Hybrid Active Wave/Mode Control of Space Prestressed Taut Cable Net Structures

The space environments and special mission demands require large-scale and high shape accuracy cable net structures. The vibration control is an essential issue for shape control and performance conservation of large flexible cable net structures. This paper investigates the hybrid active wave/mode control of space prestressed taut cable net structures. First, the traveling wave dynamic model of cable net structures is explored by elemental waveguide and propagation equations of cables together with force balance conditions and compatibility conditions of joints. Then, the active wave control model is established by using the assumption forms of wave controllers to adjust the mechanical boundaries of the controlled joints. Finally, the hybrid active wave/mode control model is proposed by constructing the mapping relationship between wave control force, modal damping and natural frequencies. The proposed control method is verified by a planar cable net structure and the results show that the hybrid active wave/mode control can give a better broadband vibration attenuation performance for space prestressed taut cable net structures.

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Vibration Reduction of the Nonlinearly Tufted Carpet Yarn by a Modified Sliding Mode Control Method

Shock and Vibration ◽

10.1155/2019/5075983 ◽

2019 ◽

Vol 2019 ◽

pp. 1-10

Author(s):

Shuang Huang ◽

Xin Wu ◽

Peixing Li

Keyword(s):

Sliding Mode Control ◽

High Frequency ◽

Control Algorithm ◽

Control Method ◽

Sliding Mode ◽

Control Law ◽

Control Force ◽

Fuzzy Sliding Mode Control ◽

Mode Control ◽

Fuzzy Sliding Mode

The yarn vibration causes the yarn tension value to fluctuate, causing a change in the amount of yarn feed, thus causing a deviation of the carpet pile height from the predetermined value. To solve this problem, the sliding mode control algorithm is used to design the sliding mode function and the sliding mode control law. And four variables in the yarn vibration system are controlled by the MATLAB software. For solving the chattering problem of the control law, the sliding mode control law is improved. The fuzzy sliding mode control algorithm based on the quasisliding mode is adopted. The results show that the sliding mode control algorithm is effective, but the sliding mode control force needs to be switched at high frequency and there is severe chattering. The fuzzy sliding mode control algorithm based on quasisliding mode is adopted to achieve better control effect with a smaller force. In addition, the control force does not have high-frequency switching, and the change is relatively stable, which reduces the chattering phenomenon of sliding mode control.

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Research on Broken Edge Wave Control Strategy Caused by Edge Drop Control in UCMW Cold Tandem Rolling

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.655-657.1525 ◽

2013 ◽

Vol 655-657 ◽

pp. 1525-1529 ◽

Cited By ~ 1

Author(s):

Lu Bing Wang ◽

Lin Jing Yan ◽

An Rui He ◽

Yu Jing Liu

Keyword(s):

Control Strategy ◽

Shape Control ◽

Work Roll ◽

Control Model ◽

Edge Wave ◽

Effective Contact ◽

Work Roll Shifting ◽

Control Accuracy ◽

Edge Drop ◽

Wave Control

Taking MH UCMW cold tandem mill as research object, broken edge wave generating mechanism and characteristics were analyzed which caused by edge drop control. Based on original control strategy, an automatic edge wave control model was developed, and edge drop control strategy was optimized. Effect of taper work roll shifting and taper shape on broken edge wave were analyzed by actual rolling data. Results show that broken edge wave decreases with effective contact depth increasing of taper work roller and strip. Optimized control system application eliminate broken edge wave, and improve automatic shape control accuracy.

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Wave Mode Control of Cantilever Slab Structure of T-Beam Bridge with Large Aspect Ratio

Advances in Civil Engineering ◽

10.1155/2021/6544058 ◽

2021 ◽

Vol 2021 ◽

pp. 1-9

Author(s):

Tingting Liu ◽

Chuanping Zhou ◽

Zhigang Yan ◽

Guojin Chen

Keyword(s):

Aspect Ratio ◽

Elastic Wave ◽

Wave Mode ◽

Control Force ◽

Cantilever Plate ◽

Large Aspect Ratio ◽

Plate Structure ◽

Beam Bridge ◽

T Beam ◽

Wave Control

The cantilever plate structure in a T-beam bridge with a large aspect ratio will cause vibration under the influence of environmental disturbance and self-stress, resulting in fatigue damage of the plate structure. Wave control based on elastic wave theory is an effective method to suppress the vibration of the cantilever plate structure in a beam bridge. Based on the classical thin plate theory and the wave control method, the active vibration control of the T-shaped cantilever plate with a large aspect ratio in the beam bridge is studied in this paper. The wave mode control strategy of structural vibration is analyzed and studied, the controller is designed, the vibration mode function of the cantilever plate is established, and the control force/sensor feedback wave control is implemented for the structure. The dynamic response of the cantilever plate before and after applying wave control force is analyzed through numerical examples. The results show that the response of the structure is intense before control, but after wave control, the structure increases damping, absorbs the energy carried by the elastic wave in the structure, weakens the sharp response, and changes the natural frequency of the structure to a certain extent.

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Development of Negative Stiffness Dampers for Seismic Protection

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.82.645 ◽

2011 ◽

Vol 82 ◽

pp. 645-650 ◽

Cited By ~ 1

Author(s):

Hirokazu Iemura ◽

Akihiro Toyooka ◽

Masaki Higuchi ◽

Osamu Kouchiyama

Keyword(s):

Large Scale ◽

Control Method ◽

Dynamic Performance ◽

Relative Displacement ◽

Shaking Table ◽

Negative Stiffness ◽

Control Force ◽

Shaking Table Tests ◽

Active Devices ◽

Bridge Model

In the first part of this study, theoretical and numerical evaluation of negative stiffness appearing in the skyhook control is conducted. The skyhook control is widely known for the vibration control method in the mechanical engineering field. The skyhook control can also achieve absolute response reduction. In order to realize a negative stiffness, however, the control force that accelerates the deformation should be generated. At present, such a performance is achieved only by using loading actuators or semi-active devices with sophisticated controllers and sensors. In the second part of this research, a new damper realizing a negative stiffness and stable energy dissipation in a passive manner is proposed, and its dynamic performance is investigated through large-scale shaking table tests. It is confirmed that the innovative negative stiffness passive damper reduces both the absolute acceleration and the relative displacement of a bridge model.

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Investigation of sliding mode control for nonlinear suspension systems with state estimation

Mechanics & Industry ◽

10.1051/meca/2020081 ◽

2020 ◽

Vol 21 (6) ◽

pp. 611

Author(s):

Xing Chen ◽

Sen Han ◽

Tianhong Luo ◽

Du Guo

Keyword(s):

Sliding Mode Control ◽

Control Method ◽

Sliding Mode ◽

Active Suspension ◽

Control Force ◽

State Response ◽

Suspension Systems ◽

Mode Control ◽

Lqr Controller ◽

Absorption Performance

This paper presented a new control strategy for active suspension of nonlinear quarter-vehicle model. An active suspension controller designed for using sliding mode control with noise filtering. The Kalman filter (KF) predicted the state response of the nonlinear one-quarter automobile model, and the estimated values used for the design of the active control force. Finally, the shock absorption performance compared with the LQR controller and the passive suspension. The simulation results showed that the control method significantly improve the ride performance and safety of the vehicle.

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Model of Heating Fuzzy Intelligent Control System of Large-Scale Coke Oven

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.29-32.979 ◽

2010 ◽

Vol 29-32 ◽

pp. 979-984 ◽

Cited By ~ 1

Author(s):

Gong Fa Li ◽

Jian Yi Kong ◽

Guo Zhang Jiang ◽

Liang Xi Xie

Keyword(s):

Control System ◽

Intelligent Control ◽

Large Scale ◽

Control Method ◽

Coke Oven ◽

Control Model ◽

Actual Condition ◽

Heating Process ◽

Flow Adjustment ◽

Intermittent Heating

Coke oven production has the characteristics of nonlinear, large inertia, large disturbances, and highly-coup ling and so on. The control method of “intermittent heating control” is adopted in traditional heating control system of coke oven, and cannot satisfy the command of heating control on coke oven. The control principle of combining the “intermittent heating control” with the heating gas flow adjustment is adopted according to analysis the difficulty and strategy of heating control on coke oven. On the basis of studying deficiency of the existing control strategy, fuzzy compound control is proposed to establish heating intelligent control model of coke oven, which combines feedback control, feedforward control and fuzzy intelligent control. Carbonization index is used in the model to control coking management of coke oven. Then heating fuzzy intelligent control structure of coke oven is built. According to artificial experience and actual condition, fuzzy controller is designed. Fuzzy control can deal with fuzzy, inexact or uncertainty information and has great robust, which can realize intelligent control of heating process of coke oven. Better control result of temperature control is realized by fuzzy intelligent control model. The system has great practical value.

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Swing control for a three-link brachiation robot based on sliding-mode control on irregularly distributed bars

Mechanical Sciences ◽

10.5194/ms-12-1073-2021 ◽

2021 ◽

Vol 12 (2) ◽

pp. 1073-1081

Author(s):

Zhiguo Lu ◽

Guoshuai Liu ◽

Haibin Zhao ◽

Ruchao Wang ◽

Chong Liu

Keyword(s):

Sliding Mode Control ◽

Control Strategy ◽

Control Method ◽

Sliding Mode ◽

Target Position ◽

Control Model ◽

Important Research ◽

Link Structure ◽

Mode Control ◽

Simulation Results

Abstract. The bionic-gibbon robot is a popular bionic robot. The bionic-gibbon robot can imitate a gibbon in completing brachiation motion between branches. With nonlinear and underactuated properties, the robot has important research value. This paper designs a type of bionic-gibbon robot with three links and two grippers. To simplify the controller, a plane control model is proposed, and its dynamic model is established. The control strategy in this paper divides the brachiation motion into several processes: adjust posture, open the gripper, the swing process and close the gripper. Based on sliding-mode control (SMC), the control method for the swing process is designed. The target position of the brachiation motion is set as the origin of the sliding-mode surface. In a finite time, the robot will reach the target position along the approach rate we adopt. In this way, the robot can complete the desired brachiation motion only by setting the position parameters of the target bar. We perform some simulations in ROS-Gazebo. The simulation results show that the bionic-gibbon robot can complete continuous brachiation motion on irregularly distributed bars. The sliding-mode control and the three-link structure significantly improve the robustness and swing efficiency of the bionic-gibbon robot.

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