Development of the method of laser Doppler anemometry for diagnostics of turbulent flows at high speed

The aim of the work was to develop a laser Doppler anemometry method for high-speed turbulent aerodynamic flow diagnostic. As a result, this allowed us to measure two projections of the velocity vector in the range of 0.1 - 400 m/s with a relative error not exceeding 0.5%. The measurement area was 0.1x0.1x0.5mm. The positioning device moved the measuring unit in the area of 250 x 250 x 250 mm with an accuracy of 0.1 mm. This method also provides the ability to measure local flow rate fluctuations.

Planar Micro-Positioning Device Based on a 3D Digital Electromagnetic Actuator

In this paper, a novel micro-positioning device based on a 3D digital actuator is presented. The proposed system allows realizing planar motions of micro-objects, which could be implemented in several applications where micro-positioning tasks are needed such as micro-component manufacturing/assembly, biomedicine, scanning microscopy, etc. The device has three degrees of freedom, and it is able to achieve planar motions of a mobile plate in the xy-plane at two different levels along the z-axis. It consists of a hexagonal mobile part composed of a permanent magnet that can reach twelve discrete positions distributed between two z-axis levels (six at each level). Two different approaches are presented to perform positioning tasks of the plate using the digital actuator: the stick-slip and the lift-mode approaches. A comparison between these two approaches is provided on the basis of the plate displacement with respect to different current values and conveyed mass. It was observed that for a current of 2 A, the actuator is able to displace a mass of 1.15 g over a distance of 0.08 mm. The optimal positioning range of the planar device was found to be ±5.40 mm and ±7.05 mm along the x- and y-axis, respectively.

Precise Linear Positioning Method Based on Transmissive Two-Stage Diffraction Grating System

This paper mainly studies the precise linear positioning method based on the transmissive type two-stage diffraction grating system. Starting from the analysis of the two-stage diffraction principle, the mathematical model of the two-stage grating diffraction is established, and the positioning characteristics of the differential positioning method and the modified positioning method are discussed. The simulation experiment of the linear positioning device is carried out to study the displacement characteristics. The experimental results show that the precise positioning based on the diffraction grating can obtain a positioning accuracy of ±0.4 μm.

Developing the laser doppler anemometry method for the diagnostics of kinematic parameters of a turbulent flow in the near wall region

The aim of the work is to develop a laser Doppler anemometry method for diagnosing turbulent aerodynamic flows in the near wall region. This will enable measuring two projections of the velocity vector in the range of 0.001 … 400 m/s with a relative error not exceeding 0.1%. The measurement area is 0.1×0.1x0.5mm. The positioning device allows moving the measuring unit in the area of 250×250x250 mm with an accuracy of 0.1 mm. This method also provides the ability to measure local flow rate fluctuations.

KINEMATICS OF POSITIONING DEVICE FOR MATERIAL HANDLING IN MANUFACTURING

Different types of robots are used in many areas of industry. Industrial manipulators are used to ensure productivity and flexibility in automated production lines. Most of them is used for tasks that automatically repeat the same operation in a familiar environment. The key element in the development and analysis of industrial robots is their kinematic analysis. The article deals with the kinematic analysis of this positioning equipment. Individual relations of kinematic quantities are plotted graphically. Matrix methods were used for the analysis.