Structure Design Of Robot Research Articles

Design and Motion Control of Master-Slave Control Endotracheal Intubation Robot.

Master-slave remote control technology allows patients to be treated promptly during transport and also reduces the risk of contagious infections. Endotracheal intubation, guided by endoscopy and a master-slave system, enables doctors to perform the procedure efficiently and accurately. In this paper, we present the development of a master-slave controlled endotracheal intubation robot (EIR). It is based on operation incremental mapping, a weighted recursive average filtering method to reduce vibration, and a virtual fixture designed to reduce mishandling in minimally invasive surgery. Simulation analysis of the master-slave control demonstrates that the weighted recursive average filtering method effectively reduces vibration, while the virtual fixture assists in confining the operator's movement within a delimited area. Experimental validation confirms the validity of the robot's structural design and control method. The developed robot successfully achieves the necessary motion for endotracheal intubation surgery through master-slave control.

Research on gravity compensation control of BPNN upper limb rehabilitation robot based on particle swarm optimization

AbstractA four‐degree‐of‐freedom upper limb exoskeleton rehabilitation robot system with a gravity compensation device is constructed. The objective is to address the rehabilitation training needs of patients with upper limb motor dysfunction. A BP neural network adaptive control method based on particle swarm optimization is proposed. First, the degrees of freedom of the human body are analyzed, and a Lagrange method is employed to construct a dynamic model. Second, a particle swarm optimization back propagation neural network adaptive control algorithm based on particle swarm optimization is presented. Subsequently, the range of motion of the upper limbs is analyzed with reference to muscle anatomy and a three‐dimensional motion capture system. And the robot structure design is analyzed in detail. Finally, simulation experiments were conducted, and the results demonstrated that the proposed method exhibited high effectiveness and accuracy.

How Do Combustions Actuate High-Speed Soft Robots?

The combustion actuation method opens a unique pathway for high-performance soft robots, allowing for high accelerations in multifunctional applications. Along with multifunctionality come great challenges in effective robot structure design, accurate control and prediction of combustion-actuated motions, and practical implementation of various applications. However, research in this nascent field remains fragmented, lacking central guiding principles. To systematize these works, this review article summarizes state-of-the-art technologies in combustion-actuated soft robots, addressing three key questions: How to design a combustion-enabled soft robot? How to predict its movements and control it? and How to practically apply it.

Bistable click mechanism for dipteran flight robot

The flight mechanism of the dipteran insects is commonly used to design the flapping robot. However, the nonlinear dynamics of the buckling click mechanism of the flapping robot with bistability still unclear. In this paper, a novel flapping robot model with the click mechanism proposed based on the bistability of snap-through buckling. The nonlinear governing equations of the flight robot are obtained by using the Euler–Lagrange equation. The nonlinear potential energy, moment of the elastic force, equilibrium bifurcation, as well as equilibrium stability are investigated to show the bistable characteristics. The transitional and persistent sets of bifurcation regions in the parameter plane and the corresponding phase portraits are obtained with single and double well behaviors. Then, the periodic response of the free flight are defined by the analytical solution of three kinds of elliptical functions, as well as the amplitude frequency responses are investigated by numerical integration. Based on the topological equivalent, the chaotic thresholds of the homo-clinic and heteroclinic orbits for the chaotic vibration of the perturbed robot system are derived. Finally, the prototype of nonlinear flapping robot is manufactured and the experimental system is setup. The nonlinear static moment of force curves, periodic response and dynamic flight vibration of dipteran robot system are carried out. It is shown that the test results are agree well with the theoretical analysis and numerical simulation. Those results have the potential application for the structure design of the efficient flight robot.

Research and Implementation of Pneumatic Amphibious Soft Bionic Robot

To meet the requirements of amphibious exploration, ocean exploration, and military reconnaissance tasks, a pneumatic amphibious soft bionic robot was developed by taking advantage of the structural characteristics, motion forms, and propulsion mechanisms of the sea lion fore-flippers, inchworms, Carangidae tails, and dolphin tails. Using silicone rubber as the main material of the robot, combined with the driving mechanism of the pneumatic soft bionic actuator, and based on the theory of mechanism design, a systematic structural design of the pneumatic amphibious soft bionic robot was carried out from the aspects of flippers, tail, head–neck, and trunk. Then, a numerical simulation algorithm was used to analyze the main executing mechanisms and their coordinated motion performance of the soft bionic robot and to verify the rationality and feasibility of the robot structure design and motion forms. With the use of rapid prototyping technology to complete the construction of the robot prototype body, based on the motion amplitude, frequency, and phase of the bionic prototype, the main execution mechanisms of the robot were controlled through a pneumatic system to carry out experimental testing. The results show that the performance of the robot is consistent with the original design and numerical simulation predictions, and it can achieve certain maneuverability, flexibility, and environmental adaptability. The significance of this work is the development of a pneumatic soft bionic robot suitable for amphibious environments, which provides a new idea for the bionic design and application of pneumatic soft robots.

Research on Mechanical Leg Structure Design and Control System of Lower Limb Exoskeleton Rehabilitation Robot Based on Magnetorheological Variable Stiffness and Damping Actuator

During the walking process of lower limb exoskeleton rehabilitation robots, inevitable collision impacts will occur when the swinging leg lands on the ground. The impact reaction force from the ground will induce vibrations in the entire robot’s body from bottom to top. To address this phenomenon, considering the limitations of traditional active compliance and passive compliance methods, a variable stiffness and damping actuator (VSDA) leg structure using a magnetorheological damper (MRD) is proposed. Firstly, experimental methods are used to obtain the ground reaction force (GRF) exerted on a normal person during walking. Then, a mathematical model of the VSDA leg structure is constructed, and its working principle is analyzed. Based on human mass and dimensions, a 3D model is designed and selected. Finally, a simulation model is built in the MATLAB/Simulink environment using the fuzzy switch damping control strategy to simulate the acceleration and displacement of the human body under sinusoidal and random excitations. The results indicate that under sinusoidal excitation, employing fuzzy switch damping control optimizes human displacement by 72.47% compared to the high stiffness and high damping system, and by 16.95% compared to the switch damping system. Human acceleration is optimized by 52.09% compared to the high stiffness and high damping system, and by 25.2% compared to the switch damping system. Under random excitation, adopting fuzzy switch damping control optimizes human displacement by 59.09% compared to the high stiffness and high damping system, and by 21.74% compared to the switch damping system. Human acceleration is optimized by 78.74% compared to the high stiffness and high damping system, and by 31.66% compared to the switch damping system. This validates the VSDA design structure and control method, demonstrating certain advantages in improving the compliance and stability of lower limb exoskeleton rehabilitation robots.

Advancing Legged Wall Climbing Robot Performance Through Dynamic Contact-Integrated Climbing Model

Abstract Climbing robots have gained significance in hazardous and steep terrains, yet adapting to complex environments remains a challenge. Inspired by nature's climbers, this paper introduces a climbing dynamics model that integrates foot-end contact forces, crucial for safe and efficient wall climbing. Drawing insights from animal locomotion and biomechanics, we present a comprehensive dynamic model for quadruped robots. Our model, built upon multibody dynamics and a dynamic contact model based on spiny claw mechanisms, accurately simulates robot forces and motion during climbing, even predicting failure scenarios. Experimental validation further establishes model accuracy. This study advances climbing robot research by addressing attachment interaction dynamics and provides valuable insights for optimizing robot structural design and gait strategies.

Structure and Gait Design of a Lunar Exploration Hexapod Robot Based on Central Pattern Generator Model

To address the challenges of sinking, imbalance, and complex control systems faced by hexapod robots walking on lunar soil, this study develops an umbrella-shaped foot lunar exploration hexapod robot. The overall structure of the robot is designed to mimic the body structure of insects. By incorporating a four-bar linkage mechanism to replace the commonly used naked joints in traditional hexapod robots, the robot reduces the number of degrees of freedom and simplifies control complexity. Additionally, an extension mechanism is added to the robot’s foot, unfolding into an umbrella shape to provide a larger support area, effectively addressing the issue of foot sinking instability during walking. This study adopts and simplifies the Central Pattern Generator (CPG) model to generate stable periodic control signals for the robot’s legs. Precise control of the extension mechanism’s unfolding period is achieved through mapping functions. A joint simulation platform using Solid Works and Matlab is established to analyze the stability of the robot’s walking. Finally, walking experiments are conducted on the prototype, confirming the smooth walking of the lunar exploration hexapod robot. The results indicate that the designed lunar exploration hexapod robot has a reasonable structure, excellent stability in motion, and the CPG control scheme is feasible.

Mechanical Structure Design of Wearable Assistive Robot Driven by ADAMS System

Mechanical Structure Design of Wearable Assistive Robot Driven by ADAMS System

Design and kinematic analysis of a rope-driven linkage frog-like swimming robot with multidirectional controllable motion

In this paper, a rope-driven linkage frog swimming robot is constructed in accordance with the delicate structure of the frog swimming mode. First, a rope-driven linkage limb propulsion mechanism is proposed. This mechanism not only enables the robot to achieve the superior motion characteristics and mechanical performance of the four limbs of a frog swimming in water but also makes the limb structures more flexible and lightweight. Using the D-H parametric method with geometric relations, the swimming kinematic model of this robotic limb propulsion mechanism is established, and the stability margin and recovery moment equations are derived. Second, based on the above mathematical model, the motion space and stability analysis of the robot limb ends are simulated by MATLAB software. Finally, an experimental prototype with a size of 18 cm in length × 7 cm in width × 7 cm in height, combined with a control system, is developed. The experimental result verifies the rationality and correctness of the robot's structural design, theoretical derivation and control system and proves that it has superior motion capability with a straight-line swimming speed of 0.54 m/s, a horizontal surface turning speed of 100°/s (turning radius of approximately 0.18 m), and an upwards and downwards submerged swimming speed of 9 cm/s during a single swim in the water.

Amoeboid soft robot based on multi-material composite 3D printing technology

A core–shell structured, amoeba-like, magnetically controlled soft robot is proposed for 3D printing using magnetically controlled smart materials and silicone materials. The purpose of this robot is to overcome the limitations of existing soft robot kinematic mechanisms that rely on the elastic deformation of flexible materials. The printability of the magnetically controlled smart material was verified through rheological tests. The effect of different component ratios on the rheological properties of the material was investigated and a suitable material ratio for printing was selected by adjusting the amount of SiO2 in the silicone and conducting rheological tests. Mechanical simulation was used to select and optimize the design of the amoeboid soft robotic shell structures. Printing was then used to verify the stability of the shell structures. The self-supporting capability of the magnetically controlled smart materials was investigated under different magnetic field strengths. To solve the problem of the phase of the magnetron smart material and the silicone material, the composite printing of the two materials was accomplished by adjusting the printing process. Soft robots mimicking amoebas were then printed and fabricated. The magnetron array-based driving method is proposed, and the magnetic field of the array used to drive the amoeba-like soft robot is constructed. The magnetic field of the array surface was then simulated under several different driving modes. Based on the simulation results, a suitable driving mode was selected. Using the material mechanism of the magnetron-only material sol–gel transformation, the pseudopod extension gait of the amoeba-like soft robot was designed, and the localized deformation of the amoeba-like soft robot was realized.This paper leveraged the distinctive properties of magnetorheological smart materials to devise and fabricate an integrated 3D-printed soft robot. Such magnetorheological smart materials can function as both the supporting framework for hollow cavities and the propelling substance for the robot. During the course of this process, we investigated material properties pertinent to 3D printing and refined the design of the robot's structure and driving mechanism.

Study on throttling pressure control flow field for traction speed regulation and braking mechanism of the pipeline intelligent plugging robot

This study analyzes the throttling pressure control flow field, and the influencing factors of its traction speed regulation and braking mechanism are determined. Throttling pressure control flow field characteristics of the traction speed regulation and braking mechanism are analyzed and the principle experiment of the throttling pressure control flow field is also carried out. The results show that the throttling pressure control flow field of the traction speed regulation and braking mechanism of the pipeline intelligent plugging robot is greatly affected by the structure and shape of the speed control valve. When the opening of the speed control valve decreases, the flow rate of the backward jet increases, and the flow rate is faster. This is convenient for scouring the front pipe wall of the device. Conversely, as the opening of the speed control valve increases, the maximum deceleration effect can be achieved by increasing the pressure difference before and after the device. This study provides a theoretical basis for the structure design and selection of the pipeline intelligent plugging robot. Moreover, it is helpful for providing data reference and theoretical guidance for the design of passive fluid-propulsion robots in pipes equipped with bypass rotary valves.

Structure Design, Kinematics Analysis, and Effect Evaluation of a Novel Ankle Rehabilitation Robot

This paper presents a novel ankle rehabilitation (2-CRS+PU)&R hybrid mechanism, which can meet the size requirements of different adult lower limbs based on the three-movement model of the ankle. This model is related to three types of movement modes of the ankle movement, without axis offset, which can cover the ankle joint movements. The inverse and forward position/kinematics results analysis of the mechanism is established based on the closed-loop vector method and using the optimization of particle groups algorithm. Four groups of position solutions of the mechanism are obtained. The kinematics simulation is analyzed using ADAMS software. The variations of the velocity and acceleration of all limbs are stable, without any sudden changes, which can effectively ensure the safety and comfort of the ankle model end-user. The dexterity of the mechanism is analyzed based on the transport function, and the results indicate that the mechanism has an excellent transfer performance in yielding the structure parameters. Finally, the rehabilitation evaluation is conducted according to the three types of movement modes of the ankle joint. The results show that this ankle rehabilitation mechanism can provide a superior rehabilitation function.

Structure design and analysis of upper limb wearable passive power-assisted exoskeleton robot

The upper limb exoskeleton robot has been a key research direction at home and abroad in recent years. Still, the existing upper limb exoskeleton robot has poor coupling with the human body, and the power assistance effect could be better. In this paper, the strength of each muscle group of the upper limb when the human body is carrying objects is measured as reflected by the surface EMG signal of the human body, and the human kinematics is analyzed to guide the design of the passive exoskeleton robot of the upper limb. First, the spring tension and compression system model is established for the upper limb of the human body. The model is statically analyzed, the forces and moments on each joint are calculated, and each muscle’s actual output data when carrying objects is estimated. Based on the muscle kinematics model, a passive upper limb exoskeleton robot is designed. The robot is divided into three modules, namely, the arm module, shoulder module, and back module, using ergonomics and modular design ideas. The energy storage module and joint degree of freedom of the exoskeleton are analyzed to ensure that the exoskeleton meets the requirements of ergonomics, and the key components are checked and simulated. The results show that the designed upper limb wearable passive power-assisted exoskeleton robot meets the strength requirements, which verifies the rationality of the structure design.

Mechanical System Structure Design of Transmission Line Maintenance Robot

Aiming at the problems of insufficient research and difficult control of existing transmission line maintenance robots, a modular four-wheel mobile robot mechanical configuration scheme is proposed. We analyze the working environment of the existing transmission line and the working requirements of the inspection robot. Then, the overall architecture design, function division and mechanical simulation of the robot are carried out, and a joint motion model that is easy to expand and universal is put forward. Finally, a prototype robot is developed, and corresponding software and hardware design of the control system is completed. The live line maintenance operation experiment is performed on simulated lines and actual transmission lines. The results show that the effective module division and reconstruction scheme of the configuration scheme are correct and feasible, and the joint motion trajectory of the robot is optimized, which also improves the work efficiency and safety.

Perspective Of Vision, Motion Planning, And Motion Control for Quadruped Robots

In recent years, robot technology has made great progress, especially quadruped robots. Quadruped robot is a bionic robot that imitates the movement of quadruped animals. For quadruped machines in complex environments, our group first investigate the control of quadruped robots in complex situations. It is found that the current quadruped robots can achieve better motion control under various complex conditions, but there are still limitations. Its structure includes the trunk and four legs located in front and behind the trunk. Each leg has the same structure, including the thigh, calf, and foot. This paper summarizes the research on foot structure design and foot tip trajectory optimization of quadruped robot. Machine Vision is a branch of artificial intelligence that is developing rapidly. Simply put, machine vision is to use machines instead of human eyes to make measurements and judgments. The following passage discusses about two main kinds of algorithm, while making analytic and comparisons among others and why to choose these two out in the machine vision part of quadruped robots. By summarizing and analyzing the research status, this paper proposes some challenging and valuable future research directions.

Simulation-Based Reliability Design Optimization Method for Industrial Robot Structural Design

Robots are main elements in Industry 4.0. Research on the design optimization of robots has a great significance in manufacturing industries. There inevitably exist various uncertainties in robot design that have an important influence on the reliability of robots. At present, the design optimization of robots considering the uncertainties is mainly focused on joints design and trajectory optimization. However, for the structural design of robots, deterministic design optimization still plays a leading role. In this paper, a simulation-based reliability design optimization method is proposed to improve the reliability of robots’ structural design. In the proposed method, the Latin hypercube sampling (LHS), computer simulation, response surface method (RSM) and SORA (Sequential Optimization and Reliability Assessment) algorithm are integrated to complete the structural design of the robot. Firstly, samples of the uncertainty design variables were obtained by LHS, and then, the reliability performance constraint functions were firstly constructed through the RSM in which the joint simulation of MTLAB and ANSYS was adopted. Afterwards, the reliability design optimization model was established on the basis of the probabilistic reliability theory. At last, the SORA algorithm was employed to realize the optimization. The design optimization problems of the big arm and the small arm of a 6 Kg industrial robot were considered to verify the proposed method. The results showed that the weights of the big arm and the small arm were, respectively, reduced by 7.73% and 25.70% compared with those of the original design, and the design was more effective in ensuring the reliability requirements compared with the deterministic optimization. Moreover, the results also demonstrated that the proposed method has a better computational efficiency compared with the reliability design optimization of the double-loop method.

Bird-inspired robotics principles as a framework for developing smart aerospace materials

Birds are notable for their ability to seamlessly transition between different locomotory functions by dynamically leveraging their shape-shifting morphology. In contrast, the performance of aerial vehicles is constrained to a narrow flight envelope. To understand which functional morphological principles enable birds to successfully adapt to complex environments on the wing, engineers have started to develop biomimetic models of bird morphing flight, perching, aerial grasping and dynamic pursuit. These studies show how avian morphological capabilities are enabled by the biomaterial properties that make up their multifunctional biomechanical structures. The hierarchical structural design includes concepts like lightweight skeletons actuated by distributed muscles that shapeshift the body, informed by embedded sensing, combined with a soft streamlined external surface composed of thousands of overlapping feathers. In aerospace engineering, these functions are best replicated by smart materials, including composites, that incorporate sensing, actuation, communication, and computation. Here we provide a review of recently developed biohybrid, biomimetic, and bioinspired robot structural design principles. To inspire integrative smart material design, we first synthesize the new principles into an aerial robot concept to translate it into its aircraft equivalent. Promising aerospace applications include multifunctional morphing wing structures composed out of smart composites with embedded sensing, artificial muscles for robotic actuation, and fast actuating compliant structures with integrated sensors. The potential benefits of developing and mass-manufacturing these materials for future aerial robots and aircraft include improving flight performance, mission scope, and environmental resilience.

Design of a Modular Pipeline Robot Structure and Passing Ability Analysis

Design of a Modular Pipeline Robot Structure and Passing Ability Analysis

Stability analysis of the food delivery robot with suspension damping structure

Aiming at the shock absorption and stability under complex terrain conditions, a six-wheeled food delivery robot with a suspension damping structure was designed. The food delivery robot is mainly composed of a take-out box, a chassis mobile structure and a suspension damping structure. The dynamic analysis of the suspension damping structure of the robot is carried out through the Lagrangian equation, and the offset of the wheels in different driving environments is obtained. Then, the zero-moment point method is used to analyze the stability of the food delivery robot in two non-horizontal movement environments of the left and right wheels and the front and rear wheels. Based on this, taking speed bumps and ramp terrain with different slopes as examples, the stability of the food delivery robot is analyzed by ADAMS simulation. The simulation and experiment results verify the rationality of the structure design of the food delivery robot with a suspension damping structure and the correctness of the theoretical analysis.