Abstract:The signal characteristic of a magnetic object, such as a submarine, is indeterminate in the magnetic object detection, which may appear as a magnetic anomaly signal or an extremely low frequency magnetic signal with undetermined coefficients. This paper proposes a universal fast detection method for both the weak magnetic anomaly signal and the weak extremely low frequency magnetic signal with undetermined coefficients. A sineGauss mixture model is built based on the piecewise sinusoidal statistical characteristics of the magnetic anomaly signal and extremely low frequency magnetic signal. This universal model can represent both the magnetic anomaly signal and extremely low frequency magnetic signal with undetermined coefficients. A detector is developed based on the sineGauss mixture model and the sequential detection theory, which realizes the universal fast detection for both types of signals mentioned above. The unknown parameters in the detector are identified, and the sequential detection performance of the detector is studied. In addition, the detection performance for different weak magnetic anomaly signals and weak extremely low frequency magnetic signals is analyzed. The universality and rapidity of the designed detector for both the weak magnetic anomaly signal and the weak extremely low frequency magnetic signal are verified based on experiment system with geomagnetism. The experimental results indicate that the signaltonoise rate can be -8 dB, the amount of calculation is reduced by 4 orders compared with the traditional detection methods.

Abstract:The detection of rail defect is of great significance for guaranteeing railway safety. In the background of studying the nondestructive testing and evaluation technology of rail, this paper comprehensively reviews the methods of rail defect detection adopted at home and abroad, including physical detection method and machine vision inspection method. The application of rail defect evaluation method by machine vision is presented and analyzed. Meanwhile, the nondestructive testing technology and evaluation technology for rail are compared. The differetiation of physical inspection by radiation inspection and the machine vision detection by image processing is discussed and summarized. The modern nondestructive testing, evaluation technology, and related technical problems involved in the development are analyzed and discussed. The future development of nondestructive testing and evaluation technology for rail defect is assumed.

Abstract:The conventional circuit breaker is one kind of complex mechanical system. The remaining useful life (RUL) prediction of its operating accessories is essential for maintaining the reliability of the circuit breaker. To accurately grasp this RUL, this article proposes a remaining mechanical life prediction method of operating accessories for the conventional circuit breaker based on Wiener process. First, the action time of operating accessories is selected as the performance degradation feature by analyzing the coil current waveform during the operation process of the operating accessories. The performance degradation process of operating accessories is linear and nonmonotonic. Hence, the performance degradation model is established by employing Wiener process. The maximum likelihood estimation method is utilized to estimate the parameters of the degradation model. Then, based on the concept of first hitting time, RUL prediction model is formulated and its probability density function is derived, which realizes the RUL prediction of operating accessories. Finally, the whole life tests and the RUL prediction for the shunt release and the release electromagnet as operating accessories installed in the conventional circuit breaker are carried out. The prediction results demonstrate the effectiveness of the proposed method.

Abstract:The motorized spindle is a spindle unit that integrates the rotating shaft and the rotor of the motor, and its structure is complicated. Due to machining or assembly errors, the rotor of the motorized spindle has a certain amount of eccentricity. In order to explore the vibration characteristics of the rotor caused by the eccentricity of the motorized spindle, the rotor eccentric model of the motorized spindle was established. The unbalanced magnetic pull (UMP) caused by the eccentricity was calculated with Maxwell stress tensor method. The UMP analytical equation was substituted into the Jeffcott rotor model, and the rotor eccentric vibration equation was obtained. Taking the permanent magnet synchronous (PMS) motorized spindle of a certain grinding machine as an example, the UMP was analyzed with FEM, and the UMP characteristic acting on the rotor was obtained. It was found that the UMP is always pointing to the direction of the smallest air gap. The vibration responses of the rotor under the action of the mass eccentric centrifugal force and UMP were studied under different rotational speeds. The research results show that when the motorized spindle is operating at low speed, the UMP is the main source of rotor vibration. With the increasing of the rotational speed, the effect of mass eccentric centrifugal force on the rotor vibration is more obvious. The magnitude of the UMP remains unchanged, and its frequency increases with the rotational speed, while the effect on the rotor vibration is weakened. The vibration issue of the grinding motorized spindle developed by a machine tool factory in trial operation was tested. Through the spindle vibration spectrum analysis it is concluded that the tested spindle has static eccentricity, and the spindle axis trajectory was measured, which verifies the aforementioned analysis.

Abstract:Aiming at the comfort and efficiency problems of respiratory rate detection in the field of physiological health monitoring, this paper proposes a visionbased noncontact measurement method, which uses a common camera to capture the human respiratory video and enlarges the displacement of the chest and abdomen motion during breathing with Euler algorithm. Considering the influence of the position extraction accuracy of the chest and abdomen area on the accuracy of the respiratory rate detection, this paper proposes a method based on optical flow signal to extract the respiratory region. The optical flow algorithm is used to convert the chest and abdomen motion into optical flow information, which are encoded and displayed in the form of a color image. The pixel brightness sequence of the chest and abdomen breathing region is extracted to obtain respiratory waveform information, and the respiratory rate is obtained with peak detection. Finally, experiment was conducted, and the breath signals extracted using the proposed algorithm were compared with the measurement results using Embla N7000 polysomnography. The results show that the average error of respiratory rate detected with the proposed algorithm is 054 times/min, which has high accuracy.

Abstract:In the hydraulic system, metal abrasive particles are the important indicator which effects the normal operation of the hydraulic system. In this study, one kind of chip with a circular flow channel is introduced. The microfluidic oil metal particle counter is based on the principle of inductance and capacitance, which causes magnetic flux change or dielectric when abrasive particles, bubbles and water droplets in the hydraulic oil flow through the space micro solenoid. Inductive detection method is utilized to detect 30 μm iron particle and 110 μm copper particle using a 27inch coil at an excitation frequency of 2 MHz. The 100 μm water droplets and 180 μm bubbles are detected by a capacitance detection method at an excitation frequency of 13 MHz. Experimental results show that the detection accuracy of iron is obviously improved. The signaltonoise ratio based on the original detection accuracy is improved. Meanwhile, the diameter of the flow channel is increased, the flux of the detected hydraulic oil is increased, and the efficiency of detecting the particles is enhanced. This improved chip has good practical application value and broad development prospects.

Abstract:The marine controlled source electromagnetic (MCSEM) signals are susceptible to various kinds of noises, which affects the accuracy of the inversion interpretation of subsequent data. Waveletbased denoising theory and methods have been widely used in the field of MCSEM signal denoising. However, the applied wavelet bases are generalpurpose ones, and the denoising effect needs to be improved. This study proposes to construct a new wavelet base specially used for MCSEM signals. Firstly, through the particle swarm optimization (PSO) algorithm, the optimal coefficients of the filter banks were iteratively calculated taking the average similarity of the new wavelet function and the MCSEM signal as the constraints, and then the new wavelet base was constructed using the obtained coefficients. Secondly, aiming at the seawater turbulence noise in deep sea exploration, a denoising method based on the new waveletbase was designed. An experiment was conducted to compare the new waveletbased denoising method and the traditional waveletbased denoising method using the simulated noisy data. The signal to noise ratio (SNR) and mean square error (RSE) were used to evaluate the denoising effects, and the results demonstrate that the new waveletbased denoising method is superior to the traditional waveletbased denoising method. Finally, the new waveletbased denoising method was applied to the actually measured MCSEM data. The time domain signals and magnitude versus offset (MVO) curves before and after denoising were compared and analyzed, the results show that the proposed method can not only remove the noise of sea water turbulence, but also extend the interpretation range of the MVO curves, which proves the effectiveness and practicability of the new waveletbased denoising method.

Abstract:Stroke is the leading cause of motor dysfunction in modern society. Aiming at the key problems that the means of traditional rehabilitation training of passive intensive limb motion is relatively simple, the mechanism for recovery is unclear and the training strategy lacks guidance with objective evaluation indexes, an experiment task canonical form of right upper limb motor imagery fusing functional electrical stimulation with different intensity (including supraliminal and subliminal stimulation and nonstimulation) was designed. Seventeen righthanded healthy young subjects were recruited to participate in various experiment tasks. Electroencephalogram timefrequency features and statistical results show that there are significance statistic differences in the energies of alpha band at C3/C4 leads and beta band at CPz lead between the stimulation and nonstimulation modes, and there is significant activation difference in the energy at alpha band only at supplementary motor cortex in supraliminal and subliminal stimulation modes. The above results preliminarily prove that the rehabilitation training mode of motor imagery combining with FES is more conducive to motor cortex activation, and it may be deduced that FES could enhance the cortex neural activities of alpha rhythm at supplementary motor cortex, primary motor cortex and sensorimotor cortex, as well as the cortex neural activities of beta rhythm at sensorimotor cortex.

Abstract:Based on the theory of electromagnetic waves, the surface impedance method is a finite element method used surface impedance as a boundary condition, whose advantages are of low calculation and high computational efficiency. Firstly, Magnet is used to simulate the model by finite element method and surface impedance. Then, based on the P21B model in the TEAM Problem 21 reference family, a stray loss test system is built. The stray loss is measured under different current excitation conditions. The temperature coefficient is introduced to improve the measurement, and the improved coil loss method is adopted to obtain more accurate stray loss measurement results. The calculation results of the finite element method and the surface impedance are verified with experimental measurements. The surface impedance is much smaller than the finite element method in terms of calculation scale and time, which greatly saves computational resources.

Abstract:Thermal power units have been widely put into operation for the electrical peakshaving, which results in the increase of unsteady state operating conditions and the deviation of common operating conditions from design conditions. Thus, the operating condition classification model based on the historical data clustering is proposed in this work. Firstly, considering the coexistence of unsteady and steady state operating conditions, the output power is applied as the key indicator between the steady state and unsteady state. The interval estimation of expectation of the output power difference value is used to classify the historical data into the steady and unsteady samples. Then, due to the distribution difference among external boundary variables under the steadystate operating conditions, the improved multistep Kmeans clustering algorithm is proposed. The optimal clustering number for each step is determined by using the silhouette evaluation criterion. Finally, a real heavy gas turbine is used to validate the established model. Compared with the traditional Kmeans clustering, the results prove that the proposed operating condition classification model can effectively solve the problems of less classifications of operating condition and uneven distribution of samples.

Abstract:To improve the time synchronization protocol in automotive environment, this paper proposes optimization methods including master clock arbitration, startup timing, redundant path selection and fault recovery mechanism. The feasibility and effectiveness of these methods are tested on the real network. Without reducing synchronization accuracy, the optimization methods keep the new time synchronization process in a predictable state. Synchronous clock is faulttolerant to node and link fault. Moreover, the faulttolerant mechanism is proposed when synchronization fails completely, so as to avoid the impact of synchronous failure on normal driving.

Abstract:Aiming at the difficult problems of complex types of faults, difficulties in obtaining typical fault information and being subject to the impacts of environment, such as noise and temperature in analog circuit fault diagnosis, an analog circuit fault diagnosis method based on random projection and naive Bayesian network is proposed in this paper. The method firstly extracts the analog circuit fault information, and random projection method is used to perform the dimension reduction of the fault features and obtain the analog circuit fault feature vectors. Then, the naive Bayesian classifier diagnostic model is used to identify various faults of the analog circuit. The experiment results of CSTV filter circuit, four opamp biquad highpass filter circuit and actual SallenKey bandpass filter circuit indicate that compared with traditional analog circuit fault diagnosis method, the proposed method shows higher fault diagnosis performance and stronger antiinterference ability.

Abstract:The ant colony algorithm is slow in convergence and easy to fall into local optimal value in complex environment. To solve these problems, an improved ant colony optimization algorithm is proposed. The position information of the starting point and the target point are utilized to select the global favorable region. In this way, the initial pheromone concentration is increased and the efficiency of early ant search is improved. The obstacle avoidance strategy is added to avoid ant blind search. A large number of cross paths are generated and the number of ant deadlocks is effectively reduced. Based on the pseudorandom transfer strategy of dynamic parameter control, the global performance of the algorithm is improved. The updating principle of high quality ant pheromone and adjusting the volatility coefficient adaptively are proposed. The second path planning is carried out to optimize the path and reduce the loss of energy consumption of mobile robots. Experimental results show that the algorithm has the feature of higher global searching ability, faster convergence speed and higher working efficiency of mobile robot. The proposed algorithm is verified to be effective and superior.

Abstract:It is the key issue of tracking travel that intelligent vehicle travels fast, smoothly and accurately in curved path. An intelligent vehicle control scheme based on CCD camera path identification is presented in this paper, and the intelligent vehicle can achieve full closedloop control at different stages of the curved path. During the travel process, the intelligent vehicle recognizes the straight and curved paths according to the curvature of the navigation line. Different control methods are adopted in the straight and curved sections of the path to realize the advanced deceleration for the curved section and the accelerated passing through for the straight section, and the full closed loop control is adopted in both the straight and curved sections. The visual system extracts the navigation line in the path with the CCD camera and calculates the curvature of the navigation line as well as the parallel deviation value and course angle deviation of the intelligent vehicle relative to the navigation line. The main control system selects the control strategy according to the curvature of the navigation line, calculates the steering angle and travel speed according to the parallel deviation value and course angle deviation, and completes steering and speed adjustment through the actuator. The control results are fed back to the main control system through the visual system and speed measurement device to achieve the full closed loop control. An experiment system was set up in the background of the 15th national college student robot competition, through multiple debugging and experiments, the maximum travel speed of the intelligent vehicle on the track reaches to 35 m/s, the average speed in the whole course is about 28 m/s, and the actually measured maximum deviation distance is 35 mm, which is within the allowable error range. The actual experiment system verifies the feasibility of the staged full closedloop control method of intelligent vehicle.

Abstract:Energysaving and lowcarbon technology for vehicles is a research hotspot. Considering the large power dissipation in suspension system, a hybrid electromagnetic energysuspension suspension damper is proposed based on Halbach permanent magnet array. The eddy current generation structure and an electromagnetic energy harvesting device are combined, and the relationship between feed energy damping performance and eddy current damper is studied. The equivalent magnetic circuit model of the electromagnetic energy harvesting device is established. The dislocation rate between the two sets of permanent magnets is defined. The influence of the dislocation rate on the output electrical performance of the composite damper and the eddy current loss of the eddy current structure is analyzed. Finally, the prototype and a corresponding damping test platform are built. The damping coefficient adjustment range of the prototype can be widened from 500 to 1 270 N·s/m, and the maximum energy harvesting power can be up to about 17 W at a dislocation rate of γ=1 (Simple harmonic excitation with frequency f=5 Hz and amplitude Y=6 mm). The maximum specific mass damping coefficient can reach 1 4270 s-1. The hybrid electromagnetic regenerative suspension damper provides a new idea for future research on suspension energy recovery and electromagnetic damper design.

Abstract:To meet the requirements of big survey area and rapid exploration of groundairborne frequencydomain electromagnetic method, an aircore sensor (ACS) is developed for GAFEM with high sensitivity, low noise and low weight. First, based on the onedimension forward method, the equivalent area normalized response voltage at 10 km is calculated. And the index requirements for ACS′s sensitivity and noise levels are determined. Then, the circuit model of the sensor is built, and the noise of the aircore sensor is analyzed. Low noise and low weight are achieved by optimizing the design parameters of the sensor through lagrangian multiplier method. Finally, according to the optimized parameters, the aircore coil sensor is designed and fabricated, and the sensor is tested in the electromagnetic shielding room. Results show that the noise of coil at noise reference point (100 Hz) reaches 009 pT/Hz1/2, the sensitivity is 147 mV/nT, and the total weight is 125 kg. In addition, field experiments show that the optimized ACS obtained the magnetic which is consistent with that of the AMTC30 at the same measuring point, and the ACS can acquire effective magnetic data in the practical survey.

Abstract:The transition zone less than 55 m is accomplished in a portable micro pulse (MPL) Lidar system based on the dual fieldofview (FOV) design. This dual FOV lidar system overcomes the traditional deficiency of the Mielidars with a wide blindtransition zone which based on the single FOV design due to the geometricfactor effect. The schematic structure and the technical parameters of this dual FOV Lidar system are revealed in this study. The combination method of the two FOVs′ return signals is explored. In this way, not only ensure the effective detection for the far field but also the blind zone to almost zero for the near field detection is squeezed. The parallel comparison with a longterm running traditional Mie Lidar is conducted with a pearson coefficient of 098, slop of 292 and intercept of 011 a.u., which proves the novel performance of this dual FOV Lidar. Due to the portability, it can be easily applied on the vehicle, aircraft, etc. The typical online diurnal variation of vertical aerosol extinction coefficient profiles verifies the effective measurement for the atmospheric aerosol in range of 10 km.

Abstract:Soft robot has the incomparable advantage in surgery and narrow space due to its flexibility, adaptation, etc. To realize the attitude sensing monitoring of soft actuator in small space (e.g., minimally invasive surgery), a flexible sensing method based on the implantable fiber Bragg grating (FBG) is proposed in this study. First, the FBG is implanted into the soft actuator. Then, under different bending states of soft actuator, the spectral, wavelength drift and curvature information of FBG are analyzed by experimental test. Threedimensional shape fitting and reconstruction of soft actuator are realized by cubic spline interpolation algorithm. Experimental results show that the error between the actuator′s actual bending angle and the reconstruction algorithm is less than 45%. The repeatability deviation index of sensor is less than 7%. The flexible sensing method based on implantable FBG can realize the attitude sensing and monitoring of soft robot, which has a broad application prospect in the field of medical surgery.

Abstract:In clinical operation, transrectal ultrasound prostate biopsy is the most commonly used method for diagnosing prostate cancer. During operation, the doctor has to hold the ultrasound probe for repeated adjustments all the time, which is difficult to ensure the efficiency, accuracy and safety of the operation. In this paper, through analyzing the transrectal ultrasound guided prostate biopsy operation procedure, a 7DOF passive transrectal ultrasound probe position and posture adjustment remote center mechanism is designed. The posture adjustment module designed based on double parallelogram mechanism realized the centering function of the ultrasound probe, and the kinematics analysis of the posture adjustment mechanism was carried out. The working posture and centering effect of the ultrasonic probe at different feeding distances was simulated based on SimMechanics. The physical prototype of the passive transrectal ultrasound probe position and posture adjustment mechanism was developed and measured in experiment. The experiment results show that the maximum errors of the azimuth angle remote center point motion and the pitch angle remote center point motion of the ultrasonic probe are 4 and 34 mm, respectively, which are less than the deformation of 6 mm that the anus can bear. The random error correlation in different directions is weak, the confidence interval width of the remote center point motion error of azimuth and pitch angles are less than 25 mm, and the maximum relative fixed point error and the maximum relative standard error are 1473% and 1498%, respectively. Therefore, the simulation results, experiment results and the measurement error analysis verify the effectiveness and stability of the centering performance of the proposed transrectal ultrasonic probe position and posture adjustment mechanism.

Abstract:To improve the adaptability to vibrancy and impact condition on the vehicle platform, a fast steering mirror (FSM) with the center and outer doubleaxis flexure hinges is designed. Based on the basis of application requirements of the vehicle tracklaunch system, the lightweight mirror, actuators, sensors for angle and flexure hinges of FSM are designed and selected, respectively. The eddy current sensors with four channels, which measurement noise is suppressed by using difference data of two channels, are used to improve measurement accuracy of FSM. Mode and stiffness of the combined hinges with center and outer flexure hinges are analyzed by the finite element method and two flexure hinges are designed optimally, which are beneficial to improve the control bandwidth of FSM system. Finally, the pointing precision, control bandwidth and step response time of FSM are tested respectively after fine manufacturing and assembling. Experimental results show that the pointing error of the FSM is less than 1″, the control bandwidth is more than 200 Hz, and the step response time is about 10 ms. Hence, the designed FSM with two doubleaxis flexure hinges can meet the application requirements of vehicle tracklaunch system.

Abstract:We have realized a time synchronization system using the one pulse per second (1PPS) signal provided by the global navigation satellite system (GNSS) receiver as reference signal to synchronize the 1PPS signal output of the local oscillator. Aiming at the influence of the jitter noise of GNSS receiver 1PPS signal on synchronization performance of the time synchronization system, we designed a filter that can suppress the jitter effect. The filter adopted the manner of wavelet filter combining with moving average filter, in which the wavelet filter used customdefined threshold and threshold functions. Filtering processing experiment was conducted using the designed filter, the experiment results reveal that the jitter noise suppression effect for the 1PPS signal of the GNSS receiver using the proposed filtering scheme is better than that using commonly used Kalman filter. The 1PPS output signal accuracy of the proposed time synchronous system reaches 117 ns, which is one order superior to the 1PPS signal accuracy of GNSS receiver.

Abstract:The articulated arm coordinate measuring machine is one of the portable highprecision coordinate measuring instruments. It is hence necessary to establish accurate mathematical model for achieving the required accuracy due to the relationship between the central coordinate of the probes at the end of the measuring machine and the complexity of rotation angle of the joints. The classic DenavitHartenberg (DH) model has defects when adjacent axes are parallel and ignores static flexibility error. Thus, this paper focuses a new mathematical model based on the generalized geometric error model for improving the DH model. Additionally, the very fast simulated annealing algorithm is applied to calibrate the generalized geometric error parameters. Experiments demonstrat that the average error, after the calibration by the generalized geometric error model, is reduced by 0500 1 mm and the standard deviation is reduced by 0337 3 mm. The average error of the measurement based on the generalized geometric error model is 0045 4 mm and the standard deviation is 0032 3 mm. Both of the methods are superior to the MDH model, which verifies the effectiveness of the proposed method.

Abstract:Based on meteorological sounding motion dynamics theory, "ringing about one hourflatfloating about four hoursfalling about one hour" three stages about six hours sounding system was designed. The movement trajectory of flatfloating was studied and analyzed. The station net was theoretically redesigned in accordance with the detectability of ground receiver to meet the requirements of World Meteorological Organization. Afterwareds, Changsha upperair station and two circumjacent site were selected to form an experimental network and to carry out the verification experiment of small area. Experiments show that the accuracy of the system rising is higher than the single operation sounding by balloon. The overall deviation of temperature is within ±20℃. The system falling can realize the time encryption of the original single balloon sounding, and could capture subtle weather changes by combining with the system rising. The system flatfloating can make up the lack of data of stratospheretroposphere continuous direct detection with long aging, which has a good prospect of application.

Abstract:In order to improve the tooth pitch measurement accuracy of the visual measurement instrument for medium and small module straighttooth cylindrical gear, the influence law of the gear base circle positioning eccentricity on the tooth pitch measurement error in the visual coordinate system was analyzed. Through theoretical analysis and simulation calculation, the sinusoidal curve model of tooth profile initial phase angle error caused by base circle positioning eccentricity was obtained. Furthermore, the influence law of base circle positioning eccentricity on tooth pitch measurement error was studied. Based on the tooth pitch measurement principle of the relative method of visual measurement instrument, the increment formula of tooth pitch measurement error was deduced, and the actual gear measurement experiment was carried out using gear visual measurement instrument. The experiment results show that for the increment model of the tooth pitch measurement error caused by base circle positioning eccentricity has high calculation accuracy, which can be used in the accuracy analysis during the research and development of gear visual measurement instrument. it is also found that when the eccentricity e≤40 μm and the positioning error Δψj>1°, the model can meet the measurement requirement of the gears with the accuracy of class5; and when the number of gear teeth z≥45, the double tooth pitch measurement method can be adopted to improve the visual measurement efficiency, which can meet the requirement of the gears with the accuracy of class5.

Abstract:In order to meet the urgent requirements for joint flexibility and variable stiffness characteristics in the dynamic motions of legged robot, such as running and jumping, inspired by the flexible features and activepassive stiffness adjustment mechanism of biological joints, a new type of variable stiffness bionic flexible joint based on cam mechanism was proposed innovatively. Based on the analysis of the joint stiffness characteristics, a joint integral stiffness model was constructed. Then, the joint structural parameters affecting its stiffness characteristics were designed optimally and systematically, and a compact highly integrated joint prototype was developed. The joint prototype performance experiment results show that the variable stiffness bionic flexible joint based on cam mechanism has desired joint output torque and stiffness adjustment range. Through the activepassive fusion control of joint intrinsic and dynamic stiffness characteristics, the nonlinear and accurate adjustment of joint instantaneous stiffness is achieved dynamically, which meets the requirements for joint flexibility and stiffness of robot dynamic movement.

Abstract:To improve the cutting deformation of the weak rigid multiframe workpieces, the realtime adjustment of feedrate based on the realtime cutting force measurement is proposed. According to the milling finite element simulation, one kind of nonlinear numerical model with feed speed, cutting force and the maximum deformation of workpiece is formulated. The optimal feedrate under maximum deformation and cutting force are achieved. Meanwhile, the control module is developed in the open numerical control system. The cutting experiments of aluminum alloy thin wall frame are carried out by using the developed wireless force measuring device and control module. Experimental results show that prediction accuracy of the numerical model is over 90%. The cutting force and maximum deformation of workpiece are reduced around 23% and 123%, respectively. Experimental results show that deformation of the thinwalled frames can be effectively controlled within specified range by the realtime cutting force constraint and feedrate adaptive adjustment.

Abstract:Battery equalization technology can effectively reduce the inconsistency in the process of using the seriesconnected lithium battery packs. A new equalization topology is proposed using Cuk chopper circuit as the equalizer. The equalization topology uses a twolayer switch to select the single equalization cells to connect to the Cuk equalization converter. At the same time, the Cuk equalization converter adopts zero voltage conduction technology. The equalization scheme uses a singlelayer equalizer to achieve simultaneous transfer of the equalization energy among the single cells in the module and the single cells in different modules. The equalization scheme has the advantages of continuous equalization current, small fluctuation and high equalization energy transfer efficiency. The chargedischarge equalization experiment and static equalization comparison experiment on a battery pack with 12 series lithium batteries were performed. The experiment results show that this scheme can effectively reduce the inconsistency among single cells and improve the overall performance of the battery pack.

Abstract:In order to compensate the power of pulsed power source, an ultracapacitorbattery active hybrid pulsed power source is proposed based on the bandwidth control strategy. Firstly, the pulsed load is defined and its static and dynamic characteristics are analyzed. Secondly, the mathematical model of hybrid pulsed power source is established and its working mechanism is introduced. Thirdly, an active hybrid pulsed power source based on the bandwidth control of Butterworth secondorder lowpass filter is designed. Finally, the hybrid pulsed power source is verified theoretically under the SIMULINK simulation environment, and an experimental platform is set up to verify the proposed pulsed power source. The simulation and experiment results indicate that the pulsed power source adequately meets the loadrequirements of both energy. The ultracapacitor has significant effect on the battery power compensation with 17 A current output at the pulse time, which optimizes the battery discharge process, so that the battery current fluctuation is only 05 A with the almost smooth current curve.

Abstract:Photonic networkonchip (PNoC) has been a new trend for next generation networkonchip development. Microring resonator is the key component in PNoC. However, microring resonators are sensitive to process variation and prone to fault. Therefore, how to tolerant the microring resonator fault due to process variation is a key problem to improve the reliability of PNoC. Aiming at this problem, a finegrain based tolerance method of microring resonator process variation is proposed. Firstly, the model of microring resonator process variation was built; then, a tolerance method of microring resonator process variation based on salp swarm algorithm was proposed; finally, the tolerance of a multistrategy redundant microring resonator was conducted. The experiment results indicate that compared with integer linear programming method, the proposed approach increases the bandwidth by 21% and decreases the trimming power consumption by 667%, which proves the effectiveness of the proposed approach.

Abstract:Field monitoring is one of the main applications of wireless sensor networks, which has the characteristics of long deployment period, battery powered nodes, realtime uploading sensing data and etc. Aiming at the characteristics of this type realtime data acquisition applications, in this paper a scheduling scheme for media access control (MAC) layer based on preamble sequence wake up mechanism is proposed. Through coordinating the scheduling of the node wake up time of the data uploading path, this scheme decreases the length of the preamble sequence of the sender, reduces the node energy consumption and channel contention overhead, and improves the realtime performance of abnormal data uploading. The energy consumption analysis and comparison for multihop tree network between the proposed scheme and the existing lowpower MAC protocols were conducted. The simulation and experiment results verify the effectiveness of the proposed scheme, the proposed scheme greatly increases the network lifetime, while ensures the real time performance and delivery ratio of the data at the same time.