RU176009U1 - DEVICE FOR DETERMINING THE POSITION AND ORIENTATION OF OBJECTS - Google Patents

Abstract

The utility model relates to instrumentation, in particular to a device for determining the position and orientation of objects, and can be used in systems where it is important to know the relative position and orientation of two objects.

The device for determining the position and orientation of two objects consists of two platforms of the upper and lower, made with the possibility of fixing one object at a time, six distance measurement sensors connecting the upper and lower platforms, and a data processing unit connected to the distance measurement sensors by connecting wires. Moreover, each distance measuring sensor is an elastic tube filled with electrolyte, while two electrodes are located inside the tube near its ends; each platform has six supports for rigidly fixing the ends of the elastic tubes of distance measuring sensors in them so that the bends of the elastic tubes do not exceed 3 ° within the permissible limits of mutual displacements and rotations of the platforms; and the location of the supports on the platforms is chosen so that the elastic tubes of the distance sensors are not parallel.

The technical result of the claimed utility model is to simplify the design and measurement, increase the mobility of the device. 4 s.p. f-ly, 4 ill.

Description

Technical field

This utility model relates to a measurement technique, in particular, to a device for determining the position and orientation of objects. The utility model can be used in systems where it is important to know the relative position and orientation of two objects.

State of the art

The prior art device for measurements (US 6226884 B1, B23Q 1/44, G01B 21/00, G01B 7/00, publ. 05.08.2001). The device contains two triangular-shaped platforms. At least one platform has three spherical supports, and at least one platform has one support. Spherical bearings can be made in the form of spherical joints or nests. The platforms are interconnected by six racks, and in each support the ends of two racks are fixed. The racks are passive extendable measuring rods, and the platforms are respectively connected to the stationary and moving parts of the manipulator so that the movement of the parts of the manipulator would cause relative movement between the platforms with a change in the length of the measuring racks (rods). The actual movement of a part of the manipulator can be determined from measurements of lengths on racks. The device allows calibration and measurement. The disadvantage of this device is the design complexity and the limited angular displacements of the spherical joints, in which the ends of the two posts are fixed, and the design is not very mobile.

Also from the prior art (CN 202836538 U, G01B 21/00, publ. 03/27/2013) a measuring device with six columns, with six support points and six degrees of freedom is known (prototype utility model, CN 202836538 U, G01B 21/00, publ. 03/27/2013).

The device comprises a movable connecting part, a fixed connecting part and six connecting movable racks on which displacement sensors are mounted. The fixed and moving parts have three pins equally mounted around the perimeter. Each rack has a pin mount at its ends. Each fulcrum is a transverse elbow joint mounted on a pin. In the elbow connection there are two holes for installing two pins from the racks. Thus, at each point of support two racks are installed.

The device allows convenient measurement and calculation, increases the accuracy of measurements at a relatively low cost of the device itself. The disadvantages of the device are the high friction in the attachment points of the movable measuring racks to the platforms and the presence of the positions of the platforms in which changing the lengths of the racks requires a lot of mechanical effort, as well as the difficulty in transportation.

To solve many technical problems, it is necessary to control the relative position and orientation of objects, as well as their change over time.

A technical problem is the need to create a device for determining the position and orientation of objects, devoid of the disadvantages of known devices of similar purpose. Utility Model Disclosure

The technical result of the claimed utility model is to simplify the design and measurement, increase the mobility of the device (for example, when transporting it to a new location). The inventive device also expands the arsenal of technical means-devices for determining the position and orientation of objects.

The technical result is achieved due to the device for determining the position and orientation of two objects, which consists of two platforms: the upper and lower, made with the possibility of fixing one object at a time, six distance measurement sensors connecting the upper and lower platforms, and a data processing unit connected to distance measuring sensors with connecting wires; wherein each distance measuring sensor is an elastic tube filled with electrolyte, while two electrodes are located inside the tube near its ends; each platform has six supports for rigidly fixing the ends of the elastic tubes of distance measuring sensors in them so that the bends of the elastic tubes do not exceed 3 ° within the permissible limits of mutual displacements and rotations of the platforms; and the location of the supports on the platforms is chosen so that the elastic tubes of the distance sensors are not parallel.

Platforms can be made in the form of a circle, or an ellipse, or a square, or a hexagon, or a triangle.

The upper platform can be made in area and size larger or smaller, or the same size and shape as the lower platform.

The platforms can be made with the possibility of screw connection, or gluing, or welding, or riveting objects.

At least on one of the device platforms, the supports of the ends of the elastic tubes are coupled in pairs.

Brief Description of the Drawings

In FIG. 1 shows a General view of the inventive device for determining the position and orientation of objects.

In FIG. 2 schematically shows a sensor for measuring distances, which is an electrolytic sensor with a variable length and section of the channel (tube).

In FIG. 3 and FIG. 4 depicts embodiments of the inventive device when on both (Fig. 3) platforms or on one (Fig. 4) platform the ends of elastic (rubber) tubes are paired.

The positions in the drawings indicate

1 - the upper platform of the device;

2 - lower platform of the device;

3-8 - six distance measurement sensors;

9 - data processing unit;

10-15 - supports located on the lower platform of the device for fixing the six ends of six sensors;

16-21 - supports located on the upper platform of the device for fixing the six ends of six sensors;

22 - electrodes;

23 - conductive fluid;

24 - elastic (rubber) tube.

Utility Model Implementation

The proposed device, as well as the prototype, is powerless, i.e. a purely measuring analogue of the Gew-Stuart platform. In the claimed utility model, rigid measuring rods (racks) are replaced that are somehow movably attached to the platforms by distance sensors, each of which is a thin elastic (rubber) tube filled with an electrolyte and electrodes located inside the tubes; the change in the length of the rubber tubes is recorded during the operation of the device.

The device for determining the position and orientation of objects (Fig. 1) consists of two platforms: upper 1 and lower 2, six sensors of distance meters: 3, 4, 5, 6, 7, 8 and data processing unit 9. Data processing unit 9 is connected with distance measuring sensors 3-8 with connecting wires for reading readings from these sensors. Sensors measuring 3-8 distances are made in the form of electrolytic sensors. A detailed description and the principle of operation of electrolytic sensors is widely known ("Handbook of Radio Electronics", Volume 2, Edited by A. A. Kulikovsky, Publishing House "Energy", Moscow, 1968, pp. 462-463 [1]).

The action of the electrolytic sensors 3-8 (Fig. 2) is based on a change in the resistance of the electrically conductive fluid 23 when the electrodes move 22. The electrolytic sensor with a variable length and cross section is a thin elastic (e.g. rubber) tube 24 filled with an electrically conductive fluid (electrolyte) 23. With a change in the length and cross section of the thin elastic (rubber) tube 24, the tube 24 stretches, as a result of which the resistance of the sensor changes due to the movement of the electrodes 22 mounted on the ends of the electric -particle tube 24. Thus, the resistance value depends on the displacement (offset) of the tube 24. As the electroconductive liquid mercury can be used and conducting electrolytes.

The ends of each distance sensor 3-8 are rigidly fixed in the corresponding supports 10-21 located on the lower 2 and upper 1 platforms (i.e., without the possibility of displacements and turns - at a certain point of the platform and at certain angles to its surface, so that with the mutual position of the platforms 1, 2, which is considered to be the initial one and relative to which their mutual displacements and turns are counted, the bends of the elastic (rubber) tubes 24 did not exceed 3 ° within the permissible limits of the mutual displacements and turns of the platforms 1, 2). So, for example, the ends of the distance sensor 3 are fixed in the support 10 of the lower platform 2 and the support 16 of the upper platform 1. The sensors 3-8 can be attached to the respective supports 10-21 in various ways, for example, when the ends of the electrodes 22 of each sensor 3- 8 threaded connections are made for fixing them with nuts through the holes in the platforms 1, 2. The data processing unit 9 registers signals from sensors 3-8.

Thus, due to the smallness (not exceeding 3 °) of the recorded permissible mutual displacements and rotations of the platforms 1, 2, the bends of the elastic (rubber) tubes 24 of the sensors 3-8 remain small and make a small contribution to changing the lengths of the elastic (rubber) tubes 24 , in comparison with their direct elastic extension or compression.

The arrangement of supports 10-15 on the lower platform 2 and supports 16-21 on the upper platform 1 is selected so that the elastic (rubber) tubes 24 of each sensor 3-8 are not parallel. This is done so that the system of equations solved to determine the displacements is not degenerate, i.e. the system of equations must have a solution.

The choice of the location of the supports 10-21 on the platforms 1, 2, to which the ends of the elastic (rubber) tubes 24 are attached, certain restrictions are imposed. First, with permissible movements or rotations of platforms 1, 2, tubes 24 should not touch each other. Secondly, the configuration of the tubes 24 is made in such a way that the direct kinematics problem of the Stuart platform in this configuration has a solution. (The mathematical direct problem of the kinematics of the Stuart platform does not always have a solution. The presence of a solution is associated with the configuration of the measuring threads. See: Zenkevich S.L., Yushchenko A.S. Fundamentals of manipulation robot control: Textbook for universities. - 2nd ed., corrected and additional M: Publishing House of MSTU named after NE Bauman, 2004. - 480 p. [2]).

When taking measurements on each of the platforms 1, 2, one object is fixed (not shown in the drawings). The connection of the object with the platform must be rigid, so that the platform and the object move and rotate together as a single solid. The connection can be as follows: screw, gluing, welding, riveting, etc.

Platforms 1, 2 can be made in mutually different shapes (circle, ellipse, square, hexagon, triangle). The upper platform 1 can be made in area and size larger or smaller, or the same size as the lower platform 2.

Changing the length of elastic (rubber) tubes 24 of sensors 3-8 can be carried out in various ways: by changing its electrical resistance, by changing the tension of the elastic (rubber) tube, by changing the frequency of free vibrations of the elastic (rubber tube), or by changing the amplitude of the forced vibrations of the elastic ( rubber) tube, or by other means. The measurement method in this case is determined by the design of the used sensor and is not the subject of this utility model.

To determine the position of one device platform relative to another (respectively, one object relative to another) using the known lengths of the tubes 24 of six sensors 3-8, a mathematical problem is solved, called the direct kinematics problem of the Stuart platform. For this problem, a number of solution methods have been proposed ([2]).

The inventive device allows you to control two objects attached to the measuring platforms 1, 2 of the device. Objects can be displaced by distance and rotated, while both displacement and angles of rotation of objects are limited. Limitations of angles and displacements are due to the fact that the elastic (rubber) tubes 24 should not sag (always stay taut) and should not bend much. The following objects can be used as objects attached to platforms 1, 2: photo / video cameras, gyroscopes, orientation sensors, magnetometers, particle detectors, etc.

An embodiment of the device is also possible when on one or both platforms the attachment points of the ends of the elastic (rubber) tubes can be combined in pairs, i.e. at one point two ends of two tubes of different sensors 3-8 are fixed (two supports at one point) (Figs. 3, 4).

The device operates as follows.

On each platform 1, 2, one object is fixed (for example, a gyroscope). The fastening is carried out by screwing the protruding parts of the gyroscope into the platforms 1 and 2. A manipulator (not shown) is brought under the upper platform 1, which lifts the upper platform 1 to tension six elastic (rubber) tubes 24 of sensors 3-8 within the permissible mutual displacements and turns of platforms 1 and 2. Depending on the conditions of the experiment, the lower platform 2 is either rigidly fixed or another second manipulator (similar to the one brought under the upper platform 1) is brought under it.

Any displacement and / or rotation of objects attached to platforms 1 and 2, respectively, causes a change in the lengths of all or part of the stretched rubber tubes 24 of the sensors 3-8. Changing the length of the rubber tubes 24 of the sensors 3-8 leads to a change in the signals read from them by the data processing unit 9. For each set of data read from the sensors 3-8 (i.e., for each set of lengths of the rubber tubes 24), a relative offset and turning objects by solving the direct mathematical problem of the kinematics of the Stuart platform. Thus, the claimed device allows you to determine the relative position and orientation of two objects while simplifying the design and measurement. The device can also be easily transported to a new installation location.

Claims (5)

1. A device for determining the position and orientation of two objects, consisting of two platforms: the upper and lower, made with the possibility of fixing one object at a time, six distance measurement sensors connecting the upper and lower platforms, and a data processing unit connected to connecting distance sensors wires wherein each distance measuring sensor is an elastic tube filled with electrolyte, while two electrodes are located inside the tube near its ends; each platform has six supports for rigidly fixing the ends of the elastic tubes of distance measuring sensors in them so that the bends of the elastic tubes do not exceed 3 ° within the permissible limits of mutual displacements and rotations of the platforms; and the location of the supports on the platforms is chosen so that the elastic tubes of the distance sensors are not parallel. 2. The device according to claim 1, characterized in that the platforms are made in the form of a circle, or an ellipse, or a square, or a hexagon, or a triangle. 3. The device according to p. 1, characterized in that the upper platform can be made in area and size larger or smaller, or the same size and shape as the lower platform. 4. The device according to claim 1, characterized in that the platforms are made with the possibility of screw connection, or gluing, or welding, or riveting objects. 5. The device according to claim 1, characterized in that, at least on one of the device platforms, the supports for attaching the ends of the elastic tubes are combined in pairs.

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