The analysis of the heat distribution between a stationary pin and rotating ring was considered. To solution of the governing quasi-stationary heat conductivity equation the finite Fourier transform was used. The convective cooling from outer and internal surface of the ring as the boundary conditions were considered. The ring surface temperature, the average temperature on the ring surface and the heat distribution coefficient for the studied system were determined. The numerical results for the temperatures and heat distribution coefficient which demonstrated the effects of the Biot number and internal radius of the ring on them, were presented. List of symbols Ring AArea of the heating zone (m 2 ) Bi = h R/K Dimensionless Biot number associated with the external surface of the ring Bi 0 = h 0 R/K Dimensionless Biot number associated with the internal surface of the ring Bi = h R/K Dimensionless Biot number associated with the sides of the ring h Heat transfer coefficient on external surface of the ring (Wm −2 K −1 ) h 0 Heat transfer coefficient on the internal surface of the ring, (Wm −2 K −1 ) hHeat transfer coefficient on the sides of the ring (Wm −2 K −1 ) k Thermal diffusivity (m 2 s −1 ) K Thermal conductivity (Wm −1 K −1 )Intensity of the heat flow into the ring (Wm −2 ) Q = q A Total rate of friction heat directed into the ring supply from area A (W) rRadial coordinate (m) R External radius (m) R 0Internal radius (m) T Temperature rise ( • C) T

No abstract

No abstract

The purpose of this article is to establish a partitioning heat ratio between two stationary cylindrical pins and a rotating ring. The mixed quasi-stationary heat conduction problem for the ring is solved. The fast-moving heating on the external surface of the ring due to two rotating locally distributed heat flows is considered. The heat conduction from the sliding contact zones in the axial direction of the ring, as well as the heat convection from the sides, external, and internal surfaces of the ring are taken into account. The solution of this problem is obtained by using a finite Fourier transformation. The solution of the steady heat conduction problem for the semi-infinite pins which are heated up at end faces taking account of cooling from lateral sides is known. By matching the average temperatures of the ring and the pins in the contact regions, the coefficients of the heat distribution between them is found. The influence of the circumferential distance between the pins and the ratio of the intensities of the frictional heat flows on the surface temperature is studied.

Presented paper focuses on design process of Soil Sample Retrieval System for simple on-board analysis of collected material and cashing it for further examination. System is created to be mounted on mobile robotic platforms to provide a tool suitable for sampling scientifically interesting sites in remote and even hazardous for human environments [1,2,4].Considered solution will be thoroughly tested during University Rover Challenge 2016 aiding #next team efforts to proof life existence in mock-up Mars surface setting located nearby Mars Desert Research Station, Hanksville Utah. This procedure is one of challenge’s task that proves scientific usefulness of a built rover. It requires collection of unaltered sub-surface soil sample, preliminary examination and cashing it on-board for further analysis.The device needs to be capable of collecting sub-surface soil samples, then transporting gathered material to cash and experiment containers also embedded onto platform [3]. It uses a drilling technique similar to one used to crush concrete and hard rocks.Powder created during sampling is further transported via system of tubes powered with vacuum. In order to create under pressure system was equipped with high-efficient turbine capable of producing up to 45 kg of suction force. This new approach has never been used before during such competition. We believe it will provide much needed advantage during this task over other competitors.The system allows an equal distribution of collected soil into designated containers. They are fitted out with desired scientific equipment. In considered exemplary model there are three containers. One being equipped with pH sensor, second-a humidity sensor and third one for cashing unaltered sample for further laboratory experimentations. It can also be equipped with additional sensors such as black light emitter with CCD sensor to determine cyanobacteria presence.The paper consists of three parts. First one focuses on problem analysis [2,3], system design and preliminary tests description. Second one describes device manufacturing and tests. Last part consists of results analysis with a critical validation of presented solution and recommendations for further development.

In recent years, an intense development in the mobile devices such as smartphones, tablets or smartwatches can be noticed. Each of them is equipped with various peripherals [1,2], for example touch screen, GPS, Wi-Fi, accelerometer or Bluetooth module which give a lot of possibilities for engineering use. Control of an intelligent home, positioning clients at the shopping centers through beacons or translation of the speech in real time are just some of the practical uses of mobile technology. On the other hand, a noticeable growth in usage of mobile robots for specific tasks results in an increased demand for a dedicated controller that would enable an intuitive, convenient, and precise control of such devices. The document presents an unconventional way of differential control of the six-wheeled robot through an application on Android device using Bluetooth connectivity. This solution will be presented on an example of a #next Mars rover analogue [fig. 1]. The vehicle was built to participate in University Rover Challenge. This prestigious competition of Mars rovers occurs yearly in the United States on the Utah desert. Measured linear acceleration via the built-in smartphone accelerometer, allows to control the direction and speed of the drive motors and joints of manipulator. The author gives a solution to the most important problems in the presented control method such as correction of accelerometer error or a negative impact of temperature. It also provides solutions to accelerate the establishment of communication such as the inclusion of bluetooth while lunching application or resuming it automatically after incoming call when communication app works in the background. The solution is confronted with currently the most popular ways of mobile robots control.

The solution of the mixed quasi-stationary heat conduction problem for the ring has been obtained by using a finite Fourier transformation. The heating on the external side surface of the ring due to any locally distributed heat flux, as well as the convective cooling from internal side surface and from the end faces are considered. It has been proved that for some special geometrical and thermo-physical parameters of problem the received solution agrees with well known studies. The influence of some distribution intensity form of heat flux on the maximum temperature was studied. List of symbolsBi = h R/K dimensionless Biot number associated with the external side surface of the ring Bi 0 = h 0 R/K dimensionless Biot number associated with the internal side surface of the ring Bi = h R/K dimensionless Biot number associated with the end faces of the ring h heat transfer coefficient on external side surface of the ring (W m −2 K −1 ) h 0 heat transfer coefficient on the internal side surface of the ring (W m −2 K −1 ) h heat transfer coefficient on the end faces of the ring (modified Bessel function of the first kind of the order k(k = 1, 2) k thermal diffusivity of the ring (m 2 s −1 ) K thermal conductivity of the ringmodified Bessel function of the second kind of the order k(k = 1, 2) n non-negative integer Pe = ω R 2 /k dimensionless Peclet number q 0 characteristic (maximum) intensity of the heat flux (W m − 2) q * (θ ) dimensionless function, describing the change of intensity of the heat flux in circumferential direction Q total rate of friction heat directed into the ring (W) r radial coordinate (m) R external radius (m) R 0 internal radius (m) T temperature rise (K) T V bulk temperature of the ring (K) 768 A. Yevtushenko, J. Tolstoj-Sienkiewicz T f flash temperature on the external surface of the ring (K)flash temperature on the external surface of the ring T * * f = T * f /(2θ 0 ) dimensionless flash temperature on the external surface of the ringGreek symbols δ thickness of the ring (m) = δ/R dimensionless thickness of the ring θ circumferential coordinate (rad) θ 0 half of the contact angle (rad) θ * = θ/2θ 0 dimensionless circumferential coordinate ρ = r/R dimensionless radial coordinate ρ 0 = R 0 /R dimensionless internal radius σ = Bi / dimensionless parameter ω rotational speed of the ring (rad s −1 )

No abstract