In order to solve the problem of difficulty in testing and performance verification of compliant mechanisms in the process of optimal design, the mechanical properties of thermoplastic polyurethane (TPU) material were studied by 3D printing technology. The effects of material hardness and print fill rate on the mechanical properties of TPU material were analyzed, and the better 3D printing parameters of TPU material were obtained. Using single factor and two factor tset combined with variance analysis, the primary and secondary factors that significantly affect the flexibility of TPU specimens were identified as TPU material hardness and print fill rate. Combined with the mechanical property test data of TPU material, the mapping relationships between the material parameters and material hardness, print fill rate of four commonly used hyperelastic material constitutive models, i.e. Mooney-Rivlin, Yeoh, Ogden and Valanis-Landel, were obtained. The results showed that with the increase of TPU material hardness and print fill rate, the flexibility of the specimens decreased; among the four hyperelastic models, Ogden model has a good prediction effect on the mechanical properties of TPU specimens under different printing parameters; there was no significant difference in the predictive effect of the four models under the same TPU material hardness and different print fill rates. The research results can provide reference for 3D printing and finite element simulation analysis of TPU material, and provide reliable technical support for the test, performance verification and sample production of compliant mechanisms in the design process.

PDC (polycrystalline diamond compact) bit is the main rock-breaking tool in oil and gas drilling field, which has the advantages of high abrasion, high rate of penetration and high rock-breaking efficiency. As a cutting unit, PDC cutter determines the rock-breaking performance of PDC bit. The purpose of PDC bit cutter arrangement is to determine the spatial position of each PDC cutter on the bit, so that the bit has excellent performance and reliable life when drilling and breaking rock. PDC bits designed based on different cutter arrangement technologies show different rock-breaking performance during drilling. Therefore, the PDC bit cutter arrangement technology has been widely concerned by scholars at home and abroad. At present, a large number of scholars have made corresponding research on the cutter arrangement technology of PDC bit since its birth, but there is still a lack of systematic summary. For this reason, based on the literature about PDC bit cutter arrangement technology at home and abroad in recent years, the development process of PDC bit cutter arrangement technology since its birth was summarized, mainly including the early cutter arrangement stage, the classical cutter arrangement stage and the modern cutter arrangement stage. Through analyzing and summarizing the development process of PDC bit cutter arrangement technology, it was pointed out that the cutter arrangement technology of PDC bit in composite PDC bit, compatible intelligent PDC bit, long-life PDC bit, force-balanced PDC bit, PDC bit under impact and vibration and PDC bit in special formation represented the future development trend. The research results can provide some reference for the subsequent research of PDC bit cutter arrangement technology, and are expected to promote the further development of PDC bit cutter arrangement technology.

In order to improve the folding rate and support performance of deployable mechanisms, a scissor deployable mechanism with variable Poisson motion characteristics is proposed and its kinematics analysis is conducted. Firstly, a thick panel support unit with single-closed-loop was proposed and applied to sandwich structures. Through analyzing the influence of different shape sandwich layers on the support stiffness of sandwich structure by using ANSYS Workbench software, it was found that the sandwich structure with thick plate support unit had better support effect and smaller mass, and the positive and negative Poisson' ratio could be switched by changing the structural design parameters. Secondly, according to the definition of Poisson' ratio, a regular n-sided scissor deployable mechanism with variable Poisson motion characteristics was designed. Based on the screw theory, the screw constraint topology graph of the closed-loop deployable mechanism was drawn to analyze its degree of freedom as 1. The deployable mechanism was divided into three modules, and the principle and process of modular longitudinal expansion were described. Finally, the kinematics model of the m-layer regular n-sided scissor deployable mechanism was established and the prototype of the regular quadrilateral scissor deployable support structure was set up to further verify the variable Poisson motion characteristics of the mechanism, which could provide a theoretical basis for the follw-up research.

With the gradual shift of oil and gas exploration to deep, ultra-deep and complex rock formations, the existing mechanical drill bits have the problems of low rock breaking efficiency and high operating cost. Therefore, a new type of laser-PDC (polycrystalline diamond compact) drill bit was proposed to achieve efficient rock-breaking and energy-saving and cost-reducing. Using finite element method and based on the HJC (Holmquist-Johnson-Cook) constitutive model of rock, a nonlinear dynamic model of laser-PDC drill bit joint rock-breaking was established, and simulation research on laser-PDC drill bit joint rock-breaking was conducted. The simulation results showed that the radiation effect of laser generated higher temperature and greater prestress in the radiated area of rock surface, which in turn formed interpenetrating damage zones on the rock surface, reduced the strength of the rock, and was more conducive to cutting teeth to break the rock; compared with non-laser single PDC drill bit, laser-PDC drill bit experienced a 24.8% reduction in anti-torque during rock breaking, a 10.5% reduction in axial acceleration fluctuation, an increase in drilling displacement of 8.67 mm, and an increase in drilling speed of 112.79%. A laser-mechanical joint rock-breaking experimental bench was built to conduct laser-PDC drill bit joint rock-breaking experiment. The experimental results showed that laser-PDC drill bit joint rock-breaking had better drilling stability and continuity, greatly improving the rock-breaking efficiency. The research results can provide theoretical and technical support for the development and application of laser-mechanical rock-breaking technology.

Fatigue failure of metal components is a common form of failure in industry. In order to improve the prediction accuracy of fatigue life of components, aiming at the influence of average strain on fatigue life under low cycle fatigue load, a low cycle fatigue life prediction model considering average strain was established based on the continuum damage mechanics and its irreversible thermodynamic framework, by introducing the Ramberg-Osgood cyclic constitutive model and using equivalent intrinsic damage dissipation work as an equal life condition. In order to compare and verify the effectiveness and progressiveness of the new model, the new model, modified Ohji model, Sandor model and Wei-Wong model were used to predict the low cycle fatigue life of 45 steel and 2124-T851 aluminum alloy with superimposed average strain, and compared with the corresponding test results. The results showed that the prediction results of the new model were in good agreement with the experimental results, and its prediction effect was better than the existing models. The fatigue life prediction method based on the intrinsic damage dissipation theory provides a new idea for the fatigue life prediction of metal materials.

Multi-functional small robots have broad application prospects. To meet different operational requirements, a small land-air deformable amphibious robot was designed, which could achieve efficient ground movement and avoid obstacles through takeoff flight. The robot adopted a dual-mode design, in which the ground mode adopted a two-wheel drive motion design, and the airplane mode adopted a four-rotor flight design. The switching between the two modes was realized through the support and extension of the robot tilting mechanism. In order to verify the motion performance of the robot, the whole robot model was established by SolidWorks software, the kinematics modeling for the robot was carried out, and the kinematics equation of the robot mode switching process was derived. Then, the robot servo output was simulated by MATLAB and the robot prototype mode switching experiment was carried out. The simulation results of the output torque were basically consistent with the measured results, with a range of 0-250 N·cm. Finally, the robot prototype was used to conduct ground movement and air flight tests, and its motion process was analyzed to verify the stability of the land-air motion and mode switching of the robot. The research results verify the effectiveness of the designed robot, and it has a long endurance, which can provide a reference for the design of land-air amphibious robots.

In order to achieve the topological optimization of the volume constraint and the minimum compliance of the continuous structure and solve the numerical instability problems, such as gray-scale element and checkerboard grid caused by classical variable density method, a new topology optimization method was proposed. Firstly, the method of improved solid isotropic material with penalization was used as the material interpolation scheme to establish a structural topology optimization model；secondly, the numerical instability problem was solved by introducing sensitivity filtering method based on the Gaussian weight function and designing a new gray-scale element suppression operator; finally, the optimization model was solved by the optimality criterion method. Through example analysis, it could be seen that the new strategy could improve the topology optimization method. The method had the advantages of faster convergence, acquisition of optimized structures with small compliance and good topological configuration and better suppression of gray-scale element generation. The results provide new ideas for the study of topological optimization of other continuum structures.

Aiming at the problems of poor forming quality and long printing time of concrete 3D printing components, a path planning algorithm based on continuous vertex partitioning was proposed. Firstly, the continuous vertex partitioning method based on Hamiltonian circuit was used to divide the print area into several continuous regions to ensure that the print nozzle would not pass the same vertex many times during the printing process, thus avoiding the problem of repeated printing and poor forming quality. Then, the genetic algorithm was used to search each region, and the shortest printing path was determined through iteration and optimization. The experimental results showed that compared with other path planning algorithms, the proposed algorithm could significantly reduce the empty travel and start-stop times of the print nozzle, and shorten the printing time by more than 10%, which effectively improved the forming quality and printing efficiency for concrete components. The concrete 3D printing path planning algorithm based on continuous vertex partitioning solves the problems of poor forming quality and long printing time of concrete components by effectively dividing the print area, intelligentiy searching the shortest path and combining the optimal path, which can provide strong technical support for the development and application of concrete 3D printing technology.

In the current civil aircraft cabin door operation panel design, there is a lack of unified standards and specifications for human-machine efficacy and interface design, and the design process overly relies on personal experience and personal preferences, resulting in poor human-machine efficacy of the designed operation panel during use. For this purpose, the design principles for the display and operation of the civil aircraft cabin door operation panel were discussed based on the ergonomics principle, and a design scheme of centralized cabin door operation panel and regional control panel was proposed. Firstly, the information organization, coding, display elements and display forms of the cabin door operation panel were determined through questionnaire survey. Then, the three-dimensional models of the cabin door operation panel, the regional control panel and the aircraft were conducted. Finally, the ergonomics simulation software DELMIA was used to conduct dynamic operation simulation on the layout, key size and touch area of the operation panel. The simulation results showed that the designed cabin door operation panel could enhance the human-machine efficacy, improve the safety and efficiency of the operation, and reduce the misoperation and workload of flight attendants. The designed operation panel and regional control panel not only realize centralized monitoring and management and regional actuation control for the entire cabin door, but also can be used as a human-machine interaction device, which is suitable for the cabin and cargo hold of large-sized wide-body aircraft in the future, and has a very broad application prospect.

Aiming at the problems of insufficient automation and limited vision and observation angle of existing power tunnel inspection robots, a parent-child automatic inspection robot was designed. Among them, the master machine of inspection robot with mobile function could complete the main routine inspection work, and it had the ability to surmount and avoid obstacles; the slave machine with climbing function could complete the survey task under complex environment and extreme angle conditions. The slave machine and master machine could cooperate to complete the automatic inspection of the entire power tunnel. Firstly, based on the overall functional requirements, the specific form of each module of the inspection robot was proposed, and the hierarchical design of its automatic inspection logic system was completed. Then, the power tunnel operation environment was established in the ADAMS (automatic dynamic analysis of mechanical systems) software based on the virtual prototype technology, and the structure of the inspection robot master machine was optimized by combining the results of kinematic simulation analysis, so as to improve the stability of the robot operating in the tunnel and ensure that the sensors carried by the robot could work normally. The results showed that the inspection robot could run smoothly after the optimization of the master machine structure, the jitter amplitude of the sensor platform was within 5 mm, and all the sensors could work normally, which verified the rationality of the robot design. The relevant theoretical research results can provide reliable technical support for the development of the power tunnel automatic inspection robot physical prototype.

In order to further improve the response speed and lightweight extent of piezoelectric wavefront correctors, the dynamics simulation and optimization method of unimorph piezoelectric deformable mirrors for high dynamic shape control was studied. Firstly, based on the parameterized finite element model of unimorph piezoelectric deformable mirror, an efficient and high-precision electromechanical coupling dynamics simulation analysis method was proposed. Then, through orthogonal traversal of multi-dimensional design parameters (material type, geometric dimension and fixation mode of the optical reflector and piezoelectric ceramic), the influence of different parameters on the dynamic shape control performance of unimorph piezoelectric deformable mirrors was explored. Finally, the optimized design scheme of the unimorph piezoelectric deformable mirror with expected response bandwidth and actuation displacement performance was obtained. The experimental results show that the natural frequency and mirror actuation displacement amplitude of the developed unimorph piezoelectric deformable mirror are in line with expectations, which verifies the effectiveness of the proposed dynamics simulation and optimization method and provides a scientific theoretical method for the efficient development of high-bandwidth unimorph piezoelectric deformable mirrors.

In view of the problem that the transmission accuracy of RV (rotate vector) reducer decreased due to the wear of its parts in the working process, a dynamic reliability model of the transmission accuracy of RV reducer considering the wear of cycloid wheel was established, the reliability of transmission accuracy was analyzed, and the tolerance of key parts and the modification parameters of cycloid wheel were optimized. Taking a heavy-load RV reducer as the research object, the wear depth of cycloidal gear was calculated by using Archard wear formula, the distribution of gear tooth profile wear was analyzed, and the wear amount was predicted by using Gaussian process regression model based on numerical simulation data; the reliability model of RV reducer transmission accuracy with dynamic wear was established, and its dynamic reliability was solved by Monte Carlo method; an optimization model was established with the dynamic reliability of transmission accuracy as the constraint condition, the minimum machining cost and the minimum maximum wear in the rated life cycle as the optimization objectives, and the optimal solution was obtained adopting multi-objective genetic algorithm. The results showed that after optimization, the wear of cycloidal gear was slightly increased, and the machining cost of reducer was obviously reduced; the reliability of transmission accuracy of the reducer had been significantly improved, and the reliability within the rated life of 6 000 h met expected requirements. The research results can provide reference for the design of high-precision RV reducer.

In extremely harsh working environments such as strong impacts, intense radiation and extremely high temperature, the fault modes of mechanical equipment are complex and varied, and it is very difficult to obtain sufficient and effective fault data, even difficult to achieve, so that the accuracy of fault diagnosis is limited, and subsequent maintenance and repair programs are difficult to be effectively developed.To solve this problem, a data enhancement algorithm for multi-discriminator auxiliary classifier generative adversarial network was proposed. By setting up 3 discriminators, 1 generator and adding independent classifier, a new auxiliary classifier generative adversarial network model was constructed. Aiming at the instability issue in the model's training, the Wasserstein distance was introduced to construct a new loss function, and the unilateral soft constraint regularization term with more stability was used to replace the original L2 gradient penalty term to solve the problem of model collapse. Building on this, an efficient channel attention mechanism was adopted to further improve the model's feature extraction capability. The proposed model was applied to extend the fault data set of mechanical equipment to assist the training of deep learning intelligent diagnosis model. Multiple fault data set expansion experiments showed that compared with the existing model, the new model could generate higher quality data, and the accuracy of fault diagnosis was further improved, so it had high application value.

The impact load is an important factor in the structural design of aerospace equipment. The design of thin-walled structures with high load-bearing capacity and good energy-absorbing characteristics is a research focus. Based on Voronoi algorithm, the pseudo-random arrangement of structure similar to honeycomb hexagon was developed by combining the structural characteristics of bone and honeycomb. According to the arrangement of loose inside and tight outside of the bone, a new type of impact resistant structure was constructed by partition design.The impact resistance simulation of bio-inspired thin-walled structure and uniform honeycomb structure of laser selective melted titanium alloy and laser selective sintered carbon fiber/PEEK (polyether ether ketone) composites was conducted to compare the energy-absorbing characteristics of the two kinds of structure. The simulation results showed that the maximum energy-absorption of the bio-inspired thin-walled structure of laser selective melting titanium alloy and laser selective sintered carbon fiber/PEEK composites was increased by 17.7% and 27.7% respectively, compared with the uniform honeycomb structure under axial impact, and the maximum energy-absorption was increased by 422.6% and 99.2% respectively under lateral impact.The bio-inspired thin-walled structure designed has important application prospects in aerospace field.

Aiming at the problems of traditional rigid picking manipulators, such as small scope of application, poor environmental adaptability and great damage to fruits and vegetables, a rigid-flexible coupling pneumatic soft picking manipulator for crabapple picking was designed. According to the characteristics and picking requirements of crabapple, the six-finger wrapped picking form was determined. Taking Longfeng fruit as an example, the bending angle calculation model for the soft finger of picking manipulator was established, and the bending angle of single finger was determined; the HY-E620 type silicone was selected as the material of soft fingers through the tensile contrast experiment of three kinds of silicone materials; the ABAQUS finite element simulation analysis of the influence of various structures on the bending performance of soft fingers was carried out, and the optimal structure was determined; the corresponding relationships between the bending angle and the output force of a single soft finger under different driving pressure conditions were measured by experiments, and the three-finger grasping experiment for various fruits under the driving pressure of 0.08 MPa was carried out, which verified the rationality of the soft finger structure. Finally, a six-finger wrapped pneumatic soft picking manipulator was trial-produced, and the picking experiments were carried out on crabapple, apple, pear and orange. The results showed that the designed picking manipulator could not only pick clustering crabapples containing 3?6 fruits with a success rate of 80%, but also pick apples, pears, oranges and other spherical fruits, which had a certain versatility, and could provide a new idea for the design and research of fruit picking manipulator.

Aiming at the key issues in the overall development of snakelike robots, including material selection, structure design and motion realization, a new multi-joint snakelike robot was developed. This snakelike robot was composed of 11 two-degree-of-freedom orthogonal joints, which could achieve three-dimensional high biomimetic motion while ensuring flexibility. The basic gaits of snakelike robot such as meandering, wriggling and tumbling were designed by using the serpentine curve, and an improved obstacle surmounting gait was further proposed. At the same time, the gaits of the snakelike robot were simulated in the V-REP software, and the motion trajectories and efficiency of different gaits were compared. Finally, through the gait experiment of the snakelike robot prototype, the influence of each control parameter in the gait model on the motion waveform and speed of the snakelike robot was analyzed, and the reliability of the body structure and control system of the snakelike robot was verified. The research results have important theoretical significance and practical guiding value for realizing the gait planning and motion control of snakelike robots.

The container reach stacker (hereinafter referred to as reach stacker) plays a crucial role in practical port operations. With the increasing attention of society to energy and environmental issues, the electrification trend of reach stackers is becoming more and more significant, and the number of electric reach stackers on the market has been steadily rising year by year. The electric energy consumption performance directly affects endurance capacity, working efficiency and working cost of electric reach stackers, which is one of the important performance of electric reach stackers. Various factors such as driving behavior, operation conditions and equipment malfunctions will have diverse effects on the energy consumption of electric reach stackers. Therefor, by collecting the actual operating data of the customer side of electric reach stackers and based on the LightGBM (light gradient boosting machine) model, the energy consumption modeling for the driving and operational processes of electric reach stackers was conducted at the micro and macro levels, respectively. The SHAP (Shapley additive explanations) theory was used to quantitatively analyze the impact of different operation conditions and behaviors on the energy consumption of reach stackers, while simultaneously identifying energy consumption anomalies caused by equipment malfunctions. The results show that the energy consumption model based on SHAP-LightGBM can accurately predict and analyze the driving and operational energy consumption of reach stackers, which provides valuable input for the design and optimization of energy consumption strategy for electric reach stackers. Additionally, the energy consumption model establishes a theoretical energy consumption benchmark for the actual operational processes of electric reach stackers, effectively guiding driving behavior and identifying energy consumption anomalies caused by malfunctions.

Because of the asymmetric structure of axial piston pump, its output pressure and output flow have pulsating characteristics, which affects the output stability and reliability of hydraulic system. Therefore, an optimization design method of low pulsation structure of swashplate axial piston pump based on multi-objective genetic algorithm is proposed. Firstly, the CFD (computational fluid dynamics) simulation analysis method was used to analyze the generation mechanism of pressure-flow pulsation at the upper/lower dead points of the axial piston pump; secondly, the influence of damping groove structural parameters on the output pressure-flow pulsation of axial piston pump was analyzed, and a multi-objective optimization model of damping groove structure was constructed; finally, the structure of the low pulsation damping groove was solved. The optimized structural parameters were as follows: the damping groove radius was 2.21 mm, the damping groove length was 10.32 mm, and the damping groove deflection angle was 16.54°. After optimization, the pressure pulsation rate was 0.59%, which was reduced by 0.16% compared to the pre-optimization value of 0.75%, and the pulsation amplitude was 0.25 MPa. The flow pulsation rate was 12.02%, which was reduced by 43.59% compared to the pre-optimization rate of 55.61%. The research results provide effective theoretical support and practical guidance for the optimal design of low pulsation structure of axial piston pump.

Wind turbine blade is the core component of wind turbines. The blade bolt is not only the part that bears complex stress, but also the part that bears the highest load. In order to avoid potential hazard and economic loss caused by bolt breakage, an axial stress measurement system for in-service bolts based on ultrasonic guided waves is designed, which can achieve accurate measurement of axial stress for various types of bolts. Firstly, the group velocity dispersion curve of ultrasonic guided wave was obtained through numerical calculation, and a linear mathematical model of bolt axial stress and ultrasonic guided wave acoustic time was established based on the Hooke's law and acoustic elasticity effect. The effectiveness of ultrasonic guided wave stress measurement by single longitudinal wave transducer was verified by simulation in COMSOL software. Then, in view of the modal aliasing of ultrasonic guided wave echo signals and the interference of noise on the measured results of ultrasonic guided wave acoustic time in actual measurement, the denoising algorithm based on echo compensation was used to denoise the actual measurement signal. The empirical wavelet transform algorithm was used to decompose the modal of ultrasonic guided wave echo signal, and the cross-correlation method was used to obtain the accurate acoustic time of ultrasonic guided wave modal. Finally, the precise measurement of axial stress for 18 types of bolts within the 30%-90% yield strength was completed through experimental tests, and the relative measurement error was less than 2%. The research results are helpful to improve the bolt assembly process and standardize the worker's operation process.

In order to realize the customization, reusability and economy of atomization assisted CVD (chemical vapor deposition) cavity, and meet the actual requirements of high-quality single crystal Ga₂O₃ thin film preparation, a new atomization assisted CVD cavity was designed and developed. The cavity was mainly composed of reaction chamber module, cooling module and buffer chamber module. Ga₂O₃ thin films were prepared by using a new cavity and a conventional cavity, and then the X-ray diffraction (XRD) patterns analysis and its surface morphology observation by atomic force microscope (AFM) were carried out. The experimental results showed that the new cavity could produce better performance α-Ga₂O₃ and β-Ga₂O₃ thin film; the half-peak widths of (006) crystal plane of the α-Ga₂O₃ thin films prepared by the new cavity and the conventional cavity were 0.172° and 0.272°, respectively, and the surface roughness was 25.6 nm and 26.8 nm, respectively. It could be seen that the α-Ga₂O₃ thin film made with the new cavity had better crystallinity, surface smoothness and density. Through the design of the new cavity, a stable environment conducive to the growth of single crystal Ga₂O₃ thin film was constructed, which provided a reliable path for the optimization of the preparation process of Ga₂O₃ thin film. The research results provide a reference for the preparation of high-quality metal oxide semiconductor films.

In order to improve the walking stability of amphibious turtle inspired robot, a dynamics model was established, and a force/position control model was proposed based on the PID (proportional integral derivative) feedback control strategy. Firstly, according to the kinematics model of the robot, the transformation matrix and Jacobian matrix of the outrigger were obtained, and a force transfer model between foot end and hydraulic cylinder was established by the virtual work principle. Then, the Lagrange method was used to model the dynamics of the robot, and the dynamics equation of the outrigger was derived. At the same time, the dynamics simulation was carried out, and the real-time force on the foot end was introduced into the dynamics equation for calculation, which verified the correctness of the dynamics model. Finally, a hydraulic simulation model was built, and the robot motion simulation was carried out in the ADAMS?AMESim?MATLAB co-simulation environment. The simulation results showed that compared with the pure position control mode, the rotation of the robot knee joint under the force/position control mode was more stable, and the power output of the hydraulic cylinder was more stable and the power consumption was less. The research results have reference significance for improving the stability of robot motion, enhancing the robustness of motion control system and improving the overall efficiency of hydraulic system.

In order to reduce the risk of the integrated leakage rate measurement test of reactor containment and make the leakage rate test results more conservative and reliable, an optimization method for the integrated leakage rate measurement stage duration of containment for China's nuclear power plants is proposed based on the air stability criteria, function curvature criteria and data distribution criteria. Combined with the adjustment method for the containment integrated leakage rate measurement stage duration of the French Power Group, the determination requirements for the end of integrated leakage rate measurement test for containment were clarified, and an optimization method was proposed to add the criteria for determining the stability of air inside the containment and the termination of integrated leakage rate measurement. Taking 20 groups of containment pressure test samples as examples, the integrated leakage rate measurement stage duration for containment was calculated. The results showed that 17 groups of samples met the optimization conditions, of which 15 groups of samples were able to meet the integrated leakage rate measurement termination criteria within 16 h, and 2 groups of samples met all acceptance criteria within 19.25 h and 18.25 h, respectively. The proposed optimization method can shorten the duration of the integrated leakage rate measurement stage for reactor containment, which is more conservative and reliable than the French method.

In order to provide high-precision force feedback to doctors in robot-assisted remote interventional surgery, a novel vascular interventional surgery robot with force detection mechanism is designed. It is a master-slave control system, including a convenient master device and a slave device for delivering guide wire/catheter. Firstly, the force detection mechanism of the vascular interventional surgery robot was designed to realize the accurate measurement of axial proximal force and the perception of radial clamping force. Then, based on the dynamics analysis of the vascular interventional surgery robot, a fuzzy PID (proportional integral derivative) controller with online parameter setting function was designed to improve the delivery accuracy and anti-interference ability of the slave device. At the same time, the step signal was selected to verify the fuzzy PID controller. Finally, the physical prototype of vascular interventional surgery robot was built, and the master-slave motion tracking experiment and the detection and evaluation experiment of axial proximal force and radial clamping force were carried out. The experimental results showed that the vascular interventional surgery robot had a motion tracking error of [?0.31, 0.25] mm, could detect the axial proximal force with an average error of 0.12 N, and could sense the radial clamping force of 0.47-4 N. The research results verified the robustness of the designed vascular interventional surgery robot and the feasibility of its force detection mechanism, which can provide a reference for the design and improvement of similar products.

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.