Development of Hardware Simulator and Controller for Web Transport Process

2005 ◽  
Vol 128 (1) ◽  
pp. 378-381 ◽  
Author(s):  
Jeetae Kim
Keyword(s):  
Force Control ◽  
Transport Process ◽  
Closed Loop ◽  
Controller Design ◽  
Transport Model ◽  
Tension Force ◽  
Closed Loop Control ◽  
Measuring Device ◽  
Loop Control ◽  
Process Simulator

In this study a hardware simulator and controller for web transport process are developed. First the dynamics of web transport process is analyzed for simulator and controller design. An example Polypropylene transport process is investigated and its simplified transport model is derived. Then the web transport process simulator and its controller are developed. Accurate tension force control is needed to produce high quality web formed materials. The process controller uses the loadcell as a tension measuring device and closed-loop control is used for tension force regulation. The response of the system is tested under the disturbances in tension and the experimental results show that the system regulates tension disturbances properly.

Combined Temperature and Force Control for Robotic Friction Stir Welding

2013 ◽  
Author(s):  
Axel Fehrenbacher ◽  
Christopher B. Smith ◽  
Neil A. Duffie ◽  
Nicola J. Ferrier ◽  
Frank E. Pfefferkorn ◽  
...  
Keyword(s):  
Control System ◽  
Force Control ◽  
Closed Loop ◽  
Interface Temperature ◽  
Closed Loop Control ◽  
Weld Quality ◽  
Loop Control ◽  
Friction Stir ◽  
Tool Position ◽  
Robotic Friction Stir Welding

The objective of this research is to develop a closed-loop control system for robotic friction stir welding (FSW) that simultaneously controls force and temperature in order to maintain weld quality under various process disturbances. FSW is a solid-state joining process enabling welds with excellent metallurgical and mechanical properties, as well as significant energy consumption and cost savings compared to traditional fusion welding processes. During FSW, several process parameter and condition variations (thermal constraints, material properties, geometry, etc.) are present. The FSW process can be sensitive to these variations, which are commonly present in a production environment; hence, there is a significant need to control the process to assure high weld quality. Reliable FSW for a wide range of applications will require closed-loop control of certain process parameters. A linear multi-input-multi-output process model has been developed that captures the dynamic relations between two process inputs (commanded spindle speed and commanded vertical tool position) and two process outputs (interface temperature and axial force). A closed-loop controller was implemented that combines temperature and force control on an industrial robotic FSW system. The performance of the combined control system was demonstrated with successful command tracking and disturbance rejection. Within a certain range, desired axial forces and interface temperatures are achieved by automatically adjusting the spindle speed and the vertical tool position at the same time. The axial force and interface temperature is maintained during both thermal and geometric disturbances and thus weld quality can be maintained for a variety of conditions in which each control strategy applied independently could fail.

Robotic force control for deburring using an active end effector

Robotica ◽  
1989 ◽  
Vol 7 (4) ◽  
pp. 303-308 ◽  
Author(s):  
G. M. Bone ◽  
M. A. Elbestawi
Keyword(s):  
Control System ◽  
Force Control ◽  
Pid Controller ◽  
Closed Loop ◽  
Least Squares Method ◽  
Closed Loop Control ◽  
End Effector ◽  
Loop Control ◽  
Positioning Errors ◽  
Force Control System

SUMMARYAn active force control system for robotic deburring based on an active end effector is developed. The system utilizes a PUMA-560 six axis robot. The robot's structural dynamics, positioning errors, and the deburring cutting process are examined in detail. Based on ARMAX plant models identified using the least squares method, a discrete PID controller is designed and tested in real-time. The control system is shown to maintain the force within l N of the reference, and reduce chamfer depth errors to 0.12 mm from the 1 mm possible without closed-loop control.

Controller Design for Active Closed-Loop Control of Cavity Flows

2004 ◽  
Author(s):  
Hitay Ozbay ◽  
Onder Efe ◽  
Mo Samimy ◽  
Edgar Caraballo ◽  
Jim DeBonis ◽  
...  
Keyword(s):  
Closed Loop ◽  
Controller Design ◽  
Closed Loop Control ◽  
Cavity Flows ◽  
Loop Control

Nonlinear Model-Based Controller Design for a Hydraulic Rack and Pinion Gear Actuator

2018 ◽  
Author(s):  
Pauli Mustalahti ◽  
Jouni Mattila
Keyword(s):  
Closed Loop ◽  
Controller Design ◽  
Dynamical Behavior ◽  
Control Design ◽  
Closed Loop Control ◽  
Loop Control ◽  
Hydraulic Manipulators ◽  
Pinion Gear ◽  
Hydraulic Manipulator ◽  
Heavy Loads

Hydraulic manipulators are extensively utilized to move heavy loads in many industrial tasks. In commercial applications, a manipulator base is required to rotate a motion range of the full 360°. This is usually implemented by using a hydraulic rack and pinion gear actuator. Due to the manipulator’s long reach and heavy loads, manipulator tip acceleration can produce significant torque to the rotation gear in free-space motion. Imposed by nonlinear dynamical behavior (involving, e.g., the gear backlash and actuator friction) added to high inertia, a system closed-loop control design becomes a challenging task. An advanced closed-loop control enables to increase the automation-level of hydraulic manipulators. This study designs a novel subsystem-dynamics-based controller for a hydraulic rack and pinion gear actuator utilizing the control design principles of the virtual decomposition control (VDC) approach. An adaptive backlash compensation is incorporated in the control design. Furthermore, the proposed controller is implemented in previously-designed state-of-the-art hydraulic manipulator control. The stability of the overall control design is proven. Experiments with a full-scale commercial hydraulic manipulator demonstrate the effectiveness of the proposed adaptive backlash compensation and the overall control performance.

scholarly journals Limit Cycle Behavior of Smart Fluid Dampers Under Closed Loop Control

2005 ◽  
Vol 128 (4) ◽  
pp. 413-428 ◽  
Author(s):  
Neil D Sims
Keyword(s):  
Limit Cycle ◽  
Closed Loop ◽  
Controller Design ◽  
Nonlinear Models ◽  
Control Strategies ◽  
Nonlinear Behavior ◽  
Closed Loop Control ◽  
Loop Control ◽  
Fluid Dampers ◽  
Limit Cycle Behavior

Semiactive vibration dampers offer an attractive compromise between the simplicity and fail safety of passive devices, and the weight, cost, and complexity of fully active systems. In addition, the dissipative nature of semiactive dampers ensures they always remain stable under closed loop control, unlike their fully active counterparts. However, undesirable limit cycle behavior remains a possibility, which is not always properly considered during the controller design. Smart fluids provide an elegant means to produce semiactive damping, since their resistance to flow can be directly controlled by the application of an electric or magnetic field. However, the nonlinear behavior of smart fluid dampers makes it difficult to design effective controllers, and so a wide variety of control strategies has been proposed in the literature. In general, this work has overlooked the possibility of undesirable limit cycle behavior under closed loop conditions. The aim of the present study is to demonstrate how the experimentally observed limit cycle behavior of smart dampers can be predicted and explained by appropriate nonlinear models. The study is based upon a previously developed feedback control strategy, but the techniques described are relevant to other forms of smart damper control.

Type-III closed loop control systems-Digital PID controller design

2013 ◽  
Vol 23 (10) ◽  
pp. 1401-1414 ◽  
Author(s):  
Konstantinos G. Papadopoulos ◽  
Nikolaos D. Tselepis ◽  
Nikolaos I. Margaris
Keyword(s):  
Control Systems ◽  
Pid Controller ◽  
Closed Loop ◽  
Controller Design ◽  
Closed Loop Control ◽  
Loop Control ◽  
Type Iii ◽  
Digital Pid ◽  
Pid Controller Design
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