阅读说明：本技术 用于塔式起重机拉杆的减振系统和减振方法 (Vibration reduction system and vibration reduction method for tower crane pull rod ) 是由 左旸 王爱红 马浩钦 秦泽 王恺 于 2020-06-03 设计创作，主要内容包括：本发明涉及一种用于塔式起重机拉杆的减振系统和减振方法,目的是为了解决塔式起重机拉杆容易在风载荷的激励下产生振动,进而影响塔式起重机起重臂运行平稳性的技术问题。本发明的减振系统包括两个加速度传感器、电荷放大器、模拟数字转换器、控制器、D/A转换器、U/I转换电路和若干作动器；本发明利用磁流变阻尼器阻尼可变的的特性快速吸收振动能量,从而减小振动,使拉杆在短时间之内恢复稳定,避免发生由振动带来的塔机事故。本发明采用模糊PID控制器,采用模糊控制与PID控制相结合,可以弱化磁流变阻尼器结构时滞带来的负面效应,响应迅速,鲁棒性好,能够很好地适应条件的变化,解决系统的非线性问题,减振效果显著,能耗低,且具有高度的智能化。(The invention relates to a vibration reduction system and a vibration reduction method for a tower crane pull rod, and aims to solve the technical problem that the tower crane pull rod is easy to vibrate under the excitation of wind load, so that the operation stability of a crane boom of a tower crane is influenced. The vibration damping system comprises two acceleration sensors, a charge amplifier, an analog-digital converter, a controller, a D/A converter, a U/I conversion circuit and a plurality of actuators; the invention utilizes the characteristic of variable damping of the magnetorheological damper to quickly absorb vibration energy, thereby reducing vibration, enabling the pull rod to recover stably in a short time and avoiding tower crane accidents caused by vibration. The invention adopts the fuzzy PID controller, combines the fuzzy control and the PID control, can weaken the negative effect caused by the time lag of the magnetorheological damper structure, has quick response and good robustness, can well adapt to the change of conditions, solves the nonlinear problem of the system, has obvious vibration reduction effect, low energy consumption and high intellectualization.)

1. A damping system for a tower crane draw bar, characterized in that: the device comprises two acceleration sensors, a charge amplifier, an analog-digital converter, a controller, a D/A converter, a U/I conversion circuit and a plurality of actuators; the two acceleration sensors are respectively arranged on the top of a tower and a crane boom at the end part of a pull rod of the tower crane, the signal output ends of the acceleration sensors are connected with a charge amplifier, the signal output end of the charge amplifier is connected with an analog-digital converter, the signal output end of the analog-digital converter is connected with a controller, the output end of the controller is connected with a D/A converter, the signal output end of the D/A converter is connected with a U/I conversion circuit, the output end of the U/I conversion circuit is connected with an actuator, and the actuator is connected in series on the pull rod of the tower crane.

2. The vibration damping system for a tower crane drawbar according to claim 1, wherein: the actuator is a magneto-rheological damper.

3. The vibration damping system for a tower crane drawbar according to claim 1, wherein: the number of the actuators is two.

4. The vibration damping system for a tower crane drawbar according to claim 1, wherein: the vibration damping system is based on a digital computer.

5. The vibration damping system for a tower crane drawbar according to claim 1, wherein: the controller is a fuzzy PID controller combining a fuzzy control system and a PID control system.

6. Method for damping the vibrations of a crane rod using a damping system according to any one of claims 1 to 5, characterized in that it comprises the following steps:

(1) the pull rod of the tower crane vibrates under the influence of wind load, and the acceleration sensor collects vibration signals and transmits the vibration signals to the charge amplifier;

(2) the charge amplifier amplifies the collected signals and transmits the signals to the analog-digital converter, and the analog-digital converter converts the collected analog signals into digital signals and transmits the digital signals to the controller;

(3) after the digital signal is input into the controller, PID parameters are adjusted through fuzzy rule calculation of the controller, then required control force is obtained through analysis and calculation of a calculation module in the controller, the control force is corrected through a judgment module in the controller, and finally the corrected digital signal is output;

(4) the digital signal output by the controller is converted into a voltage signal through a D/A converter;

(5) the voltage signal is converted into a current signal through the U/I conversion circuit and flows into the actuator;

(6) the actuator receives the current signal, an external magnetic field is generated through current, the external magnetic field influences the output of the damping force of the actuator, the damping force output by the actuator is controlled in real time according to the vibration condition of the crane pull rod, the vibration of the crane pull rod is restrained, and therefore the vibration reduction effect is achieved.

Technical Field

The invention belongs to the technical field of vibration prevention of pull rods of tower cranes, and particularly relates to a vibration reduction system and a vibration reduction method for the pull rods of the tower cranes.

Background

Tower cranes, also known as tower cranes or tower cranes (hereinafter referred to as tower cranes), can perform vertical and horizontal operations within a certain three-dimensional space. The tower crane has very high work efficiency in the construction industry, and has the characteristics of convenient transportation, simple operation mode, wide application range and the like. As a common hoisting device in construction sites, a tower crane is used to hoist construction raw materials such as reinforcing steel bars, wood beams, concrete, steel pipes and the like for construction. Due to the nature of the operation and the environment of operation, tower cranes are subjected to wind loads. The pull rod is one of main stressed components of the tower crane, has the characteristics of small rigidity, small damping and small mass, and is easy to vibrate under the excitation of wind load, so that the stability of the operation of a crane boom of the tower crane and the like is damaged.

Disclosure of Invention

The invention aims to solve the technical problem that the tower crane pull rod is easy to vibrate under the excitation of wind load so as to influence the operation stability of a crane boom of the tower crane, and provides a vibration damping system and a vibration damping method for the tower crane pull rod, so that the tower crane pull rod is prevented from generating large vibration under the excitation of the wind load and other loads, and the stability and the safety of the tower crane are improved.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a vibration damping system for a pull rod of a tower crane comprises two acceleration sensors, a charge amplifier, an analog-digital converter, a controller, a D/A converter, a U/I conversion circuit and a plurality of actuators; the two acceleration sensors are respectively arranged on the top of a tower and a crane boom at the end part of a pull rod of the tower crane, the signal output ends of the acceleration sensors are connected with a charge amplifier, the signal output end of the charge amplifier is connected with an analog-digital converter, the signal output end of the analog-digital converter is connected with a controller, the output end of the controller is connected with a D/A converter, the signal output end of the D/A converter is connected with a U/I conversion circuit, the output end of the U/I conversion circuit is connected with an actuator, and the actuator is connected in series on the pull rod of the tower crane.

Further, the actuator is a magneto-rheological damper.

Further, the number of the actuators is two.

Further, the vibration damping system is based on a digital computer.

Further, the controller is a fuzzy PID controller combining a fuzzy control system and a PID control system.

The vibration reduction method of the crane pull rod by adopting the vibration reduction system comprises the following steps:

(1) the pull rod of the tower crane vibrates under the influence of wind load, and the acceleration sensor collects vibration signals and transmits the vibration signals to the charge amplifier;

(2) the charge amplifier amplifies the collected signals and transmits the signals to the analog-digital converter, and the analog-digital converter converts the collected analog signals into digital signals and transmits the digital signals to the controller;

(3) after the digital signal is input into the controller, PID parameters are adjusted through fuzzy rule calculation of the controller, then required control force is obtained through analysis and calculation of a calculation module in the controller, the control force is corrected through a judgment module in the controller, and finally the corrected digital signal is output;

(4) the digital signal output by the controller is converted into a voltage signal through a D/A converter;

(5) the voltage signal is converted into a current signal through the U/I conversion circuit and flows into the actuator;

(6) the actuator receives the current signal, an external magnetic field is generated through current, the external magnetic field influences the output of the damping force of the actuator, the damping force output by the actuator is controlled in real time according to the vibration condition of the crane pull rod, the vibration of the crane pull rod is restrained, and therefore the vibration reduction effect is achieved.

The invention has the beneficial effects that:

1. according to the invention, the magnetorheological damper is arranged on the pull rod of the tower crane, and the special performance of the magnetorheological damper is utilized to weaken the vibration of the pull rod of the tower crane in real time, so that the damage of wind load to the tower crane is reduced. When the pull rod vibrates, the damping variable characteristic of the magnetorheological damper can be utilized to quickly absorb vibration energy, so that the vibration is reduced, the pull rod is enabled to recover stably in a short time, and tower crane accidents caused by vibration are avoided

2. The invention adopts the fuzzy PID controller, adopts the combination of the fuzzy control system and the PID control system, can weaken the negative effect caused by the time lag of the magnetorheological damper structure, has quick response and good robustness, can well adapt to the change of conditions, solves the nonlinear problem of the system, has obvious vibration reduction effect, low energy consumption and high intelligence.

Drawings

FIG. 1 is a schematic structural view of the damping system of the present invention;

FIG. 2 is a schematic view of the mounting of an actuator in the damping system of the present invention;

FIG. 3 is a schematic diagram of the composition of a fuzzy control system;

FIG. 4 is a schematic diagram of a PID control system.

Detailed Description

The invention is further described below with reference to examples and figures.

As shown in fig. 1, the damping system for the tower crane pull rod in the embodiment includes two acceleration sensors, a charge amplifier, an analog-digital converter, a controller, a D/a converter, a U/I conversion circuit, and two actuators.

The two acceleration sensors are respectively arranged on the tower top and the crane boom at the end part of a pull rod of the tower crane, the signal output ends of the acceleration sensors are connected with a charge amplifier, the signal output end of the charge amplifier is connected with an analog-digital converter, the signal output end of the analog-digital converter is connected with a controller, the output end of the controller is connected with a D/A converter, the signal output end of the D/A converter is connected with a U/I conversion circuit, the output end of the U/I conversion circuit is connected with an actuator, and the actuator is connected in series on the pull rod of the tower crane, as shown in figure 2. The actuator is a magneto-rheological damper and only receives a current signal.

The shock absorbing system is based on a digital computer and receives only digital signals. The fuzzy controller has the characteristics of quick response, strong robustness, large occupied storage space of a computer and low control precision; and PID control has good adaptability, but manual adjustment of parameters is complicated. The controller of the invention adopts a fuzzy PID controller combining a fuzzy control system and a PID control system to realize the control of the vibration reduction system.

The vibration reduction method of the crane pull rod by adopting the vibration reduction system comprises the following steps:

(1) the pull rod of the tower crane vibrates under the influence of wind load, and the acceleration sensor collects vibration signals and transmits the vibration signals to the charge amplifier; because the information collected by the sensor is generally weak, the charge amplifier and the sensor need to be connected in series;

(2) the charge amplifier amplifies the collected signals and transmits the signals to the analog-digital converter, and the analog-digital converter converts the collected analog signals into digital signals and transmits the digital signals to the controller;

(3) after the digital signal is input into the controller, PID parameters are adjusted through fuzzy rule calculation of the controller, then required control force is obtained through analysis and calculation of a calculation module in the controller, the control force is corrected through a judgment module in the controller, and finally the corrected digital signal is output;

the controller is a fuzzy PID controller combining a fuzzy control system and a PID control system.

Although the fuzzy control has the characteristics of quick response, small overshoot and strong robustness, the nonlinear problem of the system can be solved, but the fuzzy controller comprises a fuzzy theory, a knowledge base and the like, needs to occupy a large storage space of a computer, and conflicts with the storage space of the computer, so the fuzzy controller cannot fully play the role of the fuzzy controller, and the control precision is not high. The PID controller has better adaptability, but manual parameter adjustment is more complex; even if the PID parameters are well regulated, control performance may be affected when the control system parameters change. Based on the complex working environment of the pull rod of the tower crane, the invention combines fuzzy control and PID control.

The fuzzy control system is divided into four parts, namely a fuzzification interface (for carrying out fuzzy operation on input and converting the input into a symbol which can be identified by the fuzzy control system), a knowledge base (comprising a database and a rule base and providing data and rules for the fuzzy operation process), a fuzzy logic inference engine (a process of solving unknown results by known knowledge) and a defuzzification interface (a process of converting fuzzy language into actual required output). The basic structure is shown in fig. 3. The fuzzy rule determines the control quality of the fuzzy controller, and is the heart of the fuzzy controller.

PID control is based on analysis of past states, regulation of present states and a kind of confidence in future states. In a PID control system, a given value r (t) and a deviation e (t) of a feedback value are used as input, linear combination operation is realized by different weight proportion links, integration links and differentiation links according to different influence factors, and an output control quantity u (t) directly controls a controlled object. A schematic diagram of a PID control system is shown in fig. 4. The input-output relationship of the controller is expressed as follows:

in the formula K_pIs a proportional gain coefficient, T_iAs an integral coefficient, T_dIs a differential coefficient.

The fuzzy PID controller can utilize fuzzy rules to control the PID parameter K_p，T_i，T_dAnd real-time control is realized. And automatically adjusting PID parameters on line by using fuzzy reasoning decision according to the deviation of the system to adapt to the change of the working environment and the system parameters. The fuzzy controller is associated with PID parameters, the performance of the system is influenced, and the precision and the adaptability of the control system can be effectively improved through the fuzzy PID control. And performing fuzzification calculation on input variables of the fuzzy controller, performing inference decision according to a fuzzy rule, and finally performing defuzzification to obtain output variables of the fuzzy controller. Then, whether the calculated control force F meets the condition is judged through a judging module, and if the calculated control force F is smaller than the F of the actuator_minIf F is equal to F_min(ii) a If the control force F is greater than F of the actuator_maxIf F is equal to F_max(ii) a And finally, obtaining a digital signal matched with the actuator through calculation and analysis.

(4) The digital signal output by the controller is converted into a voltage signal through a D/A converter;

(5) the voltage signal is converted into a current signal through the U/I conversion circuit and flows into the actuator;

(6) the actuator receives the current signal, an external magnetic field is generated through current, the external magnetic field influences the output of the damping force of the actuator, the damping force output by the actuator is controlled in real time according to the vibration condition of the crane pull rod, the vibration of the crane pull rod is restrained, and therefore the vibration reduction effect is achieved.

The above-described embodiments are only for illustrating the technical ideas and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and to carry out the same, and the scope of the present invention is not limited only by the embodiments, i.e., all equivalent changes or modifications made in the spirit of the present invention are still within the scope of the present invention.