A compliance modeling method of flexible rotary joint for collaborative robot using passive network synthesis theory

Collaborative robots have become a research focus because of their wide applications. However, the previous compliance design method of the flexible rotary joint for collaborative robot mainly relied on experience of designers, and “trial and error” method is usually adopted, no feasible and systematic theory for the designer to select numerical value and series-parallel connection mode of the springs and dampers for the flexible rotary joint. Thus, developing a feasible compliance modeling theory to guide the design of the flexible rotary joint is a particularly challenging task. The main contribution of this paper is to present a novel and effective compliance modeling theory of the flexible rotary joint for collaborative robot based on electrical and mechanical passive network synthesis, to provide theoretical and systematic guidances for compliance design of the flexible rotary joint. First, inerter element is introduced into the mechanical system, and the compliance of the flexible rotary joint is expressed as an angular velocity admittance function using electrical and mechanical network analogy. Then, by passive network synthesis theory, the three kinds of compliance realization forms of rational function and four-element compliance realization conditions of biquadratic function for the flexible rotary joint are given using inerters, springs, and dampers. Moreover, numerical examples and simulations are conducted to illustrate effectiveness of the proposed compliance realization method. Finally, discussions are given to illustrate advantages of the proposed compliance modeling and design methods compared with the previous method.

Development of a Mechatronic System for Demonstration Purposes

The aim of the paper is to present a modular system, with the help of which it is possible to reveal the structure and analysis of a mechatronic system, taking into account several disciplines that contribute to the structure of the system. The planned system will include devices from different disciplines, the operation and coordination of which will be observable. The designed system is a two-degree-of-freedom mechanism with a translational and a rotary joint. The movement of the joints are obtained by different types of energy converters (pneumatic, electric). The replacement of the different types of drives can be performed quickly and easily without drastically changing the system setup. The simulations are implemented using the MATLAB Simscape software package.

Methods of antenna and «antenna- radome» system analysis based on amplitude and phase measurements of their far field spherical components

The main principles of electric intensity recovery of electrical field in tested antenna aperture or in the «antenna radome» system radome-close aperture field (false aperture) by amplitude and phase long-range measurements are proposed. Measurements zone means a part of the spherical surface that envelopes analyzed antenna, the boarder of this surface are determined by the kinematic scheme of rotary joint of the scanner. Recovery of amplitude and phase distribution of the field in a flat aperture area or on the plane where array irradiators are located is used in case of wave diagnostics of such type of antennas. It is proposed to use the recovered phase distribution in a false aperture for a phase correction on phased array irradiators in order to compensate phase errors appeared because of the radome. The method of radome dielectric permittivity is discussed.

Broadband Rotary Joint Concept for High-Power Radar Applications

To allow antenna movements in azimuth and elevation in high-power radar applications, rotary joints are essential. They allow the rotation of a transmission line and therefore are important transmission line components. In the present paper, a broadband rotary joint concept for high-power W-band radar applications is proposed. To avoid a twist of the polarization plane of a linearly polarized mode, like HE11, a combination of two broadband polarizer is used. A cross polarization of Xpol ≤ − 20 dB can be achieved within the considered frequency range from 90 GHz to 100 GHz. This corresponds to a suitable value for radar applications.