Spherical hinge fault on-line detection device and method

Abstract

The invention discloses a spherical hinge fault online detection device and method, and relates to the field of moving part fault real-time detection. The problems that in the prior art, the state of the spherical hinge is indirectly judged through manual observation or pretightening force detection by means of a torque wrench, the false detection rate is high, and equipment needs to stop running are solved. The device comprises a spherical hinge and an actuator, the spherical hinge comprises a flange, a bearing socket, a bearing, a hinge support and a first sensor, the flange is connected with the actuator through the upper portion of a bolt, the lower portion of the flange is connected with the bearing socket, and the first sensor is arranged on the bearing socket and used for collecting position information of the actuator; the position information is sent to a control computer, the two ends of the bearing are supported at the two ends of a hinged support, and the hinged support is used for fixing the bearing to a platform. The method is realized based on the device, and is also suitable for connecting parts between an actuator and a foundation and between the actuator and a motion platform in heavy hydraulic motion equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of real-time detection of moving component faults, and in particular to an online detection device and method for ball joint faults. Background Art

[0002] As a connection device, the ball joint is a component connected to the force control loop. This component is used when it is necessary to compensate for bending or when two components are not in a straight line. The ball joint allows for gapless use, has very low friction and a long service life. It is mainly used in the connection between the actuator and the foundation, and between the actuator and the motion platform of heavy hydraulic motion equipment. The ball joint is installed at the front and rear ends of the servo actuator to ensure the follow-up of the loading direction, and can prevent the actuator from being subjected to lateral force, thereby extending the life of the actuator. It mainly transmits force, and at the same time, according to the needs of the equipment, it adjusts the angle between the actuator and the foundation, and between the actuator and the motion platform in real time. It is a key component.

[0003] During installation, especially during use, ball joints often experience sudden changes in performance or even failure. The main reason is that the internal components or fastening bolts are displaced, causing the state of the ball joint to change. Due to the heavy weight, large load-bearing capacity and tight structure of this component, it is impossible to install a device inside it for detection. The current existing technology mainly relies on manual observation, which is to indirectly judge the state of the ball joint by stopping the movement of the equipment, manual observation or using a torque wrench to detect the preload.

[0004] However, conventional methods have a high false detection rate and require the equipment to stop running. In particular, some equipment is in a poor working condition. If not discovered in time, it may cause damage to the ball joint or even platform collapse. Therefore, an effective detection method is needed to realize the real-time status detection function of the ball joint. Summary of the invention

[0005] The present invention aims to solve the problem that the prior art mainly relies on manual observation, stops the equipment from moving, and uses a torque wrench to detect the preload force to indirectly judge the state of the ball joint, but the false detection rate is high and the equipment needs to be stopped. To solve the above technical problems, the present invention is implemented through the following technical solutions:

[0006] Solution 1: The present invention proposes an online detection device for ball joint faults, the device comprising:

[0007] A ball joint, an actuator, the ball joint includes a flange, a bearing socket, a bearing, a hinge support, and a first sensor. The flange is connected to the actuator through bolts at the upper part and is connected to the bearing socket at the lower part. A first sensor is provided on the actuator. The first sensor is used to collect position information of the actuator and send the position information to a control computer. Both ends of the bearing are supported at both ends of the hinge support, and the hinge support is used to fix the bearing on the platform.

[0008] Furthermore, a preferred embodiment is provided, wherein the rotation angle between the bearing socket and the bearing is ±30°, and the swing angle is ±10°.

[0009] Furthermore, a preferred embodiment is provided, wherein the device further comprises a wedge block, and the wedge block is used to adjust the preload force of the ball joint.

[0010] Furthermore, a preferred embodiment is provided, in which the pre-tightening force of the ball joint is adjusted based on the wedge block and the position is locked by the pre-tightening bolt.

[0011] Furthermore, a preferred embodiment is provided, in which a second sensor is provided on one side of the flange for collecting acceleration information of the flange and sending the information to the AD collection module.

[0012] Furthermore, a preferred embodiment is provided, in which a third sensor is provided on one side of the bearing socket for collecting acceleration information of the bearing socket and sending the information to the AD collection module.

[0013] Furthermore, a preferred embodiment is provided, in which a fourth sensor is provided inside the bearing for collecting bearing acceleration information and sending the information to the AD acquisition module.

[0014] Furthermore, a preferred embodiment is provided, in which a fifth sensor is provided on one side of the hinge support for collecting acceleration information of the hinge support and sending the information to the AD collection module.

[0015] Solution 2: A method for online detection of ball joint faults, characterized in that the method is implemented based on the device described in Implementation 1, and the method includes:

[0016] Assume that the input and output of the sensor are u(t) and v(t), and the noise at the input and output are a(t) and b(t), respectively.

[0017] Assume that the input and output noises are uncorrelated and uncorrelated with the signal, that is,

[0018] G ua (f) = G vb (f) = G ab (f) = 0 (1)

[0019] In the formula, G ua (f) represents the cross-spectral power spectrum between the input signal u(t) and the input noise a(t); G vb (f) represents the cross-spectral power spectrum between the output signal v(t) and the output noise b(t); G ab (f) represents the cross-spectral power spectrum between the input noise a(t) and the output noise b(t);

[0020] G(f) represents the calculation of the signal power spectrum, because G aa (f)≥0, G bb (f)≥0, then

[0021]

[0022] In the formula, G uu (f) represents the autospectral power spectrum of the input signal u(t); G vv (f) represents the autospectral power spectrum of the output signal v(t); G aa (f) represents the autospectral power spectrum of the input signal noise a(t); G bb (f) represents the autospectral power spectrum of the output signal noise b(t); G ry (f) represents the cross-spectral power spectrum of the noisy input signal r(t) and the noisy output signal y(t); G rr (f) represents the autospectral power spectrum of the noisy input signal r(t); G yy (f) represents the autospectral power spectrum of the output signal y(t) containing noise;

[0023] That is, the relationship between the input and output signals of any component of the ball joint is

[0024] Y(f)-b(f)=H(f)(X(f)-a(f)) (3)

[0025] Where, Y(f) is the frequency domain signal of y(t), b(f) is the frequency domain signal of b(t), R(f) is the frequency domain signal of r(t), and a(f) is the frequency domain signal of a(t);

[0026] Then the ideal input and output in this relatively noise-free situation, the error is

[0027] E(f)=H(f)a(f)-b(f) (4)

[0028] Substitute equations (1), (2), and (3) into equation (4), and take the expected spectrum matrix [E(f)]

[0029]

[0030] Based on the spectrum matrix [E(f)], the input-output characteristic K(f) of the ball joint fault is solved.

[0031] Further, a preferred embodiment is provided, wherein the calculation method for solving the input-output characteristic K(f) of the ball joint fault is:

[0032]

[0033] The present invention is beneficial in that:

[0034] The device and method for online detection of ball joint faults described in the present invention solve the problem in the prior art that the working status of the ball joint cannot be detected in real time. The device and method are simple and effective, and the method is universal and can be extended to other components with reference to the working environment.

[0035] The ball joint fault online detection device described in the present invention mainly includes heavy hydraulic motion equipment. The ball joint is installed at the front and rear ends of the servo actuator to ensure the follow-up performance in the loading direction and to prevent the actuator from being subjected to lateral force, thereby extending the life of the actuator. It mainly transmits force and adjusts the angle between the actuator and the foundation, and between the actuator and the motion platform in real time according to the needs of the equipment. It is a key component.

[0036] The present invention is also applicable to connecting rotating parts and positioning devices, such as vibrators, connectors and joints. In the field of aviation, the ball joint structure is also used for the control of aircraft wings and tails, and the adjustment of fuselage connections. In addition, the ball joint structure can also be used for the connection and control of building structures, such as the steel structure connection of overpasses and large buildings.

[0037] The present invention is also mainly applied to the connection parts between the actuator and the foundation, and between the actuator and the motion platform in heavy hydraulic motion equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 A diagram of a large test equipment for installing a ball joint as described in Implementation Example 11.

[0039] Figure 2 This is an external structural diagram of the ball joint described in the eleventh embodiment.

[0040] Figure 3 This is a diagram of the internal structure of the ball joint described in embodiment eleven.

[0041] Figure 4 This is an input-output characteristic diagram of a certain component of the ball joint described in the eleventh embodiment.

[0042] Figure 5 This is an observation curve diagram of the ball joint characteristics used in a certain type of equipment described in Implementation Example 11.

[0043] Figure 6 This is an electrical schematic diagram of the AD acquisition module described in Implementation Example 11.

[0044] In the figure, the upper ball joint 1, the lower ball joint 2, the first sensor 3, the flange 4, the ball joint flange 4-1, the sensor piston flange 4-2, the bearing socket 5, the bearing 6, the hinge support 7, the wedge block 8, the pre-tightening bolt 9, the platform 10, and the actuator 11. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solutions and advantages of the implementation methods of the present application clearer, the technical solutions in the implementation methods of the present application will be clearly and completely described below in conjunction with the drawings in the implementation methods of the present application. Obviously, the described implementation methods are only part of the implementation methods of the present application, not all of the implementation methods.

[0046] Embodiment 1. This embodiment provides an online detection device for ball joint faults, the device comprising: a ball joint, the ball joint comprising a flange 4, a bearing socket 5, a bearing 6, a hinge support 7, and a first sensor 3. The flange 4 is connected to the actuator 11 at the upper part through bolts, and is connected to the bearing socket 5 at the lower part. The actuator 11 is provided with a first sensor 3, the first sensor is used to collect position information of the actuator 11 and send the position information to the control computer, the two ends of the bearing 6 are supported on the two ends of the hinge support 7, and the hinge support 7 is used to fix the bearing on the platform 10.

[0047] The flange 4 described in this embodiment can be used as the installation position of the sensor, and can also be installed at any position of the flange. Similarly, the installation method of other sensors described in this embodiment is the same as the flange 4, and it is only necessary to ensure that the sensitive axes of all sensors are consistent.

[0048] Embodiment 2: This embodiment further limits the ball joint fault online detection device described in Embodiment 1, wherein the rotation angle between the bearing socket 5 and the bearing 6 is ±30°, and the swing angle is ±10°.

[0049] Embodiment 3: This embodiment further limits the device for online detection of ball joint faults described in Embodiment 2. The device further includes a wedge block 8, and the wedge block 8 is used to adjust the preload force of the ball joint.

[0050] Embodiment 4: This embodiment is a further limitation of the online detection device for ball joint faults described in Embodiment 3, based on adjusting the pre-tightening force of the ball joint by the wedge block 8 and locking the position by the pre-tightening bolt 9 .

[0051] Embodiment 5: This embodiment further limits the online detection device for ball joint faults described in Embodiment 2. A second sensor is provided on one side of the flange to collect acceleration information of the flange and send it to the AD acquisition module.

[0052] Embodiment 6: This embodiment further limits the ball joint fault online detection device described in Embodiment 2. A third sensor is provided on one side of the bearing socket for collecting acceleration information of the bearing socket and sending it to the AD acquisition module.

[0053] Embodiment 7: This embodiment further limits the ball joint fault online detection device described in Embodiment 2. A fourth sensor is provided on the inner side of the bearing for collecting bearing acceleration information and sending it to the AD acquisition module.

[0054] Embodiment 8: This embodiment further limits the online detection device for ball joint faults described in embodiment 4. A fifth sensor is provided on one side of the hinge support for collecting acceleration information of the hinge support and sending it to the AD acquisition module.

[0055] Embodiment 9: This embodiment proposes a method for online detection of ball joint faults. The method is implemented based on the device described in embodiment 1, and the method includes:

[0056] Assume that the input and output of the sensor are u(t) and v(t), and the noise at the input and output are a(t) and b(t), respectively.

[0057] Assume that the input and output noises are uncorrelated and uncorrelated with the signal, that is,

[0058] G ua (f) = G vb (f) = G ab (f) = 0 (1)

[0059] In the formula, G ua (f) represents the cross-spectral power spectrum between the input signal u(t) and the input noise a(t); G vb (f) represents the cross-spectral power spectrum between the output signal v(t) and the output noise b(t); G ab (f) represents the cross-spectral power spectrum between the input noise a(t) and the output noise b(t);

[0060] G(f) represents the calculation of the signal power spectrum, because G aa (f)≥0, G bb (f)≥0, then

[0061]

[0062] In the formula, G uu (f) represents the autospectral power spectrum of the input signal u(t); G vv (f) represents the autospectral power spectrum of the output signal v(t); G aa (f) represents the autospectral power spectrum of the input signal noise a(t); G bb (f) represents the autospectral power spectrum of the output signal noise b(t); G ry (f) represents the cross-spectral power spectrum of the noisy input signal r(t) and the noisy output signal y(t); G rr(f) represents the autospectral power spectrum of the noisy input signal r(t); G yy (f) represents the autospectral power spectrum of the output signal y(t) containing noise;

[0063] That is, the relationship between the input and output signals of any component of the ball joint is

[0064] Y(f)-b(f)=H(f)(X(f)-a(f)) (3)

[0065] Where, Y(f) is the frequency domain signal of y(t), b(f) is the frequency domain signal of b(t), R(f) is the frequency domain signal of r(t), and a(f) is the frequency domain signal of a(t);

[0066] Then the ideal input and output in this relatively noise-free situation, the error is

[0067] E(f)=H(f)a(f)-b(f) (4)

[0068] Substitute equations (1), (2), and (3) into equation (4), and take the expected spectrum matrix [E(f)]

[0069]

[0070] Based on the spectrum matrix [E(f)], the input-output characteristic K(f) of the ball joint fault is solved.

[0071] Embodiment 10: This embodiment further limits the online detection method for ball joint faults described in Embodiment 9. The calculation method for solving the input-output characteristic K(f) of the ball joint fault is:

[0072]

[0073] Implementation eleven: This implementation provides an example, which is used to explain the above implementations one to eight. The specific example is as follows:

[0074] See also Figures 1 to 6 The present embodiment is described. The ball joint described in the present embodiment is mainly used for large-scale test equipment. The equipment and its load are relatively heavy, such as Figure 1 As shown in the figure, the equipment connects the motion platform through the ball joint and the actuator, and the ball joint at this time is called the upper ball joint; the actuator is fixed to the reaction force foundation through the ball joint and the actuator, and the ball joint at this time is called the lower ball joint. It can be seen that the ball joint bears a large load force when the equipment moves, and at the same time requires a certain angle of joint swing.

[0075] like Figure 2 As shown in the figure, the ball joint consists of the following parts: flange, bearing socket, bearing, and bearing seat. The flange is connected to the sensor in the actuator through the upper part of the bolt. Figure 1 The lower part is connected to the bearing socket, which is mainly used as a connecting part between an actuator and a hinge. The inside of the bearing socket and the bearing undergo low-friction movement, which requires a certain relative movement between each other. Generally, the rotation angle is ±30° and the swing angle is ±10°. Figure 3 As shown. The specific angle depends on the type of ball joint, that is, the amount of bearing force. During the initial installation, the clearance of the bearing socket is adjusted by the wedge block 8, and then the friction between the bearing socket and the bearing is adjusted by the pre-tightening bolt 9. The bearing is installed on the hinge support, and the hinge support is connected to the ball joint on the motion platform or to the ball joint under the foundation. When the motion platform is moving, if the flange, pre-tightening bolt 9 or bearing seat are prone to bolt loosening and bearing wear, the performance of the entire motion platform will be affected.

[0076] Based on the ball joint structure and motion relationship, a real-time observation method is used to perform performance testing. Figure 2 The positions of several key components are monitored by external acceleration sensors, and the observed values ​​of several acceleration sensors are used to determine whether the performance of each kinematic pair has changed.

[0077] Since both the upper and lower ball joints transmit the characteristics of the actuator, it can be considered that the output of the actuator tail enters the ball joint completely without noise. The acceleration sensor used for collection has noise, so the output is considered to have noise. Figure 4 The figure shows the mechanism diagram of ball joint detection. The input and output are u(t) and v(t) respectively. The noise at the input and output are a(t) and b(t) respectively. a(t) does not enter the ball joint, and b(t) enters the acceleration acquisition.

[0078] Assume that the input and output noises are uncorrelated and uncorrelated with the signal, that is,

[0079] G ua (f) = G vb (f) = G ab (f) = 0 (1)

[0080] Here, G(f) represents the calculation of the signal power spectrum, and the same applies below.

[0081] Because G aa (f)≥0, G bb (f)≥0, then

[0082]

[0083] Therefore, the relationship between the input and output signals of any component of the ball joint is:

[0084] Y(f)-b(f)=H(f)(X(f)-a(f)) (3)

[0085] Then the ideal input and output in this relatively noise-free situation, the error is

[0086] E(f)=H(f)a(f)-b(f) (4)

[0087] Substitute equations (1), (2), and (3) into equation (4), and take the expected spectrum matrix [E(f)]

[0088]

[0089] To optimize the working characteristics of the reaction ball joint with the best input-output characteristics, the sum of the diagonal elements of the spectrum matrix [E(f)] must be minimized. According to the matrix analysis theory, the optimal input-output characteristic is the eigenvector corresponding to the minimum eigenvalue of [E(f)]. For each ball joint, each component is a single-input single-output system, because only the output noise is considered here, so the eigenvector, that is, the input-output characteristic K(f) is

[0090]

[0091] The key components of the ball joint are collected by the acceleration sensor and then expressed in real time in the form of graphics. Furthermore, the difference between several characteristic curves can be judged by the error threshold, and the program can automatically judge. By specifying each component as the input and the others as the output, the characteristics of all components can be obtained by traversing and solving, so that the fault type can be automatically divided and the fault point can be confirmed by the program.

[0092] exist Figure 1 , Figure 2 Five acceleration sensors are placed at corresponding positions. Figure 5 The upper ball joint characteristic curves of the three actuators are shown, among which the characteristic curves between the sensor piston flange 4-2 and the ball joint flange 4-1, the ball joint flange 4-1 and the bearing socket 5, the bearing socket 5 and the bearing 6, and the bearing 6 and the bearing seat 7 are respectively drawn. It can be seen that within the specified bandwidth, the characteristics of the bearing socket 5 and the bearing 6 of the upper hinge of the actuator 11 deteriorate, and the preload bolt 9 may be loose.

[0093] Similarly, a characteristic curve with the sensor piston flange as input and other components as output can be made to further refine the fault type and fault point.

[0094] See also Figure 6 As shown, Figure 6 The information collected by the first sensor 1 in the AD acquisition module is transmitted by the computer analog acquisition board LC2-1 through the P1 port of the analog conditioning board AG2, and its power supply 24V is provided by pin 3 in the port, and the force signal is collected by pin 6 in the port. Other sensors can be collected in turn by ports P2 to P5.

[0095] Those skilled in the art will appreciate that the above are only preferred embodiments of the present invention, and the various embodiments of the present disclosure and / or the features described in the claims may be combined or combined in various ways, even if such combinations or combinations are not explicitly described in the present disclosure. It is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments, or perform equivalent substitutions on some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

[0096] Although preferred embodiments of the present invention have been described, additional changes and modifications may be made to these embodiments by those skilled in the art once the basic inventive concepts are known. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A ball joint fault online detection device, characterized in that: The device comprises: a ball joint, an actuator (11), the ball joint comprises a flange (4), a bearing socket (5), a bearing (6), a hinge support (7), and a first sensor (3), the flange (4) is connected to the actuator (11) at the upper part through bolts, and is connected to the bearing socket (5) at the lower part, the actuator (11) is provided with a first sensor (3), the first sensor is used to collect position information of the actuator (11), and send the position information to a control computer, the two ends of the bearing (6) are supported at the two ends of the hinge support (7), and the hinge support (7) is used to fix the bearing on the platform (10).

2. The ball joint fault online detection device according to claim 1 is characterized in that: The rotation angle between the bearing socket (5) and the bearing (6) is ±30°, and the swing angle is ±10°.

3. The ball joint fault online detection device according to claim 1 is characterized in that: The device also includes a wedge block (8), which is used to adjust the preload force of the ball joint.

4. The ball joint fault online detection device according to claim 3 is characterized in that: The pre-tightening force of the ball joint is adjusted based on the wedge block (8) and the position is locked by the pre-tightening bolt (9).

5. The ball joint fault online detection device according to claim 2, characterized in that: A second sensor is provided on one side of the flange for collecting acceleration information of the flange and sending the information to the AD collection module.

6. The ball joint fault online detection device according to claim 2, characterized in that: A third sensor is provided on one side of the bearing socket for collecting acceleration information of the bearing socket and sending the information to the AD collection module.

7. The ball joint fault online detection device according to claim 2, characterized in that: A fourth sensor is provided inside the bearing for collecting bearing acceleration information and sending it to the AD acquisition module.

8. The ball joint fault online detection device according to claim 4 is characterized in that: A fifth sensor is provided on one side of the hinge support for collecting acceleration information of the hinge support and sending it to the AD acquisition module.

9. A method for online detection of ball joint faults, characterized in that: The method is implemented based on the device according to claim 1, and the method includes: Assume that the input and output of the sensor are u(t) and v(t), and the noise at the input and output are a(t) and b(t), respectively. Assume that the input and output noises are uncorrelated and uncorrelated with the signal, that is, G ua (f)=G vb (f)=G ab (f)=0 (1) In the formula, G ua (f) represents the cross-spectral power spectrum between the input signal u(t) and the input noise a(t); G vb (f) represents the cross-spectral power spectrum between the output signal v(t) and the output noise b(t); G ab (f) represents the cross-spectral power spectrum between the input noise a(t) and the output noise b(t); G(f) represents the calculation of the signal power spectrum, because G aa (f)≥0, G bb (f)≥0, then In the formula, G uu (f) represents the autospectral power spectrum of the input signal u(t); G vv (f) represents the autospectral power spectrum of the output signal v(t); G aa (f) represents the autospectral power spectrum of the input signal noise a(t); G bb (f) represents the autospectral power spectrum of the output signal noise b(t); G ry (f) represents the cross-spectral power spectrum of the noisy input signal r(t) and the noisy output signal y(t); G rr (f) represents the autospectral power spectrum of the noisy input signal r(t); G yy (f) represents the autospectral power spectrum of the output signal y(t) containing noise; That is, the relationship between the input and output signals of any component of the ball joint is Y(f)-b(f)=H(f)(X(f)-a(f)) (3) Where, Y(f) is the frequency domain signal of y(t), b(f) is the frequency domain signal of b(t), R(f) is the frequency domain signal of r(t), and a(f) is the frequency domain signal of a(t); Then the ideal input and output in this relatively noise-free situation, the error is E(f)=H(f)a(f)-b(f) (4) Substitute equations (1), (2), and (3) into equation (4), and take the expected spectrum matrix [E(f)] Based on the spectrum matrix [E(f)], the input-output characteristic K(f) of the ball joint fault is solved.

10. The method for online detection of ball joint faults according to claim 9, characterized in that: The calculation method for solving the input-output characteristic K(f) of the ball joint fault is:

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