Abstract:As an important research content in the field of rehabilitation,intelligent myoelectric prosthetic hand research has always been a hot research spot through the world.With the advancement of robotics,the prosthetic hand is moving toward humanoid type,dexterity,intuitive control,and intelligent perception.The intelligent myoelectric prosthetic hand should have similar function with human hand.It not only assists the daily life of the disabled by rebuilding motor function,but also recreate the proprioception by restoring the perceptual feedback function.This paper reviews years of domestic and foreign research results on myoelectric prosthetic hand and analyzes the mechanical design of the prosthetic hand from the perspectives of weight,dexterity,grasping performance,and design principle.In the area of user motion intention decoding,this study systematically summarizes the state-of-the-art in gesture recognition based on surface electromyography signals,and introduces various of research ideas based on residual limb biological signal recognition.In addition,a variety of prosthetic hand tactile perception technologies based on different principles are analyzed,and adaptive control and user awareness feedback using the finger tip force tactile sensor are introduced.Finally,the problems and challenges faced in the research and development of prosthetic hands are summarized,and the direction of future research in myoelectric prosthetic hand is proposed.

Abstract:To reduce the development complexity of underwater remote-operated vehicles and increase their adaptability and applications,a monitor system for underwater remote-operated vehicles based on ROS is developed.First,the hardware structure of the monitor system is introduced briefly.The software framework of the monitor system based on ROS is proposed.The compositions and functions of the perceptual execution,navigation control,and monitoring operation layers are introduced.The design of three functional modules,namely the motion control,human-robot interaction,and attitude control nodes,are described.Experiments show that the monitor system of the underwater remote-operated vehicle based on ROS can coordinate the work of each functional module.It is characterized by a short development cycle and good expansibility.

Abstract:In order to improve the absolute positioning accuracy of a robot end-effector,a calibration method based on an improved particle swarm algorithm (IPSO) is proposed.Firstly,in order to avoid singularity in the model when two adjacent axes of the robot are parallel or close to parallel,the MDH model of series robot is founded.Secondly,according to the calibration features of robot geometric parameters,IPSO is used to optimize and calibrate the robot geometric parameters.The initial positions are generated based on Halton sequences and the particle velocity is modified by the constriction factor approach.The mathematical model of the objective function to calibrate robot geometric parameters based on IPSO is established,and detailed steps are provided for using IPSO to optimize geometric parameters.The results of the simulation and real calibration of the ER10L-C10 industrial robot show that the proposed method can quickly calibrate the geometric parameters of the robot,and the absolute positioning accuracy of the end-effector is greatly improved.The proposed algorithm is simple and robust,and is suitable to be popularized and applied in industry robot calibration.

Abstract:Existing Kinect-based rehabilitation training systems,which focus on active rehabilitation training executed by the patients themselves and are seldom applied to robot-aided rehabilitation training,have certain limitations.To solve these problems,a Kinect-based robot-aided upper-limb passive rehabilitation training method was proposed.Firstly,Kinect-based upper-limb skeleton tracking and inverse kinematics computation were conducted.Secondly,the virtual rehabilitation environment based on Linux/QT and Kinect was developed.Using the reference trajectories of the training task demonstrated by the therapist and the impaired limb's real-time motion position feedback,a fuzzy-based passive rehabilitation training controller was developed.Finally,using Kinect and the 4-DOF WAM^TM-compliant manipulator of Barrett Inc.,the experimental system platform was constructed to evaluate the effectiveness of the proposed method.The results show that the proposed method can fully learn the therapist's rehabilitation experiences,make the robot manipulator smoothly stretch the upper-limb of the patient along predefined training task trajectories,and achieve human-robot collaborations between therapist-robot-patient.

Abstract:Identification of biological significance using brain activity data is a research hotspot in neuroscience theory and practice.The emotional recognition and study of the correlation between emotions and brain mechanisms based on electroencephalograms (EEGs) are important topics in the fields of neuroscience and biomedical engineering.In this study,the emotional state of a subject was evaluated using EEG signalscollected using the MindWave Mobile 2EEG headphone,and the "clueless" mind wave was monitored as well.An experimental study on improving the state of anxiety by auditory excitation was conducted.Auditory signal stimulation was achieved with specific antique Chinese pure music sets,which stimulated the emotional state of calm relaxation in the subjects.Thus,their anxiety was reduced,and the possible relationship between music and emotion was derived.In the future,brain-computer interface (BCI) technology can help meet the more advanced emotional recognition needs of patients with specific diseases (such as ALS,cerebral palsy,brainstem stroke,and spinal cord injury) via EEG analysis of their preferences for aspects such as choice of music.Thus,a more user-friendly and intelligent BCI system,with good application prospects in the field of medical rehabilitation,could be designed.

Abstract:According to the low intelligence level of agricultural tractors used nowadays,and the existing artificial intelligent technology can't satisfy the need of fully autonomous driving in the complicated field environment.Thisstudy designed a tractor-driving robot based on human-machine cooperation,which can upgrade a traditional tractor into an intelligent tractor nondestructively and rapidly.The driving robot structure consists of four parts:a steering control manipulator,shifting manipulator,rotary tiller lifting control manipulator,and pedal control mechanical leg.By studying the control method of human-machine cooperation,a human-machine cooperation intervention criterion is proposed,and a human-machine cooperation mode switching method is designed based on torque detection by steering motor current feedback.A human-machine cooperative control system and strategy was developed and evaluated in experiments.The performance of the tractor-driving robot and the effectiveness of human-machine cooperative control strategy have important practical significance for promoting precision agriculture and improving the intelligence level of modern agricultural equipment.

Abstract:The locations of electromyography (EMG) measurements are directly related to the accuracy of motion recognitionin hand gesture recognition based on EMG signals.This study proposes an EMG measurement position optimization strategy based on ANOVA and back propagation (BP) neural network to obtain the best motion recognition with the fewest EMG sensors.Four EMG sensors are used to capture the EMG signals when the subjects perform specific hand gestures.Feature data extracted from the raw EMG signals are combined into 15 different vectors according to different measurement position combinations.These 15 feature vectors are used to train and test the BP neural network.Single factor analysis of variance (ANOVA)is employed to analyze the significance of the influence of the measured position on themotion recognition.Tukey's honest significant differencetest is adopted to classify the position combinations.The position combinations are divided into several subsets.In the subset with the highest recognition rate,the position combination with the least measurement position and the highest recognition accuracy is considered to be the optimized measurement position.The experimental results show that the measurement position has a significant impact on the results of motion recognition.The accuracy of motion recognition shows an upward trend with the increase in measurement position.The optimal combination of measurement position is P1+P3+P4,and the accuracy of motion recognition is 94.6%.

Abstract:Electromagnetic formation flights(EMFFs) can be stabilized in low Earth orbit owing to the influence of Earth's magnetic field.Formation control is realized by changing the current magnitude of the magnetic pole of the EMFF.Although Earth's magnetic field is generally considered to be a dipole and rotates with Earth,the interaction between the magnetic fields of Earth and the EMFF is considered to be an internal force.When a small magnetic satellite formation encounters an obstacle that must be avoided,the current magnetic force,which acts as an internal force,cannot promote directional changes.Therefore,it is necessary to exert external forces on the EMFF to gain control.As a continuation of the application of electric propulsion (EP) to Coulomb satellite formation,this study investigates how EP may be applied to collision avoidance by EMFFs.During the process,the external thrust of the EMFF was provided by EP,which served as supplementary propulsion to realize obstacle avoidance.EP adopted multimode Hall thrusters,and a linear formation was employed by the EMFF.Using the linear quadratic regulator control method with an added fuzzy reference system,EMFF achieved collision avoidance with numerical simulation.

Abstract:To facilitate accurate control of the output force at the arm end during live working,a prediction method for arm end force based on surface electromyography (sEMG) and support vector machine regression (SVR) is proposed.By forcing the handle at the end of the manipulator to provide the reciprocating push and pull movement,the data of the force sensor at handle Fare recorded.Simultaneously,the EMG signals of the arm are synchronously collected by three sets of EMG sensors.The feature extraction from the EMG signal and F are combined as sample set S inthe sample collection.Half of the sample data is randomly selected as the training set for different machine learning methods,and trained using the back propagation,generalized regression,and SVR neural networks.Finally,the trained neural network is used to predict force F in the whole sample set,and the prediction effect of the model is obtained by means of the root mean square error (RMSE) and correlation coefficient.The results show that the prediction effect of the SVR neural network is better,the RMSE is 3.074 0,and the correlation coefficient R is 0.951 7.

Abstract:This study investigates the dynamics of 3-dimensional pinching movements by dual two degree-of-freedom fingers with redundant muscles.The pinching movements are realized by the finger-thumb opposition.Both the thumb and index finger adopted the model with one monoarticular muscle and two biarticular muscles.During the pinching movements,the object may rotate along two axes so that it may achieve time-varying in 3-dimensional pinching.The dynamics and stability of the pinching movements are analyzed taking into account the co-contraction between the flexor and extensor muscles as well as the nonholonomic constraints.The numerical simulation is performed with a simple control signal to verify the effect of gravity.

Abstract:This study focuses on the formation,migration and dissipation mechanisms of the Sri Lanka Dome (SLD) and its combination with Bay of Bengal Dome (BBD) using Simple Ocean Data Assimilation reanalysis data and AVISO data.The SLD is a cyclonic eddy in the southwest Bay of Bengal,which occurs during May through September coinciding with the intrusion of southwest monsoon current into the Bay of Bengal.The results show that,Ekman pumping due to positive wind stress curl east off Sri Lanka is the governing mechanism of the SLD formation and migration during developing stage.Besides,a positive impact of cold Rossby waves propagation contribute to the SLD developing as well.Further,weakening positive wind stress curl and the eastern boundary reflected warm Rossby wave effect are important factors for dissipation of SLD.During the decaying stage of SLD,the BBD evolves independently because of the Ekman Pumping driven by local positive wind curl.The regression analysis proves that the local wind stress curl has a strong positive relationship with upwelling within the BBD.After September,weak positive wind stress curl dominates in the southwest BOB,the BBD starts to merge with the SLD.There are two kinds of links between SLD and BBD.The first is a dynamic interaction revealed by eddy kinetic energy analysis and the second is a thermodynamic interaction described by combination of subsurface cold cores of the SLD and the BBD.

Abstract:This paper focuses on block partitioning and strain calculation in the Sichuan-Yunnan region.First,the K-medoids clustering method is used to cluster the GPS horizontal velocity field in Sichuan-Yunnan.Next,the initial classification results are further clustered based on constraints from the geographical location and velocity field of GPS stations by using the improved K-medoids method.Subsequently,the F statistical test method is used to determine the boundary of each block.Finally,the strain parameters of each block are calculated using an integral rotation linear strain model and the relationship between horizontal motion,spatial distribution of strain field,and regional tectonic deformation is analyzed.The results of the velocity field clustering analysis of GPS stations in the Sichuan-Yunnan region are consistent with the results of the alternative block division methodology based on geological theory of plate division.The strain results,which are calculated using the integral rotation linear strain model,show that the Sichuan-Yunnan rhombic block has the maximum shear strain and the highestsurface strain rate gradient.In addition,this region has accumulated some elastic strain energy,an indicator of earthquake risk.

Abstract:Aiming at the limitation of the common remote control and the application of mobile internet,a new research scheme for a human-computer interaction driven intelligent vehicle control system is proposed:a bluetooth based vehicle control system utilizing android mobile phone direction sensor (gravity sensor) and voice control is designed.The design uses android mobile phone as host computer,including the voice and direction sensor systems and uses bluetooth communication technology to communicate with the lower computer,which is composed of the MCU control center,bluetooth module,motor drive module,buzzer,led module,and obstacle avoidance module.The operability and practicability of the system is verified through physical production and testing.This research also lays a technical foundation for the practical application of intelligent control systems in wheelchair design and warehouse management among other fields.

Abstract:The ground states of D-glyceric acid under different intense electric fields are optimized by using density functional theory DFT/B3LYP at 6-311G basis set level.The excitation energies and oscillator strength under the applied electric fields are calculated employing TD-DFT method.The results reveal the variations of electronic state,molecular geometry,total energy,dipolemoment,and excitation energy of the first six excited states with the applied electric field.Moreover,the results show that the set of molecular structures have changed obviously in the external electric field when the electric field strength is 0.003 a.u.,characterized by the decrease of molecular total energy,the sudden rise of dipolemoment,and an obvious red shift in UV-Vis spectra peak.When the electric field continues to increase,the indices return to normal levels and the sudden changes disappear.

Abstract:Carbon microspheres and C/TiO₂ microspheres with core/shell structure were successfully synthesized by hydrothermal method using glucose and Ti(SO₄)₂ as carbon source and titanium source,respectively.To improve the dielectric loss of these materials,the synthesized samples were carbonized at different temperatures under N₂ atmosphere.The structures and morphologies of the samples were characterized by X-ray diffraction,scanning electron microscopy and transmission electron microscopy.The relative complex permittivity of the composites was measured by a vector network analyzer in the frequency range of 2-18 GHz and their reflection losses were calculated.The results show that the carbon microspheres have high microwave dielectric loss.After the carbon microspheres were composited with TiO₂,the absorption peak migrated to low frequency under the same thickness.Particularly,the carbon and C/TiO₂ composites carbonized at 700℃ and 800℃ display excellent microwave absorption performances.The minimum reflection loss value arrives at -41.2 dB and -30.0 dB and the maximum band width less than -10 dB is 4.5 GHz and 4.2 GHz for C-700 and C/Ti-700 composites,respectively.

Abstract:Under the guidelines of the natural disaster system theory,this study aims at a methodology for the risk zoning of thunder and lightning in Henan province.Specifically,this study utilizes the AHP method and uses meteorological,geo-informational,socioeconomic,and thunder and lightning disaster data to establisha quantitative relation between the assessment indexes and the risk zoning of thunder and lightning.Considering the disaster-inducing factors,environment of breeding disasters and hazard-bearing bodies.based on the GIS platform,Distribution of the disaster-inducing factors,Vulnerability of Hazard-affected Body,frangibility of Hazard-affected Body were formed.Finally,the result of risk zoning of thunder and lightning over Henan province was achieved via superposition.The results show that ahigh risk of thunder and lighting is mainly in East and Northwest Henan,while low risk is mainly in parts of North Henan and Southwest Henan.