Rotating structure for large-scale civilian applications, such as a telescope in an astronomical observatory, equipped with a sensor to control the rotation speed and angular rotation.

Abstract

Rotating structure (4) for civil applications, comprising - a fixed part (8) and a movable part (12) which rotates about an axis of rotation (XX) and is equipped with drive means (16) for its rotation about the axis of rotation (XX), - wherein the fixed part (8) and the movable part (12) are coaxial with respect to the axis of rotation (XX), - wherein the drive means (16) are arranged on an outer diameter of the movable part (12) antipodal to the axis of rotation (XX), - wherein the fixed part (8) and the movable part (12) are connected to each other at an inner circular interface (20), corresponding to an inner diameter on the side of the axis of rotation (XX), and at an outer circular interface (24), corresponding to an outer diameter, opposite the inner diameter along a radial direction (RR) perpendicular to and intersecting the axis of rotation (XX), - wherein the rotating structure (4) comprises a first position band (28) with indices and at least one first position encoder (32) configured for optical reading of the first position band (28) in order to provide a measurement of the angular position of the moving part (12), or encoder - wherein the rotating structure (4) comprises a first velocity band (36) with indices and at least one first velocity encoder (40) configured for optical reading of the first velocity band (36) in order to provide a measurement of the angular velocity of the moving part (12), - wherein the first position band (28) and the first position transmitter (32) are arranged according to the inner circular interface (20), - wherein the first speed band (36) and the first speed sensor (40) are arranged according to the outer circular interface (24), - wherein the first speed sensor (40) and the first position sensor (32) are functionally connected to the drive means (16) to enable feedback control of the drive of the drive means (16).

Description

SCOPE

[0001] The present invention relates to a rotating structure for large civilian applications, such as a telescope of an astronomical observatory, which is equipped with a transmitter (or encoder) for controlling the rotational speed and angular rotation. STATE OF THE ART

[0002] In particular, but not exclusively, the present invention is applicable to rotating structures with extremely high mass, even on the order of tens of thousands of tons, such as large telescopes, but generally to civil structures equipped with rotary movements about an axis.

[0003] In engineering, the production of rotary structures is known, which rotate on very thick round supports to support the rotational movement of the rotary structure and to limit deformations as much as possible.

[0004] These structures are set in motion by means of drives that must enable extremely precise and controlled movements. In particular, the rotation of the rotating structure, for example the mount for the telescope mirrors, must be precisely controlled, otherwise the measurements taken with the telescope will not be reliable.

[0005] Of course, there are various technical problems that arise from the fact that these structures have considerable dimensions and masses, so that the structures deform elastically after the motors are driven, even before they shift angularly.

[0006] The delay between the activation of the motors and the actual movement of the structures due to relative elastic deformation therefore leads to significant technical problems that can impair the proper functioning of the device.

[0007] In engineering, it is known to equip the device with an optical sensor that measures the speed and displacement of the structure: This measurement is used as feedback for the drive of the motors, which are equipped with current and / or torque control.

[0008] Ideally, the sensor should be positioned near the drive mechanism so that it can read the same quantities (speed and angular position) that the drive mechanism "sees".

[0009] In some cases, the drive elements are located at the smaller diameter of the structure, i.e., at the axis of rotation. This means, on the one hand, that the optical band to be read by the sensor has a limited length and can therefore be positioned relatively accurately; on the other hand, however, the measured displacements and velocities are far from the outer diameter and do not take into account the actual deformations to which the rotating structure is subjected when the motion is transmitted from the inner diameter to the outer diameter.

[0010] The problem of taking deformations into account when taking readings could be solved by attaching the measuring tape and the corresponding sensor directly to the outer diameter, but this solution also brings problems.

[0011] In fact, applying a measuring tape over a diameter of several tens of meters presents measurement problems, for example at the joints between adjacent tape sections. Furthermore, a large measuring tape would lead to uncertainties or inaccuracies in the measurement, especially regarding the angular position.

[0012] The problem becomes even more complicated when the structure is used in environments exposed to seismic phenomena, including those of considerable strength, as is often the case with large telescopes located in inaccessible and often mountainous places.

[0013] Furthermore, the problem is made even more complicated by strong temperature fluctuations and the shrinkage of the concrete from which the foundation and / or other parts of the solid structure are made: As we have seen, these phenomena have a particularly large impact on large telescopes that are set up in inaccessible and often mountainous locations.

[0014] In fact, the encoder sensors and strips are mounted on metal and concrete elements, which are known to have different coefficients of thermal expansion. For this reason, measurements can be less accurate due to temperature fluctuations, as misalignments can occur between the reading / measuring devices, such as optical encoders, and the corresponding reading strips. PRESENTATION OF THE INVENTION

[0015] Therefore, it is necessary to overcome the aforementioned disadvantages and limitations of the known technology.

[0016] This requirement is met by a rotating structure for civilian applications according to claim 1. DESCRIPTION OF THE FIGURES

[0017] Further features and advantages of the present invention will be better understood from the following description of its preferred and non-limiting embodiments, wherein: Fig. 1 represents a perspective view of a rotating structure for civil applications according to a possible embodiment of the present invention; Fig. 2-3 partial side views from opposite sides of the upper part of the rotating structure Fig. 1 represent; Fig. 4 a partially perspective view of the rotating structure from Fig. 1 represents; Fig. 5 an enlargement of the in Fig. 4 represents the special feature V; Fig. 6 a top view of the special feature from Fig. 5 shows; Fig. 7-9 Sectional views of details of the in Fig. 4. Show the special feature V shown. Fig. 10-11 a perspective view and a top view of the lower part of the rotating structure Fig. Show 1. Fig. 12 a top view of feature XII from Fig. 11 shows; Fig. 13 a cut of the in Fig. 12. Special feature XIII is shown.

[0018] The elements or parts of elements that are common to the embodiments described below are identified by the same reference numerals. DETAILED DESCRIPTION

[0019] Referring to the figures above, reference numeral 4 designates a rotary structure for civil applications according to the present invention.

[0020] First, for the purposes of the present invention, it is necessary to clarify that the term "rotational structure" is to be understood in a broad sense and refers to any structure that exhibits a relative rotational movement with respect to a base; this movement can be rotary and / or rototranslatory. In this case, the rotational movement can, for example, occur about a vertical axis, i.e., perpendicular to an overall support surface for the structure, as described in more detail below.

[0021] Furthermore, a rotational structure is also understood to be a structure that exhibits a relative rotational movement with respect to a partially enclosing shell. In this case, the rotational movement can, as described in more detail below, occur, for example, around a horizontal axis, i.e., parallel to the overall bearing surface of the structure.

[0022] Preferably, but not exclusively, this rotating structure 4 for civilian applications can include a dome for covering and / or mounting a telescope, but also a residential structure.

[0023] The rotary structure 4 for civil applications comprises a fixed part 8 and a movable part 12, which rotates about a rotary axis XX and is equipped with drive means 16 for its rotation about the rotary axis XX.

[0024] The axis of rotation XX can be defined by one or more bearings or similar supports. The axis of rotation XX can be, for example, horizontal or vertical. A single rotating structure 4, such as a telescope, can comprise several fixed parts 8 and several moving parts 12 that rotate about different axes of rotation XX, which can, for example, be perpendicular to each other.

[0025] For example, in the case of a telescope, a first axis of rotation XX can be a vertical axis or an azimuth axis, while a second axis of rotation XX can be a horizontal axis or an altitude axis.

[0026] In other words, the same structure can include several fixed parts 8 and several movable parts 12 that rotate about different axes of rotation XX.

[0027] The fixed part 8 and the movable part 12 are coaxial with respect to the axis of rotation XX.

[0028] The drive means 16 are arranged on an outer diameter of the moving part 12, antipodal to the axis of rotation XX.

[0029] The drive means can be of different types; preferably they are electric motors with torque and / or current feedback control for moving the movable part 12 about the respective axis of rotation XX.

[0030] The fixed part 8 and the movable part 12 are connected to each other via an inner circular interface 20, which is located on the side of the axis of rotation XX according to an inner diameter, and via an outer circular interface 24, which is located opposite the inner diameter according to an outer diameter, along a radial direction RR perpendicular to and intersecting the axis of rotation XX.

[0031] The rotating structure 4 comprises a first position band 28 with indices and at least one first position transmitter (or encoder) 32, which is configured for optically reading the first position band 28 to provide a measurement of the angular position of the moving part 12. The term "position band" is to be understood in a broad sense; in other words, any suitable scaled instrument that can be read by a corresponding optical transmitter can be used. Therefore, a rigid band as well as a flexible band can be used; it is also possible to apply or print the indices directly onto a physical, preferably rigid, substrate.

[0032] The rotating structure 4 comprises a first speed band 36 with indices and at least one first speed sensor (or encoder) 40, which is configured for optically reading the first speed band 36 in order to provide a measurement of the angular velocity of the moving part 12.

[0033] The first position belt 28 and the first position sensor 32 are arranged according to the inner circular interface 20, while the first speed belt 36 and the first speed sensor 40 are arranged according to the outer circular interface 24. This mutual arrangement is advantageous because the speed sensors have large tolerances when handling misalignments and deviations of the belt and can therefore be operated according to the outer circular interface 24, which has a significantly larger extent and is therefore more susceptible to misalignments and deviations between the sensors and the belt.In contrast, the position measurement sensors have a lower ability to cope with misalignments and deviations from the belt, and are therefore positioned according to the inner circular interface 20, which offers greater geometric stability due to its significantly smaller dimensions.

[0034] The first speed sensor 40 and the first position sensor 32 are functionally connected to the drive means 16 to enable feedback control of the drive of the drive means 16.

[0035] According to one embodiment, the first positioning band 28 is anchored to the fixed part 8, while the first position sensor 32 is anchored to the movable part 12.

[0036] According to one embodiment, the first speed band 36 is anchored to the fixed part 8, while the first speed sensor 40 is anchored to the movable part 12.

[0037] According to one embodiment, the first speed band 36 comprises at least two adjacent sections 44, 48 which are connected to each other at a connection point 52; furthermore, the first speed sensor 40 comprises at least two adjacent read heads 56, 60, which are arranged in front of and behind the connection point 52, respectively.

[0038] In particular, the first speed sensor 40 includes a control unit which is functionally connected to the adjacent read heads 56, 60 and is programmed to deactivate the read head that is closest to the connection point 52 when the first speed sensor 40 passes the connection point 52.

[0039] For example, the control unit is programmed to weight the signals read by each of the read heads 56, 60 at 50% if the connection point 52 is not detected by either of the read heads 56, 60.

[0040] According to one embodiment, the control unit is programmed to progressively weight the signals read by each of the read heads 56, 60 when the connection point 52 is near the read heads 56, 60, in order to progressively decrease the weighting of the signal from the read head that detects the connection point 52 first and to progressively increase the weighting of the signal from the read head that detects the connection point 52 last by the same amount.

[0041] Preferably the rotary structure 4 comprises a plurality of position encoders 32 configured for optical reading of the first position band 28, wherein the position encoders 32 are arranged at an equal angular distance from each other.

[0042] Preferably the rotary structure 4 comprises a plurality of speed encoders 40 configured for optical reading of the first speed band 36, wherein the speed encoders 40 are arranged at equal angular intervals from each other.

[0043] As can be seen from the description, the structures according to the invention make it possible to overcome the disadvantages that occur in the known technology.

[0044] Advantageously, the described solution enables extremely accurate measurement of both the angular position and the speed of the rotating structure thanks to the distribution of the sensors on the outer and inner circumferences.

[0045] In particular, it is possible to read the angular velocity at the outer diameter using velocity sensors that exhibit high tolerance for misalignments or deviations from the measuring tape. Simultaneously, the angular position at the inner diameter can be read. This reading is extremely precise and accurate, allowing the position of the rotating structure to be accurately determined during its movement. By using these two different sensors, the advantages of positioning the measuring tapes at both the inner and outer diameters can be optimized.

[0046] This approach also solves the problem of differing coefficients of thermal expansion, as measurements requiring higher accuracy in tape measure positioning compared to the sensor are performed on the structure's inner diameter, which, due to its smaller size, is less susceptible to differential expansion. Conversely, the outer diameter, which is more affected by differential thermal expansion, is used to measure speed, requiring lower tape measure positioning accuracy compared to the sensor. Furthermore, measuring on the outer diameter also utilizes the sensor's redundancy, which, through averaging of measurements, contributes to increased accuracy and precision.

[0047] Thanks to the doubling of the reading heads on the outer diameter, it is also possible to position the outer measuring tape with several independent sections without affecting the reading accuracy at the joints between successive tape sections.

[0048] Therefore, the use of pairs of optical sensors does not represent a simple redundancy of measuring instruments, but rather a complementarity between measurements that do not overlap but complement each other in order to achieve extremely precise control of the position and speed of the rotating structure.

[0049] As seen, the azimuth track system for encoders includes a subdivision into sections, a planimetric distribution and a fastening system defined to ensure the functionality and integrity of the tracks even under strong temperature fluctuations and shrinkage of the concrete.

[0050] The azimuth track system for encoders thus enables correct reading of both the rotational speed and the position for large rotating machines, such as telescopes.

[0051] Furthermore, the azimuth track system for encoders of the present invention was designed to provide correct measured values ​​of the parameters, position and speed over time, even under changing environmental conditions, including strong temperature fluctuations and / or seismic phenomena.

[0052] The track system for encoders enables correct measurement of both rotational speed and position, in both azimuth and height, for large rotating machines, such as telescopes.

[0053] The track system for transducers for astronomical telescopes is able to maintain the correct alignment and distance between the scales and the corresponding reading devices in altitude and azimuth, even with primary mirror diameters of 40 m.

[0054] Advantageously, in the track systems for encoders, brackets for the readers were developed which are equipped with compensation systems to continuously compensate for the geometric changes caused by temperature changes and / or elastic deformations of the structure in the various configurations.

[0055] Furthermore, the encoder-track system for astronomical telescopes of the present invention prevents any form of looping and rolling of elements that are in contact with the main structure.

[0056] Furthermore, the track system for sensors for astronomical telescopes is equipped with a system for gravity-induced compensation of the distance between the heads and the band for the altitude position sensor.

[0057] Furthermore, the track system for transducers for astronomical telescopes provides transducers that are attached to elements for compensating thermal expansions, based on the difference between the expansion coefficients of steel and aluminum, to compensate for the radial distance between the heads and the band for the azimuth velocity transducer.

[0058] Advantageously, as seen, the device incorporates a track system for transducers used in astronomical telescopes, where position measurement is separated from velocity measurement and where the component measuring the angle, i.e., the angular position, is located near the vertical axis of rotation. This ensures that the measurement of the angular position, which is the most critical value, is particularly accurate and reliable.

[0059] Furthermore, in the track system for encoders for astronomical telescopes according to the invention, the component that detects the angular velocity is attached to the outer circumference of the machine; this measurement is less accurate than that of the angular position, nevertheless the encoders can provide an optimal reading and thus an optimal control of the position and speed of the rotating structure.

[0060] The encoder tracking system for astronomical telescopes of the present invention also ensures high geometric stability of the bands by dividing the scaled bands, on which the angular velocity is read, into several partially overlapping sections.

[0061] To meet specific requirements, a specialist can make numerous changes and variations to the solutions described above.

[0062] The scope of protection of the invention is defined by the following claims. Reference sign 4 Rotating structure for civilian applications 8 fixed part 12 moving parts 16 propulsion devices 20 inner circular interface 24 outer circular interface 28 first position band 32 first position giver 36 first speed band 40 first speed sensor 44.48 sections 52 connection point 56.60 read heads XX axis of rotation RR radial direction

Claims

[1] Rotating structure (4) for civilian applications, comprising - a fixed part (8) and a movable part (12) which rotates about an axis of rotation (XX) and is equipped with drive means (16) for its rotation about the axis of rotation (XX), - wherein the fixed part (8) and the movable part (12) are coaxial with respect to the axis of rotation (XX), - wherein the drive means (16) are arranged on an outer diameter of the movable part (12) antipodal to the axis of rotation (XX), - wherein the fixed part (8) and the movable part (12) are connected to each other at an inner circular interface (20), corresponding to an inner diameter on the side of the axis of rotation (XX), and at an outer circular interface (24), corresponding to an outer diameter, opposite the inner diameter along a radial direction (RR) perpendicular to and intersecting the axis of rotation (XX), - wherein the rotating structure (4) comprises a first position band (28) with indices and at least one first position encoder (32) configured for optical reading of the first position band (28) in order to provide a measurement of the angular position of the moving part (12), or encoder - wherein the rotating structure (4) comprises a first velocity band (36) with indices and at least one first velocity encoder (40) configured for optical reading of the first velocity band (36) in order to provide a measurement of the angular velocity of the moving part (12), - wherein the first position band (28) and the first position transmitter (32) are arranged according to the inner circular interface (20), - wherein the first speed band (36) and the first speed sensor (40) are arranged according to the outer circular interface (24), - wherein the first speed sensor (40) and the first position sensor (32) are functionally connected to the drive means (16) to enable feedback control of the drive of the drive means (16). [2] Rotating structure (4) for civil applications according to claim 1, wherein the drive means (16) are electric motors with torque and / or current feedback control. [3] Rotating structure (4) for civil applications according to claim 1 or 2, wherein the first positioning band (28) is anchored to the fixed part (8) and the first position sensor (32) is anchored to the movable part (12). [4] Rotating structure (4) for civil applications according to claim 1, 2 or 3, wherein the first velocity band (36) is anchored to the fixed part (8) and wherein the first velocity sensor (40) is anchored to the movable part (12). [5] Rotating structure (4) for civil applications according to any one of claims 1 to 4, wherein the first speed band (36) comprises at least two adjacent sections (44, 48) which are connected to each other at a connection point (52), and wherein the first speed sensor (40) comprises at least two adjacent read heads (56, 60) which are arranged in front of and behind the connection point (52), respectively. [6] Rotating structure (4) for civil applications according to claim 5, wherein the first speed sensor (40) comprises a control unit which is operationally connected to the adjacent read heads (56, 60) and is programmed to deactivate the read head nearest to the connection point (52) in the vicinity of the passage of the connection point (52) through the first speed sensor (40). [7] Rotating structure (4) for civil applications according to claim 6, wherein the control unit is programmed to weight the signals read by each of the read heads (56, 60) by 50% when the connection point (52) is not detected by any of the read heads (56, 60). [8] Rotating structure (4) for civil applications according to claim 6 or 7, wherein the control unit is programmed to progressively weight the signals read by each of the read heads (56, 60) when the connection point (52) is near the read heads (56, 60) in order to progressively decrease the weight of the signal originating from the read head that detects the connection point (52) first and to progressively increase the weight of the signal originating from the read head that detects the connection point (52) last by the same amount. [9] Rotating structure (4) for civil applications according to any one of claims 1 to 8, wherein the rotating structure (4) comprises a plurality of position sensors (32) configured to optically read the first position band (28), wherein the position sensors (32) are arranged at an equal angular distance from each other. [10] Rotating structure (4) for civil applications according to any one of claims 1 to 9, wherein the rotating structure (4) comprises a plurality of speed sensors (40) configured for optical reading of the first speed band (36), wherein the speed sensors (40) are arranged at an equal angular distance from each other. [11] Rotating structure (4) for civil applications according to any one of claims 1 to 10, wherein the rotating structure (4) is a telescope and wherein the axis of rotation (XX) is a vertical axis or an azimuth axis. [12] Rotating structure (4) for civil applications according to any one of claims 1 to 11, wherein the rotating structure (4) is a telescope and the axis of rotation (XX) is a horizontal axis or a vertical axis.

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