Passenger detecting apparatus

Abstract

A passenger detecting apparatus determines the presence of a passenger or an object, such as a child seat, in a seat unit, estimates the weight of the passenger or determines the build of the passenger, thereby improving the usability of peripheral devices of a seat. The passenger detecting apparatus has a dielectric sensor ( 111 ) and a pressure-sensitive sensor ( 112 ) in a seat cushion ( 102 ) and detects the presence of a passenger or an object on a seat based on their outputs, or has a dielectric sensor and a pressure-sensitive sensor in the seat cushion and a dielectric sensor ( 113 ) in the back rest and an angle sensor ( 114 ) for detecting an angle defined by the seat cushion and the back rest and determines the build of a passenger based on their outputs.

What is claimed is:  
     
         1 . A passenger detection apparatus for detecting the presence of a passenger or an object on a seat cushion, said apparatus comprising: 
 at least one pressure sensor having an output signal;    at least one dielectric sensor having an output signal;    a decision unit coupled to said pressure sensor and said dielectric sensor configured to determine the presence of a passenger or an object on said seat cushion in response to said output signals.    
     
     
         2 . The apparatus of  claim 1 , additionally comprising a temperature sensor.  
     
     
         3 . The apparatus of  claim 1 , wherein said decision unit is configured to detect moisture on said seat cushion.  
     
     
         4 . The apparatus of  claim 1 , wherein said pressure sensor comprises a matrix of a plurality of independent pressure sensor elements arranged in said seat cushion, and wherein said detection unit is configured to determine a build of a passenger sitting on said seat cushion.  
     
     
         5 . A passenger detection apparatus comprising: 
 a first detector having an output signal in a seat cushion for detecting passenger contact with said seat cushion;    a second detector having an output signal in a seat back for detecting passenger contact with said seat back;    an angle detector having an output signal for measuring an angle defined by the relative orientation of said seat cushion and said seat back; and    a decision unit configured to determine a build of said passenger in response to said output signals.    
     
     
         6 . The apparatus of  claim 5 , wherein said first detector comprises one or more of a dielectric sensor, a pressure sensor, and a temperature sensor.  
     
     
         7 . The apparatus of  claim 5 , wherein said second detector comprises one or more of a dielectric sensor, a pressure sensor, and a temperature sensor.  
     
     
         8 . A method of determining characteristics of a passenger in a vehicle seat comprising: 
 measuring a load distribution in a seat cushion of said vehicle seat;    measuring vehicle seat weight;    measuring a total load applied to said vehicle seat; and    classifying a passenger sitting in said vehicle seat based on said measurements.    
     
     
         9 . A method of determining characteristics of a passenger in a vehicle seat comprising: 
 detecting a child seat situated in said vehicle seat;    measuring vehicle seat weight;    measuring a total load applied to said vehicle seat; and    classifying a passenger sitting in said vehicle seat based on said measurements.    
     
     
         10 . A method of determining characteristics of a passenger in a vehicle seat comprising: 
 measuring vehicle seat weight;    measuring a total load applied to said vehicle seat;    measuring a barycenter position of said passenger; and    estimating the weight of said passenger sitting in said vehicle seat based on said measurements.    
     
     
         11 . The method of  claim 10 , wherein said barycenter position is measured with a pressure sensitive film having a plurality of pressure sensors arranged thereon.  
     
     
         12 . The method of  claim 10 , wherein said seat is moveable on seat rails, and wherein said barycenter is measured with respect to said seat rails.  
     
     
         13 . The method of  claim 10 , additionally comprising measuring the position of the head of said passenger.  
     
     
         14 . The method of  claim 10 , additionally comprising measuring the width of the buttocks of said passenger.  
     
     
         15 . A method of determining characteristics of a passenger in a vehicle seat comprising: 
 measuring vehicle seat weight;    measuring a total load applied to said vehicle seat;    measuring a barycenter position of said passenger; and    estimating a seating posture of said passenger based on said measurements.    
     
     
         16 . The method of  claim 15 , wherein said barycenter position is measured with a pressure sensitive film having a plurality of pressure sensors arranged thereon.  
     
     
         17 . The method of  claim 15 , wherein said seat is moveable on seat rails, and wherein said barycenter is measured with respect to said seat rails.  
     
     
         18 . The method of  claim 15 , additionally comprising measuring the position of the head of said passenger.  
     
     
         19 . The method of  claim 15 , additionally comprising measuring the width of the buttocks of said passenger.  
     
     
         20 . A method of determining the characteristics of a passenger in a vehicle seat comprising: 
 acquiring weight information from at least one sensor associated with said vehicle seat both when a passenger is seated in said vehicle seat and when no passenger is seated in said vehicle seat; and    correcting a determination of passenger weight with information obtained from said sensors when no passenger is seated in said vehicle seat.    
     
     
         21 . The method of  claim 20 , comprising acquiring said weight information from a plurality of sensors.  
     
     
         22 . The method of  claim 20 , additionally comprising detecting an abnormality in said at least one sensor.