Testing methods for inductive receiver elements

Abstract

Method for testing a measurement object (1) with three-dimensional inductive receiving elements (2, 3, 4), characterized in that a Helmholtz coil having a coil pair (6, 7) is used to generate a magnetic field (8), that the measurement object (1) to be tested is arranged in the substantially constant homogeneous magnetic field (8) between the coil pair (6, 7), and that the measurement object (1) is arranged with respect to the three substantially perpendicular axis directions (x, y, z) of the Helmholtz coil (6, 7) such that the three-dimensional receiving elements (2, 3, 4) are each substantially tilted by 45° to the axis directions (x, y, z).

Description

The invention relates to a method for checking a measurement object according to the preamble of claim 1.The method can be used as a measurement object in the checking of transponder and / or radio keys for keyless access authorisation systems, which are used, for example, in motor vehicles.Transponder and / or radio keys for keyless entry / go systems are equipped with one-, two- or three-dimensional inductive receiving elements. The functionality of these inductive receiver elements must be checked after the transponder key and / or radio key has been produced. Up to now, the testing of specific functional units for transponder and / or radio keys of keyless systems of this type with three-dimensional inductive receiving elements is very susceptible to interference because of the high inherent sensitivity of the functional units. In addition, the test sometimes also takes a very long time because each direction has to be tested on its own.The invention is based on the object of improving the method for checking a measurement object with three-dimensional inductive receiving elements with regard to the susceptibility to faults and / or the time duration.This object is achieved in a method of the generic type by the characterizing features of claim 1.In the method according to the invention for testing the object under test, a Helmholtz coil having a coil pair is used to generate a magnetic field. The object to be tested is placed in the substantially constant homogeneous magnetic field between the coil pairs. In this case, the measurement object is arranged with respect to the three axis directions of the Helmholtz coil which are substantially perpendicular to one another in such a way that the three-dimensional receiving elements are each tilted substantially by 45° with respect to the axis directions. Advantageously, a simultaneous measurement of all three spatial positions of the measurement object is made possible, so that a cost optimization and / or an increase in functional reliability is achieved during the testing of three-dimensional inductive reception elements by means of the invention. Further embodiments of the invention are the subject matter of the dependent claims.In a further embodiment, the three-dimensional inductive receiving elements of the measurement object can consist of three coils. In each case one coil is arranged in such a way that the coil axis substantially corresponds to a respective coordinate axis of a Cartesian coordinate system. The inductive receiving elements thus each have an x-coil, a y-coil and a z-coil, which act in the direction of the x-, y- and z-axes of the coordinate system.The measurement object can be a mobile transponder and / or radio key, having three-dimensional inductive reception elements, of a keyless access and / or driving authorisation system having a keyless entry and / or keylessgo functionality for a motor vehicle. By means of the invention, cost optimization and / or increase of functional reliability is then achieved during the testing of three-dimensional inductive reception elements in mobile transponder and / or radio keys of a keyless access and / or driving authorisation system.For a particularly preferred embodiment of the method according to the invention, the following can be stated. The method comprises the use of a Helmholtz coil in the measuring and / or testing device with the advantage of a constant homogeneous magnetic field B between the coil pairs. For the Helmholtz coil, the winding of the coil is pulled apart in a ratio of 1:1 divided into the distance R (radius of the coil). Within this distance, the desired field then forms. The special feature of the arrangement is now to tilt the arrangement with respect to the measurement object by 45° to each reference direction, i.e. the constant field generates three equal field components (Bx, By and Bz). Two advantages can thereby be derived. On the one hand, the functional reliability is optimized by a homogeneous constant magnetic field B simultaneously for all three directions. On the other hand, all three positions of the measurement object can be measured simultaneously, so that the resulting time advantage and thus the corresponding cost advantage are obtained.The advantages achieved with the invention consist in particular in that optimization of the functional reliability is achieved during the testing of inductively operating LF (low frequency) systems. A more rapid examination of the measurement object is possible. Furthermore, cost optimization for the test also results. The improvement in the interference safety achieved also increases the availability for the test device.An exemplary embodiment of the invention with various refinements and configurations is illustrated in the drawings and is described in more detail below. They show FIG. 1 schematically shows an electronic key for an access and / or driving authorisation system of a motor vehicle, and FIG. 2 shows a checking device for the key from FIG. 1.The method serves for testing a measurement object 1 with three-dimensional inductive reception elements. As an example of such a measurement object 1, a mobile transponder and / or radio key of a keyless access and / or driving authorisation system for a motor vehicle having a keyless entry and / or keyless entry functionality can be seen in FIG. 1. The key 1 has three-dimensional inductive receiving elements. The three-dimensional inductive receiving elements of the object to be measured 1 consist of three coils 2, 3, 4. one coil 2, 3, 4 each is arranged in such a way that its coil axis substantially corresponds to a respective coordinate axis x, y, z of a Cartesian coordinate system, thus an x coil 2, a y coil 3 and a z coil 4 are present in the key 1. The coordinate system is essentially placed in such a way that the x-axis coincides with the longitudinal axis s of the key 1.The object to be measured 1 is now tested in a test device 5 with regard to the functionality of the inductive receiving elements 2, 3, 4 in all three dimensions. The test device 5 consists of a Helmholtz coil having a coil pair 6, 7. The coils 6, 7 have the radius R, i.e. a diameter 2R. The two coils 6, 7 are arranged at a distance R from one another. The current flows through the windings 9 of the coils 6, 7 in the same direction. The magnetic field (B-field) 8 generated by the Helmholtz coil 6, 7 and serving for testing the object 1 to be measured is thus running in the x-direction within the Helmholtz coil 6, 7 and is substantially constant and homogeneous. The object 1 to be tested is now arranged in the substantially constant homogeneous magnetic field 8 between the coil pairs 6, 7. In this case, the object to be measured 1 is arranged with respect to the three axis directions x, y, z of the Helmholtz coil 6, 7 which are substantially perpendicular to one another in such a way that the three-dimensional receiving elements 2, 3, 4 are each tilted with their coil axes substantially by 45 degrees with respect to the axis directions x, y, z. The angles, denoted by α, β, γ in FIG. 2, between the axis directions x, y, z and the longitudinal axis s of the measurement object 1 are thus each 45°. Because of this arrangement, each coil 2, 3, 4 sees a component of the (B) coil 8 running in the x direction, thus enabling simultaneous measurement or testing of all three coils 2, 3, 4.The invention is not limited to the embodiment described and illustrated. Rather, it also includes all technical developments within the scope of the invention defined by the patent claims. The invention is thus explained on the basis of a mobile key for an access and / or driving authorisation system, but it can be used for checking any measurement objects with three-dimensional inductive reception and / or transmission elements.List of Reference Numerals:1 Measurement object / key 2 (x) coil / inductive receiving element 3 (y) coil / inductive receiving element 4 (z) coil / inductive receiving element 5 Testing device 6, 7 coil / coil pair / Helmholtz coil 8 Magnetic field / field 9 winding (of Helmholtz coil)

Claims

Method for testing a measurement object (1) having three-dimensional inductive receiving elements (2, 3, 4), characterized in that a Helmholtz coil having a coil pair (6, 7) is used for generating a magnetic field (8), in that the measurement object (1) to be tested is arranged between the coil pair (6, 7) in the substantially constant homogeneous magnetic field (8), and in that the measurement object (1) is arranged in relation to the three axis directions (x, y, z) of the Helmholtz coil (6, 7) which are substantially perpendicular to one another in such a way that the three-dimensional receiving elements (2, 3, 4) are each tilted substantially by 45° to the axis directions (x, y, z).Method according to Claim 1, characterized in that the three-dimensional inductive reception elements (2, 3, 4) of the measurement object (1) consist of three coils, wherein in each case one coil (2, 3, 4) is arranged in such a way that the coil axis substantially corresponds in each case to a coordinate axis (x, y, z) of a Cartesian coordinate system.Method according to Claim 1 or 2, characterized in that the measurement object (1) is a mobile transponder and / or radio key, which has three-dimensional inductive reception elements (2, 3, 4), of a keyless access and / or driving authorisation system for a motor vehicle.

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