Study of the two-rotor electric motor of a drive of vehicle drive wheels

In recent years, electric and hybrid vehicles have taken more and more attention due to their apparent advantages in saving fuel resources and reducing harmful emissions into the environment. Even though electric vehicles can solve the ecological problem, their operation is faced with a number of inconveniences associated with a limited driving distance from a single charge due to limited storage of energy from an independent power source and a lack of the required service and repair infrastructure. In hybrid and electric vehicles one of the main parameters is the curb weight, which affects energy consumption, vehicle speed, stability, controllability and maneuverability. In this regard, leading car manufacturers use parts with a low specific weight (non-metallic, aluminum alloys, etc.) in the design and also exclude some units from the design. Due to these technical solutions, the vehicle's operating is improved. One of the groups of parameters to be defined when designing a new electric vehicle is the parameters relating to the electric motor. The purpose of the article is determination of the mechanical characteristics of a two-rotor electric motor during magnetic flux control and assessment of the possibility of organizing the drive of the drive wheels of the vehicle. The electric motor has two mechanically independent outputs. For the study, an electrical equivalent diagram has been developed for the given two-rotor electric motor. A simulation model of the equivalent diagram has been built. Simulating the interaction processes of the rotors with the stator made it possible to obtain data for building the mechanical characteristics for each output of the electric motor. Analysis and processing of the mechanical characteristics data of the electric motors showed the conformity and the range of changes in the torque on each of the rotors when changing their slip and revolution, which are required when building algorithms for the operation of electric motor control systems as part of drives for various purposes. Analysis of the simulation results made it possible to assess the possibility of using the considered two-rotor electric motor for the drive of drive wheels in an electric and hybrid wheeled vehicle.

A Distributed Terahertz Metasurface with Cold-Electron Bolometers for Cosmology Missions

We developed and tested a 2D periodic array of cold-electron bolometers arranged into a wideband frequency selective metasurface that absorbs more than 70% of the incident power in the frequency range 100–800 GHz. The array had 10 × 10 unit cells, each containing four bolometers incorporated into a ring. The chip with bolometers was mounted on the back side of the silicon lens without a back-reflector. Preliminary experiments demonstrated voltage responsivity as high as 109 V/W for the current-biased series array. Simulation of the noise performance shows realization of background noise-limited performance with NEPtot < NEPphot for the optical power load P0 > 15 pW. Results of numerical simulation made for the unit cell of the array are presented together with the equivalent diagram based on lumped network elements. The unit cell also was developed numerically to operate in two radiation modes.

Study on a Gripping Biomechanism Represented by the Human Dento-Maxillary Apparatus

In this paper presents the gripping biomechanism of the dento-maxillary apparatus. Here are some important studies conducted worldwide on the structure, kinematics and dynamics of biomechanism. In the paper the authors present their experimental research conducted to determine the movements made by the biomechanism. Using data obtained from video films, and radiographs we identified in detail the permitted movements of temporomandibular joint. The kinematic equivalent diagram of mechanism was established. The kinematic calculations performed but not presented due to lack of space in the paper showed that the mechanism is optimal for the required movements.

Kinematic analysis of a 5-DOF hybrid-driven MR compatible robot for minimally invasive prostatic interventions

SUMMARYThis paper introduces the design and kinematic analysis of a 5-DOF (multiple degree of freedom) hybrid-driven MR (Magnetic Resonance) compatible robot for prostate brachytherapy. It can slip the leash of template and rely on the high precise of MR imaging. After a brief introduction on design requirements of MR compatible robot, a description of our robot structure, material selection, hybrid-driven, and control architecture are presented. Secondly, the forward kinematics equations are obtained according to the equivalent diagram of this robot, and the actual workspace can be outlined. This will help the designer to determine whether this robot can be operated in the MR core without intervention with patient. And then, the inverse kinematics equations combined with trajectory planning are used to calculate the actuators movement. This will help the control system to manipulate the robotic accurately. Finally, vision based experiments on phantoms are used to verify the mechanism precision. As the results shown, the needle tip precision of mechanism is 0.9 mm in the general lab environment.

The Volterra series of distortion analysis

The Volterra series method of distortion analysis is presented in the analysis of a common emitter circuit. There are presented the model of the integrated circuit and evaluated their non-linearity’s.According to the provided equivalent diagram and using the method of Volterra series, kernels of the respective linear, square and cube system have been figured out. Changes in an operation mode ofa IT within a frequency range influenced by an input signal have been defined taking into account IT parameters and outer elements.

Assessing Risk with Analytical Procedures: Do Systems-Thinking Tools Help Auditors Focus on Diagnostic Patterns?

SUMMARY This study investigated whether auditors who used a diagram designed around systems-thinking principles to acquire information for analytical procedures would focus more on patterns of changes in accounts and assess misstatement risk differently than auditors who used an informationally equivalent diagram organized by business-process categories. During a laboratory experiment, experienced auditors performed analytical procedures using one of two alternative diagrams. Participants documented their concerns about misstatement risk and rated the diagnostic relevance of information about patterns of changes in accounts. Auditors who used the systems-thinking tool focused more on diagnostic patterns of fluctuations in accounts and came to different conclusions about risk. Data Availability: Data will be made available by the authors upon request.