Design and Analysis of a Wire-Driven Robot Tadpole

Author(s):  
Zheng Li ◽  
Wenqi Gao ◽  
Ruxu Du ◽  
Baofeng Liao

Besides fish there are a lot of animals can swim effectively in the water, such as tadpole. Different from fishes using multiple fins to swim, tadpole has only one tail. It is well known that most fish employ the caudal fin to generate thrust, and use the pectoral fin, pelvic fin, etc. to balance the body and control its moving direction. However, the tadpole fulfilled all these tasks by the tail only. Hence, it is interesting to build a robot tadpole and study its motion. In this paper, a robot tadpole is designed. It has a blunt head and a tail. The control system, power supply and actuator are inside the head. The tail is a novel wire driven flapping propeller. The tail has a serpentine backbone with 7 joints, which are controlled by just one actuator. A prototype is built. The overall length of the robot tadpole is 328cm. Experiment results show that the robot tadpole can swim freely in the water. Its speed is affected by the flapping amplitude and frequency. In the experiments, the tadpole’s speed can reach 0.413 body length per second (BL/s), which matches the prediction from the propulsion model.

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Junzhi Yu ◽  
Kai Wang ◽  
Min Tan ◽  
Jianwei Zhang

This paper focuses on the development and control issues of a self-propelled robotic fish with multiple artificial control surfaces and an embedded vision system. By virtue of the hybrid propulsion capability in the body plus the caudal fin and the complementary maneuverability in accessory fins, a synthesized propulsion scheme including a caudal fin, a pair of pectoral fins, and a pelvic fin is proposed. To achieve flexible yet stable motions in aquatic environments, a central pattern generator- (CPG-) based control method is employed. Meanwhile, a monocular underwater vision serves as sensory feedback that modifies the control parameters. The integration of the CPG-based motion control and the visual processing in an embedded microcontroller allows the robotic fish to navigate online. Aquatic tests demonstrate the efficacy of the proposed mechatronic design and swimming control methods. Particularly, a pelvic fin actuated sideward swimming gait was first implemented. It is also found that the speeds and maneuverability of the robotic fish with coordinated control surfaces were largely superior to that of the swimming robot propelled by a single control surface.


Zootaxa ◽  
2012 ◽  
Vol 3586 (1) ◽  
pp. 329 ◽  
Author(s):  
ZACHARY S. RANDALL ◽  
LAWRENCE M. PAGE

The genus Homalopteroides Fowler 1905 is resurrected and distinguished from the genus Homaloptera van Hasselt 1823based on a combination of characters including a unique mouth morphology, dorsal-fin origin over pelvic fin,≤60 lateral-line scales, and≤30 predorsal scales. Species included in Homalopteroides are H. wassinkii (Bleeker 1853), H. modestus(Vinciguerra 1890), H. rupicola (Prashad & Mukerji 1929), H. smithi (Hora 1932), H. stephensoni (Hora 1932), H. weberi(Hora 1932), H. tweediei (Herre 1940), H. indochinensis (Silas 1953), H. nebulosus (Alfred 1969), H. yuwonoi (Kottelat1998), and possibly H. manipurensis (Arunkumar 1999). Homalopteroides modestus (Vinciguerra 1890) is a poorlyknown species that was originally described from the Meekalan and Meetan rivers of southern Myanmar. It occurs in theSalween, Mae Khlong, and Tenasserim basins, and can be distinguished from all other species of Homalopteroides by thecombination of caudal-fin pattern (black proximal and distal bars, median blotch), 15 pectoral-fin rays, pectoral-fin lengthgreater than head length, 5½–6½ scales above and 5–6 scales below the lateral line (to the pelvic fin), 39–44 total lateral-line pores, no axillary pelvic-fin lobe, pelvic fin not reaching anus, orbital length less than interorbital width in adult, and maxillary barbel reaching to or slightly past the anterior orbital rim.


2000 ◽  
Vol 203 (22) ◽  
pp. 3391-3396 ◽  
Author(s):  
J.A. Walker

Whether a rigid body limits maneuverability depends on how maneuverability is defined. By the current definition, the minimum radius of the turn, a rigid-bodied, spotted boxfish Ostracion meleagris approaches maximum maneuverability, i.e. it can spin around with minimum turning radii near zero. The radius of the minimum space required to turn is an alternative measure of maneuverability. By this definition, O. meleagris is not very maneuverable. The observed space required by O. meleagris to turn is slightly greater than its theoretical minimum but much greater than that of highly flexible fish. Agility, the rate of turning, is related to maneuverability. The median- and pectoral-fin-powered turns of O. meleagris are slow relative to the body- and caudal-fin-powered turns of more flexible fish.


1987 ◽  
Vol 24 (12) ◽  
pp. 2351-2361 ◽  
Author(s):  
Hans-Peter Schultze ◽  
Marius Arsenault

Quebecius quebecensis (Whiteaves 1889) is a porolepiform crossopterygian related to Glyptolepis. A large nariodal, a large tabular, a separate intertemporal, and a large fused nasosupraorbital are features of Quebecius that characterize it as a porolepiform. The small size of the operculum, median extrascapular larger than the lateral one, small lower squamosals, and deep maxilla are additional features separating Quebecius from Glyptolepis. As in Glyptolepis, the median fins are not lobed. The pectoral fin possesses a long fleshy lobe. The internal, ventral side of the broadly based pelvic fin suggests that the internal axis has shifted towards the body. Pectoral fins with a long fleshy lobe are a common feature of porolepiforms, but lobed bases in the pelvic and unpaired fins are a feature found in Holoptychius, and not in Glyptolepis and Quebecius. Quebecius quebecensis is conspecific with Quebecius williamsi Schultze 1973, mistakenly described as an onychodont crossopterygian.


2019 ◽  
Vol 12 (1) ◽  
pp. 2 ◽  
Author(s):  
Wen An ◽  
Jun Jie Ma ◽  
Hong Yang Zhou ◽  
Hong Shan Chen ◽  
Xu Jun ◽  
...  

With the development of wireless communication technology and computer technology, more and more smart technologies have been applied in electricity distribution networks. This paper presents an adaptive current differential protection and fast auto-closing system for application in 10 kV distribution networks in China Southern Power Grid. The current differential protection can adaptively change its settings according to the topology change of the primary distribution networks, thus the system effectively reduces the operation and maintenance cost of the power distribution network. In order to restore the power supply for the healthy part of the 10 kV networks quickly after a power system fault is cleared, the protection and control system provides wide area control function for automatic fault isolation and automatic switching. The traditional overcurrent protection and control system have no fault location function, it may take several minutes or even hours to manually locate a fault and then restore the power supply. Compared with the protection and control system of the traditional 10 kV distribution networks, the system developed can locate and isolate faults within 900 ms (assuming that the operating time of the load switch is 700 ms), and can quickly restore power supply in less than one second after a power system fault is cleared.


Zootaxa ◽  
2007 ◽  
Vol 1440 (1) ◽  
pp. 1 ◽  
Author(s):  
XU LI ◽  
WEI ZHOU ◽  
ALFRED W. THOMSON ◽  
QING ZHANG ◽  
YING YANG

This study reports five species of Pareuchiloglanis in the Lancangjiang drainage of China, including descriptions of two new species: P. abbreviatus sp. nov., P. gracilicaudata, P. kamengensis, P. myzostoma and P. prolixdorsalis sp. nov. The two new species are distinguished from P. feae, P. poilanei, P. sichuanensis and P. tianquanensis by a shorter adipose-fin base and the adipose-fin base being separated from the caudal fin, differ from P. sinensis, P. macrotrema, P. longicauda and P. rhabdurus by a more restricted gill opening (not reaching the base of the first pectoral-fin element ventrally), and differ from P. songmaensis by an anal-fin ray count of ii-3-4 (vs. ii-8). Pareuchiloglanis abbreviatus is distinguished from congeners by the tip of the dorsal fin reaching the origin of the adipose fin when depressed. Pareuchiloglanis prolixdorsalis is distinguished from P. gongshanensis, P. macropterus and P. kamengensis by lacking a sulcus between the lower lip and the base of the maxillary barbel, and differs from P. anteanalis by the shorter pectoral fin, the pectoral fin not reaching to the origin of pelvic fin. It differs from P. gracilicaudata, P. myzostoma, P. nebulifer and P. robusta by a caudal-fin ray count of 6+7 (vs. 7+8), and differs from P. abbreviatus by the tip of dorsal fin not reaching to the origin of the adipose fin when depressed (vs. reaching). It differs from P. songdaensis by the distance between the origin of the pelvic fin to the base of the anal fin being longer than that to the mouth (vs. equal).  


Zootaxa ◽  
2017 ◽  
Vol 4320 (1) ◽  
pp. 121
Author(s):  
JEFFREY W. JOHNSON ◽  
HIROYUKI MOTOMURA

Five new species of sandperch (Pinguipedidae: Parapercis) from southeast Asia and northwest Australia are described. Parapercis soliorta sp. nov., known from a single specimen acquired from the Iloilo Central Market, taken off Iloilo, Panay Island, Philippines, is readily distinguished by a unique colour pattern including a series of nine brilliant yellow-ringed red spots along the body and caudal fin. Parapercis rubricaudalis sp. nov. is described from 15 specimens trawled between Dampier and Cape Leveque, Western Australia in 70–119 m and a single specimen taken by aquarium fish collectors off Zambales, Luzon, Philippines. It has the posterior end of the opercular ridge armed with two or three strong spines, the margin of the preopercle, subopercle and interopercle strongly serrated, and colouration including six broad irregular orange to reddish bands across the body, and the pelvic fins and lower third of the caudal fin crimson-red. A complex of three closely related species, Parapercis flavipinna sp. nov. from the Philippines, Parapercis caudopellucida sp. nov. from Myanmar and Parapercis hoi sp. nov. from northwest Australia and the Philippines, share a series of six or seven irregular dusky double blotches along the sides, a series of small black spots along the base of the soft dorsal-fin, a pair of dusky blotches on the caudal-fin base, and mostly similar meristic values. Parapercis hoi sp. nov. is known from four specimens trawled off Broome, Western Australia, in 97–109 m and one specimen trawled in the Sibuyan Sea, Philippines, in 73–84 m. It may be distinguished from its two closest congeners by cycloid cheek scales, a distinctive anal-fin colouration, and lower pectoral-fin ray, gill raker and lateral-line scale counts. Parapercis caudopellucida sp. nov., trawled in 125–129 m in the Andaman Sea off southern Myanmar, is described from two specimens. It differs from its two closest congeners most obviously by cycloid cheek scales, caudal-fin colouration, and the presence of a dusky bar extending posteroventrally from the tip of the maxilla to the anteroventral edge of the preopercle. Parapercis flavipinna sp. nov. is described from two specimens acquired from the Iloilo Central Market, taken off Iloilo, Panay Island, in the Philippines. It is distinguished most readily by the presence of ctenoid cheek scales and colouration including rows of bright yellow spots on the anal and caudal fins, a yellow upper lip, a series of yellow streaks and spots on the head, and fleshy pectoral-fin base with a large dark purplish grey blotch followed by a distinct white-edged black bar. 


1996 ◽  
Vol 32 (4) ◽  
pp. 2490-2494 ◽  
Author(s):  
M. Tezuka ◽  
T. Kojo ◽  
M. Naito ◽  
E. Toyoda ◽  
S. Hanai ◽  
...  

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