Comparison of Adaptive and Robust Controllers for Fully-Constrained and Redundant Planar Cable Robots

Author(s):  
Sergio J. Torres-Mendez ◽  
Gokhan Gungor ◽  
Baris Fidan ◽  
Amir Khajepour

This work deals with the design and comparison of two adaptive position control schemes with a classical PID controller for fully constrained and redundant planar robots. First, a novel method based on inclusion of virtual cables facilitates the linear separation of the uncertain parameters from the input-output signals. Then, two Lyapunov based adaptive controllers based on the sliding mode and PD schemes are designed to compensate for the structure matrix uncertainties, which result from errors in the anchor point locations. Finally, the adaptive controllers are evaluated and compared with a classical PID controller through simulations for a desired 2D singularity-free pose of the mobile platform. The simulation results have shown that the adaptive PD control scheme has the best performance for both fully constrained and redundant cases.

2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Ji Min Lee ◽  
Sung Hwan Park ◽  
Jong Shik Kim

A robust control scheme is proposed for the position control of the electrohydrostatic actuator (EHA) when considering hardware saturation, load disturbance, and lumped system uncertainties and nonlinearities. To reduce overshoot due to a saturation of electric motor and to realize robustness against load disturbance and lumped system uncertainties such as varying parameters and modeling error, this paper proposes an adaptive antiwindup PID sliding mode scheme as a robust position controller for the EHA system. An optimal PID controller and an optimal anti-windup PID controller are also designed to compare control performance. An EHA prototype is developed, carrying out system modeling and parameter identification in designing the position controller. The simply identified linear model serves as the basis for the design of the position controllers, while the robustness of the control systems is compared by experiments. The adaptive anti-windup PID sliding mode controller has been found to have the desired performance and become robust against hardware saturation, load disturbance, and lumped system uncertainties and nonlinearities.


Author(s):  
Nasim Ullah ◽  
Irfan Sami ◽  
Wang Shaoping ◽  
Hamid Mukhtar ◽  
Xingjian Wang ◽  
...  

This article proposes a computationally efficient adaptive robust control scheme for a quad-rotor with cable-suspended payloads. Motion of payload introduces unknown disturbances that affect the performance of the quad-rotor controlled with conventional schemes, thus novel adaptive robust controllers with both integer- and fractional-order dynamics are proposed for the trajectory tracking of quad-rotor with cable-suspended payload. The disturbances acting on quad-rotor due to the payload motion are estimated by utilizing adaptive laws derived from integer- and fractional-order Lyapunov functions. The stability of the proposed control systems is guaranteed using integer- and fractional-order Lyapunov theorems. Overall, three variants of the control schemes, namely adaptive fractional-order sliding mode (AFSMC), adaptive sliding mode (ASMC), and classical Sliding mode controllers (SMC)s) are tested using processor in the loop experiments, and based on the two performance indicators, namely robustness and computational resource utilization, the best control scheme is evaluated. From the results presented, it is verified that ASMC scheme exhibits comparable robustness as of SMC and AFSMC, while it utilizes less sources as compared to AFSMC.


2009 ◽  
Vol 23 (16) ◽  
pp. 2021-2034 ◽  
Author(s):  
XINGYUAN WANG ◽  
DA LIN ◽  
ZHANJIE WANG

In this paper, control of the uncertain multi-scroll critical chaotic system is studied. According to variable structure control theory, we design the sliding mode controller of the uncertain multi-scroll critical chaotic system, which contains sector nonlinearity and dead zone inputs. For an arbitrarily given equilibrium point of the uncertain multi-scroll chaotic system, we achieve global stabilization for the equilibrium points. Particularly, a class of proportional integral (PI) switching surface is introduced for determining the convergence rate. Furthermore, the proposed control scheme can be extended to complex multi-scroll networks. Finally, simulation results are presented to demonstrate the effectiveness of the proposed control scheme.


2019 ◽  
Vol 8 (2S8) ◽  
pp. 1448-1454

The statistical analyses in the past showing the important properties of the electrohydraulic actuator (EHA) system, especially in the growth of the world economy. Dealing with the existing drawback in the EHA system, various types of control schemes have been introduced in the past. In this paper, to produce a more insightful view of the performance and the capabilities of the controller, three different types of controllers have been designed and compared. The favourite controller in the industry field, which is the proportional-integral-derivative (PID) controller will be first introduced. Follow by the improved PID controller, named Fractional Order (FO-PID) controller will be designed. Then, the prominent robust controller in the control field, called sliding mode controller (SMC) will be established. Instead of obtaining the controller’s parameters without any appropriate technique, the well-known tuning technique in computer science, named particle swarm optimization (PSO) will be utilized. Referring to the performances produced by these controllers, it can be concluded that the SMC is capable to generate most desired control performance that produced the highest accuracy with the smallest error in the analyses.


Robotica ◽  
2019 ◽  
Vol 38 (9) ◽  
pp. 1642-1664 ◽  
Author(s):  
Ali Fayazi ◽  
Naser Pariz ◽  
Ali Karimpour ◽  
V. Feliu-Batlle ◽  
S. Hassan HosseinNia

SUMMARYThis paper proposes an adaptive robust impedance control for a single-link flexible arm when it encounters an environment at an unknown intermediate point. First, the intermediate collision point is estimated using a collision detection algorithm. The controller, then, switches from free to constrained motion mode. In the unconstrained motion mode, the exerted force to environment is nearly zero. Thus, the reference trajectory is a prescribed desired trajectory in position control. In the constrained motion mode, the reference trajectory is determined by the desired target dynamic impedance. The simulation results demonstrate the efficiency of proposed control scheme.


2012 ◽  
Vol 157-158 ◽  
pp. 88-93 ◽  
Author(s):  
Guang Hui Chang ◽  
Jie Chang Wu ◽  
Chao Jie Zhang

In this paper, an intelligent controller of PM DC Motor drive is designed using particle swarm optimization (PSO) method for tuning the optimal proportional-integral-derivative (PID) controller parameters. The proposed approach has superior feature, including easy implementation, stable convergence characteristics and very good computational performances efficiency.To show the validity of the PID-PSO controller, a DC motor position control case is considered and some simulation results are shown. The DC Motor Scheduling PID-PSO controller is modeled in MATLAB environment.. It can be easily seen from the simulation results that the proposed method will have better performance than those presented in other studies.


Author(s):  
Mehmet Akar

This paper presents a multiple model/controller scheme for robust tracking of a class of nonlinear systems in the presence of large plant uncertainties and disturbance. Each model is associated with a sliding mode controller, and a switching logic is designed to pick the model that best approximates the plant at each instant. Theoretically, it is shown that the proposed control scheme achieves perfect tracking despite the existence of disturbance, whereas simulation results verify the improvement in the transient performance.


Author(s):  
P. Sekhavat ◽  
N. Sepehri ◽  
Q. Wu

The focus of this work is stabilization of hydraulic actuators during the transition from free motion to constraint motion and regulating the intermediate impacts that could drive the system unstable. In our past research, we introduced Lyapunov-based nonlinear control schemes capable of fulfilling the above goal by resting the implement on the surface of the environment before starting the sustained-contact motion. The hydraulic actuator’s stick-slip friction effect was, however, either not included in the analysis or not compensated by the control action. In this paper, the application of our previously introduced friction compensating position control scheme is extended to impact regulation of a hydraulic actuator. Theoretical solution and stability analyses as well as actual experiments prove that such control scheme is also effective for asymptotic impact control (with no position steady-state error) of hydraulic actuators in the presence of actuator’s dry friction.


2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Salahuddin Abdul Rahman ◽  
Mohamed Zribi ◽  
Nejib Smaoui

The synchronous reluctance motor (SynRM) drive system is known to exhibit chaotic behavior under specified conditions. In this paper, the discrete-time sliding mode control (DSMC) technique is used to synchronize two SynRMs starting from different sets of initial conditions. The mixed variable speed reaching law is adopted in the design of the controller scheme. The parameters of the designed control scheme are tuned using a genetic algorithm (GA). Simulation results are presented to demonstrate the effectiveness of the proposed controller. In addition, the performance of the proposed control scheme is studied through simulations when bounded disturbances and mismatches between the parameters of the systems and those of the control scheme exist. The simulation results show that the designed control scheme is robust to bounded external disturbances and to mismatches in the parameters of the systems.


Information ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 65 ◽  
Author(s):  
Amjad Humaidi ◽  
Akram Hameed

This paper investigates the performance of two different adaptive control schemes for controlling the angular position of an electronic throttle (ET) plate. The adaptive backstepping controller and adaptive sliding mode backstepping controller are the controllers under consideration. The control design based on these adaptive controllers is firstly addressed and the stability analysis of each controller has been presented and the convergence of both position and estimation errors for both controllers have been proved. A comparison study of the performance of both controllers has been conducted in terms of system transient characteristics and the behavior of their associated adaptive gain. The simulation has been implemented within the environment of the MATLAB package.


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