Minimum Base Disturbance Control of Free-Floating Space Robot during Visual Servoing Pre-capturing Process

Robotica ◽  
2019 ◽  
Vol 38 (4) ◽  
pp. 652-668 ◽  
Author(s):  
Xiaoyu Zhao ◽  
Zongwu Xie ◽  
Haitao Yang ◽  
Jiarui Liu
Keyword(s):  
Visual Servoing ◽  
Degrees Of Freedom ◽  
Control Method ◽  
System Modeling ◽  
Space Robot ◽  
Order Continuity ◽  
Control Center ◽  
Optimal Control Method ◽  
And Control ◽  
Base Disturbance

SUMMARYDuring visual servoing space activities, the attitude of free-floating space robot may be disturbed due to dynamics coupling between the satellite base and the manipulator. And the disturbance may cause communication interruption between space robot and control center on earth. However, it often happens that the redundancy of manipulator is not enough to fully eliminate this disturbance. In this paper, a method named off-line optimizing visual servoing algorithm is innovatively proposed to minimize the base disturbance during the visual servoing process where the degrees-of-freedom of the manipulator is not enough for a zero-reaction control. Based on the characteristic of visual servoing process and the robot system modeling, the optimal control method is applied to achieve the optimization, and a pose planning method is presented to achieve a second-order continuity of quaternion getting rid of the interruption caused by ambiguity. Then simulations are carried out to verify the method, and the results show that the robot is controlled with optimized results during visual servoing process and the joint trajectories are smooth.

Dynamics and control of a 6-DOF space robot with flexible panels

2016 ◽  
Vol 231 (6) ◽  
pp. 1022-1034 ◽  
Author(s):  
Yu Zhang-Wei ◽  
Liu Xiao-Feng ◽  
Li Hai-Quan ◽  
Cai Guo-Ping
Keyword(s):  
Dynamic Model ◽  
Control Method ◽  
Torque Control ◽  
Space Robot ◽  
Velocity Variation ◽  
Variation Principle ◽  
Dynamics Modeling ◽  
Dynamics And Control ◽  
Flexible Panels ◽  
And Control

With the development of space exploration, researches on space robot will cause more attentions. However, most existing researches about dynamics and control of space robot concern planar problem, and the effect of flexible panel on dynamics of the system is not considered. In this article, dynamics modeling and active control of a 6-DOF space robot with flexible panels are investigated. Dynamic model of the system is established based on the Jourdain's velocity variation principle and the single direction recursive construction method. The computed torque control method is used to design point-to-point active controller of the space robot. The validity of the dynamic model is verified through the comparison with ADAMS software; the effects of panel flexibility on the system performance and the active controller design are studied in detail. Simulation results indicate that the proposed model is effective to describe the dynamics of space robot; panel flexibility has large influence on the dynamic behavior of space robot; the designed controller can effectively make the robot reach a specified position and the elastic vibration of the panels may be suppressed simultaneously.

Design and Modeling of Three Joint Mechanical Arm Based on the Free Floating Space Robot Project

2014 ◽  
Vol 621 ◽  
pp. 533-539
Author(s):  
Xi Zhang ◽  
Da Qi Wu
Keyword(s):  
Robot Control ◽  
Control Method ◽  
Space Exploration ◽  
Structure Design ◽  
Space Robot ◽  
Practical Significance ◽  
Main Research ◽  
Research Level ◽  
Exploration Mission ◽  
And Control

The frequence and complex of space exploration activeities makes the life of the spacecraft and on-orbit service technologies becoming research hotspot in recent years. But the limitation of non-renewable fuels makes exploration mission costly and maintenance difficult, so the free floating space robot has its unique advantages. Because the research level and control technology is not maturity, study on the free floating space robot control method is the key theory and technology which is the difficulty that our country now needs to overcome, also, the research is of great theoretical and practical significance. This paper introduct an experiment scara mechanical arm based on the free floating space robot project. Main research contents of this paper include the mechanical structure design, and combining with the characteristic of the free floating mechanical arm , it makes kinematics and dynamics modals of the mechanical arm system, additional, it conduct statics test and dynamic modal analysis, which is to make sure that the mechanical arm could satisfy needs and to study its dynamic characteristics.This topic focus on structure design and mathematical modeling of the mechanical arm, it makes the research of control method and trajectory planning no longer stay on the paper, and makes the research more authenticity and accuracy.

Design and Control of Supporting Arm for Reducing Factory Worker Load With Desired Support Force and Stiffness Characteristics

2016 ◽  
Author(s):  
Tetsuro Miyazaki ◽  
Takuya Iijima ◽  
Kazushi Sanada
Keyword(s):  
Degrees Of Freedom ◽  
Control Method ◽  
Robot Manipulator ◽  
Experimental System ◽  
Factory Worker ◽  
Target Weight ◽  
Support Force ◽  
Stiffness Characteristics ◽  
And Control ◽  
Pneumatic Cylinders

This paper proposes a design and control method of a supporting arm which reduces factory worker load. The supporting arm is a robot manipulator, which is driven by pneumatic cylinders, and is attached to the worker’s hip. In some situation, the factory worker is forced to work with an uncomfortable posture. By using the supporting arm, the worker leg loads are relaxed, and the worker posture is stabilized. To support 50 % weight of the worker, the link system of the supporting arm is designed, and the pneumatic cylinders for actuation are selected. There are two required specifications: (i) support force is sufficient for supporting target load, and (ii) desired stiffness characteristics in the hip height direction can be obtained. The support force is controlled by a two degrees of freedom control system to satisfy the required specifications. An experimental system of the supporting arm was developed, and its performance was evaluated by experiments. As a result, the experimental system shows capability of supporting the target weight and controllability of stiffness.

Mechanical Design and Control Method of a Hollow Modular Joint for Minimally Invasive Spinal Surgery

2018 ◽  
Vol 15 (04) ◽  
pp. 1850017
Author(s):  
Guoli Song ◽  
Che Hou ◽  
Yiwen Zhao ◽  
Xingang Zhao ◽  
Jianda Han
Keyword(s):  
Minimally Invasive ◽  
Spinal Surgery ◽  
Degrees Of Freedom ◽  
Control Method ◽  
Mechanical Design ◽  
Control Design ◽  
Torque Sensor ◽  
Minimally Invasive Spinal Surgery ◽  
Minimally Invasive Surgical ◽  
And Control

Design of the hollow modular joint plays an important role in modern robot layout, fixation, and wiring. In this paper, a hollow modular joint that meets the requirement of a minimally invasive surgical robot is proposed. The mechanical and control design is sequentially illustrated, and the torque sensor and its optimization are provided. Furthermore, a free-force control method is introduced. To analyze the designed module, the simulation of the redundant robot, comprised of the designed joint in seven degrees of freedom, is presented. The results of analyses showed that the designed hollow modular joint is valid and effective.

scholarly journals Minimum time optimal control simulation of a GP2 race car

2017 ◽  
Vol 232 (9) ◽  
pp. 1180-1195 ◽  
Author(s):  
Nicola Dal Bianco ◽  
Roberto Lot ◽  
Marco Gadola
Keyword(s):  
Optimal Control ◽  
Degrees Of Freedom ◽  
Load Transfer ◽  
Control Method ◽  
Multibody Model ◽  
Race Car ◽  
Optimal Control Method ◽  
Time Problem ◽  
Time Optimal ◽  
The Impact

In this work, optimal control theory is applied to minimum lap time simulation of a GP2 car, using a multibody car model with enhanced load transfer dynamics. The mathematical multibody model is formulated with use of the symbolic algebra software MBSymba and it comprises 14 degrees of freedom, including full chassis motion, suspension travels and wheel spins. The kinematics of the suspension is exhaustively analysed and the impact of tyre longitudinal and lateral forces in determining vehicle trim is demonstrated. An indirect optimal control method is then used to solve the minimum lap time problem. Simulation outcomes are compared with experimental data acquired during a qualifying lap at Montmeló circuit (Barcelona) in the 2012 GP2 season. Results demonstrate the reliability of the model, suggesting it can be used to optimise car settings (such as gearing and aerodynamic setup) before executing track tests.

Summary of Vehicle Suspension Vibration Systems Control Technology Research

2012 ◽  
Vol 549 ◽  
pp. 843-847
Author(s):  
Jian Feng Wang ◽  
Chuan Xue Song ◽  
Zhong Xiang Lei
Keyword(s):  
Intelligent Control ◽  
Control Method ◽  
System Modeling ◽  
Development Trend ◽  
Future Research ◽  
Modeling And Control ◽  
Compound Control ◽  
Automobile Suspension ◽  
And Control ◽  
Suspension Structure

This paper expounds the automobile suspension structure based on the characteristics of three control strategy and its development, and focuses on modern control method and intelligent control method were discussed, and points out that the compound control method is more suitable to the car complex nonlinear suspension system modeling and control. Finally in the future research needs to be some problems and development trend are discussed.

scholarly journals Autonomous Rendezvous and Docking with Nonfull Field of View for Tethered Space Robot

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Panfeng Huang ◽  
Lu Chen ◽  
Bin Zhang ◽  
Zhongjie Meng ◽  
Zhengxiong Liu
Keyword(s):  
Relative Position ◽  
Attitude Control ◽  
Visual Servoing ◽  
Control Method ◽  
Region Growing ◽  
Space Robot ◽  
Field Of View ◽  
Autonomous Rendezvous ◽  
Rendezvous And Docking ◽  
Typical Point

In the ultra-close approaching phase of tethered space robot, a highly stable self-attitude control is essential. However, due to the field of view limitation of cameras, typical point features are difficult to extract, where commonly adopted position-based visual servoing cannot be valid anymore. To provide robot’s relative position and attitude with the target, we propose a monocular visual servoing control method using only the edge lines of satellite brackets. Firstly, real time detection of edge lines is achieved based on image gradient and region growing. Then, we build an edge line based model to estimate the relative position and attitude between the robot and the target. Finally, we design a visual servoing controller combined with PD controller. Experimental results demonstrate that our algorithm can extract edge lines stably and adjust the robot’s attitude to satisfy the grasping requirements.

Dynamic Coupling and Control of Flexible Space Robots

2020 ◽  
Vol 20 (09) ◽  
pp. 2050103
Author(s):  
Yanfeng Du ◽  
Cong Wang
Keyword(s):  
Dynamic Model ◽  
Control Method ◽  
Coupling Effect ◽  
Space Robot ◽  
Flexible Manipulator ◽  
Flexible Manipulators ◽  
Dynamic Coupling ◽  
Input Shaper ◽  
Flexible Panels ◽  
And Control

The dynamic modeling and coupling effect of a space robot are complex when the flexible manipulator and solar panels are considered. This paper investigates the dynamic coupling effect and control of a flexible space robot with flexible manipulators and flexible panels. The equations of motion are derived for the robot model both of the rigid-flexible type and flexible-flexible type. The flexible space robot dynamic model is verified by comparison with the results generated by the ADAMS software, for which good agreement has been obtained. The dynamic coupling matrix of the flexible space robot is derived based on the dynamic model. The effects of the central rigid body mass and the joints angle on the dynamic coupling are analyzed. A control method is proposed to manipulate the flexible space robot based on the system dynamic model. The multiple-impulse robust (MIR) input shaper is used to suppress the vibration of flexible structures in the proposed controller. Appropriate design parameter and frequency scaling factor are selected for the MIR input shaper to suppress the flexible vibration. The flexible space robot control is conducted to illustrate the effect of the proposed controller. It is shown that the proposed control method can realize the desired joints manipulation, while suppressing the vibration of the flexible manipulators and flexible panels.

Positioning Control System Based on ZPETC and Optimal Control Method for Plant with Dead-Time

2012 ◽  
Vol 152-154 ◽  
pp. 1795-1800
Author(s):  
Junichi Endo ◽  
Kazuhiro Sasaki ◽  
Kazusa Matsumoto ◽  
Hiroki Shibasaki ◽  
Yoshihisa Ishida
Keyword(s):  
Optimal Control ◽  
Dead Time ◽  
Control Method ◽  
Phase Error ◽  
Smith Predictor ◽  
Experimental Result ◽  
Positioning Control ◽  
Optimal Control Method ◽  
Modified Smith Predictor ◽  
And Control

In this paper, a method for positioning control based on zero phase error tracking controller (ZPETC), optimal control method for plant with dead-time is proposed. A discrete transformed unstable plant is composed of unstable zeros and poles. In the proposed method, we subject stabilization of a plant by optimal control method, compose inverse model of a system with unstable zeros by ZPETC and control a plant with dead-time by predicted-state feedback technique and modified smith predictor composed of a predictor and an observer. In addition, optimal control method achieves good robustness for modeling errors by adjusting the weight of the LQR-scheme. The simulation studies and the experimental result, it is shown that the proposed method is effective for these plants and DC motor.

Ground verification of space robot capturing the free-floating target based on visual servoing control with time delay

2014 ◽  
Vol 41 (6) ◽  
pp. 543-556 ◽  
Author(s):  
Haitao Yang ◽  
Minghe Jin ◽  
Zongwu Xie ◽  
Kui Sun ◽  
Hong Liu
Keyword(s):  
Time Delay ◽  
Motion Planning ◽  
Visual Servoing ◽  
Space Robot ◽  
Hardware In The Loop ◽  
Space Manipulator ◽  
Content Type ◽  
Operating Space ◽  
Base Disturbance ◽  
Target Satellite

Purpose – The purpose of this paper is to solve the ground verification and test method for space robot system capturing the target satellite based on visual servoing with time-delay in 3-dimensional space prior to space robot being launched. Design/methodology/approach – To implement the approaching and capturing task, a motion planning method for visual servoing the space manipulator to capture a moving target is presented. This is mainly used to solve the time-delay problem of the visual servoing control system and the motion uncertainty of the target satellite. To verify and test the feasibility and reliability of the method in three-dimensional (3D) operating space, a set of ground hardware-in-the-loop simulation verification systems is developed, which adopts the end-tip kinematics equivalence and dynamics simulation method. Findings – The results of the ground hardware-in-the-loop simulation experiment validate the reliability of the eye-in-hand visual system in the 3D operating space and prove the validity of the visual servoing motion planning method with time-delay compensation. At the same time, owing to the dynamics simulator of the space robot added in the ground hardware-in-the-loop verification system, the base disturbance can be considered during the approaching and capturing procedure, which makes the ground verification system realistic and credible. Originality/value – The ground verification experiment system includes the real controller of space manipulator, the eye-in-hand camera and the dynamics simulator, which can veritably simulate the capturing process based on the visual servoing in space and consider the effect of time delay and the free-floating base disturbance.

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