Coil arrangement for generating a rotating electromagnetic field and positioning system for determining a position of an identification transmitter

Abstract

A coil arrangement is provided for generating a rotating electromagnetic field, comprising at least three coils, each having at least one associated coil winding. The coil arrangement further comprises a ferromagnetic coil yoke which establishes a magnetic coupling between the at least three coils.

What is claimed is: 
     
         1 . A locating system for determining a position of an identification transmitter for a motor vehicle, the locating system comprising:
 at least two coils that are mounted location-fast at different locations of the motor vehicle and are each set up to be operated as transmitters for an electromagnetic field, each of the at least two coils being coupled to a power supply line;   an identification transmitter having a receiver coil, the identification transmitter configured to be operated as a receiver for the at least two electromagnetic fields; and   a control device configured to actuate the at least two coils via a computer unit via a bus system with a pre-specified sequence for generating the electromagnetic field.   
     
     
         2 . A locating system for determining a position of an identification transmitter for a motor vehicle, the locating system comprising:
 at least two coil arrangements according to  claim 1 , wherein the at least two coil arrangements are mounted and set up location-fast at different locations of the motor vehicle, each being operated as a transmitter for a rotating electromagnetic field; and   the identification transmitter having a receiver coil, wherein the identification transmitter is operated as a receiver for the at least two rotating electromagnetic fields.   
     
     
         3 . The locating system in accordance with  claim 2 , further comprising a control device that actuates the at least two coil arrangements for transmitting the specific rotating electromagnetic field in a pre-specified sequence. 
     
     
         4 . The locating system in accordance with  claim 3 , wherein the control device is coupled to the at least two coil arrangements via a bus system, wherein each of the at least two coil arrangements is coupled to a power supply line, wherein each of the at least two coil arrangements is set up in order to receive a control signal of the control device via the bus system and to generate the rotating electromagnetic field as a function of the control signal, and wherein the energy for transmitting the rotating electromagnetic field is obtained via the power supply line. 
     
     
         5 . The locating system in accordance with  claim 3 , wherein the control device is set up for actuating the at least two coil arrangements such that they transmit the specific rotating electromagnetic field sequentially. 
     
     
         6 . The locating system in accordance with  claim 2 , wherein at least one alternating voltage source is connected to the at least two coil arrangements and to one power supply line and is configured to supply the at least two coils in each coil arrangement with an alternating voltage in order to generate the rotating electromagnetic field, wherein the alternating voltages of the at least two coils are in a pre-specified phase relationship with one another, and wherein the phase relationship of adjacent coils is pre-specified as a function of an angle that these adjacent coils form with one another within a coil plane. 
     
     
         7 . The locating system in accordance with  claim 2 , wherein a first coil arrangement of the at least two coil arrangements is installed in an area of a left-hand B column of the motor vehicle, wherein a second coil arrangement of the at least two coil arrangements is installed in an area of a right-hand B column of the motor vehicle, and wherein a third coil arrangement of the at least two coil arrangements is installed in the area of a rear of the motor vehicle. 
     
     
         8 . The locating system in accordance with  claim 2 , wherein the at least two coil arrangements are arranged such that planes of rotation of the at least two rotating electromagnetic fields are essentially parallel to one another, and/or wherein the at least two coil arrangements are installed in an area of 70 cm to 130 cm above the ground.