JP2005271745A - Occupant sensing device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an occupant sensing device for a vehicle capable of performing a positive sensing whether or not an occupant kept under a predetermined state is present in a vehicle compartment of the vehicle such as an automobile and the like without using any special standard pattern for a comparison of the occupant's present position, frame and attitude. <P>SOLUTION: This occupant sensing device for a vehicle comprises an optical sensor light receiving unit where an inner side of a compartment of the vehicle is divided into N sections to detect a light reflected from a reflection item contained in each of the divided regions, an item presence discrimination means for discriminating for every regions whether or not the reflected item is present in reference to the reflected light, and an occupant sensing means for sensing a state of the reflected item. The divided regions of the N-sections are set perpendicular to an optical axis of the light receiving unit of the optical sensor and concurrently a presence or a non-presence of the reflected item, its position and its frame or its attitude are discriminated under application of the divided region and the distribution of the reflection light. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an occupant detection device for a vehicle that detects the state of an occupant in a passenger compartment of a vehicle such as an automobile, and more particularly to an occupant detection device used to perform appropriate airbag control in an automobile. .

  As a conventional occupant detection device of this type, for example, those disclosed in Patent Documents 1 and 2 are known. The occupant detection device disclosed in Patent Document 1 has an occupant discrimination processing device, and in the occupant discrimination processing device, by comparing the distance distribution output from the distance measurement calculation processing device with a standard pattern stored in advance. The determination of the occupant's posture is performed. The occupant detection device disclosed in Patent Document 2 detects a large object by the AND outputs of a plurality of sensors, and determines the occupant.

Japanese Patent Laid-Open No. 10-329641 (particularly paragraph [0015]) JP 2001-30872 A (particularly paragraphs [0046] [0047])

  However, in the occupant detection device disclosed in Patent Literature 1, in order to reliably determine the occupant's posture, it is necessary to store many standard patterns in advance and compare them with each other. It is difficult to make this determination at high speed. Further, in the occupant detection device disclosed in Patent Document 2, a large object is determined as an occupant, so that, for example, a newspaper spread by the occupant may be erroneously determined as an occupant, and accurate occupant determination is difficult.

  The present invention has been made to solve such a conventional problem, and more quickly and more reliably determine the state of the occupant, particularly the presence / absence of the occupant, position, physique, or posture. It proposes a vehicle occupant detection device that can be used.

  A vehicle occupant detection device according to the present invention divides a vehicle interior of a vehicle into a plurality of regions, a light receiving unit that detects reflected light from a reflecting object included in each of the divided regions, and the light detection unit that detects the light A reflecting object detection means for determining the presence or absence of a reflecting object for each divided area based on reflected light for each divided area; and an occupant determining means for determining the state of an occupant based on the presence or absence of a reflecting object for each divided area; The divided area is set perpendicular to the optical axis of the light receiving unit.

  According to the vehicle occupant detection device of the present invention, without using a special standard pattern for comparison, the occupant in the vehicle interior, the presence of a reflective object, its position, physique, or its posture can be reliably obtained at a higher speed. Can be detected.

Embodiment 1 FIG.
Next, an optimal embodiment of a vehicle occupant detection device according to the present invention will be described with reference to the drawings. FIG. 1 shows Embodiment 1 of a vehicle occupant detection device according to the present invention. In FIG. 1, the occupant detection device is indicated by block 100. The occupant detection device 100 generates an output 100a, and this output 100a is supplied to an electronic control device 150 for controlling an airbag of an automobile. The output 100a is a deployment permission signal ALL that permits deployment of the airbag when there is an occupant to be protected by the airbag in the vehicle interior and the occupant is in a normal position to be protected.

  The electronic control device 150 for airbag control controls the deployment of each airbag arranged corresponding to the driver seat and the passenger seat of the front seat of the automobile. The electronic control device 150 for airbag control receives the output 140a of the collision sensor 140 as well as the output 100a of the occupant detection device 100. The collision sensor 140 detects the impact when the automobile collides with an obstacle or the like, and becomes high level, for example. The airbag control electronic control device 150 deploys the airbag when the output 140a becomes a high level in a state where the output 100a is the permission signal ALL.

  The occupant detection device 100 includes an optical sensor 110, a scanning mechanism (not shown), a CPU 130, and a signal processing IC 114. The optical sensor 110 includes a light emitting element (LED) 111 and a light receiving element (imaging element) 112. The light emitting element 111 has a predetermined size and a predetermined shape, for example, a rectangular light emitting surface LS, and irradiation light from the light emitting surface LS is irradiated toward the interior of the automobile. The light receiving element 112 is disposed at a position where the light irradiated from the light emitting surface LS receives reflected light reflected by the reflecting object R in the vehicle interior. The light receiving surface of the light receiving element 112 has a reflected image LR of the light emitting surface LS. Forms an image.

  The reflected image LR is formed on the light receiving element 112. Both the light emitting element 111 and the light receiving element 112 are formed of semiconductor elements. The light receiving element 112 is not an image pickup element, but may be a light receiving element array including, for example, a photodiode (PD).

  The light emitting element 111 is connected to the light emitting element driving circuit 113, and the light emitting surface LS emits light according to the drive signal from the light emitting element driving circuit 113. The light receiving element 112 is connected to a signal processing IC 114 that performs signal processing of the light receiving element 112. The signal processing IC 114 transmits a signal SigB (AD) obtained by preprocessing the light reception signal SigA (AD) from the light receiving element 112 to the CPU 130.

  As shown in FIG. 2, the light emitting element 111 and the light receiving element 112 constituting the optical sensor 110 are arranged in a passenger compartment 160 of the automobile. Specifically, the light receiving element 112 is disposed near the door portion 161 of the passenger compartment 160, for example, the A pillar 162. Further, the light emitting element 111 is disposed near the center of the dashboard 163 portion of the passenger compartment 160, for example. Here, two light emitting elements 111 are arranged. Here, it is desirable to arrange the optical axis of the light emitting element 111 and the optical axis of the light receiving element 112 to be substantially perpendicular. If the optical axes of the light receiving element 112 and the light emitting element 111 are arranged in parallel and the sensor is directed from the door on the passenger seat side toward the passenger compartment, an object present on the driver seat side becomes a false detection factor. However, as described above, if the light emitting element 111 is disposed on the passenger side dashboard and the light receiving element 112 having an optical axis perpendicular thereto is disposed on the door portion, the object on the driver side is irradiated with light. There is no problem because there is no. In FIG. 2, reference numeral 164 denotes the front seat. The front seat 164 is a driver seat or a passenger seat.

  As shown by a broken line in FIG. 2, the optical sensor 110 is divided into a two-dimensional area D1 located above the front seat 164 and a two-dimensional area D2 located below the front seat 164 in the passenger compartment 160. Arrange to irradiate light. The light irradiation areas D1 and D2 are set so as to be located on a plane parallel to the front-rear direction of the passenger compartment 160 orthogonal to the axle of the automobile. Further, as shown in FIG. 3, the light receiving element 112 divides the output 165 into regions E1 and E2 shown in FIG. 3 on the basis of the optical axis 166, and images LR1 of reflected light from the light irradiation areas D1 and D2, respectively. , LR2 are arranged as shown in FIG. Since the boundary between the areas E1 and E2 is used as an area threshold value for determining the physique in the occupant physique determining means which is a processing means described below, a light receiving element is arranged and set in advance at that position.

  Referring to FIG. 1, CPU 130 is configured by a microcomputer, for example, and includes a memory 131 and an occupant detection unit 132. The CPU 130 generates a light emission control signal St for the light emitting element 111 and a control signal Ss for the signal processing IC 114.

  The light emission control signal St causes the light emitting element 111 to emit light via the light emitting element driving circuit 113. The control signal Ss is used for, for example, processing inside the signal processing IC 114 and control of the light receiving element 112. The light reception output signal obtained from the light receiving element 112 is an analog signal or a digital signal generated corresponding to the reflected light. The light reception output signal is preprocessed in the signal processing IC 114 and then stored in the memory 131. Remembered. Here, for simplicity, a digital signal is used. However, the signal processing IC 114 may not be used, and only the light receiving element 112 and the CPU 130 may perform the same function.

  The occupant detection unit 132 of the CPU 130 outputs a deployment permission signal ALL for the airbag if there is an occupant to be protected by the airbag in the vehicle interior 160 based on the received light output signal stored in the memory 131. Issue 100a.

  The light receiving element 112 is mounted on a main body substrate (not shown). Here, the light emitting element 111 is separated from the light receiving element 112. It is assumed that a light projecting lens (not shown) is arranged in front of the light emitting element 111 and a light receiving lens (not shown) is arranged in front of the light receiving element 112.

  FIG. 4 is a flowchart of processing performed by the CPU 130. This processing flowchart includes eight processing steps S1 to S8 following the start. It should be understood that these processing steps S1 to S8 also mean processing means, and the flowchart of FIG. 4 shows the processing procedure of these processing means. Processing steps (processing means) S1 to S8 are sequentially executed in that order. When the processing step (processing means) S8 is executed, the process returns to the processing step (processing means) S1, and the processing steps (processing means) S1 to S8 are repeated. Processing steps (processing means) from processing steps S4 to S8 are processing steps (processing means) by the occupant detection unit 132.

  The first processing step (processing means) S1 is a light quantity control step (control means) for the light emitting element 111. In this control step (control means) S1, the light quantity of the irradiation light of the light emitting element 111 is set. This light quantity is basically set to be a constant light quantity within one processing step and between each light emitting element, but the set light quantity can be adjusted.

  The next processing step (processing means) S2 is a control step (control means) for the light emitting element drive circuit 113 of the light emitting element 111. For example, the light emitting element is only exposed during the exposure of the reflected light existing section of the light emitting element 111 by the light receiving element 112. 111 is driven. The light emitting element 111 is driven at the same timing every processing cycle.

  Processing step S3 is a processing step (processing means) for preprocessing in the signal processing IC 114 of the light receiving element 112. For example, a light reception output signal obtained from the light receiving element 112 is input to the signal processing IC 114, and the next step S5 is performed. The process for setting the brightness threshold value for detecting the reflective object is performed.

FIG. 5 is an explanatory diagram for explaining the principle of calculating the luminance threshold for use in the processing step S5 based on the light reception output signal in the processing step (processing means) S3 of FIG. 4, and FIG. An output image of the element 112 is shown, and FIG. 5B shows a processing flowchart in the signal processing IC 114. In FIG. 5 (a),
LR1: an image of reflected light in the region E1,
LR2: image of reflected light in the region E2,
E1s: signal readout start position of region E1,
E1e: signal read end position of region E1,
E2s: signal read start position of region E2,
E2e: It is set as the signal reading end position in the region E2. The timing signals E1s and E1e, E2s, and E2e are input from the CPU 130 connected to the signal processing IC 114 or generated in the signal processing IC 114 by signals obtained from the CPU 130.

  Next, a method for detecting whether or not an image of reflected light exists in the areas E1 and E2 will be described according to the flowchart of FIG. First, in step S301, the integrators S1 and S2 of the light reception signals SigA (AD) of the areas E1 and E2, the counters C1 and C2 of the number of integrated signals in each area, and AD indicating the current scanning address are initialized. Here, AD indicates an address that is currently being scanned, and here it is shown in one dimension for simplicity, but it may be shown in two dimensions. In step S302, it is confirmed whether or not the address AD currently being scanned exists in the area E1. The presence in the region E1 means that AD ≧ E1s and AD ≦ E1e. When AD exists in the area | region E1, the process of step S303 is performed. In step S303, the light reception signal SigA (AD) is integrated into the integrator S1.

  In step S304, the integrated signal number counter C1 is incremented. Here, the integration of the integrator S1 is the total number of light reception signals in the region E1, but a threshold for the light reception signal SigA may be provided to reduce the integration target. In step S305, it is determined whether or not the scanning position address AD is E1e. If AD = E1e, the threshold TH1 calculating means S306 is processed, and if not, step S308 is processed. In step S306, for example, the result obtained by dividing the final value S1A (= S1) of the calculation result S1 in step S303 by the final value C1A (= C1) of the counter C1 is set as the threshold value TH1. After the threshold TH1 is calculated, the integrator S1 and the counter C1 are initialized in step S307.

  In step S308, it is determined whether the address AD being scanned is the final address ADE. If it is the final address, the processing step S3 is terminated. If it is not the final address, the address is incremented by one in step S309, and the process returns to step S302.

  If it is determined in step S302 that the address is not in the area E1, step S310 is processed to check whether the address AD currently being scanned exists in the area E2. The presence in the region E2 means that AD ≧ E2s and AD ≦ E2e. When the AD exists in the area E2, the processing in steps S311 to S315 is performed to calculate the threshold value TH2 as in the case where it is determined in step S302 that the AD is in the area E1. If the AD does not exist in the area E2, since the area is set to be divided into E1 and E2 here, the process proceeds to step S308. If the area is divided into three or more, a branch is set as in steps S302 and S310.

  In addition, although the area indicated by E1s to E2e is the entire area of the light receiving element here, it may be a part of the area included in the light receiving element area as indicated by WIN in FIG. Furthermore, although the luminance threshold value is an average value, the luminance threshold value may be a value set based on a value (maximum value, minimum value, etc.) representative of the light reception output signal (luminance) of each region. When the signal processing IC 114 is not used, it is also possible to store the light reception output signal using a CPU or a dedicated image memory and calculate the threshold value by S / W inside the CPU after the memory.

  Returning to FIG. 4, the next control step (control means) S4 is a control step for transferring all or part of the signal subjected to the processing of step S3 to the CPU. This light reception output signal transfer means is performed in the CPU 130, and sequentially stores the light reception output signal from the signal processing IC 114 in the memory 131 at every predetermined sampling period. Processing step S3 and processing step S4 are sequentially repeated until one frame of the light receiving element is processed.

  The processing step (processing means) S5 determines whether or not there is a reflecting object in each region E1 and E2 of the light reception signal based on the light reception signal stored in the memory 131 and the threshold values TH1 and TH2 set in the processing step S3. judge. FIG. 6 shows a process flowchart of process step S5. Here, for each of the regions E1 and E2, a region having a brightness brighter than the brightness threshold values TH1 and TH2 set in the processing step S3 is detected, and the number of pixels MC1 or MC2 is counted. Judge that. If there is a reflecting object, flags Mflg1 and Mflg2 are set to 1 for each of the areas E1 and E2. Hereinafter, each processing step will be described. In step S501, among the light reception signals in the region E1, the counter MC1 that counts the number of pixels having a brightness brighter than the threshold TH1 set in step S3, and the threshold value that is set in step S3 among the light reception signals in the region E2. A counter MC2 that counts the number of pixels with brightness brighter than TH2, flags Mflg1 and Mflg2 indicating the presence / absence of reflection objects in the areas E1 and E2, and AD indicating the current scanning address are initialized.

  In step S502, as in step S302, it is determined whether or not the address AD currently being scanned exists in the area E1. If the address AD currently being scanned exists in the area E1, the process of step S503 is performed. In step S503, it is determined whether the light reception signal SigA (AD) of the address AD currently being scanned is brighter than the threshold value TH1. If the light reception signal SigA (AD) is brighter than the threshold value TH1, the counter MC1 is incremented in step S504, and then the process proceeds to step S505. If the light reception signal SigA (AD) is not brighter than the threshold value TH1, nothing is done and the process proceeds to step S505. In step S505, it is determined whether or not the current scanning address AD is the final address E1e of the region E1, and if it is the final address E1e, it is determined in step S506 whether or not the counter MC1 is larger than the counter MC. For example, in step S507, the flag Mflg1 indicating that the reflecting object exists in the area E1 is set, and the process proceeds to step S508. If the current scanning address AD is not the final address E1e of the area E1, nothing is done and the process proceeds to step S508. In step S508, it is determined whether or not the current scanning address AD is the final address ADE, and if it is the final address, processing step S6 is terminated. If it is not the final address, the current scanning address AD is incremented in step S509, and the process returns to step S502.

  If it is determined in step S502 that the address AD is not in E1, step S510 is processed to check whether the address AD currently being scanned exists in the area E2. When the AD exists in the area E2, the processes in steps S511 to S515 are performed as in the case where it is determined in step S502 that the AD is in the area E1. If the AD does not exist in the area E2, here, since the area is set to be divided into E1 and E2, the process proceeds to step S508. In the case of three or more divisions, a branch similar to steps S502 and S510 is set. Although the threshold values TH1 and TH2 are calculated in the processing step S3, the threshold values TH1 and TH2 in the preprocessing cycle may be used. In addition, the reflective object may be detected based on the difference between the data irradiating the light emitting element and the data not irradiating the light emitting element, instead of the luminance threshold.

  Returning to FIG. 4, the next processing step (processing means) S6 uses the boundary between the regions E1 and E2 as a region threshold, and based on the result determined in processing step S5, the region E1 located above in the vehicle vertical direction. If there is a reflective object only in the area, the object other than the hand or other occupant, and if the reflective object exists only in the area E2 located below the vehicle in the vertical direction, both the small occupant and the areas E1 and E2 If there is an occupant, this is a processing step (processing means) for determining the occupant's physique, which is determined to be that there is an unoccupied passenger.

  The determination of the occupant physique by this processing step (processing means) S6 will be described along the flowchart shown in FIG. 7 and the specific examples shown in FIGS. 8 (a) to 8 (c). FIG. 7 is a flowchart showing details of the process in step S6. The result of the processing step S5 is classified into one of Tall, Small, and No based on the flags Mflg1 and Mflg2. In step S601, the state of Mflg1 indicating that there is a reflecting object in the area E1 is confirmed. When Mflg1 is set, the process proceeds to step S602, and the state of Mflg2 indicating that a reflective object is present in the area E2 is confirmed. If Mflg2 is also set, the occupant state is determined to be Tall, and the process proceeds to the next step. When Mflg2 is not set, an object exists only in the area E1, but the area E1 is an upper area in the vehicle vertical direction. Accordingly, since there is no possibility that the occupant is present in the air, if an object exists only in the region E1, it is determined that the occupant's hand is behind the vehicle or an object other than the occupant, and the state of the occupant is determined as No. .

  When Mflg1 is not set, the process proceeds to step S603, and the state of Mflg2 indicating that there is a reflecting object in the area E2 is confirmed. If Mflg2 is set, the occupant state is determined to be Small, and the process proceeds to the next step. If Mflg2 is not set, it is determined that there is no object in any region, and the occupant state is determined as No. Here, Tall is a non-small passenger, and Small is a small passenger in the detection area. No may be the case where no occupant is present or the occupant is behind the vehicle. In this case, the rear of the vehicle is a safe area even if the airbag is deployed. In the case of No, the airbag is deployed. It shall be.

  FIG. 8A shows a specific example in the case where a small passenger X (for example, a three-year-old child) exists. In this case, there is an occupant X as shown on the left side of FIG. When light as shown by the broken line in the figure is projected from the light emitting element 111, the seated occupant X is irradiated as shown in FIG. An image as shown on the right side (shown in white surrounded by a broken line on a gray background, the same applies hereinafter) is formed. Whether or not the occupant is small is determined by whether or not the reflecting object exists in one or both of the areas E1 and E2, as shown in the flowchart of FIG. 7, and in this case, the reflecting object is only in the area E2. Since it exists, it is judged that it is a small passenger.

  FIG. 8B is a specific example in the case where there is a non-small passenger Y (for example, an adult male). In this case, there is an occupant Y as shown on the left side of FIG. When light as shown by the broken line in the figure is projected from the light emitting element 111, the seated occupant Y is irradiated as shown in FIG. 8B, and the light receiving element 112 disposed on the door is exposed to the same figure. An image as shown on the right side is formed. Whether or not the occupant is small is determined by whether or not the reflective object is present in one or both of the areas E1 and E2, as shown in FIG. 7, and in this case, the reflective object is present in both E1 and E2. Therefore, it is determined that the passenger is not a small passenger.

  FIG. 8C is a specific example showing a case where an adult occupant Y puts his hand forward from outside the detection area. In this case, there is an occupant Y as shown on the left side of FIG. When light as shown by the broken line in the figure is projected from the light emitting element 111, the seated occupant Y is irradiated as shown in FIG. 8C, and the light receiving element 112 disposed on the door has the same figure. An image as shown on the right side is formed. Whether or not the occupant is small is determined by whether or not the reflecting object exists in one or both of the areas E1 and E2, as shown in FIG. 7, and in this case, the reflecting object exists only in the area E1. Therefore, it is determined that the occupant is in a special situation such as putting his hand forward from outside the detection area.

  Returning to FIG. 4, the processing step (processing means) S7 determines whether or not the occupant is small from the determination result of the occupant by the processing step (processing means) S6. Outputs the signal ALL. When it is determined that no occupant is present, and even if it is determined that the occupant is present, it is determined that the occupant is small, the output of the deployment inhibition signal INH is output.

  The processing step (processing unit) S8 is a processing step (processing unit) that transmits the deployment permission signal ALL output or the deployment inhibition signal INH output from the processing step (processing unit) S7 to the electronic control device 150 for airbag control. is there.

  As described above, according to the first embodiment of the present invention, the area threshold necessary for determining the physique of the occupant is set to the optical axis reference of the light receiving element and the system is arranged. The physique of the occupant can be more quickly determined according to whether or not the occupant is present by merely detecting the presence or absence of a reflecting object in the light receiving element output without preparing a special standard pattern. Therefore, the airbag deployment permission signal ALL or the deployment inhibition signal INH can be output more reliably.

Embodiment 2. FIG.
Next, a second embodiment in which the divided region En of the light receiving element and the processing step (processing means) S6 are changed will be described. In the second embodiment, the configuration other than the divided region En of the light receiving element and the processing step (processing means) S6 is the same as that of the first embodiment, and the detailed description thereof is omitted.

  In the second embodiment, the light receiving element 112 divides the output 165 into regions E3 and E4 shown in FIG. 9 with the optical axis 166 as a reference, and images LR3 and LR4 of reflected light from the light irradiation areas D1 and D2, respectively. Are arranged as shown. Since the boundary between the areas E3 and E4 is used as an area threshold value for determining the occupant position in the processing means (occupant position determination means) described below, a light receiving element is arranged and set in advance at that position. .

  In processing steps S3 and S5, processing similar to that in which the regions E1 and E2 in the first embodiment are replaced with the regions E3 and E4 shown in FIG. 9 is performed.

  In the second embodiment, a processing step (processing means) S6 shown in FIG. 10 is used. The processing step (processing means) S6 in FIG. 9 reflects only the region E3 located in the front in the vehicle front-rear direction based on the result determined in the processing step S5 with the boundary between the regions E3 and E4 as the region threshold value. If there is an object, if the airbag is deployed, there is a high possibility that a large injury will occur. If there is a reflective object only in the rear area E4, deploy the airbag. If there is an occupant in both the E3 and E4 occupants that are highly likely not to cause a major injury, it is assumed that the large occupant is in a danger area where a large injury will occur if the airbag is deployed. This is a processing step (processing means) for determining the occupant position to be determined.

  The determination of the occupant position by this processing step (processing means) S6 will be described along the flowchart shown in FIG. 10 and the specific examples shown in FIGS. 11 (a) and 11 (b). FIG. 10 is a flowchart showing details of the processing in step S6. As a result of the processing step S5, it is classified into one of Front, Back, and No based on Mflg1 and Mflg2. Here, Front is a dangerous area where there is a high possibility that a large injury will occur if the airbag is deployed, and Back is a case where a passenger is present in a region where there is a high possibility that a large injury will not occur even if the airbag is deployed. . No may be the case where no occupant is present or the occupant is behind the vehicle. In this case, the rear of the vehicle is a safe area even if the airbag is deployed. In the case of No, the airbag is deployed. It shall be.

  FIG. 11A is a specific example in the case where the occupant X is present in a dangerous area where there is a high possibility that a large injury will occur when the airbag is deployed. In this case, there is an occupant X as shown on the left side of FIG. When light as shown by the broken line in the figure is projected from the light emitting element 111, the seated occupant is irradiated as shown in FIG. 11 (a), and the light receiving element 112 disposed on the door is exposed to the right side of the figure. An image as shown in FIG. Whether or not the occupant is in the dangerous area is determined by whether or not the reflecting object exists in one or both of the areas E3 and E4, as shown in FIG. 9. In this case, the reflecting object exists only in E3. Therefore, it is determined that the passenger is present in the dangerous area.

  FIG. 11B is a specific example in the case where the occupant Y is present in a region where there is a high possibility that a large injury will not occur even if the airbag is deployed. In this case, there is an occupant Y as shown on the left side of FIG. When light as shown by the broken line in the figure is projected from the light emitting element 111, the seated occupant is irradiated as shown in FIG. 11B, and the light receiving element 112 disposed on the door has a right side in the figure. An image as shown in FIG. Whether or not the occupant is in the dangerous area is determined by whether or not the reflecting object exists in one or both of the areas E3 and E4, as shown in FIG. 9. In this case, the reflecting object exists only in E4. Therefore, it is determined that the passenger is present in a safe area even if the airbag is deployed.

Embodiment 3 FIG.
Subsequently, Embodiment 3 in which the divided region En of the light receiving element and the processing step (processing means) S6 are changed will be described. In the third embodiment, the configuration other than the divided region En of the light receiving element and the processing step (processing means) S6 is the same as that of the first embodiment, and the detailed description thereof is omitted.

  In the third embodiment, the light receiving element 112 divides the output 165 into regions E5 to E8 shown in FIG. 12 with the optical axis 166 as a reference, and shows the light reception signals LR5 to LR8 of the reflected light from the regions D1 and D2, respectively. Arrange like this. If it is difficult to form a reflected image of the light reception signals LR6 and LR8 with only the regions D1 and D2, a light emitting element may be further added. The boundaries between the areas E5 and E6, E5 and E7, E6 and E8, and E7 and E8 are used as area threshold values for determining the occupant position and physique in the processing means (occupant determination means) described below. A light receiving element is arranged at a position and set.

  Processing steps S3 and S5 are the same as those in the first and second embodiments, but since there are four areas, flowcharts are shown in FIGS. First, a method for detecting whether or not an image of reflected light exists in the areas E5 to E8 will be described with reference to the flowchart of FIG. In step S3011, the integrators S1 to S4 of the light reception signals SigA (AD) in the regions E5 to E8 and the counters C1 to C4 of the number of integrated signals in each region are initialized. Here, AD indicates the address currently being scanned, and here it is shown in one dimension for simplicity, but it may be shown in two dimensions. In step S3012, it is confirmed whether or not the address AD currently being scanned exists in the area E5. The presence in the region E5 means that AD ≧ E5s and AD ≦ E5e. When AD exists in the area | region E5, the process of step S3013 is performed. In step S3013, the light reception signal SigA (AD) is integrated into the integrator S1. In step S3014, the cumulative number counter C1 is incremented. Here, although the integration of the integrator S1 is the total number of light reception signals in the region E5, a threshold for the light reception signal SigA may be provided to reduce the integration target.

  In step S3015, it is determined whether or not the scanning position address AD is E5e. If AD = E5e, the threshold value TH1 calculating means in step 3016 is processed. If not, step S3018 is processed. In step S3016, for example, a result obtained by dividing the final value S1A (= S1) of the calculation result S1 in step S3013 by the final value C1A (= C1) of the counter C1 is set as a threshold value TH1. After the calculation of the threshold value TH1, the integrator S1 and the integration number counter C1 are initialized in step S3017. In step S3018, it is determined whether the address AD being scanned is the final address ADE. If it is final, the process step S3 is terminated. If not final, in step S3019, the address is incremented by one, and the flow returns to step S3012.

  If it is determined in step S3012 that the address AD is not in the area E5, step S3020 is processed to check whether the address AD currently being scanned exists in the area E6. The presence in the region E6 means that AD ≧ E6s and AD ≦ E6e. When the AD exists in the area E6, the processes in steps S3021 to S3025 are performed as in the case where it is determined in step S3012 that the area is in the area E5. If the AD does not exist in the area E6, here, since the area is set to four divisions E5 to E8, the process proceeds to step S3026. Since the same applies to the following, description of steps S3027 to S3037 will be omitted.

  Next, the flowchart of FIG. 14 will be described. Here, for each of the regions E5 to E8, a region having a brightness brighter than the brightness thresholds TH1 to TH4 set in step S3 is detected, and the number of pixels MC1 to MC4 is counted. judge. If there is a reflecting object, flags Mflg1 to Mflg4 are set to 1 for each of the areas E5 to E8.

  Hereinafter, each processing step will be described. In step S5011, the counter MC1 that counts the number of pixels brighter than the threshold TH1 set in step S3 among the received light signals in the region E5, and the threshold TH2 set in step S3 among the received light signals in the region E6. Counter MC2 that counts the number of pixels of luminance, among the received light signals in the region E7, counter MC3 that counts the number of pixels brighter than the threshold TH3 set in step S3, and among the received light signals in the region E8, in step S3 The counter MC4 that counts the number of pixels brighter than the set threshold TH4, the flags Mflg1 to Mflg4 that indicate the presence or absence of each reflecting object in the areas E5 to E8, and the AD that indicates the address currently being scanned are initialized.

  In step S5012, similarly to step S3012 described above, it is determined whether or not the address AD currently being scanned exists in the area E5. If the address AD currently being scanned exists in the area E5, the process of step S5013 is performed. In step S5013, it is determined whether the light reception signal SigA (AD) of the address AD currently being scanned is brighter than the threshold value TH1. If the light reception signal SigA (AD) is brighter than the threshold value TH1, the counter MC1 is incremented in step S5014, and the process proceeds to step S5015. If the received light signal SigA (AD) is not brighter than the threshold value TH1, nothing is done and the process proceeds to step S5015. In step S5015, it is determined whether or not the current scanning address AD is the final address E5e of the region E5. If it is the final address E5e, it is determined in step S5016 whether or not the counter MC1 is larger than MC. In step S5017, a flag Mflg1 indicating that a reflecting object exists in the region E5 is set, and the flow advances to step S5018. If the current scan address AD is not the final address E5e of the area E5, the process proceeds to step S5018 without doing anything. In step S5018, it is determined whether or not the current scanning address AD is the final address ADE. If it is the final address, step S5 is terminated. If it is not the final address, the current scanning address AD is incremented in step S5019, and the process returns to step S5012.

  If it is determined in step S5012 that the address AD is not in E5, step S5020 is processed to check whether the address AD currently being scanned exists in the area E6. When the AD exists in the area E6, the processing in steps S5021 to S5025 is performed as in the case where it is determined in step S5012 that it is in E5. If the AD does not exist in the area E6, here, since the area is set to four divisions E5 to E8, the process proceeds to step S5026. Hereinafter, since it is the same, description of step S5027-S5037 is abbreviate | omitted. Although the threshold values TH1 to TH4 are calculated in step S3, the threshold values TH1 to TH4 in the preprocessing cycle may be used. In addition, the reflective object may be detected based on the difference between the data irradiating the light emitting element and the data not irradiating the light emitting element, instead of the luminance threshold.

In the third embodiment, a processing step (processing means) S6 shown in FIG. 15 is used. The processing step (processing means) S6 in FIG. 15 makes the following determination based on the result determined in the processing step S5 with the boundary of each region E5, E6, E7, E8 as the region threshold value.
E5: A hand or other object other than an occupant present in the dangerous area,
E6: Hand or other non-occupant object present in the safety area,
E7: A small occupant in the danger zone,
E8: A small occupant in the safety area,
E5, E6: Hands or other objects other than passengers present in the danger area
E5, E7: non-small occupants present in the danger area,
E5, E8: non-small passengers present in the danger area,
E6, E7: non-small passengers present in the safety area,
E6, E8: non-small occupants present in the safety area,
E7, E8: Small occupants present in the danger area,
E5, E6, E7: non-small passengers present in the safety area,
E5, E6, E8: non-small passengers present in the safety area,
E5, E7, E8: non-small occupants present in the danger zone,
E6, E7, E8: non-small passengers present in the safety area,
E5, E6, E7, E8: Non-small passengers present in the danger area.

  The determination of the occupant physique and the occupant position by the processing step (processing means) S6 will be described with reference to the flowchart shown in FIG. 15 and the specific examples shown in FIGS. 16 (a) to 16 (c). FIG. 15 is a flowchart showing details of the process in step S6. As a result of step S5, based on the flags Mflg1 to Mflg4, it is classified into one of Front-Tall, Front-Small, Front-No, Back-Tall, Back-Small, and Back-No.

  In step S6011, the state of the flag Mflg1 indicating that there is a reflecting object in the area E5 is confirmed. When the flag Mflg1 is set, the process proceeds to step S6012, and the state of the flag Mflg2 indicating that there is a reflecting object in the area E6 is confirmed. If the flag Mflg2 is also set, the process proceeds to step S6014, and the state of the flag Mflg3 indicating that there is a reflecting object in the area E7 is confirmed. If the flag Mflg3 is set, the process advances to step S6018 to check the state of the flag Mflg4 indicating that there is a reflecting object in the area E8. When the flags Mflg1 to M4 are set, it is determined that a large occupant has entered the danger area and the process proceeds to the next step. When the flags Mflg 1 to 3 are set, it is determined that the large occupant is in the safety area and is in a state where his hand is put forward, and the process proceeds to the next step. If the flags Mflg 1 and 2 are set, it is determined that the large occupant is Back-Tall existing in the safety area, and the process proceeds to the next step. When only the flag Mflg1 is set, an object exists only in the area E5, but the area E5 is an upper area in the vehicle vertical direction. Therefore, since an occupant cannot exist in the air, if an object exists only in the area E5, it is determined that the occupant's hand or an object other than the occupant exists behind the vehicle, and the occupant state is determined as No. To the next step.

  If the flag Mflg1 is not set, the process proceeds to step S6013, and the state of the flag Mflg2 indicating that there is a reflecting object in the area E6 is confirmed. If the flag Mflg2 is not set, the process proceeds to step S6017, and the state of the flag Mflg3 indicating that there is a reflecting object in the area E7 is confirmed. If the flag Mflg3 is set, the process proceeds to step S6024, and the state of the flag Mflg4 indicating that there is a reflecting object in the area E8 is confirmed. When the flags Mflg 3 to 4 are set, it is determined that a large occupant exists behind the vehicle and only the limbs are detected, and the process proceeds to the next step. When only the flag Mflg3 is set, it is determined that there is a small occupant in the dangerous area, and it is determined as Front-Small. When only the flag Mflg4 is set, it is determined that there is a small occupant in the safe area, and it is determined as Back-Small. If no flag is set, the seat is vacant and it is determined as No. Hereinafter, since it is the same, description is abbreviate | omitted.

  Here, Front is a dangerous area where there is a high possibility that a large injury will occur if the airbag is deployed, and Back is a case where a passenger is present in a region where there is a high possibility that a large injury will not occur even if the airbag is deployed. . Small is a small passenger, and Tall is a non-small passenger. No may be the case where no occupant is present or the occupant is behind the vehicle. In this case, the rear of the vehicle is a safe area even if the airbag is deployed. In the case of No, the airbag is deployed. It shall be.

  FIG. 16A is a specific example in the case where a small occupant X exists in a dangerous area where there is a high possibility that a large injury will occur when the airbag is deployed. In this case, there is an occupant X as shown on the left side of FIG. When light as shown by the broken line in the figure is projected from the light emitting element 111, the light is irradiated to the seated occupant as shown in FIG. 16 (a), and the light receiving element 112 disposed on the door is irradiated with the same light. An image as shown on the right side of the figure is formed. Whether or not the occupant is in the dangerous area or whether the occupant is small is determined by whether or not the reflective object exists in one or more of the areas E5, E6, E7, and E8, as shown in FIG. Therefore, in this case, since the reflective object exists only in E7, it is determined that the passenger is a small passenger existing in a dangerous area.

  FIG. 16B is a specific example in the case where a non-small occupant Y exists in a region where there is a low possibility of causing a large injury even when the airbag is deployed. In this case, there is an occupant Y as shown on the left side of FIG. When light as shown by the broken line in the figure is projected from the light emitting element 111, the light is irradiated to the seated occupant Y as shown in FIG. 16B, and the light receiving element 112 disposed on the door has An image as shown on the right side of the figure is formed. Whether or not the occupant is in the dangerous area or whether the occupant is small is determined by whether or not the reflective object exists in one or more of the areas E5, E6, E7, and E8, as shown in FIG. Therefore, in this case, since reflective objects exist in both E6 and E8, it is determined that there is a small passenger in a region where there is a low possibility of causing a large injury even if the airbag is deployed.

  FIG. 16C is a specific example in the case where a non-small occupant is present in a dangerous area where there is a high possibility that a large injury will occur when the airbag is deployed. In this case, there is an occupant as shown on the left side of FIG. When light as shown by the broken line in the figure is projected from the light emitting element 111, the light is irradiated to the seated occupant as shown in FIG. 16 (c), and the light receiving element 112 arranged at the door has the same light. An image as shown on the right side of the figure (the part shown in white in the gray background, the same applies hereinafter) is formed. Whether or not the occupant is in the dangerous area or whether the occupant is small is determined by whether or not the reflecting object exists in one or more of the areas E5, E6, E7, and E8, as shown in FIG. Therefore, in this case, since there are reflecting objects at E5, E7, and E8, it is determined that the passenger is not a small passenger in a dangerous area that is likely to cause a large injury when the airbag is deployed.

Embodiment 4 FIG.
Next, a fourth embodiment in which the occupant determination step of the third embodiment is changed will be described. In the fourth embodiment, the configuration other than the occupant determination step is the same as that of the third embodiment, and the detailed description thereof is omitted. Here, a description is given using the third embodiment.

  In the fourth embodiment, a processing step (processing means) S6 shown in FIG. 17 is used. In the fourth embodiment, the physique + posture is simply determined by performing linear approximation of the distribution shape of the reflected light image. The determination of the occupant physique and the occupant position by this processing step (processing means) S6 will be described with reference to the flowchart shown in FIG. FIG. 17 is a flowchart showing details of the process in step S6. As a result of the processing step S5, the body is classified into any of physique + postures A to I based on the flags Mflg1 to Mflg4. In the present embodiment, the physique + posture is further classified by performing linear approximation of the distribution shape of the reflected light image in the classified physique + posture. As an example, the case of physique + posture E will be described. As shown in FIG. 18A, the physique + posture E corresponds to the case where the reflected light images are detected in the areas E5 and E7 and the reflected light images are not detected in the areas E6 and E8. When only the presence / absence determination of the reflected light image is performed, whether the adult is tilted as shown in FIG. 18 (b) or the child is standing upright as shown in FIG. 18 (c) Judgment may be difficult. Therefore, as shown by straight lines 200 and 201 shown in FIG. 18 (d), the physique + posture is simply determined by performing linear approximation of the distribution shape of the reflected light image. Here, the inclination of the approximate line 200 is large and the inclination of 201 is small. Therefore, it is determined that posture A-1 is a state in which an adult tilts his upper body, and posture A-2 is a state in which a child is standing upright. Further, not only inclination but also linearity or the like may be used for discrimination.

Embodiment 5 FIG.
For example, in step S607 of FIG. 7, neither flag Mflg1 nor Mflg2 is set. Therefore, in this case, it is determined as No (vacant seat) in the processing of the first embodiment, but there is a possibility that an occupant may actually exist in an area that cannot be detected by the irradiation light of D1 and D2. However, when the detection range by D1 and D2 is expanded, there is a risk that the seat back is erroneously determined as an occupant. Therefore, in the fifth embodiment, a function of identifying the position of the seat using the seat position sensor of the seat on which the occupant is seated and determining whether the detected object is the occupant or the backrest is added.

  Next, a fifth embodiment in which a seat position sensor is added to the occupant (physique, position, posture) determination step of the first to fourth embodiments will be described. In the fifth embodiment, the configuration other than adding the seat position sensor to the occupant (physique, position, posture) determination step is the same as in the first to fourth embodiments, and a detailed description thereof is omitted. In the following, processing in which the first embodiment is changed will be described, but the same applies to the second to fourth embodiments.

  In the fifth embodiment, the processing steps (processing means) shown in FIG. 19 are used. The processing step (processing means) S10 shown in FIG. 19 is a sheet position determination process (means) using the output from the sheet position sensor. By attaching the seat position sensor, the detection area in the first to fourth embodiments is extended to the entire passenger seat, and the detection performance when the occupant is present among the occupant determination results No is given. For example, in the first embodiment, when the detection area is extended to the area outside the detection area, there is a possibility that the seat back of the passenger seat and the passenger cannot be identified. Therefore, information from the seat position sensor is added to identify the occupant and the seat back.

  In the fifth embodiment, since the detection in the first to fourth embodiments is possible for the passengers in the entire passenger seat area, the airbag can be controlled with higher accuracy.

Embodiment 6 FIG.
Next, a sixth embodiment that operates as an antitheft monitoring camera as an auxiliary function of the first to fifth embodiments will be described. In the sixth embodiment, the passenger detection function is the same as in the first to fifth embodiments, and a detailed description thereof is omitted.

  In the sixth embodiment, a processing step (processing means) S21 shown in FIG. 20 is used as a theft prevention function. Of the processing steps shown in FIG. 20, step S20 is a function corresponding to the occupant detection device shown in the first to fifth embodiments.

  The psychology of the theft is likely to intrude from the driver's seat instead of the passenger seat. Therefore, in this embodiment, for example, the engine stop time of the vehicle is monitored, and if it is confirmed that the engine OFF time T is OFF for a predetermined time TTH, it is determined that the vehicle is not in use. The anti-theft function is activated and the light receiving element operates as an anti-theft camera to monitor the situation on the driver's seat side.

  According to the sixth embodiment, not only the passenger detection function but also the anti-theft of the vehicle can be utilized when the vehicle is not used, and the added value can be improved.

  According to the occupant detection device of the present invention, it is possible to reliably detect the occupant, its position and physique, and its posture in the passenger compartment at a higher speed without using a special standard pattern for comparison. It can be used for air bag control.

1 is a block diagram showing an overall configuration of an occupant detection device according to the present invention. It is a side view which shows arrangement | positioning of the optical sensor in the vehicle interior of the motor vehicle based on Embodiment 1 of this invention. It is a perspective view which shows the structure of the optical sensor which concerns on Embodiment 1 of this invention. It is a flowchart of the control processing by CPU which concerns on Embodiment 1 of this invention. It is explanatory drawing for demonstrating the principle of the light reception signal threshold value setting in Embodiment 1 of this invention. It is a flowchart explaining operation | movement of the reflective object detection means which concerns on Embodiment 1 of this invention. It is a flowchart explaining operation | movement of the passenger | crew physique determination means based on Embodiment 1 of this invention. It is a figure explaining the specific example of the passenger | crew physique determination means which concerns on Embodiment 1 of this invention. It is a perspective view which shows the structure of the optical sensor of the passenger | crew detection apparatus which concerns on Embodiment 2 of this invention. It is a flowchart explaining operation | movement of the passenger | crew position determination means which concerns on Embodiment 2 of this invention. It is a figure explaining the specific example of the passenger | crew position determination means which concerns on Embodiment 2 of this invention. It is a perspective view which shows the structure of the optical sensor of the passenger | crew detection apparatus which concerns on Embodiment 3 of this invention. It is a flowchart explaining operation | movement of the light reception signal threshold value setting means which concerns on Embodiment 3 of this invention. It is a flowchart explaining operation | movement of the reflective object detection means which concerns on Embodiment 3 of this invention. It is a flowchart explaining operation | movement of the passenger | crew determination means which concerns on Embodiment 3 of this invention. It is a figure which shows the specific example of the passenger | crew position determination means by Embodiment 3 of this invention. It is a flowchart of the passenger | crew determination means of Embodiment 4 of the passenger | crew detection apparatus by this invention. It is a figure explaining the specific example of the passenger | crew determination means which concerns on Embodiment 4 of this invention. It is a flowchart of the control processing by CPU of the passenger | crew detection apparatus which concerns on Embodiment 5 of this invention. It is a flowchart of the control processing by CPU of the passenger | crew detection apparatus which concerns on Embodiment 6 of this invention.

Explanation of symbols

110 optical sensor, 111 light emitting element,
112 light receiving element, 113 drive circuit,
114 signal processing IC, 130 CPU,
131 memory, 132 occupant detection unit,
160 Car cabin, LR Reflected light image,
X crew (small), Y crew (large).

Claims (8)

  A vehicle interior is divided into a plurality of regions, a light receiving unit that detects reflected light from a reflecting object included in each of the divided regions, and the division based on the reflected light for each of the divided regions detected by the light receiving unit. A reflecting object detecting means for determining the presence or absence of a reflecting object for each area; A vehicle occupant detection device characterized in that the vehicle occupant detection device is set vertically.   The vehicle occupant detection device according to claim 1, wherein boundary lines of the plurality of divided regions are used as region threshold values for position determination or physique determination of the occupant.   2. The vehicle occupant detection device according to claim 1, wherein the plurality of divided regions are divided into two in the vertical direction of the vehicle based on the optical axis of the light receiving unit.   2. The vehicle occupant detection device according to claim 1, wherein the plurality of divided regions are divided into two in the front-rear direction of the vehicle based on the optical axis of the light receiving unit.   2. The vehicle occupant according to claim 1, wherein the plurality of divided regions are divided into two in each of the front and rear and upper and lower directions of the vehicle based on the optical axis of the light receiving unit, for a total of four. Detection device.   The occupant posture is determined by approximating the distribution shape of the reflected light by the reflecting object received by the light receiving unit by the occupant determination means. The vehicle occupant detection device according to the item.   7. A seat position sensor for detecting a front-rear position of a seat on which an occupant of the vehicle is seated, and an output of the seat position sensor is used for reflection object detection. The vehicle occupant detection device according to claim 1.   8. A vehicle occupant detection device according to claim 1, wherein the vehicle occupant detection device has a function of monitoring the inside of the vehicle as a theft prevention when the vehicle is not used.

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