Handheld laser distance meter and surveying system

Abstract

Handheld laser distance measuring device (100) for non-contact measurement of a distance to a target object (200), comprising: - a housing designed for manual use (10); - a measuring device (20) arranged in the housing (10) utilizing optical measuring radiation (1), by means of which the distance to the target object (200) can be measured without contact, with: a laser unit (21), an optical unit (OE) with optical elements at least comprehensively: a transmitting and receiving optic (22, 23), an optical transmission path (24) having an optical axis for emitting measurement radiation (1) onto the target object (200), an optical receiving path (25) having an optical axis for receiving measurement radiation (2) reflected and / or scattered from the target object (200), characterized by the fact that - at least one optical element influencing the optical transmission path (24) is movable from a starting position, - a motion sensor (90) is designed to detect movement of the housing (10) during the measurement; wherein - that at least one movable optical element can be moved from the initial position to a variable compensation position in such a way that the transmit path (24) can be stabilized to a fixed position in space while compensating for the movement of the housing (10) during the measurement.

Description

Technical field

[0001] The invention relates to a handheld laser distance measuring device for non-contact measurement of a distance to a target object according to the preamble of claim 1. State of the art

[0002] A distance measuring device of the type mentioned above is used particularly as a handheld laser distance meter. Non-contact measurement of the distance to a target object is usually performed using optical measuring radiation, such as laser radiation. In principle, various methods for distance measurement are known, regardless of the measuring radiation used. For example, the distance to a target object can be determined non-contact using time-of-flight measurement, phase measurement, or laser triangulation. To implement such or similar methods, the housing of the measuring device provides a measuring device arranged within the housing that utilizes optical measuring radiation, by means of which the distance to the target object can be measured without contact. An exemplary, advantageously designed measuring device for non-contact distance measurement via time-of-flight measurement is described, for example, in DE 101 12 833 C1.This device features a radiation unit in the form of a laser unit. Furthermore, an optical unit with optical elements for radiation guidance is provided. The optical elements comprise at least one transmitting and one receiving optic, which may be configured as a single optical element or as separate optical elements. A transmitting optic is arranged in an optical transmission path having an optical axis for emitting measurement radiation onto the target object. A receiving optic is arranged in an optical reception path having an optical axis for receiving measurement radiation reflected and / or scattered by the target object.

[0003] The aforementioned method for non-contact distance measurement, or the optical measuring device designed for this purpose, can be further improved. For example, DE 100 51 302 C5 describes a laser distance measuring device in which the transmit and receive paths are aligned in parallel and the sensitivity of the measuring device is increased. Other measuring devices are known, for example, from EP 1 718 989 B1 or EP 1 913 416 A1. EP 0 701 702 describes an optical measuring device in which the image plane and the object plane are displaceable relative to each other. DE 196 43 287 discloses a calibration method for an optical measuring device in a measuring device of the type mentioned above. Another possibility for compensating for measurement uncertainties is described in DE 102 32 878, in which characteristic curves of predetermined measurement uncertainties are stored in a storage medium.Similar to EP 0 701 702 or DE 100 51 302, DE 101 57 378 attempts to increase measurement accuracy by intervening in the optical measuring device, namely by deflecting the optical axes.

[0004] A desirable feature is a distance measuring device for non-contact distance measurement, in which measurement accuracy is further improved, particularly with regard to the measurement uncertainties of handheld devices. When measuring distances handheld, i.e., especially without the use of a tripod, it is practically impossible to keep the measurement spot still on the object being measured. The measurement is typically performed—as described, for example, in DE 103 44 586 or DE 198 04 051 B4—by directing the optical measurement radiation of the measuring device towards a target object and detecting the optical measurement radiation reflected from the target object within the measuring device using the transmitting and receiving optics described above.

[0005] Since every user, to a greater or lesser degree, possesses a natural tremor, the manual use of a measuring device proves particularly problematic with relatively narrow objects such as columns, streetlights, or the like. Edges on the object can also pose a problem, as even with a tremor present, it is not guaranteed that the measuring point reflecting the measurement radiation from the target object lies either only to the right or only to the left of the edge. This problem becomes increasingly serious the greater the distance between the measuring device and the target object. Description of the invention

[0006] This is where the invention comes in, the object of which is to provide a measuring device for non-contact measurement of the distance to a target object, in which the measurement accuracy is improved and the dynamic range of the measuring device is increased. In particular, measurement uncertainty resulting from user-induced handling should be reduced. Specifically, user-induced movement of the measuring device, especially tremor-induced movement in a measuring device, should leave the fundamental measurement inaccuracy of the device as unaffected as possible.

[0007] The problem relating to the laser distance measuring device is solved by the invention by means of a laser distance measuring device of the type mentioned at the outset, in which the features of claim 1 are provided according to the invention.

[0008] The invention is based on the consideration that, beyond the measurement inaccuracies inherent in the measurement method, a large proportion of the measurement uncertainties in a laser distance measuring device of the type mentioned above arise from movement of the housing during the measurement – ​​this applies particularly to a handheld laser distance measuring device. Furthermore, the invention is based on the consideration that such movements occur within a certain dynamic range, which on the one hand may not be perceptible to the user and on the other hand nevertheless has an influence on the measurement, and is therefore technically detectable by a motion sensor. Recognizing this, the concept of the invention proposes that at least one optical element influencing the optical transmission path be movable relative to a starting position and that a motion sensor be configured to detect movement of the housing during the measurement.Building on this combination, the concept of the invention proposes that the at least one movable optical element can be moved from its initial position to a compensation position. The movement is controlled such that the transmission path—outside the housing—can be stabilized in a fixed position, compensating for the movement of the housing during the measurement. Advantageously, the invention utilizes the benefits of a motion sensor to detect movement of the housing. The signals from the motion sensor can be used to cause the movable optical element to perform a suitable counter-movement, i.e., such that the transmission path can be stabilized in a fixed position, compensating for the movement of the housing during the measurement.

[0009] In a particularly preferred embodiment, a control unit, connected at input to a motion sensor and at output to an optical actuator, enables the conversion of a motion signal provided by the motion sensor into an actuator signal for the optical actuator. Specifically, the movable optical element can be moved via the optical actuator according to the actuator signal. In other words, the embodiment comprises a control unit with a control loop that uses a motion signal from the motion sensor to control an optical actuator in such a way that the movable optical element is caused to perform the appropriate counter-movement. In other words, the control variable is not so much a fixed position in space, but rather the movement of the housing.

[0010] According to the concept of the invention or its further development, it is advantageous that measurement results are unaffected by measurement uncertainties arising from the movement of a measuring point on the target object. In particular, the spatially fixed stabilization of the transmission path during measurement ensures that a measuring point on the target object remains stationary. This applies especially to movement dynamics and amplitudes within the range of a natural tremor of a user of the laser distance measuring device. This advantage is particularly pronounced with a handheld laser distance measuring device. As a result, a laser distance measuring device can be handled more precisely and conveniently in a simplified manner, since aiming at a target object by the user is more precise, or at least more convenient. In particular, a user is able to detect even narrow irregularities on the target object during the measurement.It is capable of reliably targeting even narrow objects for extended periods. At the very least, the invention's concept significantly reduces the fluctuation range of a measurement signal. This also leads to improved readability of distance values ​​on the laser distance measuring device.

[0011] Advantageous further developments of the invention can be found in the dependent claims and specify in detail advantageous possibilities for realizing the concept explained above within the scope of the task and with regard to further advantages.

[0012] In a particularly preferred embodiment, the movable optical element is realized by means of an optical unit that is movable as a whole – in particular, including all optical elements. In other words, the entire optical unit can be moved from a starting position to a compensation position such that the transmission path can be stabilized in a fixed position while compensating for the movement of the housing during the measurement. In particular, it can be provided that all optical elements can be moved together and to the same extent via an optical actuator according to an actuator signal – for example, a platform of the optical unit or similar connecting elements of all optical elements can be caused to perform a suitable counter-movement.Likewise, additionally or alternatively, and particularly preferably and equally applicable to the variants described below, the movable optical element can be formed separately from a transmitting and receiving optics unit, and in particular completely separately from the optical unit itself. For example, a mirror or the like, a movable deflecting optical element in the transmitting and / or receiving path, is suitable as a movable optical element. In order to stabilize the transmitting path at a fixed position while compensating for the movement of the housing during measurement, an optical unit can advantageously be manufactured in a proven manner, and the movable optical element can also be provided separately.

[0013] The measuring device utilizing optical measurement radiation, by means of which the distance to the target object can be measured without contact, can advantageously be implemented in a so-called biaxial or a so-called coaxial variant. The aforementioned designation refers to the relative arrangement of the transmit and receive paths. In the biaxial variant, it is advantageously provided that the transmit path is routed biaxially to the receive path via an output element of the transmitting optics. The output element of the transmitting optics can advantageously be a coupling lens or the like. It has proven particularly advantageous in the biaxial variant that the movable optical element is formed in the form of the output element. In other words, the output element of the transmitting optics can be moved relatively easily and advantageously according to the actuator signal.This has the advantage that the transmission path can be stabilized in a fixed position without interfering with other areas of the measuring device, while compensating for the movement of the housing during the measurement.

[0014] Advantageously, an input element of the receiving optics, such as a coupling lens or similar component, can also be movable as needed. In particular, the input element can be moved via an optical actuator connected to the control unit, according to an actuator signal. This measure has the advantage that even high-amplitude transmit path stabilization is possible without adversely affecting the received signal amplitude. Additionally, a sensor area of ​​the receiving path can be designed to be sufficiently large so that the detection of reflected and / or scattered measurement radiation is possible even with a stabilized transmit path and a comparatively high stabilization amplitude. As the size of the sensor area increases, more noise is generated by ambient light, which reduces the sensitivity.

[0015] In a particularly preferred second embodiment, the transmit path of the measuring device is guided coaxially to the receive path via a common output element of the transmitting and receiving optics. For example, the common output element can be a collimator lens or the like. In this embodiment, it has proven particularly advantageous that the movable optical element is formed in the form of the common output element. In this way, the transmit path of the measuring device can be relatively easily stabilized in a fixed position, compensating for the movement of the housing during the measurement. Simultaneously, the receive path is also adjusted accordingly, since the movable optical element is formed in the form of the common output element. Stabilizing the transmit path has practically no adverse effect on the signal level in the receive path.

[0016] Advantageously, in this further development, the optical unit features a movable beam splitter forming the movable optical element in the transmit and receive paths. A beam splitter of this type initially combines separately guided transmit and receive paths into a common transmit and receive path and directs this to a common output element of the transmit and receive optics. According to this further development, the movable beam splitter can be moved from a starting position to a compensation position such that the transmit path—in particular, a transmit path deflected by the beam splitter—is stabilized in space, compensating for the movement of the housing during the measurement.

[0017] Advantageously, the transmission path is rotated, i.e., subjected to an angular movement, while compensating for housing movement. In a particularly preferred embodiment—especially for all the variants mentioned above—the movable optical element is rotatable about at least one axis, preferably two axes. It is also possible, in a further embodiment, to design the movable optical element to be rotatable about three axes. In this embodiment, the optical actuator can advantageously be designed as a rotary motor or the like. This embodiment recognizes that a rotation of a measurement beam is generally quite sensitive with regard to signal quality in the receiving path. It has been found that a rotation of a measurement beam in the transmission path by, for example, 0.1° at a distance of 20 m already results in a displacement of the target point of the measurement beam on a target object by 3.5 cm.An amplitude of 0.1° is well within the range of a user's tremor. Measurements are regularly and unconsciously influenced by the user due to a rotation of the measurement beam. This is particularly true under poor measurement conditions, such as bright ambient light and a dark target surface. For targets narrower than 3.5 cm, it can typically take several seconds to achieve a stable measurement signal. The aforementioned improved design, utilizing a compensatingly rotated transmission path, ensures that a target point on the target remains at the target point with a comparatively reduced fluctuation amplitude, meaning the transmission path is stabilized at a fixed position.

[0018] Preferably, in this further development, the motion sensor is designed as a rotational acceleration sensor, a rotation rate sensor, or the like. In particular, a rotational acceleration sensor should be able to measure rotational acceleration about at least one, preferably two, and optionally three axes. A MEMS (Micro-Electro-Mechanical System) rotation rate sensor, a gyroscope, or other miniaturized angle sensors have proven particularly suitable.

[0019] Furthermore, and especially additionally, it has proven advantageous for the movable optical element to be displaceable along at least one, two, or three axes. In particular, an optical actuator can be configured as a linear actuator or the like. Within the scope of this further development, the motion sensor is preferably configured as a linear accelerometer, displacement sensor, or the like. Even if the displacement of the transmission path itself has a minor influence on the received signal, the contribution is nevertheless not always negligible. Stabilizing the transmission path by means of a displacement movement—in addition to or as an alternative to a rotational movement—which reacts to and compensates for a displacement of the measuring device housing, provides a further advantageous contribution to ensuring measurement accuracy.

[0020] Specifically, an optical actuator can be advantageously designed as a miniature motor, a piezoelectric actuator, or a magnetic and / or electrical actuator, or the like. Such an optical actuator can be integrated into a measuring device utilizing optical measurement radiation in a relatively compact form with low mass and easy controllability. Examples of implementation

[0021] Exemplary embodiments of the invention are now described below with reference to the drawing. These drawings are not necessarily to scale; rather, where explanatory, they are presented in a schematic and / or slightly distorted form. For further details regarding the teachings directly apparent from the drawing, reference is made to the relevant prior art. It should be noted that numerous modifications and changes concerning the form and details of an embodiment can be made without deviating from the general idea of ​​the invention. The features of the invention disclosed in the description, the drawing, and the claims can be essential for the further development of the invention, both individually and in any combination.Furthermore, the invention encompasses all combinations of at least two of the features disclosed in the description, the drawing, and / or the claims. The general idea of ​​the invention is not limited to the exact shape or detail of the preferred embodiment shown and described below, nor is it limited to an object that would be restricted compared to the object claimed in the claims. Where specified dimensioning ranges are given, values ​​lying within the stated limits are also disclosed as limit values ​​and may be used and claimed as desired. For the sake of simplicity, identical or similar parts, or parts with identical or similar functions, are used below as reference numerals.

[0022] Further advantages, features and details of the invention will become apparent from the following description of the preferred embodiments and from the drawing; this shows in: Fig. 1A, Fig. 1B: A schematic view of a handheld distance measuring device for non-contact distance measurement in a front view ( Fig. 1A) and a side view ( Fig. 1B); Fig. 2A, Fig. 2B: two particularly preferred variants of the distance measuring device of the Fig. 1 with varied measuring device - in Fig. 2A with biaxial beam guidance and in Fig. 2B with coaxial beam guidance; Fig. 3A, Fig. 3B: an illustrative representation of the effects of device rotation ( Fig. 3A) or device relocation ( Fig. 3B) on a distance measurement; Fig. 4: a measuring device with a transmit path stabilization increasing the measurement accuracy for a measuring device with a biaxial beam guidance, wherein a separate output element of the transmitting optics is movable into a suitable variable compensation position; Fig. 5: one in relation to Fig. 4. Modified embodiment in which the entire optical unit can be rotated into a suitable variable compensation position via an optical actuator according to an actuator signal; Fig. 6: a measuring device with a transmit path stabilization that increases the measurement accuracy for a measuring device with a coaxial beam path, in which a common output element of the transmitting and receiving optics can be moved into a variable compensation position in such a way that the transmit path can be stabilized to a fixed position while compensating for the movement of the housing during the measurement; Fig. 7: one in relation to Fig. 6. Modified embodiment in which the entire optical unit can be rotated via an optical actuator according to an actuator signal; Fig. 8: a particularly preferred embodiment in which a movable tilting mirror in the transmit and receive path of a - biaxial or coaxial - measuring device can be rotated into a variable compensation position such that the transmit path is stabilized in space while compensating for the movement of the housing during the measurement.

[0023] Fig. 1A and Fig. Figure 1B shows a distance measuring device 100 in the form of a handheld device for non-contact measurement of a distance to a target object, wherein the distance measuring device 100 is in Fig. 1A is shown in a front view of an operator side of the housing 10 and in Fig. Figure 1B shows a side view of the housing 10 - the components of the distance measuring device 100 are shown schematically.

[0024] The distance measuring device 100, which can also be described as a handheld laser distance measuring device, has a housing 10 designed for manual use – in this case, considerably larger than the surface area of ​​a hand, with corresponding haptics and, if applicable, ergonomics; nevertheless, for the sake of simplicity, the housing 10 is shown as rectangular. A measuring device 20, which can also be described as a laser distance measuring unit, utilizing optical measuring radiation 1, is housed in the housing 10. Possible variants of the measuring device 20 are shown in Fig. 2A and Fig. Figure 2B illustrates different handling situations for non-contact measurement of the distance to a target object. Fig. 3 shown in more detail.

[0025] The distance measuring device 100 has an operating and input arrangement 30 located on the housing 10, which in this case is a keypad embedded in the operating side of the housing 10. A display 40 is embedded in the operating side of the housing 10, on which both the measured distance to a target object and the operating status of the distance measuring device 100 can be shown. The measuring device 20 can be operated via the operating and input arrangement 30, and one of the reference stops of the housing 10, described below, can be selected. While the measurement via the optical measuring radiation 1 – here, for example, a laser beam – refers to an internal reference zero point NP, a user will regularly want to measure the distance to the target object with respect to one of the reference stops 50A, 50B, 50C, or 50D.By selecting the reference stop, for example via the operating and input arrangement 30, the distance to the target object can be referenced to different reference stops using fixed addition constants. The most important reference stop 50A is located on the rear of the device 10A. There are also other reference stops 50B, 50C, and 50D, for example on the front of the device 10B, at the tip 10D of a measuring extension, or at a mounting point 10C for a tripod thread, the center point of which can also serve as a reference stop 50C.

[0026] Referring to Fig. 3A and Fig. 3B The methods described above can be used to determine the distance between a target object 200 and the reference zero point NP of the measuring device 100. In this case, the distance measuring device 100 has a measuring device 20 utilizing optical measuring radiation 1, which is based on a time-of-flight measurement. Two variants of the measuring device 20A, 20B, which can be used for a measuring device 20, are shown as examples in Fig. 2A and Fig. Figure 2B shows both measuring devices 20A and 20B. Each device has a radiation unit 21, e.g., a laser unit, as well as a transmitting optic 22 and a receiving optic 23. The measuring device 20A and 20B also has an optical transmitting path 24 with an optical axis for emitting measurement radiation 1, here a laser beam, onto the target object 200. Furthermore, the measuring device 20A and 20B has an optical receiving path 25 with an optical axis for receiving measurement radiation 2 reflected from the target object 200. A detector 26, e.g., a photodiode, is arranged in the receiving path 25 for detecting the reflected and / or scattered measurement radiation 2. In both cases, the receiving optics 23 serve the measuring device 20A, 20B to focus the reflected and / or scattered measuring radiation 2 onto the detector 26. The measuring device 20A is designed with separate transmitting optics 22 and receiving optics 23, so that the transmitting path 24 and the receiving path 25 do not overlap.This arrangement of paths 24, 25 in measuring device 20A is also referred to as biaxial. In contrast, measuring device 20B is configured with a coaxial arrangement of paths 24, 25, wherein the transmit path 24 and the receive path 25 are brought together via a beam splitter 27 and overlap in the two common transmit and receive optics 22, 23. In the area between laser unit 21 and beam splitter 27, and between detector 26 and beam splitter 27, respectively, the transmit path 24 and the receive path 25 are routed separately.

[0027] Specifically, it will be determined how things will proceed. Fig. 3A and Fig. As shown in Figure 3B, in the measuring device 20, which is designed as a laser distance measuring unit, the measuring radiation 1 from a laser unit 21 in the form of a laser diode is focused by an optical lens of the transmitting optics 22. The focused measuring radiation 1 is directed from the front of the housing 10B towards the target object 200 – for example, a measuring point P1, P2, P3 – and forms a spot of light at the measuring point P1, P2, P3. The reflected and / or scattered measuring radiation 2 is focused by an optical lens of the receiving optics 23 onto the active area of ​​a photodiode of the detector 26 in the manner described. The measuring device 20 can be biaxial or coaxial. To determine the distance of the target object 200 to the reference zero point NP of the measuring device 100 – corresponding to the outward and return path – the measuring radiation 1, in this case laser light from the laser beam, is modulated. This modulation can be pulsed or sinusoidal.The modulation is such that the time difference between a transmitted and received measurement beam modulation can be measured. Using the speed of light factor, the simple distance between the reference zero point NP of the measuring device 100 and the target object 200 can be determined. This distance can be calculated, for example, in a control unit (not shown).

[0028] Fig. Figure 3A also illustrates the problem of handheld distance measurement without a tripod. Since everyone has a natural tremor to a greater or lesser degree, this is particularly noticeable with narrow target objects, such as... Fig. 3A the target object 200 - there is a high risk that, for example, if the measurement radiation 1 is rotated by even 0.1° to become a rotated measurement radiation 1' during the measurement, the target object 200 will no longer be hit by the measurement point P3. This occurs with transmission paths that are usually fixed to the housing under tremor-induced movement of the housing 10. In any case, a measurement point P1 can have a different reflected and / or scattered measurement radiation 2 than a measurement point P3, so that the change in the reflected and / or scattered measurement radiation 2 under rotation of the usually fixed transmission path 24 leads to a different measurement result. This circumstance must be expected in practically every measurement where a rotated measurement radiation 1' originates from a measuring device 20' that is rotated with the housing 10. It has been recognized that a rotation of the measuring device 20 to become a rotated measuring device 20' is comparatively critical. One of Fig. 3B The apparent displacement of measuring device 20 to a displaced measuring device 20" is comparatively uncritical, but nevertheless has an influence. While the displaced measuring device 20" also leads from a measurement radiation 1 to a displaced measurement radiation 1", this displaced measurement radiation 1" still has a measurement point P2 on the target object 200 with the same movement amplitude, which, like measurement point P1, generates reflected and / or scattered measurement radiation 2. Nevertheless, a change in the reflected and / or scattered measurement radiation 2 is to be expected, so that even a displaced measuring device 20" can lead to a measurement inaccuracy as a result of a tremor movement by the user.

[0029] For the sake of simplicity, the same reference symbols are used below for identical or similar parts or parts with identical or similar functions. Fig. 4 and Fig. Figure 5 shows slightly modified embodiments according to a first variant of a measuring device 20A.1 and 20A.2, which are used in a measuring device 100 as measuring device 20 or, by further development of the measuring device 20A, respectively. Fig. 2A can be used according to the concept of the invention.

[0030] Fig. 6 and Fig. Figure 7 shows modified embodiments of a measuring device 20B.1, 20B.2, which replace the measuring device 20 or in modification of the one described in Figure 20. Fig. The measuring device shown in 2B can be used with 20B.

[0031] Fig. Figure 8 shows a particularly preferred embodiment of a measuring device 20C.

[0032] Fig. Figure 4 illustrates a first preferred embodiment of a measuring device 20A.1 based on the measuring device 20A of the Fig. 2A. The measuring device 20A.1 has an optical unit OE comprising the transmitting optics 22, the receiving optics 23, the radiation unit 21, and the detector 26. A control unit SE for regulating the radiation unit 21 and the detector 26 is connected to the optical unit OE, which is implemented with a biaxial design. The transmitting optics 22, in this case an output coupling lens, is movable to a starting position, as indicated by the double arrow in the transmitting optics 22. An optical actuator 80 of the measuring device 20A.1 is connected to the transmitting optics 22 and can move them laterally in two directions x, y, thereby influencing the measurement radiation 1 coupled out via the transmitting optics 22. Additionally, the measuring device 20A.1 includes a motion sensor 90, which is configured to detect movement of the housing 10 and / or the measuring device 20A.1 during the measurement. The motion sensor 90 is implemented here as a gyroscope.This allows the rotation of the housing 10 and / or the measuring device 20A.1, and thus also of the measuring radiation 1, to be recorded around both the y-axis and the x-axis during the measurement. Suitable sensors include, for example, MEMS rotation rate sensors or gyroscopes. These can be used in single-axis, dual-axis, or triple-axis configurations. A motion signal can be supplied to the control unit SE via a control line SL and converted by the control unit SE into an actuator signal for the optical actuator 80, which functions as a linear actuator. In this case, this has the advantage that the control unit SE can digitally control the optical actuator 80 via a processor. Alternatively, the motion signal from the motion sensor 90 can also be used directly for the optical actuator 80, for example, via an amplifier and in analog form, to control it.As a result, the movable optical element, in the form of a transmitting optic 22, can be moved according to the actuator signal – in this case, laterally displaced in the y- and / or y-direction. This utilizes the fact that the lateral displacement of the transmitting optic 22 relative to the optical axis implies a change in the angle of the measurement radiation 1 in the transmission path 24. Specifically, using the optical actuator 80, the transmitting optic 22 can be displaced in the x- and / or y-direction based on the motion signals as a motion sensor 90, such that the transmission path 24 outside the measuring device 20A.1 is stabilized at a fixed position, compensating for the movement of the housing 10 during the measurement.

[0033] In the Fig. In the embodiment shown in Figure 4, the motion sensor 90 is a gyroscope. Additionally, the displacement of the housing 10 in the x and y directions can also be detected using a MEMS accelerometer. Here too, the optical actuator 80, controlled by the control unit SE via the control line SL, can be controlled by means of the motion signals via an actuator signal.

[0034] To convert the motion signals resulting from the rotation and displacement of the housing 10 into an actuator signal, a rough intermediate result of a measured distance to the target object 200 can initially be used. This allows for a more efficient control loop. Miniature motors, piezoelectric actuators, or those based on magnetic and / or electrical forces are suitable as optical actuators 80. Other operating principles for actuators, not listed here, are also conceivable.

[0035] The in Fig. The embodiment shown in Figure 4 works particularly well with a variable movement of the receiving optics 23, as indicated by the dashed double arrow. This movement can be achieved by an additional actuator (not shown) or by the optical actuator 80. Since the reflected and / or scattered measurement radiation 2 is held on the detector 26 in the receiving path 25 even when the compensation position of the transmitting path 24 changes, even large movement amplitudes can be realized. If necessary, the detector area of ​​the detector 26 can be made sufficiently large. This ensures high sensitivity of the detector 26 with respect to the reflected and / or scattered measurement radiation 2 in any case, even though the transmitting path is fixed in space and assumes a constantly changing compensation position.

[0036] Fig. Figure 5 shows a slightly modified measuring device 20A.2, in which the optical unit OE is again implemented using a biaxial design. Here, too, a motion sensor 90 in the form of a gyroscope serves to detect the rotation of the housing 10 as well as the measuring device 20A.2 about both the y-axis and the x-axis during a measurement. The control unit SE converts a corresponding motion signal into an actuator signal for the optical actuator 80 and transmits this via the control line SL. To detect individual movements of both the transmitting optics 22 and the receiving optics 23 – as in Fig. 4. To avoid potential issues, an optical actuator 80, specifically a rotary motor, is provided to rotate the entire optical unit OE around the x- and / or y-axis based on the actuator signals. This rotation ensures that the angle of the measurement beam 1 in the transmission path 24 is fixed in space, thus stabilizing a measurement point P1 on the target object 200. The optical actuator 80 can again be controlled via the control unit SE or via an amplifier (not shown) – i.e., digitally or analogously. In addition to rotating the housing 10, a displacement of the housing 10 can also be recorded. Furthermore, an intermediate result of the measured distance to a target object 200 can be used to stabilize the transmission path 24 and thus the measurement point P1 on the target object 200.

[0037] Fig. Figure 6 shows a second preferred embodiment of a measuring device 20B.1 based on a coaxial structure of an optical unit OE, as already described in Fig. Figure 2B shows that a control unit SE and an optical actuator 80, acting as a linear actuator, are connected to the optical unit OE. The control unit SE again serves to control the laser unit 21 and to acquire detector data from the detector 26. A motion signal provided by the motion sensor 90 – again in the form of a gyroscope of the type described above – is converted into an actuator signal for the optical actuator 80 by means of a control unit SE connected at its input to the motion sensor 90 – in this case, a gyroscope of the type described above – and at its output to an optical actuator 80 – acting as a linear actuator. The optical actuator 80 then acts on a movable optical element according to the actuator signal, the optical element being a transmitting and receiving optic 22, 23 in the form of a collimator lens.The collimator lens 22, 23 is common to the overlapping transmit and receive path 24, 25, whereby the measurement radiation 1 is coupled out via the collimator lens 22, 23 and the measurement radiation 2 reflected and / or scattered by the target object 200 is coupled in via the collimator lens 22, 23. The sketch on the right shows as in . Fig. Figure 4 clearly shows that the optical actuator 80 essentially comprises two actuator functions – an actuator unit 80x and an actuator unit 80y, each designed for a lateral displacement in the x and y directions. Here, too, it is exploited that a displacement of the collimator lens of the transmitting and receiving optics 22, 23 implies a change in the angle of the collimated laser beam.

[0038] Fig. Figure 7 shows a measuring device 20B.2, slightly modified from measuring device 20B.1, in which – similar to in Fig. 5 - the entire optical unit OE is rotated by the optical actuator 80 in the form of a rotary motor according to an actuator signal. This rotates the optical unit OE from its initial position into a variable compensation position such that the transmission path 24 in the coupled area outside the measuring device 20B.1 is stabilized in a fixed position, compensating for the movement of the housing 10 during the measurement.

[0039] Fig. Figure 8 shows a third embodiment of a measuring device 20C, comprising an optical unit OE, a control unit SE, an optical actuator 80, and a motion sensor 90 comprising a rotational acceleration sensor and a linear acceleration sensor. The motion sensor 90 is connected to the control unit SE and provides a motion signal—in this case, a rotational acceleration and a linear acceleration signal—to the control unit SE. The control unit SE converts the motion signal into an actuator signal for the optical actuator 80, which in turn consists of an actuator unit 80x and an actuator unit 80y, each for movement in the x and y directions. Based on and according to the actuator signal, a movable optical element, namely, in the case of the Fig. In the embodiment shown in Figure 8, a tiltable mirror 28 is moved from a starting position to a variable compensation position. In this case, a tilting movement in the x- or y-direction is performed such that the transmission path 24 for the measurement radiation 1 is stabilized in space while compensating for the movement of the housing 10 during the measurement. In contrast to the embodiments described above, the tiltable mirror 28 is formed as a movable optical element separately from the previously described optical unit OE and separately from a transmitting and receiving optic 22, 23. Thus, the optical unit OE can be configured in this case according to the example shown in Figure 8. Fig. 2A measuring device shown 20A biaxial or according to the example in Fig.The measuring device 20B shown in Figure 2B is coaxially configured. The measuring radiation 1 in the transmission path 24 is emitted via the optical unit OE and reaches the measuring point P1 of the target object 200 via the tiltable mirror 28. Using a motion sensor 90 – here a combination of gyroscope and displacement sensor – the control unit SE digitally converts the rotation of the housing 10 into a compensating, variable compensation position of the tiltable mirror 28. Here too, instead of the digital implementation with a control unit SE, the tiltable mirror 28 can be directly controlled by the optical actuator 80 via an amplifier. For this purpose, as in the previously described embodiments, the amplifier is suitable for generating an analog optical actuator signal from the motion signal.

Claims

[1] Handheld laser distance measuring device (100) for non-contact measurement of a distance to a target object (200), comprising: - a housing (10) designed for manual use; - a measuring device (20) arranged in the housing (10) and using optical measuring radiation (1), by means of which the distance to the target object (200) can be measured without contact, with: a laser unit (21), an optical unit (OE) with optical elements comprising at least: a transmitting and receiving optics (22, 23), an optical transmission path (24) having an optical axis for emitting measuring radiation (1) onto the target object (200), an optical receiving path (25) having an optical axis for receiving measuring radiation (2) reflected and / or scattered by the target object (200), characterized by , that - at least one optical element influencing the optical transmission path (24) is movable to a starting position, - a motion sensor (90) is designed to detect a movement of the housing (10) during the measurement; wherein - the at least one movable optical element can be moved from the starting position into a variable compensation position such that the transmission path (24) can be stabilized to a spatially fixed position while compensating for the movement of the housing (10) during the measurement. [2] Distance measuring device (100) according to claim 1, characterized by that a movement signal provided by the movement sensor (90) can be converted into an actuator signal for the optical actuator (80) by means of a control unit (SE) connected at the input to the movement sensor (90) and at the output to an optical actuator (80), wherein the movable optical element can be moved via the optical actuator (80) in accordance with the actuator signal. [3] Distance measuring device (100) according to claim 1 or 2, characterized by that the movable optical element is formed by means of an optical unit (OE) which is movable as a whole and which is movable in accordance with an actuator signal via an optical actuator (80). [4] Distance measuring device (100) according to one of claims 1 to 3, characterized by that the transmission path (24) is guided biaxially to the reception path (25) via an output element of the transmission optics (22) and the movable optical element is formed in the form of the output element. [5] Distance measuring device (100) according to claim 4, characterized by that an input element of the receiving optics (23) is movable, in particular via an optical actuator (80) connected to the control unit (SE) in accordance with an actuator signal. [6] Distance measuring device (100) according to one of claims 1 to 3, characterized bythat the transmission path (24) is guided coaxially to the reception path (25) via a common output element of the transmission and reception optics (22, 23) and the movable optical element is formed in the form of the common output element. [7] Distance measuring device (100) according to claim 6, characterized by that the optical unit (OE) has a movable beam splitter (27) forming the movable optical element in the transmission and reception path (24, 25), in particular a displaceable and / or tiltable beam splitter (27). [8] Distance measuring device (100) according to one of claims 1 to 7, characterized by that the movable optical element is formed separately from a transmitting and receiving optics (22, 23) as a mirror (28) in the transmitting path (24) and / or receiving path (25). [9] Distance measuring device (100) according to one of claims 1 to 8, characterized bythat the movable optical element is rotatable about at least one axis, wherein the optical actuator (80) is formed as a rotary motor or the like. [10] Distance measuring device (100) according to one of claims 1 to 9, characterized by that the motion sensor (90) is formed as a rotational acceleration sensor or rotation rate sensor or the like. [11] Distance measuring device (100) according to one of claims 1 to 10, characterized by that the movable optical element is displaceable along at least one axis, wherein the optical actuator (80) is formed as a path motor or the like. [12] Distance measuring device (100) according to one of claims 1 to 11, characterized by that the motion sensor (90) is formed as a linear acceleration sensor or displacement sensor or the like. [13] Distance measuring device (100) according to one of claims 1 to 12, characterized bythat the optical actuator (80) is formed in the form of a miniature motor, piezo actuator, magnetoelectric actuator or the like.

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