DE102017214430B4 - foreign object detection - Google Patents

Abstract

Vehicle charging interruption control device (10) with foreign body detection, having: - at least two measuring coils (21, 22, 23, 24, 25, 26) for detecting an induced voltage in each case; and- a control unit (11); wherein the control unit (11) is set up to carry out a first evaluation,wherein the control unit (11) is set up to compare the induced voltages with a respective predefined expected value during the first evaluation and to calculate a first deviation between the detected induced voltage and to determine the respective predefined expected value, the control unit (11) being set up to carry out a second evaluation, the control unit (11) also being set up to compare the induced voltages with one another in the second evaluation and to determine a second deviation between the induced ones To determine voltages, the control unit (11) being set up to conclude that there is a foreign body (50) in the area of the measuring coils (21, 22, 23, 24, 25, 26) if the first deviation of the first evaluation is a first predefined one threshold value and/or the second deviation of the second evaluation falls below or exceeds a second predefined threshold value, and the control unit (11) is also set up to calculate the deviation of the first evaluation and the deviation of the second evaluation as a function of an operating point of a charging station (40). weight.

Description

The invention relates to a vehicle charging termination control device with foreign object detection, a vehicle with such a vehicle charging termination control device, a charging station with a vehicle charging termination control device, a foreign object detection system, a method for foreign object detection, a program element and a computer-readable medium.

As part of the increasing spread of electric and plug-in hybrid vehicles, the charging infrastructure is constantly being expanded. More and more charging stations are being set up and put into operation. On the one hand, the charging stations can be connected directly to an interface on the vehicle to be charged via a charging cable. On the other hand, vehicles can be charged wirelessly using induction. The exchange of energy between a charging station and a vehicle takes place by means of two charging coils, which are coupled via an electromagnetic field. The inductive charging of the vehicle is very convenient for the user, since they do not have to plug a charging cable into the interface on their vehicle. Furthermore, with inductive charging, the charging cable cannot be damaged, e.g. by vandalism and/or if a vehicle drives over the charging cable.

If the vehicle is charged using an inductive charging station, the vehicle should be in the middle or centered over the charging coil of the charging station. Furthermore, there should be no objects between the two charging coils, otherwise the efficiency of the energy transfer can be adversely affected.

The document DE 10 2014 207 885 A1 relates to a foreign matter detection device having a plurality of coils. The coils are arranged side by side and are in the form of ring sectors. The coils can detect a foreign object in the area of a power inductive charging device.

In the U.S. 2015/0 109 000 A1 a system, a device and a method for foreign body detection is proposed. The device includes a plurality of electrically conductive loops arranged in an array. Furthermore, the device has a measuring circuit which can detect and evaluate the characteristic of each of the loops. For this purpose, the measuring circuit can evaluate the characteristics of certain parameters and thus conclude that there is a foreign body in the area of the loops. Furthermore, the measurement circuit can compare the parameters of individual loops against a threshold value or determine the difference between adjacent loops.

The document DE 10 2013 219 131 A1 relates to a device and a corresponding method for detecting a foreign body in a magnetic field for wireless energy transmission, the device having at least a first and a second coil stack. Each coil stack has an excitation coil and a first and a second measuring coil. The measuring voltages, which are induced in the measuring coils, can be evaluated to detect the foreign body.

The document WO 2013/127 445 A1 relates to wireless charging of an electric vehicle in a safe and reliable manner. For this purpose, a device has at least one measuring coil, which detects electrically conductive bodies in the power transmission area.

The document U.S. 2012/0 077 537 A1 proposes a system for wireless power transmission which, by comparing the power supplied to the power consumed, detects whether power is lost during power transmission.

The procedure of the document DE 10 2010 042 395 A1 involves placing a primary and a secondary coil which are inductively coupled to each other.

The document U.S. 2014/0 111 019 A1 proposes an apparatus, method and system for wireless power transmission.

It is the object of the invention to improve an inductive charging process.

This object is solved by the subject matter of the independent claims. Embodiments and developments can be found in the dependent claims, the description and the figures.

A first aspect of the invention relates to a vehicle load termination control device with foreign body detection. The vehicle charge termination control device has at least two measuring coils for detecting an induced voltage in each case and a control unit. The control unit is set up to carry out a first evaluation. During the first evaluation, the control unit compares each of the induced voltages with a corresponding predefined expected value in order to determine a first deviation between the detected induced voltage and the respective predefined expected value. The The control unit is also set up to carry out a second evaluation. The control unit is set up to compare the induced voltages with one another or with one another during the second evaluation and to determine a second discrepancy between the induced voltages. The control unit is set up to conclude that there is a foreign body in the area of the measuring coil if the first deviation of the first evaluation falls below or exceeds a first predefined threshold value and/or the second deviation of the second evaluation falls below or exceeds a second predefined threshold value, the deviation of the first evaluation and the deviation of the second evaluation are weighted depending on an operating point of a charging station. The difference formed between the induced voltage and another induced voltage or the expected value can be either positive or negative. In the case of the first deviation, the induced voltage can preferably be subtracted from the expected value, since the induced voltage is typically reduced by a foreign body. It follows from this that the first deviation will tend to exceed a first threshold value. In the second evaluation, the induced voltages of two measuring coils can be evaluated relative to one another, so that negative second deviations are also possible. These can fall below a second predefined threshold value. In this example, the threshold can also represent a range that the second deviation should not exceed.

In other words, the control unit can carry out at least two evaluations. On the one hand, a first, absolute, evaluation can be carried out by comparing the induced voltage with a predefined expected value. Furthermore, a first deviation can be determined by comparing the induced voltages of the measuring coils with the respective predefined expected value. A second, relative, evaluation can also be carried out. In this second evaluation, the control unit can compare the induced voltages of the measuring coils with one another or with one another. A second deviation can be determined from this, for example a difference or a percentage deviation. If the first deviation from the first evaluation and/or the second deviation from the second deviation exceeds and/or falls below a predefined first or second threshold value, it can be concluded that a foreign object is in the area of the vehicle charge termination control device. It should be noted that the first threshold value and the second threshold value can be the same but also different. It should be noted that the induced voltage corresponds to a measured value and this measured value can be compared. This can be converted or sampled into a digital signal that correlates with the induced voltage using an analog-to-digital converter (A/D converter).

The first deviation and the second deviation can be determined, for example, by means of subtraction. In the case of the first deviation, for example, the difference between the induced voltage and the expected value at the respective operating point of the induced voltage can be formed. In the case of the second deviation, the difference between two induced voltages of the at least two measuring coils can be formed. Furthermore, the first deviation and the second deviation can also be specified in relation to their respective expected value and/or to another induced voltage, for example as a percentage.

According to one embodiment of the invention, the control unit of the vehicle charge termination control device can conclude that there is a foreign body or an object in the area of one of the measuring coils if the first deviation falls below the first predefined threshold value or, according to another embodiment, exceeds it if the second deviation exceeds the falls below or, according to a further embodiment, exceeds the second predefined threshold value or the first and the second deviation fall below or exceed the first or the second predefined threshold value.

The second evaluation, i.e. the relative comparison, of the induced voltages can be carried out without an expected value for each operating point, since it can be assumed that all measuring coils behave the same or at least similarly when there is an electromagnetic field. As soon as one of the measuring coils has an induced voltage that differs from the remaining measuring coils and is not caused by a different structural shape or design, a foreign body in the area of the measuring coil can be inferred. The relative evaluation can offer advantages over an absolute evaluation, in particular in the case of a dynamic adaptation of a power during the energy transmission, since the respective expected value does not have to be calculated here. Another advantage of the second evaluation can be the independence from environmental influences, such as temperature, air pressure and/or humidity. These affect all measuring coils equally. This does not affect the relative result between the measuring coils. In particular, two immediately adjacent measuring coils can be compared with one another in the second evaluation.

Furthermore, the control unit can weight the two deviations differently from one another. For example, 60% of the first deviation and 40% of the second deviation can be included in the foreign object detection of the vehicle charge termination control device. In other words, the control unit can take more account of one of the two evaluations when deciding whether there is a foreign body in the area of the measuring coils. In addition to a fixed weighting of the first and second deviations from one another, the weighting can also take place as a function of a current operating point of the charging station. In other words, the first or the second deviation for the current operating point can be weighted more or less. This is advantageously done based on the reliability of the respective evaluation at the respective operating point of the charging station. For example, in the case of energy transmission with a low power level, the second deviation can be weighted more heavily than the first deviation, or vice versa. Furthermore, it may also be possible to adjust the weighting of the first or the second deviations based on the current dynamics of the energy transmission. For example, in a more dynamic range related to performance, the second deviation may be weighted more heavily and in a more constant range related to performance, the first deviation may be weighted more heavily.

It should be noted that the deviation can also be a group of values and can have several individual deviations. In particular in the case of a vehicle charge termination control device with more than two measuring coils, the first deviation from a respective expected value can be determined for each measuring coil. In addition, the second deviation between each of the induced voltages of the measuring coils can also be determined.

The first or the second threshold value, with which the first or the second deviation is compared, can be a fixed value, a curve, a characteristic map, a model or a family of values. The first and/or the second deviation can fall below or exceed this. In addition, the respective threshold value used can depend on a current operating point of the charging station. In other words, the first or the second threshold value in the case of energy transmission with a low power level can differ from the first or the second threshold value in the case of energy transmission with a higher power level. Furthermore, the first or the second threshold value can be adjusted or varied depending on environmental conditions.

It should be noted that mean values, peak values, intermediate values or a mixture thereof can be compared to a predefined threshold value.

The vehicle charge termination control device can also have a large number of measuring coils, such as a dozen or 200. These individual measuring coils can be identical but also different from one another and differ, for example, in size, number of windings, resistance or material. Different sectors of the vehicle charge termination control device can also be equipped with different types of measuring coils. The properties of the measuring coils used can be known in advance or they can be determined by a reference measurement.

A measuring coil is a device that can detect or measure induced voltages. The induced voltage results from an electromagnetic field. The measured induced voltage allows conclusions to be drawn about the electromagnetic field, and in particular about its strength and energy. The voltage induced in the measuring coil can depend on the electromagnetic field strength, the number of windings, the resistance of the measuring coil, the material of the measuring coil and the geometric design of the measuring coil. However, environmental influences such as humidity, air pressure or temperature can also influence the voltage induced in the measuring coil. As soon as a foreign body is in front of, next to, behind or generally in the area of the measuring coil, the foreign body changes the electromagnetic field and thus also the voltage induced in the measuring coil.

The measured or detected induced voltages can be converted, for example, by an A/D converter (analog-to-digital converter) from an analog, continuous measurement signal into a digital signal that correlates with the measurement signal. This digital signal can be processed by the control unit, for example a microchip, an FPGA, a PLC or, more generally, a CPU. For this purpose, the control unit can also have a memory unit and digital inputs and outputs.

According to one embodiment of the invention, the control unit is set up to compare the sum of all induced voltages of all measuring coils with the sum of the induced voltages of a predefined number of measuring coils of the vehicle charging interruption control device in the second evaluation in order to determine the second deviation.

As a result, the second evaluation can be designed to be more error-tolerant, since a larger number of induced voltages is compared and thus the mean value or the mean value of a predefined number of measuring coils. Foreign bodies can thus be detected more reliably without too many incorrect detections taking place. Furthermore, a group of measuring coils (mean values or sums) can also be compared with one another in order to determine the second deviation.

According to one embodiment of the invention, the control unit is set up to compare a behavior of a measuring coil with the behavior of the measuring coil of a previous evaluation in the first evaluation and in the second evaluation and to determine the first and the second deviation.

“Behaviour” is a measure of how the induced voltage of a given sensing coil changes as a function of the electromagnetic field present and how it changes. In other words, the behavior of the measuring coil can be described by a dead time, an overshoot or an inertia in the electromagnetic field. This behavior of the measuring coil can change if there is a foreign body in the area of the measuring coil, so that the behavior of the measuring coil from a previous measurement can be compared with the behavior of the measuring coil of the current measurement. The comparison can in turn be used to draw conclusions about any foreign bodies in the area of the measuring coil.

According to a further embodiment of the invention, the control unit is set up to compare identical or similar measuring coils of the vehicle charging interruption control device with one another during the second evaluation and to determine the second deviation.

If the vehicle charge termination control device has a large number of measuring coils, the second evaluation, ie the relative evaluation or the comparison, can also be limited to the measuring coils with the same or similar structure or behavior. In this way, a conversion between the different types of measuring coils used can be avoided.

According to one embodiment of the invention, the foreign body in the area of the measuring coil is a metallic or a biological object.

Especially with inductive charging, a metal or biological object between the charging coil of the charging station and the charging coil of the vehicle can affect the charging process. The metallic object can be, for example, a screw, a nail, a tool or a toy such as a bicycle. The biological object can be, for example, leaves, a branch or an animal such as a cat.

A further aspect of the invention relates to a vehicle with the vehicle charge termination control device described above and below.

The vehicle is, for example, a motor vehicle such as a car, bus or truck, or else a rail vehicle, a ship, an aircraft such as a helicopter or plane, or a bicycle, for example, in particular an electric bicycle. The vehicle charging interruption control device can preferably be located in front of the charging coil of the vehicle, ie between the charging coil of the vehicle and the charging coil of the charging station.

A further aspect of the invention relates to a charging station with the vehicle charging termination control device described above and below.

The vehicle charging interruption control device described can be used not only in the vehicle, but also in the charging station. The vehicle charging interruption control device is advantageously located in front of the charging coil of the charging station, ie between the charging coil of the vehicle and the charging coil of the charging station. As a result, the measuring coils of the vehicle charge termination control device can detect the electromagnetic field and draw conclusions about any foreign bodies in the area of the measurement coil and thus in the area of the vehicle charge termination control device.

Another aspect of the invention relates to a foreign body detection system for a vehicle. The foreign object detection system has a first charging coil for energy transmission, a second charging coil for energy transmission and the vehicle charging interruption control device described above and below. The first charging coil is coupled to the second charging coil via an electromagnetic field, and the first charging coil is configured to transmit electrical and/or magnetic energy to the second charging coil. The control unit of the vehicle charge termination control device is set up to interrupt the energy transmission between the first charging coil and the second charging coil when the vehicle charge termination control device concludes that the foreign object is present. Furthermore, an adjustment of the power of the energy transfer between the first charging coil and the second charging coil lead to a corresponding (percentage) change in the induced voltage in one of the measuring coils. Furthermore, all measuring coils should behave in such a way that an increase in the power of the energy transfer leads to an increase in the induced voltages in all measuring coils.

The vehicle charge termination control device is preferably arranged between the first charging coil and the second charging coil, so that the electromagnetic field induces a voltage in at least one measuring coil of the vehicle charge termination control device. If at least one of the measuring coils deviates too much from the respective expected value and/or from another measuring coil, the control unit can interrupt the energy transfer between the first charging coil and the second charging coil of the foreign body detection system.

As an alternative or in addition, the vehicle charge termination control device of the foreign body detection system can receive information about the delivered and received energy of the first charging coil or the second charging coil. Thus, the expected value of the first evaluation can be predicted more precisely.

According to one embodiment of the invention, the control unit is set up to gradually increase or ramp up the energy transfer between the first charging coil and the second charging coil.

The energy transfer between the first charging coil and the second charging coil can take place in stages. In other words, the power of the energy transmission can be increased or changed in stages. Furthermore, the power of the energy transmission can be kept constant in the meantime, in order to then increase or decrease again. In the case of energy transmission with constant power, the induced voltage of the first evaluation can be compared or adjusted with the induced voltage of the second evaluation. In particular, in the case of energy transmission with constant power, the expected value can be compared with a reference, so that an intermediate calibration of the first and the second evaluation can take place.

According to a further embodiment of the invention, the control unit is set up to calibrate the measuring coils of the vehicle charge termination control device when the energy transfer between the first charging coil and the second charging coil reaches or exceeds a predefined power. The calibration sets all induced voltages of all measuring coils of the vehicle charge interruption control device to a reference value.

The calibration can ensure that the first deviation and the second deviation or the first evaluation and the second evaluation do not drift away over time. It should be noted that the calibration is preferably carried out starting from a predefined and constant power of the energy transmission, thus interference influences on the calibration in the measuring coils can be minimized. Alternatively or additionally, the induced voltages can also be set to the mean value of the induced voltages.

According to one embodiment of the invention, the control unit is set up to compare the energy induced in the second charging coil with the energy delivered by the first charging coil. The control unit is also set up to interrupt the energy transfer between the first charging coil and the second charging coil if the ratio between the induced power and the power delivered falls below or exceeds a predefined threshold value. This deviation can be evaluated in absolute, relative or percentage terms. The evaluation of the emitted energy in relation to the received energy can be carried out in addition to the first evaluation and the second evaluation in order to further improve the foreign body detection of the foreign body detection system.

According to a further embodiment of the invention, each charging coil can have its own vehicle charging interruption control device. In this case, the measuring coils of the first vehicle charge termination control device and the corresponding or matching measurement coils of the second vehicle charge termination control device can advantageously be compared with one another. These should show the same behavior, i.e. behave in the same way. In other words, the change in induced voltages should be the same or similar.

• - Erfassen von induzierten Spannungen durch wenigstens zwei Messspulen;
• - Vergleichen der induzierten Spannungen mit jeweils einem vordefinierten Erwartungswert und Bestimmen einer ersten Abweichung;
• - Vergleichen der induzierten Spannungen untereinander und Bestimmen einer zweiten Abweichung;
• - Entscheiden, dass sich ein Fremdkörper im Bereich der Fahrzeug-Ladeabbruchsteuerungseinrichtung befindet, wenn die erste Abweichung der ersten Auswertung einen ersten vordefinierten Schwellwert und/oder die zweite Abweichung der zweiten Auswertung einen zweiten vordefinierten Schwellwert unterschreitet oder überschreitet;
• - Unterbrechen einer Energieübertragung zwischen einer ersten Ladespule und einer zweiten Ladespule, wenn sich ein Fremdkörper im Bereich der Fahrzeug-Ladeabbruchsteuerungseinrichtung befindet.

A further aspect of the invention relates to a method for foreign body detection for a vehicle load termination control device. The procedure has the following steps:

• - Detection of induced voltages by at least two measuring coils;
• - Comparing the induced voltages with a predefined expected value and determining a first deviation;
• - Comparing the induced voltages with each other and determining a second deviation;
• - Deciding that there is a foreign body in the area of the vehicle charge termination control device if the first deviation of the first evaluation falls below or exceeds a first predefined threshold value and/or the second deviation of the second evaluation falls below or exceeds a second predefined threshold value;
• - Interruption of an energy transfer between a first charging coil and a second charging coil when there is a foreign body in the area of the vehicle charge termination control device.

A further aspect of the invention relates to a program element which, when it is executed on a control unit of a charging termination control device, instructs the charging termination control device to carry out the method described above and below.

A further aspect of this invention relates to a computer-readable medium on which a program element is stored, which instructs the control unit of a charge termination control device to execute the method described above and below

Further features, advantages and possible applications of the invention result from the following description of the exemplary embodiments and the figures.

• 1 zeigt ein Blockschaltbild einer Fahrzeug-Ladeabbruchsteuerungseinrichtung gemäß einer Ausführungsform der Erfindung.
• 2 zeigt eine schematische Darstellung einer Fahrzeug-Ladeabbruchsteuerungseinrichtung gemäß einer weiteren Ausführungsform der Erfindung.
• 3 zeigt eine schematische Darstellung eines Fremdkörpererkennungssystems inklusive Fahrzeug und Ladestation gemäß einer Ausführungsform der Erfindung.
• 4 zeigt eine weitere schematische Darstellung eines Fremdkörpererkennungssystems inklusive Fahrzeug und Ladestation gemäß weiteren einer Ausführungsform der Erfindung.
• 5 zeigt ein Flussdiagramm für ein Verfahren zur Fremdkörpererkennung gemäß einer Ausführungsform der Erfindung.

The figures are schematic and not drawn to scale. If the same reference symbols are given in the following description of the figures, then these designate the same or similar elements.

• 1 FIG. 12 shows a block diagram of a vehicle charge cancellation control device according to an embodiment of the invention.
• 2 shows a schematic representation of a vehicle charge termination control device according to a further embodiment of the invention.
• 3 shows a schematic representation of a foreign body detection system including vehicle and charging station according to an embodiment of the invention.
• 4 shows a further schematic representation of a foreign body detection system including vehicle and charging station according to another embodiment of the invention.
• 5 shows a flow chart for a method for foreign body detection according to an embodiment of the invention.

1 1 shows a block diagram of a vehicle charge termination control device 10 . This vehicle charge termination control device 10 has a first measuring coil 21 , a second measuring coil 22 and a control unit 11 . The first and the second measuring coil 21, 22 are set up to detect an induced voltage or to measure it. This correlates with an electromagnetic field to be measured. The detected voltages of the measuring coils 21, 22 can be evaluated by the control unit 11. In this case, the control unit 11 can carry out at least a first and a second evaluation. In the first evaluation, each of the measuring coils 21, 22 can be evaluated individually, and the induced voltage can be compared with a predefined expected value. So an absolute evaluation. The second evaluation can compare the induced voltages of the measuring coils 21, 22 with one another, ie relative to one another. For example, by forming an average value that is compared with an expected value or by determining the difference between the induced voltages. Alternatively or additionally, the induced voltages of the measuring coils 21, 22 can also be set in relation to determine a percentage deviation.

In the first and the second evaluation, the control unit 11 can determine a deviation in each case. For example, in the first evaluation, the control unit 11 can determine the difference between the induced voltage and a respective expected value. In the second evaluation, the control unit 11 can, for example, determine the difference between the two detected induced voltages as a deviation. Furthermore, in the case of the second deviation, the control unit 11 can also compare the mean value of the induced voltages with a predefined expected value. Furthermore, the deviation of the second evaluation can also be the ratio between the induced voltages. Furthermore, the control unit 11 can also compare the sum of all induced voltages with a predefined number of induced voltages and determine the deviation from this.

Alternatively or additionally, only the same or similar measuring coils 21, 22 can be compared with one another. In particular, if the vehicle charging interruption control device 10 has a large number of measuring coils 21, 22 with different sizes, number of windings, resistance, material and/or geometric design.

Alternatively or additionally, the control unit 11 can also compare a behavior of the measuring coil 21, 22, for example the time course, the inertia or the dead time of the measuring coil 21, 22, with the behavior of the same measuring coil 21, 22 in a previous measurement. Typically, the measuring coils should not change significantly between individual measurements, so that the behavior of a measuring coil 21, 22 in a specific electromagnetic field should be the same over time. If this behavior changes, it can be concluded that there is a foreign body in the area of the vehicle charge termination control device 10 .

The control unit 11 of the vehicle charge termination control device 10 can conclude that there is a foreign body in the area of the measuring coil 21, 22 if the first deviation and/or the second deviation exceeds its own predetermined threshold value. Furthermore, the first and the second evaluation can be weighted differently, so that the first or the second evaluation is more important in determining the foreign body. The weighting can be done by a fixed distribution, e.g. 50% to 50%, or depending on the respective operating point of a charging station. The first evaluation can be given preference over the second evaluation, or vice versa, particularly in the case of low or high performance of the energy transmission. The first or the second evaluation can also be more advantageous in the event of a dynamic change in the power of the energy transmission.

By weighting the first or the second evaluation, errors in the foreign body detection can be reduced or foreign bodies in the area of the measuring coil 21, 22 can be detected more reliably, since the appropriate weighting between the first and the second evaluation is selected or adjusted for each operating point can (absolutely and/or relatively).

2 shows a vehicle charge termination control device 10 with a large number of measuring coils 21, 22, 23, 24, 25, 26. These measuring coils 21, 22, 23, 24, 25, 26 can be arranged side by side, around one another, one above the other and/or one behind the other. All measuring coils 21, 22, 23, 24, 25, 26 can be evaluated individually against a respective predefined expected value (absolutely), but measuring coils 21, 22, 23, 24, 25, 26 can also be evaluated relative to one another, using the second Evaluation. Furthermore shows 2 a foreign object 50 which has been recognized as a foreign object 50 by the vehicle charge-cancellation control device 10 . The bottom 60 will be in 2 represented by a solid line. The regarding 1 The evaluations and determinations of the deviations described above can also be carried out by the vehicle charge termination control device 10 2 be applied. The measuring coils 21, 22, 23, 24, 25, 26 can be identical but also different.

3 12 shows a foreign body detection system 1. The foreign body detection system 1 has a first charging coil 41, a second charging coil 31 and the vehicle charging interruption control device 10. FIG. Furthermore, in 3 a vehicle 30 having the second charging coil 31, and a charging station 40 having the first charging coil 41 is shown. Furthermore, there is a foreign body 50 or an object 50 in the area of the foreign body detection system 1. An electromagnetic field can exist between the first charging coil 41 and the second charging coil 31, so that an energy exchange between the two charging coils 31, 41 can take place. This exchange of energy is 3 indicated by the three quadrants arranged one above the other. The vehicle charge termination control device 10 with the measuring coils 21, 22, 23, 24, 25, 26 can be arranged in the electromagnetic field. In 3 the vehicle charge-cancellation control device 10 is arranged in the vehicle 30 .

The foreign body detection system 1 can gradually increase the energy transmission or the power of the energy transmission, ie the electromagnetic field. Alternatively, the foreign body detection system 1 can ramp up the energy transmission. If a foreign body 50 is detected, the foreign body detection system 1 can interrupt or stop the energy transmission between the first charging coil 41 and the second charging coil 31 .

The control unit 11 of the foreign body detection system 1 can also compare the output power of the first charging coil 41 with the received power of the second charging coil 31 . If the ratio between the power delivered and the power received deviates by more than a predefined threshold value, the foreign body 50 can also be inferred and the energy transmission can be interrupted.

Alternatively or additionally, with a gradual increase in energy transmission, the energy can be kept constant for a predetermined period of time and with constant energy transmission, the first deviation of the first evaluation can be compared with the second deviation of the second evaluation and adjusted if necessary. In other words, with predefined constant operating points of the foreign body detection system 1, the rela tive evaluation and the absolute evaluation can be compared or compared with a reference value.

Alternatively or additionally, the measuring coils of the vehicle charge termination control device 10 can be calibrated. For this purpose, the induced voltage of the measuring coils can be set to a reference value with a constant predefined power between the first charging coil 41 and the second charging coil 31 . The power can be, for example, 90% of the maximum power that can be transmitted.

In contrast to 3 shows 4 a foreign object detection system 1, in which the vehicle charging interruption control device 10 is arranged in the charging station 40.

In 5 a flowchart for a method for foreign body detection is shown. In step S1, the induced voltages are detected by at least two measuring coils. This is followed in step S2 by a comparison of the induced voltages with a predefined expected value and a first deviation from this expected value is determined. In step S3, the induced voltages are compared with one another and a second deviation is determined therefrom. If the first deviation and/or the second deviation exceeds and/or falls below a predefined threshold value, a decision is made in step S4 as to whether there is a foreign object in the area of the vehicle charge termination control device. An energy transmission between a first charging coil and a second charging coil is interrupted in step S5 if a foreign body was detected or if a foreign body was inferred.

Claims (14)

Vehicle loading abort control device (10) with foreign body detection, having: - At least two measuring coils (21, 22, 23, 24, 25, 26) for detecting an induced voltage in each case; and - a control unit (11); wherein the control unit (11) is set up to carry out a first evaluation, wherein the control unit (11) is set up to compare the induced voltages with a respective predefined expected value during the first evaluation and to determine a first deviation between the detected induced voltage and the respective predefined expected value, wherein the control unit (11) is set up to carry out a second evaluation, wherein the control unit (11) is also set up to compare the induced voltages with one another during the second evaluation and to determine a second deviation between the induced voltages, wherein the control unit (11) is set up to conclude that there is a foreign body (50) in the area of the measuring coils (21, 22, 23, 24, 25, 26) if the first deviation of the first evaluation exceeds a first predefined threshold value and/or the second deviation of the second evaluation falls below or exceeds a second predefined threshold value, and wherein the control unit (11) is also set up to weight the deviation of the first evaluation and the deviation of the second evaluation depending on an operating point of a charging station (40). Vehicle loading abort control device (10) according to claim 1 , wherein the control unit (11) is set up to, in the second evaluation, the sum of all induced voltages of all measuring coils with the sum of the induced voltages of a predefined number of measuring coils (21, 22, 23, 24, 25, 26) of the vehicle charge termination control device (10) to determine the second deviation. Vehicle loading abort control device (10) according to claim 1 and 2 , wherein the control unit is set up to compare a behavior of a measuring coil (21, 22, 23, 24, 25, 26) with the behavior of the measuring coil (21, 22, 23, 24, 25 , 26) of a previous evaluation and to determine the first and the second deviation. Vehicle charge termination control device (10) according to one of the preceding claims, wherein the control unit (11) is set up to use the same and/or similar measuring coils (21, 22, 23, 24, 25, 26) of the vehicle charge termination control device ( 10) and to determine the second deviation. Vehicle charge abort control device (10) according to any one of the preceding claims, wherein the foreign body (50) is a metallic and/or biological object. Vehicle (30) with the vehicle charge termination control device (10) according to one of the preceding claims. Charging station (40) with the vehicle charging termination control device (10) according to one of Claims 1 until 5 . Foreign body detection system (1) for a vehicle (30), comprising: - a first charging coil (41) for energy transmission; - A second charging coil (31) for energy transmission; and - the vehicle charge termination control device (10) according to one of Claims 1 - 5 ; wherein the first charging coil (41) is coupled to the second charging coil (31) via an electromagnetic field and wherein the first charging coil (41) is set up to transmit electrical and/or magnetic energy to the second charging coil (31), the Control unit (11) of the vehicle charge termination control device (10) is set up to interrupt the energy transmission between the first charging coil (41) and the second charging coil (31) if the vehicle charge termination control device (10) concludes that the foreign object (50) is present. Foreign body detection system (1) according to claim 8 , wherein the control unit (11) is set up to gradually increase and/or ramp up the energy transfer between the first charging coil (41) and the second charging coil (31). Foreign body detection system (1) according to claim 8 and 9 , wherein the control unit (11) is set up to calibrate the measuring coils (21, 22) of the vehicle charge termination control device (10) when the energy transfer between the first charging coil (41) and the second charging coil (31) reaches a predefined power and /or exceeds it, with all the induced voltages of all measuring coils (21, 22, 23, 24, 25, 26) of the vehicle charge termination control device (10) being set to a reference value by the calibration. Foreign body detection system (1) according to one of Claims 8 - 10 , wherein the control unit (11) is set up to compare the energy induced in the second charging coil (31) with the output power of the first energy (41), wherein the control unit (11) is set up to transmit energy between the first charging coil (41) and the second charging coil (31) to interrupt when the ratio between induced power and output power falls below or exceeds a predefined threshold. Foreign body detection method for a vehicle charge abort control device, comprising the steps: - Detection (S1) of induced voltages by at least two measuring coils (21, 22, 23, 24, 25, 26); - Comparing (S2) the induced voltages with a respective predefined expected value and determining a first deviation; - Comparing (S3) the induced voltages with one another and determining a second deviation; - Weighting of the first deviation and the second deviation depending on an operating point of a charging station; - decide (S4) that there is a foreign object (50) in the area of the vehicle charge termination control device (10) if the first deviation of the first evaluation falls below a first predefined threshold value and/or the second deviation of the second evaluation falls below a second predefined threshold value or exceeds; - Interrupting (S5) an energy transfer between a first charging coil (41) and a second charging coil (31) if a foreign body is in the area of the vehicle charging termination control device (10). Program element which, when executed on a control unit of a vehicle charge termination control device, directs the vehicle charge termination control device according to the method claim 12 to perform. Computer-readable medium on which a program element according to Claim 13 is saved.

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