EP3397988A1

EP3397988A1 - Position-determining device

Info

Publication number: EP3397988A1
Application number: EP16825767.3A
Authority: EP
Inventors: Andreas Diewald
Original assignee: IEE International Electronics and Engineering SA
Current assignee: IEE International Electronics and Engineering SA
Priority date: 2015-12-31
Filing date: 2016-12-22
Publication date: 2018-11-07
Also published as: CN108474847A; WO2017114762A1; CN108474847B; US20190011546A1; DE102016119484A1; US11112496B2

Abstract

The invention relates to a position-determining device (1) for determining a position of an object (O1, O2) in relation to the position-measuring device (1), wherein the position-determining device (1) comprises: a transmitter (SE1) at a first location (X1), a receiver (EE2) at a second location (X2), wherein the receiver (EE2) is configured for receiving a transmission signal (SS1) from the first transmitter (SE1) and for determining a runtime (L) of the transmission signal (SS1) from the transmitter (SE1) to the object (O1, O2) and from the object (O1, O2) to the receiver (EE2), wherein the first location (X1) and the second location (X2) have a distance (D) from each other and the position-determining device (1) is configured to determine an ellipse (E) from the runtime (L), on which the object (O1, O2) lies, and which has the first location (X1) and the second location (X2) as focal points.

Description

Position-determining device

This invention relates to a position detecting device for detecting a position of an object with respect to the position measuring device, wherein the position detecting device comprises a transmitting device at a first location and a receiving device at a second location. The receiving device is set up to receive a transmission signal from the first transmission device and to determine a transit time of the transmission signal from the transmission device to the object and from the object to the reception device. Furthermore, the invention relates to a method for determining the position of an object.

In the prior art, it has long been known to detect an object by means of a Radarabstandsmesseinnchtung and to determine the distance between the object and the Radarabstandsmesseinnchtung from the duration of a signal from the Radarabstandsmesserecht to the object and back to Radarabstandsmesseinnchtung. This is possible with a single antenna used for transmission and reception. A distance can also be determined by sending and receiving a continuous wave signal with a frequency modulation.

A speed of an object can be measured from time series measurements and / or by the Doppler effect. It is possible to differentiate different objects by their different speeds, unless they are not equally fast with respect to the Radarabstandsmesserechtung. Figure 1A shows schematically this prior art.

From a receiver and transmitter RuT radar pulses are emitted to the objects O1 and O2, which are shown as black filled circles, the object O2 is also shown with a black circle around the periphery.

Under a pulse in this patent application, a signal change in the waveform understood, for example, a peak, a rectangular or delta waveform o- a sine half-wave or an approximation thereto or a differently shaped rising and falling or decreasing and increasing amplitude change in waveform. A pulse can have one, but also several related include signal drops. Compared to the duration of the total signal, the duration of the pulse is short.

The objects 01 and 02 have the distances R1 and R2 from the receiver and transmitter RuT. The receiver and transmitter RuT is controlled by an electronic control unit ECU, which also receives the received signals.

Figure 1 B shows in a graph of amplitude values A over the term the signals that are received again after sending a pulse from the same antenna and the information about the distance R of the objects 01 and 02 of the receiver and transmitter RuT included , Different distances of objects can be assigned to different received pulses.

In many cases, it is desirable to know the angular position of an object with respect to the radar distance measuring device. With the variant shown in FIG. 1A, this is possible, for example, by rotation of the antenna. In the prior art, the monopulse method is known (also called the Angle-of-Arrival or Direction-of-Arrival method, in which two antennas with a constant and superimposed emission and reception area are used to detect the angular position of an object to each other at a distance D. Usually, this distance D is half a wavelength, that is, at 24 GHz about 6.25 mm.

Both antennas transmit at the same frequency. The received signals both antennas are mixed down coherently with the transmission signal. Thus, the phase delays of both received signals can be measured, from which the direction of incidence of the reflected wave can be determined. This is included in the phase difference ΔΦ between the pulses of the same object, each received by an antenna. The angle of incidence α can be calculated as follows:

ΔΦ ^■ c _Q

sin a = -

ω ^■ a

where c _{0 is} the speed of light and ω is the angular velocity of the transmission frequency.

In Figure 2A, the structure of such a system is shown. There are only slight differences in construction compared to the variant shown in Figure 1 A. The same features are designated by like reference numerals and will not be described again separately. As already mentioned, the receiver and transmitter RuT comprises two antennas TX1 and TX2. Figure 2B shows two diagrams with signals received at the antenna TX1 and TX2, respectively. In each case, the amplitude A of the reflected signal over the distance R is shown.

[001 1] If multiple objects are to be tracked with such a system, the objects must be separated from each other to use this method so that the phase shift between reflected signals from the same object can be determined. However, there are situations where objects can not be uniquely separated using this technique. If, for example, several objects are located at the same distance when measuring a static scene, then one direction can not be determined because the pulses are superimposed on one another during reception. Therefore, a determination of the angular position of several objects with the monopulse method is not possible in every situation. In order to achieve a reliable resolution in the angular direction, beam-pivoting methods or even digital beam-forming methods with a large number of antennas are possible.

Another way to determine distance and angle provides the trilateration method. In this case, two antennas are used, which are each fed by a separate oscillator. Preferably, such an oscillator operates at a very stable frequency. The oscillators are not synchronized with each other. They can run on different frequencies so as not to disturb each other. Compared to the monopulse method, the antennas preferably have a greater distance D from each other. In this way, a smaller error in the angle calculation is possible.

FIG. 3A shows the structure of a measuring device which uses the trilateration method. Same features have the same numbers and will not be described separately again. The angle a lies between a central emission direction of the receiver-and-transmitter unit RuT1 and the angle direction to the object O1, while the angle β lies between a central emission direction of the receiver-and-transmitter unit RuT1 and the angle direction to the object O1 , Due to the different angles .alpha. And .beta., Different distances R1 and R2 result between the receiver-and-transmitter units RuT1 and RuT2 and the object O1, and thus also different distances. different durations of the reflected pulses in the received signals. The receiver-and-transmitter units RuT1 and RuT2 are located at the locations X1 and X2 and have the distance D from one another. The receive signals of the receiver-and-transmitter units RuT1 and RuT2 are shown in FIG. 3B ,

The angle α can be calculated from the triangle of R1, R2 and D as follows: d R1 R2 ²

sin a = 1

2 - R1 2 - D 2 - D - R1

The angle β can be calculated as follows: d R2 Rl ²

S ^m ^ ^~ 2 - R2 ⁺ 2 ^~ D ^~ 2 - O - R2

Again, a unique identification of the object must take place before the angle determination, so that it is certain that the routes R1 and R2 belong to the same object. However, as with the monopulse method, there are also constellations in such a trilateration method in which unambiguous assignment is not possible. Such a constellation is shown in FIG. 4A. Here, the object O1 has the distance R1 'to the receiver-and-transmitter unit RuT1 and the object O2 the distance R2 "to the receiver-and-transmitter unit RuT2, wherein the distances R1' and R2" are equal. In addition, the object O2 has the distance R1 "to the receiver-and-transmitter unit RuT1 and the object O2 the distance R2 'to the receiver and transmitter unit RuT2, wherein the distances R1" and R2' are also equal , Within this situation, the objects O1 and O2 can indeed be distinguished from one another; however, their position is by no means unique, as shown by a comparison with the constellation shown in FIG. 5A. In FIG. 5A, the same distances R1 'and R1 "lie between the object 01 and the receiver-and-transmitter unit RuT1 and the same distances R2' and R2" between the object 02 and the receiver-and-transmitter unit RuT2 as in Figure 4A. It can be deduced that N clearly identifiable objects N! (Faculty of N) Possibilities of assignment exist. However, not all conceivable positions of two objects are ambiguous with respect to a trilateration measuring device. Description of the invention

It is proposed independently of the invention presented below as an independent invention to track the positions of the objects and to derive in an ambiguous constellation of previous positions, which of the possible constellations is the true. It uses the fact that objects are always on an uninterrupted trajectory. In this case, the position determination is preferably carried out so frequently that it is not to be expected that more than one possible constellation will be passed through within a period of time between two position determinations.

Alternatively, the subject of the invention is a position determining device for determining a position of an object with respect to a position measuring device.

In particular, the position determination device is suitable for assigning a received signal to a specific object. As a result, in the presence of a plurality of objects, the correct ones can be determined from a plurality of, in particular two, possible position constellations for the objects, in particular for two objects. For this purpose, the position detection device comprises a transmitting device at a first location and a receiving device at a second location. The receiving device is configured to receive a transmission signal from the first transmission device and to determine a transit time of the transmission signal from the transmission device to the object and from the object to the reception device. According to the invention, the first location and the second location have a distance from one another and the position determination device is set up to determine an ellipse from the transit time on which the object lies. If measured in three dimensions, an ellipsoid can also be determined.

The delay can be determined by known methods, for example, with phase comparison between the transmission signal and received signal, modulation of the transmission signal and mixing a received signal with a signal for down-mixing and extracting the delay information, interferometry, encoding the transmission time in the transmission signal and comparison with the reception time and other methods known in length measurement. The method can be carried out, for example, optically, with ultrasound or preferably with electromagnetic radio waves, in particular radar waves. The position detection device or a corresponding method provides a position of the object. This can be determined from the entire travel path of the transmission signal from the transmitter to an object and from there to the receiver, which is arranged at a location other than the transmitter. In this case, the distance or the positions of the transmitter and the receiver can be included. If this distance is fixed, the distance can be entered by embedding it in an algorithm or in hardware implemented signal processing steps that determines the ellipse from the runtime. A position of an object lies on an ellipse, which has as focal points the transmitter and the receiver. If the distance from the transmitter via the object to the receiver, which is located at another location, is determined from the transit time, the ellipse on which the object must lie can be determined.

It is clear to a person skilled in the art that it is not necessary to explicitly calculate in terms of distances, but other variables can also be used which contain the same information. An ellipse can be uniquely defined by two independent parameters, which is general knowledge in mathematics. For example, the distance from the transmitter and the receiver to one another and the determined distance from the transmitter via the object to the receiver can serve as these two parameters. If the distance between transmitter and receiver is constant with respect to each other, there is only one variable parameter that uniquely defines the ellipse. Thus, when the transmitter and receiver are fixed to each other, it is sufficient to determine the distance from the transmitter via the object to the receiver in order to determine on which ellipse the object is located. For example, a transmitting device and a receiving device at different locations on a vehicle during operation can be secured immovably to each other.

The position of the object on the ellipse can not be determined unambiguously on the basis of the two parameters of an ellipse because the connecting distance of the focal points over a point on the elliptic curve is the same for all points on the elliptic curve. This is a well-known property of an ellipse found in relevant textbooks of mathematics. Although the position of the object can not be determined unambiguously, it can be clearly determined on which ellipse it lies. Thus, objects found to be on a particular ellipse may be subject to objec- be distinguished on a different ellipse. In this way, for example, in a trilateration process, in a situation with an ambiguous constellation of several objects, one can distinguish which constellation is the real one.

These considerations can be extended out of the plane of an ellipse out into the three-dimensional, if not an ellipse, but an ellipsoid with the transmitting device and the receiving device is considered in the focal points. In principle, nothing changes in the above considerations. A plane with an ellipse can be defined for each object by its position on the ellipsoid surface and the two focal points.

Preferably, the first receiving device and the first transmitting device and / or the second receiving device and the second transmitting device are each combined to form a receiver-and-transmitter unit, in which the transmitting device and the receiving device are arranged at the same location. The same location should also apply if the transmitting device and the receiving device use separate antennas which are arranged close to one another, for example at a distance of less than 25 cm from one another, for example for position detection of objects in the vicinity of a Vehicle is a suitable value. In another variant, a single antenna of a receiver-and-transmitter unit may be provided for transmission and reception.

The method can be configured as a radar technique; However, it is also possible to use it for analog other non-contact distance measurements such as optical or acoustic measurement methods. The oscillators then correspond to light sources. Preferably, the transmission frequency is modulated.

The position detection device can also be operated with more than two transmitters and more than two receivers. Preferably, the number of transmitters corresponds to the number of receivers.

In one embodiment, the position determination device further comprises a first transmission device at the first location and a first reception device at the first location. These may be combined in a receiver-and-transmitter unit and separate or common antennas use. The first receiving device generates a first received signal from a transmission signal of a second transmitting device. The second transmitting device is arranged at a second location, on which a second receiving device is arranged. These can be combined in a receiver-and-transmitter unit and use separate or common antennas. The second receiving device generates a second received signal from a transmission signal of the first transmitting device. An illumination region of the first transmission device overlaps with an illumination region of the second transmission device, wherein an object is located in the overlap region during a position determination.

The first transmitting device transmits at a first transmitting frequency and the second transmitting device transmits at a second transmitting frequency, wherein the first transmitting frequency differs from the second transmitting frequency by a difference frequency. The first and second transmission frequencies are preferably frequency-modulated in the same way, so that the difference frequency remains constant. The modulation frequency and / or the difference frequency are preferably in the range between 1 kHz and 1 GHz, in which they can be processed with conventional electronics, if they are separated to determine a position of the transmission frequency. The transmission frequency is preferably higher than 1 GHz. Preferably, the first and the second transmission frequency is linearly frequency-modulated, in particular with repeating ramps. Alternatively or additionally, a phase modulation can also be carried out. The modulation may be, for example, a harmonic modulation of the first and the second transmission frequency or a modulation with a digital signal. Preferably, the difference frequency is kept very constant, for example by using a well-known in the art PLL circuit (Phased Locked Loop). Oscillators of the first and second transmitting means may be incoherent. The position determination device further comprises a first receiving device at the location of the first transmitting device for receiving signals from the second transmitting device and for generating a first received signal and a second receiving device at the location of the second transmitting device for receiving signals from the first transmitting device and for generating a second received signal. The frequency modulation of the first and the second transmission frequency preferably takes place in the same way. This has the advantage that the transit time information, which is preferably connected to the frequency modulation of the transmission frequency, is contained in the first and the second received signal alike, which can have advantages for the signal processing. For example, an average may be determined to increase accuracy.

The position detecting means further comprises a first received signal mixing means for mixing the first received signal with the first transmission signal to produce a first intermediate signal and a second reception signal mixing means for mixing the second reception signal with the second transmission signal to produce a second intermediate signal. Preferably, the first received signal mixing device is part of a receiver-and-transmitter unit, which also includes the first transmitting device and the first receiving device, in particular in the same housing. Analogously, the second received signal mixing device is preferably part of a receiver-and-transmitter unit, which also comprises the second transmitting device and the second receiving device, in particular in the same housing.

The mixture is a mixture of two signals which can be described by the following trigonometric theorem: cos (x) * cos y) = ^ (cos (x-y) + cos (x + y))

This shows that the result is a sum of two cosine functions. In the first term, the argument of the cosine function is a subtraction of the original arguments x and y. This term is called a subtractive mixed term. Analogously, the other term is called an additive mixed term in which the argument of the cosine function is an addition of the original arguments x and y.

The first transmission signal can be described by the following formulation:

SSl = co 2 - - fO {t) - t + l)

Where SS1 is the first transmit signal, f0 (t) is a time-modulated transmit frequency, and Φ1 is an associated first phase shift. The second transmission signal can be described by the following formulation:

SS2 = cos (2 · π ^■ (f0 (t) + Jf) - t + Φ2)

Where SS2 is the second transmit signal, Af is the difference frequency and Φ1 is an associated second phase shift.

The first received signal can be described by the following formulation:

ES \ = k \ \ - co ^ 2 - - fü (t) - {t - T \ \) + Φ \) + k \ 2 - co ^ 2 - π - {f ü {t) + Af) - { t - T \ \) + Φ2)

In this ES1 denote the first received signal, k1 1 a damping factor by the transmission from the first transmitting device to the first receiving device, k12 a damping factor by the transmission from the second transmitting device to the first receiving device, T1 1 a duration for the transmission of the first transmission device via an object to the first receiving device and T12 a transit time for the transmission from the second transmission device via an object to the first receiving device. The first term in the mixed term describes the part of the first received signal received by the first transmitting device located at the same location as the first receiving device, while the second term describes the part of the first receiving signal transmitted by the second transmitting device. which is arranged at a location other than the first receiving device is received.

The second received signal can be described by the following formulation:

ES2 = £ 21 · cos (2 · π ^■ f0 {t) ^■ {t - T21) + ΐ) + k22 ^■ cos (2 · π ^■ {f0 {t) + f) - (t - T2 l) + Φ2 )

In this ES2 denote the first received signal, k21 a damping factor by the transmission from the first transmitting device to the second receiving device, k22 a damping factor by the transmission from the second transmitting device to the second receiving device, T21 a transit time for the transmission from the first transmitting device to the second receiving device and T22 a transit time for the transmission from the second transmitting device to the second receiving device. The first term describes the part of the second received signal received from the first transmitting device connected to it The second term describes the part of the first received signal which is received by the second transmitting device, which is arranged at a location other than the first receiving device.

By applying the multiplicative mixture of the first received signal with the first transmission signal, the following formulation results for the subtractive mixing term of the first intermediate signal:

ZSlSMT = k ^ - cos (2 - ^ - / 0 (i) - ni) + Ä: - cos (2 - n - (f0 (t) + f) - T12 - 2 - n ^■ Af - t + ΦΙ - Φΐ)

In it ZS1 SMT means the subtractive mixing term of the first intermediate signal. This includes two terms. Of these, the first is a quasidynamic term whose dynamics depends exclusively on the modulation of the transmission frequency. In this term, information about the distance of the object to the first transmitting device is included, which is arranged at the same location as the first receiving device. This term is called first direct share. The second term is a dynamic term whose dynamics depend both on the modulation of the transmission frequency and directly on time as an argument of the cosine function. In this term, information about the transit time from the second transmitting device to the object and from there to the first receiving device is included. This term is called the first cross part.

By applying the multiplicative mixture of the second received signal with the second transmission signal, the following formulation results for the subtractive mixing term of the second intermediate signal:

ZS2SMT = * y * cos (2 * π ^■ fO (t) - T21 + 2 ^■ π ^■ Af ^■ t - 1 + Φ2) + fcy • cos (2 · π ^■ (f0 (t) + Af) - T22)

In this ZS2SMT means the subtractive mixing term of the second intermediate signal. This includes two terms. Of these, the second is a quasi-static term whose dynamic part depends exclusively on the modulation of the transmission frequency. In this term, information about the distance of the object to the second transmitting device is included, which is arranged at the same location as the second receiving device. This term is called second direct share. The first term, which receives the reception from the transmitting device at the whose location means receiving means is a dynamic term whose dynamics depend on both the modulation of the transmission frequency and on the difference frequency, which are both time-dependent quantities in the argument of the cosine function. In this term, information about the transit time from the first transmitting device to the object and from there to the second receiving device is included. This term is called the second cross part.

The subtractive mixing term of the first intermediate signal largely corresponds to the subtractive mixing term of the second intermediate signal. The difference frequency is present in the subtractive mixing term of both intermediate signals in each case in the dynamic term. These are the first and the second cross term. In the subtractive mixed term of the first intermediate signal, the difference frequency in the dynamic term is additionally present as a static offset in the argument of the cosine function. In the subtractive mixing term of the second intermediate signal, instead, the difference frequency is additionally present in the quasi-static term as a static offset in the argument of the cosine function. These two terms are the first and the second in the direct share. In general, the transit times T12 and T21 as well as the damping coefficients k12 and k21 correspond to one another, since in this respect it is generally not important in which direction the signal is traveling.

Further, the position detecting means in this embodiment comprises an intermediate signal mixing means for mixing the first intermediate signal with the second intermediate signal to generate an ellipse detection signal. Preferably, the intermediate signal mixing device is a central unit that can mix at least two, preferably more intermediate signals with each other. In a variant, it can be arranged outside the receiver-and-transmitter units, with intermediate signal connections to the participating receiver-and-transmitter units. Compared to the large number of possibly required intermediate signal connections between receiver and transmitter units, this solution can have advantages in design. In another variant, it is also conceivable that an intermediate signal mixing device is arranged in a receiver-and-transmitter unit or a plurality of intermediate signal mixing devices in a plurality of receiver-and-transmitter units. In this way, an additional unit is avoided. Zwischensignal- Connections between receiver and transmitter units are required.

Preferably, not the entire first intermediate signal and the entire second intermediate signal are mixed with each other, but only the respective cross parts of the subtractive intermediate signal mixing terms. These can be previously extracted from the intermediate signals. For this purpose, for example, a certain frequency range from the intermediate signal can be used.

The ellipse detection signal may be represented as the following additive term:

EES = - cos (2 · π ^■ (fO (t) + Af) ^■ Tl 2 + 2 ^■ π ^■ fO (t) ^■ T21)

8th

The ellipse detection signal is denoted EES. If the ellipse detection signal is generated exclusively from the cross terms, this is the only term of the ellipse detection signal. In the ellipse detection signal, the information about the transit time is contained by a transmitting device at one location to the object and from there to a receiving device at another location in both directions. The ellipse detection signal comprises three terms in the argument of the cosine function. One of them, which includes the difference frequency, forms a phase term. The other two terms depend on the modulation of the transmission frequency.

Assuming that the transit times T12 and T21, ie the forward and reverse travel times, are the same and are referred to as T, the formulation of the ellipse determination signal can be simplified:

EES = ^{kU 'k21} - cos (2 - 2 - n - f0 (t) - T + 2 - n - Af - T)

8th

The transit time lies both in the phase term and in the dynamic term of the argument of the cosine function. Preferably, the frequency of the dynamic part is evaluated, since this advantageously allows good accuracy and is easy to evaluate.

Since the ellipse detection signal represents the sum of the distances from the transmitting device to the object and from the object to the receiving device, which is arranged at a location other than the transmitting device, and the distance between the transmitting devices of the receiving device is known and preferably fixed, a value of the ellipse detection signal can be unambiguously assigned to a specific ellipse.

In a further embodiment, the position detection device comprises a signal separator for separating or filtering a portion of a signal in the position detector to further process a desired portion of the signal. In principle, it is possible to filter out parts of the spectrum of signals in order to retain and further process desired signal parts, or to split a signal in order to continue processing the different parts obtained thereby. The different parts of a signal differ in particular in their frequency or their information content. This can also be applied here.

In particular, the position determining means may comprise a first low pass filter means for low pass filtering the first intermediate signal to obtain the subtractive mixing term of the first intermediate signal. Similarly, the position detecting means may comprise a second low-pass filter means for low-pass filtering the second intermediate signal to obtain the subtractive mixing term of the second intermediate signal. In this way, the high-frequency components of the transmission signal contained therein are hidden. As a filter, a passive component can be used, for example, a line or an RC element, which can not be passed by the high-frequency additive mixing term of the first and second intermediate signal. Then a lower bandwidth can be used in the further processing. In addition, the further processed subtractive mixing term contains the information sought in a suitable form.

Further, the position detecting means may comprise a signal separating means for the subtractive mixing term of the first and / or the second intermediate signal. The signal separation device can divide the subtractive mixing term of the first and / or the second intermediate signal into a direct component, in which the information about the transit time of a transmission signal from a location to a reflection on an object and back to the same location is contained, and a cross component in which the information about the transit time of a transmission signal at one location leads to a reflection at one object and further to another Place is included. The direct component and the cross component differ in their frequency and in that in the cross component in the cosine function the difference frequency has a product of the time and the limit frequency as an argument, while the direct component in the cosine function has the modulation of the transmission frequency as an argument as the only time-variable component Has. Thus, by defining the different frequencies of the difference frequency and the modulation of the transmission frequency, a separation by means of the signal separation device based on the frequency can be made possible.

Furthermore, it is possible in particular for the position determination device to comprise a signal separation device for the ellipse detection signal. As derived above, the ellipse detection signal comprises an additive and a subtractive mixing component. Preferably, the additive mixing component is further processed to determine the transit time. For this purpose, the additive mixing component can be extracted from the ellipse detection signal by means of a high-pass filter device functioning as a signal separation device by high-pass filtering the ellipse detection signal.

Alternatively, instead of separating the signals into a direct and cross component, the entire intermediate signal can also be processed. Through digitization and subsequent (inverse) Fourriertransformation to get both the direct component and the cross component in the frequency domain. The transformed cross component results in pulses that are shifted by the difference frequency delta f in the frequency domain. One must therefore generally ensure that the highest frequencies that result in the intrinsic proportion are much smaller than the difference frequency, so that in the frequency range both shares can be separated cleanly. Due to the larger frequency range of the direct and cross section, a higher sampling frequency must be maintained than if the direct component is used solely for position determination.

Preferably, the position determination device has an ellipse determination device for determining an ellipse, wherein the ellipse can be determined by means of the ellipse determination device from the frequency of an additive mixing component of the ellipse determination signal. The information about the ellipse is present in this proportion. The position determination device may include a thinning device or perform a trilateration. The position determination device can then receive a first trilateration received signal from the first transmitting device at the first receiving device and a second trilateration received signal from the second transmitting device at the second receiving device in order to use the floating device to determine a position of an object with respect to the first location and / or to determine the second place. This position can be determined from a total of four distance information of the two objects to the two mutually arranged transmitting and receiving stations. The Thalaterationseinrichtung is particularly adapted to perform the trilateration by means of a first direct component and a second direct component. The first direct component is taken from the first subtractive intermediate signal mixing term and / or the second direct component from the second subtractive intermediate signal mixing term. If the trilateration can not assign pulses in the received signals to certain objects, an ambiguous constellation can result.

In a further embodiment, a position of an object, which is determined in particular by means of the trilateration method, can be checked for plausibility. For this purpose, the position determining device can determine whether the position of the same object lies on an ellipse which is determined by the position-determining device for this object.

The ellipse detection signal contains in its time course for each object that is detected by the position detection device, a pulse. The time from the emission of a pulse from the transmitter to the pulse in the ellipse detection signal represents the distance from the transmitter of the pulse at one of the locations across the object to the receiver of the pulse in the ellipse detection signal located at the other location. From this distance, taking into account the distance of the transmitter from the receiver, the ellipse can be determined. The detected object lies on the ellipse. When two objects are detected, two pulses are produced in the ellipse detection signal when the two objects are on different ellipses. If the two objects are on an ellipse, a superimposed pulse is created. There may be constellations of the position information of the two objects based on the detection the objects are ambiguous by the receivers in the same place as the respective transmitter. Then, the measurements of the two receivers provide pulses of equal duration and it is not clear which pulse belongs to which object. Then the objects can be assigned unique positions by means of the information as to whether the objects lie on one or two ellipses.

Correspondingly, in another embodiment, the position determination means comprises a plausibility device, by means of which it is possible to determine whether a position of an object determined by the trilateration method lies on an ellipse which is derived from the ellipse detection signal. If this is the case, the position determination device determines that two objects are in an ambiguous constellation on the ellipse. If it is determined that an object is not on the ellipse, the position detection device may determine that two objects in an ambiguous constellation lie on a small half-axis of the ellipse or an extension thereof.

The proposed method, if there are more than two objects, may be performed multiple times with combinations of two objects. Preferably, the method is performed only when an upstream trilateration method determines that there is an ambiguous configuration.

The method for determining an ellipse on which an object is located can also be performed in order to increase the accuracy of the position determination. For this purpose, the position of the ellipse can be included in the calculation of the position of an object. In particular, the position error can be reduced by calculating an optimized position from positions which have been determined by means of trilateration and elliptical determination. For example, an average can be formed and / or the least squares method applied.

Preferably, a transmitter and a receiver are connected to a unit. With at least two such units, the position determination device according to the invention can be constructed.

It is proposed in a further aspect of the invention, a method which can be carried out by means of Positionermittlungseinnchtung. It comprises the above-mentioned features of the position determination device as method steps.

Description of the figures

In the appended figures, by way of example only, embodiments of the invention are shown in which:

Figure 1A shows schematically a radar distance measuring device in the measurement of two objects operating with a single antenna and frequency modulation,

FIG. 1B shows a diagram in which the amplitude of two pulses received by the objects are shown over the distance of the objects from the radar distance measuring device,

FIG. 2A schematically shows a radar distance measuring device with two antennas in the measurement of two objects which operates according to the monopulse method,

FIG. 2B shows two diagrams each belonging to one of the receivers and in which the amplitudes of two pulses each received by the two objects are shown over the distance of the objects from the radar distance measuring device;

FIG. 3A schematically shows a radar distance measuring device with two separate antennas in the measurement of an object which operates according to the trilateration method,

FIG. 3B shows two diagrams each belonging to one of the receivers and in which the amplitude of each one pulse received by the object is shown over the distance of the object from the radar distance measuring device;

FIG. 4A schematically shows the radar distance measuring device from FIG

Shows measurement of two objects that are in an ambiguous constellation,

Figure 4B shows two diagrams, each belonging to one of the receivers and in which the amplitudes of two pulses, that of the two Objects are shown above the distance of the objects from the radar distance measuring device,

FIG. 5A schematically shows the radar distance measuring device from FIG

Measure two objects that are in a different ambiguous constellation

FIG. 5B shows two diagrams each belonging to one of the receivers and in which the amplitudes of every two pulses received by the two objects are shown over the distance of the objects from the radar distance measuring device,

FIG. 6 schematically shows an ellipse, which was determined by means of the invention and on which two objects lie, as well as two further positions of an ambiguous constellation of two objects,

Figure 7 shows an arrangement of six position detecting devices according to the invention and their illumination areas on a vehicle, and

Figure 8 shows a first part of a schematic diagram in which

Process steps or signals and conversions of signals are shown and

Figure 9 shows a second part of the schematic diagram in which

Process steps or signals and conversions of signals are shown.

Description of preferred embodiments

FIG. 6 shows an ellipse E, which was calculated from the ellipse detection signal of the position determination device. The objects 01 and 02 lie on the ellipse. The positions of the objects 01 and 02 were determined beforehand by means of the temporal flattening method. The positions 01 and 02 shown are ambiguous due to the peculiarities of the temporalization process and could also be the positions of the virtual objects 01 'and 02'. However, the virtual objects 01 'and 02' do not lie on the ellipse E. Therefore, it can be excluded by means of the position detection device according to the invention that the positions of the virtual objects 01 'and 02' are real. FIG. 7 shows a passenger vehicle in plan view, on the circumference of which twelve receiver and transmitter units RuT1 to RuT12 are arranged. Each receiver-and-transmitter unit RuT1 to RuT12 comprises a transmitting device SE1, SE2 and a receiving device EE1, EE2, which are arranged at the same location. The transmitting devices SE1, SE2 and the receiving devices EE1, EE2 are shown in FIG. Each receiver-and-transmitter unit RuT1 to RuT12 has a triangular illumination area. Adjacent illumination areas of the receiver and transmitter units RuT1 to RuT12 overlap. In these overlapping regions, the position-determining device according to the invention can act.

The position detection device can be used for example as a parking radar. The opening angle of the illumination area is preferably 1 10 °. Preferably, the areas in which the illumination areas of individual transmitters do not overlap are narrow and preferably have a short length. Then, by means of the trilateration method and without the position-determining device, the position can be determined with good certainty. During a movement of the vehicle, the position of an object can be tracked, which can be legally performed to determine the position by means of the position determining device. It is also conceivable to apply the Synthetic Aperture Radar (SAR) method known from the prior art from a moving vehicle in areas in which the position-determining device can not act.

FIG. 8 shows a first part of a schematic diagram in which method steps or signals and conversions of signals are shown. In detail, a first transmission signal SS1 is transmitted from a first transmission device SE1, which is located at location X1, and a second transmission signal SS2 from a second transmission device SE2, which is located at location X2. The frequencies of the transmission signals SS1 and SS2 are each temporally modulated in time f0 (t) and differ from each other by a difference frequency Af. fO is referred to as the oscillator frequency, while the time dependence (t) describes the modulation of the oscillator frequency. Both transmit signals SS1, SS2 in each case hit one or in particular two objects O1, O2 and are reflected from there. FIG. 8 shows the propagation of the transmission signal SS1 in a solid line and the propagation of the transmission signal SS2 in a dashed line. For the sake of simplicity, only one object is shown in FIG. 8, which is designated 01, 02; however, the signal flow scheme shown in FIG. 8 applies individually for each object 01, 02. Shares of both transmit signals SS1 and SS2 are each reflected by each of the existing objects 01, 02 to a first receiving device EE1 and to a second receiving device EE2. The first transmitting device SE1 and the first receiving device EE1 are located at the same first location X1, while the second transmitting device SE2 and the second receiving device EE2 are located at the same second location X2, which is spatially different from the first location. The locations X1 and X2 have a distance D from each other. The transmission device SE1 and the reception device EE1 can use the same antenna and are then referred to as a receiver-and-transmitter unit RuT1. Likewise, the transmitting device SE2 and the receiving device EE2 can use the same antenna and are then referred to as receiver-and-transmitter unit RuT2. Symbolically, a term L is shown as a dot-dashed arrow. This transit time L denotes all transit times of signals which run from one of the transmitting devices SE1, SE2 to one of the receiving devices EE1, EE2, independently of their path and independently of the symbolically represented curve in FIG. 8.

Superimposed on the receiving devices EE1, EE2, the first transmission signal and the second transmission signal are received by one or two different objects 01, 02. The first receiving device EE1 generates a first received signal ES1 and the second receiving device generates a second received signal ES2. The first received signal ES1 is mixed in a first received signal mixing device EM1 with the oscillator frequency f0 (t) of the first transmission signal SS1. This results in the first intermediate signal ZS1. The second received signal ES2 is mixed in a second received signal mixing device EM2 with the oscillator frequency fO (t) + Af of the second transmission signal SS2. This results in the second intermediate signal ZS2. FIG. 9 shows a second part of the schematic diagram in FIG. 8. FIG. 9 shows process steps for processing the first and the second intermediate signal ZS1, ZS2.

The first intermediate signal ZS1 is low-pass filtered in a first intermediate signal low-pass filter device TPF1, resulting in a first subtractive intermediate signal mixing term SMT1. In parallel, the second intermediate signal ZS2 is low-pass filtered in a second intermediate signal low-pass filter device TPF2, resulting in a second subtractive intermediate signal mixing term SMT2. The subtractive intermediate signal mixing terms SMT1, SMT2 each comprise a portion of the respective associated intermediate signal ZS1, ZS2 whose frequency results from a subtraction of the received frequencies and the oscillator frequency, so that the subtractive intermediate signal mixing terms SMT1, SMT2 the respective modulation frequencies of the transmission signals SS1, SS2 of Figure 8 included.

Each receiving device EE1 or EE2 receives two different transmission signals SS1 and SS2 from two transmitting devices SE1 and SE2, which are located at different locations. Therefore, in each of the subtractive intermediate signal mixing terms SMT1 and SMT2 there is a respective portion which originates from the transmitting device SE1 or SE2, which is located at the same location as the considered receiving device SE1 or SE2. This proportion is called first or second direct share DA1 or DA2. In addition, the subtractive intermediate signal mixing terms SMT1 and SMT2 each comprise a further component, which originates from a transmitting device SE1 or SE2, which is not located at the location of the receiving device EE1 or EE2. This component is called first or second cross component KA1 or KA2, the numbering being based on the corresponding receiving device EE1 or EE2. In a first intermediate signal separating device ZTE1, the first direct component DA1 can be separated from the first cross component KA1. Accordingly, in a second intermediate signal separating device ZTE2, the second direct component DA2 can be separated from the second cross component KA2.

The objects O1 and O2 appear in each case as pulses in the received signals ES1 and ES2, the intermediate signals ZS1 and ZS2, the subtractive intermediate signal mixing terms SMT1 and SMT2 and the direct shares DA1 and DA2 and the cross shares KA1 and KA2. The temporal position of the pulses contains the information about the distances of the objects 01 and 02 from the first and the second location. Therefore, it is possible to perform a trilateration T with the first and second direct components DA1 and DA2. Since this can lead to ambiguity when measuring two objects, the first and second cross parts KA1 and KA2 can be used to resolve such ambiguities.

The signal propagation times, which represent the pulses in the cross parts KA1 and KA2, correspond to the distance of the transmitting transmitting device SE1 or SE2 to the object 01, 02, which generates the pulse, and from there to the receiving device EE2 or EE1, which adjoin another location than the transmitting device SE1 or SE2. With this information and the distance between the two locations, an ellipse can be defined on which the relevant object 01, 02, which generated the pulse, is located. In order to generate from the two cross parts KA1 and KA2 a single signal as a precursor for determining the ellipse, namely the ellipse detection signal EES, the first cross part KA1 and the second cross part KA2 are fed into a cross-share mixing device KME. In this case, the original modulation of the oscillator signal in the transmission signals SS1 and SS2 is eliminated. The information for determining the ellipse is present in a high-frequency portion of the ellipse detection signal EES, which results when mixing the first and second cross portion KA1 and KA2 as a proportion in which the frequencies of the first and second cross portion KA1 and KA2 are added. In order to extract from this mixing additive component AME of the ellipse determination signal EES from the complete ellipse determination signal EES, the ellipse determination signal EES is fed to an ellipse detection signal high-pass filter device HPF.

Claims

Position determining device (1) for determining a position of an object (01, 02) in relation to the position-measuring device (1), wherein the position-determining device (1) comprises:

a transmitting device (SE1) at a first location (X1),

a receiving device (EE2) at a second location (X2),

wherein the receiving device (EE2) is set up

- For the reception of a transmission signal (SS1) from the first transmitting device (SE1) and

for determining a transit time (L) of the transmission signal (SS1) from the transmitting device (SE1) to the object (01, 02) and from the object (01, 02) to the receiving device (EE2),

characterized in that the first location (X1) and the second location (X2) from each other have a distance (D) and the position determining means (1) is adapted to determine from the running time (L) an ellipse (E) on the the object (01, 02) is located and has the first location (X1) and the second location (X2) as focal points.

Position-determining device (1) according to claim 1, characterized in that the position-determining device (1) comprises the following:

a first transmitting device (SE1) at the first location (X1),

a first receiving device (EE1) at the first location (X1) for generating a first received signal (ES1) from a transmission signal (SS2) of a second transmitting device (SE2),

a second transmitting device (SE2) at the second location (X2),

a second receiving device (EE2) at the second location (X2), for generating a second received signal (ES2) from a transmission signal (ES1) of the first transmitting device (SS1),

wherein an illumination region (A) of the first transmission device (SE1) overlaps with an illumination region (A) of the second transmission device (SE2),

wherein the first transmission device (SE1) for transmission with a first transmission frequency (fO) and the second transmission device (SE2) for transmission with a second transmission frequency (f0 + Af) is established, wherein the first transmission frequency (f0) differs from the second transmission frequency (f0 + Af) by a difference frequency (Af),

wherein the first transmission frequency (f0) and the second transmission frequency (f0 + Af) are modulated in the same way, wherein they are in particular frequency-modulated, phase-modulated and / or amplitude-modulated, and

the position determining device (1) further comprises:

a first received signal mixing device (EM1) for mixing the first received signal (ES1) with the first transmitting frequency (f0) for generating a first intermediate signal (ZS1),

a second received signal mixing device (EM2) for mixing the second received signal (ES2) with the second transmitting frequency (f0 + Af) for generating a second intermediate signal (ZS2),

- An intermediate signal mixing means (KME) for mixing the first intermediate signal (ZS1) or a portion thereof with the second intermediate signal (ZS2) or a portion thereof for generating an ellipse detection signal (EES).

Position determining device (1) according to claim 2, characterized in that the intermediate signal comprises a direct component and a cross component, and that the entire intermediate signal is used for position determination, wherein the direct and cross components are separated from one another by a Fourier transformation.

A position detecting device (1) according to claim 2, characterized in that the position detecting means (1) further comprises: signal separating means for separating a portion of a signal in the position detecting means (1) from another portion of the signal to further process a desired portion of the signal; namely in particular

a first intermediate signal low-pass filter device (LPF1) for low-pass filtering of the first intermediate signal (ZS1) in order to obtain a first subtractive mixing term (SMT1) of the first intermediate signal (ZS1), and / or

- A second intermediate signal low-pass filter means (TPF2) for low-pass filtering of the second intermediate signal (ZS1) to a second subtractive Mixed term (SMT2) of the second intermediate signal (ZS2), and / or

- A first intermediate signal separating means (ZTE1) for removing a first cross portion (KA1) from the first subtractive mixing term (SMT1) of the first intermediate signal (ZS1) and / or

- A second intermediate signal separating means (ZTE2) for removing a second cross portion (KA2) from the subtractive mixing component (SMT2) of the second intermediate signal (ZS2) and / or

a high pass filter means (HPF) for high pass filtering the ellipse detection signal (EES) to extract the additive mixing component (AME) for further processing from the ellipse detection signal (EES).

Position determining device (1) according to any one of claims 2 to 4, characterized in that the position determining means (1) comprises an ellipse detection means (EEE) for determining an ellipse (E), wherein the ellipse (E) by means of the ellipse detection means (EEE) from the frequency an additive mixing component of the ellipse detection signal (EES) can be determined.

Position determining device (1) according to one of the preceding claims, characterized in that the position determining device (1) comprises a device for Tnlateration (T), wherein the Positionsermittlungsein- direction (1) is adapted to the first receiving means (EE1) a first Trilaterations Receiving signal from the first transmitting device (SE1) and

receiving at the second receiving device (EE2) a second trilateration received signal from the second transmitting device (SE2) in order, by means of the trilateration device (T), to position a object (01, 02) with respect to the first location and / or the to determine the second location, wherein the means for trilateration (T) is arranged in particular to perform the trilateration (T) by means of a first direct component (DA1) and a second direct component (DA2), wherein the first direct component (DA1) from the first subtractive Intermediate signal mixing term (SMT1) and / or the second direct component (DA2) is taken from the second subtractive intermediate signal mixing term (SMT2). Position determining device (1) according to one of the preceding claims, characterized in that by means of the position determining device (1) a position of an object (01, 02), which is determined in particular by means of trilateration (T), for plausibility can be checked by the Positionsermitt- (1) is adapted to determine whether the position of the same object (01, 02) on an ellipse (E), which is determined by the position detection means (1) for this object (01, 02).

Method for determining a position of an object (01, 02) with respect to a position-determining device (1), wherein the position-determining device (1) comprises:

a transmitting device (SE1) at a first location (X1),

a receiving device (EE2) at a second location (X2), wherein the receiving device (EE2) receives a transmission signal which runs from the first transmitting device (SE1) via the object (01, 02) to the receiving device (EE2), and

a transit time (L) of the transmission signal from the transmitting device (SE1) to the object (01, 02) and from the object (01, 02) to the receiving device (EE2) is determined, characterized in that the first location (X1) and the second place (X2) have a distance (D) from each other and

the position determining device (1) determines from the transit time (L) an ellipse (E) on which the object (01, 02) lies, wherein the first location (X1) and the second location (X2) each have a focal point of the ellipse (E ) form.

Method according to Claim 8, characterized in that the position-finding device (1) comprises the following:

a first transmitting device (SE1) at the first location (X1),

a second transmitting device (SE2) at the second location (X2),

a first receiving device (EE1) at the first location (X1) for generating a first received signal (ES1) from a transmission signal (SS2) of the second transmitting device (SE2), a second receiving device (EE2) at the second location (X2) for generating a second received signal (ES2) from a transmission signal (SS1) of the first transmitting device (SE1),

wherein the first transmission device (SE1) transmits at a first transmission frequency (f0) and transmits the second transmission device (SE2) at a second transmission frequency (f0 + Af), the first transmission frequency (f0) being from the second transmission frequency (f0 + Af) differs by a difference frequency (Af), characterized in that the first transmission frequency (f0) and the second transmission frequency (f0 + Af) are modulated in the same way, wherein they are in particular frequency modulated, phase modulated and / or amplitude modulated, and

the first received signal (ES1) is mixed with the first transmitting frequency (f0), whereby a first intermediate signal (ZS1) is generated,

the second received signal (ES2) is mixed with the second transmitting frequency (f0 + Af), wherein a second intermediate signal (ZS2) is generated, and the first intermediate signal (ZS1) is mixed with the second intermediate signal (ZS2), wherein an ellipse detection signal (EES) is generated.

10. The method according to claim 9, characterized in that a portion of a signal in the position detecting means (1) is separated to further process a desired portion of the signal, in particular the first intermediate signal (ZS1) is low-pass filtered to a first subtractive mixing proportion (SMT1) of the first intermediate signal (ZS1), and / or

the second intermediate signal (ZS2) is low-pass filtered to obtain a second subtractive mixing component (SM2) of the second intermediate signal (ZS2), and / or

from the first subtractive mixing component (SMT1) a first cross component (KA1) is removed for further processing, and / or

from the second subtractive mixing component (SMT2) a second cross component (KA2) is removed for further processing, and / or the ellipse detection signal (EES) is high-pass filtered to extract an additive mixing component (AME) from the ellipse detection signal (EES).

1 1. Method according to one of claims 9 or 10, characterized in that the ellipse (E) from the frequency of the additive mixing component (AME) of the ellipse detection signal (EES) is determined, the trilateration (T) in particular by means of a first direct component (DA1) and a second direct component (DA2) is performed, wherein the first direct component (DA1) is taken from the first subtractive intermediate signal mixing term (SMT1) and / or the second direct component (DA2) is taken from the second subtractive intermediate signal mixing term (SMT).

12. The method according to any one of the preceding claims, characterized in that at the first receiving means (EE1) a portion of the first received signal (ES1) from the first transmitting means (SE1) is received, and at the second receiving means (EE2) a portion of the second Receiving signal (ES2) from the second transmitting device (SE2) is received, and a position of an object (01, 02) with respect to the first location (X1) and / or the second location (X2) by trilateration (T) from said Proportions of the received signals (ES1, ES2) is determined. 13. The method according to any one of the preceding claims, characterized in that a determined position of an object (O1, 02), which is determined in particular by trilateration (T) is checked for plausibility by determining whether the position of the same object (01 , 02) lies on an ellipse (E), which is determined by one of the methods according to one of claims 7 to 11 for this object (01, 02).