METHOD FOR OPERATING A LASER DISTANCE MEASURING DEVICE

Description

State of the art

[0001] The present invention relates to a method for operating a handheld laser distance measuring device.

[0002] Methods for operating handheld laser distance measuring devices have already been proposed, for example in DE 10 2012 214 880 A1 or in EP 2669707 A1.

[0003] From DE 10 2011 003 495 A1 a system with a measuring rail and a measuring device is known, which has at least one computing unit, an inclination measuring device and an electronic distance measuring device.

[0004] EP 2 051 102 A1 describes an electro-optical measuring device with at least one measuring device housing, an optical transmission path which has at least one optical transmitter for transmitting a measurement signal, a reception path with at least one reception optic for bundling a measurement signal in the direction of a receiver, and with an optics carrier body which accommodates components of the transmission and reception paths and has an optical axis. Disclosure of the invention

[0005] A method according to claim 1 is proposed for operating a handheld laser distance measuring device for contactless distance measurement between the laser distance measuring device and a distant object. The method is based on a handheld laser distance measuring device with a housing in which at least one laser distance measuring unit of the laser distance measuring device can determine a distance to a target point by emitting a laser beam, and in which an inclination can be determined using an acceleration sensor.

[0006] "Handheld" means that the laser distance measuring device is at least guided, preferably carried, and particularly preferably held by an operator during a measuring process. For this purpose, the total mass of the laser distance measuring device is in particular less than 2 kg, preferably less than 1 kg, particularly preferably less than 500 g. Furthermore, in one embodiment of the laser distance measuring device, all components of the laser distance measuring device can be housed in a housing that essentially encloses the components. In particular, the length of the longest side of this housing is less than 30 cm, advantageously less than 20 cm, particularly advantageously less than 15 cm. In one application example, the handheld laser distance measuring device can be used, for example, to measure objects or interior spaces during manual work.

[0007] For distance measurement, the handheld laser distance measuring device has a transmitting device for emitting laser radiation, a receiving optics for receiving laser radiation returning from a distant object and at least one detector device for detecting received laser radiation as well as an evaluation device.

[0008] The transmitting device of the laser distance measuring device for emitting laser radiation has at least one light source, preferably in the form of a laser, a semiconductor laser or a laser diode, which in particular emits time-modulated light, preferably laser radiation, in the direction of a distant object. Time modulation can be continuous and / or periodic, for example sinusoidal. Light pulses can also be emitted in the direction of a target object. Furthermore, pulse trains can also be emitted, for example non-periodically, such as in the form of so-called pseudo-noise pulse sequences. In one embodiment, the laser radiation can be in a spectral wavelength range visible to the human eye, ie in particular between 380 nm and 780 nm.Advantageously, an operator of the laser distance measuring device can detect the laser radiation emitted by the laser distance measuring device without the aid of optical aids and, in particular, perceive its projection onto the distant object as a projected laser marking.

[0009] A laser beam reflected and / or scattered, i.e., returning, from the target object illuminated by the emitted laser beam is projected, preferably imaged, onto the detector device, in particular its detector element, using receiving optics. For example, the receiving optics can comprise optical elements that shape and / or direct beams and / or influence the properties of the laser radiation, such as lenses, filters, diffractive elements, mirrors, reflectors, optically transparent panes, or the like.

[0010] The returning laser beam is at least partially detected by the detector device and used to determine the distance to be measured. The detector device is understood to be at least one radiation-sensitive detector element, such as a photodiode, a PIN diode, an avalanche photodiode (APD), a single-photon avalanche diode (SPAD), or the like, which delivers a detection signal depending on the incident light intensity.

[0011] The "evaluation device" has an information input, an information processing unit, and an information output. In one embodiment, the evaluation device can have a processor as well as operating programs and / or control routines and / or evaluation routines and / or calculation routines stored in a memory of the evaluation device. The evaluation device is intended to determine a distance from a distance measurement using the laser distance measuring unit. In particular, the evaluation device can be intended to determine a light propagation time from a phase comparison performed between the emitted laser radiation and the laser radiation returning from the surface of the target object, and to calculate or determine the desired distance between the laser distance measuring device and the target object using the speed of light.Furthermore, the evaluation device is provided to determine inclinations determined by means of an acceleration sensor optionally as an inclination of a reference of the housing, in particular of a side of the housing, of the laser distance measuring device or as an inclination of the laser beam, in particular as an inclination of the emission direction of the laser beam, of the laser distance measuring device.

[0012] A determined distance measurement value in the direction of the emitted laser beam and / or a result of the calculation can be further processed by the evaluation device of the laser distance measuring device and / or output to an operator of the laser distance measuring device by means of an output device of the laser distance measuring device, for example using a screen, in particular a touch-sensitive screen, or an acoustic output device.

[0013] According to the invention, the laser distance measuring device has at least one acceleration sensor and / or at least one yaw rate sensor. In principle, in one embodiment, multiple acceleration sensors and / or multiple yaw rate sensors can also be provided in the laser distance measuring device. Using the at least one acceleration sensor and / or the at least one yaw rate sensor, the laser distance measuring device is provided to determine an inclination of the laser distance measuring device. An inclination is understood in particular to mean an axis inclination (or also: axis tilt, axis skew), which refers to a deviation of an axis of the laser distance measuring device from the horizontal or the vertical.In one embodiment of the laser distance measuring device, the inclination is determined by the evaluation device, which receives measurement signals for evaluation from the at least one acceleration sensor and / or the at least one yaw rate sensor. The measurement signals determined by an acceleration sensor relate, for example, to the acceleration of the laser distance measuring device in the Earth's gravitational field, from which the inclination can be determined absolutely or relatively. The measurement signals determined by a yaw rate sensor, on the other hand, relate to the respective angular velocity of the laser distance measuring device along a rotational axis, from which an inclination can also be determined absolutely or relatively.

[0014] "Intended" should be understood in particular as specifically "programmed," "designed," and / or "equipped." The fact that an object is "intended" for a specific function should be understood in particular as meaning that the object fulfills and / or performs this specific function in at least one application and / or operating state, or is designed to fulfill the function.

[0015] It should be noted that the term "determinable" or "switchable" expresses that a determination or switching is actually possible during operation of the laser distance measuring device.

[0016] It should be noted that the laser distance measuring device also has a power source, for example a battery or an accumulator, as well as control elements for its operation.

[0017] The method for operating the handheld laser distance measuring device is based on the proposed laser distance measuring device, wherein according to the invention in a first operating mode of the laser distance measuring device the inclination of a reference of the housing, in particular of a side of the housing, of the laser distance measuring device is determined and in a second operating mode the inclination of the laser beam, but at least the inclination of the theoretical emission direction of the laser beam in the switched-off state of the laser diode, of the laser distance measuring device is determined.

[0018] "Reference of the housing" is understood in particular to mean a design-related feature of the housing, for example, a side of the housing, an edge of the housing, a reference surface, a reference marking, or the like of the housing. The reference preferably has an extension in at least one dimension. Particularly preferably, the reference has an extension in the direction in which the inclination of the reference is determined.

[0019] It should be noted that the term "inclination of the laser beam" is also used below when no laser beam is emitted, for example, when the laser diode of the laser rangefinder is switched off. In this case, the term refers to the inclination of the theoretical emission direction of the laser beam, i.e., the inclination that the laser beam would have when switched on.

[0020] In contrast to laser distance measuring devices known from the prior art, in which the inclination of the device housing is determined, the method according to the invention allows the provision of two operating modes in which the determination of the inclination of a reference of the housing, in particular of a side of the housing, of the laser distance measuring device is made possible and the determination of the inclination of the laser beam of the laser distance measuring device is made possible.

[0021] Typically, the device's inclination relative to the horizontal or vertical is displayed, for example, by outputting a numerical value, as a digital spirit level, or as an angle scale. However, if a user of the laser distance meter performs indirect length measurements (for example, using two measured distances and the angle between the measured values ​​in the two measurement directions), outputting an inclination value relative to the housing can be confusing, as there is typically an angular difference between the housing's reference and the laser beam's emission direction due to its design. This angular difference occurs in varying magnitudes depending on the adjustment processes during production of the laser distance meter.During production, the accelerometer is calibrated to the housing's reference, and the actual direction of the laser beam (angle of elevation and azimuth) relative to the reference is determined. This data is stored and kept available in the laser rangefinder for correction of acceleration and / or inclination measurements.

[0022] Depending on the operating mode, either the inclination of the device, particularly in the case of pure angle measurements, or the inclination of the laser beam, particularly in the case of direct or indirect length measurements, is displayed. This makes it possible to always present the calculated values ​​consistently and in a way that is comprehensible and understandable for the user of the laser distance meter. This does not suggest to the user that the laser beam emitted from the housing of the laser distance meter is parallel to the housing edges. Nevertheless, the user of the laser distance meter can use the laser distance meter (within the specified accuracy) as an angle measuring device or as a spirit level with a horizontal / vertical beam.

[0023] According to the invention, it is possible to switch between the first operating mode and the second operating mode.

[0024] According to the invention, switching between the first operating mode and the second operating mode is possible using an input device. In particular, a user of the laser distance measuring device can manually select between the first operating mode and the second operating mode. The user can therefore select the evaluation of the inclination of either the reference of the housing, in particular one side of the housing, of the laser distance measuring device, or of the laser beam of the laser distance measuring device that is advantageous in a given measuring situation. In this way, a particularly flexibly operable laser distance measuring device can be realized.

[0025] In one embodiment of the method, the first operating mode is automatically selected, in particular switching from the second operating mode to the first operating mode, when a flat placement of the laser distance measuring device is detected or when the placement of the laser distance measuring device on a tripod is detected. In this way, a particularly user-friendly implementation of the laser distance measuring device can be specified, in which the user of the laser distance measuring device does not have to make any further choices. Furthermore, user confusion can be prevented in this way by always automatically selecting the correct operating mode and thus the advantageous evaluation of the inclination of either the reference of the housing, in particular of a side of the housing, of the laser distance measuring device, or of the laser beam of the laser distance measuring device in a measuring situation.

[0026] According to the invention, the inclination of the laser distance measuring device is output using an output device, in particular using a screen, of the laser distance measuring device. In this way, the inclination can be checked and / or adjusted directly by the user of the laser distance measuring device. Thus, the laser distance measuring device can be used with the function of a spirit level or a protractor. Furthermore, the user of the laser distance measuring device can reproduce, and in particular, recalculate, the values ​​calculated from the determined distances.

[0027] In one embodiment of the method, the inclination of the laser distance measuring device is output in the form of a numerical value, an angle scale, or a digital spirit level. This allows for a particularly intuitive functionality of the laser distance measuring device, which, in particular, minimizes the learning time required for proper operation of the laser distance measuring device.

[0028] Furthermore, a handheld laser distance measuring device according to claim 5 is proposed for carrying out the method according to the invention. The handheld laser distance measuring device has at least one laser distance measuring unit for contactlessly measuring a distance to a target point, an acceleration sensor or a yaw rate sensor for determining an inclination, and an evaluation device. The evaluation device is provided to determine a distance from a distance measurement by means of the laser distance measuring unit and to determine an inclination of a reference of the housing, in particular a side of the housing, of the laser distance measuring device or of the laser beam of the laser distance measuring device, determined by means of the acceleration sensor or the yaw rate sensor.

[0029] According to the invention, the laser distance measuring device has an output device, in particular a screen, for outputting the inclination. Drawings

[0030] The invention is explained in more detail in the following description with reference to exemplary embodiments illustrated in the drawings. The drawings, the description, and the claims contain numerous features in combination. Those skilled in the art will expediently consider the features individually and combine them into useful further combinations. Like reference numerals in the figures denote like elements.

[0031] They show: Figure 1 shows a perspective view of an embodiment of the laser distance measuring device according to the invention, Figure 2 shows a schematic representation of components integrated in an embodiment of the laser distance measuring device according to the invention, Figure 3 shows a schematic representation of an embodiment of the method according to the invention in a process diagram, Figure 4a shows schematic side views of an embodiment of the laser distance measuring device according to the invention, which is in exemplary measuring scenarios. Description of the embodiments

[0032] Figure 1shows a perspective view of an exemplary handheld laser distance measuring device 10, which has a housing 12, a touch-sensitive screen 14a as an input and output device 14, and an actuating element 16 for switching the laser distance measuring device 10 on and off and for starting and / or ending a measuring process. In the illustrated embodiment, the handheld laser distance measuring device 10 weighs less than 500 g, with the longest side of the housing 12 measuring less than 15 cm.

[0033] To measure the distance of the laser distance measuring device 10 to a target object (not shown in detail here), parallel laser radiation (not shown in detail here) is transmitted towards the target object via a transmitting optics 18, which consists, for example, of a lens system (not shown in detail here). The laser radiation reflected from a surface of the target object (not shown in detail here) is guided via a receiving optics 20 to a detector device (not shown in detail here) and detected there. From a phase comparison performed between the emitted laser radiation and the laser radiation reflected from the surface of the distant object, a light propagation time can be determined, and the desired distance between the laser distance measuring device 10 and the target object in the corresponding distance measuring direction can be determined using the speed of light.In this embodiment, the laser radiation is implemented as red laser light. The emitted laser radiation creates a projected laser spot on the target object.

[0034] In Figure 2The internal components of the handheld laser distance measuring device essential to the invention are shown in a schematic view. The laser distance measuring device 10 has a laser diode 22 for generating the laser radiation, a detector device 24, an evaluation device 26, an acceleration sensor 28, and a rotation rate sensor 30. In this exemplary embodiment, the detector device 24 has at least one single-photon avalanche diode (SPAD), preferably a SPAD array. The evaluation device 26 is provided to determine a light propagation time from a phase comparison performed between the emitted laser radiation and the laser radiation returning from the surface of the target object, and to calculate or determine the desired distance between the laser distance measuring device 10 and the target object using the speed of light.Furthermore, the evaluation device 26 is provided to determine inclination values ​​determined by means of an acceleration sensor 28 optionally as an inclination of a reference of the housing 12, in particular of a side of the housing 12, of the laser distance measuring device 10 or as an inclination of the laser beam, in particular as an inclination of the emission direction of the laser beam, of the laser distance measuring device 10.

[0035] In this exemplary embodiment, the acceleration sensor 28 measures at least the acceleration in a direction corresponding to the direction in which the laser beam is emitted. Furthermore, a rotation rate sensor 30 in this exemplary embodiment can determine the rotation rate around three mutually perpendicular axes (Cartesian coordinate system, not shown in detail). The measurement signals from both the acceleration sensor 28 and the rotation rate sensor 30 are forwarded to the evaluation device 26 for evaluation. The evaluation device evaluates the provided signals and determines from them either an inclination 32a of a reference of the housing 12, in particular a side 34 of the housing 12, or an inclination 32b of the laser beam 36, in particular the inclination of the emission direction of the laser beam 36.

[0036] A determined distance measurement value can be further processed by the evaluation device 26 of the laser distance measuring device 10 and / or output to the operator of the laser distance measuring device by means of the output device 14, in particular the screen 14a of the laser distance measuring device 10.

[0037] The laser distance measuring device 10 has a power supply device (not shown in detail) for its power supply, in particular a battery or an accumulator, preferably a lithium-ion accumulator.

[0038] In Figure 3A process diagram of an exemplary embodiment of the method according to the invention for operating the handheld laser distance measuring device 10 is shown. In a first method step 100, the measurement signals of the acceleration sensor 28 and / or the yaw rate sensor 30 are read out and forwarded to the evaluation device 26. In a first operating mode 102 of the laser distance measuring device 10, the inclination 32a of a reference of the housing 12, in particular a side 34 of the housing 12, is then determined from the measurement signals provided by the acceleration sensor 28 and / or the yaw rate sensor 30. In the second operating mode 104 of the laser distance measuring device 10, the inclination 32b of the laser beam 36 (or equivalently, the inclination 32b of the emission direction of the laser beam 36) of the laser distance measuring device 10 is determined.Subsequently, the result of the evaluation is output to the user of the laser distance measuring device 10 in method step 106 using the input and output device 14, in particular using the screen 14a. An output can be provided, for example, in the form of a numerical value, an angle scale, or a digital spirit level 38.

[0039] As indicated by method step 108, it is possible to switch between the two operating modes 102 and 104. A switch can be initiated, in particular, manually by the user using the input and output device 14 of the laser distance measuring device 10. Alternatively, the switch can also be initiated automatically, for example, when a flat placement of the laser distance measuring device 10 or the placement of the laser distance measuring device 10 on a tripod (not shown in detail) is detected. A separate sensor for detecting a flat placement of the laser distance measuring device 10 or the placement of the laser distance measuring device 10 on a tripod can be provided for this purpose (not shown in detail).

[0040] It should be noted that the process steps shown can be repeated, as indicated by the arrow 110 in Figure 3 is indicated.

[0041] In Figure 4Various exemplary measurement scenarios are shown in which the laser distance measuring device 10 according to the invention is used. The laser distance measuring device 10 is shown only schematically with a housing 12 and a screen 14a. Figure 4ashows, in a comparative illustration, the geometric relationship between the reference of the housing 12, which here is selected as side 34 of the housing 12, and the laser beam 36 (or at least its theoretical emission direction when the laser diode is switched off). In particular, the reference of the housing 12 and the laser beam 36 form an angle – symbolized by the angle symbol. While in the illustration the emitted laser beam 36 is inclined relative to the horizontal 40, the reference of the housing 12, here the side 34 of the housing 12, is parallel to the horizontal 40 – indicated by the "parallel symbol" on the dashed extension 34a of the side 34 of the housing 12 and the horizontal 40. This angular difference between the side 34 of the housing 12 and the emission direction of the laser beam 36 is due to the design and can vary depending on the adjustment processes during production of the laser distance measuring device 10.During production, the acceleration sensor 28 is calibrated to the reference of the housing 12, and the actual direction of the laser beam 36 (angle of elevation and azimuth) relative to the reference is determined. This data is stored and kept ready in the laser rangefinder 10 for correcting acceleration measurements and / or inclination measurements.

[0042] Figures 4b and 4c show the laser distance measuring device 10 during operation in the first operating mode 102, in which the inclination 32a of the reference of the housing 12, here the side 34 of the housing 12, is determined and output to the user of the laser distance measuring device 10. In Figure 4b the side 34 (as well as the dashed extension 34a) of the housing 12 is parallel to the horizontal 40, indicated by the "parallel symbol" on the dashed extension 34a of the side 34 and on the horizontal 40. Consequently, an inclination 32a of "0.0°" is displayed on the screen. Figure 4cIn contrast, the laser distance measuring device 10 is shown tilted, with the side 34 (as well as the dashed extension 34a) of the housing 12 tilted by the inclination 32a to the horizontal 40 (angle symbol). In this measurement scenario, an inclination 32a of "3.0°" is displayed on the screen. Furthermore, in the Figures 4b and 4c A symbol 42 is displayed on the screen, which signals that the laser distance measuring device 10 is in the first operating mode 102 (here represented by the symbol "x").

[0043] Figures 4d and 4e show the laser distance measuring device 10 during operation in the second operating mode 104, in which the inclination 32b of the laser beam 36 (or, when the laser diode is switched off, at least the inclination 32b of the theoretical emission direction) of the laser distance measuring device 10 is determined and output to the user of the laser distance measuring device 10. In Figure 4dThe laser beam 36 is inclined by the inclination 32b to the horizontal 40 (see angle symbol), since the housing 12 is aligned with its side 34 parallel to the horizontal 40. Consequently, an inclination 32b of "2.5°" is displayed on the screen. Figure 4e However, the emitted laser beam 36 is parallel to the horizontal 40 (again indicated by the "parallel symbol" on the laser beam 36 and the horizontal 40), so that an inclination 32b of "0.0°" is displayed on the screen. Furthermore, in the Figures 4d and 4e A symbol 42 is displayed on the screen, which signals that the laser distance measuring device 10 is in the second operating mode (here: "y").

[0044] Thus, depending on the operating mode of the laser distance measuring device 10, either the inclination 32a of the laser distance measuring device 10 (e.g., for use in angle measurements) or the inclination 32b of the laser beam 36 (e.g., for use in direct and indirect length measurements) is displayed. Depending on the selected operating mode, the inclinations are displayed consistently according to the selected application. Confusion for the user of the laser distance measuring device 10 is thus avoided.

Claims

1. Method for operating a hand-held laser distance measuring device (10) comprising a housing (12), in which a distance to a target point is determinable by a laser distance measuring unit of the laser distance measuring device (10) by means of emission of a laser beam (36) and in which an inclination (32a, 32b) is determinable by an acceleration sensor (28) and / or a rate-of-rotation sensor, wherein the inclination (32a) of a reference of the housing (12), in particular of one side (34) of the housing (12), of the laser distance measuring device (10) is determined in a first operating mode (102) of the laser distance measuring device (10) and the inclination (32b) of the laser beam (36) of the laser distance measuring device (10) is determined in a second operating mode (104), wherein there is switchability between the first operating mode (102) and the second operating mode (104) using an input device (14) of the laser distance measuring device (10) and the inclination (32a) of the reference of the housing (12) or the inclination (32b) of the laser beam (36) of the laser distance measuring device (10) is output using an output device (14), in particular using a screen (14a), of the laser distance measuring device (10).

2. Method according to Claim 1, characterized in that there is automatic switchability between the first operating mode (102) and the second operating mode (104).

3. Method according to Claim 2, characterized in that the first operating mode (102) is automatically selected, in particular there is switching from the second operating mode (104) to the first operating mode (102), if planar application of the laser distance measuring device (10) is detected or the placement of the laser distance measuring device (10) on a stand is detected.

4. Method according to any of Claims 1-3, characterized in that the inclination (32a, 32b) of the laser distance measuring device (10) is output in the form of a numerical value, an angle scale or a digital spirit level.

5. Hand-held laser distance measuring device (10) for carrying out a method according to any of Claims 1 to 4, at least comprising a laser distance measuring unit for non-contact measurement of a distance to a target point, an acceleration sensor (28) and / or a rate-of-rotation sensor for determining an inclination (32a, 32b) and an evaluation device (26), wherein the evaluation device (26) is provided for determining a distance from a distance measurement by means of the laser distance measuring unit and for determining inclinations (32a, 32b) determined by means of the acceleration sensor (28) and / or the rate-of-rotation sensor selectively as inclination (32a) of a reference of the housing (12), in particular of one side (34) of the housing (12), of the laser distance measuring device (10) or as inclination (32b) of the laser beam (36) of the laser distance measuring device (10), furthermore comprising an output device (14), in particular a screen (14a), for outputting the inclination (32a, 32b) and also an input device (14) for switching between the first operating mode (102) and the second operating mode (104).