Parameter Identification of Inertia Properties of Space Robot Based on Momentum Conservation

2011 ◽  
Vol 328-330 ◽  
pp. 1916-1921 ◽  
Author(s):  
Chao Wang ◽  
Yong Ming Gao ◽  
Xiao Ping Du
Keyword(s):  
Parameter Identification ◽  
Momentum Conservation ◽  
Inertia Tensor ◽  
Space Robot ◽  
Second Step ◽  
Mass Center ◽  
Unknown Parameters ◽  
Initial Momentum ◽  
Precise Control ◽  
Inertia Properties

The parameter identification is necessary for precise control orbit and attitude of Space Robot. This paper presents a method for parameter identification of inertia properties of space robot which is based on the momentum conservation. As the initial momentum of the Space Robot is hardly known, we have to discuss detailed in two options. The first option, the initial momentum is known and assumes it is zero, then we can solve all the unknown parameters in the momentum equations; the second it’s unknown, it has to be solved in two steps. The first step is to identify the mass and mass center of the spacecraft; and the second step is to identify the inertia tensor of the spacecraft. In the end, we build the model for simulation; the result shows that the method has the high precise and the error can be ignored.

scholarly journals Inertia Parameter Identification for an Unknown Satellite in Precapture Scenario

2020 ◽  
Vol 2020 ◽  
pp. 1-18
Author(s):  
Xiao-Feng Liu ◽  
Xiao-Yu Zhang ◽  
Pei-Ran Chen ◽  
Guo-Ping Cai
Keyword(s):  
Parameter Identification ◽  
Momentum Conservation ◽  
Space Robot ◽  
Control Force ◽  
Soft Contact ◽  
Identification Scheme ◽  
Inertia Parameter ◽  
Inertia Parameters ◽  
Dynamics And Control ◽  
And Control

The problem of dynamics and control using a space robot to capture a noncooperative satellite is an important issue for on-orbit services. Inertia parameters of the satellite should be identified before capturing such that the robot can design an active controller to finish the capturing task. In this paper, a new identification scheme is proposed for parameter identification of a noncooperative satellite. In this scheme, the space robot is controlled to contact softly and then maintain contact with the noncooperative target firstly, then the variation of momentum of the target during the contact-maintaining phase is calculated using the control force and torque acting on the base of the space robot and the kinematic information of the space robot, and finally, the momentum-conservation-based identification method is used to estimate inertia parameters of the target. To realize soft contact and then maintain contact, a damping contact controller is designed in this paper, in which a mass-damping system is designed to control the contact between the robot and the target. Soft contact and then contact maintenance can be realized by utilizing the buffering characteristics of the mass-damping system. The effectiveness of the proposed identification scheme is verified through numerical simulations at the end of this paper. Simulation results indicate that the proposed scheme can achieve high-precision identification results.

Dynamic Parameter Identification of the Base of a Space Robot when Considering the Gravity Gradient

2014 ◽  
Vol 945-949 ◽  
pp. 1384-1389 ◽  
Author(s):  
Han Xu Sun ◽  
Zhi Lian Chen ◽  
Gang Chen ◽  
Qing Xuan Jia
Keyword(s):  
Parameter Identification ◽  
Significant Role ◽  
Dynamic Parameter ◽  
Momentum Conservation ◽  
Space Robot ◽  
Gravity Gradient ◽  
Dynamic Parameters ◽  
Robot System ◽  
Experimental Process ◽  
Dynamic Parameter Identification

This paper presents a dynamic parameter identification method of the base of a free-flying space robot. Since the dynamic parameters play a significant role in the control of space robot system, it is necessary to identify the dynamic parameters of a space robot. First the dynamic parameters of the base are identified based on principle of momentum conservation in this paper. Then gravity gradient torque is used to identify the product of inertia for that it has effect on the attitude of a space robot. The principle and experimental process of the identification are introduced and the feasibility of the method is verified by simulation.

A systematic identification approach for biaxial piezoelectric stage with coupled Duhem-type hysteresis

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Qun Chen ◽  
Zong-Xiao Yang ◽  
Zhumu Fu
Keyword(s):  
Parameter Identification ◽  
High Efficiency ◽  
Full Range ◽  
Unknown Parameters ◽  
Content Type ◽  
De Algorithm ◽  
Complicated Model ◽  
Identification Approach ◽  
Cross Axis ◽  
Systematic Identification

Purpose The problem of parameter identification for biaxial piezoelectric stages is still a challenging task because of the existing hysteresis, dynamics and cross-axis coupling. This study aims to find an accurate and systematic approach to tackle this problem. Design/methodology/approach First, a dual-input and dual-output (DIDO) model with Duhem-type hysteresis is proposed to depict the dynamic behavior of the biaxial piezoelectric stage. Then, a systematic identification approach based on a modified differential evolution (DE) algorithm is proposed to identify the unknown parameters of the Duhem-type DIDO model for a biaxial piezostage. The randomness and parallelism of the modified DE algorithm guarantee its high efficiency. Findings The experimental results show that the characteristics of the biaxial piezoelectric stage can be identified with adequate accuracy based on the input–output data, and the peak-valley errors account for 2.8% of the full range in the X direction and 1.5% in the Y direction. The attained results validated the correctness and effectiveness of the presented identification method. Originality/value The classical DE algorithm has many adjustment parameters, which increases the inconvenience and difficulty of using in practice. The parameter identification of Duhem-type DIDO piezoelectric model is rarely studied in detail and its successful application based on DE algorithm on a biaxial piezostage is hitherto unexplored. To close this gap, this work proposed a modified DE-based systematic identification approach. It not only can identify this complicated model with more parameters, but also has little tuning parameters and thus is easy to use.

Dimensionality Reduction of High-Fidelity Machine Tool Models by Using Global Sensitivity Analysis

2021 ◽  
pp. 1-13
Author(s):  
Johannes Ellinger ◽  
Thomas Semm ◽  
Michael F. Zäh
Keyword(s):  
Sensitivity Analysis ◽  
Machine Tool ◽  
Parameter Identification ◽  
Machine Tools ◽  
Global Sensitivity Analysis ◽  
Reference Model ◽  
Evaluation Criteria ◽  
Unknown Parameters ◽  
Global Sensitivity ◽  
Process Simulations

Abstract Models that are able to accurately predict the dynamic behavior of machine tools are crucial for a variety of applications ranging from machine tool design to process simulations. However, with increasing accuracy, the models tend to become increasingly complex, which can cause problems identifying the unknown parameters which the models are based on. In this paper, a method is presented that shows how parameter identification can be eased by systematically reducing the dimensionality of a given dynamic machine tool model. The approach presented is based on ranking the model's input parameters by means of a global sensitivity analysis. It is shown that the number of parameters, which need to be identified, can be drastically reduced with only limited impact on the model's fidelity. This is validated by means of model evaluation criteria and frequency response functions which show a mean conformity of 98.9 % with the full-scale reference model. The paper is concluded by a short demonstration on how to use the results from the global sensitivity analysis for parameter identification.

Test of a Sliding Mode Controller for Trajectory Tracking of an Underactuated Surface Vessel

2011 ◽  
Author(s):  
Yaswanth Siramdasu ◽  
Farbod Fahimi
Keyword(s):  
Parameter Identification ◽  
Trajectory Tracking ◽  
Sliding Mode ◽  
Model Parameters ◽  
Sliding Mode Controller ◽  
Special Test ◽  
Excellent Performance ◽  
Unknown Parameters ◽  
Surface Vessel ◽  
Test Scenarios

Sliding mode controller for trajectory tracking of a surface vessel is designed based on a 3DOF dynamic model. The model has six unknown parameters. For parameter identification, four special test scenarios are defined to isolate and identify one of the six parameters at a time. The identification tests are performed on a robotic boat which has an onboard PC104 computer and a navigation sensor providing vessel’s dynamic states in real-time. The data from experiments are used to determine the model parameters. A sliding mode controller is designed based on the identified model, and is implemented and tested on a real robotic boat. The experiments show the excellent performance of the controller.

scholarly journals Impact motion control of a flexible dual-arm space robot for capturing a spinning object

2019 ◽  
Vol 16 (3) ◽  
pp. 172988141985753
Author(s):  
Xiali Li ◽  
Licheng Wu
Keyword(s):  
Motion Control ◽  
Control Method ◽  
Initial Conditions ◽  
Autonomous Vehicle ◽  
Stable State ◽  
Momentum Conservation ◽  
Space Robot ◽  
Dynamics Response ◽  
The Impact ◽  
Dual Arm

As an autonomous vehicle that moves on the space orbit, a space robot needs to be carefully treated on the motion planning and control method. In this article, the optimal impact and postimpact motion control of a flexible dual-arm space robot capturing a spinning object are considered. Firstly, the dynamic model of the robot systems is built by using Lagrangian formulation. The flexible links are modeled as Euler–Bernoulli beams of two bending modes. Through simulating the system’s postimpact dynamics response, the initial conditions are obtained from the impact model. Next, the initial velocities of base and joint are adjusted to minimize the velocity of the base after the capture according to generalized momentum conservation. After the capture, a proportional–derivative controller is designed to keep the robot system’s stabilization. The simulation results show that joint angles of base and manipulators reach stable state quickly, and motions of the space robots also induce vibrating motions of the flexible manipulators.

Industrial Robot Kinematics Parameter Identification

2014 ◽  
Vol 889-890 ◽  
pp. 1136-1143
Author(s):  
Yong Gui Zhang ◽  
Chen Rong Liu ◽  
Peng Liu
Keyword(s):  
Experimental Data ◽  
Genetic Algorithms ◽  
Parameter Identification ◽  
Industrial Robot ◽  
Industrial Robots ◽  
Robot Kinematics ◽  
Kinematic Parameters ◽  
Unknown Parameters ◽  
Preliminary Measurement ◽  
Kinematics Modeling

For an industrial robots with unknown parameters, on the basis of preliminary measurement and data of the Cartesian and joints coordinates which are shown on the FlexPendant, the kinematic parameters is identified by using genetic algorithms and accurate kinematics modeling of the robot is established. Experimental data could prove the validity of this method.

The coordinated motion planning of a dual-arm space robot for target capturing

Robotica ◽  
2011 ◽  
Vol 30 (5) ◽  
pp. 755-771 ◽  
Author(s):  
Wenfu Xu ◽  
Yu Liu ◽  
Yangsheng Xu
Keyword(s):  
Center Of Mass ◽  
Momentum Conservation ◽  
Conservation Equation ◽  
Space Robot ◽  
Coordinated Motion ◽  
First Case ◽  
Solution Equation ◽  
Target Capturing ◽  
Dual Arm ◽  
Momentum Conservation Equation

SUMMARYIn this paper, autonomous motion control approaches to generate the coordinated motion of a dual-arm space robot for target capturing are presented. Two typical cases are studied: (a) The coordinated dual-arm capturing of a moving target when the base is free-floating; (b) one arm is used for target capturing, and the other for keeping the base fixed inertially. Instead of solving all the variables in a unified differential equation, the solution equation of the first case is simplified into two sub-equations and practical methods are used to solve them. Therefore, the computation loads are largely reduced, and feasible trajectories can be determined. For the second case, we propose to deal with the linear and angular momentums of the system separately. The linear momentum conservation equation is used to design the configuration and the mounted pose of a balance arm to keep the inertial position of the base's center of mass, and the angular momentum conservation equation is used to estimate the desired momentum generated by the reaction wheels for maintaining the inertial attitude of the base. Finally, two typical tasks are simulated. Simulation results verify the corresponding approaches.

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