TRANCTION SYSTEM

Abstract

Data collection system with: - a detection section (2) comprising: an output function that outputs a detection wave into the environment of a vehicle and a detection function that detects an object around the vehicle based on a reflected wave corresponding to the detection wave reflected from the object; - a determination section (3, S110) which, during a journey of the vehicle at a speed below a predetermined speed, determines that the object is definitely present around the vehicle if the number of times the object is detected by the detection function of the detection section exceeds a predetermined number of times; - a control section (3, S130) that causes the detection function of the detection section to operate without the output function of the detection section when the vehicle is traveling at a speed greater than or equal to the predetermined speed; and - a tuning section (3, S180) that tunes and increases the predetermined number of times specified for the determination section when the object is detected two or more times by the detection function operated by the control section while the vehicle is traveling at a speed greater than or equal to the predetermined speed.

Description

AREA OF INVENTION

[0001] The present invention relates to a detection system. STATE OF THE ART

[0002] Progress has been made in the development of a system that detects obstacles around a vehicle using an ultrasonic wave or similar technology. This type of system typically includes an ultrasonic sensor with a generating or output function for producing an ultrasonic wave and a receiving or detection function for receiving an ultrasonic wave. This sensor is positioned at multiple locations on a vehicle's bumper. When the sensor receives an ultrasonic wave generated by the output sensor, it recognizes the received wave as a reflection from an object around the vehicle. The sensor then calculates a distance to the object based on the time between generation and reception. The sensor also alerts the driver to the object's presence if the calculated distance is less than or equal to a predetermined distance.

[0003] A technology for reducing false detection by an ultrasonic sensor can be important. For example, JP 2013-104689A discloses an ultrasonic sensor that emits an ultrasonic wave by oscillating an oscillator of the ultrasonic sensor at a frequency different from the oscillator's resonant frequency, and determines that the ultrasonic sensor is in a faulty condition when the frequency of a wave received signal matches the resonant frequency.

[0004] The inventors of the present invention have identified the following current circumstances. It has been shown that the above system for detecting an obstacle around a vehicle causes false detections in some cases by misinterpreting a raindrop or similar object falling onto and adhering to the sensor as receiving a reflected wave. Rain or similar events are possible and frequent phenomena, so this type of false detection significantly reduces the reliability of the obstacle detection system. Accordingly, there is a strong demand for a system that can reduce this type of false detection.

[0005] JP H11-304911 A discloses an ultrasonic sensor which, in addition to an ultrasonic transmitting section and an ultrasonic receiving section, has a wiper operation detection section / raindrop sensor. Upon detection of raindrops by the wiper operation detection section / raindrop sensor, successive detection cycles of reflected waves are intensified to determine the presence of an obstacle. From JP 2006-153801 A, it is known to use a contact state detection device as a rain sensor when the vehicle speed is higher than or equal to a predetermined speed, and as a distance measuring sensor when the vehicle speed is lower than the predetermined speed. BRIEF SUMMARY OF THE INVENTION

[0006] The object of the present invention is to provide a detection system that can detect an object around a vehicle and reduce the probability of false detection due to an effect such as a raindrop.

[0007] The problem is solved by the subject matter of the main claim. Advantageous further developments are specified in the dependent claims.

[0008] The detection system of the present invention increases the predetermined number of times set for object detection around the vehicle when the detection function of the detection section that is allowed to operate detects a raindrop or the like as an object, specifically while the vehicle is traveling at a speed greater than or equal to the predetermined speed. In this way, the probability of a false detection due to the detection of an object that should not be detected, such as a raindrop, can be reduced.

[0009] A detection system of the present invention can detect an object around a vehicle and simultaneously reduce the probability of false detection due to an effect such as a raindrop. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The tasks, features, and advantages of the present invention will become clearer from the following detailed description with reference to the accompanying drawings. The drawings show: Fig. 1. A diagram of a configuration of a detection system according to an embodiment; and Fig. 2. A flowchart to illustrate an example of processing flows. DESCRIPTION OF EXECUTION FORMS

[0011] An embodiment of the present invention is described below with reference to the drawings. Fig. Figure 1 shows a schematic view of a configuration of a detection system 1 of the embodiment of the present invention. The detection system 1 is provided, for example, in a vehicle and comprises an ultrasonic sensor 2, an electronic control unit (ECU) 3, a display section 4, a sound output section 5, a gearshift lever 6 and a speed sensor 7.

[0012] The ultrasonic sensor 2 (hereinafter referred to as the sensor) is a sensor for detecting obstacles around the vehicle, i.e., within the vehicle's vicinity. The sensor 2 is structured such that it can perform not only a microphone function for receiving an ultrasonic wave (wave reception, detection) but also a speaker function for emitting an ultrasonic wave (wave emission, output). More precisely, the sensor 2 comprises an oscillator 20 and a circuit unit 21. The circuit unit 21 contains a wave transmitter circuit 22, which is an electronic circuit for emitting an ultrasonic wave, and a wave receiver circuit 23, which is an electronic circuit for receiving an ultrasonic wave. The oscillator 20 can, for example, be constructed from a piezoelectric ceramic oscillator.

[0013] Detecting an obstacle around a vehicle, i.e., detecting an object around a vehicle based on a reflected wave, which is an ultrasonic wave reflected by the object, is given as an example of the detection function. Emitting an ultrasonic wave as a detection wave into the vehicle's surroundings is given as an example of the output function.

[0014] The loudspeaker function of sensor 2 generates an ultrasonic wave by oscillating the oscillator 20, which is set into vibration by an electrical signal transmitted by the wave transmitter circuit 22, i.e., by a so-called piezoelectric effect. The microphone function generates an electrical signal based on the piezoelectric effect by oscillating the oscillator 20, which is set into vibration by an ultrasonic wave reaching it from the outside, and transmits the generated electrical signal to the wave receiver circuit 23.

[0015] The wave receiver circuit 23 can, for example, include a distance calculation circuit 24. The distance calculation circuit 24 is a circuit that considers a received ultrasonic wave as a reflected wave of an ultrasonic wave generated by the sensor 2 and reflected by an object (obstacle) present around the vehicle, and calculates a distance between the vehicle and the obstacle. More precisely, the distance calculation circuit 24 has a clocking function to calculate the distance to the obstacle by multiplying the time required from generation to reception of an ultrasonic wave by the speed of the ultrasonic wave and dividing the product by two. Furthermore, the wave receiver circuit 23 can include a filter for removing noise from the received ultrasonic wave, a waveform shaping circuit, and the like.

[0016] As in Fig. As shown in Figure 1, multiple sensors 2 can be provided on the vehicle. These multiple sensors 2 can be located on a bumper of the vehicle. For example, the sensors 2 can be located in two positions on the left and right of a front bumper and in four symmetrical positions on the left and right of a rear bumper. Alternatively, only one sensor 2 can be provided.

[0017] The electronic control unit (ECU) 3 performs complete obstacle detection processing around the vehicle. The ECU 3 has a configuration similar to a conventional computer, including a CPU that performs various types of calculations and information processing, RAM as a volatile memory unit that provides a working area for the CPU, and memory 30 as a non-volatile memory unit that stores programs and data required for operations performed by the CPU. Memory 30 can store a program 31 according to which processing of the present invention is carried out.

[0018] The detection system 1 further comprises the display section 4, the sound output section 5, the shift lever 6, and the speed sensor 7 as parts relating to the present invention. The display section 4 and the sound output section 5 form a part that is linked to a notification of the detection of an obstacle. The display section 4 can, for example, be provided by a display corresponding to an operating indicator located inside the vehicle. The display section 4 provides a notification of the detection of an obstacle around the vehicle to the interior of the vehicle by displaying characters / letters, images, or the like. The sound output section 5 is, for example, a loudspeaker or the like, located inside the vehicle.The sound output section 5 provides a notification of the detection of an obstacle around the vehicle to the interior of the vehicle by emitting a sound (alarm tone, ringing, voice signals or the like).

[0019] The gearshift lever 6 is, as is known, a part operated by the driver to change gears in the vehicle's transmission. The current position (range) of the gearshift lever 6 is detected by a position sensor 60. The speed sensor 7 has a rotation detection section, such as an angular momentum sensor, to calculate the vehicle's speed based on the detection of a wheel's rotation (or to generate information indicating the vehicle's speed). The above parts are interconnected via vehicle-specific communication lines to enable information exchange.

[0020] The detection system 1 with the configuration described above performs a series of steps of an obstacle detection process, which additionally includes processing according to the present invention to detect an obstacle around the vehicle. Fig. Figure 2 shows an example of the processing sequences. The ones in the Fig. The processing sequences or procedures shown in 2 can be programmed in advance and stored in memory 30, as program 31, which is called and executed automatically by ECU 3, for example.

[0021] According to the Fig. In the process shown in Figure 2, the ECU 3 initially performs a predetermined initialization process in S10 and then determines in S20 whether the gear selector 6 is in a P position (park position, parking range), based on the output (output signal) of the position sensor 60. If it is determined that the gear selector 6 is in the P position (S20: YES), the process proceeds to S30. If it is determined that the gear selector 6 is not in the P position (S20: NO), the process proceeds to S60.

[0022] As the sequence progresses to S30, the ECU 3 performs processing from S30 to S50 to execute a sensor fault detection process in a parked state. More precisely, the ECU 3 initially transmits an ultrasonic wave from sensor 2 at S30. As described above, sensor 2 has both the transmitting and receiving functions of an ultrasonic wave. In this case, the wave receiving circuit 23 also detects an oscillation of the oscillator 20 during the transmission of the ultrasonic wave. The oscillation of the oscillator 20 during the transmission of the ultrasonic wave comprises an oscillation during the period of sending an electrical signal from the wave transmitting circuit 22 to the wave transmission and a reverberation oscillation of the oscillator 20 after the completion of this period.

[0023] In S40, the ECU 3 determines whether the entire oscillation up to the point where the reverberation oscillation ends has been correctly detected by the wave receiver circuit 23. If it is determined that the oscillation up to the reverberation oscillation has been correctly detected, the ECU 3 determines that sensor 2 is in its normal state. If it is determined that the oscillation up to the reverberation oscillation has not been detected, the ECU 3 determines that sensor 2 is in a fault condition, due to a freeze of oscillator 20, an open circuit at a specific position between oscillator 20 and the ECU 3, or any other reason.

[0024] If it is determined that sensor 2 is in its normal state (S40: YES), the sequence returns to S20. If it is determined that the sensor is in a fault state (S40: NO), the sequence advances to S50. When the sequence advances to S50, ECU 3 outputs a notification about the detected fault state of sensor 2 to the vehicle's interior. This notification can be displayed on display section 4, emitted as an audible signal (voice signal) via the audio output section, or by other means.

[0025] As the sequence progresses to S60, ECU 3 determines whether the vehicle's speed is less than or equal to a predetermined speed, based on information received from speed sensor 7. If it is determined that the vehicle's speed is below the predetermined speed (S60: YES), the sequence progresses to S70. If it is determined that the vehicle's speed is above the predetermined speed (S60: NO), the sequence progresses to S130. The predetermined speed specified here could, for example, be 10 km / h.

[0026] As the sequence progresses to S70, the ECU 3 performs an obstacle detection process around the vehicle for low-speed driving, based on the processing of S70 to S120. In contrast, as the sequence progresses to S130, the ECU 3 performs a rain estimation process for driving at a higher speed, as a main process of the present invention, and a process for reducing obstacle false detection, which occurs concurrently with the rain estimation process, based on the processing of S130 to S190.

[0027] Initially, as the sequence progresses to S70, ECU 3 emits an ultrasonic wave from sensor 2. When a reflected wave corresponding to the emitted ultrasonic wave and reflected by a specific obstacle, or an object such as a raindrop (hereinafter collectively referred to as an ultrasonic wave or the like), reaches sensor 2, ECU 3 receives a signal corresponding to the ultrasonic wave or the like from sensor 2. In this case, in the subsequent step S80, ECU 3 processes only one signal corresponding to the ultrasonic wave or the like, received at a period after the time determined to be the end of the above echo, as a target for obstacle detection in signals received at S70.Sensor 2, which has received the ultrasonic wave or similar signal, considers the received ultrasonic wave or similar signal as a reflected wave that was reflected and received by the obstacle surrounding the vehicle, and calculates a distance to the obstacle in the manner described above. The above process of sending, receiving, and calculating is performed multiple times for each of the sensors 2 on the vehicle.

[0028] The ECU 3 then determines in S80 whether a detection has occurred at sensor 2 (i.e., whether sensor 2 is receiving a signal corresponding to the ultrasonic wave or the like). If it is determined that a detection has occurred (S80: YES), the process advances to S90. If it is determined that no detection has occurred (S80: NO), the process advances to S100. When the process advances to S90, the ECU 3 increments the number of times a detection has occurred (variable A) (hereinafter also referred to as the number of detections) by one. When the process advances to S100, the ECU 3 resets the number of detections.

[0029] In S110, the ECU 3 then determines whether sensor 2 has detected the obstacle at least a predetermined number of times (determination value) at the same distance. If it is determined that the number of detections is greater than or equal to the predetermined number of times (S110: YES), the process proceeds to S120. If it is determined that the number of detections is less than the predetermined number of times (S110: NO), the process returns to S20 to repeat the processes described above. The predetermined number of times in this step can be preset to a suitable number or can be determined by a user via an input unit provided in the vehicle.

[0030] As the process progresses to S120, ECU 3 issues a notification about the presence of an obstacle around the vehicle. More precisely, this notification can be displayed on display section 4 or emitted as an audible signal (speech) via sound output section 5. Thus, based on the processing described above, the driver or a passenger is appropriately informed of the presence of an obstacle around the vehicle while driving at low speed. In this case, a notification is only issued if the presence of the obstacle is detected multiple times, based on the processing in S110.More precisely, even in a false detection scenario where an object is present at a certain distance from sensor 2, based on a collision between the sensor and the object, such as a raindrop, a notification is only triggered if the object is detected multiple times at the same distance. This reduces the likelihood of false detections of objects like raindrops.

[0031] In contrast, as the process progresses to S130, the ECU 3 executes the raindrop estimation process for a journey not at a low speed, which is the main process of the present invention, and the process for reducing obstacle false detection, which, as described above, occurs concurrently with the raindrop estimation process. More precisely, the ECU 3 initially supplies the respective sensors 2 provided on the vehicle with energy in S130 to operate the sensors 2. In this case, the ECU 3 does not operate any components associated with transmitting an ultrasonic wave (wave transmitting circuit 22 and the like), but only components associated with receiving an ultrasonic wave (wave receiving circuit 23 and the like). Accordingly, only wave reception takes place, without an ultrasonic wave being emitted by the sensor 2.

[0032] The ECU 3 then determines in S140 whether a reading has been received from each of the respective sensors 2. If it is determined that a reading has been received from sensors 2 (S140: YES), the process advances to S150. If it is determined that no reading has been received from sensors 2 (S140: NO), the process returns to S20 to repeat the above steps. When the process advances to S150, the ECU 3 increments a reading counter by one, where the reading counter counts the number of readings from each of the sensors 2.

[0033] The ECU 3 then determines in S160 whether each of the sensors 2 (wave receiver circuits 23 of the sensors 2) has operated ten times. If it is determined that each of the sensors 2 has not yet operated ten times (S160: No), the sequence returns to S120. If it is determined that the receiver of each of the sensors has operated ten times (10) (S160: Yes), the sequence advances to S170 to determine whether the multiple sensors 2 have detected the ultrasonic wave or the like at least twice. If it is determined that the multiple sensors 2 have detected the ultrasonic wave or the like at least twice (S170: Yes), the sequence advances to S180. If it is determined that the multiple sensors 2 have not detected the ultrasonic wave or the like at least twice (S170: No), the sequence advances to S190.

[0034] As described above, no ultrasonic wave is emitted by sensors 2 in S130. Accordingly, the ultrasonic wave or similar signal received (detected) in S130 is not a reflected wave from an obstacle around the vehicle. A reception in S130 is considered, for example, to be based on a collision between a raindrop and oscillator 20.

[0035] Accordingly, the process progresses to S180 if sensors 2 do not detect a raindrop or similar object while driving at low speed. Conversely, the process progresses to S190 if sensors 2 do not detect any raindrops or similar objects. Consequently, in S180, ECU 3 executes a process to increase the number of times a detection determination is made (determination value in S110). In this case, even if the number of detections in S80 includes the number of detections of an object, such as a raindrop during rain, the detection of an obstacle is only determined if the object is detected a relatively high number of times during rain, based on the processing in S180. In this way, the false detection of an obstacle during rain decreases.

[0036] In contrast, when the process progresses to S190, ECU 3 performs a process to reset the number of times a detection determination is taken (hereinafter also referred to as the number of detection determinations) (resetting the number of times to a default value). In this case, the number of detection determinations in S190 reverts to a default value suitable for a non-rain condition after it has stopped raining, even if the number of detection determinations in S180 is incremented based on the detection of a raindrop while the vehicle is moving. Accordingly, this step prevents a situation where an object is difficult to detect after it has stopped raining because the number of detection determinations has been incremented. After completing processing in S180 or S190, ECU 3 returns to S20 to repeat the above processes.

[0037] The above are those in the Fig. The processing methods shown in section 2 are described. The methods or procedures described above increase the number of detection determinations during the detection of a raindrop or similar object, which is achieved by effectively utilizing the state of driving at a speed other than low. Accordingly, the false detection of an obstacle due to the effect of a raindrop or similar object decreases. Furthermore, the number of detection determinations automatically returns to a value corresponding to a non-rain state after it has stopped raining. Furthermore, the detection of a raindrop or similar object during driving at a speed can be achieved, for example, by effectively utilizing the state of driving at a speed other than low prior to obstacle detection based on the determination process in S60.The probability of a false detection, in which a raindrop or the like is detected, is reduced by the determination process described above in S170, compared to the determination of a raindrop based on, for example, the detection only once by only one sensor.

[0038] Although the detection of a raindrop is described herein, the raindrop can include a snowflake, a hailstone, a graupel drop, and the like, and can furthermore include any phenomena that can be detected by sensor 2. Furthermore, although the determination process in S170 of the Fig. 2. Instead of performing a binary determination of whether the current state is rain or no rain, the process in S170 can be changed to one that includes determining the intensity of rainfall. To implement this, the process in S180 can be changed to one that increases the number of detection determinations as the number of detections by all sensors increases. In this case, the probability of a false detection of an obstacle during heavy rain decreases as a result of the increased number of detection determinations.

[0039] A detection system according to one aspect of the present invention comprises: a detection section comprising an output function for emitting a detection wave into the environment of a vehicle and a detection function for detecting an object around the vehicle based on a reflected wave corresponding to the detection wave reflected by the object; a determination section comprising determining that the object is definitely present around the vehicle when the number of times the object is detected by the detection function of the detection section exceeds a predetermined number of times; a control section comprising causing the detection function of the detection section to operate without the output function of the detection section to operate when the vehicle is traveling at a speed greater than or equal to a predetermined speed;and a tuning section that increases the predetermined number of times specified for the determination section when the object is detected by the detection function operated by the control section, while the vehicle is traveling at a speed greater than or equal to the predetermined speed.

[0040] The detection system of the present invention increases the predetermined number of times set for object detection around the vehicle when the detection function of the detection section, which is allowed to operate, detects a raindrop or the like as an object, while the vehicle is traveling at a speed greater than or equal to the predetermined speed. The detection system thus effectively reduces the probability of a false detection by detecting an object that should not be detected, such as a raindrop.

[0041] The above embodiment can be suitably modified within the scope of the present invention. Although, for example, the ultrasonic sensor is used in the above embodiment, the present invention is not limited to the configuration with the ultrasonic sensor. The present invention is equally applicable to any type of detection section that can detect both an object around a vehicle and an object such as a raindrop. Furthermore, although in the above description only one ECU 3 is used in the Fig. The process shown in section 2 requires multiple CPUs to allow each CPU to execute a portion of the data. Fig. 2. The process shown is to be listed individually.

[0042] It is noted that a flowchart or the execution of the flowchart in the present application comprises sections (also referred to as steps), each designated, for example, as S10. Furthermore, each section can be divided into several subsections, while several sections can be combined into a single section.

Claims

[1] Data collection system with: - a detection section (2) comprising: an output function that outputs a detection wave into the environment of a vehicle and a detection function that detects an object around the vehicle based on a reflected wave corresponding to the detection wave reflected from the object; - a determination section (3, S110) which, during a journey of the vehicle at a speed below a predetermined speed, determines that the object is definitely present around the vehicle if the number of times the object is detected by the detection function of the detection section exceeds a predetermined number of times; - a control section (3, S130) that causes the detection function of the detection section to operate without the output function of the detection section when the vehicle is traveling at a speed greater than or equal to the predetermined speed; and - a tuning section (3, S180) that tunes and increases the predetermined number of times specified for the determination section when the object is detected two or more times by the detection function operated by the control section while the vehicle is traveling at a speed greater than or equal to the predetermined speed. [2] Detection system according to claim 1, further comprising a sub-tuning section (3, S140) which tunes and decreases the predetermined number of times specified for the determination section when the object is not detected by the detection function operated by the control section, in a state in which the tuning section has tuned and increased the predetermined number of times. [3] Detection system according to claim 1 or 2, wherein the tuning section tunes and increases an increase amount of the predetermined number of times when the number of times the object is detected by the detection function operated by the control section increases. [4] Detection system according to any one of claims 1 to 3, wherein the detection wave is provided by an ultrasonic wave. [5] Detection system according to claim 1, wherein - the detection section has several sensors (2); and - the tuning section increases the predetermined number of times specified for the determination section if the object is detected two or more times by each of the multiple sensors while the vehicle is traveling at a speed greater than or equal to the predetermined speed.

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