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Santhakumar Mohan - One of the best experts on this subject based on the ideXlab platform.
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robust Task Space motion control of a mobile manipulator using a nonlinear control with an uncertainty estimator
2017Co-Authors: Swati Mishra, P. S. Londhe, Santhakumar Mohan, Santosh Kumar Vishvakarma, Balasaheb M. PatreAbstract:Abstract In this study, a robust nonlinear control method with an uncertainty estimator is proposed and applied to a kinematically redundant mobile manipulator (MM) position tracking in its Task Space. The proposed MM has four degrees-of-freedom (dof) serial manipulator mounted on three of mobile bases. The proposed method incorporates a feed-forward control term to reinforce the control action with extravagance from the desired acceleration vector; a disturbance estimator to reimburse for the unknown effects such as parametric uncertainties, external disturbances, unmodeled dynamics and a decentralized PID (proportional-integral-derivative) controller as a feedback loop to strengthen the stability of the system. The main strengths of the proposed scheme are its high robustness against parameter uncertainties and external disturbances, simplicity in design and ease of implementation. The effectiveness, feasibility, and robustness of the proposed method are illustrated using computer-based simulations with and without uncertainty estimator.
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robust Task Space control of an autonomous underwater vehicle manipulator system by pid like fuzzy control scheme with disturbance estimator
2017Co-Authors: P. S. Londhe, Santhakumar Mohan, Balasaheb M. Patre, L. M. WaghmareAbstract:Abstract This paper presents, a robust nonlinear proportional-integral-derivative (PID)-like fuzzy control scheme for a Task-Space trajectory tracking control of an autonomous underwater vehicle-manipulator system (AUVMS) employed for deep-sea intervention Tasks. The effectiveness of the proposed control scheme is numerically demonstrated on a planar underwater vehicle manipulator system (consisting of an underwater vehicle and two link rotary (2R) serial planar manipulator). The actuator and sensor dynamics of the system are also incorporated in the dynamical model of an AUVMS. The proposed control law consists of two main parts: first part uses a feed forward term to reinforce the control activity with extravagance from known desired acceleration vector and carries an estimated perturbed term to compensate for the unknown effects namely external disturbances and unmodeled dynamics and the second part uses a PID-like fuzzy logic control as a feedback portion to enhance the overall closed-loop stability of the system. The primary objective of the proposed control scheme is to track the given end-effector Task-Space trajectory despite of external disturbances, system uncertainties and internal noises associated with the AUVMS system. To show the effectiveness of the proposed control scheme, comparison is made with linear and nonlinear PID controllers. Simulation results confirmed that with the proposed control scheme, the AUVMS can successfully track the given desired spatial trajectory and gives better and robust control performance.
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robust non singular fast terminal sliding mode Task Space position tracking control of an underwater vehicle manipulator system
2017Co-Authors: P. S. Londhe, L. M. Waghmare, Balasaheb M. Patre, Santhakumar MohanAbstract:This paper addresses a Task-Space trajectory control of an underwater vehicle-manipulator system (UVMS) employed for interactive underwater Tasks. The robust Task-Space tracking control is achieved by designing a non-singular fast terminal sliding mode controller (NFTSMC) with disturbance estimator and demonstrated on a planar underwater vehicle with serial two link manipulator arm attached to it. The proposed NFTSMC integrates a non-singular fast terminal sliding mode controller (NFTSMC) with a non-linear disturbance observer. This combination not only assures finite and faster convergence of the systems states to the equilibrium from anywhere in the phase-plane but also overcomes the problem of singularity associated with conventional terminal sliding mode controller (TSMC). In addition to this, because of the disturbance observer augmented in the proposed control law, the overall stability of the closed-loop system is enhanced to a great extent. The feasibility of the proposed NFTSMC is confirmed by performing extensive numerical simulation on the UVMS for tracking a given pre-defined Task Space trajectory under the influence of parameter uncertainties, ocean current and measurement sensor noises.
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coordinated motion control in Task Space of an autonomous underwater vehicle manipulator system
2015Co-Authors: Santhakumar Mohan, Jinwhan KimAbstract:This paper presents a coordinated motion control scheme using a disturbance observer in Task Space for an autonomous underwater vehicle–manipulator system (UVMS). Since, the UVMS is kinematically redundant in nature, the proposed controller permits self-motion which can be utilized to perform power efficient trajectory tracking and at the same time it also assures that the system is able to track the given desired spatial trajectory with minimal errors (despite the presence of external disturbances, system uncertainties and internal noises). The performance of the proposed coordinated motion control of the UVMS is demonstrated numerically by simulating a few underwater Tasks such as payload conveyance. The system’s disturbance compensation capabilities are shown and the effects of external disturbances and parameter uncertainties on the station keeping performance are also analyzed. A comparative analysis on power consumption is presented to prove the effectiveness of the proposed scheme.
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a robust Task Space position tracking control of an underwater vehicle manipulator system
2015Co-Authors: Santhakumar Mohan, Jinwhan Kim, Yogesh SinghAbstract:This paper addresses a robust tracking control of an autonomous underwater vehicle-manipulator system (UVMS) based on terminal sling mode control in Task Space along with a disturbance observer. The effectiveness of the proposed scheme is demonstrated using numerical simulations having a serial planar manipulator (two rotary joints) on an underwater vehicle in a horizontal plane. An inverse dynamic solution for the system is obtained using the Newton-Euler method incorporating hydrodynamic and dynamic coupling effects. Performance of the proposed scheme is compared under various control schemes and demonstrated numerically for a predefined trajectory of the end effector (in Task Space).
Chien Chern Cheah - One of the best experts on this subject based on the ideXlab platform.
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Task Space sensory feedback control of robot manipulators
2015Co-Authors: Chien Chern CheahAbstract:Introduction.- Task-Space Setpoint Control.- Unified Analysis and Duality Property of Task-Space Setpoint Control.- Task-Space Tracking Control.- Advanced Motion Control.- Region Control.- Regional Feedback Control of Robot.
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global Task Space adaptive control of robot
2013Co-Authors: Chien Chern CheahAbstract:Task-Space feedback information such as visual feedback is used in many modern robot control systems as it improves robustness to model uncertainty. However, existing Task-Space feedback control schemes are only valid locally in a finite Task Space within a limited sensing zone where the singularity of the Jacobian matrix can be avoided. The global stability problem of a Task-Space control system has not been systemically solved. In this paper, we introduce a novel regional feedback method for robot Task-Space control. Each feedback information is employed in a local region, and the combination of regional information ensures the global convergence of robot motion. The transition from one feedback information to another is embedded in the controllers without using any hard or discontinuous switching. Using the regional feedback, a new Task-Space control method is proposed, which consists of a reaching Task variable that drives the robot from one Task Space to another and a desired Task variable to move the robot to the desired position at the ending stage. We shall show that the proposed regional feedback control method is a united formulation to address various open issues in Task-Space control problems such as singularity problem and limited sensing zone. This is the first result in Task-Space control that the global dynamic stability can be guaranteed with the consideration of singularity issues and limited sensing zones.
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Task Space setpoint control of robots with dual Task Space information
2009Co-Authors: Chien Chern Cheah, Jean-jacques E. SlotineAbstract:In conventional Task-Space control problem of robots, a single Task-Space information is used for the entire Task. When the Task-Space control problem is formulated in image Space, this implies that visual feedback is used throughout the movement. While visual feedback is important to improve the endpoint accuracy in presence of uncertainty, the initial movement is primarily ballistic and hence visual feedback is not necessary. The relatively large delay in visual information would also make the visual feedback ineffective for fast initial movements. Due to limited field of view of the camera, it is also difficult to easure that visual feedback can be used for the entire Task. Therefore, the Task may fail if any of the features is out of view. In this paper, we present a new Task-Space control strategy that allows the use of dual Task-Space information in a single controller. We shall show that the proposed Task-Space controller can transit smoothly from Cartesian-Space feedback at the initial stage to vision-Space feedback at the end stage when the target is near.
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Task-Space PD Control of Robot Manipulators: Unified Analysis and Duality Property
2008Co-Authors: Chien Chern CheahAbstract:Task-Space regulation of robots is classified into two basic approaches, namely transpose Jacobian regulation and inverse Jacobian regulation. This paper shows that, despite the distinct differences between inverse Jacobian and transpose Jacobian regulation problems, there is a unified approach for the analysis and design of the transpose Jacobian and inverse Jacobian PD controllers for non-redundant robots. Based on the unified analysis, we show that there is a fundamental property in the Task-Space regulation problem, namely the duality property. The results on the duality property show that the transpose Jacobian matrix can be replaced by the inverse Jacobian matrix and vice versa. The two basic transformations, the transpose Jacobian and the inverse Jacobian, are said to be dual. The Task-Space PD controllers are implemented on an industrial robot and experiment results are presented.
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Adaptive Jacobian tracking control of rigid-link electrically driven robots based on visual Task-Space information
2006Co-Authors: Chao Liu, Chien Chern Cheah, Jean-jacques E. SlotineAbstract:This paper studies stable adaptive tracking control of rigid-link electrically driven robot manipulators in the presence of uncertainties in kinematics, manipulator dynamics, and actuator dynamics. A new Task-Space control method using visual Task-Space information is proposed to overcome the uncertainties adaptively. Accelerations measurements are avoided in the control voltage inputs by constructing observers to specify desired armature currents. Simulation results illustrate the performance of the proposed control method.
Mohammad Mehdi Fateh - One of the best experts on this subject based on the ideXlab platform.
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Task Space control of robots using an adaptive taylor series uncertainty estimator
2019Co-Authors: Seyed Mohammad Ahmadi, Mohammad Mehdi FatehAbstract:ABSTRACTAn uncertainty estimation and compensation can improve the performance of control systems due to structured and unstructured uncertainty. This paper presents a robust Task-Space control app...
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adaptive Task Space control of robot manipulators using the fourier series expansion without Task Space velocity measurements
2018Co-Authors: Reza Gholipour, Mohammad Mehdi FatehAbstract:Abstract Many control approaches presented in the field of robotics require velocity signals, which are not usually provided by many commercial robots. The novelty of this paper is designing an adaptive model-free observer for robot manipulators in the Task-Space without the use of Task-Space velocity measurements. To compensate for the uncertainties and nonlinearities in the observer and controller, the Fourier series are utilized. Using Lyapunov stability theorem and Barbalat’s lemma, it is guaranteed that the tracking error and also the observer estimation error converge to zero. The case study is an articulated robot manipulator driven by permanent magnet DC motors. Simulation results and comparison with an extended state observer and linear observer verify the effectiveness of the proposed algorithm.
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Task Space asymptotic tracking control of robots using a direct adaptive taylor series controller
2018Co-Authors: Seyed Mohammad Ahmadi, Mohammad Mehdi FatehAbstract:This paper presents a robust Task-Space control approach using a direct adaptive Taylor series controller for electrically driven robot manipulators. In an adaptive Taylor series control scheme, the parameters of controller are directly tuned in order to reduce the Task-Space tracking error in the presence of structured and unstructured uncertainty. Also, the upper bound of approximation error is estimated to form a robustifying term and the asymptotic convergence of Task-Space tracking error and its time derivative is proven based on the stability analysis. Simulation results are included to verify the effectiveness of the proposed control method.
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observer based robust Task Space control of robot manipulators using legendre polynomial
2017Co-Authors: Reza Gholipour, Mohammad Mehdi FatehAbstract:In this paper, a simple observer-based robust control of robot manipulators in the Task-Space is presented. Many nonlinear observers require system dynamics. The novelty of this paper is designing a simple model-free observer for robot manipulators using orthogonal functions theorem. Based on this theorem, orthogonal functions such as Legendre polynomials are universal approximators. The controller is consisted of a state feedback gain using the observed states and an uncertainty estimator using Legendre polynomials. Using Lyapunov stability theorem, it is guaranteed that the controller tracking error and also the observer estimation error converge to zero. The case study is a SCARA robot manipulator driven by permanent magnet DC motors. Simulation results verify the effectiveness of the proposed algorithm.
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Robust Task-Space control of robot manipulators using Legendre polynomials for uncertainty estimation
2015Co-Authors: Saeed Khorashadizadeh, Mohammad Mehdi FatehAbstract:This paper deals with the robust Task-Space control of electrically driven robot manipulators using voltage control strategy. In conventional robust control approaches, the uncertainty bound is needed to design the control law. Usually, this bound is proposed conservatively which may increase the amplitude of the control signal and damage the system. Moreover, calculation of this bound requires some feedbacks of the system states which providing them may be expensive. The novelty of this paper is proposing a robust control law in which the uncertainty bound is calculated by Legendre polynomials. Compared to conventional robust controllers, the proposed controller is simpler, less computational and requires less feedbacks. Simulation results and comparisons verify the effectiveness of the proposed control approach applied on a SCARA robot manipulator driven by permanent magnet DC motors.
P. S. Londhe - One of the best experts on this subject based on the ideXlab platform.
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robust Task Space motion control of a mobile manipulator using a nonlinear control with an uncertainty estimator
2017Co-Authors: Swati Mishra, P. S. Londhe, Santhakumar Mohan, Santosh Kumar Vishvakarma, Balasaheb M. PatreAbstract:Abstract In this study, a robust nonlinear control method with an uncertainty estimator is proposed and applied to a kinematically redundant mobile manipulator (MM) position tracking in its Task Space. The proposed MM has four degrees-of-freedom (dof) serial manipulator mounted on three of mobile bases. The proposed method incorporates a feed-forward control term to reinforce the control action with extravagance from the desired acceleration vector; a disturbance estimator to reimburse for the unknown effects such as parametric uncertainties, external disturbances, unmodeled dynamics and a decentralized PID (proportional-integral-derivative) controller as a feedback loop to strengthen the stability of the system. The main strengths of the proposed scheme are its high robustness against parameter uncertainties and external disturbances, simplicity in design and ease of implementation. The effectiveness, feasibility, and robustness of the proposed method are illustrated using computer-based simulations with and without uncertainty estimator.
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robust Task Space control of an autonomous underwater vehicle manipulator system by pid like fuzzy control scheme with disturbance estimator
2017Co-Authors: P. S. Londhe, Santhakumar Mohan, Balasaheb M. Patre, L. M. WaghmareAbstract:Abstract This paper presents, a robust nonlinear proportional-integral-derivative (PID)-like fuzzy control scheme for a Task-Space trajectory tracking control of an autonomous underwater vehicle-manipulator system (AUVMS) employed for deep-sea intervention Tasks. The effectiveness of the proposed control scheme is numerically demonstrated on a planar underwater vehicle manipulator system (consisting of an underwater vehicle and two link rotary (2R) serial planar manipulator). The actuator and sensor dynamics of the system are also incorporated in the dynamical model of an AUVMS. The proposed control law consists of two main parts: first part uses a feed forward term to reinforce the control activity with extravagance from known desired acceleration vector and carries an estimated perturbed term to compensate for the unknown effects namely external disturbances and unmodeled dynamics and the second part uses a PID-like fuzzy logic control as a feedback portion to enhance the overall closed-loop stability of the system. The primary objective of the proposed control scheme is to track the given end-effector Task-Space trajectory despite of external disturbances, system uncertainties and internal noises associated with the AUVMS system. To show the effectiveness of the proposed control scheme, comparison is made with linear and nonlinear PID controllers. Simulation results confirmed that with the proposed control scheme, the AUVMS can successfully track the given desired spatial trajectory and gives better and robust control performance.
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robust non singular fast terminal sliding mode Task Space position tracking control of an underwater vehicle manipulator system
2017Co-Authors: P. S. Londhe, L. M. Waghmare, Balasaheb M. Patre, Santhakumar MohanAbstract:This paper addresses a Task-Space trajectory control of an underwater vehicle-manipulator system (UVMS) employed for interactive underwater Tasks. The robust Task-Space tracking control is achieved by designing a non-singular fast terminal sliding mode controller (NFTSMC) with disturbance estimator and demonstrated on a planar underwater vehicle with serial two link manipulator arm attached to it. The proposed NFTSMC integrates a non-singular fast terminal sliding mode controller (NFTSMC) with a non-linear disturbance observer. This combination not only assures finite and faster convergence of the systems states to the equilibrium from anywhere in the phase-plane but also overcomes the problem of singularity associated with conventional terminal sliding mode controller (TSMC). In addition to this, because of the disturbance observer augmented in the proposed control law, the overall stability of the closed-loop system is enhanced to a great extent. The feasibility of the proposed NFTSMC is confirmed by performing extensive numerical simulation on the UVMS for tracking a given pre-defined Task Space trajectory under the influence of parameter uncertainties, ocean current and measurement sensor noises.
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Task Space control of an autonomous underwater vehicle manipulator system by robust single input fuzzy logic control scheme
2017Co-Authors: P. S. Londhe, M Santhakumar, Balasaheb M. Patre, L. M. WaghmareAbstract:In this paper, a robust single-input fuzzy logic control Robust Single Input Fuzzy Logic Controller (RSIFLC) scheme is proposed and applied for Task-Space trajectory control of an autonomous underwater vehicle manipulator system (AUVMS) employed for underwater manipulation Tasks. The effectiveness of the proposed control scheme is numerically demonstrated on a planar underwater vehicle manipulator system [consisting of an underwater vehicle and a two link rotary (2R) serial planar manipulator]. The actuator and sensor dynamics of the system are also incorporated in the dynamical model of an AUVMS. The proposed control law consists of a feedforward term to exaggerate the control activity with immoderation from the known desired acceleration vector and an estimated perturbed term to compensate for the unknown effects namely external disturbances and unmodeled dynamics as a first part and a single-input fuzzy logic control as a feedback portion to enhance the overall closed-loop stability of the system as a second part. The primary objective of the proposed control scheme is to track the given end-effector Task Space trajectory despite of external disturbances, system uncertainties, and internal noises associated with the AUVMS. To show the efficacy of the proposed control scheme, comparison is made with conventional fuzzy logic control (CFLC), sliding mode control (SMC), and proportional–integral–derivative (PID) controllers. Simulation results confirmed that with the proposed control scheme, the AUVMS can successfully track the given desired spatial trajectory and gives better and robust control performance.
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robust nonlinear Task Space position tracking control of an autonomous underwater vehicle manipulator system
2015Co-Authors: P. S. Londhe, M Santhakumar, Balasaheb M. Patre, L. M. WaghmareAbstract:This paper presents a robust nonlinear control scheme for Task-Space trajectory control for an autonomous underwater vehicle- manipulator system (AUVMS) based on an improved proportional integral derivative (PID) control scheme used for deep-sea intervention Tasks. A planar underwater vehicle manipulator system (consists of an underwater vehicle and two link rotary (2R) serial planar manipulator) with dynamic coupling between them is considered for the study and numerical simulation. The actuator and sensor dynamics of the system are also considered. The proposed controller integrates the known approximated inverse dynamic model output as a model-base portion of the controller; uses a feed forward term to enhance the control activity with indulgence from known desired acceleration vector; carries an estimated perturbed term to compensate for the unknown effects namely external disturbances and un-modelled dynamics and a decoupled nonlinear PID controller as a feedback portion to enhance closed-loop stability and account for the estimation error of uncertainties. The primary objective of the proposed control scheme is to track the given end-effector Task-Space trajectory despite of external disturbances, system uncertainties and internal noises associated with the AUVMS system, which show the robustness of the proposed control scheme. Simulation results confirmed that the AUVMS can successfully track the given desired spatial trajectory.
Jean-jacques E. Slotine - One of the best experts on this subject based on the ideXlab platform.
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Task Space setpoint control of robots with dual Task Space information
2009Co-Authors: Chien Chern Cheah, Jean-jacques E. SlotineAbstract:In conventional Task-Space control problem of robots, a single Task-Space information is used for the entire Task. When the Task-Space control problem is formulated in image Space, this implies that visual feedback is used throughout the movement. While visual feedback is important to improve the endpoint accuracy in presence of uncertainty, the initial movement is primarily ballistic and hence visual feedback is not necessary. The relatively large delay in visual information would also make the visual feedback ineffective for fast initial movements. Due to limited field of view of the camera, it is also difficult to easure that visual feedback can be used for the entire Task. Therefore, the Task may fail if any of the features is out of view. In this paper, we present a new Task-Space control strategy that allows the use of dual Task-Space information in a single controller. We shall show that the proposed Task-Space controller can transit smoothly from Cartesian-Space feedback at the initial stage to vision-Space feedback at the end stage when the target is near.
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Adaptive Jacobian tracking control of rigid-link electrically driven robots based on visual Task-Space information
2006Co-Authors: Chao Liu, Chien Chern Cheah, Jean-jacques E. SlotineAbstract:This paper studies stable adaptive tracking control of rigid-link electrically driven robot manipulators in the presence of uncertainties in kinematics, manipulator dynamics, and actuator dynamics. A new Task-Space control method using visual Task-Space information is proposed to overcome the uncertainties adaptively. Accelerations measurements are avoided in the control voltage inputs by constructing observers to specify desired armature currents. Simulation results illustrate the performance of the proposed control method.
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adaptive Task Space regulation of rigid link flexible joint robots with uncertain kinematics
2006Co-Authors: Chao Liu, Chien Chern Cheah, Jean-jacques E. SlotineAbstract:Joint flexibility is an important factor to consider in the robot control design if high performance is expected for the robot manipulators. The research work on control of rigid-link flexible-joint (RLFJ) robot in the literature has assumed that the kinematics of the robot is known exactly. There have been no results so far that can deal with the kinematics uncertainty in RLFJ robot. In this paper, we present the first study on this problem and propose an adaptive regulation method which can deal with the kinematics uncertainty and uncertainties in both link and motor dynamics of the RLFJ robot system. An observer is designed to avoid the use of acceleration due to the fourth-order overall dynamics. Sufficient conditions are derived to guarantee the asymptotic stability of the closed-loop system. Simulation result illustrates the effectiveness of proposed control method
