Method of determining the position of an object and controlling access to an object or use ofan object

• US 20020067250A1
• Filed: 09/14/2001
• Published: 06/06/2002
• Est. Priority Date: 09/15/2000
• Status: Active Grant

• Current Assignee: Siemens AG
• Original Assignee: Siemens AG
• Inventors: Kamlah, Siegfried
• Granted Patent: US 6,965,296 B2
• Time in Patent Office: Days
• US Class Current: 340/436
• CPC Class Codes: B60R 25/00 Fittings or systems for preventing or indicating unauthorised use or theft of vehicles locks for vehicles E05B77/00-E05B85/00
• CPC Class Codes: G07C 2009/00793 by Hertzian waves
• CPC Class Codes: G07C 2209/63 Comprising locating means for detecting the position of the data carrier, i.e. within the vehicle or within a certain distance from the vehicle
• CPC Class Codes: G07C 9/00309 operated with bidirectional data transmission between data carrier and locks

Abstract

The position of a movable object is determined by a signal being transmitted by each of a number of antennas arranged in a spatially distributed manner of a fixed object to the movable object. In the movable object, on the one hand signal transit times are measured, and on the other hand the direction from which the signals are received are determined. From the two, the exact position of the object is determined with geometrical aids.

Claims

1. A method of determining the position of a movable object, comprising:

transmitting a signal in an electromagnetic field from at least two transmitting units which are arranged stationary in an object; and

measuring the distance between the movable object and the stationary object with the aid of signal transit times using a receiver arranged in the movable object,

wherein the receiver has receiving antennas and ascertains the direction of field vectors of electromagnetic fields generated by the receiving antennas, and the receiver ascertains from the direction of the field vectors and the signal transit times the position of the movable object with respect to the transmitting units of the stationary object.

2. The method as claimed in claim 1, wherein the signals are transmitted by the transmitting unit one after the other in time and at time intervals in relation to one another.

3. The method as claimed in claim 1, wherein phase differences of the transmitted signals at the receiving location are ascertained for a transit time measurement.

4. The method as claimed in claim 1, wherein the time intervals of two pulse trains of defined lengths are evaluated for a transit time measurement.

5. A method of controlling an object, comprising:

transmitting an interrogation signal and waiting for a response signal using a stationary arranged transmitting and receiving unit;

transmitting the response signal using a code generator, code information of which is checked in the transmitting and receiving unit for authorization; and

enabling, with the transmitting and receiving unit, access to or use of the object if the response signal is authorized, wherein

the interrogation signal is transmitted over a number of antennas arranged in a spatially distributed manner, and the position of the code generator is ascertained from a signal transit-time measurement of the interrogation signals received by the code generator and from direction of the field vectors.

6. The method as claimed in claim 5, wherein the response signal is generated and transmitted by the code generator when the position of the code generator lies within a predetermined area around the antennas.

7. The method as claimed in claim 5, wherein the position ascertained by the code generator is transmitted as a value in the response signal to the transmitting and receiving unit and the transmitting and receiving unit enables access to or use of the object when at least one of the code information included in the response signal coincides with expected nominal code information, and the position of the code generator included in the response signal lies within a predetermined area around the antennas.

8. An access-control and driving-authorization device, comprising:

a transmitting and receiving unit which is arranged in an object and can transmit and receive signals; and

a code generator which has a receiver and a transmitter by which signals can be received and transmitted, wherein

the transmitting and receiving unit is connected to a number of spatially distributed antennas, over each of which an interrogation signal is transmitted, the receiver has a number of receiving antennas, which are pointing in different spatial directions and with which the interrogation signals are received, the receiving antennas being connected to a field-strength measuring device and an evaluation unit, in which the direction of the field vectors are ascertained on the basis of measured field strengths of the received signals, and

the code generator has a signal transit-time measuring device, which measures the signal transit time of the interrogation signals between the transmission by the antennas in the object and reception by the receiver.