scholarly journals Mechanism Design and Experiment of a Bionic Turtle Dredging Robot

Machines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 86
Author(s):  
Tao Wang ◽  
Zhuo Wang ◽  
Bo Zhang
Keyword(s):  
Mechanism Design ◽  
Control Function ◽  
The Body ◽  
Fish Ponds ◽  
Motion Stability ◽  
Experimental Prototype ◽  
Underwater Environment ◽  
Movement Characteristics ◽  
Movement Sequence ◽  
Movement Stability

In order to clean underwater silt in artificially constructed rivers, lakes, and fish ponds, for which no suitable tool exists, a tool has been developed that imitates the structure and movement of the tortoise’s legs, and designs a four-legged dredging robot that can adapt to the complex underwater environment. The article uses the transformation matrix to analyze the kinematics of the dredging robot, determines the movement sequence of the outriggers according to the principle of stability, and analyzes the movement characteristics of the three gait modes. Then, we combined the control function of the foot trajectory with the experimental prototype based on the bionic tortoise mechanism to carry out a walking experiment. During the experiment, the motion stability is good. Additionally, the changes in the position, the posture of the outriggers, and the body prove that the movement stability of the dredging robot using coordinated gait, mixed gait, and intermittent gait has increased sequentially.

scholarly journals Study on the Motion Stability of the Autonomous Underwater Helicopter

2022 ◽  
Vol 10 (1) ◽  
pp. 60
Author(s):  
Yuan Lin ◽  
Jin Guo ◽  
Haonan Li ◽  
Hai Zhu ◽  
Haocai Huang ◽  
...  
Keyword(s):  
Autonomous Underwater Vehicle ◽  
Angle Of Attack ◽  
Vertical Movement ◽  
Plane Motion ◽  
Hydrodynamic Performance ◽  
Scale Model ◽  
Motion Stability ◽  
Movement Stability ◽  
Stability Indexes ◽  
Drag Ratio

The hydrodynamic performance of a novel hovering autonomous underwater vehicle, the autonomous underwater helicopter (AUH), with an original disk-shaped hull (HG1) and an improved fore–aft asymmetric hull (HG3), is investigated by means of computational fluid dynamics with the adoption of overlapping mesh method. The hydrodynamic performance of the two hull shapes in surge motion with variation of the angle of attack is compared. The results show that HG3 has less resistance and higher motion stability compared to HG1. With the angle of attack reaching 10 degrees, both HG1 and HG3 achieve the maximum lift-to-drag ratio, which is higher for HG3 compared to HG1. Furthermore, based on the numerical simulation of the plane motion mechanism test (PMM) and according to Routh’s stability criterion, the horizontal movement and vertical movement stability indexes of HG1 and HG3 (GHHG1=1.0, GVHG1=49.7, GHHG2=1.0, GVHG3=2.1) are obtained, which further show that the AUH has better vertical movement stability than the torpedo-shaped AUV. Furthermore, the scale model tail velocity experiment indirectly shows that HG3 has better hydrodynamic performance than HG1.

Design of and Experimentation with a Walking Assistance Robot

2013 ◽  
pp. 1600-1605
Author(s):  
Zhang Lixun ◽  
Bai Dapeng ◽  
Yi Lei
Keyword(s):  
Mechanism Design ◽  
Lower Limb ◽  
Sitting Position ◽  
Experimental Prototype ◽  
Training Mode ◽  
Standing Up

To help patients with lower limb disabilities walk, a robot was designed to help train patients to stand up. An experimental prototype was developed, and experiments to train patients stand up and walk were performed using this robot. The results show that the robot can help patients to stand from a sitting position, which is the purpose of standing-up training. At the same time, the standing-up mechanism can coordinate with the walking assistance mechanism in the walking training mode, allowing the robot to help patients to perform rehabilitation walking training. The justification of the mechanism design was demonstrated, and thus, the robot can be used for stranding-up training and walking training.

Movement paths in operating hand-held tools: tests of distal-shift hypotheses

2013 ◽  
Vol 109 (11) ◽  
pp. 2680-2690 ◽  
Author(s):  
Sandra Sülzenbrück ◽  
Herbert Heuer
Keyword(s):  
Boundary Conditions ◽  
Visual Feedback ◽  
The Body ◽  
Hand Movements ◽  
First Order ◽  
Dynamic Transformation ◽  
Movement Characteristics ◽  
Effective Part

Extending the body with a tool could imply that characteristics of hand movements become characteristics of the movement of the effective part of the tool. Recent research suggests that such distal shifts are subject to boundary conditions. Here we propose the existence of three constraints: a strategy constraint, a constraint of movement characteristics, and a constraint of mode of control. We investigate their validity for the curvature of transverse movements aimed at a target while using a sliding first-order lever. Participants moved the tip of the effort arm of a real or virtual lever to control a cursor representing movements of the tip of the load arm of the lever on a monitor. With this tool, straight transverse hand movements are associated with concave curvature of the path of the tip of the tool. With terminal visual feedback and when targets were presented for the hand, hand paths were slightly concave in the absence of the dynamic transformation of the tool and slightly convex in its presence. When targets were presented for the tip of the lever, both the concave and convex curvatures of the hand paths became stronger. Finally, with continuous visual feedback of the tip of the lever, curvature of hand paths became convex and concave curvature of the paths of the tip of the lever was reduced. In addition, the effect of the dynamic transformation on curvature was attenuated. These findings support the notion that distal shifts are subject to at least the three proposed constraints.

scholarly journals Trichodina magna Van As and Basson, 1989 (Ciliophora: Peritrichia) from cultured Nile tilapia in the state of Santa Catarina, Brazil

2008 ◽  
Vol 68 (1) ◽  
pp. 169-172 ◽  
Author(s):  
ML. Martins ◽  
L. Ghiraldelli
Keyword(s):  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Original Description ◽  
The State ◽  
The Body ◽  
Fish Ponds ◽  
Santa Catarina ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Mean Diameter ◽  
The Mean

Specimens of Trichodina magna Van As and Bassson, 1989 (Ciliophora: Peritrichia) from the Nile tilapia Oreochromis niloticus collected from October 2004 to June 2005 in fish ponds situated in three regions of Santa Catarina State, Brazil are described here. Wet smears of skin and gills were prepared in the field, air dried, impregnated with Klein’s dry silver method and Giemsa’s solution. From a total of 146 examined fish, 36 were parasitized on the skin, 14 in the gills and 33 on the skin and gills, simultaneously. The mean diameter of the body of the specimens of T. magna was 84.3 ± 12.6 µm, adhesive disc 60.7 ± 10.0 µm, denticulate ring, 38.3 ± 7.4 µm, consisting of 26 (23 to 29) denticles. The only distinguishable difference from the original description was the fact that the ray of the denticle is anteriorly directed and does not extend over the y + 1 axis.

scholarly journals Fungsi Kontrol Sosial Sekolah Islam Dalam Pencegahan Pergaulan Bebas Remaja

2013 ◽  
Vol 29 (2) ◽  
pp. 155
Author(s):  
Mintarti Hidayat ◽  
Niken Paramarti Dasuki ◽  
Wiwik Novianti
Keyword(s):  
Social Control ◽  
Control Function ◽  
Preventive Measure ◽  
The Body ◽  
Group Discussions ◽  
Islamic School ◽  
Central Java ◽  
Norms And Values ◽  
Internalization Process ◽  
Islamic Values

This paper elaborates on the social control carried out by the Islamic school. The theme of the study ranged in how Islamic schools internalize Islamic values as a preventive measure prevents teenage promiscuity. The aim of the study was to know the Islamic values internalization process in Islamic school in order to operate its social control function. The study was conducted in four Islamic high schools in the city of Purwokerto, Banyumas, Central Java. The method used is a combination of qualitative and quantitative approaches. Data collected through interviews, focused group discussions, observations, and questionnaires. The analysis showed that one of the ways that religion exercising oversight is through the control of the body and human sexuality. However, the control does not always go well,especiallyin  the problem of internalization of religious norms and values. The important thing to note is the consistency in the enforcement of the rules, the example of the teacher, and the parents support the school made the rules, so that the function of social control can run well.

scholarly journals PRODUCTION PERFORMANCE AND BLOOD PROFILE OF CLIMBING PERCH Anabas testudineus Bloch CULTURED IN PEAT POND WITH DIFFERENT STOCKING DENSITIES

2019 ◽  
Vol 14 (2) ◽  
pp. 83
Author(s):  
Ani Widiyati ◽  
Adang Saputra ◽  
Eri Setiadi
Keyword(s):  
Water Quality ◽  
Stocking Density ◽  
Mesh Size ◽  
The Body ◽  
Production Performance ◽  
Fish Ponds ◽  
Anabas Testudineus ◽  
Blood Profile ◽  
Climbing Perch ◽  
Freshwater Aquaculture

Climbing perch is one of economically-valued local fish in Indonesia, particularly in Borneo, Sumatra, and Java Islands. The fish has the potential to be developed as freshwater aquaculture species. The purpose of this experiment was to evaluate the production performance and blood profile of climbing perch cultured in peat pond with different stocking densities. The research was conducted in Kereng Bangkiray Village, Sebangau District, Palangkaraya City, Central of Borneo. Nine fish ponds sized 5.0 m x 5.0 m x 1.5 m were used. Nets with a mesh size of 1 cm measuring 2.0 m x 1.5 m x 1.0 m was installed in each fish pond for the experiment. The treatment consisted of different stocking densities, namely 15 fish/m2, 30 fish/m2, and 45 fish/m2. Fish with the body weight of 20 ± 1.25 g were used. Fish were cultured for four months. An artificial diet containing 30% protein was given with a feeding rate of 5%. The experiment was designed in a complete randomized design. The result showed that the production performances (i.e. survival, specific growth rate, absolute weight, and biomass) were significantly higher at the densities of 15 and 30 fish/m2 than that of 45 fish/m2 (P<0.05). Blood profile such as glucose, erythrocyte, leucocyte, and hemoglobin were higher at the density of 45 fish/m2 except for hematocrit which was higher at the densities of 30 and 15 fish/m2. Water quality parameters such as dissolved oxygen, nitrite, nitrate, and ammonia at the densities of 15 and 30 fish/m2 showed better values than that of 45 fish/m2 stocking density. To optimize the productivity and maintain the optimum water quality condition, the optimal stocking density for climbing perch culture is suggested at 30 fish/m2.

Design of and Experimentation with a Walking Assistance Robot

2012 ◽  
pp. 123-127
Author(s):  
Zhang Lixun ◽  
Bai Dapeng ◽  
Yi Lei
Keyword(s):  
Mechanism Design ◽  
Lower Limb ◽  
Sitting Position ◽  
Experimental Prototype ◽  
Training Mode ◽  
Standing Up

To help patients with lower limb disabilities walk, a robot was designed to help train patients to stand up. An experimental prototype was developed, and experiments to train patients stand up and walk were performed using this robot. The results show that the robot can help patients to stand from a sitting position, which is the purpose of standing-up training. At the same time, the standing-up mechanism can coordinate with the walking assistance mechanism in the walking training mode, allowing the robot to help patients to perform rehabilitation walking training. The justification of the mechanism design was demonstrated, and thus, the robot can be used for stranding-up training and walking training.

Effect of Rotation Speed and Eccentricity on Dynamic Movement Characteristics of BTA Deep-Hole Boring Bar

2014 ◽  
Vol 518 ◽  
pp. 258-263
Author(s):  
Wu Zhao ◽  
Chao Fan Sun ◽  
Zhan Qi Hu
Keyword(s):  
Cutting Force ◽  
Dynamic Characteristics ◽  
Periodic Motion ◽  
Rotation Speed ◽  
Analytic Method ◽  
Boring Bar ◽  
Dynamic Movement ◽  
Movement Characteristics ◽  
Force Variation ◽  
Movement Stability

Since the actual boring bar physical system is characteristic of strong nonlinear, it is difficult to apply analytic method to solve. For studying the effect of dynamic characteristics induced by speed changing and eccentricity, simulations are completed for bifurcation of displacement with the variable rotation speed, no matter whether there exists cutting force. It is shown that with the speed increasing, the system's dynamic characteristic become complicated, namely, the dynamic periodic motion varieties from single, multiple to quasi periodic in turn. Analogously, eccentricity leads to the increase of the complexity of systems dynamic characteristics. The periodic motion also transforms from single, quasi, triple to quasi periodic in sequence. The cutting force variation plays an importance role on the movement stability of the system.

The Effect of Magnesium Carbonate (Chalk) on Geometric Entropy, Force, and Electromyography During Rock Climbing

2016 ◽  
Vol 32 (6) ◽  
pp. 553-557 ◽  
Author(s):  
Matthew A. Kilgas ◽  
Scott N. Drum ◽  
Randall L. Jensen ◽  
Kevin C. Phillips ◽  
Phillip B. Watts
Keyword(s):  
Coefficient Of Friction ◽  
Body Position ◽  
Muscular Activity ◽  
Magnesium Carbonate ◽  
Rock Climbing ◽  
The Body ◽  
Movement Sequence ◽  
The Coefficient Of Friction ◽  
Hands And Feet ◽  
Static Coefficient Of Friction

Rock climbers believe chalk dries the hands of sweat and improves the static coefficient of friction between the hands and the surface of the rock. The purpose of this study was to assess whether chalk affects geometric entropy or muscular activity during rock climbing. Nineteen experienced recreational rock climbers (13 males, 6 females; 173.5 ± 7.0 cm; 67.5 ± 3.4 kg) completed 2 climbing trails with and without chalk. The body position of the climber and muscular activity of the finger flexors was recorded throughout the trial. Following the movement sequence participants hung from a standard climbing hold until they slipped from the climbing structure, while the coefficient of friction and the ratio of the vertical forces on the hands and feet were determined. Although there were no differences in the coefficient of friction (P = .748), geometric entropy (P = .359), the ratio of the vertical forces between the hands and feet (P = .570), or muscular activity (P = .968), participants were able to hang longer after the use of chalk 62.9 ± 36.7 s and 49.3 ± 25.2 s (P = .046). This is advantageous because it may allow for prolonged rests, and more time to plan the next series of climbing moves.

scholarly journals The Influence of Different Training Conditions on the Kinematics of Long Jump-Specific Exercise in Young Female Jumpers

2015 ◽  
Vol 22 (4) ◽  
pp. 241-246
Author(s):  
Hubert Makaruk ◽  
Andrzej Mastalerz ◽  
Marcin Starzak ◽  
Mariusz Buszta
Keyword(s):  
Repeated Measures ◽  
Female Athletes ◽  
Young Female ◽  
The Body ◽  
Jump Performance ◽  
Training Conditions ◽  
System A ◽  
Movement Characteristics ◽  
Long Jump ◽  
Key Variables

Abstract Introduction. This study examined the changes in the kinematic parameters of long jump-specific technical exercise performed in different training conditions. Material and methods. The study involved a group of young female athletes who volunteered to participate in the research. The key variables for long jump performance were measured using the Xsens MVN system. A three-way ANOVA (general linear model with repeated measures; factors: surface × hurdle × number of jumps) was used to determine if significant differences existed between the testing conditions. Results. The main finding of this study was that the tartan surface resulted in significantly (p < 0.05) greater velocities of the centre of mass of the body (CM) or parts of the athlete’s body than the grass surface. The second important finding was that the hurdles condition provided significantly (p < 0.05) greater velocity of the CM when landing and shorter contact time compared to the condition without hurdles. Conclusions. The findings of the study indicate that technical exercise should be performed on harder surfaces such as a tartan track rather than softer ones (e.g. grass) due to more beneficial movement characteristics and greater potential for the automaticity of movement during specific training tasks.

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