Method of measuring overload of a special device in a pitching motion test

Abstract

The application provides a method for measuring overload of a special device in a pitching motion test, which comprises arranging an inclination sensor in the axial direction of the pitching motion of the special device, arranging a one-way overload sensor at a measured point, and obtaining the overload of the special device by measuring the included angle between the special device and the horizontal line by the inclination sensor and the tangential direction acceleration of the special device measured by the one-way overload sensor. The method of the application avoids the influence of transverse vibration error and axial acceleration error in principle, simultaneously measures and records the angle change process of the pitching motion test by the inclination sensor in real time, intuitively reflects the dynamic motion trajectory of the special device, and the description of the motion trajectory by the mathematical model is relatively simple, the calculation amount is smaller, and the error accumulation is smaller.

Description

Technical Field

[0001] This invention belongs to the field of dynamic mechanical vibration testing technology, specifically relating to a method for measuring the overload load borne by specialized equipment during pitch motion testing. Background Technology

[0002] In the field of dynamic mechanical vibration testing, certain specialized equipment requires extensive pitch motion tests to assess the overload load borne by each measuring point along the tangential direction during the pitch motion test. The common method for measuring overload is to attach a three-dimensional overload sensor to the tested part of the specialized equipment to measure the acceleration values ​​in each direction during the pitch test, and then output the overload load along the tangential direction of the pitch trajectory curve through mathematical model calculation. A simplified schematic diagram of the pitch motion test is shown below. Figure 1 As shown.

[0003] Among them, the test is usually conducted according to Figure 1 The diagram shows the installation of a three-dimensional overload sensor, with each sensing direction of the sensor aligned with... Figure 1 The directions are consistent. G represents gravitational acceleration, Z represents the tangential acceleration of the measured part of the specialized equipment during the pitch motion test, and X represents the axial acceleration along the measured part of the specialized equipment. The tangential and axial acceleration values ​​Z and X are recorded in real time during the pitch motion test. The tangential component of gravitational acceleration G is calculated by combining the gravitational acceleration G and the axial acceleration X. Z :

[0004]

[0005] Therefore, the overload ε in the tangential direction during the pitch motion of the special equipment is:

[0006]

[0007] Among them, G, Z, G Z The units of both parameters X and G are multiples of the local gravitational acceleration. For example, G represents the local gravitational acceleration: G = lg(g = 9.8 m / s²). 2 Z, when measured, represents how many grams (G). Z The same applies to X.

[0008] The measurement method has the following problems: (1) the tangential component of gravitational acceleration G Z The measured values ​​are correlated in real time with the axial (X-direction) acceleration values; therefore, the measurement accuracy of the axial acceleration value X directly affects the tangential component of gravitational acceleration G. ZThe measurement accuracy. (2) The main technical indicators of the overload sensor are sensitivity amplitude, sensitivity frequency response and sensitivity amplitude linearity. Generally, the sensitivity amplitude error is 1% or 2%, the sensitivity frequency response error is ±5% or ±10%, and the sensitivity amplitude linearity error is ±3%. Therefore, the above mathematical model introduces a large error in the Z-direction and X-direction acceleration measurement results. (3) When the measuring point of the special equipment is subjected to vibration in a single Z-direction (tangential direction), its X and Y directions will inevitably be subjected to undesirable lateral vibrations caused by the Z-direction vibration (such as... Figure 2 (as shown in the figure). When the special equipment is subjected to pitch motion test, the X direction will be affected by lateral vibration, so the introduced lateral vibration error is difficult to evaluate and calculate accurately. (4) Due to factors such as structural form and packaging process, the manufacturing cost of the three-dimensional overload sensor is high. Therefore, it is not economical to use it to test the overload during the pitch motion test of the special equipment, especially when multi-point overload measurement is carried out during the test. Summary of the Invention

[0009] To address the problem of accurately measuring overload during large-range pitch motion tests of specialized equipment, as described above, this invention proposes a "tilt overload measurement method." This method employs a combination of tilt sensors and unidirectional overload sensors to measure the overload during pitch motion tests of the specialized equipment. This approach avoids the influence of lateral vibration and axial acceleration errors in principle. Furthermore, the tilt sensor records the pitch motion angle changes in real time, providing a direct reflection of the equipment's dynamic trajectory. The mathematical model describing this trajectory is relatively simple, requiring less computation and resulting in less error accumulation.

[0010] Specifically, the present invention provides a method for measuring the overload of a special equipment in a pitch motion test. The method is as follows: an angle sensor is set in the axial direction of the pitch motion of the special equipment, and a unidirectional overload sensor is set at the test point. The overload of the special equipment in the tangential mode is obtained by measuring the rotation angle θ between the special equipment and the horizontal line by the angle sensor and the tangential acceleration Z of the special equipment by the unidirectional overload sensor.

[0011] In this process, an angle sensor is installed on the axial direction (e.g., axis) of the specialized equipment used for pitch testing. The angle θ between the specialized equipment and the horizontal line (in real-time rotation) is measured. By decomposing the component of the (local) gravitational acceleration G in the direction of the motion angle, the real-time tangential gravitational acceleration value G during the pitch motion can be obtained. Z According to the principle of force composition, the tangential component of gravitational acceleration G can be obtained. Z for:

[0012] G Z =Gcosθ

[0013] Simultaneously, a unidirectional overload sensor is installed at the measured part (point) of the special equipment, with its sensitive direction parallel to the direction of motion of that point during the pitch test. This allows for the direct measurement and output of the acceleration Z in the tangential direction (at that point) of the special equipment during the pitch test. Therefore, the overload ε in the tangential direction during the pitch motion of the special equipment is:

[0014] ε=ZG Z =Z-Gcosθ

[0015] That is, ε = Z - Gcosθ

[0016] In the above formula, G, Z and G Z The units of the parameters are all represented as multiples of the local gravitational acceleration. For example, G is the local gravitational acceleration, G = lg(g = 9.8 m / s²). 2 Z, when measured, represents how many grams (G). Z Similarly.

[0017] Furthermore, when multiple overload measurements are required in pitch motion tests, only one tilt sensor needs to be installed in the axial direction, and a unidirectional overload sensor (with the sensitive direction parallel to the motion direction of that point) needs to be installed at each measuring point. These sensors can then be connected to a data acquisition instrument to measure the overload ε at each point.

[0018] The overload measurement method for a special equipment in pitch motion test provided by the present invention has the following advantages: (1) The "tilt overload measurement method" of the present invention avoids the influence of lateral vibration error and axial acceleration error in principle, which not only improves the measurement accuracy of tangential overload in pitch motion test of special equipment, but also provides a technical approach for high-precision measurement of tangential overload; (2) The combination of unidirectional overload sensor and tilt sensor to perform overload measurement with a new mathematical model is a new application of tangential overload measurement in pitch motion test of special equipment; (3) The "tilt overload measurement method" has low testing cost, especially for multiple measurement points, it has a great cost advantage: First, the purchase cost of the combination of unidirectional overload sensor and tilt sensor is lower than that of three-directional overload sensor, and second, the number of data acquisition channels occupied by multiple measurement points is small. Attached Figure Description

[0019] Figure 1 A simplified diagram of the pitch motion of a special-purpose device.

[0020] Figure 2 This is a schematic diagram of lateral vibration.

[0021] Figure 3 This is a schematic diagram illustrating the principle of an overload measurement method using a special device in a pitch motion test according to the present invention.

[0022] Figure 4This is a schematic diagram of a multi-point overload measurement method for an overload measurement device in a pitch motion test according to the present invention. Detailed Implementation

[0023] The "overload measurement method of a special equipment in pitch motion test" of the present invention will be further described with reference to the accompanying drawings.

[0024] like Figure 3 As shown in the figure, the present invention provides a method for measuring overload in pitch motion tests using a dedicated device. The pitch test mechanism (i.e., the dedicated device) used for the pitch test is generally cylindrical (but the method of the present invention is not limited by the shape of the device under test). A high-precision tilt sensor is installed in the axial direction of the cylindrical mechanism to measure the (real-time) angle θ between the dedicated device and the horizontal line. By decomposing the local gravitational acceleration G in the direction of the motion angle, the tangential gravitational acceleration value G can be obtained in real time. Z According to the principle of force composition, the tangential component of gravitational acceleration G can be obtained. Z for:

[0025] G Z =Gcosθ

[0026] Furthermore, by installing a unidirectional overload sensor at the measured point of the mechanism, with its sensitive direction parallel to the direction of motion of that point during the pitch test, the tangential acceleration Z of the dedicated equipment during the pitch motion test can be directly measured. Therefore, the tangential overload ε of the dedicated equipment during the pitch motion is:

[0027] ε=ZG Z =Z-Gcosθ

[0028] Furthermore, such as Figure 4 As shown, when multiple measurement points (measurement points 1-4) are required for overload measurement in pitch motion tests, only one high-precision tilt sensor needs to be installed in the axial direction to measure the angle θ between the dedicated equipment and the horizontal line; and a unidirectional overload sensor (unidirectional overload sensor 1-4, sensitive direction parallel to the motion direction of measurement point 1-4) is installed at each of the measurement points 1-4, and connected to a data acquisition instrument to obtain the tangential acceleration Z at each measurement point 1-4. 1-4 This allows the overload ε at measuring points 1-4 to be measured. 1-4 Measurement.

[0029] Although the overload measurement of large-range pitch motion tests of special equipment is generally carried out using a three-dimensional overload sensor, it is a relatively suitable measurement method when the measurement accuracy requirements are not high and the budget is sufficient.

[0030] However, the novel "tilt overload measurement method" combining a unidirectional overload sensor and a tilt sensor is quite novel and unique: ① The output parameters of the overload sensor and the tilt sensor belong to the categories of mechanical and geometric quantities, respectively. Using parameters from interdisciplinary fields to construct mathematical models is difficult for testers to apply and easily overlooked; the tilt sensor is mainly used to measure geometric angle changes and is generally not used in mechanical parameter testing; ② The "tilt overload measurement method" has higher measurement accuracy. The combination of the unidirectional overload sensor and the tilt sensor not only avoids the influence of lateral vibration error and axial acceleration error in principle, but also the tilt sensor's accuracy is much higher than that of the overload sensor. Therefore, the error introduced in calculating the tangential component of gravitational acceleration during pitch motion tests is minimal; ③ Applying the "tilt overload measurement method" can significantly reduce testing costs. The procurement and metrological traceability cost of the unidirectional overload sensor is reduced by 2 / 3 compared to the triaxial overload sensor; when performing multi-point overload measurements, the number of channels required for the data acquisition instrument can be reduced, lowering the channel requirements and greatly reducing data acquisition costs. For example, measuring the overload at 7 measurement points using a three-dimensional overload sensor requires at least 14 channels, while the "tilt overload measurement method" only requires 8 channels (the more channels the data acquisition instrument occupies, the higher the testing cost). Under the same measurement accuracy and testing cost conditions, there is currently no other better or more economical measurement technology to achieve tangential overload measurement in pitch motion tests of dedicated equipment.

[0031] The above-described apparatus is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-described technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for measuring overload in a pitch motion test using specialized equipment, characterized in that, The method is as follows: an inclination sensor is set in the axial direction of the pitch motion of the special equipment, and a one-way overload sensor is set at the measurement point. The overload of the special equipment is obtained by measuring the angle θ between the special equipment and the horizontal line by the inclination sensor and the tangential acceleration Z of the special equipment by the one-way overload sensor. The overload ε of the special equipment in the tangential direction is: ε=Z-Gcosθ Where G is the gravitational acceleration of the measurement site; In the pitch motion test, when multiple overload measurements are required, only one tilt sensor needs to be set up, and a unidirectional overload sensor needs to be set up at each measured point to realize the measurement of overload at multiple measured points.

Images