In order to improve the agility and safety of emergency steering, a steering intention-based agility control strategy based on active lateral stabilizer bar system was proposed. The rolling dynamics mechanism of wheel load transfer during steering is analyzed and an improved driver steering intention recognition method is developed. According to the steering intention and the vehicle roll dynamics mechanism, the left and right wheel loads on the front and rear axles were dynamically distributed, and the stability control method was introduced to improve the agility control strategy during vehicle driving. Simulink-CarSim vehicle model was built for simulation and verification. The simulation results show that compared with traditional vehicles, the use of steering wheel angle decreases by about 9%, the peak angle of centroid side angle decreases by about 22%, and the yaw angle speed increases by 4%. Emergency steering control is achieved by using smaller steering wheel angle to improve the yaw steering response, and the agility and stability of the vehicle are enhanced. Finally， the simulation algorithm is verified on the ECU in-the-loop test bench and laid the foundation for the subsequent development of stabilizer rod prototypes.

A reduced combustion mechanism of gasoline/butanol blends containing 425 elementary reactions and 96 species was developed using direct relation graph with error propagation and sensitivity analysis， based on a detailed mechanism of gasoline/butanol containing 7714 elementary reactions and 1765 species. In this reduced mechanism， i-butanol， n-butanol， t-butanol and s-butanol sub-mechanisms are included， and the n-heptane/iso-octane/toluene mixtures are used as the gasoline model fuel. The ignition delay times， species concentration profiles and laminar flame speeds predicted by the reduced mechanism were compared with those predicted by the detailed mechanism and experimental data， with satisfactory agreement being observed. Finally， this reduced mechanism was used in a three-dimension computational fluid dynamics software CONVERGE to simulate the combustion processes of a spark-ignited engine fueled with gasoline/butanol blends. The results showed that the in-cylinder combustion behaviors in this spark-ignited engine could be well captured by this reduced mechanism.

Aiming at the hybrid electric vehicle that adopts the dual planetary power coupling mechanism， the transient mode switching process from pure electric mode to hybrid driving mode is studied. In order to reduce the deterioration of the system dynamic performance caused by the engine torque fluctuation and the driving condition during the transient mode switching process， the robust compound coordinated strategy based on the finite-time extended state observer is proposed. Firstly， the mode switching process is analyzed and the system dynamic models for each switching stage are established. Then， aiming at the stages that cause large mode switching jerk， the extended state observer is designed to estimate the disturbance of the engine and load torque based on the finite time stability theory. On this basis， the feed-forward compensation strategy is constructed and the robust H_∞ controller based on the state feed-back control is designed to realize the robust compound coordinated control. Simulation results demonstrate that the finite time extended state observer improves the observation accuracy of the engine torque and load torque disturbances effectively， as well as the engine speed tracking performance. The proposed robust compound controller based on the finite-time extended state observation can reduce the influence of the vehicle external disturbance on the HEV mode switching effectively， and reduce the mode switching impact significantly.

In order to study the effect of Molten inert gas welding（MIG） lap weld on the lightweight design of aluminum alloy welded structure， the equivalent model of shell element was established through tensile of welding seam， and it was applied to the lightweight design method based on multi-objective optimization of structural parameterized model. The results show that after considering the influence of weld， the results are closer to the engineering practice， the performance of each target is optimized， besides the reasonable distribution of stress at the weld and a more ideal weld layout are realized， but with increased quality. Therefore， the lightweight design method of welding structure of aluminum alloy considering the effect of MIG lap weld has better engineering practical application significance.

In order to realize the high precision simulation of the vehicle external flow field， the grid distortion position is explored on the basis of analyzing the distortion grid quality evaluation criteria，with the simplified car model in actual use as the research object. In order to prevent the negative volume phenomenon caused by the deviation of the center node during the optimization of the volume mesh， the length weighted Laplacian algorithm is proposed to carry out the simulation calculation of the local optimization of the distortion grid， and verified by the test results of HD-2. The results show that the transition areas of the body side feature line，the front windshield and hood，the rear windshield and luggage lid are prone to volumetric grid distortion.The length weighted Laplacian algorithm can reduce the number of distorted grids， increase the simulation accuracy of the drag coefficient by 3.90%， and the error from the wind tunnel test is 2.26%.The simulation of vehicle tail flow field is more accurate than before the optimization compared with the PIV test， which shows the effectiveness of the length weighted Laplacian algorithm.

Aiming at the phenomenon of single product， existing load imbalance and environmental pollution during the two-side disassembly process， a mathematical model of multi-objective mixed-model two-sided disassembly line was established to minimize the number of workstations， load balancing index， demand indexl， and hazard index. An elite differential evolution algorithm was designed to solve the proposed model. And the algorithm designed a new encoding and decoding method to fit the actual disassembly process. The elite strategy was combined to improve the algorithm's random process and evolution process. Pareto comparison and NSGA-II mechanism were used to screen non-inferior solutions. The feasibility and well performance of the algorithm are verified by comparing it with the actual two-side disassembly examples. Finally， the model and the algorithm were applied to a mixed-model TV disassembly case， then giving several better schemes for decision-makers to choose.

A three-dimensional finite element model of spiral thread is established in the paper， and the effectiveness of the model scheme is verified by the numerical calculations of "stress distribution on the surface of thread"， the mechanical properties of threaded structure under torsional load are numerically studied. The results show that： The thread structure experiences three states： adhesion， partial slip and macro slip in the loading and unloading stages； In the macro sliding stage of the tightening process， the torque increases due to the increase of axial force， and decreases due to the decrease of axial force in the loosening process. Based on the finite element calculation results of threaded structure， for the three-dimensional threaded structure with lifting angle under torsional load， the modified IWAN model is established by adding the overall correction of residual stiffness and torque during macro slip. The calculation results show that the modified IWAN model can accurately reproduce the relationship between torque and rotation angle in the finite element simulation results， The modified IWAN model composed of three Jenkins element models can accurately restore the dissipated energy obtained by finite element simulation.

Through the research on color matching evaluation of automotive human-machine interface （HMI） systems， the user experience of the display interface is improved. Based on the mechanism of color preference among different populations， three hypotheses about people's color preference are proposed. Then a crowdsourcing survey was conducted. Descriptive statistics and chi-square tests were used to compare the color choices of different groups in the four parts of the interface. The selection of fuel quantity signs is mainly in red， and the background color， instrument light， and road display are mainly in blue and green. There are also significant differences in color preferences among residents of different genders and regions. Warm colors are recommended for warning parts， while cool colors are recommended for other parts. Various interface color schemes are conducive to meeting different user needs.

In this work， the mechanical contact model between normal triangular atomic force microscopy（AFM） probe and coating film was established， which aims to measure the elastic modulus of polyurethane coating film. Whilst the force-indentation depth relationship between the probe and the coating film was obtained by analyzing the AFM's mechanical test curve， and the elastic modulus of the coating film was determined by combining the newly established model. In addition， the microstructure of the coating film was tested using positron-annihilation technology， and compared with its elastic modulus. Finally， the grey correlation theory is used to analyze the correlation between the microstructure parameters and the elastic modulus of the coating film. The results show that the elastic modulus of the coating film was measured within the region of 6.118 MPa to 6.917 MPa. This is consistent with the research results of the elastic modulus of polyurethane coating in existing literature， which guarantees the validity and accuracy of the present method. The elastic modulus of the coating film is negatively correlated with its free volume aperture and free volume fraction since that the restriction ability of the substrate to its molecular chain segment movement is significantly lowered with the increase of free volume size and content. Among them， the free volume average pore diameter of the coating film has higher effects on its elastic modulus.

The technique electron backscatter diffraction was used to investigate the microstructure， grain orientation， grain size and texture of the interface intermetallic compound of aluminum alloy/ultrahigh-strength steel plasma arc welding-brazing joint. The results indicated that the interface zone exhibited an obvious double-layer structure with different sizes and morphologies， which is composed of Fe₄Al₁₃ phase and Fe₂Al₅ phase. The Fe₄Al₁₃ phase has fine equiaxed grains morphology and is dominated by high-angle one， while the Fe₂Al₅ phase has columnar grains morphology and is dominated by low-angle grain boundary. The grain size of Fe₄Al₁₃ is obviously smaller than that of Fe₂Al₅. The main texture of Fe₄Al₁₃ phase is <010> silk texture， while the main texture of Fe₂Al₅ phase is <001> silk texture with obvious preferred orientation.

The effect of welding parameters on the tensile-shear mechanical properties and the fracture modes of probeless friction stir spot welding（PFSSW） joints was analyzed by Box-Behnken test design. The base material is 1.5 mm thick AA6061-T6 aluminum thin plate， which is commonly used in automobile body coverings. The tensile shear performance of PFSSW joints was optimized by response surface methodology（RSM）. The results show that the metallographic structure of PFSSW joint is basin-shaped. The maximum tensile-shear failure load（TSFL） of 6.41 kN was obtained with the rotating speed of 2950 r/min， the plunging depth of 0.6 mm and the dwell time of 7 s. There are three types of PFSSW joint fracture modes. Among them， the nugget pull-out mode exhibited the highest average failure load（6.26 kN）， interface separation mode was the lowest（4.89 kN） and mixed-mode was in the middle（5.60 kN）.

To study the influence of advertising signs on driving behaviors on flat curves sections of highways， the speed and lateral lanegap data were collected from 50 subjects on 20 groups of different advertising signs setting parameters and flat curve radius. The indicators of speed area， lane crossing behavior， and lateral lanegap were constructed to determine the starting and ending points of significant changes in driving behaviors under the influence of advertising signs. The results show that the erection form， distance from the road edge， and flat curve radius have significant effects on the starting and ending points of driving behaviors. The density of advertising signs only affects the ending point of speed and lateral lanegap. And it is not suitable to install advertising signs on flat curve sections with a radius less than 1000 m， even if they are floor-mounted billboards which have the least influence.

The vehicle trajectory and traffic flow data of the long longitudinal gradient roadway are collected through aerial photography by UAV， radar speed measurement and manual field survey. Based on the traffic conflict technology， the Time to Collision and the probability of rear-end collision caused by the conflict are calculated， and the loss of crash kinetic energy based on the law of conservation of kinetic energy is given for the rear-end collision on the long longitudinal gradient roadway， which are used to quantify the severity of vehicle rear-end conflict and collision consequences. The index of rear-end risk index is constructed to evaluate the degree of rear-end risk on long longitudinal gradient roadway. The zero-inflated negative binomial regression（ZINB） and ordered logistic regression were used to predict the frequency of rear-end conflicts and the risk level of rear-end， and analyze the influence of traffic flow characteristics indicators on them. The results showed that： the frequency of conflicts in uphill and downhill directions were well predicted with R² of 0.556 and 0.482， respectively； the risk level of rear-end collisions in uphill and downhill directions were well predicted with R² of 0.643 and 0.632， respectively； the effects of vehicle speed， acceleration， traffic volume and vehicle composition on the number of conflicts and the risk level of rear-end collisions were different.

In this paper， considering the stochastic characteristics of the electric vehicle flow and the initial residual electricity on the path， the extended network theory is introduced to build a mathematical model for the potential location of the power exchange station under the condition of multi-path. Combined with 'elitism'， the genetic algorithm is used to solve the location model and obtain the initial location solution. Finally， the statistical analysis method is used to screen the initial solution to get the final optimal location. On this basis， the relationship between electric vehicle mileage and station construction cost， and the relationship between the number of replacement stations and service flow are analyzed. By comparison， the introduction of 'elitism' can significantly reduce the initial construction cost and solution time of the charging pile， while the application of statistical analysis method can not only meet the power demand of the vast majority of vehicle owners in the expressway network， but also effectively reduce the initial cost required for the construction of the station.

To explore the impact of the abutment back wall on the seismic fragility of each continuous girder bridge component， two nonlinear models of the four-span continuous girder bridge with or without back wall were built separately using OpenSees software. Models were analyzed by 100 seismic waves selected from PEER（Pacific Earthquake Engineering Research Center） database， based on class II site. Then the fragility curves of each component were established by cloud method. The results show that the abutment back wall has significant effect on the seismic fragility of continuous girder bridge. The effect of the abutment back wall on seismic responses of each component increases with the increase of the damage degree. In the state of complete damage， the influence degree reaches maximum， and the mean deviation of pier fragility reaches 85.5%. Considering the abutment back wall have the greatest influence on the seismic response of piers. Therefore， it is suggested that the abutment back wall should be considered when analyzing the seismic performance of continuous bridge structures.

To determine the optimal ratio of reactive elastomer terpolymer（RET） and rubber modified asphalt， the quantitative relationship between asphalt performance and the content of RET， rubber and oil was comprehensively investigated based on Design-Expert. The modification mechanism of composite modified asphalt was investigated by Dynamic Shear Rheometer， Infrared Spectrometer and fluorescence microscope and the road performance and fatigue performance of composite modified asphalt were verified and evaluated. The results show that the relationship between asphalt performance and the content of RET and rubber is not linearly， the optimum content of RET， rubber powder and oil is respectively 1.69%， 16.52% and 1.83% of the asphalt. The RET/rubber powder composite system can react with asphalt to generate new absorption peaks， which weakens the boundary between the modifier and asphalt. Thus， the compatibility of rubber powder and asphalt and the low temperature performance of RET modified asphalt were improved， which can significantly improve the road performance of asphalt mixture.

Taking the setting of connectors as parameters， an experimental study on the flexural performance of pipe curtain prefabricated structural members was conducted in this paper. The crack development and failure mode of specimens were observed， and the load， deflection and strain of the specimens were measured. Based on the test results， the stress mechanism of tubular roof prefabricated （TRP） structures was studied， and the influence of connectors on the flexural performance of TRP structural members was analyzed. The results show that the failure process and stress mechanism of flexural members in the TRP structures are quite different from that of the equal section double steel plate concrete flexural members. The failure of flexural members in the TRP structures generally occurs at the intersection of steel pipe curtains and steel plates， which is due to the tendency of the steel plate part to be pulled outward by arc steel pipe part in the steel pipe curtain. The failure starts from the yielding of transverse reinforcement， and ends at the yielding of steel pipe curtain after it is completely separated from the concrete. The setting of bi-steels can improve the mechanical properties of flexural members of TRP structures.

A new Reduced Beam Section（RBS） connection of steel beams used high-strength friction bolts was investigated in this paper. A H-shaped shear key was designed as a horizontal plate at the midline of the web plate and the steel beam under its midline. Lots of the resisting shear friction bolt groups at the web of the beam section were saved， and the H-shaped shear key could also be used as the landing platform for the purpose of fast installation when the steel beam was lifted in the air. Based on the experimental verification of the high-strength friction bolted connection of the H-shaped steel beams， the Finite Element Analysis models were built using ABAQUS software. Compared with the traditional steel beam connections， the bearing capacity process of the high-strength friction bolted RBS connection could be divided into four parts： elastic stage， sliding stage， strengthen stage and plastic stage， and two energy dissipation mechanisms were formed during the frictional sliding and plastic yield stages， respectively. The mechanical performance of the high-strength friction bolted RBS connection was analyzed with different parameters such as bolt pretension force， thickness of the connection plate and strength of the steel materials etc. The working mechanism and bearing capacity of the high-strength friction bolted RBS connection were analyzed in this paper. The bearing capacity and ductility of the high-strength friction bolted RBS connection was good， and the relocation of plastic hinge similar to the flange Reduced Beam Section steel beam was also found， the angular ductility factor increased from 1.7 to 12. The moment inter force at the beginning of frictional sliding was determined by the friction resistance capacity of the high-strength friction bolt groups at the steel beam flange， however， the bearing capacity during the plastic stage was relevant to the bolt strength， bolt diameter and the ultimate plastic moment of the steel beam.

Active melting of ice and snow has gradually become an important method to solve the problem of road ice and snow. The preparation method of conductive rubber composites is produced in this paper. The snow melting effect was determined through outdoor experiments. Moreover, the corresponding finite element model was constructed. The active ice and snow melting system was used for engineering and the threshold of intelligent sensing system was determined. The results show that conductive rubber can melt 20 mm snow on the road in 3.17 h at 14 V and -8 ℃, which can realize rapid snow melting at low voltage. The outdoor test verifies the accuracy of the finite element model. The sensing system indicates that the intelligent sensing active ice and snow removal system can remove road ice and snow in time.

To realize high-efficiency， light-weight， and non-contact bridge crack disease identification， a bridge crack identification network based on the （bridge crack extraction model，BCEM） is proposed. The network combines deep learning with traditional image processing methods. First， the crack image is preprocessed to enhance the expression of crack information. Then the sliding window method is used to divide the crack into patches. According to the characteristics of the patches， the improved lightweight model named BC-MobileNet is used to classify crack features. Finally， misdetected and undetected cracks are identified to achieve accurate identification of bridge cracks. Compared with different crack identification methods such as target detection and pattern recognition， the results show that the BCEM has improved in various experimental indicators， which proves the effectiveness of this network for bridge crack identification.

A new method for Chinese named entity recognition at word level based on transformer and hidden Markov model is proposed. The position coding calculation function of transformer model is improved， so that the modified position coding function can express the relative position information and directivity between characters. The character sequence encoded by transformer model is used to calculate the transfer matrix and emission matrix， and a hidden Markov model is established to generate a group of named entity soft labels. The soft label generated by hidden Markov model is brought into Bert-NER model， the divergence loss function is used to update the parameters of Bert-NER model， and the final named entity strong label is output to find the named entity. Through comparative experiments， the F₁ value of the proposed method in Chinese cluster-2020 data set and Weibo data set reaches 75.11% and 68%， which improves the effect of Chinese named entity recognition.

The blockchain consensus mechanism with directed acyclic graph structure can be executed transactions in parallel， but its efficiency and stability are poor. Therefore， some consensus mechanisms deal with transactions in the way of alliance chain. In this paper， a parallel storage structure based on directed acyclic graph is designed and proposed to realize the Transaction block confirmation mechanism （TBCM） consensus mechanism through this storage structure. Therefore， TBCM consensus mechanism can effectively improve the parallel processing ability of the alliance chain for a large number of transactions. In TBCM， the nodes are organized in the way of alliance chain， and the verification node groups verifie the transaction blocks generated in the network. The synchronous users in the network of parallel storage structure do not have to deal with the transaction load of the whole network， and the verification node group processes the blocks in the network of parallel. The consensus mechanism designed by this structure makes the alliance chain system have the ability to process transactions in parallel， so as to improve the real-time performance of transactions. TBCM has the advantage of parallel real-time transaction， and can achieve higher stability and transaction confirmation efficiency.

If there is a delay in the operation node of the clean energy system， it will affect the effect of collaborative optimization scheduling of clean energy. To avoid this problem， a collaborative optimization scheduling method of clean energy based on big data technology and particle swarm optimization algorithm is proposed. According to the operation characteristics of the clean energy system， the big data technology is used to analyze the operation parameters，the operation node delay scheduling strategy is desgined， and then the output power scheduling model is constructed. Taking the maximum operating benefit and the minimum energy discarding cost as the optimization objectives， a collaborative optimization scheduling model of clean energy system is constructed， and then the particle swarm optimization algorithm is used to solve the model to obtain the optimal scheduling scheme. The experimental results show that this method can obtain better results of clean energy collaborative scheduling.

Aiming at the problem of great difficulty and low accuracy in the detection of magnetic tile surface defects（DMTSD）， a novel algorithm of DMTSD is proposed. In this paper， a multi-branch network structure is designed， and a convolutional neural network which can effectively extract the features of the magnetic tile images is constructed in each branch， and then the attention module is introduced to highlight the important features of the image. Finally， the correlation of the intra-class features and the difference of the inter-class features is maximized through discriminant correlation analysis， and the optimized fusion feature of magnetic tile images is obtained by concatenation fusion. The performance of the algorithm is tested on the magnetic tile image data set， and the test accuracy is up to 99.90%. In the actual detection work， the detection accuracy of the algorithm remains above 99%， and the detection speed reaches 129 pcs/min. The results of test and operation show that the algorithm has the advantage of high detection accuracy and stable performance， and can meet the requirements of real-time online detection in mass production of magnetic tiles.

In order to ensure the personal safety of underground operators， a real-time tracking method of underground moving target based on weighted centroid positioning of wireless sensor network is proposed. The location and number of sensors in the mine is determined， and communication with neighbor nodes is established； The node closest to the target is selected to form a positioning edge. The weighted centroid positioning algorithm is used to give the node weight. The concept of virtual node is introduced to calculate the virtual node position and estimate the specific location of the moving target. The autonomous decision-making approach is adopted to determine the node transition states, and a tracking process is established based on the states to achieve real-time tracking of the target.. The results show that the tracking loss rate of the proposed method is always less than 0.02%， the error is small， and the tracking efficiency is high.

In order to improve the accuracy of qualitative analysis of visible near infrared spectroscopy， noise reduction pretreatment is needed. Aiming at the problem that it is easy to produce additional small spectral peaks which deteriorate the accuracy of qualitative analysis during noise reduction， a noise reduction method based on spectral transformation and high-order sparse Hodrick-Prescott decomposition is proposed. In the optimization model of this method， it is assumed that the visible near infrared spectroscopy is composed of low-pass basic waveform spectrum， band-pass characteristic waveform spectrum and noise. In this method， the L2 norm of the residual between the noisy spectroscopy， the basic waveform spectroscopy and the band-pass characteristic waveform spectroscopy is taken as the residual term to ensure that the estimated value is close to the real value. According to the sparsity of the characteristic waveform spectrum， taking the L1 norm of the second-order difference of it as the regularization term， it is constrained to estimate that the characteristic waveform spectrum has a certain sparsity to characterize absorption peaks of the important chemical components in tea. In this method， the low-pass and band-pass zero phase filter matrices are obtained by using the spectral transformation of the filter to help decompose the basic waveform spectroscopy and the characteristic waveform spectroscopy， and the optimal regularization parameters in the optimization equation are obtained by using the L-curve method. The experiment takes the visible near infrared spectroscopy of six kinds of tea as the basic experimental data. In the experiment， our method compares with the wavelet decomposition method， improved Hodrick-Prescott method and savitzky-Golay method by the signal-to-noise ratio，root mean square difference， and the accuracy of the classification model of qualitative analysis of tea varieties as the measures. The experimental results show that our method has the highest signal-to-noise ratio in synthetic spectra containing Gaussian noise and synthetic spectra containing Gaussian pulse mixed noise. For synthetic spectral data sets and real spectral data sets， the test accuracy of the classification model is higher than that of the above three methods， and much higher than the results obtained using their noisy spectral data sets. Therefore， this method has been proved to have advantages in noise reduction of visible near infrared spectroscopy， and can be applied to the pretreatment of the qualitative detection of tea varieties based on visible near infrared spectroscopy.

A vehicle deep-interaction coding model combined with a decoder based on the attention-mechanism to solve this problem was presented in this work. The model's multi-modal behavior predictions and trajectory predictions were output. The proposed model is evaluated by the public NGSIM US-101 and I-80 data sets. The results show that the model has a better root mean square error and achieves higher trajectory prediction accuracy while improving computational efficiency. This paper also shows a qualitative analysis of the prediction of multi-modal behavior maneuvering.

A hierarchical control strategy based on PID and Q-Learning algorithm for hybrid electric vehicle platooning. In the upper-level controller is proposed in this paper， the speed and position information of the preceding vehicle in the platooning are obtained based on vehicle-vehicle communication，the PID controller to realize the longitudinal control is adopt and the target speed of the following vehicle is obtained. In the lower-level controller， Q-Learning is adopted to distribute the energy of the hybrid vehicle platooning according to the target speed. The simulation results show that the average vehicle spacing in the upper control is maintained at about 14 m， which can ensure good driving safety. The average fuel consumption per 100 kilometers in the lower control is only 2.57% higher than that of DP， and the offline calculation time is reduced by 23%. This strategy can not only adapt to random working condition， but can also be implemented online， which maintains basically the same fuel economy as DP.

The channel distribution of wireless sensor communication network is complex， and it is greatly affected by external factors， resulting in low accuracy of fault detection. Therefore， a method of wireless sensor communication network blocking fault detection based on random forest is proposed. The change of attribute vector of sample set is simulated by preset random variables under the two states of blocking fault and non-blocking fault， and the decision threshold is set. Considering the influence of external factors， random forest decision rules are established， sample datas are input， external intervention factors through preset variables simulated， make the detection results approach the true value， and iterated until the detection results based on the decision threshold meet the rules. The simulation results show that the detection results of the proposed method are in good agreement with the measured values， and can also ensure the detection accuracy in the presence of interference environment， with short time consumption.

Typically, blind selection mapping techniques require high computational complexity when blind estimation is performed using the Euclidean distance between the original quadrature amplitude modulation (QAM) constellation and the received signal after demapping. In order to minimize the computational complexity of the system under the premise of ensuring the communication quality, a phase rotation sequence estimation method based on the minimum Euclidean distance of the quartile constellation is proposed. Due to the application of constellations to the power of the fourth power in this algorithm, the total number of signals used to calculate the minimum Euclidean distance can be reduced, thereby reducing the computational complexity of the system. In addition, a set of phase rotation sequences constructed by \left\{\mathrm{0}°,\mathrm{135}°\right\} random selection are introduced to further reduce the complexity while maintaining high estimation accuracy. The simulation results show that when [Eb/N0>6 dB], for different modulation modes 16QAM and 64QAM, the computational complexity of phase rotation estimation is reduced to about 35% and 14% of the traditional blind SLM estimation based on the maximum likelihood estimation algorithm (ML), and reduced to about 50% and 21% of the two-step estimation, while the bit error rate (BER) is not significantly reduced. Therefore, the proposed method can effectively reduce the complexity of the algorithm without reducing the performance of the wireless communication system.

According to the positioning requirements of the spherical detector independently developed in the water supply pipeline， an arc-shaped composite ultrasonic vibrator is designed. Based on the piezoelectric equation， its vibration characteristics are analyzed theoretically and simulated， and the main vibration modes and the optimal working frequency are obtained. The impedance matching design between the ultrasonic transmitting circuit and the composite ultrasonic vibrator is studied to achieve the optimal ultrasonic energy conversion drive efficiency. Based on ultrasonic signal detection technology of wavelet transform envelope detection method， the accurate time of ultrasonic signal transmission is calculated. The spherical detector positioning system is realized. After testing， the static ranging positioning accuracy of 100 meters of pipeline length is 2%， the dynamic positioning distance reaches 170 meters， and the error between the calculated distance and the inertial navigation data is not more than 6%， which meets the real-time positioning requirements of the spherical detector in the water supply pipeline.

In order to meet the needs of 'containing increments' of residual film pollution control in Xinjiang cotton areas， and improve the problems of high power consumption， large dust， low residual film recovery rate， short unloading distance and poor separation effect of membrane stalk in the residual film recovery machine after autumn， a combined operation machine of side row cotton straw returning and residual film recovery was designed. At the same time， many operations were completed such as crushing cotton straw side returning， picking residual film， separating membrane miscellaneous， collecting and compressing， unloading and accumulation. The crushed cotton straw were transmitted to the membrane junction line by spiral stirrer. The depth limit roller was used to imitate the ground to ensure the stability of the stubble height and achieve the stability of the depth of the residual film pickup spring tooth into the soil. In the process of picking up residual films， wind cleaning was used to realize secondary cleaning in the process of picking up residual film and reduce the impurity rate of residual film after recycling. The recovered residual film was compacted by conveying device to improve the loading capacity. The main working parts were designed and analyzed， the functional principle of picking， unloading and compressing residual film were expounded，and the structure and working parameters of the main parts were determined. The response surface test of three factors and three levels was designed by using Design-Expert software. The results showed that the optimum operating parameters of the machine were as follows： the operating speed of the machine was 1.09 m/s， the stubble height was 9.37 cm， the depth of the spring-tooth into the soil was 4.07 cm， and the of cotton straw crushing qualified rate， the film picking up rate and the residual film impurity rate were 96.20%， 88.48% and 12.00%，respectively. The rounded operation parameters were used for experimental verification. The test results showed that the cotton straw crushing qualified rate was 94.83%， the film picking up rate was 87.26%， and the residual film impurity rate was 12.23%. The test results showed that the error between the cotton straw crushing qualified rate， the film picking up rate and the residual film impurity rate and the theoretical optimization value was 1.4%， 0.3% and 1.9%respectively. The research methods and results can provide reference for the research of related equipment.