Process for recognizing the movement of a motor vehicle

• US 20040088096A1
• Filed: 08/19/2003
• Published: 05/06/2004
• Est. Priority Date: 11/04/2002
• Status: Active Grant

• Current Assignee: Draeger Safety Incorporated (Dragerwerk AG)
• Original Assignee: Draeger Safety Incorporated (Dragerwerk AG)
• Inventors: Thomsen, Henning, Wahlbrink, Gunter, Stock, Burkhard
• Granted Patent: US 7,103,454 B2
• Time in Patent Office: Days
• US Class Current: 701/70
• 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: B60R 25/1004 Alarm systems characterised by the type of sensor, e.g. current sensing means using door lock sensors B60R25/1001

Abstract

A process and system are provided for recognizing the movement of a motor vehicle as well as a process for using an acceleration sensor in a device for blocking the starting of a motor vehicle. Reliable information is obtained on whether or not the motor vehicle was moved. In the process for recognizing the movement of a motor vehicle, the accelerating forces acting on the motor vehicle are measured for this purpose as time-dependent functions and are subjected to a discrete Fourier analysis. If the majority of the frequencies determined is below a preset limit frequency, e.g., 0.3 Hz, movement of the motor vehicle is assumed, and an irrelevant vibration is otherwise assumed. An acceleration sensor is used in a device for blocking the starting of a motor vehicle and/or to demonstrate an inadmissible circumventing of the blocking.

Claims

1. A process for recognizing the movement of a motor vehicle comprising the steps:

measuring the accelerating forces acting on the motor vehicle at preset time intervals by a acceleration sensor as time-dependent functions and sending the functions to an evaluating and control unit;

determining a frequency spectrum of the functions with the evaluating and control unit on the basis of a Fourier analysis;

if a preset percentage of the frequency spectrum is below a set limit frequency, storing, with the evaluating and control unit, information indicating that the motor vehicle was moved; and

if the preset percentage of the frequency spectrum is not below the set limit frequency, storing, with the evaluating and control unit, information indicating that the motor vehicle was not moved.

2. A process in accordance with claim 1, wherein the accelerating forces acting on the motor vehicle are measured by the acceleration sensor in at least two mutually independent directions.

3. A process in accordance with claim 1, wherein the frequency spectrum is determined on the basis of a discrete Fourier analysis.

4. A process in accordance with claim 1, wherein the limit frequency is a function of the spring system and the weight of the motor vehicle.

5. A process for using an acceleration sensor in a device for blocking the starting of a motor vehicle, the process comprising:

providing an evaluating and control unit and an acceleration sensor;

measuring the accelerating forces acting on the motor vehicle with the acceleration sensor;

using the evaluating and control unit to evaluate the accelerating forces acting on the motor vehicle;

providing a handset connected to the evaluating and control unit by which a breath alcohol concentration of a user is measured and is sent as a signal to the evaluating and control unit;

activating a relay or switch by the evaluating and control unit for either interrupting or closing a circuit to a starter of the motor vehicle as a function of the signal by opening or closing a switch.

6. A system for blocking the starting of a motor vehicle, the system comprising:

an acceleration sensor measuring the accelerating forces acting on the motor vehicle with the acceleration sensor at preset time intervals as time-dependent functions;

an evaluating and control unit receiving the functions from the acceleration sensor and determining a frequency spectrum of the functions with the evaluating and control unit on the basis of a Fourier analysis;

a handset connected to the evaluating and control unit by which a breath alcohol concentration of a user is measured and is sent as a signal to the evaluating and control unit;

a relay or switch activated by the evaluating and control unit for either interrupting or closing a circuit to a starter of the motor vehicle as a function of the signal by opening or closing a switch.

7. A system according to claim 6, wherein:

if a preset percentage of the frequency spectrum is below a set limit frequency the evaluating and control unit stores information indicating that the motor vehicle was moved; and

if the preset percentage of the frequency spectrum is not below the set limit frequency the evaluating and control unit stores information indicating that the motor vehicle was not moved.