An Adaptive PI/Sliding Mode Controller for a Speed Drive

1989 ◽  
Vol 111 (3) ◽  
pp. 409-415 ◽  
Author(s):  
R. M. DeSantis
Keyword(s):  
Performance Improvement ◽  
Sliding Mode ◽  
Experimental Tests ◽  
Industrial Applications ◽  
Open Loop ◽  
Sliding Mode Controller ◽  
Switching Element ◽  
Parallel Addition ◽  
Self Tuning ◽  
Theoretical Results

A classical PI speed drive controller modified with the parallel addition of an on-off switching element appears to offer a potential for reasonable improvement over the performance of the original version. This improvement is obtained by combining classical transfer function techniques, sliding mode systems ideas, and self-tuning. While theoretical results, extended simulations, and preliminary experimental tests are encouraging, they do suggest that in actual industrial applications performance improvement may be conditioned by the usage of better performing open loop components.

Compensating the flexibility uncertainties of a cable suspended robot using SMC approach

Robotica ◽  
2014 ◽  
Vol 33 (3) ◽  
pp. 578-598 ◽  
Author(s):  
M. H. Korayem ◽  
M. Taherifar ◽  
H. Tourajizadeh
Keyword(s):  
Sliding Mode ◽  
Longitudinal Vibration ◽  
Experimental Tests ◽  
Sliding Mode Controller ◽  
Parametric Uncertainties ◽  
Load Carrying Capacity ◽  
Load Carrying ◽  
Varying Length ◽  
The Impact ◽  
Positive Effect

SUMMARYA sliding mode controller is designed to compensate for the flexibility uncertainties of a cable robot and improve its tracking performance. Of the most significant sources of these uncertainties are the elasticity of the cables and the flexibility of the joints. A favorable approach to improve the accuracy of the system is first to model the cable and joint flexibilities and then convert the model uncertainties into parametric uncertainties. Parametric uncertainties are the product of imprecise flexibility coefficients and are finally neutralized by a sliding mode controller. The flexibility in cables is modeled by considering the longitudinal vibration of the time-varying length cables. A simulation study is carried out to confirm the presented model and the positive effect of the designed controller. Then the impact of these uncertainties on the dynamic load carrying capacity (DLCC) of the robot is examined and compared for different cases. Finally, experimental tests are conducted on the IUST (Iran University of Science and Technology) cable-suspended robot to validate the presented theories and simulation results.

scholarly journals Implicit Euler Implementation of Twisting Controller and Super-Twisting Observer without Numerical Chattering: Precise Quasi-Static MEMS Mirrors Control

2019 ◽  
Vol 256 ◽  
pp. 03004 ◽  
Author(s):  
Dong Luo ◽  
Xiaogang Xiong ◽  
Shanhai Jin ◽  
Wei Chen
Keyword(s):  
Sliding Mode Control ◽  
Closed Loop ◽  
Sliding Mode ◽  
Industrial Applications ◽  
Euler Method ◽  
Open Loop ◽  
Closed Loop Control ◽  
Control Input ◽  
Loop Control ◽  
Mode Control

The quasi-static operations of MEMS mirror are very sensitive to undesired oscillations due to its very low damping. It has been shown that closed-loop control can be superior to reduce those oscillations than open-loop control in the literature. For the closed-loop control, the conventional way of implementing sliding mode control (SMC) algorithm is forward Euler method, which results in numerical chattering in the control input and output. This paper proposes an implicit Euler implementation scheme of super twisting observer and twisting control for a commercial MEMS mirror actuated by an electrostatic staggered vertical comb (SVC) drive structure. The famous super-twisting algorithm is used as an observer and twisting SMC is used as a controller. Both are discretized by an implicit Euler integration method, and their implementation algorithms are provided. Simulations verify that, as compared to traditional sliding mode control implementation, the proposed scheme reduces the chattering both in trajectory tracking output and control input in presence of model uncertainties and external disturbances. The comparison demonstrates the potential applications of the proposed scheme in industrial applications in terms of feasibility and performance.

scholarly journals Finite-Time Spacecraft’s Soft Landing on Asteroids Using PD and Nonsingular Terminal Sliding Mode Control

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Keping Liu ◽  
Fengxia Liu ◽  
Shenquan Wang ◽  
Yuanchun Li
Keyword(s):  
Sliding Mode ◽  
Landing Site ◽  
Open Loop ◽  
Sliding Mode Controller ◽  
Reference Trajectory ◽  
Continuous Control ◽  
Soft Landing ◽  
Terminal Sliding Mode ◽  
Nonsingular Terminal Sliding Mode ◽  
Motion Characteristics

This paper presents a continuous control law of probe, which consists of PD (proportional-derivative) controller and nonsingular terminal sliding mode controller for probe descending and landing phases, respectively, in the case of the asteroid irregular shape and low gravity. The probe dynamic model is deduced in the landing site coordinate system firstly. Then the reference trajectory based on optimal polynomial in open-loop state is designed, with the suboptimal fuel consumption. Taking into account different characteristics of phases, PD controller and nonsingular terminal sliding mode controller can be employed in the descending phase and the landing phase, respectively, to track the designed reference trajectory. The controller which used the corresponding control methods can meet the motion characteristics and requirements of each stage. Finally simulation experiments are carried out to demonstrate the effectiveness of the proposed method, which can ensure the safe landing of probe and achieve continuous control.

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