WO2018177930A1

WO2018177930A1 - Method and system for locating a mobile device, and mobile device

Info

Publication number: WO2018177930A1
Application number: PCT/EP2018/057449
Authority: WO
Inventors: Thomas Buck; Simon Schneider; Stefan Leidich; Matthias Kuehnel
Original assignee: Robert Bosch Gmbh
Priority date: 2017-03-29
Filing date: 2018-03-23
Publication date: 2018-10-04
Also published as: DE102017205271A1

Abstract

The invention relates to a method for locating a mobile device (1), said method comprising the following steps: transmitting ultrasound signals by means of a plurality of transmitting devices (21 to 23) arranged in a spatially distributed manner; determining a spectrum of the received ultrasound signals; and locating the mobile device (1) by comparing the determined spectrum with predefined map information, wherein the map information comprises an attribution of spectrum information to position information.

Description

description

Title Method and system for locating a mobile device and mobile device

The present invention relates to a method for locating a mobile device, in particular a smartphone, a mobile device and a system for

Localization of mobile devices.

State of the art

While outdoor navigation using GPS is now well established and can be performed with high accuracy, navigation within buildings still poses a major technical challenge, especially in multilevel

Buildings, GPS navigation is hardly possible. The signal strength is in

Generally too low and multiple reflections cause large deviations.

From the document US 2009/0154294 AI a method for localization is known, wherein ultrasonic signals are transmitted at different frequencies and based on a calculation of distances to the respective transmitters, the position of the receiver is determined.

Disclosure of the invention

The invention provides a method for locating a mobile device with the features of claim 1, a mobile device with the features of

Patent claim 9 and a system for localization of mobile devices with the features of claim 10 ready.

According to a first aspect, the invention accordingly relates to a method for

Localization of a mobile device. Ultrasonic signals are emitted by means of a plurality of spatially distributed transmitting devices and the

Ultrasound signals are received by the mobile device. A spectrum of the received ultrasound or the received ultrasound signals is determined and the mobile device is located by comparing the determined spectrum with predetermined map information. The map information includes an assignment of spectrum information to location information. According to a second aspect, the invention accordingly relates to a mobile device with a receiver device and a computing device. The receiver device is designed to receive ultrasound signals which are transmitted by a multiplicity of spatially distributed transmission devices. The

Computing device is adapted to a spectrum of the received

To determine ultrasound signals and the mobile device by comparing the determined

To localize spectrum with given map information, with the

Map information an assignment of spectrum information to

Include location information. Finally, the invention according to a third aspect relates to a system for

Localization of mobile devices, with a variety of spatially distributed

arranged transmitting devices, which are adapted to emit ultrasonic signals, and at least one mobile device, which is adapted to be located on the basis of the emitted ultrasonic signals.

Preferred embodiments are the subject of the respective subclaims. Advantages of the Invention The invention provides a means of locating a mobile device from an acoustic card. The spectrum depends heavily on the exact position of the mobile device, so that an accurate localization of the mobile device is possible based on an evaluation of the spectrum. In many buildings currently already installed loudspeakers are present, which provide an acoustic pilot tone in the

Send out ultrasonic range. Examples are hospitals,

Educational institutions, airports, industrial buildings, shopping centers or sports facilities. The localization according to the invention can therefore be implemented simply and without major additional costs since only an implementation of the comparison of the spectrum and the preparation of the map information are required. The ultrasonic signals of the transmitting devices make themselves through respective peaks in the corresponding Spectrum frequencies noticeable. The amplitude of the peaks depends strongly on the distance of the mobile device from the respective transmitting device, so that the exact shape of the spectrum makes it possible to determine the location coordinates of the mobile device. The distance of the mobile device from the corresponding one

Transmitter can be known.

According to a preferred embodiment of the method, a speed of the mobile device is further determined on the basis of a Doppler analysis of the determined spectrum. Due to a Doppler shift of the signals, the spectrum depends on the speed of the mobile device. Depending on the movement of the mobile device relative to the respective transmitting devices, the respective peak shifts in the spectrum of the received ultrasonic signals. By means of Doppler analysis, the respective speed can be determined relative to the transmitting devices, and based on the knowledge of the position of the transmitting devices, the speed of the mobile device can be determined in addition to the location coordinates of the mobile device.

According to a preferred embodiment of the method, the card information is determined by the ultrasonic signals are received by means of a reference microphone with a known position and known speed and using the ultrasonic signals received from the reference microphone, a reference spectrum is determined. The reference spectrum is determined by the known position and velocity of the

Assigned to reference microphones. The position and speed of the

Reference microphones can be determined as accurately as possible in a known manner, for example by means of laser distance measurements. Preferably, the

Reference microphone moves along a plurality of trajectories and / or at different speeds and determined at a plurality of location points a respective reference spectrum. A plurality of location points in a mapped area, for example in a building, are thus assigned reference spectra. In particular, the location points can be assigned reference spectra which correspond to different speeds. After this initialization phase, the map information thus generated is provided to the mobile devices. The speed here preferably denotes both a velocity vector and an amount of the velocity. The map information may be stored locally on the respective mobile device, but the mobile device may also be able to access the map information via a wireless network connection. By comparing the spectrum detected by the mobile device with the spectrum information of the map information, the exact position of the mobile device can be determined. In particular, the mobile device may be located at a particular location location, if the associated one

Reference spectrum has the largest matches with the determined by the mobile device spectrum.

According to a preferred development of the method, the emitted ultrasonic signals have essentially the same frequency. For example, the ultrasonic signals may have a frequency of 20 kHz. If the mobile device is at rest, the spectrum of the received ultrasound signals will essentially have an isolated peak at this frequency. Based on an amplitude of the peak, the position of the mobile device can be determined. Upon movement of the mobile device, the peak will split into several smaller peaks corresponding to the respective transmitting devices. The shift of the peaks in the spectrum relative to the frequency of the emitted ultrasonic signals depends on the respective relative speed of the mobile device to the corresponding transmitting device.

According to a preferred embodiment of the method, frequencies and / or amplitudes of the emitted ultrasonic signals differ for different

Transmitting devices at least partially. For example, in different parts of the building or in different spatial areas, the frequencies may differ. As a result, a rough localization of the mobile device is already possible based on the region of the spectrum in which there is a peak. The accuracy of the localization of the mobile device can be increased because, for example, only map information of the corresponding building part must be taken into account in order to locate the mobile device. The frequencies can either be shifted relative to one another statically or varied by means of frequency modulation or chirp.

According to a preferred embodiment of the method, the spectrum is analyzed before the comparison with the map information to the ultrasonic signals

different transmitter devices to identify and separate. In particular, can the spectrum is analyzed by means of a Fourier transformation or a wavelet transformation in order to determine the individual signals of the respective transmitting devices. Furthermore, frequency differences of individual peaks can be filtered out by means of a Doppler analysis in order to determine the relative speed of the mobile device to the transmitting devices.

Further, noise filtering of the spectrum detected by the mobile device may be performed to improve the comparison with the predetermined map information.

According to a preferred embodiment of the method, the comparison of the determined spectrum with the map information comprises the evaluation of frequencies and / or amplitudes of peaks of the spectrum. For example, based on the amplitudes of the respective distance of the mobile device to the corresponding

Transmitter devices are determined and based on the frequencies, a

Relative speed of the mobile device to the transmitting devices are determined.

According to a preferred development of the method, the comparison of the determined spectrum with the map information takes place by means of a neural network. The parameters of the neural network can be used in the initialization phase, i. H. during the

Creation of map information to be trained.

Preferably, when localizing the mobile device, a

Takes into account the localization history or acoustic history of the mobile device. Thus, the location history can be used to identify the position in which the mobile device was located in previous periods of time. The localization of the mobile device may be performed such that a location position of the mobile device is determined only at a predetermined distance from the last detected position and / or from a plurality of positions of the localization history.

Brief description of the drawings

Show it: Figure 1 is a schematic block diagram of a mobile device according to a

Embodiment of the invention;

Figure 2 is a schematic scenario for explaining a location of a mobile device according to an embodiment of the invention;

FIG. 3 shows a spectrum determined by a mobile device;

Figure 4 is a block diagram of a system for locating mobile

Devices; and

FIG. 5 shows a flow diagram of a method for localizing a mobile

Device.

In all figures, the same or functionally identical elements and devices are provided with the same reference numerals. The numbering of method steps is for the sake of clarity and generally should not imply a particular chronological order. In particular, several method steps can be carried out simultaneously. Various embodiments can be combined as desired, if appropriate.

Description of the embodiments

FIG. 1 illustrates a block diagram of a mobile device 1 according to an embodiment of the invention. The mobile device 1 comprises a receiver device 11, which is designed to receive the ultrasound signals. The mobile device 1 may be a smartphone, a laptop or a separate sensor device.

FIG. 2 shows a plan view of an exemplary scenario. In a floor of a building 4 are a plurality of rooms 41 to 46, wherein a plurality of spatially distributed transmitting devices 21 to 27 is arranged in the spaces 41 to 46. The transmitting devices 21 to 27 may be respective speakers which are adapted to output ultrasonic signals. Preferably, all transmitting devices 21 to 27 output an ultrasonic signal of a same frequency. However, the frequencies of the ultrasonic signals may also differ. The mobile device 1 now moves through the building 4 at a speed v. The received ultrasound results from a superimposition of the ultrasound signals of the transmission devices 21 to 27. The mobile device 1 further comprises a computing device 12, which determines a spectrum of the received ultrasound signals and locates the mobile device 1 by comparing the determined spectrum with predetermined map information. The

Map information may be stored on a memory of the mobile device 1. The mobile device 1 may also have a radio interface, wherein the

Map information stored on a server and the mobile device 1 are provided via the radio interface.

The map information includes an assignment of spectrum information to position information. For example, the location information may include an indication of a floor of a building as well as the exact coordinates within the building

Floor. The position information may also include two-dimensional or three-dimensional coordinates. The position information is associated with respective spectrum information, in particular each location point can be assigned at least one reference spectrum. The reference spectrum may have previously been created by means of a reference microphone and stored in the map information. The exact coordinates of the reference microphone are known and can be determined for example by means of laser measurements.

FIG. 3 illustrates an exemplary spectrum. The mobile device 1 moves at a speed v relative to three transmitting devices 21, 22, 23. The

Relative speed Vi, rei of the mobile device 1 to a respective transmitting device i is given by the following formula:

Vi, _re l = v · r, where r is the distance vector normalized to 1 from the mobile device 1 to the

Transmitter i denotes and v denotes the velocity vector of the mobile device 1. The positions of the transmitting devices 2 can be known here and, for example, also stored in the map information.

Due to the Doppler effect, the relative velocity Vi, _re i leads to a shift in the frequency of the emitted ultrasound signal. The shifted frequency f _lv is related to the originally transmitted frequency f according to the following formula: fi, fi = v ^■ (1 + v _iirel / c), where c is the speed of sound.

In the scenario illustrated in FIG. 3, all transmitting devices 2 emit a respective ultrasonic signal with a constant frequency of 20 kHz. Due to the Doppler shift, the receiver device 11 receives a superimposed one

Ultrasound signal with the spectrum illustrated in FIG. A first peak PI corresponds to the ultrasound signal emitted by a first transmitting device 21 and is red-shifted, d. H. shifted to a lower frequency of 19.5 kHz, as the mobile device 1 moves away from the first transmitting device 21. A second peak P2, corresponding to a second transmitting device 22, is at an unshifted

Frequency of 20 kHz, since the relative speed of the mobile device 1 along the link to the second transmitting device 22 is equal to zero. Finally, the spectrum has a third peak P3, which corresponds to a third transmission device 23 and is blue-shifted, d. H. shifted to a larger frequency of 20.5 kHz, as the mobile device 1 moves toward the third transmitting device 23.

The computing device 12 is designed to analyze the received ultrasonic signals by means of a wavelet transformation or a Fourier transformation and to extract the features generated by the Doppler effect. The extracted features, d. H. the frequencies of the peaks and / or the amplitudes of the peaks are compared with the

Map information, for example via multivariant data analysis. For matching, a neural network can also be used. Based on this comparison, the computing device 11 locates the mobile device 1. The coordinates of the mobile device 1 are hereby determined as those coordinates whose reference spectrum has the most matches with the spectrum determined by the mobile device 1. In particular, the features, d. H. the frequencies and / or the

Amplitudes of the peaks of the spectrum to be matched with features of the reference spectrum.

FIG. 4 illustrates a block diagram of a system 3 for locating mobile devices 1. The system 3 has a plurality of spatially distributed transmission devices 21 to 2n, which are designed to emit ultrasonic signals. The system 3 further comprises at least one mobile device 1, which is designed to locate itself on the basis of the emitted ultrasound signals. Each mobile device 1 has, as described above, a receiver device 11 for receiving the

Ultrasound signals, and a computing device 12 for locating the mobile device 1 on.

FIG. 5 illustrates a flow chart for explaining a method for localization of a mobile device 1.

In a first method step S 1, ultrasound signals are emitted by means of a multiplicity of spatially distributed transmission devices 2. The respective positions of the transmitting devices 2 are known in this case. In a method step S2, by means of a reference microphone with known

Position and speed receive the ultrasonic signals.

In a method step S3, a reference spectrum is determined on the basis of the ultrasonic signals received by the reference microphone.

In a method step S4, the reference spectrum is assigned the known position and the known speed of the reference microphone.

The reference microphone is moved along a trajectory and the method steps S2 to S4 are repeated so that respective points on the trajectory are assigned the corresponding reference spectra. Instead of the reference spectrum, it is also possible to assign certain features of the reference spectrum, in particular an amplitude and / or a frequency of peaks of the reference spectrum, to the known position and the known velocity. Preferably, the trajectories are traversed at different speeds, with the respective

Reference spectra in each case the speed of the reference microphone is assigned.

The reference spectra assigned to the respective positions form

Card information. Based on this map information, mobile devices 1 can be located in the following steps. In a fifth method step S5, the ultrasound signals are received by the mobile device 1 for this purpose. In a method step S6, a spectrum of the ultrasound signals received by the mobile device 1 is determined, wherein wavelet transforms or Fourier transformations can be performed to determine the spectrum.

In a method step S7, the mobile device 1 is localized by comparison of the determined spectrum with the map information generated in steps S2 to S4.

The comparison can be done using a neural network. Preferably, the comparison comprises the evaluation of frequencies and / or amplitudes of peaks of the determined spectrum with frequencies and / or amplitudes of the respective ones

Reference spectra. The comparison can be carried out by means of multivariable data analysis. The mobile device 1 is located where the corresponding one

Reference spectrum best matches the determined by the mobile device 1 spectrum.

For locating the mobile device 1, a location history of the mobile device 1 can be taken into account, i. h., the determined spectra of the last N

Time intervals, where N is between 5 and 100, for example. Since the mobile device 1 covers a continuous trajectory, the search space for the algorithm for comparing the determined spectrum with the predetermined map information can be limited. Larger local jumps are excluded and the spectrum determined by the mobile device 1 is merely compared with map information which corresponds to location coordinates in the vicinity of the hitherto determined trajectory of the mobile device 1. The size of the examined area may vary and depend on the particular application. For localization in buildings, the examined area may include, for example, all location points which lie at a predetermined distance of, for example, 10 m or 5 m around the respective determined location points of the last N time intervals.

Further, to localize the mobile device 1 additional

Localization methods are used, for example via a wireless network, via inertial sensors or beacons. This can already be a rough localization of the mobile device 1 can be performed and the examined area can be at locations a predetermined distance from that by means of the additional

Localization methods are limited to certain location point.

The localization can either be performed by the mobile device 1 itself or performed on a server connected to the mobile device 1 via a wireless interface.

Claims

claims

1. A method for locating a mobile device (1), comprising the steps of:

Emitting (S l) ultrasound signals by means of a plurality of spatially distributed transmitting means (21 to 27);

Receiving (S5) the ultrasonic signals by the mobile device (1);

Determining (S6) a spectrum of the received ultrasonic signals; and

Locating (S7) the mobile device (1) by comparing the determined

Spectrum with predetermined map information, with the

Map information an assignment of spectrum information to

Include location information.

2. The method of claim 1, further using a Doppler analysis of

determined spectrum a speed of the mobile device (1) is determined.

3. The method according to any one of claims 1 or 2, further comprising the step:

Determine the map information by using a reference microphone of known position and speed to receive the ultrasound signals (S2) and from those received from the reference microphone

Ultrasound signals a reference spectrum is determined (S3), which is assigned the known position and speed of the reference microphone (S4).

4. The method according to any one of the preceding claims, wherein the emitted ultrasonic signals have substantially the same frequency.

5. The method according to any one of claims 1 to 3, wherein frequencies and / or amplitudes of the emitted ultrasonic signals for different

At least partially distinguish transmitting devices (21 to 27). Method according to one of the preceding claims, wherein before the comparison with the card information for identifying the spectrum

Ultrasound signals of various transmitting devices (21 to 27) is analyzed.

Method according to one of the preceding claims, wherein the comparison of the determined spectrum with the map information, the evaluation of

Frequencies and / or amplitudes of peaks of the spectrum includes.

Method according to one of the preceding claims, wherein the comparison of the determined spectrum with the map information takes place by means of a neural network.

Mobile device (1), having a receiver device (11) which is designed to receive ultrasound signals which are emitted by a multiplicity of spatially distributed transmission devices (21 to 27); and a computing device (12) which is designed to determine a spectrum of the received ultrasound signals and to locate the mobile device (1) by comparison of the determined spectrum with predetermined map information, wherein the map information has an association of

Include spectrum information about position information.

System (3) for locating mobile devices (1), comprising a multiplicity of spatially distributed transmission devices (21 to 27), which are designed to emit ultrasonic signals; and at least one mobile device (1) according to claim 9, which is adapted to localize on the basis of the emitted ultrasonic signals.