Vehicle seat thermistor for classifying seat occupant types

Abstract

System for classifying an object occupying a vehicle seat, the system comprising: a seat (10) with a seat backrest (12) and a seat base (14); a signal-generating classification thermal sensor (16) attached to the seat backrest (12); a signal-generating classification thermal sensor (18) attached to the seat base (14); a signal-generating reference sensor (22, 24, 26, 28, 30, 32, 34); and a controller (20) to which the sensors (16, 18; 22, 24, 26, 28, 30, 32, 34) are operationally assigned, and which is programmed with an algorithm for classifying the object in the vehicle seat (10) based on signals generated by the sensors to distinguish between an adult (O) and a child (LC, SC) and between a child (LC) on a booster seat (B) and a child (SC) in a child restraint system (CRS).

Description

TECHNICAL AREA

[0001] The disclosed concept according to the invention relates generally to vehicle seats and safety systems. In particular, the disclosed concept according to the invention relates to a method and a system for classifying differences between seat occupant types, wherein a child in a child seat is distinguished from a child on a booster seat and from an adult. BACKGROUND OF THE INVENTION

[0002] Automotive safety systems provide both passive and active protection for seated passengers in both the front and rear seats. The effectiveness of these systems depends on several factors, including the type of passenger. In the rear seats, some passengers are adults while others are children. Some of the children may be in a child restraint system (CRS), while others may be in a booster seat. The ideal safety system would be tailored to differentiate between these passengers and, in the case of children, their seat type.

[0003] It is recommended that children use rear seats up to a certain point, which makes improvements to rear seat identification systems desirable. However, such improvements could also be applied to front seat classification. Such features could also add additional confidence or detail to current classification procedures, either in combination with other existing systems or, depending on the final design, perhaps as an alternative to those systems.

[0004] Accordingly, the provision of a safety system capable of distinguishing between three conditions is desired – a seated adult versus a seated child and, if it is a child, a child sitting in a CRS versus a child sitting on a booster seat. BRIEF SUMMARY OF THE INVENTION

[0005] The disclosed concept according to the invention provides a solution to the need to differentiate between adults and children as vehicle passengers, as well as between a child sitting in a child safety seat and a child sitting on a booster seat. The disclosed concept according to the invention is based on the fact that humans, even when clothed, transmit and absorb heat differently than inanimate objects.

[0006] In particular, the concept according to the invention provides a temperature-based method for minimally separating three conditions relating to adult versus child in CRS versus child on booster seat. A variety of thermal sensors can be used, although the thermistor is a preferred, non-limiting example of such a sensor. Since the resistance of a thermistor changes more with temperature than that of conventional resistors, this type of resistor is highly sensitive to changes in local temperature. However, it is understood that conventional resistors and resistance temperature detectors (RTDs) can also be suitable for use in the disclosed concept according to the invention.

[0007] The disclosed concept according to the invention includes at least one thermistor or temperature-sensing classification device, at least one reference thermistor, an algorithm for calculating and classifying the conditions, and associated wiring and hardware.

[0008] The thermistor, or temperature-sensing classification device, is located in a vehicle seat cushion assembly and another in a vehicle seat backrest assembly. The temperature sensors are used to detect heat transfer between an object in contact with the cushion, through the seat cover, and, where applicable, through a certain amount of seat comfort base material, such as foam.

[0009] The reference thermistor can be used to increase the robustness of the classification determination. For example, existing thermistors, such as those providing vehicle exterior temperatures or those associated with the interior climate control in one or more rows of seats in a vehicle, can be used for reference value comparisons and to measure the rate of change between the "reference" and each "classification" sensor, as well as the magnitude of the temperature difference.

[0010] The algorithm calculates and classifies conditions based on at least the size and / or the temperature change rate between at least one classification sensor and one or more reference sensors.

[0011] The disclosed concept according to the invention provides advanced technology that is less complex and more cost-efficient in distinguishing between types of seated passengers than known systems. The disclosed concept according to the invention combines new algorithms and today's improved thermistors with existing vehicle technologies.

[0012] The above advantages and other advantages and features can be readily seen from the following detailed description of the preferred embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] For a better understanding of the present invention, reference is now made to the embodiments, which are illustrated in more detail in the accompanying drawings and are described below as examples of the invention:

[0014] Fig. Figure 1 is a side view of a seat with the sensor arrangement of the disclosed concept according to the invention;

[0015] Fig. 2 illustrates the location of the Fig. 1 of the disclosed concept according to the invention, showing a seated adult passenger;

[0016] Fig. 3 illustrates the location of the Fig. 1 of the disclosed concept according to the invention, which shows a seated child passenger on a booster seat;

[0017] Fig. 4 illustrates the location of the Fig. 1 of the disclosed concept according to the invention, showing a seated child passenger in a child restraint system;

[0018] Fig. Figure 5 is a perspective view of a first alternative embodiment of the sensor arrangement for a vehicle seat according to the disclosed concept according to the invention;

[0019] Fig. Figure 6 is a perspective view of a second alternative embodiment of the sensor arrangement for a vehicle seat according to the disclosed concept of the invention; and

[0020] Fig. Figure 7 is a perspective view of a third alternative embodiment of the sensor arrangement for a vehicle seat according to the disclosed concept of the invention. DETAILED DESCRIPTION OF THE PREFERRED EXECUTION FORM

[0021] The same reference numbers are used in the following figures to designate the same components. The following description details various operating parameters and components for differently configured embodiments. These specific parameters and components are listed as examples and should not be interpreted as limitations.

[0022] Fig. Figure 1 shows a side view of a seat of the disclosed concept according to the invention. The seat, which is generally referred to as 10 It is marked as such and includes a seat backrest. 12 and a seat base 14 It goes without saying that the seat 10 shown for illustrative purposes only, and that the shapes and sizes of the seat backrest 12 and the seat base 14 Therefore, they should not be interpreted as restrictive.

[0023] The seat 10 It includes thermal classification sensors for detecting the presence and type of passenger. The thermal classification sensors can be of any type of temperature sensor, although thermistors are preferred as non-restrictive examples. Specifically, the seat backrest 12 with at least one thermal classification sensor 16 equipped and the seat base 14is equipped with at least one thermal classification sensor 18 equipped. The number and positions of the thermal classification sensors 16 and 18 The figures shown are merely an indication, as additional thermal sensors are located in other places in the seat backrest. 12 and the seat base 14 They may be provided for. The thermal classification sensors 16 and 18 are preferably positioned between the seat foam and the seat cover and can be embedded in the seat foam.

[0024] The thermal classification sensors 16 and 18 provide output signals for a control system 20 ready. The control 20 It can also receive additional information from reference sensors, such as an outdoor temperature sensor. 22 , an interior climate sensor 24, which is provided in one or more rows or locations, a glass-mounted temperature sensor 26 , which can be attached, for example, to the windshield, a sunroof or another glass roof, a side or rear window to detect solar exposure, a seat-integrated climate control temperature sensor 28 , a seatbelt buckle sensor 30 , a first occupant weight sensor 32 , which is located in the seat back 12 located and a second occupant weight sensor 34 , which is located in the seat base 14 located. One or more of these sensors may be part of the occupant classification system (OCS), which is commonly found in modern vehicles. The reference sensors 22 , 24 , 26 , 28 , 30 , 32 and 34 They can be single-functional or multi-functional and can be very close to the seat. 10The reference sensors can be positioned or, depending on their function, be located remotely. 22 , 24 , 26 , 28 , 30 , 32 and 34 can be on, inside or on the seat backrest 12 or the seat base 14 They should be placed adjacent to the thermal classification sensors. Additionally, they can be used individually or in combination. These reference sensors compare the size or rate of change of the thermal classification sensors. 16 and 18 associated thermal conditions. How the thermal classification sensors 16 and 18 , the reference sensors 22 , 24 , 26 , 28 , 30 , 32 and 34 be of any sensor type, such as thermistors, among others.

[0025] The control 20 receives the data from the thermal classification sensors 16 and18 generated information as well as that from the reference sensors 22 , 24 , 26 , 28 , 30 , 32 and 34 The generated information is calculated and classified using a programmed algorithm, based on conditions that are at least on the size and / or the temperature change rate between at least one of the thermal classification sensors. 16 and 18 and one or more of the reference sensors 22 , 24 , 26 , 28 , 30 , 32 and 34 based on the control algorithm. 20The embedded thermal classification system can be combined with non-thermal information, such as information generated by a seatbelt buckle switch detector, a seat weight sensor, thermal images, vision-based shape / pattern detection, or other occupant classification systems, to further improve the robustness and / or the level of detail of the classification.

[0026] Once the passenger type is determined based on input from the thermal classification sensors 16 and 18 and from the reference sensors 22 , 24 , 26 , 28 , 30 , 32 and 34 Once classified, the seated occupant is classified, and this information is then sent to one or more elements of the vehicle safety system. 36 forwarded, such as the airbag deployment control.

[0027] The Fig. 2, Fig. 3 and Fig. Figure 4 illustrates the seat 10 with various passengers sitting inside. Fig. Figure 2 illustrates an adult occupant O who is in the seat 10 is seated. With this passenger type, both thermal classification sensors measure 16 and 18 a temperature increase. This information is sent to the controller. 20 transmitted and, based on information from the reference sensors 22 , 24 , 26 , 28 , 30 , 32 and 34 If the passenger is received, the seat occupant is classified as an adult occupant.

[0028] Fig. Figure 3 illustrates a larger child than occupant LC, who is sitting on a booster seat B, which is placed on the seat 10 is positioned. For this passenger type, who sits on the booster seat B, only the measurement in the seat backrest is taken. 12 located thermal classification sensor 16a temperature. The one in the seat base 14 located thermal classification sensor 18 Due to the booster seat B, the sensor is insulated from the body heat of the child occupant LC and therefore does not detect any temperature change. This information is transmitted to the control unit. 20 transmitted and, based on information from the reference sensors 22 , 24 , 26 , 28 , 30 , 32 and 34 If the passenger is received, the seat occupant is classified as a child sitting on a booster seat.

[0029] Fig. Figure 4 illustrates a smaller child than occupant SC, sitting in a child restraint system CRS that is mounted on the seat. 10 is positioned. With this passenger type in the CRS child restraint system, neither the measurement in the seat backrest is taken. 12 located thermal classification sensor 16 still the one in the seat base 14located thermal classification sensor 18 a temperature, since both thermal classification sensors 16 and 18 The child occupant SC is insulated from the body heat of the child restraint system (CRS). This information, along with information generated by the occupant classification system, is transmitted to the control unit. 20 transferred and the seat occupant is classified as a child sitting in a child restraint system.

[0030] Although Fig. 1 to Fig. 4 a seat according to the basic disclosed concept of the invention with thermal classification sensors attached thereto 16 and 18 To illustrate, it goes without saying that other arrangements are possible. Fig. 5 to Fig. Figure 7 illustrates some possible variations of both the number and placement of the classification sensors on the vehicle seat. The array of in the Fig. 5 to Fig. The seven illustrated sensors are designed for more precise detection, or as a grid to detect gradations indicative of a large adult occupant, as opposed to a small adult occupant, where the radiative heat pattern is spread out or heat over the surface area indicates occupant size. The array can also be tuned to account for clothing effects. It is understood that the in Fig. 5 to Fig. The variants shown in section 7 are intended to be merely illustrative and are not to be interpreted as restrictive, since other variants are possible without deviating from either the nature or the scope of protection of the disclosed concept according to the invention.

[0031] Fig. Figure 5 shows a perspective view of a seat according to a first variant of the disclosed concept according to the invention, which is generally associated with 40 is marked. The seat40 includes a seat backrest 42 and a seat base 44 Several thermal classification sensors 46 are in the seat backrest 42 Positioned. Several thermal classification sensors. 48 are in the seat base 44 Positioned. The number and placement of the thermal classification sensors. 44 and 46 They serve only illustrative purposes and are not to be regarded as restrictive.

[0032] Fig. Figure 6 shows a perspective view of a seat according to a second variant of the disclosed concept according to the invention, which is generally associated with 50 is marked. The seat 50 includes a seat backrest 52 and a seat base 54 A thermal classification sensor 56 is in the seat backrest 52 provided for, while a pair of thermal classification sensors 58 and58' in the seat base 54 is planned. The relative to the thermal classification sensors 56 , 58 and 58' The concentric rings shown illustrate the fact that the most direct contact with the seat occupant has the greatest thermal measurement effect.

[0033] Fig. Figure 7 shows a perspective view of a seat according to a third variant of the disclosed concept according to the invention, which is generally associated with 60 is marked. The seat 60 includes a seat backrest 62 and a seat base 64 A thermal classification sensor 66 is in the seat backrest 62 provided for, while a pair of thermal classification sensors 68 and 68' in the seat base 64 is planned. Although the in Fig. 7 thermal classification sensors shown 66 , 68 and 68'the above with reference to Fig. 6 thermal classification sensors discussed 56 , 58 and 58' Because they are similar in shape and placement, they are therefore larger than thermal classification sensors. 56 , 58 and 58' and consequently be more sensitive to changes in temperature levels. As with thermal classification sensors. 56 , 58 and 58' illustrate the relative values ​​of the thermal classification sensors 66 , 68 and 68' The concentric rings shown demonstrate that the most direct contact with the seat occupant exhibits the greatest thermal measurement effect. VARIANTS AND ADDITIONAL CONSIDERATIONS

[0034] For the purpose of additional robustness, one or more of the reference sensors can be used. 22 , 24 , 26 , 28 , 30 , 32 and 34The sensor can be placed adjacent to the seat cushion, in a door panel, or within the side of a vehicle seat cushion where the occupant is not in contact with the cushion and the sensor is not exposed to sunlight. Alternatively, the ideal location may be under a cushion or seat frame. It can be located in the lower front area of ​​a seat cushion, on top of the cushion under or adjacent to the headrest area, or on a seat back. The location can be optimized for different vehicle environments and packing conditions.

[0035] It should also be noted that it may be possible to relocate an existing interior climate control temperature sensor to provide optimal dual or multi-purpose functionality, serving both as a reference interior climate control temperature sensor and as a near reference temperature sensor for use in determining the most accurate rate and magnitude of difference relative to a thermal classification sensor.

[0036] Currently, more front seats than rear seats feature seat-based cushion and / or seatback climate controls integrated into the seat assembly. It is speculated that this option will become available for more rear seats over time. In any case, it may also be possible, using parts of the same hardware, to integrate or combine functionality with the presumed thermistor-based temperature controls associated with seat-based climate control, to provide dual or multi-purpose functionality. A seat will likely be the first to have heating or cooling activated, but this cannot be guaranteed solely based on the activation of seat-based climate control. The rate or magnitude of a thermal change is affected when an object that emits or absorbs heat energy is in contact with the seat surface.In cold temperatures, a seat can reach a target temperature relative to the outside or inside air temperature more quickly if an occupant is sitting on it. Conversely, in summer, a seat with an occupant whose body temperature remains constant within a few degrees will cool down more slowly. These considerations can be programmed into computer algorithms and would require some development to optimize them using whatever technology is employed. The use of sensors that may be included in current or future vehicles, which detect solar exposure or heat on the glass, can also be incorporated into algorithmic temperature rate and magnitude changes for a classification sensor relative to any suitable combination of reference sensors for a given vehicle.

[0037] The disclosed thermal sensor-based occupant classification system could likely detect the difference between heat transfer at the seat cushion and seat backrest of an adult occupant, a booster seat child transferring heat only to the seat backrest, and an empty seat / child condition in a CRS. When used in combination with a seatbelt buckle sensor, seat weight sensor, optical circuit switching, thermal imaging, sight-, shape-, or pattern-based recognition, or other occupant classification systems, the robustness and / or accuracy of the classification will be further improved.

[0038] Accordingly, the person skilled in the art will readily recognize from such a description and from the accompanying drawings and claims that various changes, modifications and variations can be made to it without deviating from the true idea and appropriate scope of protection of the invention as defined by the following claims.

Claims

[1] System for classifying an object that occupies a vehicle seat, comprising the following: a seat with a seat back and a seat base; a signal-generating classification thermosensor that is attached to the back of the seat; a signal-generating classification thermosensor that is attached to the seat base; a signal-generating reference sensor; a control system to which the sensors are operationally assigned; and an algorithm for classifying the object in the vehicle seat based on signals generated by the sensors. [2] System according to claim 1, wherein the thermosensors are thermistors. [3] System according to one of claims 1 or 2, wherein the reference sensor is associated with the seat. [4] System according to any of the preceding claims, wherein the reference sensor is positioned at a location in the vehicle that is set away from the seat. [5] System according to any of the preceding claims, wherein the reference sensor is an outdoor temperature sensor. [6] System according to any of the preceding claims, wherein the reference sensor is an indoor climate sensor. [7] System according to any of the preceding claims, wherein the reference sensor is a glass-mounted temperature sensor. [8] System according to one of the preceding claims, wherein the reference sensor is a seat-integrated climate control temperature sensor. [9] System according to any of the preceding claims, wherein the reference sensor is a seatbelt buckle sensor. [10] System according to any of the preceding claims, wherein the reference sensor is an occupant weight sensor. [11] System for classifying an object that occupies a vehicle seat, comprising the following: a seat with a seat back and a seat base; a signal-generating classification thermosensor assigned to the seat; a signal-generating reference sensor; a control system to which the sensors are operationally assigned; and an algorithm for classifying the object in the vehicle seat based on signals generated by the sensors. [12] System according to claim 11, wherein the signal-generating classification thermosensor is attached to the seat backrest. [13] System according to claim 11, wherein the signal-generating classification thermosensor is attached to the seat base. [14] System according to claim 11, comprising two signal-generating classification thermosensors, one of which is attached to the seat backrest and the other to the seat base. [15] System according to any of the preceding claims, wherein the thermosensor is a thermistor. [16] System according to one of the preceding claims, wherein the reference sensor is associated with the seat. [17] System according to any of the preceding claims, wherein the reference sensor is positioned at a location in the vehicle that is set away from the seat. [18] Method associated with a vehicle seat for distinguishing between an adult and a child and between a child on a booster seat and a child in a child restraint system, the method comprising the following steps: Providing a vehicle comprising a seat with a backrest and base, a thermal sensor attached to the backrest and base, a reference sensor, and a control unit; and To instruct the controller to classify the object based on sensor input. [19] Method according to claim 18, wherein the control includes an algorithm for classifying the object in the vehicle seat based on sensor inputs. [20] Method according to one of claims 18 or 19, wherein the reference sensor is selected from the group consisting of an outside temperature sensor, an inside climate sensor, a glass-mounted temperature sensor, a seat-internal climate control temperature sensor, a seatbelt buckle sensor and a weight sensor.

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