Abstracted/indexed

In the early stage of the creative design of mechanisms, design work was accomplished mainly based on researchers' experience and inspiration, resulting in a low design efficiency. Moreover, the derived mechanism configurations were very limited. An effective mechanism design method is based on the atlas of topological structures of kinematic chains. Our research on the structural synthesis of kinematic chain inversions plays an important role in the improvement of mechanism design efficiency.

This study is focused on analyzing signal changes according to internal flow and temperature change by generating micro-leakage, unlike previous studies that experimented with no flow inside a chamber. In addition, a new application method utilizing a phase shift by post-processing the ultrasonic reception signal was proposed. By using the ultrasonic sensor, a different method was proposed for the measurement of micro-leakage of gaseous fuel that relied on the existing pressure sensor.

This paper presents the force analysis and optimization of four versions of self-adaptive robotic fingers based on the simplest closed-loop 1 degree-of-freedom mechanism possible, namely the four-bar linkage. Two of these versions include prismatic joints. It was concluded that simpler designs in adaptive fingers do not necessarily mean weaker performances since the results are at least comparable with other designs with more degrees of freedom.

The electrically driven Stewart platform (EDSP) is used widely. However, the passive rotation (PR) on driven branch chains can generate posture error on the end effector. Compensation control strategy is designed to avoid effects of PR on posture accuracy of the 6-DOF (degrees of freedom) EDSP based on calculation and analysis. The validity of analysis and the effectiveness of the compensation method used to improving posture accuracy are proven by simulation and experiments on a 6-DOF EDSP.

To solve the kinematics mapping problem for the joint space and the drive space of a hyper-redundant manipulator based on flexible cable actuation, which is the key for hyper-redundant manipulators to move strictly according to trajectory planning and avoid obstacles, a decoupling method for kinematics analyses of the flexible cable actuation space and the joint rotation space was proposed.

Small motor stator winding at the same time is difficult to guarantee the uniform arrangement of enameled wire. This paper proposes a three-phase parallel equivalent multi-wire winding robot. The manipulator structure is designed, and the joint motion planning simulation is carried out to verify the feasibility of the multi-wire parallel winding hybrid robot. The research results of this paper provide a theoretical reference for multi-wire parallel winding equipment control.

This paper investigates planetary gear reducers with double satellite gears. These reducers are present in present-day industrial robots, electric vehicles, etc. The paper deals with the dynamic behavior of the reducer as a whole system. The acceleration, velocities, and movements are solved for all elements based on the defined dynamic model. For a dynamic model definition, we used Lagrangian equations of the second kind. The results can be used in design, investigation, etc.

Based on the freedom and constraint topology approach and atlas approach, a new method for the synthesis of a redundant actuated compliant parallel mechanism is proposed, the synthesis conditions are given, and the synthesis process is formulated. With this proposed method, two new translation redundant actuated compliant parallel mechanisms are synthesized, and some new mechanisms have been synthesized. The degree of freedom analysis verifies the correctness and effectiveness of the method.

The new pneumatic–electric hybrid actuator with pneumatic and electric driving modes has the problem of speed fluctuation in the process of driving switching. This affects the stability in the positioning process. In order to solve this problem, the motion characteristics of piston rod in pneumatic locking are studied. A relay and run strategy is proposed to solve the problem of speed fluctuation.

This article contains new propositions for modelling piezoelectric stack models by using existing classical and non-classical methods with the aim of improving piezoelectric stack capabilities. Polynomial chain fractioning is used to obtain a mechanical model with a cascade structure. To verify model output frequencies and amplitudes, edge graphs and structural numbers are used. With the help of Kelvin–Voigt, Mason and Maxwell slip models, an electromechanical model solutions are proposed.

A universal test-machine-based mechanically driven friction device was designed and manufactured. Friction tests were conducted on a third-generation high-strength steel QP980 with flat and curved dies at different pulling speeds and clamping forces. The formula for calculating the friction coefficients between curved contact surfaces was derived.

The problem of inverse folding, determining the distribution of creases according to the desired shape, requires luck and artist inspiration, and it is a very complicated process. Here, we try to solve an inverse folding problem about a folding toy and get some kirigami patterns. It opens up a new way to solve the problem and can also help students understand the theory of mechanisms and machines.

The variable hyperbolic circular-arc-tooth-trace (VH-CATT) cylindrical gear is a new type of gear. In order to research the contact characteristics of the VH-CATT cylindrical gear, tooth surface mathematical models of this kind of gear pair are derived based on the forming principle of the rotating double-edged cutting method with great cutter head in this regard.

This paper proposes a global interpolation algorithm that uses the trajectory pattern method for synthesizing low-harmonic trajectories. The synthesized trajectories and axis kinematic profiles are all smooth and only contain the fundamental frequency and its first three harmonics, which could avoid excitation of the system modes of vibration and reduce demand on the actuator dynamic response, thereby allowing the system to operate at higher speed and precision.

The monk I-Hsing (621–727) was an outstanding astronomer and mathematician during the Tang Dynasty. He was the first person to use scientific methods to measure the length of the meridian. History records that the waterwheel drove his hydromechanical clock, and the time-reporting device could accurately tell the time. Therefore, his hydromechanical clock had a timing function and an escapement regulation device.

This paper aims to investigate the problem of the complex structure optimization of a thin-film diffraction imaging system. A method based on the Kriging model and the improved particle swarm algorithm is proposed to optimize the structure of the thin-film diffraction imaging system. After optimization, the flexible vibration of the improved thin-film diffraction imaging system is effectively suppressed, and the stiffness and stability of the supporting structure are significantly improved.

The approximate calculation of a Stockbridge type damper's natural frequencies and its sensitivity were studied. The low-order frequency is highly sensitive to the cable's length, moderately sensitive to the damper's mass, and slightly sensitive to the eccentric distance and the damper's gyration radius. The high-order frequency is highly sensitive to the cable's length and the damper's gyration radius, moderately sensitive to the damper's mass, and slightly sensitive to the eccentric distance.

Few pieces of literature could be found on vibration investigations of the 3K planetary gear set, a basic planetary drive structure with a more compact structure and wider transmission ratio range than the 2K-H. In this paper, the features of casing vibration and output torsional vibration are analyzed by establishing a dynamics model of a 3K-II gearbox. The advantages and disadvantages of these two vibration signals as a basis for 3K planetary gear system fault diagnosis are also compared.

In this paper, a new parameter, the compliance ratio λ, which could reflect the sensitivity of the main form of the flexible hinge's output displacement, is proposed and discussed in detail. The optimization of the compliant actuator is carried out analyzing the compliance features of different types of flexible hinges. Finally, an actual precision linear position platform will be taken as an example, to prove the key performance of the compliant actuator is much better.