The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
One aim of controlling a manipulator robot is to maximize its performances such as accuracy, speed, time etc…. However, limiting the power of actuators causes a limitation of their generalized accelerations and velocities; this is due to the high inertial forces, which create dangerous voltages at the machines elements.
In the resolution of redundancy in systems, by far the most popular approach involves optimization with respect to the 2-norm, due to it's ease of use, uniqueness, and continuity of resolution. Due to the 2-norm's inability to consider input bounds, however, such methods fail to exploit systems' full feasible output range. The Cascaded Generalized Inverse (CGI) was introduced to extend the realizable...
For the planning of time-critical paths for redundant continuum manipulators, dynamic input constraints such as the maximum air mass flow on the pressure dynamics of a pneumatically actuated system have a significant impact on the transition time. This paper presents a trajectory generation framework by using optimal control strategies that consider not only the mechanical dynamics, but also the pressure...
The aim of this article is design and control system developing of multirotational UAV equipped with a robotic manipulator. As a combined model of the robot a quadrocopter and a two-link manipulator were chosen. The mathematical model of this robot, its dynamic equations and problem of trajectory tracking are described in this paper. Mutual reactive influence of the robotic manipulator and the UAV...
In this paper, we investigate the problem of space-craft attitude regulation and end-effector trajectory tracking for free-floating space manipulators with uncertain kinematics and dynamics. We propose an extended-Jacobian-based adaptive zero reaction controller for free-floating space manipulators so as to realize both the spacecraft attitude regulation and end-effector trajectory tracking. The major...
The underwater stationary intervention object is moving relatively to underwater manipulator base when underwater vehicle is hovering. To realize the relative dynamic object operation, cubic B-spline is used in manipulator trajectory planning. This paper provides maximum interval of two adjacent control points to adjust the control points near dynamic object to generate smooth trajectory in real time...
The adaptive trajectory and force tracking control is considered for mobile manipulator with holonomic constraints and affine constraints in this paper. A new state transformation is proposed to deal with the affine constraints, and then based on a suitable reduced dynamic model, adaptive controller is presented to ensure that the states of closed-loop system asymptotically track to desired trajectories...
In order to increase the workspace size of parallel robots (largely reduced by the presence of singularities) several solutions have been proposed. One promising solution consists in the definition of optimal trajectories that ensure the non degeneracy of the dynamic model in the singularity and therefore are able to cross the Type 2 singularities. Those works are based on the computation of the optimal...
Cooperative manipulation, where several robots jointly manipulate an object from an initial configuration to a final configuration while preserving the robot formation, poses a great challenge in robotics. Here, we treat the problem of designing motion primitives for cooperative manipulation such that the robots move in formation and are robust with respect to external disturbances. Individual robot...
Dexterous hand manipulation is one of the most complex types of biological movement, and has proven very difficult to replicate in robots. The usual approaches to robotic control — following pre-defined trajectories or planning online with reduced models — are both inapplicable. Dexterous manipulation is so sensitive to small variations in contact force and object location that it seems to require...
Mobile manipulators provide more advantages and flexibility in a wide range of applications than standard manipulators by introducing mobility. However, adding mobile platforms to standard manipulators, especially nonholonomic mobile platforms, introduces new challenges to the system modeling and control. Most existing methods for mobile manipulators do not consider the performance difference between...
This paper presents a new free-flight controller for aerial manipulators, unmanned aerial vehicles endowed with a robotic manipulator. The control strategy exploits the dynamics of the manipulator to improve the tracking performance and maneuverability of the UAV by expanding its flight envelop. The controller increases the spectrum of deployable manipulators, which otherwise are limited to be light-weighted...
This study proposes a robust controller in conjunction with the dynamic modeling of an existing three degrees of freedom planar parallel manipulator which can perform effectually in the presence of parameter uncertainties and external disturbances. The planar manipulator discussed here has three legs each with a prismatic-prismatic-revolute (3-PPR) joint configuration and located on the same plane...
The present paper discusses a planning and control strategy for robotic whole-arm manipulation of a slippery polygonal object by taking into account the estimated bounds of the frictional coefficient. In this study, randomized planning methods are first proposed in order to generate contact state transitions. Second, a novel control strategy that can switch manipulation between quasi-static, dynamic,...
High accuracy trajectory tracking is challenging topic in robotic manipulator control. This is due to nonlinearities and input coupling present in robotic arm. In this paper, a chattering free sliding mode control (SMC) for a robot manipulator including PID part with a fuzzy tunable gain is designed. The main idea is that the robustness property of SMC and good response characteristics of PID are...
Minimum time optimization trajectory planning problem which can generate smooth trajectory of joints of robot is still complex and difficult to solve. A novel hybrid cubic B-spline and convex optimization method was presented for trajectory planning of robotic manipulator in this paper. First, the first and second derivatives of path trajectory coordinates s, called pseudo-velocity and pseudo-acceleration...
This paper seeks to develop simple yet efficient modelling and control scheme for robotic manipulators in joint space wherein a control law is developed based on sliding mode that provides robustness against uncertainties and perturbations and a stability analysis guarantees the asymptotic stability of origin. Given the bounds of disturbance and a switching manifold that enforces trajectory tracking,...
In this paper an iterative learning controller (ILC) is designed based on the identified model of a single-link flexible manipulator (SLFM). As the system is nonlinear and time-varying so to meet the demands of the control system design, an adaptive nonlinear autoregressive with exogenous input (NARX) model is identified using the input/output experimental data. Tuning of the ILC controller is carried...
In order to solve the problems of flexible joint space manipulators in dynamics modeling and simulation, a model with three-dimensional four-link flexible-joint manipulators is taken into account. Considering the nonlinear stiffness coefficient of the torsion-spring, and inertia coupling, the dynamics model of flexible-joint manipulators with revolute joints is established by applying the Lagrange...
In this paper, a new method of observer based quasi-static deformation compensation control is proposed to track the end position trajectory for a three-link rigid-flexible manipulator with a large payload. Firstly, an observer is developed based on the model of the three-link rigid-flexible manipulator to estimate the vibratory modals and their time derivatives, which are practically impossible to...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.