This paper is devoted to a system for aerial manipulation, composed of a helicopter and an industrial manipulator. The usage of an industrial manipulator is motivated by practical applications which were identified in different cooperation projects with the industry. We address the coupling between manipulator and helicopter and show that even in case when we have an ideal controller for manipulator and a highperformance controller for helicopter, an unbounded energy flow can be generated by internal forces between helicopter and manipulator if both controllers are used independently. To solve this problem we propose a new kinematical coupling for control by introducing an additional manipulation DoF realized by helicopter rotation around its yaw axis. The new experimental setup and required modifications in the manipulator controller for this purpose are described. Further, we propose dynamical coupling which is implemented by modification of the helicopter controller feeding the interaction force/torque, measured between manipulator base and fuselage, directly to the actuators of the rotor blades. At the end, we present experimental results for aerial manipulation and their analysis.

In this paper we describe a system for aerial manipulation composed of a helicopter platform and a fully actuated seven Degree of Freedom (DoF) redundant industrial robotic arm. We present the first analysis of such kind of systems and show that the dynamic coupling between helicopter and arm can generate diverging oscillations with very slow frequency which we called phase circles. Based on the presented analysis, we propose a control approach for the whole system. The partial decoupling between helicopter and arm - which eliminates the phase circles - is achieved by means of special movement of robotic arm utilizing its redundant DoF. For the underlying arm control a specially designed impedance controller was proposed. In different flight experiments we showcase that the proposed kind of system type might be used in the future for practically relevant tasks. In an integrated experiment we demonstrate a basic manipulation task - impedance based grasping of an object from the environment underlaying a visual object tracking control loop.

In this paper, we present a multi-sensor system for automatic landing of fixed wing UAVs. The system is composed of a high precision aircraft controller and a vision module which is currently used for detection and tracking of runways. Designing the system we paid special attention to its robustness. The runway detection algorithm uses a maximum amount of information in images and works with high level geometrical models. It allows detecting a runway under different weather conditions even if only a small part is visible in the image. In order to increase landing reliability under sub-optimal wind conditions, an additional loop was introduced into the altitude controller. All control and image processing is performed onboard. The system has been successfully tested in flight experiments with two different fixed wing platforms at various weather conditions, in summer, fall and winter.

The use of unmanned aerial systems (UAS) is growing in research and civil applications. Advancing technology offers huge potential which is just starting being used. We present a method to have a helicopter UAS interacting with the environment physically. This basic technology, which includes high precision control and a vision system can be adapted for different in situ measurement tasks. Applications cover a wide range from placement of sensors or direct measurements to sampling. While UAS systems get more complex, we describe a way of interacting with a them by means of an interactive control framework, which can also include other systems and sensors.

Directional reflection properties are unique for every surface. These values are important for many remote sensing applications since large errors are introduced in remote sensing products when neglecting viewing geometry influences. Measurements of directional reflectance values are required as a basis for further research. We present a system and procedures to calculate angular dependent reflection properties, including the use of measured incident diffuse radiation in an iterative algorithm. Furthermore, validation of the measured data by fitting a model is presented.

The advances in the capabilities of sensors and methods used for remote sensing the earth call for taking into account angular effects. The effect is described through the ¿bidirectional reflectance distribution function¿ (BRDF). For most applications BRDF models are used. To validate such models and for in-flight calibration purposes the measurement of BRDF of natural surfaces is necessary. Most of the methods used to measure angular reflection properties in the past had to use interpolation or smoothing algorithms in the data processing. These computations influence the resulting BRDF. We present the instrument GRADIS (Ground Reflectance Angular Distribution Investigation System) which avoids this problem by using a new principle for acquiring the data. Several measurement campaigns were conducted for basic measurements of different surfaces and for calibration measurements of airborne instruments.