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In this article, a complete and original method to analyse both the epitrochoidal and the hypotrochoidal rotary machines is presented. The internal trochoidal machines consist of two rotors: the first rotor is an envelope of a trochoid, the second rotor is its conjugate. In particular, in this article, the profiles of the trochoidal rotor and its conjugate are expressed by original and particularly synthetic equations using a method based on the theory of gearing. Then the geometry of these machines is completely defined by the choice of four non-dimensional parameters. Once these parameters are selected, the geometric and kinematic characteristics of the rotor profiles are obtained in an original analytic form; hence, the main theoretical performance indexes are computed by a proper method. The results of the analysis allow us to choose the best geometric configuration for a specific application.

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In this study an original analysis of the geometric design of a particular internal rotary machine and an investigation on its theoretical performances are presented. The first part of the work is focused on the geometry of the machine, characterized by more complex rotor profiles compared with the classical epitrochoidal pumps. Suitable parameters are pointed out to completely define the geometry of the machine. In the second part of the study, proper indices are set and evaluated as functions of the design parameters, in order to evaluate the performance of the machine. Finally a specific configuration of the considered pump is compared with the conventional trochoidal pumps in terms of flow-rate indices. The analysis performed allows one to highlight the basic advantages and drawbacks of this original design in comparison with the classical trochoidal profiles and can be used as a basis for CAD/CAE (Computer-Aided Design and Engineering) or experimental studies.

Multirotors are well suited for application tasks such as surveillance and exploration of otherwise inaccessible areas. Standard quadrotors have limitations in their possible configurations due to their underactuation. For this reason, some spatial configurations are not possible, such as hovering while maintaining a nonhorizontal orientation. This paper presents an overactuated quadrotor platform with double axes tilting propellers. The peculiarity of the proposed platform is that, beside the usual control on the four propellers, it allows to tilt each arm where motors are mounted along two independent axis. The resulting number of control inputs is 12, allowing a higher number of stable configurations with respect to traditional quadrotors. As a result, it can assume spatial orientations that are not possible for traditional quadcopters, enabling the possibility to deal with obstacles that would generally impede the motion of normal quadcopters. This feature allows to potentially explore a larger space. This paper presents the design and modeling of the quadrotor. Numerical simulations are carried out to show the effectiveness of the proposed solution.