Aiming at the problem of large flow pulsation caused by severe swash plate oscillation in variable displacement asymmetric axial piston pump, the variable resistance moment was regarded as the interference signal, and the anti-interference control algorithm was adopted to improve its variable displacement control performance. Under the action of variable resistance moments with different frequencies, the response characteristics of the swash plate angle of the variable displacement asymmetric axial piston pump under conventional PID (proportion integration differentiation) control, exponential convergence disturbance observer control, nonlinear PID control, active anti-interference control and sliding mode control were compared through the co-simulation of SimulationX and Simulink platforms, so as to obtain the most suitable anti-interference control algorithm. On this basis, a parallel tuning method of control parameters based on the particle swarm optimization (PSO) was proposed. The simulation results showed that, under the action of 10, 20 and 100 Hz interference signals, the swash plate angle fluctuation of the variable displacement asymmetric axial piston pump under the sliding mode control was 1.7%, 2.2% and 23.0% of that under the conventional PID control, which proved that the sliding mode control algorithm could greatly reduce the swash plate oscillation and flow pulsation. The parallel tuning method of control parameters based on the PSO effectively reduced the tracking error of sliding mode control, and the maximum overshoot was reduced by 87.5% after tuning; the parallel tuning method could be separated from the professional simulation software, and its simulation efficiency was improved by more than 10 times compared with SimulationX platform simulation. The research results have certain reference value for the simulation and optimization of conventional hydraulic control systems.

The quality assessment of parts is a very important link in flexible intelligent manufacturing. The existing automatic identification device generally adopts the non-artificial contact optical detection system, but due to the complex working environment, many interference factors affect the accuracy of quality detection and assessment for parts. In addition, the continuous operation of industrial site puts forward higher requirements on the running speed of industrial control machine hardware, the environmental adaptability of optical detection system and the prediction accuracy of part quality assessment algorithm. Based on this, a comprehensive quality assessment method for parts based on the machine vision and machine learning was proposed. Firstly, the real-time acquisition and processing of the measured part image was completed with the help of machine vision technology, and then the gray matching algorithm and geometric matching algorithm were used to compare the images and the CAD (computer aided design) machining drawings of parts, so as to solve the geometric feature parameters of gray matching score and the geometric matching score. Then, according to the surface defects of parts (such as scratch, wear, edge material shortage and rust), the surface defect feature parameters of mean and standard deviation of image gray were solved on the basis of image pretreatment (gray, image enhancement, Gaussian noise reduction and binary). Finally, the four-dimensional feature data set of parts was dimensionally reduced by the principal component analysis (PCA), and the K-nearest neighbor (KNN) algorithm was used to train and predict the data set after dimension reduction to complete the comprehensive quality assessment for parts. On this basis, the accuracy, recall rate, specificity and other indicators of the KNN algorithm and other machine learning algorithms were compared to verify its feasibility. The experimental results showed that, the recognition accuracy of optical detection and processing system was more than 96.15% under different lighting conditions; when the camera shutter time was set to 100 μs, the image processing speed of this system reached 45.2 frames/s. The proposed comprehensive quality assessment method for parts has high accuracy and processing speed, which is suitable for comprehensive quality assessment of parts under complex working conditions.

Spatial composite force measurement is one of the important development directions of spatial sensing technology. As a main spatial composite force measuring device, the six-axis force sensor is widely used in rocket engine thrust test, spacecraft docking and other fields. At present, lightweight has become one of the main research directions of six-axis force sensors. However, due to the large number of design indicators and mutual constraints among various indicators, the method of theoretical derivation, numerical simulation and experimental verification was adopted in the research. Firstly, the force mapping model of Stewart type six-axis force sensor under ideal conditions was established based on the spiral theory, and the structural parameters when the theoretical isotropy was optimal were determined by solving the comprehensive performance objective function. Then, the simulation model of Stewart type six-axis force sensor was built by using the ABAQUS finite element analysis software, and the mass, stiffness, strength and sensitivity of its initial prototype were analyzed in detail. On this basis, the influence of the main structural parameters of upper and lower loading plates on the mass, stiffness and strength of sensor was analyzed, the structural parameters of upper and lower loading plates were optimized, and a hemispherical weight reduction structure with regular tetrahedron characteristics was designed, which realized the lightweight design of sensor. Finally, the performance of optimized Stewart type six-axis force sensor was simulated and verified by experiments. The results showed that multi-objective parameter optimization combined with numerical simulation and experimental verification could effectively improve design efficiency and reduce design cost; the designed weight reduction structure could effectively improve the mass distribution of Stewart type six-axis force sensor and improve its mass utilization. After optimization, the mass of the sensor was reduced by 17.65% and its comprehensive performance was excellent. The research results can provide reference for lightweight design and comprehensive performance optimization of six-axis force sensors.

The phenomena of dust sticking, hardening and bridging on the inner wall of ash silo in thermal power plant seriously affect the safe operation of thermal power units, so it is necessary to clean the ash on the inner wall of ash silo regularly. In view of the limited working range of the existing ash silo cleaning robot and the poor cleaning effect caused by the insufficient telescopic ratio and low stiffness of its mechanical arms, reciprocating rope row drive mechanism and multi-level nested box-type arm body was introduced into the design of the overall structure of the mechanical arm with large stiffness and telescopic ratio of 1: 7. Therefore, an efficient working robot for the all-round cleaning of the inner wall of the ash silo was developed. Based on the depth analysis of the intrinsic structure of the cascade arm and the internal and external coupling force system of the mechanical arm combined with Castigliano's second theorem and the principle of linear elasticity, an overall stiffness model of the variable length mechanical arm under complex alternating loads was established. Considering the stress distribution characteristics of the mechanical arm under extreme working conditions, through the periodic topology optimization of hole shape of each discrete sub region in the low stress region, a global stiffness optimization method of the mechanical arm under severe mass constraint was proposed. The performance simulation and test results showed that the mass of the mechanical arm was greatly reduced after optimization, and the mechanical arm had ideal telescopic interval and stiffness characteristics. There was a certain deviation between the simulation value and test value of the end offset of the mechanical arm, which was caused by the machining and assembly errors of the mechanical arm. The research results provide an important reference for the structural design and stiffness optimization of ash silo cleaning robot.

Aiming at the problem of lower computational efficiency in the sensitivity analysis of aerodynamic characteristics of wind turbine airfoil, a sensitivity analysis method of airfoil aerodynamic characteristics based on number theoretical net (NT-net) method and Morris method was proposed. Firstly, a airfoil parameterized model with higher fitting accuracy was constructed; secondly, the calculation principle of NT-net method was described and the method was used to sample polynomial coefficients of airfoil parameterized model; then, taking wind turbine airfoil S832 as research object, global sensitivity analysis of airfoil aerodynamic characteristics was carried out by Morris method; finally, the influence of polynomial coefficients of parameterized model of wind turbine airfoil on airfoil profile and aerodynamic characteristics under specific conditions was further analyzed. The results showed that main factors affecting airfoil aerodynamic characteristics were maximum relative thickness, maximum relative camber, leading edge radius and trailing edge thickness of airfoil. When the angle of attack of the incoming flow was smaller, taking the appropriate smaller value of the maximum relative thickness and the maximum relative camber, and taking the appropriate larger value of the leading edge radius could effectively improve the aerodynamic characteristics of wind turbine airfoil under that working condition, and also verified that the calculation efficiency of NT-net method was higher. The research results provide a theoretical reference for the aerodynamic design of wind turbine airfoil.

When the PDC (polycrystalline diamond compact) bit breaks rock in the strong abrasive formation, its drill teeth rub violently with cuttings and rocks while scraping and breaking the rock, and the generated local high temperature accelerates the wear failure of drill teeth, which will greatly shorten the service life of the whole bit. Therefore, exploring the influence of temperature on PDC bit wear and improving its hydraulic structure is of great significance to enhance the footage depth of a single bit and reduce the drilling cost. To this end, the relationship between temperature and wear was verified through drill tooth cutting experiment, and the PDC bit bottom hole thermal-fluid-solid coupling model was established on the basis of considering the flow state of bottom hole drilling fluid and the convective heat transfer between the drilling fluid and the drill teeth, and then the interaction between the bottom hole drilling fluid and the PDC bit was analyzed. At the same time, optimization measures for the hydraulic structure of the original PDC bit were proposed. The results showed that: 1) the phenomenon of temperature rise was very obvious in the cutting process of drill teeth, which indicated that temperature was an important factor affecting the wear of PDC bit; 2) the bottom hole flow field of PDC bit was in the state of thermal-fluid-solid coupling, and the flow state of drilling fluid had a great influence on the heat transfer of its drill teeth, which provided a optimization direction for the hydraulic structure of the PDC bit; 3) by adjusting the hydraulic structure such as the flow and angle of the nozzle, the average temperature of drill teeth was reduced, and the wear of PDC bit could be effectively improved. The research results have important guiding significance for the optimal design of drill bits in strong abrasive formations.

The dynamic characteristics of hydrostatic thrust bearing directly determine the stability of its operating state, and the recess structure and throttling pattern are important factors affecting its dynamic characteristics. Therefore, based on the small perturbation method, the Reynolds equation of annular recess hydrostatic thrust bearing was decomposed into dynamic equation and static equation, and then the analytical expressions of its oil film stiffness and damping coefficient under the throttling patterns of orifice and capillary were obtained. At the same time, the correctness of theoretical calculation results was verified by oil film stiffness measurement experiment, which showed that the relative error was less than 15%. The theoretical calculation results showed that： for the hydrostatic thrust bearing, the annular recess was better than the circular recess, and the orifice throttling was better than the capillary throttling. By analyzing the influence of the area and position of recess on the oil film stiffness and damping coefficient of annular recess hydrostatic thrust bearing with orifice throttling, it was found that when the internal and external diameters and other basic structural parameters were determined, the dynamic characteristic coefficients of this bearing could be effectively optimized by adjusting the area and position of recess. The research results were conducive to the structural optimization design of hydrostatic thrust bearings with dynamic characteristics as target.

In the process of shale gas exploitation, the shale gas in the cylinder of the compressor host is rapidly compressed in a short time, resulting in high shale gas pressure and large fluctuation, and fast unit speed. As a result, the host is subjected to a variety of complex and periodic excitation loads, and the host and its components produce complex vibration, which seriously affects the working reliability of the compressor. Therefore, taking large reciprocating compressor host as research object, combining the transient response analysis with experimental test, the vibration research of the compressor host was carried out. The vibration simulation and test results of the host showed that the largest vibration deformation of the host was 0.09 mm at the end of the fourth cylinder; the maximum stress of the host was 29.66 MPa at the connection between the primary air intake buffer tank and the fourth cylinder; the vibration intensity of the free end of the secondary air intake buffer tank of the host in the reciprocating direction was the largest, which was 14.75 mm/s. In this state, the vibration intensity met the requirement, and the vibration of the host was in a safe state; the maximum error of vibration intensity obtained by simulation and test was 12.7%, which was within the allowable error range of the project, and verified the rationality and correctness of the simulation method. The research results provide a reference for further reducing the vibration and optimizing the structure of the compressor host.

In order to verify the structural strength of limb-leg systems of the limb-leg crawler foot mechanism, taking the single limb-leg system as the research object, the dynamics model of its lifting condition was established based on the Lagrange method, and the expressions of driving torque of its upper and lower limb joints were derived and verified. At the same time, through the dynamics simulation of single leg lifting condition of the limb-leg crawler foot mechanism, the time-domain variation law of the force on each hinge point of its supporting leg and lifting leg was revealed, and the strength of the lifting leg with large force was simulated by finite element method and verified by experiment. The results showed that, under the single leg lifting condition of the limb-leg crawler foot mechanism, the maximum stress of the upper limb of the lifting leg was 165.9 MPa, with a safety factor of 3.04, and the maximum stress of the lower limb was 122.9 MPa, with a safety factor of 2.81, which met the strength requirements during the lifting process of a single leg; the relative error between the simulated value and the test value of the maximum stress at each hinge point of the lifting leg was within 18%. The research results verify the correctness of the dynamics analysis method for the leg lifting condition of the limb-leg crawler foot mechanism and the safety and rationality of its structure, which can provide a reference for the design and application of other limb-leg mechanism.

Aiming at the problem that the transmission torque decreases or even the magnetorheological fluid fails due to internal heat accumulation in the magnetorheological clutch during slip operation, the temperature distribution characteristics of a multipole magnetorheological clutch with excitation coils and permanent magnets superimposed were studied by combining simulation and experiment. Firstly, the heat source of multipole magnetorheological clutch was analyzed, and its temperature field mathematical model was established. Then, the finite element simulation method was used to simulate and analyze the temperature field of multipole magnetorheological clutch under the conditions of natural heat dissipation and forced air-cooling heat dissipation. Finally, the multipole magnetorheological clutch experimental platform was built to carry out the temperature characteristic test experiment. The results showed that the maximum allowable slip power was 160?170 W when the multipole magnetorheological clutch operated continuously under the condition of natural heat dissipation; under the condition of forced air-cooling heat dissipation, the maximum allowable slip power was 730?830 W; if the instantaneous slip power was 3 000 W, the allowable slip time was 280 s without failure of magnetorheological fluid. Regardless of the transient or steady state conditions, the lowest temperature of the multipole magnetorheological clutch occurred at the shaft end of the power input disc far away from the outer housing, and the highest temperature occurred at the second magnetorheological fluid working gap. When the way of forced air-cooling heat dissipation was adopted, the temperature rise speed of the multipole magnetorheological clutch decreased, so as to prolong its slip operation time. The research results provide a theoretical reference for the study of temperature distribution characteristics of magnetorheological devices.

Solar energy independent power supply is one of the important ways to solve the power supply problem of long-term field observation activities in the Antarctic region. According to the specific environment of polar region, a mobile photovoltaic (PV) power supply device based on container was designed. Firstly, the calculation model of solar radiation on the inclined plane of PV modules under the constraint of structural integration was constructed, and the optimal inclination angle of PV modules was determined; secondly, CFD (computational fluid dynamics) method was used to analyze the wind load of PV modules at the optimal inclination angle and different wind direction angles, and the typical wind load conditions of PV modules were determined; finally, the mechanical properties of PV bracket under typical working conditions were analyzed by finite element method. The results showed that for the integrated double row PV modules, the optimal inclination angle of the upper and lower rows of PV modules were 29° and 39° respectively. There were three typical working conditions for PV modules: when wind direction angle was 20°, all PV modules were subject to downward pressure; when wind direction angle was 120°, one row of PV modules was subject to downward pressure and the other row was subject to upward lifting; when wind direction angle was 140°, both rows were subject to upward lifting. Under three typical working conditions, the maximum stress of the PV bracket was 103.93 MPa, and the safety factor was 2.98, which met the strength requirements; the hinge joint of 2 rows of PV brackets had large deformation, with the maximum value of 4.33 mm; the bracket deformation distribution was greatly affected by wind direction, in which the deformation on the windward side was up to 3.7 mm, and the deformation on the other side was less than 1 mm. The research results can provide some reference for solving the power supply problem of long-term field independent observation activities in the polar region.

In order to make up for the deficiency of simulation ability and test accuracy of rotor airfoil dynamic test in high speed wind tunnel at domestic, based on the FL-20 continuous transonic wind tunnel, a method of dual-end synchronous driving rotor airfoil test model was proposed, and a dynamic test equipment for the high speed wind tunnel was designed. The equipment relied on the way of dual-balance dynamic load measurement combined with surface dynamic pressure measurement, which could improve the dynamic aerodynamic load measurement accuracy of rotor airfoil. The wind tunnel test results showed that: when the pitch oscillation amplitude of rotor airfoil test model was 10°, its oscillation frequency could reach 17 Hz, the test Mach number was 0.6, and the Reynolds number was 5×10⁶, which was at the international leading level. The developed dynamic test equipment and its related test technology have high reliability, and the test data is reliable and its law is reasonable, which has the ability to carry out high speed wind tunnel dynamic test. It can provide important technical support for the research of rotor airfoil dynamic stall and the simulation of real helicopter test parameters.

FISH (fluorescence in situ hybridization) staining is an important technique applied to pathological analysis. Traditional manual staining method is difficult to control hybridization quality due to the cumbersome operation and the limitations of experimental conditions, while the existing domestic staining system has the disadvantages of low degree of automation. In order to solve the above problems, a fully automatic pathological staining control system was developed based on STM32 embedded system and GUI (graphical user interface). With STM32F103ZET6 as the lower processor, GUI interface designed by QT software and C++ language, the system realized the fully automatic control of multi-sample FISH staining process. The developed control system could meet the control requirements of the fully automatic pathological staining system. The position accuracy of the dropping reagent could reach 0.05 mm, the reagent volume accuracy could reach 0.6 μL, the equipment fault response time was less than 0.5 s, the failure rate of equipment in multiple experiments was less than 3%, the accuracy of reagent type selection during sample addition reached 100%, and the image legibility rate was more than 90%. The control system has the advantages of high efficiency and high robustness. Combined with the fully automatic pathological staining hardware system, the staining experiment could achieve a uniform and good staining effect. So, it has good application value.

In order to deeply understand the working characteristics of the swing system of concrete wet spraying machine, according to the structure and working principle of the swing system, the bond graph model and dynamic equation of the swing system were established by taking into account the motion response time of components such as the internal valve core of hydraulic element. The working characteristics of hydraulic components such as constant pressure pump, accumulator and electro-hydraulic directional valve were simulated and analyzed in the process of swing arm movement, and a swing arm swing test platform was built for experimental verification. The research results showed that the swash plate of constant pressure pump was in a maximum inclination angle state before swing arm movement reached a stable state. The high-pressure oil pumped out was used for the movement of left and right swing cylinders and the charging of the accumulator. The pressure of the accumulator gas chamber gradually increased with the increase of swing times of swing arm and finally stabilized at 14 MPa; after the swing arm movement reached a stable state, the inclination angle of the swash plate of the constant pressure pump changed periodically at 0°-19°, and the maximum instantaneous flow of the accumulator discharge reached 322.5 L/min, and the S-shaped distribution valve could realize the reversing within 0.24 s; the test results of the working pressure of the rodless cavity of swing cylinder were basically consistent with the simulation results, which verified the accuracy of the established model. The research results provide a reference for the further optimization of the swing system of wet shotcrete machine.