Error attenuation in the control of a parallel robot manipulator using a dual-model-based structure

2003 ◽  
Vol 217 (2) ◽  
pp. 161-171 ◽  
Author(s):  
Q Li
Keyword(s):  
Control Structure ◽  
Robot Manipulator ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Internal Model Control ◽  
Sensitivity Analyses ◽  
Parallel Structure ◽  
Dual Model ◽  
Model Based ◽  
Model Control

Parallel structure robots have been receiving growing attention from both academia and industry in recent years. This is due to their advantages over serial structure robots, such as high stiffness, high motion accuracy and a high load-structure ratio. Control of parallel robots, however, produces difficulties to control engineers due to the modelling errors arising from the highly non-linear and complex structures. This paper proposes a dual-model-based structure for error attenuation in the trajectory-tracking control of a parallel robot manipulator. In this design, a conventional model-based control algorithm employing an estimated robot dynamic model is first implemented in the inner loop of the control structure. Then, in order to reduce the unwanted effects caused by modelling erros, another model-based structure, developed based on the concept of the internal model control, is appended in the outer loop of the control structure as a compensator. A combination of these two model-based components results in a novel dual-model-based structure for parallel robot control. Sensitivity analyses show that the effects due to modelling errors and external disturbances can be significantly reduced by applying this new control structure without relying on a high-gain control solution. The effectiveness of this control design is successfully demonstrated by numerical studies on a planar parallel robot with 2 degrees of freedom.

Control of Robot Manipulators Using a Dual-Model-Based Structure

1998 ◽  
Author(s):  
Q. Li ◽  
W. J. Zhang ◽  
S. K. Tso
Keyword(s):  
Control Structure ◽  
Robot Manipulators ◽  
Gain Control ◽  
Internal Model Control ◽  
Sensitivity Analyses ◽  
Dual Model ◽  
Trajectory Tracking Control ◽  
Model Based Control ◽  
Model Based ◽  
Model Control

Abstract This paper proposes a dual-model-based structure for uncertainty attenuation in the trajectory-tracking control of robot manipulators. A conventional model-based control algorithm with an estimated robot dynamic model employed is first placed in the overall structure as a basic control component. To further attenuate the unwanted effects caused by modelling uncertainties, another model-based structure, appended in the outer-loop of the basic control structure as a compensator, is developed based on the concept of the internal model control. Combination of these two model-based structures results in a novel dual-model-based controller for robot manipulators. Sensitivity analyses show that the effects due to both modelling errors and external disturbances can be significantly reduced by applying this dual-model-based control structure without relying on a high-gain control solution. Effectiveness of this control design is successfully demonstrated by simulation studies on a 2 degree-of-freedom robot.

scholarly journals Fractional-order internal model control algorithm based on the force/position control structure of redundant actuation parallel robot

2020 ◽  
Vol 17 (1) ◽  
pp. 172988141989214 ◽  
Author(s):  
Shuhuan Wen ◽  
Xueheng Hu ◽  
Baowei Zhang ◽  
Miao Sheng ◽  
HK Lam ◽  
...  
Keyword(s):  
Internal Model ◽  
Control Structure ◽  
Control Method ◽  
Hybrid Control ◽  
Parallel Robot ◽  
Internal Model Control ◽  
Redundant Actuation ◽  
Model Control ◽  
Fractional Filter ◽  
Derivative Control

This article proposes a new control structure for the complex redundant actuation parallel robot based on force/position hybrid control structure. The traditional proportional–integral–derivative control method, integer-order internal model control method and fractional-filter internal model control–proportional–derivative control method are used in the position structure of force/position hybrid control. The fractional-filter internal model control–proportional–derivative control method is used in the position loop of the permanent magnet synchronous motor to reduce the position error. A fractional-order theory with the internal model control method is used in redundant actuation force control structure, which can improve the control precision of the driving force of the parallel robot. The Admas/Matlab simulation results show that the proposed method outperforms other methods and can obtain good robustness and tracking performance.

scholarly journals Stabilization of the Magnetic Levitation System

2021 ◽  
Vol 11 (21) ◽  
pp. 10369
Author(s):  
Štefan Chamraz ◽  
Mikuláš Huba ◽  
Katarína Žáková
Keyword(s):  
Closed Loop ◽  
Magnetic Levitation ◽  
Internal Model Control ◽  
Pass Filter ◽  
Low Pass Filter ◽  
First Order ◽  
Model Based ◽  
Model Control ◽  
Levitation System ◽  
Magnetic Levitation System

This paper contributes toward research on the control of the magnetic levitation plant, representing a typical nonlinear unstable system that can be controlled by various methods. This paper shows two various approaches to the solution of the controller design based on different closed loop requirements. Starting from a known unstable linear plant model—the first method is based on the two-step procedure. In the first step, the transfer function of the controlled system is modified to get a stable non-oscillatory system. In the next step, the required first-order dynamic is defined and a model-based PI controller is proposed. The closed loop time constant of this first-order model-based approach can then be used as a tuning parameter. The second set of methods is based on a simplified ultra-local linear approximation of the plant dynamics by the double-integrator plus dead-time (DIPDT) model. Similar to the first method, one possible solution is to stabilize the system by a PD controller combined with a low-pass filter. To eliminate the offset, the stabilized system is supplemented by a simple static feedforward, or by a controller proposed by means of an internal model control (IMC). Another possible approach is to apply for the DIPDT model directly a stabilizing PID controller. The considered solutions are compared to the magnetic levitation system, controlled via the MATLAB/Simulink environment. It is shown that, all three controllers, with integral action, yield much slower dynamics than the stabilizing PD control, which gives one motivation to look for alternative ways of steady-state error compensation, guaranteeing faster setpoint step responses.

scholarly journals Controller Design and Control Structure Analysis for a Novel Oil–Water Multi-Pipe Separator

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 190
Author(s):  
Sveinung Ohrem ◽  
Håvard Skjefstad ◽  
Milan Stanko ◽  
Christian Holden
Keyword(s):  
Structure Analysis ◽  
Oil And Gas ◽  
Control Structure ◽  
Oil And Gas Industry ◽  
Internal Model Control ◽  
Step Response ◽  
Efficient Production ◽  
Proportional Integral ◽  
Model Control ◽  
Inlet Conditions

To enable more efficient production of hydrocarbons on the seabed in waters where traditional separator equipment is infeasible, the offshore oil and gas industry is leaning towards more compact separation equipment. A novel multi-pipe separator concept, designed to meet the challenges of subsea separation, has been developed at the Department of Geoscience and Petroleum at the Norwegian University of Science and Technology. In this initial study, a control structure analysis for the novel separator concept, based on step-response experiments, is presented. Proportional-integral controllers and model reference adaptive controllers are designed for the different control loops. The proportional-integral controllers are tuned based on the well-established simple internal model control tuning rules. Both control methods are implemented and tested on a prototype of the separator concept. Different measurements are controlled, and results show that the performance of the separator under varying inlet conditions can be improved with proper selection of control inputs and measurements.

Model-Based Gain Scheduling Strategy for an Internal Model Control-Based Boost Pressure Controller in Variable Geometric Turbocharger System of Diesel Engines

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Seungwoo Hong ◽  
Inseok Park ◽  
Myoungho Sunwoo
Keyword(s):  
Diesel Engines ◽  
Internal Model ◽  
Gain Scheduling ◽  
Internal Model Control ◽  
Operating Conditions ◽  
Boost Pressure ◽  
Scheduling Strategy ◽  
Model Based ◽  
Model Control ◽  
Pressure Controller

This paper proposes a model-based gain scheduling strategy of a Skogestad internal model control (SIMC)-based boost pressure controller for passenger car diesel engines. This gain scheduling strategy is proposed with a new scheduling variable to handle the nonlinear variable geometric turbocharger (VGT) plant characteristics. The scheduling variable is derived from the pressure ratio between the exhaust and intake manifolds and the exhaust air-to-fuel ratio to estimate the static gain of the VGT plant, which varies widely with change in the engine operating conditions. The proposed static gain model was designed with the scheduling variable, engine speed, and fuel injection quantity. Compared to the steady-state experimental data, the static gain model showed an R-squared value of 0.91. The boost pressure controller had the proportional-integral (PI) structure to allow for online calibration, and the PI gains were determined using the SIMC method. The proposed static gain model for the VGT plant was integrated into the SIMC control structure to obtain the appropriate control gains under wide engine operating area. The proposed control algorithm was compared with a fixed gain boost pressure controller through various step tests of the desired boost pressure. The fixed gain controller showed a large overshoot of 64% when the exhaust gas recirculation (EGR) operating condition was changed. In contrast, the proposed gain scheduled boost pressure controller reduced the overshoot to 12%. The model-based gain scheduling strategy successfully adjusted the control gains to achieve consistent control performance under various engine operating conditions.

Robust and Effective PID Controller Identification for Delay Dominant Systems

2014 ◽  
Vol 625 ◽  
pp. 478-481
Author(s):  
Lemma Dendena Tufa ◽  
Marappagounder Ramasamy
Keyword(s):  
Time Delay ◽  
Time Constant ◽  
Pid Controller ◽  
Internal Model ◽  
Control Structure ◽  
Internal Model Control ◽  
Controller Tuning ◽  
Model Control ◽  
Pid Controller Tuning ◽  
Improved Performance

A novel PID controller identification method based on internal model control structure is proposed. The proposed method avoids the necessity of approximating the time delay for designing the PID controller. It results in a robust and effective PID controller tuning. The method is effective for both time constant and time delay dominant systems, with much improved performance for the latter case.

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