Design and motion analysis of double quadrilateral mobile mechanism

Design in Mainland China

IN MEMORIAM: Dr. An Tzu Yang (1923–2003)

Simulation-based studies (SBS) have become an interesting investigation approach for Software Engineering (SE). However, the reports on experiments with dynamic simulation models found in the technical literature lack relevant information, hampering the full understanding of the procedures and results reported, as well as their replicability. Apart from the limitations on the length in conferences and journal papers, some of the relevant information seems to be missing due to methodological issues not considered when conducting such studies. This is the case of missing research questions and goals, lack of evidence regarding the dynamic simulation model validity, poorly designed simulation experiments, amongst others. Based on findings from a previous quasi-systematic literature review, we propose a set of reporting guidelines for SBS with dynamic models in the context of SE aiming at providing guidance on which information the report should contain. Furthermore, these guidelines were evolved to support SBS planning by identifying potential threats to simulation study validity and in making recommendations to avoid them, through qualitative analysis and external evaluation. Finally, we conducted different evaluations regarding both the reporting and planning guidelines, apart from using them to support the planning of a SBS as regards software evolution. A set of 33 reporting and planning guidelines for different stages of the simulation lifecycle and focused on the experimentation with dynamic simulation models have been put together. The first assessments point to a comprehensive set of guidelines, supporting a comprehensive preparation and review of the plans and reports from the studies, apart from the planning of a SBS focused on software evolution, potentially reducing the threats to the experimentation with the validity of dynamic simulation models. The 33 guidelines cannot be understood as separate groups for reporting and planning as they overlap in many aspects. The main goal is to use the guidelines to support the planning of a simulation-based study with dynamic models so that experimenters may identify potential threats to validity and produce relevant information for a complete simulation experiment report in advance. Despite their initial contribution to increase the validity of SBS, the reporting and planning of simulation-based experiments with dynamic models still has to be discussed and improved in SE. Therefore, additional assessments of this set of guidelines are needed to strengthen the confidence in their completeness and usefulness.

Selecting a Dynamic Simulation Modeling Method for Health Care Delivery Research—Part 2: Report of the ISPOR Dynamic Simulation Modeling Emerging Good Practices Task Force

Conventional power grids consist of a complex fabric of generation plants, substations and transmission lines that help supply electricity to cities, homes and small businesses. Microgrids are smaller bound power grids that can function independent from the main power grid. Microgrids optimize power system efficiency, supply loads effectively, and enable easy integration of renewable energy resources. To verify microgrid designs, complex and dynamic simulation models are typically used. In most cases, computer simulations are limited by slow computational speed, which can lead to unrealistic and unreliable results. The concept of Real Time (RT) simulation introduces faster computational speed, which allows computational models to obtain specific solutions in RT. This paper presents an implementation of a dynamic RT state space average simulation model of multiple power electronic converters in a grid-connected DC Microgrid network for rural electrification. A RT MATLAB/Simulink simulation is constructed and executed using the OPAL-RT 5600 platform.

The kinematic analysis had carried on large-scale linear vibration screen, which was based on the theory of multi-rigid-body system and the theory of self-synchronous vibration. According to the dynamic analysis, the displacement equation was established. The vibration screen of motion was decomposed into two vertical directions. It included the vertical direction and the horizontal direction. The model of vibration screen is analyzed in the vertical direction. The dynamic model is established and analyzed by COSMOSMotion software. The paper is consisted of three parts.1) Kinematic theory analysis of double motors on the linear vibrating machine. 2) Dynamic model is built. Fixed frame is replaced with simple parts in order that the model is observed later. Through the motion analysis of the vertical direction, it is concluded that the different stiffness of the spring group was corresponding to the moving distance. 3) It is judged that reasonable range of spring parameters and the system damping, and model parameters will be modified

This paper presents a novel, precision, maneuverable, 3-DOF translational parallel mechanism. The mechanism’s important feature is that all of the kinematic joints are the revolute joints. The paper derives the mechanism’s kinematic forward solution and inverse solution by using of coordinate transformation elimination method and vector method, and establishes proper kinematic modeling. Kinematic simulation is carried out by ADAMS virtual prototyping software. The operating data is obtained, it verifies the correctness of solving the forward and inverse solution, and solve the question of choices for many results during the theoretical solution. This technique can provide a useful tool in the design of kinematic trajectory of the parallel mechanism’s end-effector and the kinematic analysis of other parallel mechanism.

Lower extremity exoskeleton rehabilitation robot is a research focus in the field of robotics, which is meant to assist rehabilitation doctors in rehabilitation training for patients. This paper mainly discusses a new type of bionic lower limb rehabilitation robot. First, the main mechanical structure of the rehabilitation robot is analyzed, including the leg structure, the backboard system and the auxiliary rehabilitation platform. Secondly, the kinematics analysis of the external bones was carried out and the space of motion was calculated. Finally, the whole model of the rehabilitation robot is imported into ADAMS, and the correctness of the analysis is verified by kinematics simulation. In addition, the force on the connecting shaft of each electric push rod is measured by ADAMS, which provides a basis for the dynamic analysis and verification of the exoskeleton of the lower extremity. Kinematics analysis and simulation can help plan and optimize gait curves.

Purpose The purpose of this paper is to propose a deformable two-wheel-like mobile mechanism based on overconstrained mechanism, with the abilities of fast rolling and obstacle surmounting. The drive torque of the multi-mode motions is generated by self-deformation. Moreover, the analyses of feasibility and locomotivity of two mobile modes are presented. Design/methodology/approach The main body of the two-wheel-like mobile mechanism is a kind of centrally driven 4 R linkages. The mobile mechanism can achieve the capabilities of fast rolling and obstacle surmounting through integrating two mobile modes (spherical-like rolling mode and polyhedral-like obstacle-surmounting mode) and can switch to the corresponding mode to move or surmount obstacles. The mobility and kinematics of the mobile modes are analyzed. Findings Based on the results of kinematics analysis and dynamics analysis of the wheel-like mechanism, the spherical-like rolling mode has the capability of fast rolling, and the polyhedral-like obstacle-surmounting mode has the capability of surmounting different obstacle heights by two submodes (quasi-static obstacle-surmounting submode and dynamic obstacle-surmounting submode). The proposed concept is verified by experiments on a physical prototype. Originality/value The work presented in this paper is a novel exploration to apply bar linkages in the field of scout. The two-wheel-like mobile mechanism improves the torque imbalance of bar linkages by centrally driven method, removes the rear support structures of the traditional two-wheeled mechanisms by self-deformation and increases the height of obstacle surmounting by mode switching angle.

The aim of this work is to approach the difficulties students usually encounter when facing up to kinematic analysis of mechanisms. A deep understanding of the kinematic analysis is necessary to go a step further into design and synthesis of mechanisms. We can conclude from experience that supporting and complementing the theoretical lectures with specific software is really helpful. In this sense, software is used during the practical exercises, serving as an educational complementary tool reinforcing the knowledge acquired by the students. Several questions are outlined to the students, so that they are encouraged to justify the validity of their results. GIM software performs kinematic analysis and motion simulation of planar mechanisms. The main capacities of the software are: solving the position problem, computing velocities and accelerations, singular analysis, and visualization of instantaneous center of rotation, acceleration pole, curvature center and circle, fixed and moving centrodes and main circles. The graphical representation of all results favors the learning of the theoretical concepts explained in the subject and also, stimulates the critical reasoning the students must acquire.

Design, modeling and analysis of a novel self-crossing mechanism

With the increasing incidence of ophthalmic diseases and changes in the medical environment, virtual surgical simulation systems are receiving increasing attention in the training of doctors. Haptic handle is one of the main structures of virtual surgery simulator. Its configuration directly affects the stability, maneuverability and workspace of the simulator. In terms of the mechanical structure design of force feedback handle, this paper adopts the 4-branch 6-6-6-3 type 3RSS-RRR series-parallel hybrid mechanism, and applies the idea of Yang tingli building parallel platform to construct the overall configuration of the arm parallel mechanism. The improved D-H method is used to perform a kinematic analysis of the handle mechanism and the effective solution is obtained. Based on the analysis results, the working space of the haptic handle is simulated by Matlab, and the simulation results meet the demand.

Development and evaluation of a dynamic simulation model of reproductive performance in pasture based suckler beef systems

This paper overviews the kinematics and workspace computer simulation of humanoid robot KUBO, a four-limbed robot with 20-DOF. Made entirely from aluminum and assembled with commercial off-the-shelf actuators and sensors, KUBO is a self-developed low-cost platform for research into humanoid robots, human-like motion, bipedal walking, and control. KUBO is able to perform with high precision simple human tasks such as walking, balancing, turn around, bend over, lie down, get up, etc. In this paper, the mechanical design, kinematic analysis, and workspace simulation of this prototype are presented and discussed. The proposed methodology is useful for predicting the humanoid's limbs motion while performing a task and for preventing collisions with the environment and the robot itself.

Identification, design and kinematic analysis of an earthmoving mechanism