1,720,973 research outputs found
Design and experimental validation of a second order sliding-mode motion controller for robot manipulators
No full textVision-Based Sliding Mode Observers for Fault Detection, Isolation and Identification in Robot Manipulators
No full textTrajectory Planning and Second Order Sliding Mode Motion/Interaction Control for Robot Manipulators in Unknown Environments
No full text
An Inverse Dynamics-Based Discrete-Time Sliding Mode Controller for Robot Manipulators
No full textIn the past years an extensive literature has been devoted to the subject of motion control of rigid robot manipulators. Many approaches have been proposed, such as feedback linearization, model predictive control, as well as sliding mode or adaptive control. The basic idea of feedback linearization, known in the robotic context as inverse dynamics control, is to exactly compensate all the coupling nonlinearities in the dynamical model of the manipulator in a first stage so that a second stage compensator may be designed based on a linear and decoupled plant. Although global feedback linearization is possible in theory, in practice it is difficult to achieve, mainly because the coordinate transformation is a function of the system parameters and, hence, sensitive to uncertainties which arise from joint and link flexibility, frictions, sensor noise, and unknown loads. This is the reason why the inverse dynamics approach is often coupled with robust control methodologies
Hybrid Position/Force Sliding Mode Control of a Class of Robotic Manipulators
No full textThis paper deals with the hybrid position/force
control of a class of robotic manipulators. To perform the
control scheme design, it is necessary to characterize the
dynamical model of the force sensor which is mounted at the
end-effector of the robot. The objective is to perform reliable
contact force measurements by estimating all the forces which
are generated at the level of the tip which is directly connected
to the sensor. A dynamical model of the sensor motion is
formulated and identified, by considering also the kinematics of
the robot. The proposed hybrid control scheme includes position
and force controllers based on first and second order sliding
modes. These kind of controllers guarantee suitable robustness
properties to perform a satisfactory trajectory tracking, also
allowing one to make the robot move in an environment
with unknown obstacles by using the possibility of touching
the obstacles as a way to pass them by. Experimental tests
are performed on a COMAU SMART3-S2 anthropomorphic
rigid robot manipulator with an ATI Gamma force sensor by
comparing four different position/force control schemes
Fault detection for robot manipulators via second order sliding modes
No full textThis paper presents a model-based fault detection
(FD) and isolation scheme for rigid manipulators. A single fault
acting on a specific actuator or on a specific sensor of the manipulator
is detected (and, if possible, the exact location of the fault),
and an estimation of the fault signal is performed. Input-signal
estimator and output observers are considered in order to make
the FD procedure possible. By using the suboptimal second-order
sliding-mode (SOSM) algorithm to design the input laws of the
observers, satisfactory stability properties of the observation error are established. The proposed algorithm is verified in simulation and experimentally on a COMAU SMART3-S2 robot manipulator
Actuators and sensors fault detection for robot manipulators via second order sliding mode observers
No full textReal-time networked control of an industrial robot manipulator via discrete-time second order sliding modes
No full textThis article presents the networked control of a robotic anthropomorphic manipulator based on a second-order
sliding mode technique, where the control objective is to track a desired trajectory for the manipulator. The
adopted control scheme allows an easy and effective distribution of the control algorithm over two networked
machines. While the predictability of real-time tasks execution is achieved by the Soft Hard Real-Time Kernel
(S.Ha.R.K.) real-time operating system, the communication is established via a standard Ethernet network.
The performances of the control system are evaluated under different experimental system configurations using,
to perform the experiments, a COMAU SMART3-S2 industrial robot, and the results are analysed to put into
evidence the robustness of the proposed approach against possible network delays, packet losses and unmodelled
effects
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