In this paper the design, analysis and implementation of improved first-order continuous adaptive sliding mode control (CASMC) based on online estimation of the lumped time-varying uncertainties for tracking control o...
详细信息
In this paper the design, analysis and implementation of improved first-order continuous adaptive sliding mode control (CASMC) based on online estimation of the lumped time-varying uncertainties for tracking control of the robot manipulators is presented. The proposed method allows to address the main drawbacks of conventional sliding mode control: the chattering phenomenon, and the requirement for a priori knowledge of the bounds of the uncertainties, and also the chattering problem associated with adaptive discontinuous sliding mode controllers, while the robustness property of the conventional sliding mode control is preserved. Furthermore, in the previously published version of the controller [1], the estimate of robot inertia matrix is needed to realize the adaptive component of the control law. In this work, the skew-symmetry property (passivity property) of robot dynamic is used to eliminate that requirement. The global stability and robustness of the proposed controller are established in the presence of time-varying uncertainties using Lyapunov's approach and fundamentals of sliding mode theory. The robustness is achieved without knowing the bound of uncertainties. The dynamic model of a two-degrees of freedom (2-DOF) rigid robot is used for simulation study and a 2-DOF flexible-link robot is used as an experimental test-bed to evaluate the performance, and robustness of the controller. Based on the simulations and experimental results, the proposed controller performs remarkably well in terms of the tracking error convergence, estimation of lumped uncertain parameter. And it is robust against un-modeled dynamics and external disturbances.
The nonlinear action of hybrid PI controllers makes possible to achieve almost none overshot with the smallest rise time possible (for the available input energy) and a settling time almost equal to the rise time. How...
详细信息
The nonlinear action of hybrid PI controllers makes possible to achieve almost none overshot with the smallest rise time possible (for the available input energy) and a settling time almost equal to the rise time. However, all of these nice properties require changes on the control loop. Our contribution is the proposition of a plug-in control action that can be added to the classical linear PI to avoid changes in the hardware, and still achieve the same behavior of a recently introduced adaptive hybrid PI controller. Our proposal is illustrated by real-time level control experiments in a nonlinear reservoir. Performance indexes are presented to evaluate the experimental tests.
This paper proposes an improved version of a grid-impedance estimation method based on imposed variations of active and reactive power injected by inverters into the grid. The variations cause changes in the synchrono...
详细信息
ISBN:
(数字)9781728141800
ISBN:
(纸本)9781728141817
This paper proposes an improved version of a grid-impedance estimation method based on imposed variations of active and reactive power injected by inverters into the grid. The variations cause changes in the synchronous voltage v d and current i q at the point of common coupling (PCC) between the inverter and the grid. These variations are used to calculate the grid impedance. The proposed improvement relies on a positive sequence estimator enhanced by a Fourier filter which provides harmonic rejection capability to the method. A complete evaluation of the proposed method is performed through simulations in Matlab/Simulink environment. The results show that the method notably refines the impedance computation in moderate weak grids.
This paper experimentally verifies that the Universal Adaptive Stabilization (UAS) based Li-ion battery terminal voltage collapse strategy can be implemented on a simple embedded platform i.e. microcontrollers. Due to...
详细信息
The ability to predict springback on sheet metal bending processes is like an important feature of the ability to predict the final geometry of sheet metal parts. The grain size effect makes the application of traditi...
详细信息
The ability to predict springback on sheet metal bending processes is like an important feature of the ability to predict the final geometry of sheet metal parts. The grain size effect makes the application of traditional design method difficult in processing. Understanding the effects of grain size effects is an important and powerful way to effectively compensate for and eliminate springback as it passes through tool and process design. In this paper, 99.5% pure iron specimens were heat treated at different temperature to obtain the specified grain sizes. The effects of different grain sizes on the saddle after Vbending of the thin sheet metal were investigated. The results show that at the same thickness of specimens,the grain size has no significant effect on the saddle height. However, with the increase of the thickness of the specimens, the saddle will also be more prominent protruding height.
In this work, the mathemtical model of a railway passenger car with conventional and radial-elastic wheels is analyzed. Stochastic excitations are applied to the wheelsets. The local elasticity between the wheel and t...
详细信息
The development of Microcontroller-Based Water Level and Temperature Control is the development of Microcontroller-Based Water Level Control Design. This equipment is a tool that can be used to monitor and control the...
The development of Microcontroller-Based Water Level and Temperature Control is the development of Microcontroller-Based Water Level Control Design. This equipment is a tool that can be used to monitor and control the level and temperature of water. The aim of this research is to make a water level and temperature control device based on microcontroller, and to display the information of water level and temperature on the computer. The research methods used during the implementation process of this research are : literature study, hardware and software design, and data retrieval. The Microcontroller-based Water Level and Temperature Control uses two sensors, namely : ultrasonic sensor to detect water level, then the second sensor is a thermocouple sensor which is used to detect water temperature. This equipment uses a water pump to flow water from one tank to another, and the heater that used to heat water. The device has 2 buttons, where the first button is used to control the water level, and the second button is used to control the level and temperature of the water. Based on the results of the study it can be concluded that this water level and temperature control system works well as expected, where this equipment uses a multi position control system mode that has been programmed in the Arduino software and can display sensor readings in the form graphs using matlab software.
This paper presents application of Proportional Integral Derivative (PID) and Non-linear PID (NPID) controllers to optimally operate the master slave robotic system. Teleoperation is widely used in different applicati...
This paper presents application of Proportional Integral Derivative (PID) and Non-linear PID (NPID) controllers to optimally operate the master slave robotic system. Teleoperation is widely used in different applications, such as surgical robots, underwater vehicles, power lines and even in space. However there are problems in teleoperation systems that may lead to degradation in system performance or even to system instability. This paper presents new and optimal control schemes that can satisfy the required performance, insure system stability and achieve zero tracking error in presence of constant time delay and model approximation. Optimal gains are obtained using the Genetic Algorithm in a systematic way that could be applied to other control schemes. The results proved the effectiveness of both control schemes than the previously applied scheme. The NPID control scheme has better performance, provided position tracking and achieved zero tracking error in less settling time than PID one. The results obtained by the presented control schemes are evaluated based on comparing the system performance using three different types of controllers which are P-like, Genetic PID and Genetic NPID. The study was carried out using MATLAB/SIMULINK 2017a.
A thruster is a device used for station keeping, attitude control, in the reaction control system, or long-duration, low-thrust acceleration. Thruster is one of the main components in autonomous surface vehicle. In th...
A thruster is a device used for station keeping, attitude control, in the reaction control system, or long-duration, low-thrust acceleration. Thruster is one of the main components in autonomous surface vehicle. In this paper, we discuss the linearization of two-state thruster model by using the Jacobian method.
Piezoelectric materials exhibit a response to mechanical-electrical coupling, which represents an important contribution to the electrical-mechanical interaction in bone remodeling process. Therefore, the study of the...
详细信息
Piezoelectric materials exhibit a response to mechanical-electrical coupling, which represents an important contribution to the electrical-mechanical interaction in bone remodeling process. Therefore, the study of the piezoelectric effect on bone re- modeling has high interest in applied biomechanics. The effects of mechano-regulation and electrical stimulation on bone healing are explained. The Boundary Element Method (BEM) is used to simulate piezoelectric effects on bones when shearing forces are applied to collagen fibers to make them slip past each other. The piezoelectric fundamental solutions are obtained by using the Radon transform. The Dual Reciprocity Method (DRM) is used to simulate the particular solutions in time-dependent problems. BEM analysis showed the strong influence of electrical stimulation on bone remodeling. The examples discussed in this work showed that, as expected, the electrically loaded bone surfaces improved the bone deposition. BEM results confirmed previous findings obtained by using the Finite Element Method (FEM). This work opens very promising doors in biomechanics research, showing that mechanical loads can be replaced, in part, by electrical charges that stimulate strengthening bone density. The obtained results herein are in good agreement with those found in literature from experimental testing and/or other simu- lation approaches.
暂无评论