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In the field of architecture, 3D printing technology has the advantage of shortening the construction period by continuous addition and installing the desired shape and structure directly on site. However, the conventional 3D printer structure has limitations in practical use because of its versatility, mobility, and limited accessibility. In this study, a 3-axis gantry robot type 3D printing simulator...
This paper presents an adaptive nonsingular terminal sliding mode formation control by means of output recurrent fuzzy wavelet neural networks for a group of networked heterogeneous Mecanum-wheeled omnidirectional robots with uncertainties. The dynamic behavior of each uncertain heterogeneous omnidirectional robot is modelled by a reduced three-input-three-output second-order state equation with uncertainties...
In this work, we consider a testbed for a robotic astronomical 0.5-m. telescope mount. We focus on the problem of identification uncertainty that cannot be obtained from analytical consideration (i.e. friction phenomena). Thus, we use a recursive least-squares algorithm for identification values of friction terms. Since the required signals cannot be obtained directly from the object (or they are...
Model based approaches, such as those that use partial differential equations (PDE), lend themselves to gas distribution mapping and gas source localization. Moreover, they also permit constructing intelligent sampling strategies. However, a realistic mathematical model of gas dispersion is complex and computationally expensive to solve. This is especially the case for inverse problems, where sources...
The exoskeleton robots because of its potential applications in rehabilitation engineering, assistive robotics, and power augmentation are getting more attention in the field of robotics. Besides kinematics model and dynamic model, three type controllers are applied in position control mode, PID control, computed torque control and time delay control, respectively. For the sake of the difficulty in...
Parallel manipulators play a key role in robotic rehabilitation. In reality, such systems operate under uncertainty due to the changes in the characteristics of the patients and lack of knowledge about the physical and geometrical properties of the system. In this paper, we present a robust control scheme to control a six-degree-of-freedom Stewart platform. In this application, it is aimed to follow...
Robotic behaviors are mainly described by differential equations. Those mathematical models are usually not precise enough because of inaccurately known parameters or model simplifications. Nevertheless, robots are often used in critical contexts as medical or military fields. So, uncertainties in mathematical models have to be taken into account in order to produce reliable and safe analysis results...
This paper considers a tractable simplified problem of model-based Bayesian reinforcement learning (BRL) in terms of real-world samples, computational complexity, and target uncertainties. Robust control and adaptive control are two of the most successful and tractable conventional control design theories against uncertainties in various domain, while they have contrasting ideas. We show that both...
Tethered Segway is a robotic platform inspired by human climbers. It is a two-wheeled mobile platform tethered to the top of a structure in order to climb steep surfaces with varying slopes, such as domes. The unstructured environment may cause uncertainties in the dynamic behavior of the robot while operating on different parts of the dome. In this paper analysis and synthesis of a robust controller...
Teleoperation systems allow a surgeon to perform a remote distance operation with or without magnification. Nonlinearity and unknown dynamics of master and slave robots, in teleoperation systems, make it challenging to guarantee stability and convergence of the position tracking error in such systems. This paper presents an interval Type-2 Fuzzy (T2F) logic controller to control position of a teleoperation...
This conference paper figures out the tracking control issue of a flapping wing micro aerial vehicle (FWMAV) subject to uncertain system parameters based on the model in Lagrangian form. As we know, there are many uncertainties in the complex nonlinear system. To deal with this problem, radial basis function neural networks (RBFNNs) are considered to substitute uncertainties of FWMAV model. Through...
In this paper, design and control of a rotary series elastic actuator (RSEA) in human rehabilitation are considered. Actuators consist of some parameters that should be determined. Here genetic algorithm (GA) is used for optimally design the actuator parameters for tracking human joint angle and a new robust hybrid adaptive sliding mode control method for its control is presented. Also the actuators...
Automation of excavators offers a promise for increasing productivity of digging. At the same time, it's a highly difficult issue due to presence of various nonlinearities and uncertainties in excavator mechanical structures and hydraulic actuators, disturbance when a bucket contacting the ground etc. This paper concerns the problem of robust trajectory tracking control of an excavator arm. To solve...
Two-Wheeled Inverted Pendulum (TWIP) robot is considered as an unstable and underactuated system affected by physical and environmental constrains. In addition, due to the model uncertainties, a robust control approach is needed to stabilize the posture of the TWIP. Robust Model Predictive Control (RMPC) based on linear matrix inequality (LMIs) is addressed to an optimization problem of the “worst-case”...
In recent years, different exoskeleton devices have been developed to provide the users with the mechanical power required in augmentation and rehabilitation applications. The exoskeleton control is one of the most challenging issues causes widely attention of researches during recent decade. Although different methods of control have been presented, there are several issues which have not been answered...
In this paper we consider the application problem of a redundant cable-driven parallel robot, tracking a reference trajectory in presence of uncertainties and disturbances. A Super Twisting controller is implemented using a recently proposed gains adaptation law [1], thus not requiring the knowledge of the upper bound of the lumped uncertainties. The controller is extended by a feedforward dynamic...
This paper presents a novel spherical rolling robot and the design procedure of an adaptive sliding mode controller for the proposed robot. Towards containing the uncertainties, the sliding mode controller is utilized and simulation tests represent the effectiveness of this method. However, the chattering phenomenon in the robot operation is the main insufficiency of this controller. Hence, in order...
This paper proposes a framework called nonlinear robust internal-loop compensator that enables us to bring nonlinear $\mathcal {H}_\infty$ optimality to robot controllers in a unified and simple way. Using the framework, a controller designed for the nominal plant can achieve additional robustness by simply adding PID-type auxiliary input to the original control law. Robust performance is guaranteed...
Simultaneous position and force tracking are two critical factors in teleportation systems to achieve transparency. In this paper, a new control scheme is proposed to guarantee asymptotic position and force tracking in teleportation systems with disturbances. To this end, two sliding mode controllers are designed for the master and the slave robots respectively and are incorporated into the 4-channel...
In this paper, we use sliding mode control theory to design a 3D vision based controller that is robust to bounded parametric estimation errors. First, we give a model of an eye-in-hand 6 DOF robotic system, including the Pose Reconstruction Algorithm (PRA) used to estimate the position and orientation of the camera with respcet to the scene. In a second step, we propose a model for the uncertainties...
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