Mobile semi-active tuned mass damper based on computer vision and monitoring data

Abstract

The invention provides a mobile semi-active tuned mass damper based on computer vision and monitoring data, which comprises a footbridge main body structure part, a mobile semi-active control part and a computer vision and monitoring data part, and is characterized in that the footbridge main body structure part comprises a bridge deck, a box girder cavity and a guide rail; the movable semi-active control part comprises a rolling trolley, a semi-active tuned mass damper, a temperature controller and a current controller; the computer vision and monitoring data part comprises a camera, an acceleration sensor and a control center computer, the frequency, rigidity and damping force of the semi-active tuned mass damper are adjusted through the control center computer, and the positions of the rolling trolley and the semi-active tuned mass damper are controlled. According to the damper, the vertical frequency, rigidity and damping force of the tuned mass damper can be adjusted in real time, intelligent vibration control over moving random crowds with different densities is achieved, and the better vibration reduction effect is achieved.

Description

Technical Field

[0001] The invention belongs to the field of civil engineering and health monitoring technology, and in particular relates to a mobile semi-active tuned mass damper based on computer vision and monitoring data. Background Art

[0002] Tuned mass dampers have attracted widespread attention due to their advantages such as small changes to the original structure, convenient construction, and significant vibration reduction control effects. They have been used in the vertical vibration comfort control of pedestrian bridges at home and abroad. However, traditional tuned mass dampers have the disadvantage of tuning sensitivity to frequency, and the damage to the main structure itself will affect the vibration reduction effect of the tuned mass damper. Moreover, there is a difference between the estimated value of the natural frequency of the structure during design and its actual natural frequency. Therefore, how to achieve adaptive control of the tuned mass damper so that it can adjust its own frequency in real time to be close to the frequency of the structure to achieve a good vibration reduction effect has become a new and meaningful research direction.

[0003] Traditional supported tuned mass dampers use hydraulic viscous dampers to provide damping. While providing damping, they also have a certain stiffness, and cannot completely separate stiffness from damping, which affects design analysis. In addition, hydraulic viscous dampers also have problems such as oil leakage, difficulty in maintenance, and difficulty in later adjustment, which increases the difficulty and cost of maintenance. Magnetorheological dampers are a major innovation in hydraulic viscous damping. Magnetorheological fluid is a new type of intelligent material that can change the current intensity to change the magnetic field intensity to control the transition of magnetorheological fluid between liquid and solid, thereby achieving real-time changes in its damping force.

[0004] Shape memory alloys (SMA) are materials composed of two or more metal elements that have shape memory effects through thermoelasticity and martensitic phase transformation and its inversion. Shape memory alloys are currently the best shape memory materials. Taking shape memory alloy springs as an example, by changing their temperature, the elongation and shortening of the spring can be controlled, thereby changing its stiffness.

[0005] The traditional tuned mass damper is fixed in position on the footbridge. However, due to the random distribution of pedestrians on the footbridge and the randomness of human-induced excitation, this does not provide the best vibration control effect when considering the multi-modal vibration of the footbridge. Summary of the invention

[0006] The purpose of the present invention is to provide a mobile semi-active tuned mass damper based on computer vision and monitoring data, and to realize a mobile intelligent tuned mass damper through technologies such as computer vision, intelligent sensing and mobile machines to overcome the above-mentioned shortcomings in the prior art.

[0007] To achieve the above object, the present invention adopts the following technical solutions: The mobile semi-active tuned mass damper based on computer vision and monitoring data includes a pedestrian bridge main structure part, a mobile semi-active control part, and a computer vision and monitoring data part, wherein: The main structure of the pedestrian bridge includes a bridge deck, a box beam cavity and a guide rail, wherein the guide rail is located at the bottom of the box beam cavity; The mobile semi-active control part includes a rolling trolley, a semi-active tuned mass damper, a temperature controller and a current controller; the semi-active tuned mass damper is arranged on the rolling trolley, and the rolling trolley is located on the guide rail; the temperature controller is used to adjust the frequency and stiffness of the semi-active tuned mass damper; the current controller is used to adjust the damping force of the semi-active tuned mass damper; The computer vision and monitoring data part includes a camera, an acceleration sensor and a control center computer; the camera monitors the density and position of pedestrians on the bridge deck in real time, and transmits image information to the control center computer; there are multiple acceleration sensors, which are adsorbed under the bridge deck and transmit acceleration signals of the bridge deck at different positions to the control center computer; the control center computer receives and analyzes the data from the camera and acceleration sensor, adjusts the frequency and stiffness of the semi-active tuned mass damper by controlling the temperature controller, adjusts the damping force of the semi-active tuned mass damper by controlling the current controller, and controls the displacement of the rolling cart, thereby realizing intelligent vibration control of random people of different densities.

[0008] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention discloses a mobile semi-active tuned mass damper based on computer vision and monitoring data, which can realize real-time adjustment of the vertical frequency, stiffness and damping force of the tuned mass damper, and realize intelligent vibration control of random people of different densities, so as to achieve better vibration reduction effect. The frequency of the semi-active tuned mass damper can be adjusted by controlling the power supply, temperature and stiffness of the shape memory alloy spring through a temperature controller to realize real-time control of the vertical frequency of the tuned mass damper; the damping force can be adjusted by controlling the power supply, electromagnetic field strength and damping coefficient of the magnetorheological damper through a current controller to improve the vibration reduction effect of the semi-active tuned mass damper; the control center computer controls the rolling trolley to change the position of the semi-active tuned mass damper on the guide rail to further improve the intelligent control effect of random human-induced vibration of the semi-active tuned mass damper. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural schematic diagram of a mobile semi-active tuned mass damper based on computer vision and monitoring data of the present invention.

[0010] Figure 2 It is a schematic diagram of the semi-active tuned mass damper of the present invention.

[0011] Figure 3 It is a control flow chart of the present invention.

[0012] Numbers in the figure: 1-camera, 2-acceleration sensor, 3-bridge deck, 4-rolling cart, 5-semi-active tuned mass damper, 5-1-mass block, 5-2-shape memory alloy spring, 5-3-magnetorheological damper, 6-box girder cavity, 10-control center computer, 11-temperature controller, 12-current controller, 13-guide rail. DETAILED DESCRIPTION

[0013] The technical solution provided by the present application will be further described below in conjunction with specific embodiments and accompanying drawings. The advantages and features of the present application will become more apparent with the following description.

[0014] like Figure 1 As shown, a mobile semi-active tuned mass damper based on computer vision and monitoring data of the present invention includes a pedestrian bridge main structure part, a mobile semi-active control part, and a computer vision and monitoring data part, wherein: The main structure of the pedestrian bridge includes a bridge deck 3, a box beam cavity 6 and a guide rail 13, wherein the guide rail 13 is located at the bottom of the box beam cavity 6; The mobile semi-active control part includes a rolling trolley 4, a semi-active tuned mass damper 5, a temperature controller 11 and a current controller 12; the semi-active tuned mass damper 5 is arranged on the rolling trolley 4, and the rolling trolley 4 is located on the guide rail 13; the temperature controller 11 is used to adjust the frequency and stiffness of the semi-active tuned mass damper 5; the current controller 12 is used to adjust the damping force of the semi-active tuned mass damper 5; The computer vision and monitoring data part includes a camera 1, an acceleration sensor 2 and a control center computer 10; the camera 1 monitors the density and position of pedestrians on the bridge deck in real time, and transmits image information to the control center computer 10; there are multiple acceleration sensors 2, which are adsorbed under the bridge deck, and transmit acceleration signals of the bridge deck at different positions to the control center computer 10; the control center computer 10 receives and analyzes the data from the camera 1 and the acceleration sensor 2, adjusts the frequency and stiffness of the semi-active tuned mass damper 5 by controlling the temperature controller 11, adjusts the damping force of the semi-active tuned mass damper 5 by controlling the current controller 12, and controls the displacement of the rolling cart 4, thereby realizing intelligent vibration control of random people of different densities.

[0015] like Figure 2As shown, the semi-active tuned mass damper 5 includes a mass block 5-1, a shape memory alloy spring 5-2 and a magnetorheological damper 5-3.

[0016] The control center computer 10 obtains the instantaneous vibration frequency of the structure by wavelet transform signal processing based on the acceleration signal monitored by the acceleration sensor 2, and calculates the instantaneous optimal frequency and stiffness based on the mass of the semi-active tuned mass damper.

[0017] like Figure 3 As shown, the frequency of the semi-active tuned mass damper can be adjusted by controlling the current, temperature and stiffness of the shape memory alloy spring 5-2 through a temperature controller 11 controlled by a control central computer 10, so as to achieve real-time control of the vertical frequency of the tuned mass damper; The damping force of the semi-active tuned mass damper can be adjusted by controlling the current flow, electromagnetic field strength and damping coefficient of the magnetorheological damper 5-3 through a current controller 12 controlled by a control central computer 10, so as to readjust its damping ratio to a set optimal value, thereby improving the vibration reduction effect of the semi-active tuned mass damper.

[0018] The semi-active tuned mass damper moves along the track following the rolling trolley under the control of the control center computer. During low-peak hours of pedestrian flow, the control center computer controls the rolling trolley to change its position according to the position of pedestrians on the bridge deck monitored by the camera, so that the position of the semi-active tuned mass damper on the guide rail is consistent with the position of pedestrians in real time; during peak hours of pedestrian flow, the control center computer controls the rolling trolley to change its position according to the real-time monitoring signal of the acceleration sensor adsorbed under the bridge deck, so that the position of the semi-active tuned mass damper on the guide rail is consistent with the position with the maximum acceleration response in real time; thereby further improving the intelligent vibration control effect of the semi-active tuned mass damper on the moving random crowds of different densities.

[0019] Furthermore, the number of the cameras may be 1 or 2.

[0020] Preferably, there may be 5 to 10 acceleration sensors, which are evenly arranged along the bridge deck.

[0021] Furthermore, the rolling cart may also be replaced by a robot, and the robot drives the semi-active tuned mass damper to move on the guide rail.

[0022] Furthermore, the camera may be replaced by a drone to monitor the position of pedestrians passing by.

[0023] The above description is only a description of the preferred embodiments of the present application, and is not intended to limit the scope of the present application. Any changes or modifications made by any person skilled in the art based on the above disclosed technical contents shall be deemed as equivalent effective embodiments and shall fall within the scope of protection of the technical solution of the present application.

Claims

1. A mobile semi-active tuned mass damper based on computer vision and monitoring data, characterized in that: It includes the main structure of the pedestrian bridge, the mobile semi-active control part, and the computer vision and monitoring data part, among which: The main structure of the pedestrian bridge comprises a bridge deck (3), a box beam cavity (6) and a guide rail (13), wherein the guide rail (13) is located at the bottom of the box beam cavity (6); The mobile semi-active control part comprises a rolling trolley (4), a semi-active tuned mass damper (5), a temperature controller (11) and a current controller (12); the semi-active tuned mass damper (5) is arranged on the rolling trolley (4), and the rolling trolley (4) is located on a guide rail (13); the temperature controller (11) is used to adjust the frequency and stiffness of the semi-active tuned mass damper (5); and the current controller (12) is used to adjust the damping force of the semi-active tuned mass damper (5); The computer vision and monitoring data part comprises a camera (1), an acceleration sensor (2) and a control center computer (10); the camera (1) monitors the density and position of pedestrians on the bridge deck in real time, and transmits image information to the control center computer (10); there are a plurality of acceleration sensors (2), which are adsorbed under the bridge deck, and transmit acceleration signals of the bridge deck at different positions to the control center computer (10); the control center computer (10) receives and analyzes the data of the camera (1) and the acceleration sensor (2), adjusts the frequency and stiffness of the semi-active tuned mass damper (5) by controlling the temperature controller (11), adjusts the damping force of the semi-active tuned mass damper (5) by controlling the current controller (12), and controls the displacement of the rolling cart (4), thereby realizing the intelligent vibration control of the moving random crowd of different densities.

2. The mobile semi-active tuned mass damper based on computer vision and monitoring data as claimed in claim 1, characterized in that: The semi-active tuned mass damper (5) comprises a mass block (5-1), a shape memory alloy spring (5-2) and a magnetorheological damper (5-3); The frequency and stiffness of the semi-active tuned mass damper (5) are adjusted by controlling the current flow, temperature and stiffness of the shape memory alloy spring (5-2) through a temperature controller (11) controlled by a control central computer (10), so as to achieve real-time tuning of the vertical frequency of the tuned mass damper; The damping force of the semi-active tuned mass damper (5) is adjusted by controlling the current flow, electromagnetic field strength and damping coefficient of the magnetorheological damper (5-3) through a current controller (12) controlled by a control central computer (10), so as to readjust its damping ratio to a set optimal value, thereby improving the vibration reduction effect of the semi-active tuned mass damper (5).

3. The mobile semi-active tuned mass damper based on computer vision and monitoring data as claimed in claim 1, characterized in that: The control central computer (10) obtains the instantaneous vibration frequency of the structure by wavelet transform signal processing based on the acceleration signal monitored by the acceleration sensor (2), and obtains the instantaneous optimal frequency and stiffness based on the mass calculation of the semi-active tuned mass damper.

4. The mobile semi-active tuned mass damper based on computer vision and monitoring data as claimed in claim 1, characterized in that: During the off-peak period of pedestrian flow, according to the position of pedestrians on the bridge deck (3) monitored by the camera (1), the control center computer (10) controls the rolling trolley (4) to change its position so that the position of the semi-active tuned mass damper (5) on the guide rail (13) is consistent with the position of the pedestrians in real time; During peak traffic hours, based on real-time monitoring signals from an acceleration sensor (2) attached to the bottom of the bridge deck (3), the control center computer (10) controls the rolling trolley (4) to change its position, so that the position of the semi-active tuned mass damper (5) on the guide rail (13) is consistent with the position with the maximum acceleration response in real time.

5. The mobile semi-active tuned mass damper based on computer vision and monitoring data as claimed in claim 1, characterized in that: The plurality of acceleration sensors are evenly arranged along the bridge deck.

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