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The robotic welding processes have been highly widespread in manufacturing industries due to large-scale production. An area where these processes are widely applied are shipyards, where there are necessary hundreds to thousands of kilograms of weld by hour. However, systems that operate in open-air environments are vulnerable to sundry disturbances, noises in measures, as well as possible unavailability...
This paper proposes an adaptive control for a rigidlink, flexible-joint robot using the Cerebellar Model Articulation Controller (CMAC) and the backstepping method, which is a suitable method when joints are underdamped and exhibit a large amount of flexibility. A previously proposed robust weight update method, deemed the introspective method, is placed into a Lyapunov-stable framework. In the introspective...
We propose a robust two-dimensional polynomial beamformer design method, formulated as a convex optimization problem, which allows for flexible steering of a previously proposed data-independent robust beamformer in both azimuth and elevation direction. As an exemplary application, the proposed two-dimensional polynomial beamformer design is applied to a twelve-element microphone array, integrated...
In the realm of surface electromyography (sEMG) gesture recognition, deep learning algorithms are seldom employed. This is due in part to the large quantity of data required for them to train on. Consequently, it would be prohibitively time consuming for a single user to generate a sufficient amount of data for training such algorithms. In this paper, two datasets of 18 and 17 able-bodied participants...
This work proposes a modification to the Cerebellar Model Articulation Controller (CMAC) for use in a direct adaptive control scheme. With the original CMAC, when an oscillation in the input occurs between two CMAC cells and across the origin, the weights in the adjacent cells drift in opposite directions — resulting in control signal chatter. When the chatter is severe it can cause a sudden increase...
This paper presents a new under-actuated resilient robot that has the three recovery processes available, as we proposed elsewhere. The new feature with the proposed resilient robot is such that all the recovery strategies can be accomplished in a 2D plane instead of a 3D space, thus reducing the complexity of the recovery process. The robot also has the ability of switching between a fully-actuated...
This paper presents an implementation of a system that is autonomously able to find, follow and land on a car moving at 15 km/h. Our solution consists of two parts, the image processing for fast onboard detection of landing platform and the Model Predictive Control tracker for trajectory planning and control. This approach is fully autonomous using only the onboard computer and onboard sensors with...
The problem of balancing a flying inverted pendulum on an unmanned aerial vehicle (UAV) has been solved using linear and nonlinear control approaches. However, to the best of our knowledge, the problem of swinging-up a flying pendulum has not been addressed in the literature. In this paper, we solve the general problem of swinging-up and balancing an inverted pendulum attached to a quadrotor using...
This study is aimed to find low order, stable and proper controllers for the linearized models of two well known underactuated robots i.e. Acrobot and Pendubot around their upright equilibrium points in order to maximize the robustness of the feedback loop to uncertainties. The proposed method makes use of the robust stabilization of finite dimensional plants by Nevanlinna-Pick interpolation problem...
This paper presents a method for estimating the number, as well as the activity periods of spatially distributed sound sources using an uncalibrated microphone array. This methodology is applied for the purposes of speaker diarization. In general, speaker diarization has difficulty with: 1) estimating the number of sound sources (speakers), and 2) activity detection of multiple sound sources including...
We present a novel multimodal interaction framework supporting robust human-robot communication. We consider a scenario where a human operator can exploit multiple communication channels to interact with one or more robots in order to accomplish shared tasks. Moreover, we assume that the human is not fully dedicated to the robot control, but also involved in other activities, hence only able to interact...
Autonomous scene understanding by object classification today, crucially depends on the accuracy of appearance based robotic perception. However, this is prone to difficulties in object detection arising from unfavourable lighting conditions and vision unfriendly object properties. In our work, we propose a spatial context based system which infers object classes utilising solely structural information...
This paper adresses the problem of simultaneously estimating the state and the fault of nonlinear discrete-time stochastic systems in light of the unknown input filtering framework. The fault and unknown disturbances which may cause great estimate errors and even divergence of conventional filters, affect both the system state and the measurements. Inspired by the robust two stage Kalman filter for...
A wheeled mobile robotic system (WMR) is a kind modular robotic, nonlinear and the system subjected to nonholonomic constraints. It is impossible to obtain an exact dynamics model due to unknown parameters, unpredictable and irregular features, external disturbance. This paper proposes an adaptive robust controller to guide WMR to follow the desired trajectory. The cascade control system is applied...
Currently, the only mass-market service robots are floor cleaners and lawn mowers. Although available for more than 20 years, they mostly lack intelligent functions from modern robot research. In particular, the obstacle detection and avoidance is typically a simple physical collision detection. In this work, we discuss a prototype autonomous lawn mower with camera-based non-contact obstacle avoidance...
Reconstructing a 3D model of an unknown object via incremental registration of multiple appearance models is a challenging task. With availability of low cost sensors and robust algorithms, the field of visual scene reconstruction has advanced considerably. While these advances has enabled robust reconstructions of cluttered and unstructured scenes, an active 3D reconstruction of a generic handheld...
This paper considers the robust cooperative output regulation problem for a class of linear uncertain multi-agent systems. It is assumed that the agents in the system can only access incomplete measurements of the exosystem, and the local regulated error signals are not available to the agents to be used in control. Under these assumptions, the agents in the system cannot independently reconstruct...
When used as part of a hybrid controller, finite-memory strategies synthesizedfrom linear-time temporal logic (LTL) specifications rely on an accurate dynamics model in order to ensure correctness of trajectories. In the presence of uncertainty about the underlying model, there may exist unexpected trajectories that manifest as unexpected transitions under control of the strategy. While some disturbances...
In this paper the authors introduce a method focusing on the robustness improvement of the landmark tracking system for mobile robot operation in natural environments. We extract feature points from the data obtained by a stereo vision system with CenSurE (Center Surround Extremas for Realtime Feature Detection and Matching) used as a detector, and FREAK (Fast Retina Keypoint) as a descriptor. RANSAC...
Marine robotics is a rapidly growing field, with applications of both Autonomous Underwater Vehicles (AUV) and Autonomous Surface Vehicles (ASV) becoming extensive and within reach for many people. Presented is a low-cost design for an ASV, focusing on the ability for the average person with only little mechanical and electrical skills to assemble. The ASV also incorporates a winch into its design,...
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