IoA Experience on Aerial Delivery

This paper presents some selected results of the project SKY MULE which is conducted in the Institute of Aviation (IoA) in Warsaw. The aim of this research is to design and construct an automatic trajectory controller for an unmanned parafoil and payload system to make it usefull for precise aerial delivery tasks. SKY MULE’s payload is composed of two connected but separable modules: the control module consisting electronic and electro mechanical equipment, and cargo module (various dimensions and shapes of that module are allowable). SKY MULE’s motion is controlled by two control cords being operated by electro – mechanical servo actuators with DC motors and PWM controllers. Example results of laboratory tests carried on these units is presented. Control unit is designed with PC-104 computer as a central sub-system. It is provided with software for pre-programming the site of destination and flight trajectory. The attention is focused mainly on robust control algorithms designed to assure stable realization of SKY MULE’s desired trajectory, even for large changes of system parameters, occured due to different shapes and parameter changes of cargo modules. Feedback signals are provided by measuring unit based on MEMS type sensors integrated with GPS receiver. The system is controlled in two alternative modes: autonomously, by automatic system, or remotely, by a human operator. 1.0 INTRODUCTION Problems of precise aerial delivery appeared in the Institute of Aviation in Warsaw (IoA) some years ago as an idea of unmanned parafoil and payload system named SKY MULE [6], [8]. This system was planned to be controlled in two alternative modes: autonomously, by automatic system, or remotely, by a human operator. Thus, general idea of the project was to design and construct an automatic flight control and trajectory stabilizing system for SKY MULE’s mission. Basic structure of this vehicle is depicted on Figure 1 with the following denotations: {E,N,H} reference system being in quiescentstate towards the Earth, (x,y,h) SKY MULE’s position determined in {E,N,H} reference system, V flight velocity vector, Vh descending rate vector (projection of V onto vertical line), Vp horizontal velocity vector (projection of V onto horizontal {E,N} plane), ΨT track angle (0 ≤ ΨT < 2π). Solutions we are looking for are adapted to the typical product (parafoil) manufactured by the Polish company AirPol Sp. z.o.o. Typical parameters of such parafoil, determined for calm air conditions, are listed in Table 1 [8]. Motion of SKY MULE’s wing shaped parafoil and payload unit is controlled by two control cords (Figure 1) being operated by two electro – mechanical actuators, each one for one control cord (“right” and “left” control signals uR, uL represent lengths of right and left control cord reductions respectively). The structure of payload is modular – it is composed of two connected and separable parts (modules): the control module consisting electronic and electro mechanical equipment, and cargo module. It is assumed that various dimensions and shapes of cargo module will be allowable. RTO-MP-AVT-133 4 1 UNCLASSIFIED/UNLIMITED UNCLASSIFIED/UNLIMITED Krawczyk, M.; Graffstein, J.; Masłowski, P. (2006) IoA Experience on Aerial Delivery. In Fluid Dynamics of Personnel and Equipment Precision Delivery from Military Platforms (pp. 4-1 – 4-10). Meeting Proceedings RTO-MP-AVT-133, Paper 4. Neuilly-sur-Seine, France: RTO. Available from: http://www.rto.nato.int/abstracts.asp. Report Documentation Page Form Approved OMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE 01 OCT 2006 2. REPORT TYPE N/A 3. DATES COVERED 4. TITLE AND SUBTITLE IoA Experience on Aerial Delivery 5a. CONTRACT NUMBER