Pepper to fall: a perception method for sweet pepper robotic harvesting

Intelligent Service Robotics - In this paper we propose a robotic system for picking peppers in a structured robotic greenhouse environment. A commercially available robotic manipulator is equipped...     

Visual Target Localization with the Spincopter

The goal of the Spincopter project was to design an energy efficient aircraft capable of autorotation glide that could be used for both indoor and outdoor surveillance. This paper demonstrates how to utilize the self-rotating capability of the Spincopter in order to acquire a 3D image of its environment and localize predefined object(s). The omnidirectional capabilities of such an UAV extends the otherwise very limited field of view of conventional cameras usually used for aerial photography and surveillance. The paper presents the theoretical background and the actual implementation of such a system. It presents the resulting images and offers a brief survey of the image quality.     

Hybrid Adaptive Control for Aerial Manipulation

This paper presents a control scheme to achieve dynamic stability in a mobile manipulating unmanned aerial vehicle (MM-UAV) using a combination of Gain scheduling and Lyapunov based model reference adaptive control (MRAC). Our test flight results indicate that we can accurately model and control our aerial vehicle when both moving the manipulators and interacting with target objects. Using the Lyapunov stability theory, the controller is proven to be stable. The simulation results showed how the MRAC is capable of stabilizing the oscillations produced from the unstable PI-D attitude control loop. Finally a high level control system based on a switching automaton is proposed in order to ensure the saftey of the aerial manipulation missions.     

Our experience with the use of cerium sulphadiazine in the treatment of extensive burns

The development of the burn disease with infection as the most important complication represents still a major problem in burn patients. With the introduction of the method of early surgical excision of the Af1p4r with immediate grafting in major burns, improved survival has been achieved, particularly in children. However, especially in adults, early massive excisions did not prove to be of much benefit for survival. In these cases, more-or-less sequential staged excisional procedures have been introduced by many renown burn surgeons. In 1976 Monafo et al. presented the cerium nitrate-silver sulphadiazine cream (CSD) combination for topical therapy. The addition of 2.2% of the rare earth metal cerium salt to silversulphadiazine causes the formation of a relatively hard, yellow, leather-like eschar with excellent resistance to infection and good long-term adherence to the burn wound. This allows the surgeon to perform late tangential excision and immediate autografting thus decreasing the open wound size and the rate of severe infections originating in the burn wound itself. We report our experience with the treatment of 20 patients with deep burns exceeding 20% of the BSA with cerium nitrate-silver sulphadiazine cream compared with a similar group of burn patients treated by silver sulphadiazine cream alone. CSD proved to be safe and effective in the treatment of deep and extensive burns. Its advantages include easy and painless application and removal, turning the necrotic skin to yellow, and a leathery crust with good resistance to infection, thus enabling later, or staged, sequential excisions in cases where early massive excisions are not possible.     

Modeling and Control of MM-UAV: Mobile Manipulating Unmanned Aerial Vehicle

Compared to autonomous ground vehicles, UAVs (unmanned aerial vehicles) have significant mobility advantages and the potential to operate in otherwise unreachable locations. Micro UAVs still suffer from one major drawback: they do not have the necessary payload capabilities to support high performance arms. This paper, however, investigates the key challenges in controlling a mobile manipulating UAV using a commercially available aircraft and a light-weight prototype 3-arm manipulator. Because of the overall instability of rotorcraft, we use a motion capture system to build an efficient autopilot. Our results indicate that we can accurately model and control our prototype system given significant disturbances when both moving the manipulators and interacting with the ground.     

Spincopter Wing Design and Flight Control

This paper presents dynamical properties of an unmanned aerial vehicle (UAV), called spincopter. The vehicle structure is based on two wings that are forced in rotation (spinning) by propulsion system formed of two propellers. Based on devised dynamical model, that reveals inherent stability of the vehicle, composition of control algorithms for vertical and horizontal movement is proposed. Due to the specific configuration of the propulsion system, movement in horizontal direction is produced by pulsations in rotational speed of propulsion motors. An analysis of influence that such a configuration has on the vehicle dynamics is given. Finally, design recommendations for rotational wings are elaborated, based on extensive simulations of spincopter by using X-Plane® software package.     

Hardware-in-the-Loop Verification for Mobile Manipulating Unmanned Aerial Vehicles

A hardware-in-the-loop test rig is presented to bridge the gap between basic aerial manipulation research and the ability of flying robots to perform tasks such as bridge repair, agriculture care, container inspection and other applications requiring interaction with the environment. Unmanned aerial vehicles have speed and mobility advantages over ground vehicles and can operate in 3-dimensional workspaces. In particular, the usefulness of these capabilities is highlighted in areas where ground robots cannot reach or terrains they are unable to navigate. However, most UAVs operating in near-earth or indoor environments still do not have the payload capabilities to support multi-degree of freedom manipulators. We present a rotorcraft emulation environment using a 7 degree of freedom manipulator. Since UAVs require significant setup time and to avoid potential crashes, our test and evaluation environment provides repeatable experiments and captures reactionary forces experienced during ground interaction. Recent experiments in insertion tests are presented. The lessons learned from these experiments will be ported onto an actual air vehicle with manipulator.     

Decentralized planning and control for UAV–UGV cooperative teams

In this paper we study a symbiotic aerial vehicle-ground vehicle robotic team where unmanned aerial vehicles (UAVs) are used for aerial manipulation tasks, while unmanned ground vehicles (UGVs) aid and assist them. UGV can provide a UAV with a safe landing area and transport it across large distances, while UAV can provide an additional degree of freedom for the UGV, enabling it to negotiate obstacles. We propose an overall system control framework that includes high-accuracy motion planning for each individual robot and ad-hoc decentralized mission planning for complex missions. Experimental results obtained in a mockup arena for parcel transportation scenario show that the system is able to plan and execute missions in various environments and that the obtained plans result in lower energy consumption.