Abstract:Stainless steels and PEEK composites are frequently used in key friction pair of seawater hydraulic components. The stainless steel has an important influence on tribological properties of stainless steel/PEEK composite pairing. Focused on AISI 316L, AISI 630 and S32750, tribological tests were conducted under seawater lubrication. Friction coefficient and wear rate of the three kinds of stainless steels sliding against PEEK were comparatively investigated. The tribological mechanism of the friction pairs were explored through observing and measuring the worn surfaces of samples.It is shown that the average friction coefficients of the three kinds of stainless steels have little difference; compared with AISI 316L, wear resistance of S32750 and AISI 630 is admirable, and wear rate of AISI 630 is less affected by load; wear resistance of S32750 and AISI 316L is positively correlated with their hardness, while high carbon content in AISI 630 will weaken its corrosion resistance and affect its friction and wear properties in seawater.The research provides reference for selection of stainless steel material in key friction pair of seawater hydraulic components.

Abstract:Aiming at the problem of oil-starvation lubrication of floating ring bearings, based on Reynolds equation, the starvation lubrication model of floating ring bearings was established. The mathematical model was solved by finite difference method with variable oil supply at the inlet of lubricating oil. The influence of oil supply on the static characteristics of oil film force for inside and outside floating ring bearings was analyzed. The results show that the oil supply obviously affects the starting angle of lubricating oil film force and bearing ring velocity ratio,and the friction power consumption increases with the decrease of oil supply of floating ring bearing.

Abstract:The swing hydraulic motor has a large power density ratio and a fast dynamic response, and has a wide range of applications in the field of servo simulation turntables. In order to drive the load to swing in the range of 100°,the swing hydraulic motor based on ADINA software was analyzed, and the test bench was established to conduct the position control experiment of the swing angle.The experiments show that the maximum speed of the oscillating hydraulic motor is 90°/s and the minimum speed is about 0.02°/s in the test system. Based on the test bench, the sealing performance and control strategy of the oscillating hydraulic motor can be further studied.

Abstract:The stiffness of the intermediate shaft connected between the two stages affects the working condition of the planetary gear drive system. The secondorder spur gear system of a test bed was used as the research object, and the secondorder gear shifttorsion dynamic model was built, the influence of the change of the stiffness of the intermediate shaft on the dynamic characteristics of the system was discussed. The results show that the change of the stiffness of the intermediate shaft is more obvious for the dynamic load of the adjacent two teeth connected by the intermediate shaft. With the increase of the connecting stiffness of the intermediate shaft, the dynamic load of the tooth is gradually decreased. At the same time, the influence on each frequency component and its frequency doubling is obvious, and the energy of each frequency component and its frequency multiplication component decreases linearly with the increase of connection stiffness. The change of the stiffness of the intermediate shaft connection causes the natural frequency of the system and its mode to produce mode transition.

Abstract:In order to improve the machining accuracy of the permanent magnet synchronous spindle, reduce vibration, reduce its electromagnetic noise，considering the influence of the harmonic magnetomotive force, the analytical expression of the airgap flux density of the permanent magnet synchronous motor was derived and the calculation accuracy of the radial flux density of the permanent magnet synchronous motor was improved.Radial flux density and its harmonics were calculated by analytic method, and radial electromagnetic force was solved by finite element method.The threedimensional model of the permanent magnet synchronous spindle was established and mode analysis and harmonic response analysis were carried out. The vibration acceleration of the spindle was measured.The model electromagnetic force frequency and modal analysis results were compared with the measured vibration acceleration spectrum. The results show that the radial electromagnetic force is the main cause of vibration. Resonance is the main factor of noise.By optimizing the structure of the permanent magnets, the radial electromagnetic force of the permanent magnet synchronous motor spindle is reduced. The noise reduction is verified by the noise simulation analysis.

Abstract:The technology of concrete dismantling with ultrahigh pressure water has a prominent advantage relative to traditional mechanical operation. The Bernoulli equation was used to analyze the process of ultrahigh pressure water breaking concrete. The relationship between pump pressure parameters and ultrahigh pressure water of concrete surface was established. On the basis of the experiment， the relationship between the parameters of the ultrahigh pressure water concrete dismantling and the effect of dismantling was investigated. The results have a certain reference significance for the analysis and application of ultrahigh pressure water concrete dismantling.

Abstract:In order to improve cooling and lubrication effect of little quantity lubrication, air jet assisted little quantity lubrication (AJLQL) was put forward and milling experiment of aviation aluminum alloy 7050T7451 was carried out by using AJLQL system. A comparative study of dry cutting, AJLQL cutting and flood lubrication cutting was conducted based on cutting force signals. The results show that the cutting force under dry cutting condition is larger than that of AJLQL cutting. With the increase of cutting fluid flow rate, the lubricating ability of airliquid two phase coolinglubrication medium increases, which results in the decrease of cutting force. Comparison of cutting force between AJLQL cutting and flood lubrication cutting shows that the cutting force of AJLQL cutting is smaller than that of flood lubrication cutting, which indicates that the lubrication effect of AJLQL is better than that of flood lubrication, but the cutting fluid usage is only 3% of the latter.

Abstract:In order to prevent the manhole cover to be stolen and destroyed, a detection method based on sound signal processing, which was for detecting the behavior of stealing and destroying manhole cover, was proposed. Because there were differences in the distribution of energy in frequency between different sound signals, the vibration sound signal generated by the manhole cover was transformed into the energy spectrum by using FFT method. Specific distribution interval on the frequency axis and distribution threshold of the vibration sound signal could be determined by using statistical method. It could be judged whether the vibration sound of the manhole covers was caused by the robbery and knocking by calculating the probability distribution value in the specific distribution interval of 20 maximum energy points of other interference sound signals. Experiment result indicates that the energy distribution of the percussion sound is significantly different from other interference sound. The characteristic frequency range of its energy distribution is 48~504 Hz and the distribution threshold is 85%. The method can be used to effectively identify the sound of stealing and destroying the manhole cover and has strong robustness under a certain SNR environment.

Abstract:The machining of titanium alloy Ti17 with WC/Co cemented carbide cutting tools under the traditional cutting and highpressure water jet assistance cutting methods was introduced, and a comparative analysis was made.Under the different cutting speeds and the water jet pressures, the evolution of tool wear and the changes of cutting forces and axial force were studied,the corresponding discussion was also carried out. The optimum water jet pressure and cutting speed were determined by experiments between cutting speed of 50~100 m/min and water jet pressure of 5~25 MPa. When the water jet pressure is 10 MPa，the best cutting speed is 8140 m/min.Compared to conventional lubrication,the tool life is increased by about 9 times and the efficiency is increased by about 30%.

Abstract:In order to quickly and effectively destroy the powder arch formed above the outlet of the hopper, a convergentdivergent nozzle which could form a high speed air jet was designed. The influence of nozzle structure parameters on air jet velocity was analyzed by using CFD simulation and orthogonal test. The nozzle with conical degree of 60°, throat diameter of 2 mm and inlet diameter of 12 mm was selected. The test results are in good agreement with the numerical simulation results, and the average relative error is 48%. It is proved by experiments that the air jet can break the arch effectively and quickly. The jet penetration region simulated by Fluent is the same as experimental result. The process mechanism of air jet penetrating the powder is revealed, which can provide theoretical guidance for reasonable layout of jet nozzle to break arch.

Abstract:Based on the principle of vibration drilling machining, the mathematical model of average drilling force in the process of vibration drilling was established, and a measurement test of the force of conventional drilling and vibration drilling of micro deep hole on 0Cr17Ni4Cu4Nb stainless steel material was carried out on the ultrasonic axial vibration drilling experimental device, and the influence law of feed rate on drilling force and bit wear was analyzed through the test. The test results prove that the drilling force in the vibration drilling is obviously less than that of the conventional drilling, but the drilling force curve is gentler. With the increase of feed rate, the drilling force increases gradually as well as the bit wear increases in the process of vibration drilling.

Abstract:PCBN tools were used for highspeed milling of TC4 alloy based on single factor experiment. Cutting force and cutting vibration were measured and analyzed with different cutting parameters. Cutting parameter optimization method was proposed considering cutting force, cutting vibration and surface roughness. The results show that with cutting speed and feed per tooth increasing, the cutting force and cutting vibration have a certain fluctuation. As the radial cutting depth and axial cutting depth increasing, the cutting force and cutting vibration increase. The cutting force has a significant influence on cutting vibration. Considering the cutting performance, the cutting parameters optimization model was established, taking the maximum rate of metal removal as optimization objective, the cutting force, cutting vibration and surface roughness as the constraint conditions. The optimized cutting parameters under different constraints condition were obtained.

Abstract:According to highprecision measurement needs, a hierarchical adjustment of automatic leveling device was developed. The automatic leveling device comprised a twolayer angle adjusting mechanism arranged up and down, each of which included a servo motor and the electronic level measuring the level deviation of the twoangle angle adjusting mechanism in the corresponding direction, and the measured value was fed back to the computer terminal.The computer terminal was connected to the upper and lower two servo motor,and the servo motor was driven by the feedback value. The leveling time is 1″, and the leveling time of the whole optoelectronic equipment is about 120 s.The experimental results show that compared with the conventional leveling system, the system shortens the preparation time of the photoelectric equipment and improves the leveling accuracy.

Abstract:In order to realize the detection and feedback control of the processing position of drip holes in drip irrigation tape with labyrinth emitters inlaid, the machine vision was used to detect the position of drip holes, and a optimized recognition algorithm based on multiple depth extraction of ROI from ROI in the image whitening area was proposed. Firstly, ROI was extracted preliminarily by removing the background. Secondly, ROI of drip irrigation tape image in whitening region was extracted by applying algorithms of global fixed threshold segmentation, dilation, closed operation and region growing. Thirdly, the global threshold segmentation algorithm based on histogram was used to improve the image edges, and the Hough circle transform was used to extract the position of drip hole, and the Hough line transformation and additional constraint conditions were used to detect the position of labyrinth emitter front edge.Finally, the relative distance from the drip hole to the front edge of labyrinth emitter could be calculated. The experiment results show that with the optimized algorithms, the accuracy of drip holes identification is over 98%, and the distance measurement error is reduced from more than 10% before optimization to about 5%.

Abstract:At present, the research on hydraulic power chuck in our country is relatively backward, especially the lack of research on mechanics characteristics seriously affects the improvement of clamping force and transmission accuracy of chuck, which seriously restricts the development of CNC machine tools in our country. Therefore, the research on mechanics characteristics of the hydraulic power chuck is imminent. The method based on ANSYS software was presented to analyze the mechanics characteristics of the hydraulic power chuck. The contact methods of the wedgecore sleeve, disc body, slide and workpiece were defined, the bolt links were simulated, and under the working load, the stress and displacement of the chuck were analyzed. It lays foundation for failure analysis. In addition, the clamping force was analyzed by ANSYS. The analysis results were compared with the test results and theoretical calculations to verify the correctness of the proposed analytical method of mechanics characteristics.

Abstract:The hydrostatic guide stiffness is one of the key indicators to measure the performance of the guide. The hydrostatic guide with fixed liquid resistance were used as the research object, and the mathematical equations for the hydrostatic guide stiffness, oil film displacement ratio, and initial liquid resistance ratio were derived through theoretical derivation. The results show that with the increase of the initial liquid resistance ratio, the guide shows a distinct stiffness peak, the peak increases with the increase of the initial liquid resistance ratio, and moves to the right. As the stiffness peak increases, the bearing capacity of the guide decreases, and the system overflow loss increases. A method for determining the optimal initial liquid resistance ratio based on the stiffness of the guide under loading conditions is proposed, which provides a basis for improving the overall performance of the hydrostatic guide.

Abstract:Caged regulating valve technology development is started late in our country. The traditional design process often depends on empirical formula. There is a great error between the experimental results and the design requirements of the product. Therefore, taking the sleeve of caged regulating valve as the design object, based on the theorem of orificeplate flowmeter, general formulae for the cross section of sleeve and cross section area under different opening of sleeve of four kinds of flow characteristics(linear flow characteristics, equal percentage flow characteristics, parabolic flow characteristics and fast open flow characteristics) were obtained. The model was built and simulation was made with FLUENT software. The experimental values of the relative flow of the regulating valve under different open degrees were compared with the design values. The simulation results show that the design method is reliable when the control valve opening is 30%~80%, which not only meets the design requirements effectively, but also has short design cycle, low cost and high accuracy. In addition, through the general area formula of the caged regulating valve’〖KG-*2〗s sleeve, sleeve with specific requirement can be gotten through change the pressure value of the inlet and outlet of the sleeve and different inherent flow characteristics, so it has certain engineering application value.

Abstract:Aiming at the problems of slow processing speed and serious environmental pollution in hand washing and processing technology, an automatic laser washing technology combined with NC technology and laser machining was designed. A kind of method based on digital integral（DDA） method and square interpolation algorithm was designed, ensuring better accuracy under the condition of reducing redundant interpolation trajectory, improving the interpolation arithmetic speed and machining efficiency, reducing frequent startstop of motor, ensuring stability and effectiveness of the system.The dynamic simulation system of curved image was developed in VB60 programming software.The image graph was processed by laser processing on the surface of jeans, the disadvantages of washing water technology was solved, machining efficiency was improved, so batch production could be realized. The realization of laser water processing technology provides reference for design and manufacture of laser washing water.

Abstract:Industrial Ethernet fieldbus EtherCAT is widely used in the field of motion control due to its high speed, high efficiency and good synchronization.Based on X86 platform, a design scheme, design flow and implementation flow of EtherCAT master were proposed. The control network was composed of EtherCAT master, servo controller and servo motor. It was discussed in detail the master kernel transformation, the master process of parsing XML files from the slave station and the clock distribution mechanism for master/slave precise realtime synchronization of EtherCAT.The experimental results show that the developed master is stable and reliable in real time and the error of multiaxis synchronization is on the nanosecond level, which meets the performance requirements to the EtherCAT master in industrial applications.

Abstract:The existing medical device products are generally determined by setting the size of the model, so the products may not fit with the body parts of the patient, resulting in unconspicuous protection and rehabilitation effect. By using reverse engineering technology, the personalized medical device design method based on Geomagic Deign X was proposed. Taking the design of foot brace as an example, by scanning the human foot with a body scanner, the point cloud data were processed，the surface model of the foot was generated via mesh fit. On this basis, the needed surfaces were cut out to get the basic model of the device, then the subsequent design was completed according to the requirements of patients and doctors. The combination of reverse modeling and forward design is realized. It provides a convenient and efficient method for the design of personalized medical device products.

Abstract:To improve the efficiency of solar energy device for solar receiving, a new sun tracking device adopting parallel mechanism was put forward. The kinematics model was established by the position closedloop vector equation,the velocity Jacobian matrix was deduced, the agency’〖KG-*2〗s flexibility performance evaluation index was defined; the task working space of the sun tracking device was drawn,the relationship between the parameters was optimized by given constraint conditions in its task working space. It lays foundations for the device structure design.

Abstract:A new type of the optical fiber fluid pressure sensor was designed and studied. Firstly, the sensor system was designed based on the principle of intensity compensation, and the compensation model of the sensor system was established. Then, the optical 〖JP2〗fiber fluid pressure sensor probe based on piston structure was presented, and the mathematical model of sensor was established. Finally,〖JP〗 on the basis of theoretical analysis, the sensor was studied, and the p-M curves under different structural parameters NA、l、d values were obtained.The experimental results show that there is a linear relationship between the output value of the sensor and the pressure p, and the sensor has good sensitivity. The results show that the sensor can meet the requirements of different occasions.

Abstract:Networked remote control of workshop information brings user convenience while accompanied by security risks, in order to eliminate the potential threat of mobile terminal access workshop information system communication process, in view of the possible security problems in mobile terminal access workshop information system, the security mechanism of identity authentication, access control, abnormal behavior detection, black and white list filtering and access to the audit was designed, and a three layer to protect the security of information system was established. The test results show that the designed security mechanism can effectively improve the security of the mobile terminal access workshop information system, and can prevent the possible malicious attacks on the mobile terminal access workshop information system.

Abstract:The principle of heave movement simulation was introduced.A heave movement simulation system controller was developed, including upper computer system and DSP controller in which DSP was used as the main processing unit. Through experiments, the sin type wave heave movement and P-M type heave movement were simulated.The experimental results prove that heave movement can be realized by using the heave movement simulation system based on DSP and the structure of the controller is scientific.

Abstract:Because of the advantages of small volume and convenient installation,the hydraulic retarder is used more and more widely in vehicle. A small hydraulic retarder and its hydraulic control system were designed. The control system is simple, compact and easy to operate and suitable for small vehicles. The rotary valve was adopted to control the inlet and outlet area of the retarder then to control the braking torque of the retarder.The rotary valve has the advantages of simple structure, quick response and small hydrodynamic force. The hydraulic retarder and its control system can provide stable auxiliary power for small vehicles, and the precise control of multiposition can be realized.

Abstract:Vacuum handling system which property directly affects working condition of palletizing manipulator is the important component of palletizing manipulator. A suitable solution for vacuum handling system is an effective way to improve efficiency of the palletizing manipulator. Based on SMC pneumatic components, for the palletizing manipulator, a solution that single vacuum suction combinated with single vacuum generator for vacuum handling system was proposed. Then corresponding diagnostic methods and treatment processes were given for its typical failures.

Abstract:Based on the analysis of the equipment structure and high speed operating condition of highspeed compression molding machines, the frequency control technology was used to control middle pressure mold closing, high pressure forming and low pressure demolding，and a hydraulic control system which could meet highspeed compression molding machines was developed.The practical application shows that the system has stable performance, fast response and good energy saving effect.

Abstract:To study the electromagnetic driven performance, temperature rise performance and micturition performance of the bladder power pump, 3D FE models of the electromagnetic driven system and the bladder power pump were established. Based on the models, the electromagnetic driven force, temperature rise, intravesical pressure, urine flow rate and urination time were investigated, taking into account the effects of the electromagnet current, air gap and number of permanent magnets. The results show that the 3D FE models are effective and practical; the electromagnetic driven force, intravesical pressure and urine flow rate are enhanced and the times of intravesical pressure peak and urination are reduced by increasing the current, number of permanent magnets and reducing the air gap; the initial electromagnetic driven force is 8.50 N, the maximum intravesical pressure is 8.36 kPa, the maximum urine flow rate is 25 mL/s, the time to intravesical pressure peak is 5 s, the urination time is 40 s, the temperature rise is 9.42 ℃, the results accord with the micturition performance of human.The research provides theoretical guidance for design of the bladder power pump for animal and clinical studies.

Abstract:In order to study the effect of two phases of hydroviscous drive on the fluid transmission characteristics of the friction film, also to reduce the two phase flow and improve the ability of the oil film to transfer shear torque, the flow field of oil film based on the VOF model was simulated numerically by fluid dynamics simulation software. The production and development rules of two phase flow regions in oil film flow field were gotten. The results show that the oil groove is the main area that produces two phase flow, and the air occupies a volume ratio of 1 to the side transition position of the oil groove near the outer diameter.What’s more, the production of two phase flow regions is mainly influenced by fluid pressure, and its production starts from near the outer diameter and gradually develops towards the inner diameter. The volume of air in the oil film flow field decreases with the increase of oil supply, but increases with the increase of rotational speed. The oil film transmitted torque increases with the increase of oil supply and input speed.

Abstract:In order to solve the problem of medical disputes caused by traditional massage training, a novel pneumatic human organ simulator was designed. A pneumatic drive system was developed and a thoracic/abdominal cavity simulator mathematical model was established. The influence of different factors such as pressure and compression displacement on the stiffness of thoracic/abdominal cavity simulator was analyzed. The experiment verified the validity of the model. The results show that the pressure of the simulator can simulate the thoracic/abdominal cavity stiffness of patients of different ages. The results provide a basis for the design of new teaching and training devices.

Abstract:Aiming at the requirements of dynamic performance test of servo actuator, giving full play to the advantages of electric loading, such as easy installation and maintenance, flexible control and high dynamic characteristics of linear motor，a scheme of the booster module driven by a linear motor was proposed to realize small displacement，large thrust force and highfrequency dynamic loading program. Based on the mathematic model of the loading system and the servo actuator system, a composite control scheme based on multiloop control and feedforward control was introduced to improve the force loading accuracy, stability and response speed of the system，the feedforward compensation scheme based on the invariance principle was used to restrain the redundant force. The simulation results of MATLAB/Simulink show that the dynamic loading control scheme of servo actuator can effectively improve the dynamic loading performance，restrain the redundant force and has good engineering reference value.

Abstract:In order to improve the stability and reliability of firefighting robot, a dynamic model of a new firefighting robot with single wheel suspension system was established by using the ADAMS. Based on the dynamics and impact collision principle of tracktype mobile robot, a stochastic pavement excitation model was established in MATLAB/Simulink, the plane mathematical model was simplified to build foundation and parameterizing analysis for the singlewheel suspension system was made. The kinematic analysis and dynamic simulation analysis under Dclass stochastic simulation pavement conditions were carried out to study the influence of the torsion barliquid damper on the performance of firefighting robot suspension system. The results show that the torsion barliquid damper suspension system model is simple, stable and reliable, with nonlinear, variable damping and other characteristics.

Abstract:In the power add and subtract system of high speed dynamometer, unbalanced dynamic load would be produced during absorption and testing of the power generated by the engine. Its strength and stiffness must meet the design requirements in order to absorbing vibration energy. According to the relevant technical requirements of high speed dynamometer, structural design of the mounting rack was completed, its calculation model was built based on ANSYS and the finite element analysis was done, ensuing the design of the mounting rack meet the requirements of stiffness and the lowest natural frequency. In addition, the inherent characteristics of the mounting rack in the load state of the equipment were obtained by test. The maximum error was less than 5%, comparing with the numerical results, which shaw the effectiveness of the numerical calculation method. Based on this, the dynamic response characteristics were studied systematically to ensure the safe operation of the engine unit.

Abstract:Expansion technique is widely used in oil and gas drilling field. Expansive force is the key technology parameter of expansion tool reasonable design in expansion technique field.Expansive force calculation model of the expansion pipe was established by stress method. For expansive force analytic expression was relatively complex, introducing hole enlargement factor, by changing the expansion cone angle, expansion vertebral body finite element model and expansion pipe finite element model were established. Adopting finite element analysis method with different friction coefficient, the expansive force of expansion tube was numerically simulated. Results show that the theoretical value and measured value of expansion force are consistent. Through the relationship between the expansion cone angle and hole enlargement factor with different friction coefficient, with the same friction coefficient, hole enlargement factor increases along with the expansion cone angle. When half expansion cone angle was 10°，expansive force was compared between the measured values and the values obtained by the optimized theory model. The results are basically consistent. It is proved that the optimized theory model is reasonable.The introduction of expansion coefficient simplifies the calculation of the expansive force, which provides convenience for the design of the expansion tool.

Abstract:The friction thermal deformation of guide rail during the reciprocating movement of linear guide rail was simulated. Considering the relative position between the guide rail and the slider, the influence of frictional heat on the thermal deformation of linear guide rail during the roundtrip movement was analyzed.The thermal load distribution of the linear guide pair was analyzed,the thermal strain finite element model was established, and the guide rail deformation under the load friction heat source was calculated.It provides guide for thermal error compensation in machining process.

Abstract:Taking the outside meshing spur gear as the research object, the meshing stiffness of fault gear was calculated by finite element method, the fault gear surface stress distribution characteristics and the load distribution on driving wheel tooth were analyzed, the impact of fault gear pairs with tooth root crack, tooth fracture, tooth surface pitting failure on meshing stiffness and the change of the meshing stiffness of the tooth crack gear caused by load change were studied. The analysis results show that the through crack gear meshing stiffness changes obviously than oblique crack gear, the single tooth meshing stiffness change is more prominent; under the condition of low load, crack fault tooth meshing stiffness increases as the load increases, the meshing stiffness tends to a fixed value when the load exceeds a certain value; the tooth fracture size affects the gear meshing stiffness heavily.

Abstract:In the traditional process of the aviation solenoid valve function detection, the test efficiency is low and error is big mainly due to the maintenance personnel manual test. A kind of situ traversal function test system for aircraft solenoid valve was designed.Using the test system, the control circuit of the solenoid valve was not disassembled or decomposed. The test cable and aviation solenoid valve test ports were directly connected in order to achieve situ test; through assigning matrix switch node and the measured port, all the test loops were closed to achieve traverse test.According to the electromagnetic valve fault simulation, data analysis and verification of the test results, the test system can be used to quickly test whether the function of the air solenoid valve is intact, and the test results are accurate and reliable.

Abstract:A reliability evaluation method based on mean time to first failure (MTTFF) was proposed for the CNC system reliability evaluation problem. The health status of 20 CNC machines which were equipped with FANUC 0i CNC system were monitored for 24 months, and the experimental data about first failure time were acquired. Then the distribution function parameters of the first failure time data were estimated. The interval of the distribution function was estimated based on Monte Carlo method, and the interval estimation value of the first failure time about the CNC system with high degree of confidence was gotten. This estimation value is of guiding significance to the reliability design and evaluation of CNC systems.

Abstract:According to the hydraulic requirements of the largescale gantry milling machine, on the basis of analyzing the loosening, shifting and shaft locking functions of the machine tool, the safe starting function of the hydraulic station of the machine tool was realized by optimizing the hydraulic system start control logic, and the reliability and stability of hydraulic system were improved.