Theft detection procedures

Abstract

The invention relates to a method for detecting theft of an attachment (A1, A2) of a vehicle (1). According to the invention, - the theft of an attachment (A1) electrically connected to the vehicle (1) is detected by monitoring an electrical capacity of an electrical circuit of the electrical attachment (A1) and - the theft of an electrically conductive attachment (A2) which is not electrically connected to the vehicle (1) and is electrically insulated from a vehicle body is capacitively detected via an electrical connection of an electrical monitoring line which is electrically connected to at least one electrically conductive connection point (P1) of the electrically insulated attachment (A2) and to the vehicle body, wherein - a threshold circuit detects a significantly changing electrical capacitance in relation to a respective circuit and - when a significant change in the electrical capacity in the respective circuit is detected, an alarm signal is triggered at least on the vehicle side.

Description

The invention relates to a method for detecting theft of an attachment part of a vehicle.US 2022 / 0277628 A1 discloses a product security system for an electronic product. The product security system comprises a continuous alarm current cable which has an electrical conductor. The alarm power cable has a first end electrically connected to the electronic good and a second end. The product security system also includes a coil for receiving the second end of the alarm power cable and is configured to place a portion of the alarm power cable thereon. In addition, the product security system includes a monitoring circuit in electrical communication with the alarm power cable and configured to detect an interruption in an electrical signal supplied to the alarm power cable.The invention is based on the object of specifying a method for detecting theft of an attachment part of a vehicle.The object is achieved according to the invention by a method.Advantageous embodiments of the invention are the subject matter of the dependent claims.According to the invention, a method for detecting theft of an attachment part of a vehicle provides that the theft of an attachment part electrically connected to the vehicle is detected on the basis of monitoring an electrical capacitance of an electrical circuit of the electrical attachment part. In addition, the theft of an electrically conductive attachment part which is not electrically connected to the vehicle and is electrically insulated from a vehicle body is detected capacitively via an electrical connection of an electrical monitoring line which is electrically conductively connected to at least one electrically conductive connection point of the electrically insulated attachment part and to the vehicle body. In this case, a significantly changing electrical capacitance with respect to a respective circuit is detected via a threshold value circuit, and a wake-up and alarm signal is triggered at least on the vehicle side when a significant change in the electrical capacitance in the respective circuit is detected.By using the method, theft protection for external add-on parts of the vehicle is realized. These add-on parts are included in the vehicle in relation to an anti-theft warning system of the vehicle. By means of the method, losses of add-on parts of a vehicle can be reduced by an theft warning system of the vehicle realized by means of the method.Exemplary embodiments of the invention are explained in more detail below with reference to a drawing.The following shows: FIG. 1 schematically shows a vehicle.The single figure shows a vehicle 1 with two exterior mirrors 2 and a roof carrier 3.The exterior mirrors 2 are add-on parts A 1 electrically connected to the vehicle 1, for example since a mirror heater is connected to vehicle electronics, whereas the roof carrier 3 is not electrically connected to the vehicle 1, in particular to the vehicle electronics. Therefore, the roof carrier 3 is an electrically non-connected attachment part A 2 of the vehicle 1.It is generally known that add-on parts A 1, A 2 arranged on the outside and accessible from the outside can be disassembled comparatively quickly and in an imperceptible manner on a vehicle 1. For example, exterior mirrors 2 of a vehicle 1 which are fastened from the outside can be partially disassembled from the latter in a non-destructive manner within a short time. In particular, comparatively cost-intensive add-on parts A 1, A 2 are often used, for example vehicle wheels 4 or a bicycle carrier, not shown in more detail.A method for detecting theft of an attachment part A 1, A 2 of the vehicle 1 is described below. In particular, the method provides for the inclusion of components A 1, A 2 of the vehicle 1 at risk of theft in a vehicle-side theft warning system without an additional device having to be installed in the vehicle 1 or the component A 1, A 2 to be monitored.For this purpose, the add-on parts A 1, A 2 that are accessible from outside the vehicle 1 are divided into two categories. In this case, add-on parts A 1 electrically connected to the vehicle 1, such as, for example, the exterior mirrors 2, bumpers, a trailer lighting system, a vehicle exterior lighting system, etc., are assigned to a category. A further category is assigned the add-on parts A 2 which are not connected to vehicle electronics, for example the roof rail 3 and the vehicle wheels 4.For the external mirrors 2 as electrically connected add-on parts A 1, electrical circuits are usually already present in the vehicle 1, by means of which circuits it is checked whether the add-on part A 1 is installed on the vehicle 1. Such a function is expedient for vehicle production in order to be able to ensure whether the attachment part A 1 has been installed and electrical contacting has taken place.In the case that such a checking function is not yet implemented or is implemented in the vehicle 1 in such a way that this checking function represents a comparatively high energy load for the vehicle 1 on account of continuous operation, two embodiments are provided for monitoring the presence of such an attachment part A 1 electrically connected to the vehicle 1, in particular to vehicle electronics.In one embodiment, the monitoring is carried out by means of electrical current. Conventionally, electronics in an electrically connected attachment A 1 are supplied with electric current by means of a positive voltage supply and a ground line as an electrical reference potential. A drive unit is partially discretely connected to a control device arranged in the vehicle 1. At least one supply line, in particular the ground line, is connected to a vehicle body. An electrical voltage is measured on a further supply line, in particular for the positive voltage supply, and a high-resistance resistor is used with respect to another electrical voltage, for example a supply voltage.If an external mirror 2 is mounted and electrically contacted as an electrically connected attachment part A 1, an electric current flowing through the electrical high-resistance resistor is not sufficient to electrically operate the devices present in the electrically connected attachment part A 1, for example an electric drive unit and / or a heating element, for example a mirror heater. In addition, the electrical current required for monitoring is so low that a significant quiescent current load can be ruled out.If an exterior mirror 2 or another attachment A 1 electrically connected to the vehicle electronics is unauthorized from the vehicle 1, an electrical current flow is interrupted. As a result, an electrical voltage measured on the further supply line increases up to a voltage applied to the electrical resistor or a voltage drop at the electrical resistor decreases to zero.A threshold value circuit can then be used to generate a wake-up and alarm signal, which is output on the vehicle side.In a further embodiment, the monitoring with regard to the presence of electrically connected add-on parts A 1, for example the exterior mirrors 2, takes place on the basis of a measurement of electrical capacitance. If an electrical circuit in the DC range is closed on the basis of a characteristic of the electronics integrated in the electrically connected attachment A 1, for example an exterior mirror 2 and / or an antenna, the electrical capacitance is measured via an electrical circuit. Alternatively or additionally, a measurement of an inductance with respect to the electrically connected attachment A 1 can be carried out.If a significant change in the electrical capacitance in a respective circuit is detected on the basis of a threshold value circuit, an output of an alarm is triggered at least on the vehicle side. For example, a wake-up and alarm signal is generated and output for this purpose.In order to monitor add-on parts A 2 of the further category, i.e. add-on parts A 2 which are not electrically connected to the vehicle electronics, with respect to a possible theft, the following steps are carried out, so that the monitoring can be carried out as described above.First, the electrically non-connected attachment part A 2, for example the roof carrier 3, is electrically decoupled from the vehicle 1 if the electrically non-connected attachment part A 2 is electrically conductive and is connected to the vehicle 1, in particular the vehicle body, via at least one electrically conductive connection point P 1, P 2. The electrical decoupling can be realized, for example, by means of an intermediate layer in the form of an electrically non-conductive layer. For example, the electrically non-connected attachment part A 2 can be electrically insulated, i.e. electrically decoupled, from the vehicle body by means of a sleeve made of an electrically non-conductive material as an intermediate layer.A monitoring line is then connected to the one electrically conductive vehicle-side connection point P 1, a suitable monitoring solution then being selected.If the roof carrier 3 is electrically conductive as an electrically non-connected attachment part A 2, the monitoring can be carried out via the flowing electrical current from the connection point P 1 electrically connected to the monitoring line and further connection points P 2 as an electrical reference potential.If a trailer coupling of the vehicle 1 is used as an electrically non-connected attachment part A 2 and a trailer is connected to the trailer coupling, the electrical capacitance, which is measured by means of a monitoring line at the hitch ball, is significantly higher, so that a disconnection of the trailer from the trailer coupling can be detected.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedUS 2022 / 0277628 A1

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Claims

Method for detecting theft of an attachment part (A1, A2) of a vehicle (1), characterized in that - the theft of an attachment part (A1) which is electrically connected to the vehicle (1) is detected on the basis of monitoring an electrical capacitance of an electrical circuit of the electrical attachment part (A1), and - the theft of an attachment part (A2) which is electrically non-connected to the vehicle (1) and is electrically insulated from a vehicle body is detected capacitively via an electrical connection of an electrical monitoring line which is electrically connected to at least one electrically conductive connection point (P1) of the electrically insulated attachment part (A2) and is electrically conductively connected to the vehicle body, wherein - a significantly changing electrical capacitance with respect to a respective circuit is detected via a threshold circuit, and - a wake-up and alarm signal is triggered at least on the vehicle side when a significant change in the electrical capacitance in the respective circuit is detected.Method according to Claim 1, characterized in that external mirrors (2) and / or bumpers and / or a trailer lighting and / or a vehicle external lighting is or are monitored capacitively as the electrically connected attachment (A1) or electrically connected attachments (A1) of the vehicle (1).Method according to Claim 1 or 2, characterized in that a roof carrier (3), superstructures on a roof rail or on a roof carrier (3) and / or a coupled trailer and / or vehicle wheels 4 is or are monitored capacitively as the electrically non-connected attachment (A2) or electrically non-connected attachments (A2).

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