Control of a Slewing Motor-Beam System With Coulomb Friction

Author(s):  
Agamemnon L. Crassidis ◽  
Roger W. Mayne

Abstract In this paper, a sliding mode controller is studied in the experimental control of a flexible undamped beam actuated by a DC motor and including Coulomb friction. A model of the system is described which includes a finite element representation for the beam and a representation for Coulomb friction. The model has been used in the study of closed-loop transient response of the slewing system and predicts the critical factors observed in slewing behavior. Development of the sliding mode controller is based on the nonlinear model of the system. The performance and characteristics of the controller are summarized in a simulation study. The sliding mode controller is particularly effective at eliminating the negative effects of shaft lock-up which tends to result from Coulomb friction and counteracts these nonlinear effects in the presence of modeling uncertainties. The system model includes the interaction that occurs between the DC motor and the slewing beam and a gear train that influences the motor-beam interaction. The effect of motor-beam dynamic interaction is studied for the nonlinear slewing system under sliding mode control. It is found that the motor-beam interaction continues to be an important factor in the closed-loop performance. The paper concludes with a summary of experimental results for the nonlinear control of the motor-beam system.

Author(s):  
Agamemnon L. Crassidis ◽  
Roger W. Mayne

Abstract This paper considers the effect of Coulomb friction on the behavior of a slewing motor-beam system. A model of the system is described which includes a finite element representation for the beam, dynamic interaction between the motor and the beam, and a representation for Coulomb friction. The model is used in the study of closed-loop transient response of the slewing system. Simulation results are compared against laboratory behavior. The model reasonably predicts slewing behavior. It simulates steady state error in the control of slewing angle and can represent the case of shaft lock-up which leaves the beam oscillating freely. The system gear ratio is adjusted to produce different levels of motor-beam dynamic interaction. Control performance is similar to that expected from studies of the linear slewing system. For a gear ratio that yields little motor-beam interaction, beam vibration is difficult to suppress. A gear ratio that heavily loads the motor and has too much interaction shows considerable actuation effort for a given level of transient response speed.


Energies ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 3091 ◽  
Author(s):  
Pedro Ponce ◽  
J. Antonio Rosales ◽  
Arturo Molina ◽  
Hiram Ponce ◽  
Brian MacCleery

Electric direct-current (DC) drives based on DC motor are extremely important in the manufacturing process, so it must be crucial to increase their performance when they are working on load disturbances or the DC motor’s parameters change. Usually, several load torque suddenly appears when electric drives are operating in a speed closed-loop, so robust controllers are required to keep the speed high-performance. One of the most well-known robust strategies is the sliding mode controller (SMC), which works under discontinue operation. This controller can handle disturbances and variations in the plant’s parameters, so the controller has robust performance. Nevertheless, it has some disadvantages (chattering). Therefore, this paper proposed a fuzzy logic controller (FLC) that includes an artificial organic network for adjusting the command signal of the SMC. The proposed controller gives a smooth signal that decrements the chattering in the SMC. The stability condition that is based on Lyapunov of the DC motor is driven is evaluated; besides, the stability margins are calculated. The proposed controller is designed using co-simulation and a real testbed since co-simulation is an extremely useful tool in academia and industry allows to move from co-simulation to real implementation in short period of time. Moreover, there are several universities and industries that adopt co-simulation as the main step to design prototypes. Thus, engineering students and designers are able to achieve excellent results when they design rapid and functional prototypes. For instance, co-simulation based on Multisim leads to design directly printed circuit boards so engineering students or designers could swiftly get an experimental DC drive. The experimental results using this platform show excellent DC-drive performance when the load torque disturbances are suddenly applied to the system. As a result, the proposed controller based on fuzzy artificial organic and SMC allows for adjusting the command signal that improves the dynamic response in DC drives. The experimental response using the sliding-mode controller with fuzzy artificial organic networks is compared against an auto-tuning, Proportional-Integral-Derivative (PID), which is a conventional controller. The PID controller is the most implemented controller in several industries, so this proposal can contribute to improving manufacturing applications, such as micro-computer numerical control (CNC) machines. Moreover, the proposed robust controller achieves a superior-speed response under the whole tested scenarios. Finally, the presented design methodology based on co-simulation could be used by universities and industry for validating and implementing advanced control systems in DC drives.


Author(s):  
Cheng Liu ◽  
Zaojian Zou ◽  
Jianchuan Yin

Trajectory tracking is an importance practice in ship motion control field. It attracts more attention recently due to its difficulties. Trajectory tracking requires the ship to arrive pinpoint location at exact time. It is a underactuated system because the degrees of freedom of control inputs are fewer than the degrees of freedom that needed to be controlled. In this paper, a hierarchical sliding mode controller and a common sliding mode controller are proposed to deal with the trajectory tracking problem of underactuated surface vessels. Simulation results validate the tracking performance of the proposed controllers. The closed-loop stability is testified by the Lyapunov stability theorem.


2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Sami ud Din ◽  
Qudrat Khan ◽  
Fazal ur Rehman ◽  
Rini Akmeliawati

This paper presents a robust control design for the class of underactuated uncertain nonlinear systems. Either the nonlinear model of the underactuated systems is transformed into an input output form and then an integral manifold is devised for the control design purpose or an integral manifold is defined directly for the concerned class. Having defined the integral manifolds discontinuous control laws are designed which are capable of maintaining sliding mode from the very beginning. The closed loop stability of these systems is presented in an impressive way. The effectiveness and demand of the designed control laws are verified via the simulation and experimental results of ball and beam system.


Author(s):  
V. Jouppila ◽  
S. A. Gadsden ◽  
S. R. Habibi ◽  
G. M. Bone ◽  
A. Ellman

In this paper, a robust and stable control strategy is applied to a Festo fluidic muscle actuator, with the objective of trajectory following control. A complete model of this system is not available which leads to unmodeled dynamics and uncertainties. Furthermore, full-state feedback is required for this type of control. However, in practice not all of the states are measurable or available due to cost or availability of instruments, thus a full-state observer is required. The Smooth Variable Structure Filter (SVSF) is a recently introduced robust predictor-corrector method used for state and parameter estimation, and has a form that is able to provide full-state information. In this regard, a new strategy that combines Sliding Mode Control (SMC) with the SVSF is used to control this system. The estimated states from the SVSF are used by the sliding mode controller to obtain a discontinuous control signal. This signal drives the plant to follow a desired state trajectory required by the pneumatic McKibben muscle actuator. Simulation results were generated based on a realistic desired trajectory. The results of the SMC-SVSF control strategy are compared with a tuned PID controller. The described control strategy is able to overcome the nonlinearities present in the system, has a fast response time, and is robust to modeling uncertainties and measurement noise.


Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4376 ◽  
Author(s):  
Taimoor Ahmad Khan ◽  
Kalim Ullah ◽  
Ghulam Hafeez ◽  
Imran Khan ◽  
Azfar Khalid ◽  
...  

Electricity demand is rising due to industrialisation, population growth and economic development. To meet this rising electricity demand, towns are renovated by smart cities, where the internet of things enabled devices, communication technologies, dynamic pricing servers and renewable energy sources are integrated. Internet of things (IoT) refers to scenarios where network connectivity and computing capability is extended to objects, sensors and other items not normally considered computers. IoT allows these devices to generate, exchange and consume data without or with minimum human intervention. This integrated environment of smart cities maintains a balance between demand and supply. In this work, we proposed a closed-loop super twisting sliding mode controller (STSMC) to handle the uncertain and fluctuating load to maintain the balance between demand and supply persistently. Demand-side load management (DSLM) consists of agents-based demand response (DR) programs that are designed to control, change and shift the load usage pattern according to the price of the energy of a smart grid community. In smart grids, evolved DR programs are implemented which facilitate controlling of consumer demand by effective regulation services. The DSLM under price-based DR programs perform load shifting, peak clipping and valley filling to maintain the balance between demand and supply. We demonstrate a theoretical control approach for persistent demand control by dynamic price-based closed-loop STSMC. A renewable energy integrated microgrid scenario is discussed numerically to show that the demand of consumers can be controlled through STSMC, which regulates the electricity price to the DSLM agents of the smart grid community. The overall demand elasticity of the current study is represented by a first-order dynamic price generation model having a piece-wise linear price-based DR program. The simulation environment for this whole scenario is developed in MATLAB/Simulink. The simulations validate that the closed-loop price-based elastic demand control technique can trace down the generation of a renewable energy integrated microgrid.


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