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We designed a motion controller through deep reinforcement learning. The laparoscopic visual field image is input to the controller, and the controller outputs the joint motion of the laparoscopic arm to adjust the visual field. During the movement of the surgical instrument in different trajectories, the controller keeps the surgical instrument in an appropriate position in the visual field. It proves that the method is widely effective and can meet the needs of doctors during surgery.

This paper use the topological characteristic constants for isomorphism identification, such as the power value sequence (PVS), least distance matrix sequence (LDMS), and loop number (LN). The fourth PVS, the LDMS, and the LN are compared and arranged in descending order, forming a strong complementary chain. Our results show that solving the problem of the isomorphism identification of the kinematic chain (KC) based on graph theory definition has no advantage in efficiency.

In this paper, the traditional bee colony algorithm is improved, and its roundness error evaluation method is improved. For the roundness profile data of the part, the improved bee colony algorithm is used to determine the position and size of the circle. In order to improve the efficiency of the algorithm, the local search region of the population initialization is determined according to the definition of roundness error. The evaluation accuracy of this algorithm is better than common ones.

Robotic ultrasonic scanning needs to apply an appropriate force for a long time during the acquisition process. Excessive contact force may lead to deformation and even hurt the patient, while insufficient force would lead to poor image quality. We proposed a varying rate hybrid position–impedance control strategy, which can partly play the role of an ultrasound sonographer and serve as a medical assistant to reduce their workload.

The creation method of a 1 degree of freedom double plant carrier gear train (DPGT) transplanting mechanism was proposed based on the functional constraints. Within the eight components of the DPGT, the automatic creation of a transplanting mechanism was realized. A total of 528 DPGTs, which are suitable for transplanting, including 3 five-bar, 13 six-bar, 92 seven-bar, and 420 eight-bar configurations, were obtained for the first time.

The epicyclic gear train (EGT) is a gear transmission mechanism. When the number of designed structures is increasing and structures are becoming ever more complex, manual screening is very difficult. Therefore, scholars are committed to developing an algorithm that can distinguish repetitive structures. In this paper, we use a method to transform the structural information of EGT into a matrix and extract the hidden information in the matrix to judge whether there is a repeated structure.

Space deployable antenna is a new type of space structure, and one of the key payloads of spacecraft, which is widely used in mobile communication, navigation and remote sensing, deep space exploration, military reconnaissance, and other fields of science and technology and national defense. Aiming at the urgent need for the development of space deployable antenna with large aperture and a high storage rate, a new configuration of a multifold rib modular deployable antenna mechanism is proposed.

An analytical solution for designing the optimal parameters of dynamic vibration absorbers attached to the damped main system is found to be difficult and complicated. In this paper, the adaptive multiswarm particle swarm optimization is applied to parameter optimization, and the numerical solutions of the system are given for the damped main system under sinusoidal force excitation.

To date, most underwater manipulators have been rigid-link structures with a small number of degrees of freedom and have been unable to perform well in confined spaces. Due to their high dexterity and good adaptability to different environments, snake-like manipulators have strong potential for use in complex underwater applications. In this study, a tip-following algorithm is presented to weave through confined and hazardous spaces along a defined path with high efficiency.

A new measurement method for the dynamical response of a marine propeller shaft with lower cost, simple maintenance and high accuracy is proposed. The shaft vibration predicted from the vibration signals of the bearings is easy to measure. The convolutional neural network can fit the nonlinear relationship between the vibration signals of the bearing and propeller shaft.

Due to the high hardness of alumina ceramics, the gap in magnetorheological polishing efficiency is very low. The three-point magnetorheological polishing method is designed, which has a strong magnetic field generator and pressure polishing characteristics. The surface microstructure and surface quality of the polished alumina ceramics under different process parameters were studied, and the optimal process parameters were obtained by analysis.

A performance analysis of the PFDV using a steering mechanism (^SMHPTS_PFDV) and wind turbine power development system using a hydraulic system with PFDV (^WTHPTS_PFDV) is conducted. Dynamic modeling and analysis of the ^SMHPTS_PFDV and ^WTHPTS_PFDV systems is presented. We find that the power and energy loss through the PFDV is higher when it is connected with the dual loads for performing dual functions compared to the other hydraulic drive system used in wind turbines to obtain stable output.

Internal gearing power honing (IGPH) is a one-of-a-kind gear finishing process which is widely used in automobile gearbox systems, high-speed rail gears, etc. Current IGPH technology can cause an uneven quality of gears in mass production because of the invariable IGPH process parameters, so this paper presents a new method to ensure the stable cutting speed between the honing wheel and workpiece gear through a series of theoretical and experimental research studies.

This paper presents a novel united propulsive mechanism inspired by the frog’s hindlimb. This hybrid mechanism is composed of a planar six-bar linkage, which is designed using homotopy continuation and a spatial four-bar mechanism. The two sub-chains connected on the foot form a closed loop, which decreases the degrees of freedom (DoF) of the foot to 2. The preliminary simulations validate the amphibious function of the designed mechanism.

Industrial robots are required to perform a given task repetitively with high tracking precision. Iterative learning control (ILC) calculates the tracking error of each iteration and corrects the output control signals in accordance with a predefined learning operator. This research considers the changes of the dynamics characteristics when the robot has different types of payload. It provides an approach for adaptation of the ILC to the specific payload to achieve faster convergence.

Due to the defects of the internal structure and energy supply carrier, conventional deep sea unoccupied marine equipment cannot meet the requirements of low power consumption. The energy efficiency characteristics of floating bodies with different shapes were simulated, and the amplitude response operator (RAO), radiation damping, added mass and Froude–Krylov force of floating bodies with different shapes were compared.

Transrectal prostate brachytherapy (BT) can effectively treat prostate cancer. During the operation, doctors need to hold the ultrasound probe for repeated adjustments, which makes it difficult to ensure the efficiency, accuracy, and safety of the operation. We designed an 11 DOF (degrees of freedom) active and passive transrectal BT robot based on the analysis of the transrectal prostate BT process.

We present a novel exoskeleton based on deformable pneumatic actuators, known as McKibben muscles or artificial muscles. The aim of this system is to support a worker during overhead tasks, in which they need to lift the arms and hold that position for a long time. Simulations have been performed, starting from a mathematical model of the exoskeleton and of the artificial muscle. A first architecture of the complete device is also presented.

Similarity recognition of kinematic chains (KCs) is an important part of the mechanism innovation design, which can avoid isomorphism in the synthesis process and reduce the generation of redundant design schemes. In this paper, the new concepts of a loop tree (LT) and a loop tree matrix (LTM) have been proposed, which improve the efficiency of similarity recognition.

We introduce different test scenarios and set-ups for a force control assessment. The force control of Universal Robots (UR10e) and FerRobotics (ACF-K 109/04) are evaluated. A force/torque sensor, mounted below a work piece, measures the applied force by the UR or by the ACF. Results for both UR and ACF force control are presented for varying desired contact velocities and forces. These results show the advantage of the ACF-K 109/04 over the UR10e force control for highly dynamic scenarios.

To obtain all mechanical schemes, scholars in this field have proposed an innovative design method using kinematic chain configuration synthesis. However, the existing innovative design method easily produces redundant design schemes. We analyze the similar component discrimination method for mechanisms from the perspective of graph theory and apply it to the specialization of topological graphs to solve the problem of redundant design schemes.

We propose a novel mechanism synthesis approach for a 1-degree-of-freedom (DOF) rehabilitation robot, based on chord angle descriptor (CAD) and error tolerance expansion, to generate a pool of mechanism solutions from which mathematically and practically optimal solutions can be selected. A design example of a 1-DOF rehabilitation robot for upper-limb training is provided to demonstrate the efficacy of our novel approach.

We show how the operational modal analysis of a nonuniform wind turbine tower can be performed and used to acquire effective and reliable test results and dynamic behavior. Results show that a tailor-made genetic algorithm (using auto-MAC as the fitness function) is a practical approach to finding the optimal position of the sensors to obtain the best results for objective modes. We also accessed the updated finite element model with less than 1 % error compared to the frequencies from the test.

The article presents an approach to constructing the stability boundary in the parameter space of a nonlinear model of a wheeled vehicle – a bifurcation set, which extends the well-known concept of the critical speed of rectilinear motion to the case of circular modes. The approaches considered in the work are important for understanding the regularities of the change in the stability properties of the movement of wheeled transport systems.

A novel parallel leaf-spring carrying mechanism was designed and studied for high-precision fast wafer positioning and transfer in lithography. Displacement was used to calculate the equilibrium attitude, and the laser triangulation coordinate method was used for attitude measurement. The effectiveness of the attitude model was shown by numerical analysis and experimental verification. The methods can be used as a reference for the analysis and design of a complex parallel compliant mechanism.