Permanent magnet synchronous motor(PMSM)is widely used in different fields because of its simple structure, stable operation, high efficiency and various shapes.During the use of the PMSM, various faults will inevitably occur, such as the demagnetization fault, the circuit fault, the rotor eccentricity fault, the bearing fault and so on.Based on the structure and working principle of the PMSM, the causes and diagnosis methods of various faults were summarized, and the advantages of model construction and signal processing in fault diagnosis were analyzed.The research results provide a certain theoretical basis for the fault diagnosis of PMSMs.

In view of the existing automatic extraction method for drawing text information that can only extract the contents of title bars and detail lists in a single drawing, a text information automatic extraction method for multiple CAD(computer aided design)drawings is proposed, and the supporting automatic extraction and verification system is developed.The block table record iterator was used to traverse all attribute blocks in the multiple CAD drawings, and the drawing block and its insertion point coordinates and format were filtered based on the block name, so as to determine the position of each drawing; the text information of multiple CAD drawings was classified according to the multi segment lines and attribute blocks, and the text information in the drawings was obtained and extracted by constructing the window selection set; the extracted text information was output in the form of array and compared with the original file.Finally, an automatic text information extraction and verification system for multiple CAD drawings was developed, and the feasibility of the proposed method and system was verified by extracting and verifying the text information of connector circuit diagrams.The results show that the proposed method provides a new idea for the extraction of CAD drawing text information, and the developed system provides a new tool for operators to extract text information of CAD drawings, which can significantly improve the working efficiency.

Aiming at the problems that angle size tolerance cannot control the angle deviation between two planes and the angle deviation may be out of control when using geometrical tolerance, the tangent feature symbol for toleranced feature was introduced. When the geometric tolerance was used to control the angle deviation between the toleranced surface and the datum, the tangent feature symbol would be added to the toleranced feature. The conversion method between geometric tolerance and angle tolerance was given. Aiming at the problem of the accumulation calculation of angle deviation between two planes in assembly layer, the illustration of angle dimension chain and the accumulation calculation method of angle dimension chain deviation were studied for the parts which had been assembled. Finally, taking the electric wood cutting machine as an example, the angle accumulation deviation of the relative features of each part was controlled by geometric tolerance to meet the design requirement. The conversion of geometric tolerances to angular tolerance of each feature was realized. The angle accumulation deviation calculation using angle dimension chain was analyzed. The example can be used as a reference for geometric tolerance analysis control between planes and pattern annotation.

In view of the adverse effects of dynamic modeling errors and uncertain perturbations on the high-precision trajectory tracking control of the end of manipulators, a novel sliding mode control strategy for manipulators based on the adaptive neural network was proposed. The control strategy could be divided into three parts: adaptive neural network compensation term, switching control term and equivalent control term. The introduction of adaptive neural network avoided the influence of modeling error and unknown external disturbance on the manipulator system, and improved the trajectory tracking accuracy. The switching control term could enable the manipulator system performance to quickly approach the sliding mode surface while approaching the equilibrium point at a very small rate, so as to ensure system stability while avoiding excessive chattering. The equivalent control term was used to compensate the gravity term and Coriolis force term of the manipulator dynamics model, which realized the linearization of the model and ensured the system control accuracy. Finally, the stability of the designed control system was proved by constructing the Lyapunov function, and the simulation experiment and comparison experiment were carried out in MATLAB/Simulink environment and robot system toolbox. The results showed that the proposed control algorithm could achieve high-precision trajectory tracking while maintaining the stability of the manipulator, which verified the correctness and superiority of this control algorithm. The adaptive neural network sliding mode control algorithm provides a solution for enhancing the trajectory tracking accuracy of the end of manipulators.

At present, maintenance operations such as derusting, painting and testing of petrochemical storage tanks in my country are usually completed manually, which is inefficient and dangerous.The wall-climbing robot can complete the above maintenance work instead of manual work, but its frequently-used contact permanent magnet adsorption method will affect its obstacle-surmounting operation.Therefore, aiming at the wheel-legged wall-climbing robot with obstacle-surmounting ability, a design and optimization method for improving the adsorption capacity of its permanent magnet adsorption device was proposed.Firstly, based on the principle of obstacle-surmounting and permanent magnet adsorption of the wheel-legged wall-climbing robot, four design schemes of non-contact permanent magnet adsorption device were proposed.The two-dimensional static magnetic field simulation analysis for the permanent magnet adsorption device was carried out by the Ansoft Maxwell software, and its optimal structure was obtained.Then, through force analysis, the structural parameters affecting the magnetic adsorption force of the permanent magnet adsorption device were determined.Finally, based on the principle of control variable method, the influence of structural parameters of permanent magnet adsorption device and steel wall on the magnetic adsorption force was analyzed through simulation, and the optimal value of each structural parameter was determined.The results showed that when the radius of steel wall was 10-14 m, the gap between adjacent permanent magnet adsorption units and the number of permanent magnet adsorption unit had a relatively great influence on the magnetic adsorption force; when the gap between adjacent permanent magnet adsorption units was 2-4 mm and the number of permanent magnet adsorption unit was 3-5, the utilization rate of magnetic adsorption force was relatively high.Experiments under certain conditions had verified the accuracy of optimization results.After optimization, the measured value of the magnetic adsorption force of the permanent magnet adsorption device was about 16.45% higher than the simulated value on average, and the optimized device could effectively ensure the stable movement of the wheel-legged wall-climbing robot on the steel wall of petrochemical storage tanks.The research results can provide reference for the structural design and optimization of the magnetic adsorption device.

Aiming at the difficulties of status monitoring and predictive maintenance of complex mining equipment under harsh working conditions, a predictive maintenance system based on digital twin was proposed by combining various comprehensive modeling, analysis and prediction techniques, such as status monitoring, fault warning and predictive maintenance.Firstly, the design flow and construction principle of digital twin of complex mining equipment were introduced, and the function of predictive maintenance system was realized in the process of building digital twin.Then, the status data acquisition method based on the LabVIEW, MySQL and Unity3D was studied, and the Unity3D development engine was used to build a three-dimensional visual status monitoring platform for complex mining equipment, and the current equipment status was visualized through virtual space.Finally, the applicability of optimized BP(back propagation)neural network in the fault warning of complex mining equipment was analyzed.At the same time, the predictive maintenance model of key parts of complex mining equipment was established by MATLAB software, and the warning results were transmitted to the Unity3D development engine through MySQL database to drive and deploy the preset maintenance process, so as to achieve the fault warning of key parts under the real-time monitoring of equipment status.According to the actual maintenance process of shearer hydraulic system, a mixed reality(MR)predictive maintenance strategy was formulated, and the effectiveness of the hydraulic plunger pump of shearer rocker arm was verified by taking it as the experimental object.The results showed that the fault prediction accuracy of the proposed predictive maintenance system was higher than 90%, and the fault warning results could drive HoloLens glasses to achieve the maintenance interaction of virtual guidance, which verified the effectiveness of the predictive maintenance function of the system.The research results can provide new ideas for predictive maintenance of complex mining equipment.

The lower limb exoskeleton assisted robot has problems such as whether the human-machine joints match, and whether the active joint design meets the driving force requirements of human joint during motion.In order to solve these problems, based on the designed electro-hydraulic servo driven lower limb exoskeleton assisted robot, by simplifying it into a seven-link structure, the instantaneous dynamic model of swing phase and support phase were constructed by Newton-Euler method combining with the gait balance theory.Then, the angle data, velocity data of human motion under different gait phases and the robot structure parameters were substituted into the Newton-Euler dynamic iteration equations to obtain the theoretical driving torque of each joint of the robot.Finally, the ADAMS(automatic dynamic analysis of mechanical systems) simulation experiment and human-machine cooperative walking aid experiment were carried out, and the correctness and effectiveness of the constructed dynamic iteration equations were verified by comparing the peak driving torque of each joint of the robot.The results showed that using the Newton-Euler method to solve the driving torque of the lower limb exoskeleton assisted robot joint could provide important theoretical support for its structural optimization and control strategy formulation.

In order to shorten the development cycle of omni-directional mobile navigation system of robots and improve the reusability and portability of codes, the ROS(robot operating system)with open source and distributed architecture was used as the research platform.In view of the inconsistency of protocol, poor real-time performance and complex application of traditional bus, the IgH master station under Linux was proposed to conduct EtherCAT(ether control for automation technology)communication between the control system and drivers.Firstly, an appropriate task period was selected, and the IgH master station was integrated with ROS platform.Then, kinematics modeling of omni-directional mobile platform was establish.By establishing URDF(unified robot description format)model and odometry model and combining the Navigation function package provided by ROS, an omni-directional mobile navigation system with good openness, high code reusability and stable performance was developed.The research showed that the navigation system could effectively realize autonomous navigation, with the advantage of simple structure, excellent synchronization and low cost.The research result provides a new method for the precision control of omni-directional mobile robot.

In view of the problem of mathematical nonlinear regression, it is necessary to continuously improve the design model and design parameters, so that the design effect is the best. The response surface method is often used to optimize the minimum volume problem under the constraint conditions, which means that the simulation model is fitted by the function relation and the optimization direction is determined by the screening test. In order to optimize the shape of the classic 10-bar truss structure,based on the response surface, the APDL (ANSYS parametric design language) program was written and run, and the initial stress and volume of the truss were obtained. The change of node coordinates was used to reflect the change of shape. Each factor was set at three levels and encoded as -1, 0 and 1, and the center and level were adjusted by response surface method (RSM). Based on the adjusted level, the best neighborhood was found, and then the optimal solution of the volume under the allowable stress in the best neighborhood was solved by the optimization software. Finally, the determined node vertical coordinate value was returned to the APDL program to verify whether the constraint condition was satisfied. If it was satisfied, the volume was the best solution at this time. The results indicated that the iterations number was only 3 times when using the response surface method, which could quickly locate the optimal solution and reduce the previous design cost. By comparing the experimental design method in literature[9], it was found that the RSM was more efficient in optimizing the shape of the structure. In engineering applications, it is efficient to locate the design test program and find the best matching design under constraint conditions.

Biomechanical study of human upper limb is one of the most referenced aspects for the optimization of upper limb posture and the design of related products. Firstly, a real-time optical motion capture system was used to capture the real-time position of key points of the human body in the course of executing the specified action. The focus of the work was to calculate and deeply analyze the experimental data of the human upper limb by MATLAB software. Then, the human upper limb was simplified as a club model, and the variation value of each joint angle of the human upper limb during the motion process was calculated by the cosine theorem. The dynamic joint torque was computed by the inverse dynamics and the change of main muscle force was calculated by the optimization analysis. Lastly, the human upper limb motion comfort was evaluated by calculating the real-time load rate of human upper limb muscles, and the motion comfort index evaluation model of human upper limb was established. The experiment result proved that the human upper limb muscles were in the comfort state when the body executed the specified action at a sitting posture. The results provide a theoretical basis for the depth analysis of human upper limb motion.

As an important spatial force sensing element, the six-dimensional force sensor is widely used in robot force/position control, grasping assembly, contour detection, autonomous obstacle avoidance and human-computer interaction. At present, improving the accuracy is one of the main research directions of six-dimensional force sensors. However, due to the influence of own structure and processing error and other factors, the six-dimensional force sensor will produce the interdimensional coupling phenomenon, and the interdimensional coupling is an important factor affecting its accuracy. In order to reduce the influence of coupling error, the decoupling algorithm of six-dimensional force sensor is studied by combining error analysis, theoretical derivation and experimental verification. Firstly, the coupling analysis of the six-dimensional force sensor was carried out, and its coupling model was obtained. Then, the linear decoupling algorithm of the six-dimensional force sensor was studied, and on this basis, the decoupling algorithm based on polynomial fitting was proposed to reduce the coupling error without changing the structure of the six-dimensional force sensor, so as to improve its accuracy. Finally, the orthogonal parallel six-dimensional force sensor was selected to carry out calibration experiments, and two algorithms were used for decoupling solution. The results showed that the decoupling algorithm based on polynomial fitting could reduce the influence of interdimensional coupling on the accuracy of six-dimensional force sensors. The proposed decoupling algorithm effectively improved the accuracy of the six-dimensional force sensor. Compared with the linear decoupling algorithm, the maximum coupling error was reduced by 8.914 percentage points and the linearity error was reduced by 0.111 percentage points. The research results can provide reference for reducing the coupling error and improving the accuracy of six-dimensional force sensors.

To improve the mechanical performance of the all-terrain mobile robot body structure, an optimization method combining multi-body dynamics, finite element analysis and orthogonal test is proposed.Aiming at the full-load bending and torsion conditions of the all-terrain mobile robot, the external load of this mobile robot during motion was obtained by the multi-body dynamics analysis, and the dynamic mechanical performance parameters of the body structure were obtained by combining the finite element analysis, so as to verify the mechanical performance of the body structure under extreme conditions.Based on the orthogonal test of four factors and three levels, the influence of the thickness of bottom plate, the thickness of the suspension support, the length of the suspension support stiffener and the thickness of the raised support stiffener on the maximum stress, maximum deformation and mass of the all-terrain mobile robot was studied.The results of orthogonal test were analyzed by the grey correlation analysis method.Through the comparison of grey correlation degree of all factors, the best optimization scheme for the all-terrain mobile robot body structure was obtained as follows:the thickness of bottom plate was 5 mm, the thickness of the suspension support was 2 mm, the length of suspension support stiffener was 65 mm and the raised support was added stiffener with thickness of 2 mm.The analysis results showed that compared with the original scheme, the optimized all-terrain mobile robot body reduced the mass by 6.93%, while the maximum stress was reduced by 12.47%, and the maximum deformation was reduced by 41.69%.It indicated that this optimization scheme could improve the performance of body structure and reduce the body mass and the power consumption, which verified that the effectiveness of the proposed optimization method.The research results can provide a reference for the dynamic mechanical performance analysis and optimization of mechanical structures.

In order to study the temperature distribution of the electromagnetic micro hammer peening mechanism in the working process and improve its power density, first of all, based on the existing electromagnetic micro hammer peening mechanism, the relationship between its thermal effect and output power was analyzed from the perspective of energy, and it was clarified that the thermal effect would limit the maximum output power of mechanism.Then, the CFD(computational fluid dynamics) simulation analysis of the temperature field of electromagnetic micro hammer peening mechanism under air-cooling and water-cooling mode was carried out by the COMSOL Multiphysics software, and the equivalent convective heat transfer coefficients under different inlet boundary conditions were determined; at the same time, according to the relationship between the equivalent convective heat transfer coefficient and the inlet boundary condition, a transient temperature analysis model for this mechanism was established.Finally, a temperature measurement experimental platform for the electromagnetic micro hammer peening mechanism was built, and the temperature rise characteristics and the steady-state temperature characteristics of the mechanism were experimentally studied.The experimental results showed that the proposed thermal effect simulation analysis method for the electromagnetic micro hammer peening mechanism was relatively reasonable and accurate, which could provide a reference for the temperature control and structure optimization of micro hammer peening mechanisms.

Aiming at the requirements of obstacle-surmounting performance of search and rescue robots in complex terrain environment, a passive terrain adaptive mechanism for wheeled search and rescue robot is designed, and its obstacle-surmounting performance is analyzed. Firstly, based on the analysis of traditional obstacle-surmounting mechanism, the terrain adaptive mechanism was selected and optimized by genetic algorithm, so that the design of passive terrain adaptive mechanism for wheeled search and rescue robot was completed. Then, the dynamics model of wheeled search and rescue robot was established based on the D'Alembert principle, and its obstacle-surmounting ability was analyzed and calculated. Finally, a multi-rigidbody dynamics model of wheeled search and rescue robot was established, and its obstacle-surmounting performance simulation was carried out and compared with the theoretical calculation results. The comparison results verified the ability of obstacle-surmounting and terrain adaptation of the wheeled search and rescue robot. The research results can provide a theoretical basis for the prototype construction and subsequent research of wheeled search and rescue robots.

The co-simulation method can be used to analyze the kinematics, dynamics performance and hydraulic system characteristics of piston pump in real time, which can be widely used in the design and optimization of piston pump products. A distributed co-simulation of axial piston pump based on functional mock-up interface (FMI) was proposed to address the shortcomings of high discretization of analysis and optimization and low efficiency in traditional optimization processes. By developing automatic optimization components, the iterative optimization of key structural parameters of damping groove was achieved. Firstly, kinematics and dynamics analysis was carried on the piston pump shaft system, and the motion model and force model of the piston pump shaft system were established to determine the constraint relationship of shaft system components; secondly, a co-simulation model of the piston pump was established to study the motion, force, and deformation characteristics of the piston pump; then, a distributed co-simulation model of the piston pump was built based on cloud server, and heterogeneous scheduling of each simulation software was achieved through FMI technology; finally, based on cloud platform architecture, an optimization calculation template for the damping groove of piston pump was developed, achieving the solution of the optimal structural parameters of the damping groove and its automatic model creation. The simulation results showed that after optimizing the damping groove structure, the outlet flow pulsation rate of the piston pump was reduced by 35.78%. The proposed method can effectively improve the efficiency of simulation and optimization , and reduce the workload of research and development personnel.

Aiming at the steering driving conditions of four-wheel independent drive and four-wheel independent steering(4WID-4WIS) intelligent vehicles, a new method for trajectory planning using third-order Bézier curve was proposed based on the Ackerman steering principle.Firstly, an optimal trajectory with minimum curvature difference was obtained by using the optimal function, which met the initial state constraints and target state constraints of intelligent vehicle and the curvature continuity constraints.Then, a position estimation algorithm was proposed, which calculated the position increment of intelligent vehicle based on the navigation angle measured by the inertial navigation system and the pulse number of encoder, so as to estimate its position during driving and calculate the driving trajectory length.Finally, the planned intelligent vehicle trajectory was simulated in the MATLAB software, and the rationality and feasibility of the trajectory planning method and position estimation algorithm were verified on the real vehicle test platform.The results showed that the 4WID-4WIS intelligent vehicle could drive to the given end point according to the planned trajectory, and its lateral position estimation error was 0.19%, the longitudinal position estimation error was 0.20% and the driving trajectory length calculation error was 0.22%; compared with other single algorithms such as mileage calculation method and ranging method, the proposed position estimation algorithm had high precision, which can provide reference for trajectory planning and position estimation of other mobile robots.

Under the specific wind load, the stress conditions of different components and parts of overhead transmission lines are very different. In severe cases, it can lead to instability of the transmission tower line system and fracture of insulator string even, which greatly affects the safety of power grid operation. Taking an overhead line in a mountainous area of Yunnan as the research object, the isotropic and anisotropic eigenvalue buckling analysis of composite insulator string mandrels was carried out based on ANSYS finite element simulation software. A new type of quadruple V-shaped insulator string was constructed. The mechanical properties of bigeminy and quadruple V-shaped insulator strings under different wind loads were compared and analyzed by introducing the coefficient of P_h/G_v (horizontal load/vertical load), and the deformation, maximum stress of the windward side and leeward side and horizontal displacement of the lowest point of V-shaped insulator strings were analyzed. The results showed that when P_h/G_v=2.34, the maximum stress on the leeward side of the V-shaped insulator string was minimal; as the P_h/G_v increased, the stress variation curve of the quadruple V-shaped insulator string was smoother than that of the the bigeminy V-shaped insulator string, and the horizontal displacement of its lowest point was smaller.When the angle between the V-shaped insulator string and the vertical plane was 10°-30°, the smaller the angle was, the more stable the overall performance of V-shaped insulator string was. The research provides a strong basis for the design improvement of V-shaped insulator string and has strong engineering practicability.

In order to alleviate the congestion of multi-lane stereo garage during parking and picking-up peak, realize the safety, energy saving and time reduction of vehicle access, the optimization design of garage and vehicle access strategy were studied.A multi-lane intelligent stereo garage with accompanying bearing plate was designed, which was divided into two parts: electromechanical execution system and computer control system.The electromechanical execution system was mainly composed of human-vehicle separation cabin, horizontal transmission mechanism, lifting mechanism, stackable storage rack, accompanying bearing plate warehouse and safety protection mechanism.The computer control system was mainly composed of the upper computer (computer server) in the control room and the lower computer (PLC,programmable logic controller) on the roadway locomotive.According to the mechanical design method, an optimization design was carried out on the horizontal transmission mechanism, which eliminated the roll moment of the roadway locomotive caused by the stacking action of the horizontal transmission mechanism, and saved the motor action time.In order to improve the satisfaction degree of car pick-up owners’waiting for the service, the strategy of "pick-up priority+cross queue access" was proposed, which employed the computer control method to realize the automatic control of pick-up and cross queue access.Genetic algorithm (GA)toolbox of MATLAB was used to optimize the empty space search in parking.The research results provide a realization path for the low energy consumption and low time consumption of lane-type stereo garage.

Due to the dramatic changes during the course of missile fight, the temperature and thermal load of fairing skin have a rapid change, and that will bring a great influence on the operational performance of the missile. To ensure the design accuracy of the electronic device, a design calculation method based on the fluid-solid coupling nonstationary numerical simulation was proposed. Meanwhile, by solving the heat transfer equation of the fluid and the solid surface, the energy piecewise function of each point in the flow field was obtained. The piecewise function of transient power curve corresponding to each structure microelement of flow field was calculated by MATLAB software, and the Fluent thermal simulation analysis method was used to predict the transient variation of working temperature and ambient temperature of the whole missile-borne electronic equipment intuitively through the power curve piecewise function. By the study of aerodynamic heating problem of a type of anti-radiation seeker and its missile-borne electronic equipment, the space distribution of transient thermal every moment in the flow field of the seeker and its missile-borne electronic equipment was calculated, and the obtained results were in good agreement with the practice. The results show that the method has a certain reference for transient thermal analysis and corresponding heat dissipation design of similar electronic devices.

Roundness error is an important parameter to evaluate the machining accuracy of machine tools.In order to realize the evaluation of the roundness error measurement uncertainty of machine tools, the contributing factors and uncertainty evaluation method of the machine tool roundness error based on the ballbar measurement are studied. Firstly, the least square method (LSM) was used to evaluate the roundness error. Secondly, a multi-source fusion error measurement uncertainty evaluation method was proposed based on the black box theory. Thirdly, according to the basic principle of machine tool roundness error measured by the ballbar, an evaluation model of machine tool roundness error measurement uncertainty was established. Finally, multiple sets of repeated measurement experiments on the roundness error of the ZX plane of a machining center were carried out by the ballbar, and the roundness error measurement uncertainty was calculated by the proposed method, which was compared with the calculation results based on the Monte Carlo method (MCM) for verification. The results showed that the roundness error uncertainty evaluation results of the machine tool based on the proposed method and MCM were 1.1900 and 1.1600 μm, respectively, and the relative deviation was about 2.5%, which verified that the feasibility of the proposed method. The proposed method avoids the complicated process of solving the functional relationship between inputs and outputs, and simplifies the evaluation process of the roundness error measurement uncertainty of machine tools, which has strong practicability.

In order to improve the utilization of solar energy, a solar intelligent tracking system based on light intensity perception was designed according to the maximum power tracking principle.Firstly, based on the working principle of the solar intelligent tracking system, its overall structure was designed; then, based on the performance requirements of each module of the solar intelligent tracking system, the hardware equipment selection and the software design were carried out; finally, the corresponding experimental platform was built to assemble and debug the solar intelligent tracking system, and its performance was verified through functional test.The results showed that the designed solar intelligent tracking system could realize the intelligent tracking of solar panel to sunlight, and could complete remote control; in addition, the system had the advantages of simple structure and low cost, and it could not only save energy, but also provided good power supply, which met the needs of high-tech products, and conformed to the development trend of modern energy utilization.

Aiming at the problems of high cost, large floor space and failure to meet the emission standards of the existing wet waste treatment device nearby, a new type of mechanical compressive wet waste treatment device is developed. Firstly, the functions and technical characteristics of the mechanical compressive wet waste treatment device were introduced. Then, the modular design of the mechanical compressive wet waste treatment device was carried out, which mainly included the lifting device, the conveyor belt sorting device, the crushing and dewatering device, the sewage treatment device and the briquetting device. Finally, the technical parameters of the mechanical compressive wet waste treatment device were designed and calculated, and its automatic control scheme was designed. The designed mechanical compressive wet waste treatment device integrated the traditional waste crusher and the press dehydrator to realize the efficient dehydration of the wet waste; through the treatment of the briquetting device, the compression of the waste residue was realized, which could effectively relieve the problems of tight capacity and secondary pollution in the waste transportation; by the treatment of the sewage treatment device, the recycling and reuse of sewage was realized.The mechanical compressive wet waste treatment device has the advantages of low cost, small volume, simple treatment process and less labor resource consumption. It is suitable for small and medium-sized waste collection stations that have implemented waste classification and collection, and has broad market prospects in the wet waste treatment industry.

The screw motor is the power assembly of the screw drilling tool, and its cross-sectional shape directly affects its working performance. Good working performance is the design goal of screw motors. In order to obtain a screw motor with good working performance, the evaluation criteria of efficiency, sealing cavity reliability and stability were proposed according to the working principle and structural characteristics of the screw motor. Then, a three-dimensional finite element model of fluid-structure coupling of the screw motor was established, and the contact force change of the sealing cavity contact strip of the short-amplitude endocycloid screw motor under different load conditions was analyzed based on the explicit nonlinear transient dynamics method. Finally, based on the evaluation criteria for the efficiency of screw motors, a new screw motor with quasi circular-arc contour-pattern was designed to address the key factors affecting the efficiency of short-amplitude endocycloid screw motors, and the good working performance of this screw motor was proved by numerical simulation and experiment. The results showed that under the same load conditions, the sealing cavity of the screw motor with quasi circular-arc contour-pattern was more stable and reliable than that of the short-amplitude endocycloid screw motor, and it had better working performance under higher load conditions. The research results lay a foundation for the contour-pattern design of high-performance screw motors in the future.

In order to solve the problems of inconvenience in experimental operation, difficulty in monitoring equipment operation status and poor interactivity caused by concealed installation position and difficulty in installing auxiliary devices on the self-built laser parallel processing experimental platform, taking a single optical displacement stage in the experimental platform as an example, an interactive control system based on digital twin technology was designed by using Unity engine. This interactive control system used MQTT(message queuing telemetry transport) communication protocol protocol to complete the cross-software information interaction by using the server to transfer data. The Kinesis control software of optical displacement stage and the virtual control panel in Unity engine served as clients in MQTT communication, acting as subscribers and publishers. The digital twin model of the optical displacement stage performed real-time mapping of the motion state of its physical entity based on data information. Users completed synchronous interactive control of the physical entity and the digital twin model through the Kinesis control software or virtual control panel. The secondary development of Kinesis control software was carried out by referencing.dll file, and the motion control class of Kinesis control software was called to complete the motion control of the optical displacement stage. The motion data variables were set to high-precision float type and decimal type to ensure that the data precision was not lost. Ten groups of actual processing data were selected to test the operation latency and synchronization of the interactive control system. The results showed that the data publishing time on the Kinesis control software and the data subscription time on the Unity engine were controlled within 20 ms and 10 ms, respectively. The designed system can better ensure the consistency of synchronous control and real-time action mapping between the digital twin model and the physical entity, which achieves the visual monitoring function of the motion state of the optical displacement stage. In addition, the motion data type can meet the micron level information transmission, ensuring the accuracy requirements of the optical displacement stage. At the same time, the functions of virtual control panel run normally, which improves the convenience of the optical displacement stage control.

Aiming at the problem of poor synchronous steering capability existing wheeled omnidirectional mobile robot in practical engineering applications,a synchronous steering structure of driving wheel is designed. Firstly, the working mechanism of the synchronous steering mechanism was analyzed based on virtual prototyping technology. Then, the kinematics analysis of the robot with the synchronous steering mechanism was carried out based on the kinematics principle and the relationship between the motor input speed and the steering speed of the driving wheel was obtained. Lastly, according to the structural parameters of the system, a physical prototype of the robot which was mainly used in the material handling of the factory was manufactured and verified by experiment. The results of lateral movement experiment of the robot showed that this robot can move in all directions through different ways, which verified the omnidirectional moving function of the robot. The research indicates that the application of synchronous steering mechanism can reduce the control difficulty of wheeled omnidirectional mobile robot and realize the omnidirectional mobile robot with high speed, high precision and high stability.

At present, the energy conversion efficiency of passive walking aid exoskeleton is relatively low.Based on the gait characteristic of human body and the gravitational potential energy and kinetic energy generated during walking, the power assisted principle of exoskeleton was analyzed, and a lower limb passive exoskeleton was designed using multi-level energy locking mechanism.Dynamic simulation model of exoskeleton was established, and the energy storage performance of exoskeleton was simulated and analyzed with weight and walking speed as variables.Based on EMG(electromyography) signals, the assistance performance of exoskeleton was studied, and the timedomain curves and integral values of EMG signals of lower limb muscles with and without exoskeleton were compared.The results showed that the multi-level energy locking mechanism could improve the energy storage efficiency of the exoskeleton.The exoskeleton had excellent adaptability to different weight and walking speed, while the stored energy was positively correlated with both weight and speed.The exoskeleton has good boosting effect under different walking states.

The utilization of unmanned aerial vehicle(UAV)technology to realize the power line laying is gradually becoming the main trend of power industry development.Studying the UAV autonomous stringing technology can effectively improve operational efficiency, reduce construction cost and ensure security of workers.However, the problems of UAV stringing technology at this stage are mainly as follows:1)Most UAVs rely on manual control or ground station to release waypoint control, which has a low level of intelligence, and long-term operation will bring strong load to electric workers; 2)The UAV lacks autonomous obstacle avoidance ability and has insufficient perception ability, and the obstacles such as wires and poles will cause safety hazards to it.In order to solve the above problems, fitstly, the hardware framework and the modular software framework based on ROS(robot operating system)of UAV autonomous stringing system were constructed, and on this basis, the stringing task planning algorithm and the stringing bow detection algorithm were implemented, so that the UAV had a stable autonomous stringing capability.Then, the collision model of UAV was constructed by using collision detection method, and the path planning algorithm of UAV was proposed.At the same time, the ground station-based obstacle avoidance strategy was introduced to effectively improve the safety of UAV.The experimental results showed that the software and hardware framework of the designed UAV autonomous stringing system was reasonable, and the stringing task planning algorithm could help the UAV complete the autonomous stringing task efficiently and stably.The ground station could monitor the status of the UAV in real-time, and assisted the UAV to avoid obstacles when necessary, so as to ensure the safety of UAV to the greatest extent.The designed system is safe and reliable, and can meet the actual electric stringing operation requirements.

The steel cord will produce residual torsion stress during twisting, which will cause different degrees of rotation opposite the twisting direction after the twisting progress is finished, and it will seriously affect the performance of steel cord. In order to reduce the residual torsion stress in the process of wire twisting, the on-line monitoring and automatic elimination control system for the residual torsion of steel cord was designed. The software and hardware of the control system were reasonably configured by the SIEMENS S7-200 series PLC (programmable logic controller), and the hardware and the software design of the system were expounded in detail. The touch screen of the delta DOP series was used to realize the on-line real-time monitoring of the residual torsion value of steel cord. The whole machine has stable performance and realizes the control and elimination of the residual torsion, which meets the requirements of automatic production with high flexibility, high efficiency and high quality in the production line.

In order to realize the stable rotation of a spacecraft in space with low power consumption, a design method of space large inertia load driving system based on buffer damping was proposed from the perspective of improving its dynamic performance and steady-state performance.Through the matching design of system damping parameter and the use of spring damping technology, the fast starting and stable braking of the driving system in the process of large inertia rotation were realized, the problem of large overshoot of angle stroke was solved, and the requirement of motion accuracy was met.The dynamic modeling of the driving system was carried out by SimulationX software, and the influence of transmission stiffness and damping characteristic on the starting and braking of the driving system was simulated and analyzed.Finally, the experiment verified that the driving system could start and brake large inertia load smoothly, with stable performance and high motion accuracy, which verified the rationality of the design method of the driving system.The research results provide a better implementation method for driving large inertia load with low power.

Brake-by-wire technology is a development direction of the future automotive brake technology which has aroused extensive concern of domestic and foreign car manufacturers. Since the existing automotive electromechanical brake (EMB) was lack of wear compensation device which was specified in the national standard, GB12676-2014, an innovative EMB with gap automatic adjustment function was designed. The mathematical models of drive motor, motor friction, worm and gear, ball screw and loading were established by MATLAB/Simulink. By building the EMB bench, the braking performance differences between simulation and experiment were tested and analyzed under the signal of step, triangle wave, square wave and sinusoidal wave. The braking performances of EMB with the gap automatic adjustment function or nor were also tested and analyzed. The experimental results showed that the start-current of the EMB system had a "peak" characteristic and the clamping force was sensitive, which could meet the braking requirements. According to the experimental data, the parameter relations were concluded:the clamping force was linearly related to the locked-rotor current, and the characteristics of cubic polynomial were met by the relationship between clamping force and screw displacement. The correctness of the mathematical model was verified by the simulation and experimental results. A theoretical basis for reducing the force sensor and other devices could be provided by the conclusion of parameters relational characteristics. The experimental outcome indicates that the gap automatic adjustment function of the new EMB can guarantee that the brake gap and the response time are consistent at each time, which can further improve the safety of brakes.

In order to improve the speed control accuracy and adaptability of mobile robots under the complex environment, a speed control method of the mobile robot based on the multi-sensor fusion information is proposed. Firstly, according to the multi-sensor nonlinear optimization fusion theory, an optimized estimation model of mobile robot motion states was constructed by minimizing the residual errors of the motion observation. Then, the observation methods of the mobile robot motion by the monocular camera, the wheel odometer and the inertial measurement unit (IMU) were introduced, and the residual errors and their Jacobian matrices of the mobile robot motion observed by different sensors were calculated. Finally, the speed control system of the mobile robot was designed by combining the estimated motion state information with the incremental PID (proportion integration differentiation)control strategy, and the performance of this control system was verified through a number of tests.The test results showed that the proposed speed control method of the mobile robot effectively reduced the speed estimation error, and had a greater improvement in accuracy and robustness than the speed control method based on the wheel odometer information. The research result has significant significance for improving the performance of mobile robots in complex environments.

Metallurgical industrial robots play an increasingly irreplaceable role in modern industrial production.Due to the great improvement of industrial automation, people constantly put forward new requirements for the performance of metallurgical industrial robots, especially for the stability of them control system.In view of the problems of low trajectory tracking accuracy and lack of adaptive dynamic adjustment characteristics of metallurgical industrial robots, a fuzzy iterative Q-learning control algorithm was proposed.Taking 6-DOF(six-degree-of-freedom)dual-arm robot as the research object, the fuzzy control rules were compiled by using the Fuzzy toolbox and the position error and its change rate generated by the robot were taken as the input of the fuzzy controller, and then the quantization factor and scale factor in the fuzzy controller and the PD(proportional derivative)parameter in the iterative learning control was adjusted by introducing the Q-learning strategy, so as to complete the design of fuzzy iterative Q-learning controller.Then, combined with ADAMS(automatic dynamic analysis of mechanical systems)and MATLAB software, a 6-DOF dual-arm robot simulation platform was built to carry out the simulation of shaft hole assembly task with high-precision trajectory tracking.The simulation results showed that the 6-DOF dual-arm robot had high trajectory tracking accuracy in joint space, and could complete the coordinated assembly task of dual arm shaft holes, which verified the effectiveness and advancement of the proposed control algorithm.The research results can provide reference for the shaft hole assembly of dual-arm cooperative robot with high-precision trajectory tracking, and have certain practical application value.

Multi-motor driving plays a crucial role in the way of high-speed, long-distance and large-capacity for conveying equipment. Because of the advantages of no friction, no rotating drive components, arbitrary arrangement along the conveyor length direction and the reduction of the characteristics of belt tension, the linear motor becomes an ideal middle drive form in the high performance special belt conveyor. The merits and demerits of linear motor were compared with rotary motor based on its fundamental principle. The type of secondary structure was determined by comparative analysis for linear motor used in belt conveyor. And the secondary structure of belt was designed. According to the closed bulk handing material testing system, the test rig of static and dynamic characteristics were established. The thrust (tension difference of belt) of the linear motor was obtained using the Euler formula and the point by point tension method. Meanwhile, the proportional relationship between voltage and thrust was verified by experimental as well as air-gap and thrust. And the dynamic test (mechanical properties test) was carried out indirectly. Then the mathematical relationship between the thrust and belt speed was obtained. Moreover, the pulling force of stable running and starting process of belt were simulated based on Belt Analyst software and they also were compared with the experimental results. The experimental results showed that the thrust was proportional to the square of the voltage and the square of the reciprocal of air-gap respectively. It was also concluded that the theoretical curve between voltage and thrust (as well as air-gap and thrust) was consistent with experiment value. The ratio of thrust and input power on the linear motor was large, and the smaller the air-gap, the greater the ratio. In addition, compared with rotary motor, the linear motor had no critical speed, and it represented very soft for its mechanical properties. Ultimately, the simulation value of pulling force of stable running was basically consistent with the test value and all relative error within 2%. But the error was larger in starting-up process, which indirectly indicated the importance of ensuring the uniform of air-gap. This work can be applicable to the practical application and improvements for multi-motor coordination driving the ultra-long distance belt conveyor.

So far, the overhaul of large spherical tank is carried out by building an all-round scaffold in most cases. However, there are many problems in this way, such as high labor intensity, long overhauling period, poor safety, and easy to cause secondary damage and so on. In order to solve problems mentioned above, an interior overhaul workbench of large spherical tank was designed. The workbench consisted of a bottom supporting platform, a central supporting column, a revolving supporting platform, a top revolving platform and pulling devices. What's more, it combined a kind of bidirectional traction from the top and bottom and a revolving motion from the top, which ensured manned workbasket could be delivered to all the overhauling spots quickly and accurately. The manned workbasket, central supporting column and both of the top and bottom revolving supporting arms formed a four-bar mechanism to ensure the manned workbasket remained horizontal throughout the travelling process. In order to verify the reasonability of this workbench, simulation analysis of dynamics and statics was done by MATLAB and ADAMS. The result showed that this workbench met the requirements of bearing capacity, stability and safety. With a simple structure, handling facility, the overhaul workbench is powered by electricity, which is easy to monitor. Therefore, this overhaul workbench will greatly improve the working efficiency of overhauling large spherical tank.

According to the characteristics of engineering vehicles, on the basis of engine configuration,a novel turbine pneumatic starter motor is designed. Some innovations was applied to the devices in starter drive, such as gear propulsion and the installing connection, and the gear clash was avoided, and the small volume, good strength, reliable transmission, long service lifetime and convenient exchanging of small gears were realized. The two stage impact turbine rotor was used on the powerplant mounting system and the intake port was made up of two stators and two rotors raising the gas kinetic energy utilization. The power transmission assembly was improved based on the ratchet clutch, the rolling friction and bearing supports were used to make the piston axial travel by the air through airway interface, which decreased the number of parts and friction. The planetary reducer was used on the decelerator assembly that could run on low speed, which had a good advantage of light weight, small volume, big torque and overload, little friction and simple structure. The in-situ test was made on the motor. The experiment showed that the structure was proportion to the car engine and more adaptive to the engine starting characteristics and requirement, which could be applied on the start of locomotive engine. The motor had wider source conditions, and the vehicles could be started multi-times without air admission, which made the start more reliable. The structure design provides an alternative way for engine starting, which also plays a role in promoting the domestic pneumatic starter motor.

Autonomous underwater vehicle (AUV), especially the revolving AUV, is an important tool in the sea floor exploration,ocean landform observation and marine military ocea-nography research,but the endurance has been a key issue to limit its completion of long distance and long hours.At present,the underwater docking device only can dock with AUV with the par-ticular size and has poor versatility.In order to solve the problem of providing energy supplement and data uploading/downloading for different sizes of revolving AUVs,the different underwater docking forms were introduced and a universal underwater docking device was designed on this basis.The device used the underwater lighting guidance to guide the positioning of AUV, through the shroud to guide the AUV navigation when AUV entered the docking device,and used the screw slide to clamp and fix AUV finally.The device could provide energy supplement and upload/download tasks for different sizes of revolving AUVs,and improve its endurance,da-ta collection capabilities and cruising range. The light guide and clamping device of the underwater docking device were tested in the pool,and the reliability and feasibility of the under-water docking device were verified.The device is simple,versatile,stable and reliable,in addi-tion,it has a certain reference for the overall design of the underwater docking device.

In order to meet the needs of oil and gas exploration enterprises for clean, economic and highly reliable production under the background of carbon neutralization, a new electricity-replace-oil driving device based on the variable frequency speed regulation of two megawatt alternating current asynchronous motors was designed.Based on the modularization idea, the split modular box structure for high-voltage transformer and low-voltage transmission was designed, which improved the convenience of dispatch and use of the electricity-replace-oil driving device.The high-voltage transformer module was adopted the twelve-pulse rectifier transformer, which realized that only the transformer cost increased by 25% under the premise of no significant increase in the inverter cost, so as to greatly save the reactive power compensation cost.Especially in the high-power drilling section where the proportion of on-site electricity consumption was low, the measured power factor of the device was over 0.95.Aiming at the problem of unbalanced load in the dual-motor cooperative control, a PLC(programmable logic controller) control system based on the master-slave control structure was designed, and the speed matching control was combined with the converter droop control to control the motor speed deviation within 10%; at the same time, the designed control system could support the multi-place operation and remote monitoring of field data, which improved the reliability of the electricity-replace-oil driving device.The test run results showed that the designed electricity-replace-oil driving device could meet the actual engineering needs; compared with the traditional diesel driving device, it could save cost by 52% and reduce the carbon dioxide(CO₂) emission by 27% per month.The designed device has certain practical value in the field of energy conservation in oil and gas exploration.

The sodium combustion process will cause a significant increase in temperature and pressure of the test plant.As a part of the plant boundary, the door of the test plant should have the functions of fire and heat insulation and pressure sealing, but there is no engineering door that can meet this requirement in the current practical application.Based on this, according to the characteristics of sodium combustion process and combined with the actual working conditions of nuclear engineering, a new heat insulation sealing door with the functions of fire and heat insulation and pressure sealing was designed.Based on the structure of special engineering doors under different working conditions in the nuclear engineering, combined with the actual working conditions of temperature and pressure in this engineering, the locking mechanism, door panel assembly, door frame assembly, hinge and sealing strip of the heat insulation sealing door were designed, respectively.At the same time, the force of the locking mechanism components, the heat insulation performance of the door panel assembly and the selection of the sealing strip were analyzed through the design calculation, and the strength of key components such as door panel and compression rod of the heat insulation sealing door were analyzed by using theANSYS finite element software.Finally, according to the theoretical calculation results, the heat insulation sealing door prototype was made.The prototype test verified that the designed heat insulation sealing door had the functions of fire and heat insulation and pressure sealing and relatively high reliability at the environment of 280℃.The proposed design and analysis method of heat insulation sealing door can provide basis and reference for the design of equipment under similar working conditions.

In the course of oil drilling, high-quality drill bits play a vital role in reducing cost and improving drilling efficiency. A new hybrid single cone bit was designed by connecting the teeth palm with conical tooth and the cone with PDC teeth. The hybrid single cone bit was added with the PDC teeth based on general single cone bit, which broke rock by shocking and shearing. The big end of hybrid single cone passed through the center of bottom hole, and all teeth rings contacted with wall of hole which could achieve gauge protection during rock breaking. A finite element model of interaction between hybrid single cone bit and rock was established, and the bottom hole model, the main cutting force and rock breaking volume were simulated and analyzed. Bench test was carried out to verify the drilling pressure and the drilling depth which were obtained by the numerical simulation. Research results showed that the drilling pressure and the drilling depth obtained by numerical simulation conformed to bench test results, and the regulation of rock breaking load was consistent with the design characteristics of the cone bit structure. Comparing with the spherical single cone bit, the side force of hybrid single cone bit was reduced by 39.6%, and the rock breaking efficiency increased by 33%. The stability was higher when drilling using the hybrid single cone bit, and it could reduce the probability of well deviation as well. According to the results, the numerical simulation is effective to study the rock breaking law of the hybrid single cone bit, which provides a basis for further design and performance evaluation of the drill bit.

In order to improve the interrupting capacity of MCCB (molded case circuit breaker), the arc chamber of MCCB is optimized.Based on the theoretical study of the arc breaking process,three methods were used to improve the arc voltage.Firstly,the structures of arc plates were optimized,the pattern of the first piece's guide,the last piece's obstruction and the middle pieces' normal arrangement was used to achieve a good effect of arc cutting.Secondly,the mag-netic flux structure of slot motor was added,the speed of arc could be increased by increasing the intensity of magnetic field,the results of ANSYS simulation showed that the new structure in-creased 97 N magnetic blow force.Thirdly,air blowing structure was added,the voltage drop of arc column was increased by reducing the temperature of arc column,and PA66 was used as the gassing insert which had the fast recovery rate of medium.The methods were combined to get the optimized design scheme and to make the prototype sample to do short circuit interrupting test under the condition of 25℃ & 415 V AC voltage.Originally,it could only pass 50 kA,after op-timization it could pass 70 kA and the arcing time was shortened from 5 ms to 3 ms at the same time.It could be found that some of the products appeared arc chamber shell cracked issue after disassembling these samples,so the wall thickness of the crack position was increased 2 mm,the static analysis module of ANSYS was used to compare the equivalent stress of the shell before and after the change.The results showed that the new structure improved the strength of 40.2%, and it passed the engineering test after the new prototype samples were assembled again.The re-searching achievement has a certain significance for the follow -up new development and design improve-ment of MCCB products.