A hybrid switched reactive-based visual servo control of 5-DOF robot manipulators for pick-and-place tasks

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The high-speed rotorcraft unmanned aerial vehicle path planning based on the biogeography-based optimization algorithm

A three-dimensional path planning method based on the biogeography-based optimization algorithm is presented for high-speed rotorcraft unmanned aerial vehicle which has a maximum speed of 20 m/s. In this study, a novel exponential artificial potential field is used to prevent saturation, for its peculiarity of smoothness and boundness. Several parameters, which can make a large influence to the result of path planning, are picked out and used to improve the process of planning. Biogeography-based optimization algorithm is first used to optimize the parameters of artificial potential fields, for its best performance in stability and speed. The algorithm has good stability and fast operation speed, which can realize the global path planning of multi-rotor aircraft well, verified by the simulation results

Towards Autonomous Selective Harvesting: A Review of Robot Perception, Robot Design, Motion Planning and Control

This paper provides an overview of the current state-of-the-art in selective harvesting robots (SHRs) and their potential for addressing the challenges of global food production. SHRs have the potential to increase productivity, reduce labour costs, and minimise food waste by selectively harvesting only ripe fruits and vegetables. The paper discusses the main components of SHRs, including perception, grasping, cutting, motion planning, and control. It also highlights the challenges in developing SHR technologies, particularly in the areas of robot design, motion planning and control. The paper also discusses the potential benefits of integrating AI and soft robots and data-driven methods to enhance the performance and robustness of SHR systems. Finally, the paper identifies several open research questions in the field and highlights the need for further research and development efforts to advance SHR technologies to meet the challenges of global food production. Overall, this paper provides a starting point for researchers and practitioners interested in developing SHRs and highlights the need for more research in this field.Comment: Preprint: to be appeared in Journal of Field Robotic

Towards adaptive and autonomous humanoid robots: from vision to actions

Although robotics research has seen advances over the last decades robots are still not in widespread use outside industrial applications. Yet a range of proposed scenarios have robots working together, helping and coexisting with humans in daily life. In all these a clear need to deal with a more unstructured, changing environment arises. I herein present a system that aims to overcome the limitations of highly complex robotic systems, in terms of autonomy and adaptation. The main focus of research is to investigate the use of visual feedback for improving reaching and grasping capabilities of complex robots. To facilitate this a combined integration of computer vision and machine learning techniques is employed. From a robot vision point of view the combination of domain knowledge from both imaging processing and machine learning techniques, can expand the capabilities of robots. I present a novel framework called Cartesian Genetic Programming for Image Processing (CGP-IP). CGP-IP can be trained to detect objects in the incoming camera streams and successfully demonstrated on many different problem domains. The approach requires only a few training images (it was tested with 5 to 10 images per experiment) is fast, scalable and robust yet requires very small training sets. Additionally, it can generate human readable programs that can be further customized and tuned. While CGP-IP is a supervised-learning technique, I show an integration on the iCub, that allows for the autonomous learning of object detection and identification. Finally this dissertation includes two proof-of-concepts that integrate the motion and action sides. First, reactive reaching and grasping is shown. It allows the robot to avoid obstacles detected in the visual stream, while reaching for the intended target object. Furthermore the integration enables us to use the robot in non-static environments, i.e. the reaching is adapted on-the- fly from the visual feedback received, e.g. when an obstacle is moved into the trajectory. The second integration highlights the capabilities of these frameworks, by improving the visual detection by performing object manipulation actions

Biomimetic Manipulator Control Design for Bimanual Tasks in the Natural Environment

As robots become more prolific in the human environment, it is important that safe operational procedures are introduced at the same time; typical robot control methods are often very stiff to maintain good positional tracking, but this makes contact (purposeful or accidental) with the robot dangerous. In addition, if robots are to work cooperatively with humans, natural interaction between agents will make tasks easier to perform with less effort and learning time. Stability of the robot is particularly important in this situation, especially as outside forces are likely to affect the manipulator when in a close working environment; for example, a user leaning on the arm, or task-related disturbance at the end-effector. Recent research has discovered the mechanisms of how humans adapt the applied force and impedance during tasks. Studies have been performed to apply this adaptation to robots, with promising results showing an improvement in tracking and effort reduction over other adaptive methods. The basic algorithm is straightforward to implement, and allows the robot to be compliant most of the time and only stiff when required by the task. This allows the robot to work in an environment close to humans, but also suggests that it could create a natural work interaction with a human. In addition, no force sensor is needed, which means the algorithm can be implemented on almost any robot. This work develops a stable control method for bimanual robot tasks, which could also be applied to robot-human interactive tasks. A dynamic model of the Baxter robot is created and verified, which is then used for controller simulations. The biomimetic control algorithm forms the basis of the controller, which is developed into a hybrid control system to improve both task-space and joint-space control when the manipulator is disturbed in the natural environment. Fuzzy systems are implemented to remove the need for repetitive and time consuming parameter tuning, and also allows the controller to actively improve performance during the task. Experimental simulations are performed, and demonstrate how the hybrid task/joint-space controller performs better than either of the component parts under the same conditions. The fuzzy tuning method is then applied to the hybrid controller, which is shown to slightly improve performance as well as automating the gain tuning process. In summary, a novel biomimetic hybrid controller is presented, with a fuzzy mechanism to avoid the gain tuning process, finalised with a demonstration of task-suitability in a bimanual-type situation.EPSR

Visual Servoing in Robotics

Visual servoing is a well-known approach to guide robots using visual information. Image processing, robotics, and control theory are combined in order to control the motion of a robot depending on the visual information extracted from the images captured by one or several cameras. With respect to vision issues, a number of issues are currently being addressed by ongoing research, such as the use of different types of image features (or different types of cameras such as RGBD cameras), image processing at high velocity, and convergence properties. As shown in this book, the use of new control schemes allows the system to behave more robustly, efficiently, or compliantly, with fewer delays. Related issues such as optimal and robust approaches, direct control, path tracking, or sensor fusion are also addressed. Additionally, we can currently find visual servoing systems being applied in a number of different domains. This book considers various aspects of visual servoing systems, such as the design of new strategies for their application to parallel robots, mobile manipulators, teleoperation, and the application of this type of control system in new areas

On the development and enhancement of artificial intelligence algorithms for swarm robots in real world applications

Swarm robotics is an area where using artificial intelligence (AI) can show a great deal of improvement. Obstacle avoidance, object detection, mapping and navigation are some the major algorithms required for successful execution of various tasks in the field of robotics. There is a challenge in applying these algorithms in a manner that swarm robots can use effectively. These five areas can be further researched to provide a platform for real world applications. This research aims to tackle the challenges involved in applying the aforementioned algorithms to swarm robotics and comparing the results with single robot systems. These techniques can be optimized by leveraging the advantage of swarm robots communication and scalability. The proposed algorithms were tested and validated using swarm robots along with profiling and simulations. For obstacle avoidance, two algorithms were devoloped. The first used a novel and modified force field method and the second used artificial neural networks (ANN). The results showed that the modified force field method performed better for static environments while ANNs worked better for dynamic environments. For object detection, the proposed algorithm uses an image classifier developed using ANN. The image classifier was trained to identify blocks of various colours using a convolutional neural network technique. This algorithm was then applied to swarm robotics using two proposed methods and results showed that multiple robots viewing objects from different angles provided better results as compared to single robot systems. This was validated with a 97% accuracy. In two dimension (2D) mapping, the proposed algorithm was developed using simultaneous localization and mapping (SLAM). The results showed that a single robot can require upto 3.5x more time for covering a given area compared to a swarm size of ten robots. This research shows a great deal of contribution in applying swarm robotics for surveilance purposes by showcasing the ability for swarm robotics to coordinate and execute the required task in an efficient time frame. The proposed three-dimension (3D) mapping algorithm used octomaps and occupancy grids to map out an image taken from a camera mounted on swarm robots. The images were obtained from various angles using multiple swarm robots. AI algorithms with a focus on swarm robotics are developed and enhanced for real world applications including fire-fighting, surveillance, fault analysis and construction. Results showed that swarm robots were able to complete a given task by up to six times faster as compared to a single robot. The overall contribution of this research lays a platform for further applications by showcasing the effectiveness of robotic algorithms in a swarm robot environment.Heriot-Watt University Fee Scholarshi

Control of a single-link flexible manipulator

RESUMEN: En aplicaciones de robótica es común utilizar elementos mecánicos y eslabones rígidos. Esto se realiza así especialmente porque simplifica enormemente el modelado matemático, así como la obtención de controladores dinámicos y cinemáticos. Todo esto conlleva el poder obtener manipuladores que permiten una elevada precisión en el movimiento y en el posicionamiento. Sin embargo, cada día es más frecuente que los robots interaccionen con los operadores humanos en diferentes tareas. Ejemplos de esto pueden encontrarse en las aplicaciones industriales donde los robots colaborativos tienen mucho éxito, pero también en aplicaciones médicas y de servicio a personas discapacitadas, donde un robot puede hacer tareas de atención que conlleven una interacción con la persona. Es en estos campos de interacción con las personas donde un robot que incorpore segmentos mecánicos flexibles, tales que el contacto con las personas sea totalmente inocuo, presenta un futuro de interés (además de las aplicaciones espaciales). En el presente trabajo se analizarán y diseñarán distintos controladores basados en redes neuronales, lógica difusa y control GPI con el objetivo de evaluar su funcionamiento en un sistema que incluya eslabones mecánicos flexibles.ABSTRACT: In robotics applications it is common to use mechanical elements and rigid links. This is done especially because it greatly simplifies mathematical modeling, as well as obtaining dynamic and kinematic controllers. All this leads to manipulators that allow high precision in movement and positioning. However, it is becoming increasingly common for robots to interact with human operators in different tasks. Examples of this can be found in industrial applications where collaborative robots are very successful, but also in medical and service applications for disabled people, where a robot can perform care tasks that involve interaction with the person. It is in these fields of interaction with people that a robot incorporating flexible mechanical segments, such that contact with people is completely harmless, presents a future of interest (in addition to space applications). In this work, different controllers based on neural networks, fuzzy logic and GPI control will be analyzed and designed in order to evaluate their performance in a system including flexible mechanical links.Grado en Ingeniería en Electrónica Industrial y Automátic

Advanced Strategies for Robot Manipulators

Amongst the robotic systems, robot manipulators have proven themselves to be of increasing importance and are widely adopted to substitute for human in repetitive and/or hazardous tasks. Modern manipulators are designed complicatedly and need to do more precise, crucial and critical tasks. So, the simple traditional control methods cannot be efficient, and advanced control strategies with considering special constraints are needed to establish. In spite of the fact that groundbreaking researches have been carried out in this realm until now, there are still many novel aspects which have to be explored