In order to solve the problem that the trajectory is not straight when piecewise polynomial interpolation method is used to plan the trajectory of excavator's linear operation in joint space, which leads to the inaccurate trajectory, this paper proposes a quintic polynomial interpolation method based on multidimensional trajectory to realize the accurate trajectory of excavator's linear operation. While using Matlab to draw the relevant images in motion, ikunc function is used to optimize the inverse solution of each point in the motion process, and joint Angle trajectory smoothing algorithm and particle swarm optimization algorithm are used to verify the minimum change of joint Angle in the optimal inverse solution of ikunc function. It is verified that the ikunc function is correct to obtain the minimum and best inverse solution of the joint Angle change, which indirectly achieves the energy optimal effect.

In recent years, intelligent control technology has occupied an increasingly significant position in the field of modern engineering research. With the rise of artificial intelligence technology, it provides more possibilities for construction machinery to realize intelligent control. In the development process of intelligent technology, the control accuracy of construction machinery system is improved, industrial production is more reliable and safe, and the production efficiency of enterprises is improved. This paper starts from the content of intelligent control technology, introduces various intelligent control technology theories and methods, and discusses the application of intelligent control technology in various construction machinery according to intelligent technology methods. At the same time, the key problems and technical system of future construction machinery under intelligent control are analyzed and studied, which provides reference for the intelligent development of construction machinery control technology.

In order to deal with the problems of single evaluation criteria and too subjective weight allocation in the evaluation scheme of module division, the evaluation criteria and calculation methods of module degree, module replaceable and module structural integrity of the product module division scheme were proposed. On this basis, multiple secondary evaluation indicators of module division were proposed to determine the weight allocation among evaluation criteria. The optimal and worst many criterion decision model in the distributed multiplicative preference environment is applied to determine the weight distribution of the relevant parameters in the method, and the will of all decision makers is comprehensively considered to make the final module division scheme more objective. Finally, the module division of the excavator working arm is used to verify the feasibility of the method.

To achieve rapid prediction of aerodynamic noise in the rearview mirror area of vehicles, an stochastic noise generation and propagation (SNGR) method is adopted. Unlike general aerodynamic noise simulation methods, this method is based on the reynolds-averaged navier-stokes (RANS) equation to solve the steady flow field, reconstructing the sound source term through a velocity random model, and finally using the finite interpolation method to solve the acoustic analogy equation, greatly reducing the computational period of aerodynamic noise simulation. Based on actual vehicle data, a wind tunnel model is established, with a speed of 120 km/h as the simulation condition. Under the same conditions, the SNGR method and the general unsteady method using large eddy simulation as the flow field calculation model are respectively used for simulation. The results show that the calculation time of the SNGR method is greatly reduced, and the calculation results are consistent in the frequency range of 500-5 000 Hz, proving the efficiency of this method. On this basis, the flow field results in the rearview mirror area are analyzed, and the design of the car rearview mirror is optimized based on the principle of aerodynamic noise generation. Install the rearview mirrors before and after optimization on the entire vehicle for wind tunnel experiments, and verify the accuracy of the SNGR method calculation results by comparing the sound pressure level reduction before and after rearview mirror optimization. The simulation and experimental error of this method is between 4%-5%, proving that this method can be used in the optimization stage of aerodynamic noise performance of vehicle rearview mirrors.

Aiming at the problems of multi-dimensional small failure probability and implicit function in the reliability analysis for bridge crane structure, that is difficult to solve using traditional reliability analysis methods, the one based on dynamic Kriging surrogate model combined with important sampling method is proposed. Firstly, the dynamic Kriging surrogate model of the implicit function is constructed utilizing two learning functions, and then the most probable failure point (MPP) is obtained by using the improved first order second moment method combined with the Kriging surrogate model. Secondly, the importance sampling density function is constructed with the MPP as the central point. Finally, the reliability degree is calculated by the importance sampling method based on the established surrogate model. By introducing a new stop criterion combined with learning function, the number of finite element calls is reduced. Verified by an engineering case, the proposed method can well balance the model accuracy, result error and calculation cost.

Middle outrigger is the main support leg of tunnel erecting machine, and hydraulic system plays an important role in the erection process of prefabricated utility tunnel sections. To solve the problems of slow action and low positioning accuracy of hydraulic cylinder of middle outrigger, the hydraulic system of tunnel erecting machine is optimized through on-site experiments and AMESim simulation analysis. According to the erection process and hydraulic system principle of tunnel erecting machine, a preliminary analysis and on-site measurements of original middle outrigger hydraulic system are conducted, and an optimized system scheme applying high-frequency response proportional valve and accumulator is proposed. Then, the reasonable accumulator working parameters of optimized hydraulic system are explored, and the high-frequency response proportional valve control strategy based on feedforward compensation is studied. Finally, the optimized hydraulic system is simulated and compared with measurement data. The results show that the combination of high-frequency response proportional valve and accumulator can significantly improve the response characteristics and position control accuracy of hydraulic system. The hydraulic cylinder displacement of optimized system is increased by 82.2% within 0.5 s of system startup, and the maximum hoisting positioning error is ±2.0 mm, which can meet the erection and installation requirements of utility tunnels.

For the nut connection problems of narrow and deep cavity, invisibility, no access to traditional operating tools of aero-engine rotor, a new automation assembly method is advocated based on the image recognition and laser assisted positioning technology. The automated blind assembly torque device is developed with the functions of automatic folding of wrench head, accurate positioning, rapid nut recognizing, and electric loading, which can enter the narrow and deep operation space that is invisible to naked eye, to solve the low-level errors caused by artificial missing and wrong nuts, avoiding collision and damage on the inner wall of the shaft cavity. The device can carry out the compound tightening strategy with torque and angle to achieve the accurate automatic connection of engine rotor nut all the time, and the %GageR&R and %P/T of system precision are %22.21, %3.78 respectively through the test of automatic blind nut assembly, which will increase the accuracy and consistency on the large degree, which will lay the important foundation of the working stability and reliability of aero-engine farther.

The paper introduces mechanical character of boom for luffing jib crane, structural form and construction type of the inverted-Y boom are explained. A conversion section is arranged in the middle of the boom, the hoisting or luffing wire rope enters the boom head after bypassing the conversion section, the load of the boom is reduced by the pull of the wire rope. The example of derrick crane with maximum rated lifting capacity of 500 t is given, calculation of the boom shaft pressure, boom dead weight bending moment, wire rope tension and other loads on the boom chord of the magnitude of the axial force exerted, and analyze its proportion. It shows that the effect of hoisting or luffing wire rope can effectively reduce the dead weight bending moment of the boom, and offset part of the boom chord and belly rod axial force, improve the overall stability and bearing capacity of the boom, thus the design of the boom is optimized.

In order to improve the operating efficiency of excavator hydraulic system, a pump-driven valve-controlled load sensing system was designed. Pressure sensors are installed at the inlet and outlet of the multi-way valve respectively to perform real-time pressure feedback instead of the pressure compensation valve of the load sensitive system to achieve pressure compensation, and dynamically adjust the position of the main valve core and the swash plate swing angle of the electro-hydraulic proportional pump to drive the action of the hydraulic cylinder. The valve-controlled cylinder system in the pump drive valve control system is analyzed theoretically and the mathematical model is established. The experimental platform is designed with proportional valve test bench, BODAS controller and other electronic control and acquisition components, and the principle test of pump drive valve control is carried out, which verifies the correctness of the simulation model and pump drive valve control principle. The results show that when the system is in the pump drive valve control program, the output flow rate changes abruptly with the load change of step rise under different pressure differences. With the continuous increase of load pressure, the flow mutation becomes larger and larger, and the error between the output flow and the set flow also increases.

In shield construction, the tunneling attitude of the shield tunnel is an important parameter affecting the quality of the tunneling, which directly affects the track and the quality of the tunnel. Taking an earth pressure balance tunnel boring machine (TBM) as an example, the relationship between the weight of the main machine and the earth pressure and the bearing capacity of the foundation is determined from the theoretical level at the design of the shield machine, which is based on the analysis of the floating and sinking. The influence of the uneven mass distribution on the center of gravity is further analyzed. Finally, through the comprehensive study of the relationship between the force of the host and the thrust of the cylinder under the soil pressure model, the necessary conditions for the control of the driving attitude of the shield machine are determined. The results of this paper have important practical siginificance for improving the design and manufacturing of the shield machine and the construction level of the shield method in China.