Performance Analysis of Pre-launch Attitude Compound Control Method Based on Grid Rudder and RCS

The cable-driven hyper-redundant snake-like manipulator (CHSM) inspired by the biomimetic structure of vertebrate muscles and tendons, which consists of numerous joint units connected adjacently driven by elastic materials with hyper-redundant DOF, performs flexible kinematic skills and competitive compound capability under complicated working circumstances. Nevertheless, the drawback of lacking the ability to perceive the environment to perform intelligently in complex scenarios leaves a lot to be improved, which is the original intention to introduce visual tracking feedback acting as an instructor. In this paper, a cable-driven snake-like robotic arm combined with a visual tracking technique is introduced. A visual tracking approach based on dual correlation filter is designed to guide the CHSM in detecting the target and tracing after its trajectory. Specifically, it contains an adaptive optimization for the scale variation of the tracking target via pyramid sampling. For the CHSM, an explicit kinematics model is derived from its specific geometry relationships and followed by a simplification for the inverse kinematics based on some assumption or limitation. A control scheme is brought up to combine the kinematics with visual tracking via the processing tracking errors. The experimental results with a practical prototype validate the availability of the proposed compound control method with the derived kinematics model.

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Electro-hydraulic position servo system based on sliding mode active disturbance rejection compound control

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/09544062211028258 ◽

2021 ◽

pp. 095440622110282

Author(s):

Zhang He ◽

Zhao Jiyun ◽

Wang Yunfei ◽

Zhang Zhonghai ◽

Ding Haigang ◽

...

Keyword(s):

Disturbance Rejection ◽

Control Method ◽

Sliding Mode ◽

Servo System ◽

Active Disturbance Rejection Control ◽

Compound Control ◽

Active Disturbance Rejection ◽

Disturbance Rejection Control ◽

Uncertain Disturbances ◽

Position Servo

This study proposes a compound control method based on sliding mode and active disturbance rejection control to address the difficulty of controlling the cutting head for boom-type roadheader with parameter changes and uncertain disturbances. The fastest discrete tracking differentiator and extended state observer based on the traditional active disturbance rejection control are designed. Additionally, the controller of the sliding mode and active disturbance rejection control is constructed. Theoretical analysis indicates that the proposed controller ensures asymptotic stability, despite the existing uncertain disturbances. Moreover, a system based on AMESim and MATLAB/Simulink Co-simulation model is developed to further verify the performance of proposed algorithm. Compared with traditional active disturbance rejection control, proportional-integral-derivative(PID) and sliding mode control, co-simulation results demonstrate that the sliding mode active disturbance rejection compound control improves the tracking accuracy and robustness of the position servo system.

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Ultrastable Offset-Locking Continuous Wave Laser to a Frequency Comb with a Compound Control Method for Precision Interferometry

Sensors ◽

10.3390/s20051248 ◽

2020 ◽

Vol 20 (5) ◽

pp. 1248

Author(s):

Ruitao Yang ◽

Haisu Lv ◽

Jing Luo ◽

Pengcheng Hu ◽

Hongxing Yang ◽

...

Keyword(s):

Continuous Wave ◽

Control Method ◽

Frequency Comb ◽

Frequency Control ◽

Beat Frequency ◽

Laser Interferometry ◽

Optical Frequency ◽

Interference Signal ◽

Compound Control ◽

Cw Laser

A simple and robust analog feedforward and digital feedback compound control system is presented to lock the frequency of a slave continuous wave (CW) laser to an optical frequency comb. The beat frequency between CW laser and the adjacent comb mode was fed to an acousto-optical frequency shifter (AOFS) to compensate the frequency dithering of the CW laser. A digital feedback loop was achieved to expand the operation bandwidth limitation of the AOFS by over an order of magnitude. The signal-to-noise ratio of the interference signal was optimized using a grating-based spectral filtering detection unit. The complete system achieved an ultrastable offset-locking of the slave CW laser to the frequency comb with a relative stability of ±3.62 × 10−14. The Allan deviations of the beat frequency were 8.01 × 10−16 and 2.19 × 10−16 for a gate time of 10 s and 1000 s, respectively. The findings of this study may further improve laser interferometry by providing a simple and robust method for ultrastable frequency control.

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Nonlinear Compound Control for Nonsinusoidal Vibration of the Mold Driven by Servo Motor with Variable Speed

Mathematical Problems in Engineering ◽

10.1155/2019/1728768 ◽

2019 ◽

Vol 2019 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Qiang Li ◽

Yi-ming Fang ◽

Jian-xiong Li ◽

Zhuang Ma

Keyword(s):

Control Method ◽

Controller Design ◽

Rotation Speed ◽

Pi Control ◽

Variable Speed ◽

Servo Motor ◽

Motor Speed ◽

Vector Method ◽

Compound Control ◽

The Relationship

In this paper, a fuzzy PI control method based on nonlinear feedforward compensation is proposed for the nonsinusoidal vibration system of mold driven by servo motor, rotated in single direction with variable speed. During controller design, there are mainly two issues to consider: (i) nonlinear relationship (approximate periodic function) between mold displacement and servo motor speed and (ii) uncertainties caused by backlash due to motor variable speed. So, firstly, the relationship between mold displacement and motor rotation speed is built directly based on the rotation vector method. Then, an observer is designed to estimate the uncertainties and feedforward compensation. Secondly, as the motor rotates in single direction with variable speed, a fuzzy control with bidirectional parameter adjustment is adopted to improve rapidity and stability based on the traditional PI method. Finally, some simulation results show the effectiveness of the proposed control method.

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Stable Switching Control Strategy of the Support Pressure and Velocity of Shield Machine Gripper Shoes

Shock and Vibration ◽

10.1155/2019/6108796 ◽

2019 ◽

Vol 2019 ◽

pp. 1-8

Author(s):

Nannan Liu ◽

Jishen Peng ◽

Liye Song ◽

Pinhe Wang ◽

Kun Zhang

Keyword(s):

Position Control ◽

Control Method ◽

Control Strategies ◽

Pressure Control ◽

Surrounding Rock ◽

Support Pressure ◽

Hydraulic Pressure ◽

Compound Control ◽

Hydraulic Servo ◽

Shield Machine

An electro-hydraulic servo position and pressure compound control method was investigated considering the working principle of a hydraulic stepping motor of a shield machine gripper shoe and its practical working characteristics in the supporting process. The control targets were to improve the support efficiency and reduce the disturbance of gripper shoes on the surrounding rock. In this method, a fuzzy switching controller was used to switch between electro-hydraulic position control and electro-hydraulic pressure control. Numerical and prototype simulation experiments were conducted on the control method. The theoretical analysis and experimental results showed that the control method could effectively convert the gripper shoes from an unsupported state to a supported state in a short amount of time, as well as realize surge-free switching between position control and pressure control. Thus, disturbance of the gripper shoes on the surrounding rock could be reduced. The results of this study provide a theoretical basis for research on control strategies of hydraulic stepping propulsion of shield machines.

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