Method for identifying the presence and orientation of an object in a vehicle

Abstract

A method for determining the location of an object in a passenger compartment of a vehicle in which ultrasonic waves are transmitted from a first transducer into the passenger compartment, waves reflected off an object in the passenger compartment are received by the first transducer and a first distance from the first transducer to the object is calculated based on the time difference between the transmitted waves and reflected waves when received by the first transducer. Further, different ultrasonic waves are transmitted from a second transducer into the passenger compartment which then receives reflected waves off the object and a second distance from the second transducer to the object is calculated based on the time difference between the transmitted waves and reflected waves when received by the second transducer. The approximate location of the object in the passenger compartment is determined based on the first distance and the second distance.

We claim:  
     
       1. A method for determining the location of an object in a passenger compartment of a vehicle, comprising the steps of: 
       arranging a first ultrasonic transducer on a ceiling of the vehicle and a second ultrasonic transducer at a different location in the vehicle such that a first axis connecting the first and second transducers is substantially parallel to a second axis traversing a volume in the passenger compartment above a seat in which the object is situated,  
       transmitting ultrasonic waves from the first transducer into the passenger compartment;  
       receiving ultrasonic waves reflected off an object in the passenger compartment by means of the first transducer;  
       calculating a first distance from the first transducer to the object based on the time difference between the transmitted waves and reflected waves when received by the first transducer;  
       transmitting different ultrasonic waves from the second transducer into the passenger compartment;  
       receiving ultrasonic waves reflected off the object in the passenger compartment by means of the second transducer;  
       calculating a second distance from the second transducer to the object based on the time difference between the transmitted waves and reflected waves when received by the second transducer; and  
       determining an approximate location of the object in the passenger compartment based on the first distance and the second distance.  
     
     
       2. The method of claim  1 , further comprising the steps of: 
       transmitting different ultrasonic waves from a third ultrasonic transducer into the passenger compartment;  
       receiving ultrasonic waves reflected off the object in the passenger compartment by means of the third transducer;  
       calculating a third distance from the third transducer to the object based on the time difference between the transmitted waves and reflected waves when received by the third transducer; and  
       determining the approximate location of the object in the passenger compartment based on the first distance, the second distance and the third distance.  
     
     
       3. The method of claim  2 , further comprising the steps of: 
       transmitting different ultrasonic waves from a fourth ultrasonic transducer into the passenger compartment;  
       receiving ultrasonic waves reflected off the object in the passenger compartment by means of the fourth transducer;  
       calculating a fourth distance from the fourth transducer to the object based on the time difference between the transmitted waves and reflected waves when received by the fourth transducer; and  
       determining the approximate location of the object in the passenger compartment based on the first distance, the second distance, the third distance and the fourth distance.  
     
     
       4. The method of claim  1  wherein said first and second distance calculation steps each comprise the step of using waves reflected from multiple locations on the object. 
     
     
       5. The method of claim  4 , wherein said first and second distance calculation steps each further comprises the step of employing pattern recognition techniques based on the time distribution of the echo pattern of the reflected waves. 
     
     
       6. The method of claim  5 , wherein said step of employing pattern recognition techniques comprises the step of generating an algorithm by means of a neural network computer program. 
     
     
       7. The method of claim  1 , further comprising the steps of: 
       identifying a first volume within the passenger compartment adjacent the airbag where occupancy by a human at the time of airbag deployment would place the human in danger;  
       identifying a second volume within the passenger compartment where occupancy by a human requires deployment of an airbag in a sufficiently severe vehicle crash; and  
       defining the second axis as the axis connecting the centers of the first and second volumes.  
     
     
       8. The method of claim  1 , further comprising the step of: 
       positioning the second transducer on a dashboard of the vehicle.  
     
     
       9. The method of claim  2 , further comprising the steps of: 
       positioning the second transducer on a dashboard of the vehicle, and  
       positioning the third transducer on or adjacent an interior side surface of said passenger compartment.  
     
     
       10. The method of claim  3 , further comprising the steps of: 
       positioning the second transducer on a dashboard of the vehicle,  
       positioning the third transducer on an interior side surface of said passenger compartment, and  
       positioning the fourth transducer on or adjacent an interior side surface of said passenger compartment.  
     
     
       11. A method for identifying an object in a passenger compartment, comprising the steps of: 
       mounting at least first and second ultrasonic transducers at different locations in the passenger compartment;  
       conducting training identification tests on a plurality of different classes of objects when situated in the passenger compartment, each of said tests comprising the steps of transmitting ultrasonic waves from the first transducer into the passenger compartment, receiving waves reflected off the object by means of the first transducer, transmitting different ultrasonic waves from the second transducer into the passenger compartment, receiving waves reflected off the object by means of the second transducer, and associating an object class with data from each test,  
       generating a pattern recognition algorithm from the training test results and associated object classes such that the algorithm is able to process information from the reflected waves from the first and second transducers and provide the identification of the class of the object;  
       transmitting ultrasonic waves from the first transducer into the passenger compartment when identification of an object in the passenger compartment is desired;  
       receiving waves reflected off the object by means of the first transducer;  
       transmitting different ultrasonic waves from the second transducer into the passenger compartment when identification of the object in the passenger compartment is desired;  
       receiving waves reflected off the object by means of the second transducer; and  
       applying the algorithm based on the first and second reflected waves to identify the object in the passenger compartment.  
     
     
       12. The method of claim  11 , wherein said object class is a child seat in the rear facing position. 
     
     
       13. The method of claim  11 , wherein said object class is an out-of-position occupant. 
     
     
       14. The method of claim  11 , further comprising the step of normalizing the reflected waves. 
     
     
       15. The method of claim  11 , further comprising the step of performing a system diagnosis by transmitting waves from the first transducer to the second transducer. 
     
     
       16. The method of claim  11 , further comprising the step of recording the reflected waves for subsequent analysis of a vehicle event. 
     
     
       17. The method of claim  11 , further comprising the step of providing an output from the system to control another vehicle system based on the identification results. 
     
     
       18. The method of claim  11 , further comprising the step of combining at least two sets of reflected waves prior to their use in identifying an object. 
     
     
       19. The method of claim  17 , further comprising the step of comparing at least two identification cycles before the output is provided to the another vehicle system. 
     
     
       20. The method of claim  11 , further comprising the step of compensating for changes in the speed of sound. 
     
     
       21. The method of claim  11 , further comprising the step of: 
       selecting the different classes of objects to be rear facing child seats, forward facing child set, adult passengers and infant passengers.  
     
     
       22. The method of claim  11 , further comprising the steps of: 
       positioning the first transducer on a ceiling of the vehicle, and  
       positioning the second transducer on a dashboard of the vehicle.  
     
     
       23. A method for determining the location of an object in a passenger compartment of a vehicle, comprising the steps of: 
       arranging a first receiver on a ceiling of the vehicle and a second receiver at a different location in the vehicle such that a first axis connecting the first and second receivers is substantially parallel to a second axis traversing a volume in the passenger comment above a seat in which the object is situated;  
       mounting a third receiver at a different location in the passenger compartment than the first and second receiver each receiver comprising distance measurement means;  
       calculating a first distance from the first receiver to the object based on the output of the first receiver;  
       calculating a second distance from the second receiver to the object based on the output of the second receiver;  
       calculating a third distance from the third receiver to the object based on the output of the third receiver; and  
       determining an approximate location of the object in the passenger compartment based on the first distance, the second distance and the third distance.  
     
     
       24. The method of claim  23 , wherein said receivers are arranged to receive ultrasonic radiation. 
     
     
       25. The method of claim  23 , wherein said receivers are arranged to receive electromagnetic radiation. 
     
     
       26. The method of claim  23 , further comprising the steps of: 
       mounting a fourth receiver at a different location in the passenger compartment, the fourth receiver comprising distance measurement means,  
       calculating a fourth distance from the fourth receiver to the object based on the output of the fourth receiver,  
       determining an approximate location of the object in the passenger compartment based on the first distance, the second distance, the third distance and the fourth distance.  
     
     
       27. The method of claim  23 , wherein the first, second and third receivers are of the same type. 
     
     
       28. A method for determining the location of an object in a passenger compartment of a vehicle, comprising the steps of: 
       transmitting ultrasonic waves from a first transducer into the passenger compartment;  
       receiving waves reflected off an object in the passenger compartment by means of the first transducer;  
       calculating a first distance from the first transducer to the object based on the time difference between the transmitted waves and reflected waves when received by the first transducer;  
       transmitting different ultrasonic waves from a second transducer into the passenger compartment;  
       receiving waves reflected off the object in the passenger compartment by means of the second transducer;  
       calculating a second distance from the second transducer to the object based on the time difference between the transmitted waves and reflected waves when received by the second transducer; and  
       determining an approximate location of the object in the passenger compartment based on the first distance and the second distance;  
       said first and second distance calculation steps comprising the step of applying an algorithm generated by means of a neural network computer program based on the time distribution of the echo pattern of the reflected waves in order to determine the distance from the respective transducer to the object.