Ball bearing angle measuring device and measuring method

Abstract

The present invention provides a ball bearing angle measuring device and a measuring method, which are applied to the fields of spacecraft simulation, precision measurement and precision control, and include a convex ball, a concave ball and a CCD camera. The convex ball and the concave ball are contactingly arranged and the action surface is a spherical structure. The CCD camera is arranged on the convex ball or the concave ball. When the CCD camera is arranged on the convex ball, the concave ball is provided with a plurality of identification marks sensed by the CCD camera. When the CCD camera is arranged on the concave ball, the convex ball is provided with a plurality of identification marks sensed by the CCD camera. Within the measurable range of the CCD camera, the number of identification marks is not less than 4. The present invention provides a method for measuring three-axis angular displacement simultaneously, which is convenient to measure and has high precision. By measuring the three-axis angular displacement between the convex ball and the concave ball in real time, the implementation structure is monitored in real time. The real-time three-axis angular displacement measurement data can also be used as signal feedback, as part of the control system, to achieve the dynamic or static control target of the angular displacement.

Description

Technical Field

[0001] The invention belongs to the field of space simulation precision measurement, is applied to spacecraft simulation, precision measurement and precision control, and relates to a ball bearing angle measuring device and a measuring method. Background Art

[0002] With the development of aerospace technology, it has become a reality for humans to go into space. In the space field, equipment and machinery are in a state of weightlessness, which is very different from the environment with the earth's gravity. However, the transportation cost and operation cost of aerospace equipment are very high, and there is a strict control on the success rate, requiring a high success rate, otherwise there will be huge losses. Therefore, aerospace equipment needs to be tested and tested in a weightless simulation state to ensure the stability and reliability of subsequent actual operation in the space field. During the flight of a spacecraft, attitude control is one of the most important control targets. Therefore, it is necessary to perform non-contact attitude measurement in real time in ground simulation and simulation tests, that is, non-contact measurement of three-axis angles. Various inertial navigation systems can perform non-contact real-time measurement of three-axis angles, but because it is an indirect measurement, there are various defects such as zero drift, and the accuracy, stability and bandwidth are relatively poor. Summary of the invention

[0003] The problem to be solved by the present invention is to provide a ball bearing angle measuring device and a measuring method, which can measure the position angle more conveniently and with high measurement accuracy. It can timely feedback the attitude of the simulated space vehicle and feedback the data, which is conducive to controlling the simulated aircraft to reach the specified position in time. This equipment can simulate the space field with higher control accuracy. At the same time, it provides a method and device for precise real-time measurement of three-axis angles, which can be used in various precision measurement and control occasions.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a ball bearing angle measuring device and a measuring method, comprising a convex ball, a concave ball and a CCD camera, wherein the convex ball and the concave ball are arranged in contact with each other and the contact surface is a spherical structure, and the CCD camera is arranged on the convex ball or the concave ball;

[0005] When the CCD camera is arranged on the convex ball, the concave ball is provided with a plurality of identification marks sensed by the CCD camera;

[0006] When the CCD camera is arranged on the concave ball, the convex ball is provided with a plurality of identification marks sensed by the CCD camera;

[0007] Within the measurable range of the CCD camera, the number of the identification marks is no less than 4.

[0008] Furthermore, the convex ball and the concave ball are both universal ball bearing structures.

[0009] Furthermore, the concave ball is fixedly arranged, the concave ball is a cylinder, a positioning plate protruding inward is arranged inside the concave ball, the CCD camera is fixed on the positioning plate and arranged corresponding to the convex ball, and a avoidance hole is arranged at the position corresponding to the concave ball and the CCD camera.

[0010] Furthermore, the avoidance hole is a square structure with rounded corners at four corners.

[0011] Furthermore, there are multiple identification marks, and within the measurable range of the CCD camera, the angles A1, A2, A3, ..., B1, B2, B3, ... of the four identification marks in two directions are all different.

[0012] Furthermore, the identification mark is arranged in the concave blind hole and is arranged flush with the outer surface of the carrier where the identification mark is located.

[0013] The measurement method using the ball bearing angle measuring device is carried out according to the following steps:

[0014] The first step is calibration. The reference of the CCD camera is the reference of the entire device. After the convex ball and the concave ball are installed, the relative position of the axis of the CCD camera and the axis of the carrier on which it is installed is clarified. That is, if the CCD camera is installed on the concave ball, the relative position of the axis of the CCD camera and the axis of the concave ball is clarified. If the CCD camera is installed on the convex ball, the relative position of the axis of the CCD camera and the axis of the convex ball is clarified.

[0015] The second step is to set identification marks. Set the device marks corresponding to the CCD camera on the floating carrier. If the concave ball is fixed, set the identification marks on the convex ball. If the convex ball is fixed, set the identification marks on the concave ball. Within the recognition range of the CCD camera, the number of identification marks is not less than 4.

[0016] The third step is to form a recognition area through four identification marks. The angles of the four identification marks in two directions, A1, A2, A3, B1, B2, B3, are all different. The deflection angle relative to the Z axis is determined by b1 and b2, and the combined deflection angle and angle in the X and Y directions are determined by a1, a2 and α.

[0017] The fourth step is to determine the rotation angle of the floating carrier relative to the fixed carrier through the distance and position in the third step, that is, θ in the arc length formula below. When the concave sphere is fixed, determine the rotation angle of the convex sphere relative to the concave sphere, that is, the rotation angle relative to the CCD camera; the arc length S of the recognition area and the radius R' corresponding to the arc length are determined through the relationship between the rotation angle and the arc length. The distance between the recognition marks is the chord length L.

[0018] S = Lθ / π(sinθ / 2);

[0019] The arc length is equal to n (center angle) multiplied by π multiplied by R (radius) over 180°; in the present application, that is, S=θπR' / 180, where θ is the degree of the center angle, R' is the radius, and S is the arc length of the center angle, and R' is calculated;

[0020] Step 5: Data comparison, comparing R' in step 4 with the radius of the floating carrier. In the embodiment of the present application, R' is compared with the radius of the convex ball to determine the angle of movement and deviation of the convex ball.

[0021] Furthermore, the coordinates are defined as follows: the X-axis is the left-right direction of the horizontal plane, the Y-axis is the direction of the horizontal plane perpendicular to the X-axis, and the Z-axis is the vertical direction perpendicular to the plane formed by the X-axis and the Y-axis. The convex sphere and the concave sphere will produce relative rotation in three directions, namely, relative rotation between the X-axis, the Y-axis, and the Z-axis.

[0022] Compared with the prior art, the present invention has the following advantages and positive effects.

[0023] 1. The present invention is provided with a convex ball, a concave ball and a CCD camera. Within the measurable range, the number of identification marks where the mark points fall within the field of view is not less than 4, which facilitates the extraction and calculation of coordinate parameters and improves the accuracy of detection. The present invention has a simple structure, convenient and quick operation, and more accurate angular displacement measurement. The angular displacement is evaluated to monitor the position of the execution structure, that is, the position of the convex ball, and is used as a signal feedback to ensure that the executed part, that is, the convex ball, moves in place; the existing position and angle are measured, and real-time monitoring is performed to determine that the angular displacement is correct;

[0024] 2. The CCD camera is small in size, light in weight, unaffected by magnetic fields, and highly resistant to vibration and impact, which is beneficial to improving the detection effect;

[0025] 3. There are multiple identification marks, which are evenly distributed circumferentially relative to the axis of the convex ball or concave ball and are evenly distributed from the inside to the outside in multiple circles, which expands the test range and increases the number of identification marks tested, which is conducive to further improving the test results. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0027] Figure 1 is a cross-sectional view of a ball bearing angle measuring device and a measuring method of the present invention;

[0028] Figure 2 It is a schematic diagram of the structure of the concave sphere of the present invention when viewed from above;

[0029] Figure 3 It is a schematic diagram of the structure of the concave sphere of the present invention when viewed from above;

[0030] Figure 4 is a bottom view of the convex ball of the present invention;

[0031] Figure 5 The present invention Figure 4 KK rotation section view;

[0032] Figure 6 is a front view of the convex ball of the present invention;

[0033] Figure 7 It is a measurement principle diagram of the identification mark of the present invention.

[0034] Reference numerals:

[0035] 1. Convex ball; 2. Concave ball; 21. Positioning plate; 22. Avoidance hole; 23. Rounded corner; 3. CCD camera; 4. Identification mark. DETAILED DESCRIPTION

[0036] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0039] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0040] CCD cameras are mainly used in security systems. Currently, images are mainly generated from CCD cameras. CCD is the abbreviation of charge coupled device, which can convert light into electric charges and store and transfer the charges. It can also take out the stored charges to change the voltage. Therefore, it is an ideal CCD camera component. The CCD cameras constructed with it are widely used because of their small size, light weight, unaffected by magnetic fields, and resistant to vibration and impact.

[0041] like Figure 1 to Figure 7 As shown, the present invention is a ball bearing angle measuring device and a measuring method, comprising a convex ball 1, a concave ball 2 and a CCD camera 3, wherein the convex ball 1 and the concave ball 2 are arranged in contact with each other and the contact surface or the action surface is a spherical structure, and the CCD camera 3 is arranged on the convex ball 1 or the concave ball 2. In the present application, the ball bearing includes a sliding ball bearing, a rolling ball bearing, a liquid static pressure ball bearing and an air floating ball bearing;

[0042] When the CCD camera 3 is disposed on the convex ball 1, a plurality of identification marks 4 sensed by the CCD camera 3 are disposed on the concave ball 2;

[0043] When the CCD camera 3 is disposed on the concave ball 2, a plurality of identification marks 4 sensed by the CCD camera 3 are disposed on the convex ball 1;

[0044] Within the measurable range of the CCD camera 3, the number of identification marks 4 is not less than 4, ensuring the accuracy and reliability of the test structure.

[0045] Preferably, both the convex ball 1 and the concave ball 2 are universal ball bearing structures, so as to realize the spherical surface detection of the ball bearing and reduce the difficulty of the spherical surface detection.

[0046] Preferably, the concave ball 2 is fixedly arranged, the concave ball 2 is a cylinder, a positioning plate 21 protruding inward is provided inside the concave ball 2, the CCD camera 3 is fixed on the positioning plate 21 and is arranged corresponding to the convex ball 1, and a avoidance hole 22 is provided at the position corresponding to the concave ball 2 and the CCD camera 3. After the avoidance hole 22 is set, it is ensured that the preparation of the CCD camera 3 corresponds to the identification mark 4. The whole structure is simple, convenient to process, and the processing cost is low.

[0047] Preferably, the avoidance hole 22 is a square structure with rounded corners 23 at four corners to avoid injuries to the operator during operation and improve the safety of the structure.

[0048] Preferably, there are multiple identification marks 4, and within the measurable range of the CCD camera 3, the angles A1, A2, A3, ..., B1, B2, B3, ... of the four identification marks in two directions are all different.

[0049] Preferably, the identification mark is arranged in the concave blind hole and is arranged flush with the outer surface of the carrier where the identification mark is located. This can be achieved by processing using a CNC machine tool. It has a simple structure, is easy to process, has a low processing cost, and makes the setting of the identification mark faster and more convenient.

[0050] In the actual working process, an identification mark 4 that can be sensed by a CCD camera 3 is made on the surface of the convex ball 1 of the ball bearing, and the CCD camera 3 is installed on the mating concave ball 2 to take real-time photos of the identification mark 4. The identification mark 4 can also be made on the concave ball 2. The CCD camera 3 is installed on the convex ball 1. The rotation of the convex ball 1 or the concave ball 2 can be achieved manually, by air flotation or by other external forces. The CCD camera 3 takes photos at the right time and transmits the image signal to a computer or a dedicated processor. The processor can be an industrial processor, preferably a PLC control center, and the program debugging is simple. The relative position and specific angle of the convex ball 1 and the concave ball 2 are calculated. The angles A1, A2, A3..., B1, B2, B3... of the identification mark 4 in two directions are all different. Within the measurable range, the number of identification marks 4 whose mark points fall on the field of view is not less than 4, thereby ensuring the correctness of the coordinate data extraction, thereby improving the accuracy of the detection. The structure is simple, the operation is convenient and fast, and the angle measurement is simplified.

[0051] In the present application, the CCD camera 3 and the identification mark 4 can also be replaced by equivalent structures, such as the structure of a sensing switch and a sensing protrusion, and technologies such as infrared sensors or laser photography can all implement the technical solution of the present application.

[0052] During the actual test, the measurement method using the ball bearing angle measuring device is carried out according to the following steps.

[0053] First, define the coordinates. The X-axis is the left-right direction of the horizontal plane, the Y-axis is the direction of the horizontal plane perpendicular to the X-axis, and the Z-axis is the vertical direction perpendicular to the plane formed by the X-axis and the Y-axis. The convex sphere and the concave sphere will produce relative rotation in three directions, namely the relative rotation between the X-axis, the Y-axis and the Z-axis.

[0054] The first step is calibration. The reference of CCD camera 3 is the reference of the whole device. After the convex ball 1 and the concave ball 2 are installed, the relative position between the axis of CCD camera 3 and the axis of the carrier on which it is installed is determined. That is, if CCD camera 3 is installed on concave ball 2, the relative position between the axis of CCD camera 3 and the axis of concave ball 2 is determined. If CCD camera 3 is installed on convex ball 1, the relative position between the axis of CCD camera 3 and the axis of convex ball 1 is determined. The relative position relationship in the initial state is determined to provide a reference for the subsequent relative position comparison.

[0055] The second step is to set the identification mark 4. Set the device mark corresponding to the CCD camera 3 on the floating carrier. If the concave ball 2 is fixed, set the identification mark 4 on the convex ball 1. If the convex ball 1 is fixed, set the identification mark 4 on the concave ball 2. Within the recognition range of the CCD camera 3, the number of identification marks 4 is not less than 4.

[0056] The third step is to form a device identification area through four identification marks 4. The angles A1, A2, A3, B1, B2, B3, etc. in two directions of the four identification marks 4 are all different. The deflection angle relative to the Z axis is determined by b1 and b2, and the deflection angle and angle of the X and Y directions are determined by a1, a2 and α.

[0057] The fourth step is to determine the rotation angle of the floating carrier relative to the fixed carrier through the distance and position in the third step, that is, θ in the arc length formula below. When the concave ball 2 is fixed, determine the rotation angle of the convex ball 1 relative to the concave ball 2, that is, the rotation angle relative to the CCD camera 3; determine the arc length S of the recognition area and the radius R' corresponding to the arc length through the relationship between the rotation angle and the arc length. The distance between the recognition marks 4 is the chord length L.

[0058] S = Lθ / π(sinθ / 2);

[0059] The arc length is equal to n (center angle) multiplied by π multiplied by R (radius) over 180°; in the present application, that is, S=θπR' / 180, where θ is the degree of the center angle, R' is the radius, and S is the arc length of the center angle, and R' is calculated;

[0060] Step 5: Data comparison, compare R' in the fourth step with the radius of the floating carrier. In the embodiment of the present application, R' is compared with the radius of the convex ball 1 to determine the angle of movement and the deviation of the convex ball 1. In the present application, the angular displacement is mainly measured. Through the evaluation of this structure, the implementation structure is monitored; that is, the implementation of the convex ball 1, and it is used as a signal feedback to ensure that the executed part, that is, the convex ball 1, is in place; measure the existing position and angle, monitor in real time, and determine that the angular displacement is correct.

[0061] The present invention is a brief optical three-axis measurement method and device, which can perform non-contact measurement accurately, in real time, at high frequency, i.e., at high bandwidth. The present invention can also be used in many fields of precision measurement and control, and can be applied to any occasion requiring precise, real-time, high-frequency measurement of three-axis angles.

[0062] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. Ball bearing angle measuring device, characterized in that: It includes a convex ball, a concave ball and a CCD camera, wherein the convex ball and the concave ball are arranged in contact with each other and the action surface is a spherical structure; The CCD camera is arranged on the concave ball, and the convex ball is provided with a plurality of identification marks sensed by the CCD camera; Within the measurable range of the CCD camera, the number of the identification marks is not less than 4; The concave ball is fixedly arranged, the concave ball is a cylinder, a positioning plate convex inwardly is arranged inside the concave ball, the CCD camera is fixedly arranged on the positioning plate and arranged corresponding to the convex ball, and a position avoidance hole is arranged at the position corresponding to the concave ball and the CCD camera; The convex ball and the concave ball are both universal ball bearing structures.

2. The ball bearing angle measuring device according to claim 1, characterized in that: The avoidance hole is a square structure with rounded corners at four corners.

3. The ball bearing angle measuring device according to claim 1, characterized in that: The identification mark is arranged in the concave blind hole and is arranged flush with the outer surface of the carrier where the identification mark is located.

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