JP4258931B2 - Child seat detection device and child seat detection method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a child seat detection device and a child seat detection method, and more particularly, to a child seat detection device and a child seat detection method suitable for detecting whether or not a child seat is mounted on a vehicle seat.
[0002]
[Prior art]
Conventionally, as disclosed in Japanese Patent Laid-Open No. 9-226516, a child seat detection device for detecting whether or not a child seat is mounted on a vehicle seat in order to control the operation / non-operation of the airbag device at the time of a vehicle collision. It has been known. The child seat detection apparatus includes a passive element provided on the bottom surface of the child seat and a detection element provided on the seat surface of the vehicle seat. The child seat detection device detects that a child seat is mounted on the vehicle seat when the detection element detects a passive element. In this case, even if the vehicle collides, the deployment of the airbag device is prohibited.
[0003]
[Problems to be solved by the invention]
However, in the conventional child seat detection apparatus, it is necessary to provide a passive element or a detection element on the child seat and the vehicle seat, respectively. For this reason, the above-mentioned conventional child seat detection device has a complicated configuration.
[0004]
The present invention has been made in view of the above points, and provides a child seat detection device and a child seat detection method that can accurately determine whether a child seat is mounted on a vehicle seat with a simple configuration. The purpose is to provide.
[0005]
[Means for Solving the Problems]
  The above purpose isUsing a seat sensor composed of a plurality of cells arranged on the vehicle seat,A seat pressure distribution detecting means for detecting a pressure distribution state acting on the seat surface of the vehicle seat;When acceleration exceeding a predetermined value occurs in the vehicle in a situation where an object larger than the predetermined value exists on the vehicle seatThe seat pressure distribution detecting meansAs a result of detection, the number of cells whose load changes more than a predetermined value among all cells is less than the predetermined numberOn the vehicle seatFixed by seat beltIt is achieved by a child seat detection apparatus comprising: a child seat wearing determination unit that determines that a child seat is attached.
[0006]
  Also, the above purpose isUsing a seat sensor composed of a plurality of cells arranged on the vehicle seat,A seat pressure distribution detecting step for detecting a pressure distribution state acting on the seat surface of the vehicle seat;When acceleration exceeding a predetermined value occurs in the vehicle in a situation where an object larger than the predetermined value exists on the vehicle seatThe seat pressure distribution detecting stepAs a result of detection, the number of cells whose load changes more than a predetermined value among all cells is less than the predetermined number.On the vehicle seatFixed by seat beltIt is achieved by a child seat detection method comprising: a child seat attachment determination step for determining that a child seat is attached.
[0007]
  These aspectsIn this invention, the pressure distribution state acting on the seat surface of the vehicle seat is detected.When a certain acceleration occurs on the vehicle when there is an object larger than the predetermined size on the vehicle seatWhen the pressure distribution state acting on the seat surface of the vehicle seat does not change beyond the reference state, it is determined that the child seat is mounted on the vehicle seat. In general, when the vehicle accelerates or decelerates in a situation where an occupant is seated on a vehicle seat, the posture of the occupant becomes unstable, and the pressure distribution state on the seat surface of the vehicle seat changes greatly. On the other hand, when the vehicle accelerates or decelerates in a situation where the child seat is mounted on the vehicle seat, the child seat is securely fixed to the vehicle seat by the seat belt, so the pressure distribution state on the seat surface of the vehicle seat is almost Maintained constant. Therefore, it is possible to determine whether or not the child seat is mounted on the vehicle seat based on the change in the pressure distribution state on the seat surface of the vehicle seat. For this reason, according to this invention, the presence or absence of the child seat on a vehicle seat can be accurately determined with a simple configuration.
  In the child seat detection device described above,At the time of starting the vehicle, it is provided with a start-time mounting determination means for determining whether or not the child seat is mounted on the vehicle seat based on whether or not the object on the vehicle seat is angular, the child seat mounting determination means May determine whether or not the child seat is mounted on the vehicle seat based on a change in the pressure distribution state detected by the seat pressure distribution detecting means during traveling of the vehicle.
Furthermore, in the child seat detection method described above, at the time of starting the vehicle, it is determined whether or not the child seat is mounted on the vehicle seat based on whether or not the object on the vehicle seat is angular. A step of determining whether the child car seat is mounted on the vehicle seat based on a change in the pressure distribution state detected by the seat pressure distribution detecting means when the vehicle is running. It may be determined.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a cross-sectional view of a vehicle equipped with a child seat detection apparatus according to an embodiment of the present invention, cut along a plane passing through the center in the vehicle width direction of a vehicle seat 10 on the passenger seat side. The system of this embodiment includes an electronic control unit (hereinafter referred to as ECU) 12. The vehicle seat 10 is guided to be movable in the vehicle front-rear direction by a lower seat rail 14 fixed to the passenger compartment floor.
[0009]
As shown in FIG. 1, an airbag module 16 and an indicator 18 are connected to the ECU 12. The airbag module 16 is accommodated in the instrument panel 20 in the vehicle compartment, and operates when a predetermined drive signal is supplied from the ECU 12. The indicator 18 is disposed on the surface of the instrument panel 20 and lights up when a predetermined lighting signal is supplied from the ECU 12. The ECU 12 lights up the indicator 18 when the operation of the airbag module 16 is prohibited.
[0010]
The ECU 12 is connected with an ignition switch (hereinafter referred to as an IG switch) 22 for switching between starting and stopping of the vehicle. The IG switch 22 is configured so that its state is sequentially switched to three states of off, on, and starter on. The ECU 12 determines whether or not the IG switch 22 is in the on state based on the output signal of the IG switch 22, and starts the vehicle when determining that the IG switch 22 is in the on state.
[0011]
The ECU 12 is also connected with a longitudinal acceleration sensor 30, a lateral acceleration sensor 32, and a vertical acceleration sensor 34. The longitudinal acceleration sensor 30 outputs a signal corresponding to the acceleration in the vehicle traveling direction that acts near the center of gravity of the vehicle. The lateral acceleration sensor 32 outputs a signal corresponding to the acceleration in the vehicle width direction that acts near the center of gravity of the vehicle. The vertical acceleration sensor 34 outputs a signal corresponding to the acceleration in the vertical direction acting near the center of gravity of the vehicle. The ECU 12 determines the longitudinal acceleration G acting on the vehicle based on the output signals of the longitudinal acceleration sensor 30, the lateral acceleration sensor 32, and the vertical acceleration sensor 34._X, Lateral acceleration G_Y, And vertical acceleration G_ZIs detected.
[0012]
FIG. 2 shows a top view of the vehicle seat 10 provided with the child seat detection device of the present embodiment. As shown in FIG. 2, the vehicle seat 10 includes a seat cushion 40 that supports the bottom of the seated occupant and a seat back 42 that supports the back of the seated occupant. Both the seat cushion 40 and the seat back 42 are made of a cushioning member. The seat cushion 40 is held on its lower surface by a seat cushion pan (not shown) formed of a rigid body.
[0013]
A seat sensor 44 that is provided over the entire area of the surface of the seat cushion 40 is embedded in the vicinity of the skin within the seat cushion 40. The sheet sensor 44 includes a plurality of (for example, 60) cells 46 that divide the entire area into predetermined sections. The cell 46 is configured such that no current flows when a load less than a predetermined value is applied to the seat cushion 40 on its own compartment, and a current corresponding to the load flows when a load greater than the predetermined value is applied. It is configured.
[0014]
Each cell 46 is electrically connected to the ECU 12. The ECU 12 determines the load W in each cell based on the current value flowing through each cell of the seat sensor 44._ij, And the load W acting on the seat surface of the vehicle seat 10 based on the sum of those loads_TOTALIs detected. Note that i represents the address of each cell 46 in the vehicle width direction, and j represents the address of each cell 46 in the vehicle front-rear direction.
[0015]
As shown in FIG. 1, two pressure conductive cables 48 and 50 extending in the vehicle width direction are embedded in parallel with each other in the vicinity of the skin in the seat cushion 40. The pressurizing conductive cables 48 and 50 include a rubber member having a predetermined thickness having flexibility, and a conductive ink applied to the lower surface of the rubber member. The conductive ink is applied in a state where the rubber member is bent to some extent. For this reason, when the load acts on the vicinity of the center of the seat cushion 40 from above, the pressurizing conductive cables 48 and 50 can be bent so that the center portion becomes convex downward. Further, the pressure conductive cable 48 is configured to stop the flow of current when the radius of curvature thereof falls below a predetermined value, that is, when bent at an acute angle.
[0016]
Each pressurization conductive cable 48 and 50 is electrically connected to ECU12, respectively. The ECU 12 determines whether or not the current flow is stopped in any one of the pressure conductive cables 48 and 50, or whether or not the current is flowing in all the pressure conductive cables 48 and 50.
By the way, as a method for determining whether or not a child seat (hereinafter referred to as CRS) is mounted on the vehicle seat 10, a load W that acts on the seat surface of the vehicle seat 10._TOTALIt may be determined that the CRS is mounted on the vehicle seat 10 when is smaller than a predetermined threshold value. However, since the CRS is securely fixed to the vehicle seat 10 by the seat belt so as not to move with respect to the vehicle seat 10 during traveling, the load W acting on the seat surface of the vehicle seat 10_TOTALMay become larger. For this reason, with the above-described method, it may not be possible to accurately determine whether or not the CRS is mounted on the vehicle seat 10.
[0017]
Further, it is conceivable that a passive element is provided in the CRS, a detection element is provided in the vehicle seat 10, and it is determined that the CRS is mounted on the vehicle seat 10 when the detection element detects the passive element. However, in this method, it is necessary to provide a passive element or a detection element in the CRS and the vehicle seat 10, and a complicated configuration is required to determine whether or not the CRS is attached.
[0018]
In this embodiment, when the IG switch 22 changes from the off state to the on state, the ECU 12 first determines whether or not the radius of curvature of the pressure conductive cables 48 and 50 is below a predetermined value, that is, the pressure conductive cable. Whether or not a CRS is mounted on the vehicle seat 10 is determined based on whether or not current is flowing through the 48 and 50.
[0019]
FIG. 3 (A) is a diagram showing the degree of bending of the pressure conductive cables 48 and 50 when an occupant is seated on the vehicle seat 10. FIG. 3B is a diagram showing how the pressure conductive cables 48 and 50 are bent when the CRS is mounted on the vehicle seat 10.
When the CRS is mounted on the vehicle seat 10, the CRS acts on the seat cushion 40 because it is securely fixed to the vehicle seat 10 by the seat belt so as not to move with respect to the vehicle seat 10 during traveling. The load is increasing. In this case, the seat cushion 40 is greatly deformed downward. Further, even when an occupant sits on the vehicle seat 10, the seat cushion 40 is greatly deformed downward due to the weight of the occupant.
[0020]
The pressure conductive cables 48 and 50 embedded in the seat cushion 40 are bent and deformed in accordance with a load from an object on the vehicle seat 10. Generally, the occupant's buttocks contacting the vehicle seat 10 are rounded, while the bottom end of the CRS is squared. Therefore, as shown in FIG. 3A, when the occupant is seated on the vehicle seat 10, the pressure conductive cables 48 and 50 are bent with a large curvature radius according to the shape of the butt portion of the occupant. (Point A in FIG. 3A). On the other hand, as shown in FIG. 3B, when the CRS is mounted on the vehicle seat 10, the pressurized conductive cables 48 and 50 are bent with a small curvature radius according to the shape of the bottom end of the CRS. This occurs (point B in FIG. 3B). Therefore, it is possible to determine whether or not the CRS is mounted on the vehicle seat 10 by appropriately setting the bending state of the pressurized conductive cables 48 and 50 that stops the current flow.
[0021]
The ECU 12 has the CRS mounted on the vehicle seat 10 based on whether or not current is flowing through the pressurized conductive cables 48 and 50, that is, based on whether or not the object on the vehicle seat 10 is angular. If it is determined that the CRS is mounted on the vehicle seat 10, the operation of the airbag module 16 is prohibited and the indicator 18 is turned on. If it is determined that the airbag module 16 is seated, the operation of the airbag module 16 is permitted.
[0022]
FIG. 4A shows lateral acceleration G acting on the vehicle._YAn example of the time change is shown. FIG. 4B shows the lateral acceleration G under the situation where the CRS is mounted on the vehicle seat 10._Y4 changes in the load W acting on each cell 46 of the sheet sensor 44 when it changes as shown in FIG._ijThe results are shown. FIG. 4C shows the lateral acceleration G under the situation where an occupant is seated on the vehicle seat 10._Y4 changes in the load W acting on each cell 46 of the sheet sensor 44 when it changes as shown in FIG._ijThe results are shown. 4B and 4C, the load W acting on the four cells 46 is representative of all the cells 46 in the sheet sensor 44._ijThe results are shown.
[0023]
When the CRS is mounted on the vehicle seat 10, as shown in FIG. 4B, the load W acting on each cell 46_ijIs the lateral acceleration G_YDespite changes, it remains almost constant. This is because the CRS is securely fixed to the vehicle seat 10 by the seat belt. On the other hand, when an occupant is seated on the vehicle seat 10, as shown in FIG. 4C, the load W acting on each cell 46._ijIs the lateral acceleration G_YIt changes greatly with the change of. This is the lateral acceleration G_YThis is because a large inertial force acts on the occupant as the vehicle changes.
[0024]
FIG. 5A shows a predetermined lateral acceleration G applied to the vehicle in a situation where the CRS is mounted on the vehicle seat._YThe figure showing an example of distribution change of the load which acts on the seat seating surface of vehicle seat 10 when this occurs. FIG. 5B shows a predetermined lateral acceleration G on the vehicle in a situation where an occupant is seated on the vehicle seat 10._YThe figure showing an example of distribution change of the load which acts on the seat seating surface of vehicle seat 10 when this occurs. In FIGS. 5A and 5B, the case where the load exceeds the predetermined first threshold value is a hatched region, and the predetermined second threshold value where the load is greater than the predetermined first threshold value. The case where the value is exceeded is shown in the satin area.
[0025]
Lateral acceleration G greater than or equal to a predetermined value due to a curve or the like while the vehicle is running_YWhen this occurs, the distribution of the load acting on the seat surface of the vehicle seat 10 is maintained substantially constant when the CRS is mounted on the vehicle seat 10 (FIG. 5A). 10 (FIG. 5B), the load tends to decrease on one side in the vehicle width direction (left side in FIG. 5B), and the other (FIG. 5B). The right side) tends to increase the load.
[0026]
Thus, the lateral acceleration G greater than or equal to the predetermined value is applied to the vehicle._YIn a situation where the CRS is mounted on the vehicle seat 10, and when a passenger is seated on the vehicle seat 10, there is a change in the distribution of the load acting on the seat surface of the vehicle seat 10. Different. Therefore, the lateral acceleration G exceeding the predetermined value in the vehicle_YIt is possible to accurately detect whether or not the CRS is mounted on the vehicle seat 10 by detecting a change in the distribution of the load acting on the seat surface of the vehicle seat 10 under the situation where the vehicle seat 10 occurs.
[0027]
Therefore, the system of the present embodiment determines whether or not the CRS is attached based on whether or not current is flowing through the pressurized conductive cables 48 and 50 at the time of starting the vehicle. Load W acting on seat seat_ijSpecifically, it is characterized in that the presence or absence of the CRS on the vehicle seat 10 is determined based on the change in the current value flowing through each cell 46 of the seat sensor 44 based on the distribution change of the vehicle seat. .
[0028]
In the present embodiment, the ECU 12 has a load W acting on the vehicle seat 10._ijAfter determining whether or not the CRS is attached based on the distribution change, the airbag module 16 and the indicator 18 are operated based on the result.
FIG. 6 shows a flowchart of an example of a control routine executed by the ECU 12 in this embodiment in order to determine whether or not the airbag module 16 can be deployed according to whether or not the CRS is mounted on the vehicle seat. The routine shown in FIG. 6 is a scheduled interrupt routine that is repeatedly activated every predetermined time. When the routine shown in FIG. 6 is started, first, the process of step 100 is executed.
[0029]
In step 100, (1) among all the cells 46 of the sheet sensor 44, the cell 46 through which the current flows is a predetermined value n.₀Exist at least (n (W_ij> 0) ≧ n₀) And (2) the load W acting on the seat surface of the vehicle seat 10_TOTALIs the predetermined threshold C₀It is determined whether or not this is the case. The predetermined value n₀Is set to such a small value that it can be determined that any object is present on the vehicle seat 10, and a predetermined threshold C₀Is the load W when an adult is seated on the vehicle seat 10_TOTALThe lower limit is set.
[0030]
If the above condition (1) is not satisfied, it can be determined that no object is present on the vehicle seat 10. In this case, it can be determined that it is not necessary to permit the operation of the airbag module 16. Therefore, if such a determination is made in step 100, the process of step 112 is executed next.
If the condition (2) is not satisfied, it can be determined that a child is seated on the vehicle seat 10. In this case, it is appropriate to prohibit the operation of the airbag module 16. Therefore, if such a determination is made in step 100, the process of step 112 is executed next.
[0031]
On the other hand, in the above step 100, the condition (1) (n (W_ij> 0) ≧ n₀) And condition (2) (W ≧ C₀) Is established, it can be determined that a large object is present on the vehicle seat 10. If such a determination is made in step 100, the process of step 102 is executed next.
In step 102, it is determined whether or not the IG switch 22 is switched from the off state to the on state from the previous routine to the current routine. As a result, when the IG switch 22 is switched from the off state to the on state, it can be determined that the vehicle is started in the stopped state. In this case, it is appropriate to determine whether or not the CRS is mounted on the vehicle seat based on whether or not current is flowing through the pressurized conductive cables 48 and 50. Therefore, if such a determination is made, the process of step 104 is executed next.
[0032]
In step 104, it is determined whether or not current is flowing through the pressure conductive cables 48 and 50. When current flows through the pressurizing conductive cables 48 and 50, the pressurizing conductive cables 48 and 50 are not bent at an acute angle, and there is an object on the vehicle seat 10 whose bottom end is not square. It can be judged. In this case, it can be determined that an occupant is seated on the vehicle seat 10, and it can be determined that the CRS is not mounted. Therefore, if such a determination is made, the process of step 106 is executed next.
[0033]
In step 106, a process of turning on a flag indicating that an occupant is seated on the vehicle seat 10 is executed.
In step 108, processing for permitting deployment of the airbag module 16 at the time of a vehicle collision is executed. When the processing of step 108 is completed, the current routine is terminated.
[0034]
If no current flows through the pressure conductive cables 48 and 50 in the above step 104, the pressure conductive cables 48 and 50 are bent at an acute angle, and there is an object whose bottom end is angular on the vehicle seat 10. It can be judged that In this case, it can be determined that the CRS is mounted on the vehicle seat 10. Therefore, if such a determination is made, the process of step 110 is executed next.
[0035]
In step 110, a process of turning on a flag indicating that the CRS is mounted on the vehicle seat 10 is executed.
In step 112, processing for prohibiting deployment of the airbag module 16 at the time of a vehicle collision is executed. When the processing of step 112 is finished, the current routine is finished.
[0036]
According to the above processing, it is possible to determine whether or not the CRS is mounted on the vehicle seat 10 based on whether or not current is flowing through the pressurized conductive cables 48 and 50 when the vehicle is started. it can.
In step 102, if the IG switch 22 has not changed from the OFF state to the ON state from the previous routine to the current routine, that is, if the IG switch 22 is maintained in the ON state, the vehicle is in operation. It can be judged that there is. If such determination is made, the process of step 114 is executed next.
[0037]
In step 114, the lateral acceleration G of the vehicle_YThe absolute value of is the predetermined value G_Y0It is determined whether or not this is the case. As a result, | G_Y| ≧ G_Y0If it is determined that is not established, the current routine is terminated. On the other hand, | G_Y| ≧ G_Y0If it is determined that is established, the process of step 116 is performed next.
In step 116, the cell 46 satisfying both the following expressions (1) and (2) is changed to the threshold value m.₀It is determined whether or not there are more than one. The threshold value m₀Is a predetermined value G_Y0This is the minimum value of the number of cells 46 whose load fluctuates due to the inertial force acting on the occupant, which can be determined that the occupant is seated on the vehicle seat 10 when the above lateral acceleration occurs, for example, set to 5 Is done.
[0038]
W_ij≦ W_ijmax/ 2 (1)
ΔW_ij≦ −α (2)
However, W_ijmaxIs a predetermined value G_YOLoad W applied to each cell 46 before the above lateral acceleration occurs_ijAnd is set for each cell 46. ΔW_ijIs the load per unit time W_ijChange amount (W_ij2-W_ij1). Α is a predetermined value G for the vehicle._YOLoad W acting on each cell 46 when the above lateral acceleration occurs_ijAmount of change ΔW_ijIs set to a constant positive value.
[0039]
In each cell 46, when the conditions of the above expressions (1) and (2) are both satisfied, the load W_ijCan be judged to have greatly changed in the decreasing direction. On the other hand, if any of the above conditions is not satisfied, the load W_ijCan be judged to have not changed much. Load W_ijWhen there are a large number of cells 46 that greatly change in the decreasing direction, it can be determined that the distribution of the load acting on the seat seating surface tends to decrease, and the occupant's posture becomes unstable due to the inertial force due to the lateral acceleration of the vehicle. Can be judged. In this case, it can be determined that an occupant is seated on the vehicle seat 10.
[0040]
  Therefore, when it is determined in step 116 that there are more than threshold cells m0 that satisfy both the conditions of the above expressions (1) and (2), the process of step 106 is performed next. Processing for turning on a flag indicating that an occupant is seated on the vehicle seat 10 is executed.
  Meanwhile, the above steps116When the number of cells 46 satisfying both the above formulas (1) and (2) is not more than the threshold value m0, the vehicle acts on the seat seat surface even though a certain degree of lateral acceleration is generated in the vehicle. It can be determined that the load distribution is maintained substantially constant, and it can be determined that the state of the object on the vehicle seat 10 is stable. In this case, it can be determined that the CRS is mounted on the vehicle seat 10. Therefore, the above step116If it is determined that there are no more than the threshold value m0 cells 46 that satisfy both the above formulas (1) and (2), the processing of step 110 is executed next, and the CRS is displayed on the vehicle seat 10. A process of turning on a flag indicating that it is attached is executed.
[0041]
According to the above processing, the lateral acceleration G greater than a predetermined value is applied to the vehicle after the vehicle is started._YWhen the distribution of the load acting on the seat seat surface changes greatly under the situation where the occupant occurs, it can be determined that an occupant is seated on the vehicle seat 10 and the operation of the airbag module 16 can be permitted. Further, when the load distribution is maintained substantially constant under the above-described situation, it can be determined that the CRS is mounted on the vehicle seat 10 and the operation of the airbag module 16 can be prohibited.
[0042]
In other words, in this embodiment, whether or not the CRS is mounted on the vehicle seat 10 is determined based on whether or not the object on the vehicle seat 10 is angular when the vehicle is started. Lateral acceleration G_YThe load W acting on the vehicle seat 10 under the situation where_ijIt is determined based on the distribution change.
In the present embodiment, the mounting of the CRS on the vehicle seat 10 is performed without using a sensor other than the sensor (specifically, the seat sensor 44) for detecting the load acting on the seat surface of the vehicle seat 10. Presence / absence is determined. Therefore, according to the present embodiment, it is possible to accurately determine whether or not the CRS is mounted on the vehicle seat 10 with a simple configuration.
[0043]
In the present embodiment, whether or not the CRS is mounted on the vehicle seat 10 is determined according to whether or not the distribution of the load acting on the seat seat surface changes. In such a configuration, it is sufficient to provide at least two cells 46 arranged in the vehicle width direction in order to detect a change in the distribution of the load acting on the seat seat when lateral acceleration occurs in the vehicle. For this reason, according to the present embodiment, it is unnecessary to provide a large number of cells 46 in the sheet sensor 44. Therefore, according to the present embodiment, an increase in the number of parts of the seat sensor 44 can be suppressed, and the seat sensor 44 for determining whether or not the CRS is mounted on the vehicle seat 10 can be realized with a simple configuration. Become.
[0044]
In the above embodiment, the lateral acceleration G_YThe absolute value of is the predetermined value G_Y0The above is equivalent to the “predetermined state” described in the claims, the condition of the step 116 is equivalent to the “reference state” described in the claims, and the ECU 12 A load W acting on the seat surface of the vehicle seat 10 based on the current value flowing through each cell 46 of the seat sensor 44._ijThe "sitting pressure distribution detecting means" and the "sitting pressure distribution detecting step" described in the claims by detecting the distribution state of the above are described in the claims by making an affirmative determination in step 116. The “child seat wearing determination means” and “child seat wearing determination step” are implemented.
[0045]
By the way, in the above embodiment, the load change amount ΔW_ijThe threshold value α of the vehicle is maintained at a constant value._YIt is good also as changing suitably according to. Lateral acceleration G_YThe larger the is, the load W in each cell 46_ijThe change of becomes remarkable. Therefore, the threshold value α is set to the lateral acceleration G._YIf it is changed according to the above, it is possible to accurately determine whether or not the CRS is mounted on the vehicle seat 10.
[0046]
Further, in the above embodiment, it is determined whether or not the CRS is mounted on the vehicle seat 10 by determining whether or not the distribution of the load acting on the seat surface of the vehicle seat 10 shows a decreasing tendency. However, it may be determined whether or not the CRS is mounted on the vehicle seat 10 by determining whether or not the load distribution shows an increasing tendency, or by combining them.
[0047]
In the above embodiment, the lateral acceleration G of the vehicle_YThe absolute value of is the predetermined value G_Y0Under the circumstances described above, it is determined whether or not the CRS is mounted on the vehicle seat 10, but the present invention is not limited to this, and the longitudinal acceleration G of the vehicle is determined._XAbsolute value and vertical acceleration G_ZThe presence or absence of CRS may be determined in a situation where the absolute value of is not less than a predetermined value. In this case, the longitudinal acceleration G_XAbsolute value or vertical acceleration G_ZThat the absolute value of is equal to or greater than a predetermined value corresponds to the “predetermined state” recited in the claims.
[0048]
Further, in the above embodiment, the lateral acceleration G detected based on the output signal of the lateral acceleration sensor 22 is used._YThe absolute value of is the predetermined value G_Y0In the above case, it is determined whether or not the CRS is mounted on the vehicle seat 10, but the lateral acceleration G_YThe absolute value of is the predetermined value G_Y0In the state predicted to be above, specifically, the presence or absence of the CRS may be determined when the operation amount is a predetermined value or more in a situation where the steering wheel is operated. Furthermore, the longitudinal acceleration G of the vehicle_XAbsolute value and vertical acceleration G_ZSpecifically, it is also possible to determine whether or not the CRS is mounted when the accelerator operation or the brake operation is performed for a predetermined amount or more in a state where the absolute value is predicted to be equal to or greater than a predetermined value. In these cases, the operation amount of the steering operation, the accelerator operation, or the brake operation being equal to or greater than a predetermined amount corresponds to the “predetermined state” recited in the claims.
[0049]
【The invention's effect】
As described above, according to the first and second aspects of the present invention, it is possible to accurately determine whether or not the child seat is mounted on the vehicle seat with a simple configuration.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a vehicle on which a child seat detection apparatus according to an embodiment of the present invention is mounted, cut along a plane passing through the center in the vehicle width direction of a vehicle seat on the passenger seat side.
FIG. 2 is a top view of a vehicle seat provided with the child seat detection device of the embodiment.
FIG. 3 is a diagram comparing the degree of bending of a pressurized conductive cable between a case where an occupant is seated on a vehicle seat and a case where a CRS is mounted on the vehicle seat.
FIG. 4 acts on each cell of the seat sensor when the CRS is mounted on the vehicle seat and when an occupant is seated on the vehicle seat and the vehicle is accelerated in the vehicle width direction. It is the figure which compared the load.
FIG. 5 shows a case where the vehicle seat is seated on the seat when the CRS is mounted on the vehicle seat and when an occupant is seated on the vehicle seat under acceleration in the vehicle width direction. It is the figure which compared the distribution change of the load which acts.
FIG. 6 is a flowchart of an example of a control routine executed in the present embodiment in order to determine whether or not the airbag module can be deployed according to whether or not a CRS is mounted on the vehicle seat.
[Explanation of symbols]
10 Vehicle seat
12 Electronic control unit (ECU)
22 Lateral acceleration sensor
40 seat cushion
44 Sheet sensor
46 cells

Claims (4)

A seat pressure distribution detecting means for detecting a pressure distribution state acting on the seat surface of the vehicle seat using a seat sensor constituted by a plurality of cells arranged on the vehicle seat;
In a situation where an object larger than a predetermined value is present on the vehicle seat, when an acceleration exceeding a predetermined value occurs in the vehicle, the load of all cells changes to a predetermined value or more as a detection result of the seat pressure distribution detecting means. Child seat wearing determination means for determining that a child seat fixed by a seat belt is mounted on the vehicle seat when the number of cells is less than a predetermined number ;
A child seat detection apparatus comprising: At the time of vehicle start-up, it is provided with a start-up wearing determination means for determining whether or not the child seat is mounted on the vehicle seat based on whether or not the object on the vehicle seat is angular.
  The child seat wearing determining means determines whether or not the child seat is mounted on the vehicle seat based on a change in the pressure distribution state detected by the seat pressure distribution detecting means when the vehicle is traveling. The child seat detection device according to claim 1, wherein: A seat pressure distribution detecting step for detecting a pressure distribution state acting on a seat surface of the vehicle seat using a seat sensor configured by a plurality of cells arranged on the vehicle seat;
When there is an object larger than a predetermined size on the vehicle seat and the vehicle has an acceleration higher than a predetermined value, the load of all the cells changes as a result of detection in the seat pressure distribution detection step. A child seat mounting determination step for determining that a child seat fixed by a seat belt is mounted on the vehicle seat when the number of cells to be performed is less than a predetermined number ;
A child seat detection method comprising: At the time of starting the vehicle, the vehicle has a start-up wearing determination step for determining whether the child seat is mounted on the vehicle seat based on whether or not the object on the vehicle seat is angular.
  The child seat wearing determination step determines whether or not the child seat is mounted on the vehicle seat based on a change in the pressure distribution state detected by the seat pressure distribution detecting means during traveling of the vehicle. The child seat detection method according to claim 3.