Kinematic Simulation Research Articles

Kinematic simulations and design of a steering upright for a single seater electric car

Kinematic simulations and design of a steering upright for a single seater electric car

Study on dynamic collision avoidance during UAV inspection based on improved graph theory network algorithm

Abstract With the development of the times, UAVs are gradually promoted and popularized in military and civil fields, and the future airspace will also face more security risks. This paper combines the graph theory network algorithm to plan the initial path of UAV inspection and completes the dynamic collision avoidance path planning in the process of UAV inspection through the established joint model of UAV inspection sensing and avoidance. At the same time, the ant colony algorithm is introduced to improve the graph theory network algorithm to solve the dynamic collision avoidance optimal path in the process of UAV inspection. On this basis, simulation experiments of path planning design for UAV collision avoidance and kinematic simulation with two-fold priority judgment are carried out, and the kinematic parameters corresponding to the collision avoidance path are selected as the analysis anchor points. The extreme values of horizontal speed, climb speed, trajectory inclination angular rate, and heading angular rate are 31.6 m/s, 3 m/s, 5.7°/s, and 18.4°/s, respectively, which are within the given constraints, and verify the reasonableness and effectiveness of the proposed optimization scheme. The average time of the proposed algorithm is 0.0458s, which is much lower than the corresponding 0.7105s of the original scheme algorithm, through data comparison of simulation experiments and experimental validation. Using a graph theory network algorithm, the proposed optimization scheme is more efficient and stable and has a higher success rate for collision avoidance.

Simulative and experimental investigation of the surface integrity obtained by Non-Circular-Rotary-Turning (NCRT)

Components with non-circular contours are increasingly used in technical applications, for example in shaft-hub connections or for medical implants with bionic-induced contours. A novel process approach for the production of these contours is the Non-Circular-Rotary-Turning (NCRT). The technology is based on the principle of kinematic coupling of workpiece and tool rotation, which allows to transfer the non-circular shape of the tool to the component within certain limits. All linear axes except the feed axis are not in motion during this process. In contrast to conventional turning, the non-circular contour and the complex kinematics of NCRT lead to surfaces that are strongly depending on the measuring position on the component. In this work, the surfaces obtainable by NCRT are generally investigated. Using an example cross section, a kinematic dexel-based simulation is utilized to predict the kinematic surface topography depending on the process parameters. The surfaces are also investigated in experiments and compared with the simulation. The results show a characteristic surface topography, as well as a strong dependence on the ratio of tool to workpiece diameter. Better surfaces are generally achieved in downturning.

基于ADAMS的协作机械臂运动学分析与仿真

基于ADAMS的协作机械臂运动学分析与仿真

MPC Path Following with Macroscopic Shape Adjustment for AIAUVs

This paper treats the problem of adjusting the macroscopic shape of an articulated robotic system following a path, such that the shape fits the path curve as closely as possible. We propose a way of quantifying the fit of the robot's shape to the path through the errors of the individual links, and investigate a kinematic MPC solution to the problem. The MPC generates position and velocity reference trajectories, which respect the constraints of the system, to be fed to a low-level controller. The scheme is evaluated in a kinematic level simulation study with constant irrotational ocean currents.

A Novel Passive Occupational Shoulder Exoskeleton With Adjustable Peak Assistive Torque Angle For Overhead Tasks.

Overhead tasks are a primary inducement to work-related musculoskeletal disorders. Aiming to reduce shoulder physical loads, passive shoulder exoskeletons are increasingly prevalent in the industry due to their lightweight, affordability, and effectiveness. However, they can only handle specific tasks and struggle to balance compactness with a sufficient range of motion effectively. We proposed a novel passive occupational shoulder exoskeleton designed to handle various overhead tasks at different arm elevation angles, ensuring sufficient ROM while maintaining compactness. By formulating kinematic models and simulations, an ergonomic shoulder structure was developed. Then, we presented a torque generator equipped with an adjustable peak assistive torque angle to switch between low and high assistance phases through a passive clutch mechanism. Ten healthy participants were recruited to validate its functionality by performing the screwing task. Measured range of motion results demonstrated that the exoskeleton can ensure a sufficient ROM in both sagittal (164°) and horizontal (158°) flexion/extension movements. The experimental results of the screwing task showed that the exoskeleton could reduce muscle activation (up to 49.6%), perceived effort and frustration, and provide an improved user experience (scored 79.7 out of 100). These results indicate that the proposed exoskeleton can guarantee natural movements and provide efficient assistance during overhead work, and thus have the potential to reduce the risk of musculoskeletal disorders. The proposed exoskeleton provides insights into multi-task adaptability and efficient assistance, highlighting the potential for expanding the application of exoskeletons.

Design and motion analysis of a space crank rocker biomimetic aircraft

Abstract In order to better understand the flight performance and kinematics performance of flapping wing aircraft designed and developed based on the principle of bionics, a space crank rocker mechanism was tried to carry out the virtual prototype design of the bionic aircraft in space motion, and on this basis, its movement characteristics were analyzed. Analyzing the flight mechanisms and scale laws of common flying organisms yields various physical estimation parameters that affect flight characteristics. Flight patterns and motion patterns are analyzed based on the design principles of seabirds, and structural designs and mathematical models are established. Secondly, carry out the design of its flapping and transmission structures, and based on this, carry out the overall structural design and establish a three-dimensional model. Here, the kinematics analysis of its flapping amplitude and angular velocity value is carried out by combining its mechanism motion diagram, and the kinematics simulation results are compared with the theoretical results, which proves the correctness of the theoretical analysis and the feasibility of the design structure.

Kinematic Simulation of Divertor Remote Handling Equipment for DTT

Kinematic Simulation of Divertor Remote Handling Equipment for DTT

A Unified Real-Time Motion Generation Algorithm for Approximate Position Analysis of Planar N-Bar Mechanisms

Abstract This paper presents a novel real-time kinematic simulation algorithm for planar N-bar linkage mechanisms, both single- and multi-degrees-of-freedom, comprising revolute and/or prismatic joints and actuators. A key feature of this algorithm is a reinterpretation technique that transforms prismatic elements into a combination of revolute joint and links. This gives rise to a unified system of geometric constraints and a general-purpose solver which adapts to the complexity of the mechanism. The solver requires only two types of methods—fast dyadic decomposition and relatively slower optimization-based—to simulate all types of planar mechanisms. From an implementation point of view, this algorithm simplifies programming without requiring handling of different types of mechanisms. This versatile algorithm can handle serial, parallel, and hybrid planar mechanisms with varying degrees-of-freedom and joint types. Additionally, this paper presents an estimation of simulation time and structural complexity, shedding light on computational demands. Demonstrative examples showcase the practicality of this method.

Investigation on carbon fiber fracture mechanism of honeycomb composites in longitudinal‐torsional ultrasonic‐assisted milling processes

AbstractA multi‐edge micro‐tooth longitudinal‐torsional ultrasonic‐assisted milling (LTUAM) model was established based on the hard brittle characteristics of carbon fiber honeycomb composites and the weak strength characteristics of the hole wall interface. The study analyzed the effects of ultrasonic characterization parameters on the cutting force, honeycomb wall width, and surface morphology. The results indicate that using LTUAM significantly reduced the cutting force and decreased the length and height of the burrs at an appropriate ultrasound amplitude. The spindle speed had the least impact on the width of the honeycomb wall, but increased with the longitudinal‐torsional ultrasonic amplitude and feed rate. The maximum error between the simulated and experimental cutting force values was approximately 19%. The longitudinal amplitude and torsional amplitude were 3 and 5 μm, respectively, the length of burrs decreased by 52.7%, and there was less delamination and tearing damage. LTUAM proved to be beneficial in improving cutting performance. Compared with conventional milling (CM), LTUAM resulted in regular fiber fracture morphology and smaller fragments on the honeycomb surface. In addition, the high‐frequency ultrasonic vibration promoted carbon fiber fracture and the surface roughness value under LTUAM was approximately 36.72% smaller than that of CM.Highlights Ultrasonic milling mechanism of carbon honeycomb is studied. Kinematic simulation of the tool of carbon honeycomb was studied during LTUAM. LTUAM promotes the fracture of carbon fibers. A multi‐edge micro‐tooth LTUAM model was established of carbon honeycomb. Deformation of the cell wall can be avoided by ultrasonic vibration of the cutter.

The Design of and Experiments with a Double-Row Seed-Metering Device for Buckwheat Breeding in an Experimental Area

Existing plot seeders have several problems, e.g., seeding uniformity is poor, the breakage rate is higher, and so on. The design of a cone-grid format seed-metering device can both meet the experimental area’s seeding-operation requirements and the plant-to-row seeding requirements. We clarified the overall structure, working principle, and technical parameters of a novel seed-metering device. The gap-adjustment range of the seed-distributing mechanism was determined by analyzing the force on buckwheat seeds. A kinematic simulation using Simulink clarified that the seed-metering control mechanism is capable of realizing precise seed-discharge control. In this experiment, we used the layout of seed gaps, seed displacement, and the rotation rate as influencing factors, respectively. We determined the sowing uniformity coefficient of variation and the broken rate as indicators of the orthogonal experiment. The test results were then subjected to modeling analysis and optimization using Design-Expert12 software to determine the optimal operating parameters. Subsequently, validation experiments were conducted. The results show that the optimal configuration of parameters consisted of a layout seed gap of 13.42 mm, a seed displacement of 17.67 g, and a rotation rate of 15.59 min−1. Under these optimal conditions, the coefficient of variation for sowing uniformity was measured at 14.56%, while the broken rate was 0.39%. The test results meet the technical requirements of buckwheat seed experimental-area sowing and plant-to-row sowing; for further research on buckwheat experimental-area breeding, this study provides a reference.

Design, kinematic and fluid-structure interaction analysis of a morphing wing

The application of morphing wing enables vehicles to show better aerodynamic performance in various flight conditions. This article proposes a modular bilateral triangular pyramid (BTP) unit-based morphing wing skeleton (MWS) mechanism that may achieve continuous variable span-wise bend, span-wise twist, and sweep. A lockable morphing (LM) unit with the BTP unit is designed. Based on the Denavit–Hartenberg coordinate method and motion influence coefficient method, the kinematics of MWS mechanism is conducted. The theoretical models of the kinematic characteristics of the MWS mechanism during the three morphing patterns are obtained. The kinematic simulation models of three morphing configurations of the MWS mechanism are performed. The driving speed ratio of the linear actuator of span-wise bend and twist is analyzed during the twisting phase, and the analysis shows that there be a speed ratio minimizes the coupling bend angle. By comparing the results between the theoretical and simulation models, the accuracies of kinematic theoretical models under different morphing configurations are verified. At last, this article conducted a two-way fluid-structure interaction (FSI) analysis of morphing wing to obtain the influence of aerodynamic load on the flexible skin and skeleton mechanism, as well as the influence of structural deformation on the aerodynamic characteristics. Results show that the initial and swept states have the greatest impact on the out of plane bearing capacity of the flexible skin. In addition, the out-of-plane bulging deformation located at the trailing edge of the flexible skin is beneficial for improving aerodynamic performance, while the protrusion located at the leading edge increases air resistance. These findings provide important theoretical basis for the application of the MWS mechanism.

Design and flight test of the fixed-flapping hybrid morphing wing aerial vehicle

Bionic aircrafts have become a hot topic in the research on unmanned aerial vehicles (UAVs). By mimicking the flight mechanics and wing morphology of living organisms, bionic aircraft not only improve aerodynamic performance, stealth, and convenience but also enable single aircraft to complete multiple specific tasks. To further improve the practical performance of bionic aircraft, a fixed-flapping hybrid morphing wing aerial vehicle (F-FWAV) is designed, and the aerodynamic and flight mechanics are studied. First, kinematic simulations are conducted on the designed F-FWAV, and the kinematic characteristics of the flapping wing are analyzed. Then, flight tests are conducted on the aircraft model, and time-domain and frequency-domain analyses were performed on the data of the pitch angle and roll angle during level flight, high angle of attack (AOA) maneuvering and landing, indicating that the pitch and roll angles of the F-FWAV are coupled. CFD numerical simulations are used to obtain the cruise points of the F-FWAV under different AOAs, frequencies, and freestream velocities. The results of the mutual interference between the fixed wing and flapping wing sections show that the flapping wing section provides more than 50 % of the lift of the entire flight process, and the downward flapping movement of the flapping wing section increases the edge vortex of the fixed wing section, thereby increasing the lift of the fixed wing section.

Contribution of the Photonic Component to the Ionization of the Atmosphere by Earth Crust Nuclides and Radioactive Emanations

Abstract—We investigate the contribution of gamma radiation of natural radionuclides constituting the Earth crust, radioactive emanations, and their decay product in the ground to the intensity of production of ion pairs in the atmosphere against the background of ionization of the atmosphere by radioactive gases flowing to the atmosphere from the ground and propagating together with their short-lived daughter products. The density of the radon flux to the atmosphere is estimated by three methods: the reservoir method, the integration of altitude profiles of volume activity of radon, based on gamma spectroscopic observation and diffusion model. The distribution of the gamma dose rate dose from the earth radionuclides in the soil and in the atmosphere is calculated using Gleant4 software. The propagation of the radon isotopes and their decay products in the atmosphere is calculated using large eddy simulations supplemented with kinematic simulations of the subgrid transport of a passive scalar. It is shown that depending on the specific activity of nuclides in the ground and the turbulent regime of the atmosphere, the total contribution of the γ-radiation to the ion pair production rate in the atmospheric boundary layer is approximately from 1% to 20% and increases upon a decrease in the penetrability of the upper ground layer for radioactive emanations.

Shape-locking in architected materials through 3D printed magnetically activated joints

Shape morphing is the ability of objects to adapt to different shapes and reduce stress concentrations through increased contact area. This is a common trait of natural and engineered objects and has several applications in, among others, soft robotics and orthopedic implants. Shape morphing is achieved through flexible materials or rigid components with either kinematic or compliant joints. An additional step, namely shape locking, is needed for sustained load support. Activation of a locking mechanism can be done with any energy, among which magnetism is one. Here, we present the implementation of a magnetic locking mechanism for kinematically deformable metamaterial structures that maintain shape and support loads upon locking. The structure consists of 3D printed rigid magnetic and non-magnetic components connected by hinges. We created several prototypes of the proposed designs using two additive manufacturing methods (i.e., material extrusion and multi-material jetting) and demonstrated its application in a closed-loop grid for arbitrary shapes. Moreover, we characterized the performance of the prototypes using mechanical tests and multibody kinematic system simulations. This work highlights the viability of the locking concept and provides design considerations for future applications. Further improvement and optimizations are needed for increased efficiency and effectiveness.

Design and Fabrication of Robotic arm for Multiple Degrees of Freedom Control

This paper details the design, construction, and evaluation of a highly flexible, high-precision robotic arm primarily used in prosthetic and rehabilitation engineering applications. The robotic arm was designed using 3D printing and SolidWorks and features a modular design that simplifies the manufacturing process and improves scalability. The arm has three degrees of freedom and is realized by a well-designed circuit program integrating ESP32 and STM32 microcontrollers. The structural integrity and functionality of the arm were verified through finite element analysis and kinematic simulation. The study also presents a novel path-planning algorithm for the robot arm, which is based on linear position and Gaussian velocity models and is effective in generating smooth, continuous, and physically constrained paths. This work provides an open-source solution that offers a cost-effective and robust platform for diverse robotics applications.

CONSTRUCTION OF THE KINEMATIC MODEL OF ROBOTIC SYSTEMS IN THE MATLAB ENVIRONMENT

Robotics has become relatively accessible with low-cost projects, but there is still a need to create models that accurately represent the robot's physical behavior. Creating a virtual platform allows us to test behavioral algorithms using artificial intelligence. In addition, it will enable us to find potential problems in the physical design of the robot. The article describes the methodology of building a kinematic model and simulation of an autonomous robot. The development of a kinematic model and its implementation using several tools are presented. The environment used for the experiment is very close to natural conditions and reflects the kinematic characteristics of the robot. As a result, the simulation of the model following the mobile robot's kinematics is executed and tested in MATLAB. As a study, the m-file creation in MATLAB, its use with the Simulink package, and the solution of the forward and inverse problem of kinematics are shown. In addition to constructing the robot body using Simulink blocks, the structure of the kinematic scheme is simulated using the Denavit-Hartenberg (DH) parameters of the robot without blocks. "Simscape" and "Robotics System Toolbox" packages simulate forward and inverse kinematics using the Simulink package, and the robot's handle and body movement are observed. In the forward kinematics problem, the readings in the Scope compare the signals received from joint one and the end effector. For the inverse kinematic problem, the parameters of the manipulator along the XYZ axes are entered using the "Signal builder" block, and the circular movement of the arm is observed. In contrast, the handle of the manipulator remains fixed at a given point. Keywords: mobile robot, kinematic model, the forward and inverse problem of kinematics, Denavit-Hartenberg parameters, joint types

Validation of a novel bicycle simulator with realistic lateral and roll motion

Bicycle simulators have been the subject of considerable research, however, few of these attempts have integrated direct balance control and realistic freedom of motion to deliver a real-world dynamic cycling experience. This study presents the BIKE (Bicycle Intrinsic Kinematics Emulator) system, a kinematic bicycle simulator, developed with the purpose of letting its users experience realistic steer, roll, yaw and sway motions. Motion is provided with Carvallo–Whipple bicycle model-based control of sway and yaw combined with passive steer and roll. This study validates the BIKE simulator by comparing cycling behaviour and subjective evaluation for the simulator with and without motion to outdoor tests with an instrumented bicycle. 15 participants of varying age and mass, performed straight-line cycling, at low ( 5 km/h ) to high ( 40 km/h ) velocities and zig-zag manoeuvres. Results show that users can successfully rely on existing cycling skills to use the simulator with motion. Objectively, in the kinematic sense, the simulator with motion performs similarly to an outdoor bicycle. Subjectively, the simulator performs better with motion and is experienced by riders as close to real outdoor cycling.

Research and Simulation of Kinematics and Dynamics of Tracked Support Equipment Based on Multi-Body Dynamics

Aiming at addressing the problems of low production efficiency and low safety factors in coal mines, this study designed a new type of support equipment and verified its theoretical reliability through the analysis of driving theory. The analysis was carried out through kinematics and dynamics, the position coordinates of the prototype at different times were analyzed using the RPY angles, and the spatial coordinate system of the prototype was established. Then, the position coordinates at different times could be solved by establishing the plane kinematics equations of the prototype. A 14-degree-of-freedom dynamic system model was established to reflect the longitudinal dynamic characteristics of the traveling mechanism of the prototype, and the differential equations of the traveling mechanism were established via the Lagrange dynamic equation method. Finally, the dynamic stability of the prototype under different working conditions was studied by using multi-body dynamic simulation technology. The research results show that the prototype meets the design requirements, has good reliability, realizes the mechanization, automation and high-efficiency production of coal mines, and realizes safe underground production. The research results provide effective solutions for ensuring the sustainable development of coal resources and the safe production of coal mines.

A comparative analysis of kinematic simulation results obtained by manually and automated scaled OpenSim models during walking – preliminary findings

A comparative analysis of kinematic simulation results obtained by manually and automated scaled OpenSim models during walking – preliminary findings