To address the problems of complex structure, poor versatility, and cumbersome fabrication of existing micro-crawling robots, an insect-scale parallel leg module is proposed. The module is a general-purpose insect-scale micro-crawling module that can not only move independently but can also be used with multiple modules to create a wide range of robots that can be applied to accomplish different tasks. The insect-scale parallel leg module has a weight of 0.2 g and size of 1.5 ×0.8 ×2.5 cm and is driven by piezoelectric ceramics. The overall structure of the module consists of the piezoelectric actuator unit and the parallel leg unit, which are fabricated in an integrated manner using micromachining technology and lamination techniques. The prototype of the insect-scale parallel leg module and the experimental environment were built, the movement displacement of the piezoelectric actuator and the plantar of the parallel leg module were tested, and the independent motion capability of the prototype was demonstrated.

Amphibious robots have broad prospects in the fields of industry, defense, and transportation. To improve the propulsion performance and reduce operation complexity, a novel bionic amphibious robot, namely AmphiFinbot-II, is presented in this paper. The swimming and walking components adopt a compound drive mechanism, enabling simultaneous control for the rotation of the track and the wave-like motion of the undulating fin. The robot employs different propulsion methods but utilizes the same operation strategy, eliminating the need for mode switching. The structure and the locomotion principle are introduced. The performance of the robot in different motion patterns was analyzed via computational fluid dynamics simulation. The simulation results verified the feasibility of the wave-like swimming mechanism. Physical experiments were conducted for both land and underwater motion, and the results were consistent with the simulation regulation. Both the underwater linear and angular velocity were proportional to the undulating frequency. The robot’s maximum linear speed and steering speed on land were 2.26 m/s (2.79 BL/s) and 442°/s, respectively, while the maximum speeds underwater were 0.54 m/s (0.67 BL/s) and 84°/s, respectively. The research findings indicate that the robot possesses outstanding amphibious motion capabilities and a simplistic yet unified control approach, thereby validating the feasibility of the robot’s design scheme, and offering a novel concept for the development of high-performance and self-contained amphibious robots.

Amphibious robots offer promising applications in field scenarios such as search and rescue, exploration and reconnaissance, and environment monitoring. However, achieving high locomotion performance in terrestrial, aquatic, and soft muddy transition areas remains challenging. This study presents a novel amphibious robot based on the hybrid drive of tracks and bionic fins. The robot is driven by a pair of tracks on land and by a pair of undulating fins underwater, without the need for switching operating modes due to the simultaneous drive of the two components. The structure design is introduced and the united operating strategies are derived for propulsion in multiple environments propulsion. A land-water united controller for the heading angle and track/fin frequency is designed based on a mathematical model. In field experiments, the robot achieved the maximum linear velocities of 2 m/s on land and 0.51 m/s underwater, with maximum yaw rates of 225 / degrees s ${}<^>{\circ }/{\rm{s}}$ and 100 / degrees s ${}<^>{\circ }/{\rm{s}}$, respectively. The robot could transition seamlessly between land and water in less than 2 s. The closed-loop control experiments demonstrated that the robot could quickly follow the desired angle with minimal error in both media using the same controller and parameters. The proposed simultaneous drive method enhances the multi-terrain motion capacity and cross-medium performance while reducing control complexity of amphibious robot, providing a new perspective for the development of self-adaptive and high-performance amphibious robots for practical application.

Inefficiency is a technical bottleneck that affects the widespread use of wearable robots. Inspired by the efficient motor mechanism of human muscles, we designed a high efficiency Bio-inspired Hydraulic Actuator (BHA) that combines pump, cylinder, valve and motor in a compact structure. By mimicking the structure of the multi-fiber motor unit and the power supply mode of human muscles, the new actuator adopts a two-stage energy supply mode and an innovative structure of two pumps and two cylinders. Through such a design, the output power and force of the BHA can precisely match the change of load, reducing the throttling loss in the traditional hydraulic system and greatly improving the system efficiency of the bionic wearable robot. The analysis and experiments in this paper show that the actuator of the integrated pump cylinder has good energy efficiency, and the prosthesis using BHA can achieve a gait consistent with human normal walking.

The structure design of the robotic leg is a core and hot research area for legged robots. In this paper, we report a series-parallel reconfigurable 3D thrust vector leg mechanism with 3 degree-of-freedom (DOF). Upper leg is a spatial dual-parallelogram-linkages parallel mechanism, lower leg is a spatial closed-loop eight-bar mechanism. The kinematic model of the mechanism is built based on the screw theory, and the mechanism's control complexity is examined and contrasted. The kinematic performance and static performance of the leg mechanism are analyzed. A quadruped robot is built based on the proposed leg mechanism., and the omnidirectional legged locomotion is verified by simulation.

This paper presents a novel two-body counter-rotating wave energy converter (CR-WEC) designed to power deep-sea exploration equipment. In contrast to conventional two-body structures, which employ relative motion, the CR-WEC powers the Power Take-Off (PTO) via absolute motion to circumvent the issue of a limited working stroke. We present the power equation of CR-WEC in the frequency domain, based on the actuator disk model from the wind turbine field, in order to elucidate the energy absorption characteristics of this type of two-body absorber and investigate the influence of parameters on power acquisition. Experiments conducted as part of this study have confirmed this theory's applicability to the CR-WEC. Through an approximation, we derive the frequency point corresponding to the maximum value of the equation, which we refer to as the Power Maximum Frequency Point (PM-FP) in this paper. Under the external excitation of both regular and irregular waves, we investigate how parameter modification can enhance the absorber's capture characteristics in specific cases. After modifying the parameters according to the principles derived from the aforementioned research, the system's theoretical power output can more than double. In addition, this study's conclusions emphasize the benefits of CR-WEC with cascade expansion. By connecting multiple PTOs in series, power generation can be enhanced.

This comprehensive review systematically investigates diverse Maximum Power Point Tracking (MPPT) control strategies in Point Absorber Wave Energy Conversion (PA-WEC) systems. It elucidates each technique's key characteristics, advantages, and limitations, along with their scope and principle, providing a crucial roadmap for future research in renewable and sustainable energy. A highlight is the proposition of an innovative hybrid MPPT method combining a wide-range input LLC resonant converter with an Advanced Particle Swarm Optimization (APSO) strategy, optimizing energy extraction under various wave conditions. The review evaluates existing MPPT techniques for PA-WEC systems, dissecting their efficiency, tracking speed, cost, complexity, and robustness. By utilizing the Improved Analytic Hierarchy Process (IAHP) entropy weighting method, the study facilitates a detailed analysis of performance metrics, recent advancements, and eighteen diverse MPPT strategies. Multi-index case study outcomes from the IAHP entropy weight method, supplemented with MATLAB simulations, vouch for the impressive comprehensive performance of the proposed hybrid MPPT method. By employing a mix of qualitative and quantitative methodologies for a rigorous analysis of the algorithmic principles integral to wave energy MPPT and an examination of their practical adaptability. In essence, this review serves as a valuable compass for industry professionals, policymakers, and researchers aiming to advance the field of wave energy conversion. It emphasizes the potential of pioneering MPPT control strategies to enhance the efficiency of PA-WEC systems, thereby providing a solid foundation for the pursuit of sustainable energy solutions.

A wave energy converter features the ability to convert wave energy into the electrical energy required by unmanned devices, and its energy-conversion efficiency is an essential aspect in practical applications. This paper proposes a novel point-absorption wave energy converter with passive morphing blades to meet the demand for improved energy-conversion efficiency. We first introduce its concept and design, with its blades forming their shape by adaptive changes with the direction of the water flow. Next, the three-dimensional geometrical-morphing model, energy-conversion model, and energy-conversion-efficiency model of the wave energy converter were established. Then, the CFD model was built to optimize the design parameters, and the simulation results revealed that the maximum conversion efficiency can be obtained at 90% solidity with 10 blades, a 40–60% load, and 20~25 degrees for the external deflection angle. The simulations also showed that the passive morphing-blade group provides ~40% higher torque and ~60% higher hydraulic efficiency than the flat-blade group.

For the energy supplement of deep-sea equipment, we examine a multi-body absolute motion counter-rotating wave energy converter (CR-WEC) in the research. In order to improve the capture efficiency of the absorber, a nonlinear bistable structure is proposed to improve the overall wave-following vibration capability of the CRWEC. And then, we suggest to employing the harmonic balance method to solve the system dynamics equation in the CR-WEC 2-DOF absolute motion state. Combining the essential assumptions results in an analytical solution that is approximative. The paper also investigates the influence of system-related parameter modifications on absorption efficiency. A multi-degree-of-freedom arrangement with an unaltered overall mass is proposed to further increase the device ability to absorb energy. According to the numerical calculation and simulation results, the combination of 3-DOF state and bistable structure can make the device have the maximum capture width and peak value. In the irregular incident wave under the natural state, the multi-body bistable-linear configuration proposed in this study obtains the highest average absorption power.

The problem of insufficient power supply for unmanned marine equipment at sea limits its development and utilization. In this paper, we designed a power supply unit capable of absorbing wave energy and converting it into electricity, which helps to solve the problem of limited power supply ability. Its main structure is demonstrated by theoretical design and modeling, and its operating principle is presented. Its performance (power coefficient and torque coefficient) was numerically simulated via Computational Fluid Dynamics tools, and the effect of blade groups’ solidity on its operating performance was investigated. The study found that the blades of the blade groups can absorb more energy by arranging along the outer ring, and the energy conversion efficiency of the blade groups is related to their load.

Fluctuation and unpredictability of wave power output affect the safe operation of the power grid, which greatly restricts the development of wave power generation. This paper firstly introduces the principle and control strategy of wave to wire (W2W) model, whose input is from wave energy conversion (WEC) system and output to the electrical power injected into grid for stable power. Then, an adapted particle swarm optimization (APSO) algorithm-based maximum power point tracking technology (APSO-MPPT) considering adaptive inertia weighting variables is presented for quick dynamic reaction. Comparisons are made with the traditional constant voltage method, INC method, P&Q method, and PSO algorithm, the APSO-MPPT method can reduce the tracking time by 9.3% less than the quickest traditional. Secondly, a K–SOC curve algorithm-based hybrid energy storage system (KSC-HESS) optimization is conducted for smoothing the wave power output, with real time control performance. Simulations under output power fluctuation, load pulsation and load unbalancing situations are occupied for demonstrating high performance for the characteristics of the proposed KSC-HESS, in both reducing high-frequency burden for super-capacitors and protecting batteries from over voltage. Furthermore, results of prototype experiment verified the effectiveness with better efficiency by adapting the proposed APSO-MPPT and KSC-HESS for the proposed W2W system. Analysis shows the proposed W2W approach has comparative advantages of control complexity and high reliability for renewable power output.

Abstract. Due to the defects of the internal structure and energy supply carrier, conventional deep sea unoccupied marine equipment cannot meet the requirements of low power consumption. In this paper, the whole structure of a multi-body heave wave energy conversion system was designed to capture and convert wave energy. The conversion system consists of a floating body, an underwater absorber and a power takeoff system (PTO). The dynamic model of the energy conversion system and the mathematical model of energy efficiency evaluation were established according to the dynamic analysis. Based on the real service environment in the South China Sea, the energy efficiency characteristics of floating bodies with different shapes were simulated, and the amplitude response operator (RAO), radiation damping, added mass and Froude–Krylov force of floating bodies with different shapes were compared. Then, the optimal energy efficiency parameters of surface floating body were explored. Finally, the correctness of the conclusion was verified by the energy efficiency test. The results show that, under the limitation of low power consumption and space scale, the energy conversion system of an axisymmetric rotary body with the same sea conditions, same material and the largest scale can significantly improve the conversion efficiency, and the spherical rotary body performs the best, which makes the unoccupied marine equipment have a broad prospect for development.

当前机械化和信息化技术是现代武器装备中的核心技术,军队建设迫切需要大批掌握有关机电一体化技术、懂装备和会用装备的新型军事人才.装备虚拟仿真实验教学成为院校教育在无装备或少装备条件下的一种有效手段.文章详细介绍了一类虚拟仿真实验教学平台的系统技术架构和虚拟仿真实验教学系统的建设思路以及面向高校及社会的应用和服务计划.该架构下虚拟仿真实验教学平台的建设,能够有效弥补各类实践课程教学中实装匮乏的现状,可以加快学生任职能力培养、科技素质培养.

未来战场需要军事院校培养懂得使用、维修高技术装备的军事人才,然而当前综合性军事技术院校存在无实装、少实装的问题.为此,文章提出基于反坦克武器系统的装备原理类课程线上线下混合式教学模式,通过线上的虚拟仿真实验和线下的装备模型实操,提升了学生对装备运行原理和内部结构的熟悉度,增强了学生的综合实践能力,保证了其首次部队任职时具备较高的专业技术水准.

In this paper, a staggered vernier generator suitable for a counter-rotating self-adaptable WEC is proposed to meet the energy demand of the small-scale engineering equipment in the deep sea. According to the vernier effect of the magnetic gear, the generator modulates the low-order rotating magnetic field generated by the rotation of the low-speed permanent magnet rotor into a high-order magnetic field rotating at a high speed, thereby realizing the acceleration of the generator magnetic field. A staggered structure permanent magnet vernier generator with 18 teeth/28 poles is designed. The main magnetic flux path on the staggered structure in the staggered vernier generator is analyzed, and the air-gap magnetic field distribution of the generator is analyzed with the help of numerical simulation software. The influence of different design parameters on the vernier generator is discussed. The staggered vernier structure can improve the main magnetic flux of the generator, reduce the magnetic flux leakage, and improve the performance of the generator without adding additional structures and materials.

For unmanned underwater vehicles (UUV) endurance is limited and it is difficult to accomplish long-endurance mission, the key technologies that drive UUV through the environmental energy have been studied. Environmental energy has the advantages of large amount of storage, renewable and clean, can be absorbed and transformed. It can be used to drive unmanned underwater vehicles. First of all, this paper analyzed the endurance and power demand of UUVs; the second, according to the type of environmental energy, the application of solar energy, ocean temperature difference energy and wave energy used in UUVs’ drive is described respectively. Mainly includes: natural characteristics and distribution of environmental energy; the feasibility of driving UUVs; The development of environmental driving UUVs and the research of its key technologies. In the end, the application prospect of environmental energy in unmanned underwater vehicle is stated.

直接挤出成型制造适用于任何含或不含添加剂的膏状或凝胶状复合材料,对复合材料制造技术具有深远意义.通过探讨热固性环氧树脂的流变学行为与挤出成型特性,得出热固性环氧树脂在直接挤出成型制造应用中的通用性流变学参数.通过向复合材料中加入增稠剂,对其流变学行为进行设计.结果表明:在高剪切速率(50 s-1)和低剪切速率(0.01 s-1)下,添加30％纳米黏土的环氧树脂的流变学行为较适合挤出式3D打印工艺.利用龙门式气动挤出式3D打印机,对复合材料的打印成型质量进行试验分析和验证.结合试验结果探讨了喷头高度对复合材料成型质量的影响,并且提出适用于喷头高度临界值的计算方法.探讨了挤出率、剪切速率等因素对成型质量的作用规律.针对多层打印问题,提出包含补偿系数的多层打印的临界喷头高度的计算方法.以上研究对促进基于复合材料的挤出式3D打印具有积极意义.

Small moving vehicles represent an important category of marine engineering tools and devices (equipment) typically used for ocean resource detection and maintenance of marine rights and interests. The lack of efficient power supply modes is one of the technical bottlenecks restricting the effective utilisation of this type of equipment. In this work, the performance characteristics of a new type of elastic-blade/wave-energy converter (EBWEC) and its core energy conversion component (named wave energy absorber) are comprehensively studied. In particular, computational fluid dynamics (CFD) simulations and experiments have been used to analyze the hydrodynamics and performance characteristics of the EBWEC. The pressure cloud diagrams relating to the surface of the elastic blade were obtained through two-way fluid-solid coupling simulations. The influence of blade thickness and relative speed on the performance characteristics of EBWEC was analyzed accordingly. A prototype of the EBWEC and its bucket test platform were also developed. The power characteristics of the EBWEC were analyzed and studied by using the blade thickness and motion cycle as control variables. The present research shows that the EBWEC can effectively overcome the performance disadvantages related to the transmission shaft torque load and power curve fluctuations of rigid blade wave energy converters (RBWEC).

Nowadays, drifters are used for a wide range of applications for researching and exploring the sea. However, the power constraint makes it difficult for their sampling intervals to be smaller, meaning that drifters cannot transmit more accurate measurement data to satellites. Furthermore, due to the power constraint, a modern Surface Velocity Program (SVP) drifter lives an average of 400 days before ceasing transmission. To overcome the power constraint of SVP drifters, this article proposes an adaptively counter-rotating wave energy converter (ACWEC) to supply power for drifters. The ACWEC has the advantages of convenient modular integration, simple conversion process, and minimal affection by the crucial sea environment. This article details the design concept and working principle, and the interaction between the wave energy converter (WEC) and wave is presented based on plane wave theory. To verify the feasibility of the WEC, the research team carried out a series of experiments in a wave tank with regular and irregular waves. Through experiments, it was found that the power and efficiency of the ACWEC are greatly influenced by parameters such as wave height and wave frequency. The maximum output power of the small scale WEC in a wave tank is 6.36 W, which allows drifters to detect ocean data more frequently and continuously.