ES2387442B1

ES2387442B1 - METHOD AND APPARATUS FOR CONTINUOUS SEAT OCCUPATION DETECTION BY JOINT USE OF WEIGHT, TRAINING AND THERMAL SENSORS

Info

Publication number: ES2387442B1
Application number: ES201000255A
Authority: ES
Inventors: Ramón Pallàs Areny; Jaime Óscar Casas Piedrafita; Manuel Gasulla Forner; Carles Aliau Bonet; Jorge Gaitan Pitre
Original assignee: Universitat Politecnica de Catalunya UPC
Current assignee: Universitat Politecnica de Catalunya UPC
Priority date: 2010-02-23
Filing date: 2010-02-23
Publication date: 2013-08-08
Anticipated expiration: 2030-02-23
Also published as: WO2011104399A1; ES2387442A1

Abstract

Método de aparato para detección continua de ocupación de asientos por uso conjunto de sensores de peso, capacitivos y térmicos que detectan el cambio de peso en un asiento mediante sensores de fuerza, lo que activa el sensor capacitivo para medir los cambios volumétricos del campo eléctrico y los sensores térmicos para medir la evolución temporal de los cambios de temperatura. Se corrobora así que los cambios se deben a una persona y no a un objeto. El utilizar el cambio de peso como evento para iniciar las otras dos medidas permite una monitorización continua con un mínimo consumo eléctrico ya que los sensores de fuerza presentan una alta impedancia. El método se puede aplicar en cualquier tipo de asiento por cuanto el aparato puede ser incorporado en la estructura del asiento, debajo de su tapicería, o en una funda protectora o cojín externos.Device method for continuous detection of seat occupancy by joint use of weight, capacitive and thermal sensors that detect the change of weight in a seat by force sensors, which activates the capacitive sensor to measure the volumetric changes of the electric field and Thermal sensors to measure the temporal evolution of temperature changes. It is corroborated so the changes are due to a person and not an object. Using the weight change as an event to start the other two measures allows continuous monitoring with minimal power consumption since the force sensors have a high impedance. The method can be applied in any type of seat because the device can be incorporated in the seat structure, under its upholstery, or in an external protective cover or cushion.

Description

Método y aparato para detección continua de ocupación de asientos por uso conjunto de sensores de peso, capacitivos y térmicos. Method and apparatus for continuous detection of seat occupancy by joint use of weight, capacitive and thermal sensors.

SECTOR DE LA TÉCNICA SECTOR OF THE TECHNIQUE

La presente invención se refiere en general a los aparatos para la determinación física de las condiciones existentes en un asiento, aplicable por ejemplo en los vehículos automotores, y más en particular, a un aparato y un método de detección continua de la ocupación de asientos a través de la medida conjunta de un cambio de peso, de un cambio en el campo eléctrico y de la evolución de la temperatura en el asiento. The present invention relates in general to the apparatus for the physical determination of the conditions existing in a seat, applicable for example in motor vehicles, and more particularly, to an apparatus and a method of continuous detection of seat occupancy at through the joint measurement of a change in weight, a change in the electric field and the evolution of the temperature in the seat.

OBJETO OBJECT

El objeto de la presente invención es desarrollar una combinación de diferentes instrumentos para la detección continua de la ocupación de cualquier tipo de asiento, aplicable en los vehículos automotores, basado en los instrumentos de medida de cambio de peso, capacidad eléctrica o cambio en el campo eléctrico, y evolución de la temperatura del asiento; concibiendo dicho aparato como una combinación de un número finito de sensores de cambio de peso de alta impedancia; un número finito de sensores de temperatura; y dos o más tiras de material conductor o elementos metálicos, que pueden formar parte o no de la estructura del asiento, así como su situación en la estructura del asiento, bajo su tapicería, o en una funda o cojín dispuestos sobre el asiento. The object of the present invention is to develop a combination of different instruments for the continuous detection of the occupation of any type of seat, applicable in motor vehicles, based on the instruments of measurement of weight change, electrical capacity or change in the field electric, and evolution of the seat temperature; conceiving said apparatus as a combination of a finite number of high impedance weight change sensors; a finite number of temperature sensors; and two or more strips of conductive material or metal elements, which may or may not be part of the seat structure, as well as its location in the seat structure, under its upholstery, or in a cover or cushion arranged on the seat.

Un segundo objeto es desarrollar un aparato basado en dicha combinación de diferentes instrumentos de cambio de peso, capacidad eléctrica o cambio en el campo eléctrico, y evolución de la temperatura que implemente, con una máxima autonomía y un mínimo coste, dichos tres sistemas sensores y procese sus medidas, registrando, mostrando y/o transmitiendo la información a otros sistemas digitales. A second object is to develop an apparatus based on said combination of different instruments of weight change, electrical capacity or change in the electric field, and temperature evolution that implements, with maximum autonomy and minimum cost, said three sensor systems and process your measurements, recording, displaying and / or transmitting the information to other digital systems.

Un tercer objeto de la presente invención es desarrollar, basado en dicho aparato anterior, un método de detección continua de la ocupación de cualquier A third object of the present invention is to develop, based on said previous apparatus, a method of continuous detection of the occupation of any

tipo de asiento, capaz de funcionar en diferentes variantes de operación para la medida de dichos tres parámetros de cambio de peso, capacidad eléctrica y temperaturas. type of seat, capable of operating in different operating variants for the measurement of said three parameters of weight change, electrical capacity and temperatures.

ANTECEDENTES DE LA INVENCIÓN BACKGROUND OF THE INVENTION

Los métodos propuestos en el estado de la técnica para detectar la ocupación de asientos son numerosos. En un primer grupo están los métodos basados en detectar la interferencia o reflexión que sufre una onda emitida hacia el asiento. Según la frecuencia a la que se trabaje, hay sistemas basados en radiación infrarroja (documento del modelo de utilidad CN200997157Y, “Seat monitor” de Chuan Wan, Chuansheng Wu, Chenying Chi, Zuoqi Xu), infrarroja o microondas/radar (documento DE19812745, “System for identifying occupancy of seat in vehicle” de Funkler Wolfgang), y ultrasonidos (R. Seip, B. Adamcyzyk, D. Rundell “Use of ultrasound in automotive interior occupancy sensing: optimum frequency, beamwidth, and SNR from empirical data”, IEEE Proceedings of the Ultrasonics Symposium, Nevada, USA, pp.749-752, octubre 1999). La imposibilidad que tienen estos sistemas de diferenciar en algunos casos entre personas y animales, o entre personas y objetos, limita mucho su uso. Una alternativa son los sistemas basados en el uso de vídeo y el posterior procesado de las imágenes capturadas (documento US2003007072, “Method and device for detecting seat occupancy by means of a video sensor system and foot room system” de Bernhard Mattes, Hans-Peter Lang, Pascal Kocher), pero por su elevado coste es un diseño difícilmente asumible en aplicaciones de bajo o medio coste. Todos estos sistemas quedan además limitados por la necesidad de ubicar un sistema de emisión y recepción fuera de la estructura del asiento y enfocado hacia él, cosa que en muchas aplicaciones o es imposible, o encarece aún más el coste del sistema. The methods proposed in the state of the art for detecting seat occupancy are numerous. In a first group are the methods based on detecting the interference or reflection suffered by a wave emitted towards the seat. Depending on the frequency at which one works, there are systems based on infrared radiation (utility model document CN200997157Y, “Seat monitor” by Chuan Wan, Chuansheng Wu, Chenying Chi, Zuoqi Xu), infrared or microwave / radar (document DE19812745, “System for identifying occupancy of seat in vehicle” by Funkler Wolfgang), and ultrasound (R. Seip, B. Adamcyzyk, D. Rundell “Use of ultrasound in automotive interior occupancy sensing: optimum frequency, beamwidth, and SNR from empirical data” , IEEE Proceedings of the Ultrasonics Symposium, Nevada, USA, pp. 749-752, October 1999). The impossibility of these systems to differentiate in some cases between people and animals, or between people and objects, greatly limits their use. An alternative is the systems based on the use of video and the subsequent processing of the captured images (document US2003007072, "Method and device for detecting seat occupancy by means of a video sensor system and foot room system" by Bernhard Mattes, Hans-Peter Lang, Pascal Kocher), but because of its high cost, it is a design that is hardly acceptable in low or medium cost applications. All these systems are also limited by the need to locate an emission and reception system outside the seat structure and focused on it, which in many applications or is impossible, or makes the cost of the system even more expensive.

En un segundo grupo están aquellos sistemas que pueden ser incorporados en la estructura del asiento o en un elemento auxiliar colocado sobre él (Documento US7457695 “Portable, self-contained vehicle seat occupancy alert device” de Marvin Fields and Lisha Fields). Los métodos utilizados en estos sistemas de detección son: In a second group are those systems that can be incorporated in the seat structure or in an auxiliary element placed on it (Document US7457695 "Portable, self-contained vehicle seat occupancy alert device" of Marvin Fields and Lisha Fields). The methods used in these detection systems are:

Sensores mecánicos, basados en la medida del peso (documento EP1683677, “Détecteur d´occupation d´un siège et véhicule équipé d`un tel détecteur ” de Laurent Certin, Stephane Berthet, Benedicte Sol), la presión, la fuerza o la aceleración (documento US5915281 “Silicon force and displacement sensor” de Douglas Ray Sparks), que mediante medidas puntuales o distribuidas en todo el asiento detectan la presencia de un objeto encima suyo y alguna de sus características. Las medidas con estos sensores difícilmente pueden distinguir entre personas y objetos suficientemente pesados. Mechanical sensors, based on weight measurement (EP1683677, “Détecteur d´occupation d´un siège et véhicule équipé d`un tel détecteur” by Laurent Certin, Stephane Berthet, Benedicte Sol), pressure, force or acceleration (US5915281 "Silicon force and displacement sensor" by Douglas Ray Sparks), which by means of specific measures or distributed throughout the seat detect the presence of an object on top of it and some of its characteristics. Measures with these sensors can hardly distinguish between people and objects that are sufficiently heavy.

Sensores capacitivos, basados en la medida de los cambios de campo eléctrico ocasionados por la presencia de una persona. Se han estudiado numerosas dimensiones y configuraciones de los electrodos para detectar la presencia de Capacitive sensors, based on the measurement of the electric field changes caused by the presence of a person. Numerous electrode dimensions and configurations have been studied to detect the presence of

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una persona y también para poder discriminar entre adultos y niños (B. George, H. Zangl, T. Bretterklieber, G. Brasseur, “Seat occupancy detection based on capacitive sensing” IEEE Transactions on Instrumentation and Measurement, Vol. 58, pp. 1487-1494, 2009), e incluso determinar la posición de la persona en el asiento. Su principal limitación es que objetos grandes con agua u otros elementos conductores puede que sean detectados como si fueran una persona. a person and also to discriminate between adults and children (B. George, H. Zangl, T. Bretterklieber, G. Brasseur, “Seat occupancy detection based on capacitive sensing” IEEE Transactions on Instrumentation and Measurement, Vol. 58, pp. 1487-1494, 2009), and even determine the position of the person in the seat. Its main limitation is that large objects with water or other conductive elements may be detected as if they were a person.

Mayoritariamente la temperatura ha sido considerada como una interferencia en otros sistemas de detección de la ocupación de asientos, que debe ser corregida o compensada. Por ejemplo, en la patente FR2863704 (“Measurement signal processing method for characterizing seat occupancy state involves correcting measurement signal, from detection layer placed in seat, based on environment derivatives related to temperature and humidity” de Herve Dirand, Yann Rogard, Laurent Chabert, Bertrand Billon, Frederic Fays, Eric Rochat), se presenta el efecto de los cambios de temperatura y humedad ambiente en sensores capacitivos y diferentes métodos para compensarlos. Sin embargo, en la patente US 6490515 B1 “Passenger detecting apparatus” de Hiroyo Okamura, Naobumi Kuboki, Takayuki Enomoto, Soichi Negami, Kyosuke Hashimoto) se proponen dos alternativas de medida: la primera consiste en el uso de medios de detección que tienen al menos un sensor capacitivo y un sensor de presión y la segunda utiliza medios de detección que tienen al menos un sensor capacitivo y un sensor de temperatura. En ella se plantea, por tanto, el uso de la temperatura como alternativa de medida conjuntamente a un sensor capacitivo, no planteándose específicamente su uso de forma simultánea con sensores de cambio de peso, ni la optimización de consumo que supone usar el sensor de cambio de peso como señal de disparo de los sensores capacitivos y de temperatura. Mostly the temperature has been considered as interference in other systems for detecting seat occupancy, which must be corrected or compensated. For example, in FR2863704 ("Measurement signal processing method for characterizing seat occupancy state involves correcting measurement signal, from detection layer placed in seat, based on environment derivatives related to temperature and humidity" of Herve Dirand, Yann Rogard, Laurent Chabert, Bertrand Billon, Frederic Fays, Eric Rochat), presents the effect of ambient temperature and humidity changes in capacitive sensors and different methods to compensate them. However, in US patent 6490515 B1 “Passenger detecting apparatus” of Hiroyo Okamura, Naobumi Kuboki, Takayuki Enomoto, Soichi Negami, Kyosuke Hashimoto) two measurement alternatives are proposed: the first consists in the use of detection means that have the less a capacitive sensor and a pressure sensor and the second uses detection means that have at least one capacitive sensor and a temperature sensor. In it, therefore, the use of temperature is proposed as an alternative measure in conjunction with a capacitive sensor, not specifically considering its use simultaneously with weight change sensors, nor the consumption optimization of using the change sensor of weight as a trigger signal of the capacitive and temperature sensors.

Una solución para solventar las limitaciones de los diferentes sistemas desarrollados para detectar la ocupación de un asiento se ha visto en la patente US 6490515 B1 es usar simultáneamente sensores de varios tipos distintos. Edemas de esta referencia, en Philip W. Kithil, “Capacitive Occupant Sensing” Occupant detection and sensing for smarter air bag systems. PT-107. Society of Automotive Engineers, Inc, pp. 185-190, 2004 se recomienda el uso de un sensor capacitivo conjuntamente con un sistema de infrarrojos, ultrasonidos, radar o peso. En el documento MX9604777 (“Automotive occupant sensor system and method of operation by sensor fusion” de Anthony P. Corrado, Stephen W. Decker, Paul K. Benbow) se presenta el uso conjunto de un sistema de infrarrojos y un sistema de ultrasonidos; y en US6445988 (“System for determining the occupancy state of a seat in a vehicle and controlling a component based thereon” de David S. Bread, Willbur E. Duvall, Wendell C. Johnson, Jeffrey L. Morin, Kunhong Xu, Michael E. Kussul) se reivindica el uso de múltiples sistemas sensores: de peso, inductivos, capacitivos, de movimiento, electromagnéticos, de ultrasonidos, infrarrojos y de radar por microondas, combinados mediante un procesado basados en redes neuronales para detectar y clasificar la ocupación de asientos. Como puede apreciarse en esta última patente, aunque se presenta el uso de hasta ocho métodos sensores diferentes, no se contempla el uso de sensores de temperatura para detectar la ocupación de un asiento por una persona. Por último, en el documento US 2006267321 A1 (“On-board vehicle seat capacitive force sensing device and method” de Divyasimha Harish y William D. Dallenbach) se presenta un sistema capacitivo para la medida del peso de la persona que es complementada con diferentes medidas sensoriales del ocupante que pueden incluir datos visuales, olfativos, textiles o térmicos. Por otro lado, el empleo de un número elevado de sensores tan complejos carece de posibilidad de implementación en aplicaciones de mediano y bajo costo. Menos aún, en el estado de la técnica tampoco existe información sobre aparatos y métodos sencillos y viables económicamente de instrumentos para la determinación de la ocupación de asientos en general y en vehículos automotores en particular, que proporcionen la información de una forma fiable. A solution to solve the limitations of the different systems developed to detect the occupancy of a seat has been seen in US patent 6490515 B1 is to simultaneously use sensors of several different types. Edemas of this reference, in Philip W. Kithil, “Capacitive Occupant Sensing” Occupant detection and sensing for smarter air bag systems. PT-107 Society of Automotive Engineers, Inc, pp. 185-190, 2004 it is recommended to use a capacitive sensor in conjunction with an infrared, ultrasound, radar or weight system. In document MX9604777 ("Automotive occupant sensor system and method of operation by sensor fusion" by Anthony P. Corrado, Stephen W. Decker, Paul K. Benbow) the joint use of an infrared system and an ultrasound system is presented; and in US6445988 (“System for determining the occupancy state of a seat in a vehicle and controlling a component based thereon” by David S. Bread, Willbur E. Duvall, Wendell C. Johnson, Jeffrey L. Morin, Kunhong Xu, Michael E Kussul) claims the use of multiple sensor systems: weight, inductive, capacitive, motion, electromagnetic, ultrasonic, infrared and microwave radar, combined by processing based on neural networks to detect and classify seat occupancy . As can be seen in this last patent, although the use of up to eight different sensor methods is presented, the use of temperature sensors to detect the occupation of a seat by a person is not contemplated. Finally, in US 2006267321 A1 (“On-board vehicle seat capacitive force sensing device and method” of Divyasimha Harish and William D. Dallenbach) a capacitive system for measuring the weight of the person is presented, which is complemented with different occupant sensory measurements that may include visual, olfactory, textile or thermal data. On the other hand, the use of a large number of such complex sensors lacks the possibility of implementation in medium and low cost applications. Even less, in the state of the art there is also no information on simple and economically viable devices and methods of instruments for determining the occupancy of seats in general and in motor vehicles in particular, which provide the information in a reliable manner.

DESCRIPCIÓN DE LA INVENCIÓN DESCRIPTION OF THE INVENTION

Se han desarrollado un aparato y un método nuevos para detectar continuamente la ocupación de asientos mediante el uso conjunto y secuencial de tres sistemas sensores: de cambio de peso, capacitivo y térmico. Su uso conjunto solventa las limitaciones inherentes a los actuales métodos existentes en el estado de la técnica al usar cada uno de ellos por separado. Más aún, su uso resulta totalmente viable en los vehículos actuales por la sencillez de su concepción y fiabilidad de los resultados. A new device and method have been developed to continuously detect seat occupancy through the joint and sequential use of three sensor systems: weight change, capacitive and thermal. Its joint use solves the limitations inherent to the current methods in the state of the art by using each of them separately. Moreover, its use is totally viable in current vehicles due to the simplicity of its conception and reliability of the results.

El aparato desarrollado se basa en un controlador digital al cual están conectados dichos tres sistemas sensores de cambio de peso, capacitivo y térmico, mediante las interfaces electrónicas correspondientes, un circuito de comunicación transceptor o modem, y un sistema de alimentación que suministra energía a los diferentes subsistemas. En la presente invención, tanto el controlador como el transceptor/módem están normalmente en estado de espera, con un consumo muy bajo, hasta que el primer sistema sensor detecta la presencia de una persona u objeto. The developed device is based on a digital controller to which said three weight, capacitive and thermal sensor systems are connected, by means of the corresponding electronic interfaces, a transceiver or modem communication circuit, and a power system that supplies power to the Different subsystems In the present invention, both the controller and the transceiver / modem are normally in the waiting state, with very low consumption, until the first sensor system detects the presence of a person or object.

Dicho primer sistema sensor se basa en la detección de un cambio de peso, por ejemplo mediante una pluralidad de sensores piezorresistivos. Algunos de estos sensores están basados en polímeros conductores que tienen una resistencia eléctrica en vacío muy elevada, y su valor se reduce en varios órdenes de magnitud cuando son sometidos a una carga mecánica, esto es, el peso de un pasajero. Por ejemplo, hay modelos cuya resistencia en vacío es superior a 20 MO, la cual se reduce por un factor superior a 300 al aplicarles un peso de 30 kg. Ese valor tan elevado de resistencia en vacío permite tenerlos en funcionamiento garantizando un consumo muy reducido (inferior a 1 μA). Los sensores se pueden situar en cualquier punto de la estructura del asiento donde se ejerza una fuerza al sentarse, o en cualquier elemento externo apto para decorar, proteger u obtener una mayor comodidad (funda o cojín), lo que los hace muy versátiles y adecuados para su aplicación en vehículos automotores. En cuanto se detecta un cambio debido a la acción de un cambio de peso sobre el asiento, el controlador pone en marcha los otros dos sistemas sensores: Said first sensor system is based on the detection of a change in weight, for example by means of a plurality of piezoresistive sensors. Some of these sensors are based on conductive polymers that have a very high electrical resistance in vacuum, and their value is reduced by several orders of magnitude when subjected to a mechanical load, that is, the weight of a passenger. For example, there are models whose vacuum resistance is greater than 20 MO, which is reduced by a factor greater than 300 by applying a weight of 30 kg. This high vacuum resistance value allows them to be operated, guaranteeing a very low consumption (less than 1 μA). The sensors can be placed anywhere in the seat structure where a force is exerted when sitting, or in any external element suitable for decorating, protecting or obtaining greater comfort (cover or cushion), which makes them very versatile and suitable For application in motor vehicles. As soon as a change is detected due to the action of a weight change on the seat, the controller starts the other two sensor systems:

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capacitivo y térmico, para evaluar si el cambio de peso es debido a una persona o a otro tipo de objeto. El umbral de detección para el cambio de peso se puede ajustar según el uso previsto para el asiento, incluso para sillas infantiles para automóviles. capacitive and thermal, to assess whether the change in weight is due to a person or another type of object. The detection threshold for weight change can be adjusted according to the intended use for the seat, even for child car seats.

El segundo sensor utilizado es de tipo capacitivo. Mediante dos elementos conductores tales como dos cintas metálicas debajo de la tapicería del asiento o en una funda o cojín externos, se crea un campo eléctrico volumétrico cuyo valor cambiará con la presencia de una persona. Estos cambios pueden permitir la diferenciación entre adultos y niños, y son suficientemente grandes para no depender excesivamente de las diferentes posiciones que puede adoptar una persona al sentarse. Sin embargo, objetos de gran tamaño que contengan elementos conductores pueden provocar cambios en el campo eléctrico similares a los debidos a una persona. Por ejemplo, un recipiente grande de agua sobre el asiento, aunque tales situaciones son fácilmente previsibles. De ahí que su uso demanda el empleo complementario de otros sensores. The second sensor used is capacitive. By means of two conductive elements such as two metal tapes under the seat upholstery or in an external cover or cushion, a volumetric electric field is created whose value will change with the presence of a person. These changes can allow differentiation between adults and children, and are large enough not to depend excessively on the different positions that a person can take when sitting. However, large objects that contain conductive elements can cause changes in the electric field similar to those due to a person. For example, a large container of water on the seat, although such situations are easily predictable. Hence its use demands the complementary use of other sensors.

Para solventar este problema, y aumentar así la fiabilidad del detector, en la presente invención se usa un tercer sistema sensor basado en medir la evolución temporal de la temperatura de la superficie del asiento. Para que un objeto caliente esta superficie, debe tener una fuente de energía interna, que en el caso de las personas es su metabolismo. La evolución temporal de la temperatura del asiento depende también de la indumentaria de la persona y de un posible sistema de calefacción incorporado en el asiento; pero mediante un umbral de diferenciación respecto a una temperatura de referencia y el estudio de la pendiente de la evolución temporal, es posible identificar la presencia de una persona sentada. El dilatado tiempo de respuesta de esta evolución térmica dificulta su uso como único sensor para detectar la ocupación del asiento. To solve this problem, and thus increase the reliability of the detector, in the present invention a third sensor system is used based on measuring the temporal evolution of the temperature of the seat surface. For an object to heat this surface, it must have an internal energy source, which in the case of people is its metabolism. The temporal evolution of the seat temperature also depends on the person's clothing and on a possible heating system incorporated in the seat; but by means of a threshold of differentiation with respect to a reference temperature and the study of the slope of the temporal evolution, it is possible to identify the presence of a seated person. The long response time of this thermal evolution makes it difficult to use it as a single sensor to detect seat occupancy.

En asientos incorporados por ejemplo en vehículos, la información del sistema de detección, que puede ser transmitida por cable o sin hilos a otro sistema digital, puede complementarse con los datos adquiridos por otros sistemas de medida del vehículo. Por ejemplo, si en un coche que circula con una determinada velocidad se detectan tres personas, el único hecho que podría acaecer mientras se mantenga la marcha es que las personas cambiaran de asiento, por lo que el número global de personas sólo podrá volver a cambiar después de que el vehículo se haya detenido. La incorporación de estos datos en el sistema global permite reducir el número o la frecuencia de las medidas y por tanto el consumo de energía del sistema. In seats incorporated for example in vehicles, the information of the detection system, which can be transmitted by cable or wireless to another digital system, can be complemented with the data acquired by other vehicle measurement systems. For example, if three people are detected in a car that runs at a certain speed, the only fact that could occur while the gear is being maintained is that people change seats, so the global number of people can only change again after the vehicle has stopped. The incorporation of this data in the global system allows to reduce the number or frequency of the measurements and therefore the energy consumption of the system.

Existe otro modo de realización alternativo en el cual el controlador, cuando se detecta un cambio de peso, activa únicamente el sensor capacitivo en vez de activar a la vez, cuando se detecta un cambio de peso, el sensor capacitivo y los sensores de temperatura. Esta alternativa puede ser utilizada intermitentemente para ahorrar consumo respecto al descrito anteriormente. There is another alternative embodiment in which the controller, when a weight change is detected, activates only the capacitive sensor instead of activating at the same time, when a weight change is detected, the capacitive sensor and the temperature sensors. This alternative can be used intermittently to save consumption compared to the one described above.

BREVE DESCRIPCIÓN DE LOS DIBUJOS BRIEF DESCRIPTION OF THE DRAWINGS

Se describe a continuación una realización preferente de la invención de acuerdo con las figuras que se acompañan, en las cuales: A preferred embodiment of the invention according to the accompanying figures, in which:

La Fig. 1 muestra la arquitectura del aparato para la detección continua de ocupación de asientos. Fig. 1 shows the architecture of the apparatus for the continuous detection of seat occupancy.

La Fig. 2 muestra la pluralidad de sensores de medida de cambio de peso 101 basada en un número finito (n) de sensores de fuerza piezorresistivos de alta impedancia (SF1, SF2,…,SFn). Fig. 2 shows the plurality of weight change measurement sensors 101 based on a finite number (n) of high impedance piezoresistive force sensors (SF1, SF2, ..., SFn).

La Fig. 3 muestra diferentes posiciones posibles de los sensores de fuerza piezorresistivos. Fig. 3 shows different possible positions of the piezoresistive force sensors.

La Fig. 4 muestra valores de resistencia obtenidos para los sensores de fuerza piezorresistivos en función de su posición en el asiento y de la ocupación o no de éste. Fig. 4 shows resistance values obtained for the piezoresistive force sensors according to their position in the seat and their occupation or not.

La Fig. 5 muestra diferentes formas y posiciones en las que pueden ubicarse en el asiento dos tiras metálicas que conformen los sensores capacitivos 102 Fig. 5 shows different shapes and positions in which two metal strips that form the capacitive sensors 102 can be located in the seat

La Fig. 6 muestra posiciones en las que pueden colocarse en la plataforma del asiento dos tiras metálicas que conforman el sensor capacitivo 102. Fig. 6 shows positions in which two metal strips that make up the capacitive sensor 102 can be placed on the seat platform.

La Fig. 7 muestra posiciones en las que el sensor capacitivo 102 puede colocarse en elementos externos tales como una funda de asiento. Fig. 7 shows positions in which the capacitive sensor 102 can be placed in external elements such as a seat cover.

La Fig. 8 muestra posiciones en las que el sensor capacitivo 102 puede colocarse en un simple cojín. Fig. 8 shows positions in which the capacitive sensor 102 can be placed in a simple cushion.

La Fig. 9 muestra un ejemplo de una posible disposición de sensores de temperatura 103 utilizando siete sensores, uno de referencia (S1) y seis de medida de la temperatura de la superficie del asiento (S2) a (S7). Fig. 9 shows an example of a possible arrangement of temperature sensors 103 using seven sensors, one reference (S1) and six measuring the surface temperature of the seat (S2) to (S7).

La Fig. 10 muestra resultados de las capacidades medidas para diferentes disposiciones de los electrodos que conforman el sensor capacitivo 102, en ausencia o presencia de una persona sentada en un asiento abatible. Fig. 10 shows results of the capacities measured for different arrangements of the electrodes that make up the capacitive sensor 102, in the absence or presence of a person sitting in a folding seat.

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La Fig. 11 muestra variaciones de capacidades eléctricas medidas con el movimiento del usuario en el asiento o el uso de aparatos de comunicación que pudieran crear interferencias. Fig. 11 shows variations of electrical capacities measured with the user's movement in the seat or the use of communication devices that could create interference.

La Fig. 12 muestra una evolución temporal del cambio de temperatura en la superficie del asiento debido a su ocupación por una persona. Fig. 12 shows a temporary evolution of the temperature change in the surface of the seat due to its occupation by a person.

La Fig. 13 muestra cambios en la evolución temporal de la temperatura medida por los sensores colocados en las posiciones indicadas en la Fig. 9. Fig. 13 shows changes in the temporal evolution of the temperature measured by the sensors placed in the positions indicated in Fig. 9.

La Fig. 14 muestra la evolución temporal de la temperatura ante la ocupación intermitente de un asiento. Fig. 14 shows the temporal evolution of the temperature before the intermittent occupation of a seat.

DESCRIPCIÓN DE UNA REALIZACIÓN PREFERENTE DESCRIPTION OF A PREFERRED EMBODIMENT

La Figura 1 muestra la arquitectura del sistema propuesto que consta de los sensores de medida de cambio de peso 101, sensores capacitivos 102 y de temperatura 103, que son conectados al microcontrolador 105 a través de los circuitos de acondicionamiento 104. El microcontrolador 105 transmite la información directamente a un sistema de visualización 106, o a otro elemento digital externo a través de los sistemas de comunicación con cable y/o inalámbrica Figure 1 shows the architecture of the proposed system consisting of the weight change measurement sensors 101, capacitive sensors 102 and temperature sensors 103, which are connected to the microcontroller 105 through the conditioning circuits 104. The microcontroller 105 transmits the information directly to a display system 106, or to another external digital element through wired and / or wireless communication systems

107. El sistema de alimentación 108 está conectado al microcontrolador 105, a los sistemas de comunicación 107 y a los sistemas sensores 101, 102 y 103, y a sus circuitos de acondicionamiento 104. Si la autonomía del sistema lo requiere, los sensores 101, 102 y 103, y sus circuitos de acondicionamiento 104, pueden alimentarse directamente de un puerto digital del microcontrolador 105. 107. The power supply system 108 is connected to the microcontroller 105, the communication systems 107 and the sensor systems 101, 102 and 103, and its conditioning circuits 104. If the autonomy of the system requires it, the sensors 101, 102 and 103, and its conditioning circuits 104, can be fed directly from a digital port of the microcontroller 105.

Para obtener una mayor eficiencia energética, tanto el microcontrolador como los sistemas de comunicación 107 y los sistemas sensores capacitivos 102 y térmicos 103 se encontrarán, por defecto, en un estado de bajo consumo. Estará pues activado únicamente el sistema sensor de cambio de peso 101. To obtain greater energy efficiency, both the microcontroller and the communication systems 107 and the capacitive sensor systems 102 and thermal sensors 103 will, by default, be in a state of low consumption. Only the weight change sensor system 101 will be activated.

De la Figura 2 se aprecia el sistema de sensores de medida de cambio de peso 101 que se basa en el uso de una pluralidad, un número finito (n) de sensores de fuerza piezorresistivos de alta impedancia (SF1, SF2,…SFn), colocados debajo de la tapicería del asiento, en su soporte, en una funda o en un cojín, y conectados en paralelo en un circuito divisor de tensión. La salida de este circuito se conecta a una entrada analógica del microcontrolador 105 y/o al circuito de interrupción de un puerto digital (no se muestra). Dicha pluralidad de sensores de cambio de peso consta de uno o varios sensores piezorresistivos 101 cuyo circuito de interfaz es un divisor de tensión, donde el resistor Rs se elige para ajustar el umbral de detección de cambio de peso (Figura 2). El valor de Rs es alto (1 MO) para que cuando el sensor piezorresistivo tenga un valor bajo, el consumo del sistema no aumente demasiado. La salida del divisor de tensión se conecta a una entrada de interrupciones externas del microcontrolador 105 y a la entrada de un convertidor analógico digital (no se muestra). Un cambio en la señal de la interrupción externa activará los otros dos sistemas sensores de medida. La entrada analógica permite obtener una primera estimación del cambio de peso del objeto que ocupa el asiento. Si se utiliza, generalmente, más de un sensor piezorresistivo 101, éstos se conectan en paralelo, de modo que basta que uno de ellos detecte un cambio de peso lo suficientemente grande para que el microcontrolador active el sensor capacitivo y el sensor térmico. Figure 2 shows the weight change measurement sensor system 101 based on the use of a plurality, a finite number (n) of high impedance piezoresistive force sensors (SF1, SF2, ... SFn), placed under the seat upholstery, in its support, in a cover or in a cushion, and connected in parallel in a voltage divider circuit. The output of this circuit is connected to an analog input of the microcontroller 105 and / or to the interrupt circuit of a digital port (not shown). Said plurality of weight change sensors consist of one or several piezoresistive sensors 101 whose interface circuit is a voltage divider, where the resistor Rs is chosen to adjust the weight change detection threshold (Figure 2). The value of Rs is high (1 MO) so that when the piezoresistive sensor has a low value, the system consumption does not increase too much. The output of the voltage divider is connected to an external interrupt input of the microcontroller 105 and to the input of a digital analog converter (not shown). A change in the signal of the external interruption will activate the other two measurement sensor systems. The analog input allows to obtain a first estimate of the change in weight of the object that occupies the seat. If, generally, more than one piezoresistive sensor 101 is used, these are connected in parallel, so that it is enough that one of them detects a weight change large enough for the microcontroller to activate the capacitive sensor and the thermal sensor.

Son diferentes las posiciones donde pueden ubicarse los sensores de fuerza piezorresistivos, véase la Figura 3: tanto encima o debajo de la espuma del asiento, así como en su estructura mecánica. La Figura 4 muestra los resultados obtenidos de valores de resistencia para un sensor piezorresistivo, tipo FlexiForce A201-100, en tres posiciones diferentes. En todos ellos se aprecia que una persona sentada produce un cambio significativo en la resistencia del sensor, superior a un factor de 2,6. El uso de varios sensores conectados en paralelo aumenta la magnitud de estos cambios. The positions where the piezoresistive force sensors can be located are different, see Figure 3: both above or below the seat foam, as well as in its mechanical structure. Figure 4 shows the results obtained of resistance values for a piezoresistive sensor, type FlexiForce A201-100, in three different positions. In all of them it can be seen that a seated person produces a significant change in the resistance of the sensor, greater than a factor of 2.6. The use of several sensors connected in parallel increases the magnitude of these changes.

Una vez detectada la presencia de un objeto en el asiento se activan los sistemas sensores capacitivos 102 y térmicos Once the presence of an object in the seat is detected, the capacitive sensing systems 102 and thermal are activated

103. 103.

Los sensores capacitivos 102 son dos cintas adhesivas conductoras, que pueden disponerse en formas y posiciones diferentes, como se muestran en la Figura 5, igualmente sobre la plataforma del asiento, así como sobre el material que la cubre, véase la Figura 6, o en elementos externos tales como una funda de asiento, Figura 7, o un simple cojín, Figura 8. The capacitive sensors 102 are two conductive adhesive tapes, which can be arranged in different shapes and positions, as shown in Figure 5, also on the seat platform, as well as on the material that covers it, see Figure 6, or in external elements such as a seat cover, Figure 7, or a simple cushion, Figure 8.

Los sensores de temperatura 103 también pueden colocarse en distintos puntos de la base del asiento o en elementos externos. Un primer sensor térmico se sitúa fuera de la zona de contacto entre el objeto/persona y el asiento, y mide la temperatura a la que se encuentra en todo momento el asiento, la que se tomará como medida de referencia respecto a la que se estudiarán los cambios de temperatura. El resto de sensores térmicos de medida 103, uno o generalmente más sensores, se disponen en diferentes posiciones del asiento, en posiciones próximas a la superficie que entre en contacto con una persona al sentarse. En la figura 9 se presenta un ejemplo de una posible disposición utilizando siete sensores, uno de referencia (S1) y seis de medida de la temperatura de la superficie del asiento (S2) a (S7). The temperature sensors 103 can also be placed at different points of the seat base or external elements. A first thermal sensor is located outside the contact area between the object / person and the seat, and measures the temperature at which the seat is at all times, which will be taken as a reference measure with respect to which they will be studied temperature changes The rest of the measuring thermal sensors 103, one or generally more sensors, are arranged in different positions of the seat, in positions close to the surface that come into contact with a person when sitting. An example of a possible arrangement using seven sensors, one reference (S1) and six measuring the temperature of the seat surface (S2) to (S7) is presented in Figure 9.

Un posible circuito de acondicionamiento 104 para los sensores capacitivos es una interfaz directa (F. Reverter, R.Pallàs-Areny, Direct sensor-to-microcontroller interface circuits, Editorial Marcombo, Barcelona, 2005), o también un A possible conditioning circuit 104 for capacitive sensors is a direct interface (F. Reverter, R. Pals-Areny, Direct sensor-to-microcontroller interface circuits, Editorial Marcombo, Barcelona, 2005), or also a

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circuito de transferencia de carga (J. Gaitán-Pitré, M. Gasulla, R. Pallàs-Areny, “Analysis of a direct interface circuit for capacitive sensors”. IEEE Transactions on Instrumentation and Measurement, Vol. 58, pp. 2931-2937, 2009). En la Figura 10, se muestran los resultados de las capacidades eléctricas medidas para diferentes disposiciones de los dos electrodos que forman el sensor capacitivo 102, en ausencia o presencia de una persona sentada en un asiento abatible. Los cambios, superiores a un factor de 1,5, validan la capacidad de detección para distintas posturas del cuerpo. Además, estos cambios no sufren grandes variaciones con el movimiento del usuario en el asiento o el uso de aparatos de comunicación que pudieran crear interferencias, véase la Figura 11. Objetos, como ordenadores portátiles o cajas de herramientas, son también diferenciables. Sin embargo objetos mayores con alto contenido de agua podrían proporcionar detecciones positivas falsas. load transfer circuit (J. Gaitán-Pitré, M. Gasulla, R. Pallàs-Areny, “Analysis of a direct interface circuit for capacitive sensors.” IEEE Transactions on Instrumentation and Measurement, Vol. 58, pp. 2931-2937 , 2009). In Figure 10, the results of the electrical capacities measured for different arrangements of the two electrodes that form the capacitive sensor 102 are shown, in the absence or presence of a person sitting in a folding seat. The changes, higher than a factor of 1.5, validate the detection capacity for different body positions. In addition, these changes do not suffer large variations with the user's movement in the seat or the use of communication devices that could create interference, see Figure 11. Objects, such as laptops or toolboxes, are also differentiable. However, larger objects with a high water content could provide false positive detections.

Las Figuras 12 y 13 muestran los cambios de temperatura ocasionados por una persona sentada en el asiento: Figures 12 and 13 show the temperature changes caused by a person sitting in the seat:

En la Figura 12 se aprecia el aumento de la señal de un sensor S2 de medida de temperatura 103, respecto al sensor de referencia S1; se evidencia que después de los 15-20 minutos se alcanza casi una cima en el aumento de temperatura, de la cual la señal cae en forma brusca cuando el pasajero se levanta del asiento. Figure 12 shows the increase in the signal of a temperature measuring sensor S2 103, with respect to the reference sensor S1; it is evident that after 15-20 minutes almost a peak is reached in the temperature increase, from which the signal falls sharply when the passenger gets up from the seat.

En la Fig. 13 se aprecia los cambios en la evolución temporal de la temperatura medida por los sensores colocados en las posiciones indicadas en la Fig. 9. Se constata una diferente sensibilidad de la señal dependiendo de la posición que ocupan los sensores, siendo el más sensible el que se encuentra en la posición S2 (Fig. 9), posición superior izquierda que evidencia el desplazamiento del pasajero hacia este lado. Igualmente se evidencia que después de los 15-20 minutos se alcanza casi una cima en el aumento de temperatura, de la cual la señal cae en forma brusca cuando el pasajero se levanta del asiento. In Fig. 13 the changes in the temporal evolution of the temperature measured by the sensors placed in the positions indicated in Fig. 9 are observed. A different sensitivity of the signal is observed depending on the position occupied by the sensors, being the more sensitive is the one in position S2 (Fig. 9), upper left position that shows the passenger's movement to this side. It is also evident that after 15-20 minutes almost a peak is reached in the temperature increase, from which the signal falls sharply when the passenger gets up from the seat.

En la Figura 14 se expone la evolución temporal de la temperatura ante la ocupación intermitente de un asiento para uno de los detectores más sensibles S4 (Fig. 9). Se evidencia la falta de sensibilidad del sensor de temperatura 103 para detectar la desocupación del asiento cuando su ocupación es intermitente. Esto es debido a que si la ocupación ha sido larga, la inercia térmica del asiento hace que la disipación del calor residual luego de levantarse el pasajero sea tan lenta que el sensor detecte una temperatura más alta que la temperatura ambiente durante un cierto tiempo. Esto impediría detectar la ocupación del asiento de forma fiable si sólo se emplearan sensores de temperatura. Aunque una ocupación intermitente de un asiento es poco probable en automóviles, sí lo es en cambio en autocares, aviones o trenes, y por supuesto en asientos empleados en una vivienda o cualquier otro tipo de edificio. Figure 14 shows the temporal evolution of the temperature before the intermittent occupation of a seat for one of the most sensitive detectors S4 (Fig. 9). The lack of sensitivity of the temperature sensor 103 is detected to detect the vacancy of the seat when its occupation is intermittent. This is because if the occupancy has been long, the thermal inertia of the seat makes the dissipation of the residual heat after the passenger is lifted so slow that the sensor detects a temperature higher than the ambient temperature for a certain time. This would prevent detecting seat occupancy reliably if only temperature sensors were used. Although an intermittent occupation of a seat is unlikely in cars, it is instead in coaches, airplanes or trains, and of course in seats used in a home or any other type of building.

Los sensores 103 utilizados han sido termopares de tipo J, pero podría utilizarse cualquier otro tipo de sensor. El uso, por ejemplo, de sensores resistivos como las RTD o termistores permitirían aplicar circuitos de interfaz directa entre sensor 103 y microcontrolador 105, simplificando el circuito de acondicionamiento 104. La evolución temporal de la temperatura indicada por estos sensores depende del volumen de la persona, la ropa que lleva, la posición del sensor 103 y la temperatura ambiente. Para una temperatura ambiente de 20 ºC se producen incrementos de temperatura de más de 5 ºC según la posición de medida. La temperatura medida en puntos del asiento debajo del cuerpo tarda hasta 20 minutos en estabilizarse, por lo que este método no es práctico para ser utilizado de forma independiente. Además, como regla para decidir la ocupación o no de un asiento, no se puede utilizar la comparación con un umbral fijo porque situaciones tales como la ocupación intermitente del asiento podrían producir falsos positivos, según muestra la Figura The sensors 103 used have been type J thermocouples, but any other type of sensor could be used. The use, for example, of resistive sensors such as RTDs or thermistors would allow direct interface circuits between sensor 103 and microcontroller 105 to be applied, simplifying the conditioning circuit 104. The temporal evolution of the temperature indicated by these sensors depends on the volume of the person , the clothes he wears, the position of the sensor 103 and the ambient temperature. For an ambient temperature of 20 ºC, temperature increases of more than 5 ºC are produced depending on the measurement position. The temperature measured in points of the seat under the body takes up to 20 minutes to stabilize, so this method is not practical to be used independently. In addition, as a rule for deciding whether or not to occupy a seat, comparison with a fixed threshold cannot be used because situations such as intermittent seat occupancy could produce false positives, as shown in Figure

14. Un algoritmo basado en el valor instantáneo de la temperatura y su derivada permite, en cambio, detectar la ocupación, pues cuando hay una persona sentada, la derivada es positiva o nula. Una derivada negativa durante un tiempo prolongado indica que la persona se ha levantado del asiento. 14. An algorithm based on the instantaneous value of the temperature and its derivative allows, instead, to detect the occupation, because when a person is seated, the derivative is positive or zero. A negative derivative for a long time indicates that the person has risen from the seat.

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Claims

1.- An apparatus for the continuous detection of seat occupancy characterized in that it consists of a plurality of force sensors for measuring the weight change (101), a capacitive sensor (102), a plurality of temperature sensors (103), conditioning circuits (104), microcontroller (105), display medium (106), a transceiver or modem communication circuit (107) and a power system (108).

2. The apparatus for the continuous detection of seat occupancy according to claim 1 characterized in that said plurality of force sensors for measuring the weight change (101), said capacitive sensor (102), and said plurality of temperature sensors ( 103) can be incorporated into the seat structure, under your upholstery, or to an external protective cover or cushion.

3. The apparatus for the continuous detection of seat occupancy according to claim 1 characterized in that said plurality of force sensors for measuring weight (101) is based on a finite number (n) of high impedance piezoresistive sensors, which are they can be placed under the seat upholstery, in their support, in a cover or in a cushion, and can be connected in parallel in a voltage divider circuit where the resistor Rs is chosen according to the weight change detection threshold.

4. The apparatus for the continuous detection of occupancy of seats according to claim 1 characterized in that said capacitive sensor (102) detects changes in the electric field due to a volume of water within the limits of measurements of the electrical capacity corresponding to the of a human body.

5. The apparatus for the continuous detection of seat occupancy according to claim 1, characterized in that said plurality of temperature sensors (103) can be placed in different points of the seat base or in external elements, wherein a first sensor thermal reference (103) is located outside the contact area between the object / person and the seat, and measures the temperature of said seat; and because a plurality of thermal measurement sensors (103) are arranged in different positions close to the surface in contact with a seated person.

6. A method for the continuous detection of seat occupancy, using the apparatus according to claims 1 to 5, characterized in that said plurality of weight change sensors (101) in a variant starts up jointly, through the controller, said capacitive sensor (102) and said plurality of temperature sensors (103).

7. A method for the continuous detection of seat occupancy, using the apparatus according to claims 1 to 5, characterized in that said plurality of weight change sensors (101) in an alternative variant starts, through the controller, only said capacitive sensor (102) and keeps said plurality of temperature sensors inactive (103).

SPANISH OFFICE OF THE PATENTS AND BRAND

Application no .: 201000255

SPAIN

Date of submission of the application: 02.22.2010

Priority Date:

REPORT ON THE STATE OF THE TECHNIQUE

51 Int. Cl.: B60R21 / 015 (2006.01)

RELEVANT DOCUMENTS

Categoría Category: 56 Documentos citados Reivindicaciones afectadas 56 Documents cited Claims Affected

X X: US 6490515 B1 (OKAMURA ET AL.) 03/12/2002, resumen; columna 1, línea 59 -columna 5, línea 1-7 US 6490515 B1 (OKAMURA ET AL.) 12/03/2002, summary; column 1, line 59 - column 5, line 1-7

47; columna 9, línea 51 -columna 14, línea 58; columna 16, líneas 10 -55; columna 20, líneas 19 47; column 9, line 51-column 14, line 58; column 16, lines 10 -55; column 20, lines 19

-22; columna 29, línea 39 – columna 32, línea 21; figuras 1 -6, 10, 11, 46 -50. -22; column 29, line 39 - column 32, line 21; Figures 1-6, 10, 11, 46-50.

X X: US 2006267321 A1 (HARISH ET AL.) 30/11/2006, resumen; párrafos [6 -13]; párrafos [30 -31]; 1, 2 US 2006267321 A1 (HARISH ET AL.) 11/30/2006, summary; paragraphs [6-13]; paragraphs [30 -31]; 1, 2

párrafos [39 -49]; párrafos [54 -61]; párrafos[ 66 -70]; figuras 3 -4, 6 -9, 11; reivindicación 5. paragraphs [39-49]; paragraphs [54-61]; paragraphs [66-70]; Figures 3-4, 6-9, 11; claim 5.

Categoría de los documentos citados X: de particular relevancia Y: de particular relevancia combinado con otro/s de la misma categoría A: refleja el estado de la técnica O: referido a divulgación no escrita P: publicado entre la fecha de prioridad y la de presentación de la solicitud E: documento anterior, pero publicado después de la fecha de presentación de la solicitud Category of the documents cited X: of particular relevance Y: of particular relevance combined with other / s of the same category A: reflects the state of the art O: refers to unwritten disclosure P: published between the priority date and the date of priority submission of the application E: previous document, but published after the date of submission of the application

El presente informe ha sido realizado • para todas las reivindicaciones • para las reivindicaciones nº: This report has been prepared • for all claims • for claims no:

Fecha de realización del informe 03.09.2012 Date of realization of the report 03.09.2012: Examinador A. Figuera González Página 1/6 Examiner A. Figuera González Page 1/6

REPORT OF THE STATE OF THE TECHNIQUE

Application number: 201000255

Minimum documentation sought (classification system followed by classification symbols) B60R, B60N, G01G Electronic databases consulted during the search (name of the database and, if possible, terms of

search used) INVENES, EPODOC, WPI, TXTEN

State of the Art Report Page 2/6

WRITTEN OPINION

Application number: 201000255

Date of Completion of Written Opinion: 03.09.2012

Statement

Novedad (Art. 6.1 LP 11/1986) Novelty (Art. 6.1 LP 11/1986): Reivindicaciones Reivindicaciones 1 -7 SI NO Claims Claims 1-7 IF NOT

Actividad inventiva (Art. 8.1 LP11/1986) Inventive activity (Art. 8.1 LP11 / 1986): Reivindicaciones Reivindicaciones 1 -7 SI NO Claims Claims 1-7 IF NOT

The application is considered to comply with the industrial application requirement. This requirement was evaluated during the formal and technical examination phase of the application (Article 31.2 Law 11/1986).

Opinion Base.-

This opinion has been made on the basis of the patent application as published.

State of the Art Report Page 3/6

WRITTEN OPINION

Application number: 201000255

1. Documents considered.-

The documents belonging to the state of the art taken into consideration for the realization of this opinion are listed below.

Documento Document: Número Publicación o Identificación Fecha Publicación Publication or Identification Number publication date

D01 D01: US 6490515 B1 (OKAMURA et al.) 03.12.2002 US 6490515 B1 (OKAMURA et al.) 03.12.2002

D02 D02: US 2006267321 A1 (HARISH et al.) 30.11.2006 US 2006267321 A1 (HARISH et al.) 11/30/2006

2. Statement motivated according to articles 29.6 and 29.7 of the Regulations for the execution of Law 11/1986, of March 20, on Patents on novelty and inventive activity; quotes and explanations in support of this statement

CLAIM 1

Document D01 is considered to be the closest state of the art document to the object of claim 1.

Document D01 describes an apparatus 110 for detecting passengers that determines whether a passenger or an object is in the seat, such as for example a child seat, estimating the passenger's weight and classifying the passenger according to their constitution or your posture when sitting. The apparatus has a dielectric sensor 111 and a pressure sensor 112 in a seat cushion 102. See D01, summary and figure 1.

The passenger detection apparatus 110 also has decision-making means that determine, depending on the measurement of the pressure sensor 112, whether or not there is a passenger or an object in the seat and which determines whether it is a passenger or of an object depending on the measurement of the dielectric sensor 111. See D01, column 3, line 65 to column 4, line 5, column 5, lines 18 to 27.

The values measured by the dielectric sensor 111 and the pressure sensor 112 arranged in the pad 102 are subjected to signal processing in the unit of measure 115 corresponding to the pad 102. See D01, column 9, line 55 to column 10 line 2 and figure 1.

The pressure sensor 112 comprises a plurality of independent pressure sensitive elements disposed in the seat cushion 102. See D01, column 10, lines 42 to 56 and Figure 2.

A temperature sensor can be used instead of the pressure sensor 112 to detect the state of the seat. That is, a plurality of elements can be arranged that detect a change in temperature in the seat cushion so that the position of the seated person is detected by detecting the temperature difference between the temperature sensitive elements in contact with the person and those who are not. See D01, column 10, line 65 to column 11, line 6.

Therefore, the following correspondence can be established between the elements object of claim 1 and the passenger detection apparatus of document D01:

-Purality of force sensors to measure weight 101 <-> plurality of pressure sensitive elements of the pressure sensor 112

--: Sensor capacitivo 102 <-> sensor dieléctrico 111 Capacitive sensor 102 <-> dielectric sensor 111

- Temperature sensor temperature <-> plurality of elements that detect the temperature change in the seat cushion

--: Circuitos de acondicionamiento 104 <-> unidad de medida 115 Conditioning circuits 104 <-> measuring unit 115

-Microcontroller 105 <-> Decision unit 117 formed by a CPU 117c and a memory 117b (see column 12, lines 6 to 11 and figure 1)

State of the Art Report Page 4/6

WRITTEN OPINION

Application number: 201000255

Thus, the differences between what is disclosed in document D01 and the object of claim 1 are:

--: En el documento D01 se usan los sensores de temperatura como alternativa a los sensores de peso y no de forma simultánea. In document D01 temperature sensors are used as an alternative to weight sensors and not simultaneously.

However, combining multiple sensors to rule out non-disposable situations by a lower number of sensors is a solution known in the state of the art as explained in the application itself on page 4, lines 9 to 12. Thus, the expert in the field, knowing the teachings of document D01, if I wanted to rule out the possibility that a weight of water with a capacity similar to that of a human body would be confused with a human body, I could have resorted to the use of temperature sensors used in another embodiment of the same document D01 for the same purpose of analyzing the presence of a human being.

Therefore, this difference is not considered sufficient to confer inventive activity to claim 1.

--: En el documento D01 no se especifica que la unidad de decisión 117 sea un microcontrolador, puesto que solo se habla de CPU, ni que haya medios de visualización y un circuito de comunicación ni que exista un sistema de alimentación. In document D01 it is not specified that the decision unit 117 is a microcontroller, since there is only talk of a CPU, neither that there are display means and a communication circuit nor that there is a power supply system.

But it is evident that the decision unit 117 performs functions equivalent to those of a microcontroller so that for the person skilled in the art it would have been evident to use a microcontroller being the communications and the display media design options of the usual microcontrollers in the state of technique

Therefore, this difference is not considered to imply the existence of inventive activity.

In short, it is considered that claim 1 lacks inventive activity in accordance with article 8 of Patent Law 11/1986.

Claim 2

In document D01, the dielectric sensors 111 and the pressure sensors 112 are disposed between the seat cushion and the seat upholstery.

Thus, claim 2, dependent on claim 1 lacking inventive activity, does not provide any new additional technical characteristic, and therefore lacks inventive activity.

The rest of the claimed alternative provisions are considered mere design options whose implementation would have been obvious to the person skilled in the art.

CLAIM 3

The pressure sensors 112 used in document D01 are sensors based on conductive inks that vary according to the force of the pressure. See D01, column 1, lines 35 to 42. It is therefore equivalent to piezoelectric sensors.

Furthermore, in document D01 itself, in column 20, lines 19 to 22 explicitly mention the use of piezoelectric sensors as an alternative to pressure sensitive ink sensors as sensors capable of accurately measuring weight.

As for the configuration, it is clear that the pressure sensors should not be placed in series since then, if one does not act on a sufficiently large number of sensors, the weight would not be detected. They must therefore be independent or connected in parallel, the latter option being an obvious design alternative as it saves connections. The use of a series resistor to obtain a voltage divider and reduce consumption is also a design option known in the state of the art.

Therefore, the person skilled in the art in the face of the technical problem of how to connect the plurality of pressure sensors so that any activation above a certain weight generates a signal and that the consumption is low, would have resorted to a parallel configuration with a voltage divider without using anything other than common knowledge.

In conclusion, claim 3, dependent on claim 1 lacking inventive activity, in turn lacks inventive activity.

State of the Art Report Page 5/6

WRITTEN OPINION

Application number: 201000255

CLAIM 4

In document D01 in dielectric detector 111, it is used to confirm the presence of a person in case there is a weight in the seat, so it is obvious that its measurement limits should allow measuring the electrical capacity corresponding to a human body formed mostly by Water.

Therefore, claim 4, dependent on claim 1 lacking inventive activity, in turn lacks inventive activity.

CLAIM 5

Document D01 does not explicitly distinguish between temperature sensitive elements used as a reference for the seat temperature and elements intended to measure the temperature in areas in contact with the seated passenger. But in fact the temperature difference between the elements in contact with the passenger and those that are not is detected.

It can be considered that these elements that are not in contact with the passenger serve as the first thermal sensor claimed.

Thus, claim 5, dependent on claim 1 lacking inventive activity, in turn lacks inventive activity.

CLAIMS 6 and 7

Document D01 is considered to be the closest state of the art document to the subject of independent claim 6.

In document D01 in the first step S101 of the method of detecting the presence of a passenger the pressure sensor is used and then the dielectric sensor in step S102. The dielectric sensor is used to determine if the seat is wet in case the pressure sensor is not activated but the dielectric sensor is.

Thus, the procedure is different from that of the method object of claim 6.

However, given the technical problem of saving energy, the person skilled in the art should have chosen between three possible sensors to leave on alert while the others are at rest so as not to consume. Among the three, the pressure sensor is the most obvious candidate, first because of its low consumption and second because of its rapid response (it is known that the response of the temperature sensors is slower in general).

Then activating the two sensors, the capacitive sensor and the temperature sensors or only the first one is a mere design option that does not require overcoming any special technical problem or producing any technical effect other than expected.

Therefore, independent claim 6 and claim 7 that is dependent on it are considered to have no inventive activity.

State of the Art Report Page 6/6