Configuration-based compliance control of kinematically redundant robot arm Part I: Theoretical framework

The purpose of this work is to compare, with the same digging diagrams, the velocity, accelerations and dynamic performances of two excavators with different arm configurations. In particular, constructive solutions involving the use of two and three mobile arms will be examined. For excavators the different construction geometry (2-3 arms) is mainly dictated by reasons of use, in fact the 3 arms solution is normally used in areas that allow poor mobility of vehicle and present obstacles during the excavation phase. The dynamic comparison between the two solutions is performed on real working conditions to which they can be subjected during the exercise. The elaborations are performed both analytically and numerically. Essentially the analysis shows that in the condition of leveling and lifting at minimum distance from the rotation axis the dynamic performances are similar, there are significant differences in the lifting condition at the maximum distance. The diversity also implies significant variations in the forces of the hydraulic cylinders used to move both the load and the arms, an aspect which finds greater emphasis even in the case in which the arms are made by adopting unconventional materials for their realization as aluminum and composites.

Section: Load Conditionsmentioning

confidence: 99%

Excavator with two or three arms: Dynamical behavior and structural implications

Ceresoli¹

2020

“…Compliance helps robots to mitigate the effects of position and velocity errors and handle uncertainties in the location, size and shape of the workpiece [29]. Robot compliance can be active or passive [30].…”

Section: Active Compliance Controlmentioning

confidence: 99%

“…Therefore, it is more easily adapted to different situations and was adopted for this application. Active compliance control enables robots to interact with human operators safely and achieve complex tasks such as assembly and disassembly [33]. For example, the end effector of a compliant robot can move to different positions and exert different forces on an object depending on external conditions.…”

Section: Active Compliance Controlmentioning

confidence: 99%

A strategy for human-robot collaboration in taking products apart for remanufacture

Huang¹,

Pham²,

Wang³

et al. 2019

Using humans and robots working together to disassemble end-of-life (EoL) products so that they can be remanufactured enables catering for the effects of uncertainties in the condition of those products and unpredictability in remanufacturing operations. Collaborative robots are one of the key elements of Industry 4.0. This paper presents a strategy for human-robot collaborative disassembly that exploits the active compliance control capability of collaborative robots. The paper outlines the proposed human-robot collaboration strategy and active compliance control. It then presents a case study of robotic disassembly designed to show a practical implementation of the proposed strategy to take products apart. The study involved the dismantling of an automotive water pump by a collaborative industrial robot working with a human operator and by two collaborative robots and a human operator. Active compliance control was implemented to separate press-fitted components from the water pump. The results demonstrate the feasibility of the strategy and its effectiveness at increasing flexibility and adaptability by reducing setup efforts.

“…A finite element model of the robot was established by utilizing the software of ANSYS Workbench and the model was designed in CATIA V5 with crack and without crack and the frequencies at three different modes are obtained. Finally, the weak parts of the robot arm were found out and improved in the optimized design [7][8][9].…”

Section: Current Status Of Workmentioning

confidence: 99%

Investigation on adaptability of carbon fiber tube for serial manipulator

Kartikejan¹,

Sabarianand²,

Sugantan³

2019

This work describes the investigation on adapting the carbon fiber tube for building lightweight serial manipulator links. The carbon fiber is chosen based on its significant properties such as lightweight and superior mechanical strength, as an alternative to the existing conventional alloys such as steel and aluminium. A serial manipulator also suffers from a few disadvantages. A typical serial manipulator generally has a structure weight to payload ratio of approximately 200:1, which in turn drastically increases the power and torque requirements of the link actuators. So, there is a need to address this serious problem by investigating the lightweight construction for robot arm links through alternative designs. Such a design will significantly decrease the power requirements of the robot arm without compromising on stability. A comparative study has been done considering three different materials: steel, aluminium and carbon fiber using finite element analysis to check payload capability and stress concentrations.