Negotiating Uneven Terrain by a Simple Teleoperated Tracked Vehicle with Internally Movable Center of Gravity

We propose a mechanical design for a simple teleoperated unmanned ground vehicle (UGV) to negotiate uneven terrain. UGVs are typically classified into legged, legged-wheeled, wheeled, and tanked forms. Legged vehicles can significantly shift their center of gravity (COG) by positioning their multi-articulated legs at appropriate trajectories, stepping over a high obstacle. To realize a COG movable mechanism with a small number of joints, a number of UGVs have been developed that can shift their COG by moving a mass at a high position above the body. However, these tend to pose a risk of overturning, and the mass must be moved quite far to climb a high step. To address these issues, we design a novel COG shift mechanism, in which the COG can be shifted forward and backward inside the body by moving most of its internal devices. Since this movable mass includes DC motors for driving both tracks, we can extend the range of the COG movement. We demonstrate that a conventional tracked vehicle prototype can traverse a step and a gap between two steps, as well as climb stairs and a steep slope, with a human operating the vehicle movement and the movable mass position.

Fast Extraction Algorithm for Local Edge Features of Super-Resolution Image

Image super-resolution is getting popularity these days in diverse fields, such as medical applications and industrial applications. The accuracy is imperative on image super-resolution. The traditional approaches for local edge feature point extraction algorithms are merely based on edge points for super-resolution images. The traditional algorithms are used to calculate the geometric center of gravity of the edge line when it is near, resulting in a low feature recall rate and unreliable results. In order to overcome these problems of lower accuracy in the existing system, an attempt is made in this research work to propose a new fast extraction algorithm for local edge features of super-resolution images. This paper primarily focuses on the super-resolution image reconstruction model, which is utilized to extract the super-resolution image. The edge contour of the super-resolution image feature is extracted based on the Chamfer distance function. Then, the geometric center of gravity of the closed edge line and the nonclosed edge line are calculated. The algorithm emphasizes on polarizing the edge points with the center of gravity to determine the local extreme points of the upper edge of the amplitude-diameter curve and to determine the feature points of the edges of the super-resolution image. The experimental results show that the proposed algorithm consumes 0.02 seconds to extract the local edge features of super-resolution images with an accuracy of up to 96.3%. The experimental results show that our proposed algorithm is an efficient method for the extraction of local edge features from the super-resolution images.

EFFECT OF NEURAC THERAPY ON PLANTAR PRESSURES DISTRIBUTION AND THE CENTER OF GRAVITY OF THE HUMAN BODY

Nowadays, the pathophysiological posture is a problem for a large part of the population, which leads to a deterioration in the quality of life as a result of functional disorders of the human musculoskeletal system. The aim of the presented article is to point out the effectiveness of movement therapy for the correction of the pelvic position and subsequent adjustment of the body posture, which is evaluated by a change in the distribution of plantar pressures as well as the position of the center of gravity projection. Observations were made on three subjects who reported pain in different areas of the body as a result of incorrect body posture. Input and control measurements were performed on a baropodometer, and Neurac movement therapy in the Redcord system was applied between the individual measurements. The individual exercises were chosen specifically with regard to affect the specific muscle groups. After evaluating the measured data, it can be stated that the selected movement therapy has a significant effect on the correction of pathophysiological position, which is also demonstrated by changing the distribution of plantar pressures, adjusting the position of the center of gravity projection and also significantly eliminating painful symptoms and increasing movement comfort.

Relationship of Selected Anthropometric and Linear Kinematical Variables with the Performance of Toe-Touch Skill in Kabaddi

The purpose of this study was to find out the relationship of selected anthropometric and linear kinematical variables with the performance of toe-touch skill among male kabaddi players (raiders). Materials and Methods. One hundred male raiders were selected for this study. The age of the subjects ranged between 18 to 25 years. Selected anthropometric variables: foot length, upper leg length, lower leg length, thigh girth and calf girth were measured by standardized equipment. Selected linear kinematical variables were measured by digital software ‘Kinovea version-0.9.3’. The toe-touch skill performed by raiders was assessed by three experts rating. The inter-rater reliability of the scores awarded by the experts to the subjects was tested by Cohen’s Kappa test and Kappa coefficient was found significant. Results. Spearman’s rank correlation revealed that there was significant correlation in case of thigh girth (rs = 0.230, p = 0.022), distance (rs = 0.245, p = 0.014) and center of gravity (rs = -0.270, p = 0.007) variables, and there was not significant correlation in case of upper leg length (rs = 0.048, p = 0.634), lower leg length (rs = -0.90, p = 0.373), calf girth (rs = 0.093, p = 0.355), foot length (rs = -0.17, p = 0.863) and time (rs = -0.006, p = 0.952) variables with the performance of toe-touch skill in kabaddi. Conclusion. The study concludes that thigh girth and distance positively and center of gravity negatively contributes to the performance of toe-touch skill in male kabaddi players.

Spatial-Temporal Responses of Ecosystem Services to Land Use Transformation Driven by Rapid Urbanization: A Case Study of Hubei Province, China

Exploring the changes of ecosystem services value caused by land use transformation driven by urbanization is crucial for ensuring the safety of the regional ecological environment and for enhancing the value of ecosystem services. Based on the land use remote sensing data during the rapid urbanization development period of Hubei Province from 1995 to 2015, this study analyzed the characteristics of land use/land cover change and land use transformation. The spatial–temporal response characteristics and evolution of ecosystem services value (ESV) to land use transformation driven by urbanization were measured by equivalent factor method, spatial autocorrelation analysis, hot spot analysis and gravity model. We found that: (1) Driven by urbanization, the most significant feature of land use transformation in Hubei Province was the expansion of the built-up land and the significant reduction of cropland and forest, among which 90% of the new built-up land was converted from cropland and forest. (2) This land use transformation became the main source of ESV losses. Especially, the sharp increase of the built-up land from 2010 to 2015, occupying cropland and forest, resulted in ESV losses of nearly USD 320 million. The service capacity of climate regulation, soil conservation, gas regulation and food production undertaken by cropland and forest decreased. (3) The ecosystem services value in the study area showed spatial distribution characteristics of high in the west and low in the middle and east regions. The center of gravity of ESV shifted from northwest to southeast. Due to the sharp increase of the built-up land from 2010 to 2015, the center of gravity shift rebounded. This study can help policymakers better understand the trade−offs between land use transformation and ecosystem services driven by urbanization.

Acoustic correlates of the advanced vs. retracted tongue root feature in Igbo

Vowel harmony based on the advanced tongue root (±ATR) feature is a well-known attribute of the languages of the Macro-Sudan belt. Igbo (< Benue-Congo), one of these languages, on basis of which first instrumental studies of ±ATR articulation were conducted, has an asymmetric vowel system /i, ɪ, e, a, ɔ, o, ʊ, u/, so that root ±ATR harmony exists within three pairs and a single vowel /e/. This paper describes an acoustic realization of ±ATR in Igbo. According to the hypothesis that the value of the first formant in combination with the distribution of energy over the spectrum combine into a single perceptual cue that allows to distinguish vowels opposed by ±ATR we investigate (along with the description of the formant space) three spectral parameters that were shown to be acoustic correlates of ±ATR in other Macro-Sudan languages. The results of the instrumental analysis indicate that acoustic correlates of ±ATR harmony in Igbo are the value of the first formant, its bandwidth and normalized center of gravity. In addition, all parameters relevant for the ±ATR contrast in our data divided /ɔ/ utterances in different roots into two groups with contrasting values of the feature.

Construction and Simulation of Athlete’s Wrong Action Recognition Model in Sports Training Based on Embedded Wireless Communication and Computer Vision

Embedded networking has a broad prospect. Because of the Internet and the rapid development of PC skills, computer vision technology has a wide range of applications in many fields, especially the importance of identifying wrong movements in sports training. To study the computer vision technology to identify the wrong movement of athletes in sports training, in this paper, a hidden Markov model based on computer vision technology is constructed to collect video and identify the landing and take-off movements and badminton serving movements of a team of athletes under the condition of sports training, Bayesian classification algorithm to analyze the acquired sports training action data, obtain the error frequency, and the number of errors of the landing jump action, and the three characteristic data of the displacement, velocity, and acceleration of the body’s center of gravity of the athlete in the two cases of successful and incorrect badminton serve actions and compared and analyzed the accuracy of the action recognition method used in this article, the action recognition method based on deep learning and the action recognition method based on EMG signal under 30 experiments. The training process of deep learning is specifically split into two stages: 1st, a monolayer neuron is built layer by layer so that the network is trained one layer at a time; when all layers are fully trained, a tuning is performed using a wake-sleep operation. The final result shows that the frequency of the wrong actions of the athletes on the landing jump is concentrated in the knee valgus, the total frequency of error has reached 58%, and the frequency of personal error has reached 45%; the problem of the landing distance of the two feet of the team athletes also appeared more frequently, the total frequency reached 50%, and the personal frequency reached 30%. Therefore, athletes should pay more attention to the problems of knee valgus and the distance between feet when performing landing jumps; the difference in the displacement, speed, and acceleration of the body’s center of gravity during the badminton serve will affect the error of the action. And the action recognition method used in this study has certain advantages compared with the other two action recognition methods, and the accuracy of action recognition is higher.

Research Civil Aircraft Model (RCAM) Dengan Metode Dinamis 6 Derajat Kebebasan Menggunakan MATLAB

Model Pesawat merupakan suatu usaha untuk menciptakan atau membuat simulasi pesawat yang sebenarnya dan model ini bisa disebut Research Civil Aircraft Model (RCAM), yaitu model pesawat sipil bermesin ganda yang dikembangkan oleh Group for Aeronautical Riset dan Teknologi di Eropa (GARTEUR). Model pesawat ini mirip dengan Boeing 757-200. Research Civil Aircraft Model yang dibuat menggunakan 6 derajat kebebasan. 6 derajat kebebasan terdiri dari 3 translasi yaitu 3 derajat untuk koordinat kartesian pada sumbu (x,y,z) dan 3 rotasi yaitu 3 derajat (pitch, roll, dan yaw) yang digunakan untuk mengontrol defleksi surface dan posisi throttle. Untuk membuat model, diperlukan parameter, yaitu parameter dari massa pesawat dan parameter dari chord aero dan juga CoG (Center of Gravity) dari suatu pesawat. Algoritma yang dimasukkan berasal dari control limits/Saturasi, Variabel Intermediate, Koefisien Force, Koefisien Momen, Efek Propulsi, Efek Gravitasi hingga akhirnya disimulasikan menggunakan “Simulink” pada MATLAB. Agar yang dihasilkan tidak hanya grafik maka diperlukannya animasi untuk melihat sikap pesawat sehingga digunakanlah 3D Animation pada MATLAB. Hasil dari permodelan pesawat sipil ini untuk melihat simulasi stabilitas dari aileron, rudder, elevator, dan throttle saat pesawat itu terbang. Hasil yang ada dapat berubah-ubah karena pada 3D Animation, pesawat dapat dikendalikan dari sikap pesawat saat miring kanan atau kiri dan juga saat pesawat berguling. Dengan adanya hal ini diharapkan simulasi tersebut bisa effective untuk melihat hasil yang sebenarnya saat pesawat terbang dan juga bisa dijadikan untuk simulator sebelum pesawat tersebut lepas landas.

Generic Upscaling Methodology of a Floating Offshore Wind Turbine

This study presents a generic method to upscale a semi-submersible substructure and tower-nacelle-blade for a floating offshore wind turbine from 5 MW to 15 MW and beyond. The effects of upscaling the column radius and/or distance of the floating base are investigated, and a comparison is made with a 15 MW reference design. It is found that scaling column radius increases the mass of the platform and the heave natural period, while scaling column distance raises the center of gravity and metacentric height of the floating system and slightly decreases the heave natural period. The 15 MW reference design addresses these issues through design changes that increase the ballast mass to lower the center of gravity, and increase the added mass to raise the heave natural period. Finally, a method for estimating the scaling of platform parameters with different assumptions is proposed.