Measuring unit and charging device

Abstract

The invention relates to a measuring unit comprising at least one first primary positioning sensor and a connector for use in positioning a primary coil of a charging unit and a secondary coil of an electric vehicle. The measuring unit is designed in such a way that it can be fixedly connected to the charging unit by means of the connector, and the at least one first primary positioning sensor is designed to communicate wirelessly with at least one secondary positioning sensor of the electric vehicle during the positioning process. The invention also relates to a charging device comprising a measuring unit and a charging unit.

Description

[0001] Description

[0002] Measuring unit and charging device

[0003] The invention relates to a measuring unit and a charging device.

[0004] Electric vehicles can be charged inductively with electrical energy. For this purpose, the electric vehicle comprises a secondary coil which can be inductively coupled to a primary coil of a charging station. The primary coil is usually located in the floor of a charging station so that the electric vehicle can be positioned with the secondary coil above the primary coil. The secondary coil is expediently located on the underbody of the electric vehicle, particularly in the area of ​​the front axle. For inductive charging, the primary and secondary coils must be positioned one above the other as precisely as possible. The positioning tolerance is a few centimeters in the direction of travel of the electric vehicle and in the direction perpendicular to it and parallel to the ground. The maximum angle of rotation around the vertical axis is only a few degrees. It is correspondingly difficult to position the electric vehicle appropriately for inductive charging.

[0005] On the one hand, a method for determining the arrangement of the electric vehicle relative to the charging station is helpful in supporting an electric vehicle driver when approaching a position suitable for inductive charging of the electric vehicle. On the other hand, determining the arrangement of the electric vehicle relative to the charging station is also safety-relevant, since charging can only be enabled—i.e., permission to activate the charging field of the primary coil—if the secondary coil is located within a defined tolerance range above the primary coil. Furthermore, optimal energy flow is only guaranteed if the primary and secondary coils are optimally aligned with one another.To determine the arrangement of the electric vehicle relative to the charging station, it is known to transmit an alternating magnetic field using a transmitting device arranged on the electric vehicle. This alternating magnetic field is received at the location of the charging station and can be used to determine the arrangement, see, for example, US 2016 / 0089997 A1. However, the reliability and accuracy of determining the arrangement are still not satisfactory.

[0006] It is therefore an object of the invention to provide a measuring unit and a charging device with which a positioning of a primary coil of a charging unit with a secondary coil of an electric vehicle can be improved.

[0007] This object is achieved by the independent claims. Further developments of the invention can be found in the dependent claims.

[0008] The invention relates to a measuring unit with at least one first primary positioning sensor and a connecting means for use for positioning a primary coil of a charging unit and a secondary coil of an electric vehicle, in which the measuring unit is designed such that it can be firmly connected to the charging unit by means of the connecting means and the at least one first primary positioning sensor is designed to communicate wirelessly with at least one secondary positioning sensor of the electric vehicle during positioning.

[0009] This measuring unit has the advantage that it is arranged spatially separated from the primary coil, thereby enabling the primary coil to be positioned relative to the secondary coil in a reliable manner. For example, electromagnetic waves used for positioning are not disturbed, or only slightly disturbed, by the spatially separated arrangement of the at least one first primary positioning sensor by the primary coil. The fixed connection of the measuring unit to the charging unit by means of the connecting means advantageously ensures that the spatial position of the at least one first primary positioning sensor relative to the primary coil is not changed, even in the event of external influences such as vandalism or displacement of the charging unit, so that positioning can be carried out extremely reliably and precisely, even in the event of external influences.

[0010] The term “firmly connectable” means that the measuring unit and the charging unit can be firmly connected to one another via the connecting means, for example by means of a screw connection, by plugging them together and / or by means of an adhesive bond. This term can also be understood to mean that once a connection has been established between the charging unit and the measuring unit, the two units are inseparably connected to one another. In addition, this term expresses that the connection firmly defines the spatial position of the charging unit in relation to the measuring unit or of the primary coil in relation to the at least one primary positioning sensor, and that the spatial position remains virtually unchanged even in the event of external influences, such as a displacement of the charging unit."Almost" means that a change in the distance between the center of the at least one first primary positioning sensor and the center of the primary coil is very small, e.g., a change of 0.2 cm is small compared to the distance of 100 cm before the displacement, and thus the spatial position is virtually unchanged. This property is important so that the determination of the position of the secondary coil relative to the primary coil, i.e., the positioning, can be carried out with sufficient accuracy, for example, to within a few millimeters.

[0011] The term "communicate" in the context of the application means that a respective primary positioning sensor can wirelessly transmit information as a transmitter, which can be received by a respective secondary positioning sensor and used to position the primary coil relative to the secondary coil. Alternatively, a respective secondary positioning sensor can serve as a transmitter and a respective primary positioning sensor as a receiver. The communication can be unidirectional or bidirectional. The information can be coded and transmitted in the form of electromagnetic waves. The information can also be coded and transmitted using WLAN (WLAN - Wireless Local LAN) and an IP protocol (IP - Internet Protocol) with a PTP according to IEEE1588 (PTP - Precision Time Protocol).

[0012] In a preferred development, the measuring unit is elongated, with the connecting means being arranged on a first side of the measuring unit and the first primary positioning sensor being arranged on a second side of the measuring unit opposite the first side. The elongated design of the measuring unit results in a greater distance between the primary coil and the at least one first positioning sensor, thereby reducing or avoiding interference from the coil, for example from its windings, during positioning. The elongated design also has the advantage of preventing the electric vehicle from driving over the measuring unit if the elongated design of the measuring unit is selected in the direction of travel of the electric vehicle. Thus, the elongated design of the measuring unit can also advantageously ensure the robustness of the measuring unit in practical use.

[0013] In a preferred development, the measuring unit is at least partially designed as a tube, in particular at least partially with a rectangular or round cross-section. Designing the measuring unit as a tube is advantageous because it allows the measuring unit to be manufactured and provided simply and cost-effectively using standard components. A tube that is hollow on the inside has the advantage that a power supply cable and / or wires for signal transmission from the at least one first primary positioning sensor can be guided in an orderly manner inside the tube and are also protected from damage, such as when driven over by an electric vehicle. A rectangular cross-section is advantageous because it gives the measuring unit a smooth side that can lie flat on a surface, and thus gives the measuring unit additional stability against slipping or displacement relative to the ground.A round cross-section of the pipe is also advantageous because it provides good protection against damage if the electric vehicle drives over the pipe, even if the material is thin. In an alternative development, the pipe can also have a cross-section such that it is round except for one point on its circumference and is flat at that point. This special development ensures that the round part of the pipe offers particularly good protection against damage and that the flat part of the pipe offers good protection against slipping or displacement when it is resting on the ground. The pipe can therefore also be made from one or more parts.For example, the tube is constructed in two parts, with a first part being flat and lying at least partially on a floor and being able to be fixed to the floor in particular by means of fastening means such as screws, and a second part of the tube being shaped as a round arch and being able to be connected to the first part by means of a closure means, for example by means of a snap connection with snap hooks. The tube can be hollow or filled on the inside. Furthermore, the tube can also have fastening means for connecting it to a cable of the charging unit, for example the tube has eyelets through which a cable tie is passed and pulled around the cable.

[0014] In a preferred embodiment of the measuring unit, a cable for supplying power to the primary coil is integrated into the tube. This refinement allows the measuring unit to protect the cable from damage. Furthermore, the measuring unit ensures a fixed, predefined local routing of the cable, thereby reducing potential damage to the cable caused by driving over it.

[0015] In a preferred embodiment, at least one of the first primary positioning sensors (Sil) can receive electrical energy for its operation (EK) by means of an electrical connection to the cable (EK). This results in a more cost-effective solution than using dedicated wiring.

[0016] In a preferred development, the measuring unit is Y-shaped or T-shaped, has the connecting means at one end of the Y / T and a respective first primary positioning sensor is arranged at a respective other end of the Y / T. This development enables cost-effective and reliable positioning when using two first primary positioning sensors. Furthermore, the specific geometric shape of the Y / T can provide additional protection against slipping or shifting of the measuring unit if it lies almost flat on the floor.

[0017] In a preferred further development, the charging unit has a cable for energy supply or signal exchange, which is led out of a housing of the charging unit, wherein

[0018] - the connecting means is designed such that the at least one first primary positioning sensor can be firmly connected to the cable (EK). This development has the advantage that the first primary positioning sensor can be firmly connected to the charging unit via its cable with little effort and / or very cost-effectively. With a charging unit power of 22 kW, for example, the diameter of the cable is several centimeters thick and therefore not very flexible. Even if the charging unit including the cable is moved, the location of the first primary sensor changes only slightly - if at all - so that positioning can be carried out with sufficiently high quality after the move. In this development, the first primary positioning sensor can be supplied with electrical energy, for example, by means of its own battery.The connection can be achieved by clamping, screwing, plugging, or gluing the at least one first primary positioning sensor. The connecting means can be implemented, for example, by a clamp, a screw, a pin, a clip, a Velcro strip, adhesive tape, or adhesive.

[0019] The invention further relates to a charging device for inductively charging an electric vehicle, with the charging unit and the measuring unit according to one of the preceding embodiments, in which the charging unit, in addition to the primary coil, further comprises at least one second primary positioning sensor which, together with the at least one first primary positioning sensor and the at least one secondary positioning sensor of the electric vehicle, carries out the positioning.

[0020] This preferred further development enables an improvement in positioning accuracy. This is based, among other things, on the fact that the second primary positioning sensors also have a fixed spatial position relative to the primary coil, so that a joint evaluation of measurement signals from the first primary positioning sensors and the second primary positioning sensors achieves the accuracy in determining the position of the primary coil relative to the secondary coil.

[0021] In a preferred development of the charging device, at least one of the second primary positioning sensors is arranged in the charging unit in such a way that a distance between the primary coil and the at least one first primary positioning sensor is smaller than a distance between the second primary positioning sensor and the at least one first primary positioning sensor. The second primary positioning sensor could in principle be attached at any point in or on or at the charging unit. To improve positioning, a distance between the primary sensors should be as large as possible. This development makes it possible for a distance of the at least one second primary positioning sensor from the first primary positioning sensor to be greater than the distance between the first primary positioning sensor and the primary coil.This improves the accuracy of positioning by the loading device.

[0022] In a preferred development of the charging device, the at least one first primary positioning sensor and the two second primary positioning sensors are arranged such that these sensors span an isosceles triangle, with a base formed by a distance between the two second primary positioning sensors.

[0023] This further development improves positioning further, since the selected geometric arrangement of the sensors ensures that the distance between the first primary sensor and a respective second primary sensor is the same, and is maximum in particular in a specific configuration of the measuring unit and the charging unit.

[0024] Furthermore, the advantages mentioned for the measuring unit also apply to the charging device. Within the scope of the application, a distance between a coil and / or one or more of the positioning sensors can be considered. This can be understood as determining the respective distance from / to a center of the respective positioning sensor or from / to a center of the respective coil.

[0025] The invention and its further developments are explained in more detail with the aid of drawings. In detail:

[0026] Fig. 1 A charging device with a measuring unit and a charging unit;

[0027] Fig. 2 A measuring unit; Fig. 3 An alternative embodiment of a measuring unit;

[0028] Fig. 4 A further alternative embodiment of a measuring unit;

[0029] Fig. 5 An optional embodiment of a measuring unit

[0030] Elements with the same function and effect are provided with the same reference symbols in the figures.

[0031] Figure 1 shows a charging device LAV according to an exemplary embodiment of the invention, toward which an electric vehicle EV drives (see arrow), in order to be able to inductively charge a battery of the electric vehicle. This charging device has a charging unit E1, which has a primary coil PSP for transferring energy to a secondary coil SSP of an electric vehicle EV. The primary coil can have several windings / layers. The first unit can cover an area of ​​50 cm x 50 cm on a floor and have a height of 10 cm.

[0032] The charging device LAV further comprises a measuring unit E2. In Figure 1, this is designed as a cable duct with a square cross-section, through which an electrical cable EK is routed to the charging unit E1, which supplies the primary coil with electrical energy. This electrical energy is then applied via a magnetic flux to a secondary coil SPS of the electric vehicle to charge the battery of the electric vehicle.

[0033] The measuring unit has a connecting means VEM which is suitable for firmly connecting the measuring unit E2 to the charging unit E1, for example designed as a screw or snap connection. Furthermore, the measuring unit has a first primary positioning sensor S11 near an end of the cable duct opposite the connecting means. In practice, the first primary positioning sensor can be arranged 0 to 10 cm from the end of the measuring unit. In addition to the first primary positioning sensor S11, the charging unit has second primary positioning sensors S21, S22. The primary positioning sensors can be arranged such that they form an isosceles triangle D with the primary positioning sensors at the triangle edges, wherein a distance between the two second primary positioning sensors S21, S22 forms the base of the triangle. The triangle D is shown in dashed lines in Figure 1.

[0034] The primary positioning sensors S 11, S 12, S21, S22 are designed to communicate wirelessly with secondary positioning sensors ES 1, ES2 installed in the electric vehicle. For example, the primary positioning sensors are designed as transmitters that emit electromagnetic waves at a frequency of 125 kHz. These electromagnetic waves are received by the secondary positioning sensors and, after evaluating one or more measurement signals, e.g. by means of propagation time measurements, a measurement of the field strength and field direction of the electromagnetic signal or field direction of the magnetic waves, the position of the secondary coil of the electric vehicle relative to the primary coil of the charging device is determined. This is referred to as positioning and is based, for example, on triangulation or a field model of the electromagnetic signal.This can be used to automatically guide or move the electric vehicle in such a way that the primary coil and the secondary coil can be positioned one above the other in such a way that a magnetic flux with low losses is enabled after the positioning is completed.

[0035] The position can be determined particularly well if the second primary positioning sensor in the second unit is arranged in such a way that it is not located below the electric vehicle, at least until the positioning of the primary coil and the secondary coil has been completed. For example, the center of the secondary coil is arranged 80 cm from the outside of the body of the electric vehicle, for example the bumper. Thus, with a distance of more than 80 cm between the first primary positioning sensor and the center of the primary coil SPS, the electromagnetic signal of the first primary positioning sensor is hardly or not at all disturbed by the vehicle.

[0036] Due to the fixed, i.e. fixed mechanical, connection of the measuring unit E1 with the loading unit E2 and a defined local position of the primary sensors, positioning can be carried out very precisely, since even external influences on the measuring unit and / or loading unit do not change the local position of the measuring unit in relation to the local position of the loading unit, since there is a fixed connection between the measuring unit and the loading unit.

[0037] In the exemplary embodiment shown in Figure 1, the primary positioning sensors are configured as transmitters and the secondary positioning sensors as receivers. Alternatively, the primary positioning sensors can be configured as receivers and the secondary positioning sensors as transmitters, or a combination of the two. Communication between the sensors can be achieved via electromagnetic signals, such as UWB (UWB - ultra wideband) or in the LE frequency range (LF - low frequency).

[0038] In addition to a single first primary positioning sensor, the measuring unit can have two or more first primary positioning sensors. The respective first primary positioning sensor can be integrated into the body of the measuring unit to protect it from contamination or damage and / or applied to an outer side of the body of the measuring unit. Since the charging device can lie on a surface, the first primary positioning sensor(s) is / are preferably not arranged on a side of the measuring unit facing the surface, but rather on a side of the measuring unit opposite the surface. Figure 2 shows the measuring unit E2 with the connecting means VEM designed as a plug-in device and a first primary positioning sensor S il. In this example, a body of the measuring unit is in the form of a tube, with an outer diameter of approximately 5 cm and an inner diameter of approximately 3 cm made of hard plastic.The first primary sensor S il can be connected to the charging unit El for energy supply via a cable (in Figure 2 arranged inside the measuring unit and therefore not shown graphically).

[0039] Figure 3 shows an alternative arrangement of the measuring unit E2 in the form of a "T". At the base of the "T" the connecting means VEM is arranged and at each of the two outer points of the "T" a first primary positioning sensor S 11 , S 12 .

[0040] Figure 4 shows a further alternative arrangement of the measuring unit E2 in the form of a "Y". At the base of the "Y" the connecting means VEM is arranged and at each of the two outer points of the "Y" a first primary positioning sensor S 11 , S 12 .

[0041] Figure 5 shows a further example of an optimal design of the measuring unit E2. In this case, a power supply cable EK is permanently connected to the charging unit EDI. The at least one first primary positioning sensor is permanently connected with a cable tie. The cable tie implements the connecting means in such a way that the cable tie is guided around the cable EK and is then pressed firmly onto the cable by means of the closure element associated with the cable tie. In this exemplary embodiment, the second measuring unit is preferably attached, for example, 50 cm to 100 cm from the charging unit. It is advantageous that the specific location of the first primary positioning sensor S il can be adapted to the electric vehicle. This first primary positioning sensor can be placed in such a way that if the primary coil and the secondary coil overlap, the first primary positioning sensor does not collapse under the electric vehicle.The measuring unit can be used in charging units and / or charging devices, for example, for electric vehicles used to transport people or goods. The electric vehicles can be controlled either by a person or autonomously. The electric vehicle can be designed as a transport robot in a factory or as a cleaning robot in a hospital.

Claims

Patent claims 1. Measuring unit (E2) with at least one first primary positioning sensor (Sil) and a connecting means (VEM) for use for positioning a primary coil (PSP) of a charging unit (El) and a secondary coil (SSP) of an electric vehicle (EV), wherein the measuring unit (E2) is designed in such a way that it can be permanently connected to the charging unit (El) by means of the connecting means (VEM) and wherein at least one first primary positioning sensor (Sil) is designed to communicate wirelessly with at least one secondary positioning sensor (ESI) of the electric vehicle (EV) during positioning.

2. Measuring unit (E2) according to claim 1, wherein the measuring unit (E2) is elongated, on a first side of the The measuring unit (E2) consists of the connecting element (VEM) and the first primary positioning sensor (Sil) on a second side of the measuring unit (E2) opposite the first side.

3. Measuring unit (E2) according to one of the preceding claims, wherein the measuring unit (E2) is at least partially designed as a tube, in particular at least partially with a rectangular or round cross-section.

4. Measuring unit (E2) according to claim 3, in which a cable (EK) for supplying energy to the primary coil (PSP) is integrated in the tube.

5. Measuring unit (E2) according to claim 4, in which at least one of the first primary positioning sensors (Sil) receives electrical energy for its operation (EK) by means of an electrical connection with the cable (EK).

6. Measuring unit (E2) according to one of the preceding claims, wherein the measuring unit (E2) is Y-shaped or T-shaped, the connecting means (VEM) at one end of the Y / T has a respective first primary positioning sensor (Sil, S12) located at a respective other end of the Y / T.

7. Measuring unit (E2) according to one of the preceding claims, wherein - the charging unit (E2) has a cable (EK) for power supply or signal exchange that is led out of a housing of the charging unit (E2), - the connecting element (VEM) is designed in such a way that the at least one first primary positioning sensor (Sil) can be firmly connected to the cable (EK), in particular by clamping, screwing, plugging or gluing.

8. Charging device (LAV) for inductive charging of an electric vehicle (EV) , comprising the charging unit (El) and the measuring unit (E2) according to one of claims 1 to 7, wherein the charging unit (El) further comprises at least one second primary positioning sensor (S21, S22) which, together with the at least one first primary positioning sensor (Sil) and the at least one secondary positioning sensor (ESI) of the electric vehicle (EV), performs the positioning .

9. Charging device (LAV) according to claim 8, wherein at least one of the second primary positioning sensors (S21) is arranged in the charging unit such that a distance between the primary coil (PSP) and the at least one first primary positioning sensor (Sil) is smaller than a distance between the second primary positioning sensor (S21) and the at least one first primary positioning sensor (Sil).

10. Charging device (LAV) according to one of claims 7 to 9, wherein the at least one first primary positioning sensor (Sil) and the two second primary positioning sensors (S21, S22) are arranged such that these sensors form an isosceles triangle with a base by creating a distance between the two second primary positioning sensors (S21, S22).

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