Testing and selection of electrical actuators for multi-rotor flying robot

Artykuł omawia metody doboru elementów składających się na jednostkę napędową wielowirnikowego robota latającego. Przedstawiono wymagania, jakie powinny spełniać badane jednostki napędowe. Praca zawiera przykładowe wyniki testów przeprowadzonych na hamowni oraz wyciągnięte na ich podstawie wnioski. Przeprowadzone badania pokazują, że nie jest konieczna budowa dedykowanych regulatorów obrotów, czy też modyfikowanie gotowych układów, by mogły być one stosowane jako napęd do wielowirnikowych robotów latających. Na podstawie przeprowadzonych testów zaobserwowano, że pomimo zastosowania zestawów składających się z identycznych elementów, otrzymane charakterystyki znacząco się różnią. Prowadzi to do trudności w stabilizacji robota podczas lotu, a także skraca jego czas pracy.This paper discusses selection criteria and assumptions for multi-rotor flying robot actuators. Results of tests for units made of electrical (high rpm) motors, propellers and rotation speed governors are presented in Section 2 (Fig. 1). Driving units were selected by three tests (Section 4). The first one allowed specifying the maximum thrust of a tested driving unit (Fig. 5). The second test simulated the work of a driving unit during stabilizing movements of the flying platform (Fig. 6). The purpose was to determine the quadrocopter reaction rate to changes in the control signal. The third test was related to simulating tilting of the platform while maneuvering (Fig. 7). In another series of tests the frequency of the pulse speed governor was increased from 45 to 400 Hz (Fig. 8). The conclusions are based on the tests results. The general one is that the typical governors can be used in multi-rotor UAV without particular modifications and there is no need to design customized governors. However, it was observed that driving units made of elements having identical nominal parameters, had quite different regulatory characteristics (Fig. 10). Due to it, stabilization was more difficult and, at the same time, the power consumption increased. The experiments were conducted with a dedicated measurement system (Fig. 4, Section 3). The representative number of motors, propellers and rotation speed governors was tested and compared in order to select the optimal driving unit, satisfying the initial assumptions and criteria

The influence of drive unit on measurement error of ultrasonic sensor in multi - rotor flying robot

The article describes the impact of the drive units on the data obtained from ultrasonic sensors. These sensors are mounted on the multi-rotor flying robot. In experiments, previously designed ultrasonic sensor was used. On purpose of this study special testbed, consisted of a dynamometer and manipulator from KUKA company was created. In the research the influence of the location of the drive unit on the aforementioned sensor was measured. For this purpose, the sensor was placed in front, behind and in the line of the rotating propeller. The obtained results allowed to identify places where there are the least interference from the drive units that affect the ultrasonic sensor. Thanks to this, the results of measurements of the obstacles distance from a flying robot were improved

A distributed control system for multirotor aerial platforms

In a variety of microavionics systems for multirotor flying platforms, only a few are designed as open hardware and software solutions, suitable for scientific research. In this paper, we present our own approach – a modular, distributed control system. The developed solution is adaptive for new tasks, unified between each module and designed in an innovative hardware manner. The presented solution has been already developed in various designs of multirotor platforms intended for different applications

Comparison of different methods of flight data logging used in multirotor UAVs

This paper describes the comparison of different methods of flight data logging in multirotor unmanned aerial vehicles. Solutions used in commercial avionics systems are presented and compared with the current design developed by authors. Based on the literature and analyzed examples, requirements for two separate logging systems are formulated. This approach allowed to modify current solutions and develop new methods for the high frequency data logging. Three different memory storages were considered for this task - SD card, RAM and external NAND Flash. Based on the theoretical calculations, developed prototypes and performed experiments, the best solution was selected

An adequate mathematical model of four-rotor flying robot in the context of control simulations

In this paper a model of the dynamics of four-rotor flying robot is described in details. Control design must be preceded by the modeling and subsequent analysis of the robot behavior in simulator. It is therefore necessary to develop the mathematical model as accurate as it is possible. The paper contains a detailed derivation of the mathematical model in the context of physics laws affecting the quadrocopter. The novelty of presented notation is an extention of Coriolis forces in linear acceleration and the gyroscopic effect on angular acceleration. In the validation phase, the mathematical model was verified with the use of proposed control algorithms. Simulation studies have demonstrated the adequacy of a MATLAB model to properly reflect the real quadrocopter dynamics. This would allow for its use in the simulator and afterwards to implement and verify of control laws on the real fourrotor flying robot

Bürgerwissenschaftliche Forschungsansätze in Medizin und Gesundheitsforschung. Ausgewählte Begriffe mit Fokus auf den Beteiligungsgrad

In den Bürgerwissenschaften, auch bekannt unter dem englischen Begriff Citizen Science, existiert eine Vielzahl an Forschungsansätzen und Methoden. Während diese in vielen wissenschaftlichen Disziplinen gut etabliert sind, finden sich augenscheinlich relativ wenige davon in der medizinischen und Gesundheitsforschung. Allerdings zeigt ein Blick in die Praxis, dass bürgerwissenschaftliche Ansätze in der Medizin und Gesundheitsforschung durchaus praktiziert werden, jedoch häufig unter anderen Namen. Der Artikel bietet aus interdisziplinärer Perspektive einen (selektiven) Überblick über Begriffe, reflektiert diese und die dahinterstehenden Methoden und diskutiert sie vergleichend. Im Fokus steht dabei der Grad der Beteiligung der Bürger*innen bzw. Patient*innen an wissenschaftlicher Forschung

In vivo margin assessment during partial mastectomy breast surgery using Raman spectroscopy, Cancer Res.

Abstract We present the first demonstration of in vivo collection of Raman spectra of breast tissue. Raman spectroscopy, which analyzes molecular vibrations, is a promising new technique for the diagnosis of breast cancer. We have collected 31 Raman spectra from nine patients undergoing partial mastectomy procedures to show the feasibility of in vivo Raman spectroscopy for intraoperative margin assessment. The data was fit with an established model, resulting in spectral-based tissue characterization in only 1 second. Application of our previously developed diagnostic algorithm resulted in perfect sensitivity and specificity for distinguishing cancerous from normal and benign tissues in our small data set. Significantly, we have detected a grossly invisible cancer that, upon pathologic review, required the patient to undergo a second surgical procedure. Had Raman spectroscopy been used in a real-time fashion to guide tissue excision during the procedure, the additional reexcision surgery might have been avoided. These preliminary findings suggest that Raman spectroscopy has the potential to lessen the need for reexcision surgeries resulting from positive margins and thereby reduce the recurrence rate of breast cancer following partial mastectomy surgeries. (Cancer Res 2006; 66(6): 3317-22