A Hydraulically-Actuated Reconfigurable Tool for Flexible Fabrication: Implementation and Control

1999 ◽  
Vol 122 (3) ◽  
pp. 562-568 ◽  
Author(s):  
Daniel F. Walczyk ◽  
Yong-Tai Im

An automatically reconfigurable discrete tool (matrix of pins) has been developed and demonstrated for sheet metal part forming and composite part molding in the aerospace industry. A GUI-based control system positions each of the hydraulically-actuated pins according to a computer model of the intended tool surface. Open-loop position control of individual pins (timing the upward movement of each pin) is possible but accuracy and repeatability are inadequate for most sheet metal forming and composite molding applications. However, closed-loop position control is shown to provide sufficient accuracy and repeatability for these same applications. Once the pin matrix shape is set, it can be made into a rigid forming or molding tool by side clamping with a hydraulic ram. Since the pin ends are spherical in shape, the resulting dimpled tool surface is covered with an interpolating layer of material. The pins can be reset to their lowest position by either withdrawing hydraulic fluid or pushing them down with the setting platen. [S1087-1357(00)01403-9]

2011 ◽  
Vol 143-144 ◽  
pp. 913-916
Author(s):  
Xun Mei Han

With CAXA software I designed the structure of the handling manipulator in the FMS. And focus for the design of the structure, introduced the hardware implementation of robot manipulator with the same characteristics of stepping away from its open-loop position control. The manipulator is mainly used for flexible manufacturing systems in material handling, flexible movement, safe, reliable, easy to adjust and control, simple operation, easy to implement process automation.


Author(s):  
Shyam Sunder Nishad ◽  
Anupam Saxena ◽  
Ashish Dutta

A three-finger exoskeleton is designed and controlled to translate and or rotate a slender object held between the fingertips. Each finger exoskeleton comprises of three serially concatenated planar external four-bar linkages, all on one plane, except for the thumb exoskeleton, for which one linkage is out of plane. Linkages are constrained to be on the dorsal side (sagittal plane) of each finger. To design each linkage, when performing coordinated translation and rotation, trajectories of all phalanges of the index and middle fingers and the thumb are obtained through video capture and post-processing that involves coordinate transformation. Optimal kinematic synthesis for each linkage is then performed via the three accuracy point method coupled with a stochastic search algorithm. Post manufacturing, the exoskeleton is mounted on the dorsal side of the hand using Velcro bands. Fastening is accomplished on each phalanx, palm and forearm via a fixture designed to house all three exoskeletons. Nine micro-servo motors are employed for actuation. To perform coordinated translation and rotation tasks, trajectory following is accomplished using open loop position control, incorporating artificial neural network to convert known finger joint angles into the required driving link angles. Based on experimental tests conducted, the exoskeleton is found to be successful in reproducing the requisite finger motions involved in coordinated object manipulation.


Author(s):  
David Moreno Giner ◽  
Claudio Brenna ◽  
Ioannis Symeonidis ◽  
Gueven Kavadarlic

Multibody dynamics simulation technology can provide a great help to understand and analyze motorcycle dynamics. In fact, its application in this field has grown very fast in the last years. However, apart from the mathematical model of the vehicle, a virtual rider is essential in order to properly simulate a motorcycle. This is due to the unstable nature of two-wheeled vehicles, which makes them very difficult to simulate by using open-loop maneuvers. The problem of developing a virtual rider for motorcycles has already been covered in literature but most of the proposed control algorithms achieved their purpose without considering the physiological limits of the rider. The objective of the research activities presented here are the preliminary development of a realistic virtual rider based on an experimental campaign and its subsequent simulation together with a detailed multibody model of a motorcycle. Special emphasis was put on making the rider model as simple as possible to facilitate the posterior design of the controller. Real rider movements were measured under laboratory conditions by means of the Motion Analysis technique. Several volunteers with different riding experiences, gender and anthropometry were involved in the experiments in order to provide a valid dataset for the analysis. For the present research, the virtual rider controls the direction of the motorcycle by means of both a torque on the handlebars and the movement of his body. The upper part of the rider’s body was modeled as an inverted pendulum. With regard to the longitudinal dynamics, the motorcycle is controlled by means of the brake torques and by the engine torque, which is transmitted to the rear wheel by means of a simplified model of the chain. First results of the developed virtual rider are presented at the end of this paper.


2021 ◽  
Author(s):  
Athul K. Sundarrajan ◽  
Yong Hoon Lee ◽  
James T. Allison ◽  
Daniel R. Herber

Abstract This paper discusses a framework to design elements of the plant and control systems for floating offshore wind turbines (FOWTs) in an integrated manner using linear parameter-varying models. Multiple linearized models derived from high-fidelity software are used to model the system in different operating regions characterized by the incoming wind speed. The combined model is then used to generate open-loop optimal control trajectories as part of a nested control co-design strategy that explores the system’s stability and power production in the context of crucial plant and control design decisions. A cost model is developed for the FOWT system, and the effect of plant decisions and subsequent power and stability response of the FOWT is quantified in terms of the levelized cost of energy (LCOE) for that system. The results show that the stability constraints and the plant design decisions affect the turbine’s power and, subsequently, LCOE of the system. The results indicate that a lighter plant in terms of mass can produce the same power for a lower LCOE while still satisfying the constraints.


Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4930
Author(s):  
Francisco Elvis Carvalho Souza ◽  
Werbet Silva ◽  
Andrés Ortiz Salazar ◽  
José Paiva ◽  
Diego Moura ◽  
...  

In order to reduce the costs of implementing the radial position control system of a three-phase bearingless machine with split winding, this article proposes a driving method that uses only two phases of the system instead of the three-phase traditional one. It reduces from six to four the number of inverter legs, drivers, sensors, and current controllers necessary to drive and control the system. To justify the proposal, this new power and control configuration was applied to a 250 W machine controlled by a digital signal processor (DSP). The results obtained demonstrated that it is possible to carry out the radial position control through two phases, without loss of performance in relation to the conventional three-phase drive and control system.


Author(s):  
Yogesh V. Hote ◽  
A. N. Jha ◽  
J. R. P. Gupta

In this paper, simple approach is proposed to determine reduced order model of a unstable open-loop position control system. This approach is based on Krishnamurthy’s approach on Routh criterion on reduced order modelling. The results are simulated in Matlab environment.


2013 ◽  
Vol 705 ◽  
pp. 616-620
Author(s):  
Li Xia Wang ◽  
Zhan Rong Feng ◽  
Ran Yang Zhang

In order to apply the PTO pulse function of Siemens PLC in a more systematic, convenient and effective way, this thesis adopts the position control wizard to generate envelop and control subroutine. The thesis also makes detailed descriptions and case discussions on the four subroutines of PTO0_CTRL, PTO0_RUN, PTO0_MAN, PTO0_LDPOS, and the results show that using the position control wizard can not only generate envelop and control subroutine conveniently but also bring convenience to the application of the subroutine. Especially, the parameters of the four subroutines interact both independently and mutually. If we make a deeper research on the parameters, we can master their relations further more and apply them more proficiently.


2008 ◽  
Vol 575-578 ◽  
pp. 186-191
Author(s):  
Jun Zhao ◽  
Chun Jian Su ◽  
Ying Ping Guan

The main problem in bending process of sheet metal is that it is difficult to control bending springback accurately. Springback produced from the unloading of bending makes the shape and size incongruent between bending workpiece and working portion of die. Because the final shape of bending workpiece is related with the whole deformation process, the geometric parameter of die, material performance parameter will have great effect on springback. Therefore, the springback problem is very complicated and the prediction and control of springback is the key to improve the accuracy of bending workpiece. Taking the V free bending of wide sheet as an object of study, the neural networks technology and data acquisition system based on LabVIEW are used to establish intelligent control experiment system for V free bending of wide sheet metal. The control accuracy of system is high and it provides the basis for the realization of intelligent control for V-shape free bending of wide sheet metal in practice in future.


2021 ◽  
pp. 1-15
Author(s):  
Mario E. Herrera-Cordero ◽  
Manuel Arias-Montiel ◽  
Marco Ceccarelli ◽  
Esther Lugo-Gonzalez

Abstract Co-simulation is widely used as a powerful tool for performance evaluation of systems design. This approach presents advantages over traditional design methodologies for saving money and time in the development process and the possibility of evaluating rapidly design alternatives by using virtual prototypes. This article presents an ADAMS/Matlab co-simulation for the dynamics and control of a Single-Wheel pendulum ROBot (SWROB) with inertial locomotion actuation to characterize design solutions by means of validation of analytical results. The obtained results by the proposed co-simulation show a significant performance based on the analytical and programming efforts in characterizing and simulating the designed system model. Moreover, open-loop experimental results are presented to validate both the analytical model and the virtual prototype.


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