Rangefinder with grating

Abstract

A grating for determining a distance between a transmitter strip and a receiver strip, having a transmitter strip with one or more transmitter elements, which emit a beam with a certain intensity, a receiver strip with one or more receiver elements, which receive the beam of the assigned transmitter element, a control device for controlling the transmitter elements and / or the receiver elements and for evaluating the receiver elements, wherein the transmitter elements and the receiver elements, respectively, or at least one of the transmitter elements and / or at least one of the receiver elements, respectively, are designed as qualified transmitter elements and receiver elements, wherein the qualified transmitter element or the qualified transmitter elements are designed to emit different intensities and / or the qualified receiver element or the qualified receiver elements are designed to use different amplification factors and to output an intensity value of the received and amplified beam, and the control device is designed to control different combinations of intensities and amplification factors of the qualified transmitter elements and / or receiver elements and to derive a distance value from the sum of the resulting intensity values of the controlled combinations.

Description

TECHNICAL FIELD

[0001] The invention relates to a light barrier for object recognition. BACKGROUND

[0002] From the prior art, light barriers are known which have emitter strips and receiver strips and form a grid of light rays between them for object recognition. In particular, one or both slats of the light barrier can be fixed on one or more sliding doors of an elevator car in order to detect the passage of an object through the open door area.

[0003] CN 111 273 371 A discloses a light curtain, in which case the emitters and receivers can be actuated by a control unit, respectively, so that the emitters emit at different intensities and the receivers provide different amplification factors. Furthermore, the number of time periods of the scan during reception can be adjusted. This makes it possible to improve the installation of the light curtain, in particular at greater distances, to reduce or eliminate installation inaccuracies and inaccuracies caused by ambient light. SUMMARY

[0004] It is an object of the invention to propose a light barrier which enables a more differentiated monitoring at low cost.

[0005] The object is achieved by a light barrier of the type mentioned above according to claim 1. Advantageous designs are given in the other dependent claims.

[0006] The light barrier according to the invention is a light barrier for determining a distance between an emitter strip and a receiver strip, having an emitter strip with one or more emitter elements which emit a beam with an intensity, a receiver strip with one or more receiver elements which receive the beam of the assigned emitter element, a control device for controlling the emitter elements and / or the receiver elements and for evaluating the receiver elements, wherein the emitter elements and the receiver elements, respectively, or at least one of the emitter elements and / or at least one of the receiver elements, respectively, are designed as qualified emitter elements and receiver elements, wherein the or the qualified emitter elements are designed to emit different intensities and / or the or the qualified receiver elements are designed to use different amplification factors and to output an intensity value of the received and amplified beam, and the control device is designed to control different combinations of intensities and amplification factors of the qualified emitter elements and / or receiver elements and to determine a distance value from the sum of the resulting intensity values of the controlled combinations.

[0007] This has the advantage that the distance between the transmitter strips and the receiver strips can be determined. At the same time, however, dynamic processes can also be tracked and analyzed well. The grid also does not sacrifice any safety requirements.

[0008] Preferably, the grating, in particular the transmitter strips and the receiver strips, also has at least one or more further transmitter elements and receiver elements, which are each designed as simple transmitter elements and simple receiver elements and are each designed as light barriers and preferably do not contribute to the combination and / or from which no distance value is determined and / or which are used for object detection and / or whose simple transmitter elements emit at least one intensity like the qualified transmitter elements and whose receiver elements have at least one amplification factor like the qualified receiver elements.

[0009] This has the advantage that the grating can be used for object detection. This can have the advantage that not all transmitter elements and receiver elements have to be designed as qualified, whereby the complexity of the grating can be reduced and costs can be saved. This embodiment of the invention, however, also achieves a compromise between accurate object recognition and cost advantage, since not all transmitter elements or receiver elements have to be equipped with the same functionality, but individual elements can also be equipped with less functionality at low cost.

[0010] According to the invention, the control device is designed to control the combinations in a sequence one after the other and in particular for the sequence to be repeated periodically and in particular for the sum of the controlled combinations of the sequence to be determined and in particular for a distance value to be determined for each sequence. Preferably, the control device is designed to control all different combinations of the intensities and amplification factors of the qualified transmitter elements and / or receiver elements, however in particular without using the highest intensity of the qualified transmitter elements for these combinations and / or using the following intensities and amplification factors of the qualified transmitter elements and receiver elements, which correspond to the intensities and amplification factors of the simple (unqualified) transmitter elements and / or receiver elements.

[0011] This has the advantage that a distance value occurs after a certain period of time, which is fixed, is determined repeatedly quasi-continuously and occurs dynamically in chronological order. This has the advantage that the distance value can be calculated simply and quickly. This can have the advantage that the greatest resolution or accuracy of the distance value is achieved. This can have the advantage that the number of transmitter elements and receiver elements required for object recognition does not have to be increased by the qualified transmitter elements and receiver elements.

[0012] Preferably, the one or more qualified transmitter elements are designed to emit a plurality of different intensities, respectively, individually, and / or to emit intensities which differ from one another, and / or to emit the same intensity, respectively, which is in particular the highest intensity and in particular corresponds to the intensity of the unqualified transmitter elements.

[0013] This can have the advantage that for different distance ranges optimized intensities are available, the resolution of the distance values is increased and the resolution of the distance values is consistently constant over the entire distance range. The advantage of this is that the qualified transmitter elements can also be used for object recognition.

[0014] Preferably, the one or more qualified receiver elements are designed to use a plurality of different amplification factors, respectively, individually, and / or to use the same different amplification factors, and / or to use the same amplification factor, respectively, which is in particular the highest and in particular corresponds to the amplification factor of the unqualified, i.e. simple, receiver elements.

[0015] This can have the advantage that for different distance ranges optimized amplification factors are available, the resolution of the distance values is increased, the resolution of the distance values is consistently constant over the entire distance range. The advantage of this is that the qualified receiver elements can also be used for object recognition.

[0016] The grating preferably has three qualified transmitter elements and receiver elements, respectively, in addition to further simple transmitter elements and receiver elements which do not contribute to the combination and / or from which no distance value can be determined. Preferably, the one or more qualified transmitter elements are designed to emit three intensities, respectively, wherein one intensity is the same as the intensity of the unqualified, i.e. simple, transmitter elements which are set up for object recognition, and wherein two intensities are lower than this same intensity and differ from all other intensities. Preferably, the one or more qualified receiver elements are designed to use the same two different amplification factors, respectively, wherein the higher amplification factor corresponds to the amplification factor of the unqualified, i.e. simple, receiver elements which are set up for object recognition. Preferably, the control device is designed such that twelve combinations are formed by the three qualified transmitter elements and receiver elements, the two different lower intensities of the qualified transmitter elements and the same two different amplification factors of the receiver elements, respectively. Preferably, the control device is designed to use the following intensities and amplification factors of the qualified transmitter elements and receiver elements for identifying an object, which correspond to the intensities and amplification factors of the unqualified, i.e. simple, transmitter elements and / or receiver elements.

[0017] The advantage of this is that a very fine resolution can be provided for the distance values.

[0018] Preferably, the grating has a sending device designed to send the distance value wirelessly.

[0019] This has the advantage that the behavior of the car door can be transmitted and evaluated without intervention in the control and electronics of the elevator.

[0020] Further features of the invention are shown in the drawings.

[0021] The advantages mentioned individually can also be achieved with some combinations of features for which these advantages are not mentioned in connection with these combinations of features. BRIEF DESCRIPTION OF DRAWINGS

[0022] Embodiments of the invention are shown in the drawings and explained in more detail below. Identical reference signs in the various figures represent elements corresponding to one another.

[0023] Figure 1 A grating is shown;

[0024] Figure 2a An open double sliding door of an elevator car with a grating is shown;

[0025] Figure 2b A half-open double sliding door as Figure 2a is shown;

[0026] Figure 2c A closed double sliding door as Figure 2a is shown;

[0027] Figure 3 A measurement curve diagram is shown;

[0028] Figure 4 All measurement curve diagrams are shown;

[0029] Figure 5 A distance value curve diagram is shown. DETAILED DESCRIPTION

[0030] Figure 1 A grating 20 with a transmitter strip 21 and a receiver strip 22 according to the invention is shown. The transmitter strip 21 has three qualified transmitter elements 31 and other unqualified transmitter elements 33, to which IR radiation can be emitted with a certain intensity. The receiver strip 22 has three qualified receiver elements 32 and other unqualified receiver elements 34. The transmitter strip and the receiver strip are each arranged vertically and parallel to one another and opposite one another at the same height. Each qualified transmitter element 31 is assigned a qualified receiver element 32 at the same height, and these receiver elements together form a horizontal emission beam 30. The grating 20 also has a control device 35.

[0031] Figures 2a to 2cA grating 20 is shown on a double sliding door 10 of an elevator car. Figure 1 The emitter strip 31 is fixed on one door leaf of the double sliding door, while the receiver strip 32 is fixed on the opposite door leaf of the double sliding door. The rest of the arrangement is shown as in Figure 1 The emitter strip 31 and the receiver strip move with the double sliding door and remain arranged parallel to each other and at the same height, so that the light beams remain horizontal and are assigned to the respective eligible emitter elements and receiver elements. When the door is closed, they reduce their distance together with the door, while when the door is opened, they increase their distance together with the door. The distance between the emitter strip and the receiver strip is equal to the distance between the two door leaves of the double sliding door, except for a constant factor. Figure 2a An open door is shown. Figure 2b A half-closed door is shown. Figure 2c A closed door is shown.

[0032] The ineligible emitter elements emit with intensity Tx:High, and the ineligible receiver elements have two amplification factors, Rx:High and Rx:Low. Rx:Low is lower than Rx:High. These amplification factors are used simultaneously and evaluated separately.

[0033] The first eligible emitter element T1 can emit with intensity T1:Lowl, T1:Mid1 or T1:High, the second eligible emitter element T2 can emit with intensity T2:Low2, T2:Mid2 or T3:High, and the third eligible emitter element T3 can emit with intensity T3:Low3, T3:Mid3 or T3:High. The intensities Tx:High, T1:High, T2:High and T3:High are the same. All other intensities are lower. The intensities are in ascending order: T1:Lowl < T2:Low2 < T3:Low3 < Mid1 < Mid2 < Mid3 < Tx:High. The three eligible receiver elements R1, R2, R3 can each use the amplification factor Rx:Low or Rx:High.

[0034] The control device controls the ineligible emitter elements and receiver elements using Rx:High for distances over 1 m and Rx:Low for distances below 1 m, so that reflections can be avoided.

[0035] The control device controls a series of combinations of different intensities and amplification factors and evaluates them for a distance value. The highest intensity Tx:High is not used for this purpose. The combinations are controlled and evaluated individually, respectively. The combinations are: Tl:Lowl+Rl:Low, Tl:Midl+Rl:Low, Tl:Lowl+Rl:High, Tl:Midl+Rl:High, T2:Low2+R2:Low, T2:Mid2+R2:Low, T2:Low2+R2:High, T2:Mid1+R2:High, T3:Low3+R3:Low, T3:Mid3+R3:Low, T3:Low3+R3:High, T3:Mid1+R2:High.

[0036] This is 12 combinations.

[0037] Figure 3 is a graph 40 of intensity versus distance and shows a measurement curve for one combination. The x-axis 41 shows the distance from the transmitter strip to the receiver strip. The point 42 shows the minimum distance that can be evaluated and the point 43 shows the maximum distance that can be evaluated. The y-axis 44 shows the intensity value output by the eligible receiver element for the particular combination.

[0038] The measurement curve 51 exemplarily shows a combination of a medium intensity of the eligible transmitter element and a medium amplification factor of the eligible receiver element. The measurement curve 51 shows a very steep course at medium distances and is in saturation at short distances and has no signal at longer distances. Thus, the measurement curve shows only a small distance range with good resolution.

[0039] Figure 4 is a graph 40 according to Figure 3 and shows the overlap of all twelve measurement curves 52 of the twelve combinations.

[0040] Various different intensities and amplification factors Rx:Low are selected so that a roughly uniform sequence of steep courses of the measurement curves is achieved at this distance.

[0041] Figure 5 is a graph showing the total intensity value of all twelve combinations. The x-axis is similar to Figure 3 The y-axis shows Figure 4 the sum 71 of the intensity values of all twelve combinations in the middle. The sum indicates a substantially linear course over the entire distance.

[0042] The control device adds the measured and amplified intensity values of the twelve combinations of the sequence and outputs a distance value from the sum. The control device repeats the sequence periodically and outputs a distance value periodically.

[0043] By means of the grating according to the application, the opening movement of the elevator car door can be measured. Likewise, the distance from the movable boundary of the passage to be monitored by the light curtain can be measured by the light curtain itself.

[0044] The grating according to the application can have a transmitter device which wirelessly transmits the distance value, in particular to a network cloud. Thereby, the data are also available for evaluation, or stored for a longer time, in order to be able to provide information about the process like a black box. In particular, this allows monitoring of the elevator door independently of the elevator control.

[0045] List of reference signs

[0046] 10 car door

[0047] 20 grating

[0048] 21 transmitter strip

[0049] 22 receiver strip

[0050] 30 light beam

[0051] 31 qualified transmitter element

[0052] 32 qualified receiver element

[0053] 33 simple transmitter element

[0054] 34 simple receiver element

[0055] 35 control device

[0056] 40 distance-dependent intensity diagram

[0057] 41 X axis: distance of transmitter strip and receiver strip

[0058] 42 minimum distance

[0059] 43 maximum distance

[0060] 44 Y axis: received and amplified intensity

[0061] 45 not detected

[0062] 46 saturation

[0063] 51 measurement curve of intensity and amplification factor

[0064] 52 12 measurement curves consisting of 6 intensities and 2 amplification factors

[0065] 60 diagram of the sum of the 12 received measurement curves

[0066] 64 Y axis: sum of amplified intensities

[0067] 71 Sum of 12 measurement curves of 6 intensities and 2 amplification factors.

Claims

1. A grating, for determining a distance between a transmitter strip and a receiver strip; the grating having: a transmitter strip with one or more transmitter elements, the transmitter elements emitting beams with intensities; a receiver strip with one or more receiver elements, the receiver elements receiving the beams assigned to the transmitter elements; and a control device, for controlling the transmitter elements and / or the receiver elements, and for evaluating the receiver elements; wherein the transmitter elements and the receiver elements, respectively, or at least one transmitter element of the transmitter elements and / or at least one receiver element of the receiver elements, respectively, are designed as qualified transmitter elements and receiver elements, wherein this or these qualified transmitter elements are designed to emit different intensities, and / or this or these qualified receiver elements are designed to use different amplification factors and output intensity values of the received and amplified beams, and the control device is designed to control different combinations of intensities and amplification factors of the qualified transmitter elements and / or receiver elements, and to determine a distance value from the sum of the resulting intensity values of the controlled combinations, wherein the grating further has one or more further transmitter elements and receiver elements, the one or more further transmitter elements and receiver elements are designed as simple transmitter elements and simple receiver elements, respectively, and the one or more further transmitter elements and receiver elements are designed as light barriers, respectively, wherein the control device is designed to control the combinations in a sequence one after the other, and the sequence is repeated periodically, and to determine the sum of the controlled combinations of the sequence, and to determine a distance value for each sequence.

2. The grating according to claim 1, characterized in that the one or more further transmitter elements and receiver elements designed as simple transmitter elements and simple receiver elements, respectively, and designed as light barriers, respectively, do not contribute to the combinations and / or the distance value cannot be determined therefrom, and / or the one or more further transmitter elements and receiver elements are used for object detection, and / or the simple transmitter elements of the one or more further transmitter elements and receiver elements emit at least one intensity like the qualified transmitter elements, and the receiver elements of the further transmitter elements and receiver elements have at least one amplification factor like the qualified receiver elements.

3. The grating according to claim 1 or 2, characterized in that the control device is designed to control all different combinations of intensities and amplification factors of the qualified transmitter elements and / or receiver elements.

4. The grating according to claim 3, characterized in that the control device is designed to ​ all different combinations of the strengths and amplification factors of the qualified transmitter elements and / or receiver elements are controlled, however, for the combinations the highest strength of the qualified transmitter elements is not used, or the following strengths and amplification factors of the qualified transmitter elements and receiver elements are used for identifying the object, which correspond to the strengths and amplification factors of unqualified transmitter elements and / or receiver elements.

5. The grating according to claim 1 or 2, characterized in that one or more qualified transmitter elements are designed to emit, respectively individually, a plurality of different strengths, or to emit strengths which differ from one another, or to emit, respectively, the same strength.

6. The grating according to claim 5, characterized in that the one or more qualified transmitter elements are designed to emit the strength which is the highest and which corresponds to the strength of a simple transmitter element.

7. The grating according to claim 1 or 2, characterized in that one or more qualified receiver elements are designed to use, respectively individually, a plurality of different amplification factors, and / or to use the same different amplification factors, and / or to use, respectively, the same amplification factor.

8. The grating according to claim 7, characterized in that the one or more qualified receiver elements are designed to use the amplification factor which is the highest and which corresponds to the amplification factor of a simple receiver element.

9. The grating according to claim 1 or 2, characterized in that the grating respectively has three qualified transmitter elements and receiver elements, and further has additional simple transmitter elements and receiver elements which do not contribute to the combinations and / or from which the distance value cannot be determined, the one or more qualified transmitter elements are designed to emit, respectively, three strengths, of which one strength is the same as the strength of a simple transmitter element which is set up for object identification, and of which two strengths are lower than this same strength and are respectively different from all other strengths, and the one or more qualified receiver elements are designed to use, respectively, the same two different amplification factors, of which the higher amplification factor corresponds to the amplification factor of a simple receiver element which is set up for object identification, and the control device is designed such that twelve combinations are formed from the three qualified transmitter elements and receiver elements, the total of two different lower strengths of the qualified transmitter elements and the same two different amplification factors of the receiver elements, respectively, and the following strengths and amplification factors of the qualified transmitter elements and receiver elements are used for identifying the object, which correspond to the strengths and amplification factors of simple transmitter elements and / or receiver elements.

10. The grating according to claim 1 or 2, characterized in that the grating has a transmission device which is designed to transmit the distance value wirelessly.

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