Abstract:
The disclosure proceeds from a system with a measurement bar and a measurement device, having at least one computation unit, an inclination measurement means and an electronic distance measurement means. The disclosure proposes that the system have a coupling apparatus which is provided for coupling the measurement bar and the measurement device such that they can be separated by an operator.

Description:
This application is a 35 U.S.C. §371 National Stage Application of PCT/EP 2012/050205, filed on Jan. 9, 2012, which claims the benefit of priority to Serial No. DE 10 2011 003 495.1, filed on Feb. 2, 2011 in Germany, the disclosures of which are incorporated herein by reference in their entirety. 
     BACKGROUND 
     The disclosure proceeds from a system with a measuring bar and a measuring device as described herein. 
     A system with a measuring bar and a measuring device which has at least one arithmetic logic unit, an inclination measuring means and an electronic distance measuring means has already been proposed. The measuring bar and the measuring device are integrally formed in this case. 
     SUMMARY 
     The disclosure proceeds from a system with a measuring bar and a measuring device which has at least one arithmetic logic unit, an inclination measuring means and an electronic distance measuring means. 
     It is proposed that the system have a coupling device which is provided so that an operator can releasably couple the measuring bar and the measuring device. “Measuring bar” is to be understood, in particular, as a device which has at least two stop areas which are spaced apart from one another and define a measuring plane. The stop areas are preferably formed as parallel, in particular continuous surfaces. In particular, the stop areas are arranged spaced apart from one another at least partially by at least 20 cm, preferably at least 40 cm, with particular preference at least 60 cm. The two stop areas are advantageously subareas of an, in particular continuous stop surface arranged on the plane. The measuring bar preferably has at least two stop surfaces. The measuring bar is preferably at least partially made from a material which seems sensible to the person skilled in the art, but preferably of plastic and/or advantageously of aluminum. In particular, an “arithmetic logic unit” is intended to mean a unit having an information input, an information processing means and an information output. The arithmetic logic unit advantageously has at least one processor, input interfaces, output interfaces and/or advantageously operating programs and/or computing routines stored in a memory of the arithmetic logic unit. An “inclination measuring means” is intended, in particular, to be understood as a means which is provided at least in order to determine an alignment about at least one axis relative to a direction of gravity and, in particular, to provide at least one information item relating thereto, preferably in electronic form. The inclination measuring means preferably measures an alignment about at least two axes, preferably three axes, which are preferably aligned perpendicular to one another. In particular, a “distance measuring means” is intended to be understood as a means which is provided in order to determine a distance between a reference point and a measurement object. In this context, “electronic” is intended, in particular, to mean that the distance measuring means outputs at least one electric parameter with at least one information item relating to a measured distance. The arithmetic logic unit is preferably provided for the purpose of reading out these parameters and/or receiving them. In particular, a “coupling device” is intended to be understood as a device which is provided, in particular, in order to align the measuring bar and the measuring device in a provided position in a fashion immobile relative to one another. The coupling device preferably has a coupling means which seems sensible to the person skilled in the art, but preferably a means for establishing a non-positive closure and/or a positive closure. In particular, the coupling means is formed as a latching element, preferably as a locking element, with particular preference as an eccentric element. “Provided” is intended to be understood as, in particular, specifically programmed, designed and/or equipped. In particular, the expression “capable of being released by an operator” is intended to mean that the connection of the coupling device is designed such that the operator can separate the connection without destruction and advantageously without any tools. Owing to the design of the system, the measuring device can be used conveniently with particular versatility. A high measuring accuracy, particularly as regards an inclination measurement, is possible with a simple design. 
     In a further refinement, it is proposed that the measuring bar have a main extent which is at least twice as large as a main extent of the measuring device, the result being to enable a particularly high measuring accuracy, in particular as regards an inclination measurement. In particular, a “main extent” is to be understood as a maximum extent, specifically advantageously parallel to at least one stop surface. The main extent of the measuring bar is advantageously at least three times, preferably four times as large as the main extent of the measuring device. 
     Moreover, it is proposed that the measuring bar have a coupling means of the coupling device which is provided for fastening the measuring device on the measuring bar, as a result of which it is possible for the measuring device to dispense with an optically visible coupling means of complicated design. The coupling means is preferably provided so as to effect a fastening force on an outer surface of the measuring device. With particular preference, the coupling means exerts a fastening force on an area of the outer surface which cannot be distinguished from other areas of the outer surface. 
     Furthermore, it is proposed that the measuring device have a bar detecting means which in at least one operating state provides at least one information item relating to a coupling to the measuring bar, thus enabling an inclination to be measured with particular ease and with accuracy owing to an improved calibration. A “bar detecting means” is intended, in particular, to be understood as a means with a sensor which appears sensible to the person skilled in the art and serves to detect a connection to the measuring bar, but advantageously to a capacitive sensor, an electric contact, an inductive sensor, in particular a Hall sensor, and/or an optical sensor. The bar detecting means preferably has at least one computing routine which is executed by the arithmetic logic unit in at least one operating state. It is particularly preferred for the bar detecting means to be designed as a computing routine which is executed by the arithmetic logic unit in at least one operating state. In particular, an “information item relating to a coupling” is intended to be understood as an information item which is at least partially dependent on a connection of the measuring bar to the measuring device. The term “provide” is intended, in particular, to mean that the bar detecting means is provided so as to transmit the information and/or output it to be read out. 
     Furthermore, it is proposed that the distance measuring means be provided so as to determine a distance by means of a laser beam, thus enabling the attainment of high accuracy and great convenience. A “laser beam” is intended, in particular, to mean a light beam with an aperture angle of less than 2 degrees, preferably less than 1 degree, with particular preference less than 0.5 degrees. The light beam preferably has at least 75% of its emitted energy in the aperture angle. 
     In an advantageous design, it is proposed that the bar detecting means be provided in order to determine the information at least with the aid of the laser beam so that it is possible to dispense with an additional sensor, in particular only for detecting a coupling between the measuring device and the measuring bar. The phrase “to determine the information at least with the aid of the laser beam” is intended, in particular, to mean that the information of the bar detecting means is a function of a parameter determined by the laser beam. 
     Furthermore, it is proposed that the arithmetic logic unit be provided in order to fix a stop surface as a function of a parameter of the inclination measuring means, thus enabling a particularly convenient operation with a simple design. The measuring device and/or preferably the measuring bar advantageously has/have at least two, advantageously at least three differently aligned stop surfaces. A “stop surface” is intended to be understood, in particular, as a surface which touches the measurement object when an inclination is being measured thereon. The stop surface preferably defines a measuring plane whose alignment determines the inclination measuring means. During a measurement, the inclination measuring means advantageously determines an inclination of the measuring plane relative to a direction of gravity. “Fix” is, in particular, intended in this context to mean that the arithmetic logic unit fixes a measuring plane from at least one parameter, in particular of the inclination measuring means, relative to which the inclination measuring means determines an alignment. 
     Furthermore, it is proposed that the arithmetic logic unit be provided in order to activate an angle measuring mode as a function of the information via a coupling with the measuring bar, as a result of which the operator need not activate the angle measuring mode by hand. “Angle measuring mode” is intended, in particular, to mean a mode in which at least one information item relating to an alignment of the arithmetic logic unit is evaluated and/or, in particular, is advantageously output to the operator, as a priority. In addition to the angle measuring mode, the arithmetic logic unit preferably has a distance measuring mode in which a measured distance is output with priority. 
     It is proposed, in addition, that the arithmetic logic unit have at least one memory which in at least one operating state comprises at least one calibration data set for calibrating the inclination measuring means, thus enabling particularly accurate inclination measurements. A “memory” is intended, in particular, to mean a means that is provided in order to store at least one information item, advantageously independently of a power supply. In particular, a “calibration data set” is intended to mean an information item which describes a difference between a direction of gravity determined by the sensor and an actual direction of gravity. 
     Furthermore, it is proposed that the arithmetic logic unit have at least one calibration routine which is provided in order to create a calibration data set of the inclination measuring means, thereby enabling particularly accurate inclination measurements to be achieved under various conditions of use. In particular, it is advantageously possible to detect and/or compensate a malfunction of the inclination measuring means. A “calibration routine” is intended, in particular, to mean a program which can be executed by a processor of the arithmetic logic unit. In particular, it is to be understood under the term “check” that the calibration routine determines a difference between a direction, determined by the sensor, of gravity and an actual direction of gravity, and compares it with the calibration data set. The calibration routine preferably changes the calibration data set after the checking. Alternatively or in addition, the routine could change the calibration data set without checking. 
     Furthermore, it is proposed that the measuring bar have an optical means which is provided in order to direct a laser beam so as to detect a coupling, thus rendering it possible to achieve convenient manipulation with a low design outlay. An “optical means” is intended, in particular, to be understood as a means which is provided in order to deflect a laser beam. The optical means preferably has at least one reflector. In particular, the phrase “to detect a coupling” is intended to mean that the optical means deflects the laser beam in the case of a coupling, thus enabling detection of the coupling, specifically between the measuring bar and the measuring device. 
     In addition, it is proposed that the measuring bar comprise a recess which is provided in order to hold the measuring device in at least one operating state, as a result of which the measuring device is advantageously protected during a measurement of inclination. A “recess” is intended, in particular, to be understood as an area delimited by the measuring bar which, in at least one operating state, the measuring device surrounds by more than 180 degrees, advantageously more than 270 degrees, on at least one plane which is advantageously aligned parallel to the main extent. The recess preferably takes up more than 50%, with particular preference more than 75% of the measuring device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Further advantages emerge from the following description of the drawings. An exemplary embodiment is illustrated in the drawings. The drawings, the description and the claims contain numerous features in combination. The person skilled in the art will expediently also individually consider the features and combine them to form sensible further combinations. 
       In The Drawings: 
         FIG. 1  shows a system according to the disclosure with a measuring bar and a measuring device, in a plan view, and  FIG. 2  shows the system from  FIG. 1  in perspective illustration. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  and  FIG. 2  show a system according to the disclosure with a measuring bar  12  and a measuring device  14 . The measuring device  14  has an arithmetic logic unit  16 , an inclination measuring means  18 , an electronic distance measuring means  20 , a display  38  and an operating device  40 . During a measurement of distance, the distance measuring means  20  detects a distance between the distance measuring means  20  and a measurement object (not illustrated in more detail). For this purpose, it has a laser (not illustrated in more detail) which emits a laser beam  32 . The measurement object reflects a portion of the laser beam  32  during the measurement of distance. A sensor (not illustrated in more detail) of the distance measuring means  20  detects a portion of the reflected light of the laser beam  32 . 
     The arithmetic logic unit  16  has a computing routine which determines the distance by means of the laser beam  32 . The arithmetic logic unit  16  in this case evaluates a propagation time, a phase angle and/or an amplitude of the portion of the reflected light of the laser beam  32 . The arithmetic logic unit  16  constitutes a value of the distance for the operator on the display  38 . An operator controls the measuring device  14  by means of the operating device  40 . The measuring device  14  can be used separately from the measuring bar  12  in order to measure a distance. Alternatively or in addition, a measuring bar could be designed to enable a distance to be measured with the aid of a coupled measuring device  14 . 
     During operation, the inclination measuring means  18  detects an alignment of the measuring device  14  and, if appropriate, of the measuring bar  12  relative to a direction of gravity. To this end, the inclination measuring means  18  detects an acceleration value in three directions aligned at right angles to one another. Alternatively, an inclination measuring means could also determine only acceleration values in two directions aligned at right angles to one another. The inclination measuring means  18  determines a direction of gravity by detecting gravity acting on a mass. The arithmetic logic unit  16  evaluates the alignment determined by the inclination measuring means  18 . During a distance measuring operation, the arithmetic logic unit  16  signals to the operator an alignment of the laser beam  32  that is horizontal, vertical and/or some other predetermined alignment. 
     The system has a coupling device  22 . At least for a measuring of inclination on a measurement object, the coupling device  22  couples the measuring bar  12  and the measuring device  14  so as to be releasable by an operator without any tools and without destruction. The measuring bar  12  has a main extent  24  which is approximately four times as large as a main extent  26  of the measuring device  14 . The main extent  24  of the measuring bar  12  is approximately 60 cm. The measuring bar  12  has three stop surfaces  34  which are aligned parallel to the main extent  26 . A first and a second of the stop surfaces  34  are aligned at right angles to a third one of the stop surfaces  34 . The stop surfaces  34  extend substantially along the entire main extent  24  of the measuring bar  12 . 
     The measuring bar  12  has a recess  42  and a coupling means  28  of the coupling device  22 . At least during a measurement of inclination on a measurement object, the coupling means  28  fastens the measuring device  14  on the measuring bar  12 . In a coupled operating state, the measuring device  14  is arranged in the recess  42  of the measuring bar  12 , as a result of which the measuring device  14  is advantageously protected. In this case, the coupling means  28  fixes the measuring device  14  in the recess  42 . The coupling means  28  has a rotatably mounted eccentric element (not illustrated here in more detail), and an operating element  44  with the aid of which the operator can rotate the eccentric element. A rotation of the operating element  44  acts to change a fastening force which acts on the measuring device  14  by means of the eccentric element and fastens the measuring device  14  at least non-positively. The measuring bar  12  has two spirit levels  46 , thus enabling the measuring bar  12  to be used as a conventional water level without the measuring device  14 . 
     The measuring device  14  has a bar detecting means  30 . During operation, the bar detecting means  30  provides an information item relating to a coupling to the measuring bar  12 . The information indicates whether the measuring bar  12  is coupled to the measuring device  14 . The arithmetic logic unit  16  activates an angle measuring mode as a function of the information. In the angle measuring mode, the arithmetic logic unit  16  firstly represents an alignment of the system  10  on the display  38 . 
     The bar detecting means  30  determines the information with the aid of the laser beam  32 . To this end, the bar detecting means  30  measures the distance. The bar detecting means  30  detects the bar when the measuring device  14  is switched on. Alternatively, the bar detecting means  30  could detect the bar periodically. The measuring bar  12  has an optical means  36  which directs the laser beam  32  so as to detect a coupling. The optical means  36  has two reflecting surfaces  48 ,  50 . In a coupled operating state, the reflecting surfaces  48 ,  50  direct the laser beam  32  from the laser to the sensor over a defined distance, in particular less than 8 cm. The arithmetic logic unit  16  uses the received laser beam  32  to determine whether the measuring bar  12  and the measuring device  14  are coupled. For this purpose, in addition to the distance the arithmetic logic unit  16  advantageously evaluates an amplitude of the received laser beam  32 . 
     During measurement of an inclination, the arithmetic logic unit  16  determines a used stop surface  34  as a function of a parameter of the inclination measuring means  18 . The arithmetic logic unit  16  adjusts a reading of the display  38  as a function of the stop surface  34  used. In addition, the operator can use the operating device  40  to change an adjustment of the reading of the display  38 . 
     The arithmetic logic unit  16  has a memory (not illustrated in more detail here) which comprises two calibration data sets for calibrating the inclination measuring means  18 . A first of the two calibration data sets serves for calibration when the measuring bar  12  and the measuring device  14  are decoupled. A second of the two calibration data sets serves for calibration when the measuring bar  12  and the measuring device  14  are coupled. The arithmetic logic unit  16  automatically loads the appropriate calibration data set. The arithmetic logic unit  16  has a calibration routine. During a calibration operation, the calibration routine creates one of the two calibration data sets. For this purpose, the calibration routine uses a method which appears sensible to the person skilled in the art, but advantageously measurement of a 180 degrees change, a measurement of a known, in particular horizontal alignment and/or a shaking calibration.