An industrial robot kinematic model with joint geometric error parameters and a calibration algorithm is proposed. Firstly， based on the DH model， six geometric error parameters are introduced for each joint to establish a more comprehensive error calibration model. The solutions of forward and inverse kinematic for the model are realized. Then， a differential kinematic Jacobian matrix containing 45 parameters， including joint errors， base coordinate errors， and tool coordinate errors is established. An iterative algorithm based on a small sample test set is used to solve the error parameters. Finally， experimental verification is carried out using a laser tracker on the SIASUN SR10C robot. The calibrated error parameters are then compensated into the model. Results show that， after calibration compensation， the maximum position error of the robot decreases by approximately 80%， the average position error decreases by approximately 80%， and the error variance decreases by approximately 97%， demonstrating that this method can significantly improve the absolute position accuracy and determinacy of industrial robots.

Universal filtered multi-carrier （UFMC） is a multi-carrier modulation technology for 5G communication systems. In order to verify the advantages of the UFMC system and further improve the channel estimation effect， an adaptive orthogonal matching pursuit algorithm （J-SAWOMP） based on Jaccard similarity criterion is proposed， which uses the Jaccard similarity metric criterion to calculate the similarity coefficient between atoms， and optimizes the screening method of matching atoms， and selects the best atoms by using the weak threshold selection method. Finally， the backtracking idea is used to further select the atoms with better correlation to improve the accuracy of signal reconstruction. Experimental results show that compared with the classical match-chase algorithm， the J-SAWOMP algorithm has better channel estimation performance under the UFMC system.

The effects of swirling-flow gas injection angles on multiphase flow， circulation flow and mixing time in the RH refining process were investigated using numerical simulation. Compared with the conventional gas injection mode， the circulation flow increased by 17.8% and 20.1%， respectively， when the swirling-flow gas injection nozzles with 30° horizontal angle + 15° vertical angle and 30° horizontal angle + 30° vertical angle were employed. Moreover， the mixing time was reduced by 32.6% and 21.4%， respectively. With the swirling-flow gas injection technology， a swirling steel flow was generated in the up-snorkel and the steel flow velocity was more uniform. The swirling-flow caused argon bubbles to move centripetally in the up-snorkel. The bubble dispersion was improved compared to the conventional gas injection mode. This promoted the gas-liquid two-phase interaction， mass transfer and mixing efficiency. Additionally， the wall shear stress was reduced from 500 Pa to around 100 Pa when the swirling-flow gas injection of 30° horizontal angle 15°vertical angle was applied， compared to swirling-flow gas injection with only 30° horizontal angle. Also， the area of the high wall shear stress region was decreased greatly， which is helpful to reduce the erosion of refractory materials by molten steel.

Based on the geometric model and experimental data of the pilot air cushion furnace at Northeastern University， a fluid-structure coupling model was established to investigate the factors affecting strip floating morphology in the air cushion furnace. The results show that the model can accurately simulate the floating morphology of copper strips in air cushion furnace under different influencing factors. Air cushion pressure， strip tension， and strip thickness are the main influencing factors of strip floating morphology： the deformation of the strip will decrease or increase significantly when the air cushion pressures above and below the strip surface are changed. When the tension of thin strip is doubled， the maximum deformation near the lower and upper nozzles of the strip is reduced to 1/2 of the original value. When the thickness of the strip increases by 0.5 mm， the maximum deformation of the strip decreases significantly under the same surface air cushion pressure. The temperature in the air cushion furnace is a secondary factor. The furnace temperature is different， but the air cushion pressures on the surface and under the strip are the same， and the strip deformation is approximately the same. The numerical simulation provides a new method and idea for studying the deformation mechanism of strip suspension in air cushion furnaces.

TiSi （atomic ratio 80∶20） and AlTi （atomic ratio 67∶33） alloys were used as target materials by the vacuum arc ion plating technique. Two layers and multiple layers of TiAlSiN coating were deposited on the WC-Co substrates to study the effects of the coating structure on the microstructure， mechanical properties， and tribological properties of the coatings. TEM，SEM， EDS， XRD， nano-indentation instrument， microhardness instrument and binding force tester were used to analyze the cross sections of the coatings and the morphologies， compositions， microstructures， elastic moduli， microhardness and binding force of the coating. The tribological properties of the coatings were analyzed by the friction and wear testing machine. The results showed that the binding force （greater than 200 N） of the multilayer coatings is higher than that of the double-layer coatings. The double-layer coatings exhibit stronger resistance to plastic deformation， while the multilayer coatings show stronger resistance to elastic deformation. The friction coefficient of the coatings under low loads is greatly affected by the surface topography of the coating， while the surface topography of the coating under large load has little effect on the friction coefficient. Oxidation wear occurs only in the double-layer coatings， while abrasive wear occurs in the friction wear process of both coatings. The wear resistance of the multi-layer coatings is higher than that of the double-layer coatings.

Based on the neural network parameter indentification method and component mode synthesis （CMS）， a modeling approach for the nonlinear powertrain system is proposed to investigate the coupled vibrations of the engine and auxiliary components， and the multi-objective optimization design using genetic algorithms is applied to optimize the connection stiffness and damping. Firstly， a neural network-based model was employed to fit the dynamic model of the powertrain system. According to the experimental modal parameters， the genetic algorithms were applied to identify the connection stiffness and damping of the powertrain system. The results showed that the maximum discrepancies between simulated and experimental modal frequencies and damping ratios were -5.98% and -15.72%， respectively. Subsequently， the CMS is employed to reduce the degrees of freedom of the powertrain system， and the engine-equipment coupling vibration response is evaluated. Finally， a multi-objective optimization design was performed to achieve the optimal vibration performance of the auxiliary components. The maximum peak values displacement of the intercooler and air filter for the optimized model decreased by 34.6% and 4.61%， respectively， compared to the original ones.

One of the main factors affecting the obstacle crossing performance is the base rotation joint of the walking arms. To improve the walking performance of the robot under the obstacle crossing conditions， an active adjustment method of the base rotation joint was proposed. Firstly， a dual-inertia dynamic model of the base rotation joint was established， and a joint controller was designed based on linear quadratic regulator （LQR） control theory. Through comparison， it is found that the performance of the base rotation joint is mainly determined by the weight coefficient matrices Q_c and R_c. Genetic algorithm is used to optimize the parameters in the coefficient matrices of the joint controller， and the optimization results are compared and analyzed to find the best scheme to improve the walking performance of the robot under obstacle crossing condition. Finally， the obstacle crossing experiment of the multi-joint double-arm inspection robot is carried out， and the results showed that the joint controller with optimized parameters can better control the robot to complete obstacle crossing tasks.

Under variable load conditions， machine learning-based gear fault diagnosis models face the challenge of relying on specific target condition samples for training. To overcome this limitation， the feature components in the signal that can reflect the health status of gears and remain invariant to load variations were solved based on the gear fault mechanism， thereby constructing a fault frequency waveform convolution module and embedding it into the convolutional neural network. Additionally， to enhance the network’s feature extraction capability， a multi-scale attention module was introduced. Based on these modules， a variable load gear fault diagnosis model named FWaveNet was constructed and applied to the gear fault dataset from Northeastern University. The results showed that its diagnostic accuracy is significantly better than that of existing models. Through specific signal processing techniques and network architecture design， precise identification of gear health status under load fluctuations is achieved， and a solution for engineering applications in the fault diagnosis of variable load gears is provided.

In order to improve the control accuracy and performance quality of fuel pump regulators for an aero engine， a simulation model and an experimental bench of the metering valve were built based on AMESim， and the linear relationship between the engine outlet flow and the valve’s opening degree was analyzed. It was found that the engine outlet flow changes linearly with valve opening， but both the inlet and outlet pressures change slowly initially and then increase greatly when the valve’s opening reaches 60%. Meanwhile， the pressure difference of the inlet and outlet is almost at 0.5 MPa. The simulation results agree well with the experimental results， and the differences of the steady and dynamic states are below 5% and 10%， respectively. Furthermore， the effects of the system’s rotating speed and outlet load on the metering valve performance were also studied， and it was found that the system’s rotating speed plays a large role on the metering valve performance as there can be some pressure overshoot and hydraulic impact when it changes， whereas the outlet load plays a small role on the metering valve performance as there is no pressure overshoot but there is a little lagging.

In order to evaluate the risk of deflagration in high temperature environments caused by NCM lithium-ion battery vent gas （BVG） after thermal runaway， the explosion characteristics and laminar burning velocity of BVG at different initial temperature θ₀ （25~120 ℃） were tested using an 8 L explosive chamber and a Bunsen burner. At the same time， the influence mechanisms of laminar burning velocity（S_L） at room temperature and high temperatures were further analyzed by CHEMKIN numerical simulations. The results show that the LFL doesn’t change significantly with the increase of the initial temperature， and UFL increases. When θ₀ increases to 120 °C， p_max decreases from 0.62 MPa to 0.45 MPa， and the relationship with θ₀ is exponential. Affected by both positive and negative effects， （dp/dt）_max decreases to different degrees with the increase of θ₀； LOC decreases exponentially from 7.39% to 7.03%； S_L increases with the increase of θ₀. It is also found that C₂H₄ and H₂ are the decisive factors affecting the combustion and explosion damage degree of BVG. The research results can provide a reference for the risk assessment and prevention of environmental deflagration caused by thermal runaway in NCM lithium-ion batteries.

In order to solve the problems of quick setting time and poor safety when using strong alkali activator such as sodium hydroxide in alkali-activated slag-fly ash cementitious system， a compound activator with the amount of substance ratio of lime to sodium sulfate of 1∶1 was used to activate the slag-fly ash cementitious system. The effects of activator dosage and fly ash content on the properties of lime-sodium sulfate compound-activated slag-fly ash cementitious system were analyzed. The hydration products and hydration process of the cementitious system were explored by XRD and other detection methods. The results show that the composite activator composed of lime and sodium sulfate can replace sodium hydroxide to activate the cementitious system of slag-fly ash， and the fluidity and setting time of the cementitious system can be controlled. The optimal dosage of the composite activator in the cementitious system is 10%， and when the fly ash content is less than 50%， the 28 d compressive strength of the cementitious system is above 36MPa. Lime-sodium sulfate compound activator can effectively destroy the shell of fly ash， promote fly ash to participate in the hydration reaction of cementitious system， and enhance the later compressive strength of cementitious system. C-（A）-S-H gel and ettringite cement slag and fly ash with different reaction degrees and particle sizes to form a compact matrix structure， which provides the main compressive strength for the cementitious system. This study provides a reference for the preparation of noval low-carbon cementitious materials.

Rock masses are often simplified as homogeneous materials when evaluating rock mass quality and analyzing slope stability. However， natural rock masses actually exhibit heterogeneous characteristics. To address this issue， a detailed characterization of rock mass quality and a modeling method for mechanical parameters considering heterogeneitying are proposed. Taking the Wulagen lead-zinc mine as an example， the process of the detailed modeling method for rock mass mechanical parameters is elaborated in detail. Based on the established detailed mechanical parameter model， a stability analysis of the southern slope was conducted using both homogeneous and heterogeneous rock mass mechanical parameters. The results indicate that the calculations using heterogeneous mechanical parameters can more accurately reflect the true stability conditions of open-pit slopes. The detailed block model established in this study can identify weak and unstable areas in open-pit slopes， providing a scientific and effective solution for rock mass quality evaluation， stability analysis， and support design.

When tunneling in clay stratum， the shield may encounter some problems such as “mud cake” on the cutterhead， soil accumulation in the chamber， and poor soil discharge. Therefore， based on the shield project between Wenchu Road Station and Guanyin Road Station of Shenyang Metro Line 6， muck improvement was carried out based on foaming ratio and half-life test， dispersant settlement test， rotating shear test， mobility test and stirring test. Finally， scanning electron microscopy， Zeta potential and double electric layer theory were used to analyze the mechanism of clay improvement by dispersant. The results show that the performance of the modifier is better when the volume fraction of foam agent is 4% and the sodium hexametaphosphate mass fraction is 2%. The improvement effect is better when the moisture content of soil layer is 30%， the dispersant injection ratio is 10% and the foam injection ratio is 30%~60%. Scanning electron microscopy and Zeta potential tests showed that 2% sodium hexametaphosphate solution can increase the thickness of the clay double electric layer and disperse the clay.

An evaluation index system was established based on the green development and its efficiency in the construction industry.The static and dynamic efficiencies of green development in the construction industry at the national and provincial levels were estimated using the super efficiency SBM-ML model from 2008 to 2021. The results demonstrate that the static efficiency of green development in the construction industry in China is fluctuant rising. The efficiency value is greater than 1 for nine years. This implies that the green development in the construction industry is relatively effective. The green development efficiency in the construction industry has increased by an average of 1.7% annually， but the stability of dynamic efficiency in different years needs to be improved. The static efficiency of green development in the construction industry in each province shows a distribution of "high in the southeast and low in the northwest"， and the efficiency value in each province shows an obvious differentiation of "high， medium and low". While there are fluctuations in the dynamic efficiency levels of green development in the construction industry in each province， there is no obvious manifestation of specific geographical distribution patterns. Through analyzing the calculation results， relevant suggestions are put forward from the aspects of policies and enterprises to optimize the green development efficiency and promote the high-quality development in the construction industry.

A multi-sensor fusion positioning method was proposed to address the limitations of single-sensor localization in complex environments. In terms of vision， line features were added to point features to overcome the interference caused by repetitive textures in visual images. In the global navigation satellite system （GNSS）， the introduction of carrier phase with higher accuracy was used to smooth the pseudorange observations， which improved the accuracy of single point positioning. The accuracy and stability of the algorithm were validated by using both public datasets and measured data. In both public datasets and actual data， the accuracy of the proposed method is improved by 32.2%， 23.3%， 24.5%， and 25.7%， 25.8%， and 14.1% in the X， Y， and Z directions， respectively， compared to the GVINS （visual inertial GNSS tightly coupled algorithm） in the geocentric coordinate system. In addition， in the environments where satellite signals are severely obstructed， the proposed method still has good positioning performance for a certain period of time， with a positioning accuracy of 0.74 m in plane and 0.91m in elevation. Research results provide new insights for multi-sensor fusion position in complex environments.

In order to evaluate the seismic reliability of steel staggered truss framing （SSTF） structural systems， the limit state function for the bearing capacity of the SSTF structure was established by taking the ultimate base shear force of the total horizontal seismic action at the bottom of the structure as the limit state. An ordinary steel frame structure model and six SSTF structure models with different truss arrangements were established under the same amount of steel usage. Higher order moment method was adopted to calculate the failure probability of established structure models under different seismic intensities， and then the failure probability curves were depicted. The results show that the SSTF structure starts to exhibit the failure risks of slight， moderate， severe， and complete damage when the seismic intensities is 6， 7， 8 and 9 degrees， respectively. The use of vertical webs alone in trusses is not sufficient to improve the seismic performance of the structure， while the addition of diagonal webs can significantly reduce the failure probability. The seismic performance of the rigid joint between the vertical web and the chord is better than that of the hinged joint， and the failure probability of the rigid form is reduced by at least 10% compared with the hinged form.

Establishing the moisture stress analytical model of wood members is the basis for studying the laws of wood shrinkage cracking and their impact on the bearing capacity. Firstly， the stress distribution model of cross-section under moisture content gradient was established by analyzing the stress balance in the cross-section of wood member. Secondly， the equilibrium conditions， physical conditions， geometric conditions and coordination equations for wood members under non-uniform moisture content gradient were established based on the temperature stress elastic analytical model and the thermo-analogy relationship. The analytical solutions of tangential and radial moisture stresses， critical moisture content of cracking and critical point of tangential tension and compression were obtained by solving the equations. Finally， the correctness of the analytical solutions was verified by numerical simulations. Taking Chinese fir members as an example， the influence of different parameters （moisture content difference， member diameter， initial and final moisture content values） on the radial and tangential moisture stress distributions of the cross-section of wood members was analyzed. The results show that the moisture stress distributions in the cross-section of the wood member is not related to the initial and final moisture content of the wood member and the size of the member， but is related to the moisture content difference and material properties.

To investigate the feasibility and effectiveness of improving the mechanical properties of tailings mud by electroosmosis， voltage gradient and voltage loading method were used as variables， and the self-made electroosmotic test chamber was used to carry out indoor electroosmotic tests on copper tailings mud and phosphorus tailings mud. By analyzing the drainage volume and current attenuation during the electroosmosis， as well as the moisture， dry density and shear strength of the tailings mud after electroosmotic improvement， combined with the energy consumption of electroosmosis， the effectiveness and best way for improving the mechanical properties of tailings mud by electroosmosis were explored. The test results show that electroosmotic drainage is positively correlated with voltage intensity and voltage loading stages. Compared with single-stage voltage loading， the current attenuation trend of multi-stage voltage loading slows down. After the end of electroosmosis， the water content of tailings mud is lower， the dry density is larger， the shear strength is higher， and the improvement effect of mechanical properties is better. During the electroosmotic process， the average energy consumption of multi-stage voltage loading is lower than that of single-stage loading. The best way to improve the mechanical properties of tailings mud by electroosmosis is 15—20—25—30 V four-stage voltage loading.