The existing research on dynamics and slip ratio of wheeled mobile robot （WMR） are derived without considering the effect of height, and the existing models can not be used to analyze the dynamics performance of the...The existing research on dynamics and slip ratio of wheeled mobile robot （WMR） are derived without considering the effect of height, and the existing models can not be used to analyze the dynamics performance of the robot with variable height while moving such as NOROS- Ⅱ. The existing method of dynamics modeling is improved by adding the constraint equation between perpendicular displacement of body and horizontal displacement of wheel into the constraint conditions. The dynamic model of NOROS- Ⅱ in wheel motion is built by the Lagrange method under nonholonomic constraints. The inverse dynamics is calculated in three different paths based on this model, and the results demonstrate that torques of hip pitching joints are inversely proportional to the height of robot. The relative error of calculated torques is less than 2% compared with that of ADAMS simulation, by which the validity of dynamic model is verified, Moreover, the relative horizontal motion between fore/hind wheels and body is produced when the height is changed, and thus the accurate slip ratio can not be obtained by the traditional equation. The improved slip ratio equations with the parameter of the vertical velocity of body are introduced for fore wheels and hind wheels respectively. Numerical simulations of slip ratios are conducted to reveal the effect of varied height on slip ratios of different wheels. The result shows that the slip ratios of fore/hind wheels become larger/smaller respectively as the height increases, and as the height is reduced, the reverse applies. The proposed research of dynamic model and slip ratio based on the robot height provides the effective method to analyze the dynamics of WMRs with varying height.展开更多
The wheel-legged hybrid structure has been utilized by ground mobile platforms in recent years to achieve good mobility on both flat surfaces and rough terrain.However,most of the wheel-legged robots only have one-dir...The wheel-legged hybrid structure has been utilized by ground mobile platforms in recent years to achieve good mobility on both flat surfaces and rough terrain.However,most of the wheel-legged robots only have one-directional obstacle-crossing ability.During the motion,most of the wheel-legged robots’centroid fluctuates violently,which damages the stability of the load.What’s more,many designs of the obstacle-crossing part and transformation-driving part of this structure are highly coupled,which limits its optimal performance in both aspects.This paper presents a novel wheel-legged robot with a rim-shaped changeable wheel,which has a bi-directional and smooth obstacle-crossing ability.Based on the kinematic model,the geometric parameters of the wheel structure and the design variables of the driving four-bar mechanism are optimized separately.The kinetostatics model of the mobile platform when climbing stairs is established to determine the body length and angular velocity of the driving wheels.A pro-totype is made according to the optimal parameters.Experiments show that the prototype installed with the novel transformable wheels can overcome steps with a height of 1.52 times of its wheel radius with less fluctuation of its centroid and performs good locomotion capabilities in different environments.展开更多
Design and manufacturing play pivotal roles in hydraulic-driven robotic development.However,previous studies have emphasized mainly results and performance,often overlooking the specifics of the design and manufacturi...Design and manufacturing play pivotal roles in hydraulic-driven robotic development.However,previous studies have emphasized mainly results and performance,often overlooking the specifics of the design and manufacturing process.This paper introduces a novel approach known as light weight design and integrated manufacturing(LD&IM)for hydraulic wheel-legged robots.The LD&IM method leverages topology optimization and generative design techniques to achieve a substantial 45%weight reduction,enhancing the robot’s dynamic motion capabilities.This innovative design method not only streamlines the design process but also upholds the crucial attributes of light weight construction and high strength essential for hydraulic wheel-legged robots.Furthermore,the integrated manufacturing method,incorporating selective laser melting(SLM)and high-precision subtractive manufacturing(SM)processes,expedites the fabrication of high-quality components.Using the LD&IM approach,a hydraulic-driven single wheel-legged robot,denoted as WLR-IV,has been successfully developed.This robot boasts low mass and inertia,high strength,and a simplified component structure.To assess its dynamic jumping capabilities,the control loop integrates a linear quadratic regulator(LQR)and zero dynamic-based controller,while trajectory planning uses the spring-loaded inverted pendulum(SLIP)model.Experimental jumping results confirm the WLR-IV single-legged robot’s exceptional dynamic performance,validating both the effectiveness of the LD&IM method and the rationale behind the control strategy.展开更多
Though the studies of wheel-legged robots have achieved great success, the existing ones still have defects in load distribution, structure stability and carrying capacity. For overcoming these shortcomings, a new kin...Though the studies of wheel-legged robots have achieved great success, the existing ones still have defects in load distribution, structure stability and carrying capacity. For overcoming these shortcomings, a new kind of wheel-legged robot（Rolling-Wolf） is designed. It is actuated by means of ball screws and sliders, and each leg forms two stable triangle structures at any moment, which is simple but has high structure stability. The positional posture model and statics model are built and used to analyze the kinematic and mechanical properties of Rolling-Wolf. Based on these two models, important indexes for evaluating its motion performance are analyzed. According to the models and indexes, all of the structure parameters which influence the motion performance of Rolling-Wolf are optimized by the method of Archive-based Micro Genetic Algorithm（AMGA） by using Isight and Matlab software. Compared to the initial values, the maximum rotation angle of the thigh is improved by 4.17%, the maximum lifting height of the wheel is improved by 65.53%, and the maximum driving forces of the thigh and calf are decreased by 25.5% and 12.58%, respectively. The conspicuous optimization results indicate that Rolling-Wolf is much more excellent. The novel wheel-leg structure of Rolling-Wolf is efficient in promoting the load distribution, structure stability and carrying capacity of wheel-legged robot and the proposed optimization method provides a new approach for structure optimization.展开更多
Serving the Stewart mechanism as a wheel-legged structure,the most outstanding superiority of the proposed wheel-legged hybrid robot(WLHR)is the active vibration isolation function during rolling on rugged terrain.How...Serving the Stewart mechanism as a wheel-legged structure,the most outstanding superiority of the proposed wheel-legged hybrid robot(WLHR)is the active vibration isolation function during rolling on rugged terrain.However,it is difficult to obtain its precise dynamic model,because of the nonlinearity and uncertainty of the heavy robot.This paper presents a dynamic control framework with a decentralized structure for single wheel-leg,position tracking based on model predictive control(MPC)and adaptive impedance module from inside to outside.Through the Newton-Euler dynamic model of the Stewart mechanism,the controller first creates a predictive model by combining Newton-Raphson iteration of forward kinematic and inverse kinematic calculation of Stewart.The actuating force naturally enables each strut to stretch and retract,thereby realizing six degrees-of-freedom(6-DOFs)position-tracking for Stewart wheel-leg.The adaptive impedance control in the outermost loop adjusts environmental impedance parameters by current position and force feedback of wheel-leg along Z-axis.This adjustment allows the robot to adequately control the desired support force tracking,isolating the robot body from vibration that is generated from unknown terrain.The availability of the proposed control methodology on a physical prototype is demonstrated by tracking a Bezier curve and active vibration isolation while the robot is rolling on decelerate strips.By comparing the proportional and integral(PI)and constant impedance controllers,better performance of the proposed algorithm was operated and evaluated through displacement and force sensors internally-installed in each cylinder,as well as an inertial measurement unit(IMU)mounted on the robot body.The proposed algorithm structure significantly enhances the control accuracy and vibration isolation capacity of parallel wheel-legged robot.展开更多
The continuous development of smart agriculture puts forward the requirement of high accuracy slope path tracking for the agricultural wheel-legged robot.Compared to flat terrain,path tracking control on sloped terrai...The continuous development of smart agriculture puts forward the requirement of high accuracy slope path tracking for the agricultural wheel-legged robot.Compared to flat terrain,path tracking control on sloped terrain faces the obstacle of motion instability of the wheel-legged robot induced by the slope gravitational force component,which causes instantaneous steering center to offset.To address this problem,this study proposed a slope path tracking control algorithm by combining the methods of virtual sensing radar and two-level neural network.Firstly,the kinematic and dynamic models of the wheel-legged robot are deduced,from which the crucial factors affecting control accuracy of slope path tracking are recognized.Secondly,this study constructs the slope path tracking control algorithm,in which the virtual sensing radar is utilized to realize route perception,and the two-level neural network is employed to provide drive motors’speeds to adapt to path tracking on different slopes.Furthermore,the corresponding compensation methods of the identified impacting factors are embedded in the proposed algorithm,including the lateral tracking deviation factor,heading angle deviation factor,slope change factor,and slip rate factor.Finally,the co-simulation model of slope path tracking control is constructed,including the multi-body dynamic model of the wheel-legged robot in RecurDyn and the proposed slope path tracking algorithm complied by Python.Subsequently,the simulation tests of the wheel-legged robot are carried out under various slope angles and velocities.The results reveal that the proposed algorithm’s effectiveness and accuracy are superior,with tracking errors reduced by more than 47.2%compared to an optimized pure pursuit algorithm.展开更多
In-pipe robots have been widely used in pipes-with smooth inner walls.However,current in-pipe robots face challenges in terms of moving past obstacles and climbing in marine-vessel pipeline systems,which are affected ...In-pipe robots have been widely used in pipes-with smooth inner walls.However,current in-pipe robots face challenges in terms of moving past obstacles and climbing in marine-vessel pipeline systems,which are affected by marine biofouling and electrochemical corrosion.This paper takes inspiration from the dual-hook structure of Trypoxylus dichotomus’s feet and gecko‑like dry adhesives,proposing an in-pipe robot that is capable of climbing on rough and smooth pipe inwalls.The combination of the bioinspired hook and dry adhesives allows the robot to stably attach to rough or smooth pipe inwalls,while the wheel-leg hybrid mechanism provides better conditions for obstacle traversal.The paper explores the attachment and obstacle-surmounting mechanisms of the robot.Moreover,motion strategies for the robot are devised based on different pipe structural features.The experiments showed that this robot can adapt to both smooth and rough pipe environments simultaneously,and its motion performance is superior to conventional driving mechanisms.The robot’s active turning actuators also enable it to navigate through horizontally or vertically oriented 90°bends.展开更多
The wheel-legged biped robot is a typical ground-based mobile robot that can combine the high velocity and high efficiency pertaining to wheeled motion and the strong,obstacle-crossing performance associated with legg...The wheel-legged biped robot is a typical ground-based mobile robot that can combine the high velocity and high efficiency pertaining to wheeled motion and the strong,obstacle-crossing performance associated with legged motion.These robots have gradually exhibited satisfactory application potential in various harsh scenarios such as rubble rescue,military operations,and wilderness exploration.Wheel-legged biped robots are divided into four categories according to the open–close chain structure forms and operation task modes,and the latest technology research status is summarized in this paper.The hardware control system,control method,and application are analyzed,and the dynamic balance control for the two-wheel,biomimetic jumping control for the legs and whole-body control for integrating the wheels and legs are analyzed.In summary,it is observed that the current research exhibits problems,such as the insufficient application of novel materials and a rigid–flexible coupling design;the limited application of the advanced,intelligent control methods;the inadequate understanding of the bionic jumping mechanisms in robot legs;and the insufficient coordination ability of the multi-modal motion,which do not exhibit practical application for the wheel-legged biped robots.Finally,this study discusses the key research directions and development trends for the wheel-legged biped robots.展开更多
Robots are widely used to replace people in some burdensome or hamaful areas. Not only the moving ability but also the manipulating ability is needed in the missions of complex multitasking requirements. In the last d...Robots are widely used to replace people in some burdensome or hamaful areas. Not only the moving ability but also the manipulating ability is needed in the missions of complex multitasking requirements. In the last decades, wheel-legged hexapod robots are extensively studied to ineet this condition.展开更多
An adaptive wheel-legged shape reconfigurable mobile robot,based on a scissor-like mechanism,is proposed for an obstacle detecting and surmounting robot,moving on complex terrain.The robot can dynamically adjust its o...An adaptive wheel-legged shape reconfigurable mobile robot,based on a scissor-like mechanism,is proposed for an obstacle detecting and surmounting robot,moving on complex terrain.The robot can dynamically adjust its own shape,according to the environment,realizing a transformation of wheel shape into leg shape and vice versa.Each wheel-legged mechanism has one degree of freedom,which means that only the relative motion of the inner and outer discs is needed to achieve the transformation of the shape into a wheel or a leg.First,the force analysis of the conversion process of the wheel-legged mechanism is carried out,while the relationship between the driving torque and the friction factor in the non-conversion trigger stage and in the conversion trigger stage is obtained.The results showed that the shape conversion can be better realized by increasing the friction factor of the trigger point.Next,the kinematics analysis of the robot,including climbing the obstacles,stairs and gully,is carried out.The motion of the spokes tip is obtained,in order to derive the folding ratio and the surmountable obstacle height of the wheel-legged mechanism.The parameters of the wheel-legged structure are optimized,to obtain better stability and obstacle climbing ability.Finally,a dynamic simulation model is established by ADAMS,to verify the obstacle climbing performance and gait rationality of the robot,in addition to a prototype experiment.The results showed that the surmountable obstacle height of the robot is about3.05 times the spoke radius.The robot has the stability of a traditional wheel mechanism and the obstacle surmount performance of a leg mechanism,making it more suitable for field reconnaissance and exploration missions.展开更多
The robot used for disaster rescue or field exploration requires the ability of fast moving on flat road and adaptability on complex terrain.The hybrid wheel-legged robot(WLR-3P,prototype of the third-generation hydra...The robot used for disaster rescue or field exploration requires the ability of fast moving on flat road and adaptability on complex terrain.The hybrid wheel-legged robot(WLR-3P,prototype of the third-generation hydraulic wheel-legged robot)has the characteristics of fast and efficient mobility on flat surfaces and high environmental adaptability on rough terrains.In this paper,3 design requirements are proposed to improve the mobility and environmental adaptability of the robot.To meet these 3 requirements,2 design principles for each requirement are put forward.First,for light weight and low inertia with high stiffness,3-dimensional printing technology and lightweight material are adopted.Second,the integrated hydraulically driven unit is used for high power density and fast response actuation.Third,the microhydraulic power unit achieves power autonomy,adopting the hoseless design to strengthen the reliability of the hydraulic system.What is more,the control system including hierarchical distributed electrical system and control strategy is presented.The mobility and adaptability of WLR-3P are demonstrated with a series of experiments.Finally,the robot can achieve a speed of 13.6 km/h and a jumping height of 0.2 m.展开更多
Aiming to solve the steering instability and hysteresis of agricultural robots in the process of movement,a fusion PID control method of particle swarm optimization(PSO)and genetic algorithm(GA)was proposed.The fusion...Aiming to solve the steering instability and hysteresis of agricultural robots in the process of movement,a fusion PID control method of particle swarm optimization(PSO)and genetic algorithm(GA)was proposed.The fusion algorithm took advantage of the fast optimization ability of PSO to optimize the population screening link of GA.The Simulink simulation results showed that the convergence of the fitness function of the fusion algorithm was accelerated,the system response adjustment time was reduced,and the overshoot was almost zero.Then the algorithm was applied to the steering test of agricultural robot in various scenes.After modeling the steering system of agricultural robot,the steering test results in the unloaded suspended state showed that the PID control based on fusion algorithm reduced the rise time,response adjustment time and overshoot of the system,and improved the response speed and stability of the system,compared with the artificial trial and error PID control and the PID control based on GA.The actual road steering test results showed that the PID control response rise time based on the fusion algorithm was the shortest,about 4.43 s.When the target pulse number was set to 100,the actual mean value in the steady-state regulation stage was about 102.9,which was the closest to the target value among the three control methods,and the overshoot was reduced at the same time.The steering test results under various scene states showed that the PID control based on the proposed fusion algorithm had good anti-interference ability,it can adapt to the changes of environment and load and improve the performance of the control system.It was effective in the steering control of agricultural robot.This method can provide a reference for the precise steering control of other robots.展开更多
The Chinese SME’s vision shows the bright side of humanoid robots:rather than replacing human workers,they are handling everyday mechanical tasks,leaving human staff to focus on improving service and emotional experi...The Chinese SME’s vision shows the bright side of humanoid robots:rather than replacing human workers,they are handling everyday mechanical tasks,leaving human staff to focus on improving service and emotional experiences.IN the Jinqiao Economic and Technological Development Zone in Pudong New Area,Shanghai,KEENON Robotics,a national-level“Little Giant”(innovative SME),is leading the transformation of the service robots industry.Amid the wave of embodied intelligence development,the humanoid service robots created by this company have become a focal point of the industry and businesses alike.展开更多
This research is applied mainly for routine inspection,rescue missions in multi-terrains environment.The main process of developing this hexapod based wheel-legged robot includes mechanism structure design,electronic ...This research is applied mainly for routine inspection,rescue missions in multi-terrains environment.The main process of developing this hexapod based wheel-legged robot includes mechanism structure design,electronic devices configuration,gaits’control adjustment and pathing route simulation.With the use of transformable wheel-legs,the robot can run flexibly in flat under the wheeled mode,and through the gear and mechanism system,it would shift to legged mode to show enough capability for overring the unstructured obstacles.As the expectation,this robot would have bright prospects for variable terrains application and substitute current rivals by its higher efficiency and adaptability.展开更多
Objective:Robotic colorectal surgery(RCS)provides a stable,magnifiedthree-dimensional visual field and enhanced ergonomics enabling precise dissection and tremor suppression.We postulate that this technique is associa...Objective:Robotic colorectal surgery(RCS)provides a stable,magnifiedthree-dimensional visual field and enhanced ergonomics enabling precise dissection and tremor suppression.We postulate that this technique is associated with less tissue trauma and improved postoperative outcomes than laparoscopic colorectal surgery(LCS).This study aimed to explore the inflammatoryresponse following RCS by measuring postoperative C-reactive protein(CRP)levels and compare them with LCS data reported in the literature.Methods:This single centre retrospective study included consecutive elective robotic colon and rectum resections via the da Vinci®Xi platform for benign and malignant colorectal tumours,performed by a single surgeon between January 2017 and December 2023 at the Sydney Adventist Hospital,Sydney.CRP values were measured on post-operative days(PODs)3 and 5.A narrative review of the literature was performed via EMBASE,MEDLINE via PubMed and Google Scholar from inception to December 2024 for comparative CRP values following LCS.Descriptive statistical comparisons were performed between the RCS and LCS.Results:One hundred ninety-three patients were identifiedin the RCS cohort.The median age was 73 y(range:62–83 y).Most colectomies were performed for adenocarcinoma(90.2%),with right hemicolectomy being the most common type of procedure(49.3%).The median CRP levels on PODs 3 and 5 were 83.10 mg/L(IQR:49.80–124.12 mg/L)and 26.20 mg/L(IQR:17.70–80.00 mg/L),respectively.The reported CRP after LCS was heterogeneous,with mean POD 3 values ranging from 69 mg/L to 99.5 mg/L,and mean POD 4–5 values ranging from 62.4 mg/L to 72.85 mg/L.Conclusions:There were similar,if not lower,POD 3 and 5 CRP values,suggesting that RCS was probably non-inferior to LCS regarding postoperative tissue trauma.In particular,there appeared to be a quicker recovery of the inflammatory response with RCS.展开更多
Single-cell biomechanics and electrophysiology measuring tools have transformed biological research over the last few decades,which enabling a comprehensive and nuanced understanding of cellular behavior and function....Single-cell biomechanics and electrophysiology measuring tools have transformed biological research over the last few decades,which enabling a comprehensive and nuanced understanding of cellular behavior and function.Despite their high-quality information content,these single-cell measuring techniques suffer from laborious manual processing by highly skilled workers and extremely low throughput(tens of cells per day).Recently,numerous researchers have automated the measurement of cell mechanical and electrical signals through robotic localization and control processes.While these efforts have demonstrated promising progress,critical challenges persist,including human dependency,learning complexity,in-situ measurement,and multidimensional signal acquisition.To identify key limitations and highlight emerging opportunities for innovation,in this review,we comprehensively summarize the key steps of robotic technologies in single-cell biomechanics and electrophysiology.We also discussed the prospects and challenges of robotics and automation in biological research.By bridging gaps between engineering,biology,and data science,this work aims to stimulate interdisciplinary research and accelerate the translation of robotic single-cell technologies into practical applications in the life sciences and medical fields.展开更多
In this research,a comparative analysis was conducted on the performance and efficiency of the dual-anchor soft robot(DASR)and the extension-contraction soft robot(ECSR).These robots were constructed by imitating the ...In this research,a comparative analysis was conducted on the performance and efficiency of the dual-anchor soft robot(DASR)and the extension-contraction soft robot(ECSR).These robots were constructed by imitating the locomotion of razor clams.The penetration force for extension actuators and the anchorage force for expansion actuators in dry sand with distinct relative densities were tested by differentiating input air pressure and length-to-diameter ratios(λ).On the basis of the findings,a DASR and an ECSR were developed.DASR comprised two expansion actuators as the head and the tail segments at two ends,and one extension actuator as the middle segment.ECSR was composed of an extension actuator.A method based on the force equilibrium was introduced to ascertain and adjust the geometric parameters(length of each segment)of DASR.The burrowing-out performance and efficiency of DASR and ECSR in sands with distinct relative densities were explored.The results revealed that DASR exhibited high efficiency in dense sand in terms of lower time of burrowing-out,slip-to-advancement ratio,and cost of transport.ECSR might perform better in looser sand in terms of higher average burrowing-out velocity,higher advancement in each cycle,and lower energy consumption.However,it had larger slips than DASR.DASR could realize steady advancement and net displacement in each cycle and effectively decrease slips.These findings demonstrate the benefits and usability of the dual-anchor motion and offer new insights into the application of the dual-anchor mechanism in the burrowing of robots.展开更多
This paper presents an intelligent patrol and security robot integrating 2D LiDAR and RGB-D vision sensors to achieve semantic simultaneous localization and mapping(SLAM),real-time object recognition,and dynamic obsta...This paper presents an intelligent patrol and security robot integrating 2D LiDAR and RGB-D vision sensors to achieve semantic simultaneous localization and mapping(SLAM),real-time object recognition,and dynamic obstacle avoidance.The system employs the YOLOv7 deep-learning framework for semantic detection and SLAM for localization and mapping,fusing geometric and visual data to build a high-fidelity 2D semantic map.This map enables the robot to identify and project object information for improved situational awareness.Experimental results show that object recognition reached 95.4%mAP@0.5.Semantic completeness increased from 68.7%(single view)to 94.1%(multi-view)with an average position error of 3.1 cm.During navigation,the robot achieved 98.0%reliability,avoided moving obstacles in 90.0%of encounters,and replanned paths in 0.42 s on average.The integration of LiDAR-based SLAMwith deep-learning–driven semantic perception establishes a robust foundation for intelligent,adaptive,and safe robotic navigation in dynamic environments.展开更多
Protective hardware is essential for mitigating damage caused by unavoidable falls in humanoid robots.Despite notable progress in fall protection hardware,the theoretical foundation for modeling and the feasibility of...Protective hardware is essential for mitigating damage caused by unavoidable falls in humanoid robots.Despite notable progress in fall protection hardware,the theoretical foundation for modeling and the feasibility of conducting full-scale fall experiments on robots or their surrogates remain somewhat limited.This paper proposes a method for optimizing the thickness of Expandable Polyethylene(EPE),which is used as back protection for the Chubao humanoid robot,based on small-scale impact test data to predict full-scale behavior.The optimal thickness is defined as a balance between compact design and protective effectiveness.An equivalent impact model characterized by four parameters:contact area S,mass m,fall height h,and cushioning material thickness d is introduced to describe impact conditions.The relationship between the peak impact acceleration ap and material thickness d,which forms the core of the method and gives rise to the name AP-D,is analyzed through their plotted curves.After introducing three characteristic parameters and two correction fac-tors,the relationship among the aforementioned variables is derived.Subsequently,both the optimal thickness do and its corresponding peak impact acceleration aop are predicted via nonlinear and linear regression models.Finally,the accuracy and effectiveness of the theoretically derived optimal thickness are validated on both a dummy and the actual robot.With the cushioning material applied,the peak chest acceleration is reduced to 41.57g for the dummy and 32.08g for the robot.展开更多
基金supported by National Outstanding Youth Science Foundation of China (Grant No. 51125020)National Hi-tech Research and Development Program of China (863 Program, Grant No. 2006AA04Z207)Program for New Century Excellent Talents in University, China
文摘The existing research on dynamics and slip ratio of wheeled mobile robot （WMR） are derived without considering the effect of height, and the existing models can not be used to analyze the dynamics performance of the robot with variable height while moving such as NOROS- Ⅱ. The existing method of dynamics modeling is improved by adding the constraint equation between perpendicular displacement of body and horizontal displacement of wheel into the constraint conditions. The dynamic model of NOROS- Ⅱ in wheel motion is built by the Lagrange method under nonholonomic constraints. The inverse dynamics is calculated in three different paths based on this model, and the results demonstrate that torques of hip pitching joints are inversely proportional to the height of robot. The relative error of calculated torques is less than 2% compared with that of ADAMS simulation, by which the validity of dynamic model is verified, Moreover, the relative horizontal motion between fore/hind wheels and body is produced when the height is changed, and thus the accurate slip ratio can not be obtained by the traditional equation. The improved slip ratio equations with the parameter of the vertical velocity of body are introduced for fore wheels and hind wheels respectively. Numerical simulations of slip ratios are conducted to reveal the effect of varied height on slip ratios of different wheels. The result shows that the slip ratios of fore/hind wheels become larger/smaller respectively as the height increases, and as the height is reduced, the reverse applies. The proposed research of dynamic model and slip ratio based on the robot height provides the effective method to analyze the dynamics of WMRs with varying height.
基金Supported by State Key Lab of Mechanical System and Vibration Project of China(Grant No.MSVZD202008).
文摘The wheel-legged hybrid structure has been utilized by ground mobile platforms in recent years to achieve good mobility on both flat surfaces and rough terrain.However,most of the wheel-legged robots only have one-directional obstacle-crossing ability.During the motion,most of the wheel-legged robots’centroid fluctuates violently,which damages the stability of the load.What’s more,many designs of the obstacle-crossing part and transformation-driving part of this structure are highly coupled,which limits its optimal performance in both aspects.This paper presents a novel wheel-legged robot with a rim-shaped changeable wheel,which has a bi-directional and smooth obstacle-crossing ability.Based on the kinematic model,the geometric parameters of the wheel structure and the design variables of the driving four-bar mechanism are optimized separately.The kinetostatics model of the mobile platform when climbing stairs is established to determine the body length and angular velocity of the driving wheels.A pro-totype is made according to the optimal parameters.Experiments show that the prototype installed with the novel transformable wheels can overcome steps with a height of 1.52 times of its wheel radius with less fluctuation of its centroid and performs good locomotion capabilities in different environments.
基金Heilongjiang Provincial Youth Science and Technology Talent Support Project(No.2023QNTJ008)Self-Planned Task of State Key Laboratory of Robotics and System from Harbin Institute of Technology(HIT)(No.SKLRS 202301A03)Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems(No.GZKF-202203),China.
文摘Design and manufacturing play pivotal roles in hydraulic-driven robotic development.However,previous studies have emphasized mainly results and performance,often overlooking the specifics of the design and manufacturing process.This paper introduces a novel approach known as light weight design and integrated manufacturing(LD&IM)for hydraulic wheel-legged robots.The LD&IM method leverages topology optimization and generative design techniques to achieve a substantial 45%weight reduction,enhancing the robot’s dynamic motion capabilities.This innovative design method not only streamlines the design process but also upholds the crucial attributes of light weight construction and high strength essential for hydraulic wheel-legged robots.Furthermore,the integrated manufacturing method,incorporating selective laser melting(SLM)and high-precision subtractive manufacturing(SM)processes,expedites the fabrication of high-quality components.Using the LD&IM approach,a hydraulic-driven single wheel-legged robot,denoted as WLR-IV,has been successfully developed.This robot boasts low mass and inertia,high strength,and a simplified component structure.To assess its dynamic jumping capabilities,the control loop integrates a linear quadratic regulator(LQR)and zero dynamic-based controller,while trajectory planning uses the spring-loaded inverted pendulum(SLIP)model.Experimental jumping results confirm the WLR-IV single-legged robot’s exceptional dynamic performance,validating both the effectiveness of the LD&IM method and the rationale behind the control strategy.
基金Supported by National Hi-tech Research and Development Program of China (863 Program,Grant No.CDJZR13110073)
文摘Though the studies of wheel-legged robots have achieved great success, the existing ones still have defects in load distribution, structure stability and carrying capacity. For overcoming these shortcomings, a new kind of wheel-legged robot（Rolling-Wolf） is designed. It is actuated by means of ball screws and sliders, and each leg forms two stable triangle structures at any moment, which is simple but has high structure stability. The positional posture model and statics model are built and used to analyze the kinematic and mechanical properties of Rolling-Wolf. Based on these two models, important indexes for evaluating its motion performance are analyzed. According to the models and indexes, all of the structure parameters which influence the motion performance of Rolling-Wolf are optimized by the method of Archive-based Micro Genetic Algorithm（AMGA） by using Isight and Matlab software. Compared to the initial values, the maximum rotation angle of the thigh is improved by 4.17%, the maximum lifting height of the wheel is improved by 65.53%, and the maximum driving forces of the thigh and calf are decreased by 25.5% and 12.58%, respectively. The conspicuous optimization results indicate that Rolling-Wolf is much more excellent. The novel wheel-leg structure of Rolling-Wolf is efficient in promoting the load distribution, structure stability and carrying capacity of wheel-legged robot and the proposed optimization method provides a new approach for structure optimization.
基金Supported by National Natural Science Foundation of China(Grant No.61773060).
文摘Serving the Stewart mechanism as a wheel-legged structure,the most outstanding superiority of the proposed wheel-legged hybrid robot(WLHR)is the active vibration isolation function during rolling on rugged terrain.However,it is difficult to obtain its precise dynamic model,because of the nonlinearity and uncertainty of the heavy robot.This paper presents a dynamic control framework with a decentralized structure for single wheel-leg,position tracking based on model predictive control(MPC)and adaptive impedance module from inside to outside.Through the Newton-Euler dynamic model of the Stewart mechanism,the controller first creates a predictive model by combining Newton-Raphson iteration of forward kinematic and inverse kinematic calculation of Stewart.The actuating force naturally enables each strut to stretch and retract,thereby realizing six degrees-of-freedom(6-DOFs)position-tracking for Stewart wheel-leg.The adaptive impedance control in the outermost loop adjusts environmental impedance parameters by current position and force feedback of wheel-leg along Z-axis.This adjustment allows the robot to adequately control the desired support force tracking,isolating the robot body from vibration that is generated from unknown terrain.The availability of the proposed control methodology on a physical prototype is demonstrated by tracking a Bezier curve and active vibration isolation while the robot is rolling on decelerate strips.By comparing the proportional and integral(PI)and constant impedance controllers,better performance of the proposed algorithm was operated and evaluated through displacement and force sensors internally-installed in each cylinder,as well as an inertial measurement unit(IMU)mounted on the robot body.The proposed algorithm structure significantly enhances the control accuracy and vibration isolation capacity of parallel wheel-legged robot.
基金supported by the National Key R&D Program of China(Grant No.2022YFD2202102)the Key Laboratory of Modern Agricultural Intelligent Equipment in South China,Ministry of Agriculture and Rural Affairs,China.
文摘The continuous development of smart agriculture puts forward the requirement of high accuracy slope path tracking for the agricultural wheel-legged robot.Compared to flat terrain,path tracking control on sloped terrain faces the obstacle of motion instability of the wheel-legged robot induced by the slope gravitational force component,which causes instantaneous steering center to offset.To address this problem,this study proposed a slope path tracking control algorithm by combining the methods of virtual sensing radar and two-level neural network.Firstly,the kinematic and dynamic models of the wheel-legged robot are deduced,from which the crucial factors affecting control accuracy of slope path tracking are recognized.Secondly,this study constructs the slope path tracking control algorithm,in which the virtual sensing radar is utilized to realize route perception,and the two-level neural network is employed to provide drive motors’speeds to adapt to path tracking on different slopes.Furthermore,the corresponding compensation methods of the identified impacting factors are embedded in the proposed algorithm,including the lateral tracking deviation factor,heading angle deviation factor,slope change factor,and slip rate factor.Finally,the co-simulation model of slope path tracking control is constructed,including the multi-body dynamic model of the wheel-legged robot in RecurDyn and the proposed slope path tracking algorithm complied by Python.Subsequently,the simulation tests of the wheel-legged robot are carried out under various slope angles and velocities.The results reveal that the proposed algorithm’s effectiveness and accuracy are superior,with tracking errors reduced by more than 47.2%compared to an optimized pure pursuit algorithm.
基金supported by the Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(1005-IZD23002-25)the National Natural Science Foundation of China under Grant nos.52075248.
文摘In-pipe robots have been widely used in pipes-with smooth inner walls.However,current in-pipe robots face challenges in terms of moving past obstacles and climbing in marine-vessel pipeline systems,which are affected by marine biofouling and electrochemical corrosion.This paper takes inspiration from the dual-hook structure of Trypoxylus dichotomus’s feet and gecko‑like dry adhesives,proposing an in-pipe robot that is capable of climbing on rough and smooth pipe inwalls.The combination of the bioinspired hook and dry adhesives allows the robot to stably attach to rough or smooth pipe inwalls,while the wheel-leg hybrid mechanism provides better conditions for obstacle traversal.The paper explores the attachment and obstacle-surmounting mechanisms of the robot.Moreover,motion strategies for the robot are devised based on different pipe structural features.The experiments showed that this robot can adapt to both smooth and rough pipe environments simultaneously,and its motion performance is superior to conventional driving mechanisms.The robot’s active turning actuators also enable it to navigate through horizontally or vertically oriented 90°bends.
基金supported by the Research Fund of State Key Laboratory of Mechanics and Control for Aerospace Structures(1005-IZD23002-25).
文摘The wheel-legged biped robot is a typical ground-based mobile robot that can combine the high velocity and high efficiency pertaining to wheeled motion and the strong,obstacle-crossing performance associated with legged motion.These robots have gradually exhibited satisfactory application potential in various harsh scenarios such as rubble rescue,military operations,and wilderness exploration.Wheel-legged biped robots are divided into four categories according to the open–close chain structure forms and operation task modes,and the latest technology research status is summarized in this paper.The hardware control system,control method,and application are analyzed,and the dynamic balance control for the two-wheel,biomimetic jumping control for the legs and whole-body control for integrating the wheels and legs are analyzed.In summary,it is observed that the current research exhibits problems,such as the insufficient application of novel materials and a rigid–flexible coupling design;the limited application of the advanced,intelligent control methods;the inadequate understanding of the bionic jumping mechanisms in robot legs;and the insufficient coordination ability of the multi-modal motion,which do not exhibit practical application for the wheel-legged biped robots.Finally,this study discusses the key research directions and development trends for the wheel-legged biped robots.
文摘Robots are widely used to replace people in some burdensome or hamaful areas. Not only the moving ability but also the manipulating ability is needed in the missions of complex multitasking requirements. In the last decades, wheel-legged hexapod robots are extensively studied to ineet this condition.
基金financially supported by the National Key R&D Program of China(No.2017YFE0112200)Hebei Province Science and Technology Support Program(No.19391825D)Postgraduate Innovation Subsidy Project of Hebei Province(No.CXZZBS2021134)。
文摘An adaptive wheel-legged shape reconfigurable mobile robot,based on a scissor-like mechanism,is proposed for an obstacle detecting and surmounting robot,moving on complex terrain.The robot can dynamically adjust its own shape,according to the environment,realizing a transformation of wheel shape into leg shape and vice versa.Each wheel-legged mechanism has one degree of freedom,which means that only the relative motion of the inner and outer discs is needed to achieve the transformation of the shape into a wheel or a leg.First,the force analysis of the conversion process of the wheel-legged mechanism is carried out,while the relationship between the driving torque and the friction factor in the non-conversion trigger stage and in the conversion trigger stage is obtained.The results showed that the shape conversion can be better realized by increasing the friction factor of the trigger point.Next,the kinematics analysis of the robot,including climbing the obstacles,stairs and gully,is carried out.The motion of the spokes tip is obtained,in order to derive the folding ratio and the surmountable obstacle height of the wheel-legged mechanism.The parameters of the wheel-legged structure are optimized,to obtain better stability and obstacle climbing ability.Finally,a dynamic simulation model is established by ADAMS,to verify the obstacle climbing performance and gait rationality of the robot,in addition to a prototype experiment.The results showed that the surmountable obstacle height of the robot is about3.05 times the spoke radius.The robot has the stability of a traditional wheel mechanism and the obstacle surmount performance of a leg mechanism,making it more suitable for field reconnaissance and exploration missions.
基金supported by the Innovative Research Groups of the National Natural Science Foundation of China(51521003)the Natural Science Foundation of Heilongjiang Province of China(YQ2021F011)+1 种基金Key Research Project of Zhejiang Lab(no.115002-AC2101)funded by Open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems。
文摘The robot used for disaster rescue or field exploration requires the ability of fast moving on flat road and adaptability on complex terrain.The hybrid wheel-legged robot(WLR-3P,prototype of the third-generation hydraulic wheel-legged robot)has the characteristics of fast and efficient mobility on flat surfaces and high environmental adaptability on rough terrains.In this paper,3 design requirements are proposed to improve the mobility and environmental adaptability of the robot.To meet these 3 requirements,2 design principles for each requirement are put forward.First,for light weight and low inertia with high stiffness,3-dimensional printing technology and lightweight material are adopted.Second,the integrated hydraulically driven unit is used for high power density and fast response actuation.Third,the microhydraulic power unit achieves power autonomy,adopting the hoseless design to strengthen the reliability of the hydraulic system.What is more,the control system including hierarchical distributed electrical system and control strategy is presented.The mobility and adaptability of WLR-3P are demonstrated with a series of experiments.Finally,the robot can achieve a speed of 13.6 km/h and a jumping height of 0.2 m.
文摘Aiming to solve the steering instability and hysteresis of agricultural robots in the process of movement,a fusion PID control method of particle swarm optimization(PSO)and genetic algorithm(GA)was proposed.The fusion algorithm took advantage of the fast optimization ability of PSO to optimize the population screening link of GA.The Simulink simulation results showed that the convergence of the fitness function of the fusion algorithm was accelerated,the system response adjustment time was reduced,and the overshoot was almost zero.Then the algorithm was applied to the steering test of agricultural robot in various scenes.After modeling the steering system of agricultural robot,the steering test results in the unloaded suspended state showed that the PID control based on fusion algorithm reduced the rise time,response adjustment time and overshoot of the system,and improved the response speed and stability of the system,compared with the artificial trial and error PID control and the PID control based on GA.The actual road steering test results showed that the PID control response rise time based on the fusion algorithm was the shortest,about 4.43 s.When the target pulse number was set to 100,the actual mean value in the steady-state regulation stage was about 102.9,which was the closest to the target value among the three control methods,and the overshoot was reduced at the same time.The steering test results under various scene states showed that the PID control based on the proposed fusion algorithm had good anti-interference ability,it can adapt to the changes of environment and load and improve the performance of the control system.It was effective in the steering control of agricultural robot.This method can provide a reference for the precise steering control of other robots.
文摘The Chinese SME’s vision shows the bright side of humanoid robots:rather than replacing human workers,they are handling everyday mechanical tasks,leaving human staff to focus on improving service and emotional experiences.IN the Jinqiao Economic and Technological Development Zone in Pudong New Area,Shanghai,KEENON Robotics,a national-level“Little Giant”(innovative SME),is leading the transformation of the service robots industry.Amid the wave of embodied intelligence development,the humanoid service robots created by this company have become a focal point of the industry and businesses alike.
文摘This research is applied mainly for routine inspection,rescue missions in multi-terrains environment.The main process of developing this hexapod based wheel-legged robot includes mechanism structure design,electronic devices configuration,gaits’control adjustment and pathing route simulation.With the use of transformable wheel-legs,the robot can run flexibly in flat under the wheeled mode,and through the gear and mechanism system,it would shift to legged mode to show enough capability for overring the unstructured obstacles.As the expectation,this robot would have bright prospects for variable terrains application and substitute current rivals by its higher efficiency and adaptability.
文摘Objective:Robotic colorectal surgery(RCS)provides a stable,magnifiedthree-dimensional visual field and enhanced ergonomics enabling precise dissection and tremor suppression.We postulate that this technique is associated with less tissue trauma and improved postoperative outcomes than laparoscopic colorectal surgery(LCS).This study aimed to explore the inflammatoryresponse following RCS by measuring postoperative C-reactive protein(CRP)levels and compare them with LCS data reported in the literature.Methods:This single centre retrospective study included consecutive elective robotic colon and rectum resections via the da Vinci®Xi platform for benign and malignant colorectal tumours,performed by a single surgeon between January 2017 and December 2023 at the Sydney Adventist Hospital,Sydney.CRP values were measured on post-operative days(PODs)3 and 5.A narrative review of the literature was performed via EMBASE,MEDLINE via PubMed and Google Scholar from inception to December 2024 for comparative CRP values following LCS.Descriptive statistical comparisons were performed between the RCS and LCS.Results:One hundred ninety-three patients were identifiedin the RCS cohort.The median age was 73 y(range:62–83 y).Most colectomies were performed for adenocarcinoma(90.2%),with right hemicolectomy being the most common type of procedure(49.3%).The median CRP levels on PODs 3 and 5 were 83.10 mg/L(IQR:49.80–124.12 mg/L)and 26.20 mg/L(IQR:17.70–80.00 mg/L),respectively.The reported CRP after LCS was heterogeneous,with mean POD 3 values ranging from 69 mg/L to 99.5 mg/L,and mean POD 4–5 values ranging from 62.4 mg/L to 72.85 mg/L.Conclusions:There were similar,if not lower,POD 3 and 5 CRP values,suggesting that RCS was probably non-inferior to LCS regarding postoperative tissue trauma.In particular,there appeared to be a quicker recovery of the inflammatory response with RCS.
基金the National Natural Science Foundation of China[62525301,62127811,62433019]the New Cornerstone Science Foundation through the XPLORER PRIZEthe financial support by the China Postdoctoral Science Foundation[GZB20240797].
文摘Single-cell biomechanics and electrophysiology measuring tools have transformed biological research over the last few decades,which enabling a comprehensive and nuanced understanding of cellular behavior and function.Despite their high-quality information content,these single-cell measuring techniques suffer from laborious manual processing by highly skilled workers and extremely low throughput(tens of cells per day).Recently,numerous researchers have automated the measurement of cell mechanical and electrical signals through robotic localization and control processes.While these efforts have demonstrated promising progress,critical challenges persist,including human dependency,learning complexity,in-situ measurement,and multidimensional signal acquisition.To identify key limitations and highlight emerging opportunities for innovation,in this review,we comprehensively summarize the key steps of robotic technologies in single-cell biomechanics and electrophysiology.We also discussed the prospects and challenges of robotics and automation in biological research.By bridging gaps between engineering,biology,and data science,this work aims to stimulate interdisciplinary research and accelerate the translation of robotic single-cell technologies into practical applications in the life sciences and medical fields.
基金financially supported by the Natural Science Foundation of Jiangsu Province,China(No.BK 20221502)the National Natural Science Foundation of China(No.42477147)。
文摘In this research,a comparative analysis was conducted on the performance and efficiency of the dual-anchor soft robot(DASR)and the extension-contraction soft robot(ECSR).These robots were constructed by imitating the locomotion of razor clams.The penetration force for extension actuators and the anchorage force for expansion actuators in dry sand with distinct relative densities were tested by differentiating input air pressure and length-to-diameter ratios(λ).On the basis of the findings,a DASR and an ECSR were developed.DASR comprised two expansion actuators as the head and the tail segments at two ends,and one extension actuator as the middle segment.ECSR was composed of an extension actuator.A method based on the force equilibrium was introduced to ascertain and adjust the geometric parameters(length of each segment)of DASR.The burrowing-out performance and efficiency of DASR and ECSR in sands with distinct relative densities were explored.The results revealed that DASR exhibited high efficiency in dense sand in terms of lower time of burrowing-out,slip-to-advancement ratio,and cost of transport.ECSR might perform better in looser sand in terms of higher average burrowing-out velocity,higher advancement in each cycle,and lower energy consumption.However,it had larger slips than DASR.DASR could realize steady advancement and net displacement in each cycle and effectively decrease slips.These findings demonstrate the benefits and usability of the dual-anchor motion and offer new insights into the application of the dual-anchor mechanism in the burrowing of robots.
基金supported by the National Science and Technology Council of under Grant NSTC 114-2221-E-130-007.
文摘This paper presents an intelligent patrol and security robot integrating 2D LiDAR and RGB-D vision sensors to achieve semantic simultaneous localization and mapping(SLAM),real-time object recognition,and dynamic obstacle avoidance.The system employs the YOLOv7 deep-learning framework for semantic detection and SLAM for localization and mapping,fusing geometric and visual data to build a high-fidelity 2D semantic map.This map enables the robot to identify and project object information for improved situational awareness.Experimental results show that object recognition reached 95.4%mAP@0.5.Semantic completeness increased from 68.7%(single view)to 94.1%(multi-view)with an average position error of 3.1 cm.During navigation,the robot achieved 98.0%reliability,avoided moving obstacles in 90.0%of encounters,and replanned paths in 0.42 s on average.The integration of LiDAR-based SLAMwith deep-learning–driven semantic perception establishes a robust foundation for intelligent,adaptive,and safe robotic navigation in dynamic environments.
基金Natural Science Foundation of Beijing Municipality under Grant L243004the National Natural Science Foundation of China under Grant 62403060.
文摘Protective hardware is essential for mitigating damage caused by unavoidable falls in humanoid robots.Despite notable progress in fall protection hardware,the theoretical foundation for modeling and the feasibility of conducting full-scale fall experiments on robots or their surrogates remain somewhat limited.This paper proposes a method for optimizing the thickness of Expandable Polyethylene(EPE),which is used as back protection for the Chubao humanoid robot,based on small-scale impact test data to predict full-scale behavior.The optimal thickness is defined as a balance between compact design and protective effectiveness.An equivalent impact model characterized by four parameters:contact area S,mass m,fall height h,and cushioning material thickness d is introduced to describe impact conditions.The relationship between the peak impact acceleration ap and material thickness d,which forms the core of the method and gives rise to the name AP-D,is analyzed through their plotted curves.After introducing three characteristic parameters and two correction fac-tors,the relationship among the aforementioned variables is derived.Subsequently,both the optimal thickness do and its corresponding peak impact acceleration aop are predicted via nonlinear and linear regression models.Finally,the accuracy and effectiveness of the theoretically derived optimal thickness are validated on both a dummy and the actual robot.With the cushioning material applied,the peak chest acceleration is reduced to 41.57g for the dummy and 32.08g for the robot.
