Measurement methods for checking plug connections

Abstract

The invention relates to a measuring method (1) for checking plug connections (2), wherein a sensor of a magnetometer is used. The invention is characterized in that an alternating magnetic field is generated using an electromagnet (3), which is induced as an external alternating magnetic field into the plug connection (2).

Description

[0001] The invention relates to a measuring method for checking plug connections.

[0002] A vehicle uses a large number of electrical connectors, often 1000 or more. To ensure proper functionality, these connectors must be tested. Checking the connections is difficult, and improperly connected connectors, in particular, pose a major problem in production.

[0003] Optical inspection methods, particularly for Connector Position Assurance (CPA) connectors, can be used to check connector connections. Quantum magnetometers can also be used to verify connector connections.

[0004] It is still desirable to check not only individual plug connections, but also connections of different wires or wire pairs.

[0005] From DE 10 2008 043 491 A1, a device is known in which cables with a multitude of different conductors or conductor pairs can be tested without separating them from one another. A first detector with a coupling is arranged in the area of ​​the first conductor, and a second detector is arranged in the area of ​​the second conductor. The detectors and the coupling are connected to an evaluation unit. As a result of the two detectors positioned on either side of the connection to be tested...

[0006] Patent DD 2 59 765 A3 discloses a method and a device for locating faulty connectors at the ends of connecting cables. In this method, either induced voltages generated in the cable under test as a result of an alternating magnetic field passing through the cable are used to detect the fault, or measurement voltages generated by a magnetic field surrounding the current-carrying cable are evaluated in a sensor coil.

[0007] Detectors can calculate a difference between the two measurement signals of the detectors.

[0008] A disadvantage of the known methods and devices is that a current must flow through the wires to determine the state of the connectors using a magnetic field. This is particularly problematic because, in a complete vehicle, a current can only be passed through the wires at a relatively late stage in the production process. By this time, however, the connectors are already installed and often very difficult to access.

[0009] The object of the present invention is therefore to provide a method which overcomes the aforementioned disadvantages. In particular, it aims to create a way to check the plug connections at an early stage of production, while they are still freely accessible.

[0010] According to the invention, this problem is solved by a measuring method with the features in claim 1, and in particular in the characterizing part of claim 1. Advantageous embodiments and further developments are described in the dependent claims.

[0011] At the core of the method according to the invention, an alternating magnetic field is generated using an electromagnet, which is induced into the plug connection as an external alternating magnetic field.

[0012] This allows for the automatic testing of cables or electrical connectors without requiring an intrinsic current to flow through the cables. According to the invention, the current is therefore induced into the connector via an external alternating magnetic field.

[0013] Advantageously, the process can therefore be applied even before current can flow through the cables, i.e., at a very early stage of production. This can advantageously increase production yield, particularly by increasing production speed. Furthermore, production costs can be reduced because defective cables can be detected early and replaced without significant time or expense, especially if they are not yet installed in the vehicle.

[0014] The measurement method is designed for checking electrical connections, utilizing a magnetometer sensor. In particular, the magnetometer possesses very high sensitivity and can therefore have a very wide bandwidth in the range of measurable field strength. This allows for a very wide bandwidth to be used to check the electrical connections. Specifically, a magnetometer based on quantum effects in NV centers in diamond can be used.

[0015] The alternating magnetic field induces a current in the electrically conductive components of the connector. In particular, the alternating magnetic field induces a current in electrically conductive components located in the immediate vicinity of the at least one electromagnet. Specifically, a current can be induced in an electrically conductive connector located in the immediate vicinity of the electromagnet.

[0016] In particular, the induced current depends on the strength and / or frequency of the alternating magnetic field generated by the electromagnet. Furthermore, the induced current can be significantly dependent on the electrical resistance of the connector. Thus, a high electrical resistance in the connector results in a lower induced current.

[0017] The induced current generates its own magnetic field, which opposes the alternating magnetic field. This allows, in particular, the implementation of Lenz's law.

[0018] According to the invention, the magnetometer measures the sum of the two magnetic fields. In particular, the measured total magnetic field can provide information about the electrical resistance of the connector, and thus about the physical condition of the connector.

[0019] Another advantageous embodiment involves using a reference measurement at an intact connector, subtracting this reference measurement from the sum of the two measured magnetic fields. This allows deviations from an ideal case to be detected easily. Furthermore, a wide variety of connectors with different electrical resistances, resulting in different measured magnetic fields, can be evaluated, as these can be assessed in relation to a specific reference field. Therefore, the evaluation does not involve an absolute value, but rather a relative assessment of a measured value to a specific reference value.

[0020] According to a highly advantageous further development of this idea, the electromagnet can be powered by an alternating electric field of a specific frequency. This allows for the filtering out of interfering magnetic fields from the environment, such as the static geomagnetic field or magnetic fields generated in the vicinity by running motors or similar sources. The measurement can be specifically limited to the measurement of the magnetic field at this particular frequency. The specific frequency can be determined, for example, by Fourier analysis or a lock-in approach. This allows all static fields and fields of other frequencies to be filtered out. In particular, this enables a measurement without magnetic shielding, while still achieving high measurement accuracy.

[0021] In an alternative embodiment, at least one sensor of a magnetometer with an integrated electromagnet can be guided along a connector. Alternatively, at least two sensors with integrated electromagnets can be used. These can be guided, for example, in parallel, particularly with the aid of robotic arms or robots, into the immediate vicinity of the connectors. This allows the measurement to be performed at any desired location.

[0022] According to the invention, a measuring device is designed in the form of a frame or gate, wherein at least two sensors of a magnetometer with integrated electromagnets are arranged at different heights in the frame or gate, a cable harness is routed through the frame or gate, and the measured magnetic fields are stored as a function of time during passage. This advantageously allows a complete cable harness, to which a plurality of connectors are attached, to be measured.

[0023] The sensors can be arranged at different heights on the frame or gate, with the height being determined via a Y-position on the frame or gate.

[0024] The measured magnetic fields are compared with a reference time series, whereby an X-position of the defect in the direction of travel and a Y-position of the defect at a height in the frame or gate can be determined by a point in time of a deviation from the reference time series.

[0025] Consequently, in the event of deviations from the reference time series, the X-position of the defect in the direction of travel can be determined by the time of the deviation, and the Y-position by the largest deviation of the sensors mounted at different heights. Advantageously, this allows not only the inspection of numerous connectors in a wiring harness, but also of the entire wiring system.

[0026] Further advantageous embodiments of the method according to the invention also result from the exemplary embodiment, which is described in more detail below with reference to the figures.

[0027] This shows: Fig. 1. One possible embodiment of the method; and Fig. 2 another possible embodiment of the method.

[0028] In the presentation of the Fig. Figure 1 shows a possible embodiment of the method in which a magnetometer based on quantum effects is used in NV centers 8 in diamond 7. This magnetometer can be used, for example, as a highly sensitive quantum sensor for quantum magnetic fields. A signal can be emitted from a laser 4 through a semi-transparent mirror 5, which is measured by the NV center 8 as a sensor. The diamond 7 with the NV center 8 is located near a connector 2 to be tested. An electromagnet 3 is also provided, and a specific RF signal 6 can be used. For evaluation, the measured fields can be directed through the semi-transparent mirror 5 to a photodetector 9.For the method according to the invention, in particular a magnetometer is used which has a very high sensitivity and a very high bandwidth in the range of measurable field strength.

[0029] Another variant of method 1 is in Fig. 2 to recognize. Unlike Fig. Figure 1 shows a frame or gate 11 through which a complete cable harness 10 can be routed. The cable harness 10 is, for example, mounted on a mounting board. In the illustration, the cable harness 10 can be routed from left to right through the frame or gate 11, so that it moves through the frame or gate 11 in the direction of movement X.

[0030] At least two sensors 12, and in particular a plurality of sensors 12, can be arranged one above the other on the frame or gate 11 at different heights, characterized by different Y-positions. The sensors have a magnetometer with an integrated electromagnet, as described according to the invention.

[0031] During passage, the measured magnetic fields can be recorded as a function of time and compared with a corresponding reference time series. In case of deviations, the X-position of the defect in the direction of passage can be determined from the time of the deviation. Furthermore, the Y-position can be determined from the greatest deviation of the sensors 12 mounted at different heights. In this way, not only connectors in the wiring harness, but also entire wiring systems in general, can be checked.

Claims

[1] Measuring method (1) for checking plug connections (2), using a sensor of a magnetometer, where using an electromagnet (3) an alternating magnetic field is generated which penetrates the plug connection (2) as an external alternating magnetic field, wherein the external alternating magnetic field induces a current in the electrically conductive components of the plug connection (2), where the induced current generates its own magnetic field, which counteracts the alternating magnetic field, where the magnetometer measures a sum of the two magnetic fields, wherein a measuring device is designed in the form of a frame or gate, wherein at least two sensors of a magnetometer with integrated electromagnets (3) are arranged at different heights in the frame or gate, wherein a cable harness is guided through the frame or gate and the measured magnetic fields are stored as a function of time during the passage, characterized by , that the measured magnetic fields are compared with a reference time series, whereby an X-position of the defect in the direction of passage and a Y-position of the defect at a height in the frame or gate can be determined by a time of a deviation from the reference time series. [2] Measuring method (1) according to claim 1, characterized by , that a reference measurement is taken on an intact connector, where the reference measurement is subtracted from the sum of the two measured magnetic fields. [3] Measuring method (1) according to claim 1 or 2, characterized by that the electromagnet (3) is supplied with an alternating electric field of a specific frequency.

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