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power consumption Characteristics Research on Mobile System of Electrically Driven Large-Load-Ratio Six-Legged Robot

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Chinese Journal of Mechanical Engineering 2023年第1期36卷 237-267页

作者： Hongchao Zhuang Ning Wang Haibo Gao Zongquan Deng School of Mechanical Engineering Tianjin University of Technology and EducationTianjin300222China School of Information Technology Engineering Tianjin University of Technology and EducationTianjin300222China State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin150001China

The electrically driven large-load-ratio six-legged robot with engineering capability can be widely used in outdoor and planetary exploration.However,due to the particularity of its parallel structure,the effective utilization rate of energy is not high,which has become an important obstacle to its practical application.To research the power consumption characteristics of robot mobile system is beneficial to speed up it toward practicability.Based on the configuration and walking modes of robot,the mathematical model of the power consumption of mobile system is set up.In view of the tripod gait is often selected for the six-legged robots,the simplified power consumption model of mobile system under the tripod gait is established by means of reducing the dimension of the robot’s statically indeterminate problem and constructing the equal force distribution.Then,the power consumption of robot mobile system is solved under different working conditions.The variable tendencies of the power consumption of robot mobile system are respectively obtained with changes in the rotational angles of hip joint and knee joint,body height,and span.The articulated rotational zones and the ranges of body height and span are determined under the lowest power consumption.According to the walking experiments of prototype,the variable tendencies of the average power consumption of robot mobile system are respectively acquired with changes in duty ratio,body height,and span.Then,the feasibility and correctness of theory analysis are verified in the power consumption of robot mobile system.The proposed analysis method in this paper can provide a reference on the lower power research of the large-load-ratio multi-legged robots.

关键词： Electrically driven Large-load-ratio six-legged robot power consumption Mobile system

Effect of an Inclined Slots on the power consumption and Vortices Size in a Rushton Turbine Agitated Tank

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Chinese Journal of Mechanical Engineering 2023年第6期36卷 261-276页

作者： Sarra Youcefi Mohamed Bouzit Abdelkader Youcefi Abderrahim Mokhefi Laboratory of Applied Mechanics Department of Mechanical EngineeringUniversity of Sciences and Technology of OranOran 31000Algeria Laboratory of Maritime Sciences and Engineering Department of Marine EngineeringUniversity of Science and Technology of OranOran 31000Algeria Laboratory of Aeronautics and Propulsion Systems Department of Mechanical EngineeringUniversity of Science and Technology of OranOran 31000Algeria Laboratory of Mechanics Modeling and ExperimentationDepartment of Mechanical EngineeringTahri Mohamed University of BecharBechar 08000Algeria

Mechanical agitation in baffled vessels with turbines plays a vital role in achieving homogeneous fluid mixing and promoting various transfer operations.Therefore,designing vessels with optimal energy efficiency and flow dynamics is essential to enhance operational performance and eliminate flow perturbations.Hence,the present research focuses on a numerical investigation of the impact of inclined slots with different angles installed at the side-wall of a cylindrical vessel equipped with a Rushton turbine.This study explores power consumption and vortex size while considering various rotation directions of the impeller with different rotation speeds.The numerical simulations are conducted for Reynolds numbers ranging from 104 to 105,using the RANS k-εturbulence model to govern the flow inside the stirred vessel,accounting for mass and momentum balances.The results have shown that the installation of slots reduces power consumption and vortex size compared to conventional vessel configu-rations.Moreover,increasing the slot angle from 0 to 32.5°further reduces energy consumption and vortex size,especially with negative rotation speeds.On the other hand,increasing the Reynolds numbers leads to a decrease in power consumption and an increase in vortex size.The present research therefore proposes a design for con-structing Rushton-turbine stirred vessels offering optimal operation,characterized by reduced energy consumption and minimized vortex size.

关键词： Mixing Stirred tank Rushton turbine Inclined slots Hydrodynamic power consumption Vortices size

Load distribution strategy for multi-lift system with helicopters based on power consumption and robust adaptive game control

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Chinese Journal of Aeronautics 2023年第4期36卷 268-285页

作者： Dengyan DUAN Gen LENG Jie GAO Xinming FENG Jianbo LI National Key Laboratory of Rotorcraft Aeromechanics Nanjing University of Aeronautics and AstronauticsNanjing 210016China

It is of great significance to reasonably distribute the slung load to each helicopter while considering difference in power consumption,relative position and interaction comprehensively.Therefore,the load distribution strategy based on power consumption and robust adaptive game control is proposed in this paper.The study is on a"2-lead"multi-lift system of four tandem heli-copters carrying a load cooperatively.First,based on the hierarchical control,the load distribution problem is divided into two parts:the calculation of expected cable force and the calculation of the anti-disturbance cable force.Then,aimed at minimizing the maximum equivalent power of heli-copter,an optimization problem is set up to calculate the expected cable force.Specially,the agent power model is trained by BP neural network,the safe distance constraint between helicopters is set to 2.5 rotor diameters to reduce aerodynamic interference,and the helicopters with different perfor-mance can be considered by introducing the equivalent power factor into the objective function.Next,considering the difference and interaction between helicopters,the robust adaptive differen-tial game control is proposed to calculate the anti-disturbance cable force.Particularly,to solve the coupled Hamiltonian equations,an adaptive solving method for value function is proposed,and its stability is proved in the sense of Lyapunov.The simulation results indicate that the proposed load distribution method based on power consumption is applicable to the entire flight trajectory even there are differences between helicopters.The game control can consider interaction between heli-copters,can deal with different objective functions,and has strong robustness and small steady-state error.Based on the entire strategy,the cable force can be reasonably allocated so as to resist disturbance and improve the flight performance of the whole system.

关键词： Differential game Helicopter Load distribution Multi-lift system power consumption Tracking control

Effect of the Inclination of Baffles on the power consumption and Fluid Flows in a Vessel Stirred by a Rushton Turbine

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Chinese Journal of Mechanical Engineering 2017年第4期30卷 1008-1016页

作者： Youcef Kamla Mohamed Bouzit Houari Ameur Mohammed Ilies Arab Abdessalam Hadjeb Faculty of Mechanical Engineering University of Scienceand Technology USTO-MB1505 E1 M'naouarOranAlgeria Institute of Science and Technology University Center Ahmed Salhi(Ctr-Univ Naama)BP 6645000 NaamaAlgeria

The role of baffles in mechanically stirred tanks is to promote the stability of power drawn by the impeller and to avoid the fluid swirling, thus enhancing mixing. The present paper numerically investigates the baffles effects in a vessel stirred by a Rushton turbine. The geometric factor of interest is the baffle inclination which is varying between 25°, 32.5°, 45°, 70° and 90° at different impeller rotational speeds. The impeller rotational direction has also been varied. The vortex size and power consumption were evaluated for each geometrical configuration. It was found that the best configuration is the baffle inclination by = 70° at a negative angular velocity.

关键词： Stirred tanks power consumption Baffles Rushton turbine CFD simulation

Unsteady Aerodynamic Forces and power consumption of a Micro Flapping Rotary Wing in Hovering Flight

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Journal of Bionic Engineering 2018年第2期15卷 298-312页

作者： Chao Zhou Yanlai Zhang Jianghao Wu School of Transportation Science and Engineering Beihang University Beijing 100191 China

The micro Flapping Rotary Wing （FRW） concept inspired by insects was proposed recently. Its aerodynamic performance is highly related to wing pitching and rotational motions. Therefore, the effect of wing pitching kinematics and rotational speed on unsteady aerodynamic forces and power consumption of a FRW in hovering flight is further studied in this paper using computational fluid dy- namics method. Considering a fixed pitching amplitude （i.e., 80°）, the vertical force of FRW increases with the downstroke angle of attack and is enhanced by high wing rotational speed. However, a high downstroke angle of attack is not beneficial for acquiring high rotational speed, in which peak vertical force at balance status （i.e., average rotational moment equals zero.） is only acquired at a comparatively small negative downstroke angle of attack. The releasing constraint of pitching amplitude, high rotational speed and enhanced balanced vertical force can be acquired by selecting small pitching amplitude despite high power consumption. To confirm which wing layout is more power efficient for a certain vertical force requirement, the power consumed by FRW is compared with the Rotary Wing （RW） and the Flapping Wing （FW） while considering two angle of attack strategies without the Reynolds number （Re） constraint. FRW and RW are the most power efficient layouts when the target vertical force is produced at an angle of attack that corresponds to the maximum vertical force coefficient and power efficiency, respectively. However, RW is the most power efficient layout overall despite its insufficient vertical force production capability under a certain Re.

关键词： micro air vehicle flapping rotary wing aerodynamic forces power consumption computational fluid dynamics

Suspension quality and power consumption of the complex multiphase flow field in a draft-tube stirred reactor

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Particuology 2021年第3期19卷 91-102页

作者： Licheng Wang Yanxing Tian Yu Qi Yiwei Gao Mengya Wang School of Chemistry and Chemical Engineering Tianjin University of TechnologyTianjin 300384China

Experiment and simulation were used to study the flow fields of a liquid-solid-solid three-phase system in a draft-tube stirred reactor with a six-flat-bladed turbine impeller(BT)and a 45°pitched six-bladed upflow turbine impeller(PBTU45).The computational fluid dynamics(CFD)formulation was based on a 3D Eulerian multi-fluid model along with a renormalization group(RNG)k-ε turbulence model,which took into account the inter-phase momentum exchange between different phases.The CFD model was validated using experimental data,and the suspension quality was validated by determining the standard deviation of the solid concentration.Good solid suspension was achieved in flow fields agitated by the BT impeller at low impeller speeds.The draft tube adversely affected solid dispersion at most impeller speeds.In flow fields agitated by the PBTU45 impeller,good solid suspension required a faster impeller speed.The suspension quality with the draft tube was better than that without the draft tube under most operating conditions.The power consumption of the BT or PBTU45 impeller with the draft tube was less than that without the draft tube at most impeller speeds.

关键词： Liquid-solid-solid Stirred reactor Draft tube Computational fluid dynamics power consumption Suspension quality

Numerical investigation of granular mixing in an intensive mixer:Effect of process and structural parameters on mixing performance and power consumption

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Chinese Journal of Chemical Engineering 2021年第4期34卷 241-252页

作者： Zhijian Zuo Shuguang Gong Guilan Xie School of Mechanical Engineering Xiangtan UniversityXiangtan 411105China

Discrete element method(DEM)simulations of particle mixing process in an intensive mixer were conducted to study the influence of structural and process parameters on the mixing performance and power consumption.The DEM model was verified by comparing the impeller torque obtained from simulation with that from experiment.Impeller and vessel torque,coordination number(CN)and mixing index(Relative standard deviation)were adopted to qualify the particle dynamics and mixing performance with different parameters.A method based on cubic polynomial fitting was proposed to determine the critical mixing time and critical specific input work during the mixing process.It is found that the mixing performance and energy efficiency increases with the decrease of impeller offset.The mixing performance is improved slightly with the increase of blade number and the impeller with 3 blades has the highest energy efficiency due to its low input torque.Results indicate that the energy efficiency and the mixing performance increase with the decrease of filling level when the height of granular bed is higher than that of blade.

关键词： Intensive mixer Particle mixing DEM Mixing performance power consumption

Evaluation of the power consumption of a high-speed parallel robot

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Frontiers of Mechanical Engineering 2018年第2期13卷 167-178页

作者： Gang HAN Fugui XIE Xin-Jun LIU The State Key Laboratory of Tribology & Institute of Manufacturing Engineering Department of Mechanical Engineering Tsinghua University Beijing 100084 China Beijing Key Laboratory of Precision/Ultra-precision Manufacturing Equipments and Control Tsinghua University Beijing 100084 China

An inverse dynamic model of a high-speed parallel robot is established based on the virtual work principle. With this dynamic model, a new evaluation method is proposed to measure the power consumption of the robot during pick-and-place tasks. The power vector is extended in this method and used to represent the collinear velocity and acceleration of the moving platform. After- ward, several dynamic performance indices, which are homogenous and possess obvious physical meanings, are proposed. These indices can evaluate the power input and output transmissibility of the robot in a workspace. The distributions of the power input and output transmissibility of the high-speed parallel robot are derived with these indices and clearly illustrated in atlases. Furtherly, a low- power-consumption workspace is selected for the robot.

关键词： high-speed parallel robot dynamic model power consumption evaluation method power vector

Cognitive radio adaptation for power consumption minimization using biogeography-based optimization

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Chinese Physics B 2016年第12期25卷 499-506页

作者：齐佩汉郑仕链杨小牛赵知劲 School of Telecommunications Engineering Xidian University Xi'an 710071 China Science and Technology on Communication Information Security Control Laboratory Jiaxing 314033 China School of Telecommunications Hangzhou Dianzi University Hangzhou 310018 China

Adaptation is one of the key capabilities of cognitive radio, which focuses on how to adjust the radio parameters to optimize the system performance based on the knowledge of the radio environment and its capability and characteristics. In this paper, we consider the cognitive radio adaptation problem for power consumption minimization. The problem is formulated as a constrained power consumption minimization problem, and the biogeography-based optimization （BBO） is introduced to solve this optimization problem. A novel habitat suitability index （HSI） evaluation mechanism is proposed, in which both the power consumption minimization objective and the quality of services （QoS） constraints are taken into account. The results show that under different QoS requirement settings corresponding to different types of services, the algorithm can minimize power consumption while still maintaining the QoS requirements. Comparison with particle swarm optimization （PSO） and cat swarm optimization （CSO） reveals that BBO works better, especially at the early stage of the search, which means that the BBO is a better choice for real-time applications.

关键词： cognitive radio power consumption adaptation optimization