ANKUR JAISWAL - Academia.edu (original) (raw)

Papers by ANKUR JAISWAL

Materials Today: Proceedings, 2022

2021 IEEE Bombay Section Signature Conference (IBSSC), 2021

The role of mechanisms in robotics is pivotal in deciding the accuracy and working range of a par... more The role of mechanisms in robotics is pivotal in deciding the accuracy and working range of a particular robot. A planar closed loop, single degree of freedom (DoF) mechanism can be used in various machines. The main advantage of such mechanism is the single input that can control the complete mechanical movement. Position of the end effector in real time depends on various factors. A P3R mechanism has been considered in this paper. A detailed position and compensation analysis is carried out and the effect of joint clearances are considered. The orientation of input and output links under the effect of joint clearances and their deviation and errors are calculated. A mathematical computer model is developed to compute the positional and orientation error.

Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2022

Four-bar linkages form a primitive configuration of many mechanisms. The output of these mechanis... more Four-bar linkages form a primitive configuration of many mechanisms. The output of these mechanisms deviates from the desired one due to many factors including tolerance on links. For satisfactory application, the mechanism performance needs to be characterized. This article presents a treatment on the synthesis and analysis of linear-input P3R (1-Prismatic, 3-Revolute) and rotary-input 4R (4-Revolute) planar mechanism configurations, and the estimation of mechanical error under the influence of link tolerances. A detailed methodology is presented for error estimation as part of performance analysis for each mechanism. As an illustrative case, mechanisms are considered to operate under identical output generation conditions and comparative performance evaluation is carried out. Effect of link proportion is studied to investigate the mechanism behavior related to mechanical error. Comparison of error provides the basis for selecting the mechanism that gives better performance. The pr...

Force transducers are capable of determining the magnitude of force applied by measuring strain d... more Force transducers are capable of determining the magnitude of force applied by measuring strain deformations. The strain induced on the transducer is measured using strain gauges. Usually, the force transducers, being unidirectional, are able to sense only axial force or torque. This paper presents an innovative force transducer for sensing triaxial loads and moments pertaining to its unique shape which allows strategic placement of strain gauges. The transducer is designed in a frame-like structure by stacking three cantilever beams one in each orthogonal axis. Each frame is sensitive to the load applied in the corresponding orthogonal direction. This configuration provides advantage of uniform sensitivity in triaxial loading applications with negligible cross sensitivity. The transducer is having a proportional force and moment conversion due to its single body structure and isotropic material properties. A new design for the transducer is also proposed and the comparative behavio...

AIP Conference Proceedings, 2018

Function generation is synthesis of mechanism for specific task, involves complexity for speciall... more Function generation is synthesis of mechanism for specific task, involves complexity for specially synthesis above five precision of coupler points. Thus pertains to large structural error. The methodology for arriving to better precision solution is to use the optimization technique. Work presented herein considers methods of optimization of structural error in closed kinematic chain with single degree of freedom, for generating functions like log(x), ex, tan(x), sin(x) with five precision points. The equation in Freudenstein-Chebyshev method is used to develop five point synthesis of mechanism. The extended formulation is proposed and results are obtained to verify existing results in literature. Optimization of structural error is carried out using least square approach. Comparative structural error analysis is presented on optimized error through least square method and extended Freudenstein-Chebyshev method.Function generation is synthesis of mechanism for specific task, involves complexity for specially synthesis above five precision of coupler points. Thus pertains to large structural error. The methodology for arriving to better precision solution is to use the optimization technique. Work presented herein considers methods of optimization of structural error in closed kinematic chain with single degree of freedom, for generating functions like log(x), ex, tan(x), sin(x) with five precision points. The equation in Freudenstein-Chebyshev method is used to develop five point synthesis of mechanism. The extended formulation is proposed and results are obtained to verify existing results in literature. Optimization of structural error is carried out using least square approach. Comparative structural error analysis is presented on optimized error through least square method and extended Freudenstein-Chebyshev method.

Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2018

Many planar manipulators are composed of a basic four-bar mechanism. The output delivered by the ... more Many planar manipulators are composed of a basic four-bar mechanism. The output delivered by the mechanism deviates from desired one due to factors like link tolerances. The performance needs to be characterized for satisfactory application. This article presents investigation of mechanical error in four-bar mechanism with revolute joints (4R) under the influence of link tolerance. The classical partial derivative formulation (PDA) in uncertainty analysis technique is primarily used for estimating the mechanical error. The error estimation is carried out with proposed modification in PDA formulation. A geometric approach is also developed to estimate the mechanical error for 4R configuration. The mechanical error obtained through PDA is verified using geometric approach. The generalized formulation is demonstrated, and comparative estimation is presented. The methods and conclusions proposed herewith are adaptable for other planar configurations.

World Journal of Engineering, 2019

Purpose The force sensing is used in robotic assembly tasks. The sensors developed are much advan... more Purpose The force sensing is used in robotic assembly tasks. The sensors developed are much advanced and costly. The force transducers are generally configured and deployed at the wrist of the robotic arm. The purpose of this paper is to describe the concept of an elastic transducer to make available cost-effective force sensor with simple construction and analysis. Design/methodology/approach The analytical formulation is developed herewith for one-, two- and three-axis elastic cantilever configuration. The force to be measured can be calculated analytically using derived strain expressions. The strains are estimated using proposed formulation, further crosschecked through FEA approach. The analytical method for strain estimation using moment equations is presented along with validation using finite element method (FEM) tool (ANSYS 15.0) with the case study. Findings The derivation of expressions for force components from strains is developed. The resulting formulation found to con...

Volume 5B: 40th Mechanisms and Robotics Conference, 2016

This article incorporates formulation and application for the varying position of output link of ... more This article incorporates formulation and application for the varying position of output link of P3R and 4R manipulator configuration and estimation of mechanical error. The behavior of the output link is analyzed for linear and rotary inputs for both the type of configurations. The variation in link tolerance is introduced as input for estimating the mechanical error for P3R and 4R manipulator with the derived formula. Comparison of the errors provides the basis of selecting the best manipulator with the minimum mechanical error. Sample case is illustrated for the identical operational features in these P3R and 4R manipulators and the performance of these manipulators is quantified in this paper. The methodology is successful in considering the effect of source of mechanical errors in general; the proposed methodology is going to be helpful for the analysis of spatial and parallel manipulator.

This article describes the synthesis of four-bar mechanism for hyperbolic function generation wit... more This article describes the synthesis of four-bar mechanism for hyperbolic function generation with four accuracy point and its optimized using least square method. This research is concerned with the development of mathematical formulation of Freudenstein-Chebyshev approximation theory extended from three points to four point synthesis problems. The objective function has been analyzed based on the structural error between the generated and desired function. Their comparison has been shown with regard to minimum structural. Structural error is found to be optimized with least square method. Three hyperbolic functions are solved and demonstrated for study purpose.

Archive of Applied Mechanics

Kinematic mechanisms are synthesized for a task. Function generation provides precise displacemen... more Kinematic mechanisms are synthesized for a task. Function generation provides precise displacement at output links that obeys a given functional relations. This article describes the synthesis of four-bar mechanism for the hyperbolic function generation with four and five accuracy point, which is further optimized using least square method. This research is concerned with development of mathematical formulation based on Freudenstein–Chebyshev approximation theory, extended to four- and five-point synthesis function generation problem. The objective function is analyzed for the structural error between the generated function and the desired function. Resulting nonlinear equations are converted into set of linear equations applying the compatibility conditions and are solved using Gauss elimination method. The formulation is proposed for five position synthesis for algebraic and trigonometric function generation problem. Associated structural error is estimated. Comparison of estimated error through the formulation is carried out with the reported errors through graphical method. The error for hyperbolic function is estimated. Attempt is made to minimize the error through simple of least square technique. The results obtained are compared with Freudenstein–Chebyshev approximation method. Three hyperbolic functions, namely sinh(x), cosh(x) and tanh(x), are used to demonstrate the effectiveness of the proposed synthesis method.