Abstract:
A manual positioning device includes at least one receiver, a reference network, a first switch, and at least one second switch. The at least one second switch, together with the first switch, is configured to switch at least two different reference signal paths for determining reference signals on the reference network.

Description:
This application is a 35 U.S.C. §371 National Stage Application of PCT/EP2011/051379, filed on Feb. 1, 2011, which claims the benefit of priority to Serial No. DE 20 2010 007 111.9, filed on May 21, 2010 in Germany, the disclosures of which are incorporated herein by reference in their entirety 
     BACKGROUND 
     The disclosure is based on a hand-held locating appliance apparatus as described herein. 
     A hand-held locating appliance apparatus having at least a receiver, a reference network and a first switch has already been proposed. 
     SUMMARY 
     The disclosure is based on a hand-held locating appliance apparatus having at least a receiver, a reference network and a first switch. 
     It is proposed that the hand-held locating appliance apparatus have at least one second switch which is provided, together with the first switch, to connect at least two different reference signal paths to the reference network for the purpose of determining reference signals. A “receiver” is intended to be understood to mean particularly an element which decodes a piece of information contained in a received signal and/or one of the reference signals and advantageously determines a value profile, that is to say a value over a time. Preferably, the receiver has at least one analog-to-digital converter. The term “reference network” is intended to be understood to mean particularly a circuit which emulates at least one portion of a transmission and/or reception channel. Preferably, the reference network has at least one filter, a balancing element and/or advantageously an attenuator. Advantageously, at least one region of the reference network has an identical spatial structure to the transmission and/or reception channel. Alternatively and/or additionally, the reference network could have regions which emulate a response from the transmission and/or reception channel, particularly a temperature-dependent response. In particular, a “switch” in this context is intended to be understood to mean an element which is provided to couple a signal selectively to at least two at least partially different signal paths. Advantageously, the switch is in the form of a semiconductor switch. Alternatively, the switch could be in the form of a mechanical switch, for example in the form of a coaxial switch. “Provided” is intended to be understood to mean particularly specifically programmed, designed, equipped and/or connected. In particular, the term “signal path” is intended to be understood to mean an operative electrical connection between two points. A “reference signal path” is intended to be understood to mean particularly a signal path for transmitting a reference signal. In particular, a “reference signal” is intended to be understood to mean a signal which has at least one piece of information about a state, particularly an environment-dependent state, of the transmission and/or reception channel and/or advantageously provides said information particularly for the receiver. Preferably, the state is dependent on the temperature, humidity and/or another disturbance variable which appears meaningful to a person skilled in the art. The inventive refinement of the hand-held locating appliance apparatus allows particularly effective compensation for disturbance variables, particularly temperature compensation and compensation for other disturbance variables, such as humidity, to be achieved simply in terms of design and with advantageously little outlay. 
     In a further refinement, it is proposed that the hand-held locating appliance apparatus have a signal generator, wherein at least the first switch is operatively arranged between the signal generator and the reference network, which means that a signal from the signal generator can be connected to one of the reference signal paths or to another path, particularly to a transmission path, simply in terms of design. In particular, a “signal generator” is intended to be understood to mean an apparatus which produces at least one transmission signal in at least one operating state. Advantageously, the signal generator also produces the reference signals. The signal generator advantageously produces a wideband radio-frequency signal, specifically particularly according to the IEEE 802.15.4a standard, and/or another radio-frequency signal which appears meaningful to a person skilled in the art. Alternatively or additionally, the signal generator could produce a signal for a capacitive measurement, an inductive measurement and/or for another measurement which appears meaningful to a person skilled in the art. The expression “operatively arranged in-between” is intended to be understood to mean particularly that the switch can be used to switch at least one of the reference signal paths from the signal generator to the reference network. 
     Furthermore, it is proposed that the hand-held locating appliance apparatus have an antenna separating filter, wherein the second switch is operatively arranged between the reference network and the antenna separating filter, as a result of which the signal from the signal generator can be connected to an antenna or to the reference network simply in terms of design. An “antenna separating filter” is intended to be understood to mean particularly an apparatus which, during transmission, routes a signal from the signal generator in the direction of an antenna and which during reception, routes a received signal from the antenna in the direction of the receiver. Preferably, the antenna separating filter is in the form of a directional coupler, specifically in a form which appears meaningful to a person skilled in the art. Alternatively, the antenna separating filter could be in the form of a circulator. Preferably, the hand-held locating appliance apparatus is in the form of a monostatic hand-held locating appliance apparatus, that is to say that it sends and receives a locating signal using the same antenna. 
     In addition, it is proposed that the two switches be provided to connect a reference signal path for the purpose of determining crosstalk, as a result of which the crosstalk can be determined and advantageously determined and calculated from a locating measurement. Preferably, the reference signal used for determining crosstalk remains unsent. “Crosstalk” is intended to be understood to mean particularly a signal, specifically a portion of the reference signal, which the antenna separating filter unintentionally couples in the direction of the receiver. Preferably, the crosstalk equates to a signal which the antenna separating filter unintentionally couples in the direction of the receiver during the transmission of a locating signal. 
     In addition, it is proposed that the two switches be provided to connect a reference signal path for the purpose of determining a normalization signal, as a result of which corruption of the received signal by an alteration—particularly a temperature-dependent alteration—in the transmission and reception channels can be determined and calculated. A “normalization signal” is intended to be understood to mean particularly a signal, specifically a component of the reference signal, which has a piece of information about a state of the reference network, which piece of information allows a state of the transmission and reception channels to be inferred. In particular, the normalization signal has a piece of information about a current gain, particularly a frequency-dependent gain, of the transmission and reception channels independently of the radio link. Preferably, the reference signal used for determining a normalization signal remains unsent. The normalization signal can be used to determine a normalization factor. A “normalization factor” is intended to be understood to mean particularly a quotient comprising a calibration signal measured under controlled conditions, particularly during factory calibration, and a normalization signal which is measured in real time with a locating measurement. By way of example, the factory calibration involves the hand-held locating appliance apparatus being tempered at a prescribed humidity over a relatively long period. 
     It is also proposed that the hand-held locating appliance apparatus have a computation unit which is provided to determine an at least temperature-compensated received signal particularly on the basis of the crosstalk and the normalization signal, as a result of which it is possible to achieve particularly precise locating under a wide variety of ambient conditions simply in terms of design and with little outlay on parts. A “computation unit” is intended to mean particularly a controller having a processor, a memory unit and/or an operating, control and/or calculation program stored in the memory unit. Preferably, the computation unit is in the form of a digital signal processor. Alternatively or additionally, the computation unit could be in the form of an RISC processor. 
     In one advantageous form of the disclosure, it is proposed that the computation unit be provided to transform at least one profile of a signal to a frequency domain, as a result of which it is possible to achieve advantageous and rapid data processing with little outlay. The expression “transform to a frequency domain” is intended to be understood to mean particularly conversion of a signal in the time domain, for example a voltage profile, to the particularly complex frequency domain. Advantageously, the computation unit has a computation routine with Fourier transformation, particularly advantageously with fast Fourier transformation. Preferably, the temperature-compensated received signal is determined at least partially in the frequency domain. Particularly subtraction of the crosstalk from a transformed value profile of the received signal and/or advantageously multiplication by the normalization factor take place in the frequency domain. Alternatively or additionally, the temperature-compensated received signal could be determined at least partially in the time domain. Particularly convolution with the normalization factor and/or advantageously subtraction of the crosstalk from an untransformed value profile of the received signal take place in the time domain. 
     Furthermore, it is proposed that the hand-held locating appliance apparatus have two antenna separating filters which each form part of two essentially separate transmission and reception channels, as a result of which particularly precise locating is possible, and both transmission and reception channels can be subjected to temperature compensation with little outlay. A “transmission and reception channel” is intended to be understood to mean particularly an apparatus for sending and receiving signals. Preferably, a transmission and reception channel has at least one antenna separating filter, an antenna and a receiver. In this case, “essentially separate” is intended to be understood to mean that the two transmission and reception channels have primarily separate parts and/or signal paths. Advantageously, the two transmission and reception channels are of separate design apart from the first switch and the signal generator. 
     In addition, it is proposed that the computation unit be provided to determine the crosstalk and the normalization signal simultaneously, as a result of which particularly rapid reference measurement which is in real time with a locating measurement and is therefore precise is possible. In this connection, “simultaneously” is intended to be understood to mean particularly that the computation unit determines the crosstalk of a transmission and reception channel in one position of the switches and determines the normalization signal of the other transmission and reception channel in the same position of the switches and particularly at an identical time. 
     In addition, the disclosure is based on a hand-held locating appliance having a hand-held locating appliance apparatus, wherein all hand-held locating appliances which appear meaningful to a person skilled in the art, such as particularly distance measuring appliances, humidity locating appliances and/or wall locating appliances, would be conceivable for operation with a hand-held locating appliance apparatus, as a result of which it is possible to provide a particularly precise hand-held locating appliance simply in terms of design. Advantageously, the hand-held locating appliance is provided to locate objects arranged in a wall, such as power lines and/or water lines, and/or wall properties, such as wooden elements, stone elements and/or supports, that is to say particularly to determine a distance from a wall surface. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages can be found in the description of the drawings below. The drawing shows two exemplary embodiments of the disclosure. The drawing, the description and the claims contain numerous features in combination. A person skilled in the art will expediently also consider the features individually and will combine them into meaningful further combinations. 
       In the drawing: 
         FIG. 1  shows a hand-held locating appliance according to the disclosure with a hand-held locating appliance apparatus according to the disclosure, 
         FIG. 2  shows a schematic illustration of the hand-held locating appliance apparatus from  FIG. 1  with a transmission and/or reception channel, and 
         FIG. 3  shows a schematic illustration of an alternative exemplary embodiment of the hand-held locating appliance apparatus from  FIG. 1  with two transmission and/or reception channels. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  shows a hand-held locating appliance  40   a  according to the disclosure with a hand-held locating appliance apparatus  10   a , a grip  42   a , a display  44   a , four rollers  46   a  and a housing  48   a . During a measurement process, a user—not shown in more detail—moves the hand-held locating appliance  40   a  along a measurement object, preferably along a wall, a ceiling or a floor in a building, on the rollers  46   a . Therefore, the hand-held locating appliance  40   a  is in the form of a hand-held wall locating appliance. The hand-held locating appliance apparatus  10   a  is arranged within the housing  48   a . It sends a transmission signal in a direction that is remote from the display  44   a.    
     As  FIG. 2  shows, the hand-held locating appliance apparatus  10   a  has a receiver  12   a , a reference network  16   a , a first switch  18   a , a second switch  20   a , a signal generator  28   a , an antenna separating filter  30   a , a computation unit  34   a , an antenna  50   a  and a terminating element  52   a . The signal generator  28   a  produces a signal which is in the form of a radio-frequency ultra wideband radio-frequency signal. The signal is used as a transmission signal and as a reference signal. The radio-frequency signal has a bandwidth of greater than 500 MHz. A line  54   a  in the hand-held locating appliance apparatus  10   a  connects the signal generator  28   a  to the first switch  18   a . The line  54   a  is, like all the lines shown, which are not denoted in more detail, provided to transmit the ultra wideband radio-frequency signal. 
     The first switch  18   a  is connected to the reference network  16   a , to the antenna separating filter  30   a  and to the terminating element  52   a . Alternatively, a first switch could have a terminating element. The first switch  18   a  is in the form of a semiconductor switch. In a first switching state, it switches a conductive connection between the signal generator  28   a  and the antenna separating filter  30   a  and between the reference network  16   a  and the terminating element  52   a . In a second switching state, the first switch  18   a  switches a conductive connection between the signal generator  28   a  and the reference network  16   a . Hence, the first switch  18   a  is operatively arranged between the signal generator  28   a  and the reference network  16   a . In the second switching state, the first switch  18   a  connects the antenna separating filter  30   a  to the terminating element  52   a . The terminating element  52   a  absorbs incoming signals largely without reflection. Instead of the terminating element  52   a , an attenuator in the reference network  16   a  could suppress reflections arising on the open port of the switch  18   a  in the first switching state. 
     The antenna separating filter  30   a  is in the form of a directional coupler, specifically in the form of a three-port network. It is connected to the receiver  12   a , to the first switch  18   a  and to the second switch  20   a . The antenna separating filter  30   a  couples a signal coming from the first switch  18   a  onward essentially only in the direction of the second switch  20   a . A small, unintentional component of the signal is coupled by the antenna separating filter  30   a  in the direction of the receiver  12   a . This component is subsequently denoted by crosstalk R A . The antenna separating filter  30   a  couples signals coming from the second switch  20   a , that is to say a reference signal and a received signal, onward essentially only in the direction of the receiver  12   a.    
     The second switch  20   a  is connected to the reference network  16   a , the antenna separating filter  30   a  and the antenna  50   a . In a first switching state, the second switch  20   a  connects the reference network  16   a  to the antenna separating filter  30   a . Hence, the second switch  20   a  is operatively arranged between the reference network  16   a  and the antenna separating filter  30   a . In a second switching state, the second switch  20   a  connects the antenna  50   a  to the antenna separating filter  30   a.    
     The signal generator  28   a , the antenna separating filter  30   a  and the antenna  50   a  together form a transmission channel. In addition, the transmission channel could have a filter, a balancing element, an amplifier, a modulator and/or other elements which appear meaningful to a person skilled in the art. The antenna  50   a , the antenna separating filter  30   a  and the receiver  12   a  together form a reception channel. In addition, the reception channel could have a filter, a balancing element, an amplifier, a mixer, an intermediate-frequency filter, a demodulator and/or other elements which appear meaningful to a person skilled in the art. The transmission channel and the reception channel are partly in integral form as a transmission and reception channel  36   a . Hence, the hand-held locating appliance apparatus  10   a  is of single-channel design. 
     A transmission and reception path  56   a  runs from the signal generator  28   a  via the first switch  18   a , via the antenna separating filter  30   a , via the second switch  20   a  to the antenna  50   a . From there, the transmission and reception path  56   a  is formed by a radio channel, which extends from the antenna  50   a  through a portion of a measurement object  58   a  to a reflector  60   a  on the measurement object  58   a . The reflector  60   a  reflects a locating signal that runs along the transmission and reception path  56   a  back to the antenna  50   a . Prior to the antenna  50   a , the transmission and reception path  56   a  runs via the second switch  20   a  to the antenna separating filter  30   a  and via the antenna separating filter  30   a  on to the receiver  12   a.    
     The two switches  18   a ,  20   a  connect two different reference signal paths  24   a ,  26   a  to the reference network  16   a  in two different operating states in order to determine reference signals. The reference single paths  24   a ,  26   a  are different in part than the transmission and reception path  56   a . The first reference signal path  24   a  runs from the signal generator via the first switch  18   a , via the antenna separating filter  30   a , via the second switch  20   a  to the reference network  16   a . From the reference network  16   a , the first reference signal path  24   a  runs to the terminating element  52   a . The first reference signal path  24   a  ends in the terminating element  52   a . Alternatively, the first reference signal path  24   a  could also end unterminated, with reflections being largely prevented by an attenuator in the reference network  16   a . Since the first reference signal path  24   a  runs via the antenna separating filter  30   a  and at the same time the second switch  20   a  decouples the antenna  50   a  from the antenna separating filter  30   a , a reference signal running via the first reference signal path  24   a  can be used to determine the crosstalk R A  of the antenna separating filter  30   a  from the transmission path to the reception path. 
     The second reference signal path  26   a  runs from the signal generator via the first switch  18   a , via the reference network  16   a , via the second switch  20   a , via the antenna separating filter  30   a , to the receiver  12   a . The reference network  16   a  has—not shown in more detail—an attenuator and two balancing elements. The attenuator is in the form of a pi-attenuator matched to a characteristic impedance. The balancing elements are in the form of baluns. Hence, the reference signal path  26   a  has essentially the same environment-dependent properties as the transmission and reception path  26   a  without a dependency on the radio channel. Hence, the two switches  18   a ,  20   a  are provided to switch the reference signal path  26   a  to determine a normalization signal R M . 
     The receiver  12   a  has a demodulator and an analog-to-digital converter. The demodulator transfers a received signal F to a center frequency and to a bandwidth which the analog-to-digital converter can process. The receiver  12   a  and the signal generator  28   a  are connected to the computation unit  34   a . The computation unit  34   a  is in the form of a digital signal processor (DSP). During locating, the computation unit  34   a  controls the signal generator  28   a  such that it outputs a signal. The signal passes through the transmission and reception path  26   a  and is digitized by the analog-to-digital converter. The computation unit  34   a  evaluates a signal delay between the signal generator  28   a  and the receiver  12   a . This signal delay is dependent on a length of the radio channel and disturbance variables such as a temperature, a humidity and other disturbance variables for the transmission and reception path  56   a . In addition, a portion of a transmission power acts directly on the receiver  12   a  via the antenna separating filter  30   a.    
     In real time with a locating operation, the computation unit  34   a  determines the crosstalk R A  and the normalization signal R M . The computation unit  34   a  has computation routines for determining a temperature-compensated received signal F comp . In addition, the computation unit  34   a  has a memory which stores a calibration signal R M,Ref  that is picked up under particular external conditions. The calibration signal R M,Ref  has been picked up in a climatic chamber, for example. The temperature-compensated received signal F comp  is calculated in the frequency domain from the received signal F on the basis of the following specification:
 
 F   comp =( F−R   A )( R   M,Ref   /R   M )
         F comp : temperature-compensated received signal   F: received signal   R A : crosstalk   R M,Ref : calibration signal   R M : normalization signal       

     The computation unit  34   a  subtracts the crosstalk R A  from the received signal F in the time domain. Subtraction is possible both in the time domain and in the frequency domain. The result is convoluted by the computation unit  34   a  with a normalization factor using a fast convolution. That is to say that the computation unit  34   a  transforms the result of the subtraction and the normalization signal R M  to the frequency domain, specifically using fast Fourier transformation (FFT). The calibration signal R M,Ref  is stored in the memory in the frequency domain. The computation unit  34   a  multiplies the result of the subtraction by the calibration signal R M,Ref  in the frequency domain and divides it by the normalization signal R M , specifically each in complex form. Next, the computation unit  34   a  transforms the final result, that is to say the temperature-compensated received signal to the time domain, specifically using inverse fast Fourier transformation. From the temperature-compensated received signal in the time domain, the computation unit  34   a  determines the signal delay between the signal generator  28   a  and the receiver  12   a , and from this determines a distance between the antenna  50   a  and the reflector  60   a . Hence, the computation unit  34   a  is provided to transform a profile of one of the signals to the frequency domain. 
       FIG. 3  shows a further exemplary embodiment of the disclosure. The descriptions below and the drawings are essentially limited to the differences between the exemplary embodiments, with reference also being able to be made, in principle, to the drawings and/or the description of the other exemplary embodiments for parts having the same designation, particularly for parts having the same reference symbols. In order to distinguish between the exemplary embodiments, the letter a has been placed after the reference symbols for the exemplary embodiment in  FIGS. 1 and 2 . In the exemplary embodiment in  FIG. 3 , the letter a has been replaced by the letter b. 
       FIG. 3  shows a hand-held locating appliance apparatus  10   b  according to the disclosure which comprises a first receiver  12   b , a second receiver  14   b , a reference network  16   b , a first switch  18   b , a first second switch  20   b , a second second switch  22   b , a signal generator  28   b , a first antenna separating filter  30   b  and a second antenna separating filter  32   b . These parts form two essentially separate transmission and reception channels  36   b ,  38   b , specifically one of the receivers  12   b ,  14   b , one of the second switches  20   b ,  22   b  and one of the antenna separating filters  30   b ,  32   b  each form a portion of the two essentially separate transmission and reception channels  36   b ,  38   b . The transmission and reception channels  36   b ,  38   b  are provided to form a portion of two transmission and reception paths  56   b.    
     The first switch  18   b  is connected to the signal generator  28   b  and to the two antenna separating filters  30   b ,  32   b . The first switch  18   b  routes a transmission signal or the reference signals either to the first antenna separating filter  30   b  of the first transmission and reception channel  36   b  or to the second antenna separating filter  32   b  of the second transmission and reception channel  38   b . The second switches  20   b ,  22   b  are each connected to the reference network  16   b , to one of the antenna separating filters  30   b ,  32   b  and to one of two antennas  50   b  of the hand-held locating appliance apparatus  10   b . The second switches  20   b ,  22   b  route a transmission signal from the respective antenna separating filter  30   b ,  32   b  on to the respective antenna  50   b.    
     Each of the second switches  20   b ,  22   b  together with the first switch  18   b  connects two different reference signal paths  24   b ,  26   b  to the reference network  16   b  in two different operating states in order to determine reference signals. Each of the reference signal paths  24   b ,  26   b  is used to determine crosstalk R A,1  or R A,2  from one of the antenna separating filters  30   b ,  32   b  and to determine a normalization signal, R M,1  or R M,2 . The first reference signal path  24   b  runs from the signal generator  28   b  via the first switch  18   b , via the first antenna separating filter  30   b  of the first transmission and reception channel  36   b , via the first second switch  20   b , via the reference network  16   b , via the second second switch  22   b , via the second antenna separating filter  32   b  to the second receiver  14   b . If the first reference signal path  24   b  is connected, the computation unit  34   b  can use the first receiver  12   b  to determine crosstalk R A,1  from the first antenna separating filter  30   b . At the same time, the computation unit  34   b  can use the second receiver  14   b  to determine the normalization signal R M,2 . 
     In order to connect the second reference signal path  26   b , the signal generator  28   b  is connected to the second antenna separating filter  32   b . The positions of the second switches  20   b  are the same as in the case of the connection of the first reference signal path  24   b . Hence, the switches  18   b ,  20   b ,  22   b  are provided to connect the two reference signal paths  24   b ,  26   b  via the two antenna separating filters  30   b ,  32   b . If the second reference signal path  26   b  is connected, the computation unit  34   b  can use the second receiver  14   b  to determine crosstalk R A,2  from the second antenna separating filter  32   b . At the same time, the computation unit  34   b  can use the first receiver  12   b  to determine the normalization signal R M,1 . 
     A temperature-compensated received signal F comp  can be calculated for each transmission and reception channel  36   b ,  38   b  separately after the reference signal paths  24   b ,  26   b  have been used to determine crosstalk R A,1 , R A,2  and a normalization signal R M,1 , R M,2  for both transmission and reception channels  36   b ,  38   b  according to the method described in the other exemplary embodiment.