To address the problem of sparrow search algorithm (SSA) has poor global ability, weak local development and easily falls into optimal solution, a multi-strategy improved evolutionary (MSSA) is proposed. The introduction tent chaotic map improves diversity initialization population, accelerates convergence, convergence accuracy. Endow finders with random ability to coordinate balance between development. discover dangerous individuals, mutation evolution operation completed, greedy strategy...

The appearance and development of additive manufacturing technology promotes the production manufacture parts with more complex designs smaller sizes realizes topology that cannot be made by equal-material submanufacturing. Nowadays, application tri-periodic minimal surface (TPMS) in optimization design has become a new choice, and, because its excellent structure properties, gradually mainstream. In this paper, mechanical properties four different topologies prepared selective laser melting...

To address the shortcomings of basic crow search algorithm (CSA), an enhanced based on disturbance method (DMCSA) is proposed. The CSA has slightly weak exploration and development abilities. fixed flight length causes to conduct intensive searches in small areas, it cannot comprehensive broad entire space. trigonometric function updating strategy adopted obtain a random walk model, so global ability strong DMCSA. In addition, searching operation for detailed local DMCSA, as can...

Purpose This paper aims to study a parameter tuning method for the active disturbance rejection control (ADRC) improve anti-interference ability and position tracking of performance servo system, ensure stability accuracy practical applications. Design/methodology/approach proposes self-tuning ADRC based on an improved glowworm swarm optimization algorithm. The algorithm is by using sine cosine local operators adaptive mutation strategy. then used system controller parameters. Findings...

Aiming at the multi-parameter identification problem of an electro-hydraulic servo system, a method based on penalty mechanism reverse nonlinear sparrow search algorithm (PRN-SSA) is proposed, which transforms non-linear system into optimization in high-dimensional parameter space. In initial stage (SSA), population distribution not uniform, and process easily disturbed by local optimal solution. First, adopting learning strategy increases exploratory nature individuals population, improves...

During the operation of valve-controlled cylinder position systems, there are some problems, such as uncertainty and time-varying system parameters, imprecise modeling, external interference. These problems will affect loading accuracy safety reliability electro-hydraulic servo system. This paper used a research object, mathematical model was established. Then, sliding mode variable structure controller dynamic soft were designed, Grey Wolf algorithm to adjust parameters. The control effect...

A valve-controlled hydraulic cylinder system has the characteristics of uncertainty and time-variance, electro-hydraulic servo unit encounters shock, vibration, other external interference when working, which seriously affect stability system. Therefore, it is necessary to introduce an active disturbance rejection controller (ADRC) into control. However, there are many ADRC parameters, difficult set these only with expert experience. we propose applying gray wolf optimization algorithm (GWO)...

According to the robot’s walking motion characteristics, position/force switching control is studied realize segmental of robot stroke. This stroke controlled by position when foot end descends from suspension ground. To avoid excessive contact force touches ground, carried out Due and methods parameters hydraulic quadruped robots are different, precise mathematical model for joint leg joints established using system identification method. A fuzzy multi-model algorithm proposed solve problem...

The nonlinearity of clearance has a significant influence on the performance system while ensuring reliability variable-speed transmission, and hinders development controlled object according to predetermined trajectory. Aimed at transmission problem in different systems, this study summarizes existing literature provides reference for research compensation characteristics. First, is analyzed summarized, it shown that existence causes problems, such as response delay limited cycle...

Background: ADRC (active disturbance rejection controller) technology is a new practical that does not rely on the mathematical model of controlled object and has strong robustness. It integrates essence modern control theory classical proportion integral derivative good engineering application prospects. But with research development adaptive controller, problem many parameters difficulty to adjust also arises. Objective: To act as guide for future studies enhancement parameter setting,...

Background: The single position control or force of the electro-hydraulic servo system has long been unable to meet actual needs production and life. To achieve a good effect solve various problems in real life, people no longer only consider control. Objective: proposed method provides technical support for multi-objective collaborative system, completes requirements multitasking operation, improves positioning accuracy response velocity realizes synergy between force. Methods: A outer loop...

: In order to obtain the precise mathematical model of position control system hydraulic quadruped robot, and meet requirements parameters in different stages motion, this paper studies single-leg joint robot: First all, uses closed-loop indirect identification method identify leg joints robot system; And then, speed PID algorithm planning are designed, so that can quickly respond changes input according speeds; Finally, is simulated verified by experiments. Background: The positioning...

In order to improve the work precision, finite element models of crossbeam heavy NC gantry moving boring & milling machine were established, and static/dynamic characteristics analyzed. The itself stiffness tip displacement converted by beam deformation under largest cutting force gravity load calculated. According results calculation analysis, optimal structures designed, in which structure form size modified. And was obtained distortion three schemes Kl, K2 K3. dynamic analysis show that...

The quadruped robot is subject to self and external interference during the running process. In this paper, in order improve stability of robot, a disturbance suppression strategy based on kinematic model virtual proposed. Through whole‐body kinematics modeling body, cause analyzed. At same time, two spring‐damping elements are introduced body. force generated by according displacement speed CoM (center mass) when moving. By simulating tort gait sorting out data obtained from experiment,...

Background: 3D printing technology is widely used, with its application majorly prevailing in the medical field. Objective: In this paper, applications of field are classified and summarized, their characteristics introduced. Methods: This paper mainly summarizes contribution to medicine, as well four also introduces some examples clinical printing. Results: has proved be an emerging art a new innovation. It variety different applications. Because limitations, it not routinely used practice....

Abstract: Selective laser melting (SLM) is considered to be a widely promising additive manufacturing technology with the advantages of high machining precision, freedom, and short cycle time, which used in aerospace, integration medicine, industry, chemical, other fields. The research progress on temperature field, stress forming quality, mechanical properties during SLM process reviewed. study aims systematically analyze how parameters affect properties, discuss importance selection...

Background: Based on the development of selective laser melting technology, machining porous structures has become more delicate than conventional methods and great advantages in manufacturing many fields. Objective: Types, properties, design are described, along with application areas structures. The influence SLM process parameters molding is also described. Methods: Journals cited used to demonstrate excellent areas, processes Results: Porous formed based have properties a wide range...

Background: The spindle top is an important component used to withstand the shaft workpiece on machine tools so that can meet high efficiency and precision requirements. However, selection principles under various load conditions are not stipulated in use. In addition, material selection, manufacturing, heat treatment technology, etc., of practical significance for production hardness, wear resistance, tops. Objectives: type, principles, treatment, cold working, other manufacturing processes...

Abstract: The electro-hydraulic load simulator can simulate any force (torque) required by the loaded object under test conditions, which greatly reduces equipment development time and cost. However, process of loading inevitably creates a surplus (torque). existence in system will seriously interfere with accuracy even damage serious cases. In this paper, based on research status suppression compensation simulator, effective control strategies methods to overcome are summarized. This paper...