To solve the problem of no direct mechanical or hydraulic connection between the brake actuator and the brake pedal in an electronic mechanical braking system, leading to no feedback of road feel, a brake pedal feeling simulator was proposed based on magnetorheological dampers.

Ansys/Maxwell and Matlab/Simulink were used as the platform. The structural design of the sinking brake pedal feeling simulator, the structural design of magnetorheological damper, magnetic circuit analysis and electromagnetic simulation were carried out respectively, and the simulation analysis of traditional proportional-integral-derivative (PID) and fuzzy adaptive PID control under different working conditions of the whole system was compared.

The simulation results show that the brake pedal feeling simulator can track the characteristic curve of the traditional pedal well under different working conditions and has wide applicability. Compared with the traditional PID control effect, the fuzzy adaptive PID control has higher control precision and smaller control error, and has good application prospects.

A novel two-stage compound amplification mechanism design scheme was proposed to address the friction and clearance issues inherent in traditional revolute pairs within the large stroke design of micro-displacement platforms. The aim was to achieve high-precision and significant stroke displacement amplification through structural innovation.

Utilizing the theory of material mechanics, a static model was established. A two-stage compound amplification structure that integrated a flexible hinge lever amplification mechanism with a bridge amplification mechanism was employed. Piezoelectric ceramics served as the driving source, and a parameter optimization model was developed using Matlab software. The impact of key structural parameters on both the amplification ratio and input stiffness was systematically analyzed to identify the optimal parameter combination. The optimized structure underwent validation through multi-physical field simulation via finite element analysis.

Following optimization, the mechanism attains an impressive displacement amplification ratio of 13.1 times, with its natural frequency reaching 92.2 Hz. The maximum discrepancies between theoretical calculations and simulation results of the amplification ratio and natural frequency are recorded at 2.4% and 3.5%, respectively, thereby demonstrating the feasibility of this structural design.

The pipe belt conveyors are crucial equipment for bulk material transportation with significant environmental advantages. This study is aimed to quantify the lateral bending stiffness of steel cord conveyor belts.

Based on the analysis of standard ISO 703:2017, the measurement and analysis method for the lateral bending stiffness was determined. Numerical model and 3D simulation model of the steel cord conveyor belt were established. Deformation data under different schemes was obtained using numerical analysis method and finite element method. Error analysis was conducted to demonstrate the validity of the models. Furthermore, a generalized deflection formula for the lateral bending stiffness was derived based on the functional dependence of the belt's troughability on elastic modulus, linear mass, and cross-sectional geometric parameters.

The results provide a new perspective for quantifying the lateral bending stiffness of pipe conveyor belts and offer a basis for their design and engineering practice.

A health state assessment method combining deep residual shrinkage network (DRSN) and adversarial domain adaptation (ADA) was proposed to address the problems of vibration signal noise interference and inconsistent data distribution under different working conditions in the remaining useful life (RUL) prediction of rolling bearings, so as to improve the accuracy and generalization ability of RUL prediction.

Firstly, a health state assessment model combining deep residual shrinkage network and adversarial domain adaptation was constructed. The performance of DRSN in avoiding noise in vibration signals and adaptively extracting bearing degradation features was utilized to build the health indicator curve. Then, ADA was used to align the distribution of health indicators between the test set and the training set, so as to eliminate the difference in data distribution under different working conditions. Finally, the health indicators output by the DRSN-ADA model were input into the convolutional long short-term memory (ConvLSTM) network model, and the accurate RUL prediction of rolling bearings was realized.

In the XJTU-SY dataset and engineering tests, the health indicators constructed by DRSN-ADA are superior to the comparison methods in monotonicity, robustness and correlation, with their mean values reaching 0.61, 0.97 and 0.98 respectively. The mean values of mean squared error (MSE) and mean absolute error (MAE) of the RUL prediction results are 2.52% and 2.19% respectively, and the average score is 0.86, which is significantly better than the DRN, principal component analysis and root mean square (RMS) methods. These results verify the effectiveness of the proposed method in noise suppression and cross-working condition prediction.

The risks of losing magnetism upon power-off and high energy consumption are suffered by traditional electromagnetic grippers. And the problem of lacking the active magnetic force regulation function is still faced by permanent magnegrippers. A lightweight magnetic pole rotation gripper with optimized methodology was developed.

Based on the magnetic flux continuity principle and magnetic field superposition effect, the optimal design strategy integrating theoretical analysis, numerical simulation, and test verification was established through coordinated regulation of three key parameters: magnetic pole rotation angle, geometric dimensions, and air gap distance. The global optimal solution of the magnetic pole structural parameters was finally obtained.

Both simulation and test results demonstrate that the optimized gripper achieves superior magnetic adhesion performance per unit mass compared to existing models. The proposed device exhibits distinctive advantages including compact structure, simplified control mechanism, and quasi-linear control characteristics, showing broad application potential in material handling operations.

To solve the problems of fixed damping force and poor pseudo-humanity of traditional lower limb prosthetic knee joints, a magnetorheological damper was designed to meet the vibration reduction requirements of the lower limb prosthetic knee joint.

Through theoretical calculation, the maximum damping forces required for the knee joint swing phase during flat walking and flat running were obtained, which were 179.6 N and 1 377 N respectively. In order to adapt to the motion state of the lower limb prosthesis, a vibration absorber was designed to meet the damping force required by the knee joint swing phase. Through numerical simulation and test research, the influence of external disturbed magnetic field and temperature rise effect on the dynamics characteristics of magnetorheological damper were analyzed. The test of influence of external disturbance magnetic field and temperature rise effect on the dynamics characteristic of the lower limb prosthetic knee joint was conducted by using the lower limb prosthetic knee joint simulator.

The results show that the output damping force of the magnetorheological damper increases with the increasing magnetic flux density of the external disturbed magnetic field. Under the same conditions, the output damping force of the magnetorheological damper decreases with the rising temperature of the magnetorheological fluid. In the early stage of knee joint swing and the first half of its middle stage, with the increase of the magnetic flux density of external disturbed magnetic field, the hysteresis of knee joint movement increases, and the angle error increases. When the magnetic flux density of external disturbed magnetic field is 10, 20 and 30 mT respectively, the maximum bending angle of the lower limb prosthetic knee joint is 59.0°, 57.8° and 55.7° respectively, and the maximum angle error reaches 3.0°, 6.8° and 11.9° respectively. As the rise of the temperature of the magnetorheological fluid, the hysteresis of knee joint movement increases, and the angle error increases. When the temperature of the damper rises to 30, 35 and 40 ℃ respectively, the maximum bending angle of the lower limb prosthetic knee joint is 57.1°, 54.0° and 49.8° respectively, and the maximum angle error reaches 1.9°, 5.1° and 9.8° respectively. These conclusions provide a basis for the design and optimization of the lower limb prosthetic knee joint based on the magnetorheological damper.

Alternating magnetic fields induce vibrations in mechanical components, thereby generating noise. Fluctuations in electromagnetic excitation forces and electromagnetic torque are the primary causes of electromagnetic vibration noise. To analyze the generation mechanisms and functional patterns of these fluctuations, an electromagnetic vibration noise analysis was conducted on a slotted disk-type asynchronous magnetic coupler with 9 pole pairs and 16 slots.

Firstly, theoretical formulas for air-gap magnetic flux density and electromagnetic excitation force were derived using the magnetic scalar potential permeance method and Maxwell stress tensor method. Combined with finite element simulation, the harmonic order amplitudes of the Fourier decomposition of air-gap magnetic flux density and electromagnetic excitation force were obtained. Secondly, based on the energy method, an expression for cogging torque was derived. Finite element simulation was employed to determine the cogging torque and electromagnetic torque fluctuations generated during the operation of the magnetic coupler. Thirdly, an electromagnetics-structural-acoustic multi-physics coupling model was established. Using the modal superposition method, vibration acceleration and displacement produced during stable operation of the magnetic coupler were obtained, and the characteristics of its electromagnetic noise were analyzed. Finally, a test platform for the magnetic coupler was constructed to measure electromagnetic noise during stable operation. Test results were compared with simulation outcomes to validate the theoretical analysis.

The results indicate that low-order electromagnetic excitation forces are the main causes of vibrations in the magnetic coupler, and significant vibrations occur when the frequency of the electromagnetic excitation force approaches the natural frequency of the magnetic coupler. Comparison with simulation results shows that the test data obtained from the magnetic coupler test platform confirm the accuracy of the theoretical analysis.

In response to the visualization requirements of the models and analysis results necessary for the development of simulation analysis software for spiral bevel gear transmission systems, based on the structural characteristics of the bevel gear transmission system, the topological structure of the transmission system and the complete expression of the interrelationships among components were achieved by applying graph theory and object-oriented data structures.

The generation method of regularized point sets on the geometric surfaces of key heterogeneous components in the transmission system was investigated, and the precise construction and rapid assembly of the geometric models of bevel gears, transmission shafts, and bearings were accomplished using the open-source 3D computer graphics tool VTK. On this basis, the mapping between the geometric model of the transmission system and the mechanical model of loading contact analysis was established, and the visualization methods for the analysis results such as system deformation under loading and tooth surface meshing state were studied. Finally, the visualization effects of modeling and simulation analysis results of the bevel gear transmission system were verified through examples.

Research has shown that the comprehensive application of graph theory and object-oriented data structures can achieve a complete expression of the topological configuration and geometric correlation properties of bevel gear transmission systems. By applying the parameter expression modeling, sweep modeling, and triangulation modeling methods of the VTK library, accurate modeling of heterogeneous components can be achieved. Based on this, a mapping between the system geometry model and the mechanical analysis model can be established to complete the loading contact analysis of the bevel gear transmission system, and visualize the analysis results. The above research results provide technical support for the development of modeling and simulation analysis software for bevel gear transmission systems.

Aiming at the problems of unbalanced magnetic pull (UMP) and low structural strength of high-speed rotor in the operation of permanent magnet assisted magnetic gear, relevant research was conducted.

Firstly, the phase tuning method was used to study the influence of different transmission ratios on the UMP. Then, according to the structural characteristics for the high-speed permanent magnet rotor of the magnetic gear, the analytical solution of the rotor strength was obtained by using the equivalent mass ring method. Finally, taking reducing the maximum stress and ensuring a certain output torque as the optimization objectives, the multi-objective optimization was performed on the relevant parameters of the magnetic isolation bridge and magnetic barrier.

The analysis results indicate that a transmission ratio where the maximum common divisor of the number of magnetic blocks and the number of poles of the low-speed rotor G_{\mathrm{C}\mathrm{D}}=\mathrm{2} can effectively decrease UMP. The relative error between the analytical solution of the maximum stress obtained from the equivalent mass ring method and the result of finite element simulation is less than or equal to 1%, validating the accuracy of the analytical method. Through the optimized design, the maximum stress on the rotor is significantly reduced.

The industrial robot industry has put forward higher requirements for RV reducers, and the precision life reflects the ability of the reducer to maintain transmission accuracy, which is one of the most important design criteria and usage indicators. To improve the precision performance of precision reducers, it is crucial to evaluate their reliability. Therefore, the degradation characteristics of precision reducers were analyzed.

Taking the RV80E reducer as an example, a random degradation model based on Gamma process was proposed. Combined with the performance degradation data of the reducer transmission accuracy, the model parameters were estimated based on the matrix method and the maximum likelihood estimation method. A Gaussian process regression model optimized by genetic algorithm was established using vibration characteristic data to optimize the prediction of transmission accuracy.

The results show that the prediction accuracy based on Gaussian process regression model is significantly better than that of the traditional regression model. The posterior distribution parameters of the random degradation model are updated by using the algorithm to predict the results, which can effectively evaluate the reliability of the accuracy life of RV reducer and lay the foundation for further reliability optimization design of accuracy life.