OPTICAL POSITIONING AID FOR A DISTANCE SENSOR, DISTANCE MEASURING SYSTEM AND CORRESPONDING METHOD

Abstract

An optical positioning aid for a distance sensor for assisting in the positioning of the distance sensor relative to a measurement object includes a light source and a control unit. The light source is generates a setting light beam having a wavelength in the visible range and is suitable for generating a light spot on a measurement object. The control unit has a distance input and is communicatively connected to the light source to control at least one property of the setting light beam. The control unit evaluates an input value input into the distance input and influences at least one property of the setting light beam on the basis of a result of the evaluation such that the setting light beam allows conclusions to be drawn concerning the input value. A distance measuring system and a method for assisting in the positioning of a distance sensor are also disclosed.

Claims

1. An optical positioning aid for a distance sensor for assisting in the positioning of the distance sensor relative to a measured object, comprising: a light source for generating a setting light beam, wherein the setting light beam has a wavelength in a visible range and is suitable for generating a light spot on a measured object, and a control unit which has a distance input and is communicatively connected to the light source in order to control at least one property of the setting light beam, wherein the control unit is designed to evaluate an input value input into the distance input and to influence at least one property of the setting light beam on the basis of a result of the evaluation in such a way that the setting light beam allows conclusions to be drawn about the input value.

2. The optical positioning aid according to claim 1, wherein the at least one property of the setting light beam comprises a wavelength, an intensity, a variation pattern, and/or a variation frequency of the setting light beam.

3. The optical positioning aid according to claim 1, wherein the light source comprises a light generator and a focusing device for influencing the beam path of the setting light beam.

4. The optical positioning aid according to claim 1, wherein the light source comprises an optical means for influencing the at least one property of the setting light beam.

5. The optical positioning aid according to claim 1, wherein the input value is formed by a measured distance value, an evaluation measure representative of a measured distance, or a difference of a measured distance value relative to a reference point in a distance measuring range of the distance sensor.

6. A distance measuring system comprising: a distance sensor for measuring a distance between the distance sensor and a measured object; and an optical positioning aid according to claim 1, wherein the distance sensor is communicatively connected to the optical positioning aid and inputs an input value that is representative of a measured distance value, into the distance input of the optical positioning aid.

7. The distance measuring system according to claim 6, wherein the setting light beam is arranged relative to the distance sensor in such a way that the setting light beam marks a lateral measuring range of the distance sensor.

8. The distance measuring system according to claim 6, wherein the distance sensor is formed by an optical sensor.

9. The distance measuring system according to claim 8, further comprising an optical coupler that couples a measuring light beam emitted by the distance sensor and the setting light beam such that the measuring light beam and setting light beam can be directed by a common optical means to the measured object.

10. The distance measuring system according to claim 8, wherein the optical sensor emits a measuring light beam that is used as a setting light beam during a setting mode of the sensor.

11. The distance measuring system according to claim 6, wherein the distance sensor is a capacitive sensor or an inductive sensor.

12. A method for assisting in the positioning of a distance sensor relative to a measured object, comprising the steps of: generating an input value by measuring a distance between the measured object and the distance sensor, evaluating the input value in order to generate a result of the evaluation, generating a setting light beam by a light source of a positioning aid, and directing the setting light beam at the measured object in order to generate a light spot on the measured object, wherein at least one property of the setting light beam is influenced on the basis of the result of the evaluation such that the setting light beam allows conclusions to be drawn about the input value.

13. The method according to claim 12, wherein the input value is compared with a target value and/or a target range in the step of evaluating the input value.

14. The method according to claim 13, wherein the target value and/or the target range characterizes a distance measuring range of the distance sensor, wherein, in the case of an input value within the distance measuring range, the setting light beam is generated with a first set of properties and, in the case of an input value outside the distance measuring range, the setting light beam is generated with a second set of properties, wherein the first and second sets of properties are different from one another.

15. The method according to claim 13, wherein the target value and/or the target range characterizes a distance measuring range of the distance sensor, wherein, in the case of an input value within a characteristic range of the distance measuring range, the setting light beam is generated with a third set of properties and, in the case of an input value outside the characteristic range, the setting light beam is generated with a fourth set of properties, wherein the third and fourth sets of properties are different from one another.

16. The optical positioning aid according to claim 3, wherein the light generator is a light-emitting diode or a laser diode.

17. The distance measuring system according to claim 8, wherein the optical sensor is an interferometry sensor, a confocal chromatic sensor, or a triangulation sensor.

18. The distance measuring system according to claim 9, wherein the common optical means is an optical waveguide.

19. The method according to claim 15, wherein the characteristic range of the distance measuring range is a beginning of the measuring range, a center of the measuring range, or an end of the measuring range.

20. The method according to claim 12, wherein the method is performed using a distance measuring system comprising: a distance sensor for measuring the distance between the distance sensor and the measured object; and an optical positioning aid comprising: a light source for generating a setting light beam, wherein the setting light beam has a wavelength in a visible range and is suitable for generating a light spot on the measured object, and a control unit which has a distance input and is communicatively connected to the light source in order to control at least one property of the setting light beam, wherein the control unit is designed to evaluate an input value input into the distance input and to influence at least one property of the setting light beam on the basis of a result of the evaluation in such a way that the setting light beam allows conclusions to be drawn about the input value; and wherein the distance sensor is communicatively connected to the optical positioning aid and inputs the input value that is representative of a measured distance value, into the distance input of the optical positioning aid.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0053] There are various possibilities for designing and developing the teaching of the present disclosure in an advantageous manner. In this regard, with the aid of the drawings, reference is made, on the one hand, to the claims subordinate to the independent claims and, on the other hand, to the following explanation of preferred exemplary embodiments of the present disclosure. Generally preferred embodiments and developments of the teaching are also explained in conjunction with the explanation of the preferred exemplary embodiments of the present disclosure with reference to the drawings. Shown in the drawing are the following:

[0054] FIG. 1 illustrates a schematic representation of a first exemplary embodiment of a distance measuring system according to the present disclosure with a distance sensor in the form of an interferometry sensor,

[0055] FIG. 2 illustrates a schematic representation of an exemplary embodiment of a positioning aid according to the present disclosure,

[0056] FIG. 3 illustrates a schematic representation of a second exemplary embodiment of a distance measuring system according to the present disclosure with a distance sensor in the form of a triangulation sensor,

[0057] FIG. 4 illustrates a diagram showing an exemplary curve of a variation of the pulse duration and/or of the duty cycle of a setting light beam,

[0058] FIG. 5 illustrates a diagram showing an exemplary curve of an intensity by varying a duty cycle as a function of a measurement path x,

[0059] FIG. 6 illustrates a diagram showing an exemplary curve of an intensity as a function of a measurement path x, and

[0060] FIG. 7 illustrates a diagram showing an exemplary curve of a variation of the wavelength of a setting light beam.

DETAILED DESCRIPTION

[0061] FIG. 1 shows a schematic representation of a first exemplary embodiment of a distance measuring system according to the present disclosure. The distance measuring system 1 comprises a distance sensor 2 in the form of a white light interferometry sensor, which generates a polychromatic measuring light in the near infrared range (NIR). The measuring light beam is directed by means of an optical waveguide to an optical coupler 3, at the output of which an optical waveguide 4 is arranged. The optical waveguide 4 forwards the measuring light beam to a measuring head 5. A second input of the optical coupler 3 is connected to a positioning aid 6 which generates a setting light beam and also outputs the setting light beam to the measuring head 5 via the optical coupler 3 and the optical waveguide 4. The measuring head 5 radiates an illumination light beam 7 onto a measured object 8, wherein the illumination light beam 7 is a sum of the measuring light beam and the setting light beam. Since the measuring light beam and the setting light beam use the same measuring optics, both light beams are arranged coaxially to one another. The illumination light beam 7 is reflected at the surface of the measured object 8. The spectral portion of the illumination light beam 7 which is focused on the surface of the measured object 8 passes back into the distance sensor 2 via the measuring head 5, the optical waveguide 4 and the optical coupler 3. The distance a from the measured object 8 is deduced from the received spectral portion. An evaluation unit 9 is used to evaluate, store, and display measured values for a user.

[0062] FIG. 2 shows the positioning aid 6 again in more detail. The positioning aid 6 has a light source 10 which generates and outputs a setting light beam 11. The light source 10 itself comprises a light generator 12 and an optical means 13. The light generator 12 can be formed by an LED or a laser diode. The optical means 13 can comprise a focusing device or a further optical means for influencing at least one optical property of the setting light beam 11. The positioning aid 6 additionally has a control unit 14 which is communicatively connected to the light source 10. The control unit 14 additionally has a distance input in which an input value representative of a measured distance can be input.

[0063] During operation of the distance measuring system 1, the distance sensor 2 generates a measured distance value by measuring the distance a from the measured object 8. This measured distance value is input into the distance input 15 of the control unit 14, possibly using the evaluation unit 9. The control unit 14 is designed to evaluate the input value and to influence at least one property of the setting light beam on the basis of a result of the evaluation so that the setting light beam allows conclusions to be drawn about the input value. By means of the coaxial arrangement of the measuring light beam and the setting light beam, the lateral measuring range of the distance sensor 2 can be deduced by means of a light spot generated by the setting light beam on the surface of the measured object 8. Even if the measuring light beam is outside the visible range, a correct positioning of the distance measuring system 1 relative to the measured object 8 can be deduced by the setting light beam 11 in the visible range and by influencing at least one property of the setting light beam on the basis of the input value.

[0064] FIG. 3 schematically depicts a second exemplary embodiment of a distance measuring system 1′ according to the present disclosure, wherein the distance sensor is designed as a triangulation sensor 16. For the sake of clarity, only the light source for generating the measuring light beam 17, but not the detection unit of the sensor, is shown. In this exemplary embodiment too, a positioning aid 6 is provided, which generates a setting light beam 11 and radiates it in the direction of the measured object 8. Since the illumination light beam 11 and the measuring light beam 17 form a triangle, the setting light beam only roughly marks the lateral measuring range of the triangulation sensor 16. However, the measuring light beam 17 of a triangulation sensor 16 is in the visible range so that the lateral measuring range of the distance measuring system 1′ can be seen from the measuring light beam 17. In this case, the setting light beam 11 serves exclusively for making the distance measuring range recognizable.

[0065] In one development of this second exemplary embodiment, an optical coupler can be used as in the first exemplary embodiment, which coupler couples the measuring light beam and the setting light beam coaxially, for example. It is also conceivable that no separate positioning aid is used, but that the positioning aid is an integral component of the triangulation sensor, i.e., the measuring light beam is used as a setting light beam in a setting mode and varies in its intensity as a function of a measured distance, for example.

[0066] In FIGS. 4 to 7, four options of how a property of the setting light beam can be changed are shown by way of example. In FIG. 4, the intensity of the setting light beam is varied over time between an upper intensity value I.sub.0 and an intensity value equal to 0. The period length T of the variation and thus the variation frequency can be selected as a function of a measured distance value.

[0067] FIG. 5 shows a different change in the intensity as a function of a measurement path x, namely by changing the duty cycle t.sub.1/T. In this case, t.sub.1 denotes the period of time during which the intensity assumes an upper intensity value I.sub.0. The period length T can be kept constant. The further a measured distance deviates from the center of the measuring range x.sub.M, the more quickly the intensity assumes the upper intensity value I.sub.0. At a duty cycle of 100%, the upper intensity value I.sub.0 is used continuously. With a period length T in the range of seconds, a setting light beam is produced in this way, which pulses less and less when the center of the measuring range is reached. In the case of short period lengths, for example in the range of 10 milliseconds or below, the setting light beam always appears to become brighter, the closer the measurement path comes to the center of the measuring range x.sub.M.

[0068] In FIG. 6, the intensity I is changed as a function of a measurement path x. In the area of a center of a measuring range x.sub.M, a maximum intensity I.sub.max of the setting light beam is reached. The further a measured distance deviates from the center of the measuring range x.sub.M, the further the intensity I decreases. In the example shown, the intensity has a dependence on the measured value in the form of a bell curve.

[0069] FIG. 7 shows a quite similar dependence. However, here, the wavelength λ of the setting light beam is varied continuously (or semi-continuously) between a lower wavelength value λ.sub.1 and an upper wavelength value λ.sub.2 as a function of the measurement path x. In this case, the upper wavelength value λ.sub.2 is reached in the center of the measuring range x.sub.M.

[0070] With regard to other advantageous embodiments of the positioning aid according to the present disclosure and of the distance measuring system according to the present disclosure, reference is made to the general portion of the description and the appended claims, to avoid repetition.

[0071] Finally, it is expressly pointed out that the above-described exemplary embodiments serve only to explain the claimed teaching but do not restrict it to the exemplary embodiments.

LIST OF REFERENCE SIGNS

[0072] 1 Distance measuring system

[0073] 2 Distance sensor

[0074] 3 Optical coupler

[0075] 4 Optical waveguide

[0076] 5 Measuring head

[0077] 6 Positioning aid

[0078] 7 Illumination light beam

[0079] 8 Measured object

[0080] 9 Evaluation unit

[0081] 10 Light source

[0082] 11 Setting light beam

[0083] 12 Light generator

[0084] 13 Optical means

[0085] 14 Control unit (of the positioning aid)

[0086] 15 Distance input

[0087] 16 Triangulation sensor

[0088] 17 Measuring light beam

[0089] The various embodiments described above can be combined to provide yet further embodiments. These and other changes can be made to the embodiments in light of the above-detailed description. In general, in the following claims, the terms used should not be construed to limit the claims to the specific embodiments disclosed in the specification and the claims, but should be construed to include all possible embodiments along with the full scope of equivalents to which such claims are entitled.