Optimal design of adaptive robust control for a planar two-DOF redundantly actuated parallel robot

2021 ◽  
Author(s):  
Jiang Han ◽  
Peng Wang ◽  
Fangfang Dong ◽  
Xiaomin Zhao ◽  
Shan Chen
Keyword(s):  
Robust Control ◽  
Optimal Design ◽  
Parallel Robot ◽  
Adaptive Robust Control ◽  
Redundantly Actuated

scholarly journals Error Analysis and Adaptive-Robust Control of a 6-DoF Parallel Robot with Ball-Screw Drive Actuators

2016 ◽  
Vol 2016 ◽  
pp. 1-15 ◽  
Author(s):  
Navid Negahbani ◽  
Hermes Giberti ◽  
Enrico Fiore
Keyword(s):  
Robust Control ◽  
Tracking Error ◽  
Parallel Robot ◽  
Adaptive Robust Control ◽  
Ball Screw ◽  
Screw Drive ◽  
Kinematic Mapping ◽  
Parallel Kinematic ◽  
Ball Screw Drive ◽  
Actuated Joints

Parallel kinematic machines (PKMs) are commonly used for tasks that require high precision and stiffness. In this sense, the rigidity of the drive system of the robot, which is composed of actuators and transmissions, plays a fundamental role. In this paper, ball-screw drive actuators are considered and a 6-degree of freedom (DoF) parallel robot with prismatic actuated joints is used as application case. A mathematical model of the ball-screw drive is proposed considering the most influencing sources of nonlinearity: sliding-dependent flexibility, backlash, and friction. Using this model, the most critical poses of the robot with respect to the kinematic mapping of the error from the joint- to the task-space are systematically investigated to obtain the workspace positional and rotational resolution, apart from control issues. Finally, a nonlinear adaptive-robust control algorithm for trajectory tracking, based on the minimization of the tracking error, is described and simulated.

scholarly journals Optimal Design of Adaptive Robust Control for the Delta Robot with Uncertainty: Fuzzy Set-Based Approach

2020 ◽  
Vol 10 (10) ◽  
pp. 3472 ◽  
Author(s):  
Linlin Wu ◽  
Ruiying Zhao ◽  
Yuyu Li ◽  
Ye-Hwa Chen
Keyword(s):  
Optimal Control ◽  
Robust Control ◽  
Optimal Design ◽  
Fuzzy Set ◽  
Dead Zone ◽  
Adaptive Robust Control ◽  
Fast Time ◽  
Theoretic Approach ◽  
Adaptation Mechanism ◽  
Delta Robot

An optimal control design for the uncertain Delta robot is proposed in the paper. The uncertain factors of the Delta robot include the unknown dynamic parameters, the residual vibration disturbances and the nonlinear joints friction, which are (possibly fast) time-varying and bounded. A fuzzy set theoretic approach is creatively used to describe the system uncertainty. With the fuzzily depicted uncertainty, an adaptive robust control, based on the fuzzy dynamic model, is established. It designs an adaptation mechanism, consisting of the leakage term and the dead-zone, to estimate the uncertainty information. An optimal design is constructed for the Delta robot and solved by minimizing a fuzzy set-based performance index. Unlike the traditional fuzzy control methods (if-then rules-based), the proposed control scheme is deterministic and fuzzily optimized. It is proven that the global solution in the closed form for this optimal design always exists and is unique. This research provides the Delta parallel robot a novel optimal control to guarantee the system performance regardless of the uncertainty. The effectiveness of the proposed control is illustrated by a series of simulation experiments. The results reveal that the further applications in other robots are feasible.

scholarly journals Optimal Design Oriented Adaptive Robust Control for A Planar 2-DOF Redundantly Actuated Parallel Robot

2021 ◽  
Author(s):  
Jiang Han ◽  
Peng Wang ◽  
Fangfang Dong ◽  
Xiaomin Zhao ◽  
Shan Chen
Keyword(s):  
Robust Control ◽  
System Performance ◽  
Parallel Robot ◽  
Adaptive Robust Control ◽  
Control Cost ◽  
Constraint Force ◽  
Performance Function ◽  
Weighting Factors ◽  
Multi Objective ◽  
Closed Chain

Abstract An adaptive robust control combined with a multi-objective parameter optimization method for the parallel robot with unknown uncertainty is proposed. In the active joint space, the accurate dynamic model of the parallel robot can be obtained by combining the closed-chain constraint force and the open-chain system's dynamic equation. According to the Udwadia-Kalaba theory, the closed-chain constraint force imposed by the end effector can be calculated in a simple way. The proposed adaptive robust control could guarantee deterministic robust performances of the system (the uniform boundedness and uniform ultimate boundedness). To seek suitable weighting factors for the proposed control, a system performance function, which includes the transient performance portion, the steady state performance portion, and the control cost, is introduced. By applying $D$-operation, the performance function is transformed into a multi-objective function with weighting factors. Meanwhile, the problem of choosing the optimal gain is equivalent to the problem of finding the minimum value of the system performance index function. An illustrative example illustrates the superiority of the proposed modeling method and the proposed adaptive robust control.

Sign in / Sign up

Export Citation Format

Share Document