A constrained assumed modes method for dynamics of a flexible planar serial robot with prismatic joints

Sharifnia, Mahdi; Akbarzadeh, Alireza

doi:10.1007/s11044-016-9525-8

Cited by 14 publications

(7 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Beside the two most popular methods of GEF and ANCF, new researches with new ideas are also performed for different problems of beam large deflection; see [33][34][35][36][37][38][39]. Analytical methods such as assumed modes method [40][41][42][43][44] can also be developed or combined with the finite element method for use in the large deflection of the beam structures.…”

Section: And Mahdi Sharifniamentioning

confidence: 99%

A new beam element for analysis of planar large deflection

Sharifnia

2018

J Braz. Soc. Mech. Sci. Eng.

Self Cite

View full text Add to dashboard Cite

In the present study, a simple and efficient finite element approach is presented for large deflection analysis of both the straight and curved Euler-Bernoulli beams in the planar static problems. The linear stress-strain relationship is assumed for the Euler-Bernoulli beam. In some of finite element methods, displacements together with rotations, and in some others, positions are considered as the main fields of interpolation. However, in the present study, the main idea for the interpolation is using the dimensions of the deformed element instead of the displacements. Therefore, the slope angle (like the previous works) and the length of beam centroidal axis (unlike the previous works) are used as the main field parameters. This treatment creates simplicity in the constitutive equations. Next, using the weighted residual method, the constitutive equations are applied to the element. Using the equilibrium equations and kinematic equations, the position coordinates of the nodes are related to the internal forces and the main field parameters. In the present study, three-node element and, consequently, Simpson's 1/3 rule is used for integration. For solving nonlinear equations of the beam, the Newton-Raphson method is used. Finally, several numerical examples are presented and compared with the previous works to illustrate the validity and efficiency of the new element.

show abstract

Section: And Mahdi Sharifniamentioning

confidence: 99%

A new beam element for analysis of planar large deflection

Sharifnia

2018

J Braz. Soc. Mech. Sci. Eng.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Finite Element Method (FEM) [ 29 , 30 , 31 ] and Assumed Modes Method (AMM) [ 32 , 33 , 34 ] approaches are the most used ones when modelling flexible links robots for control purposes. As the requirements and procedures of both approaches are different, several studies have been carried out to compare them [ 28 , 35 , 36 ].…”

Section: Theoretical Development Of the Kinematic Virtual Sensormentioning

confidence: 99%

Virtual Sensor for Kinematic Estimation of Flexible Links in Parallel Robots

Bengoa

Cabanes

Mancisidor

et al. 2017

Sensors

View full text Add to dashboard Cite

The control of flexible link parallel manipulators is still an open area of research, endpoint trajectory tracking being one of the main challenges in this type of robot. The flexibility and deformations of the limbs make the estimation of the Tool Centre Point (TCP) position a challenging one. Authors have proposed different approaches to estimate this deformation and deduce the location of the TCP. However, most of these approaches require expensive measurement systems or the use of high computational cost integration methods. This work presents a novel approach based on a virtual sensor which can not only precisely estimate the deformation of the flexible links in control applications (less than 2% error), but also its derivatives (less than 6% error in velocity and 13% error in acceleration) according to simulation results. The validity of the proposed Virtual Sensor is tested in a Delta Robot, where the position of the TCP is estimated based on the Virtual Sensor measurements with less than a 0.03% of error in comparison with the flexible approach developed in ADAMS Multibody Software.

show abstract

“…Meng et al [23] established dynamic model of multi-link multi-DOF flexible manipulator and studied the vibration characteristics of the tip under different elastic modulus, damping and joint stiffness. Sharifnia and Akbarzadeh [24] presented a three link serial robot with two flexible links having active prismatic and investigated transverse vibration from a set of partial differential equations using an approximate analytical method.…”

Section: Introductionmentioning

confidence: 99%

“…To the best of the author's understanding, it has been observed that little attempt has yet been made to exploit the inherent dynamics and vibration characteristics due to flexibility in the links and joints and resultant position inaccuracy [4,[22][23][24][26][27] for long-reach manipulators. Authors in [7,9] considered a robotic system of n-flexible-link robot connected by n revolute joints and assumed that the links can undergo a large overall rigid motion, however, the elastic deformation is considerably ignored whereas the present work for the first time, offers an analytical model of a spatial multi-link flexible manipulator manoeuvring in 3-D space with prismatic and revolute joints mounted on a mobile platform.…”

Section: Introductionmentioning

confidence: 99%

Nonlinear modelling and dynamics of spatial multi-link rigid-flexible manipulator with moving platform

Kumar,

Pratiher

2024

Int J Intell Robot Appl

View full text Add to dashboard Cite

The demand of developing lighter manipulators especially in various long-reach applications has been immensely escalated and in most of these applications, the presence of inherent structural flexibilities is more inevitable that causes vibration. As a result, this undesirable residual vibration reduces the working efficiency and positioning accuracy. For the first time, the present work formulates a nonlinear dynamical model of a spatial multi-link manipulator mounted on a mobile platform incorporating rigid and flexible links, and payload to study the end-point residual vibration characteristics. The dynamic modelling takes into account of coupled geometric and inertial nonlinearities due to impinging motion quality between joints, actuators, and elastic link deflections. The manipulator consists of rigid and two threedimensional flexible links driven by prismatic joint and revolute joints, respectively. The flexible links assume the Euler-Bernoulli beam elements and time-dependent in-plane motion is provided to the rigid link. Sets of nonlinear governing equations of motion have been developed analytically using Hamilton's variational principle. An independent generalized coordinates system is then used to obtain a nonlinear reduced form by discretizing the spatiotemporal equations of motion and study the trajectory dynamics of the robotic manipulator. The residual vibration characteristics at the payload end have been graphically investigated by imparting generalized sinusoidal and bang-bang torque profiles at respective joints. Nonlinear structural flexibility and material's class can play key factors that influence the residual end-point vibration. It is proven that Bang-Bang torque profile widens the settling period in residual vibration due to its complex transition characteristics as compared to sinusoidal motion profile for a specific torque duty cycle. The numerical simulations demonstrate that the end-point residual vibrations and joint deflections are significantly influenced by the changes in physical and geometric variables which may lead to positioning errors and control of spatial flexible manipulators.

show abstract

A constrained assumed modes method for dynamics of a flexible planar serial robot with prismatic joints

Cited by 14 publications

References 34 publications

A new beam element for analysis of planar large deflection

A new beam element for analysis of planar large deflection

Virtual Sensor for Kinematic Estimation of Flexible Links in Parallel Robots

Nonlinear modelling and dynamics of spatial multi-link rigid-flexible manipulator with moving platform

Contact Info

Product

Resources

About