Human-robot collaborative tasks foresee interactions between humans and robots with various degrees of complexity. Specifically, for tasks which involve physical contact among the agents, challenges arise in the model...
详细信息
ISBN:
(纸本)9781713867890
Human-robot collaborative tasks foresee interactions between humans and robots with various degrees of complexity. Specifically, for tasks which involve physical contact among the agents, challenges arise in the modelling and control of such interaction. In this paper we propose a control architecture capable of ensuring a flexible and robustly stable physical human-robot interaction, focusing on a collaborative transportation task. The architecture is deployed onto a mobile manipulator, modelled as a whole-body structure, which aids the operator during the transportation of an unwieldy load. Thanks to passivity techniques, the controller adapts its interaction parameters online while preserving robust stability for the overall system, thus experimentally validating the architecture. Copyright (c) 2022 The Authors. This is an open access article under the CC BY-NC-ND license (https://***/licenses/by-nc-nd/4.0/)
Human-robot collaborative tasks foresee interactions between humans and robots with various degrees of complexity. Specifically, for tasks which involve physical contact among the agents, challenges arise in the model...
详细信息
Human-robot collaborative tasks foresee interactions between humans and robots with various degrees of complexity. Specifically, for tasks which involve physical contact among the agents, challenges arise in the modelling and control of such interaction. In this paper we propose a control architecture capable of ensuring a flexible and robustly stable physical human-robot interaction, focusing on a collaborative transportation task. The architecture is deployed onto a mobile manipulator, modelled as a whole-body structure, which aids the operator during the transportation of an unwieldy load. Thanks to passivity techniques, the controller adapts its interaction parameters online while preserving robust stability for the overall system, thus experimentally validating the architecture.
When robots grasp a rigid object, homogeneous holonomic constraints give rise to stiff nonlinear constrained dynamics. As a result, a smooth motion is preferred when grasping an object in a tight but gentle manner, ma...
详细信息
When robots grasp a rigid object, homogeneous holonomic constraints give rise to stiff nonlinear constrained dynamics. As a result, a smooth motion is preferred when grasping an object in a tight but gentle manner, making it a difficult control problem that increases when uncertainties and unmodelled dynamics exist. In this paper, a fuzzy design is proposed by exploiting a physics-based orthogonalization of contact mechanics to produce desired velocity and force fields. The proposed scheme enables the regulation of the velocity component in order to navigate smoothly, while the force field enforces grasp at contact in the normal direction of the cooperative joint-velocity field. Then, the robust model-free controller is designed to track such orthogonal fields while enforcing cooperation among all robots, even under uncertainties and unknown dynamics. A representative simulation study is discussed to show the feasibility of the proposal.
This paper is concerned with the design of a state feedback control scheme for variable stiffness actuated (VSA) robots, which guarantees prescribed performance of the tracking errors despite the low range of mechanic...
详细信息
This paper is concerned with the design of a state feedback control scheme for variable stiffness actuated (VSA) robots, which guarantees prescribed performance of the tracking errors despite the low range of mechanical stiffness. The controller does not assume knowledge of the actual system dynamics nor does it utilize approximating structures (e.g., neural networks and fuzzy systems) to acquire such knowledge, leading to a low complexity design. Simulation studies, incorporating a model validated on data from an actual variable stiffness actuator (VSA) at a multi-degrees-of-freedom robot, are performed. Comparison with a gain scheduling solution reveals the superiority of the proposed scheme with respect to performance and robustness.
In this paper, a new,simple stable force tracking impedance control scheme that has the capability to track a specified desired force and to compensate for uncertainties in environment location and stiffness as well a...
详细信息
In this paper, a new,simple stable force tracking impedance control scheme that has the capability to track a specified desired force and to compensate for uncertainties in environment location and stiffness as well as in robot dynamic model is proposed. The uncertainties in robot dynamics are compensated by the robust position control algorithm. After contact, in force controllable direction the new impedance function is realized based on a desired force, environment stiffness and a position error. The new impedance. function is simple and stable. The force error is minimized by using an adaptive technique. Stability and convergence of the adaptive technique are analyzed for a stable force tracking execution. Simulation studies with a three link rotary robot manipulator are shown to demonstrate the robustness of the proposed scheme under uncertainties in robot dynamics, and little knowledges of environment position and environment stiffness. Experimental results are carried out to confirm the proposed controller's performance.
In vision-based robotcontrol typically more sensor data are available than the minimum necessary for computing robotcontrol commands. We propose an approach for utilizing the redundant sensor data to improve the rob...
详细信息
ISBN:
(纸本)0780344650
In vision-based robotcontrol typically more sensor data are available than the minimum necessary for computing robotcontrol commands. We propose an approach for utilizing the redundant sensor data to improve the robustness of robotcontrol. The key point is that the sensor data space is transformed into a space of lower dimensionality before computing the robotcontrol commands, thus avoiding to solve an over-determined system of equations. Compared to the rather simple alternative method of truncating measurements if has the advantage that, in the interest of robustness, it takes into account all available measurements The approach has been evaluated in real-world manipulation experiments with a calibration-free robot. It has proven to be suitable for a real-time implementation and has led to a more robustcontrol than the alternative approach.
暂无评论