In order to quickly and accurately solve the ergonomics problems and improve the human-machine performance of products, a solving method of product ergonomics problem based on the virtual simulation and TRIZ (Teoriya Resheniya Izobreatatelskikh Zadatch) is proposed. Firstly, the evaluation of human-machine performance for the product was carried out by the virtual simulation tool, and the product area correlation was performed based on the obtained human body data to determine product areas with ergonomics problems. The root causes of product ergonomics problems were found by using the functional model and causal analysis. Then, according to the product ergonomics design cases and expert questionnaire survey results, a correlation table of TRIZ standard engineering parameters and ergonomics design criteria was constructed, and design schemes that could solve the product ergonomics problems were obtained through the correlation table and conflict analysis tool of TRIZ; based on the concept of ideality, the ideality evaluation method of product human-machine performance was proposed and the evaluation for obtained design schemes was carried out to determine the best design scheme. The proposed method was applied to solve the ergonomics problem of electric jig saw, which not only solved the problem quickly，but also improved the usability of electric jig saw. The results show that the proposed method can improve the innovation design efficiency and the ergonomics performamce of products, which provides a new idea for solving product ergonomics problems.

The research of the human joint impedance is of great significance to studying the impedance control strategy of bionic robots. In view of the complex mechanical structure of the impedance detection device for ankle joint (IDDAJ) designed in the early stage and the difficulty of modeling by the mechanism method, an estimation method of ankle joint impedance based on the series elastic principle and the augmented upper-diagonal decomposition identification (AUDI) algorithm was proposed. In order to reduce the performance requirements for the drive unit of the IDDAJ, the large DC(direct-current) component and dynamic high frequency component required in the input disturbance was separated based on the series elastic principle. In order to reduce the difficulty of modeling, the IDDAJ impedance model was directly identified by the AUDI algorithm which was not affected by the model order, so as to obtain more accurate impedance model parameters of the device. According to the principle of union impedance detection, after the impedance model of IDDAJ was obtained, the impedance model parameters of the ankle joint under different activation levels of calf muscles were identified by the AUDI algorithm. The results showed that the reliability of the impedance model of IDDAJ identified by the AUDI algorithm was higher than that obtained by the mechanism method; when the calf muscles were relaxed, the impedance model parameters of the ankle joint were in the same order of magnitude， and the damping component B and stiffness component K of the ankle joint impedance model were positively correlated with the activation level of the calf muscles, which was consistent with the results in the existing literature. The research results can provide reference for the development of IDDAJ and the research of other joint impedance detection methods.

Aiming at the pose identification of workpieces with planar geometric features, a two-step alignment method for 3-D point cloud was proposed. Firstly, the 3-D point cloud was randomly sampled multiple times, while three points were sampled each time to calculate the unit normal vector of the plane formed by them. A set of unit normal vectors for planes was obtained after multiple sampling, and the unit normal vector of principal plane was extracted by the density clustering algorithm. The inclination correction of point cloud was achieved according to the axis angle transformation relationship between the unit normal vector of principal plane and the target vector. Then, the point cloud was projected to the principal plane, and the height of each point was mapped into the gray of principal plane to obtain the point cloud greyscale image. The image template matching algorithm was used to get the translation amount and rotation angle of the point cloud projection in the principal plane, and the final alignment of the point cloud pose was realized after translation and rotation. The proposed two-step alignment method for 3-D point cloud was applied to the automatic welding system for tower base of high-voltage transmission line to identify the pose of tower base， and a comparison was performed with the pose of tower base identified based on the sample consensus method. The experimental results proved that compared with sample consensus method, the proposed two-step alignment method not only improved the identification accuracy of workpiece pose, but also shortened the time consumption by about 76%. The research results provide reference for the rapid alignment and identification of poses of workpieces with planar features, and the two-step alignment method for 3-D point cloud has a wide application prospect in the advanced manufacturing.

In order to realize the real-time detection of railway carriage position during the loading process of the quantitative coal loading station and provide a trigger signal for the chute lifting, a railway carriage position detection model based on the semantic segmentation is proposed. Taking the FPN (feature pyramid networks) and ResNet101 (residual network) as the backbone network, the feature maps with different resolution and semantic strength were extracted and fused.Combined with the attention mechanism based on the expectation maximization (EM) algorithm, a carriage upper frame semantic segmentation model was constructed to filter the noise in the feature map and improve the semantic segmentation accuracy of the image boundary. A position detection module was designed to calculate the area of each category and their proportions in the image after semantic segmentation and the height of circumscribed rectangle of the carriage upper frame, so as to obtain the position information of railway carriage. The results showed that the mIoU (mean intersection over union) and the mPA (mean pixel accuracy) of the constructed carriage upper frame semantic segmentation model on the test set was 81.21% and 88.64%， respectively. Compared with the semantic segmentation model without attention mechanism, it was improved by 3.91% and 7.44%. The railway carriage position detection test was conducted at the coal quantitative loading station site， and the results indicated that the detection accuracy of the railway carriage position detection model based on the semantic segmentation met the requirements of the carriage position detection task in the coal loading process. It provides a new idea for the realization of intelligent quantitative coal loading system.

Aiming at the problem that the accumulation of cuttings in the inclined section of horizontal well is easy to cause the drill string friction, torque increase and stuck drill，it is necessary to evaluate and analyze the influence law and cleaning effect of cuttings bed destroyer in the inclined section. Firstly, the cleaning mechanism of cuttings bed destroyer was studied based on the CFD (computational fluid dynamics) technology, and the cleaning effect of cuttings bed destroyer was obtained through comparative analysis. Then, the influence of cuttings bed destroyer on cuttings bed in the inclined section of horizontal well was analyzed under different well angles, drilling fluid displacements and drill string rotation speeds. The working condition parameters of cuttings bed destroyer were optimized to better play its cleaning effect. Finally, through the application of cuttings bed destroyer in the on-site, its cleaning effect was verified. The results indicated that the cuttings bed destroyer was very effective in cleaning the wellbore of the inclined section of horizontal well, and the friction and torque of the drill string were reduced after it was used, which could effectively prevent the stuck drill accident during the drilling. The research results can provide guidance for the use of cuttings bed destroyer.

Aiming at the problem of vibration shock caused by clearance to the left and right adjusting mechanism of blade roll mill, a dynamics model of the roll adjusting mechanism was established, and it was decoupled by the differential geometry feedback linearization method. On this basis, a sliding mode controller based on interference observer was designed, and tracking simulation of the sliding mode control process was accomplished by MATLAB/Simulink software. The sliding mode control algorithm was applied to blade rolling site, and the effectiveness of sliding mode control was verified. The results showed that the system trajectory could be tracked with high precision by using the sliding mode control algorithm based on interference observer. The designed sliding mode controller can realize the control of the roll adjusting mechanism well, improve the roll position adjusting precision, and thus improve the machining precision of the blade.

Mass customization is the development direction of future product manufacturing. Quickly responding to customers' individual needs at low cost is the key to customized products design. Previous researches on customized product design lacked a flow-oriented design guidance method from individualized needs to product parameter, which led to the inability to quickly associate design targets and guided the design of product parameters from the individualized customer needs of customized products. For this reason, a optimization design method of customized product based on the RIR-MOO (relative importance ratings and multi-objective optimization) was proposed. Based on the customer needs, the key needs were mapped to the related design targets， and the product parameters were quickly calculated through the multi-objective optimization (MOO) method to realize the fast response and optimized design of customized products. Firstly, aiming at the fuzzy and dynamic customer needs, the weighted interval rough set analysis method was used to objectively analyze the customer needs of customized products to eliminate the controversial fuzzy needs, and the relative weights of different customer needs were calculated to obtain the relative importance ratings (RIR). Then, a correlation method between customer needs and design targets was proposed based on the conversion matrix. According to the correlation between key needs and design targets and the RIR of the key needs, the key needs were matched with the design targets to achieve the conversion of the key needs into the design targets. Lastly, the product parameters corresponding to design targets were optimized based on the MOO method to achieve the multi-objective optimization of the customized product. The feasibility of the optimization design method based on the RIR-MOO was verified by an optimization design example of the automobile engine piston mechanism. The results show that the proposed method can quickly respond to customer needs of customized products and guide their optimization design, which can provide guidance for customized manufacturing enterprises.

A bacteria foragingant colony optimization (BFACO) algorithm was proposed to solve the problem of optimal solution selection satisfying multiple constraints in process route planning. Firstly, the process route planning was transformed into the sequential optimization of machining elements, and the topological priority diagram of machining elements was constructed for satisfying various process criteria, and the objective function of the minimum processing resource replacement cost under the goal of shortening the processing cycle, improving the processing quality and reducing the processing cost was constructed. Secondly, the ant colony search in the two stages of processing element sequence and processing resource was designed, and the lack of pheromones in the sequential search stage of machining element could be compensated by the topological priority diagram. The replication and trend operations of the bacterial foraging optimization algorithm were introduced in the processing resource search stage, and the processing element could obtain the processing sequence with the lowest replacement cost of processing resources in the case of multiple alternative processing resources. Finally, based on the fusion optimization of bacterial foraging and ant colony algorithm, the pheromone accumulation of multiple machining element sequences was completed and the optimal solution was output to solve the problem of local convergence and slow calculation speed of ant colony algorithm. BFACO algorithm was applied to an example and the optimization result was compared with that obtained by other optimization algorithms. The results showed that BFACO algorithm had higher computational efficiency in process route optimization, which verified the feasibility and effectiveness of BFACO algorithm. BFACO algorithm can be effectively applied to process planning considering both process constraints and replacement cost of processing resources, providing efficient and flexible optimization selection of process routes for actual production.

In order to realize the replacement and manufacture of carbon fiber reinforced polymer （CFRP） oil pan, the concurred optimal design of structure and manufacturing process of CFRP oil pan was carried out by combining the composite material layer manufacturability analysis software FiberSim and the layer structure optimization module Optistruct. With reference to the forming process of CFRP shell components, a CFRP oil pan covering plan that met the manufacturing process requirements was developed by the FiberSim software. Based on this, taking the maximum rigidity and minimum mass of CFRP oil pan as the optimization goals, and the vibration mode and manufacturing process requirements as constraints, the layer structure of CFRP oil pan was optimized by using the Optistruct module. The simulation analysis showed that the CFRP oil pan after the adjustment of manufacturing process met various substitution requirements, and the mass of the CFRP oil pan was reduced by 56.7% compared with the original metal oil pan. The proposed concurred optimal design method of structure and manufacturing process can take into account the structure characteristics, composite material design and manufacturing process requirements, which provides a reference for the optimal design of composite material products.

An optimal design method of basic parameters of spiral bevel gears was proposed to improve the situation of little contact area caused by local conjugate contact due to the limited machining of the traditional machine tools, and the contact performance of the tooth surface.Based on the realization method of gear pair fulltooth contact, a multi-objective optimization mathematical model of tooth contact performance was established with the gear basic parameters as the optimization variable, eliminating meshing limit line and root cutting limit line (referred to as "two class limit lines")and preventing the addendum becoming sharp as the constraint conditions, aiming at maximizing the lubrication performance comprehensive parameter and total length of instantaneous contact line on the tooth surface. The modern bare-bones multi-objective particle swarm optimization algorithm which was more suitable for the model was used to solve the optimal basic parameters. A spiral bevel gears with specific parameters was taken as the research object, and the contact performance indexes of the tooth surface before and after the optimal design of the basic parameters were compared. The numerical simulation results showed that the two class limit lines were distributed outside the working flank of tooth surface, both the minimum value of the comprehensive parameters characterizing the lubrication performance and total length of instantaneous contact line on the tooth surface characterizing the carrying performance were significantly improved, and the simulation results of finite element model showed that the optimized working tooth surface contacted fully without interference. The study provides a fast and feasible method to obtain the optimal basic parameters of spiral bevel gears, which provides a reference for the optimal design of spiral bevel gears.

Traditional PDC （polycrystalline diamond compact） bit wear prediction method does not consider the dynamic change of cutting tooth temperature, cutting force and wear. It makes the wear prediction results deviatie, which leads to the force deterioration and the rapid failure of the bit after wear. To solve this problem, the functional relationship between volume wear and linear wear and the implicit line wear model of PDC bit cutting teeth were constructed, and a prediction method of dynamic wear trend of PDC bit was proposed based on the abrasive wear theory, the calculus fundamental theory and the iterative algorithm. Then, the prediction of wear trend for a six-blade PDC bit with diameter of 215.9 mm was carried out. The results showed that when the PDC bit was not worn, the initial force on the inner cone tooth was large and the temperature of cutting tooth was generally high. With the continuous wear of PDC bit, the force on the outer cone tooth showed a rapid increase trend, and the temperature of cutting tooth gradually decreased. In the initial stage of rock breaking, the wear of crown tooth was the most serious and the wear rate of outer cone tooth increased rapidly; after a period of time, the wear of outer cone tooth was the most serious. The research results can provide the theoretical basis and support for the analysis of rock breaking force characteristics of the worn bit, the wear-based PDC bit layout design, the geothermal bit design and the bit life prediction.

The horizontal well sections where deep shale gas is drilled and extracted are mostly mudstone, shale and other viscous formations. To improve the drilling efficiency and reduce the occurrence of bit balling, it is necessary to ensure that the cuttings in the downhole must be moved quickly, which puts forward requirements for the hydraulic structure of PDC bit. For this reason, based on the CFD-DEM coupling method, the numerical simulation analysis of downhole flow field of PDC bit in the horizontal well was carried out. Then, taking the cuttings retention and the cuttings migration ratio as evaluation indicators, the hydraulic structure parameters such as the flow path shape, the number of nozzles, the nozzle arrangement and the nozzle diameter of the five-blade PDC bit with a diameter of 152.4 mm were analyzed. Finally, the PDC bit with improved hydraulic structure was applied in the field. The numerical simulation results showed that the PDC bit with parabolic shape flow path had better cuttings-carrying performance; in the case of the same total injection area, the PDC bit should use a smaller number of nozzles; the PDC bit with equal-diameter arrangement of nozzles had better cuttings-carrying performance than that with nonequal-diameter arrangement; in a certain range, a moderate reduction of the nozzle diameter of PDC bit was beneficial to the migration of cuttings. The field application showed that the PDC bit with improved hydraulic structure had higher drilling efficiency when drilling in multiple horizontal well sections in the same block and same formation. The research results can provide reference for the structure optimization of PDC bit.

The wear-site electrostatic sensor is often used for on-line monitoring of wear of key components of aircraft. In order to study the monitoring performance of the new sensor, a mathematical model and a performance testing platform for the rod-like wear-site electrostatic sensor were established, and the spatial sensitivity, working efficiency, effective field of the sensor were simulated and tested. The results showed that the spatial sensitivity increased with the increase of the radiuses of probe sensing surface. The working efficiency increased with the increase of ratio of radius to distance. The variation trend of the simulation value of working efficiency was consistent with that of the test value, which proved the correctness of the mathematical model of wear-site electrostatic sensor. The effective field of view increased with the increase of the radius of probe sensing surface. The research results have important guiding significance for the design optimization and application of the new wear-site electrostatic sensor.

Sand burying at the bottom of a suspended exposed pipe section is the most important treatment method for the hidden dangers of the suspended and exposed submarine pipeline and cable. At present, the method of artificial sand throwing or caterpillar loose sand throwing is often used for sand burying, but there are problems such as inaccurate sand throwing position and difficult control of sand throwing trajectory. Therefore, it is necessary to develop an efficient sand throwing equipment that can realize fixed-point sand throwing and controllable throwing trajectory. In order to improve the accuracy of filling, a new sand throwing backfill device with positioning and orientation function was developed. In order to clarify the principle of positioning and trajectory control of the new sand throwing backfill device, the strength of its key components was calculated by using the finite element analysis method, and the sand throwing effect of the device was analyzed and the cause of its high filling precision was explored through the land and sea directional throwing tests. The results showed that the new sand throwing backfill device could accurately locate the sand throwing position to drop the sand bag to the suspended area of submarine pipeline and cable by the telescopic release mechanism, and realize the sand throwing trajectory controllable through the frame structure of the telescopic release mechanism. The strength of each key component of the device was reliable and the sand throwing effect met the requirements of pipeline protection, and the filling precision reached ±1.2 m, which not only improved the sand throwing efficiency, but also reduced the construction costs. The new sand throwing backfill device can solve the current difficulties in the suspension management of submarine pipeline and cable and ensure the construction safety, which provides reliable technical support for the management of suspended pipeline and cable in shallow sea oil fields.

At present, the conventional steering wheel and differential wheel automated guided vehicle (AGV) have low precision and flexibility, which cannot meet the requirements of accurate positioning and navigation in the assembly process of large high-end products. In order to further improve the navigation precision and flexibility of AGV, a high-precision AGV navigation control system based on IGPS (indoor global positioning system) and Mecanum wheel was proposed. Firstly, the position coordinates of the IGPS receiver was obtained through IGPS high-precision positioning and coordinate calculation. Secondly, the conversion from the coordinate value of the IGPS receiver to the center coordinate of the car body was realized by the car body center extraction algorithm and coordinate conversion matrix. Finally, through the modeling of the omnidirectional moving AGV, the path deviation of AGV was corrected by using fuzzy PI control method, so as to realize the accurate positioning and tracking navigation of AGV. By using Simulink, the simulation analysis of fuzzy PI control and traditional PI control showed that fuzzy PI control had faster response speed and smoother adjustment curve compared with traditional PI control. At the same time, the test verification was carried out on the AGV test platform based on IGPS, and the repeated positioning accuracy of AGV was measured by laser tracker. The results showed that the positioning precision reached ±0.2 mm. The research results are of reference significance for improving the high-precision positioning capability of AGV, and also provide a reference for the subsequent research on the processing mode of mobile robot.

The double-loop cooling system of gasoline engine has been gradually recognized for its rapid warm-up and low friction, however its engineering design and application in China are still in infancy and lack of relevant perfect design theories and methods.In order to meet the requirements of limits for emissions from light-duty vehicles （China 6）, the double-loop cooling system of body and cylinder head of 1.5T in-line 4-cylinder gasoline engine was studied.Firstly, based on the calculation by the classical formula, combined with the calculation of the heat dissipations of body and cylinder head calculated through the combustion gas side, the flow distribution ratio of cooling medium of double-loop was preliminarily determined.Secondly, the final flow distribution of the cooling loop was determined by one-dimensional flow heat transfer simulation and three-dimensional co-simulation based on CFD(computational fluid dynamics). On this basis, the performances of single-loop cooling system and double-loop cooling system in the warm-up stage were simulated and compared using one-dimensional transient flow heat transfer model. The simulation results showed that the body temperature under double-loop cooling system was 10 ℃ higher than that under single-loop, yet the cylinder head temperature was 9.6 ℃ lower,and the double-loop cooling could significantly accelerate the engine warming-up process, reducing friction of engine during cold start stage. Finally, the flow distribution verification test and the warm-up comparison test were carried out.The results showed that during the warm-up process, compared with the single-loop cooling system, the double-loop cooling system could make the temperature of the engine body rise faster, the friction between piston and cylinder liner decreased. Fuel consumption and HC (hydrocarbon) emissions were reduced by 20.2% and 7.58% respectively at idle speed working condition, 8.5% and 10.03% at common operating condition (2 000 r ? min-1, 200 kPa). The research results can provide reference for the design and optimization of engine cooling system.