Control of a two-link (rigid-flexible) manipulator

J Braz. Soc. Mech. Sci. Eng.

2020

Mathematical modelling plays an important role for robotic manipulators in order to design their particular controllers. Also, it is hard challenge to obtain an accurate mathematical model or obtain a suitable modelling method in such vast field. Thus, this critical review is advantageous and indispensable for researchers who are interested in the area to gain fruitful knowledge on the mathematical modelling methods. This paper is classified based on the type of robotic manipulators such as flexible link manipulators (FLMs), rigid link manipulators (RLMs) and hybrid manipulators which involves rigid links and flexible links. The used modelling methods for FLMs are the assumed mode method, the finite element method, and the lumped parameter method as approximation techniques which are well explained and reviewed. The Lagrangian method has inclusive explanation and review which is widely participated for obtaining the dynamic equations of FLMs, and it is appropriate and commonly employed for modelling RLMs. The Newtonian method, the forward kinematic, and the inverse kinematic are also well discussed and reviewed which are suitable and commonly employed for modelling RLMs. The critical discussion of 170 articles reported in this paper guides researchers to select the suitable method for modelling. This paper reviews the published articles in the period of 2010-2020 except for few older articles for the need of providing essential theoretical knowledge. The advantages and disadvantages of each method are well summarized at the end of the paper. The intelligent identification methods are briefly discussed due to the lack of publications especially on the period of 2010-2020.

Section: Modelling Methods Of Rflmsmentioning

confidence: 99%

A critical review of modelling methods for flexible and rigid link manipulators

J Braz. Soc. Mech. Sci. Eng.

2020

“…The dynamic equations are derived based on equations (17)–(19), and substituting the initial conditions of the HAR system. The initial conditions are assumed once the robot has zero torques for both joints τ1=τ2=0, so the positions of the RL and the FL are zero θ=1θ2=0 (Mahil and Al-durra, 2016; Hussein and Nemah, 2015). The dynamic model of the HAR is expressed as given in equation (21).…”

Section: System Modelingmentioning

confidence: 99%

Dynamic model and integrated optimal controller of hybrid arms robot for laser contour machining

Journal of Vibration and Control

Vijayakumar

et al. 2022

The hybrid arms robot (HAR) is a new modified robot which consists of a rigid link (RL) and a flexible link (FL), and it carries a laser head at the end-effector for laser contour machining (CM). The HAR is inspired from a rigid-flexible links manipulator (RFLM) and the aim is to bring the advantages of flexible link manipulators (FLMs) to industrial robots. The HAR gains the advantages of lightweight robots and FLMs such as fast response, less power consumption due to using small actuators, low cost, and safe to surrounding operators. However, the HAR has the drawback of a tip vibration caused by the flexibility of the second FL and leads to a position error at the end-effector position. Furthermore, the HAR has more parameters to be incorporated in a dynamic model such as the tip vibration, the laser head weight, and a force generated by the assist gas pressure. This research aims to obtain the dynamic model of the HAR using the finite element method (FEM) in conjunction with the Lagrangian equation and to propose an integrated optimal controller (IOC) which is an integration of a linear quadratic regulator (LQR) and a fuzzy logic controller (FLC). The derived dynamic model of the HAR is efficient due to the close match response with the SimMechanics model response of the HAR. The proposed IOC is tested for point-to-point (PTP) position control of the HAR and demonstrates improved response and better capability for the tip vibration suppression. The proposed IOC also reveals enhanced triangular CM trajectory, rhombic CM trajectory, and circular CM trajectory of the HAR laser head compared to the LQR performance in a proper cutting speed to ensure the machining quality.

“…118 A PD controller was compared with a PD plus feed-forward controller for controlling two rigid-flexible links manipulator (two-RFLM) which the combined controller performed better than the PD controller alone. 119 Another two-RFLM was controlled by a PD controller in ref. [120].…”

Section: Control Of Rlmsmentioning

confidence: 99%

A Critical Review of Control Techniques for Flexible and Rigid Link Manipulators

2020

Robotica

SUMMARY There is a high demand for developing effective controllers to perform fast and accurate operations for either flexible link manipulators (FLMs) or rigid link manipulators (RLMs). Thus, this paper is beneficial for such vast field, and it is also advantageous and indispensable for researchers who are interested in robotics to have sufficient knowledge about various controllers of FLMs and RLMs as the controllers’ concepts are elaborated in detail. The paper concentrates in critically reviewing classical controllers, intelligent controllers, robust controllers, and hybrid controllers for both FLMs and RLMs. The advantages and disadvantages of the aforementioned control methods are summarized in this paper; it also has a detailed comparison for the controllers in terms of the design difficulty, performance, and the suitability for controlling FLMs or RLMs.