학위논문 (박사)-- 서울대학교 대학원 : 공과대학 기계항공공학부, 2018. 2. 이동준.The framework of stable bilateral teleoperation has been well established during decades. However, the standard bilateral teleoperation framework could be a baseline
for a successful telerobotics but not sufficient for real-application because they usually concentrate on only the bilateral stability. The least considered in the previous
research is how to apply a complex robot systems such as multiple mobile robots or a large degree of freedom mobile manipulators for real applications. The main
challenges of teleoperation of complex robotic systems in real-world are to achieve two different control objectives (i.e., follow the human command and the coordination/
stabilization of the internal movement) of the slave robots simultaneously, while providing intuitive information about the complicated features of the system.
In this thesis, we develop decomposition-based semi-autonomous teleoperation framework for robotic systems which have distributed communication and underactuation
property, consisting of three steps: 1) decomposition step, where the human command is defined, and the robotic system is split into the command tracking space and its orthogonal complement (i.e., internal motion)2) control design of the slave robot, in which we design the slave controller for human command tracking and stabilization/coordination of internal motion spaceand 3) feedback interface design, through which we propose a multi-modal feedback interface (for example, visual and
haptic) designed with the consideration of the task and the characteristics of the system.
Among numerous types of robots, in this thesis, we focus on two types of robotic systems: 1) multiple nonholonomic wheeled mobile robots (WMRs) with distributed communication requirement and 2) manipulator-stage over vertical flexible beam which is under-actuated system. The proposed framework is applied to both case step by step and perform experiments and human subject study to verify/demonstrate the proposed framework for both cases.
For distributed WMRs, we consider the scenario that a single user remotely operates a platoon of nonholonomic WMRs that distributively communicate each other in
unknown environment. For this, in decomposition step, we utilize nonholonomic passive decomposition to split the platoon kinematics into that of the formation-keeping
aspect and the collective tele-driving aspect. Next, in control design step, we design the controls for these two aspects individually and distribute them into each WMR
while fully incorporating their nonholonomic constraint and distribution requirement. Finally, in the step of feedback interface design, we also propose a novel predictive
display, which, by providing the user with the estimated current and predicted future pose informations of the platoon and future possibility of collision while fully incorporating the uncertainty inherent to the distribution, can significantly enhance the tele-driving performance and easiness of the platoon.
The second part is the manipulator-stage over vertical flexible beam which is under-actuated system. Here, the human command defines the desired motion of the
end-effector (or the manipulator), and the vibration of the beam should be subdued at the same time. Thus, at the first step, we utilize the passive decomposition to split the
dynamics into manipulator motion space and its orthogonal complement, in which we design the control for the suppression of the vibration. For human command tracking,
we design the passivity-based control, and, for the suppression of the vibration, we propose two controls: LQR-based control and nonlinear control based on Lyapunov
function analysis. Finally, visuo-haptic feedback interface is preliminarily designed for successful peg-in-hole tasks.1 Introduction 1
1.1 Background and Contribution 1
1.2 Related Works 4
1.2.1 Related Works on Distributed Systems 5
1.2.2 Related Works on Manipulator-Stage System 6
1.3 Outline 6
2 Preliminary 7
2.1 Passive Decomposition 7
2.1.1 Basic Notations and Properties of Standard Passive Decomposition 7
2.1.2 Nonholonomic Passive Decomposition 9
3 Semi-Autonomous Teleoperation of Nonholonomic Wheeled Mobile Robots with Distributed Communication 11
3.1 Distributed Control Design 11
3.1.1 Nonholonomic Passive Decomposition 11
3.1.2 Control Design and Distribution 19
3.2 Distributed Pose Estimation 25
3.2.1 EKF Pose Estimation of Leader WMR 25
3.2.2 EKF Pose Estimation of Follower WMRs 28
3.3 Predictive Display for Distributed Robots Teleoperation 29
3.3.1 Estimation Propagation 31
3.3.2 Prediction Propagation 34
3.4 Experiments 38
3.4.1 Test Setup 38
3.4.2 Performance Experiment 39
3.4.3 Teleoperation Experiment with Predictive Display 40
3.4.4 Human Subject Study 44
4 Semi-Autonomous Teleoperatoin of Stage-Manipulator System on Flexible Vertical Beam 49
4.1 System Modeling 49
4.1.1 System Description 49
4.1.2 Assumed Mode Shapes 51
4.1.3 Exact Solution under Given Boundary Conditions 51
4.1.4 Euler-Lagrangian Equation 61
4.2 LQR-based Control Design 62
4.2.1 Passive Decomposition 63
4.2.2 Vibration Suppression Control Design 64
4.2.3 Joint Tracking Control Design 66
4.3 Lyapunov-based Control Design 68
4.3.1 Twice Passive Decomposition for Input Coupling 69
4.3.2 Interconnected System Description 70
4.3.3 Passivity-based Manipulator Motion Control 74
4.3.4 Dissipative Control for Vibration Suppression 74
4.4 Experiments 78
4.4.1 Test Setup 78
4.4.2 Joint Tracking and Vibration Suppression Experiment 81
4.4.3 Comparison Experiment between the LQR and the Nonlinear Control 82
5 Conclusion 83
5.1 Summary 83
5.2 Future Works 83
A Appendix 85
A.1 Internal Wrench Representation 85Docto
