Trajectory Planning and Coordinated Control of Robotic Systems

2009 ◽  
Author(s):  
Reza A. Soltan ◽  
Hashem Ashrafiuon ◽  
Kenneth R. Muske
Keyword(s):  
Trajectory Planning ◽  
Autonomous Vehicles ◽  
Tracking Control ◽  
Formation Control ◽  
Sliding Mode ◽  
Autonomous Systems ◽  
Stable Limit Cycle ◽  
Control Law ◽  
Stable Limit ◽  
Modeling Uncertainties

A new method combining trajectory planning and coordination or formation control of robotic and autonomous systems is presented. The method generates target trajectories that are either asymptotically stable or result in a stable limit cycle. The former case is used to implement formation control. Coordination is guaranteed in the latter case due to the nature of limit cycles where non-crossing independent paths are automatically generated from different starting positions that smoothly converge to closed orbits. The use of position feedback in the trajectory generation allows for simultaneous determination of a stable tracking control law and consideration of constraints and system limitations. The tracking control law presented in this work is based on sliding mode control which is suitable for real-time implementation. It is also robust to modeling uncertainties and disturbances normally encountered in autonomous operations. A system of robotic manipulators and a group of autonomous vehicles are used as examples to demonstrate the capabilities and advantages of the proposed method.

Trajectory Real-Time Obstacle Avoidance for Underactuated Unmanned Surface Vessels

2009 ◽  
Author(s):  
Reza A. Soltan ◽  
Hashem Ashrafiuon ◽  
Kenneth R. Muske
Keyword(s):  
Real Time ◽  
Limit Cycle ◽  
Obstacle Avoidance ◽  
Trajectory Planning ◽  
Sliding Mode ◽  
Stable Limit Cycle ◽  
Stable Limit ◽  
Surface Vessels ◽  
Modeling Uncertainties ◽  
Exponentially Stable

A new method for obstacle avoidance of underactuated unmanned surface vessels is presented which combines trajectory planning with real-time tracking control. In this method, obstacles are approximated and enclosed by elliptic shapes which represent the stable limit cycle solution of a special class of ODEs (ordinary differential equation). The vessel trajectory at any moment is defined by the ODEs whose solution is the limit cycle defining the obstacle immediately on its path to the target. When no obstacle remains on the vessel’s path, the trajectory is defined by exponentially stable ODEs whose solution is the target trajectory. The planned trajectories are tracked by the vessel through a sliding mode control law which is robust to environmental disturbances and modeling uncertainties and can be computed in real time. One advantage of the method is that it allows for dynamic (moving and rotating) obstacles as well as a moving target. Another advantage is that only the current information about the obstacles and the target are required for real-time trajectory planning. Since the vessel current position is used as feedback to redefine the limit cycle trajectories, the method is also robust to large disturbance.

ODE-based obstacle avoidance and trajectory planning for unmanned surface vessels

Robotica ◽  
2010 ◽  
Vol 29 (5) ◽  
pp. 691-703 ◽  
Author(s):  
Reza A. Soltan ◽  
Hashem Ashrafiuon ◽  
Kenneth R. Muske
Keyword(s):  
Differential Equations ◽  
Ordinary Differential Equations ◽  
Real Time ◽  
Obstacle Avoidance ◽  
Trajectory Planning ◽  
Sliding Mode ◽  
Control Law ◽  
Target Trajectory ◽  
Surface Vessels ◽  
Modeling Uncertainties

SUMMARYA new method for real-time obstacle avoidance and trajectory planning of underactuated unmanned surface vessels is presented. In this method, ordinary differential equations (ODEs) are used to define transitional trajectories that can avoid obstacles and reach a final desired target trajectory using a robust tracking control law. The obstacles are approximated and enclosed by elliptical shapes. A transitional trajectory is then defined by a set of ordinary differential equations whose solution is a stable elliptical limit cycle defining the nearest obstacle on the vessel's path to the target. When no obstacle blocks the vessel's path to its target, the transitional trajectory is defined by exponentially stable ODE whose solution is the target trajectory. The planned trajectories are tracked by the vessel through a sliding mode control law that is robust to environmental disturbances and modeling uncertainties and can be computed in real time. The method is illustrated using a complex simulation example with a moving target and multiple moving and rotating obstacles and a simpler experimental example with stationary obstacles.

Conditional integrator sliding mode control of an unmanned quadrotor helicopter

2021 ◽  
pp. 095965182110498
Author(s):  
Yohan Díaz-Méndez ◽  
Leandro Diniz de Jesus ◽  
Marcelo Santiago de Sousa ◽  
Sebastião Simões Cunha ◽  
Alexandre Brandão Ramos
Keyword(s):  
Sliding Mode Control ◽  
Transient Response ◽  
Tracking Control ◽  
Position Control ◽  
Sliding Mode ◽  
Control Technique ◽  
Control Law ◽  
Control Problems ◽  
Control Activity ◽  
Mode Control

Sliding mode control (SMC) is a widely used control law for quadrotor regulation and tracking control problems. The purpose of this article is to solve the tracking problem of quadrotors using a relatively novel nonlinear control law based on SMC that makes use of a conditional integrator. It is demonstrated by a motivation example that the proposed control law can improve the transient response and chattering shortcomings of the previous approaches of similar SMC based controllers. The adopted Newton–Euler model of quadrotor dynamics and controller design is treated separately in two subsystems: attitude and position control loops. The stability of the control technique is demonstrated by Lyapunov’s analysis and the effectiveness and performance of the proposed method are compared with a similar integral law, also based on SMC, and validated by tracking control problems using numerical simulations. Simulations were developed in the presence of external disturbances in order to evaluate the controller robustness. The effectiveness of the proposed controller was verified by performance indexes, demonstrating less accumulated tracking errors and control activity and improvement in the transient response and disturbance rejection when compared to a conventional integrator sliding mode controller.

Cooperative Tracking Control for Formation Keeping of Fractionated Spacecraft Based on Error Exchanging

2014 ◽  
Vol 1016 ◽  
pp. 649-654
Author(s):  
Ya Feng Niu ◽  
Yong Ming Gao
Keyword(s):  
Tracking Control ◽  
Cooperative Control ◽  
Sliding Mode ◽  
Control Law ◽  
Velocity Information ◽  
The Stability ◽  
Cooperative Tracking ◽  
Fractionated Spacecraft ◽  
High Degree ◽  
Formation Keeping

This paper discusses the cooperative control for formation keeping of fractionated spacecraft, which is a new concept in recent years. For system of second-order differential equations of formation flying dynamics, knowledge of graph and consensus theory is introduced in study. By means of the idea of sliding mode control, we design a tracking control law for time-varying desired signal. Via exchanging error information among modules, the control law can make errors synchronized up to zero to achieve tracking. Relative velocity information between modules is not needed in this control law, which will efficiently reduce the requirements for relative navigation between modules. Then we prove the stability of the control system. Finally numerical simulation results show the effectiveness of the control law. By configuring the control parameters reasonably, we can achieve high degree of control accuracy.

scholarly journals Trajectory Tracking Control for Small-Scale Unmanned Helicopters with Mismatched Disturbances Based on a Continuous Sliding Mode Approach

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Xing Fang ◽  
Yujia Shang
Keyword(s):  
Sliding Mode Control ◽  
Disturbance Rejection ◽  
Tracking Control ◽  
Closed Loop ◽  
Sliding Mode ◽  
Small Scale ◽  
Control Law ◽  
Trajectory Tracking Control ◽  
Mode Control ◽  
Mismatched Disturbances

A novel continuous sliding mode control (CSMC) strategy based on the finite-time disturbance observer (FTDO) is proposed for the small-scale unmanned helicopters in the presence of both matched and mismatched disturbances. First, a novel sliding surface is designed based on the estimates of the mismatched disturbances and their derivatives obtained by the FTDO. Then, a continuous sliding mode control law is developed, which does not lead to any chattering phenomenon. Furthermore, the closed-loop helicopter system is proved to be asymptotically stable. Finally, the excellent hovering and tracking performance, as well as the powerful disturbance rejection capability of the proposed novel CSMC method, is validated by the simulation results.

scholarly journals Adaptive output feedback integral sliding mode attitude tracking control of spacecraft without unwinding

2017 ◽  
Vol 9 (7) ◽  
pp. 168781401771040 ◽  
Author(s):  
Anuchit Jitpattanakul ◽  
Chutiphon Pukdeboon
Keyword(s):  
Output Feedback ◽  
Tracking Control ◽  
Sliding Mode ◽  
Control Technique ◽  
Control Law ◽  
Parameter Uncertainties ◽  
External Disturbances ◽  
Integral Sliding Mode ◽  
Attitude Tracking ◽  
Attitude Tracking Control

This article studies an output feedback attitude tracking control problem for rigid spacecraft in the presence of parameter uncertainties and external disturbances. First, an anti-unwinding attitude control law is designed using the integral sliding mode control technique to achieve accurate tracking responses and robustness against inertia uncertainties and external disturbances. Next, the derived control law is combined with a suitable tuning law to relax the knowledge about the bounds of uncertainties and disturbances. The stability results are rigorously proved using the Lyapunov stability theory. In addition, a new finite-time sliding mode observer is developed to estimate the first time derivative of attitude. A new adaptive output feedback attitude controller is designed based on the estimated results, and angular velocity measurements are not required in the design process. A Lyapunov-based analysis is provided to demonstrate the uniformly ultimately bounded stability of the observer errors. Numerical simulations are given to illustrate the effectiveness of the proposed control method.

A Continuous Robust Antiswing Tracking Control Scheme for Underactuated Crane Systems With Experimental Verification

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Ning Sun ◽  
Yongchun Fang ◽  
He Chen
Keyword(s):  
Trajectory Planning ◽  
Tracking Control ◽  
Sliding Mode ◽  
Maximum Velocity ◽  
Continuous Control ◽  
Robust Tracking Control ◽  
Mechatronic Systems ◽  
Crane Control ◽  
Control Scheme ◽  
Practical Constraints

Disturbances and uncertainties are unfavorable elements that always accompany industrial mechatronic systems including cranes. If not fully considered or properly dealt with, they would badly influence the control system performance and degrade the working efficiency. Though traditional sliding mode control (SMC) methods are powerful to address these issues, they are discontinuous and might bring potential damages to the actuating devices. In addition, most existing methods cannot involve such practical constraints as permitted swing amplitudes, maximum velocity, etc. To resolve these problems, we suggest a novel composite antiswing crane control scheme, which involves time-suboptimal analytical trajectory planning and continuous robust tracking control. More precisely, a new analytical suboptimal trajectory planning algorithm is presented, which can generate analytical swing-free smooth trajectories guaranteeing practical constraints. Then, we design a new nonlinear control law to make the crane follow the planned trajectories with continuous control efforts, ensuring stable asymptotic tracking in the presence of perturbations/uncertainties. As far as we know, this is the first crane control scheme that simultaneously achieves state-constrained time-suboptimal trajectory planning and robust control with continuous control efforts. We implement experiments to examine its practical control performance and robustness as well.

A Novel Control Method Using Nonlinear Observer for a XYθz Planar Actuator

2008 ◽  
Vol 381-382 ◽  
pp. 195-198 ◽  
Author(s):  
Yoshikazu Arai ◽  
S.Y. Dian ◽  
Wei Gao
Keyword(s):  
Control Method ◽  
Sliding Mode ◽  
Dynamic Performance ◽  
Experimental Results ◽  
Nonlinear Observer ◽  
Control Law ◽  
Dynamic Compensation ◽  
Modeling Uncertainties ◽  
Positioning Stage ◽  
Ultra Precision

In this study, a novel control law including a fine-tuned PID component to yield basic dynamic performance, and a component derived from the Sliding Mode Observer (SMO) to estimate and then compensate for modeling uncertainties and disturbances, has been introduced to planar actuator of an ultra-precision positioning stage. Experimental results are presented to verify the effectiveness of suggested dynamic compensation strategy and tracking performance of the non-contact planar actuator.

A novel constraint tracking control with sliding mode control for industrial robots

2021 ◽  
Vol 18 (4) ◽  
pp. 172988142110297
Author(s):  
Yaru Xu ◽  
Rong Liu ◽  
Jia Liu ◽  
Jiancheng Zhang
Keyword(s):  
Convergence Rate ◽  
Sliding Mode Control ◽  
Tracking Control ◽  
Sliding Mode ◽  
External Disturbance ◽  
Industrial Robots ◽  
Special Method ◽  
Control Law ◽  
Reaching Law ◽  
Mode Control

As industrial robots are characterized by flexibility, load variation, and unknown interference, it is necessary to develop a control strategy with strong robustness and adaptability, fast convergence rate, and simple structure. Sliding mode control is a special method widely used to handle nonlinear robot control. However, the existing control law for sliding mode control has limitations in the chattering and convergence rate. The sliding mode manifold and reaching law are firstly discussed in this article. In the meanwhile, a proposed control law for sliding mode control combining linear sliding mode manifold and double-power reaching law is developed, which is based on the robot dynamic equation derived by the Udwadia–Kalaba theory. Furthermore, a compared control law for sliding mode control combining linear sliding mode manifold with exponential reaching law is presented to test the proposed control law for sliding mode control. The comparison indicates that the proposed law effectively improves the performance in convergence rate and the chattering of constraint tracking control. Finally, the two control laws for sliding mode control are applied to the Selective Compliance Articulated Robot Arm robot system with modeling error and uncertain external disturbance to demonstrate the merit and validation of the proposed scheme.

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