Rev 4540 Rev 4685
Line 43... Line 43...
43   43  
44 %---------------------------------------------------------- 44 %----------------------------------------------------------
45 % THIS IS THE PLACE FOR ABSTRACT 45 % THIS IS THE PLACE FOR ABSTRACT
46   46  
47 \begin{abstract} 47 \begin{abstract}
48 Wind vane sensor is classical meteorology instrument used for measuring wind directions. Wind directions are reported relatively to the magnetic north of weather station coordinates. Therefore precise directional adjustment of the sensor is needed. We introduced a self calibrating wind vane sensor which report the wind direction data without adjustments. Therefore it is more tolerant to the installation mistakes. 48 Wind vane sensor is classical meteorology instrument used for measuring wind directions. Wind directions are reported relatively to the magnetic north of weather station coordinates. Therefore precise directional adjustment of the sensor is needed. We introduced a self calibrating wind vane sensor which reports the wind direction data without adjustments. Therefore it is more tolerant to the installation mistakes.
49 \end{abstract} 49 \end{abstract}
50   50  
51 %---------------------------------------------------------- 51 %----------------------------------------------------------
52 % THIS IS THE PLACE FOR KEYWORDS 52 % THIS IS THE PLACE FOR KEYWORDS
53 \begin{keywords} 53 \begin{keywords}
Line 57... Line 57...
57 %---------------------------------------------------------- 57 %----------------------------------------------------------
58 % HERE WRITE YOUR PAPER 58 % HERE WRITE YOUR PAPER
59   59  
60 \section{Introduction} 60 \section{Introduction}
61   61  
62 Wind vane is classical measuring device in meteorology. It is used for wind direction sensing at automatic weather stations. The classical construction of such sensor consist a analogue resistive position sensing or "digital" magnetic leaf switch contacts. Both discrete and continuous signal sensing approach measure the position of wind vane relatively to the local word coordinates. Although the wind direction is reported relatively to the magnetic north of weather station location. Therefore the precise direction adjustment of wind vane sensor is mandatory for achieving consistent and reliable wind direction data. 62 Wind vane is classical measuring device in meteorology. It is used for wind direction sensing at automatic weather stations. The classical construction of such sensor consist a analogue resistive position sensing or "digital" magnetic reed switch contacts \cite{wind_vane}. Both discrete and continuous signal sensing approach measure the position of wind vane relatively to the local word coordinates. Although the wind direction is occasionally reported relatively to the magnetic north of weather station location \cite{wind_direction}. Therefore the precise direction adjustment of wind vane sensor is mandatory for achieving consistent and reliable wind direction data.
63   63  
64 But we could use the state of the art technology consisting of MEMS magnetometer sensors which could directly report the wind vane position relatively to the magnetic north. This concept of wind vane is unique because it report continuous values which allows reliable auto-diagnostics of sensing element. 64 But we could use the state of the art technology consisting of MEMS magnetometer sensors which could directly report the wind vane position relatively to the magnetic north. This concept of wind vane is unique because it reports continuous values which allows reliable auto-diagnostics of sensing element.
65   65  
66 \section{Design evolution} 66 \section{Design evolution}
67   67  
68 The construction of the wind vane should be special because the sensing element in rotor part. The sensor is MAG01A module from MLAB electronic development system. This sensor is a I2C bus based sensor which requests four signals - Power, Ground, Data and clock. 68 The construction of the wind vane should be special because the sensing element in rotor part. The sensor is MAG01A module from MLAB electronic development system. This sensor is a I2C bus based sensor which requests four signals - Power, Ground, Data and clock.
69   69  
70 Therefore the one of main design problem is signal conduction from rotary part to the stator. A commercially available slip-rings were used as solution for that. 70 Therefore the one of main design problem is signal conduction from rotary part to the stator. A commercially available slip-rings were used as solution for that.
71 The used slip-ring is shown in the figure X. 71 The used slip-ring is shown in the figure \ref{fig:slip_ring}.
72   72  
73   73  
74 The integration of such device in to the wind vane construction needs special shape of the rotor and the stator part. A 3D printing technology is ideal for that task. We decided to use the Fused deposition modelling (FDM) additive manufacturing technology as a best candidate for anemometer sensor design. The main reason for that decision was a fact, that this type of 3D printing technology is widely accessible and is of sufficient quality to build the sensor body which could withstand the mechanical and weather stresses in outdoor. The second reason is the fact that this type of technology is relatively cheap in comparison to other additive manufacturing methods. 74 The integration of such device in to the wind vane construction needs special shape of the rotor and the stator part. A 3D printing technology is ideal for that task. We decided to use the Fused deposition modelling (FDM) additive manufacturing technology as a best candidate for anemometer sensor design. The main reason for that decision was a fact, that this type of 3D printing technology is widely accessible and is of sufficient quality to build the sensor body which could withstand the mechanical and weather stresses in outdoor. The second reason is the fact that this type of technology is relatively cheap in comparison to other additive manufacturing methods.
75 But there also exist technological limits due to the fact that not all shapes could be 3Dprinted. The problematic geometry include overhanging surfaces or large number of very small details in printed volume. 75 But there also exist technological limits due to the fact that not all shapes could be 3Dprinted. The problematic geometry include overhanging surfaces or large number of very small details in printed volume.
76   76  
77 The design of wind vane therefore must have special construction which allows reliable printing without costly model specific G-code tweaking. Which is common practice to print poorly designed model on lower quality printers. 77 The design of wind vane therefore must have special construction which allows reliable printing without costly model specific G-code tweaking. Which is common practice to print poorly designed model on lower quality printers.
78   78  
79 \begin{figure}[ht] 79 \begin{figure}[ht]
80 \begin{center} 80 \begin{center}
81 \resizebox{\linewidth}{!}{\includegraphics{./img/WINDGAUGE01A_Assembly.png}} 81 \resizebox{\linewidth}{!}{\includegraphics{./img/WINDGAUGE01A_Assembly.png}}
82 \caption{A sample of printable rocket design. (Experimentally printed from red ABS)} 82 \caption{A magnetic sensor wind vane assembly.}
83 \label{fig:printed_parts} 83 \label{fig:printed_parts}
84 \end{center} 84 \end{center}
85 \end{figure} 85 \end{figure}
86   86  
87   87  
88 \subsection{Wind vane rotor} 88 \subsection{Wind vane rotor}
89   89  
90 The rotor part of the wind vane houses the magnetometer sensor. The MAG01A sensor module is triple axis one chip solution for magnetic orientation measurement. Sensor module is mounted directly in rotation center of wind wane, this position was choosed as the best option to optimizing the overall sensor dimensions. 90 The rotor part of the wind vane houses the magnetometer sensor. The MAG01A sensor module is triple axis one chip solution for magnetic orientation measurement. Sensor module is mounted directly in rotation center of wind wane, this position was selected as the best option to optimizing the overall sensor dimensions. The digital magnetometer signals are guided to the stator via slip rings.
91   -  
92 \subsection{Stator and holder} -  
93   -  
94   91  
-   92 \begin{figure}[ht]
-   93 \begin{center}
-   94 \resizebox{\linewidth}{!}{\includegraphics{./img/slip_ring.jpg}}
-   95 \caption{A sample of printable rocket design. (Experimentally printed from red ABS)}
-   96 \label{fig:slip_ring}
-   97 \end{center}
-   98 \end{figure}
95   99  
-   100 Hence electrical signal chain in the sensor is very simple and reliable.
96   101  
97 \subsection{Software data processing} 102 \subsection{Software data processing}
98   103  
99 The triple axis magnetometer sensor is read directly by pymlab sensor library, this library is primarily focused on I²C based sensor data reading. 104 The triple axis magnetometer sensor is read directly by pymlab sensor library, this library is primarily focused on I²C based sensor data reading.
100 Output of the magnetometer hardware driver is a uncalibrated vector of magnetic field. Therefore a data calibration is needed to obtain a wind direction data. 105 Output of the magnetometer hardware driver is a uncalibrated vector of magnetic field. Therefore a data calibration is needed to obtain a wind direction data.
101   106  
102   107  
103   108  
104 \section{Conclusion} 109 \section{Conclusion}
105   110  
106 A considerable amount of development work resulted in a partially usable 3D printable rocket model. The FDM technology was proven to be a right selection. But large amount of development work will be needed to finish the rocket design to the level which will allow an easy usage by students. 111 The 3D printable design of the wind vane housing was successfully developed. Measuring principle based on the magnetometer sensor was also verified although long time outdoor testing in different weather conditions is needed.
107 Specifically the following problems must be resolved before widespread usage: -  
108   112  
109 \begin{itemize} -  
110 \item Reliable recovery system -  
111 \item Easily producible rocket engine design -  
112 \item On board avionics which could universally provide power source, recovery and measurement functions for any student payload. -  
113 \end{itemize} -  
114   113  
115 \section*{Acknowledgements} 114 \section*{Acknowledgements}
116   115  
117 The research presented in this proposal was not supported from any grant or from public resources. It was funded exclusively by Universal Scientific Technologies s.r.o. company. 116 The research presented in this proposal was not supported from any grant or from public resources. It was funded exclusively by Universal Scientific Technologies s.r.o. company.
118   117  
119 %---------------------------------------------------------- 118 %----------------------------------------------------------
120 % THIS IS THE PLACE FOR REFERENCES 119 % THIS IS THE PLACE FOR REFERENCES
121 \begin{thebibliography}{9} 120 \begin{thebibliography}{9}
122 \bibitem{rocket_sounding} 121 \bibitem{wind_vane}
123 NASA Sounding Rockets User Handbook, Sounding Rockets Program Office,Sub-orbital and Special Orbital Projects Directorate -  
124 NASA Goddard Space Flight Center,Wallops Flight Facility, 23.3.2016 [online] http://sites.wff.nasa.gov/code810/files/SRHB.pdf 122 The ULTIMETER PRO Anemometer/Wind Vane, 23.3.2016 [online] http://www.peetbros.com/shop/category.aspx?catid=35
125 \bibitem{grid_fins} 123 \bibitem{wind_direction}
126 Zaloga, Steve (2000). The Scud and Other Russian Ballistic Missile Vehicles. New Territories, Hong Kong: Concord Publications Co. ISBN 962-361-675-9. -  
127 \bibitem{openscad} -  
128 Marius Kintel et al. 23.3.2016 [Online] 124 Computing Magnetic Wind Direction, 23.3.2016 [online] http://www.nws.noaa.gov/asos/magwind.htm
129 http://www.openscad.org/about.html -  
130 \end{thebibliography} 125 \end{thebibliography}
131   126  
132   127  
133 %---------------------------------------------------------- 128 %----------------------------------------------------------
134 % THIS IS THE PLACE FOR AUTHOR CV 129 % THIS IS THE PLACE FOR AUTHOR CV