Slider-crank Mechanism Research Articles

Development of fast photoacoustic and ultrasound imaging system based on slider-crank scanner for small animals and humans study

Integrated photoacoustic and ultrasound (PAUS) imaging is a potential imaging method that provides simultaneous in vivo functional, and anatomical information. Several PAUS scanner systems have already been reported, but they are limited to fixed scanning range, low scanning speed, bulky size, unsustainable for long-term use. Here, we report a low-cost fast dual photoacoustic and ultrasound imaging system (F-PAUSM) based on custom-made slider-crank and ball-screw mechanisms. This custom-slider-crank mechanism is versatile in terms of changing the scanning range corresponding to a suitable B-scan frame rate for difference scanning areas. F-PAUSM allows us to stably capture wide scanning ranges of 10, 18, and 26 mm corresponding to maximum B-scan frame rates of 30, 26, and 18 Hz, respectively. To demonstrate the capability of the F-PAUSM system, a dragonfly wing, nude mouse ear, and human fingertip are imaged successfully. Furthermore, the numerical analysis is conducted to estimate the fatigue life of the custom-made mechanical parts, then demonstrate that the F-PAUSM system can operate stably for long time in nominal operating conditions. These results demonstrate the potential applications of the F-PAUSM system in biomedical imaging.

Design and Fabrication of a Flapping-Wing Robot Based on Slider-Crank Mechanism


 Tailless Flapping-Wing Micro Air Vehicles (FW-MAVs) have gained more attention recently because they utilize energy more efficiently compared to fixed-wing aircraft and rotorcrafts. FW-MAVs could be used commercially to explore confined spaces with insufficient air or serve as surveillance robots. However, due to their use of unsteady aerodynamics and small size, the research and design process is very complicated. In this paper, I propose a flight mechanism for a light-weighted, two-winged, hummingbird-inspired flapping-wing robot. Five versions of the robot were built; each version improved upon the issues of the previous one. Calculations were performed to optimize the stroke amplitude and the transmission ratio of the gears. Four groups of control experiments were conducted to investigate the relationship between different factors (voltage, motor type, wing area, and the number of veins) and the robot’s lift, which was monitored by a pressure sensor. I analyzed the results from the experiments and built a final version of the robot based on a slider-crank mechanism. The main structure of the final version is made of three 3mm carbon fiber boards, and the wings are made of 0.025mm PET (polyethylene terephthalate) material, reinforced by three carbon fiber rods: two 0.5mm ones across the membrane and a 1mm one at the leading edge. The robot weighs 16.3g and can produce enough lift to overcome its gravity under 9V with an off-board power source by exhibiting an upward trend during a tethered flight test.

Locomotion analysis of self-propelled board by inclined internal mass motion with slider-crank mechanism

Locomotion analysis of self-propelled board by inclined internal mass motion with slider-crank mechanism

Detection of critical mode-shapes in flexible multibody system dynamics: The case study of a racing motorcycle

In multibody system models, body flexibility is introduced when the structure compliance is not negligible for an accurate description of the system behaviour. Flexible multibody systems provide a more detailed description of system kinematics and dynamics, introducing the effects of the body dynamics deformations.The influence of component higher frequency harmonics is often undesired during system working conditions. Therefore, in the design of a flexible multibody system the components and assembly modal properties are optimised to avoid resonances in the operating condition frequency ranges. However, in the system optimisation phase or when the system is upgraded to a new release, the least modifications would be ideally performed to optimise the system for its working conditions. In this context, there are no straightforward methods available to recognise which component mode-shapes require structural optimisation to avoid undesired dynamics behaviours.Based on an assembly-to-components modal approach, this paper proposes a method to detect the component mode-shapes responsible for undesired dynamics in the assembled multibody systems; the method is suitable for both numerical model or experimental applications. The inputs to the detection method are the components, sub-structures and assembly mode-shapes, together with the main frequencies exciting the system in operating conditions, to which operative deformations are associated. The procedure reveals the critical components and their mode-shapes requiring modifications.The detection method is conceived especially for systems requiring fast and continuous optimisation, e.g. high-performance racing vehicles, which are at least annually upgraded, or new improved releases of industrial complex machines. Firstly, the proposed method is numerically applied to the flexible multibody model of a slider–crank mechanism, detecting high-frequency vibrations in the piston stroke. Then, it is applied to a race motorcycle chassis frame to detect the critical component mode-shapes in realistic working conditions. Independent application of the procedure to numerical and experimental data of the motorcycle chassis pinpoints the same component mode-shapes as critical, on which optimisation efforts would be required.

Interval Uncertainty Quantification for the Dynamics of Multibody Systems Combing Bivariate Chebyshev Polynomials with Local Mean Decomposition

Interval quantification for multibody systems can provide an accurate dynamic prediction and a robust reliability design. In order to achieve a robust numerical model, multiple interval uncertain parameters should be considered in the uncertainty propagation of multibody systems. The response bounds obtained by the bivariate Chebyshev method (BCM) present an intensive deterioration with the increase of time history in the interval dynamic analysis. To circumvent this problem, a novel method that combines the bivariate Chebyshev polynomial and local mean decomposition (BC-LMD) is proposed in this paper. First, the multicomponent response of the system was decomposed into the sum of several mono-component responses and a residual response, and the corresponding amplitude and phase of the mono-component were obtained. Then, the bivariate function decomposition was performed on the multi-dimensional amplitude, phase, and residual to transform a high-dimensional problem into several one-dimensional and two-dimensional problems. Subsequently, a low order Chebyshev polynomial can be used to construct surrogate models for the multi-dimensional amplitude, phase, and residual responses. Then, the entire coupling surrogate model of the system can be established, and the response bounds of the system can be enveloped. Illustrative examples of a slider-crank mechanism and a double pendulum are presented to demonstrate the effectiveness of the proposed method. The numerical results indicate that, compared to the BCM, BC-LMD can present a tight envelope in the long time-dependent dynamic analysis under multiple interval parameters.

Design and Experiment Evaluation of Load Distribution on the Dual Motors in Cam-Based Variable Stiffness Actuator with Helping Mode

This paper presents a novel cam-based variable stiffness actuator (VSA). It significantly differs from its counterparts in that the external load distributes on its two motors with a small difference. It is a feasible method to improve VSA’s output power, especially in compact joints, such as rehabilitation devices. The stiffness adjustment involves a spring-balanced crank-slider mechanism with a variable-length base frame. Its tunable node is the common node for force decomposition, synthesis, stiffness adjustment, and position control by setting it at the common groove of two differential variable-pitch cams. The paper establishes analytical expressions among the pressure angle of the cam pitch curve, load distribution, and its crucial design indexes and constraints. Based on this, the pitch curve synthesis method is put forward to optimize the load distribution. In addition, a reasonable tradeoff can be easily made by locally adjusting the cam pressure angle. So, the dual motors can work against the output load together in the same direction with a close amount. In the fabricated prototype, current stratification caused by the unstable friction direction has been observed. The estimation results of motor frictionless current matched the designed load distribution behavior.

Lightweight Piezoelectric Bending Beam-Based Energy Harvester for Capturing Energy From Human Knee Motion

Harvesting energy from the human body has attracted substantial attention from industries and academics as it is a promising solution to address the battery life issue. In this article, we developed a bimorph piezoelectric bending beam-based energy harvester to scavenge energy from the human knee motion for powering body-worn electronics such as smartwatches and health monitors. During walking, the human knee will flex and extend to periodically deform piezoelectric macro fiber composites (MFC) bounded to the bending beam, thus generating electricity. The mathematical models of the whole system including the model of the large deflection of the bending beam, movement analysis of the end of the bending beam (slider-crank mechanism), the model of piezoelectric transducers, and measurement of the human knee angle are developed to comprehensively study the harvester. To validate the presented mathematical models, experimental testing on a human body when the subject walks on a treadmill at three different walking speeds is conducted here. The experimental results show good agreement with the simulation results, which indicates that the developed models can characterize the harvester. In addition, the performance of the harvester walking in different contexts is also evaluated. The average power can reach 12.79 mW for level-ground walking, 9.91 mW for stair descending, and 7.70 mW for stair ascending, when walking at a self-selected speed.

Wheel Operated Fertilizer Sprayer

Abstract: Different kinds of insecticides sprayer are available in India. As India is a land of agriculture which comprises of small and rich farmers. Small scale farmers are very interested in manually level operated knapsack sprayer because of its versatility, costand design. Spraying is an important operation to be performed by the farmers to protect the cultivated crops from insects, pests, funguses and diseases in which various insecticides, pesticides, fungicides and nutrients are sprayed on crops. So this gadgets which we called wheel operated fertilizer sprayer can be operated manually for spreading granular materialsin farms especially forsolid fertilizerslikeurea. When the vehicle is pushed, motion is transferred form rear axle wheels whichthrough sprocket and chain mechanism which in turn rotates second sprocketconnected to a shaft having screw conveyor at both the ends. This rotation of screw conveyor will discharge the fertilizer which is supplied through a hopper acting a storage tank. Keywords: Fertilizer Sprayer Wheel operated Trolley, Slider crank mechanism, CompressionChamber, Chain and sprocket.

Design and Fabrication of Motorized Hacksaw Machine

Abstract: As we know that in large manufacturing industries, the cutting operation is very required for raw material, for this purpose they use manually operated conventional hacksaw machine for cutting operation. In that type of machine single piece can cut at a time by using an electric motor . Also,one labour utilizes for same. This project is on the design and construction of an electric supply hacksaw machine for cutting of metal to different size and length with the help of hacksaw. The objective of this project is to save man power and time in cutting metals in order to achieve high productivity. It is a cutting machine with teeth on its blade used specially for cutting metals. The power to hacksaw is provided by the motor. Here, the step down transformer is used for converting the 220-230V AC power to 12V DC power to run the machine smoothly , then the current is supplied to the motor then with the help of single slider crank mechanism. These machines can be used in remote places where electricity is regular. It is designed as a portable one which can be used for cutting in various places . It can be used for cutting in various places. It can be used for operating on materials like thin metals ,woods etc.

Global asymptotic stability of input-saturated one degree-of-freedom Euler–Lagrange systems with Rayleigh dissipation under nonlinear control

ABSTRACT In this manuscript, the regulation of one degree-of-freedom Euler–Lagrange systems subject to input saturation is addressed. In particular, the design and analysis of a nonlinear static state feedback controller is presented. As a result, it is proven via Lyapunov's direct method that, in the presence of Rayleigh dissipation, the closed-loop equilibrium point is globally asymptotically stable with a strict Lyapunov function. Since saturation occurs in the system which contains the actuator model, the proposed control law is unconstrained and can be simplified to a proportional-derivative with desired gravity compensation algorithm. As a by-product global asymptotic stability is also proven for the case where Rayleigh dissipation is null. Numerical simulations on a crank-slider mechanism are presented. Moreover, experimental results on a DC-DC buck power converter are also shown and confirm the viability of our approach.

Passive chaos suppression for the planar slider-crank mechanism with a clearance joint by attached vibro-impact oscillator

Chaotic dynamic behavior in clearance joints is the prominent nonlinear factor for multibody systems. This study presents a passive chaos suppression method to stabilize the planar slider-crank mechanism with a clearance joint. The strategy resorts to a vibro-impact oscillator attached to the slider. Primarily, the impact principle is employed to characterize the dynamics in clearance joints. The mathematical model of the integral system is conducted subsequently. The chaotic system behavior is evaluated by bifurcation analysis varying clearance size and crank speed. When the controller is activated, parametric optimizations of the stiffness, clearance coefficient, and particle mass are conducted to achieve optimum chaos elimination. Phase portraits, the largest Lyapunov exponent, and time-frequency distribution are evaluated. Numerical results illuminate that an adjusted oscillator can suppress the chaotic high-frequency composition of system response and help to maintain continuous contact between the joint elements. The results suggest applying the identical clearance size in the revolute joint and vibro-impact oscillator for fast optimization. Moreover, the method is still technology valid when considering different contact principles. Ultimately, a test platform is established to achieve some experimental validations.

Motion simulation and impact gap verification of a wheeled vibration-driven robot for pipelines inspection

Vibration-driven locomotion systems and mobile robots are widely used in different industries, in particular, for inspecting and monitoring the pipelines. Among the great variety of such robots designs, the ones based on the wheeled chassis and equipped with the vibratory drive are of the most widespread. The novelty of the present paper consists in substantiating the design parameters of the wheeled robot working under the vibro-impact conditions and driven by the crank-slider excitation mechanism. The main goal of this research is maximizing the robot average speed. While simulating the robot dynamic behavior, the numerical methods are used, in particular, the finite-element methods and the Runge-Kutta methods, which are implemented in the SolidWorks and MapleSim software. The obtained results presented in the form of time dependencies of the robot kinematic and dynamic characteristics can be of significant practical interest for the researchers and designers of the similar robotic systems.

Design and Force Analysis of Mechanical Mechanisms of Pedal Powered Hacksaw in Engineering Workshop

The design and force analysis of a mechanical pedal powered hacksaw developed to modernized and less stressful operation for cutting of engineering materials. The machine was tested and found to be very efficient with an ideal mechanical advantage of 1.22, velocity ratio of 1.64m/s, a power output of 0.395kw and an efficiency of 74.4%, which makes it very adequate and capable for cutting. Furthermore, the rotational speed of the flywheel was fond to be 10.3 rad/s. It is very useful for cutting PVC materials (pipes) and can be used widely in lather and in furniture making industries. This work can also serve as an exercising machine for fitness while cutting; it uses the principle of a slider crank mechanism which converts the rotary motion of the flywheel to the reciprocating motion of the hacksaw during pedaling.

Numerical and experimental investigation on the drive mechanisms of Alfa type Stirling engines

ABSTRACT Stirling technology has applications in both renewable energy and waste heat recovery systems. The applicability of Stirling engines in these fields depends on the development of more efficient external combustion machines using renewable energy sources or waste heat. In this study, a new drive mechanism is proposed for the low cost, low weight, low volume and high-efficiency Stirling engines. The effects of the new drive mechanism on the performance parameters of the alpha-type kinematic Stirling engine are investigated, experimentally and theoretically. The mathematical model is validated by using the experimental results. The torque values for different piston forces are presented and compared with that of the conventional slider-crank mechanism. The results show that the torque value of the engine using the new drive mechanism increases by up to 3.66 times compared with that of the conventional slider-crank mechanism.

Experimental Characterization of A-AFiM, an Adaptable Assistive Device for Finger Motions

Robot rehabilitation devices are attracting significant research interest, aiming at developing viable solutions for increasing the patient’s quality of life and enhancing clinician’s therapies. This paper outlines the design and implementation of a low-cost robotic system that can assist finger motion rehabilitation by controlling and adapting both the position and velocity of fingers to the users′ needs. The proposed device consists of four slider-crank mechanisms. Each slider-crank is fixed and moves one finger (from the index to the little finger). The finger motion is adjusted through the regulation of a single link length of the mechanism. The trajectory that is generated corresponds to the natural flexion and extension trajectory of each finger. The functionality of this mechanism is validated by experimental image processing. Experimental validation is performed through tests on healthy subjects to demonstrate the feasibility and user-friendliness of the proposed solution.

Kinematic analysis of the cyclo-variator transmission mechanism

In this paper, it was made a kinematic analysis of a driver link mechanism for multiple disks variator. The study is based on analysis of the distance between the central fixed disk packages and the mobile disk packages. The obtained analytical equations were implemented in MATLAB for visualizing the dependence between the input, the position of the prismatic joint of slider-crank mechanism and the out-put, which represents the distance between the disks and as result the overall transmission ratio.For a linear input it was obtained an exponential output, and it was found out the exponential regression that fits the best the motion law of the output. Also, we search and found an input motion low to have a linear motion law that generates a linear behavior for the transmission ratio.

STUDY THE SLIDER CRANK MECHANISM

The Slider crank mechanism is a specific barlink configuration that exhibits simultaneous rotation and rectilinear motion. This mechanism is often used to study the kinematics of machines and dynamic forces. The position, speed, acceleration and recoil generated by the sliding shaft mechanism during Where, ‘R’is the crank length L>R+E operation can be determined analytically. The mechanism is capable of operating in balanced and unbalanced configurations so that the magnitude of the shaking force can be compared.

On a pseudo-periodicity in the elastodynamics

The periodic laws of motion of a real mechanism imply the periodicity of all dynamic characteristics of the mechanism during such a movement, including the elastic displacements of its constituent links. This statement covers the most difficult problem of the dynamics of an elastically deformable body. However the existing publications devoted to the study of flexible mechanisms do not mention the periodicity of elastic displacements of the links when the mechanisms move according to periodic laws. This article discusses the periodicity and pseudo-periodicity of the elastic displacements of the links using examples of calculations of the motion of a double pendulum and a slider–crank mechanism without taking into account dissipative forces.

Design and Motion Simulation Analysis of a Novel 2D Bionic Flutter Aircraft

In order to improve the symmetry of the flutter mechanism in the bionic flutter aircraft, and then improve the overall motion stability of the flutter aircraft. In this paper, an innovative flutter wing configuration is designed based on a planar crank-slider mechanism and a sparrow model. The geometric relationship of the flutter mechanism is established, the motion of the flutter aircraft is modeled, and the dimensions of the model are optimized. The geometric relationship of the flutter structure was simulated and analyzed by CATIA. The results show that the upper limit angle of the designed flutter structure is βmax=25.82° and the lower limit angle is βmin=6.34°. The CATIA simulation data are consistent with the theoretical values of the established structural geometry model. Meeting the needs of small and medium-sized flutter aircraft.The design provides a theoretical basis for the design and development of the bionic flutter vehicle and the fabrication of a solid prototype.

Energy Dissipation Analysis for Elastoplastic Contact and Dynamic Dashpot Models

• According to the energy conservation during impact and linearized elastoplastic contact stiffness , a new hysteresis damping factor is proposed. • Anoveldynamicdashpot model ispresentedusing the elastoplasticstiffness combined with the newhysteresis damping factor. • The energy dissipationduring impactfrom the new dynamicdashpot model is fully equivalent to the one obtained from the Ma-Liumodel. • The effectivenessof the proposeddashpot model is verifiedby the experimental datafrom a granular chainand the slider-crank mechanism with clearance. This investigation aims to analyze the underlying relationship between the dynamic dashpot and the static force-displacement models used in multibody systems. By ignoring the plastic flow of the contact body made of elastoplastic material, the coefficient of restitution of the dynamic dashpot model can be calculated by using the static force-displacement model proposed by Ma and Liu (Ma-Liu model). Simulation results show the consistency of energy dissipation between the Ma-Liu model and Flores et al. model, but there are still slight differences. This is because the Hertz contact stiffness of the dynamic dashpot model overestimates the actual contact stiffness in the elastoplastic phase. Therefore, in order to eliminate this discrepancy when depicting energy dissipation during impact, the Hertz contact stiffness can be replaced by the linearized elastoplastic contact one from the Ma-Liu model; subsequently, a new hysteresis damping factor is derived based on the linearized elastoplastic contact stiffness and energy conservation during impact. Finally, a new elastoplastic dashpot model can be obtained by the elastoplastic contact stiffness combined with a new hysteresis damping factor. To verify the practicability and effectiveness of the new model, a granular chain and a slider-crank mechanism with a clearance joint are employed as numerical examples.