Generating Situation-Dependent Behavior: Decentralized Control of Multi-Functional Intestine-Like Robot that can Transport and Mix Contents

2013 ◽  
Vol 25 (5) ◽  
pp. 871-876 ◽  
Author(s):  
Takeshi Kano ◽  
◽  
Toshihiro Kawakatsu ◽  
Akio Ishiguro ◽  
◽  
...  
Keyword(s):  
Decentralized Control ◽  
Coupled Oscillators ◽  
Sensory Feedback ◽  
Specific Task ◽  
Physical Conditions ◽  
Dependent Behavior ◽  
Intestinal Movement ◽  
Control Scheme ◽  
Different Types ◽  
Simulation Results

Most robots are designed to perform a specific task in a predefined environment and have difficulty in producing situation-dependent behavior. To tackle this problem, we focus here on a mammal intestine that either transports or mixes the contents depending on the encountered circumstances. We propose a simple model for the intestinal movement and design an autonomous decentralized control scheme for an intestine-like robot by using coupled oscillators with local sensory feedback. Simulation results show that different types of motions are generated depending on the the physical conditions of the intestine and its contents. Our simulated robot does not require any input from a higher center to switch between different types of motions but determines autonomously which motion to generate. This study thus paves the way for developing “multi-functional robots” whose behavior is changed flexibly and spontaneously depending on circumstances.

scholarly journals A decentralized control scheme for orchestrating versatile arm movements in ophiuroid omnidirectional locomotion

2011 ◽  
Vol 9 (66) ◽  
pp. 102-109 ◽  
Author(s):  
Wataru Watanabe ◽  
Takeshi Kano ◽  
Shota Suzuki ◽  
Akio Ishiguro
Keyword(s):  
Decentralized Control ◽  
Coupled Oscillators ◽  
Design Methodology ◽  
Arm Movements ◽  
Rhythmic Movements ◽  
Role Assignment ◽  
Rotator Model ◽  
Proposed Model ◽  
Control Scheme ◽  
Living Organisms

Autonomous decentralized control is a key concept for understanding the mechanism underlying the adaptive and versatile behaviour of animals. Although the design methodology of decentralized control based on a dynamical system approach that can impart adaptability by using coupled oscillators has been proposed in previous studies, it cannot reproduce the versatility of animal behaviours comprehensively. Therefore, our objective is to understand behavioural versatility from the perspective of well-coordinated rhythmic and non-rhythmic movements. To this end, we focus on ophiuroids as a simple good model of living organisms that exhibit spontaneous role assignment of rhythmic and non-rhythmic arm movements, and we model such arm movements by using an active rotator model that can describe both oscillatory and excitatory properties. Simulation results show that the spontaneous role assignment of arm movements is successfully realized by using the proposed model, and the simulated locomotion is qualitatively equivalent to the locomotion of real ophiuroids. This fact can potentially facilitate a better understanding of the control mechanism responsible for the orchestration of versatile arm movements in ophiuroid omnidirectional locomotion.

scholarly journals Obstacle Avoidance of Two-Wheel Differential Robots Considering the Uncertainty of Robot Motion on the Basis of Encoder Odometry Information

Sensors ◽  
2019 ◽  
Vol 19 (2) ◽  
pp. 289 ◽  
Author(s):  
Jiyong Jin ◽  
Woojin Chung
Keyword(s):  
Obstacle Avoidance ◽  
Experimental Results ◽  
Robot Motion ◽  
Control Performance ◽  
Velocity Control ◽  
Uncertainty Sources ◽  
Control Scheme ◽  
Collision Safety ◽  
Different Types ◽  
Simulation Results

It is important to overcome different types of uncertainties for the safe and reliable navigation of mobile robots. Uncertainty sources can be categorized into recognition, motion, and environmental sources. Although several challenges of recognition uncertainty have been addressed, little attention has been paid to motion uncertainty. This study shows how the uncertainties of robot motions can be quantitatively modeled through experiments. Although the practical motion uncertainties are affected by various factors, this research focuses on the velocity control performance of wheels obtained by encoder sensors. Experimental results show that the velocity control errors of practical robots are not negligible. This paper proposes a new motion control scheme toward reliable obstacle avoidance by reflecting the experimental motion uncertainties. The presented experimental results clearly show that the consideration of the motion uncertainty is essential for successful collision avoidance. The presented simulation results show that a robot cannot move through narrow passages owing to a risk of collision when the uncertainty of motion is high. This research shows that the proposed method accurately reflects the motion uncertainty and balances the collision safety with the navigation efficiency of the robot.

Model development and control of an auto-refrigerated polystyrene polymerization reactor

2021 ◽  
pp. 014233122110251
Author(s):  
Reyhane Mokhtarname ◽  
Ali Akbar Safavi ◽  
Leonhard Urbas ◽  
Fabienne Salimi ◽  
Mohammad M Zerafat ◽  
...  
Keyword(s):  
Temperature Control ◽  
Model Development ◽  
Heat Removal ◽  
Superior Performance ◽  
Polymerization Process ◽  
Vacuum System ◽  
Control Scheme ◽  
Simulation Results ◽  
And Control ◽  
Operating Plant

Dynamic model development and control of an existing operating industrial continuous bulk free radical styrene polymerization process are carried out to evaluate the performance of auto-refrigerated CSTRs (continuous stirred tank reactors). One of the most difficult tasks in polymerization processes is to control the high viscosity reactor contents and heat removal. In this study, temperature control of an auto-refrigerated CSTR is carried out using an alternative control scheme which makes use of a vacuum system connected to the condenser and has not been addressed in the literature (i.e. to the best of our knowledge). The developed model is then verified using some experimental data of the real operating plant. To show the heat removal potential of this control scheme, a common control strategy used in some previous studies is also simulated. Simulation results show a faster dynamics and superior performance of the first control scheme which is already implemented in our operating plant. Besides, a nonlinear model predictive control (NMPC) is developed for the polymerization process under study to provide a better temperature control while satisfying the input/output and the heat exchanger capacity constraints on the heat removal. Then, a comparison has been also made with the conventional proportional-integral (PI) controller utilizing some common tuning rules. Some robustness and stability analyses of the control schemes investigated are also provided through some simulations. Simulation results clearly show the superiority of the NMPC strategy from all aspects.

Dynamic output feedback control for nonlinear large-scale interconnected systems

2020 ◽  
Vol 39 (4) ◽  
pp. 801-821
Author(s):  
Ezzeddine Touti ◽  
Ali Sghaier Tlili ◽  
Muhannad Almutiry
Keyword(s):  
Decentralized Control ◽  
Output Feedback ◽  
Large Scale ◽  
Optimization Problem ◽  
Lyapunov Theory ◽  
Interconnected Systems ◽  
Dynamic Output Feedback ◽  
Content Type ◽  
Dynamic Output ◽  
Control Scheme

Purpose This paper aims to focus on the design of a decentralized observation and control method for a class of large-scale systems characterized by nonlinear interconnected functions that are assumed to be uncertain but quadratically bounded. Design/methodology/approach Sufficient conditions, under which the designed control scheme can achieve the asymptotic stabilization of the augmented system, are developed within the Lyapunov theory in the framework of linear matrix inequalities (LMIs). Findings The derived LMIs are formulated under the form of an optimization problem whose resolution allows the concurrent computation of the decentralized control and observation gains and the maximization of the nonlinearity coverage tolerated by the system without becoming unstable. The reliable performances of the designed control scheme, compared to a distinguished decentralized guaranteed cost control strategy issued from the literature, are demonstrated by numerical simulations on an extensive application of a three-generator infinite bus power system. Originality/value The developed optimization problem subject to LMI constraints is efficiently solved by a one-step procedure to analyze the asymptotic stability and to synthesize all the control and observation parameters. Therefore, such a procedure enables to cope with the conservatism and suboptimal solutions procreated by optimization problems based on iterative algorithms with multi-step procedures usually used in the problem of dynamic output feedback decentralized control of nonlinear interconnected systems.

CONTROLLING THE UNCERTAIN MULTI-SCROLL CRITICAL CHAOTIC SYSTEM WITH INPUT NONLINEAR USING SLIDING MODE CONTROL

2009 ◽  
Vol 23 (16) ◽  
pp. 2021-2034 ◽  
Author(s):  
XINGYUAN WANG ◽  
DA LIN ◽  
ZHANJIE WANG
Keyword(s):  
Chaotic System ◽  
Sliding Mode ◽  
Equilibrium Points ◽  
Dead Zone ◽  
Variable Structure ◽  
Sliding Mode Controller ◽  
Global Stabilization ◽  
Structure Control ◽  
Control Scheme ◽  
Simulation Results

In this paper, control of the uncertain multi-scroll critical chaotic system is studied. According to variable structure control theory, we design the sliding mode controller of the uncertain multi-scroll critical chaotic system, which contains sector nonlinearity and dead zone inputs. For an arbitrarily given equilibrium point of the uncertain multi-scroll chaotic system, we achieve global stabilization for the equilibrium points. Particularly, a class of proportional integral (PI) switching surface is introduced for determining the convergence rate. Furthermore, the proposed control scheme can be extended to complex multi-scroll networks. Finally, simulation results are presented to demonstrate the effectiveness of the proposed control scheme.

A Robust Trajectory Tracking Control Scheme of Two-Link Flexible Manipulator

2011 ◽  
Vol 328-330 ◽  
pp. 2108-2112
Author(s):  
Jing Shuang Lu ◽  
Chun Mei Du ◽  
Rui Zhou ◽  
Na Li
Keyword(s):  
Trajectory Tracking ◽  
Tracking Control ◽  
Vertical Plane ◽  
Flexible Manipulator ◽  
System Model ◽  
Error Signal ◽  
Dynamics Model ◽  
Trajectory Tracking Control ◽  
Control Scheme ◽  
Simulation Results

A simple dynamics model is established based on the two-link flexible manipulator moving within the vertical plane, and a robust simple control scheme is put forward. The advantages of this scheme are simple and good robustness. Only the error signal is needed when designing the control scheme and the acquirement of control signal does not depend on the system model. The simulation results show that this method has a good robustness and stability.

Iterative learning algorithm with a quadratic criterion for linear time-varying systems

2002 ◽  
Vol 216 (3) ◽  
pp. 309-316 ◽  
Author(s):  
S N Huang ◽  
K K Tan ◽  
T H Lee
Keyword(s):  
Learning Algorithm ◽  
Linear Time ◽  
Tracking Error ◽  
Iterative Learning ◽  
Tracking Performance ◽  
Time Varying ◽  
Control Scheme ◽  
Time Varying Systems ◽  
Simulation Results ◽  
Learning Law

A novel iterative learning controller for linear time-varying systems is developed. The learning law is derived on the basis of a quadratic criterion. This control scheme does not include package information. The advantage of the proposed learning law is that the convergence is guaranteed without the need for empirical choice of parameters. Furthermore, the tracking error on the final iteration will be a class K function of the bounds on the uncertainties. Finally, simulation results reveal that the proposed control has a good setpoint tracking performance.

scholarly journals L1495 revisited: a ppmap view of a star-forming filament

2019 ◽  
Vol 489 (1) ◽  
pp. 962-976 ◽  
Author(s):  
A D P Howard ◽  
A P Whitworth ◽  
K A Marsh ◽  
S D Clarke ◽  
M J Griffin ◽  
...  
Keyword(s):  
Critical Line ◽  
Kinetic Temperature ◽  
Line Density ◽  
Star Forming ◽  
Physical Conditions ◽  
Fitting Procedure ◽  
Different Types ◽  
Prestellar Cores ◽  
Different Temperatures ◽  
Average Profile

ABSTRACT We have analysed the Herschel and SCUBA-2 dust continuum observations of the main filament in the Taurus L1495 star-forming region, using the Bayesian fitting procedure ppmap. (i) If we construct an average profile along the whole length of the filament, it has FWHM $\simeq 0.087\pm 0.003\, {\rm pc};\,\,$ but the closeness to previous estimates is coincidental. (ii) If we analyse small local sections of the filament, the column-density profile approximates well to the form predicted for hydrostatic equilibrium of an isothermal cylinder. (iii) The ability of ppmap to distinguish dust emitting at different temperatures, and thereby to discriminate between the warm outer layers of the filament and the cold inner layers near the spine, leads to a significant reduction in the surface-density, $\varSigma$, and hence in the line-density, μ. If we adopt the canonical value for the critical line-density at a gas-kinetic temperature of $10\, {\rm K}$, $\mu _{{\rm CRIT}}\simeq 16\, {\rm M_{\odot }\, pc^{-1}}$, the filament is on average trans-critical, with ${\bar{\mu }}\sim \mu _{{\rm CRIT}};\,\,$ local sections where μ > μCRIT tend to lie close to prestellar cores. (iv) The ability of ppmap to distinguish different types of dust, i.e. dust characterized by different values of the emissivity index, β, reveals that the dust in the filament has a lower emissivity index, β ≲ 1.5, than the dust outside the filament, β ≳ 1.7, implying that the physical conditions in the filament have effected a change in the properties of the dust.

An approach towards decentralized control of cooperating non-autonomous multiple robots

Robotica ◽  
2000 ◽  
Vol 18 (5) ◽  
pp. 495-504 ◽  
Author(s):  
Khalid Munawar ◽  
Masayoshi Esashi ◽  
Masaru Uchiyama
Keyword(s):  
Decentralized Control ◽  
Degrees Of Freedom ◽  
Real Life ◽  
Robotic Systems ◽  
Present System ◽  
Multiple Robots ◽  
Experimental Implementation ◽  
Control Scheme ◽  
The Common ◽  
Event Based

This paper introduces an event-based decentralized control scheme for the cooperation between multiple manipulators. This is in contrast to the common practice of using only centralized controls for such cooperation which, consequently, greatly limit the flexibility of robotic systems. The manipulators used in the present system are very simple with only two degrees of freedom, while even one of them is passive. Moreover these manipulators use very few and commonly available sensors only. Computer simulations indicated the applicability of the event-based decentralized control scheme for multi-manipulator cooperation, while real-life experimental implementation has proved that the proposed decentralized control scheme is fairly applicable for very simple and even under-actuated systems too. Hence, this work has opened new doors towards further research in this area. The proposed control scheme is expected to be equally applicable for any mobile or immobile multi-robotic system.

scholarly journals Modeling and control of a new robotic deburring system

Robotica ◽  
2005 ◽  
Vol 24 (2) ◽  
pp. 229-237 ◽  
Author(s):  
Jae H. Chung ◽  
Changhoon Kim
Keyword(s):  
Comparative Study ◽  
Decentralized Control ◽  
Control Method ◽  
Robotic Manipulator ◽  
Coordination Control ◽  
Pneumatic Actuators ◽  
Modeling And Control ◽  
Control Approach ◽  
Simulation Results ◽  
And Control

This paper discusses the modeling and control of a robotic manipulator with a new deburring tool, which integrates two pneumatic actuators to take advantage of a double cutting action. A coordination control method is developed by decomposing the robotic deburring system into two subsystems; the arm and the deburring tool. A decentralized control approach is pursued, in which suitable controllers were designed for the two subsystems in the coordination scheme. In simulation, three different tool configurations are considered: rigid, single pneumatic and integrated pneumatic tools. A comparative study is performed to investigate the deburring performance of the deburring arm with the different tools. Simulation results show that the developed robotic deburring system significantly improves the accuracy of the deburring operation.

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