Performance of an Orbiting Flexible Mobile Manipulator

1991 ◽  
Vol 113 (4) ◽  
pp. 516-524 ◽  
Author(s):  
V. J. Modi ◽  
J. K. Chan
Keyword(s):  
Space Station ◽  
Lagrangian Formulation ◽  
Mobile Manipulator ◽  
Positioning Error ◽  
Linear Quadratic ◽  
Manipulator Dynamics ◽  
Complex Interactions ◽  
Dynamics And Control ◽  
And Control

This paper presents a Lagrangian formulation for studying the dynamics and control of the Space Station based Mobile Servicing System (MSS) for a particular case of in-plane libration and maneuvers. The simplified case is purposely considered to focus on the effects of structural and joint flexibilities of the MSS on the complex interactions between the station and manipulator dynamics during slewing and translational maneuvers. The response results suggest that under critical combinations of parameters, the system can become unstable. During maneuvers, the deflection of the MSS can become excessive, leading to payload positioning error and the librational disturbance can also be significant. A linear quadratic regular is designed to simultaneously control the deflection of the manipulator and maintain the station at its operating configuration.

scholarly journals The Coupled Orbit-Attitude Dynamics and Control of Electric Sail in Displaced Solar Orbits

2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Mingying Huo ◽  
He Liao ◽  
Yanfang Liu ◽  
Naiming Qi
Keyword(s):  
Linear Quadratic Regulator ◽  
Coupled System ◽  
Control Force ◽  
Attitude Dynamics ◽  
Voltage Distribution ◽  
Linear Quadratic ◽  
Displaced Orbit ◽  
Dynamics And Control ◽  
And Control ◽  
Small Torque

Displaced solar orbits for spacecraft propelled by electric sails are investigated. Since the propulsive thrust is induced by the sail attitude, the orbital and attitude dynamics of electric-sail-based spacecraft are coupled and required to be investigated together. However, the coupled dynamics and control of electric sails have not been discussed in most published literatures. In this paper, the equilibrium point of the coupled dynamical system in displaced orbit is obtained, and its stability is analyzed through a linearization. The results of stability analysis show that only some of the orbits are marginally stable. For unstable displaced orbits, linear quadratic regulator is employed to control the coupled attitude-orbit system. Numerical simulations show that the proposed strategy can control the coupled system and a small torque can stabilize both the attitude and orbit. In order to generate the control force and torque, the voltage distribution problem is studied in an optimal framework. The numerical results show that the control force and torque of electric sail can be realized by adjusting the voltage distribution of charged tethers.

Dynamics and control of a space station based Tethered Elevator System

1993 ◽  
Vol 29 (6) ◽  
pp. 429-449 ◽  
Author(s):  
V.J. Modi ◽  
S. Bachmann ◽  
A.K. Misra
Keyword(s):  
Space Station ◽  
Dynamics And Control ◽  
And Control

On the Dynamics and Control of Robotic Manipulators with an Automatic Balancing Mechanism

1987 ◽  
Vol 201 (1) ◽  
pp. 25-34 ◽  
Author(s):  
W K Chung ◽  
H S Cho
Keyword(s):  
Control Algorithm ◽  
Controller Design ◽  
Torque Control ◽  
Manipulator Dynamics ◽  
Wide Range ◽  
Non Linear ◽  
Dynamics And Control ◽  
Characteristic Features ◽  
Automatic Balancing ◽  
And Control

Non-linear characteristics and uncertainty in manipulator dynamics caused by payload effects are major hurdles in controller design. To overcome such hurdles the authors have introduced an automatic balancing concept which has been proved to reduce the non-linear complexity in manipulator dynamics as well as to remove gravity loading. This paper examines the characteristic features of balanced manipulator dynamics in more detail and presents an efficient control algorithm suitable for the dynamics. Since the dynamics of a balanced manipulator are characterized by partially configuration-independent inertial properties, the present algorithm adopts two different control concepts ‘the computed torque control’ for the joint having coupled, configuration-dependent inertia and ‘an optimal constant feedback control’ for the joints having configuration-independent inertia. To evaluate the proposed control algorithm, simulation studies were made over a wide range of manipulator speeds and payloads. Based upon the simulation results, the efficiency of the controller is discussed in detail.

Slewing dynamics and control of the Space Station-based mobile servicing system

1995 ◽  
Vol 35 (2-3) ◽  
pp. 119-129 ◽  
Author(s):  
V.J. Modi ◽  
A.C. Ng ◽  
F. Karray
Keyword(s):  
Space Station ◽  
Dynamics And Control ◽  
And Control
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