and rear of vehicle 1 respectively (for example, the right front side sensor 11SRF and the right rear side sensor 11SRR) satisfies the second condition, the waiting time changing unit 113 sets the random time Tr to include the reference random time Tr1 and the third additional time Ta3.
[0053] According to the process described above, the random time Tr can be appropriately changed based on the object distance and the interference state on the inside and outside of the rotation direction.
[0054] Figure 8 is a flowchart showing an example of the process for setting the waiting time Tw for the side sensor 11S in the object detection system S of the embodiment. The calculation unit 101 generates distance information (object distance) indicating the distance from each side sensor 11S to an object located around (on the side) of the vehicle 1 based on the reflected wave information acquired from each side sensor 11S (S101).
[0055] The interference determination unit 105 determines whether or not vehicle 1 is in a stopped interference state based on the speed of vehicle 1 included in the vehicle information, distance information generated by the calculation unit 101, etc. (S102). The method for determining whether or not vehicle 1 is in a stopped interference state is not particularly limited, but for example, if vehicle 1 is in a stopped state, and an object is within a predetermined distance from the vehicle 1's side sensor 11S, and the distance to the object does not change or does not change substantially for a predetermined time or longer, then it is determined that vehicle 1 is in a stopped interference state.
[0056] If vehicle 1 is not in a stopped interference state (S102: No), the waiting time control unit 106 sets the waiting time Tw according to a predetermined normal setting (S115), and then the processing from step S101 onwards is executed again.
[0057] If vehicle 1 is in a stopped interference state (S102: Yes), the interference determination unit 105 determines whether or not another vehicle 1A (object) exists only outside the turning direction based on the reference steering angle (S103). If another vehicle 1A exists only outside the turning direction (S103: Yes), the interference determination unit 105 determines whether or not the object distance inside the turning direction satisfies the first and second conditions (S104). If the object distance inside the turning direction does not satisfy the first and second conditions (S104: Yes), the waiting time control unit 106 sets the additional time Ta to the first additional time Ta1 (S105), and sets the waiting time Tw (random time Tr) to the time obtained by adding the additional time Ta (first additional time Ta1 in this situation) to the reference random time Tr1 (S106). After that, the processing from step S101 onwards is executed again.
[0058] If the situation is not such that another vehicle 1A exists only on the outside of the turning direction (S103: No), the interference determination unit 105 determines whether or not another vehicle 1A exists only on the inside of the turning direction (S107). If another vehicle 1A exists only on the inside of the turning direction (S107: Yes), the interference determination unit 105 determines whether or not the object distance on the inside of the turning direction satisfies at least one of the first and second conditions (S108). If the object distance on the inside of the turning direction satisfies at least one of the first and second conditions (S108: Yes), the interference determination unit 105 determines whether or not the object distance on the outside of the turning direction does not satisfy the second condition (S109). If the distance of the object outside the rotation direction does not satisfy the second condition (S109: Yes), the waiting time control unit 106 sets the additional time Ta to the second additional time Ta2 (S110), and sets the waiting time Tw (random time Tr) to the time obtained by adding the additional time Ta (in this case, the second additional time Ta2) to the reference random time Tr1 (S106). After that, the process from step S101 onwards is executed again. If the distance of the object inside the rotation does not satisfy either the first or second condition (S108: No), or if the distance of the object outside the rotation direction satisfies the second condition (S109: No), the waiting time control unit 106 sets the waiting time Tw according to a predetermined normal setting (S115), and then the process from step S101 onwards is executed again.
[0059] If the situation is not such that another vehicle 1A is present only on the inside of the turn (S107: No), the interference determination unit 105 determines whether or not other vehicle 1A is present on both the inside and outside of the turn direction (S111). If other vehicle 1A is present on both the inside and outside of the turn direction (S111: Yes), the interference determination unit 105 determines whether or not the object distance on the inside of the turn direction satisfies at least one of the first and second conditions (S112). If the object distance on the inside of the turn direction satisfies at least one of the first and second conditions (S112: Yes), the interference determination unit 105 determines whether or not at least one of the two object distances measured by the two side sensors 11S on the outside of the turn direction satisfies the second condition (S113). If at least one of the distances between two objects measured by the two outer side sensors 11S in the rotation direction satisfies the second condition (S113: Yes), the waiting time control unit 106 sets the additional time Ta to the third additional time Ta3 (S114) and sets the waiting time Tw (random time Tr) to the time obtained by adding the additional time Ta (in this case, the third additional time Ta3) to the reference random time Tr1 (S106). After that, the processing from step S101 onwards is executed again. If no other vehicle 1A exists on the inside or outside of the turning direction (S111: No), if the object distance on the inside of the turning direction does not satisfy either the first or second condition (S112: No), or if both of the object distances measured by the two side sensors 11S on the outside of the turning direction do not satisfy the second condition (S113: No), the waiting time control unit 106 sets the waiting time Tw according to a predetermined normal setting (S115), and then the processing from step S101 onwards is executed again.
[0060] As described above, according to this embodiment, when vehicle 1 enters a stopped interference state, the steering angle is set to a predetermined reference steering angle regardless of the actual steering angle. Then, based on the ultrasonic interference state from other vehicle 1A on the inside and outside of the turning direction based on the reference steering angle, the random time Tr included in the waiting time Tw for ultrasonic transmission and reception of the side sensor 11S is set. In other words, when a stopped interference state occurs, the waiting time Tw of the side sensor 11S automatically changes according to the interference state on both sides of vehicle 1. As a result, even if another vehicle 1A equipped with an object detection system S having the same specifications as vehicle 1 is stopped on the side of vehicle 1, interference between the side sensor 11S of vehicle 1 and the ultrasonic waves from the side sensor 11S of the other vehicle 1A can be suppressed, and the occurrence of false detections can be suppressed.
[0061] The program that causes a computer (ECU15, etc.) to execute the processes necessary to realize the various functions of the object detection system S described above can be provided as an installable or executable file recorded on a computer-readable recording medium such as a CD (Compact Disc)-ROM, flexible disk (FD), CD-R (Recordable), or DVD (Digital Versatile Disk). Furthermore, the program may be provided or distributed via a network such as the Internet.
[0062] While embodiments of this disclosure have been described above, the embodiments and their modifications described herein are merely examples and are not intended to limit the scope of the invention. The novel embodiments and modifications described above can be implemented in various forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. The embodiments and modifications described above are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]
[0063] 1...Vehicle, 1A...Other vehicle, 2...Vehicle body, 11F...Front sensor, 11R...Rear sensor, 11S...Side sensor, 15...ECU, 21...Drive mechanism, 22...Braking mechanism, 23...Output device, 51...Transmitter, 52...Receiver, 101...Calculation unit, 102...Notification control unit, 103...Braking control unit, 104...Vehicle information acquisition unit, 105...Interference determination unit, 106...Waiting time control unit, 111...Random time generation unit, 112...Steering state setting unit, 113...Waiting time change unit. Ta...Additional time, Ta1...First additional time, Ta2...Second additional time, Ta3...Third additional time, Td...Detection time, Tr...Random time, Tr1...Reference random time, Tw...Waiting time
Claims
1. An object detection system for detecting objects present around a vehicle, A calculation unit that calculates the distance from the sensor to the object by transmitting and receiving ultrasonic waves from a sensor installed on the side of the vehicle body, A waiting time control unit that changes the waiting time from the end of a predetermined detection time, which is the time it takes for the sensor to transmit and receive ultrasound once, until the start of the next detection time, An interference determination unit determines whether or not the vehicle is in a stopped interference state where it may be subjected to interference from ultrasonic waves transmitted from other vehicles when stopped, based on vehicle information indicating the driving state of the vehicle and distance information indicating the distance calculated by the calculation unit. When the vehicle is in the aforementioned stop interference state, the steering state setting unit sets the steering angle of the vehicle to a predetermined reference steering angle, regardless of the actual steering angle of the vehicle. Equipped with, The interference determination unit determines the interference state, which indicates whether or not there is interference from ultrasonic waves from other vehicles between the sensors located on the inside of the vehicle's turning direction and the sensors located on the outside of the turning direction, based on the steering angle set by the steering state setting unit. The waiting time control unit sets a random waiting time for the sensors located on the inside of the turning direction and the sensors located on the outside of the turning direction, based on the reference rudder angle and the interference state. Object detection system.
2. The waiting time control unit sets the waiting time to a random time selected from a predetermined set of random times, based on the interference state of the sensor located inside the rotation direction and the interference state of the sensor located outside the rotation direction. The object detection system according to claim 1.
3. The aforementioned random time includes a base random time and an additional time. The aforementioned multiple random times are generated by adopting one of the following as the additional time: a first additional time, a second additional time longer than the first additional time, or a third additional time longer than the second additional time. The object detection system according to claim 2.
4. The sensors are installed at least once each on the front of the left side of the vehicle, the front of the right side, the rear of the left side, and the rear of the right side. The object detection system according to claim 1.
5. The aforementioned waiting time control unit, In a scenario where the distance calculated by the calculation unit is less than the first distance as the first condition, and the absolute value of the difference between the current distance and the past distance is greater than the second distance which is greater than the first distance, If another vehicle is present only on the outside of the turning direction, and the distance calculated by the sensor located on the inside of the turning direction does not satisfy the first and second conditions, the random time is set to include the base random time and the first additional time. If another vehicle is present only on the inside of the turning direction, and the distance calculated by the sensor located on the inside of the turning direction satisfies at least one of the first and second conditions, and the distance calculated by the sensor located on the outside of the turning direction does not satisfy the second condition, then the random time is set to include the reference random time and a second additional time that is longer than the first additional time. If other vehicles are present on the outside and inside of the turning direction, and the distance calculated by a sensor located on the inside of the turning direction satisfies at least one of the first and second conditions, and at least one of the two object distances calculated by two sensors located on the outside of the turning direction, which are installed on the front and rear of the vehicle respectively, satisfies the second condition, then the random time is set to include a third additional time that is longer than the reference random time and the second additional time. The object detection system according to claim 4.