Initial Development of a Novel Amphibious Robot with Transformable Fin-Leg Composite Propulsion Mechanisms

Amphibious robots are very attractive for their broad applications in resource exploration, disaster rescue, and recon- naissance. However, it is very challenging to develop the robots for their complex, amphibious working environments. In the complex amphibious environment, amphibious robots should possess multi-capabilities to walk on rough ground, maneuver underwater, and pass through transitional zones such as sandy and muddy terrain. These capabilities require a high-performance propulsion mechanism for the robots. To tackle a complex task, a novel amphibious robot （AmphiHex-I） with,transformable fin-leg composite propulsion mechanisms is developed. With the fin-leg composite propulsions, AmphiHex-I can walk on rough and soft substrates and swim in water with many maneuvers. This paper presents the structural design of the transformable fin-leg propulsion mechanism and its driving module. A hybrid model is used to explore the dynamics between the trans- formable legs and transitional environment such as granular medium. The locomotion performances of legs with various ellip- tical shapes are analyzed, which is verified by the coincidence between the model predictions and the simulation results. Further, an orthogonal experiment is conducted to study the locomotion performance of a two-legged platform walking with an asyn- chronous gait in the sandy and muddy terrain. Finally, initial experiments of AmphiHex-I walking on various lands and swimming in water are implemented. These results verify that the transformable fin-leg mechanisms enable the amphibious robot to pass through a complex, amphibious working environment.     

Study on Decentralization of Spherical Amphibious Multi-robot Control System Based on Smart Contract and Blockchain

With the development of intelligent bionic robots and the improvement of military application,a single robot cannot meet the requirements of the tasks of the current era.The more complex tasks require not only that the robot be able to pass through the field barriers and the amphibious environment,but also that the robot be able to collaborate in a multi-robot system.Consequently,research on the multi-robot control system of spherical amphibious robots is very important.Pres-ently,the main research on amphibious robots is to improve the functions of a single robot,in the absence of the study of the multi-robot control system.Existing systems primarily use a centralized control methodology.Although the transfer of central node can be achieved,there is still a problem of Byzantine fault tolerance in military applications,that is,when the amphibious multi-robot system is invaded by the enemy.The central node may not only fail to accomplish the task,but also lose control of other robots,with severe consequences.To solve the above problems,this paper proposed a decentralized method of spherical amphibious multi-robot control system based on blockchain technology.First,the point-to-point informa-tion network based on long range radio technology of low power wide area network was set up,we designed the blockchain system for embedded application environment and the decentralized hardware and software architecture of multi-robot control system.On this basis,the consensus plugin,smart contract and decentralized multi-robot control algorithm were designed to achieve decentralization.The experimental results of consensus of spherical amphibious multi-robot showed the effectiveness of the decentralization.     

A Biomimetic Study of Discontinuous-Constraint Metamorphic Mechanism for Gecko-Like Robot

Locomotion ability, efficiency and reliability are key targets for a good robot. The linkage mechanism for robot locomotion is a discontinuous-constraint metamorphic mechanism. Here we set up equations to present the discontinuous-constraint, point out that driving and controlling are the key points to improve the performance and efficiency of the linkage mechanism. Inspired by controlling strategy of the motor nervous system in peripheral vertebrae to the locomotion, we draw off motor control and drive strategy.     

Braking Performance of a Biomimetic Squid-Like Underwater Robot

In this study, the braking performance of the undulating fin propulsion system of a biomimetic squid-like underwater robot was investigated through free run experiment and simulation of the quasi-steady mathematical model. The quasi-steady equations of motion were solved using the measured and calculated hydrodynamic forces and compared with free-run test results. Various braking strategies were tested and discussed in terms of stopping ability and the forces acting on the stopping stage. The stopping performance of the undulating fin propulsion system turned out to be excellent considering the short stopping time and short stopping distance. This is because of the large negative thrust produced by progressive wave in opposite direction. It was confirmed that the undulating fin propulsion system can effectively perform braking even in complex underwater explorations.     

Effect of an Artificial Caudal Fin on the Performance of a Biomimetic Fish Robot Propelled by Piezoelectric Actuators

This paper addresses the design of a biomimetic fish robot actuated by piezoeeramic actuators and the effect of artificial caudal fins on the fish robot＇s performance. The limited bending displacement produced by a lightweight piezocomposite actuator was amplified and transformed into a large tail beat motion by means of a linkage system. Caudal fins that mimic the shape of a mackerel fin were fabricated for the purpose of examining the effect of caudal fm characteristics on thrust production at an operating frequency range. The thickness distribution of a real mackerel＇s fin was measured and used to design artificial caudal fins. The thrust performance of the biomimetic fish robot propelled by fins of various thicknesses was examined in terms of the Strouhal number, the Froude number, the Reynolds number, and the power consumption. For the same fm area and aspect ratio, an artificial caudal fin with a distributed thickness shows the best forward speed and the least power consumption.     

Development of a Biomimetic Quadruped Robot

This paper presents the design and prototype of a small quadruped robot whose walking motion is realized by two piezocomposite actuators. In the design, biomimetic ideas are employed to obtain the agility of motions and sustainability of a heavy load. The design of the robot legs is inspired by the leg configuration of insects, two joints （hip and knee） of the leg enable two basic motions, lifting and stepping. The robot frame is designed to have a slope relative to the horizontal plane, which makes the robot move forward. In addition, the bounding locomotion of quadruped animals is implemented in the robot. Experiments show that the robot can carry an additional load of about 100 g and run with a fairly high velocity. The quadruped prototype can be an important step towards the goal of building an autonomous mobile robot actuated by piezocomposite actuators.     

Biomimetic Design and Optimal Swing of a Hexapod Robot Leg

Biological inspiration has spawned a wealth of solutions to both mechanical design and control schemes in the efforts to develop agile legged machines. This paper presents a compliant leg mechanism for a small six-legged robot, HITCR-ll, based on abstracted anatomy from insect legs. Kinematic structure, relative proportion of leg segment lengths and actuation system were analyzed in consideration of anatomical structure as well as muscle system of insect legs and desired mobility. A spring based passive compliance mechanism inspired by musculoskeletal structures of biological systems was integrated into distal segment of the leg to soften foot impact on touchdown. In addition, an efficient locomotion planner capable of generating natural movements for the legs during swing phase was proposed. The problem of leg swing was formulated as an optimal control procedure that satisfies a series of locomotion task terms while minimizing a biologically-based objective function, which was solved by a Gauss Pseudospectral Method （GPM） based numerical technique. We applied this swing generation algorithm to both a simulation platform and a robot prototype. Results show that the proposed leg structure and swing planner are able to successfully perform effective swing movements on rugged terrains.     

Development of a Bionic Hexapod Robot for Walking on Unstructured Terrain

This paper reports the design methodology and control strategy in the development of a novel hexapod robot HITCR-II that is suitable for walking on unstructured terrain. First, the entire sensor system is designed to equip the robot with the perception of external environment and its internal states. The structure parameters are optimized for improving the dexterity of the robot. Second, a foot-force distribution model and a compensation model are built to achieve posture control. The two models are capable of effectively improving the stability of hexapod walking on unstructured terrain. Finally, the Posture Control strategy based on Force Distribution and Compensation （PCFDC） is applied to the HITCR-II hexapod robot. The experimental results show that the robot can effectively restrain the vibration of trunk and keep stable while walking and crossing over the un- structured terrains.     

Root Cortical Cell Spherical Bodies Associated with an Induced Resistance Reaction in Monoxenic Cultures of Meloidogyne incognita

The root-knot nematode Meloidogyne incognita was monoxenically cultured on excised roots of soybean cv. Pickett and tomato cv. Rutgers in agar media containing either 0 to 1,600 μg/ml ammonium nitrate or 0 to 100 μg/ml urea. Observations with scanning and transmission electron microscopy indicated that an elevated concentration of ammonium nitrate or urea inhibited giant cell formation and suppressed nematode development in the infected soybean roots. In the tomato roots, concentrations of ammonium nitrate above 400 μg/ml or urea above 25 μg/ml inhibited giant cell formation and nematode development. Coincident with the nitrogen concentrations that suppressed giant cell formation was the appearance of electron-dense spherical bodies in the cortical parenchyma cells of both the soybean and tomato roots. These bodies, which were 1-4 μm in diameter, appeared to form in the cytoplasm and migrate to the cell vacuole.     

Design of a Biomimetic Skin for an Octopus-Inspired Robot – Part II: Development of the Skin Artefact

Octopus skin samples were tested under quasi-static and scissor cutting conditions to measure the in-plane material properties and fracture toughness. Samples from all eight arms of one octopus were tested statically to investigate how properties vary from arm to arm. Another nine octopus skins were measured to study the influence of body mass on skin properties. Influence of specimen location on skin mechanical properties was also studied. Material properties of skin, i.e. the Young's modulus, ultimate stress, failure strain and fracture toughness have been plotted against the position of skin along the length of arm or body. Statistical studies were carried out to help analyzing experimental data obtained. Results of this work will be used as guidelines for the design and development of artificial skins for an octopus-inspired robot.     

Development of an expert system for the integration of biomarker responses in mussels into an animal health index

Biomarkers on sentinel organisms are utilised worldwide in biomonitoring programs. However, the lack of effective interpretational capacity has hampered their uptake for use for assessment of risk in environmental management. The aim of the present study was to develop and test an objective decision-support or expert system capable of integrating biomarker results into a five-level health-status index. The expert system is based on a set of rules derived from available data on responses to natural and contaminant-induced stress of marine mussels. Integration of parameters includes: level of biological organization; biological significance; mutual inter-relationship; and qualitative trends in a stress gradient. The system was tested on a set of biomarker data obtained from the field and subsequently validated with data from previous studies. The results demonstrate that the expert system can effectively quantify the biological effects of different levels of pollution. The system represents a simple tool for risk assessment of the harmful impact of contaminants by providing a clear indication of the degree of stress syndrome induced by pollutants in mussels.     

Development of an expert system for the integration of biomarker responses in mussels into an animal health index

Biomarkers on sentinel organisms are utilised worldwide in biomonitoring programs. However, the lack of effective interpretational capacity has hampered their uptake for use for assessment of risk in environmental management. The aim of the present study was to develop and test an objective decision-support or expert system capable of integrating biomarker results into a five-level health-status index. The expert system is based on a set of rules derived from available data on responses to natural and contaminant-induced stress of marine mussels. Integration of parameters includes: level of biological organization; biological significance; mutual inter-relationship; and qualitative trends in a stress gradient. The system was tested on a set of biomarker data obtained from the field and subsequently validated with data from previous studies. The results demonstrate that the expert system can effectively quantify the biological effects of different levels of pollution. The system represents a simple tool for risk assessment of the harmful impact of contaminants by providing a clear indication of the degree of stress syndrome induced by pollutants in mussels.     

Development of a room laser based real-time alignment monitoring system using an array of photodiodes

PurposeTo develop a real-time alignment monitoring system (RAMS) to compensate for the limitations of the conventional room-laser-based alignment system. To verify the feasibility of the RAMS, reproducibility and accuracy tests were conducted.MethodsRAMS was composed of a room laser sensing array (RLSA), an electric circuit, an analog-to-digital converter (ADC), and a control PC. The RLSA was designed to arrange photodiodes in a pattern that results in the RAMS having a resolution of 1 mm. The photodiodes were used for quantitative assessment of the alignment condition. To verify the usability of the developed system, we conducted tests of temporal reproducibility, repeatability, and accuracy.ResultsThe results of the temporal reproducibility test suggested that the signal of the RAMS was stable with respect to time. Further, the repeatability test resulted in a maximum coefficient of variance of 1.14%, suggesting that the signal of the RAMS was stable over repeated set-ups. The accuracy test confirmed that the “on” and “off” signals could be distinguished by signal intensity, considering that the “off” signal was below 75% of the “on” signal in every case. In addition, we confirmed that the system can detect 1 mm of movement by monitoring the pattern of the “on” and “off” signals.ConclusionWe developed a room laser based alignment monitoring system. The feasibility test verified that the system is capable of quantitative alignment monitoring in real time. We expect that the RAMS can propose the potential of the room laser based alignment monitoring method.     

Development of a quantification system of ionic dissociative metabolites using an FT-IR/ATR method

A simultaneous quantification system of ionic dissociative metabolites was developed using a Fourier transform mid-infrared spectroscopic method by focusing our attention on the enzyme reaction from glucose 6-phosphate to fructose 6-phosphate with phosphoglucose isomerase (PGI). We studied the pH dependency of the infrared spectra of the mixture solution for which the PGI reaction was assumed. The infrared spectra of ionic dissociative components in the mixture solution were extracted by multiple linear regression analysis under the assumption of ionic dissociation equilibrium. Additionally, we constructed a simultaneous quantification system using the extracted spectra of the ionic dissociative components on the basis of the ionic dissociation equilibrium. We could accurately estimate the pH value and the concentrations of the ionic dissociative materials in their mixture solution by using this quantification system. In addition, the stability of quantification results for a pK shift was also verified.     

野油菜黄单胞菌S—152遗传转移系统的建立及外源性内切葡聚糖酶基因在其体内的表达

通过细胞接合的方式将广宿主质粒pRK404、pKT230和RP4分别转入野油菜黄单胞菌S-152中,其转移频率均在10-4数量级上,从而建立起了S—152的转移系统．用同法将由载体质粒pRK404和白纹黄单胞菌XAI-1的CMC酶基因构成的重组质粒pND82转入到S－152中共得到了表达,使S—152（pND82）的胞内CMC酶酶活比出发菌株S-152提高了1倍．     

Development of an apparatus for rapid release of oligosaccharides at the glycosaminoglycan-protein linkage region in chondroitin sulfate-type proteoglycans

An apparatus, AutoGlycoCutter (AGC), was developed as a tool for rapid release of O-linked-type glycans under alkaline conditions. This system allowed rapid release of oligosaccharides at the glycosaminoglycan-protein linkage region in proteoglycans (PGs). After digestion of PGs with chondroitinase ABC, the oligosaccharides at the linkage region were successfully released from the protein core by AGC within 3 min. The reducing ends of the released oligosaccharides were labeled with 2-aminobenzoic acid and analyzed by a combination of capillary electrophoresis (CE) and matrix-assisted laser desorption time-of-flight mass spectrometry. In addition, the unsaturated disaccharides produced by chondroitinase ABC derived from the outer parts of the glycans were labeled with 2-aminoacridone and analyzed by CE to determine the disaccharide compositions. We evaluated AGC as a method for structural analysis of glycosaminoglycans in some chondroitin-sulfate-type PGs (urinary trypsin inhibitor, bovine nasal cartilage PG, bovine aggrecan, bovine decorin, and bovine biglycan). Recoveries of the released oligosaccharides were 57-73% for all PGs tested in the present study. In particular, we emphasize that the use of AGC achieved ca. 1000-fold rapid release of O-glycans compared with the conventional method.