Device for installing an angular velocity sensor

Abstract

This utility model pertains to instrument engineering, specifically to a device intended for use in stabilization systems for various objects. The device for mounting an angular velocity sensor comprises a cassette mounted on a mounting base containing an angular velocity sensor with a single sensitivity axis. The mounting base is designed for attachment to the mounting location; the cassette is designed to allow said sensor to remain in a fixed position and is rigidly connected to the mounting base by means of ball-headed adjusting screws. The ball-heads are housed in corresponding sockets and function as hinges for rotating the adjusting screws, allowing the angular velocity sensor's sensitivity axis to be adjusted to a position perpendicular to the plane of the mounting base.The technical problem involves expanding the arsenal of existing similar tools that enable the adjustment of an angular velocity sensor in its mounting position on an object in a single-, dual-, or triaxial stabilization system using one, two, or three such sensors, respectively. The technical result: enabling the adjustment of an angular velocity sensor at small installation angles by compensating for its angular position during micro-rotations. 2 clauses, 5 figs.

Description

[0001] The utility model relates to the field of instrument making, in particular to a device intended for use in stabilization systems for objects of various purposes.

[0002] In this area of ​​technology, one of the pressing issues is the need to adjust the spatial position of angular velocity sensors to minimize errors that may occur during the operation of any systems that require stabilization, including under conditions of vibration and impact.

[0003] Chinese Patent Document No. CN203053446 (published July 10, 2013) discloses a device for mounting and adjusting a gyroscopic sensor for a vehicle navigation system. The device includes a bracket and a navigation unit frame, each with corresponding adjustment means extending through adjustment mounting holes to accommodate various vehicle types.

[0004] The known device does not provide precise adjustment of the position of the gyroscopic sensor, therefore, it has limitations in application.

[0005] A device for fixing a prism that holds a laser gyroscope when adjusting its position is known from Chinese Patent Document No. CN201926446 (published on 10 / 08 / 2011).

[0006] This device allows the laser sensor and prism to be adjusted at the factory, which is then fixed using an adhesive bond to ensure the strength of the bond.

[0007] This device is not effective in adapting to conditions that require on-site adjustment, such as extreme circumstances, due to the need to re-adjust the spatial position of the sensor outside the site, which results in the repeatability of the on-site installation action.

[0008] A device for mounting a gyroscopic angular velocity sensor with an adjustable function is disclosed in Chinese Patent Document No. CN 102654402 (published September 5, 2012). The device comprises a mounting base designed to accommodate two separate cassettes, each of which contains a sensor with adjustable adjustment using three adjustment screws connecting the cassette and the mounting base. Each sensor is rigidly mounted within the cassette using a rigid connection provided by mounting bolts.

[0009] The mounting base has a concave spherical bottom section, which houses the cassette, which has a mating surface. The mounting base is attached to the installation site using mounting screws.

[0010] The position of the sensor included in the known device is adjusted under real-world operating conditions, with the system stabilizing in only two planes, corresponding to two sensor cassettes. Thus, to stabilize the system, both bolts and adjusting screws are pressed and loosened, allowing the device with the sensor to rotate and thus adjust the position of the gyroscopic sensor to the working plane in short cycles using an iterative approach.

[0011] The known device has some shortcomings.

[0012] Using two gyroscopic sensors connected by a base necessitates adjustment in two coordinates. This, therefore, is a limitation when using the device for three-coordinate stabilization. At the same time, the emerging need for a single-coordinate stabilization device allows for the use of one sensor from the two, but this creates an inefficiency in terms of the need to install a base that connects the two sensors, housed in their respective cassettes.

[0013] The spherical mating of the base and the cassette's mating surface prevents the sensor from being adjusted to small angles, in other words, it hinders precise adjustment. The high coefficient of friction negatively impacts the ability to adjust the cassette's position with the sensor at small angles.

[0014] Furthermore, the adjustment of the sensor position using three adjusting screws in combination with bolt adjustment characterizes the analyzed device as insufficiently effective due to the following reasons:

[0015] – difficulty of adjustment;

[0016] – inability to ensure micro-movements of the sensor;

[0017] – dependence of the setting in 2 coordinates on sensors united by one base.

[0018] The device according to patent document CN 102654402 is selected as the closest analogue.

[0019] The technical problem solved by the proposed utility model consists of expanding the arsenal of existing means for a similar purpose, ensuring the adjustment of an angular velocity sensor in a mounting position on an object in a system of one-, two-, or three-axis stabilization using, respectively, one, two, or three such sensors.

[0020] The technical result achieved by the utility model is to ensure the adjustment of the angular velocity sensor to small installation angles by compensating for its angular position during micro-rotations.

[0021] To address this technical issue, the device for mounting an angular velocity sensor includes a cassette mounted on a mounting base, which rigidly houses the angular velocity sensor, which has a single sensitivity axis. This mounting base is designed for attachment to the mounting location. The cassette and the mounting base are rigidly connected. Furthermore, the device includes adjusting screws for adjusting the position of the angular velocity sensor's sensitivity axis.

[0022] What is new in the proposed device is:

[0023] – ensuring a rigid connection between the cassette and the mounting base using adjusting screws;

[0024] – making the ball head adjusting screws and placing the corresponding ball head in the socket;

[0025] – the ball head functions as a hinge for turning the adjusting screws, which ensures that the sensitivity axis of the angular velocity sensor is adjusted to a position perpendicular to the plane of the mounting base.

[0026] The proposed utility model has the following practical aspects of implementation:

[0027] – the projection of the cassette and base onto the horizontal plane has the shape of a rectangle, while the rigid connection of the mounting base and cassette with the angular velocity sensor is achieved using three adjusting screws located at the corresponding corners;

[0028] – the projection of the cassette and base onto the horizontal plane has the shape of a rectangle, while the rigid connection of the mounting base and cassette with the angular velocity sensor is achieved using four adjusting screws located at the corners;

[0029] – To fix each adjusting screw, a damping gasket is installed under its ball head, pressed by a nut, and the threaded part is secured by means of a terminal clamp made in the mounting base;

[0030] – the mounting base is made with holes for mounting screws to attach the base to the installation site.

[0031] – the cassette is a split housing, the inner surface of which is designed to tightly cover the surface of the angular velocity sensor, while the fixed position of the said sensor is ensured by means of a collet clamp;

[0032] – A fiber optic gyroscope is used as an angular velocity sensor.

[0033] To clarify the essence of the claimed device, some definitions are given.

[0034] An angular velocity sensor (hereinafter referred to as a "sensor" depending on the context) is a device that measures the angular velocity of an object relative to a non-rotating inertial coordinate system; the primary measuring element of an angular velocity sensor can be implemented in the form of various types of gyroscopes: fiber-optic, laser, solid-state, or micromechanical.

[0035] "Sensitivity axis of the angular velocity sensor" – determines the direction of rotation in which the sensor signal has a maximum value; the sensitivity axis is perpendicular to the other two axes of the coordinate system of the object on which the sensor is installed.

[0036] "Working plane of the angular velocity sensor" is the plane perpendicular to the sensitivity axis and in which the rotation of the sensor occurs.

[0037] "Angular velocity sensor tuning" is the process of measuring the sensor's rotation using an actuator capable of rotation and means for recording the sensor's signal regarding the influence of the sensor's rotation angle in two planes orthogonal to the operating plane, the so-called parasitic planes, perpendicular to the corresponding parasitic axis. The sensor tuning process, which involves a methodology for reducing the influence of rotation error in two parasitic planes, is not disclosed in this description, as it does not affect the achievement of the technical result.

[0038] “Fiber optic gyroscope” is an inertial angular velocity sensor, made on the basis of a coil with wound optical fiber.

[0039] "Ball-head adjusting screw" is a fastening device that refers to a kind of screw designed to realize the positioning function by means of a ball head located in a spherical socket.

[0040] The fixed position of the angular velocity sensor in the cassette results in the formation of an integral structure, which is a module, which, in turn, is connected to the mounting base by ball-head screws.

[0041] The accuracy of sensor adjustment depends on the quality of the rigid connection provided by the adjusting screws, which ensures clearance between the mating surfaces of the integrated module and the mounting base. For example, tightening the ball head of each adjusting screw with a nut through a damping pad eliminates any play due to the elastic deformation of the damping pad. Furthermore, when using a clamp to secure the adjusting screw from its threaded portion, clearances are eliminated by friction generated by the compressive force across the entire mating surface of the threaded hole and the threaded portion of the screw.

[0042] Placing the ball head of the adjusting screws in the corresponding socket allows each ball head to function as a hinge, allowing it to rotate in any direction within a specified limit during sensor adjustment. The mating of the ball head and socket ensures a minimal coefficient of friction.

[0043] Using a hinged connection between the integrated module and the mounting base is a prerequisite for the precise adjustment of the angular velocity sensor, since this design technique results in compensation for the angular position of the sensor relative to the mounting base both when installing the integrated module on the mounting base and when adjusting the sensor when the device is attached to the mounting location inherent to the object.

[0044] Based on the above, the adjusted position of the integrated module relative to the mounting base is ensured by the ability to fix the position of the ball head of the adjusting screws with a nut. The adjusting screws act as a means for holding the integrated module in the adjusted position of the angular velocity sensor without the need for additional means, as provided in the known method according to patent document CN 102654402. The mounting base with the integrated module attached to the installation site has limited mobility due to the high rigidity of the threaded connection of the adjusting screws due to the compression of the terminal clamps, which increases friction in the connection. This circumstance allows the adjusted position of the sensor to be maintained during operation, which is characterized by impact and vibration loads.

[0045] It should be noted that any type of angular velocity sensor, regardless of shape, can be installed in the proposed device. The fixed position of the sensor in the cassette (in other words, a rigid connection between the sensor and the cassette) is ensured by means known in the art. When using, for example, a cylindrical or box-shaped fiber-optic gyroscope, the cassette can be designed to be congruent with the shape of such sensors. The cassette for any type of sensor can be split, and the sensor placed within such a cassette is clamped and centered using a collet mechanism, ensuring a fixed (rigid) connection.

[0046] Thus, the connection of the mounting base and the cassette with a fixedly mounted angular velocity sensor using adjusting screws with a ball head ensures the adjustment of the sensor when turning at small angles, achieving perpendicularity of the position of the sensor's sensitivity axis and the plane of the mounting base, in other words, achieving a plane-parallel position of the working plane relative to the mounting base.

[0047] The use of four adjusting screws to connect the mounting base and the integrated module is determined by the configuration of the said components of the proposed device, which is a rectangle, based on considerations of the design feasibility of such a shape.

[0048] In addition, the four adjusting screws determine the ability to adjust the sensor sensitivity axis by turning adjacent adjusting screws in pairs to adjust the sensor sensitivity axis to a position perpendicular to the plane of the mounting base.

[0049] The use of a four-point mounting with an equidistant location from the center of mass brings rigidity to the structure, which determines the possibility of turning the adjustment screws at small adjustment angles.

[0050] With a rectangular mounting base and cassette configuration, three adjusting screws can be used at three corners, leaving one corner free. This approach maintains the rigidity of the connection.

[0051] The utility model is explained in more detail with reference to the figures:

[0052] – Figure 1 shows a cross-section of the device in schematic form;

[0053] – Figure 2 shows a top view of the device (schematically) with three adjustment screws;

[0054] – Figure 3 shows a top view of the device (schematically) with four adjustment screws;

[0055] – Figure 4 shows a structural diagram of the arrangement of the axes of the angular velocity sensor with the designations of the axes corresponding to the designations in Figures 2 and 3;

[0056] – Figure 5 shows a terminal clamp that secures the adjusting screw to the mounting base.

[0057] The device for installing an angular velocity sensor is designed for installation on an object as part of a line of sight stabilization system.

[0058] The device contains a mounting base 1, a cassette 2, an angular velocity sensor 3.

[0059] This example discusses a device using an angular velocity sensor consisting of a fiber optic gyroscope (FOG) in the shape of a cylinder (any FOG brand known in the art). However, the proposed device could incorporate a micromechanical gyroscope, a dynamically tunable gyroscope, or a laser gyroscope. A fixed connection between the cassette and any type of gyroscope can be achieved not only in a split cassette housing, but also by arranging the cassette as a housing with a detachable upper and lower portions, between which the gyroscope can be positioned using any means known in the art.

[0060] So, for the fixed placement of the cylindrical FOG 3, the cassette 2 is made with a split body having internal cylindrical surfaces to ensure a tight fit to the corresponding surface of the FOG 3. Fixation of the FOG 3 in a fixed position with rigid fastening is carried out using a collet clamp 4.

[0061] Cassette 2 with a fixedly installed FOG 3 has a rigid connection with the mounting base 1, provided using three or four adjusting screws with a ball head 5.

[0062] In the example under consideration, the adjusting screws are installed so that the socket for the ball head 5 is made in the cavity of the cassette 2, while the threaded hole for the threaded part 6 of the screw is made in the base 1.

[0063] To select the clearances, the ball head 5 of each adjusting screw is pressed by a nut 7, and the nut acts on the ball head 5 through a damping gasket 8 made, for example, of caprolon.

[0064] In order to increase the rigid connection of the mounting base 1 and the cassette 2 with the sensor 3, the base 1 is made with terminal clamps 9 according to the number of adjusting screws. The organization of the terminal clamp is subordinated to the shape of the mounting base, which can be made like a frame (not shown in the figures) with mounting surfaces for placing the cassette 2 with the FOG 3. In Fig. 5 a fragment of the mounting base 1 with a terminal clamp 9 is shown. Based on this shape of the base 1, the terminal clamp contains a movable jaw 10 (having a longitudinal direction coinciding with the longitudinal direction of the cassette with the FOG), separated from the fixed part of the base by a groove (not indicated by a position), communicating with an open threaded hole.

[0065] When adjusting the screws, the nylon gasket 8 creates preliminary compression, which helps eliminate micro-gaps and backlashes under conditions of vibration and impact knocking.

[0066] As stated above, when using terminal clamps 9, the rigidity of the connection of the mounting base 1 and the cassette 2 with the sensor 3 placed in it increases.

[0067] The above design techniques for backlash-free adjustment make it possible to fix the position of the sensor in the adjusted position.

[0068] An alternative design of the device is possible, according to which the ball heads of the screws can be located in the sockets of the base 1, and the threaded sections, respectively, in the cassette 2. The choice of the orientation of the adjusting screws relative to the base / cassette is determined based on the conditions of the rational arrangement of the proposed device with other means used in the object stabilization system.

[0069] The mounting base 1 is provided with four holes for installing fastening screws 16, which ensure the connection of the assembled device to the installation (assembly) site, which is carried out on the object 15.

[0070] It should be noted that in this field, the process of tuning an angular velocity sensor is known as "Cross Axis Sensitivity." According to this concept, an angular velocity sensor tuned to one axis produces a distorted signal when rotating around two other orthogonal axes (parasitic axes). Tuning the sensor minimizes (eliminates) the influence of the parasitic axes.

[0071] The assembled device is installed on the object and the angular velocity sensor is adjusted.

[0072] Adjusting the sensor in one plane involves adjusting its spatial position to minimize the error that occurs when an object moves in two other planes.

[0073] In the following examples, when using three or four adjustment screws to connect the mounting base 1 and the cassette 2 with the sensor, according to Figure 4, the Z-axis is selected as the sensitivity axis perpendicular to the working plane; the parasitic axes are the Y- and X-axes.

[0074] When mounting base 1 and cassette 2 are fastened at three points (Fig. 2), the adjustment of the sensitivity axis of the angular velocity sensor to a position perpendicular to the plane of the mounting base is performed by alternately adjusting first screw 11 (paired with fixed screw 12), then screw 13 (also paired with fixed screw 12).

[0075] Using screw 11, sensor 3 is adjusted around the parasitic Y axis, ensuring that the signal from the sensor is minimized.

[0076] Screw 13 is used to adjust sensor 3 around the parasitic X-axis, ensuring that the signal from the sensor is minimized.

[0077] When mounting base 1 and cassette 2 are mounted at four points (Fig. 3), the sensitivity axis of the angular velocity sensor is adjusted to a position perpendicular to the plane of the mounting base by adjusting in pairs:

[0078] – screws 11-12 for adjusting sensor 3 around the parasitic X-axis;

[0079] – screws 12-13 for adjusting the sensor around the parasitic Y axis.

[0080] The disclosed design features of the proposed device provide for the adjustment of the tilt angle of the Z sensitivity axis of the sensor within a few degrees in two parasitic axes X and Y when achieving an angular sensitivity of adjustment of less than 5ʺ of the sensor rotation angle (estimated data based on the thread pitch and screw rotation by 1 degree).

[0081] The expansion of the arsenal of means for this purpose is confirmed by the possibility of using:

[0082] – one of the claimed devices when it is necessary to adjust the sensor in a single-axis stabilization system, when the adjustment extremum is ensured by adjusting the coaxiality of the sensor’s rotation axis with the rotation axis of the object’s mechanical unit;

[0083] – two or three declared devices when it is necessary to adjust the sensor in a two- or three-axis stabilization system, when the extreme of the adjustment of the orthogonality of the sensor axes is ensured taking into account the consistency with the axes of rotation of the mechanical units of the object with a rational arrangement of the devices, oriented accordingly in the working position.

Claims

1. A device for installing an angular velocity sensor, including a mounting base intended for connection to a mounting location, and a cassette configured to accommodate and rigidly fix an angular velocity sensor having one sensitivity axis, wherein the cassette is connected to the mounting base by means of three adjusting screws with ball heads located at the corresponding corners of the cassette and the mounting base, the ball heads are placed in corresponding spherical sockets with the possibility of adjusting the position of the cassette relative to the mounting base to adjust the sensitivity axis of the angular velocity sensor to a position perpendicular to the plane of the mounting base, wherein each adjusting screw is configured to be fixed by means of a nut interacting with the ball head through a damping gasket, and its threaded portion is secured by means of a terminal clamp,ensuring that the position of the cassette is fixed relative to the mounting base after adjustment is completed.

2. The device according to item 1, characterized in that the mounting base is made with holes for mounting screws for attaching the base to the installation site.

3. The device according to claim 1, characterized in that the cassette is a split housing, the inner surface of which is designed to tightly cover the surface of the angular velocity sensor, while the fixed position of said sensor is ensured by means of a collet clamp.

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