DE102013215340A1 - Method and apparatus for wireless energy transmission for a moving object - Google Patents

Abstract

The invention relates to a method and a device (2) for wireless energy transmission for a moving object (4) at a predetermined breakpoint (H), comprising a relatively movable antenna arrangement (6, 8) with a holding point-side transmitting device (4) or alternatively a phase-shifting device (4). Array transmitting device (4), and with an object-side receiving device (8), and an energy store (20) and a control unit (10), wherein the control unit (10) at a stop of the object, a deviation (A) between an actual position (I ) and a desired position (H) of the antenna arrangement (6, 8) by means of the transmitting device (6) and receiving device (8), and based on the determined deviation (A), a repositioning of the transmitting device (6) starts, in which the actual position (I ) is corrected.

Description

The invention relates to a method and a device for wireless energy transmission for a moving object at a predetermined breakpoint.

In recent years, a steady increase of hybrid and electric vehicles in road and rail traffic is noticeable. These electric vehicles usually do not have a classic powertrain, which transmits the kinetic energy from the drive motor to the wheels. Instead, electric motors are arranged in the wheel hubs, which remove electrical energy from a vehicle-side energy storage.

There are a variety of methods for charging the onboard electrical energy storage known. Attractive in this context, inter alia, the possibility of wireless energy transfer from the track to the vehicle to charge, for example, the on-board energy storage electrically powered buses during the stop at a breakpoint with minimal manual effort. This makes it possible, for example, continue to realize rail systems without overhead line or third rail. An advantage here is also the elimination of the drive current feedback through the rail, which can lead to EMC and safety problems without corresponding additional effort (for example, for grounding measures).

For the purpose of wireless energy transmission from the track to the vehicle, inter alia, the energy transmission by means of high-frequency or optical radiation beam is possible. The radiation beams are hereby directed by a transmitting antenna to a receiving antenna of the vehicle. In this energy transmission method, a sufficiently precise positioning of transmitting and receiving antenna to each other is crucial for the achievable efficiency of energy transfer, and thus also for the efficiency of the charging process in the context of the commercial operational capability of such a loadable vehicle.

As an alternative method of wireless energy transmission, the method of inductive magnetic resonance coupling, which is less critical with regard to vehicle positioning, is known, the energy transmission efficiency thus achieved also being influenced by the quality of the antenna alignment.

In rail vehicles, for example, it is conceivable to use an induction loop which runs in parts of the fixed route or at stops in the ground. As a result, the necessary stopping accuracy is reduced and the problem of a complex repositioning of the vehicle avoided. However, this method requires relatively extensive and expensive installation work. Furthermore, there is a large area, which is penetrated by electromagnetic radiation. As a result, the radiation load of the environment increases, and thus for example also the risk of electromagnetic interference of other electrical systems.

The invention is therefore based on the object to enable a wireless energy transfer from the track to the vehicle under the boundary conditions of a limited positioning accuracy of the vehicle as little effort and efficiently.

This object is achieved by a method having the features of claim 1 and by a device having the features of claim 9. The object is achieved alternatively by a method having the features of claim 8 and by a device having the features of claim 12. Advantageous embodiments and further developments are the subject of the dependent claims. The features mentioned with regard to the method and preferred embodiments are to be transferred analogously to the device and the alternative embodiment.

According to the method, it is provided that for wireless energy transmission for a moving object at a predetermined stopping point following a stop of the object, a deviation between an actual position and a desired position is determined by means of a holder-side transmitting device and a vehicle-side receiving device. Based on this deviation, a repositioning of the transmitting device, wherein the actual position is corrected.

The device comprises, in particular, a relatively movable antenna arrangement with the transmitting device and the receiving device and a preferably holding point-side control unit, wherein the control unit is set up in terms of switching and / or programming technology to carry out the method. The device also expediently comprises an object-side energy store.

Under object is in particular a vehicle such as a rail vehicle or a bus to understand. The breakpoint is for example a stop of the vehicle.

The control unit is formed in an expedient embodiment, at least substantially by a microcontroller, in which a Procedure automatically implementing control program is implemented. Alternatively, the control unit can also be formed, for example, by an application-specific integrated circuit (ASIC).

By detecting the positional deviation and the repositioning of the antenna arrangement derived therefrom, the requirements for the positioning accuracy of the object or vehicle for wireless energy transmission are reduced in a simple and cost-effective manner. Preferably, during an approach of the object to the breakpoint, the transmitting device sends a breakpoint signal which is received by the receiving device. On the basis of the determined signal strength distribution of the emitted signals, the position deviation can be determined by the control unit, for example in the manner of a transit time measurement. The repositioning of the antenna arrangement further ensures a particularly high degree of efficiency for wireless energy transmission.

In order to ensure that the position deviation after the stop of the moving object is determined particularly accurately, the transmitting device is moved in an advantageous embodiment of the method for determining the deviation. The transmitting device is preferably moved in a plane in a preferred embodiment. In particular, during such a relative movement of the antenna arrangement, a signal value distribution is detected, from which the position deviation can be determined, in particular based on a maximum value.

For this purpose, in the device according to the invention, the holding point-side transmitting device is arranged above a possible stopping point of the object, for example on the underside of a roof construction or with a suspension on a stop mast, and can be moved two-dimensionally by an electric motor. Appropriately, the receiving device is arranged for this purpose, for example, at the top of the object.

As a result, a device which is as space-saving as possible and thus optically inconspicuous in existing structures can be realized. Due to the automatic repositioning, a reduction in the risk of EMC interference is still achieved. For this purpose, small antenna arrangements with a relatively high transmission frequency are used in an advantageous embodiment. A high energy transfer efficiency is made possible for example by a high directivity of the antenna arrangement. The comparatively small spatial transmission range of the highly directional antennas is easily compensated due to the repositioning, so that a high efficiency in the operation of the device is ensured.

In a suitable embodiment, the antenna arrangement is designed for energy transmission in the manner of an inductive magnetic resonance coupling, whereby as the reception device approaches the transmission device, damping of the transmission device caused by resonance takes place, or at least part of the radiated power is reflected back into the transmission device.

By evaluating the signal distribution of the attenuation of the transmitting device (for example, by recording the recorded current) or the reflected transmission energy (for example, by separation with a directional coupler) the actual position of the object with respect to the target breakpoint can be determined by the control unit. By a suitable signal evaluation, the control unit is preferably further suitable and configured to detect whether the object has reached a standstill. However, the standstill information can also be transferred in a different way from the object to the breakpoint.

In the case of a determined object standstill, the antenna arrangement can be brought into position by displacement in the plane, for example by means of stepper motors, in which a maximum attenuation, or a maximum reflected transmission power, occurs within the antenna arrangement. Due to the relatively movable arrangement of the antenna arrangement and the possibility of two-dimensionally moving the antenna arrangement by motors, in particular electric motors, in one plane, the detection of the signal distribution implements a control loop.

The automatic displacement of the transmitting device can be achieved by means of the control unit, for example by control circuits in the abscissa and ordinate, wherein the control unit evaluates the attenuated or reflected signal distribution as an input variable and generates a control signal for the displacement motors as manipulated variable.

Conventionally, the transmitting device and the receiving device are at approximately conventionally achieved position accuracy only approximately aligned with each other position. Due to the comparatively precise desired positioning of the transmitting device as a result of the movement, an accurate determination of the deviation of the transmitting location (actual position) of the transmitting device from the receiving location (target position) of the receiving device is made possible. By compared to the object typically much lower Mass of the transmitting device to be moved thus a particularly simple and inexpensive determination of the deviation is realized. The location accuracy in the determination of the deviation can be further increased by means of a suitable choice of the antenna sizes and / or antenna designs in conjunction with the selected frequency and other signal properties.

In a suitable development, the determined deviation is displayed to an object operator on a display unit. As a result, manual repositioning of the movable object is advantageously facilitated, for example, in the case of a position deviation that is too large (that is to say incalculable) by means of an object operator.

In a possible further development form, for example additionally or alternatively, the signal distribution is received by an object-side control unit and its reception level is displayed or evaluated. As a result, an object operator or the object-side control unit in the case of an autonomous object allows a repositioning of the antenna arrangement.

In an advantageous embodiment, the transmitting device has a number of adjacent (single) transmitting antennas, wherein the transmitting antennas are acted upon by a modulated radio signal. Under the modulated radio signal are generally controlled influences on the signal characteristics to suppress the signal interference and thus improve the signal-to-noise ratio, such as a modulation of the object reflected back from the object transmission signal.

In one possible embodiment of the invention, the transmitting device uses a so-called phased array antenna. In this case, the radiation behavior of the existing of a plurality of individual antennas phased array antenna is dynamically influenced by a suitable electrical control of the control unit. As a result, inter alia, the directional characteristic of the transmitting device can be changed, with the possibility of a suitable control, the possibility is possible to signal the environment of the transmitting device signal technology. On the basis of the data determined therefrom, it is possible by means of the control unit, for example, to select the transmission antenna which is most suitable for the energy transmission or to correspondingly control the phased array antenna. Furthermore, it is advantageous and easy to use transmit antennas with a particularly high directivity due to the large number of individual antennas. Due to the thus improved achievable positioning of the transmitting device, the deviation from the receiving device can be measured more accurately and thus can be better utilized to position the transmitting device as close as possible to the receiving device.

In a suitable alternative embodiment, the use of such a phased array antenna makes it possible to dispense with the mechanical repositioning of the transmitting device.

In a particularly advantageous embodiment of the method, the fact is used that the condition for a particularly efficient wireless energy transmission from the breakpoint to the object is ensured by the improved accuracy of the juxtaposition of the transmitting and receiving device. For this purpose, after a repositioning of the transmitting device, a charging process is started in which an energy signal suitable for energy transmission is impressed into the transmitting device. By a suitable frequency selection and antenna characteristics results in an efficient transfer of energy from the breakpoint to the object, where the energy is stored in the energy storage.

In the preferred application, the object is a rail vehicle which is coupled to a device according to the invention. As a result, an efficient charging of the energy storage at the designated breakpoint, for example, at a stop allows. For this purpose, the rail vehicle, for example, on the front side an antenna arrangement for receiving track-side induction signals as charging signals. In principle, however, the method and / or a corresponding device can also be used for a number of further applications in which an energy store of a moving object is to be charged wirelessly, for example in motor vehicles driven by an electric motor or in vehicles for industrial applications.

Embodiments of the invention will be explained in more detail with reference to a drawing. Show:

1 in side view, a rail vehicle after arriving in a range of a track side mounted transmitting device, and

2 in perspective the rail vehicle behind 1 .

1 simplifies the construction and operation of a device 2 for wireless energy transmission for a rail vehicle 4 at a breakpoint H with five trackside antennas A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ and A _m , in particular directional antennas, a transmitting device 6 The antennas (transmit antennas) A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ and A _m are provided with high-frequency, modulated induction signals S charged. The ideal for the energy transfer breakpoint H is in this embodiment, in particular under the antenna A _m .

One of the trackside transmitter 6 facing receiving antenna 8th as a receiving device is at the top of the rail vehicle 4 arranged. At an approach of the receiving antenna 8th to the transmitting device 6 At least in part, magnetic resonance attenuation of the transmitting antennas A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ and A _{m occurs} . The attenuation of the transmitting antennas A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ and A _m is the track side by means of a control unit 10 recorded and evaluated by a current measurement. The antennas of the transmitting device 6 continuously and wirelessly generate the induction signals S as short-range electromagnetic high frequency fields. The attenuation levels detected by different antennas A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ and A _m , which can be easily separated by frequency and modulation differences and with suitable directional characteristics of the antennas A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ and A _m generate significant waveforms are from the control unit 10 evaluated and as a distance equivalent and reference variable to approximate the transmitting device 10 to the receiving antenna 8th used.

On the basis of the registered attenuation intensity distribution or by comparison of the registered attenuation of the individual antennas A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ and A _m with the maximum value is by means of the control unit 10 the deviation A between an actual position P and a target position of the transmitting device 6 for the purpose of an ideal energy transfer determinable, in the illustrated embodiment, the target position is in particular the breakpoint H.

By evaluating the signal distribution of the damping of the transmitting device 6 is track side by means of the control unit 10 the position of the rail vehicle 4 determinable with respect to the breakpoint H. By means of a suitable signal evaluation is the control unit 10 continue to be suitable and set up to detect whether the rail vehicle 4 has reached a standstill.

At a stop of the rail vehicle 4 - Following an approach to the breakpoint H - is from the control unit 10 based on the attenuation distribution, the relative position between the transmitting device 6 and the receiving antenna 8th calculated. Based on the determined, existing deviation A sends the control unit 10 Control signals S _x and S _y to an adjustment table 12 ,

The sending device 6 includes the electric motor movable planar adjustment table 12 where the transmitting antennas A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ and A _m - as in 2 visible - are arranged. The adjustment table 12 is approximately rectangular, wherein in each case a transmitting antenna A ₁₁ , A ₁₂ , A ₂₁ and A _{22 is arranged} in one of the four corners and the approximately centrally arranged transmitting antenna A _m . The sending device 6 is approximately in the middle above the breakpoint H of the rail vehicle 4 , In particular arranged on the underside of a stop and electromotive two-dimensionally by means of two servo motors 14a and 14b displaceable. During a shift of the transmitting device 4 the attenuation of the transmitting antennas A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ and A _{m is} continuously from the control unit 10 evaluated. Based on the registered damping intensity, the servomotors become 14a and 14b controlled such that at least one transmitting antenna, preferably the transmitting antenna A _m , and the receiving antenna 8th face.

In an additional or alternative variant, instead of the individual antennas, a phased array antenna is used. During startup and stopping of the rail vehicle 2 For example, the transmission antennas A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ and A _{m are} first respectively supplied with induction signals S of low power and different electromagnetic properties. In the figures, only an induction signal is provided with a reference numeral for the purpose of an improved overview. Depending on the position in which the rail vehicle 4 in relation to the trackside transmitting device 6 comes to a standstill, there are different electrical conditions at the transmitting antennas A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ and A _m in relation to the attenuation of the radiated electrical induction signals S. Based on these differences can via a control circuit of the control unit 10 a control of the servomotors 14a and 14b for shifting the transmitting antennas A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ and A _{m are made} in the x and y direction in order to obtain the maximum possible attenuation of the centrally arranged antenna A _m .

The from the receiving antenna 8th Received signal strength of the induction signal S is by means of a display unit 16 for one operator 18 representable, so that a manual repositioning is facilitated in case of too large positional deviation under the transmitting antenna A _m . After positioning of the transmitting antenna A _m on the substantially opposite receiving antenna 8th the energy transfer is started. In this case, the charging energy transmitted by the induction signal S is stored in a vehicle-side energy store 20 deposited.

In a possible alternative embodiment, trackside and vehicle-side devices may be reversed, that is, the movable transmission device 4 or the phased array antenna and the associated control unit 10 are in the rail vehicle 4 integrated. This may be useful if the number of moving objects is small and no space problems with the rail vehicle 4 concerning the integration of the device.

The invention is not limited to the embodiments described above. On the contrary, other variants of the invention can be derived therefrom by the person skilled in the art without departing from the subject matter of the invention. In particular, furthermore, all individual features described in connection with the various exemplary embodiments can also be combined with one another in other ways, without departing from the subject matter of the invention.

LIST OF REFERENCE NUMBERS

2

contraption

4

track vehicle

6

transmitting device

8th

receiving antenna

10

control unit

12

adjustment table

14a, 14b

servomotor

16

display unit

18

operator

20

energy storage

A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ , A _m

antennas

H

halt

S

induction signal

A

deviation

I

Actual position

S _x , S _y

control signal

Claims (12)

Method for wireless energy transmission for a moving object ( 4 ) at a predetermined breakpoint (H), comprising a relatively movable antenna arrangement ( 6 . 8th ) with a holding point-side transmitting device ( 4 ) and with an object-side receiving device ( 8th ), as well as an energy store ( 20 ) and a control unit ( 10 ), the control unit ( 10 ) - at a stop of the object, a deviation (A) between an actual position (I) and a desired position (H) of the antenna arrangement ( 6 . 8th ) by means of the transmitting device ( 6 ) and receiving device ( 8th ), and - based on the determined deviation (A) a repositioning of the transmitting device ( 6 ) starts, in which the actual position (I) is corrected. A method according to claim 1, characterized in that for determining the deviation (A) the transmitting device ( 6 ) is moved. Method according to claim 2, characterized in that the transmitting device ( 6 ) is moved in a plane. Method according to one of claims 1 to 3, characterized in that during a relative movement of the antenna arrangement ( 6 . 8th ) a signal value distribution is detected from which, in particular by means of a maximum value, the deviation (A) is determined. Method according to one of claims 1 to 4, characterized in that the deviation (A) on an object-side display unit ( 16 ) is pictured. Method according to one of claims 1 to 5, characterized in that the transmitting device ( 6 ) has a number of adjacent transmitting antennas (A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ , A _m ) which are supplied with a modulated radio signal (I). Method according to one of claims 1 to 6, characterized in that after a repositioning a charging operation is started, in which a suitable energy transfer energy signal (I) from the transmitting device ( 6 ) to the receiving device ( 8th ), and the charge energy transferred thereby in the energy store ( 20 ) of the object ( 4 ) is deposited. Method for wireless energy transmission for a moving object ( 4 ) at a predetermined breakpoint (H), comprising an antenna arrangement ( 6 . 8th ) with a holding-point-side phased array transmitting device ( 4 ) and with an object-side receiving device ( 8th ), as well as an energy store ( 20 ) and a control unit ( 10 ), the control unit ( 10 ) - at a stop of the object, a deviation (A) between an actual position (I) and a desired position (H) of the antenna arrangement ( 6 . 8th ) by means of the phased array transmission device ( 6 ) and receiving device ( 8th ), and - based on the determined deviation (A) a repositioning of the transmitting device ( 6 ) starts, in which the actual position (I) is corrected. Contraption ( 2 ) for wireless energy transmission for a moving object ( 4 ) at a predetermined breakpoint (H), comprising a relatively movable antenna arrangement ( 6 . 8th ) with a holding point-side transmitting device ( 6 ) and with an object-side receiving device ( 8th ), as well as an energy store ( 20 ) and a control unit ( 10 ) for determining a deviation (A) between an actual position (I) and a desired position (H) of the antenna arrangement ( 6 . 8th ) after a stop of the object ( 4 ) for a subsequent repositioning of the antenna arrangement ( 6 . 8th ). Contraption ( 2 ) according to claim 9, characterized in that the transmitting device ( 6 ) is arranged on the underside of a roof of the holding point (H) and is two-dimensionally movable by an electric motor. Contraption ( 2 ) according to claim 9 or 10, characterized in that the transmitting device ( 6 ) comprises a number of adjacent transmitting antennas (A ₁₁ , A ₁₂ , A ₂₁ , A ₂₂ , A _m ) which are subjected to a modulated radio signal (I). Contraption ( 2 ) for wireless energy transmission for a moving object ( 4 ) at a predetermined breakpoint (H), comprising an antenna arrangement ( 6 . 8th ) with a holding-point-side pased array transmitting device ( 6 ) and with an object-side receiving device ( 8th ), as well as an energy store ( 20 ) and a control unit ( 10 ) for determining a deviation (A) between an actual position (I) and a desired position (H) of the antenna arrangement ( 6 . 8th ) after a stop of the object ( 4 ) for a subsequent repositioning of the antenna arrangement ( 6 . 8th ).

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