Modern military drills and conventional training,performed under all-weather conditions,impose exacting challenges on soldiers.This has motivated the development of exoskeleton robot systems,leveraging advanced techno...Modern military drills and conventional training,performed under all-weather conditions,impose exacting challenges on soldiers.This has motivated the development of exoskeleton robot systems,leveraging advanced technology and material innovation.These systems have demonstrated their effectiveness at assisting movement,enhancing protection,promoting rehabilitation,and providing comprehensive support to soldiers.This groundbreaking technology not only reduces a soldier's physical exertion significantly but also effectively diminishes the risk of injury during training,infusing new vitality into the enhancement of military capabilities.Different types of exoskeleton robots differ in their focus.Lower-limb exoskeleton robots are designed to increase the soldier's endurance.Upper-limb exoskeleton robots enhance strength.This paper provides a detailed explanation of the key technologies of various types of exoskeleton robots,covering theirmechanical design,electromechan-ical transmission structures,sensors,and actuation methods.It also explores the diverse application scenarios of exoskeleton robots in the military field,systematically introducing their development trajectory,milestone achievements,and the cutting-edge technologies currently employed,as well as the challenges faced.The conclusion offers a prospective discussion of future development pathways,anticipating the broad prospects for exoskeleton robots in the military domain.展开更多
Accurate trajectory tracking in lower-limb exoskeletons is challenged by the nonlinear,time-varying dynamics of human-robot interaction,limited sensor availability,and unknown external disturbances.This study proposes...Accurate trajectory tracking in lower-limb exoskeletons is challenged by the nonlinear,time-varying dynamics of human-robot interaction,limited sensor availability,and unknown external disturbances.This study proposes a novel control strategy that combines flatness-based control with two cascaded observers:a high-gain observer to estimate unmeasured joint velocities,and a nonlinear disturbance observer to reconstruct external torque disturbances in real time.These estimates are integrated into the control law to enable robust,state-feedback-based trajectory tracking.The approach is validated through simulation scenarios involving partial state measurements and abrupt external torque perturbations,reflecting realistic rehabilitation conditions.Results confirm that the proposed method significantly enhances tracking accuracy and disturbance rejection capability,demonstrating its strong potential for reliable and adaptive rehabilitation assistance.展开更多
Lower extremity robotic exoskeletons(LEEX)can not only improve the ability of the human body but also provide healing treatment for people with lower extremity dysfunction.There are a wide range of application needs a...Lower extremity robotic exoskeletons(LEEX)can not only improve the ability of the human body but also provide healing treatment for people with lower extremity dysfunction.There are a wide range of application needs and development prospects in the military,industry,medical treatment,consumption and other felds,which has aroused widespread concern in society.This paper attempts to review LEEX technical development.First,the history of LEEX is briefy traced.Second,based on existing research,LEEX is classifed according to auxiliary body parts,structural forms,functions and felds,and typical LEEX prototypes and products are introduced.Then,the latest key technologies are analyzed and summarized,and the research contents,such as bionic structure and driving characteristics,human–robot interaction(HRI)and intentawareness,intelligent control strategy,and evaluation method of power-assisted walking efciency,are described in detail.Finally,existing LEEX problems and challenges are analyzed,a future development trend is proposed,and a multidisciplinary development direction of the key technology is provided.展开更多
Due to the close physical interaction between human and machine in process of gait training, lower limb exoskeletons should be safe, comfortable and able to smoothly transfer desired driving force/moments to the patie...Due to the close physical interaction between human and machine in process of gait training, lower limb exoskeletons should be safe, comfortable and able to smoothly transfer desired driving force/moments to the patients. Correlatively, in kinematics the exoskeletons are required to be compatible with human lower limbs and thereby to avoid the uncontrollable interactional loads at the human-machine interfaces. Such requirement makes the structure design of exoskeletons very difficult because the human-machine closed chains are complicated. In addition, both the axis misalignments and the kinematic character difference between the exoskeleton and human joints should be taken into account. By analyzing the DOF（degree of freedom） of the whole human-machine closed chain, the human-machine kinematic incompatibility of lower limb exoskeletons is studied. An effective method for the structure design of lower limb exoskeletons, which are kinematically compatible with human lower limb, is proposed. Applying this method, the structure synthesis of the lower limb exoskeletons containing only one-DOF revolute and prismatic joints is investigated; the feasible basic structures of exoskeletons are developed and classified into three different categories. With the consideration of quasi-anthropopathic feature, structural simplicity and wearable comfort of lower limb exoskeletons, a joint replacement and structure comparison based approach to select the ideal structures of lower limb exoskeletons is proposed, by which three optimal exoskeleton structures are obtained. This paper indicates that the human-machine closed chain formed by the exoskeleton and human lower limb should be an even-constrained kinematic system in order to avoid the uncontrollable human-machine interactional loads. The presented method for the structure design of lower limb exoskeletons is universal and simple, and hence can be applied to other kinds of wearable exoskeletons.展开更多
Robotic exoskeletons have emerged as rehabilitation tool that may ameliorate several of the existing healthrelated consequences after spinal cord injury(SCI).However,evidence to support its clinical application is sti...Robotic exoskeletons have emerged as rehabilitation tool that may ameliorate several of the existing healthrelated consequences after spinal cord injury(SCI).However,evidence to support its clinical application is still lacking considering their prohibitive cost.The current mini-review is written to highlight the main limitations and potential benefits of using exoskeletons in the rehabilitation of persons with SCI.We have recognized two main areas relevant to the design of exoskeletons and to their applications on major health consequences after SCI.The design prospective refers to safety concerns,fitting time and speed of exoskeletons.The health prospective refers to factors similar to body weight,physical activity,pressure injuries and bone health.Clinical trials are currently underway to address some of these limitations and to maximize the benefits in rehabilitation settings.Future directions highlight the need to use exoskeletons in conjunction with other existing and emerging technologies similar to functional electrical stimulation and brain-computer interface to address major limitations.Exoskeletons have the potential to revolutionize rehabilitation following SCI;however,it is still premature to make solid recommendations about their clinical use after SCI.展开更多
Unilateral motor impairment can disrupt the coordination between the joints,impeding the patient’s normal gait.To assist such patients to walk normally and naturally,an adaptive control algorithm based on inter-joint...Unilateral motor impairment can disrupt the coordination between the joints,impeding the patient’s normal gait.To assist such patients to walk normally and naturally,an adaptive control algorithm based on inter-joint coordination was proposed in this work for lower-limb exoskeletons.The control strategy can generate the reference trajectory of the affected leg in real time based on a motion coordination model between the joints,and adopt an adaptive controller with virtual windows to track the reference trajectory.Long Short-Term Memory(LSTM)network was also adopted to establish the coordination model between the joints of both lower limbs,which was optimized by preprocessing angle information and adding gait phase information.In the adaptive controller,the virtual windows were symmetrically distributed around the reference trajectory,and its width was adjusted according to the gait phase of the auxiliary leg.In addition,the impedance parameters of the controller were updated online to match the motion capacity of the affected leg based on the spatiotemporal symmetry factors between the bilateral gaits.The LSTM coordination model demonstrated good accuracy and generality in the gait database of seven individuals,with an average root mean square error of 3.5 and 4.1 for the hip and knee joint angle estimation,respectively.To further evaluate the control algorithm,four healthy subjects walked wearing the exoskeleton while additional weights were added around the ankle joint to simulate an asymmetric gait.From the experimental results,it was shown that the algorithm improved the gait symmetry of the subjects to a normal level while exhibiting great adaptability to different subjects.展开更多
Effectively controlling active power-assist lower-limb exoskeletons in a human-in-the-loop manner poses a substantial chal-lenge,demanding an approach that ensures wearer autonomy while seamlessly adapting to diverse ...Effectively controlling active power-assist lower-limb exoskeletons in a human-in-the-loop manner poses a substantial chal-lenge,demanding an approach that ensures wearer autonomy while seamlessly adapting to diverse wearer needs.This paper introduces a novel hierarchical control scheme comprising five integral components:intention recognition layer,dynamics feedforward layer,force distribution layer,feedback compensation layer,as well as sensors and actuators.The intention rec-ognition layer predicts the wearer's movement and enables wearer-dominant movement through integrated force and position sensors.The force distribution layer effectively resolves the statically indeterminate problem in the context of double-foot support,showcasing flexible control modes.The dynamics feedforward layer mitigates the effect of the exoskeleton itself on movement.Meanwhile,the feedback compensation layer provides reliable closed-loop control.This approach mitigates abrupt changes in joint torques during frequent transitions between swing and stance phases by decomposed dynamics.Validating this innovative hierarchical control scheme on a hydraulic exoskeleton platform through a series of experiments,the results demonstrate its capability to deliver assistance in various modes such as stepping,squatting,and jumping while adapting seamlessly to different terrains.展开更多
The increasing necessity of load-carrying activities has led to greater human musculoskeletal damage and an increased metabolic cost.With the rise of exoskeleton technology,researchers have begun exploring different a...The increasing necessity of load-carrying activities has led to greater human musculoskeletal damage and an increased metabolic cost.With the rise of exoskeleton technology,researchers have begun exploring different approaches to developing wearable robots to augment human load-carrying ability.However,there is a lack of systematic discussion on biomechanics,mechanical designs,and augmentation performance.To achieve this,extensive studies have been reviewed and 108 references are selected mainly from 2013 to 2022 to address the most recent development.Other earlier 20 studies are selected to present the origin of different design principles.In terms of the way to achieve load-carrying augmentation,the exoskeletons reviewed in this paper are sorted by four categories based on the design principles,namely load-suspended backpacks,lower-limb exoskeletons providing joint torques,exoskeletons transferring load to the ground and exoskeletons transferring load between body segments.Specifically,the driving modes of active and passive,the structure of rigid and flexible,the conflict between assistive performance and the mass penalty of the exoskeleton,and the autonomy are discussed in detail in each section to illustrate the advances,challenges,and future trends of exoskeletons designed to carry loads.展开更多
Musculoskeletal Symptoms(MSS)often arise from prolonged maintenance of bent postures in the neck and trunk during surgical procedures.To prevent MSS,a passive exoskeleton utilizing carbon fiber beams to offer support ...Musculoskeletal Symptoms(MSS)often arise from prolonged maintenance of bent postures in the neck and trunk during surgical procedures.To prevent MSS,a passive exoskeleton utilizing carbon fiber beams to offer support to the neck and trunk was proposed.The application of support force is intended to reduce muscle forces and joint compression forces.A nonlinear mathematical model for the neck and trunk support beam is presented to estimate the support force.A validation test is subsequently conducted to assess the accuracy of the mathematical model.Finally,a preliminary functional evaluation test is performed to evaluate movement capabilities and support provided by the exoskeleton.The mathematical model demonstrates an accuracy for beam support force within a range of 0.8–1.2 N Root Mean Square Error(RMSE).The exoskeleton was shown to allow sufficient Range of Motion(ROM)for neck and trunk during open surgery training.While the exoskeleton showed potential in reducing musculoskeletal load and task difficulty during simulated surgery tasks,the observed reduction in perceived task difficulty was deemed non-significant.This prompts the recommendation for further optimization in personalized adjustments of beams to facilitate improvements in task difficulty and enhance comfort.展开更多
The study of exoskeletons has been a popular topic worldwide.However,there is still a long way to go before exoskeletons can be widely used.One of the major challenges is control,and there is no specific research tren...The study of exoskeletons has been a popular topic worldwide.However,there is still a long way to go before exoskeletons can be widely used.One of the major challenges is control,and there is no specific research trend for controlling exoskeletons.In this paper,we propose a novel exoskeleton control strategy that combines Active Disturbance Rejection Control(ADRC)and Deep Reinforcement Learning(DRL).The dynamic model of the exoskeleton is constructed,followed with the design of the ADRC.To automatically adjust the control parameters of the ADRC,the Twin-Delayed Deep Deterministic Policy Gradient(TD3)is utilized.Then a reward function is defined in terms of the joint angle,angular velocity,and their errors to the desired values,to maximize the accuracy of the joint angle.In the simulations and experiments,a conventional ADRC,and ADRC based on Genetic Algorithm(GA)and Particle Swarm Optimization(PSO)were carried out for comparison with the proposed control method.The results of the tests show that TD3-ADRC has a rapid response,small overshoot,and low Mean Absolute Error(MAE)and Root Mean Square Error(RMSE)followed with the desired,demonstrating the superiority of the proposed control method for the self-learning control of exoskeleton.展开更多
With the acceleration of the global aging process and the increase of cardiovascular ancerebrovascular diseases,more and more patients are paralyzed due to accidents,so theexoskeleton robot began to appear in people&#...With the acceleration of the global aging process and the increase of cardiovascular ancerebrovascular diseases,more and more patients are paralyzed due to accidents,so theexoskeleton robot began to appear in people's sight,and the lower limb exoskeleton robot withrehabilitation training is also favored by more and more people.In this paper,the structural designand analysis of the lower limb exoskeleton robot are carried out in view of the patients'expectation ofnormal walking.First,gait analysis and structural design of lower limb exoskeleton robot.Based onthe analysis of the walking gait of normal people,the freedom of the three key joints of the lower limbexoskeleton robot hip joint,knee joint and ankle joint is determined.at the same time,according tothe structuralcharacteristics of each joint,the three key joints are modeled respectively,and theoverall model assembly of the lower limb exoskeleton robot is completed.Secondly,the kinematicsanalysis of the lower limb exoskeleton robot was carried out to obtain the relationship between thelinear displacement,linear speed and acceleration of each joint,so as to ensure the coordination ofthe model with the human lower limb movement.Thirdly,the static analysis of typical gait of hipjoint,knee joint and ankle joint is carried out to verify the safety of the design model under thepremise of ensuring the structural strength requirements.Finally,the parts of the model were 3Dprinted,and the rationality of the design was further verified in the process of assembling the model.展开更多
To overcome the limitations of traditional exoskeletons in complex outdoor terrains,this study introduces a novel lower limb exoskeleton inspired by the snow leopard’s forelimb musculoskeletal structure.It features a...To overcome the limitations of traditional exoskeletons in complex outdoor terrains,this study introduces a novel lower limb exoskeleton inspired by the snow leopard’s forelimb musculoskeletal structure.It features a non-fully anthropomorphic design,attaching only at the thigh and ankle with a backward-knee configuration to mimic natural human knee movement.The design incorporates a single elastic element at the hip for gravity compensation and dual elastic elements at the knee for terrain adaptability,which adjust based on walking context.The design’s effectiveness was assessed by measuring metabolic cost reduction and motor output torque under various walking conditions.Results showed significant metabolic cost savings of 5.8–8.8%across different speeds and a 7.9%reduction during 9°incline walking on a flat indoor surface.Additionally,the spring element decreased hip motor output torque by 7–15.9%and knee torque by 8.1–14.2%.Outdoor tests confirmed the design’s robustness and effectiveness in reducing motor torque across terrains,highlighting its potential to advance multi-terrain adaptive exoskeleton research.展开更多
The lower limb assisted exoskeleton is a prominent area of research within the field of exoskeleton technology.However,several challenges remain,including the development of flexible actuators,high battery consumption...The lower limb assisted exoskeleton is a prominent area of research within the field of exoskeleton technology.However,several challenges remain,including the development of flexible actuators,high battery consumption,the risk of joint misalignment,and limited assistive capabilities.This paper proposes a compact flexible actuator incorporating two elastic elements named Adjustable Energy Storage Series Elastic Actuator(AES-SEA),which combining an adjustable energy storage device with a series elastic actuator for application in exoskeleton hip joints.This design aims to enhance energy efficiency and improve assistive effects.Subsequently,we introduce a novel knee joint bionic structure based on a pulley-groove configuration and a four-link mechanism,designed to replicate human knee joint motion and prevent joint misalignment.Additionally,we propose an innovative controller that integrates concepts from Linear Quadratic Regulator(LQR)control and virtual tunnel for level walking assistance.This controller modulates the assisted reference trajectory using the virtual tunnel concept,enabling different levels of assistance both inside and outside the tunnel by adjusting the parameters Q and R.This approach enhances the assisting force while ensuring the safety of human-computer interaction.Finally,metabolic experiments were conducted to evaluate the effectiveness of the exoskeleton assistance.展开更多
Disability is defined as a condition that makes it difficult for a person to perform certain vital activities.In recent years,the integration of the concepts of intelligence in solving various problems for disabled pe...Disability is defined as a condition that makes it difficult for a person to perform certain vital activities.In recent years,the integration of the concepts of intelligence in solving various problems for disabled persons has become more frequent.However,controlling an exoskeleton for rehabilitation presents challenges due to their nonlinear characteristics and external disturbances caused by the structure itself or the patient wearing the exoskeleton.To remedy these problems,this paper presents a novel adaptive control strategy for upper-limb rehabilitation exoskeletons,addressing the challenges of nonlinear dynamics and external disturbances.The proposed controller integrated a Radial Basis Function Neural Network(RBFNN)with a disturbance observer and employed a high-dimensional integral Lyapunov function to guarantee system stability and trajectory tracking performance.In the control system,the role of the RBFNN was to estimate uncertain signals in the dynamic model,while the disturbance observer tackled external disturbances during trajectory tracking.Artificially created scenarios for Human-Robot interactive experiments and periodically repeated reference trajectory experiments validated the controller’s performance,demonstrating efficient tracking.The proposed controller is found to achieve superior tracking accuracy with Root-Mean-Squared(RMS)errors of 0.022-0.026 rad for all joints,outperforming conventional Proportional-Integral-Derivative(PID)by 73%and Neural-Fuzzy Adaptive Control(NFAC)by 389.47%lower error.These results suggested that the RBFNN adaptive controller,coupled with disturbance compensation,could serve as an effective rehabilitation tool for upper-limb exoskeletons.These results demonstrate the superiority of the proposed method in enhancing rehabilitation accuracy and robustness,offering a promising solution for the control of upper-limb assistive devices.Based on the obtained results and due to their high robustness,the proposed control schemes can be extended to other motor disabilities,including lower limb exoskeletons.展开更多
The hydraulic exoskeleton is one research hotspot in the field of robotics,which can take heavy load due to the high power density of the hydraulic system.However,the traditional hydraulic system is normally centraliz...The hydraulic exoskeleton is one research hotspot in the field of robotics,which can take heavy load due to the high power density of the hydraulic system.However,the traditional hydraulic system is normally centralized,inefficient,and bulky during application,which limits its development in the exoskeleton.For improving the robot's performance,its hydraulic actuating system should be optimized further.In this paper a novel hydraulic actuating system(HAS)based on electric-hydrostatic actuator is proposed,which is applied to hip and knee joints.Each HAS integrates an electric servo motor,a high-speed micro pump,a specific tank,and other components into a module.The specific parameters are obtained through relevant simulation according to human motion data and load requirements.The dynamic models of the HAS are built,and validated by the system identification.Experiments of trajectory tracking and human-exoskeleton interaction are carried out,which demonstrate the proposed HAS has the ability to be applied to the exoskeleton.Compared with the previous prototype,the total weight of the HAS in the robot is reduced by about 40%,and the power density is increased by almost 1.6 times.展开更多
Underwater robot technology has shown impressive results in applications such as underwater resource detection.For underwater applications that require extremely high flexibility,robots cannot replace skills that requ...Underwater robot technology has shown impressive results in applications such as underwater resource detection.For underwater applications that require extremely high flexibility,robots cannot replace skills that require human dexterity yet,and thus humans are often required to directly perform most underwater operations.Wearable robots(exoskeletons)have shown outstanding results in enhancing human movement on land.They are expected to have great potential to enhance human underwater movement.The purpose of this survey is to analyze the state-of-the-art of underwater exoskeletons for human enhancement,and the applications focused on movement assistance while excluding underwater robotic devices that help to keep the temperature and pressure in the range that people can withstand.This work discusses the challenges of existing exoskeletons for human underwater movement assistance,which mainly includes human underwater motion intention perception,underwater exoskeleton modeling and human-cooperative control.Future research should focus on developing novel wearable robotic structures for underwater motion assistance,exploiting advanced sensors and fusion algorithms for human underwater motion intention perception,building up a dynamic model of underwater exoskeletons and exploring human-in-theloop control for them.展开更多
Lower Limb Exoskeletons(LLEs)are receiving increasing attention for supporting activities of daily living.In such active systems,an intelligent controller may be indispensable.In this paper,we proposed a locomotion in...Lower Limb Exoskeletons(LLEs)are receiving increasing attention for supporting activities of daily living.In such active systems,an intelligent controller may be indispensable.In this paper,we proposed a locomotion intention recognition system based on time series data sets derived from human motion signals.Composed of input data and Deep Learning(DL)algorithms,this framework enables the detection and prediction of users’movement patterns.This makes it possible to predict the detection of locomotion modes,allowing the LLEs to provide smooth and seamless assistance.The pre-processed eight subjects were used as input to classify four scenes:Standing/Walking on Level Ground(S/WOLG),Up the Stairs(US),Down the Stairs(DS),and Walking on Grass(WOG).The result showed that the ResNet performed optimally compared to four algorithms(CNN,CNN-LSTM,ResNet,and ResNet-Att)with an approximate evaluation indicator of 100%.It is expected that the proposed locomotion intention system will significantly improve the safety and the effectiveness of LLE due to its high accuracy and predictive performance.展开更多
Lower limb rehabilitation exoskeleton robots integrate sensing, control, and other technologies and exhibit the characteristics of bionics, robotics, information and control science, medicine, and other interdisciplin...Lower limb rehabilitation exoskeleton robots integrate sensing, control, and other technologies and exhibit the characteristics of bionics, robotics, information and control science, medicine, and other interdisciplinary areas. In this review, the typical products and prototypes of lower limb exoskeleton rehabilitation robots are introduced and stateof-the-art techniques are analyzed and summarized. Because the goal of rehabilitation training is to recover patients’ sporting ability to the normal level, studying the human gait is the foundation of lower limb exoskeleton rehabilitation robot research. Therefore, this review critically evaluates research progress in human gait analysis and systematically summarizes developments in the mechanical design and control of lower limb rehabilitation exoskeleton robots. From the performance of typical prototypes, it can be deduced that these robots can be connected to human limbs as wearable forms;further, it is possible to control robot movement at each joint to simulate normal gait and drive the patient’s limb to realize robot-assisted rehabilitation training. Therefore human–robot integration is one of the most important research directions, and in this context, rigid-flexible-soft hybrid structure design, customized personalized gait generation, and multimodal information fusion are three key technologies.展开更多
After more than half a century of intense efforts, the development of exoskeleton has seen major advances, and several remarkable achievements have been made. Reviews of developing history of exoskeleton are presented...After more than half a century of intense efforts, the development of exoskeleton has seen major advances, and several remarkable achievements have been made. Reviews of developing history of exoskeleton are presented, both in active and passive categories. Major models are introduced, and typical technologies are commented on. Difficulties in control algorithm, driver system, power source, and man-machine interface are discussed. Current researching routes and major developing methods are mapped and critically analyzed, and in the process, some key problems are revealed. First, the exoskeleton is totally different from biped robot, and relative studies based on the robot technologies are considerably incorrect. Second, biomechanical studies are only used to track the motion of the human body, the interaction between human and machines are seldom studied. Third, the traditional developing ways which focused on servo-controlling have inborn deficiency from making portable systems. Research attention should be shifted to the human side of the coupling system, and the human ability to learn and adapt should play a more significant role in the control algorithms Having summarized the major difficulties, possible future works are discussed. It is argued that, since a distinct boundary cannot be drawn in such strong-coupling human-exoskeleton system, the more complex the control system gets, the more difficult it is for the user to learn to use. It is suggested that the exoskeleton should be treated as a simple wearable tool, and downgrading its automatic level may be a change toward a brighter research outlook. This effort at simplification is definitely not easy, as it necessitates theoretical supports from fields such as biomechanics, ergonomics, and bionics.展开更多
In order to overcome the drawbacks of traditional rehabilitation method,the robot-aided rehabilitation has been widely investigated for the recent years.And the hand rehabilitation robot,as one of the hot research fie...In order to overcome the drawbacks of traditional rehabilitation method,the robot-aided rehabilitation has been widely investigated for the recent years.And the hand rehabilitation robot,as one of the hot research fields,remains many challenging issues to be investigated.This paper presents a new hand exoskeleton system with some novel characteristics.Firstly,both active and passive rehabilitative motions are realized.Secondly,the device is elaborately designed and brings advantages in many aspects.For example,joint motion is accomplished by a parallelogram mechanism and high level motion control is therefore made very simple without the need of complicated kinematics.The adjustable joint limit design ensures that the actual joint angles don＇t exceed the joint range of motion（ROM） and thus the patient safety is guaranteed.This design can fit to the different patients with different joint ROM as well as to the dynamically changing ROM for individual patient.The device can also accommodate to some extent variety of hand sizes.Thirdly,the proposed control strategy simultaneously realizes the position control and force control with the motor driver which only works in force control mode.Meanwhile,the system resistance compensation is preliminary realized and the resisting force is effectively reduced.Some experiments were conducted to verify the proposed system.Experimentally collected data show that the achieved ROM is close to that of a healthy hand and the range of phalange length（ROPL） covers the size of a typical hand,satisfying the size need of regular hand rehabilitation.In order to evaluate the performance when it works as a haptic device in active mode,the equivalent moment of inertia（MOI） of the device was calculated.The results prove that the device has low inertia which is critical in order to obtain good backdrivability.The experiments also show that in the active mode the virtual interactive force is successfully feedback to the finger and the resistance is reduced by one-third;for the passive control mode,the desired trajectory is realized satisfactorily.展开更多
基金supported by the Natural Science Foundation of China(52405016)the Postdoctoral Fellowship Program of CPSF(GZC20230660)+1 种基金the Natural Science Foundation of Hebei Province,China(A2023202049)the S&T Program of Hebei(24464401D).
文摘Modern military drills and conventional training,performed under all-weather conditions,impose exacting challenges on soldiers.This has motivated the development of exoskeleton robot systems,leveraging advanced technology and material innovation.These systems have demonstrated their effectiveness at assisting movement,enhancing protection,promoting rehabilitation,and providing comprehensive support to soldiers.This groundbreaking technology not only reduces a soldier's physical exertion significantly but also effectively diminishes the risk of injury during training,infusing new vitality into the enhancement of military capabilities.Different types of exoskeleton robots differ in their focus.Lower-limb exoskeleton robots are designed to increase the soldier's endurance.Upper-limb exoskeleton robots enhance strength.This paper provides a detailed explanation of the key technologies of various types of exoskeleton robots,covering theirmechanical design,electromechan-ical transmission structures,sensors,and actuation methods.It also explores the diverse application scenarios of exoskeleton robots in the military field,systematically introducing their development trajectory,milestone achievements,and the cutting-edge technologies currently employed,as well as the challenges faced.The conclusion offers a prospective discussion of future development pathways,anticipating the broad prospects for exoskeleton robots in the military domain.
基金funded by the King Salman Center for Disability Research,through Research Group No.KSRG-2024-468.
文摘Accurate trajectory tracking in lower-limb exoskeletons is challenged by the nonlinear,time-varying dynamics of human-robot interaction,limited sensor availability,and unknown external disturbances.This study proposes a novel control strategy that combines flatness-based control with two cascaded observers:a high-gain observer to estimate unmeasured joint velocities,and a nonlinear disturbance observer to reconstruct external torque disturbances in real time.These estimates are integrated into the control law to enable robust,state-feedback-based trajectory tracking.The approach is validated through simulation scenarios involving partial state measurements and abrupt external torque perturbations,reflecting realistic rehabilitation conditions.Results confirm that the proposed method significantly enhances tracking accuracy and disturbance rejection capability,demonstrating its strong potential for reliable and adaptive rehabilitation assistance.
基金the National Basic Research Program of China(Grant No.2016YFC0802700)the National Natural Science Foundation of China(Grant No.50975010,Grant No.51075017).
文摘Lower extremity robotic exoskeletons(LEEX)can not only improve the ability of the human body but also provide healing treatment for people with lower extremity dysfunction.There are a wide range of application needs and development prospects in the military,industry,medical treatment,consumption and other felds,which has aroused widespread concern in society.This paper attempts to review LEEX technical development.First,the history of LEEX is briefy traced.Second,based on existing research,LEEX is classifed according to auxiliary body parts,structural forms,functions and felds,and typical LEEX prototypes and products are introduced.Then,the latest key technologies are analyzed and summarized,and the research contents,such as bionic structure and driving characteristics,human–robot interaction(HRI)and intentawareness,intelligent control strategy,and evaluation method of power-assisted walking efciency,are described in detail.Finally,existing LEEX problems and challenges are analyzed,a future development trend is proposed,and a multidisciplinary development direction of the key technology is provided.
基金Supported by National Natural Science Foundation of China(Grant No.61273342)Beijing Municipal Natural Science Foundation of China(Grant Nos.3113026,3132005)
文摘Due to the close physical interaction between human and machine in process of gait training, lower limb exoskeletons should be safe, comfortable and able to smoothly transfer desired driving force/moments to the patients. Correlatively, in kinematics the exoskeletons are required to be compatible with human lower limbs and thereby to avoid the uncontrollable interactional loads at the human-machine interfaces. Such requirement makes the structure design of exoskeletons very difficult because the human-machine closed chains are complicated. In addition, both the axis misalignments and the kinematic character difference between the exoskeleton and human joints should be taken into account. By analyzing the DOF（degree of freedom） of the whole human-machine closed chain, the human-machine kinematic incompatibility of lower limb exoskeletons is studied. An effective method for the structure design of lower limb exoskeletons, which are kinematically compatible with human lower limb, is proposed. Applying this method, the structure synthesis of the lower limb exoskeletons containing only one-DOF revolute and prismatic joints is investigated; the feasible basic structures of exoskeletons are developed and classified into three different categories. With the consideration of quasi-anthropopathic feature, structural simplicity and wearable comfort of lower limb exoskeletons, a joint replacement and structure comparison based approach to select the ideal structures of lower limb exoskeletons is proposed, by which three optimal exoskeleton structures are obtained. This paper indicates that the human-machine closed chain formed by the exoskeleton and human lower limb should be an even-constrained kinematic system in order to avoid the uncontrollable human-machine interactional loads. The presented method for the structure design of lower limb exoskeletons is universal and simple, and hence can be applied to other kinds of wearable exoskeletons.
文摘Robotic exoskeletons have emerged as rehabilitation tool that may ameliorate several of the existing healthrelated consequences after spinal cord injury(SCI).However,evidence to support its clinical application is still lacking considering their prohibitive cost.The current mini-review is written to highlight the main limitations and potential benefits of using exoskeletons in the rehabilitation of persons with SCI.We have recognized two main areas relevant to the design of exoskeletons and to their applications on major health consequences after SCI.The design prospective refers to safety concerns,fitting time and speed of exoskeletons.The health prospective refers to factors similar to body weight,physical activity,pressure injuries and bone health.Clinical trials are currently underway to address some of these limitations and to maximize the benefits in rehabilitation settings.Future directions highlight the need to use exoskeletons in conjunction with other existing and emerging technologies similar to functional electrical stimulation and brain-computer interface to address major limitations.Exoskeletons have the potential to revolutionize rehabilitation following SCI;however,it is still premature to make solid recommendations about their clinical use after SCI.
基金supported by the Graduate Scientific Research and Innovation Foundation of Chongqing,China(CYB19062)the China Scholarship Council(CSC202206050121).
文摘Unilateral motor impairment can disrupt the coordination between the joints,impeding the patient’s normal gait.To assist such patients to walk normally and naturally,an adaptive control algorithm based on inter-joint coordination was proposed in this work for lower-limb exoskeletons.The control strategy can generate the reference trajectory of the affected leg in real time based on a motion coordination model between the joints,and adopt an adaptive controller with virtual windows to track the reference trajectory.Long Short-Term Memory(LSTM)network was also adopted to establish the coordination model between the joints of both lower limbs,which was optimized by preprocessing angle information and adding gait phase information.In the adaptive controller,the virtual windows were symmetrically distributed around the reference trajectory,and its width was adjusted according to the gait phase of the auxiliary leg.In addition,the impedance parameters of the controller were updated online to match the motion capacity of the affected leg based on the spatiotemporal symmetry factors between the bilateral gaits.The LSTM coordination model demonstrated good accuracy and generality in the gait database of seven individuals,with an average root mean square error of 3.5 and 4.1 for the hip and knee joint angle estimation,respectively.To further evaluate the control algorithm,four healthy subjects walked wearing the exoskeleton while additional weights were added around the ankle joint to simulate an asymmetric gait.From the experimental results,it was shown that the algorithm improved the gait symmetry of the subjects to a normal level while exhibiting great adaptability to different subjects.
基金supported by the China Postdoctoral Science Foundation(No.2020M672823)National Natural Science Foundation of China National Natural Science Foundation of China(No.52305072,U2013602)+3 种基金Natural Science Foundation of Hebei Province of China(No.E2022203095)Shenzhen Science and Technology Program(No.JSGG20201102152602007)Shenzhen Science and Technology Research and Development Foundation(No.JCYJ20190813171009236)Basic Scientific Research of Technology(No.JCKY2020603C009).
文摘Effectively controlling active power-assist lower-limb exoskeletons in a human-in-the-loop manner poses a substantial chal-lenge,demanding an approach that ensures wearer autonomy while seamlessly adapting to diverse wearer needs.This paper introduces a novel hierarchical control scheme comprising five integral components:intention recognition layer,dynamics feedforward layer,force distribution layer,feedback compensation layer,as well as sensors and actuators.The intention rec-ognition layer predicts the wearer's movement and enables wearer-dominant movement through integrated force and position sensors.The force distribution layer effectively resolves the statically indeterminate problem in the context of double-foot support,showcasing flexible control modes.The dynamics feedforward layer mitigates the effect of the exoskeleton itself on movement.Meanwhile,the feedback compensation layer provides reliable closed-loop control.This approach mitigates abrupt changes in joint torques during frequent transitions between swing and stance phases by decomposed dynamics.Validating this innovative hierarchical control scheme on a hydraulic exoskeleton platform through a series of experiments,the results demonstrate its capability to deliver assistance in various modes such as stepping,squatting,and jumping while adapting seamlessly to different terrains.
基金supported by the National Key R&D Program of China(Grant No.2020YFC2007800)the National Natural Science Foundation of China(Grant Nos.52005191 and 52027806)。
文摘The increasing necessity of load-carrying activities has led to greater human musculoskeletal damage and an increased metabolic cost.With the rise of exoskeleton technology,researchers have begun exploring different approaches to developing wearable robots to augment human load-carrying ability.However,there is a lack of systematic discussion on biomechanics,mechanical designs,and augmentation performance.To achieve this,extensive studies have been reviewed and 108 references are selected mainly from 2013 to 2022 to address the most recent development.Other earlier 20 studies are selected to present the origin of different design principles.In terms of the way to achieve load-carrying augmentation,the exoskeletons reviewed in this paper are sorted by four categories based on the design principles,namely load-suspended backpacks,lower-limb exoskeletons providing joint torques,exoskeletons transferring load to the ground and exoskeletons transferring load between body segments.Specifically,the driving modes of active and passive,the structure of rigid and flexible,the conflict between assistive performance and the mass penalty of the exoskeleton,and the autonomy are discussed in detail in each section to illustrate the advances,challenges,and future trends of exoskeletons designed to carry loads.
基金funded by China Scholarship Council,Grant Number 201906840121department of rehabilitation medicine,University Medical Center Groningen,University of Groningen,grant number:O/085350.
文摘Musculoskeletal Symptoms(MSS)often arise from prolonged maintenance of bent postures in the neck and trunk during surgical procedures.To prevent MSS,a passive exoskeleton utilizing carbon fiber beams to offer support to the neck and trunk was proposed.The application of support force is intended to reduce muscle forces and joint compression forces.A nonlinear mathematical model for the neck and trunk support beam is presented to estimate the support force.A validation test is subsequently conducted to assess the accuracy of the mathematical model.Finally,a preliminary functional evaluation test is performed to evaluate movement capabilities and support provided by the exoskeleton.The mathematical model demonstrates an accuracy for beam support force within a range of 0.8–1.2 N Root Mean Square Error(RMSE).The exoskeleton was shown to allow sufficient Range of Motion(ROM)for neck and trunk during open surgery training.While the exoskeleton showed potential in reducing musculoskeletal load and task difficulty during simulated surgery tasks,the observed reduction in perceived task difficulty was deemed non-significant.This prompts the recommendation for further optimization in personalized adjustments of beams to facilitate improvements in task difficulty and enhance comfort.
基金funded by Zhiyuan Laboratory(Grant NO.ZYL2024017a).
文摘The study of exoskeletons has been a popular topic worldwide.However,there is still a long way to go before exoskeletons can be widely used.One of the major challenges is control,and there is no specific research trend for controlling exoskeletons.In this paper,we propose a novel exoskeleton control strategy that combines Active Disturbance Rejection Control(ADRC)and Deep Reinforcement Learning(DRL).The dynamic model of the exoskeleton is constructed,followed with the design of the ADRC.To automatically adjust the control parameters of the ADRC,the Twin-Delayed Deep Deterministic Policy Gradient(TD3)is utilized.Then a reward function is defined in terms of the joint angle,angular velocity,and their errors to the desired values,to maximize the accuracy of the joint angle.In the simulations and experiments,a conventional ADRC,and ADRC based on Genetic Algorithm(GA)and Particle Swarm Optimization(PSO)were carried out for comparison with the proposed control method.The results of the tests show that TD3-ADRC has a rapid response,small overshoot,and low Mean Absolute Error(MAE)and Root Mean Square Error(RMSE)followed with the desired,demonstrating the superiority of the proposed control method for the self-learning control of exoskeleton.
基金College Student Innovation andEntrepreneurship Project(Grant No.:S202414435026)ingkou Institute of Technology campus level research project——Development of food additive supercritical extraction equipment and fluid transmission systemresearch(Grant No.HX202427).
文摘With the acceleration of the global aging process and the increase of cardiovascular ancerebrovascular diseases,more and more patients are paralyzed due to accidents,so theexoskeleton robot began to appear in people's sight,and the lower limb exoskeleton robot withrehabilitation training is also favored by more and more people.In this paper,the structural designand analysis of the lower limb exoskeleton robot are carried out in view of the patients'expectation ofnormal walking.First,gait analysis and structural design of lower limb exoskeleton robot.Based onthe analysis of the walking gait of normal people,the freedom of the three key joints of the lower limbexoskeleton robot hip joint,knee joint and ankle joint is determined.at the same time,according tothe structuralcharacteristics of each joint,the three key joints are modeled respectively,and theoverall model assembly of the lower limb exoskeleton robot is completed.Secondly,the kinematicsanalysis of the lower limb exoskeleton robot was carried out to obtain the relationship between thelinear displacement,linear speed and acceleration of each joint,so as to ensure the coordination ofthe model with the human lower limb movement.Thirdly,the static analysis of typical gait of hipjoint,knee joint and ankle joint is carried out to verify the safety of the design model under thepremise of ensuring the structural strength requirements.Finally,the parts of the model were 3Dprinted,and the rationality of the design was further verified in the process of assembling the model.
基金sponsored by the Fundamental Research Funds for the Central Universities[N2329001].
文摘To overcome the limitations of traditional exoskeletons in complex outdoor terrains,this study introduces a novel lower limb exoskeleton inspired by the snow leopard’s forelimb musculoskeletal structure.It features a non-fully anthropomorphic design,attaching only at the thigh and ankle with a backward-knee configuration to mimic natural human knee movement.The design incorporates a single elastic element at the hip for gravity compensation and dual elastic elements at the knee for terrain adaptability,which adjust based on walking context.The design’s effectiveness was assessed by measuring metabolic cost reduction and motor output torque under various walking conditions.Results showed significant metabolic cost savings of 5.8–8.8%across different speeds and a 7.9%reduction during 9°incline walking on a flat indoor surface.Additionally,the spring element decreased hip motor output torque by 7–15.9%and knee torque by 8.1–14.2%.Outdoor tests confirmed the design’s robustness and effectiveness in reducing motor torque across terrains,highlighting its potential to advance multi-terrain adaptive exoskeleton research.
基金supported by Guangdong Provincial Key Laboratory of Minimally Invasive Surgical Instruments and Manufacturing Technology(MISIMT-2021-4)the Fundamental Research Funds for the Central Universities(N2329001).
文摘The lower limb assisted exoskeleton is a prominent area of research within the field of exoskeleton technology.However,several challenges remain,including the development of flexible actuators,high battery consumption,the risk of joint misalignment,and limited assistive capabilities.This paper proposes a compact flexible actuator incorporating two elastic elements named Adjustable Energy Storage Series Elastic Actuator(AES-SEA),which combining an adjustable energy storage device with a series elastic actuator for application in exoskeleton hip joints.This design aims to enhance energy efficiency and improve assistive effects.Subsequently,we introduce a novel knee joint bionic structure based on a pulley-groove configuration and a four-link mechanism,designed to replicate human knee joint motion and prevent joint misalignment.Additionally,we propose an innovative controller that integrates concepts from Linear Quadratic Regulator(LQR)control and virtual tunnel for level walking assistance.This controller modulates the assisted reference trajectory using the virtual tunnel concept,enabling different levels of assistance both inside and outside the tunnel by adjusting the parameters Q and R.This approach enhances the assisting force while ensuring the safety of human-computer interaction.Finally,metabolic experiments were conducted to evaluate the effectiveness of the exoskeleton assistance.
基金funded by the King Salman Center For Disability Research,through Research Group No.KSRG-2024-468。
文摘Disability is defined as a condition that makes it difficult for a person to perform certain vital activities.In recent years,the integration of the concepts of intelligence in solving various problems for disabled persons has become more frequent.However,controlling an exoskeleton for rehabilitation presents challenges due to their nonlinear characteristics and external disturbances caused by the structure itself or the patient wearing the exoskeleton.To remedy these problems,this paper presents a novel adaptive control strategy for upper-limb rehabilitation exoskeletons,addressing the challenges of nonlinear dynamics and external disturbances.The proposed controller integrated a Radial Basis Function Neural Network(RBFNN)with a disturbance observer and employed a high-dimensional integral Lyapunov function to guarantee system stability and trajectory tracking performance.In the control system,the role of the RBFNN was to estimate uncertain signals in the dynamic model,while the disturbance observer tackled external disturbances during trajectory tracking.Artificially created scenarios for Human-Robot interactive experiments and periodically repeated reference trajectory experiments validated the controller’s performance,demonstrating efficient tracking.The proposed controller is found to achieve superior tracking accuracy with Root-Mean-Squared(RMS)errors of 0.022-0.026 rad for all joints,outperforming conventional Proportional-Integral-Derivative(PID)by 73%and Neural-Fuzzy Adaptive Control(NFAC)by 389.47%lower error.These results suggested that the RBFNN adaptive controller,coupled with disturbance compensation,could serve as an effective rehabilitation tool for upper-limb exoskeletons.These results demonstrate the superiority of the proposed method in enhancing rehabilitation accuracy and robustness,offering a promising solution for the control of upper-limb assistive devices.Based on the obtained results and due to their high robustness,the proposed control schemes can be extended to other motor disabilities,including lower limb exoskeletons.
基金Supported by Nati onal Key R&D Program of China(Grant No.2018YFB1305400,2018YFB1305402)National Natural Science Foundation of China(Grant No.518902883)Fun dame ntal Resea rch Funds for the Central Universities(Grant No.2018XZZX001-04).
文摘The hydraulic exoskeleton is one research hotspot in the field of robotics,which can take heavy load due to the high power density of the hydraulic system.However,the traditional hydraulic system is normally centralized,inefficient,and bulky during application,which limits its development in the exoskeleton.For improving the robot's performance,its hydraulic actuating system should be optimized further.In this paper a novel hydraulic actuating system(HAS)based on electric-hydrostatic actuator is proposed,which is applied to hip and knee joints.Each HAS integrates an electric servo motor,a high-speed micro pump,a specific tank,and other components into a module.The specific parameters are obtained through relevant simulation according to human motion data and load requirements.The dynamic models of the HAS are built,and validated by the system identification.Experiments of trajectory tracking and human-exoskeleton interaction are carried out,which demonstrate the proposed HAS has the ability to be applied to the exoskeleton.Compared with the previous prototype,the total weight of the HAS in the robot is reduced by about 40%,and the power density is increased by almost 1.6 times.
基金supported in part by the National Key Research and Development Program of China(2021YFF0501600)the National Natural Science Foundation of China(U1913601)+6 种基金the Major Science and Technology Projects of Anhui Province(202103a05020004)the China Postdoctoral Science Foundation(2021M693079)the Fundamental Research Funds for the Central Universities(WK2100000020)the State Key Laboratory of Mechanical System and Vibration(MSV202219)the Ministry of Science and Higher Education of the Russian Federation as Part of World-Class Research Center Program:Advanced Digital Technologies(075-15-2020-903)the Open Research Project of the State Key Laboratory of Industrial Control Technology,Zhejiang UniversityChina(ICT2022B42)。
文摘Underwater robot technology has shown impressive results in applications such as underwater resource detection.For underwater applications that require extremely high flexibility,robots cannot replace skills that require human dexterity yet,and thus humans are often required to directly perform most underwater operations.Wearable robots(exoskeletons)have shown outstanding results in enhancing human movement on land.They are expected to have great potential to enhance human underwater movement.The purpose of this survey is to analyze the state-of-the-art of underwater exoskeletons for human enhancement,and the applications focused on movement assistance while excluding underwater robotic devices that help to keep the temperature and pressure in the range that people can withstand.This work discusses the challenges of existing exoskeletons for human underwater movement assistance,which mainly includes human underwater motion intention perception,underwater exoskeleton modeling and human-cooperative control.Future research should focus on developing novel wearable robotic structures for underwater motion assistance,exploiting advanced sensors and fusion algorithms for human underwater motion intention perception,building up a dynamic model of underwater exoskeletons and exploring human-in-theloop control for them.
基金the financial support of Shanghai Science and Technology innovation action plan(19DZ2203600).
文摘Lower Limb Exoskeletons(LLEs)are receiving increasing attention for supporting activities of daily living.In such active systems,an intelligent controller may be indispensable.In this paper,we proposed a locomotion intention recognition system based on time series data sets derived from human motion signals.Composed of input data and Deep Learning(DL)algorithms,this framework enables the detection and prediction of users’movement patterns.This makes it possible to predict the detection of locomotion modes,allowing the LLEs to provide smooth and seamless assistance.The pre-processed eight subjects were used as input to classify four scenes:Standing/Walking on Level Ground(S/WOLG),Up the Stairs(US),Down the Stairs(DS),and Walking on Grass(WOG).The result showed that the ResNet performed optimally compared to four algorithms(CNN,CNN-LSTM,ResNet,and ResNet-Att)with an approximate evaluation indicator of 100%.It is expected that the proposed locomotion intention system will significantly improve the safety and the effectiveness of LLE due to its high accuracy and predictive performance.
基金Supported by National Key R&D Program of China(Grant No.2016YFE0105000)National Natural Science Foundation of China(Grant No.91848104)
文摘Lower limb rehabilitation exoskeleton robots integrate sensing, control, and other technologies and exhibit the characteristics of bionics, robotics, information and control science, medicine, and other interdisciplinary areas. In this review, the typical products and prototypes of lower limb exoskeleton rehabilitation robots are introduced and stateof-the-art techniques are analyzed and summarized. Because the goal of rehabilitation training is to recover patients’ sporting ability to the normal level, studying the human gait is the foundation of lower limb exoskeleton rehabilitation robot research. Therefore, this review critically evaluates research progress in human gait analysis and systematically summarizes developments in the mechanical design and control of lower limb rehabilitation exoskeleton robots. From the performance of typical prototypes, it can be deduced that these robots can be connected to human limbs as wearable forms;further, it is possible to control robot movement at each joint to simulate normal gait and drive the patient’s limb to realize robot-assisted rehabilitation training. Therefore human–robot integration is one of the most important research directions, and in this context, rigid-flexible-soft hybrid structure design, customized personalized gait generation, and multimodal information fusion are three key technologies.
基金Supported by National Defense Pre-Research Foundation of China
文摘After more than half a century of intense efforts, the development of exoskeleton has seen major advances, and several remarkable achievements have been made. Reviews of developing history of exoskeleton are presented, both in active and passive categories. Major models are introduced, and typical technologies are commented on. Difficulties in control algorithm, driver system, power source, and man-machine interface are discussed. Current researching routes and major developing methods are mapped and critically analyzed, and in the process, some key problems are revealed. First, the exoskeleton is totally different from biped robot, and relative studies based on the robot technologies are considerably incorrect. Second, biomechanical studies are only used to track the motion of the human body, the interaction between human and machines are seldom studied. Third, the traditional developing ways which focused on servo-controlling have inborn deficiency from making portable systems. Research attention should be shifted to the human side of the coupling system, and the human ability to learn and adapt should play a more significant role in the control algorithms Having summarized the major difficulties, possible future works are discussed. It is argued that, since a distinct boundary cannot be drawn in such strong-coupling human-exoskeleton system, the more complex the control system gets, the more difficult it is for the user to learn to use. It is suggested that the exoskeleton should be treated as a simple wearable tool, and downgrading its automatic level may be a change toward a brighter research outlook. This effort at simplification is definitely not easy, as it necessitates theoretical supports from fields such as biomechanics, ergonomics, and bionics.
基金supported by National Natural Science Foundation of China (Grant No. 50975009)
文摘In order to overcome the drawbacks of traditional rehabilitation method,the robot-aided rehabilitation has been widely investigated for the recent years.And the hand rehabilitation robot,as one of the hot research fields,remains many challenging issues to be investigated.This paper presents a new hand exoskeleton system with some novel characteristics.Firstly,both active and passive rehabilitative motions are realized.Secondly,the device is elaborately designed and brings advantages in many aspects.For example,joint motion is accomplished by a parallelogram mechanism and high level motion control is therefore made very simple without the need of complicated kinematics.The adjustable joint limit design ensures that the actual joint angles don＇t exceed the joint range of motion（ROM） and thus the patient safety is guaranteed.This design can fit to the different patients with different joint ROM as well as to the dynamically changing ROM for individual patient.The device can also accommodate to some extent variety of hand sizes.Thirdly,the proposed control strategy simultaneously realizes the position control and force control with the motor driver which only works in force control mode.Meanwhile,the system resistance compensation is preliminary realized and the resisting force is effectively reduced.Some experiments were conducted to verify the proposed system.Experimentally collected data show that the achieved ROM is close to that of a healthy hand and the range of phalange length（ROPL） covers the size of a typical hand,satisfying the size need of regular hand rehabilitation.In order to evaluate the performance when it works as a haptic device in active mode,the equivalent moment of inertia（MOI） of the device was calculated.The results prove that the device has low inertia which is critical in order to obtain good backdrivability.The experiments also show that in the active mode the virtual interactive force is successfully feedback to the finger and the resistance is reduced by one-third;for the passive control mode,the desired trajectory is realized satisfactorily.
